[dev.typeparams] all: merge dev.regabi (77365c5) into dev.typeparams

Conflicts:

- src/cmd/compile/internal/gc/main.go
- test/fixedbugs/issue15055.go

Merge List:

+ 2021-01-05 77365c5ed7 [dev.regabi] cmd/compile: add Name.Canonical and move Byval
+ 2021-01-05 e09783cbc0 [dev.regabi] cmd/compile: make ir.StaticValue safer
+ 2021-01-05 9aa950c407 [dev.regabi] cmd/compile: make ir.OuterValue safer
+ 2021-01-05 eb626409d1 [dev.regabi] cmd/compile: simplify CaptureVars
+ 2021-01-05 c28ca67a96 [dev.regabi] cmd/compile: fix ir.Dump for []*CaseClause, etc
+ 2021-01-04 f24e40c14a [dev.regabi] cmd/compile: remove Name.Class_ accessors
+ 2021-01-04 d89705e087 [dev.regabi] cmd/compile: fix re-export of parameters
+ 2021-01-04 290b4154b7 [dev.regabi] cmd/compile: fix ICE due to large uint64 constants
+ 2021-01-04 a30fd52884 [dev.regabi] cmd/compile: use ir.NewNameAt in SubstArgTypes
+ 2021-01-03 8fc44cf0fa [dev.regabi] cmd/compile: remove a couple CloneName calls
+ 2021-01-03 907a4bfdc7 [dev.regabi] cmd/compile: fix map assignment order
+ 2021-01-03 f2e6dab048 [dev.regabi] cmd/compile: remove walkReturn "common case" path
+ 2021-01-03 d36a6bf44d [dev.regabi] cmd/compile: improve walkReturn common case
+ 2021-01-03 a317067d65 [dev.regabi] cmd/compile: improve ascompatee
+ 2021-01-03 5d80a590a2 [dev.regabi] cmd/compile: simplify walkReturn
+ 2021-01-03 bb1b6c95c2 [dev.regabi] cmd/compile: remove Node.{,Set}Walkdef
+ 2021-01-03 57c426c9a5 [dev.regabi] cmd/compile: tighten typecheckdef to *ir.Name
+ 2021-01-03 b1747756e3 [dev.regabi] cmd/compile: reorganize escape analysis somewhat
+ 2021-01-02 f2538033c0 [dev.regabi] cmd/compile: remove Nodes.Set [generated]
+ 2021-01-02 2f2d4b4e68 [dev.regabi] cmd/compile: remove {Ptr,Set}Init from Node interface
+ 2021-01-01 1544a03198 [dev.regabi] cmd/compile: refactor redundant type conversion [generated]
+ 2021-01-01 7958a23ea3 [dev.regabi] cmd/compile: use *ir.Name where possible in inl.go
+ 2021-01-01 bfa97ba48f [dev.regabi] test: add another closure test case
+ 2021-01-01 67ad695416 [dev.regabi] cmd/compile: split escape analysis state
+ 2021-01-01 fad9a8b528 [dev.regabi] cmd/compile: simplify inlining of closures
+ 2021-01-01 7d55669847 [dev.regabi] cmd/compile: simplify dwarfgen.declPos
+ 2021-01-01 9ed1577779 [dev.regabi] cmd/compile: remove Func.ClosureEnter
+ 2021-01-01 ece345aa69 [dev.regabi] cmd/compile: expand documentation for Func.Closure{Vars,Enter}
+ 2021-01-01 6ddbc75efd [dev.regabi] cmd/compile: earlier deadcode removal
+ 2021-01-01 68e6fa4f68 [dev.regabi] cmd/compile: fix package-initialization order
+ 2021-01-01 3a4474cdfd [dev.regabi] cmd/compile: some more manual shuffling
+ 2021-01-01 0f1d2129c4 [dev.regabi] cmd/compile: reshuffle type-checking code [generated]
+ 2021-01-01 b8fd3440cd [dev.regabi] cmd/compile: report unused variables during typecheck
+ 2021-01-01 fd22df9905 [dev.regabi] cmd/compile: remove idempotent Name() calls [generated]
+ 2020-12-31 dfbcff80c6 [dev.regabi] cmd/compile: make copyExpr return *ir.Name directly
+ 2020-12-31 77fd81a3e6 [dev.regabi] cmd/compile: use names for keep alive variables in function call
+ 2020-12-31 8fe1197654 [dev.regabi] cmd/compile: remove Name.orig
+ 2020-12-31 477b049060 [dev.regabi] cmd/compile: fix printing of method expressions
+ 2020-12-30 178c667db2 [dev.regabi] cmd/compile: fix OSLICEARR comments
+ 2020-12-30 f0d99def5b [dev.regabi] cmd/compile: add newline to ir.Dump
+ 2020-12-30 451693af71 [dev.regabi] cmd/compile: simplify typecheckdef
+ 2020-12-30 0c1a899a6c [dev.regabi] cmd/compile: fix defined-pointer method call check
+ 2020-12-30 f9b67f76a5 [dev.regabi] cmd/compile: change ir.DoChildren to use bool result type
+ 2020-12-30 499851bac8 [dev.regabi] cmd/compile: generalize ir/mknode.go
+ 2020-12-30 82ab3d1448 [dev.regabi] cmd/compile: use *ir.Name for Decl.X
+ 2020-12-30 9958b7ed3e [dev.regabi] cmd/compile: unexport ir.FmtNode
+ 2020-12-29 f5816624cd [dev.regabi] cmd/compile: change AddrExpr.Alloc to AddrExpr.Prealloc
+ 2020-12-29 850aa7c60c [dev.regabi] cmd/compile: use *ir.Name instead of ir.Node for CaseClause.Var
+ 2020-12-29 37babc97bb [dev.regabi] cmd/compile: allow visitor visits *ir.Name
+ 2020-12-29 5cf3c87fa6 [dev.regabi] cmd/compile: generate case/comm clause functions in mknode.go
+ 2020-12-29 b3e1ec97fd [dev.regabi] cmd/compile: move new addrtaken bit back to the old name
+ 2020-12-29 0620c674dd [dev.regabi] cmd/compile: remove original addrtaken bit
+ 2020-12-29 0523d525ae [dev.regabi] cmd/compile: separate out address taken computation from typechecker
+ 2020-12-29 9ea272e5ec [dev.regabi] cmd/compile: simplify ir.Func somewhat
+ 2020-12-29 e40cb4d4ae [dev.regabi] cmd/compile: remove more unused code
+ 2020-12-29 6f30c95048 [dev.regabi] cmd/compile: remove unneeded indirection
+ 2020-12-29 171fc6f223 [dev.regabi] cmd/compile: remove workarounds for go/constant issues
+ 2020-12-29 33801cdc62 [dev.regabi] cmd/compile: use Ntype where possible
+ 2020-12-29 82ad3083f8 [dev.regabi] cmd/compile: remove typ from AssignOpStmt
+ 2020-12-29 e34c44a7c4 [dev.regabi] cmd/compile: refactoring typecheck arith
+ 2020-12-29 a5ec920160 [dev.regabi] cmd/compile: more Linksym cleanup
+ 2020-12-29 ec59b197d5 [dev.regabi] cmd/compile: rewrite to use linksym helpers [generated]
+ 2020-12-29 25c613c02d [dev.regabi] cmd/compile: add Linksym helpers
+ 2020-12-29 289da2b33e [dev.regabi] cmd/compile: move Node.Opt to Name
+ 2020-12-29 6acbae4fcc [dev.regabi] cmd/compile: address some ir TODOs
+ 2020-12-29 4629f6a51d [dev.regabi] cmd/compile: merge {Selector,CallPart,Method}Expr
+ 2020-12-29 e563715b30 [dev.regabi] cmd/compile: remove Sym.Importdef
+ 2020-12-29 3f370b75fb [dev.regabi] cmd/compile: cleanup //go:generate directives

Change-Id: Ibb254630924ac5873ebda6762ceb066f54a82649

src/cmd/compile/internal/deadcode/deadcode.go

@@ -0,0 +1,152 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package deadcode
+
+import (
+	"go/constant"
+
+	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+)
+
+func Func(fn *ir.Func) {
+	stmts(&fn.Body)
+
+	if len(fn.Body) == 0 {
+		return
+	}
+
+	for _, n := range fn.Body {
+		if len(n.Init()) > 0 {
+			return
+		}
+		switch n.Op() {
+		case ir.OIF:
+			n := n.(*ir.IfStmt)
+			if !ir.IsConst(n.Cond, constant.Bool) || len(n.Body) > 0 || len(n.Else) > 0 {
+				return
+			}
+		case ir.OFOR:
+			n := n.(*ir.ForStmt)
+			if !ir.IsConst(n.Cond, constant.Bool) || ir.BoolVal(n.Cond) {
+				return
+			}
+		default:
+			return
+		}
+	}
+
+	fn.Body = []ir.Node{ir.NewBlockStmt(base.Pos, nil)}
+}
+
+func stmts(nn *ir.Nodes) {
+	var lastLabel = -1
+	for i, n := range *nn {
+		if n != nil && n.Op() == ir.OLABEL {
+			lastLabel = i
+		}
+	}
+	for i, n := range *nn {
+		// Cut is set to true when all nodes after i'th position
+		// should be removed.
+		// In other words, it marks whole slice "tail" as dead.
+		cut := false
+		if n == nil {
+			continue
+		}
+		if n.Op() == ir.OIF {
+			n := n.(*ir.IfStmt)
+			n.Cond = expr(n.Cond)
+			if ir.IsConst(n.Cond, constant.Bool) {
+				var body ir.Nodes
+				if ir.BoolVal(n.Cond) {
+					n.Else = ir.Nodes{}
+					body = n.Body
+				} else {
+					n.Body = ir.Nodes{}
+					body = n.Else
+				}
+				// If "then" or "else" branch ends with panic or return statement,
+				// it is safe to remove all statements after this node.
+				// isterminating is not used to avoid goto-related complications.
+				// We must be careful not to deadcode-remove labels, as they
+				// might be the target of a goto. See issue 28616.
+				if body := body; len(body) != 0 {
+					switch body[(len(body) - 1)].Op() {
+					case ir.ORETURN, ir.ORETJMP, ir.OPANIC:
+						if i > lastLabel {
+							cut = true
+						}
+					}
+				}
+			}
+		}
+
+		if len(n.Init()) != 0 {
+			stmts(n.(ir.InitNode).PtrInit())
+		}
+		switch n.Op() {
+		case ir.OBLOCK:
+			n := n.(*ir.BlockStmt)
+			stmts(&n.List)
+		case ir.OFOR:
+			n := n.(*ir.ForStmt)
+			stmts(&n.Body)
+		case ir.OIF:
+			n := n.(*ir.IfStmt)
+			stmts(&n.Body)
+			stmts(&n.Else)
+		case ir.ORANGE:
+			n := n.(*ir.RangeStmt)
+			stmts(&n.Body)
+		case ir.OSELECT:
+			n := n.(*ir.SelectStmt)
+			for _, cas := range n.Cases {
+				stmts(&cas.Body)
+			}
+		case ir.OSWITCH:
+			n := n.(*ir.SwitchStmt)
+			for _, cas := range n.Cases {
+				stmts(&cas.Body)
+			}
+		}
+
+		if cut {
+			*nn = (*nn)[:i+1]
+			break
+		}
+	}
+}
+
+func expr(n ir.Node) ir.Node {
+	// Perform dead-code elimination on short-circuited boolean
+	// expressions involving constants with the intent of
+	// producing a constant 'if' condition.
+	switch n.Op() {
+	case ir.OANDAND:
+		n := n.(*ir.LogicalExpr)
+		n.X = expr(n.X)
+		n.Y = expr(n.Y)
+		if ir.IsConst(n.X, constant.Bool) {
+			if ir.BoolVal(n.X) {
+				return n.Y // true && x => x
+			} else {
+				return n.X // false && x => false
+			}
+		}
+	case ir.OOROR:
+		n := n.(*ir.LogicalExpr)
+		n.X = expr(n.X)
+		n.Y = expr(n.Y)
+		if ir.IsConst(n.X, constant.Bool) {
+			if ir.BoolVal(n.X) {
+				return n.X // true || x => true
+			} else {
+				return n.Y // false || x => x
+			}
+		}
+	}
+	return n
+}

src/cmd/compile/internal/dwarfgen/dwarf.go

@@ -26,7 +26,7 @@ func Info(fnsym *obj.LSym, infosym *obj.LSym, curfn interface{}) ([]dwarf.Scope,
 	fn := curfn.(*ir.Func)
 
 	if fn.Nname != nil {
-		expect := fn.Sym().Linksym()
+		expect := fn.Linksym()
 		if fnsym.ABI() == obj.ABI0 {
 			expect = fn.Sym().LinksymABI0()
 		}
@@ -76,7 +76,7 @@ func Info(fnsym *obj.LSym, infosym *obj.LSym, curfn interface{}) ([]dwarf.Scope,
 			if n.Op() != ir.ONAME { // might be OTYPE or OLITERAL
 				continue
 			}
-			switch n.Class_ {
+			switch n.Class {
 			case ir.PAUTO:
 				if !n.Used() {
 					// Text == nil -> generating abstract function
@@ -90,7 +90,7 @@ func Info(fnsym *obj.LSym, infosym *obj.LSym, curfn interface{}) ([]dwarf.Scope,
 				continue
 			}
 			apdecls = append(apdecls, n)
-			fnsym.Func().RecordAutoType(reflectdata.TypeSym(n.Type()).Linksym())
+			fnsym.Func().RecordAutoType(reflectdata.TypeLinksym(n.Type()))
 		}
 	}
 
@@ -127,24 +127,7 @@ func Info(fnsym *obj.LSym, infosym *obj.LSym, curfn interface{}) ([]dwarf.Scope,
 }
 
 func declPos(decl *ir.Name) src.XPos {
-	if decl.Name().Defn != nil && (decl.Name().Captured() || decl.Name().Byval()) {
+	return decl.Canonical().Pos()
-		// It's not clear which position is correct for captured variables here:
-		// * decl.Pos is the wrong position for captured variables, in the inner
-		//   function, but it is the right position in the outer function.
-		// * decl.Name.Defn is nil for captured variables that were arguments
-		//   on the outer function, however the decl.Pos for those seems to be
-		//   correct.
-		// * decl.Name.Defn is the "wrong" thing for variables declared in the
-		//   header of a type switch, it's their position in the header, rather
-		//   than the position of the case statement. In principle this is the
-		//   right thing, but here we prefer the latter because it makes each
-		//   instance of the header variable local to the lexical block of its
-		//   case statement.
-		// This code is probably wrong for type switch variables that are also
-		// captured.
-		return decl.Name().Defn.Pos()
-	}
-	return decl.Pos()
 }
 
 // createDwarfVars process fn, returning a list of DWARF variables and the
@@ -185,7 +168,7 @@ func createDwarfVars(fnsym *obj.LSym, complexOK bool, fn *ir.Func, apDecls []*ir
 		if c == '.' || n.Type().IsUntyped() {
 			continue
 		}
-		if n.Class_ == ir.PPARAM && !ssagen.TypeOK(n.Type()) {
+		if n.Class == ir.PPARAM && !ssagen.TypeOK(n.Type()) {
 			// SSA-able args get location lists, and may move in and
 			// out of registers, so those are handled elsewhere.
 			// Autos and named output params seem to get handled
@@ -200,10 +183,10 @@ func createDwarfVars(fnsym *obj.LSym, complexOK bool, fn *ir.Func, apDecls []*ir
 		typename := dwarf.InfoPrefix + types.TypeSymName(n.Type())
 		decls = append(decls, n)
 		abbrev := dwarf.DW_ABRV_AUTO_LOCLIST
-		isReturnValue := (n.Class_ == ir.PPARAMOUT)
+		isReturnValue := (n.Class == ir.PPARAMOUT)
-		if n.Class_ == ir.PPARAM || n.Class_ == ir.PPARAMOUT {
+		if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
 			abbrev = dwarf.DW_ABRV_PARAM_LOCLIST
-		} else if n.Class_ == ir.PAUTOHEAP {
+		} else if n.Class == ir.PAUTOHEAP {
 			// If dcl in question has been promoted to heap, do a bit
 			// of extra work to recover original class (auto or param);
 			// see issue 30908. This insures that we get the proper
@@ -211,17 +194,17 @@ func createDwarfVars(fnsym *obj.LSym, complexOK bool, fn *ir.Func, apDecls []*ir
 			// misleading location for the param (we want pointer-to-heap
 			// and not stack).
 			// TODO(thanm): generate a better location expression
-			stackcopy := n.Name().Stackcopy
+			stackcopy := n.Stackcopy
-			if stackcopy != nil && (stackcopy.Class_ == ir.PPARAM || stackcopy.Class_ == ir.PPARAMOUT) {
+			if stackcopy != nil && (stackcopy.Class == ir.PPARAM || stackcopy.Class == ir.PPARAMOUT) {
 				abbrev = dwarf.DW_ABRV_PARAM_LOCLIST
-				isReturnValue = (stackcopy.Class_ == ir.PPARAMOUT)
+				isReturnValue = (stackcopy.Class == ir.PPARAMOUT)
 			}
 		}
 		inlIndex := 0
 		if base.Flag.GenDwarfInl > 1 {
-			if n.Name().InlFormal() || n.Name().InlLocal() {
+			if n.InlFormal() || n.InlLocal() {
 				inlIndex = posInlIndex(n.Pos()) + 1
-				if n.Name().InlFormal() {
+				if n.InlFormal() {
 					abbrev = dwarf.DW_ABRV_PARAM_LOCLIST
 				}
 			}
@@ -240,7 +223,7 @@ func createDwarfVars(fnsym *obj.LSym, complexOK bool, fn *ir.Func, apDecls []*ir
 			ChildIndex:    -1,
 		})
 		// Record go type of to insure that it gets emitted by the linker.
-		fnsym.Func().RecordAutoType(reflectdata.TypeSym(n.Type()).Linksym())
+		fnsym.Func().RecordAutoType(reflectdata.TypeLinksym(n.Type()))
 	}
 
 	return decls, vars
@@ -289,7 +272,7 @@ func createSimpleVar(fnsym *obj.LSym, n *ir.Name) *dwarf.Var {
 	var abbrev int
 	var offs int64
 
-	switch n.Class_ {
+	switch n.Class {
 	case ir.PAUTO:
 		offs = n.FrameOffset()
 		abbrev = dwarf.DW_ABRV_AUTO
@@ -305,16 +288,16 @@ func createSimpleVar(fnsym *obj.LSym, n *ir.Name) *dwarf.Var {
 		abbrev = dwarf.DW_ABRV_PARAM
 		offs = n.FrameOffset() + base.Ctxt.FixedFrameSize()
 	default:
-		base.Fatalf("createSimpleVar unexpected class %v for node %v", n.Class_, n)
+		base.Fatalf("createSimpleVar unexpected class %v for node %v", n.Class, n)
 	}
 
 	typename := dwarf.InfoPrefix + types.TypeSymName(n.Type())
-	delete(fnsym.Func().Autot, reflectdata.TypeSym(n.Type()).Linksym())
+	delete(fnsym.Func().Autot, reflectdata.TypeLinksym(n.Type()))
 	inlIndex := 0
 	if base.Flag.GenDwarfInl > 1 {
-		if n.Name().InlFormal() || n.Name().InlLocal() {
+		if n.InlFormal() || n.InlLocal() {
 			inlIndex = posInlIndex(n.Pos()) + 1
-			if n.Name().InlFormal() {
+			if n.InlFormal() {
 				abbrev = dwarf.DW_ABRV_PARAM
 			}
 		}
@@ -322,8 +305,8 @@ func createSimpleVar(fnsym *obj.LSym, n *ir.Name) *dwarf.Var {
 	declpos := base.Ctxt.InnermostPos(declPos(n))
 	return &dwarf.Var{
 		Name:          n.Sym().Name,
-		IsReturnValue: n.Class_ == ir.PPARAMOUT,
+		IsReturnValue: n.Class == ir.PPARAMOUT,
-		IsInlFormal:   n.Name().InlFormal(),
+		IsInlFormal:   n.InlFormal(),
 		Abbrev:        abbrev,
 		StackOffset:   int32(offs),
 		Type:          base.Ctxt.Lookup(typename),
@@ -367,7 +350,7 @@ func createComplexVar(fnsym *obj.LSym, fn *ir.Func, varID ssa.VarID) *dwarf.Var
 	n := debug.Vars[varID]
 
 	var abbrev int
-	switch n.Class_ {
+	switch n.Class {
 	case ir.PAUTO:
 		abbrev = dwarf.DW_ABRV_AUTO_LOCLIST
 	case ir.PPARAM, ir.PPARAMOUT:
@@ -376,14 +359,14 @@ func createComplexVar(fnsym *obj.LSym, fn *ir.Func, varID ssa.VarID) *dwarf.Var
 		return nil
 	}
 
-	gotype := reflectdata.TypeSym(n.Type()).Linksym()
+	gotype := reflectdata.TypeLinksym(n.Type())
 	delete(fnsym.Func().Autot, gotype)
 	typename := dwarf.InfoPrefix + gotype.Name[len("type."):]
 	inlIndex := 0
 	if base.Flag.GenDwarfInl > 1 {
-		if n.Name().InlFormal() || n.Name().InlLocal() {
+		if n.InlFormal() || n.InlLocal() {
 			inlIndex = posInlIndex(n.Pos()) + 1
-			if n.Name().InlFormal() {
+			if n.InlFormal() {
 				abbrev = dwarf.DW_ABRV_PARAM_LOCLIST
 			}
 		}
@@ -391,8 +374,8 @@ func createComplexVar(fnsym *obj.LSym, fn *ir.Func, varID ssa.VarID) *dwarf.Var
 	declpos := base.Ctxt.InnermostPos(n.Pos())
 	dvar := &dwarf.Var{
 		Name:          n.Sym().Name,
-		IsReturnValue: n.Class_ == ir.PPARAMOUT,
+		IsReturnValue: n.Class == ir.PPARAMOUT,
-		IsInlFormal:   n.Name().InlFormal(),
+		IsInlFormal:   n.InlFormal(),
 		Abbrev:        abbrev,
 		Type:          base.Ctxt.Lookup(typename),
 		// The stack offset is used as a sorting key, so for decomposed

src/cmd/compile/internal/escape/escape.go

@@ -85,20 +85,29 @@ import (
 // u[2], etc. However, we do record the implicit dereference involved
 // in indexing a slice.
 
-type escape struct {
+// A batch holds escape analysis state that's shared across an entire
+// batch of functions being analyzed at once.
+type batch struct {
 	allLocs []*location
-	labels  map[*types.Sym]labelState // known labels
 
-	curfn *ir.Func
+	heapLoc  location
+	blankLoc location
+}
+
+// An escape holds state specific to a single function being analyzed
+// within a batch.
+type escape struct {
+	*batch
+
+	curfn *ir.Func // function being analyzed
+
+	labels map[*types.Sym]labelState // known labels
 
 	// loopDepth counts the current loop nesting depth within
 	// curfn. It increments within each "for" loop and at each
 	// label with a corresponding backwards "goto" (i.e.,
 	// unstructured loop).
 	loopDepth int
-
-	heapLoc  location
-	blankLoc location
 }
 
 // An location represents an abstract location that stores a Go
@@ -165,12 +174,16 @@ func Fmt(n ir.Node) string {
 		text = fmt.Sprintf("esc(%d)", n.Esc())
 	}
 
-	if e, ok := n.Opt().(*location); ok && e.loopDepth != 0 {
+	if n.Op() == ir.ONAME {
-		if text != "" {
+		n := n.(*ir.Name)
-			text += " "
+		if loc, ok := n.Opt.(*location); ok && loc.loopDepth != 0 {
+			if text != "" {
+				text += " "
+			}
+			text += fmt.Sprintf("ld(%d)", loc.loopDepth)
 		}
-		text += fmt.Sprintf("ld(%d)", e.loopDepth)
 	}
+
 	return text
 }
 
@@ -183,23 +196,33 @@ func Batch(fns []*ir.Func, recursive bool) {
 		}
 	}
 
-	var e escape
+	var b batch
-	e.heapLoc.escapes = true
+	b.heapLoc.escapes = true
 
 	// Construct data-flow graph from syntax trees.
 	for _, fn := range fns {
-		e.initFunc(fn)
+		b.initFunc(fn)
 	}
 	for _, fn := range fns {
-		e.walkFunc(fn)
+		if !fn.IsHiddenClosure() {
+			b.walkFunc(fn)
+		}
 	}
-	e.curfn = nil
 
-	e.walkAll()
+	b.walkAll()
-	e.finish(fns)
+	b.finish(fns)
 }
 
-func (e *escape) initFunc(fn *ir.Func) {
+func (b *batch) with(fn *ir.Func) *escape {
+	return &escape{
+		batch:     b,
+		curfn:     fn,
+		loopDepth: 1,
+	}
+}
+
+func (b *batch) initFunc(fn *ir.Func) {
+	e := b.with(fn)
 	if fn.Esc() != escFuncUnknown {
 		base.Fatalf("unexpected node: %v", fn)
 	}
@@ -208,9 +231,6 @@ func (e *escape) initFunc(fn *ir.Func) {
 		ir.Dump("escAnalyze", fn)
 	}
 
-	e.curfn = fn
-	e.loopDepth = 1
-
 	// Allocate locations for local variables.
 	for _, dcl := range fn.Dcl {
 		if dcl.Op() == ir.ONAME {
@@ -219,7 +239,8 @@ func (e *escape) initFunc(fn *ir.Func) {
 	}
 }
 
-func (e *escape) walkFunc(fn *ir.Func) {
+func (b *batch) walkFunc(fn *ir.Func) {
+	e := b.with(fn)
 	fn.SetEsc(escFuncStarted)
 
 	// Identify labels that mark the head of an unstructured loop.
@@ -242,8 +263,6 @@ func (e *escape) walkFunc(fn *ir.Func) {
 		}
 	})
 
-	e.curfn = fn
-	e.loopDepth = 1
 	e.block(fn.Body)
 
 	if len(e.labels) != 0 {
@@ -349,54 +368,52 @@ func (e *escape) stmt(n ir.Node) {
 	case ir.ORANGE:
 		// for Key, Value = range X { Body }
 		n := n.(*ir.RangeStmt)
+
+		// X is evaluated outside the loop.
+		tmp := e.newLoc(nil, false)
+		e.expr(tmp.asHole(), n.X)
+
 		e.loopDepth++
-		e.addr(n.Key)
+		ks := e.addrs([]ir.Node{n.Key, n.Value})
-		k := e.addr(n.Value)
+		if n.X.Type().IsArray() {
+			e.flow(ks[1].note(n, "range"), tmp)
+		} else {
+			e.flow(ks[1].deref(n, "range-deref"), tmp)
+		}
+
 		e.block(n.Body)
 		e.loopDepth--
 
-		// X is evaluated outside the loop.
-		if n.X.Type().IsArray() {
-			k = k.note(n, "range")
-		} else {
-			k = k.deref(n, "range-deref")
-		}
-		e.expr(e.later(k), n.X)
-
 	case ir.OSWITCH:
 		n := n.(*ir.SwitchStmt)
-		typesw := n.Tag != nil && n.Tag.Op() == ir.OTYPESW
 
-		var ks []hole
+		if guard, ok := n.Tag.(*ir.TypeSwitchGuard); ok {
-		for _, cas := range n.Cases { // cases
+			var ks []hole
-			if typesw && n.Tag.(*ir.TypeSwitchGuard).Tag != nil {
+			if guard.Tag != nil {
-				cv := cas.Var
+				for _, cas := range n.Cases {
-				k := e.dcl(cv) // type switch variables have no ODCL.
+					cv := cas.Var
-				if cv.Type().HasPointers() {
+					k := e.dcl(cv) // type switch variables have no ODCL.
-					ks = append(ks, k.dotType(cv.Type(), cas, "switch case"))
+					if cv.Type().HasPointers() {
+						ks = append(ks, k.dotType(cv.Type(), cas, "switch case"))
+					}
 				}
 			}
-
-			e.discards(cas.List)
-			e.block(cas.Body)
-		}
-
-		if typesw {
 			e.expr(e.teeHole(ks...), n.Tag.(*ir.TypeSwitchGuard).X)
 		} else {
 			e.discard(n.Tag)
 		}
 
+		for _, cas := range n.Cases {
+			e.discards(cas.List)
+			e.block(cas.Body)
+		}
+
 	case ir.OSELECT:
 		n := n.(*ir.SelectStmt)
 		for _, cas := range n.Cases {
 			e.stmt(cas.Comm)
 			e.block(cas.Body)
 		}
-	case ir.OSELRECV2:
-		n := n.(*ir.AssignListStmt)
-		e.assign(n.Lhs[0], n.Rhs[0], "selrecv", n)
-		e.assign(n.Lhs[1], nil, "selrecv", n)
 	case ir.ORECV:
 		// TODO(mdempsky): Consider e.discard(n.Left).
 		n := n.(*ir.UnaryExpr)
@@ -408,28 +425,24 @@ func (e *escape) stmt(n ir.Node) {
 
 	case ir.OAS:
 		n := n.(*ir.AssignStmt)
-		e.assign(n.X, n.Y, "assign", n)
+		e.assignList([]ir.Node{n.X}, []ir.Node{n.Y}, "assign", n)
 	case ir.OASOP:
 		n := n.(*ir.AssignOpStmt)
-		e.assign(n.X, n.Y, "assign", n)
+		// TODO(mdempsky): Worry about OLSH/ORSH?
+		e.assignList([]ir.Node{n.X}, []ir.Node{n.Y}, "assign", n)
 	case ir.OAS2:
 		n := n.(*ir.AssignListStmt)
-		for i, nl := range n.Lhs {
+		e.assignList(n.Lhs, n.Rhs, "assign-pair", n)
-			e.assign(nl, n.Rhs[i], "assign-pair", n)
-		}
 
 	case ir.OAS2DOTTYPE: // v, ok = x.(type)
 		n := n.(*ir.AssignListStmt)
-		e.assign(n.Lhs[0], n.Rhs[0], "assign-pair-dot-type", n)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair-dot-type", n)
-		e.assign(n.Lhs[1], nil, "assign-pair-dot-type", n)
 	case ir.OAS2MAPR: // v, ok = m[k]
 		n := n.(*ir.AssignListStmt)
-		e.assign(n.Lhs[0], n.Rhs[0], "assign-pair-mapr", n)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair-mapr", n)
-		e.assign(n.Lhs[1], nil, "assign-pair-mapr", n)
+	case ir.OAS2RECV, ir.OSELRECV2: // v, ok = <-ch
-	case ir.OAS2RECV: // v, ok = <-ch
 		n := n.(*ir.AssignListStmt)
-		e.assign(n.Lhs[0], n.Rhs[0], "assign-pair-receive", n)
+		e.assignList(n.Lhs, n.Rhs, "assign-pair-receive", n)
-		e.assign(n.Lhs[1], nil, "assign-pair-receive", n)
 
 	case ir.OAS2FUNC:
 		n := n.(*ir.AssignListStmt)
@@ -438,9 +451,11 @@ func (e *escape) stmt(n ir.Node) {
 	case ir.ORETURN:
 		n := n.(*ir.ReturnStmt)
 		results := e.curfn.Type().Results().FieldSlice()
-		for i, v := range n.Results {
+		dsts := make([]ir.Node, len(results))
-			e.assign(ir.AsNode(results[i].Nname), v, "return", n)
+		for i, res := range results {
+			dsts[i] = res.Nname.(*ir.Name)
 		}
+		e.assignList(dsts, n.Results, "return", n)
 	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.ORECOVER:
 		e.call(nil, n, nil)
 	case ir.OGO, ir.ODEFER:
@@ -504,7 +519,7 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
 
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		if n.Class_ == ir.PFUNC || n.Class_ == ir.PEXTERN {
+		if n.Class == ir.PFUNC || n.Class == ir.PEXTERN {
 			return
 		}
 		e.flow(k, e.oldLoc(n))
@@ -612,10 +627,10 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
 		// Flow the receiver argument to both the closure and
 		// to the receiver parameter.
 
-		n := n.(*ir.CallPartExpr)
+		n := n.(*ir.SelectorExpr)
 		closureK := e.spill(k, n)
 
-		m := n.Method
+		m := n.Selection
 
 		// We don't know how the method value will be called
 		// later, so conservatively assume the result
@@ -676,9 +691,13 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
 
 	case ir.OCLOSURE:
 		n := n.(*ir.ClosureExpr)
-		k = e.spill(k, n)
+
+		if fn := n.Func; fn.IsHiddenClosure() {
+			e.walkFunc(fn)
+		}
 
 		// Link addresses of captured variables to closure.
+		k = e.spill(k, n)
 		for _, v := range n.Func.ClosureVars {
 			k := k
 			if !v.Byval() {
@@ -772,13 +791,13 @@ func (e *escape) addr(n ir.Node) hole {
 		base.Fatalf("unexpected addr: %v", n)
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		if n.Class_ == ir.PEXTERN {
+		if n.Class == ir.PEXTERN {
 			break
 		}
 		k = e.oldLoc(n).asHole()
 	case ir.ONAMEOFFSET:
 		n := n.(*ir.NameOffsetExpr)
-		e.addr(n.Name_)
+		k = e.addr(n.Name_)
 	case ir.ODOT:
 		n := n.(*ir.SelectorExpr)
 		k = e.addr(n.X)
@@ -798,10 +817,6 @@ func (e *escape) addr(n ir.Node) hole {
 		e.assignHeap(n.Index, "key of map put", n)
 	}
 
-	if !n.Type().HasPointers() {
-		k = e.discardHole()
-	}
-
 	return k
 }
 
@@ -813,6 +828,16 @@ func (e *escape) addrs(l ir.Nodes) []hole {
 	return ks
 }
 
+func (e *escape) assignList(dsts, srcs []ir.Node, why string, where ir.Node) {
+	for i, dst := range dsts {
+		var src ir.Node
+		if i < len(srcs) {
+			src = srcs[i]
+		}
+		e.assign(dst, src, why, where)
+	}
+}
+
 // assign evaluates the assignment dst = src.
 func (e *escape) assign(dst, src ir.Node, why string, where ir.Node) {
 	// Filter out some no-op assignments for escape analysis.
@@ -874,7 +899,7 @@ func (e *escape) call(ks []hole, call, where ir.Node) {
 		switch call.Op() {
 		case ir.OCALLFUNC:
 			switch v := ir.StaticValue(call.X); {
-			case v.Op() == ir.ONAME && v.(*ir.Name).Class_ == ir.PFUNC:
+			case v.Op() == ir.ONAME && v.(*ir.Name).Class == ir.PFUNC:
 				fn = v.(*ir.Name)
 			case v.Op() == ir.OCLOSURE:
 				fn = v.(*ir.ClosureExpr).Func.Nname
@@ -1097,7 +1122,7 @@ func (e *escape) teeHole(ks ...hole) hole {
 	return loc.asHole()
 }
 
-func (e *escape) dcl(n ir.Node) hole {
+func (e *escape) dcl(n *ir.Name) hole {
 	loc := e.oldLoc(n)
 	loc.loopDepth = e.loopDepth
 	return loc.asHole()
@@ -1121,19 +1146,6 @@ func (e *escape) later(k hole) hole {
 	return loc.asHole()
 }
 
-// canonicalNode returns the canonical *Node that n logically
-// represents.
-func canonicalNode(n ir.Node) ir.Node {
-	if n != nil && n.Op() == ir.ONAME && n.Name().IsClosureVar() {
-		n = n.Name().Defn
-		if n.Name().IsClosureVar() {
-			base.Fatalf("still closure var")
-		}
-	}
-
-	return n
-}
-
 func (e *escape) newLoc(n ir.Node, transient bool) *location {
 	if e.curfn == nil {
 		base.Fatalf("e.curfn isn't set")
@@ -1142,7 +1154,9 @@ func (e *escape) newLoc(n ir.Node, transient bool) *location {
 		base.ErrorfAt(n.Pos(), "%v is incomplete (or unallocatable); stack allocation disallowed", n.Type())
 	}
 
-	n = canonicalNode(n)
+	if n != nil && n.Op() == ir.ONAME {
+		n = n.(*ir.Name).Canonical()
+	}
 	loc := &location{
 		n:         n,
 		curfn:     e.curfn,
@@ -1151,15 +1165,17 @@ func (e *escape) newLoc(n ir.Node, transient bool) *location {
 	}
 	e.allLocs = append(e.allLocs, loc)
 	if n != nil {
-		if n.Op() == ir.ONAME && n.Name().Curfn != e.curfn {
+		if n.Op() == ir.ONAME {
 			n := n.(*ir.Name)
-			base.Fatalf("curfn mismatch: %v != %v", n.Name().Curfn, e.curfn)
+			if n.Curfn != e.curfn {
-		}
+				base.Fatalf("curfn mismatch: %v != %v", n.Curfn, e.curfn)
+			}
 
-		if n.Opt() != nil {
+			if n.Opt != nil {
-			base.Fatalf("%v already has a location", n)
+				base.Fatalf("%v already has a location", n)
+			}
+			n.Opt = loc
 		}
-		n.SetOpt(loc)
 
 		if why := HeapAllocReason(n); why != "" {
 			e.flow(e.heapHole().addr(n, why), loc)
@@ -1168,9 +1184,8 @@ func (e *escape) newLoc(n ir.Node, transient bool) *location {
 	return loc
 }
 
-func (e *escape) oldLoc(n ir.Node) *location {
+func (b *batch) oldLoc(n *ir.Name) *location {
-	n = canonicalNode(n)
+	return n.Canonical().Opt.(*location)
-	return n.Opt().(*location)
 }
 
 func (l *location) asHole() hole {
@@ -1210,7 +1225,7 @@ func (e *escape) discardHole() hole { return e.blankLoc.asHole() }
 
 // walkAll computes the minimal dereferences between all pairs of
 // locations.
-func (e *escape) walkAll() {
+func (b *batch) walkAll() {
 	// We use a work queue to keep track of locations that we need
 	// to visit, and repeatedly walk until we reach a fixed point.
 	//
@@ -1220,7 +1235,7 @@ func (e *escape) walkAll() {
 	// happen at most once. So we take Θ(len(e.allLocs)) walks.
 
 	// LIFO queue, has enough room for e.allLocs and e.heapLoc.
-	todo := make([]*location, 0, len(e.allLocs)+1)
+	todo := make([]*location, 0, len(b.allLocs)+1)
 	enqueue := func(loc *location) {
 		if !loc.queued {
 			todo = append(todo, loc)
@@ -1228,10 +1243,10 @@ func (e *escape) walkAll() {
 		}
 	}
 
-	for _, loc := range e.allLocs {
+	for _, loc := range b.allLocs {
 		enqueue(loc)
 	}
-	enqueue(&e.heapLoc)
+	enqueue(&b.heapLoc)
 
 	var walkgen uint32
 	for len(todo) > 0 {
@@ -1240,13 +1255,13 @@ func (e *escape) walkAll() {
 		root.queued = false
 
 		walkgen++
-		e.walkOne(root, walkgen, enqueue)
+		b.walkOne(root, walkgen, enqueue)
 	}
 }
 
 // walkOne computes the minimal number of dereferences from root to
 // all other locations.
-func (e *escape) walkOne(root *location, walkgen uint32, enqueue func(*location)) {
+func (b *batch) walkOne(root *location, walkgen uint32, enqueue func(*location)) {
 	// The data flow graph has negative edges (from addressing
 	// operations), so we use the Bellman-Ford algorithm. However,
 	// we don't have to worry about infinite negative cycles since
@@ -1281,7 +1296,7 @@ func (e *escape) walkOne(root *location, walkgen uint32, enqueue func(*location)
 			}
 		}
 
-		if e.outlives(root, l) {
+		if b.outlives(root, l) {
 			// l's value flows to root. If l is a function
 			// parameter and root is the heap or a
 			// corresponding result parameter, then record
@@ -1290,12 +1305,13 @@ func (e *escape) walkOne(root *location, walkgen uint32, enqueue func(*location)
 			if l.isName(ir.PPARAM) {
 				if (logopt.Enabled() || base.Flag.LowerM >= 2) && !l.escapes {
 					if base.Flag.LowerM >= 2 {
-						fmt.Printf("%s: parameter %v leaks to %s with derefs=%d:\n", base.FmtPos(l.n.Pos()), l.n, e.explainLoc(root), derefs)
+						fmt.Printf("%s: parameter %v leaks to %s with derefs=%d:\n", base.FmtPos(l.n.Pos()), l.n, b.explainLoc(root), derefs)
 					}
-					explanation := e.explainPath(root, l)
+					explanation := b.explainPath(root, l)
 					if logopt.Enabled() {
-						logopt.LogOpt(l.n.Pos(), "leak", "escape", ir.FuncName(e.curfn),
+						var e_curfn *ir.Func // TODO(mdempsky): Fix.
-							fmt.Sprintf("parameter %v leaks to %s with derefs=%d", l.n, e.explainLoc(root), derefs), explanation)
+						logopt.LogOpt(l.n.Pos(), "leak", "escape", ir.FuncName(e_curfn),
+							fmt.Sprintf("parameter %v leaks to %s with derefs=%d", l.n, b.explainLoc(root), derefs), explanation)
 					}
 				}
 				l.leakTo(root, derefs)
@@ -1309,9 +1325,10 @@ func (e *escape) walkOne(root *location, walkgen uint32, enqueue func(*location)
 					if base.Flag.LowerM >= 2 {
 						fmt.Printf("%s: %v escapes to heap:\n", base.FmtPos(l.n.Pos()), l.n)
 					}
-					explanation := e.explainPath(root, l)
+					explanation := b.explainPath(root, l)
 					if logopt.Enabled() {
-						logopt.LogOpt(l.n.Pos(), "escape", "escape", ir.FuncName(e.curfn), fmt.Sprintf("%v escapes to heap", l.n), explanation)
+						var e_curfn *ir.Func // TODO(mdempsky): Fix.
+						logopt.LogOpt(l.n.Pos(), "escape", "escape", ir.FuncName(e_curfn), fmt.Sprintf("%v escapes to heap", l.n), explanation)
 					}
 				}
 				l.escapes = true
@@ -1337,7 +1354,7 @@ func (e *escape) walkOne(root *location, walkgen uint32, enqueue func(*location)
 }
 
 // explainPath prints an explanation of how src flows to the walk root.
-func (e *escape) explainPath(root, src *location) []*logopt.LoggedOpt {
+func (b *batch) explainPath(root, src *location) []*logopt.LoggedOpt {
 	visited := make(map[*location]bool)
 	pos := base.FmtPos(src.n.Pos())
 	var explanation []*logopt.LoggedOpt
@@ -1356,7 +1373,7 @@ func (e *escape) explainPath(root, src *location) []*logopt.LoggedOpt {
 			base.Fatalf("path inconsistency: %v != %v", edge.src, src)
 		}
 
-		explanation = e.explainFlow(pos, dst, src, edge.derefs, edge.notes, explanation)
+		explanation = b.explainFlow(pos, dst, src, edge.derefs, edge.notes, explanation)
 
 		if dst == root {
 			break
@@ -1367,14 +1384,14 @@ func (e *escape) explainPath(root, src *location) []*logopt.LoggedOpt {
 	return explanation
 }
 
-func (e *escape) explainFlow(pos string, dst, srcloc *location, derefs int, notes *note, explanation []*logopt.LoggedOpt) []*logopt.LoggedOpt {
+func (b *batch) explainFlow(pos string, dst, srcloc *location, derefs int, notes *note, explanation []*logopt.LoggedOpt) []*logopt.LoggedOpt {
 	ops := "&"
 	if derefs >= 0 {
 		ops = strings.Repeat("*", derefs)
 	}
 	print := base.Flag.LowerM >= 2
 
-	flow := fmt.Sprintf("   flow: %s = %s%v:", e.explainLoc(dst), ops, e.explainLoc(srcloc))
+	flow := fmt.Sprintf("   flow: %s = %s%v:", b.explainLoc(dst), ops, b.explainLoc(srcloc))
 	if print {
 		fmt.Printf("%s:%s\n", pos, flow)
 	}
@@ -1385,7 +1402,8 @@ func (e *escape) explainFlow(pos string, dst, srcloc *location, derefs int, note
 		} else if srcloc != nil && srcloc.n != nil {
 			epos = srcloc.n.Pos()
 		}
-		explanation = append(explanation, logopt.NewLoggedOpt(epos, "escflow", "escape", ir.FuncName(e.curfn), flow))
+		var e_curfn *ir.Func // TODO(mdempsky): Fix.
+		explanation = append(explanation, logopt.NewLoggedOpt(epos, "escflow", "escape", ir.FuncName(e_curfn), flow))
 	}
 
 	for note := notes; note != nil; note = note.next {
@@ -1393,15 +1411,16 @@ func (e *escape) explainFlow(pos string, dst, srcloc *location, derefs int, note
 			fmt.Printf("%s:     from %v (%v) at %s\n", pos, note.where, note.why, base.FmtPos(note.where.Pos()))
 		}
 		if logopt.Enabled() {
-			explanation = append(explanation, logopt.NewLoggedOpt(note.where.Pos(), "escflow", "escape", ir.FuncName(e.curfn),
+			var e_curfn *ir.Func // TODO(mdempsky): Fix.
+			explanation = append(explanation, logopt.NewLoggedOpt(note.where.Pos(), "escflow", "escape", ir.FuncName(e_curfn),
 				fmt.Sprintf("     from %v (%v)", note.where, note.why)))
 		}
 	}
 	return explanation
 }
 
-func (e *escape) explainLoc(l *location) string {
+func (b *batch) explainLoc(l *location) string {
-	if l == &e.heapLoc {
+	if l == &b.heapLoc {
 		return "{heap}"
 	}
 	if l.n == nil {
@@ -1416,7 +1435,7 @@ func (e *escape) explainLoc(l *location) string {
 
 // outlives reports whether values stored in l may survive beyond
 // other's lifetime if stack allocated.
-func (e *escape) outlives(l, other *location) bool {
+func (b *batch) outlives(l, other *location) bool {
 	// The heap outlives everything.
 	if l.escapes {
 		return true
@@ -1497,7 +1516,7 @@ func (l *location) leakTo(sink *location, derefs int) {
 	l.paramEsc.AddHeap(derefs)
 }
 
-func (e *escape) finish(fns []*ir.Func) {
+func (b *batch) finish(fns []*ir.Func) {
 	// Record parameter tags for package export data.
 	for _, fn := range fns {
 		fn.SetEsc(escFuncTagged)
@@ -1506,17 +1525,20 @@ func (e *escape) finish(fns []*ir.Func) {
 		for _, fs := range &types.RecvsParams {
 			for _, f := range fs(fn.Type()).Fields().Slice() {
 				narg++
-				f.Note = e.paramTag(fn, narg, f)
+				f.Note = b.paramTag(fn, narg, f)
 			}
 		}
 	}
 
-	for _, loc := range e.allLocs {
+	for _, loc := range b.allLocs {
 		n := loc.n
 		if n == nil {
 			continue
 		}
-		n.SetOpt(nil)
+		if n.Op() == ir.ONAME {
+			n := n.(*ir.Name)
+			n.Opt = nil
+		}
 
 		// Update n.Esc based on escape analysis results.
 
@@ -1526,7 +1548,8 @@ func (e *escape) finish(fns []*ir.Func) {
 					base.WarnfAt(n.Pos(), "%v escapes to heap", n)
 				}
 				if logopt.Enabled() {
-					logopt.LogOpt(n.Pos(), "escape", "escape", ir.FuncName(e.curfn))
+					var e_curfn *ir.Func // TODO(mdempsky): Fix.
+					logopt.LogOpt(n.Pos(), "escape", "escape", ir.FuncName(e_curfn))
 				}
 			}
 			n.SetEsc(ir.EscHeap)
@@ -1542,7 +1565,7 @@ func (e *escape) finish(fns []*ir.Func) {
 					n := n.(*ir.ClosureExpr)
 					n.SetTransient(true)
 				case ir.OCALLPART:
-					n := n.(*ir.CallPartExpr)
+					n := n.(*ir.SelectorExpr)
 					n.SetTransient(true)
 				case ir.OSLICELIT:
 					n := n.(*ir.CompLitExpr)
@@ -1554,7 +1577,7 @@ func (e *escape) finish(fns []*ir.Func) {
 }
 
 func (l *location) isName(c ir.Class) bool {
-	return l.n != nil && l.n.Op() == ir.ONAME && l.n.(*ir.Name).Class_ == c
+	return l.n != nil && l.n.Op() == ir.ONAME && l.n.(*ir.Name).Class == c
 }
 
 const numEscResults = 7
@@ -1847,7 +1870,7 @@ func HeapAllocReason(n ir.Node) string {
 	// Parameters are always passed via the stack.
 	if n.Op() == ir.ONAME {
 		n := n.(*ir.Name)
-		if n.Class_ == ir.PPARAM || n.Class_ == ir.PPARAMOUT {
+		if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
 			return ""
 		}
 	}
@@ -1863,7 +1886,7 @@ func HeapAllocReason(n ir.Node) string {
 	if n.Op() == ir.OCLOSURE && typecheck.ClosureType(n.(*ir.ClosureExpr)).Size() >= ir.MaxImplicitStackVarSize {
 		return "too large for stack"
 	}
-	if n.Op() == ir.OCALLPART && typecheck.PartialCallType(n.(*ir.CallPartExpr)).Size() >= ir.MaxImplicitStackVarSize {
+	if n.Op() == ir.OCALLPART && typecheck.PartialCallType(n.(*ir.SelectorExpr)).Size() >= ir.MaxImplicitStackVarSize {
 		return "too large for stack"
 	}
 
@@ -1904,7 +1927,7 @@ func addrescapes(n ir.Node) {
 
 		// if this is a tmpname (PAUTO), it was tagged by tmpname as not escaping.
 		// on PPARAM it means something different.
-		if n.Class_ == ir.PAUTO && n.Esc() == ir.EscNever {
+		if n.Class == ir.PAUTO && n.Esc() == ir.EscNever {
 			break
 		}
 
@@ -1914,7 +1937,7 @@ func addrescapes(n ir.Node) {
 			break
 		}
 
-		if n.Class_ != ir.PPARAM && n.Class_ != ir.PPARAMOUT && n.Class_ != ir.PAUTO {
+		if n.Class != ir.PPARAM && n.Class != ir.PPARAMOUT && n.Class != ir.PAUTO {
 			break
 		}
 
@@ -1968,7 +1991,7 @@ func moveToHeap(n *ir.Name) {
 	if base.Flag.CompilingRuntime {
 		base.Errorf("%v escapes to heap, not allowed in runtime", n)
 	}
-	if n.Class_ == ir.PAUTOHEAP {
+	if n.Class == ir.PAUTOHEAP {
 		ir.Dump("n", n)
 		base.Fatalf("double move to heap")
 	}
@@ -1987,7 +2010,7 @@ func moveToHeap(n *ir.Name) {
 	// Parameters have a local stack copy used at function start/end
 	// in addition to the copy in the heap that may live longer than
 	// the function.
-	if n.Class_ == ir.PPARAM || n.Class_ == ir.PPARAMOUT {
+	if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
 		if n.FrameOffset() == types.BADWIDTH {
 			base.Fatalf("addrescapes before param assignment")
 		}
@@ -1999,9 +2022,9 @@ func moveToHeap(n *ir.Name) {
 		stackcopy := typecheck.NewName(n.Sym())
 		stackcopy.SetType(n.Type())
 		stackcopy.SetFrameOffset(n.FrameOffset())
-		stackcopy.Class_ = n.Class_
+		stackcopy.Class = n.Class
 		stackcopy.Heapaddr = heapaddr
-		if n.Class_ == ir.PPARAMOUT {
+		if n.Class == ir.PPARAMOUT {
 			// Make sure the pointer to the heap copy is kept live throughout the function.
 			// The function could panic at any point, and then a defer could recover.
 			// Thus, we need the pointer to the heap copy always available so the
@@ -2023,7 +2046,7 @@ func moveToHeap(n *ir.Name) {
 			}
 			// Parameters are before locals, so can stop early.
 			// This limits the search even in functions with many local variables.
-			if d.Class_ == ir.PAUTO {
+			if d.Class == ir.PAUTO {
 				break
 			}
 		}
@@ -2034,7 +2057,7 @@ func moveToHeap(n *ir.Name) {
 	}
 
 	// Modify n in place so that uses of n now mean indirection of the heapaddr.
-	n.Class_ = ir.PAUTOHEAP
+	n.Class = ir.PAUTOHEAP
 	n.SetFrameOffset(0)
 	n.Heapaddr = heapaddr
 	n.SetEsc(ir.EscHeap)
@@ -2052,7 +2075,7 @@ const UnsafeUintptrNote = "unsafe-uintptr"
 // marked go:uintptrescapes.
 const UintptrEscapesNote = "uintptr-escapes"
 
-func (e *escape) paramTag(fn *ir.Func, narg int, f *types.Field) string {
+func (b *batch) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 	name := func() string {
 		if f.Sym != nil {
 			return f.Sym.Name
@@ -2122,8 +2145,8 @@ func (e *escape) paramTag(fn *ir.Func, narg int, f *types.Field) string {
 		return esc.Encode()
 	}
 
-	n := ir.AsNode(f.Nname)
+	n := f.Nname.(*ir.Name)
-	loc := e.oldLoc(n)
+	loc := b.oldLoc(n)
 	esc := loc.paramEsc
 	esc.Optimize()
 

src/cmd/compile/internal/gc/abiutils_test.go

@@ -7,7 +7,6 @@ package gc
 import (
 	"bufio"
 	"cmd/compile/internal/base"
-	"cmd/compile/internal/reflectdata"
 	"cmd/compile/internal/ssagen"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
@@ -39,13 +38,7 @@ func TestMain(m *testing.M) {
 	base.Ctxt.Bso = bufio.NewWriter(os.Stdout)
 	types.PtrSize = ssagen.Arch.LinkArch.PtrSize
 	types.RegSize = ssagen.Arch.LinkArch.RegSize
-	types.TypeLinkSym = func(t *types.Type) *obj.LSym {
+	typecheck.InitUniverse()
-		return reflectdata.TypeSym(t).Linksym()
-	}
-	types.TypeLinkSym = func(t *types.Type) *obj.LSym {
-		return reflectdata.TypeSym(t).Linksym()
-	}
-	typecheck.Init()
 	os.Exit(m.Run())
 }
 

src/cmd/compile/internal/gc/abiutilsaux_test.go

@@ -21,7 +21,7 @@ import (
 func mkParamResultField(t *types.Type, s *types.Sym, which ir.Class) *types.Field {
 	field := types.NewField(src.NoXPos, s, t)
 	n := typecheck.NewName(s)
-	n.Class_ = which
+	n.Class = which
 	field.Nname = n
 	n.SetType(t)
 	return field

src/cmd/compile/internal/gc/compile.go

@@ -83,7 +83,7 @@ func compile(fn *ir.Func) {
 	// because symbols must be allocated before the parallel
 	// phase of the compiler.
 	for _, n := range fn.Dcl {
-		switch n.Class_ {
+		switch n.Class {
 		case ir.PPARAM, ir.PPARAMOUT, ir.PAUTO:
 			if liveness.ShouldTrack(n) && n.Addrtaken() {
 				reflectdata.WriteType(n.Type())
@@ -174,5 +174,5 @@ func isInlinableButNotInlined(fn *ir.Func) bool {
 	if fn.Sym() == nil {
 		return true
 	}
-	return !fn.Sym().Linksym().WasInlined()
+	return !fn.Linksym().WasInlined()
 }

src/cmd/compile/internal/gc/export.go

@@ -83,7 +83,7 @@ type exporter struct {
 func (p *exporter) markObject(n ir.Node) {
 	if n.Op() == ir.ONAME {
 		n := n.(*ir.Name)
-		if n.Class_ == ir.PFUNC {
+		if n.Class == ir.PFUNC {
 			inline.Inline_Flood(n, typecheck.Export)
 		}
 	}

src/cmd/compile/internal/gc/main.go

@@ -2,14 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate go run mkbuiltin.go
-
 package gc
 
 import (
 	"bufio"
 	"bytes"
 	"cmd/compile/internal/base"
+	"cmd/compile/internal/deadcode"
 	"cmd/compile/internal/devirtualize"
 	"cmd/compile/internal/dwarfgen"
 	"cmd/compile/internal/escape"
@@ -192,9 +191,6 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	types.PtrSize = ssagen.Arch.LinkArch.PtrSize
 	types.RegSize = ssagen.Arch.LinkArch.RegSize
 	types.MaxWidth = ssagen.Arch.MAXWIDTH
-	types.TypeLinkSym = func(t *types.Type) *obj.LSym {
-		return reflectdata.TypeSym(t).Linksym()
-	}
 
 	typecheck.Target = new(ir.Package)
 
@@ -204,37 +200,60 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 
 	base.AutogeneratedPos = makePos(src.NewFileBase("<autogenerated>", "<autogenerated>"), 1, 0)
 
-	types.TypeLinkSym = func(t *types.Type) *obj.LSym {
+	typecheck.InitUniverse()
-		return reflectdata.TypeSym(t).Linksym()
-	}
-	typecheck.Init()
 
-	// Parse input.
+	// Parse and typecheck input.
-	base.Timer.Start("fe", "parse")
+	noder.LoadPackage(flag.Args())
-	lines := noder.ParseFiles(flag.Args())
-	ssagen.CgoSymABIs()
-	base.Timer.Stop()
-	base.Timer.AddEvent(int64(lines), "lines")
-	if base.Flag.G != 0 && base.Flag.G < 3 {
-		// can only parse generic code for now
-		base.ExitIfErrors()
-		return
-	}
 
 	dwarfgen.RecordPackageName()
-
+	ssagen.CgoSymABIs()
-	// Typecheck.
-	typecheck.Package()
-
-	// With all user code typechecked, it's now safe to verify unused dot imports.
-	noder.CheckDotImports()
-	base.ExitIfErrors()
 
 	// Build init task.
 	if initTask := pkginit.Task(); initTask != nil {
 		typecheck.Export(initTask)
 	}
 
+	// Eliminate some obviously dead code.
+	// Must happen after typechecking.
+	for _, n := range typecheck.Target.Decls {
+		if n.Op() == ir.ODCLFUNC {
+			deadcode.Func(n.(*ir.Func))
+		}
+	}
+
+	// Compute Addrtaken for names.
+	// We need to wait until typechecking is done so that when we see &x[i]
+	// we know that x has its address taken if x is an array, but not if x is a slice.
+	// We compute Addrtaken in bulk here.
+	// After this phase, we maintain Addrtaken incrementally.
+	if typecheck.DirtyAddrtaken {
+		typecheck.ComputeAddrtaken(typecheck.Target.Decls)
+		typecheck.DirtyAddrtaken = false
+	}
+	typecheck.IncrementalAddrtaken = true
+
+	// Decide how to capture closed variables.
+	// This needs to run before escape analysis,
+	// because variables captured by value do not escape.
+	base.Timer.Start("fe", "capturevars")
+	for _, n := range typecheck.Target.Decls {
+		if n.Op() == ir.ODCLFUNC {
+			n := n.(*ir.Func)
+			if n.OClosure != nil {
+				ir.CurFunc = n
+				typecheck.CaptureVars(n)
+			}
+		}
+	}
+	typecheck.CaptureVarsComplete = true
+	ir.CurFunc = nil
+
+	if base.Debug.TypecheckInl != 0 {
+		// Typecheck imported function bodies if Debug.l > 1,
+		// otherwise lazily when used or re-exported.
+		typecheck.AllImportedBodies()
+	}
+
 	// Inlining
 	base.Timer.Start("fe", "inlining")
 	if base.Flag.LowerL != 0 {
@@ -285,6 +304,7 @@ func Main(archInit func(*ssagen.ArchInfo)) {
 	// Prepare for SSA compilation.
 	// This must be before peekitabs, because peekitabs
 	// can trigger function compilation.
+	typecheck.InitRuntime()
 	ssagen.InitConfig()
 
 	// Just before compilation, compile itabs found on

src/cmd/compile/internal/gc/obj.go

@@ -148,8 +148,8 @@ func dumpdata() {
 	dumpglobls(typecheck.Target.Externs[numExterns:])
 
 	if reflectdata.ZeroSize > 0 {
-		zero := ir.Pkgs.Map.Lookup("zero")
+		zero := ir.Pkgs.Map.Lookup("zero").Linksym()
-		objw.Global(zero.Linksym(), int32(reflectdata.ZeroSize), obj.DUPOK|obj.RODATA)
+		objw.Global(zero, int32(reflectdata.ZeroSize), obj.DUPOK|obj.RODATA)
 	}
 
 	addGCLocals()
@@ -188,7 +188,7 @@ func dumpGlobal(n *ir.Name) {
 	if n.Type() == nil {
 		base.Fatalf("external %v nil type\n", n)
 	}
-	if n.Class_ == ir.PFUNC {
+	if n.Class == ir.PFUNC {
 		return
 	}
 	if n.Sym().Pkg != types.LocalPkg {
@@ -260,18 +260,18 @@ func addGCLocals() {
 	}
 }
 
-func ggloblnod(nam ir.Node) {
+func ggloblnod(nam *ir.Name) {
-	s := nam.Sym().Linksym()
+	s := nam.Linksym()
-	s.Gotype = reflectdata.TypeSym(nam.Type()).Linksym()
+	s.Gotype = reflectdata.TypeLinksym(nam.Type())
 	flags := 0
-	if nam.Name().Readonly() {
+	if nam.Readonly() {
 		flags = obj.RODATA
 	}
 	if nam.Type() != nil && !nam.Type().HasPointers() {
 		flags |= obj.NOPTR
 	}
 	base.Ctxt.Globl(s, nam.Type().Width, flags)
-	if nam.Name().LibfuzzerExtraCounter() {
+	if nam.LibfuzzerExtraCounter() {
 		s.Type = objabi.SLIBFUZZER_EXTRA_COUNTER
 	}
 	if nam.Sym().Linkname != "" {

src/cmd/compile/internal/inline/inl.go

@@ -199,8 +199,8 @@ func Inline_Flood(n *ir.Name, exportsym func(*ir.Name)) {
 	if n == nil {
 		return
 	}
-	if n.Op() != ir.ONAME || n.Class_ != ir.PFUNC {
+	if n.Op() != ir.ONAME || n.Class != ir.PFUNC {
-		base.Fatalf("inlFlood: unexpected %v, %v, %v", n, n.Op(), n.Class_)
+		base.Fatalf("inlFlood: unexpected %v, %v, %v", n, n.Op(), n.Class)
 	}
 	fn := n.Func
 	if fn == nil {
@@ -227,7 +227,7 @@ func Inline_Flood(n *ir.Name, exportsym func(*ir.Name)) {
 
 		case ir.ONAME:
 			n := n.(*ir.Name)
-			switch n.Class_ {
+			switch n.Class {
 			case ir.PFUNC:
 				Inline_Flood(n, exportsym)
 				exportsym(n)
@@ -265,7 +265,7 @@ var errBudget = errors.New("too expensive")
 func (v *hairyVisitor) tooHairy(fn *ir.Func) bool {
 	v.do = v.doNode // cache closure
 
-	err := ir.DoChildren(fn, v.do)
+	err := errChildren(fn, v.do)
 	if err != nil {
 		v.reason = err.Error()
 		return true
@@ -292,7 +292,7 @@ func (v *hairyVisitor) doNode(n ir.Node) error {
 		// runtime.throw is a "cheap call" like panic in normal code.
 		if n.X.Op() == ir.ONAME {
 			name := n.X.(*ir.Name)
-			if name.Class_ == ir.PFUNC && types.IsRuntimePkg(name.Sym().Pkg) {
+			if name.Class == ir.PFUNC && types.IsRuntimePkg(name.Sym().Pkg) {
 				fn := name.Sym().Name
 				if fn == "getcallerpc" || fn == "getcallersp" {
 					return errors.New("call to " + fn)
@@ -393,13 +393,13 @@ func (v *hairyVisitor) doNode(n ir.Node) error {
 		if ir.IsConst(n.Cond, constant.Bool) {
 			// This if and the condition cost nothing.
 			// TODO(rsc): It seems strange that we visit the dead branch.
-			if err := ir.DoList(n.Init(), v.do); err != nil {
+			if err := errList(n.Init(), v.do); err != nil {
 				return err
 			}
-			if err := ir.DoList(n.Body, v.do); err != nil {
+			if err := errList(n.Body, v.do); err != nil {
 				return err
 			}
-			if err := ir.DoList(n.Else, v.do); err != nil {
+			if err := errList(n.Else, v.do); err != nil {
 				return err
 			}
 			return nil
@@ -407,7 +407,7 @@ func (v *hairyVisitor) doNode(n ir.Node) error {
 
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		if n.Class_ == ir.PAUTO {
+		if n.Class == ir.PAUTO {
 			v.usedLocals[n] = true
 		}
 
@@ -419,6 +419,9 @@ func (v *hairyVisitor) doNode(n ir.Node) error {
 
 	case ir.OCALLPART, ir.OSLICELIT:
 		v.budget-- // Hack for toolstash -cmp.
+
+	case ir.OMETHEXPR:
+		v.budget++ // Hack for toolstash -cmp.
 	}
 
 	v.budget--
@@ -428,7 +431,7 @@ func (v *hairyVisitor) doNode(n ir.Node) error {
 		return errBudget
 	}
 
-	return ir.DoChildren(n, v.do)
+	return errChildren(n, v.do)
 }
 
 func isBigFunc(fn *ir.Func) bool {
@@ -541,7 +544,7 @@ func inlnode(n ir.Node, maxCost int32, inlMap map[*ir.Func]bool, edit func(ir.No
 	if as := n; as.Op() == ir.OAS2FUNC {
 		as := as.(*ir.AssignListStmt)
 		if as.Rhs[0].Op() == ir.OINLCALL {
-			as.Rhs.Set(inlconv2list(as.Rhs[0].(*ir.InlinedCallExpr)))
+			as.Rhs = inlconv2list(as.Rhs[0].(*ir.InlinedCallExpr))
 			as.SetOp(ir.OAS2)
 			as.SetTypecheck(0)
 			n = typecheck.Stmt(as)
@@ -613,18 +616,18 @@ func inlCallee(fn ir.Node) *ir.Func {
 	fn = ir.StaticValue(fn)
 	switch fn.Op() {
 	case ir.OMETHEXPR:
-		fn := fn.(*ir.MethodExpr)
+		fn := fn.(*ir.SelectorExpr)
 		n := ir.MethodExprName(fn)
-		// Check that receiver type matches fn.Left.
+		// Check that receiver type matches fn.X.
 		// TODO(mdempsky): Handle implicit dereference
 		// of pointer receiver argument?
-		if n == nil || !types.Identical(n.Type().Recv().Type, fn.T) {
+		if n == nil || !types.Identical(n.Type().Recv().Type, fn.X.Type()) {
 			return nil
 		}
 		return n.Func
 	case ir.ONAME:
 		fn := fn.(*ir.Name)
-		if fn.Class_ == ir.PFUNC {
+		if fn.Class == ir.PFUNC {
 			return fn.Func
 		}
 	case ir.OCLOSURE:
@@ -636,13 +639,15 @@ func inlCallee(fn ir.Node) *ir.Func {
 	return nil
 }
 
-func inlParam(t *types.Field, as ir.Node, inlvars map[*ir.Name]ir.Node) ir.Node {
+func inlParam(t *types.Field, as ir.InitNode, inlvars map[*ir.Name]*ir.Name) ir.Node {
-	n := ir.AsNode(t.Nname)
+	if t.Nname == nil {
-	if n == nil || ir.IsBlank(n) {
 		return ir.BlankNode
 	}
-
+	n := t.Nname.(*ir.Name)
-	inlvar := inlvars[n.(*ir.Name)]
+	if ir.IsBlank(n) {
+		return ir.BlankNode
+	}
+	inlvar := inlvars[n]
 	if inlvar == nil {
 		base.Fatalf("missing inlvar for %v", n)
 	}
@@ -736,7 +741,7 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 		callee := n.X
 		for callee.Op() == ir.OCONVNOP {
 			conv := callee.(*ir.ConvExpr)
-			ninit.Append(conv.PtrInit().Take()...)
+			ninit.Append(ir.TakeInit(conv)...)
 			callee = conv.X
 		}
 		if callee.Op() != ir.ONAME && callee.Op() != ir.OCLOSURE && callee.Op() != ir.OMETHEXPR {
@@ -745,52 +750,16 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	}
 
 	// Make temp names to use instead of the originals.
-	inlvars := make(map[*ir.Name]ir.Node)
+	inlvars := make(map[*ir.Name]*ir.Name)
 
 	// record formals/locals for later post-processing
-	var inlfvars []ir.Node
+	var inlfvars []*ir.Name
-
-	// Handle captured variables when inlining closures.
-	if c := fn.OClosure; c != nil {
-		for _, v := range fn.ClosureVars {
-			if v.Op() == ir.OXXX {
-				continue
-			}
-
-			o := v.Outer
-			// make sure the outer param matches the inlining location
-			// NB: if we enabled inlining of functions containing OCLOSURE or refined
-			// the reassigned check via some sort of copy propagation this would most
-			// likely need to be changed to a loop to walk up to the correct Param
-			if o == nil || o.Curfn != ir.CurFunc {
-				base.Fatalf("%v: unresolvable capture %v %v\n", ir.Line(n), fn, v)
-			}
-
-			if v.Byval() {
-				iv := typecheck.Expr(inlvar(v))
-				ninit.Append(ir.NewDecl(base.Pos, ir.ODCL, iv))
-				ninit.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, iv, o)))
-				inlvars[v] = iv
-			} else {
-				addr := typecheck.NewName(typecheck.Lookup("&" + v.Sym().Name))
-				addr.SetType(types.NewPtr(v.Type()))
-				ia := typecheck.Expr(inlvar(addr))
-				ninit.Append(ir.NewDecl(base.Pos, ir.ODCL, ia))
-				ninit.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, ia, typecheck.NodAddr(o))))
-				inlvars[addr] = ia
-
-				// When capturing by reference, all occurrence of the captured var
-				// must be substituted with dereference of the temporary address
-				inlvars[v] = typecheck.Expr(ir.NewStarExpr(base.Pos, ia))
-			}
-		}
-	}
 
 	for _, ln := range fn.Inl.Dcl {
 		if ln.Op() != ir.ONAME {
 			continue
 		}
-		if ln.Class_ == ir.PPARAMOUT { // return values handled below.
+		if ln.Class == ir.PPARAMOUT { // return values handled below.
 			continue
 		}
 		if ir.IsParamStackCopy(ln) { // ignore the on-stack copy of a parameter that moved to the heap
@@ -800,10 +769,10 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 			// nothing should have moved to the heap yet.
 			base.Fatalf("impossible: %v", ln)
 		}
-		inlf := typecheck.Expr(inlvar(ln))
+		inlf := typecheck.Expr(inlvar(ln)).(*ir.Name)
 		inlvars[ln] = inlf
 		if base.Flag.GenDwarfInl > 0 {
-			if ln.Class_ == ir.PPARAM {
+			if ln.Class == ir.PPARAM {
 				inlf.Name().SetInlFormal(true)
 			} else {
 				inlf.Name().SetInlLocal(true)
@@ -828,11 +797,11 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	// temporaries for return values.
 	var retvars []ir.Node
 	for i, t := range fn.Type().Results().Fields().Slice() {
-		var m ir.Node
+		var m *ir.Name
-		if n := ir.AsNode(t.Nname); n != nil && !ir.IsBlank(n) && !strings.HasPrefix(n.Sym().Name, "~r") {
+		if nn := t.Nname; nn != nil && !ir.IsBlank(nn.(*ir.Name)) && !strings.HasPrefix(nn.Sym().Name, "~r") {
-			n := n.(*ir.Name)
+			n := nn.(*ir.Name)
 			m = inlvar(n)
-			m = typecheck.Expr(m)
+			m = typecheck.Expr(m).(*ir.Name)
 			inlvars[n] = m
 			delayretvars = false // found a named result parameter
 		} else {
@@ -897,8 +866,8 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 			vas.Y = typecheck.NodNil()
 			vas.Y.SetType(param.Type)
 		} else {
-			lit := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(param.Type).(ir.Ntype), nil)
+			lit := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(param.Type), nil)
-			lit.List.Set(varargs)
+			lit.List = varargs
 			vas.Y = lit
 		}
 	}
@@ -914,7 +883,7 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	if !delayretvars {
 		// Zero the return parameters.
 		for _, n := range retvars {
-			ninit.Append(ir.NewDecl(base.Pos, ir.ODCL, n))
+			ninit.Append(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name)))
 			ras := ir.NewAssignStmt(base.Pos, n, nil)
 			ninit.Append(typecheck.Stmt(ras))
 		}
@@ -929,7 +898,7 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 		parent = b.InliningIndex()
 	}
 
-	sym := fn.Sym().Linksym()
+	sym := fn.Linksym()
 	newIndex := base.Ctxt.InlTree.Add(parent, n.Pos(), sym)
 
 	// Add an inline mark just before the inlined body.
@@ -975,9 +944,9 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 	//dumplist("ninit post", ninit);
 
 	call := ir.NewInlinedCallExpr(base.Pos, nil, nil)
-	call.PtrInit().Set(ninit)
+	*call.PtrInit() = ninit
-	call.Body.Set(body)
+	call.Body = body
-	call.ReturnVars.Set(retvars)
+	call.ReturnVars = retvars
 	call.SetType(n.Type())
 	call.SetTypecheck(1)
 
@@ -999,27 +968,27 @@ func mkinlcall(n *ir.CallExpr, fn *ir.Func, maxCost int32, inlMap map[*ir.Func]b
 // Every time we expand a function we generate a new set of tmpnames,
 // PAUTO's in the calling functions, and link them off of the
 // PPARAM's, PAUTOS and PPARAMOUTs of the called function.
-func inlvar(var_ ir.Node) ir.Node {
+func inlvar(var_ *ir.Name) *ir.Name {
 	if base.Flag.LowerM > 3 {
 		fmt.Printf("inlvar %+v\n", var_)
 	}
 
 	n := typecheck.NewName(var_.Sym())
 	n.SetType(var_.Type())
-	n.Class_ = ir.PAUTO
+	n.Class = ir.PAUTO
 	n.SetUsed(true)
 	n.Curfn = ir.CurFunc // the calling function, not the called one
-	n.SetAddrtaken(var_.Name().Addrtaken())
+	n.SetAddrtaken(var_.Addrtaken())
 
 	ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n)
 	return n
 }
 
 // Synthesize a variable to store the inlined function's results in.
-func retvar(t *types.Field, i int) ir.Node {
+func retvar(t *types.Field, i int) *ir.Name {
 	n := typecheck.NewName(typecheck.LookupNum("~R", i))
 	n.SetType(t.Type)
-	n.Class_ = ir.PAUTO
+	n.Class = ir.PAUTO
 	n.SetUsed(true)
 	n.Curfn = ir.CurFunc // the calling function, not the called one
 	ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n)
@@ -1031,7 +1000,7 @@ func retvar(t *types.Field, i int) ir.Node {
 func argvar(t *types.Type, i int) ir.Node {
 	n := typecheck.NewName(typecheck.LookupNum("~arg", i))
 	n.SetType(t.Elem())
-	n.Class_ = ir.PAUTO
+	n.Class = ir.PAUTO
 	n.SetUsed(true)
 	n.Curfn = ir.CurFunc // the calling function, not the called one
 	ir.CurFunc.Dcl = append(ir.CurFunc.Dcl, n)
@@ -1051,7 +1020,7 @@ type inlsubst struct {
 	// "return" statement.
 	delayretvars bool
 
-	inlvars map[*ir.Name]ir.Node
+	inlvars map[*ir.Name]*ir.Name
 
 	// bases maps from original PosBase to PosBase with an extra
 	// inlined call frame.
@@ -1085,6 +1054,25 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 	switch n.Op() {
 	case ir.ONAME:
 		n := n.(*ir.Name)
+
+		// Handle captured variables when inlining closures.
+		if n.IsClosureVar() {
+			o := n.Outer
+
+			// make sure the outer param matches the inlining location
+			// NB: if we enabled inlining of functions containing OCLOSURE or refined
+			// the reassigned check via some sort of copy propagation this would most
+			// likely need to be changed to a loop to walk up to the correct Param
+			if o == nil || o.Curfn != ir.CurFunc {
+				base.Fatalf("%v: unresolvable capture %v\n", ir.Line(n), n)
+			}
+
+			if base.Flag.LowerM > 2 {
+				fmt.Printf("substituting captured name %+v  ->  %+v\n", n, o)
+			}
+			return o
+		}
+
 		if inlvar := subst.inlvars[n]; inlvar != nil { // These will be set during inlnode
 			if base.Flag.LowerM > 2 {
 				fmt.Printf("substituting name %+v  ->  %+v\n", n, inlvar)
@@ -1098,7 +1086,7 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 		return n
 
 	case ir.OMETHEXPR:
-		n := n.(*ir.MethodExpr)
+		n := n.(*ir.SelectorExpr)
 		return n
 
 	case ir.OLITERAL, ir.ONIL, ir.OTYPE:
@@ -1108,15 +1096,6 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 		if n.Sym() != nil {
 			return n
 		}
-		if n, ok := n.(*ir.Name); ok && n.Op() == ir.OLITERAL {
-			// This happens for unnamed OLITERAL.
-			// which should really not be a *Name, but for now it is.
-			// ir.Copy(n) is not allowed generally and would panic below,
-			// but it's OK in this situation.
-			n = n.CloneName()
-			n.SetPos(subst.updatedPos(n.Pos()))
-			return n
-		}
 
 	case ir.ORETURN:
 		// Since we don't handle bodies with closures,
@@ -1132,11 +1111,11 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 			for _, n := range subst.retvars {
 				as.Lhs.Append(n)
 			}
-			as.Rhs.Set(subst.list(n.Results))
+			as.Rhs = subst.list(n.Results)
 
 			if subst.delayretvars {
 				for _, n := range as.Lhs {
-					as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, n))
+					as.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name)))
 					n.Name().Defn = as
 				}
 			}
@@ -1151,7 +1130,7 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 		n := n.(*ir.BranchStmt)
 		m := ir.Copy(n).(*ir.BranchStmt)
 		m.SetPos(subst.updatedPos(m.Pos()))
-		m.PtrInit().Set(nil)
+		*m.PtrInit() = nil
 		p := fmt.Sprintf("%s·%d", n.Label.Name, inlgen)
 		m.Label = typecheck.Lookup(p)
 		return m
@@ -1160,7 +1139,7 @@ func (subst *inlsubst) node(n ir.Node) ir.Node {
 		n := n.(*ir.LabelStmt)
 		m := ir.Copy(n).(*ir.LabelStmt)
 		m.SetPos(subst.updatedPos(m.Pos()))
-		m.PtrInit().Set(nil)
+		*m.PtrInit() = nil
 		p := fmt.Sprintf("%s·%d", n.Label.Name, inlgen)
 		m.Label = typecheck.Lookup(p)
 		return m
@@ -1191,7 +1170,7 @@ func (subst *inlsubst) updatedPos(xpos src.XPos) src.XPos {
 func pruneUnusedAutos(ll []*ir.Name, vis *hairyVisitor) []*ir.Name {
 	s := make([]*ir.Name, 0, len(ll))
 	for _, n := range ll {
-		if n.Class_ == ir.PAUTO {
+		if n.Class == ir.PAUTO {
 			if _, found := vis.usedLocals[n]; !found {
 				continue
 			}
@@ -1211,3 +1190,22 @@ func numNonClosures(list []*ir.Func) int {
 	}
 	return count
 }
+
+// TODO(mdempsky): Update inl.go to use ir.DoChildren directly.
+func errChildren(n ir.Node, do func(ir.Node) error) (err error) {
+	ir.DoChildren(n, func(x ir.Node) bool {
+		err = do(x)
+		return err != nil
+	})
+	return
+}
+func errList(list []ir.Node, do func(ir.Node) error) error {
+	for _, x := range list {
+		if x != nil {
+			if err := do(x); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

src/cmd/compile/internal/ir/class_string.go

@@ -1,4 +1,4 @@
-// Code generated by "stringer -type=Class"; DO NOT EDIT.
+// Code generated by "stringer -type=Class name.go"; DO NOT EDIT.
 
 package ir
 

src/cmd/compile/internal/ir/copy.go

@@ -25,6 +25,14 @@ type OrigNode interface {
 	SetOrig(Node)
 }
 
+// origNode may be embedded into a Node to make it implement OrigNode.
+type origNode struct {
+	orig Node `mknode:"-"`
+}
+
+func (n *origNode) Orig() Node     { return n.orig }
+func (n *origNode) SetOrig(o Node) { n.orig = o }
+
 // Orig returns the “original” node for n.
 // If n implements OrigNode, Orig returns n.Orig().
 // Otherwise Orig returns n itself.

src/cmd/compile/internal/ir/expr.go

@@ -14,27 +14,6 @@ import (
 	"go/token"
 )
 
-func maybeDo(x Node, err error, do func(Node) error) error {
-	if x != nil && err == nil {
-		err = do(x)
-	}
-	return err
-}
-
-func maybeDoList(x Nodes, err error, do func(Node) error) error {
-	if err == nil {
-		err = DoList(x, do)
-	}
-	return err
-}
-
-func maybeEdit(x Node, edit func(Node) Node) Node {
-	if x == nil {
-		return x
-	}
-	return edit(x)
-}
-
 // An Expr is a Node that can appear as an expression.
 type Expr interface {
 	Node
@@ -48,8 +27,7 @@ type Expr interface {
 type miniExpr struct {
 	miniNode
 	typ   *types.Type
-	init  Nodes       // TODO(rsc): Don't require every Node to have an init
+	init  Nodes // TODO(rsc): Don't require every Node to have an init
-	opt   interface{} // TODO(rsc): Don't require every Node to have an opt?
 	flags bitset8
 }
 
@@ -59,14 +37,13 @@ const (
 	miniExprTransient
 	miniExprBounded
 	miniExprImplicit // for use by implementations; not supported by every Expr
+	miniExprCheckPtr
 )
 
 func (*miniExpr) isExpr() {}
 
 func (n *miniExpr) Type() *types.Type     { return n.typ }
 func (n *miniExpr) SetType(x *types.Type) { n.typ = x }
-func (n *miniExpr) Opt() interface{}      { return n.opt }
-func (n *miniExpr) SetOpt(x interface{})  { n.opt = x }
 func (n *miniExpr) HasCall() bool         { return n.flags&miniExprHasCall != 0 }
 func (n *miniExpr) SetHasCall(b bool)     { n.flags.set(miniExprHasCall, b) }
 func (n *miniExpr) NonNil() bool          { return n.flags&miniExprNonNil != 0 }
@@ -79,16 +56,6 @@ func (n *miniExpr) Init() Nodes           { return n.init }
 func (n *miniExpr) PtrInit() *Nodes       { return &n.init }
 func (n *miniExpr) SetInit(x Nodes)       { n.init = x }
 
-func toNtype(x Node) Ntype {
-	if x == nil {
-		return nil
-	}
-	if _, ok := x.(Ntype); !ok {
-		Dump("not Ntype", x)
-	}
-	return x.(Ntype)
-}
-
 // An AddStringExpr is a string concatenation Expr[0] + Exprs[1] + ... + Expr[len(Expr)-1].
 type AddStringExpr struct {
 	miniExpr
@@ -100,7 +67,7 @@ func NewAddStringExpr(pos src.XPos, list []Node) *AddStringExpr {
 	n := &AddStringExpr{}
 	n.pos = pos
 	n.op = OADDSTR
-	n.List.Set(list)
+	n.List = list
 	return n
 }
 
@@ -108,8 +75,8 @@ func NewAddStringExpr(pos src.XPos, list []Node) *AddStringExpr {
 // It may end up being a normal address-of or an allocation of a composite literal.
 type AddrExpr struct {
 	miniExpr
-	X     Node
+	X        Node
-	Alloc Node // preallocated storage if any
+	Prealloc *Name // preallocated storage if any
 }
 
 func NewAddrExpr(pos src.XPos, x Node) *AddrExpr {
@@ -191,14 +158,14 @@ const (
 // A CallExpr is a function call X(Args).
 type CallExpr struct {
 	miniExpr
-	orig     Node
+	origNode
-	X        Node
+	X         Node
-	Args     Nodes
+	Args      Nodes
-	Rargs    Nodes // TODO(rsc): Delete.
+	Rargs     Nodes   // TODO(rsc): Delete.
-	Body     Nodes // TODO(rsc): Delete.
+	KeepAlive []*Name // vars to be kept alive until call returns
-	IsDDD    bool
+	IsDDD     bool
-	Use      CallUse
+	Use       CallUse
-	NoInline bool
+	NoInline  bool
 }
 
 func NewCallExpr(pos src.XPos, op Op, fun Node, args []Node) *CallExpr {
@@ -206,15 +173,12 @@ func NewCallExpr(pos src.XPos, op Op, fun Node, args []Node) *CallExpr {
 	n.pos = pos
 	n.orig = n
 	n.SetOp(op)
-	n.Args.Set(args)
+	n.Args = args
 	return n
 }
 
 func (*CallExpr) isStmt() {}
 
-func (n *CallExpr) Orig() Node     { return n.orig }
-func (n *CallExpr) SetOrig(x Node) { n.orig = x }
-
 func (n *CallExpr) SetOp(op Op) {
 	switch op {
 	default:
@@ -225,30 +189,10 @@ func (n *CallExpr) SetOp(op Op) {
 	}
 }
 
-// A CallPartExpr is a method expression X.Method (uncalled).
-type CallPartExpr struct {
-	miniExpr
-	Func     *Func
-	X        Node
-	Method   *types.Field
-	Prealloc *Name
-}
-
-func NewCallPartExpr(pos src.XPos, x Node, method *types.Field, fn *Func) *CallPartExpr {
-	n := &CallPartExpr{Func: fn, X: x, Method: method}
-	n.op = OCALLPART
-	n.pos = pos
-	n.typ = fn.Type()
-	n.Func = fn
-	return n
-}
-
-func (n *CallPartExpr) Sym() *types.Sym { return n.Method.Sym }
-
 // A ClosureExpr is a function literal expression.
 type ClosureExpr struct {
 	miniExpr
-	Func     *Func
+	Func     *Func `mknode:"-"`
 	Prealloc *Name
 }
 
@@ -276,7 +220,7 @@ func NewClosureRead(typ *types.Type, offset int64) *ClosureReadExpr {
 // Before type-checking, the type is Ntype.
 type CompLitExpr struct {
 	miniExpr
-	orig     Node
+	origNode
 	Ntype    Ntype
 	List     Nodes // initialized values
 	Prealloc *Name
@@ -287,13 +231,11 @@ func NewCompLitExpr(pos src.XPos, op Op, typ Ntype, list []Node) *CompLitExpr {
 	n := &CompLitExpr{Ntype: typ}
 	n.pos = pos
 	n.SetOp(op)
-	n.List.Set(list)
+	n.List = list
 	n.orig = n
 	return n
 }
 
-func (n *CompLitExpr) Orig() Node         { return n.orig }
-func (n *CompLitExpr) SetOrig(x Node)     { n.orig = x }
 func (n *CompLitExpr) Implicit() bool     { return n.flags&miniExprImplicit != 0 }
 func (n *CompLitExpr) SetImplicit(b bool) { n.flags.set(miniExprImplicit, b) }
 
@@ -308,14 +250,15 @@ func (n *CompLitExpr) SetOp(op Op) {
 
 type ConstExpr struct {
 	miniExpr
-	val  constant.Value
+	origNode
-	orig Node
+	val constant.Value
 }
 
 func NewConstExpr(val constant.Value, orig Node) Node {
-	n := &ConstExpr{orig: orig, val: val}
+	n := &ConstExpr{val: val}
 	n.op = OLITERAL
 	n.pos = orig.Pos()
+	n.orig = orig
 	n.SetType(orig.Type())
 	n.SetTypecheck(orig.Typecheck())
 	n.SetDiag(orig.Diag())
@@ -323,8 +266,6 @@ func NewConstExpr(val constant.Value, orig Node) Node {
 }
 
 func (n *ConstExpr) Sym() *types.Sym     { return n.orig.Sym() }
-func (n *ConstExpr) Orig() Node          { return n.orig }
-func (n *ConstExpr) SetOrig(orig Node)   { panic(n.no("SetOrig")) }
 func (n *ConstExpr) Val() constant.Value { return n.val }
 
 // A ConvExpr is a conversion Type(X).
@@ -344,6 +285,8 @@ func NewConvExpr(pos src.XPos, op Op, typ *types.Type, x Node) *ConvExpr {
 
 func (n *ConvExpr) Implicit() bool     { return n.flags&miniExprImplicit != 0 }
 func (n *ConvExpr) SetImplicit(b bool) { n.flags.set(miniExprImplicit, b) }
+func (n *ConvExpr) CheckPtr() bool     { return n.flags&miniExprCheckPtr != 0 }
+func (n *ConvExpr) SetCheckPtr(b bool) { n.flags.set(miniExprCheckPtr, b) }
 
 func (n *ConvExpr) SetOp(op Op) {
 	switch op {
@@ -421,8 +364,8 @@ func NewInlinedCallExpr(pos src.XPos, body, retvars []Node) *InlinedCallExpr {
 	n := &InlinedCallExpr{}
 	n.pos = pos
 	n.op = OINLCALL
-	n.Body.Set(body)
+	n.Body = body
-	n.ReturnVars.Set(retvars)
+	n.ReturnVars = retvars
 	return n
 }
 
@@ -476,24 +419,6 @@ func (n *MakeExpr) SetOp(op Op) {
 	}
 }
 
-// A MethodExpr is a method expression T.M (where T is a type).
-type MethodExpr struct {
-	miniExpr
-	T         *types.Type
-	Method    *types.Field
-	FuncName_ *Name
-}
-
-func NewMethodExpr(pos src.XPos, t *types.Type, method *types.Field) *MethodExpr {
-	n := &MethodExpr{T: t, Method: method}
-	n.pos = pos
-	n.op = OMETHEXPR
-	return n
-}
-
-func (n *MethodExpr) FuncName() *Name { return n.FuncName_ }
-func (n *MethodExpr) Sym() *types.Sym { panic("MethodExpr.Sym") }
-
 // A NilExpr represents the predefined untyped constant nil.
 // (It may be copied and assigned a type, though.)
 type NilExpr struct {
@@ -567,12 +492,13 @@ func NewNameOffsetExpr(pos src.XPos, name *Name, offset int64, typ *types.Type)
 	return n
 }
 
-// A SelectorExpr is a selector expression X.Sym.
+// A SelectorExpr is a selector expression X.Sel.
 type SelectorExpr struct {
 	miniExpr
 	X         Node
 	Sel       *types.Sym
 	Selection *types.Field
+	Prealloc  *Name // preallocated storage for OCALLPART, if any
 }
 
 func NewSelectorExpr(pos src.XPos, op Op, x Node, sel *types.Sym) *SelectorExpr {
@@ -586,7 +512,7 @@ func (n *SelectorExpr) SetOp(op Op) {
 	switch op {
 	default:
 		panic(n.no("SetOp " + op.String()))
-	case ODOT, ODOTPTR, ODOTMETH, ODOTINTER, OXDOT:
+	case OXDOT, ODOT, ODOTPTR, ODOTMETH, ODOTINTER, OCALLPART, OMETHEXPR:
 		n.op = op
 	}
 }
@@ -596,6 +522,16 @@ func (n *SelectorExpr) Implicit() bool     { return n.flags&miniExprImplicit !=
 func (n *SelectorExpr) SetImplicit(b bool) { n.flags.set(miniExprImplicit, b) }
 func (n *SelectorExpr) Offset() int64      { return n.Selection.Offset }
 
+func (n *SelectorExpr) FuncName() *Name {
+	if n.Op() != OMETHEXPR {
+		panic(n.no("FuncName"))
+	}
+	fn := NewNameAt(n.Selection.Pos, MethodSym(n.X.Type(), n.Sel))
+	fn.Class = PFUNC
+	fn.SetType(n.Type())
+	return fn
+}
+
 // Before type-checking, bytes.Buffer is a SelectorExpr.
 // After type-checking it becomes a Name.
 func (*SelectorExpr) CanBeNtype() {}
@@ -687,8 +623,13 @@ func (n *StarExpr) SetOTYPE(t *types.Type) {
 type TypeAssertExpr struct {
 	miniExpr
 	X     Node
-	Ntype Node  // TODO: Should be Ntype, but reused as address of type structure
+	Ntype Ntype
-	Itab  Nodes // Itab[0] is itab
+
+	// Runtime type information provided by walkDotType.
+	// Caution: These aren't always populated; see walkDotType.
+	SrcType *AddrExpr `mknode:"-"` // *runtime._type for X's type
+	DstType *AddrExpr `mknode:"-"` // *runtime._type for Type
+	Itab    *AddrExpr `mknode:"-"` // *runtime.itab for Type implementing X's type
 }
 
 func NewTypeAssertExpr(pos src.XPos, x Node, typ Ntype) *TypeAssertExpr {
@@ -795,7 +736,7 @@ func IsAddressable(n Node) bool {
 
 	case ONAME:
 		n := n.(*Name)
-		if n.Class_ == PFUNC {
+		if n.Class == PFUNC {
 			return false
 		}
 		return true
@@ -830,11 +771,11 @@ func staticValue1(nn Node) Node {
 		return nil
 	}
 	n := nn.(*Name)
-	if n.Class_ != PAUTO || n.Name().Addrtaken() {
+	if n.Class != PAUTO {
 		return nil
 	}
 
-	defn := n.Name().Defn
+	defn := n.Defn
 	if defn == nil {
 		return nil
 	}
@@ -882,23 +823,46 @@ func reassigned(name *Name) bool {
 	if name.Curfn == nil {
 		return true
 	}
-	return Any(name.Curfn, func(n Node) bool {
+
+	// TODO(mdempsky): This is inefficient and becoming increasingly
+	// unwieldy. Figure out a way to generalize escape analysis's
+	// reassignment detection for use by inlining and devirtualization.
+
+	// isName reports whether n is a reference to name.
+	isName := func(x Node) bool {
+		n, ok := x.(*Name)
+		return ok && n.Canonical() == name
+	}
+
+	var do func(n Node) bool
+	do = func(n Node) bool {
 		switch n.Op() {
 		case OAS:
 			n := n.(*AssignStmt)
-			if n.X == name && n != name.Defn {
+			if isName(n.X) && n != name.Defn {
 				return true
 			}
 		case OAS2, OAS2FUNC, OAS2MAPR, OAS2DOTTYPE, OAS2RECV, OSELRECV2:
 			n := n.(*AssignListStmt)
 			for _, p := range n.Lhs {
-				if p == name && n != name.Defn {
+				if isName(p) && n != name.Defn {
 					return true
 				}
 			}
+		case OADDR:
+			n := n.(*AddrExpr)
+			if isName(OuterValue(n.X)) {
+				return true
+			}
+		case OCLOSURE:
+			n := n.(*ClosureExpr)
+			if Any(n.Func, do) {
+				return true
+			}
 		}
 		return false
-	})
+	}
+	return Any(name.Curfn, do)
 }
 
 // IsIntrinsicCall reports whether the compiler back end will treat the call as an intrinsic operation.
@@ -1089,13 +1053,8 @@ func MethodExprName(n Node) *Name {
 // MethodFunc is like MethodName, but returns the types.Field instead.
 func MethodExprFunc(n Node) *types.Field {
 	switch n.Op() {
-	case ODOTMETH:
+	case ODOTMETH, OMETHEXPR, OCALLPART:
 		return n.(*SelectorExpr).Selection
-	case OMETHEXPR:
-		return n.(*MethodExpr).Method
-	case OCALLPART:
-		n := n.(*CallPartExpr)
-		return n.Method
 	}
 	base.Fatalf("unexpected node: %v (%v)", n, n.Op())
 	panic("unreachable")

src/cmd/compile/internal/ir/fmt.go

@@ -128,7 +128,7 @@ func (o Op) Format(s fmt.State, verb rune) {
 //	%L	Go syntax followed by " (type T)" if type is known.
 //	%+v	Debug syntax, as in Dump.
 //
-func FmtNode(n Node, s fmt.State, verb rune) {
+func fmtNode(n Node, s fmt.State, verb rune) {
 	// %+v prints Dump.
 	// Otherwise we print Go syntax.
 	if s.Flag('+') && verb == 'v' {
@@ -216,6 +216,7 @@ var OpPrec = []int{
 	OTINTER:        8,
 	OTMAP:          8,
 	OTSTRUCT:       8,
+	OTYPE:          8,
 	OINDEXMAP:      8,
 	OINDEX:         8,
 	OSLICE:         8,
@@ -232,6 +233,7 @@ var OpPrec = []int{
 	ODOT:           8,
 	OXDOT:          8,
 	OCALLPART:      8,
+	OMETHEXPR:      8,
 	OPLUS:          7,
 	ONOT:           7,
 	OBITNOT:        7,
@@ -551,8 +553,8 @@ func exprFmt(n Node, s fmt.State, prec int) {
 	}
 
 	nprec := OpPrec[n.Op()]
-	if n.Op() == OTYPE && n.Sym() != nil {
+	if n.Op() == OTYPE && n.Type().IsPtr() {
-		nprec = 8
+		nprec = OpPrec[ODEREF]
 	}
 
 	if prec > nprec {
@@ -630,10 +632,6 @@ func exprFmt(n Node, s fmt.State, prec int) {
 	case OPACK, ONONAME:
 		fmt.Fprint(s, n.Sym())
 
-	case OMETHEXPR:
-		n := n.(*MethodExpr)
-		fmt.Fprint(s, n.FuncName().Sym())
-
 	case ONAMEOFFSET:
 		n := n.(*NameOffsetExpr)
 		fmt.Fprintf(s, "(%v)(%v@%d)", n.Type(), n.Name_, n.Offset_)
@@ -749,16 +747,7 @@ func exprFmt(n Node, s fmt.State, prec int) {
 		n := n.(*StructKeyExpr)
 		fmt.Fprintf(s, "%v:%v", n.Field, n.Value)
 
-	case OCALLPART:
+	case OXDOT, ODOT, ODOTPTR, ODOTINTER, ODOTMETH, OCALLPART, OMETHEXPR:
-		n := n.(*CallPartExpr)
-		exprFmt(n.X, s, nprec)
-		if n.Method.Sym == nil {
-			fmt.Fprint(s, ".<nil>")
-			return
-		}
-		fmt.Fprintf(s, ".%s", n.Method.Sym.Name)
-
-	case OXDOT, ODOT, ODOTPTR, ODOTINTER, ODOTMETH:
 		n := n.(*SelectorExpr)
 		exprFmt(n.X, s, nprec)
 		if n.Sel == nil {
@@ -991,7 +980,7 @@ func (l Nodes) Format(s fmt.State, verb rune) {
 
 // Dump prints the message s followed by a debug dump of n.
 func Dump(s string, n Node) {
-	fmt.Printf("%s [%p]%+v", s, n, n)
+	fmt.Printf("%s [%p]%+v\n", s, n, n)
 }
 
 // DumpList prints the message s followed by a debug dump of each node in the list.
@@ -1160,12 +1149,6 @@ func dumpNode(w io.Writer, n Node, depth int) {
 		}
 		return
 
-	case OMETHEXPR:
-		n := n.(*MethodExpr)
-		fmt.Fprintf(w, "%+v-%+v", n.Op(), n.FuncName().Sym())
-		dumpNodeHeader(w, n)
-		return
-
 	case OASOP:
 		n := n.(*AssignOpStmt)
 		fmt.Fprintf(w, "%+v-%+v", n.Op(), n.AsOp)
@@ -1254,10 +1237,25 @@ func dumpNode(w io.Writer, n Node, depth int) {
 				fmt.Fprintf(w, "%+v-%s", n.Op(), name)
 			}
 			dumpNodes(w, val, depth+1)
+		default:
+			if vf.Kind() == reflect.Slice && vf.Type().Elem().Implements(nodeType) {
+				if vf.Len() == 0 {
+					continue
+				}
+				if name != "" {
+					indent(w, depth)
+					fmt.Fprintf(w, "%+v-%s", n.Op(), name)
+				}
+				for i, n := 0, vf.Len(); i < n; i++ {
+					dumpNode(w, vf.Index(i).Interface().(Node), depth+1)
+				}
+			}
 		}
 	}
 }
 
+var nodeType = reflect.TypeOf((*Node)(nil)).Elem()
+
 func dumpNodes(w io.Writer, list Nodes, depth int) {
 	if len(list) == 0 {
 		fmt.Fprintf(w, " <nil>")

src/cmd/compile/internal/ir/func.go

@@ -49,7 +49,6 @@ import (
 // pointer from the Func back to the OCALLPART.
 type Func struct {
 	miniNode
-	typ  *types.Type
 	Body Nodes
 	Iota int64
 
@@ -66,9 +65,15 @@ type Func struct {
 	// include closurevars until transformclosure runs.
 	Dcl []*Name
 
-	ClosureEnter Nodes   // list of ONAME nodes (or OADDR-of-ONAME nodes, for output parameters) of captured variables
+	ClosureType Ntype // closure representation type
-	ClosureType  Node    // closure representation type
+
-	ClosureVars  []*Name // closure params; each has closurevar set
+	// ClosureVars lists the free variables that are used within a
+	// function literal, but formally declared in an enclosing
+	// function. The variables in this slice are the closure function's
+	// own copy of the variables, which are used within its function
+	// body. They will also each have IsClosureVar set, and will have
+	// Byval set if they're captured by value.
+	ClosureVars []*Name
 
 	// Parents records the parent scope of each scope within a
 	// function. The root scope (0) has no parent, so the i'th
@@ -78,7 +83,7 @@ type Func struct {
 	// Marks records scope boundary changes.
 	Marks []Mark
 
-	FieldTrack map[*types.Sym]struct{}
+	FieldTrack map[*obj.LSym]struct{}
 	DebugInfo  interface{}
 	LSym       *obj.LSym
 
@@ -116,15 +121,13 @@ func NewFunc(pos src.XPos) *Func {
 
 func (f *Func) isStmt() {}
 
-func (f *Func) Type() *types.Type     { return f.typ }
+func (n *Func) copy() Node                         { panic(n.no("copy")) }
-func (f *Func) SetType(x *types.Type) { f.typ = x }
+func (n *Func) doChildren(do func(Node) bool) bool { return doNodes(n.Body, do) }
+func (n *Func) editChildren(edit func(Node) Node)  { editNodes(n.Body, edit) }
 
-func (f *Func) Sym() *types.Sym {
+func (f *Func) Type() *types.Type  { return f.Nname.Type() }
-	if f.Nname != nil {
+func (f *Func) Sym() *types.Sym    { return f.Nname.Sym() }
-		return f.Nname.Sym()
+func (f *Func) Linksym() *obj.LSym { return f.Nname.Linksym() }
-	}
-	return nil
-}
 
 // An Inline holds fields used for function bodies that can be inlined.
 type Inline struct {
@@ -240,24 +243,13 @@ func FuncSymName(s *types.Sym) string {
 	return s.Name + "·f"
 }
 
-// NewFuncNameAt generates a new name node for a function or method.
-func NewFuncNameAt(pos src.XPos, s *types.Sym, fn *Func) *Name {
-	if fn.Nname != nil {
-		base.Fatalf("newFuncName - already have name")
-	}
-	n := NewNameAt(pos, s)
-	n.SetFunc(fn)
-	fn.Nname = n
-	return n
-}
-
 // MarkFunc marks a node as a function.
 func MarkFunc(n *Name) {
-	if n.Op() != ONAME || n.Class_ != Pxxx {
+	if n.Op() != ONAME || n.Class != Pxxx {
 		base.Fatalf("expected ONAME/Pxxx node, got %v", n)
 	}
 
-	n.Class_ = PFUNC
+	n.Class = PFUNC
 	n.Sym().SetFunc(true)
 }
 

src/cmd/compile/internal/ir/mini.go

@@ -54,20 +54,13 @@ func (n *miniNode) Esc() uint16       { return n.esc }
 func (n *miniNode) SetEsc(x uint16)   { n.esc = x }
 
 const (
-	miniWalkdefShift   = 0
+	miniWalkdefShift   = 0 // TODO(mdempsky): Move to Name.flags.
 	miniTypecheckShift = 2
 	miniDiag           = 1 << 4
 	miniHasCall        = 1 << 5 // for miniStmt
 )
 
-func (n *miniNode) Walkdef() uint8   { return n.bits.get2(miniWalkdefShift) }
 func (n *miniNode) Typecheck() uint8 { return n.bits.get2(miniTypecheckShift) }
-func (n *miniNode) SetWalkdef(x uint8) {
-	if x > 3 {
-		panic(fmt.Sprintf("cannot SetWalkdef %d", x))
-	}
-	n.bits.set2(miniWalkdefShift, x)
-}
 func (n *miniNode) SetTypecheck(x uint8) {
 	if x > 3 {
 		panic(fmt.Sprintf("cannot SetTypecheck %d", x))
@@ -80,13 +73,7 @@ func (n *miniNode) SetDiag(x bool) { n.bits.set(miniDiag, x) }
 
 // Empty, immutable graph structure.
 
-func (n *miniNode) Init() Nodes     { return Nodes{} }
+func (n *miniNode) Init() Nodes { return Nodes{} }
-func (n *miniNode) PtrInit() *Nodes { return &immutableEmptyNodes }
-func (n *miniNode) SetInit(x Nodes) {
-	if x != nil {
-		panic(n.no("SetInit"))
-	}
-}
 
 // Additional functionality unavailable.
 
@@ -102,5 +89,3 @@ func (n *miniNode) HasCall() bool           { return false }
 func (n *miniNode) SetHasCall(bool)         { panic(n.no("SetHasCall")) }
 func (n *miniNode) NonNil() bool            { return false }
 func (n *miniNode) MarkNonNil()             { panic(n.no("MarkNonNil")) }
-func (n *miniNode) Opt() interface{}        { return nil }
-func (n *miniNode) SetOpt(interface{})      { panic(n.no("SetOpt")) }

src/cmd/compile/internal/ir/mknode.go

@@ -13,11 +13,16 @@ import (
 	"go/types"
 	"io/ioutil"
 	"log"
+	"reflect"
+	"sort"
 	"strings"
 
 	"golang.org/x/tools/go/packages"
 )
 
+var irPkg *types.Package
+var buf bytes.Buffer
+
 func main() {
 	cfg := &packages.Config{
 		Mode: packages.NeedSyntax | packages.NeedTypes,
@@ -26,116 +31,59 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	irPkg = pkgs[0].Types
 
-	pkg := pkgs[0].Types
-	scope := pkg.Scope()
-
-	lookup := func(name string) *types.Named {
-		return scope.Lookup(name).(*types.TypeName).Type().(*types.Named)
-	}
-
-	nodeType := lookup("Node")
-	ntypeType := lookup("Ntype")
-	nodesType := lookup("Nodes")
-	slicePtrCaseClauseType := types.NewSlice(types.NewPointer(lookup("CaseClause")))
-	slicePtrCommClauseType := types.NewSlice(types.NewPointer(lookup("CommClause")))
-	ptrFieldType := types.NewPointer(lookup("Field"))
-	slicePtrFieldType := types.NewSlice(ptrFieldType)
-	ptrIdentType := types.NewPointer(lookup("Ident"))
-
-	var buf bytes.Buffer
 	fmt.Fprintln(&buf, "// Code generated by mknode.go. DO NOT EDIT.")
 	fmt.Fprintln(&buf)
 	fmt.Fprintln(&buf, "package ir")
 	fmt.Fprintln(&buf)
 	fmt.Fprintln(&buf, `import "fmt"`)
 
+	scope := irPkg.Scope()
 	for _, name := range scope.Names() {
+		if strings.HasPrefix(name, "mini") {
+			continue
+		}
+
 		obj, ok := scope.Lookup(name).(*types.TypeName)
 		if !ok {
 			continue
 		}
-
+		typ := obj.Type().(*types.Named)
-		typName := obj.Name()
+		if !implementsNode(types.NewPointer(typ)) {
-		typ, ok := obj.Type().(*types.Named).Underlying().(*types.Struct)
-		if !ok {
-			continue
-		}
-
-		if strings.HasPrefix(typName, "mini") || !hasMiniNode(typ) {
 			continue
 		}
 
 		fmt.Fprintf(&buf, "\n")
-		fmt.Fprintf(&buf, "func (n *%s) Format(s fmt.State, verb rune) { FmtNode(n, s, verb) }\n", name)
+		fmt.Fprintf(&buf, "func (n *%s) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }\n", name)
 
 		switch name {
-		case "Name":
+		case "Name", "Func":
-			fmt.Fprintf(&buf, "func (n *%s) copy() Node {panic(\"%s.copy\")}\n", name, name)
+			// Too specialized to automate.
-		default:
+			continue
-			fmt.Fprintf(&buf, "func (n *%s) copy() Node { c := *n\n", name)
-			forNodeFields(typName, typ, func(name string, is func(types.Type) bool) {
-				switch {
-				case is(nodesType):
-					fmt.Fprintf(&buf, "c.%s = c.%s.Copy()\n", name, name)
-				case is(slicePtrCaseClauseType):
-					fmt.Fprintf(&buf, "c.%s = copyCases(c.%s)\n", name, name)
-				case is(slicePtrCommClauseType):
-					fmt.Fprintf(&buf, "c.%s = copyComms(c.%s)\n", name, name)
-				case is(ptrFieldType):
-					fmt.Fprintf(&buf, "if c.%s != nil { c.%s = c.%s.copy() }\n", name, name, name)
-				case is(slicePtrFieldType):
-					fmt.Fprintf(&buf, "c.%s = copyFields(c.%s)\n", name, name)
-				}
-			})
-			fmt.Fprintf(&buf, "return &c }\n")
 		}
 
-		fmt.Fprintf(&buf, "func (n *%s) doChildren(do func(Node) error) error { var err error\n", name)
+		forNodeFields(typ,
-		forNodeFields(typName, typ, func(name string, is func(types.Type) bool) {
+			"func (n *%[1]s) copy() Node { c := *n\n",
-			switch {
+			"",
-			case is(ptrIdentType):
+			"c.%[1]s = copy%[2]s(c.%[1]s)",
-				fmt.Fprintf(&buf, "if n.%s != nil { err = maybeDo(n.%s, err, do) }\n", name, name)
+			"return &c }\n")
-			case is(nodeType), is(ntypeType):
-				fmt.Fprintf(&buf, "err = maybeDo(n.%s, err, do)\n", name)
-			case is(nodesType):
-				fmt.Fprintf(&buf, "err = maybeDoList(n.%s, err, do)\n", name)
-			case is(slicePtrCaseClauseType):
-				fmt.Fprintf(&buf, "err = maybeDoCases(n.%s, err, do)\n", name)
-			case is(slicePtrCommClauseType):
-				fmt.Fprintf(&buf, "err = maybeDoComms(n.%s, err, do)\n", name)
-			case is(ptrFieldType):
-				fmt.Fprintf(&buf, "err = maybeDoField(n.%s, err, do)\n", name)
-			case is(slicePtrFieldType):
-				fmt.Fprintf(&buf, "err = maybeDoFields(n.%s, err, do)\n", name)
-			}
-		})
-		fmt.Fprintf(&buf, "return err }\n")
 
-		fmt.Fprintf(&buf, "func (n *%s) editChildren(edit func(Node) Node) {\n", name)
+		forNodeFields(typ,
-		forNodeFields(typName, typ, func(name string, is func(types.Type) bool) {
+			"func (n *%[1]s) doChildren(do func(Node) bool) bool {\n",
-			switch {
+			"if n.%[1]s != nil && do(n.%[1]s) { return true }",
-			case is(ptrIdentType):
+			"if do%[2]s(n.%[1]s, do) { return true }",
-				fmt.Fprintf(&buf, "if n.%s != nil { n.%s = edit(n.%s).(*Ident) }\n", name, name, name)
+			"return false }\n")
-			case is(nodeType):
+
-				fmt.Fprintf(&buf, "n.%s = maybeEdit(n.%s, edit)\n", name, name)
+		forNodeFields(typ,
-			case is(ntypeType):
+			"func (n *%[1]s) editChildren(edit func(Node) Node) {\n",
-				fmt.Fprintf(&buf, "n.%s = toNtype(maybeEdit(n.%s, edit))\n", name, name)
+			"if n.%[1]s != nil { n.%[1]s = edit(n.%[1]s).(%[2]s) }",
-			case is(nodesType):
+			"edit%[2]s(n.%[1]s, edit)",
-				fmt.Fprintf(&buf, "editList(n.%s, edit)\n", name)
+			"}\n")
-			case is(slicePtrCaseClauseType):
-				fmt.Fprintf(&buf, "editCases(n.%s, edit)\n", name)
-			case is(slicePtrCommClauseType):
-				fmt.Fprintf(&buf, "editComms(n.%s, edit)\n", name)
-			case is(ptrFieldType):
-				fmt.Fprintf(&buf, "editField(n.%s, edit)\n", name)
-			case is(slicePtrFieldType):
-				fmt.Fprintf(&buf, "editFields(n.%s, edit)\n", name)
-			}
-		})
-		fmt.Fprintf(&buf, "}\n")
 	}
 
+	makeHelpers()
+
 	out, err := format.Source(buf.Bytes())
 	if err != nil {
 		// write out mangled source so we can see the bug.
@@ -148,40 +96,131 @@ func main() {
 	}
 }
 
-func forNodeFields(typName string, typ *types.Struct, f func(name string, is func(types.Type) bool)) {
+// needHelper maps needed slice helpers from their base name to their
-	for i, n := 0, typ.NumFields(); i < n; i++ {
+// respective slice-element type.
-		v := typ.Field(i)
+var needHelper = map[string]string{}
-		if v.Embedded() {
+
-			if typ, ok := v.Type().Underlying().(*types.Struct); ok {
+func makeHelpers() {
-				forNodeFields(typName, typ, f)
+	var names []string
-				continue
+	for name := range needHelper {
-			}
+		names = append(names, name)
-		}
+	}
-		switch typName {
+	sort.Strings(names)
-		case "Func":
+
-			if strings.ToLower(strings.TrimSuffix(v.Name(), "_")) != "body" {
+	for _, name := range names {
-				continue
+		fmt.Fprintf(&buf, sliceHelperTmpl, name, needHelper[name])
-			}
-		case "Name":
-			continue
-		}
-		switch v.Name() {
-		case "orig":
-			continue
-		}
-		f(v.Name(), func(t types.Type) bool { return types.Identical(t, v.Type()) })
 	}
 }
 
-func hasMiniNode(typ *types.Struct) bool {
+const sliceHelperTmpl = `
-	for i, n := 0, typ.NumFields(); i < n; i++ {
+func copy%[1]s(list []%[2]s) []%[2]s {
-		v := typ.Field(i)
+	if list == nil {
-		if v.Name() == "miniNode" {
+		return nil
+	}
+	c := make([]%[2]s, len(list))
+	copy(c, list)
+	return c
+}
+func do%[1]s(list []%[2]s, do func(Node) bool) bool {
+	for _, x := range list {
+		if x != nil && do(x) {
 			return true
 		}
-		if v.Embedded() {
+	}
-			if typ, ok := v.Type().Underlying().(*types.Struct); ok && hasMiniNode(typ) {
+	return false
-				return true
+}
+func edit%[1]s(list []%[2]s, edit func(Node) Node) {
+	for i, x := range list {
+		if x != nil {
+			list[i] = edit(x).(%[2]s)
+		}
+	}
+}
+`
+
+func forNodeFields(named *types.Named, prologue, singleTmpl, sliceTmpl, epilogue string) {
+	fmt.Fprintf(&buf, prologue, named.Obj().Name())
+
+	anyField(named.Underlying().(*types.Struct), func(f *types.Var) bool {
+		if f.Embedded() {
+			return false
+		}
+		name, typ := f.Name(), f.Type()
+
+		slice, _ := typ.Underlying().(*types.Slice)
+		if slice != nil {
+			typ = slice.Elem()
+		}
+
+		tmpl, what := singleTmpl, types.TypeString(typ, types.RelativeTo(irPkg))
+		if implementsNode(typ) {
+			if slice != nil {
+				helper := strings.TrimPrefix(what, "*") + "s"
+				needHelper[helper] = what
+				tmpl, what = sliceTmpl, helper
+			}
+		} else if what == "*Field" {
+			// Special case for *Field.
+			tmpl = sliceTmpl
+			if slice != nil {
+				what = "Fields"
+			} else {
+				what = "Field"
+			}
+		} else {
+			return false
+		}
+
+		if tmpl == "" {
+			return false
+		}
+
+		// Allow template to not use all arguments without
+		// upsetting fmt.Printf.
+		s := fmt.Sprintf(tmpl+"\x00 %[1]s %[2]s", name, what)
+		fmt.Fprintln(&buf, s[:strings.LastIndex(s, "\x00")])
+		return false
+	})
+
+	fmt.Fprintf(&buf, epilogue)
+}
+
+func implementsNode(typ types.Type) bool {
+	if _, ok := typ.Underlying().(*types.Interface); ok {
+		// TODO(mdempsky): Check the interface implements Node.
+		// Worst case, node_gen.go will fail to compile if we're wrong.
+		return true
+	}
+
+	if ptr, ok := typ.(*types.Pointer); ok {
+		if str, ok := ptr.Elem().Underlying().(*types.Struct); ok {
+			return anyField(str, func(f *types.Var) bool {
+				return f.Embedded() && f.Name() == "miniNode"
+			})
+		}
+	}
+
+	return false
+}
+
+func anyField(typ *types.Struct, pred func(f *types.Var) bool) bool {
+	for i, n := 0, typ.NumFields(); i < n; i++ {
+		if value, ok := reflect.StructTag(typ.Tag(i)).Lookup("mknode"); ok {
+			if value != "-" {
+				panic(fmt.Sprintf("unexpected tag value: %q", value))
+			}
+			continue
+		}
+
+		f := typ.Field(i)
+		if pred(f) {
+			return true
+		}
+		if f.Embedded() {
+			if typ, ok := f.Type().Underlying().(*types.Struct); ok {
+				if anyField(typ, pred) {
+					return true
+				}
 			}
 		}
 	}

src/cmd/compile/internal/ir/name.go

@@ -7,8 +7,10 @@ package ir
 import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/types"
+	"cmd/internal/obj"
 	"cmd/internal/objabi"
 	"cmd/internal/src"
+	"fmt"
 
 	"go/constant"
 )
@@ -34,16 +36,16 @@ func (*Ident) CanBeNtype() {}
 // Name holds Node fields used only by named nodes (ONAME, OTYPE, some OLITERAL).
 type Name struct {
 	miniExpr
-	BuiltinOp Op    // uint8
+	BuiltinOp Op         // uint8
-	Class_    Class // uint8
+	Class     Class      // uint8
-	flags     bitset16
 	pragma    PragmaFlag // int16
+	flags     bitset16
 	sym       *types.Sym
 	Func      *Func
 	Offset_   int64
 	val       constant.Value
-	orig      Node
+	Opt       interface{} // for use by escape analysis
-	Embed     *[]Embed // list of embedded files, for ONAME var
+	Embed     *[]Embed    // list of embedded files, for ONAME var
 
 	PkgName *PkgName // real package for import . names
 	// For a local variable (not param) or extern, the initializing assignment (OAS or OAS2).
@@ -141,11 +143,9 @@ type Name struct {
 
 func (n *Name) isExpr() {}
 
-// CloneName makes a cloned copy of the name.
+func (n *Name) copy() Node                         { panic(n.no("copy")) }
-// It's not ir.Copy(n) because in general that operation is a mistake on names,
+func (n *Name) doChildren(do func(Node) bool) bool { return false }
-// which uniquely identify variables.
+func (n *Name) editChildren(edit func(Node) Node)  {}
-// Callers must use n.CloneName to make clear they intend to create a separate name.
-func (n *Name) CloneName() *Name { c := *n; return &c }
 
 // TypeDefn returns the type definition for a named OTYPE.
 // That is, given "type T Defn", it returns Defn.
@@ -213,7 +213,6 @@ func newNameAt(pos src.XPos, op Op, sym *types.Sym) *Name {
 	n := new(Name)
 	n.op = op
 	n.pos = pos
-	n.orig = n
 	n.sym = sym
 	return n
 }
@@ -223,8 +222,6 @@ func (n *Name) Sym() *types.Sym     { return n.sym }
 func (n *Name) SetSym(x *types.Sym) { n.sym = x }
 func (n *Name) SubOp() Op           { return n.BuiltinOp }
 func (n *Name) SetSubOp(x Op)       { n.BuiltinOp = x }
-func (n *Name) Class() Class        { return n.Class_ }
-func (n *Name) SetClass(x Class)    { n.Class_ = x }
 func (n *Name) SetFunc(x *Func)     { n.Func = x }
 func (n *Name) Offset() int64       { panic("Name.Offset") }
 func (n *Name) SetOffset(x int64) {
@@ -236,6 +233,15 @@ func (n *Name) FrameOffset() int64     { return n.Offset_ }
 func (n *Name) SetFrameOffset(x int64) { n.Offset_ = x }
 func (n *Name) Iota() int64            { return n.Offset_ }
 func (n *Name) SetIota(x int64)        { n.Offset_ = x }
+func (n *Name) Walkdef() uint8         { return n.bits.get2(miniWalkdefShift) }
+func (n *Name) SetWalkdef(x uint8) {
+	if x > 3 {
+		panic(fmt.Sprintf("cannot SetWalkdef %d", x))
+	}
+	n.bits.set2(miniWalkdefShift, x)
+}
+
+func (n *Name) Linksym() *obj.LSym { return n.sym.Linksym() }
 
 func (*Name) CanBeNtype()    {}
 func (*Name) CanBeAnSSASym() {}
@@ -273,7 +279,6 @@ const (
 
 func (n *Name) Captured() bool              { return n.flags&nameCaptured != 0 }
 func (n *Name) Readonly() bool              { return n.flags&nameReadonly != 0 }
-func (n *Name) Byval() bool                 { return n.flags&nameByval != 0 }
 func (n *Name) Needzero() bool              { return n.flags&nameNeedzero != 0 }
 func (n *Name) AutoTemp() bool              { return n.flags&nameAutoTemp != 0 }
 func (n *Name) Used() bool                  { return n.flags&nameUsed != 0 }
@@ -288,7 +293,6 @@ func (n *Name) LibfuzzerExtraCounter() bool { return n.flags&nameLibfuzzerExtraC
 
 func (n *Name) SetCaptured(b bool)              { n.flags.set(nameCaptured, b) }
 func (n *Name) setReadonly(b bool)              { n.flags.set(nameReadonly, b) }
-func (n *Name) SetByval(b bool)                 { n.flags.set(nameByval, b) }
 func (n *Name) SetNeedzero(b bool)              { n.flags.set(nameNeedzero, b) }
 func (n *Name) SetAutoTemp(b bool)              { n.flags.set(nameAutoTemp, b) }
 func (n *Name) SetUsed(b bool)                  { n.flags.set(nameUsed, b) }
@@ -306,11 +310,11 @@ func (n *Name) MarkReadonly() {
 	if n.Op() != ONAME {
 		base.Fatalf("Node.MarkReadonly %v", n.Op())
 	}
-	n.Name().setReadonly(true)
+	n.setReadonly(true)
 	// Mark the linksym as readonly immediately
 	// so that the SSA backend can use this information.
 	// It will be overridden later during dumpglobls.
-	n.Sym().Linksym().Type = objabi.SRODATA
+	n.Linksym().Type = objabi.SRODATA
 }
 
 // Val returns the constant.Value for the node.
@@ -321,8 +325,7 @@ func (n *Name) Val() constant.Value {
 	return n.val
 }
 
-// SetVal sets the constant.Value for the node,
+// SetVal sets the constant.Value for the node.
-// which must not have been used with SetOpt.
 func (n *Name) SetVal(v constant.Value) {
 	if n.op != OLITERAL {
 		panic(n.no("SetVal"))
@@ -331,6 +334,33 @@ func (n *Name) SetVal(v constant.Value) {
 	n.val = v
 }
 
+// Canonical returns the logical declaration that n represents. If n
+// is a closure variable, then Canonical returns the original Name as
+// it appears in the function that immediately contains the
+// declaration. Otherwise, Canonical simply returns n itself.
+func (n *Name) Canonical() *Name {
+	if n.IsClosureVar() {
+		n = n.Defn.(*Name)
+		if n.IsClosureVar() {
+			base.Fatalf("recursive closure variable: %v", n)
+		}
+	}
+	return n
+}
+
+func (n *Name) SetByval(b bool) {
+	if n.Canonical() != n {
+		base.Fatalf("SetByval called on non-canonical variable: %v", n)
+	}
+	n.flags.set(nameByval, b)
+}
+
+func (n *Name) Byval() bool {
+	// We require byval to be set on the canonical variable, but we
+	// allow it to be accessed from any instance.
+	return n.Canonical().flags&nameByval != 0
+}
+
 // SameSource reports whether two nodes refer to the same source
 // element.
 //
@@ -373,7 +403,7 @@ func DeclaredBy(x, stmt Node) bool {
 // called declaration contexts.
 type Class uint8
 
-//go:generate stringer -type=Class
+//go:generate stringer -type=Class name.go
 const (
 	Pxxx      Class = iota // no class; used during ssa conversion to indicate pseudo-variables
 	PEXTERN                // global variables
@@ -418,7 +448,7 @@ func IsParamStackCopy(n Node) bool {
 		return false
 	}
 	name := n.(*Name)
-	return (name.Class_ == PPARAM || name.Class_ == PPARAMOUT) && name.Heapaddr != nil
+	return (name.Class == PPARAM || name.Class == PPARAMOUT) && name.Heapaddr != nil
 }
 
 // IsParamHeapCopy reports whether this is the on-heap copy of
@@ -428,7 +458,7 @@ func IsParamHeapCopy(n Node) bool {
 		return false
 	}
 	name := n.(*Name)
-	return name.Class_ == PAUTOHEAP && name.Name().Stackcopy != nil
+	return name.Class == PAUTOHEAP && name.Stackcopy != nil
 }
 
 var RegFP *Name

src/cmd/compile/internal/ir/node.go

@@ -28,14 +28,12 @@ type Node interface {
 	// For making copies. For Copy and SepCopy.
 	copy() Node
 
-	doChildren(func(Node) error) error
+	doChildren(func(Node) bool) bool
 	editChildren(func(Node) Node)
 
 	// Abstract graph structure, for generic traversals.
 	Op() Op
 	Init() Nodes
-	PtrInit() *Nodes
-	SetInit(x Nodes)
 
 	// Fields specific to certain Ops only.
 	Type() *types.Type
@@ -48,10 +46,6 @@ type Node interface {
 	// Storage for analysis passes.
 	Esc() uint16
 	SetEsc(x uint16)
-	Walkdef() uint8
-	SetWalkdef(x uint8)
-	Opt() interface{}
-	SetOpt(x interface{})
 	Diag() bool
 	SetDiag(x bool)
 	Typecheck() uint8
@@ -92,7 +86,21 @@ func MayBeShared(n Node) bool {
 	return false
 }
 
-//go:generate stringer -type=Op -trimprefix=O
+type InitNode interface {
+	Node
+	PtrInit() *Nodes
+	SetInit(x Nodes)
+}
+
+func TakeInit(n Node) Nodes {
+	init := n.Init()
+	if len(init) != 0 {
+		n.(InitNode).SetInit(nil)
+	}
+	return init
+}
+
+//go:generate stringer -type=Op -trimprefix=O node.go
 
 type Op uint8
 
@@ -220,10 +228,10 @@ const (
 	OPAREN       // (Left)
 	OSEND        // Left <- Right
 	OSLICE       // Left[List[0] : List[1]] (Left is untypechecked or slice)
-	OSLICEARR    // Left[List[0] : List[1]] (Left is array)
+	OSLICEARR    // Left[List[0] : List[1]] (Left is pointer to array)
 	OSLICESTR    // Left[List[0] : List[1]] (Left is string)
 	OSLICE3      // Left[List[0] : List[1] : List[2]] (Left is untypedchecked or slice)
-	OSLICE3ARR   // Left[List[0] : List[1] : List[2]] (Left is array)
+	OSLICE3ARR   // Left[List[0] : List[1] : List[2]] (Left is pointer to array)
 	OSLICEHEADER // sliceheader{Left, List[0], List[1]} (Left is unsafe.Pointer, List[0] is length, List[1] is capacity)
 	ORECOVER     // recover()
 	ORECV        // <-Left
@@ -313,35 +321,11 @@ const (
 // a slice to save space.
 type Nodes []Node
 
-// immutableEmptyNodes is an immutable, empty Nodes list.
-// The methods that would modify it panic instead.
-var immutableEmptyNodes = Nodes{}
-
-func (n *Nodes) mutate() {
-	if n == &immutableEmptyNodes {
-		panic("immutable Nodes.Set")
-	}
-}
-
-// Set sets n to a slice.
-// This takes ownership of the slice.
-func (n *Nodes) Set(s []Node) {
-	if n == &immutableEmptyNodes {
-		if len(s) == 0 {
-			// Allow immutableEmptyNodes.Set(nil) (a no-op).
-			return
-		}
-		n.mutate()
-	}
-	*n = s
-}
-
 // Append appends entries to Nodes.
 func (n *Nodes) Append(a ...Node) {
 	if len(a) == 0 {
 		return
 	}
-	n.mutate()
 	*n = append(*n, a...)
 }
 
@@ -351,7 +335,6 @@ func (n *Nodes) Prepend(a ...Node) {
 	if len(a) == 0 {
 		return
 	}
-	n.mutate()
 	*n = append(a, *n...)
 }
 
@@ -546,15 +529,16 @@ func SetPos(n Node) src.XPos {
 
 // The result of InitExpr MUST be assigned back to n, e.g.
 // 	n.Left = InitExpr(init, n.Left)
-func InitExpr(init []Node, n Node) Node {
+func InitExpr(init []Node, expr Node) Node {
 	if len(init) == 0 {
-		return n
+		return expr
 	}
-	if MayBeShared(n) {
+
+	n, ok := expr.(InitNode)
+	if !ok || MayBeShared(n) {
 		// Introduce OCONVNOP to hold init list.
-		old := n
+		n = NewConvExpr(base.Pos, OCONVNOP, nil, expr)
-		n = NewConvExpr(base.Pos, OCONVNOP, nil, old)
+		n.SetType(expr.Type())
-		n.SetType(old.Type())
 		n.SetTypecheck(1)
 	}
 
@@ -584,7 +568,10 @@ func OuterValue(n Node) Node {
 			continue
 		case OINDEX:
 			nn := nn.(*IndexExpr)
-			if nn.X.Type() != nil && nn.X.Type().IsArray() {
+			if nn.X.Type() == nil {
+				base.Fatalf("OuterValue needs type for %v", nn.X)
+			}
+			if nn.X.Type().IsArray() {
 				n = nn.X
 				continue
 			}

src/cmd/compile/internal/ir/op_string.go

@@ -1,4 +1,4 @@
-// Code generated by "stringer -type=Op -trimprefix=O"; DO NOT EDIT.
+// Code generated by "stringer -type=Op -trimprefix=O node.go"; DO NOT EDIT.
 
 package ir
 

src/cmd/compile/internal/ir/scc.go

@@ -87,7 +87,7 @@ func (v *bottomUpVisitor) visit(n *Func) uint32 {
 	Visit(n, func(n Node) {
 		switch n.Op() {
 		case ONAME:
-			if n := n.(*Name); n.Class_ == PFUNC {
+			if n := n.(*Name); n.Class == PFUNC {
 				do(n.Defn)
 			}
 		case ODOTMETH, OCALLPART, OMETHEXPR:

src/cmd/compile/internal/ir/sizeof_test.go

@@ -20,8 +20,8 @@ func TestSizeof(t *testing.T) {
 		_32bit uintptr     // size on 32bit platforms
 		_64bit uintptr     // size on 64bit platforms
 	}{
-		{Func{}, 200, 352},
+		{Func{}, 184, 320},
-		{Name{}, 132, 232},
+		{Name{}, 124, 216},
 	}
 
 	for _, tt := range tests {

src/cmd/compile/internal/ir/stmt.go

@@ -13,10 +13,10 @@ import (
 // A Decl is a declaration of a const, type, or var. (A declared func is a Func.)
 type Decl struct {
 	miniNode
-	X Node // the thing being declared
+	X *Name // the thing being declared
 }
 
-func NewDecl(pos src.XPos, op Op, x Node) *Decl {
+func NewDecl(pos src.XPos, op Op, x *Name) *Decl {
 	n := &Decl{X: x}
 	n.pos = pos
 	switch op {
@@ -70,8 +70,8 @@ func NewAssignListStmt(pos src.XPos, op Op, lhs, rhs []Node) *AssignListStmt {
 	n := &AssignListStmt{}
 	n.pos = pos
 	n.SetOp(op)
-	n.Lhs.Set(lhs)
+	n.Lhs = lhs
-	n.Rhs.Set(rhs)
+	n.Rhs = rhs
 	return n
 }
 
@@ -112,7 +112,6 @@ func (n *AssignStmt) SetOp(op Op) {
 // An AssignOpStmt is an AsOp= assignment statement: X AsOp= Y.
 type AssignOpStmt struct {
 	miniStmt
-	typ    *types.Type
 	X      Node
 	AsOp   Op // OADD etc
 	Y      Node
@@ -126,9 +125,6 @@ func NewAssignOpStmt(pos src.XPos, asOp Op, x, y Node) *AssignOpStmt {
 	return n
 }
 
-func (n *AssignOpStmt) Type() *types.Type     { return n.typ }
-func (n *AssignOpStmt) SetType(x *types.Type) { n.typ = x }
-
 // A BlockStmt is a block: { List }.
 type BlockStmt struct {
 	miniStmt
@@ -145,7 +141,7 @@ func NewBlockStmt(pos src.XPos, list []Node) *BlockStmt {
 		}
 	}
 	n.op = OBLOCK
-	n.List.Set(list)
+	n.List = list
 	return n
 }
 
@@ -176,7 +172,7 @@ func (n *BranchStmt) Sym() *types.Sym { return n.Label }
 // A CaseClause is a case statement in a switch or select: case List: Body.
 type CaseClause struct {
 	miniStmt
-	Var  Node  // declared variable for this case in type switch
+	Var  *Name // declared variable for this case in type switch
 	List Nodes // list of expressions for switch, early select
 	Body Nodes
 }
@@ -188,36 +184,6 @@ func NewCaseStmt(pos src.XPos, list, body []Node) *CaseClause {
 	return n
 }
 
-// TODO(mdempsky): Generate these with mknode.go.
-func copyCases(list []*CaseClause) []*CaseClause {
-	if list == nil {
-		return nil
-	}
-	c := make([]*CaseClause, len(list))
-	copy(c, list)
-	return c
-}
-func maybeDoCases(list []*CaseClause, err error, do func(Node) error) error {
-	if err != nil {
-		return err
-	}
-	for _, x := range list {
-		if x != nil {
-			if err := do(x); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-func editCases(list []*CaseClause, edit func(Node) Node) {
-	for i, x := range list {
-		if x != nil {
-			list[i] = edit(x).(*CaseClause)
-		}
-	}
-}
-
 type CommClause struct {
 	miniStmt
 	Comm Node // communication case
@@ -231,36 +197,6 @@ func NewCommStmt(pos src.XPos, comm Node, body []Node) *CommClause {
 	return n
 }
 
-// TODO(mdempsky): Generate these with mknode.go.
-func copyComms(list []*CommClause) []*CommClause {
-	if list == nil {
-		return nil
-	}
-	c := make([]*CommClause, len(list))
-	copy(c, list)
-	return c
-}
-func maybeDoComms(list []*CommClause, err error, do func(Node) error) error {
-	if err != nil {
-		return err
-	}
-	for _, x := range list {
-		if x != nil {
-			if err := do(x); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-func editComms(list []*CommClause, edit func(Node) Node) {
-	for i, x := range list {
-		if x != nil {
-			list[i] = edit(x).(*CommClause)
-		}
-	}
-}
-
 // A ForStmt is a non-range for loop: for Init; Cond; Post { Body }
 // Op can be OFOR or OFORUNTIL (!Cond).
 type ForStmt struct {
@@ -280,7 +216,7 @@ func NewForStmt(pos src.XPos, init Node, cond, post Node, body []Node) *ForStmt
 	if init != nil {
 		n.init = []Node{init}
 	}
-	n.Body.Set(body)
+	n.Body = body
 	return n
 }
 
@@ -326,8 +262,8 @@ func NewIfStmt(pos src.XPos, cond Node, body, els []Node) *IfStmt {
 	n := &IfStmt{Cond: cond}
 	n.pos = pos
 	n.op = OIF
-	n.Body.Set(body)
+	n.Body = body
-	n.Else.Set(els)
+	n.Else = els
 	return n
 }
 
@@ -379,15 +315,15 @@ func NewRangeStmt(pos src.XPos, key, value, x Node, body []Node) *RangeStmt {
 	n := &RangeStmt{X: x, Key: key, Value: value}
 	n.pos = pos
 	n.op = ORANGE
-	n.Body.Set(body)
+	n.Body = body
 	return n
 }
 
 // A ReturnStmt is a return statement.
 type ReturnStmt struct {
 	miniStmt
-	orig    Node  // for typecheckargs rewrite
+	origNode       // for typecheckargs rewrite
-	Results Nodes // return list
+	Results  Nodes // return list
 }
 
 func NewReturnStmt(pos src.XPos, results []Node) *ReturnStmt {
@@ -395,13 +331,10 @@ func NewReturnStmt(pos src.XPos, results []Node) *ReturnStmt {
 	n.pos = pos
 	n.op = ORETURN
 	n.orig = n
-	n.Results.Set(results)
+	n.Results = results
 	return n
 }
 
-func (n *ReturnStmt) Orig() Node     { return n.orig }
-func (n *ReturnStmt) SetOrig(x Node) { n.orig = x }
-
 // A SelectStmt is a block: { Cases }.
 type SelectStmt struct {
 	miniStmt

src/cmd/compile/internal/ir/type.go

@@ -46,7 +46,7 @@ func (n *miniType) Type() *types.Type { return n.typ }
 // setOTYPE also records t.Nod = self if t.Nod is not already set.
 // (Some types are shared by multiple OTYPE nodes, so only
 // the first such node is used as t.Nod.)
-func (n *miniType) setOTYPE(t *types.Type, self Node) {
+func (n *miniType) setOTYPE(t *types.Type, self Ntype) {
 	if n.typ != nil {
 		panic(n.op.String() + " SetType: type already set")
 	}
@@ -61,11 +61,11 @@ func (n *miniType) Implicit() bool  { return false } // for Format OTYPE
 // A ChanType represents a chan Elem syntax with the direction Dir.
 type ChanType struct {
 	miniType
-	Elem Node
+	Elem Ntype
 	Dir  types.ChanDir
 }
 
-func NewChanType(pos src.XPos, elem Node, dir types.ChanDir) *ChanType {
+func NewChanType(pos src.XPos, elem Ntype, dir types.ChanDir) *ChanType {
 	n := &ChanType{Elem: elem, Dir: dir}
 	n.op = OTCHAN
 	n.pos = pos
@@ -80,11 +80,11 @@ func (n *ChanType) SetOTYPE(t *types.Type) {
 // A MapType represents a map[Key]Value type syntax.
 type MapType struct {
 	miniType
-	Key  Node
+	Key  Ntype
-	Elem Node
+	Elem Ntype
 }
 
-func NewMapType(pos src.XPos, key, elem Node) *MapType {
+func NewMapType(pos src.XPos, key, elem Ntype) *MapType {
 	n := &MapType{Key: key, Elem: elem}
 	n.op = OTMAP
 	n.pos = pos
@@ -185,45 +185,28 @@ func (f *Field) String() string {
 	return typ
 }
 
-func (f *Field) copy() *Field {
+// TODO(mdempsky): Make Field a Node again so these can be generated?
+// Fields are Nodes in go/ast and cmd/compile/internal/syntax.
+
+func copyField(f *Field) *Field {
+	if f == nil {
+		return nil
+	}
 	c := *f
 	return &c
 }
-
+func doField(f *Field, do func(Node) bool) bool {
-func copyFields(list []*Field) []*Field {
+	if f == nil {
-	out := make([]*Field, len(list))
+		return false
-	copy(out, list)
-	for i, f := range out {
-		out[i] = f.copy()
 	}
-	return out
+	if f.Decl != nil && do(f.Decl) {
+		return true
+	}
+	if f.Ntype != nil && do(f.Ntype) {
+		return true
+	}
+	return false
 }
-
-func maybeDoField(f *Field, err error, do func(Node) error) error {
-	if f != nil {
-		if err == nil && f.Decl != nil {
-			err = do(f.Decl)
-		}
-		if err == nil && f.Ntype != nil {
-			err = do(f.Ntype)
-		}
-	}
-	return err
-}
-
-func maybeDoFields(list []*Field, err error, do func(Node) error) error {
-	if err != nil {
-		return err
-	}
-	for _, f := range list {
-		err = maybeDoField(f, err, do)
-		if err != nil {
-			return err
-		}
-	}
-	return err
-}
-
 func editField(f *Field, edit func(Node) Node) {
 	if f == nil {
 		return
@@ -232,10 +215,25 @@ func editField(f *Field, edit func(Node) Node) {
 		f.Decl = edit(f.Decl).(*Name)
 	}
 	if f.Ntype != nil {
-		f.Ntype = toNtype(edit(f.Ntype))
+		f.Ntype = edit(f.Ntype).(Ntype)
 	}
 }
 
+func copyFields(list []*Field) []*Field {
+	out := make([]*Field, len(list))
+	for i, f := range list {
+		out[i] = copyField(f)
+	}
+	return out
+}
+func doFields(list []*Field, do func(Node) bool) bool {
+	for _, x := range list {
+		if doField(x, do) {
+			return true
+		}
+	}
+	return false
+}
 func editFields(list []*Field, edit func(Node) Node) {
 	for _, f := range list {
 		editField(f, edit)
@@ -246,11 +244,11 @@ func editFields(list []*Field, edit func(Node) Node) {
 // If DDD is true, it's the ...Elem at the end of a function list.
 type SliceType struct {
 	miniType
-	Elem Node
+	Elem Ntype
 	DDD  bool
 }
 
-func NewSliceType(pos src.XPos, elem Node) *SliceType {
+func NewSliceType(pos src.XPos, elem Ntype) *SliceType {
 	n := &SliceType{Elem: elem}
 	n.op = OTSLICE
 	n.pos = pos
@@ -267,11 +265,11 @@ func (n *SliceType) SetOTYPE(t *types.Type) {
 type ArrayType struct {
 	miniType
 	Len  Node
-	Elem Node
+	Elem Ntype
 }
 
-func NewArrayType(pos src.XPos, size Node, elem Node) *ArrayType {
+func NewArrayType(pos src.XPos, len Node, elem Ntype) *ArrayType {
-	n := &ArrayType{Len: size, Elem: elem}
+	n := &ArrayType{Len: len, Elem: elem}
 	n.op = OTARRAY
 	n.pos = pos
 	return n

src/cmd/compile/internal/ir/visit.go

@@ -4,23 +4,18 @@
 
 // IR visitors for walking the IR tree.
 //
-// The lowest level helpers are DoChildren and EditChildren,
+// The lowest level helpers are DoChildren and EditChildren, which
-// which nodes help implement (TODO(rsc): eventually) and
+// nodes help implement and provide control over whether and when
-// provide control over whether and when recursion happens
+// recursion happens during the walk of the IR.
-// during the walk of the IR.
 //
 // Although these are both useful directly, two simpler patterns
-// are fairly common and also provided: Inspect and Scan.
+// are fairly common and also provided: Visit and Any.
 
 package ir
 
-import (
-	"errors"
-)
-
 // DoChildren calls do(x) on each of n's non-nil child nodes x.
-// If any call returns a non-nil error, DoChildren stops and returns that error.
+// If any call returns true, DoChildren stops and returns true.
-// Otherwise, DoChildren returns nil.
+// Otherwise, DoChildren returns false.
 //
 // Note that DoChildren(n, do) only calls do(x) for n's immediate children.
 // If x's children should be processed, then do(x) must call DoChildren(x, do).
@@ -28,32 +23,32 @@ import (
 // DoChildren allows constructing general traversals of the IR graph
 // that can stop early if needed. The most general usage is:
 //
-//	var do func(ir.Node) error
+//	var do func(ir.Node) bool
-//	do = func(x ir.Node) error {
+//	do = func(x ir.Node) bool {
 //		... processing BEFORE visting children ...
 //		if ... should visit children ... {
 //			ir.DoChildren(x, do)
 //			... processing AFTER visting children ...
 //		}
 //		if ... should stop parent DoChildren call from visiting siblings ... {
-//			return non-nil error
+//			return true
 //		}
-//		return nil
+//		return false
 //	}
 //	do(root)
 //
-// Since DoChildren does not generate any errors itself, if the do function
+// Since DoChildren does not return true itself, if the do function
-// never wants to stop the traversal, it can assume that DoChildren itself
+// never wants to stop the traversal, it can assume that DoChildren
-// will always return nil, simplifying to:
+// itself will always return false, simplifying to:
 //
-//	var do func(ir.Node) error
+//	var do func(ir.Node) bool
-//	do = func(x ir.Node) error {
+//	do = func(x ir.Node) bool {
 //		... processing BEFORE visting children ...
 //		if ... should visit children ... {
 //			ir.DoChildren(x, do)
 //		}
 //		... processing AFTER visting children ...
-//		return nil
+//		return false
 //	}
 //	do(root)
 //
@@ -61,14 +56,15 @@ import (
 // only processing before visiting children and never stopping:
 //
 //	func Visit(n ir.Node, visit func(ir.Node)) {
-//		var do func(ir.Node) error
+//		if n == nil {
-//		do = func(x ir.Node) error {
+//			return
+//		}
+//		var do func(ir.Node) bool
+//		do = func(x ir.Node) bool {
 //			visit(x)
 //			return ir.DoChildren(x, do)
 //		}
-//		if n != nil {
+//		do(n)
-//			visit(n)
-//		}
 //	}
 //
 // The Any function illustrates a different simplification of the pattern,
@@ -76,57 +72,40 @@ import (
 // a node x for which cond(x) returns true, at which point the entire
 // traversal stops and returns true.
 //
-//	func Any(n ir.Node, find cond(ir.Node)) bool {
+//	func Any(n ir.Node, cond(ir.Node) bool) bool {
-//		stop := errors.New("stop")
+//		if n == nil {
-//		var do func(ir.Node) error
+//			return false
-//		do = func(x ir.Node) error {
-//			if cond(x) {
-//				return stop
-//			}
-//			return ir.DoChildren(x, do)
 //		}
-//		return do(n) == stop
+//		var do func(ir.Node) bool
+//		do = func(x ir.Node) bool {
+//			return cond(x) || ir.DoChildren(x, do)
+//		}
+//		return do(n)
 //	}
 //
 // Visit and Any are presented above as examples of how to use
 // DoChildren effectively, but of course, usage that fits within the
 // simplifications captured by Visit or Any will be best served
 // by directly calling the ones provided by this package.
-func DoChildren(n Node, do func(Node) error) error {
+func DoChildren(n Node, do func(Node) bool) bool {
 	if n == nil {
-		return nil
+		return false
 	}
 	return n.doChildren(do)
 }
 
-// DoList calls f on each non-nil node x in the list, in list order.
-// If any call returns a non-nil error, DoList stops and returns that error.
-// Otherwise DoList returns nil.
-//
-// Note that DoList only calls do on the nodes in the list, not their children.
-// If x's children should be processed, do(x) must call DoChildren(x, do) itself.
-func DoList(list Nodes, do func(Node) error) error {
-	for _, x := range list {
-		if x != nil {
-			if err := do(x); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
 // Visit visits each non-nil node x in the IR tree rooted at n
 // in a depth-first preorder traversal, calling visit on each node visited.
 func Visit(n Node, visit func(Node)) {
-	var do func(Node) error
+	if n == nil {
-	do = func(x Node) error {
+		return
+	}
+	var do func(Node) bool
+	do = func(x Node) bool {
 		visit(x)
 		return DoChildren(x, do)
 	}
-	if n != nil {
+	do(n)
-		do(n)
-	}
 }
 
 // VisitList calls Visit(x, visit) for each node x in the list.
@@ -136,8 +115,6 @@ func VisitList(list Nodes, visit func(Node)) {
 	}
 }
 
-var stop = errors.New("stop")
-
 // Any looks for a non-nil node x in the IR tree rooted at n
 // for which cond(x) returns true.
 // Any considers nodes in a depth-first, preorder traversal.
@@ -148,14 +125,11 @@ func Any(n Node, cond func(Node) bool) bool {
 	if n == nil {
 		return false
 	}
-	var do func(Node) error
+	var do func(Node) bool
-	do = func(x Node) error {
+	do = func(x Node) bool {
-		if cond(x) {
+		return cond(x) || DoChildren(x, do)
-			return stop
-		}
-		return DoChildren(x, do)
 	}
-	return do(n) == stop
+	return do(n)
 }
 
 // AnyList calls Any(x, cond) for each node x in the list, in order.
@@ -210,16 +184,3 @@ func EditChildren(n Node, edit func(Node) Node) {
 	}
 	n.editChildren(edit)
 }
-
-// editList calls edit on each non-nil node x in the list,
-// saving the result of edit back into the list.
-//
-// Note that editList only calls edit on the nodes in the list, not their children.
-// If x's children should be processed, edit(x) must call EditChildren(x, edit) itself.
-func editList(list Nodes, edit func(Node) Node) {
-	for i, x := range list {
-		if x != nil {
-			list[i] = edit(x)
-		}
-	}
-}

src/cmd/compile/internal/liveness/plive.go

@@ -181,7 +181,7 @@ type progeffectscache struct {
 // nor do we care about empty structs (handled by the pointer check),
 // nor do we care about the fake PAUTOHEAP variables.
 func ShouldTrack(n *ir.Name) bool {
-	return (n.Class_ == ir.PAUTO || n.Class_ == ir.PPARAM || n.Class_ == ir.PPARAMOUT) && n.Type().HasPointers()
+	return (n.Class == ir.PAUTO || n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT) && n.Type().HasPointers()
 }
 
 // getvariables returns the list of on-stack variables that we need to track
@@ -208,7 +208,7 @@ func (lv *liveness) initcache() {
 	lv.cache.initialized = true
 
 	for i, node := range lv.vars {
-		switch node.Class_ {
+		switch node.Class {
 		case ir.PPARAM:
 			// A return instruction with a p.to is a tail return, which brings
 			// the stack pointer back up (if it ever went down) and then jumps
@@ -255,7 +255,7 @@ func (lv *liveness) valueEffects(v *ssa.Value) (int32, liveEffect) {
 	// variable" ICEs (issue 19632).
 	switch v.Op {
 	case ssa.OpVarDef, ssa.OpVarKill, ssa.OpVarLive, ssa.OpKeepAlive:
-		if !n.Name().Used() {
+		if !n.Used() {
 			return -1, 0
 		}
 	}
@@ -386,7 +386,7 @@ func (lv *liveness) pointerMap(liveout bitvec.BitVec, vars []*ir.Name, args, loc
 			break
 		}
 		node := vars[i]
-		switch node.Class_ {
+		switch node.Class {
 		case ir.PAUTO:
 			typebits.Set(node.Type(), node.FrameOffset()+lv.stkptrsize, locals)
 
@@ -687,12 +687,12 @@ func (lv *liveness) epilogue() {
 	// don't need to keep the stack copy live?
 	if lv.fn.HasDefer() {
 		for i, n := range lv.vars {
-			if n.Class_ == ir.PPARAMOUT {
+			if n.Class == ir.PPARAMOUT {
-				if n.Name().IsOutputParamHeapAddr() {
+				if n.IsOutputParamHeapAddr() {
 					// Just to be paranoid.  Heap addresses are PAUTOs.
 					base.Fatalf("variable %v both output param and heap output param", n)
 				}
-				if n.Name().Heapaddr != nil {
+				if n.Heapaddr != nil {
 					// If this variable moved to the heap, then
 					// its stack copy is not live.
 					continue
@@ -700,21 +700,21 @@ func (lv *liveness) epilogue() {
 				// Note: zeroing is handled by zeroResults in walk.go.
 				livedefer.Set(int32(i))
 			}
-			if n.Name().IsOutputParamHeapAddr() {
+			if n.IsOutputParamHeapAddr() {
 				// This variable will be overwritten early in the function
 				// prologue (from the result of a mallocgc) but we need to
 				// zero it in case that malloc causes a stack scan.
-				n.Name().SetNeedzero(true)
+				n.SetNeedzero(true)
 				livedefer.Set(int32(i))
 			}
-			if n.Name().OpenDeferSlot() {
+			if n.OpenDeferSlot() {
 				// Open-coded defer args slots must be live
 				// everywhere in a function, since a panic can
 				// occur (almost) anywhere. Because it is live
 				// everywhere, it must be zeroed on entry.
 				livedefer.Set(int32(i))
 				// It was already marked as Needzero when created.
-				if !n.Name().Needzero() {
+				if !n.Needzero() {
 					base.Fatalf("all pointer-containing defer arg slots should have Needzero set")
 				}
 			}
@@ -785,7 +785,7 @@ func (lv *liveness) epilogue() {
 				if !liveout.Get(int32(i)) {
 					continue
 				}
-				if n.Class_ == ir.PPARAM {
+				if n.Class == ir.PPARAM {
 					continue // ok
 				}
 				base.Fatalf("bad live variable at entry of %v: %L", lv.fn.Nname, n)
@@ -818,7 +818,7 @@ func (lv *liveness) epilogue() {
 	// the only things that can possibly be live are the
 	// input parameters.
 	for j, n := range lv.vars {
-		if n.Class_ != ir.PPARAM && lv.stackMaps[0].Get(int32(j)) {
+		if n.Class != ir.PPARAM && lv.stackMaps[0].Get(int32(j)) {
 			lv.f.Fatalf("%v %L recorded as live on entry", lv.fn.Nname, n)
 		}
 	}
@@ -1063,7 +1063,7 @@ func (lv *liveness) emit() (argsSym, liveSym *obj.LSym) {
 	// (Nodes without pointers aren't in lv.vars; see livenessShouldTrack.)
 	var maxArgNode *ir.Name
 	for _, n := range lv.vars {
-		switch n.Class_ {
+		switch n.Class {
 		case ir.PPARAM, ir.PPARAMOUT:
 			if maxArgNode == nil || n.FrameOffset() > maxArgNode.FrameOffset() {
 				maxArgNode = n

src/cmd/compile/internal/noder/import.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate go run mkbuiltin.go
-
 package noder
 
 import (

src/cmd/compile/internal/noder/noder.go

@@ -28,6 +28,26 @@ import (
 	"cmd/internal/src"
 )
 
+func LoadPackage(filenames []string) {
+	base.Timer.Start("fe", "parse")
+	lines := ParseFiles(filenames)
+	base.Timer.Stop()
+	base.Timer.AddEvent(int64(lines), "lines")
+
+	if base.Flag.G != 0 && base.Flag.G < 3 {
+		// can only parse generic code for now
+		base.ExitIfErrors()
+		return
+	}
+
+	// Typecheck.
+	Package()
+
+	// With all user code typechecked, it's now safe to verify unused dot imports.
+	CheckDotImports()
+	base.ExitIfErrors()
+}
+
 // ParseFiles concurrently parses files into *syntax.File structures.
 // Each declaration in every *syntax.File is converted to a syntax tree
 // and its root represented by *Node is appended to Target.Decls.
@@ -170,6 +190,69 @@ func ParseFiles(filenames []string) (lines uint) {
 	return
 }
 
+func Package() {
+	typecheck.DeclareUniverse()
+
+	typecheck.TypecheckAllowed = true
+
+	// Process top-level declarations in phases.
+
+	// Phase 1: const, type, and names and types of funcs.
+	//   This will gather all the information about types
+	//   and methods but doesn't depend on any of it.
+	//
+	//   We also defer type alias declarations until phase 2
+	//   to avoid cycles like #18640.
+	//   TODO(gri) Remove this again once we have a fix for #25838.
+
+	// Don't use range--typecheck can add closures to Target.Decls.
+	base.Timer.Start("fe", "typecheck", "top1")
+	for i := 0; i < len(typecheck.Target.Decls); i++ {
+		n := typecheck.Target.Decls[i]
+		if op := n.Op(); op != ir.ODCL && op != ir.OAS && op != ir.OAS2 && (op != ir.ODCLTYPE || !n.(*ir.Decl).X.Alias()) {
+			typecheck.Target.Decls[i] = typecheck.Stmt(n)
+		}
+	}
+
+	// Phase 2: Variable assignments.
+	//   To check interface assignments, depends on phase 1.
+
+	// Don't use range--typecheck can add closures to Target.Decls.
+	base.Timer.Start("fe", "typecheck", "top2")
+	for i := 0; i < len(typecheck.Target.Decls); i++ {
+		n := typecheck.Target.Decls[i]
+		if op := n.Op(); op == ir.ODCL || op == ir.OAS || op == ir.OAS2 || op == ir.ODCLTYPE && n.(*ir.Decl).X.Alias() {
+			typecheck.Target.Decls[i] = typecheck.Stmt(n)
+		}
+	}
+
+	// Phase 3: Type check function bodies.
+	// Don't use range--typecheck can add closures to Target.Decls.
+	base.Timer.Start("fe", "typecheck", "func")
+	var fcount int64
+	for i := 0; i < len(typecheck.Target.Decls); i++ {
+		n := typecheck.Target.Decls[i]
+		if n.Op() == ir.ODCLFUNC {
+			typecheck.FuncBody(n.(*ir.Func))
+			fcount++
+		}
+	}
+
+	// Phase 4: Check external declarations.
+	// TODO(mdempsky): This should be handled when type checking their
+	// corresponding ODCL nodes.
+	base.Timer.Start("fe", "typecheck", "externdcls")
+	for i, n := range typecheck.Target.Externs {
+		if n.Op() == ir.ONAME {
+			typecheck.Target.Externs[i] = typecheck.Expr(typecheck.Target.Externs[i])
+		}
+	}
+
+	// Phase 5: With all user code type-checked, it's now safe to verify map keys.
+	typecheck.CheckMapKeys()
+
+}
+
 // Temporary import helper to get type2-based type-checking going.
 type gcimports struct {
 	packages map[string]*types2.Package
@@ -301,7 +384,7 @@ func (p *noder) funcBody(fn *ir.Func, block *syntax.BlockStmt) {
 		if body == nil {
 			body = []ir.Node{ir.NewBlockStmt(base.Pos, nil)}
 		}
-		fn.Body.Set(body)
+		fn.Body = body
 
 		base.Pos = p.makeXPos(block.Rbrace)
 		fn.Endlineno = base.Pos
@@ -530,8 +613,48 @@ func (p *noder) varDecl(decl *syntax.VarDecl) []ir.Node {
 		p.checkUnused(pragma)
 	}
 
+	var init []ir.Node
 	p.setlineno(decl)
-	return typecheck.DeclVars(names, typ, exprs)
+
+	if len(names) > 1 && len(exprs) == 1 {
+		as2 := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, exprs)
+		for _, v := range names {
+			as2.Lhs.Append(v)
+			typecheck.Declare(v, typecheck.DeclContext)
+			v.Ntype = typ
+			v.Defn = as2
+			if ir.CurFunc != nil {
+				init = append(init, ir.NewDecl(base.Pos, ir.ODCL, v))
+			}
+		}
+
+		return append(init, as2)
+	}
+
+	for i, v := range names {
+		var e ir.Node
+		if i < len(exprs) {
+			e = exprs[i]
+		}
+
+		typecheck.Declare(v, typecheck.DeclContext)
+		v.Ntype = typ
+
+		if ir.CurFunc != nil {
+			init = append(init, ir.NewDecl(base.Pos, ir.ODCL, v))
+		}
+		as := ir.NewAssignStmt(base.Pos, v, e)
+		init = append(init, as)
+		if e != nil || ir.CurFunc == nil {
+			v.Defn = as
+		}
+	}
+
+	if len(exprs) != 0 && len(names) != len(exprs) {
+		base.Errorf("assignment mismatch: %d variables but %d values", len(names), len(exprs))
+	}
+
+	return init
 }
 
 // constState tracks state between constant specifiers within a
@@ -657,7 +780,8 @@ func (p *noder) funcDecl(fun *syntax.FuncDecl) ir.Node {
 		name = ir.BlankNode.Sym() // filled in by typecheckfunc
 	}
 
-	f.Nname = ir.NewFuncNameAt(p.pos(fun.Name), name, f)
+	f.Nname = ir.NewNameAt(p.pos(fun.Name), name)
+	f.Nname.Func = f
 	f.Nname.Defn = f
 	f.Nname.Ntype = t
 
@@ -787,7 +911,7 @@ func (p *noder) expr(expr syntax.Expr) ir.Node {
 		for i, e := range l {
 			l[i] = p.wrapname(expr.ElemList[i], e)
 		}
-		n.List.Set(l)
+		n.List = l
 		base.Pos = p.makeXPos(expr.Rbrace)
 		return n
 	case *syntax.KeyValueExpr:
@@ -1143,8 +1267,8 @@ func (p *noder) stmtFall(stmt syntax.Stmt, fallOK bool) ir.Node {
 		if list, ok := stmt.Lhs.(*syntax.ListExpr); ok && len(list.ElemList) != 1 || len(rhs) != 1 {
 			n := ir.NewAssignListStmt(p.pos(stmt), ir.OAS2, nil, nil)
 			n.Def = stmt.Op == syntax.Def
-			n.Lhs.Set(p.assignList(stmt.Lhs, n, n.Def))
+			n.Lhs = p.assignList(stmt.Lhs, n, n.Def)
-			n.Rhs.Set(rhs)
+			n.Rhs = rhs
 			return n
 		}
 
@@ -1191,10 +1315,10 @@ func (p *noder) stmtFall(stmt syntax.Stmt, fallOK bool) ir.Node {
 		n := ir.NewReturnStmt(p.pos(stmt), p.exprList(stmt.Results))
 		if len(n.Results) == 0 && ir.CurFunc != nil {
 			for _, ln := range ir.CurFunc.Dcl {
-				if ln.Class_ == ir.PPARAM {
+				if ln.Class == ir.PPARAM {
 					continue
 				}
-				if ln.Class_ != ir.PPARAMOUT {
+				if ln.Class != ir.PPARAMOUT {
 					break
 				}
 				if ln.Sym().Def != ln {
@@ -1215,7 +1339,7 @@ func (p *noder) stmtFall(stmt syntax.Stmt, fallOK bool) ir.Node {
 	panic("unhandled Stmt")
 }
 
-func (p *noder) assignList(expr syntax.Expr, defn ir.Node, colas bool) []ir.Node {
+func (p *noder) assignList(expr syntax.Expr, defn ir.InitNode, colas bool) []ir.Node {
 	if !colas {
 		return p.exprList(expr)
 	}
@@ -1291,7 +1415,7 @@ func (p *noder) ifStmt(stmt *syntax.IfStmt) ir.Node {
 		e := p.stmt(stmt.Else)
 		if e.Op() == ir.OBLOCK {
 			e := e.(*ir.BlockStmt)
-			n.Else.Set(e.List)
+			n.Else = e.List
 		} else {
 			n.Else = []ir.Node{e}
 		}
@@ -1316,7 +1440,7 @@ func (p *noder) forStmt(stmt *syntax.ForStmt) ir.Node {
 				n.Value = lhs[1]
 			}
 		}
-		n.Body.Set(p.blockStmt(stmt.Body))
+		n.Body = p.blockStmt(stmt.Body)
 		p.closeAnotherScope()
 		return n
 	}
@@ -1374,7 +1498,7 @@ func (p *noder) caseClauses(clauses []*syntax.CaseClause, tswitch *ir.TypeSwitch
 			body = body[:len(body)-1]
 		}
 
-		n.Body.Set(p.stmtsFall(body, true))
+		n.Body = p.stmtsFall(body, true)
 		if l := len(n.Body); l > 0 && n.Body[l-1].Op() == ir.OFALL {
 			if tswitch != nil {
 				base.Errorf("cannot fallthrough in type switch")
@@ -1875,7 +1999,9 @@ func (p *noder) funcLit(expr *syntax.FuncLit) ir.Node {
 
 	fn := ir.NewFunc(p.pos(expr))
 	fn.SetIsHiddenClosure(ir.CurFunc != nil)
-	fn.Nname = ir.NewFuncNameAt(p.pos(expr), ir.BlankNode.Sym(), fn) // filled in by typecheckclosure
+
+	fn.Nname = ir.NewNameAt(p.pos(expr), ir.BlankNode.Sym()) // filled in by typecheckclosure
+	fn.Nname.Func = fn
 	fn.Nname.Ntype = xtype
 	fn.Nname.Defn = fn
 
@@ -1965,18 +2091,18 @@ func oldname(s *types.Sym) ir.Node {
 		// the := it looks like a reference to the outer x so we'll
 		// make x a closure variable unnecessarily.
 		n := n.(*ir.Name)
-		c := n.Name().Innermost
+		c := n.Innermost
 		if c == nil || c.Curfn != ir.CurFunc {
 			// Do not have a closure var for the active closure yet; make one.
 			c = typecheck.NewName(s)
-			c.Class_ = ir.PAUTOHEAP
+			c.Class = ir.PAUTOHEAP
 			c.SetIsClosureVar(true)
 			c.Defn = n
 
 			// Link into list of active closure variables.
 			// Popped from list in func funcLit.
-			c.Outer = n.Name().Innermost
+			c.Outer = n.Innermost
-			n.Name().Innermost = c
+			n.Innermost = c
 
 			ir.CurFunc.ClosureVars = append(ir.CurFunc.ClosureVars, c)
 		}

src/cmd/compile/internal/pkginit/init.go

@@ -6,6 +6,7 @@ package pkginit
 
 import (
 	"cmd/compile/internal/base"
+	"cmd/compile/internal/deadcode"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/objw"
 	"cmd/compile/internal/typecheck"
@@ -31,10 +32,10 @@ func Task() *ir.Name {
 		if n.Op() == ir.ONONAME {
 			continue
 		}
-		if n.Op() != ir.ONAME || n.(*ir.Name).Class_ != ir.PEXTERN {
+		if n.Op() != ir.ONAME || n.(*ir.Name).Class != ir.PEXTERN {
 			base.Fatalf("bad inittask: %v", n)
 		}
-		deps = append(deps, n.(*ir.Name).Sym().Linksym())
+		deps = append(deps, n.(*ir.Name).Linksym())
 	}
 
 	// Make a function that contains all the initialization statements.
@@ -48,7 +49,7 @@ func Task() *ir.Name {
 		fn.Dcl = append(fn.Dcl, typecheck.InitTodoFunc.Dcl...)
 		typecheck.InitTodoFunc.Dcl = nil
 
-		fn.Body.Set(nf)
+		fn.Body = nf
 		typecheck.FinishFuncBody()
 
 		typecheck.Func(fn)
@@ -56,7 +57,7 @@ func Task() *ir.Name {
 		typecheck.Stmts(nf)
 		ir.CurFunc = nil
 		typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
-		fns = append(fns, initializers.Linksym())
+		fns = append(fns, fn.Linksym())
 	}
 	if typecheck.InitTodoFunc.Dcl != nil {
 		// We only generate temps using initTodo if there
@@ -68,13 +69,16 @@ func Task() *ir.Name {
 
 	// Record user init functions.
 	for _, fn := range typecheck.Target.Inits {
+		// Must happen after initOrder; see #43444.
+		deadcode.Func(fn)
+
 		// Skip init functions with empty bodies.
 		if len(fn.Body) == 1 {
 			if stmt := fn.Body[0]; stmt.Op() == ir.OBLOCK && len(stmt.(*ir.BlockStmt).List) == 0 {
 				continue
 			}
 		}
-		fns = append(fns, fn.Nname.Sym().Linksym())
+		fns = append(fns, fn.Nname.Linksym())
 	}
 
 	if len(deps) == 0 && len(fns) == 0 && types.LocalPkg.Name != "main" && types.LocalPkg.Name != "runtime" {
@@ -85,9 +89,9 @@ func Task() *ir.Name {
 	sym := typecheck.Lookup(".inittask")
 	task := typecheck.NewName(sym)
 	task.SetType(types.Types[types.TUINT8]) // fake type
-	task.Class_ = ir.PEXTERN
+	task.Class = ir.PEXTERN
 	sym.Def = task
-	lsym := sym.Linksym()
+	lsym := task.Linksym()
 	ot := 0
 	ot = objw.Uintptr(lsym, ot, 0) // state: not initialized yet
 	ot = objw.Uintptr(lsym, ot, uint64(len(deps)))

src/cmd/compile/internal/pkginit/initorder.go

@@ -140,7 +140,7 @@ func (o *InitOrder) processAssign(n ir.Node) {
 		defn := dep.Defn
 		// Skip dependencies on functions (PFUNC) and
 		// variables already initialized (InitDone).
-		if dep.Class_ != ir.PEXTERN || o.order[defn] == orderDone {
+		if dep.Class != ir.PEXTERN || o.order[defn] == orderDone {
 			continue
 		}
 		o.order[n]++
@@ -197,14 +197,14 @@ func (o *InitOrder) findInitLoopAndExit(n *ir.Name, path *[]*ir.Name) {
 
 	// There might be multiple loops involving n; by sorting
 	// references, we deterministically pick the one reported.
-	refers := collectDeps(n.Name().Defn, false).Sorted(func(ni, nj *ir.Name) bool {
+	refers := collectDeps(n.Defn, false).Sorted(func(ni, nj *ir.Name) bool {
 		return ni.Pos().Before(nj.Pos())
 	})
 
 	*path = append(*path, n)
 	for _, ref := range refers {
 		// Short-circuit variables that were initialized.
-		if ref.Class_ == ir.PEXTERN && o.order[ref.Defn] == orderDone {
+		if ref.Class == ir.PEXTERN && o.order[ref.Defn] == orderDone {
 			continue
 		}
 
@@ -221,7 +221,7 @@ func reportInitLoopAndExit(l []*ir.Name) {
 	// the start.
 	i := -1
 	for j, n := range l {
-		if n.Class_ == ir.PEXTERN && (i == -1 || n.Pos().Before(l[i].Pos())) {
+		if n.Class == ir.PEXTERN && (i == -1 || n.Pos().Before(l[i].Pos())) {
 			i = j
 		}
 	}
@@ -291,7 +291,7 @@ func (d *initDeps) visit(n ir.Node) {
 	switch n.Op() {
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		switch n.Class_ {
+		switch n.Class {
 		case ir.PEXTERN, ir.PFUNC:
 			d.foundDep(n)
 		}
@@ -324,7 +324,7 @@ func (d *initDeps) foundDep(n *ir.Name) {
 		return
 	}
 	d.seen.Add(n)
-	if d.transitive && n.Class_ == ir.PFUNC {
+	if d.transitive && n.Class == ir.PFUNC {
 		d.inspectList(n.Defn.(*ir.Func).Body)
 	}
 }

src/cmd/compile/internal/reflectdata/alg.go

@@ -104,7 +104,7 @@ func genhash(t *types.Type) *obj.LSym {
 		// For other sizes of plain memory, we build a closure
 		// that calls memhash_varlen. The size of the memory is
 		// encoded in the first slot of the closure.
-		closure := types.TypeSymLookup(fmt.Sprintf(".hashfunc%d", t.Width)).Linksym()
+		closure := TypeLinksymLookup(fmt.Sprintf(".hashfunc%d", t.Width))
 		if len(closure.P) > 0 { // already generated
 			return closure
 		}
@@ -120,7 +120,7 @@ func genhash(t *types.Type) *obj.LSym {
 		break
 	}
 
-	closure := TypeSymPrefix(".hashfunc", t).Linksym()
+	closure := TypeLinksymPrefix(".hashfunc", t)
 	if len(closure.P) > 0 { // already generated
 		return closure
 	}
@@ -255,7 +255,7 @@ func genhash(t *types.Type) *obj.LSym {
 
 	// Build closure. It doesn't close over any variables, so
 	// it contains just the function pointer.
-	objw.SymPtr(closure, 0, sym.Linksym(), 0)
+	objw.SymPtr(closure, 0, fn.Linksym(), 0)
 	objw.Global(closure, int32(types.PtrSize), obj.DUPOK|obj.RODATA)
 
 	return closure
@@ -347,7 +347,7 @@ func geneq(t *types.Type) *obj.LSym {
 	case types.AMEM:
 		// make equality closure. The size of the type
 		// is encoded in the closure.
-		closure := types.TypeSymLookup(fmt.Sprintf(".eqfunc%d", t.Width)).Linksym()
+		closure := TypeLinksymLookup(fmt.Sprintf(".eqfunc%d", t.Width))
 		if len(closure.P) != 0 {
 			return closure
 		}
@@ -363,7 +363,7 @@ func geneq(t *types.Type) *obj.LSym {
 		break
 	}
 
-	closure := TypeSymPrefix(".eqfunc", t).Linksym()
+	closure := TypeLinksymPrefix(".eqfunc", t)
 	if len(closure.P) > 0 { // already generated
 		return closure
 	}
@@ -634,7 +634,7 @@ func geneq(t *types.Type) *obj.LSym {
 	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
 
 	// Generate a closure which points at the function we just generated.
-	objw.SymPtr(closure, 0, sym.Linksym(), 0)
+	objw.SymPtr(closure, 0, fn.Linksym(), 0)
 	objw.Global(closure, int32(types.PtrSize), obj.DUPOK|obj.RODATA)
 	return closure
 }

src/cmd/compile/internal/reflectdata/reflect.go

@@ -52,13 +52,13 @@ var (
 	signatslice []*types.Type
 
 	itabs []itabEntry
-	ptabs []ptabEntry
+	ptabs []*ir.Name
 )
 
 type typeSig struct {
 	name  *types.Sym
-	isym  *types.Sym
+	isym  *obj.LSym
-	tsym  *types.Sym
+	tsym  *obj.LSym
 	type_ *types.Type
 	mtype *types.Type
 }
@@ -327,21 +327,19 @@ func methods(t *types.Type) []*typeSig {
 	// generating code if necessary.
 	var ms []*typeSig
 	for _, f := range mt.AllMethods().Slice() {
+		if f.Sym == nil {
+			base.Fatalf("method with no sym on %v", mt)
+		}
 		if !f.IsMethod() {
-			base.Fatalf("non-method on %v method %v %v\n", mt, f.Sym, f)
+			base.Fatalf("non-method on %v method %v %v", mt, f.Sym, f)
 		}
 		if f.Type.Recv() == nil {
-			base.Fatalf("receiver with no type on %v method %v %v\n", mt, f.Sym, f)
+			base.Fatalf("receiver with no type on %v method %v %v", mt, f.Sym, f)
 		}
 		if f.Nointerface() {
 			continue
 		}
 
-		method := f.Sym
-		if method == nil {
-			break
-		}
-
 		// get receiver type for this particular method.
 		// if pointer receiver but non-pointer t and
 		// this is not an embedded pointer inside a struct,
@@ -351,29 +349,13 @@ func methods(t *types.Type) []*typeSig {
 		}
 
 		sig := &typeSig{
-			name:  method,
+			name:  f.Sym,
-			isym:  ir.MethodSym(it, method),
+			isym:  methodWrapper(it, f),
-			tsym:  ir.MethodSym(t, method),
+			tsym:  methodWrapper(t, f),
 			type_: typecheck.NewMethodType(f.Type, t),
 			mtype: typecheck.NewMethodType(f.Type, nil),
 		}
 		ms = append(ms, sig)
-
-		this := f.Type.Recv().Type
-
-		if !sig.isym.Siggen() {
-			sig.isym.SetSiggen(true)
-			if !types.Identical(this, it) {
-				genwrapper(it, f, sig.isym)
-			}
-		}
-
-		if !sig.tsym.Siggen() {
-			sig.tsym.SetSiggen(true)
-			if !types.Identical(this, t) {
-				genwrapper(t, f, sig.tsym)
-			}
-		}
 	}
 
 	return ms
@@ -407,11 +389,7 @@ func imethods(t *types.Type) []*typeSig {
 		// IfaceType.Method is not in the reflect data.
 		// Generate the method body, so that compiled
 		// code can refer to it.
-		isym := ir.MethodSym(t, f.Sym)
+		methodWrapper(t, f)
-		if !isym.Siggen() {
-			isym.SetSiggen(true)
-			genwrapper(t, f, isym)
-		}
 	}
 
 	return methods
@@ -636,8 +614,8 @@ func dextratypeData(lsym *obj.LSym, ot int, t *types.Type) int {
 
 		ot = objw.SymPtrOff(lsym, ot, nsym)
 		ot = dmethodptrOff(lsym, ot, WriteType(a.mtype))
-		ot = dmethodptrOff(lsym, ot, a.isym.Linksym())
+		ot = dmethodptrOff(lsym, ot, a.isym)
-		ot = dmethodptrOff(lsym, ot, a.tsym.Linksym())
+		ot = dmethodptrOff(lsym, ot, a.tsym)
 	}
 	return ot
 }
@@ -812,8 +790,8 @@ func dcommontype(lsym *obj.LSym, t *types.Type) int {
 
 // TrackSym returns the symbol for tracking use of field/method f, assumed
 // to be a member of struct/interface type t.
-func TrackSym(t *types.Type, f *types.Field) *types.Sym {
+func TrackSym(t *types.Type, f *types.Field) *obj.LSym {
-	return ir.Pkgs.Track.Lookup(t.ShortString() + "." + f.Sym.Name)
+	return ir.Pkgs.Track.Lookup(t.ShortString() + "." + f.Sym.Name).Linksym()
 }
 
 func TypeSymPrefix(prefix string, t *types.Type) *types.Sym {
@@ -845,12 +823,24 @@ func TypeSym(t *types.Type) *types.Sym {
 	return s
 }
 
+func TypeLinksymPrefix(prefix string, t *types.Type) *obj.LSym {
+	return TypeSymPrefix(prefix, t).Linksym()
+}
+
+func TypeLinksymLookup(name string) *obj.LSym {
+	return types.TypeSymLookup(name).Linksym()
+}
+
+func TypeLinksym(t *types.Type) *obj.LSym {
+	return TypeSym(t).Linksym()
+}
+
 func TypePtr(t *types.Type) *ir.AddrExpr {
 	s := TypeSym(t)
 	if s.Def == nil {
 		n := ir.NewNameAt(src.NoXPos, s)
 		n.SetType(types.Types[types.TUINT8])
-		n.Class_ = ir.PEXTERN
+		n.Class = ir.PEXTERN
 		n.SetTypecheck(1)
 		s.Def = n
 	}
@@ -869,10 +859,10 @@ func ITabAddr(t, itype *types.Type) *ir.AddrExpr {
 	if s.Def == nil {
 		n := typecheck.NewName(s)
 		n.SetType(types.Types[types.TUINT8])
-		n.Class_ = ir.PEXTERN
+		n.Class = ir.PEXTERN
 		n.SetTypecheck(1)
 		s.Def = n
-		itabs = append(itabs, itabEntry{t: t, itype: itype, lsym: s.Linksym()})
+		itabs = append(itabs, itabEntry{t: t, itype: itype, lsym: n.Linksym()})
 	}
 
 	n := typecheck.NodAddr(ir.AsNode(s.Def))
@@ -1269,7 +1259,7 @@ func genfun(t, it *types.Type) []*obj.LSym {
 	// so we can find the intersect in a single pass
 	for _, m := range methods {
 		if m.name == sigs[0].name {
-			out = append(out, m.isym.Linksym())
+			out = append(out, m.isym)
 			sigs = sigs[1:]
 			if len(sigs) == 0 {
 				break
@@ -1378,8 +1368,12 @@ func WriteTabs() {
 			//	name nameOff
 			//	typ  typeOff // pointer to symbol
 			// }
-			nsym := dname(p.s.Name, "", nil, true)
+			nsym := dname(p.Sym().Name, "", nil, true)
-			tsym := WriteType(p.t)
+			t := p.Type()
+			if p.Class != ir.PFUNC {
+				t = types.NewPtr(t)
+			}
+			tsym := WriteType(t)
 			ot = objw.SymPtrOff(s, ot, nsym)
 			ot = objw.SymPtrOff(s, ot, tsym)
 			// Plugin exports symbols as interfaces. Mark their types
@@ -1391,7 +1385,7 @@ func WriteTabs() {
 		ot = 0
 		s = base.Ctxt.Lookup("go.plugin.exports")
 		for _, p := range ptabs {
-			ot = objw.SymPtr(s, ot, p.s.Linksym(), 0)
+			ot = objw.SymPtr(s, ot, p.Linksym(), 0)
 		}
 		objw.Global(s, int32(ot), int16(obj.RODATA))
 	}
@@ -1571,7 +1565,7 @@ func dgcprog(t *types.Type) (*obj.LSym, int64) {
 	if t.Width == types.BADWIDTH {
 		base.Fatalf("dgcprog: %v badwidth", t)
 	}
-	lsym := TypeSymPrefix(".gcprog", t).Linksym()
+	lsym := TypeLinksymPrefix(".gcprog", t)
 	var p gcProg
 	p.init(lsym)
 	p.emit(t, 0)
@@ -1680,7 +1674,7 @@ func ZeroAddr(size int64) ir.Node {
 	if s.Def == nil {
 		x := typecheck.NewName(s)
 		x.SetType(types.Types[types.TUINT8])
-		x.Class_ = ir.PEXTERN
+		x.Class = ir.PEXTERN
 		x.SetTypecheck(1)
 		s.Def = x
 	}
@@ -1710,13 +1704,7 @@ func CollectPTabs() {
 		if s.Pkg.Name != "main" {
 			continue
 		}
-		if n.Type().Kind() == types.TFUNC && n.Class_ == ir.PFUNC {
+		ptabs = append(ptabs, n)
-			// function
-			ptabs = append(ptabs, ptabEntry{s: s, t: s.Def.Type()})
-		} else {
-			// variable
-			ptabs = append(ptabs, ptabEntry{s: s, t: types.NewPtr(s.Def.Type())})
-		}
 	}
 }
 
@@ -1740,22 +1728,28 @@ func CollectPTabs() {
 //
 //	rcvr - U
 //	method - M func (t T)(), a TFIELD type struct
-//	newnam - the eventual mangled name of this function
+func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
-func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
+	newnam := ir.MethodSym(rcvr, method.Sym)
-	if false && base.Flag.LowerR != 0 {
+	lsym := newnam.Linksym()
-		fmt.Printf("genwrapper rcvrtype=%v method=%v newnam=%v\n", rcvr, method, newnam)
+	if newnam.Siggen() {
+		return lsym
+	}
+	newnam.SetSiggen(true)
+
+	if types.Identical(rcvr, method.Type.Recv().Type) {
+		return lsym
 	}
 
 	// Only generate (*T).M wrappers for T.M in T's own package.
 	if rcvr.IsPtr() && rcvr.Elem() == method.Type.Recv().Type &&
 		rcvr.Elem().Sym() != nil && rcvr.Elem().Sym().Pkg != types.LocalPkg {
-		return
+		return lsym
 	}
 
 	// Only generate I.M wrappers for I in I's own package
 	// but keep doing it for error.Error (was issue #29304).
 	if rcvr.IsInterface() && rcvr.Sym() != nil && rcvr.Sym().Pkg != types.LocalPkg && rcvr != types.ErrorType {
-		return
+		return lsym
 	}
 
 	base.Pos = base.AutogeneratedPos
@@ -1804,7 +1798,7 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 	} else {
 		fn.SetWrapper(true) // ignore frame for panic+recover matching
 		call := ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
-		call.Args.Set(ir.ParamNames(tfn.Type()))
+		call.Args = ir.ParamNames(tfn.Type())
 		call.IsDDD = tfn.Type().IsVariadic()
 		if method.Type.NumResults() > 0 {
 			ret := ir.NewReturnStmt(base.Pos, nil)
@@ -1815,10 +1809,6 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 		}
 	}
 
-	if false && base.Flag.LowerR != 0 {
-		ir.DumpList("genwrapper body", fn.Body)
-	}
-
 	typecheck.FinishFuncBody()
 	if base.Debug.DclStack != 0 {
 		types.CheckDclstack()
@@ -1838,6 +1828,8 @@ func genwrapper(rcvr *types.Type, method *types.Field, newnam *types.Sym) {
 
 	ir.CurFunc = nil
 	typecheck.Target.Decls = append(typecheck.Target.Decls, fn)
+
+	return lsym
 }
 
 var ZeroSize int64
@@ -1845,7 +1837,7 @@ var ZeroSize int64
 // MarkTypeUsedInInterface marks that type t is converted to an interface.
 // This information is used in the linker in dead method elimination.
 func MarkTypeUsedInInterface(t *types.Type, from *obj.LSym) {
-	tsym := TypeSym(t).Linksym()
+	tsym := TypeLinksym(t)
 	// Emit a marker relocation. The linker will know the type is converted
 	// to an interface if "from" is reachable.
 	r := obj.Addrel(from)
@@ -1858,7 +1850,7 @@ func MarkTypeUsedInInterface(t *types.Type, from *obj.LSym) {
 func MarkUsedIfaceMethod(n *ir.CallExpr) {
 	dot := n.X.(*ir.SelectorExpr)
 	ityp := dot.X.Type()
-	tsym := TypeSym(ityp).Linksym()
+	tsym := TypeLinksym(ityp)
 	r := obj.Addrel(ir.CurFunc.LSym)
 	r.Sym = tsym
 	// dot.Xoffset is the method index * Widthptr (the offset of code pointer

src/cmd/compile/internal/ssa/deadstore.go

@@ -148,7 +148,7 @@ func elimDeadAutosGeneric(f *Func) {
 		case OpAddr, OpLocalAddr:
 			// Propagate the address if it points to an auto.
 			n, ok := v.Aux.(*ir.Name)
-			if !ok || n.Class() != ir.PAUTO {
+			if !ok || n.Class != ir.PAUTO {
 				return
 			}
 			if addr[v] == nil {
@@ -159,7 +159,7 @@ func elimDeadAutosGeneric(f *Func) {
 		case OpVarDef, OpVarKill:
 			// v should be eliminated if we eliminate the auto.
 			n, ok := v.Aux.(*ir.Name)
-			if !ok || n.Class() != ir.PAUTO {
+			if !ok || n.Class != ir.PAUTO {
 				return
 			}
 			if elim[v] == nil {
@@ -175,7 +175,7 @@ func elimDeadAutosGeneric(f *Func) {
 			// may not be used by the inline code, but will be used by
 			// panic processing).
 			n, ok := v.Aux.(*ir.Name)
-			if !ok || n.Class() != ir.PAUTO {
+			if !ok || n.Class != ir.PAUTO {
 				return
 			}
 			if !used[n] {
@@ -307,7 +307,7 @@ func elimUnreadAutos(f *Func) {
 			if !ok {
 				continue
 			}
-			if n.Class() != ir.PAUTO {
+			if n.Class != ir.PAUTO {
 				continue
 			}
 

src/cmd/compile/internal/ssa/export_test.go

@@ -70,7 +70,7 @@ func (TestFrontend) StringData(s string) *obj.LSym {
 }
 func (TestFrontend) Auto(pos src.XPos, t *types.Type) *ir.Name {
 	n := ir.NewNameAt(pos, &types.Sym{Name: "aFakeAuto"})
-	n.SetClass(ir.PAUTO)
+	n.Class = ir.PAUTO
 	return n
 }
 func (d TestFrontend) SplitString(s LocalSlot) (LocalSlot, LocalSlot) {

src/cmd/compile/internal/ssa/writebarrier.go

@@ -5,6 +5,7 @@
 package ssa
 
 import (
+	"cmd/compile/internal/reflectdata"
 	"cmd/compile/internal/types"
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
@@ -270,11 +271,11 @@ func writebarrier(f *Func) {
 			case OpMoveWB:
 				fn = typedmemmove
 				val = w.Args[1]
-				typ = w.Aux.(*types.Type).Symbol()
+				typ = reflectdata.TypeLinksym(w.Aux.(*types.Type))
 				nWBops--
 			case OpZeroWB:
 				fn = typedmemclr
-				typ = w.Aux.(*types.Type).Symbol()
+				typ = reflectdata.TypeLinksym(w.Aux.(*types.Type))
 				nWBops--
 			case OpVarDef, OpVarLive, OpVarKill:
 			}

src/cmd/compile/internal/ssagen/abi.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate go run mkbuiltin.go
-
 package ssagen
 
 import (
@@ -168,7 +166,7 @@ func selectLSym(f *ir.Func, hasBody bool) {
 			f.LSym = nam.Sym().LinksymABI0()
 			needABIWrapper, wrapperABI = true, obj.ABIInternal
 		} else {
-			f.LSym = nam.Sym().Linksym()
+			f.LSym = nam.Linksym()
 			// No ABI override. Check that the symbol is
 			// using the expected ABI.
 			want := obj.ABIInternal
@@ -305,7 +303,7 @@ func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) {
 		tail = ir.NewBranchStmt(base.Pos, ir.ORETJMP, f.Nname.Sym())
 	} else {
 		call := ir.NewCallExpr(base.Pos, ir.OCALL, f.Nname, nil)
-		call.Args.Set(ir.ParamNames(tfn.Type()))
+		call.Args = ir.ParamNames(tfn.Type())
 		call.IsDDD = tfn.Type().IsVariadic()
 		tail = call
 		if tfn.Type().NumResults() > 0 {

src/cmd/compile/internal/ssagen/nowb.go

@@ -76,7 +76,7 @@ func (c *nowritebarrierrecChecker) findExtraCalls(nn ir.Node) {
 		return
 	}
 	fn := n.X.(*ir.Name)
-	if fn.Class_ != ir.PFUNC || fn.Name().Defn == nil {
+	if fn.Class != ir.PFUNC || fn.Defn == nil {
 		return
 	}
 	if !types.IsRuntimePkg(fn.Sym().Pkg) || fn.Sym().Name != "systemstack" {
@@ -88,7 +88,7 @@ func (c *nowritebarrierrecChecker) findExtraCalls(nn ir.Node) {
 	switch arg.Op() {
 	case ir.ONAME:
 		arg := arg.(*ir.Name)
-		callee = arg.Name().Defn.(*ir.Func)
+		callee = arg.Defn.(*ir.Func)
 	case ir.OCLOSURE:
 		arg := arg.(*ir.ClosureExpr)
 		callee = arg.Func

src/cmd/compile/internal/ssagen/pgen.go

@@ -34,11 +34,11 @@ import (
 // the top of the stack and increasing in size.
 // Non-autos sort on offset.
 func cmpstackvarlt(a, b *ir.Name) bool {
-	if (a.Class_ == ir.PAUTO) != (b.Class_ == ir.PAUTO) {
+	if (a.Class == ir.PAUTO) != (b.Class == ir.PAUTO) {
-		return b.Class_ == ir.PAUTO
+		return b.Class == ir.PAUTO
 	}
 
-	if a.Class_ != ir.PAUTO {
+	if a.Class != ir.PAUTO {
 		return a.FrameOffset() < b.FrameOffset()
 	}
 
@@ -79,14 +79,14 @@ func (s *ssafn) AllocFrame(f *ssa.Func) {
 
 	// Mark the PAUTO's unused.
 	for _, ln := range fn.Dcl {
-		if ln.Class_ == ir.PAUTO {
+		if ln.Class == ir.PAUTO {
 			ln.SetUsed(false)
 		}
 	}
 
 	for _, l := range f.RegAlloc {
 		if ls, ok := l.(ssa.LocalSlot); ok {
-			ls.N.Name().SetUsed(true)
+			ls.N.SetUsed(true)
 		}
 	}
 
@@ -94,14 +94,14 @@ func (s *ssafn) AllocFrame(f *ssa.Func) {
 	for _, b := range f.Blocks {
 		for _, v := range b.Values {
 			if n, ok := v.Aux.(*ir.Name); ok {
-				switch n.Class_ {
+				switch n.Class {
 				case ir.PPARAM, ir.PPARAMOUT:
 					// Don't modify nodfp; it is a global.
 					if n != ir.RegFP {
-						n.Name().SetUsed(true)
+						n.SetUsed(true)
 					}
 				case ir.PAUTO:
-					n.Name().SetUsed(true)
+					n.SetUsed(true)
 				}
 			}
 			if !scratchUsed {
@@ -120,7 +120,7 @@ func (s *ssafn) AllocFrame(f *ssa.Func) {
 	// Reassign stack offsets of the locals that are used.
 	lastHasPtr := false
 	for i, n := range fn.Dcl {
-		if n.Op() != ir.ONAME || n.Class_ != ir.PAUTO {
+		if n.Op() != ir.ONAME || n.Class != ir.PAUTO {
 			continue
 		}
 		if !n.Used() {
@@ -207,7 +207,7 @@ func init() {
 func StackOffset(slot ssa.LocalSlot) int32 {
 	n := slot.N
 	var off int64
-	switch n.Class_ {
+	switch n.Class {
 	case ir.PAUTO:
 		off = n.FrameOffset()
 		if base.Ctxt.FixedFrameSize() == 0 {
@@ -225,7 +225,7 @@ func StackOffset(slot ssa.LocalSlot) int32 {
 
 // fieldtrack adds R_USEFIELD relocations to fnsym to record any
 // struct fields that it used.
-func fieldtrack(fnsym *obj.LSym, tracked map[*types.Sym]struct{}) {
+func fieldtrack(fnsym *obj.LSym, tracked map[*obj.LSym]struct{}) {
 	if fnsym == nil {
 		return
 	}
@@ -233,24 +233,18 @@ func fieldtrack(fnsym *obj.LSym, tracked map[*types.Sym]struct{}) {
 		return
 	}
 
-	trackSyms := make([]*types.Sym, 0, len(tracked))
+	trackSyms := make([]*obj.LSym, 0, len(tracked))
 	for sym := range tracked {
 		trackSyms = append(trackSyms, sym)
 	}
-	sort.Sort(symByName(trackSyms))
+	sort.Slice(trackSyms, func(i, j int) bool { return trackSyms[i].Name < trackSyms[j].Name })
 	for _, sym := range trackSyms {
 		r := obj.Addrel(fnsym)
-		r.Sym = sym.Linksym()
+		r.Sym = sym
 		r.Type = objabi.R_USEFIELD
 	}
 }
 
-type symByName []*types.Sym
-
-func (a symByName) Len() int           { return len(a) }
-func (a symByName) Less(i, j int) bool { return a[i].Name < a[j].Name }
-func (a symByName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
-
 // largeStack is info about a function whose stack frame is too large (rare).
 type largeStack struct {
 	locals int64

src/cmd/compile/internal/ssagen/pgen_test.go

@@ -46,7 +46,7 @@ func TestCmpstackvar(t *testing.T) {
 		n := typecheck.NewName(s)
 		n.SetType(t)
 		n.SetFrameOffset(xoffset)
-		n.Class_ = cl
+		n.Class = cl
 		return n
 	}
 	testdata := []struct {
@@ -161,7 +161,7 @@ func TestStackvarSort(t *testing.T) {
 		n := typecheck.NewName(s)
 		n.SetType(t)
 		n.SetFrameOffset(xoffset)
-		n.Class_ = cl
+		n.Class = cl
 		return n
 	}
 	inp := []*ir.Name{

src/cmd/compile/internal/ssagen/ssa.go

@@ -436,7 +436,7 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
 	var args []ssa.Param
 	var results []ssa.Param
 	for _, n := range fn.Dcl {
-		switch n.Class_ {
+		switch n.Class {
 		case ir.PPARAM:
 			s.decladdrs[n] = s.entryNewValue2A(ssa.OpLocalAddr, types.NewPtr(n.Type()), n, s.sp, s.startmem)
 			args = append(args, ssa.Param{Type: n.Type(), Offset: int32(n.FrameOffset())})
@@ -457,13 +457,13 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
 		case ir.PFUNC:
 			// local function - already handled by frontend
 		default:
-			s.Fatalf("local variable with class %v unimplemented", n.Class_)
+			s.Fatalf("local variable with class %v unimplemented", n.Class)
 		}
 	}
 
 	// Populate SSAable arguments.
 	for _, n := range fn.Dcl {
-		if n.Class_ == ir.PPARAM && s.canSSA(n) {
+		if n.Class == ir.PPARAM && s.canSSA(n) {
 			v := s.newValue0A(ssa.OpArg, n.Type(), n)
 			s.vars[n] = v
 			s.addNamedValue(n, v) // This helps with debugging information, not needed for compilation itself.
@@ -1166,7 +1166,7 @@ func (s *state) stmt(n ir.Node) {
 	case ir.OCALLINTER:
 		n := n.(*ir.CallExpr)
 		s.callResult(n, callNormal)
-		if n.Op() == ir.OCALLFUNC && n.X.Op() == ir.ONAME && n.X.(*ir.Name).Class_ == ir.PFUNC {
+		if n.Op() == ir.OCALLFUNC && n.X.Op() == ir.ONAME && n.X.(*ir.Name).Class == ir.PFUNC {
 			if fn := n.X.Sym().Name; base.Flag.CompilingRuntime && fn == "throw" ||
 				n.X.Sym().Pkg == ir.Pkgs.Runtime && (fn == "throwinit" || fn == "gopanic" || fn == "panicwrap" || fn == "block" || fn == "panicmakeslicelen" || fn == "panicmakeslicecap") {
 				m := s.mem()
@@ -1242,7 +1242,7 @@ func (s *state) stmt(n ir.Node) {
 
 	case ir.ODCL:
 		n := n.(*ir.Decl)
-		if n.X.(*ir.Name).Class_ == ir.PAUTOHEAP {
+		if n.X.Class == ir.PAUTOHEAP {
 			s.Fatalf("DCL %v", n)
 		}
 
@@ -1634,7 +1634,7 @@ func (s *state) stmt(n ir.Node) {
 		if !v.Addrtaken() {
 			s.Fatalf("VARLIVE variable %v must have Addrtaken set", v)
 		}
-		switch v.Class_ {
+		switch v.Class {
 		case ir.PAUTO, ir.PPARAM, ir.PPARAMOUT:
 		default:
 			s.Fatalf("VARLIVE variable %v must be Auto or Arg", v)
@@ -2106,13 +2106,13 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 		return s.newValue3(ssa.OpSliceMake, n.Type(), ptr, len, len)
 	case ir.OCFUNC:
 		n := n.(*ir.UnaryExpr)
-		aux := n.X.Sym().Linksym()
+		aux := n.X.(*ir.Name).Linksym()
 		return s.entryNewValue1A(ssa.OpAddr, n.Type(), aux, s.sb)
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		if n.Class_ == ir.PFUNC {
+		if n.Class == ir.PFUNC {
 			// "value" of a function is the address of the function's closure
-			sym := staticdata.FuncSym(n.Sym()).Linksym()
+			sym := staticdata.FuncLinksym(n)
 			return s.entryNewValue1A(ssa.OpAddr, types.NewPtr(n.Type()), sym, s.sb)
 		}
 		if s.canSSA(n) {
@@ -3003,7 +3003,7 @@ func (s *state) append(n *ir.CallExpr, inplace bool) *ssa.Value {
 	if inplace {
 		if sn.Op() == ir.ONAME {
 			sn := sn.(*ir.Name)
-			if sn.Class_ != ir.PEXTERN {
+			if sn.Class != ir.PEXTERN {
 				// Tell liveness we're about to build a new slice
 				s.vars[memVar] = s.newValue1A(ssa.OpVarDef, types.TypeMem, sn, s.mem())
 			}
@@ -3222,7 +3222,7 @@ func (s *state) assign(left ir.Node, right *ssa.Value, deref bool, skip skipMask
 
 	// If this assignment clobbers an entire local variable, then emit
 	// OpVarDef so liveness analysis knows the variable is redefined.
-	if base := clobberBase(left); base.Op() == ir.ONAME && base.(*ir.Name).Class_ != ir.PEXTERN && skip == 0 {
+	if base := clobberBase(left); base.Op() == ir.ONAME && base.(*ir.Name).Class != ir.PEXTERN && skip == 0 {
 		s.vars[memVar] = s.newValue1Apos(ssa.OpVarDef, types.TypeMem, base.(*ir.Name), s.mem(), !ir.IsAutoTmp(base))
 	}
 
@@ -4385,7 +4385,7 @@ func (s *state) openDeferRecord(n *ir.CallExpr) {
 		closureVal := s.expr(fn)
 		closure := s.openDeferSave(nil, fn.Type(), closureVal)
 		opendefer.closureNode = closure.Aux.(*ir.Name)
-		if !(fn.Op() == ir.ONAME && fn.(*ir.Name).Class_ == ir.PFUNC) {
+		if !(fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC) {
 			opendefer.closure = closure
 		}
 	} else if n.Op() == ir.OCALLMETH {
@@ -4578,7 +4578,7 @@ func (s *state) openDeferExit() {
 				call = s.newValue3A(ssa.OpClosureCall, types.TypeMem, aux, codeptr, v, s.mem())
 			}
 		} else {
-			aux := ssa.StaticAuxCall(fn.Sym().Linksym(), ACArgs, ACResults)
+			aux := ssa.StaticAuxCall(fn.(*ir.Name).Linksym(), ACArgs, ACResults)
 			if testLateExpansion {
 				callArgs = append(callArgs, s.mem())
 				call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux)
@@ -4651,7 +4651,7 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 	switch n.Op() {
 	case ir.OCALLFUNC:
 		testLateExpansion = k != callDeferStack && ssa.LateCallExpansionEnabledWithin(s.f)
-		if k == callNormal && fn.Op() == ir.ONAME && fn.(*ir.Name).Class_ == ir.PFUNC {
+		if k == callNormal && fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC {
 			fn := fn.(*ir.Name)
 			sym = fn.Sym()
 			break
@@ -4867,7 +4867,9 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		s.vars[memVar] = call
 	}
 	// Insert OVARLIVE nodes
-	s.stmtList(n.Body)
+	for _, name := range n.KeepAlive {
+		s.stmt(ir.NewUnaryExpr(n.Pos(), ir.OVARLIVE, name))
+	}
 
 	// Finish block for defers
 	if k == callDefer || k == callDeferStack {
@@ -4956,10 +4958,10 @@ func (s *state) addr(n ir.Node) *ssa.Value {
 		fallthrough
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		switch n.Class_ {
+		switch n.Class {
 		case ir.PEXTERN:
 			// global variable
-			v := s.entryNewValue1A(ssa.OpAddr, t, n.Sym().Linksym(), s.sb)
+			v := s.entryNewValue1A(ssa.OpAddr, t, n.Linksym(), s.sb)
 			// TODO: Make OpAddr use AuxInt as well as Aux.
 			if offset != 0 {
 				v = s.entryNewValue1I(ssa.OpOffPtr, v.Type, offset, v)
@@ -4985,7 +4987,7 @@ func (s *state) addr(n ir.Node) *ssa.Value {
 			// that cse works on their addresses
 			return s.newValue2Apos(ssa.OpLocalAddr, t, n, s.sp, s.mem(), true)
 		default:
-			s.Fatalf("variable address class %v not implemented", n.Class_)
+			s.Fatalf("variable address class %v not implemented", n.Class)
 			return nil
 		}
 	case ir.ORESULT:
@@ -5094,10 +5096,10 @@ func (s *state) canSSAName(name *ir.Name) bool {
 	if ir.IsParamHeapCopy(name) {
 		return false
 	}
-	if name.Class_ == ir.PAUTOHEAP {
+	if name.Class == ir.PAUTOHEAP {
 		s.Fatalf("canSSA of PAUTOHEAP %v", name)
 	}
-	switch name.Class_ {
+	switch name.Class {
 	case ir.PEXTERN:
 		return false
 	case ir.PPARAMOUT:
@@ -5115,7 +5117,7 @@ func (s *state) canSSAName(name *ir.Name) bool {
 			return false
 		}
 	}
-	if name.Class_ == ir.PPARAM && name.Sym() != nil && name.Sym().Name == ".this" {
+	if name.Class == ir.PPARAM && name.Sym() != nil && name.Sym().Name == ".this" {
 		// wrappers generated by genwrapper need to update
 		// the .this pointer in place.
 		// TODO: treat as a PPARAMOUT?
@@ -5978,8 +5980,8 @@ func (s *state) floatToUint(cvttab *f2uCvtTab, n ir.Node, x *ssa.Value, ft, tt *
 // commaok indicates whether to panic or return a bool.
 // If commaok is false, resok will be nil.
 func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Value) {
-	iface := s.expr(n.X)      // input interface
+	iface := s.expr(n.X)        // input interface
-	target := s.expr(n.Ntype) // target type
+	target := s.expr(n.DstType) // target type
 	byteptr := s.f.Config.Types.BytePtr
 
 	if n.Type().IsInterface() {
@@ -6086,7 +6088,7 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 		targetITab = target
 	} else {
 		// Looking for pointer to itab for target type and source interface.
-		targetITab = s.expr(n.Itab[0])
+		targetITab = s.expr(n.Itab)
 	}
 
 	var tmp ir.Node     // temporary for use with large types
@@ -6113,7 +6115,7 @@ func (s *state) dottype(n *ir.TypeAssertExpr, commaok bool) (res, resok *ssa.Val
 	if !commaok {
 		// on failure, panic by calling panicdottype
 		s.startBlock(bFail)
-		taddr := s.expr(n.Ntype.(*ir.AddrExpr).Alloc)
+		taddr := s.expr(n.SrcType)
 		if n.X.Type().IsEmptyInterface() {
 			s.rtcall(ir.Syms.PanicdottypeE, false, nil, itab, target, taddr)
 		} else {
@@ -6208,7 +6210,7 @@ func (s *state) mem() *ssa.Value {
 }
 
 func (s *state) addNamedValue(n *ir.Name, v *ssa.Value) {
-	if n.Class_ == ir.Pxxx {
+	if n.Class == ir.Pxxx {
 		// Don't track our marker nodes (memVar etc.).
 		return
 	}
@@ -6216,12 +6218,12 @@ func (s *state) addNamedValue(n *ir.Name, v *ssa.Value) {
 		// Don't track temporary variables.
 		return
 	}
-	if n.Class_ == ir.PPARAMOUT {
+	if n.Class == ir.PPARAMOUT {
 		// Don't track named output values.  This prevents return values
 		// from being assigned too early. See #14591 and #14762. TODO: allow this.
 		return
 	}
-	loc := ssa.LocalSlot{N: n.Name(), Type: n.Type(), Off: 0}
+	loc := ssa.LocalSlot{N: n, Type: n.Type(), Off: 0}
 	values, ok := s.f.NamedValues[loc]
 	if !ok {
 		s.f.Names = append(s.f.Names, loc)
@@ -6739,8 +6741,8 @@ func defframe(s *State, e *ssafn) {
 		if !n.Needzero() {
 			continue
 		}
-		if n.Class_ != ir.PAUTO {
+		if n.Class != ir.PAUTO {
-			e.Fatalf(n.Pos(), "needzero class %d", n.Class_)
+			e.Fatalf(n.Pos(), "needzero class %d", n.Class)
 		}
 		if n.Type().Size()%int64(types.PtrSize) != 0 || n.FrameOffset()%int64(types.PtrSize) != 0 || n.Type().Size() == 0 {
 			e.Fatalf(n.Pos(), "var %L has size %d offset %d", n, n.Type().Size(), n.Offset_)
@@ -6824,14 +6826,14 @@ func AddAux2(a *obj.Addr, v *ssa.Value, offset int64) {
 		a.Name = obj.NAME_EXTERN
 		a.Sym = n
 	case *ir.Name:
-		if n.Class_ == ir.PPARAM || n.Class_ == ir.PPARAMOUT {
+		if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
 			a.Name = obj.NAME_PARAM
-			a.Sym = ir.Orig(n).Sym().Linksym()
+			a.Sym = ir.Orig(n).(*ir.Name).Linksym()
 			a.Offset += n.FrameOffset()
 			break
 		}
 		a.Name = obj.NAME_AUTO
-		a.Sym = n.Sym().Linksym()
+		a.Sym = n.Linksym()
 		a.Offset += n.FrameOffset()
 	default:
 		v.Fatalf("aux in %s not implemented %#v", v, v.Aux)
@@ -6963,10 +6965,10 @@ func CheckLoweredGetClosurePtr(v *ssa.Value) {
 func AddrAuto(a *obj.Addr, v *ssa.Value) {
 	n, off := ssa.AutoVar(v)
 	a.Type = obj.TYPE_MEM
-	a.Sym = n.Sym().Linksym()
+	a.Sym = n.Linksym()
 	a.Reg = int16(Arch.REGSP)
 	a.Offset = n.FrameOffset() + off
-	if n.Class_ == ir.PPARAM || n.Class_ == ir.PPARAMOUT {
+	if n.Class == ir.PPARAM || n.Class == ir.PPARAMOUT {
 		a.Name = obj.NAME_PARAM
 	} else {
 		a.Name = obj.NAME_AUTO
@@ -6979,7 +6981,7 @@ func (s *State) AddrScratch(a *obj.Addr) {
 	}
 	a.Type = obj.TYPE_MEM
 	a.Name = obj.NAME_AUTO
-	a.Sym = s.ScratchFpMem.Sym().Linksym()
+	a.Sym = s.ScratchFpMem.Linksym()
 	a.Reg = int16(Arch.REGSP)
 	a.Offset = s.ScratchFpMem.Offset_
 }
@@ -7196,7 +7198,7 @@ func (e *ssafn) DerefItab(it *obj.LSym, offset int64) *obj.LSym {
 func (e *ssafn) SplitSlot(parent *ssa.LocalSlot, suffix string, offset int64, t *types.Type) ssa.LocalSlot {
 	node := parent.N
 
-	if node.Class_ != ir.PAUTO || node.Name().Addrtaken() {
+	if node.Class != ir.PAUTO || node.Addrtaken() {
 		// addressed things and non-autos retain their parents (i.e., cannot truly be split)
 		return ssa.LocalSlot{N: node, Type: t, Off: parent.Off + offset}
 	}
@@ -7206,7 +7208,7 @@ func (e *ssafn) SplitSlot(parent *ssa.LocalSlot, suffix string, offset int64, t
 	s.Def = n
 	ir.AsNode(s.Def).Name().SetUsed(true)
 	n.SetType(t)
-	n.Class_ = ir.PAUTO
+	n.Class = ir.PAUTO
 	n.SetEsc(ir.EscNever)
 	n.Curfn = e.curfn
 	e.curfn.Dcl = append(e.curfn.Dcl, n)

src/cmd/compile/internal/staticdata/data.go

@@ -37,8 +37,8 @@ func InitAddr(n *ir.Name, noff int64, a *ir.Name, aoff int64) {
 	if a.Op() != ir.ONAME {
 		base.Fatalf("addrsym a op %v", a.Op())
 	}
-	s := n.Sym().Linksym()
+	s := n.Linksym()
-	s.WriteAddr(base.Ctxt, noff, types.PtrSize, a.Sym().Linksym(), aoff)
+	s.WriteAddr(base.Ctxt, noff, types.PtrSize, a.Linksym(), aoff)
 }
 
 // InitFunc writes the static address of f to n. f must be a global function.
@@ -50,21 +50,21 @@ func InitFunc(n *ir.Name, noff int64, f *ir.Name) {
 	if n.Sym() == nil {
 		base.Fatalf("pfuncsym nil n sym")
 	}
-	if f.Class_ != ir.PFUNC {
+	if f.Class != ir.PFUNC {
-		base.Fatalf("pfuncsym class not PFUNC %d", f.Class_)
+		base.Fatalf("pfuncsym class not PFUNC %d", f.Class)
 	}
-	s := n.Sym().Linksym()
+	s := n.Linksym()
-	s.WriteAddr(base.Ctxt, noff, types.PtrSize, FuncSym(f.Sym()).Linksym(), 0)
+	s.WriteAddr(base.Ctxt, noff, types.PtrSize, FuncLinksym(f), 0)
 }
 
 // InitSlice writes a static slice symbol {&arr, lencap, lencap} to n+noff.
 // InitSlice does not modify n.
 func InitSlice(n *ir.Name, noff int64, arr *ir.Name, lencap int64) {
-	s := n.Sym().Linksym()
+	s := n.Linksym()
 	if arr.Op() != ir.ONAME {
 		base.Fatalf("slicesym non-name arr %v", arr)
 	}
-	s.WriteAddr(base.Ctxt, noff, types.PtrSize, arr.Sym().Linksym(), 0)
+	s.WriteAddr(base.Ctxt, noff, types.PtrSize, arr.Linksym(), 0)
 	s.WriteInt(base.Ctxt, noff+types.SliceLenOffset, types.PtrSize, lencap)
 	s.WriteInt(base.Ctxt, noff+types.SliceCapOffset, types.PtrSize, lencap)
 }
@@ -141,7 +141,7 @@ func fileStringSym(pos src.XPos, file string, readonly bool, hash []byte) (*obj.
 		if readonly {
 			sym = StringSym(pos, string(data))
 		} else {
-			sym = slicedata(pos, string(data)).Sym().Linksym()
+			sym = slicedata(pos, string(data)).Linksym()
 		}
 		if len(hash) > 0 {
 			sum := sha256.Sum256(data)
@@ -189,7 +189,7 @@ func fileStringSym(pos src.XPos, file string, readonly bool, hash []byte) (*obj.
 	} else {
 		// Emit a zero-length data symbol
 		// and then fix up length and content to use file.
-		symdata = slicedata(pos, "").Sym().Linksym()
+		symdata = slicedata(pos, "").Linksym()
 		symdata.Size = size
 		symdata.Type = objabi.SNOPTRDATA
 		info := symdata.NewFileInfo()
@@ -209,7 +209,7 @@ func slicedata(pos src.XPos, s string) *ir.Name {
 	symnode := typecheck.NewName(sym)
 	sym.Def = symnode
 
-	lsym := sym.Linksym()
+	lsym := symnode.Linksym()
 	off := dstringdata(lsym, 0, s, pos, "slice")
 	objw.Global(lsym, int32(off), obj.NOPTR|obj.LOCAL)
 
@@ -258,6 +258,13 @@ func FuncSym(s *types.Sym) *types.Sym {
 	return sf
 }
 
+func FuncLinksym(n *ir.Name) *obj.LSym {
+	if n.Op() != ir.ONAME || n.Class != ir.PFUNC {
+		base.Fatalf("expected func name: %v", n)
+	}
+	return FuncSym(n.Sym()).Linksym()
+}
+
 // NeedFuncSym ensures that s·f is exported.
 // It is only used with -dynlink.
 // When not compiling for dynamic linking,
@@ -311,7 +318,7 @@ func InitConst(n *ir.Name, noff int64, c ir.Node, wid int) {
 	if c.Op() != ir.OLITERAL {
 		base.Fatalf("litsym c op %v", c.Op())
 	}
-	s := n.Sym().Linksym()
+	s := n.Linksym()
 	switch u := c.Val(); u.Kind() {
 	case constant.Bool:
 		i := int64(obj.Bool2int(constant.BoolVal(u)))

src/cmd/compile/internal/staticdata/embed.go

@@ -145,7 +145,7 @@ func WriteEmbed(v *ir.Name) {
 		if err != nil {
 			base.ErrorfAt(v.Pos(), "embed %s: %v", file, err)
 		}
-		sym := v.Sym().Linksym()
+		sym := v.Linksym()
 		off := 0
 		off = objw.SymPtr(sym, off, fsym, 0)       // data string
 		off = objw.Uintptr(sym, off, uint64(size)) // len
@@ -187,7 +187,7 @@ func WriteEmbed(v *ir.Name) {
 			}
 		}
 		objw.Global(slicedata, int32(off), obj.RODATA|obj.LOCAL)
-		sym := v.Sym().Linksym()
+		sym := v.Linksym()
 		objw.SymPtr(sym, 0, slicedata, 0)
 	}
 }

src/cmd/compile/internal/staticinit/sched.go

@@ -78,15 +78,12 @@ func (s *Schedule) tryStaticInit(nn ir.Node) bool {
 // like staticassign but we are copying an already
 // initialized value r.
 func (s *Schedule) staticcopy(l *ir.Name, loff int64, rn *ir.Name, typ *types.Type) bool {
-	if rn.Class_ == ir.PFUNC {
+	if rn.Class == ir.PFUNC {
 		// TODO if roff != 0 { panic }
 		staticdata.InitFunc(l, loff, rn)
 		return true
 	}
-	if rn.Class_ != ir.PEXTERN || rn.Sym().Pkg != types.LocalPkg {
+	if rn.Class != ir.PEXTERN || rn.Sym().Pkg != types.LocalPkg {
-		return false
-	}
-	if rn.Defn == nil { // probably zeroed but perhaps supplied externally and of unknown value
 		return false
 	}
 	if rn.Defn.Op() != ir.OAS {
@@ -95,8 +92,16 @@ func (s *Schedule) staticcopy(l *ir.Name, loff int64, rn *ir.Name, typ *types.Ty
 	if rn.Type().IsString() { // perhaps overwritten by cmd/link -X (#34675)
 		return false
 	}
+	if rn.Embed != nil {
+		return false
+	}
 	orig := rn
 	r := rn.Defn.(*ir.AssignStmt).Y
+	if r == nil {
+		// No explicit initialization value. Probably zeroed but perhaps
+		// supplied externally and of unknown value.
+		return false
+	}
 
 	for r.Op() == ir.OCONVNOP && !types.Identical(r.Type(), typ) {
 		r = r.(*ir.ConvExpr).X
@@ -104,7 +109,7 @@ func (s *Schedule) staticcopy(l *ir.Name, loff int64, rn *ir.Name, typ *types.Ty
 
 	switch r.Op() {
 	case ir.OMETHEXPR:
-		r = r.(*ir.MethodExpr).FuncName()
+		r = r.(*ir.SelectorExpr).FuncName()
 		fallthrough
 	case ir.ONAME:
 		r := r.(*ir.Name)
@@ -165,7 +170,7 @@ func (s *Schedule) staticcopy(l *ir.Name, loff int64, rn *ir.Name, typ *types.Ty
 			}
 			x := e.Expr
 			if x.Op() == ir.OMETHEXPR {
-				x = x.(*ir.MethodExpr).FuncName()
+				x = x.(*ir.SelectorExpr).FuncName()
 			}
 			if x.Op() == ir.ONAME && s.staticcopy(l, loff+e.Xoffset, x.(*ir.Name), typ) {
 				continue
@@ -185,6 +190,11 @@ func (s *Schedule) staticcopy(l *ir.Name, loff int64, rn *ir.Name, typ *types.Ty
 }
 
 func (s *Schedule) StaticAssign(l *ir.Name, loff int64, r ir.Node, typ *types.Type) bool {
+	if r == nil {
+		// No explicit initialization value. Either zero or supplied
+		// externally.
+		return true
+	}
 	for r.Op() == ir.OCONVNOP {
 		r = r.(*ir.ConvExpr).X
 	}
@@ -195,7 +205,7 @@ func (s *Schedule) StaticAssign(l *ir.Name, loff int64, r ir.Node, typ *types.Ty
 		return s.staticcopy(l, loff, r, typ)
 
 	case ir.OMETHEXPR:
-		r := r.(*ir.MethodExpr)
+		r := r.(*ir.SelectorExpr)
 		return s.staticcopy(l, loff, r.FuncName(), typ)
 
 	case ir.ONIL:
@@ -236,7 +246,7 @@ func (s *Schedule) StaticAssign(l *ir.Name, loff int64, r ir.Node, typ *types.Ty
 
 	case ir.OSTR2BYTES:
 		r := r.(*ir.ConvExpr)
-		if l.Class_ == ir.PEXTERN && r.X.Op() == ir.OLITERAL {
+		if l.Class == ir.PEXTERN && r.X.Op() == ir.OLITERAL {
 			sval := ir.StringVal(r.X)
 			staticdata.InitSliceBytes(l, loff, sval)
 			return true
@@ -313,7 +323,7 @@ func (s *Schedule) StaticAssign(l *ir.Name, loff int64, r ir.Node, typ *types.Ty
 			return val.Op() == ir.ONIL
 		}
 
-		reflectdata.MarkTypeUsedInInterface(val.Type(), l.Sym().Linksym())
+		reflectdata.MarkTypeUsedInInterface(val.Type(), l.Linksym())
 
 		var itab *ir.AddrExpr
 		if typ.IsEmptyInterface() {
@@ -445,7 +455,7 @@ func StaticName(t *types.Type) *ir.Name {
 	statuniqgen++
 	typecheck.Declare(n, ir.PEXTERN)
 	n.SetType(t)
-	n.Sym().Linksym().Set(obj.AttrLocal, true)
+	n.Linksym().Set(obj.AttrLocal, true)
 	return n
 }
 
@@ -461,7 +471,7 @@ func StaticLoc(n ir.Node) (name *ir.Name, offset int64, ok bool) {
 		return n, 0, true
 
 	case ir.OMETHEXPR:
-		n := n.(*ir.MethodExpr)
+		n := n.(*ir.SelectorExpr)
 		return StaticLoc(n.FuncName())
 
 	case ir.ODOT:

src/cmd/compile/internal/syntax/operator_string.go

@@ -1,9 +1,37 @@
-// Code generated by "stringer -type Operator -linecomment"; DO NOT EDIT.
+// Code generated by "stringer -type Operator -linecomment tokens.go"; DO NOT EDIT.
 
 package syntax
 
 import "strconv"
 
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Def-1]
+	_ = x[Not-2]
+	_ = x[Recv-3]
+	_ = x[OrOr-4]
+	_ = x[AndAnd-5]
+	_ = x[Eql-6]
+	_ = x[Neq-7]
+	_ = x[Lss-8]
+	_ = x[Leq-9]
+	_ = x[Gtr-10]
+	_ = x[Geq-11]
+	_ = x[Add-12]
+	_ = x[Sub-13]
+	_ = x[Or-14]
+	_ = x[Xor-15]
+	_ = x[Mul-16]
+	_ = x[Div-17]
+	_ = x[Rem-18]
+	_ = x[And-19]
+	_ = x[AndNot-20]
+	_ = x[Shl-21]
+	_ = x[Shr-22]
+}
+
 const _Operator_name = ":!<-||&&==!=<<=>>=+-|^*/%&&^<<>>"
 
 var _Operator_index = [...]uint8{0, 1, 2, 4, 6, 8, 10, 12, 13, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28, 30, 32}

src/cmd/compile/internal/syntax/token_string.go

@@ -1,9 +1,62 @@
-// Code generated by "stringer -type token -linecomment"; DO NOT EDIT.
+// Code generated by "stringer -type token -linecomment tokens.go"; DO NOT EDIT.
 
 package syntax
 
 import "strconv"
 
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[_EOF-1]
+	_ = x[_Name-2]
+	_ = x[_Literal-3]
+	_ = x[_Operator-4]
+	_ = x[_AssignOp-5]
+	_ = x[_IncOp-6]
+	_ = x[_Assign-7]
+	_ = x[_Define-8]
+	_ = x[_Arrow-9]
+	_ = x[_Star-10]
+	_ = x[_Lparen-11]
+	_ = x[_Lbrack-12]
+	_ = x[_Lbrace-13]
+	_ = x[_Rparen-14]
+	_ = x[_Rbrack-15]
+	_ = x[_Rbrace-16]
+	_ = x[_Comma-17]
+	_ = x[_Semi-18]
+	_ = x[_Colon-19]
+	_ = x[_Dot-20]
+	_ = x[_DotDotDot-21]
+	_ = x[_Break-22]
+	_ = x[_Case-23]
+	_ = x[_Chan-24]
+	_ = x[_Const-25]
+	_ = x[_Continue-26]
+	_ = x[_Default-27]
+	_ = x[_Defer-28]
+	_ = x[_Else-29]
+	_ = x[_Fallthrough-30]
+	_ = x[_For-31]
+	_ = x[_Func-32]
+	_ = x[_Go-33]
+	_ = x[_Goto-34]
+	_ = x[_If-35]
+	_ = x[_Import-36]
+	_ = x[_Interface-37]
+	_ = x[_Map-38]
+	_ = x[_Package-39]
+	_ = x[_Range-40]
+	_ = x[_Return-41]
+	_ = x[_Select-42]
+	_ = x[_Struct-43]
+	_ = x[_Switch-44]
+	_ = x[_Type-45]
+	_ = x[_Var-46]
+	_ = x[tokenCount-47]
+}
+
 const _token_name = "EOFnameliteralopop=opop=:=<-*([{)]},;:....breakcasechanconstcontinuedefaultdeferelsefallthroughforfuncgogotoifimportinterfacemappackagerangereturnselectstructswitchtypevar"
 
 var _token_index = [...]uint8{0, 3, 7, 14, 16, 19, 23, 24, 26, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 42, 47, 51, 55, 60, 68, 75, 80, 84, 95, 98, 102, 104, 108, 110, 116, 125, 128, 135, 140, 146, 152, 158, 164, 168, 171, 171}

src/cmd/compile/internal/syntax/tokens.go

@@ -6,7 +6,7 @@ package syntax
 
 type token uint
 
-//go:generate stringer -type token -linecomment
+//go:generate stringer -type token -linecomment tokens.go
 
 const (
 	_    token = iota
@@ -105,7 +105,7 @@ const (
 
 type Operator uint
 
-//go:generate stringer -type Operator -linecomment
+//go:generate stringer -type Operator -linecomment tokens.go
 
 const (
 	_ Operator = iota

src/cmd/compile/internal/typecheck/const.go

@@ -509,7 +509,7 @@ func EvalConst(n ir.Node) ir.Node {
 				}
 
 				nl := ir.Copy(n).(*ir.AddStringExpr)
-				nl.List.Set(s[i:i2])
+				nl.List = s[i:i2]
 				newList = append(newList, OrigConst(nl, constant.MakeString(strings.Join(strs, ""))))
 				i = i2 - 1
 			} else {
@@ -518,7 +518,7 @@ func EvalConst(n ir.Node) ir.Node {
 		}
 
 		nn := ir.Copy(n).(*ir.AddStringExpr)
-		nn.List.Set(newList)
+		nn.List = newList
 		return nn
 
 	case ir.OCAP, ir.OLEN:
@@ -564,20 +564,11 @@ func EvalConst(n ir.Node) ir.Node {
 	return n
 }
 
-func makeInt(i *big.Int) constant.Value {
-	if i.IsInt64() {
-		return constant.Make(i.Int64()) // workaround #42640 (Int64Val(Make(big.NewInt(10))) returns (10, false), not (10, true))
-	}
-	return constant.Make(i)
-}
-
 func makeFloat64(f float64) constant.Value {
 	if math.IsInf(f, 0) {
 		base.Fatalf("infinity is not a valid constant")
 	}
-	v := constant.MakeFloat64(f)
+	return constant.MakeFloat64(f)
-	v = constant.ToFloat(v) // workaround #42641 (MakeFloat64(0).Kind() returns Int, not Float)
-	return v
 }
 
 func makeComplex(real, imag constant.Value) constant.Value {

src/cmd/compile/internal/typecheck/dcl.go

@@ -15,64 +15,7 @@ import (
 	"cmd/internal/src"
 )
 
-var DeclContext ir.Class // PEXTERN/PAUTO
+var DeclContext ir.Class = ir.PEXTERN // PEXTERN/PAUTO
-
-func AssignDefn(left []ir.Node, defn ir.Node) {
-	for _, n := range left {
-		if n.Sym() != nil {
-			n.Sym().SetUniq(true)
-		}
-	}
-
-	var nnew, nerr int
-	for i, n := range left {
-		if ir.IsBlank(n) {
-			continue
-		}
-		if !assignableName(n) {
-			base.ErrorfAt(defn.Pos(), "non-name %v on left side of :=", n)
-			nerr++
-			continue
-		}
-
-		if !n.Sym().Uniq() {
-			base.ErrorfAt(defn.Pos(), "%v repeated on left side of :=", n.Sym())
-			n.SetDiag(true)
-			nerr++
-			continue
-		}
-
-		n.Sym().SetUniq(false)
-		if n.Sym().Block == types.Block {
-			continue
-		}
-
-		nnew++
-		n := NewName(n.Sym())
-		Declare(n, DeclContext)
-		n.Defn = defn
-		defn.PtrInit().Append(ir.NewDecl(base.Pos, ir.ODCL, n))
-		left[i] = n
-	}
-
-	if nnew == 0 && nerr == 0 {
-		base.ErrorfAt(defn.Pos(), "no new variables on left side of :=")
-	}
-}
-
-// := declarations
-func assignableName(n ir.Node) bool {
-	switch n.Op() {
-	case ir.ONAME,
-		ir.ONONAME,
-		ir.OPACK,
-		ir.OTYPE,
-		ir.OLITERAL:
-		return n.Sym() != nil
-	}
-
-	return false
-}
 
 func DeclFunc(sym *types.Sym, tfn ir.Ntype) *ir.Func {
 	if tfn.Op() != ir.OTFUNC {
@@ -80,7 +23,8 @@ func DeclFunc(sym *types.Sym, tfn ir.Ntype) *ir.Func {
 	}
 
 	fn := ir.NewFunc(base.Pos)
-	fn.Nname = ir.NewFuncNameAt(base.Pos, sym, fn)
+	fn.Nname = ir.NewNameAt(base.Pos, sym)
+	fn.Nname.Func = fn
 	fn.Nname.Defn = fn
 	fn.Nname.Ntype = tfn
 	ir.MarkFunc(fn.Nname)
@@ -89,60 +33,6 @@ func DeclFunc(sym *types.Sym, tfn ir.Ntype) *ir.Func {
 	return fn
 }
 
-// declare variables from grammar
-// new_name_list (type | [type] = expr_list)
-func DeclVars(vl []*ir.Name, t ir.Ntype, el []ir.Node) []ir.Node {
-	var init []ir.Node
-	doexpr := len(el) > 0
-
-	if len(el) == 1 && len(vl) > 1 {
-		e := el[0]
-		as2 := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil)
-		as2.Rhs = []ir.Node{e}
-		for _, v := range vl {
-			as2.Lhs.Append(v)
-			Declare(v, DeclContext)
-			v.Ntype = t
-			v.Defn = as2
-			if ir.CurFunc != nil {
-				init = append(init, ir.NewDecl(base.Pos, ir.ODCL, v))
-			}
-		}
-
-		return append(init, as2)
-	}
-
-	for i, v := range vl {
-		var e ir.Node
-		if doexpr {
-			if i >= len(el) {
-				base.Errorf("assignment mismatch: %d variables but %d values", len(vl), len(el))
-				break
-			}
-			e = el[i]
-		}
-
-		Declare(v, DeclContext)
-		v.Ntype = t
-
-		if e != nil || ir.CurFunc != nil || ir.IsBlank(v) {
-			if ir.CurFunc != nil {
-				init = append(init, ir.NewDecl(base.Pos, ir.ODCL, v))
-			}
-			as := ir.NewAssignStmt(base.Pos, v, e)
-			init = append(init, as)
-			if e != nil {
-				v.Defn = as
-			}
-		}
-	}
-
-	if len(el) > len(vl) {
-		base.Errorf("assignment mismatch: %d variables but %d values", len(vl), len(el))
-	}
-	return init
-}
-
 // Declare records that Node n declares symbol n.Sym in the specified
 // declaration context.
 func Declare(n *ir.Name, ctxt ir.Class) {
@@ -201,7 +91,7 @@ func Declare(n *ir.Name, ctxt ir.Class) {
 	s.Lastlineno = base.Pos
 	s.Def = n
 	n.Vargen = int32(gen)
-	n.Class_ = ctxt
+	n.Class = ctxt
 	if ctxt == ir.PFUNC {
 		n.Sym().SetFunc(true)
 	}
@@ -565,7 +455,7 @@ func TempAt(pos src.XPos, curfn *ir.Func, t *types.Type) *ir.Name {
 	n := ir.NewNameAt(pos, s)
 	s.Def = n
 	n.SetType(t)
-	n.Class_ = ir.PAUTO
+	n.Class = ir.PAUTO
 	n.SetEsc(ir.EscNever)
 	n.Curfn = curfn
 	n.SetUsed(true)
@@ -596,6 +486,9 @@ func NewMethodType(sig *types.Type, recv *types.Type) *types.Type {
 		nrecvs++
 	}
 
+	// TODO(mdempsky): Move this function to types.
+	// TODO(mdempsky): Preserve positions, names, and package from sig+recv.
+
 	params := make([]*types.Field, nrecvs+sig.Params().Fields().Len())
 	if recv != nil {
 		params[0] = types.NewField(base.Pos, nil, recv)

src/cmd/compile/internal/typecheck/export.go

@@ -31,12 +31,8 @@ func importconst(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type, val
 // ipkg is the package being imported
 func importfunc(ipkg *types.Pkg, pos src.XPos, s *types.Sym, t *types.Type) *ir.Name {
 	n := importobj(ipkg, pos, s, ir.ONAME, ir.PFUNC, t)
-
+	n.Func = ir.NewFunc(pos)
-	fn := ir.NewFunc(pos)
+	n.Func.Nname = n
-	fn.SetType(t)
-	n.SetFunc(fn)
-	fn.Nname = n
-
 	return n
 }
 
@@ -57,9 +53,8 @@ func importsym(ipkg *types.Pkg, pos src.XPos, s *types.Sym, op ir.Op, ctxt ir.Cl
 	}
 
 	n := ir.NewDeclNameAt(pos, op, s)
-	n.Class_ = ctxt // TODO(mdempsky): Move this into NewDeclNameAt too?
+	n.Class = ctxt // TODO(mdempsky): Move this into NewDeclNameAt too?
 	s.SetPkgDef(n)
-	s.Importdef = ipkg
 	return n
 }
 

src/cmd/compile/internal/typecheck/expr.go

@@ -35,14 +35,6 @@ func tcAddr(n *ir.AddrExpr) ir.Node {
 			if ir.Orig(r) != r {
 				base.Fatalf("found non-orig name node %v", r) // TODO(mdempsky): What does this mean?
 			}
-			r.Name().SetAddrtaken(true)
-			if r.Name().IsClosureVar() && !CaptureVarsComplete {
-				// Mark the original variable as Addrtaken so that capturevars
-				// knows not to pass it by value.
-				// But if the capturevars phase is complete, don't touch it,
-				// in case l.Name's containing function has not yet been compiled.
-				r.Name().Defn.Name().SetAddrtaken(true)
-			}
 		}
 		n.X = DefaultLit(n.X, nil)
 		if n.X.Type() == nil {
@@ -55,103 +47,50 @@ func tcAddr(n *ir.AddrExpr) ir.Node {
 	return n
 }
 
-// tcArith typechecks a binary arithmetic expression.
+func tcShift(n, l, r ir.Node) (ir.Node, ir.Node, *types.Type) {
-func tcArith(n ir.Node) ir.Node {
+	if l.Type() == nil || l.Type() == nil {
-	var l, r ir.Node
+		return l, r, nil
-	var setLR func()
-	switch n := n.(type) {
-	case *ir.AssignOpStmt:
-		l, r = n.X, n.Y
-		setLR = func() { n.X = l; n.Y = r }
-	case *ir.BinaryExpr:
-		l, r = n.X, n.Y
-		setLR = func() { n.X = l; n.Y = r }
-	case *ir.LogicalExpr:
-		l, r = n.X, n.Y
-		setLR = func() { n.X = l; n.Y = r }
-	}
-	l = Expr(l)
-	r = Expr(r)
-	setLR()
-	if l.Type() == nil || r.Type() == nil {
-		n.SetType(nil)
-		return n
-	}
-	op := n.Op()
-	if n.Op() == ir.OASOP {
-		n := n.(*ir.AssignOpStmt)
-		checkassign(n, l)
-		if n.IncDec && !okforarith[l.Type().Kind()] {
-			base.Errorf("invalid operation: %v (non-numeric type %v)", n, l.Type())
-			n.SetType(nil)
-			return n
-		}
-		// TODO(marvin): Fix Node.EType type union.
-		op = n.AsOp
-	}
-	if op == ir.OLSH || op == ir.ORSH {
-		r = DefaultLit(r, types.Types[types.TUINT])
-		setLR()
-		t := r.Type()
-		if !t.IsInteger() {
-			base.Errorf("invalid operation: %v (shift count type %v, must be integer)", n, r.Type())
-			n.SetType(nil)
-			return n
-		}
-		if t.IsSigned() && !types.AllowsGoVersion(curpkg(), 1, 13) {
-			base.ErrorfVers("go1.13", "invalid operation: %v (signed shift count type %v)", n, r.Type())
-			n.SetType(nil)
-			return n
-		}
-		t = l.Type()
-		if t != nil && t.Kind() != types.TIDEAL && !t.IsInteger() {
-			base.Errorf("invalid operation: %v (shift of type %v)", n, t)
-			n.SetType(nil)
-			return n
-		}
-
-		// no defaultlit for left
-		// the outer context gives the type
-		n.SetType(l.Type())
-		if (l.Type() == types.UntypedFloat || l.Type() == types.UntypedComplex) && r.Op() == ir.OLITERAL {
-			n.SetType(types.UntypedInt)
-		}
-		return n
 	}
 
-	// For "x == x && len(s)", it's better to report that "len(s)" (type int)
+	r = DefaultLit(r, types.Types[types.TUINT])
-	// can't be used with "&&" than to report that "x == x" (type untyped bool)
+	t := r.Type()
-	// can't be converted to int (see issue #41500).
+	if !t.IsInteger() {
-	if n.Op() == ir.OANDAND || n.Op() == ir.OOROR {
+		base.Errorf("invalid operation: %v (shift count type %v, must be integer)", n, r.Type())
-		n := n.(*ir.LogicalExpr)
+		return l, r, nil
-		if !n.X.Type().IsBoolean() {
+	}
-			base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, n.Op(), typekind(n.X.Type()))
+	if t.IsSigned() && !types.AllowsGoVersion(curpkg(), 1, 13) {
-			n.SetType(nil)
+		base.ErrorfVers("go1.13", "invalid operation: %v (signed shift count type %v)", n, r.Type())
-			return n
+		return l, r, nil
-		}
+	}
-		if !n.Y.Type().IsBoolean() {
+	t = l.Type()
-			base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, n.Op(), typekind(n.Y.Type()))
+	if t != nil && t.Kind() != types.TIDEAL && !t.IsInteger() {
-			n.SetType(nil)
+		base.Errorf("invalid operation: %v (shift of type %v)", n, t)
-			return n
+		return l, r, nil
-		}
 	}
 
-	// ideal mixed with non-ideal
+	// no defaultlit for left
+	// the outer context gives the type
+	t = l.Type()
+	if (l.Type() == types.UntypedFloat || l.Type() == types.UntypedComplex) && r.Op() == ir.OLITERAL {
+		t = types.UntypedInt
+	}
+	return l, r, t
+}
+
+// tcArith typechecks operands of a binary arithmetic expression.
+// The result of tcArith MUST be assigned back to original operands,
+// t is the type of the expression, and should be set by the caller. e.g:
+//     n.X, n.Y, t = tcArith(n, op, n.X, n.Y)
+//     n.SetType(t)
+func tcArith(n ir.Node, op ir.Op, l, r ir.Node) (ir.Node, ir.Node, *types.Type) {
 	l, r = defaultlit2(l, r, false)
-	setLR()
-
 	if l.Type() == nil || r.Type() == nil {
-		n.SetType(nil)
+		return l, r, nil
-		return n
 	}
 	t := l.Type()
 	if t.Kind() == types.TIDEAL {
 		t = r.Type()
 	}
-	et := t.Kind()
-	if et == types.TIDEAL {
-		et = types.TINT
-	}
 	aop := ir.OXXX
 	if iscmp[n.Op()] && t.Kind() != types.TIDEAL && !types.Identical(l.Type(), r.Type()) {
 		// comparison is okay as long as one side is
@@ -167,15 +106,13 @@ func tcArith(n ir.Node) ir.Node {
 			if aop != ir.OXXX {
 				if r.Type().IsInterface() && !l.Type().IsInterface() && !types.IsComparable(l.Type()) {
 					base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, op, typekind(l.Type()))
-					n.SetType(nil)
+					return l, r, nil
-					return n
 				}
 
 				types.CalcSize(l.Type())
 				if r.Type().IsInterface() == l.Type().IsInterface() || l.Type().Width >= 1<<16 {
 					l = ir.NewConvExpr(base.Pos, aop, r.Type(), l)
 					l.SetTypecheck(1)
-					setLR()
 				}
 
 				t = r.Type()
@@ -188,34 +125,28 @@ func tcArith(n ir.Node) ir.Node {
 			if aop != ir.OXXX {
 				if l.Type().IsInterface() && !r.Type().IsInterface() && !types.IsComparable(r.Type()) {
 					base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, op, typekind(r.Type()))
-					n.SetType(nil)
+					return l, r, nil
-					return n
 				}
 
 				types.CalcSize(r.Type())
 				if r.Type().IsInterface() == l.Type().IsInterface() || r.Type().Width >= 1<<16 {
 					r = ir.NewConvExpr(base.Pos, aop, l.Type(), r)
 					r.SetTypecheck(1)
-					setLR()
 				}
 
 				t = l.Type()
 			}
 		}
-
-		et = t.Kind()
 	}
 
 	if t.Kind() != types.TIDEAL && !types.Identical(l.Type(), r.Type()) {
 		l, r = defaultlit2(l, r, true)
 		if l.Type() == nil || r.Type() == nil {
-			n.SetType(nil)
+			return l, r, nil
-			return n
 		}
 		if l.Type().IsInterface() == r.Type().IsInterface() || aop == 0 {
 			base.Errorf("invalid operation: %v (mismatched types %v and %v)", n, l.Type(), r.Type())
-			n.SetType(nil)
+			return l, r, nil
-			return n
 		}
 	}
 
@@ -224,85 +155,46 @@ func tcArith(n ir.Node) ir.Node {
 	}
 	if dt := defaultType(t); !okfor[op][dt.Kind()] {
 		base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, op, typekind(t))
-		n.SetType(nil)
+		return l, r, nil
-		return n
 	}
 
 	// okfor allows any array == array, map == map, func == func.
 	// restrict to slice/map/func == nil and nil == slice/map/func.
 	if l.Type().IsArray() && !types.IsComparable(l.Type()) {
 		base.Errorf("invalid operation: %v (%v cannot be compared)", n, l.Type())
-		n.SetType(nil)
+		return l, r, nil
-		return n
 	}
 
 	if l.Type().IsSlice() && !ir.IsNil(l) && !ir.IsNil(r) {
 		base.Errorf("invalid operation: %v (slice can only be compared to nil)", n)
-		n.SetType(nil)
+		return l, r, nil
-		return n
 	}
 
 	if l.Type().IsMap() && !ir.IsNil(l) && !ir.IsNil(r) {
 		base.Errorf("invalid operation: %v (map can only be compared to nil)", n)
-		n.SetType(nil)
+		return l, r, nil
-		return n
 	}
 
 	if l.Type().Kind() == types.TFUNC && !ir.IsNil(l) && !ir.IsNil(r) {
 		base.Errorf("invalid operation: %v (func can only be compared to nil)", n)
-		n.SetType(nil)
+		return l, r, nil
-		return n
 	}
 
 	if l.Type().IsStruct() {
 		if f := types.IncomparableField(l.Type()); f != nil {
 			base.Errorf("invalid operation: %v (struct containing %v cannot be compared)", n, f.Type)
-			n.SetType(nil)
+			return l, r, nil
-			return n
 		}
 	}
 
-	if iscmp[n.Op()] {
-		t = types.UntypedBool
-		n.SetType(t)
-		if con := EvalConst(n); con.Op() == ir.OLITERAL {
-			return con
-		}
-		l, r = defaultlit2(l, r, true)
-		setLR()
-		return n
-	}
-
-	if et == types.TSTRING && n.Op() == ir.OADD {
-		// create or update OADDSTR node with list of strings in x + y + z + (w + v) + ...
-		n := n.(*ir.BinaryExpr)
-		var add *ir.AddStringExpr
-		if l.Op() == ir.OADDSTR {
-			add = l.(*ir.AddStringExpr)
-			add.SetPos(n.Pos())
-		} else {
-			add = ir.NewAddStringExpr(n.Pos(), []ir.Node{l})
-		}
-		if r.Op() == ir.OADDSTR {
-			r := r.(*ir.AddStringExpr)
-			add.List.Append(r.List.Take()...)
-		} else {
-			add.List.Append(r)
-		}
-		add.SetType(t)
-		return add
-	}
-
 	if (op == ir.ODIV || op == ir.OMOD) && ir.IsConst(r, constant.Int) {
 		if constant.Sign(r.Val()) == 0 {
 			base.Errorf("division by zero")
-			n.SetType(nil)
+			return l, r, nil
-			return n
 		}
 	}
 
-	n.SetType(t)
+	return l, r, t
-	return n
 }
 
 // The result of tcCompLit MUST be assigned back to n, e.g.
@@ -330,7 +222,7 @@ func tcCompLit(n *ir.CompLitExpr) (res ir.Node) {
 
 	// Need to handle [...]T arrays specially.
 	if array, ok := n.Ntype.(*ir.ArrayType); ok && array.Elem != nil && array.Len == nil {
-		array.Elem = typecheck(array.Elem, ctxType)
+		array.Elem = typecheckNtype(array.Elem)
 		elemType := array.Elem.Type()
 		if elemType == nil {
 			n.SetType(nil)
@@ -343,7 +235,7 @@ func tcCompLit(n *ir.CompLitExpr) (res ir.Node) {
 		return n
 	}
 
-	n.Ntype = ir.Node(typecheck(n.Ntype, ctxType)).(ir.Ntype)
+	n.Ntype = typecheckNtype(n.Ntype)
 	t := n.Ntype.Type()
 	if t == nil {
 		n.SetType(nil)
@@ -626,10 +518,8 @@ func tcDot(n *ir.SelectorExpr, top int) ir.Node {
 	}
 
 	if (n.Op() == ir.ODOTINTER || n.Op() == ir.ODOTMETH) && top&ctxCallee == 0 {
-		// Create top-level function.
+		n.SetOp(ir.OCALLPART)
-		fn := makepartialcall(n)
+		n.SetType(MethodValueWrapper(n).Type())
-
-		return ir.NewCallPartExpr(n.Pos(), n.X, n.Selection, fn)
 	}
 	return n
 }
@@ -651,7 +541,7 @@ func tcDotType(n *ir.TypeAssertExpr) ir.Node {
 	}
 
 	if n.Ntype != nil {
-		n.Ntype = typecheck(n.Ntype, ctxType)
+		n.Ntype = typecheckNtype(n.Ntype)
 		n.SetType(n.Ntype.Type())
 		n.Ntype = nil
 		if n.Type() == nil {

src/cmd/compile/internal/typecheck/func.go

@@ -21,7 +21,7 @@ func MakeDotArgs(typ *types.Type, args []ir.Node) ir.Node {
 		n = NodNil()
 		n.SetType(typ)
 	} else {
-		lit := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ).(ir.Ntype), nil)
+		lit := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ), nil)
 		lit.List.Append(args...)
 		lit.SetImplicit(true)
 		n = lit
@@ -52,7 +52,7 @@ func FixVariadicCall(call *ir.CallExpr) {
 		extra[i] = nil // allow GC
 	}
 
-	call.Args.Set(append(args[:vi], slice))
+	call.Args = append(args[:vi], slice)
 	call.IsDDD = true
 }
 
@@ -91,7 +91,7 @@ func ClosureType(clo *ir.ClosureExpr) *types.Type {
 // PartialCallType returns the struct type used to hold all the information
 // needed in the closure for n (n must be a OCALLPART node).
 // The address of a variable of the returned type can be cast to a func.
-func PartialCallType(n *ir.CallPartExpr) *types.Type {
+func PartialCallType(n *ir.SelectorExpr) *types.Type {
 	t := types.NewStruct(types.NoPkg, []*types.Field{
 		types.NewField(base.Pos, Lookup("F"), types.Types[types.TUINTPTR]),
 		types.NewField(base.Pos, Lookup("R"), n.X.Type()),
@@ -106,56 +106,24 @@ func PartialCallType(n *ir.CallPartExpr) *types.Type {
 // We use value capturing for values <= 128 bytes that are never reassigned
 // after capturing (effectively constant).
 func CaptureVars(fn *ir.Func) {
-	lno := base.Pos
+	for _, v := range fn.ClosureVars {
-	base.Pos = fn.Pos()
-	cvars := fn.ClosureVars
-	out := cvars[:0]
-	for _, v := range cvars {
-		if v.Type() == nil {
-			// If v.Type is nil, it means v looked like it
-			// was going to be used in the closure, but
-			// isn't. This happens in struct literals like
-			// s{f: x} where we can't distinguish whether
-			// f is a field identifier or expression until
-			// resolving s.
-			continue
-		}
-		out = append(out, v)
-
-		// type check the & of closed variables outside the closure,
-		// so that the outer frame also grabs them and knows they escape.
-		types.CalcSize(v.Type())
-
-		var outer ir.Node
-		outer = v.Outer
 		outermost := v.Defn.(*ir.Name)
 
 		// out parameters will be assigned to implicitly upon return.
-		if outermost.Class_ != ir.PPARAMOUT && !outermost.Name().Addrtaken() && !outermost.Name().Assigned() && v.Type().Width <= 128 {
+		if outermost.Class != ir.PPARAMOUT && !outermost.Addrtaken() && !outermost.Assigned() && outermost.Type().Size() <= 128 {
-			v.SetByval(true)
+			outermost.SetByval(true)
 		} else {
-			outermost.Name().SetAddrtaken(true)
+			outermost.SetAddrtaken(true)
-			outer = NodAddr(outer)
 		}
 
 		if base.Flag.LowerM > 1 {
-			var name *types.Sym
-			if v.Curfn != nil && v.Curfn.Nname != nil {
-				name = v.Curfn.Sym()
-			}
 			how := "ref"
 			if v.Byval() {
 				how = "value"
 			}
-			base.WarnfAt(v.Pos(), "%v capturing by %s: %v (addr=%v assign=%v width=%d)", name, how, v.Sym(), outermost.Name().Addrtaken(), outermost.Name().Assigned(), int32(v.Type().Width))
+			base.WarnfAt(v.Pos(), "%v capturing by %s: %v (addr=%v assign=%v width=%d)", v.Curfn, how, v, outermost.Addrtaken(), outermost.Assigned(), v.Type().Size())
 		}
-
-		outer = Expr(outer)
-		fn.ClosureEnter.Append(outer)
 	}
-
-	fn.ClosureVars = out
-	base.Pos = lno
 }
 
 // Lazy typechecking of imported bodies. For local functions, caninl will set ->typecheck
@@ -163,6 +131,21 @@ func CaptureVars(fn *ir.Func) {
 func ImportedBody(fn *ir.Func) {
 	lno := ir.SetPos(fn.Nname)
 
+	// When we load an inlined body, we need to allow OADDR
+	// operations on untyped expressions. We will fix the
+	// addrtaken flags on all the arguments of the OADDR with the
+	// computeAddrtaken call below (after we typecheck the body).
+	// TODO: export/import types and addrtaken marks along with inlined bodies,
+	// so this will be unnecessary.
+	IncrementalAddrtaken = false
+	defer func() {
+		if DirtyAddrtaken {
+			ComputeAddrtaken(fn.Inl.Body) // compute addrtaken marks once types are available
+			DirtyAddrtaken = false
+		}
+		IncrementalAddrtaken = true
+	}()
+
 	ImportBody(fn)
 
 	// typecheckinl is only for imported functions;
@@ -247,9 +230,17 @@ func closurename(outerfunc *ir.Func) *types.Sym {
 // globClosgen is like Func.Closgen, but for the global scope.
 var globClosgen int32
 
-// makepartialcall returns a DCLFUNC node representing the wrapper function (*-fm) needed
+// MethodValueWrapper returns the DCLFUNC node representing the
-// for partial calls.
+// wrapper function (*-fm) needed for the given method value. If the
-func makepartialcall(dot *ir.SelectorExpr) *ir.Func {
+// wrapper function hasn't already been created yet, it's created and
+// added to Target.Decls.
+//
+// TODO(mdempsky): Move into walk. This isn't part of type checking.
+func MethodValueWrapper(dot *ir.SelectorExpr) *ir.Func {
+	if dot.Op() != ir.OCALLPART {
+		base.Fatalf("MethodValueWrapper: unexpected %v (%v)", dot, dot.Op())
+	}
+
 	t0 := dot.Type()
 	meth := dot.Sel
 	rcvrtype := dot.X.Type()
@@ -296,7 +287,7 @@ func makepartialcall(dot *ir.SelectorExpr) *ir.Func {
 	}
 
 	call := ir.NewCallExpr(base.Pos, ir.OCALL, ir.NewSelectorExpr(base.Pos, ir.OXDOT, ptr, meth), nil)
-	call.Args.Set(ir.ParamNames(tfn.Type()))
+	call.Args = ir.ParamNames(tfn.Type())
 	call.IsDDD = tfn.Type().IsVariadic()
 	if t0.NumResults() != 0 {
 		ret := ir.NewReturnStmt(base.Pos, nil)
@@ -306,7 +297,7 @@ func makepartialcall(dot *ir.SelectorExpr) *ir.Func {
 		body = append(body, call)
 	}
 
-	fn.Body.Set(body)
+	fn.Body = body
 	FinishFuncBody()
 
 	Func(fn)
@@ -334,7 +325,7 @@ func tcClosure(clo *ir.ClosureExpr, top int) {
 		fn.Iota = x
 	}
 
-	fn.ClosureType = typecheck(fn.ClosureType, ctxType)
+	fn.ClosureType = typecheckNtype(fn.ClosureType)
 	clo.SetType(fn.ClosureType.Type())
 	fn.SetClosureCalled(top&ctxCallee != 0)
 
@@ -379,6 +370,25 @@ func tcClosure(clo *ir.ClosureExpr, top int) {
 		ir.CurFunc = oldfn
 	}
 
+	out := 0
+	for _, v := range fn.ClosureVars {
+		if v.Type() == nil {
+			// If v.Type is nil, it means v looked like it was going to be
+			// used in the closure, but isn't. This happens in struct
+			// literals like s{f: x} where we can't distinguish whether f is
+			// a field identifier or expression until resolving s.
+			continue
+		}
+
+		// type check closed variables outside the closure, so that the
+		// outer frame also captures them.
+		Expr(v.Outer)
+
+		fn.ClosureVars[out] = v
+		out++
+	}
+	fn.ClosureVars = fn.ClosureVars[:out]
+
 	Target.Decls = append(Target.Decls, fn)
 }
 
@@ -391,7 +401,7 @@ func tcFunc(n *ir.Func) {
 	}
 
 	for _, ln := range n.Dcl {
-		if ln.Op() == ir.ONAME && (ln.Class_ == ir.PPARAM || ln.Class_ == ir.PPARAMOUT) {
+		if ln.Op() == ir.ONAME && (ln.Class == ir.PPARAM || ln.Class == ir.PPARAMOUT) {
 			ln.Decldepth = 1
 		}
 	}
@@ -401,7 +411,6 @@ func tcFunc(n *ir.Func) {
 	if t == nil {
 		return
 	}
-	n.SetType(t)
 	rcvr := t.Recv()
 	if rcvr != nil && n.Shortname != nil {
 		m := addmethod(n, n.Shortname, t, true, n.Pragma&ir.Nointerface != 0)
@@ -782,7 +791,7 @@ func tcMake(n *ir.CallExpr) ir.Node {
 		return n
 	}
 
-	n.Args.Set(nil)
+	n.Args = nil
 	l := args[0]
 	l = typecheck(l, ctxType)
 	t := l.Type()

src/cmd/compile/internal/typecheck/iexport.go

@@ -430,7 +430,7 @@ func (p *iexporter) doDecl(n *ir.Name) {
 
 	switch n.Op() {
 	case ir.ONAME:
-		switch n.Class_ {
+		switch n.Class {
 		case ir.PEXTERN:
 			// Variable.
 			w.tag('V')
@@ -450,7 +450,7 @@ func (p *iexporter) doDecl(n *ir.Name) {
 			w.funcExt(n)
 
 		default:
-			base.Fatalf("unexpected class: %v, %v", n, n.Class_)
+			base.Fatalf("unexpected class: %v, %v", n, n.Class)
 		}
 
 	case ir.OLITERAL:
@@ -574,6 +574,11 @@ func (w *exportWriter) pos(pos src.XPos) {
 }
 
 func (w *exportWriter) pkg(pkg *types.Pkg) {
+	// TODO(mdempsky): Add flag to types.Pkg to mark pseudo-packages.
+	if pkg == ir.Pkgs.Go {
+		base.Fatalf("export of pseudo-package: %q", pkg.Path)
+	}
+
 	// Ensure any referenced packages are declared in the main index.
 	w.p.allPkgs[pkg] = true
 
@@ -936,7 +941,7 @@ func (w *exportWriter) mpfloat(v constant.Value, typ *types.Type) {
 	if acc != big.Exact {
 		base.Fatalf("mantissa scaling failed for %f (%s)", f, acc)
 	}
-	w.mpint(makeInt(manti), typ)
+	w.mpint(constant.Make(manti), typ)
 	if manti.Sign() != 0 {
 		w.int64(exp)
 	}
@@ -1067,7 +1072,7 @@ func (w *exportWriter) stmt(n ir.Node) {
 		n := n.(*ir.Decl)
 		w.op(ir.ODCL)
 		w.pos(n.X.Pos())
-		w.localName(n.X.(*ir.Name))
+		w.localName(n.X)
 		w.typ(n.X.Type())
 
 	case ir.OAS:
@@ -1187,7 +1192,7 @@ func (w *exportWriter) caseList(cases []*ir.CaseClause, namedTypeSwitch bool) {
 		w.pos(cas.Pos())
 		w.stmtList(cas.List)
 		if namedTypeSwitch {
-			w.localName(cas.Var.(*ir.Name))
+			w.localName(cas.Var)
 		}
 		w.stmtList(cas.Body)
 	}
@@ -1252,21 +1257,10 @@ func (w *exportWriter) expr(n ir.Node) {
 		w.pos(n.Pos())
 		w.value(n.Type(), n.Val())
 
-	case ir.OMETHEXPR:
-		// Special case: explicit name of func (*T) method(...) is turned into pkg.(*T).method,
-		// but for export, this should be rendered as (*pkg.T).meth.
-		// These nodes have the special property that they are names with a left OTYPE and a right ONAME.
-		n := n.(*ir.MethodExpr)
-		w.op(ir.OXDOT)
-		w.pos(n.Pos())
-		w.op(ir.OTYPE)
-		w.typ(n.T) // n.Left.Op == OTYPE
-		w.selector(n.Method.Sym)
-
 	case ir.ONAME:
 		// Package scope name.
 		n := n.(*ir.Name)
-		if (n.Class_ == ir.PEXTERN || n.Class_ == ir.PFUNC) && !ir.IsBlank(n) {
+		if (n.Class == ir.PEXTERN || n.Class == ir.PFUNC) && !ir.IsBlank(n) {
 			w.op(ir.ONONAME)
 			w.qualifiedIdent(n)
 			break
@@ -1336,15 +1330,7 @@ func (w *exportWriter) expr(n ir.Node) {
 	// case OSTRUCTKEY:
 	//	unreachable - handled in case OSTRUCTLIT by elemList
 
-	case ir.OCALLPART:
+	case ir.OXDOT, ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH, ir.OCALLPART, ir.OMETHEXPR:
-		// An OCALLPART is an OXDOT before type checking.
-		n := n.(*ir.CallPartExpr)
-		w.op(ir.OXDOT)
-		w.pos(n.Pos())
-		w.expr(n.X)
-		w.selector(n.Method.Sym)
-
-	case ir.OXDOT, ir.ODOT, ir.ODOTPTR, ir.ODOTINTER, ir.ODOTMETH:
 		n := n.(*ir.SelectorExpr)
 		w.op(ir.OXDOT)
 		w.pos(n.Pos())
@@ -1540,14 +1526,18 @@ func (w *exportWriter) localName(n *ir.Name) {
 	// PPARAM/PPARAMOUT, because we only want to include vargen in
 	// non-param names.
 	var v int32
-	if n.Class_ == ir.PAUTO || (n.Class_ == ir.PAUTOHEAP && n.Name().Stackcopy == nil) {
+	if n.Class == ir.PAUTO || (n.Class == ir.PAUTOHEAP && n.Stackcopy == nil) {
-		v = n.Name().Vargen
+		v = n.Vargen
 	}
 
 	w.localIdent(n.Sym(), v)
 }
 
 func (w *exportWriter) localIdent(s *types.Sym, v int32) {
+	if w.currPkg == nil {
+		base.Fatalf("missing currPkg")
+	}
+
 	// Anonymous parameters.
 	if s == nil {
 		w.string("")
@@ -1572,8 +1562,8 @@ func (w *exportWriter) localIdent(s *types.Sym, v int32) {
 		name = fmt.Sprintf("%s·%d", name, v)
 	}
 
-	if !types.IsExported(name) && s.Pkg != w.currPkg {
+	if s.Pkg != w.currPkg {
-		base.Fatalf("weird package in name: %v => %v, not %q", s, name, w.currPkg.Path)
+		base.Fatalf("weird package in name: %v => %v from %q, not %q", s, name, s.Pkg.Path, w.currPkg.Path)
 	}
 
 	w.string(name)

src/cmd/compile/internal/typecheck/iimport.go

@@ -327,16 +327,17 @@ func (r *importReader) doDecl(sym *types.Sym) *ir.Name {
 		ms := make([]*types.Field, r.uint64())
 		for i := range ms {
 			mpos := r.pos()
-			msym := r.ident()
+			msym := r.selector()
 			recv := r.param()
 			mtyp := r.signature(recv)
 
-			fn := ir.NewFunc(mpos)
-			fn.SetType(mtyp)
-			m := ir.NewFuncNameAt(mpos, ir.MethodSym(recv.Type, msym), fn)
-			m.SetType(mtyp)
-			m.Class_ = ir.PFUNC
 			// methodSym already marked m.Sym as a function.
+			m := ir.NewNameAt(mpos, ir.MethodSym(recv.Type, msym))
+			m.Class = ir.PFUNC
+			m.SetType(mtyp)
+
+			m.Func = ir.NewFunc(mpos)
+			m.Func.Nname = m
 
 			f := types.NewField(mpos, msym, mtyp)
 			f.Nname = m
@@ -372,7 +373,7 @@ func (p *importReader) value(typ *types.Type) constant.Value {
 	case constant.Int:
 		var i big.Int
 		p.mpint(&i, typ)
-		return makeInt(&i)
+		return constant.Make(&i)
 	case constant.Float:
 		return p.float(typ)
 	case constant.Complex:
@@ -433,18 +434,21 @@ func (p *importReader) float(typ *types.Type) constant.Value {
 	return constant.Make(&f)
 }
 
-func (r *importReader) ident() *types.Sym {
+func (r *importReader) ident(selector bool) *types.Sym {
 	name := r.string()
 	if name == "" {
 		return nil
 	}
 	pkg := r.currPkg
-	if types.IsExported(name) {
+	if selector && types.IsExported(name) {
 		pkg = types.LocalPkg
 	}
 	return pkg.Lookup(name)
 }
 
+func (r *importReader) localIdent() *types.Sym { return r.ident(false) }
+func (r *importReader) selector() *types.Sym   { return r.ident(true) }
+
 func (r *importReader) qualifiedIdent() *ir.Ident {
 	name := r.string()
 	pkg := r.pkg()
@@ -533,7 +537,7 @@ func (r *importReader) typ1() *types.Type {
 		fs := make([]*types.Field, r.uint64())
 		for i := range fs {
 			pos := r.pos()
-			sym := r.ident()
+			sym := r.selector()
 			typ := r.typ()
 			emb := r.bool()
 			note := r.string()
@@ -562,7 +566,7 @@ func (r *importReader) typ1() *types.Type {
 		methods := make([]*types.Field, r.uint64())
 		for i := range methods {
 			pos := r.pos()
-			sym := r.ident()
+			sym := r.selector()
 			typ := r.signature(fakeRecvField())
 
 			methods[i] = types.NewField(pos, sym, typ)
@@ -598,7 +602,7 @@ func (r *importReader) paramList() []*types.Field {
 }
 
 func (r *importReader) param() *types.Field {
-	return types.NewField(r.pos(), r.ident(), r.typ())
+	return types.NewField(r.pos(), r.localIdent(), r.typ())
 }
 
 func (r *importReader) bool() bool {
@@ -778,17 +782,17 @@ func (r *importReader) caseList(switchExpr ir.Node) []*ir.CaseClause {
 	cases := make([]*ir.CaseClause, r.uint64())
 	for i := range cases {
 		cas := ir.NewCaseStmt(r.pos(), nil, nil)
-		cas.List.Set(r.stmtList())
+		cas.List = r.stmtList()
 		if namedTypeSwitch {
 			// Note: per-case variables will have distinct, dotted
 			// names after import. That's okay: swt.go only needs
 			// Sym for diagnostics anyway.
-			caseVar := ir.NewNameAt(cas.Pos(), r.ident())
+			caseVar := ir.NewNameAt(cas.Pos(), r.localIdent())
 			Declare(caseVar, DeclContext)
 			cas.Var = caseVar
 			caseVar.Defn = switchExpr
 		}
-		cas.Body.Set(r.stmtList())
+		cas.Body = r.stmtList()
 		cases[i] = cas
 	}
 	return cases
@@ -850,7 +854,7 @@ func (r *importReader) node() ir.Node {
 		return r.qualifiedIdent()
 
 	case ir.ONAME:
-		return r.ident().Def.(*ir.Name)
+		return r.localIdent().Def.(*ir.Name)
 
 	// case OPACK, ONONAME:
 	// 	unreachable - should have been resolved by typechecking
@@ -861,7 +865,7 @@ func (r *importReader) node() ir.Node {
 	case ir.OTYPESW:
 		pos := r.pos()
 		var tag *ir.Ident
-		if s := r.ident(); s != nil {
+		if s := r.localIdent(); s != nil {
 			tag = ir.NewIdent(pos, s)
 		}
 		return ir.NewTypeSwitchGuard(pos, tag, r.expr())
@@ -898,7 +902,7 @@ func (r *importReader) node() ir.Node {
 
 	case ir.OXDOT:
 		// see parser.new_dotname
-		return ir.NewSelectorExpr(r.pos(), ir.OXDOT, r.expr(), r.ident())
+		return ir.NewSelectorExpr(r.pos(), ir.OXDOT, r.expr(), r.selector())
 
 	// case ODOTTYPE, ODOTTYPE2:
 	// 	unreachable - mapped to case ODOTTYPE below by exporter
@@ -931,7 +935,7 @@ func (r *importReader) node() ir.Node {
 
 	case ir.OCOPY, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCAP, ir.OCLOSE, ir.ODELETE, ir.OLEN, ir.OMAKE, ir.ONEW, ir.OPANIC, ir.ORECOVER, ir.OPRINT, ir.OPRINTN:
 		n := builtinCall(r.pos(), op)
-		n.Args.Set(r.exprList())
+		n.Args = r.exprList()
 		if op == ir.OAPPEND {
 			n.IsDDD = r.bool()
 		}
@@ -944,7 +948,7 @@ func (r *importReader) node() ir.Node {
 		pos := r.pos()
 		init := r.stmtList()
 		n := ir.NewCallExpr(pos, ir.OCALL, r.expr(), r.exprList())
-		n.PtrInit().Set(init)
+		*n.PtrInit() = init
 		n.IsDDD = r.bool()
 		return n
 
@@ -988,7 +992,7 @@ func (r *importReader) node() ir.Node {
 	// statements
 	case ir.ODCL:
 		pos := r.pos()
-		lhs := ir.NewDeclNameAt(pos, ir.ONAME, r.ident())
+		lhs := ir.NewDeclNameAt(pos, ir.ONAME, r.localIdent())
 		lhs.SetType(r.typ())
 
 		Declare(lhs, ir.PAUTO)
@@ -1032,14 +1036,14 @@ func (r *importReader) node() ir.Node {
 	case ir.OIF:
 		pos, init := r.pos(), r.stmtList()
 		n := ir.NewIfStmt(pos, r.expr(), r.stmtList(), r.stmtList())
-		n.PtrInit().Set(init)
+		*n.PtrInit() = init
 		return n
 
 	case ir.OFOR:
 		pos, init := r.pos(), r.stmtList()
 		cond, post := r.exprsOrNil()
 		n := ir.NewForStmt(pos, nil, cond, post, r.stmtList())
-		n.PtrInit().Set(init)
+		*n.PtrInit() = init
 		return n
 
 	case ir.ORANGE:
@@ -1051,7 +1055,7 @@ func (r *importReader) node() ir.Node {
 		pos := r.pos()
 		init := r.stmtList()
 		n := ir.NewSelectStmt(pos, r.commList())
-		n.PtrInit().Set(init)
+		*n.PtrInit() = init
 		return n
 
 	case ir.OSWITCH:
@@ -1059,7 +1063,7 @@ func (r *importReader) node() ir.Node {
 		init := r.stmtList()
 		x, _ := r.exprsOrNil()
 		n := ir.NewSwitchStmt(pos, x, r.caseList(x))
-		n.PtrInit().Set(init)
+		*n.PtrInit() = init
 		return n
 
 	// case OCASE:
@@ -1099,7 +1103,7 @@ func (r *importReader) op() ir.Op {
 func (r *importReader) fieldList() []ir.Node {
 	list := make([]ir.Node, r.uint64())
 	for i := range list {
-		list[i] = ir.NewStructKeyExpr(r.pos(), r.ident(), r.expr())
+		list[i] = ir.NewStructKeyExpr(r.pos(), r.selector(), r.expr())
 	}
 	return list
 }

src/cmd/compile/internal/typecheck/stmt.go

@@ -631,7 +631,7 @@ func tcSwitchType(n *ir.SwitchStmt) {
 			nvar := ncase.Var
 			nvar.SetType(vt)
 			if vt != nil {
-				nvar = AssignExpr(nvar)
+				nvar = AssignExpr(nvar).(*ir.Name)
 			} else {
 				// Clause variable is broken; prevent typechecking.
 				nvar.SetTypecheck(1)

src/cmd/compile/internal/typecheck/subr.go

@@ -43,6 +43,9 @@ func NewFuncParams(tl *types.Type, mustname bool) []*ir.Field {
 			// invent a name so that we can refer to it in the trampoline
 			s = LookupNum(".anon", gen)
 			gen++
+		} else if s != nil && s.Pkg != types.LocalPkg {
+			// TODO(mdempsky): Preserve original position, name, and package.
+			s = Lookup(s.Name)
 		}
 		a := ir.NewField(base.Pos, s, nil, t.Type)
 		a.Pos = t.Pos
@@ -67,9 +70,57 @@ func NodAddr(n ir.Node) *ir.AddrExpr {
 
 // nodAddrPos returns a node representing &n at position pos.
 func NodAddrAt(pos src.XPos, n ir.Node) *ir.AddrExpr {
+	n = markAddrOf(n)
 	return ir.NewAddrExpr(pos, n)
 }
 
+func markAddrOf(n ir.Node) ir.Node {
+	if IncrementalAddrtaken {
+		// We can only do incremental addrtaken computation when it is ok
+		// to typecheck the argument of the OADDR. That's only safe after the
+		// main typecheck has completed.
+		// The argument to OADDR needs to be typechecked because &x[i] takes
+		// the address of x if x is an array, but not if x is a slice.
+		// Note: outervalue doesn't work correctly until n is typechecked.
+		n = typecheck(n, ctxExpr)
+		if x := ir.OuterValue(n); x.Op() == ir.ONAME {
+			x.Name().SetAddrtaken(true)
+		}
+	} else {
+		// Remember that we built an OADDR without computing the Addrtaken bit for
+		// its argument. We'll do that later in bulk using computeAddrtaken.
+		DirtyAddrtaken = true
+	}
+	return n
+}
+
+// If IncrementalAddrtaken is false, we do not compute Addrtaken for an OADDR Node
+// when it is built. The Addrtaken bits are set in bulk by computeAddrtaken.
+// If IncrementalAddrtaken is true, then when an OADDR Node is built the Addrtaken
+// field of its argument is updated immediately.
+var IncrementalAddrtaken = false
+
+// If DirtyAddrtaken is true, then there are OADDR whose corresponding arguments
+// have not yet been marked as Addrtaken.
+var DirtyAddrtaken = false
+
+func ComputeAddrtaken(top []ir.Node) {
+	for _, n := range top {
+		ir.Visit(n, func(n ir.Node) {
+			if n.Op() == ir.OADDR {
+				if x := ir.OuterValue(n.(*ir.AddrExpr).X); x.Op() == ir.ONAME {
+					x.Name().SetAddrtaken(true)
+					if x.Name().IsClosureVar() {
+						// Mark the original variable as Addrtaken so that capturevars
+						// knows not to pass it by value.
+						x.Name().Defn.Name().SetAddrtaken(true)
+					}
+				}
+			}
+		})
+	}
+}
+
 func NodNil() ir.Node {
 	n := ir.NewNilExpr(base.Pos)
 	n.SetType(types.Types[types.TNIL])

src/cmd/compile/internal/typecheck/syms.go

@@ -26,12 +26,12 @@ func LookupRuntime(name string) *ir.Name {
 // The result of SubstArgTypes MUST be assigned back to old, e.g.
 // 	n.Left = SubstArgTypes(n.Left, t1, t2)
 func SubstArgTypes(old *ir.Name, types_ ...*types.Type) *ir.Name {
-	n := old.CloneName()
-
 	for _, t := range types_ {
 		types.CalcSize(t)
 	}
-	n.SetType(types.SubstAny(n.Type(), &types_))
+	n := ir.NewNameAt(old.Pos(), old.Sym())
+	n.Class = old.Class
+	n.SetType(types.SubstAny(old.Type(), &types_))
 	if len(types_) > 0 {
 		base.Fatalf("substArgTypes: too many argument types")
 	}
@@ -61,15 +61,13 @@ func Lookup(name string) *types.Sym {
 	return types.LocalPkg.Lookup(name)
 }
 
-// loadsys loads the definitions for the low-level runtime functions,
+// InitRuntime loads the definitions for the low-level runtime functions,
 // so that the compiler can generate calls to them,
 // but does not make them visible to user code.
-func loadsys() {
+func InitRuntime() {
+	base.Timer.Start("fe", "loadsys")
 	types.Block = 1
 
-	inimport = true
-	TypecheckAllowed = true
-
 	typs := runtimeTypes()
 	for _, d := range &runtimeDecls {
 		sym := ir.Pkgs.Runtime.Lookup(d.name)
@@ -83,9 +81,6 @@ func loadsys() {
 			base.Fatalf("unhandled declaration tag %v", d.tag)
 		}
 	}
-
-	TypecheckAllowed = false
-	inimport = false
 }
 
 // LookupRuntimeFunc looks up Go function name in package runtime. This function

src/cmd/compile/internal/typecheck/type.go

@@ -14,7 +14,7 @@ import (
 
 // tcArrayType typechecks an OTARRAY node.
 func tcArrayType(n *ir.ArrayType) ir.Node {
-	n.Elem = typecheck(n.Elem, ctxType)
+	n.Elem = typecheckNtype(n.Elem)
 	if n.Elem.Type() == nil {
 		return n
 	}
@@ -59,7 +59,7 @@ func tcArrayType(n *ir.ArrayType) ir.Node {
 
 // tcChanType typechecks an OTCHAN node.
 func tcChanType(n *ir.ChanType) ir.Node {
-	n.Elem = typecheck(n.Elem, ctxType)
+	n.Elem = typecheckNtype(n.Elem)
 	l := n.Elem
 	if l.Type() == nil {
 		return n
@@ -103,7 +103,7 @@ func tcInterfaceType(n *ir.InterfaceType) ir.Node {
 		n.SetOTYPE(types.Types[types.TINTER])
 		return n
 	}
-	
+
 	lno := base.Pos
 	methods := tcFields(n.Methods, nil)
 	base.Pos = lno
@@ -114,8 +114,8 @@ func tcInterfaceType(n *ir.InterfaceType) ir.Node {
 
 // tcMapType typechecks an OTMAP node.
 func tcMapType(n *ir.MapType) ir.Node {
-	n.Key = typecheck(n.Key, ctxType)
+	n.Key = typecheckNtype(n.Key)
-	n.Elem = typecheck(n.Elem, ctxType)
+	n.Elem = typecheckNtype(n.Elem)
 	l := n.Key
 	r := n.Elem
 	if l.Type() == nil || r.Type() == nil {
@@ -134,7 +134,7 @@ func tcMapType(n *ir.MapType) ir.Node {
 
 // tcSliceType typechecks an OTSLICE node.
 func tcSliceType(n *ir.SliceType) ir.Node {
-	n.Elem = typecheck(n.Elem, ctxType)
+	n.Elem = typecheckNtype(n.Elem)
 	if n.Elem.Type() == nil {
 		return n
 	}

src/cmd/compile/internal/typecheck/typecheck.go

@@ -31,97 +31,6 @@ var (
 	NeedRuntimeType = func(*types.Type) {}
 )
 
-func Init() {
-	initUniverse()
-	DeclContext = ir.PEXTERN
-	base.Timer.Start("fe", "loadsys")
-	loadsys()
-}
-
-func Package() {
-	declareUniverse()
-
-	TypecheckAllowed = true
-
-	// Process top-level declarations in phases.
-
-	// Phase 1: const, type, and names and types of funcs.
-	//   This will gather all the information about types
-	//   and methods but doesn't depend on any of it.
-	//
-	//   We also defer type alias declarations until phase 2
-	//   to avoid cycles like #18640.
-	//   TODO(gri) Remove this again once we have a fix for #25838.
-
-	// Don't use range--typecheck can add closures to Target.Decls.
-	base.Timer.Start("fe", "typecheck", "top1")
-	for i := 0; i < len(Target.Decls); i++ {
-		n := Target.Decls[i]
-		if op := n.Op(); op != ir.ODCL && op != ir.OAS && op != ir.OAS2 && (op != ir.ODCLTYPE || !n.(*ir.Decl).X.Name().Alias()) {
-			Target.Decls[i] = Stmt(n)
-		}
-	}
-
-	// Phase 2: Variable assignments.
-	//   To check interface assignments, depends on phase 1.
-
-	// Don't use range--typecheck can add closures to Target.Decls.
-	base.Timer.Start("fe", "typecheck", "top2")
-	for i := 0; i < len(Target.Decls); i++ {
-		n := Target.Decls[i]
-		if op := n.Op(); op == ir.ODCL || op == ir.OAS || op == ir.OAS2 || op == ir.ODCLTYPE && n.(*ir.Decl).X.Name().Alias() {
-			Target.Decls[i] = Stmt(n)
-		}
-	}
-
-	// Phase 3: Type check function bodies.
-	// Don't use range--typecheck can add closures to Target.Decls.
-	base.Timer.Start("fe", "typecheck", "func")
-	var fcount int64
-	for i := 0; i < len(Target.Decls); i++ {
-		n := Target.Decls[i]
-		if n.Op() == ir.ODCLFUNC {
-			FuncBody(n.(*ir.Func))
-			fcount++
-		}
-	}
-
-	// Phase 4: Check external declarations.
-	// TODO(mdempsky): This should be handled when type checking their
-	// corresponding ODCL nodes.
-	base.Timer.Start("fe", "typecheck", "externdcls")
-	for i, n := range Target.Externs {
-		if n.Op() == ir.ONAME {
-			Target.Externs[i] = Expr(Target.Externs[i])
-		}
-	}
-
-	// Phase 5: With all user code type-checked, it's now safe to verify map keys.
-	CheckMapKeys()
-
-	// Phase 6: Decide how to capture closed variables.
-	// This needs to run before escape analysis,
-	// because variables captured by value do not escape.
-	base.Timer.Start("fe", "capturevars")
-	for _, n := range Target.Decls {
-		if n.Op() == ir.ODCLFUNC {
-			n := n.(*ir.Func)
-			if n.OClosure != nil {
-				ir.CurFunc = n
-				CaptureVars(n)
-			}
-		}
-	}
-	CaptureVarsComplete = true
-	ir.CurFunc = nil
-
-	if base.Debug.TypecheckInl != 0 {
-		// Typecheck imported function bodies if Debug.l > 1,
-		// otherwise lazily when used or re-exported.
-		AllImportedBodies()
-	}
-}
-
 func AssignExpr(n ir.Node) ir.Node { return typecheck(n, ctxExpr|ctxAssign) }
 func Expr(n ir.Node) ir.Node       { return typecheck(n, ctxExpr) }
 func Stmt(n ir.Node) ir.Node       { return typecheck(n, ctxStmt) }
@@ -152,13 +61,11 @@ func FuncBody(n *ir.Func) {
 	decldepth = 1
 	errorsBefore := base.Errors()
 	Stmts(n.Body)
+	CheckUnused(n)
 	CheckReturn(n)
 	if base.Errors() > errorsBefore {
-		n.Body.Set(nil) // type errors; do not compile
+		n.Body = nil // type errors; do not compile
 	}
-	// Now that we've checked whether n terminates,
-	// we can eliminate some obviously dead code.
-	deadcode(n)
 }
 
 var importlist []*ir.Func
@@ -230,7 +137,7 @@ const (
 // marks variables that escape the local frame.
 // rewrites n.Op to be more specific in some cases.
 
-var typecheckdefstack []ir.Node
+var typecheckdefstack []*ir.Name
 
 // Resolve ONONAME to definition, if any.
 func Resolve(n ir.Node) (res ir.Node) {
@@ -567,26 +474,8 @@ func indexlit(n ir.Node) ir.Node {
 
 // typecheck1 should ONLY be called from typecheck.
 func typecheck1(n ir.Node, top int) ir.Node {
-	switch n.Op() {
+	if n, ok := n.(*ir.Name); ok {
-	case ir.OLITERAL, ir.ONAME, ir.ONONAME, ir.OTYPE:
-		if n.Sym() == nil {
-			return n
-		}
-
-		if n.Op() == ir.ONAME {
-			n := n.(*ir.Name)
-			if n.BuiltinOp != 0 && top&ctxCallee == 0 {
-				base.Errorf("use of builtin %v not in function call", n.Sym())
-				n.SetType(nil)
-				return n
-			}
-		}
-
 		typecheckdef(n)
-		if n.Op() == ir.ONONAME {
-			n.SetType(nil)
-			return n
-		}
 	}
 
 	switch n.Op() {
@@ -595,22 +484,37 @@ func typecheck1(n ir.Node, top int) ir.Node {
 		base.Fatalf("typecheck %v", n.Op())
 		panic("unreachable")
 
-	// names
 	case ir.OLITERAL:
-		if n.Type() == nil && n.Val().Kind() == constant.String {
+		if n.Sym() == nil && n.Type() == nil {
-			base.Fatalf("string literal missing type")
+			base.Fatalf("literal missing type: %v", n)
 		}
 		return n
 
-	case ir.ONIL, ir.ONONAME:
+	case ir.ONIL:
+		return n
+
+	// names
+	case ir.ONONAME:
+		if !n.Diag() {
+			// Note: adderrorname looks for this string and
+			// adds context about the outer expression
+			base.ErrorfAt(n.Pos(), "undefined: %v", n.Sym())
+			n.SetDiag(true)
+		}
+		n.SetType(nil)
 		return n
 
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		if n.Name().Decldepth == 0 {
+		if n.Decldepth == 0 {
-			n.Name().Decldepth = decldepth
+			n.Decldepth = decldepth
 		}
 		if n.BuiltinOp != 0 {
+			if top&ctxCallee == 0 {
+				base.Errorf("use of builtin %v not in function call", n.Sym())
+				n.SetType(nil)
+				return n
+			}
 			return n
 		}
 		if top&ctxAssign == 0 {
@@ -620,7 +524,7 @@ func typecheck1(n ir.Node, top int) ir.Node {
 				n.SetType(nil)
 				return n
 			}
-			n.Name().SetUsed(true)
+			n.SetUsed(true)
 		}
 		return n
 
@@ -636,9 +540,6 @@ func typecheck1(n ir.Node, top int) ir.Node {
 
 	// types (ODEREF is with exprs)
 	case ir.OTYPE:
-		if n.Type() == nil {
-			return n
-		}
 		return n
 
 	case ir.OTSLICE:
@@ -672,28 +573,98 @@ func typecheck1(n ir.Node, top int) ir.Node {
 	case ir.ODEREF:
 		n := n.(*ir.StarExpr)
 		return tcStar(n, top)
-	// arithmetic exprs
+
-	case ir.OASOP,
+	// x op= y
-		ir.OADD,
+	case ir.OASOP:
-		ir.OAND,
+		n := n.(*ir.AssignOpStmt)
-		ir.OANDAND,
+		n.X, n.Y = Expr(n.X), Expr(n.Y)
-		ir.OANDNOT,
+		checkassign(n, n.X)
-		ir.ODIV,
+		if n.IncDec && !okforarith[n.X.Type().Kind()] {
-		ir.OEQ,
+			base.Errorf("invalid operation: %v (non-numeric type %v)", n, n.X.Type())
-		ir.OGE,
+			return n
-		ir.OGT,
+		}
-		ir.OLE,
+		switch n.AsOp {
-		ir.OLT,
+		case ir.OLSH, ir.ORSH:
-		ir.OLSH,
+			n.X, n.Y, _ = tcShift(n, n.X, n.Y)
-		ir.ORSH,
+		case ir.OADD, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OMOD, ir.OMUL, ir.OOR, ir.OSUB, ir.OXOR:
-		ir.OMOD,
+			n.X, n.Y, _ = tcArith(n, n.AsOp, n.X, n.Y)
-		ir.OMUL,
+		default:
-		ir.ONE,
+			base.Fatalf("invalid assign op: %v", n.AsOp)
-		ir.OOR,
+		}
-		ir.OOROR,
+		return n
-		ir.OSUB,
+
-		ir.OXOR:
+	// logical operators
-		return tcArith(n)
+	case ir.OANDAND, ir.OOROR:
+		n := n.(*ir.LogicalExpr)
+		n.X, n.Y = Expr(n.X), Expr(n.Y)
+		// For "x == x && len(s)", it's better to report that "len(s)" (type int)
+		// can't be used with "&&" than to report that "x == x" (type untyped bool)
+		// can't be converted to int (see issue #41500).
+		if !n.X.Type().IsBoolean() {
+			base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, n.Op(), typekind(n.X.Type()))
+			n.SetType(nil)
+			return n
+		}
+		if !n.Y.Type().IsBoolean() {
+			base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, n.Op(), typekind(n.Y.Type()))
+			n.SetType(nil)
+			return n
+		}
+		l, r, t := tcArith(n, n.Op(), n.X, n.Y)
+		n.X, n.Y = l, r
+		n.SetType(t)
+		return n
+
+	// shift operators
+	case ir.OLSH, ir.ORSH:
+		n := n.(*ir.BinaryExpr)
+		n.X, n.Y = Expr(n.X), Expr(n.Y)
+		l, r, t := tcShift(n, n.X, n.Y)
+		n.X, n.Y = l, r
+		n.SetType(t)
+		return n
+
+	// comparison operators
+	case ir.OEQ, ir.OGE, ir.OGT, ir.OLE, ir.OLT, ir.ONE:
+		n := n.(*ir.BinaryExpr)
+		n.X, n.Y = Expr(n.X), Expr(n.Y)
+		l, r, t := tcArith(n, n.Op(), n.X, n.Y)
+		if t != nil {
+			n.X, n.Y = l, r
+			n.SetType(types.UntypedBool)
+			if con := EvalConst(n); con.Op() == ir.OLITERAL {
+				return con
+			}
+			n.X, n.Y = defaultlit2(l, r, true)
+		}
+		return n
+
+	// binary operators
+	case ir.OADD, ir.OAND, ir.OANDNOT, ir.ODIV, ir.OMOD, ir.OMUL, ir.OOR, ir.OSUB, ir.OXOR:
+		n := n.(*ir.BinaryExpr)
+		n.X, n.Y = Expr(n.X), Expr(n.Y)
+		l, r, t := tcArith(n, n.Op(), n.X, n.Y)
+		if t != nil && t.Kind() == types.TSTRING && n.Op() == ir.OADD {
+			// create or update OADDSTR node with list of strings in x + y + z + (w + v) + ...
+			var add *ir.AddStringExpr
+			if l.Op() == ir.OADDSTR {
+				add = l.(*ir.AddStringExpr)
+				add.SetPos(n.Pos())
+			} else {
+				add = ir.NewAddStringExpr(n.Pos(), []ir.Node{l})
+			}
+			if r.Op() == ir.OADDSTR {
+				r := r.(*ir.AddStringExpr)
+				add.List.Append(r.List.Take()...)
+			} else {
+				add.List.Append(r)
+			}
+			add.SetType(t)
+			return add
+		}
+		n.X, n.Y = l, r
+		n.SetType(t)
+		return n
 
 	case ir.OBITNOT, ir.ONEG, ir.ONOT, ir.OPLUS:
 		n := n.(*ir.UnaryExpr)
@@ -925,12 +896,12 @@ func typecheck1(n ir.Node, top int) ir.Node {
 
 	case ir.ODCLCONST:
 		n := n.(*ir.Decl)
-		n.X = Expr(n.X)
+		n.X = Expr(n.X).(*ir.Name)
 		return n
 
 	case ir.ODCLTYPE:
 		n := n.(*ir.Decl)
-		n.X = typecheck(n.X, ctxType)
+		n.X = typecheck(n.X, ctxType).(*ir.Name)
 		types.CheckSize(n.X.Type())
 		return n
 	}
@@ -940,7 +911,7 @@ func typecheck1(n ir.Node, top int) ir.Node {
 	// Each must execute its own return n.
 }
 
-func typecheckargs(n ir.Node) {
+func typecheckargs(n ir.InitNode) {
 	var list []ir.Node
 	switch n := n.(type) {
 	default:
@@ -997,9 +968,9 @@ func typecheckargs(n ir.Node) {
 
 	switch n := n.(type) {
 	case *ir.CallExpr:
-		n.Args.Set(list)
+		n.Args = list
 	case *ir.ReturnStmt:
-		n.Results.Set(list)
+		n.Results = list
 	}
 
 	n.PtrInit().Append(Stmt(as))
@@ -1176,19 +1147,16 @@ func typecheckMethodExpr(n *ir.SelectorExpr) (res ir.Node) {
 		return n
 	}
 
-	me := ir.NewMethodExpr(n.Pos(), n.X.Type(), m)
+	n.SetOp(ir.OMETHEXPR)
-	me.SetType(NewMethodType(m.Type, n.X.Type()))
+	n.Selection = m
-	f := NewName(ir.MethodSym(t, m.Sym))
+	n.SetType(NewMethodType(m.Type, n.X.Type()))
-	f.Class_ = ir.PFUNC
-	f.SetType(me.Type())
-	me.FuncName_ = f
 
 	// Issue 25065. Make sure that we emit the symbol for a local method.
 	if base.Ctxt.Flag_dynlink && !inimport && (t.Sym() == nil || t.Sym().Pkg == types.LocalPkg) {
-		NeedFuncSym(me.FuncName_.Sym())
+		NeedFuncSym(n.FuncName().Sym())
 	}
 
-	return me
+	return n
 }
 
 func derefall(t *types.Type) *types.Type {
@@ -1245,6 +1213,7 @@ func lookdot(n *ir.SelectorExpr, t *types.Type, dostrcmp int) *types.Field {
 			// Already in the process of diagnosing an error.
 			return f2
 		}
+		orig := n.X
 		tt := n.X.Type()
 		types.CalcSize(tt)
 		rcvr := f2.Type.Recv().Type
@@ -1275,20 +1244,28 @@ func lookdot(n *ir.SelectorExpr, t *types.Type, dostrcmp int) *types.Field {
 			}
 		}
 
-		implicit, ll := n.Implicit(), n.X
+		// Check that we haven't implicitly dereferenced any defined pointer types.
-		for ll != nil && (ll.Op() == ir.ODOT || ll.Op() == ir.ODOTPTR || ll.Op() == ir.ODEREF) {
+		for x := n.X; ; {
-			switch l := ll.(type) {
+			var inner ir.Node
+			implicit := false
+			switch x := x.(type) {
+			case *ir.AddrExpr:
+				inner, implicit = x.X, x.Implicit()
 			case *ir.SelectorExpr:
-				implicit, ll = l.Implicit(), l.X
+				inner, implicit = x.X, x.Implicit()
 			case *ir.StarExpr:
-				implicit, ll = l.Implicit(), l.X
+				inner, implicit = x.X, x.Implicit()
 			}
-		}
+			if !implicit {
-		if implicit && ll.Type().IsPtr() && ll.Type().Sym() != nil && ll.Type().Sym().Def != nil && ir.AsNode(ll.Type().Sym().Def).Op() == ir.OTYPE {
+				break
-			// It is invalid to automatically dereference a named pointer type when selecting a method.
+			}
-			// Make n.Left == ll to clarify error message.
+			if inner.Type().Sym() != nil && (x.Op() == ir.ODEREF || x.Op() == ir.ODOTPTR) {
-			n.X = ll
+				// Found an implicit dereference of a defined pointer type.
-			return nil
+				// Restore n.X for better error message.
+				n.X = orig
+				return nil
+			}
+			x = inner
 		}
 
 		n.Selection = f2
@@ -1422,7 +1399,7 @@ notenough:
 			// Method expressions have the form T.M, and the compiler has
 			// rewritten those to ONAME nodes but left T in Left.
 			if call.Op() == ir.OMETHEXPR {
-				call := call.(*ir.MethodExpr)
+				call := call.(*ir.SelectorExpr)
 				base.Errorf("not enough arguments in call to method expression %v%s", call, details)
 			} else {
 				base.Errorf("not enough arguments in call to %v%s", call, details)
@@ -1635,14 +1612,22 @@ func checklvalue(n ir.Node, verb string) {
 }
 
 func checkassign(stmt ir.Node, n ir.Node) {
+	// have already complained about n being invalid
+	if n.Type() == nil {
+		if base.Errors() == 0 {
+			base.Fatalf("expected an error about %v", n)
+		}
+		return
+	}
+
 	// Variables declared in ORANGE are assigned on every iteration.
 	if !ir.DeclaredBy(n, stmt) || stmt.Op() == ir.ORANGE {
 		r := ir.OuterValue(n)
 		if r.Op() == ir.ONAME {
 			r := r.(*ir.Name)
-			r.Name().SetAssigned(true)
+			r.SetAssigned(true)
-			if r.Name().IsClosureVar() {
+			if r.IsClosureVar() {
-				r.Name().Defn.Name().SetAssigned(true)
+				r.Defn.Name().SetAssigned(true)
 			}
 		}
 	}
@@ -1656,11 +1641,6 @@ func checkassign(stmt ir.Node, n ir.Node) {
 		return
 	}
 
-	// have already complained about n being invalid
-	if n.Type() == nil {
-		return
-	}
-
 	switch {
 	case n.Op() == ir.ODOT && n.(*ir.SelectorExpr).X.Op() == ir.OINDEXMAP:
 		base.Errorf("cannot assign to struct field %v in map", n)
@@ -1706,8 +1686,8 @@ func stringtoruneslit(n *ir.ConvExpr) ir.Node {
 		i++
 	}
 
-	nn := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(n.Type()).(ir.Ntype), nil)
+	nn := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(n.Type()), nil)
-	nn.List.Set(l)
+	nn.List = l
 	return Expr(nn)
 }
 
@@ -1755,30 +1735,26 @@ func typecheckdeftype(n *ir.Name) {
 	types.ResumeCheckSize()
 }
 
-func typecheckdef(n ir.Node) {
+func typecheckdef(n *ir.Name) {
 	if base.EnableTrace && base.Flag.LowerT {
 		defer tracePrint("typecheckdef", n)(nil)
 	}
 
-	lno := ir.SetPos(n)
-
-	if n.Op() == ir.ONONAME {
-		if !n.Diag() {
-			n.SetDiag(true)
-
-			// Note: adderrorname looks for this string and
-			// adds context about the outer expression
-			base.ErrorfAt(base.Pos, "undefined: %v", n.Sym())
-		}
-		base.Pos = lno
-		return
-	}
-
 	if n.Walkdef() == 1 {
-		base.Pos = lno
 		return
 	}
 
+	if n.Type() != nil { // builtin
+		// Mark as Walkdef so that if n.SetType(nil) is called later, we
+		// won't try walking again.
+		if got := n.Walkdef(); got != 0 {
+			base.Fatalf("unexpected walkdef: %v", got)
+		}
+		n.SetWalkdef(1)
+		return
+	}
+
+	lno := ir.SetPos(n)
 	typecheckdefstack = append(typecheckdefstack, n)
 	if n.Walkdef() == 2 {
 		base.FlushErrors()
@@ -1793,27 +1769,23 @@ func typecheckdef(n ir.Node) {
 
 	n.SetWalkdef(2)
 
-	if n.Type() != nil || n.Sym() == nil { // builtin or no name
-		goto ret
-	}
-
 	switch n.Op() {
 	default:
 		base.Fatalf("typecheckdef %v", n.Op())
 
 	case ir.OLITERAL:
-		if n.Name().Ntype != nil {
+		if n.Ntype != nil {
-			n.Name().Ntype = typecheckNtype(n.Name().Ntype)
+			n.Ntype = typecheckNtype(n.Ntype)
-			n.SetType(n.Name().Ntype.Type())
+			n.SetType(n.Ntype.Type())
-			n.Name().Ntype = nil
+			n.Ntype = nil
 			if n.Type() == nil {
 				n.SetDiag(true)
 				goto ret
 			}
 		}
 
-		e := n.Name().Defn
+		e := n.Defn
-		n.Name().Defn = nil
+		n.Defn = nil
 		if e == nil {
 			ir.Dump("typecheckdef nil defn", n)
 			base.ErrorfAt(n.Pos(), "xxx")
@@ -1856,10 +1828,9 @@ func typecheckdef(n ir.Node) {
 		}
 
 	case ir.ONAME:
-		n := n.(*ir.Name)
+		if n.Ntype != nil {
-		if n.Name().Ntype != nil {
+			n.Ntype = typecheckNtype(n.Ntype)
-			n.Name().Ntype = typecheckNtype(n.Name().Ntype)
+			n.SetType(n.Ntype.Type())
-			n.SetType(n.Name().Ntype.Type())
 			if n.Type() == nil {
 				n.SetDiag(true)
 				goto ret
@@ -1869,7 +1840,7 @@ func typecheckdef(n ir.Node) {
 		if n.Type() != nil {
 			break
 		}
-		if n.Name().Defn == nil {
+		if n.Defn == nil {
 			if n.BuiltinOp != 0 { // like OPRINTN
 				break
 			}
@@ -1884,16 +1855,15 @@ func typecheckdef(n ir.Node) {
 			base.Fatalf("var without type, init: %v", n.Sym())
 		}
 
-		if n.Name().Defn.Op() == ir.ONAME {
+		if n.Defn.Op() == ir.ONAME {
-			n.Name().Defn = Expr(n.Name().Defn)
+			n.Defn = Expr(n.Defn)
-			n.SetType(n.Name().Defn.Type())
+			n.SetType(n.Defn.Type())
 			break
 		}
 
-		n.Name().Defn = Stmt(n.Name().Defn) // fills in n.Type
+		n.Defn = Stmt(n.Defn) // fills in n.Type
 
 	case ir.OTYPE:
-		n := n.(*ir.Name)
 		if n.Alias() {
 			// Type alias declaration: Simply use the rhs type - no need
 			// to create a new type.
@@ -1970,8 +1940,8 @@ func markBreak(fn *ir.Func) {
 	var labels map[*types.Sym]ir.Node
 	var implicit ir.Node
 
-	var mark func(ir.Node) error
+	var mark func(ir.Node) bool
-	mark = func(n ir.Node) error {
+	mark = func(n ir.Node) bool {
 		switch n.Op() {
 		default:
 			ir.DoChildren(n, mark)
@@ -2011,7 +1981,7 @@ func markBreak(fn *ir.Func) {
 			}
 			implicit = old
 		}
-		return nil
+		return false
 	}
 
 	mark(fn)
@@ -2122,6 +2092,39 @@ func isTermNode(n ir.Node) bool {
 	return false
 }
 
+// CheckUnused checks for any declared variables that weren't used.
+func CheckUnused(fn *ir.Func) {
+	// Only report unused variables if we haven't seen any type-checking
+	// errors yet.
+	if base.Errors() != 0 {
+		return
+	}
+
+	// Propagate the used flag for typeswitch variables up to the NONAME in its definition.
+	for _, ln := range fn.Dcl {
+		if ln.Op() == ir.ONAME && ln.Class == ir.PAUTO && ln.Used() {
+			if guard, ok := ln.Defn.(*ir.TypeSwitchGuard); ok {
+				guard.Used = true
+			}
+		}
+	}
+
+	for _, ln := range fn.Dcl {
+		if ln.Op() != ir.ONAME || ln.Class != ir.PAUTO || ln.Used() {
+			continue
+		}
+		if defn, ok := ln.Defn.(*ir.TypeSwitchGuard); ok {
+			if defn.Used {
+				continue
+			}
+			base.ErrorfAt(defn.Tag.Pos(), "%v declared but not used", ln.Sym())
+			defn.Used = true // suppress repeats
+		} else {
+			base.ErrorfAt(ln.Pos(), "%v declared but not used", ln.Sym())
+		}
+	}
+}
+
 // CheckReturn makes sure that fn terminates appropriately.
 func CheckReturn(fn *ir.Func) {
 	if fn.Type().NumResults() != 0 && len(fn.Body) != 0 {
@@ -2132,150 +2135,12 @@ func CheckReturn(fn *ir.Func) {
 	}
 }
 
-func deadcode(fn *ir.Func) {
-	deadcodeslice(&fn.Body)
-
-	if len(fn.Body) == 0 {
-		return
-	}
-
-	for _, n := range fn.Body {
-		if len(n.Init()) > 0 {
-			return
-		}
-		switch n.Op() {
-		case ir.OIF:
-			n := n.(*ir.IfStmt)
-			if !ir.IsConst(n.Cond, constant.Bool) || len(n.Body) > 0 || len(n.Else) > 0 {
-				return
-			}
-		case ir.OFOR:
-			n := n.(*ir.ForStmt)
-			if !ir.IsConst(n.Cond, constant.Bool) || ir.BoolVal(n.Cond) {
-				return
-			}
-		default:
-			return
-		}
-	}
-
-	fn.Body.Set([]ir.Node{ir.NewBlockStmt(base.Pos, nil)})
-}
-
-func deadcodeslice(nn *ir.Nodes) {
-	var lastLabel = -1
-	for i, n := range *nn {
-		if n != nil && n.Op() == ir.OLABEL {
-			lastLabel = i
-		}
-	}
-	for i, n := range *nn {
-		// Cut is set to true when all nodes after i'th position
-		// should be removed.
-		// In other words, it marks whole slice "tail" as dead.
-		cut := false
-		if n == nil {
-			continue
-		}
-		if n.Op() == ir.OIF {
-			n := n.(*ir.IfStmt)
-			n.Cond = deadcodeexpr(n.Cond)
-			if ir.IsConst(n.Cond, constant.Bool) {
-				var body ir.Nodes
-				if ir.BoolVal(n.Cond) {
-					n.Else = ir.Nodes{}
-					body = n.Body
-				} else {
-					n.Body = ir.Nodes{}
-					body = n.Else
-				}
-				// If "then" or "else" branch ends with panic or return statement,
-				// it is safe to remove all statements after this node.
-				// isterminating is not used to avoid goto-related complications.
-				// We must be careful not to deadcode-remove labels, as they
-				// might be the target of a goto. See issue 28616.
-				if body := body; len(body) != 0 {
-					switch body[(len(body) - 1)].Op() {
-					case ir.ORETURN, ir.ORETJMP, ir.OPANIC:
-						if i > lastLabel {
-							cut = true
-						}
-					}
-				}
-			}
-		}
-
-		deadcodeslice(n.PtrInit())
-		switch n.Op() {
-		case ir.OBLOCK:
-			n := n.(*ir.BlockStmt)
-			deadcodeslice(&n.List)
-		case ir.OFOR:
-			n := n.(*ir.ForStmt)
-			deadcodeslice(&n.Body)
-		case ir.OIF:
-			n := n.(*ir.IfStmt)
-			deadcodeslice(&n.Body)
-			deadcodeslice(&n.Else)
-		case ir.ORANGE:
-			n := n.(*ir.RangeStmt)
-			deadcodeslice(&n.Body)
-		case ir.OSELECT:
-			n := n.(*ir.SelectStmt)
-			for _, cas := range n.Cases {
-				deadcodeslice(&cas.Body)
-			}
-		case ir.OSWITCH:
-			n := n.(*ir.SwitchStmt)
-			for _, cas := range n.Cases {
-				deadcodeslice(&cas.Body)
-			}
-		}
-
-		if cut {
-			nn.Set((*nn)[:i+1])
-			break
-		}
-	}
-}
-
-func deadcodeexpr(n ir.Node) ir.Node {
-	// Perform dead-code elimination on short-circuited boolean
-	// expressions involving constants with the intent of
-	// producing a constant 'if' condition.
-	switch n.Op() {
-	case ir.OANDAND:
-		n := n.(*ir.LogicalExpr)
-		n.X = deadcodeexpr(n.X)
-		n.Y = deadcodeexpr(n.Y)
-		if ir.IsConst(n.X, constant.Bool) {
-			if ir.BoolVal(n.X) {
-				return n.Y // true && x => x
-			} else {
-				return n.X // false && x => false
-			}
-		}
-	case ir.OOROR:
-		n := n.(*ir.LogicalExpr)
-		n.X = deadcodeexpr(n.X)
-		n.Y = deadcodeexpr(n.Y)
-		if ir.IsConst(n.X, constant.Bool) {
-			if ir.BoolVal(n.X) {
-				return n.X // true || x => true
-			} else {
-				return n.Y // false || x => x
-			}
-		}
-	}
-	return n
-}
-
 // getIotaValue returns the current value for "iota",
 // or -1 if not within a ConstSpec.
 func getIotaValue() int64 {
 	if i := len(typecheckdefstack); i > 0 {
 		if x := typecheckdefstack[i-1]; x.Op() == ir.OLITERAL {
-			return x.(*ir.Name).Iota()
+			return x.Iota()
 		}
 	}
 

src/cmd/compile/internal/typecheck/universe.go

@@ -90,8 +90,8 @@ var unsafeFuncs = [...]struct {
 	{"Sizeof", ir.OSIZEOF},
 }
 
-// initUniverse initializes the universe block.
+// InitUniverse initializes the universe block.
-func initUniverse() {
+func InitUniverse() {
 	if types.PtrSize == 0 {
 		base.Fatalf("typeinit before betypeinit")
 	}
@@ -336,8 +336,8 @@ func makeErrorInterface() *types.Type {
 	return types.NewInterface(types.NoPkg, []*types.Field{method})
 }
 
-// declareUniverse makes the universe block visible within the current package.
+// DeclareUniverse makes the universe block visible within the current package.
-func declareUniverse() {
+func DeclareUniverse() {
 	// Operationally, this is similar to a dot import of builtinpkg, except
 	// that we silently skip symbols that are already declared in the
 	// package block rather than emitting a redeclared symbol error.
@@ -357,6 +357,6 @@ func declareUniverse() {
 
 	ir.RegFP = NewName(Lookup(".fp"))
 	ir.RegFP.SetType(types.Types[types.TINT32])
-	ir.RegFP.Class_ = ir.PPARAM
+	ir.RegFP.Class = ir.PPARAM
 	ir.RegFP.SetUsed(true)
 }

src/cmd/compile/internal/types/sizeof_test.go

@@ -20,7 +20,7 @@ func TestSizeof(t *testing.T) {
 		_32bit uintptr     // size on 32bit platforms
 		_64bit uintptr     // size on 64bit platforms
 	}{
-		{Sym{}, 48, 80},
+		{Sym{}, 44, 72},
 		{Type{}, 56, 96},
 		{Map{}, 20, 40},
 		{Forward{}, 20, 32},

src/cmd/compile/internal/types/sym.go

@@ -27,8 +27,7 @@ import (
 // NOTE: In practice, things can be messier than the description above
 // for various reasons (historical, convenience).
 type Sym struct {
-	Importdef *Pkg   // where imported definition was found
+	Linkname string // link name
-	Linkname  string // link name
 
 	Pkg  *Pkg
 	Name string // object name
@@ -75,6 +74,10 @@ func (sym *Sym) LinksymName() string {
 	return sym.Pkg.Prefix + "." + sym.Name
 }
 
+// Deprecated: This method should not be used directly. Instead, use a
+// higher-level abstraction that directly returns the linker symbol
+// for a named object. For example, reflectdata.TypeLinksym(t) instead
+// of reflectdata.TypeSym(t).Linksym().
 func (sym *Sym) Linksym() *obj.LSym {
 	if sym == nil {
 		return nil

src/cmd/compile/internal/types/type.go

@@ -6,7 +6,6 @@ package types
 
 import (
 	"cmd/compile/internal/base"
-	"cmd/internal/obj"
 	"cmd/internal/src"
 	"fmt"
 	"sync"
@@ -1532,10 +1531,6 @@ func (t *Type) HasPointers() bool {
 	return true
 }
 
-func (t *Type) Symbol() *obj.LSym {
-	return TypeLinkSym(t)
-}
-
 // Tie returns 'T' if t is a concrete type,
 // 'I' if t is an interface type, and 'E' if t is an empty interface type.
 // It is used to build calls to the conv* and assert* runtime routines.

src/cmd/compile/internal/types/utils.go

@@ -4,19 +4,8 @@
 
 package types
 
-import (
-	"cmd/internal/obj"
-)
-
 const BADWIDTH = -1000000000
 
-// The following variables must be initialized early by the frontend.
-// They are here to break import cycles.
-// TODO(gri) eliminate these dependencies.
-var (
-	TypeLinkSym func(*Type) *obj.LSym
-)
-
 type bitset8 uint8
 
 func (f *bitset8) set(mask uint8, b bool) {

src/cmd/compile/internal/walk/assign.go

@@ -17,7 +17,7 @@ import (
 
 // walkAssign walks an OAS (AssignExpr) or OASOP (AssignOpExpr) node.
 func walkAssign(init *ir.Nodes, n ir.Node) ir.Node {
-	init.Append(n.PtrInit().Take()...)
+	init.Append(ir.TakeInit(n)...)
 
 	var left, right ir.Node
 	switch n.Op() {
@@ -124,7 +124,7 @@ func walkAssignDotType(n *ir.AssignListStmt, init *ir.Nodes) ir.Node {
 
 // walkAssignFunc walks an OAS2FUNC node.
 func walkAssignFunc(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
-	init.Append(n.PtrInit().Take()...)
+	init.Append(ir.TakeInit(n)...)
 
 	r := n.Rhs[0]
 	walkExprListSafe(n.Lhs, init)
@@ -142,15 +142,13 @@ func walkAssignFunc(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
 
 // walkAssignList walks an OAS2 node.
 func walkAssignList(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
-	init.Append(n.PtrInit().Take()...)
+	init.Append(ir.TakeInit(n)...)
-	walkExprListSafe(n.Lhs, init)
+	return ir.NewBlockStmt(src.NoXPos, ascompatee(ir.OAS, n.Lhs, n.Rhs))
-	walkExprListSafe(n.Rhs, init)
-	return ir.NewBlockStmt(src.NoXPos, ascompatee(ir.OAS, n.Lhs, n.Rhs, init))
 }
 
 // walkAssignMapRead walks an OAS2MAPR node.
 func walkAssignMapRead(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
-	init.Append(n.PtrInit().Take()...)
+	init.Append(ir.TakeInit(n)...)
 
 	r := n.Rhs[0].(*ir.IndexExpr)
 	walkExprListSafe(n.Lhs, init)
@@ -213,7 +211,7 @@ func walkAssignMapRead(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
 
 // walkAssignRecv walks an OAS2RECV node.
 func walkAssignRecv(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
-	init.Append(n.PtrInit().Take()...)
+	init.Append(ir.TakeInit(n)...)
 
 	r := n.Rhs[0].(*ir.UnaryExpr) // recv
 	walkExprListSafe(n.Lhs, init)
@@ -232,56 +230,21 @@ func walkAssignRecv(init *ir.Nodes, n *ir.AssignListStmt) ir.Node {
 
 // walkReturn walks an ORETURN node.
 func walkReturn(n *ir.ReturnStmt) ir.Node {
-	ir.CurFunc.NumReturns++
+	fn := ir.CurFunc
+
+	fn.NumReturns++
 	if len(n.Results) == 0 {
 		return n
 	}
-	if (ir.HasNamedResults(ir.CurFunc) && len(n.Results) > 1) || paramoutheap(ir.CurFunc) {
-		// assign to the function out parameters,
-		// so that ascompatee can fix up conflicts
-		var rl []ir.Node
 
-		for _, ln := range ir.CurFunc.Dcl {
+	results := fn.Type().Results().FieldSlice()
-			cl := ln.Class_
+	dsts := make([]ir.Node, len(results))
-			if cl == ir.PAUTO || cl == ir.PAUTOHEAP {
+	for i, v := range results {
-				break
+		// TODO(mdempsky): typecheck should have already checked the result variables.
-			}
+		dsts[i] = typecheck.AssignExpr(v.Nname.(*ir.Name))
-			if cl == ir.PPARAMOUT {
-				var ln ir.Node = ln
-				if ir.IsParamStackCopy(ln) {
-					ln = walkExpr(typecheck.Expr(ir.NewStarExpr(base.Pos, ln.Name().Heapaddr)), nil)
-				}
-				rl = append(rl, ln)
-			}
-		}
-
-		if got, want := len(n.Results), len(rl); got != want {
-			// order should have rewritten multi-value function calls
-			// with explicit OAS2FUNC nodes.
-			base.Fatalf("expected %v return arguments, have %v", want, got)
-		}
-
-		// move function calls out, to make ascompatee's job easier.
-		walkExprListSafe(n.Results, n.PtrInit())
-
-		n.Results.Set(ascompatee(n.Op(), rl, n.Results, n.PtrInit()))
-		return n
 	}
-	walkExprList(n.Results, n.PtrInit())
 
-	// For each return parameter (lhs), assign the corresponding result (rhs).
+	n.Results = ascompatee(n.Op(), dsts, n.Results)
-	lhs := ir.CurFunc.Type().Results()
-	rhs := n.Results
-	res := make([]ir.Node, lhs.NumFields())
-	for i, nl := range lhs.FieldSlice() {
-		nname := ir.AsNode(nl.Nname)
-		if ir.IsParamHeapCopy(nname) {
-			nname = nname.Name().Stackcopy
-		}
-		a := ir.NewAssignStmt(base.Pos, nname, rhs[i])
-		res[i] = convas(a, n.PtrInit())
-	}
-	n.Results.Set(res)
 	return n
 }
 
@@ -342,20 +305,12 @@ func ascompatet(nl ir.Nodes, nr *types.Type) []ir.Node {
 // check assign expression list to
 // an expression list. called in
 //	expr-list = expr-list
-func ascompatee(op ir.Op, nl, nr []ir.Node, init *ir.Nodes) []ir.Node {
+func ascompatee(op ir.Op, nl, nr []ir.Node) []ir.Node {
 	// cannot happen: should have been rejected during type checking
 	if len(nl) != len(nr) {
 		base.Fatalf("assignment operands mismatch: %+v / %+v", ir.Nodes(nl), ir.Nodes(nr))
 	}
 
-	// ensure order of evaluation for function calls
-	for i := range nl {
-		nl[i] = safeExpr(nl[i], init)
-	}
-	for i := range nr {
-		nr[i] = safeExpr(nr[i], init)
-	}
-
 	var assigned ir.NameSet
 	var memWrite bool
 
@@ -376,27 +331,22 @@ func ascompatee(op ir.Op, nl, nr []ir.Node, init *ir.Nodes) []ir.Node {
 	// If a needed expression may be affected by an
 	// earlier assignment, make an early copy of that
 	// expression and use the copy instead.
-	var early []ir.Node
+	var early ir.Nodes
 	save := func(np *ir.Node) {
 		if n := *np; affected(n) {
-			tmp := ir.Node(typecheck.Temp(n.Type()))
+			*np = copyExpr(n, n.Type(), &early)
-			as := typecheck.Stmt(ir.NewAssignStmt(base.Pos, tmp, n))
-			early = append(early, as)
-			*np = tmp
 		}
 	}
 
-	var late []ir.Node
+	var late ir.Nodes
-	for i, l := range nl {
+	for i, lorig := range nl {
-		r := nr[i]
+		l, r := lorig, nr[i]
 
 		// Do not generate 'x = x' during return. See issue 4014.
 		if op == ir.ORETURN && ir.SameSafeExpr(l, r) {
 			continue
 		}
 
-		as := ir.NewAssignStmt(base.Pos, l, r)
-
 		// Save subexpressions needed on left side.
 		// Drill through non-dereferences.
 		for {
@@ -438,11 +388,11 @@ func ascompatee(op ir.Op, nl, nr []ir.Node, init *ir.Nodes) []ir.Node {
 		}
 
 		// Save expression on right side.
-		save(&as.Y)
+		save(&r)
 
-		late = append(late, convas(as, init))
+		appendWalkStmt(&late, convas(ir.NewAssignStmt(base.Pos, lorig, r), &late))
 
-		if name == nil || name.Addrtaken() || name.Class_ == ir.PEXTERN || name.Class_ == ir.PAUTOHEAP {
+		if name == nil || name.Addrtaken() || name.Class == ir.PEXTERN || name.Class == ir.PAUTOHEAP {
 			memWrite = true
 			continue
 		}
@@ -450,10 +400,16 @@ func ascompatee(op ir.Op, nl, nr []ir.Node, init *ir.Nodes) []ir.Node {
 			// We can ignore assignments to blank.
 			continue
 		}
+		if op == ir.ORETURN && types.OrigSym(name.Sym()) == nil {
+			// We can also ignore assignments to anonymous result
+			// parameters. These can't appear in expressions anyway.
+			continue
+		}
 		assigned.Add(name)
 	}
 
-	return append(early, late...)
+	early.Append(late.Take()...)
+	return early
 }
 
 // readsMemory reports whether the evaluation n directly reads from
@@ -462,7 +418,7 @@ func readsMemory(n ir.Node) bool {
 	switch n.Op() {
 	case ir.ONAME:
 		n := n.(*ir.Name)
-		return n.Class_ == ir.PEXTERN || n.Class_ == ir.PAUTOHEAP || n.Addrtaken()
+		return n.Class == ir.PEXTERN || n.Class == ir.PAUTOHEAP || n.Addrtaken()
 
 	case ir.OADD,
 		ir.OAND,

src/cmd/compile/internal/walk/builtin.go

@@ -206,7 +206,7 @@ func walkCopy(n *ir.BinaryExpr, init *ir.Nodes, runtimecall bool) ir.Node {
 
 // walkDelete walks an ODELETE node.
 func walkDelete(init *ir.Nodes, n *ir.CallExpr) ir.Node {
-	init.Append(n.PtrInit().Take()...)
+	init.Append(ir.TakeInit(n)...)
 	map_ := n.Args[0]
 	key := n.Args[1]
 	map_ = walkExpr(map_, init)
@@ -531,7 +531,7 @@ func walkPrint(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
 			t = append(t, n)
 		}
 		t = append(t, ir.NewString("\n"))
-		nn.Args.Set(t)
+		nn.Args = t
 	}
 
 	// Collapse runs of constant strings.
@@ -551,7 +551,7 @@ func walkPrint(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
 			i++
 		}
 	}
-	nn.Args.Set(t)
+	nn.Args = t
 
 	calls := []ir.Node{mkcall("printlock", nil, init)}
 	for i, n := range nn.Args {
@@ -653,7 +653,7 @@ func walkPrint(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
 	walkExprList(calls, init)
 
 	r := ir.NewBlockStmt(base.Pos, nil)
-	r.List.Set(calls)
+	r.List = calls
 	return walkStmt(typecheck.Stmt(r))
 }
 

src/cmd/compile/internal/walk/closure.go

@@ -52,7 +52,7 @@ func Closure(fn *ir.Func) {
 				v = addr
 			}
 
-			v.Class_ = ir.PPARAM
+			v.Class = ir.PPARAM
 			decls = append(decls, v)
 
 			fld := types.NewField(src.NoXPos, v.Sym(), v.Type())
@@ -67,7 +67,7 @@ func Closure(fn *ir.Func) {
 		}
 
 		types.CalcSize(f.Type())
-		fn.SetType(f.Type()) // update type of ODCLFUNC
+		fn.Nname.SetType(f.Type()) // update type of ODCLFUNC
 	} else {
 		// The closure is not called, so it is going to stay as closure.
 		var body []ir.Node
@@ -84,7 +84,7 @@ func Closure(fn *ir.Func) {
 
 			if v.Byval() && v.Type().Width <= int64(2*types.PtrSize) {
 				// If it is a small variable captured by value, downgrade it to PAUTO.
-				v.Class_ = ir.PAUTO
+				v.Class = ir.PAUTO
 				fn.Dcl = append(fn.Dcl, v)
 				body = append(body, ir.NewAssignStmt(base.Pos, v, cr))
 			} else {
@@ -92,7 +92,7 @@ func Closure(fn *ir.Func) {
 				// and initialize in entry prologue.
 				addr := typecheck.NewName(typecheck.Lookup("&" + v.Sym().Name))
 				addr.SetType(types.NewPtr(v.Type()))
-				addr.Class_ = ir.PAUTO
+				addr.Class = ir.PAUTO
 				addr.SetUsed(true)
 				addr.Curfn = fn
 				fn.Dcl = append(fn.Dcl, addr)
@@ -107,7 +107,7 @@ func Closure(fn *ir.Func) {
 
 		if len(body) > 0 {
 			typecheck.Stmts(body)
-			fn.Enter.Set(body)
+			fn.Enter = body
 			fn.SetNeedctxt(true)
 		}
 	}
@@ -129,9 +129,9 @@ func walkClosure(clo *ir.ClosureExpr, init *ir.Nodes) ir.Node {
 
 	typ := typecheck.ClosureType(clo)
 
-	clos := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ).(ir.Ntype), nil)
+	clos := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ), nil)
 	clos.SetEsc(clo.Esc())
-	clos.List.Set(append([]ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, fn.Nname)}, fn.ClosureEnter...))
+	clos.List = append([]ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, fn.Nname)}, closureArgs(clo)...)
 
 	addr := typecheck.NodAddr(clos)
 	addr.SetEsc(clo.Esc())
@@ -144,14 +144,34 @@ func walkClosure(clo *ir.ClosureExpr, init *ir.Nodes) ir.Node {
 		if !types.Identical(typ, x.Type()) {
 			panic("closure type does not match order's assigned type")
 		}
-		addr.Alloc = x
+		addr.Prealloc = x
 		clo.Prealloc = nil
 	}
 
 	return walkExpr(cfn, init)
 }
 
-func walkCallPart(n *ir.CallPartExpr, init *ir.Nodes) ir.Node {
+// closureArgs returns a slice of expressions that an be used to
+// initialize the given closure's free variables. These correspond
+// one-to-one with the variables in clo.Func.ClosureVars, and will be
+// either an ONAME node (if the variable is captured by value) or an
+// OADDR-of-ONAME node (if not).
+func closureArgs(clo *ir.ClosureExpr) []ir.Node {
+	fn := clo.Func
+
+	args := make([]ir.Node, len(fn.ClosureVars))
+	for i, v := range fn.ClosureVars {
+		var outer ir.Node
+		outer = v.Outer
+		if !v.Byval() {
+			outer = typecheck.NodAddrAt(fn.Pos(), outer)
+		}
+		args[i] = typecheck.Expr(outer)
+	}
+	return args
+}
+
+func walkCallPart(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
 	// Create closure in the form of a composite literal.
 	// For x.M with receiver (x) type T, the generated code looks like:
 	//
@@ -174,9 +194,9 @@ func walkCallPart(n *ir.CallPartExpr, init *ir.Nodes) ir.Node {
 
 	typ := typecheck.PartialCallType(n)
 
-	clos := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ).(ir.Ntype), nil)
+	clos := ir.NewCompLitExpr(base.Pos, ir.OCOMPLIT, ir.TypeNode(typ), nil)
 	clos.SetEsc(n.Esc())
-	clos.List = []ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, n.Func.Nname), n.X}
+	clos.List = []ir.Node{ir.NewUnaryExpr(base.Pos, ir.OCFUNC, typecheck.MethodValueWrapper(n).Nname), n.X}
 
 	addr := typecheck.NodAddr(clos)
 	addr.SetEsc(n.Esc())
@@ -189,7 +209,7 @@ func walkCallPart(n *ir.CallPartExpr, init *ir.Nodes) ir.Node {
 		if !types.Identical(typ, x.Type()) {
 			panic("partial call type does not match order's assigned type")
 		}
-		addr.Alloc = x
+		addr.Prealloc = x
 		n.Prealloc = nil
 	}
 

src/cmd/compile/internal/walk/complit.go

@@ -59,7 +59,7 @@ func (c initContext) String() string {
 func readonlystaticname(t *types.Type) *ir.Name {
 	n := staticinit.StaticName(t)
 	n.MarkReadonly()
-	n.Sym().Linksym().Set(obj.AttrContentAddressable, true)
+	n.Linksym().Set(obj.AttrContentAddressable, true)
 	return n
 }
 
@@ -68,7 +68,7 @@ func isSimpleName(nn ir.Node) bool {
 		return false
 	}
 	n := nn.(*ir.Name)
-	return n.Class_ != ir.PAUTOHEAP && n.Class_ != ir.PEXTERN
+	return n.Class != ir.PAUTOHEAP && n.Class != ir.PEXTERN
 }
 
 func litas(l ir.Node, r ir.Node, init *ir.Nodes) {
@@ -294,7 +294,7 @@ func slicelit(ctxt initContext, n *ir.CompLitExpr, var_ ir.Node, init *ir.Nodes)
 		// copy static to slice
 		var_ = typecheck.AssignExpr(var_)
 		name, offset, ok := staticinit.StaticLoc(var_)
-		if !ok || name.Class_ != ir.PEXTERN {
+		if !ok || name.Class != ir.PEXTERN {
 			base.Fatalf("slicelit: %v", var_)
 		}
 		staticdata.InitSlice(name, offset, vstat, t.NumElem())
@@ -539,7 +539,7 @@ func anylit(n ir.Node, var_ ir.Node, init *ir.Nodes) {
 		appendWalkStmt(init, ir.NewAssignStmt(base.Pos, var_, n))
 
 	case ir.OMETHEXPR:
-		n := n.(*ir.MethodExpr)
+		n := n.(*ir.SelectorExpr)
 		anylit(n.FuncName(), var_, init)
 
 	case ir.OPTRLIT:
@@ -549,10 +549,10 @@ func anylit(n ir.Node, var_ ir.Node, init *ir.Nodes) {
 		}
 
 		var r ir.Node
-		if n.Alloc != nil {
+		if n.Prealloc != nil {
 			// n.Right is stack temporary used as backing store.
-			appendWalkStmt(init, ir.NewAssignStmt(base.Pos, n.Alloc, nil)) // zero backing store, just in case (#18410)
+			appendWalkStmt(init, ir.NewAssignStmt(base.Pos, n.Prealloc, nil)) // zero backing store, just in case (#18410)
-			r = typecheck.NodAddr(n.Alloc)
+			r = typecheck.NodAddr(n.Prealloc)
 		} else {
 			r = ir.NewUnaryExpr(base.Pos, ir.ONEW, ir.TypeNode(n.X.Type()))
 			r.SetEsc(n.Esc())
@@ -657,7 +657,7 @@ func genAsStatic(as *ir.AssignStmt) {
 	}
 
 	name, offset, ok := staticinit.StaticLoc(as.X)
-	if !ok || (name.Class_ != ir.PEXTERN && as.X != ir.BlankNode) {
+	if !ok || (name.Class != ir.PEXTERN && as.X != ir.BlankNode) {
 		base.Fatalf("genAsStatic: lhs %v", as.X)
 	}
 
@@ -666,7 +666,7 @@ func genAsStatic(as *ir.AssignStmt) {
 		staticdata.InitConst(name, offset, r, int(r.Type().Width))
 		return
 	case ir.OMETHEXPR:
-		r := r.(*ir.MethodExpr)
+		r := r.(*ir.SelectorExpr)
 		staticdata.InitFunc(name, offset, r.FuncName())
 		return
 	case ir.ONAME:
@@ -674,7 +674,7 @@ func genAsStatic(as *ir.AssignStmt) {
 		if r.Offset_ != 0 {
 			base.Fatalf("genAsStatic %+v", as)
 		}
-		if r.Class_ == ir.PFUNC {
+		if r.Class == ir.PFUNC {
 			staticdata.InitFunc(name, offset, r)
 			return
 		}

src/cmd/compile/internal/walk/convert.go

@@ -68,12 +68,12 @@ func walkConvInterface(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 
 	if ir.Names.Staticuint64s == nil {
 		ir.Names.Staticuint64s = typecheck.NewName(ir.Pkgs.Runtime.Lookup("staticuint64s"))
-		ir.Names.Staticuint64s.Class_ = ir.PEXTERN
+		ir.Names.Staticuint64s.Class = ir.PEXTERN
 		// The actual type is [256]uint64, but we use [256*8]uint8 so we can address
 		// individual bytes.
 		ir.Names.Staticuint64s.SetType(types.NewArray(types.Types[types.TUINT8], 256*8))
 		ir.Names.Zerobase = typecheck.NewName(ir.Pkgs.Runtime.Lookup("zerobase"))
-		ir.Names.Zerobase.Class_ = ir.PEXTERN
+		ir.Names.Zerobase.Class = ir.PEXTERN
 		ir.Names.Zerobase.SetType(types.Types[types.TUINTPTR])
 	}
 
@@ -98,7 +98,7 @@ func walkConvInterface(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
 		xe := ir.NewIndexExpr(base.Pos, ir.Names.Staticuint64s, index)
 		xe.SetBounded(true)
 		value = xe
-	case n.X.Op() == ir.ONAME && n.X.(*ir.Name).Class_ == ir.PEXTERN && n.X.(*ir.Name).Readonly():
+	case n.X.Op() == ir.ONAME && n.X.(*ir.Name).Class == ir.PEXTERN && n.X.(*ir.Name).Readonly():
 		// n.Left is a readonly global; use it directly.
 		value = n.X
 	case !fromType.IsInterface() && n.Esc() == ir.EscNone && fromType.Width <= 1024:
@@ -438,18 +438,14 @@ func walkCheckPtrAlignment(n *ir.ConvExpr, init *ir.Nodes, count ir.Node) ir.Nod
 }
 
 func walkCheckPtrArithmetic(n *ir.ConvExpr, init *ir.Nodes) ir.Node {
-	// Calling cheapexpr(n, init) below leads to a recursive call
+	// Calling cheapexpr(n, init) below leads to a recursive call to
-	// to walkexpr, which leads us back here again. Use n.Opt to
+	// walkexpr, which leads us back here again. Use n.Checkptr to
 	// prevent infinite loops.
-	if opt := n.Opt(); opt == &walkCheckPtrArithmeticMarker {
+	if n.CheckPtr() {
 		return n
-	} else if opt != nil {
-		// We use n.Opt() here because today it's not used for OCONVNOP. If that changes,
-		// there's no guarantee that temporarily replacing it is safe, so just hard fail here.
-		base.Fatalf("unexpected Opt: %v", opt)
 	}
-	n.SetOpt(&walkCheckPtrArithmeticMarker)
+	n.SetCheckPtr(true)
-	defer n.SetOpt(nil)
+	defer n.SetCheckPtr(false)
 
 	// TODO(mdempsky): Make stricter. We only need to exempt
 	// reflect.Value.Pointer and reflect.Value.UnsafeAddr.

src/cmd/compile/internal/walk/expr.go

@@ -26,7 +26,7 @@ func walkExpr(n ir.Node, init *ir.Nodes) ir.Node {
 		return n
 	}
 
-	if init == n.PtrInit() {
+	if n, ok := n.(ir.InitNode); ok && init == n.PtrInit() {
 		// not okay to use n->ninit when walking n,
 		// because we might replace n with some other node
 		// and would lose the init list.
@@ -35,7 +35,7 @@ func walkExpr(n ir.Node, init *ir.Nodes) ir.Node {
 
 	if len(n.Init()) != 0 {
 		walkStmtList(n.Init())
-		init.Append(n.PtrInit().Take()...)
+		init.Append(ir.TakeInit(n)...)
 	}
 
 	lno := ir.SetPos(n)
@@ -52,9 +52,9 @@ func walkExpr(n ir.Node, init *ir.Nodes) ir.Node {
 		base.Fatalf("expression has untyped type: %+v", n)
 	}
 
-	if n.Op() == ir.ONAME && n.(*ir.Name).Class_ == ir.PAUTOHEAP {
+	if n.Op() == ir.ONAME && n.(*ir.Name).Class == ir.PAUTOHEAP {
 		n := n.(*ir.Name)
-		nn := ir.NewStarExpr(base.Pos, n.Name().Heapaddr)
+		nn := ir.NewStarExpr(base.Pos, n.Heapaddr)
 		nn.X.MarkNonNil()
 		return walkExpr(typecheck.Expr(nn), init)
 	}
@@ -100,7 +100,7 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 
 	case ir.OMETHEXPR:
 		// TODO(mdempsky): Do this right after type checking.
-		n := n.(*ir.MethodExpr)
+		n := n.(*ir.SelectorExpr)
 		return n.FuncName()
 
 	case ir.ONOT, ir.ONEG, ir.OPLUS, ir.OBITNOT, ir.OREAL, ir.OIMAG, ir.OSPTR, ir.OITAB, ir.OIDATA:
@@ -306,7 +306,7 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		return walkClosure(n.(*ir.ClosureExpr), init)
 
 	case ir.OCALLPART:
-		return walkCallPart(n.(*ir.CallPartExpr), init)
+		return walkCallPart(n.(*ir.SelectorExpr), init)
 	}
 
 	// No return! Each case must return (or panic),
@@ -359,7 +359,7 @@ func safeExpr(n ir.Node, init *ir.Nodes) ir.Node {
 
 	if len(n.Init()) != 0 {
 		walkStmtList(n.Init())
-		init.Append(n.PtrInit().Take()...)
+		init.Append(ir.TakeInit(n)...)
 	}
 
 	switch n.Op() {
@@ -477,7 +477,7 @@ func walkAddString(n *ir.AddStringExpr, init *ir.Nodes) ir.Node {
 
 	cat := typecheck.LookupRuntime(fn)
 	r := ir.NewCallExpr(base.Pos, ir.OCALL, cat, nil)
-	r.Args.Set(args)
+	r.Args = args
 	r1 := typecheck.Expr(r)
 	r1 = walkExpr(r1, init)
 	r1.SetType(n.Type())
@@ -498,8 +498,7 @@ func walkCall(n *ir.CallExpr, init *ir.Nodes) ir.Node {
 
 		// Prepend captured variables to argument list.
 		clo := n.X.(*ir.ClosureExpr)
-		n.Args.Prepend(clo.Func.ClosureEnter...)
+		n.Args.Prepend(closureArgs(clo)...)
-		clo.Func.ClosureEnter.Set(nil)
 
 		// Replace OCLOSURE with ONAME/PFUNC.
 		n.X = clo.Func.Nname
@@ -563,8 +562,8 @@ func walkCall1(n *ir.CallExpr, init *ir.Nodes) {
 		}
 	}
 
-	n.Args.Set(tempAssigns)
+	n.Args = tempAssigns
-	n.Rargs.Set(args)
+	n.Rargs = args
 }
 
 // walkDivMod walks an ODIV or OMOD node.
@@ -639,12 +638,13 @@ func walkDot(n *ir.SelectorExpr, init *ir.Nodes) ir.Node {
 func walkDotType(n *ir.TypeAssertExpr, init *ir.Nodes) ir.Node {
 	n.X = walkExpr(n.X, init)
 	// Set up interface type addresses for back end.
-	n.Ntype = reflectdata.TypePtr(n.Type())
+
+	n.DstType = reflectdata.TypePtr(n.Type())
 	if n.Op() == ir.ODOTTYPE {
-		n.Ntype.(*ir.AddrExpr).Alloc = reflectdata.TypePtr(n.X.Type())
+		n.SrcType = reflectdata.TypePtr(n.X.Type())
 	}
 	if !n.Type().IsInterface() && !n.X.Type().IsEmptyInterface() {
-		n.Itab = []ir.Node{reflectdata.ITabAddr(n.Type(), n.X.Type())}
+		n.Itab = reflectdata.ITabAddr(n.Type(), n.X.Type())
 	}
 	return n
 }
@@ -974,7 +974,7 @@ func usefield(n *ir.SelectorExpr) {
 
 	sym := reflectdata.TrackSym(outer, field)
 	if ir.CurFunc.FieldTrack == nil {
-		ir.CurFunc.FieldTrack = make(map[*types.Sym]struct{})
+		ir.CurFunc.FieldTrack = make(map[*obj.LSym]struct{})
 	}
 	ir.CurFunc.FieldTrack[sym] = struct{}{}
 }

src/cmd/compile/internal/walk/order.go

@@ -102,7 +102,7 @@ func (o *orderState) newTemp(t *types.Type, clear bool) *ir.Name {
 
 // copyExpr behaves like newTemp but also emits
 // code to initialize the temporary to the value n.
-func (o *orderState) copyExpr(n ir.Node) ir.Node {
+func (o *orderState) copyExpr(n ir.Node) *ir.Name {
 	return o.copyExpr1(n, false)
 }
 
@@ -235,7 +235,7 @@ func (o *orderState) safeExpr(n ir.Node) ir.Node {
 // because we emit explicit VARKILL instructions marking the end of those
 // temporaries' lifetimes.
 func isaddrokay(n ir.Node) bool {
-	return ir.IsAddressable(n) && (n.Op() != ir.ONAME || n.(*ir.Name).Class_ == ir.PEXTERN || ir.IsAutoTmp(n))
+	return ir.IsAddressable(n) && (n.Op() != ir.ONAME || n.(*ir.Name).Class == ir.PEXTERN || ir.IsAutoTmp(n))
 }
 
 // addrTemp ensures that n is okay to pass by address to runtime routines.
@@ -406,7 +406,7 @@ func (o *orderState) edge() {
 	// Create a new uint8 counter to be allocated in section
 	// __libfuzzer_extra_counters.
 	counter := staticinit.StaticName(types.Types[types.TUINT8])
-	counter.Name().SetLibfuzzerExtraCounter(true)
+	counter.SetLibfuzzerExtraCounter(true)
 
 	// counter += 1
 	incr := ir.NewAssignOpStmt(base.Pos, ir.OADD, counter, ir.NewInt(1))
@@ -423,7 +423,7 @@ func orderBlock(n *ir.Nodes, free map[string][]*ir.Name) {
 	order.edge()
 	order.stmtList(*n)
 	order.cleanTemp(mark)
-	n.Set(order.out)
+	*n = order.out
 }
 
 // exprInPlace orders the side effects in *np and
@@ -466,8 +466,7 @@ func (o *orderState) init(n ir.Node) {
 		}
 		return
 	}
-	o.stmtList(n.Init())
+	o.stmtList(ir.TakeInit(n))
-	n.PtrInit().Set(nil)
 }
 
 // call orders the call expression n.
@@ -517,8 +516,8 @@ func (o *orderState) call(nn ir.Node) {
 			if arg.X.Type().IsUnsafePtr() {
 				x := o.copyExpr(arg.X)
 				arg.X = x
-				x.Name().SetAddrtaken(true) // ensure SSA keeps the x variable
+				x.SetAddrtaken(true) // ensure SSA keeps the x variable
-				n.Body.Append(typecheck.Stmt(ir.NewUnaryExpr(base.Pos, ir.OVARLIVE, x)))
+				n.KeepAlive = append(n.KeepAlive, x)
 			}
 		}
 	}
@@ -538,21 +537,7 @@ func (o *orderState) call(nn ir.Node) {
 	}
 }
 
-// mapAssign appends n to o.out, introducing temporaries
+// mapAssign appends n to o.out.
-// to make sure that all map assignments have the form m[k] = x.
-// (Note: expr has already been called on n, so we know k is addressable.)
-//
-// If n is the multiple assignment form ..., m[k], ... = ..., x, ..., the rewrite is
-//	t1 = m
-//	t2 = k
-//	...., t3, ... = ..., x, ...
-//	t1[t2] = t3
-//
-// The temporaries t1, t2 are needed in case the ... being assigned
-// contain m or k. They are usually unnecessary, but in the unnecessary
-// cases they are also typically registerizable, so not much harm done.
-// And this only applies to the multiple-assignment form.
-// We could do a more precise analysis if needed, like in walk.go.
 func (o *orderState) mapAssign(n ir.Node) {
 	switch n.Op() {
 	default:
@@ -573,28 +558,7 @@ func (o *orderState) mapAssign(n ir.Node) {
 
 	case ir.OAS2, ir.OAS2DOTTYPE, ir.OAS2MAPR, ir.OAS2FUNC:
 		n := n.(*ir.AssignListStmt)
-		var post []ir.Node
-		for i, m := range n.Lhs {
-			switch {
-			case m.Op() == ir.OINDEXMAP:
-				m := m.(*ir.IndexExpr)
-				if !ir.IsAutoTmp(m.X) {
-					m.X = o.copyExpr(m.X)
-				}
-				if !ir.IsAutoTmp(m.Index) {
-					m.Index = o.copyExpr(m.Index)
-				}
-				fallthrough
-			case base.Flag.Cfg.Instrumenting && n.Op() == ir.OAS2FUNC && !ir.IsBlank(m):
-				t := o.newTemp(m.Type(), false)
-				n.Lhs[i] = t
-				a := ir.NewAssignStmt(base.Pos, m, t)
-				post = append(post, typecheck.Stmt(a))
-			}
-		}
-
 		o.out = append(o.out, n)
-		o.out = append(o.out, post...)
 	}
 }
 
@@ -938,8 +902,7 @@ func (o *orderState) stmt(n ir.Node) {
 				if !ir.IsAutoTmp(recv.X) {
 					recv.X = o.copyExpr(recv.X)
 				}
-				init := *r.PtrInit()
+				init := ir.TakeInit(r)
-				r.PtrInit().Set(nil)
 
 				colas := r.Def
 				do := func(i int, t *types.Type) {
@@ -955,7 +918,7 @@ func (o *orderState) stmt(n ir.Node) {
 						if len(init) > 0 && init[0].Op() == ir.ODCL && init[0].(*ir.Decl).X == n {
 							init = init[1:]
 						}
-						dcl := typecheck.Stmt(ir.NewDecl(base.Pos, ir.ODCL, n))
+						dcl := typecheck.Stmt(ir.NewDecl(base.Pos, ir.ODCL, n.(*ir.Name)))
 						ncas.PtrInit().Append(dcl)
 					}
 					tmp := o.newTemp(t, t.HasPointers())
@@ -1000,8 +963,7 @@ func (o *orderState) stmt(n ir.Node) {
 
 			// TODO(mdempsky): Is this actually necessary?
 			// walkselect appears to walk Ninit.
-			cas.Body.Prepend(cas.Init()...)
+			cas.Body.Prepend(ir.TakeInit(cas)...)
-			cas.PtrInit().Set(nil)
 		}
 
 		o.out = append(o.out, n)
@@ -1236,9 +1198,9 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 		// If left-hand side doesn't cause a short-circuit, issue right-hand side.
 		nif := ir.NewIfStmt(base.Pos, r, nil, nil)
 		if n.Op() == ir.OANDAND {
-			nif.Body.Set(gen)
+			nif.Body = gen
 		} else {
-			nif.Else.Set(gen)
+			nif.Else = gen
 		}
 		o.out = append(o.out, nif)
 		return r
@@ -1310,7 +1272,7 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 		return n
 
 	case ir.OCALLPART:
-		n := n.(*ir.CallPartExpr)
+		n := n.(*ir.SelectorExpr)
 		n.X = o.expr(n.X, nil)
 		if n.Transient() {
 			t := typecheck.PartialCallType(n)
@@ -1404,7 +1366,7 @@ func (o *orderState) expr1(n, lhs ir.Node) ir.Node {
 
 			statics = append(statics, r)
 		}
-		n.List.Set(statics)
+		n.List = statics
 
 		if len(dynamics) == 0 {
 			return n
@@ -1451,8 +1413,8 @@ func (o *orderState) as2(n *ir.AssignListStmt) {
 	o.out = append(o.out, n)
 
 	as := ir.NewAssignListStmt(base.Pos, ir.OAS2, nil, nil)
-	as.Lhs.Set(left)
+	as.Lhs = left
-	as.Rhs.Set(tmplist)
+	as.Rhs = tmplist
 	o.stmt(typecheck.Stmt(as))
 }
 

src/cmd/compile/internal/walk/race.go

@@ -8,13 +8,14 @@ import (
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/ssagen"
+	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
 	"cmd/internal/src"
 	"cmd/internal/sys"
 )
 
 func instrument(fn *ir.Func) {
-	if fn.Pragma&ir.Norace != 0 || (fn.Sym().Linksym() != nil && fn.Sym().Linksym().ABIWrapper()) {
+	if fn.Pragma&ir.Norace != 0 || (fn.Linksym() != nil && fn.Linksym().ABIWrapper()) {
 		return
 	}
 
@@ -36,7 +37,10 @@ func instrument(fn *ir.Func) {
 			// This only works for amd64. This will not
 			// work on arm or others that might support
 			// race in the future.
-			nodpc := ir.RegFP.CloneName()
+
+			nodpc := ir.NewNameAt(src.NoXPos, typecheck.Lookup(".fp"))
+			nodpc.Class = ir.PPARAM
+			nodpc.SetUsed(true)
 			nodpc.SetType(types.Types[types.TUINTPTR])
 			nodpc.SetFrameOffset(int64(-types.PtrSize))
 			fn.Dcl = append(fn.Dcl, nodpc)

src/cmd/compile/internal/walk/range.go

@@ -210,7 +210,7 @@ func walkRange(nrange *ir.RangeStmt) ir.Node {
 		a.SetTypecheck(1)
 		a.Lhs = []ir.Node{hv1, hb}
 		a.Rhs = []ir.Node{ir.NewUnaryExpr(base.Pos, ir.ORECV, ha)}
-		*nfor.Cond.PtrInit() = []ir.Node{a}
+		nfor.Cond = ir.InitExpr([]ir.Node{a}, nfor.Cond)
 		if v1 == nil {
 			body = nil
 		} else {
@@ -429,7 +429,7 @@ func arrayClear(loop *ir.RangeStmt, v1, v2, a ir.Node) ir.Node {
 	// 	i = len(a) - 1
 	// }
 	n := ir.NewIfStmt(base.Pos, nil, nil, nil)
-	n.Body.Set(nil)
+	n.Body = nil
 	n.Cond = ir.NewBinaryExpr(base.Pos, ir.ONE, ir.NewUnaryExpr(base.Pos, ir.OLEN, a), ir.NewInt(0))
 
 	// hp = &a[0]

src/cmd/compile/internal/walk/select.go

@@ -17,13 +17,12 @@ func walkSelect(sel *ir.SelectStmt) {
 		base.Fatalf("double walkselect")
 	}
 
-	init := sel.Init()
+	init := ir.TakeInit(sel)
-	sel.PtrInit().Set(nil)
 
 	init = append(init, walkSelectCases(sel.Cases)...)
 	sel.Cases = nil
 
-	sel.Compiled.Set(init)
+	sel.Compiled = init
 	walkStmtList(sel.Compiled)
 
 	base.Pos = lno
@@ -45,8 +44,7 @@ func walkSelectCases(cases []*ir.CommClause) []ir.Node {
 		l := cas.Init()
 		if cas.Comm != nil { // not default:
 			n := cas.Comm
-			l = append(l, n.Init()...)
+			l = append(l, ir.TakeInit(n)...)
-			n.PtrInit().Set(nil)
 			switch n.Op() {
 			default:
 				base.Fatalf("select %v", n.Op())
@@ -106,7 +104,7 @@ func walkSelectCases(cases []*ir.CommClause) []ir.Node {
 		n := cas.Comm
 		ir.SetPos(n)
 		r := ir.NewIfStmt(base.Pos, nil, nil, nil)
-		r.PtrInit().Set(cas.Init())
+		*r.PtrInit() = cas.Init()
 		var call ir.Node
 		switch n.Op() {
 		default:
@@ -138,8 +136,8 @@ func walkSelectCases(cases []*ir.CommClause) []ir.Node {
 		}
 
 		r.Cond = typecheck.Expr(call)
-		r.Body.Set(cas.Body)
+		r.Body = cas.Body
-		r.Else.Set(append(dflt.Init(), dflt.Body...))
+		r.Else = append(dflt.Init(), dflt.Body...)
 		return []ir.Node{r, ir.NewBranchStmt(base.Pos, ir.OBREAK, nil)}
 	}
 
@@ -171,8 +169,7 @@ func walkSelectCases(cases []*ir.CommClause) []ir.Node {
 	for _, cas := range cases {
 		ir.SetPos(cas)
 
-		init = append(init, cas.Init()...)
+		init = append(init, ir.TakeInit(cas)...)
-		cas.PtrInit().Set(nil)
 
 		n := cas.Comm
 		if n == nil { // default:

src/cmd/compile/internal/walk/stmt.go

@@ -55,19 +55,18 @@ func walkStmt(n ir.Node) ir.Node {
 		if n.Typecheck() == 0 {
 			base.Fatalf("missing typecheck: %+v", n)
 		}
-		init := n.Init()
+		init := ir.TakeInit(n)
-		n.PtrInit().Set(nil)
 		n = walkExpr(n, &init)
 		if n.Op() == ir.ONAME {
 			// copy rewrote to a statement list and a temp for the length.
 			// Throw away the temp to avoid plain values as statements.
 			n = ir.NewBlockStmt(n.Pos(), init)
-			init.Set(nil)
+			init = nil
 		}
 		if len(init) > 0 {
 			switch n.Op() {
 			case ir.OAS, ir.OAS2, ir.OBLOCK:
-				n.PtrInit().Prepend(init...)
+				n.(ir.InitNode).PtrInit().Prepend(init...)
 
 			default:
 				init.Append(n)
@@ -176,12 +175,12 @@ func walkStmtList(s []ir.Node) {
 
 // walkDecl walks an ODCL node.
 func walkDecl(n *ir.Decl) ir.Node {
-	v := n.X.(*ir.Name)
+	v := n.X
-	if v.Class_ == ir.PAUTOHEAP {
+	if v.Class == ir.PAUTOHEAP {
 		if base.Flag.CompilingRuntime {
 			base.Errorf("%v escapes to heap, not allowed in runtime", v)
 		}
-		nn := ir.NewAssignStmt(base.Pos, v.Name().Heapaddr, callnew(v.Type()))
+		nn := ir.NewAssignStmt(base.Pos, v.Heapaddr, callnew(v.Type()))
 		nn.Def = true
 		return walkStmt(typecheck.Stmt(nn))
 	}
@@ -191,9 +190,8 @@ func walkDecl(n *ir.Decl) ir.Node {
 // walkFor walks an OFOR or OFORUNTIL node.
 func walkFor(n *ir.ForStmt) ir.Node {
 	if n.Cond != nil {
-		walkStmtList(n.Cond.Init())
+		init := ir.TakeInit(n.Cond)
-		init := n.Cond.Init()
+		walkStmtList(init)
-		n.Cond.PtrInit().Set(nil)
 		n.Cond = walkExpr(n.Cond, &init)
 		n.Cond = ir.InitExpr(init, n.Cond)
 	}
@@ -228,7 +226,7 @@ func walkGoDefer(n *ir.GoDeferStmt) ir.Node {
 
 	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER:
 		call := call.(*ir.CallExpr)
-		if len(call.Body) > 0 {
+		if len(call.KeepAlive) > 0 {
 			n.Call = wrapCall(call, &init)
 		} else {
 			n.Call = walkExpr(call, &init)
@@ -257,7 +255,7 @@ func walkIf(n *ir.IfStmt) ir.Node {
 func wrapCall(n *ir.CallExpr, init *ir.Nodes) ir.Node {
 	if len(n.Init()) != 0 {
 		walkStmtList(n.Init())
-		init.Append(n.PtrInit().Take()...)
+		init.Append(ir.TakeInit(n)...)
 	}
 
 	isBuiltinCall := n.Op() != ir.OCALLFUNC && n.Op() != ir.OCALLMETH && n.Op() != ir.OCALLINTER
@@ -267,7 +265,7 @@ func wrapCall(n *ir.CallExpr, init *ir.Nodes) ir.Node {
 		last := len(n.Args) - 1
 		if va := n.Args[last]; va.Op() == ir.OSLICELIT {
 			va := va.(*ir.CompLitExpr)
-			n.Args.Set(append(n.Args[:last], va.List...))
+			n.Args = append(n.Args[:last], va.List...)
 			n.IsDDD = false
 		}
 	}

src/cmd/compile/internal/walk/switch.go

@@ -201,10 +201,15 @@ func (s *exprSwitch) flush() {
 
 	// Merge consecutive integer cases.
 	if s.exprname.Type().IsInteger() {
+		consecutive := func(last, next constant.Value) bool {
+			delta := constant.BinaryOp(next, token.SUB, last)
+			return constant.Compare(delta, token.EQL, constant.MakeInt64(1))
+		}
+
 		merged := cc[:1]
 		for _, c := range cc[1:] {
 			last := &merged[len(merged)-1]
-			if last.jmp == c.jmp && ir.Int64Val(last.hi)+1 == ir.Int64Val(c.lo) {
+			if last.jmp == c.jmp && consecutive(last.hi.Val(), c.lo.Val()) {
 				last.hi = c.lo
 			} else {
 				merged = append(merged, c)
@@ -440,7 +445,7 @@ type typeClause struct {
 	body ir.Nodes
 }
 
-func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar, jmp ir.Node) {
+func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar *ir.Name, jmp ir.Node) {
 	var body ir.Nodes
 	if caseVar != nil {
 		l := []ir.Node{
@@ -450,7 +455,7 @@ func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar, jmp ir.Node) {
 		typecheck.Stmts(l)
 		body.Append(l...)
 	} else {
-		caseVar = ir.BlankNode
+		caseVar = ir.BlankNode.(*ir.Name)
 	}
 
 	// cv, ok = iface.(type)

src/cmd/compile/internal/walk/walk.go

@@ -37,36 +37,6 @@ func Walk(fn *ir.Func) {
 
 	lno := base.Pos
 
-	// Final typecheck for any unused variables.
-	for i, ln := range fn.Dcl {
-		if ln.Op() == ir.ONAME && (ln.Class_ == ir.PAUTO || ln.Class_ == ir.PAUTOHEAP) {
-			ln = typecheck.AssignExpr(ln).(*ir.Name)
-			fn.Dcl[i] = ln
-		}
-	}
-
-	// Propagate the used flag for typeswitch variables up to the NONAME in its definition.
-	for _, ln := range fn.Dcl {
-		if ln.Op() == ir.ONAME && (ln.Class_ == ir.PAUTO || ln.Class_ == ir.PAUTOHEAP) && ln.Defn != nil && ln.Defn.Op() == ir.OTYPESW && ln.Used() {
-			ln.Defn.(*ir.TypeSwitchGuard).Used = true
-		}
-	}
-
-	for _, ln := range fn.Dcl {
-		if ln.Op() != ir.ONAME || (ln.Class_ != ir.PAUTO && ln.Class_ != ir.PAUTOHEAP) || ln.Sym().Name[0] == '&' || ln.Used() {
-			continue
-		}
-		if defn, ok := ln.Defn.(*ir.TypeSwitchGuard); ok {
-			if defn.Used {
-				continue
-			}
-			base.ErrorfAt(defn.Tag.Pos(), "%v declared but not used", ln.Sym())
-			defn.Used = true // suppress repeats
-		} else {
-			base.ErrorfAt(ln.Pos(), "%v declared but not used", ln.Sym())
-		}
-	}
-
 	base.Pos = lno
 	if base.Errors() > errorsBefore {
 		return
@@ -91,7 +61,7 @@ func Walk(fn *ir.Func) {
 
 func paramoutheap(fn *ir.Func) bool {
 	for _, ln := range fn.Dcl {
-		switch ln.Class_ {
+		switch ln.Class {
 		case ir.PPARAMOUT:
 			if ir.IsParamStackCopy(ln) || ln.Addrtaken() {
 				return true
@@ -111,8 +81,7 @@ func walkRecv(n *ir.UnaryExpr) ir.Node {
 	if n.Typecheck() == 0 {
 		base.Fatalf("missing typecheck: %+v", n)
 	}
-	init := n.Init()
+	init := ir.TakeInit(n)
-	n.PtrInit().Set(nil)
 
 	n.X = walkExpr(n.X, &init)
 	call := walkExpr(mkcall1(chanfn("chanrecv1", 2, n.X.Type()), nil, &init, n.X, typecheck.NodNil()), &init)
@@ -167,8 +136,8 @@ func paramstoheap(params *types.Type) []ir.Node {
 		}
 
 		if stackcopy := v.Name().Stackcopy; stackcopy != nil {
-			nn = append(nn, walkStmt(ir.NewDecl(base.Pos, ir.ODCL, v)))
+			nn = append(nn, walkStmt(ir.NewDecl(base.Pos, ir.ODCL, v.(*ir.Name))))
-			if stackcopy.Class_ == ir.PPARAM {
+			if stackcopy.Class == ir.PPARAM {
 				nn = append(nn, walkStmt(typecheck.Stmt(ir.NewAssignStmt(base.Pos, v, stackcopy))))
 			}
 		}
@@ -216,7 +185,7 @@ func returnsfromheap(params *types.Type) []ir.Node {
 		if v == nil {
 			continue
 		}
-		if stackcopy := v.Name().Stackcopy; stackcopy != nil && stackcopy.Class_ == ir.PPARAMOUT {
+		if stackcopy := v.Name().Stackcopy; stackcopy != nil && stackcopy.Class == ir.PPARAMOUT {
 			nn = append(nn, walkStmt(typecheck.Stmt(ir.NewAssignStmt(base.Pos, stackcopy, v))))
 		}
 	}
@@ -377,8 +346,6 @@ func walkAppendArgs(n *ir.CallExpr, init *ir.Nodes) {
 
 var wrapCall_prgen int
 
-var walkCheckPtrArithmeticMarker byte
-
 // appendWalkStmt typechecks and walks stmt and then appends it to init.
 func appendWalkStmt(init *ir.Nodes, stmt ir.Node) {
 	op := stmt.Op()

test/closure2.go

@@ -9,6 +9,8 @@
 
 package main
 
+var never bool
+
 func main() {
 	{
 		type X struct {
@@ -115,4 +117,16 @@ func main() {
 			panic("g() != 2")
 		}
 	}
+
+	{
+		var g func() int
+		q := 0
+		q, g = 1, func() int { return q }
+		if never {
+			g = func() int { return 2 }
+		}
+		if g() != 1 {
+			panic("g() != 1")
+		}
+	}
 }

test/fixedbugs/issue15055.go

@@ -12,6 +12,8 @@ func main() {
 	_ = string("a", "b", nil)       // ERROR "too many arguments (to conversion to string: string\(.a., .b., nil\))?"
 	_ = []byte()                    // ERROR "missing argument (to conversion to \[\]byte: \(\[\]byte\)\(\))?"
 	_ = string()                    // ERROR "missing argument (to conversion to string: string\(\))?"
+	_ = *int()                      // ERROR "missing argument (to conversion to int: int\(\))?"
+	_ = (*int)()                    // ERROR "missing argument (to conversion to \*int: \(\*int\)\(\))?"
 	_ = name("a", 1, 3.3)           // ERROR "too many arguments (to conversion to name: name\(.a., 1, 3.3\))?"
 	_ = map[string]string(nil, nil) // ERROR "too many arguments (to conversion to map\[string\]string: \(map\[string\]string\)\(nil, nil\))?"
 }

test/fixedbugs/issue23017.go

@@ -0,0 +1,113 @@
+// run
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// assignment order in multiple assignments.
+// See issue #23017
+
+package main
+
+import "fmt"
+
+func main() {}
+
+func init() {
+	var m = map[int]int{}
+	var p *int
+
+	defer func() {
+		recover()
+		check(1, len(m))
+		check(42, m[2])
+	}()
+	m[2], *p = 42, 2
+}
+
+func init() {
+	var m = map[int]int{}
+	p := []int{}
+
+	defer func() {
+		recover()
+		check(1, len(m))
+		check(2, m[2])
+	}()
+	m[2], p[1] = 2, 2
+}
+
+func init() {
+	type P struct{ i int }
+	var m = map[int]int{}
+	var p *P
+
+	defer func() {
+		recover()
+		check(1, len(m))
+		check(3, m[2])
+	}()
+	m[2], p.i = 3, 2
+}
+
+func init() {
+	type T struct{ i int }
+	var x T
+	p := &x
+	p, p.i = new(T), 4
+	check(4, x.i)
+}
+
+func init() {
+	var m map[int]int
+	var a int
+	var p = &a
+
+	defer func() {
+		recover()
+		check(5, *p)
+	}()
+	*p, m[2] = 5, 2
+}
+
+var g int
+
+func init() {
+	var m map[int]int
+	defer func() {
+		recover()
+		check(0, g)
+	}()
+	m[0], g = 1, 2
+}
+
+func init() {
+	type T struct{ x struct{ y int } }
+	var x T
+	p := &x
+	p, p.x.y = new(T), 7
+	check(7, x.x.y)
+	check(0, p.x.y)
+}
+
+func init() {
+	type T *struct{ x struct{ y int } }
+	x := struct{ y int }{0}
+	var q T = &struct{ x struct{ y int } }{x}
+	p := q
+	p, p.x.y = nil, 7
+	check(7, q.x.y)
+}
+
+func init() {
+	x, y := 1, 2
+	x, y = y, x
+	check(2, x)
+	check(1, y)
+}
+
+func check(want, got int) {
+	if want != got {
+		panic(fmt.Sprintf("wanted %d, but got %d", want, got))
+	}
+}

test/fixedbugs/issue43384.go

@@ -0,0 +1,124 @@
+// errorcheck
+
+// Copyright 2020 The Go Authors. All rights reserved.  Use of this
+// source code is governed by a BSD-style license that can be found in
+// the LICENSE file.
+
+package p
+
+type T int
+
+func (T) Mv()  {}
+func (*T) Mp() {}
+
+type P1 struct{ T }
+type P2 struct{ *T }
+type P3 *struct{ T }
+type P4 *struct{ *T }
+
+func _() {
+	{
+		var p P1
+		p.Mv()
+		(&p).Mv()
+		(*&p).Mv()
+		p.Mp()
+		(&p).Mp()
+		(*&p).Mp()
+	}
+	{
+		var p P2
+		p.Mv()
+		(&p).Mv()
+		(*&p).Mv()
+		p.Mp()
+		(&p).Mp()
+		(*&p).Mp()
+	}
+	{
+		var p P3
+		p.Mv()     // ERROR "undefined"
+		(&p).Mv()  // ERROR "undefined"
+		(*&p).Mv() // ERROR "undefined"
+		(**&p).Mv()
+		(*p).Mv()
+		(&*p).Mv()
+		p.Mp()     // ERROR "undefined"
+		(&p).Mp()  // ERROR "undefined"
+		(*&p).Mp() // ERROR "undefined"
+		(**&p).Mp()
+		(*p).Mp()
+		(&*p).Mp()
+	}
+	{
+		var p P4
+		p.Mv()     // ERROR "undefined"
+		(&p).Mv()  // ERROR "undefined"
+		(*&p).Mv() // ERROR "undefined"
+		(**&p).Mv()
+		(*p).Mv()
+		(&*p).Mv()
+		p.Mp()     // ERROR "undefined"
+		(&p).Mp()  // ERROR "undefined"
+		(*&p).Mp() // ERROR "undefined"
+		(**&p).Mp()
+		(*p).Mp()
+		(&*p).Mp()
+	}
+}
+
+func _() {
+	type P5 struct{ T }
+	type P6 struct{ *T }
+	type P7 *struct{ T }
+	type P8 *struct{ *T }
+
+	{
+		var p P5
+		p.Mv()
+		(&p).Mv()
+		(*&p).Mv()
+		p.Mp()
+		(&p).Mp()
+		(*&p).Mp()
+	}
+	{
+		var p P6
+		p.Mv()
+		(&p).Mv()
+		(*&p).Mv()
+		p.Mp()
+		(&p).Mp()
+		(*&p).Mp()
+	}
+	{
+		var p P7
+		p.Mv()     // ERROR "undefined"
+		(&p).Mv()  // ERROR "undefined"
+		(*&p).Mv() // ERROR "undefined"
+		(**&p).Mv()
+		(*p).Mv()
+		(&*p).Mv()
+		p.Mp()     // ERROR "undefined"
+		(&p).Mp()  // ERROR "undefined"
+		(*&p).Mp() // ERROR "undefined"
+		(**&p).Mp()
+		(*p).Mp()
+		(&*p).Mp()
+	}
+	{
+		var p P8
+		p.Mv()     // ERROR "undefined"
+		(&p).Mv()  // ERROR "undefined"
+		(*&p).Mv() // ERROR "undefined"
+		(**&p).Mv()
+		(*p).Mv()
+		(&*p).Mv()
+		p.Mp()     // ERROR "undefined"
+		(&p).Mp()  // ERROR "undefined"
+		(*&p).Mp() // ERROR "undefined"
+		(**&p).Mp()
+		(*p).Mp()
+		(&*p).Mp()
+	}
+}

test/fixedbugs/issue43428.go

@@ -0,0 +1,25 @@
+// errorcheck
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "time"
+
+type T int
+
+func (T) Mv()  {}
+func (*T) Mp() {}
+
+var _ = []int{
+	T.Mv,    // ERROR "cannot use T\.Mv|incompatible type"
+	(*T).Mv, // ERROR "cannot use \(\*T\)\.Mv|incompatible type"
+	(*T).Mp, // ERROR "cannot use \(\*T\)\.Mp|incompatible type"
+
+	time.Time.GobEncode,    // ERROR "cannot use time\.Time\.GobEncode|incompatible type"
+	(*time.Time).GobEncode, // ERROR "cannot use \(\*time\.Time\)\.GobEncode|incompatible type"
+	(*time.Time).GobDecode, // ERROR "cannot use \(\*time\.Time\)\.GobDecode|incompatible type"
+
+}

test/fixedbugs/issue43444.go

@@ -0,0 +1,28 @@
+// run
+
+package main
+
+var sp = ""
+
+func f(name string, _ ...interface{}) int {
+	print(sp, name)
+	sp = " "
+	return 0
+}
+
+var a = f("a", x)
+var b = f("b", y)
+var c = f("c", z)
+var d = func() int {
+	if false {
+		_ = z
+	}
+	return f("d")
+}()
+var e = f("e")
+
+var x int
+var y int = 42
+var z int = func() int { return 42 }()
+
+func main() { println() }

test/fixedbugs/issue43444.out

@@ -0,0 +1 @@
+e a b c d

test/fixedbugs/issue43479.dir/a.go

@@ -0,0 +1,27 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type Here struct{ stuff int }
+type Info struct{ Dir string }
+
+func New() Here { return Here{} }
+func (h Here) Dir(p string) (Info, error)
+
+type I interface{ M(x string) }
+
+type T = struct {
+	Here
+	I
+}
+
+var X T
+
+var A = (*T).Dir
+var B = T.Dir
+var C = X.Dir
+var D = (*T).M
+var E = T.M
+var F = X.M

test/fixedbugs/issue43479.dir/b.go

@@ -0,0 +1,38 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+var Here = a.New()
+var Dir = Here.Dir
+
+type T = struct {
+	a.Here
+	a.I
+}
+
+var X T
+
+// Test exporting the type of method values for anonymous structs with
+// promoted methods.
+var A = a.A
+var B = a.B
+var C = a.C
+var D = a.D
+var E = a.E
+var F = a.F
+var G = (*a.T).Dir
+var H = a.T.Dir
+var I = a.X.Dir
+var J = (*a.T).M
+var K = a.T.M
+var L = a.X.M
+var M = (*T).Dir
+var N = T.Dir
+var O = X.Dir
+var P = (*T).M
+var Q = T.M
+var R = X.M

test/fixedbugs/issue43479.go

@@ -0,0 +1,7 @@
+// compiledir
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ignored

test/fixedbugs/issue43480.go

@@ -0,0 +1,33 @@
+// run
+
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue #43480: ICE on large uint64 constants in switch cases.
+
+package main
+
+func isPow10(x uint64) bool {
+	switch x {
+	case 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
+		1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19:
+		return true
+	}
+	return false
+}
+
+func main() {
+	var x uint64 = 1
+
+	for {
+		if !isPow10(x) || isPow10(x-1) || isPow10(x+1) {
+			panic(x)
+		}
+		next := x * 10
+		if next/10 != x {
+			break // overflow
+		}
+		x = next
+	}
+}