diff --git a/src/cmd/compile/internal/types2/api.go b/src/cmd/compile/internal/types2/api.go
index eff90d4cdf..a40665ee17 100644
--- a/src/cmd/compile/internal/types2/api.go
+++ b/src/cmd/compile/internal/types2/api.go
@@ -119,6 +119,11 @@ type Config struct {
 	//          Do not use casually!
 	FakeImportC bool
 
+	// If CompilerErrorMessages is set, errors are reported using
+	// cmd/compile error strings to match $GOROOT/test errors.
+	// TODO(gri) Consolidate error messages and remove this flag.
+	CompilerErrorMessages bool
+
 	// If go115UsesCgo is set, the type checker expects the
 	// _cgo_gotypes.go file generated by running cmd/cgo to be
 	// provided as a package source file. Qualified identifiers
diff --git a/src/cmd/compile/internal/types2/api_test.go b/src/cmd/compile/internal/types2/api_test.go
index 403df3f941..58d7df2f1d 100644
--- a/src/cmd/compile/internal/types2/api_test.go
+++ b/src/cmd/compile/internal/types2/api_test.go
@@ -687,8 +687,8 @@ func TestPredicatesInfo(t *testing.T) {
 
 		// values
 		{`package v0; var (a, b int; _ = a + b)`, `a + b`, `value`},
-		{`package v1; var _ = &[]int{1}`, `([]int literal)`, `value`},
-		{`package v2; var _ = func(){}`, `(func() literal)`, `value`},
+		{`package v1; var _ = &[]int{1}`, `[]int{…}`, `value`},
+		{`package v2; var _ = func(){}`, `func() {}`, `value`},
 		{`package v4; func f() { _ = f }`, `f`, `value`},
 		{`package v3; var _ *int = nil`, `nil`, `value, nil`},
 		{`package v3; var _ *int = (nil)`, `(nil)`, `value, nil`},
@@ -896,10 +896,10 @@ func TestInitOrderInfo(t *testing.T) {
 			"z = 0", "a, b = f()",
 		}},
 		{`package p7; var (a = func() int { return b }(); b = 1)`, []string{
-			"b = 1", "a = (func() int literal)()",
+			"b = 1", "a = func() int {…}()",
 		}},
 		{`package p8; var (a, b = func() (_, _ int) { return c, c }(); c = 1)`, []string{
-			"c = 1", "a, b = (func() (_, _ int) literal)()",
+			"c = 1", "a, b = func() (_, _ int) {…}()",
 		}},
 		{`package p9; type T struct{}; func (T) m() int { _ = y; return 0 }; var x, y = T.m, 1`, []string{
 			"y = 1", "x = T.m",
diff --git a/src/cmd/compile/internal/types2/assignments.go b/src/cmd/compile/internal/types2/assignments.go
index 93d3255686..3178c38ade 100644
--- a/src/cmd/compile/internal/types2/assignments.go
+++ b/src/cmd/compile/internal/types2/assignments.go
@@ -63,10 +63,14 @@ func (check *Checker) assignment(x *operand, T Type, context string) {
 	}
 
 	if reason := ""; !x.assignableTo(check, T, &reason) {
-		if reason != "" {
-			check.errorf(x, "cannot use %s as %s value in %s: %s", x, T, context, reason)
+		if check.conf.CompilerErrorMessages {
+			check.errorf(x, "incompatible type: cannot use %s as %s value", x, T)
 		} else {
-			check.errorf(x, "cannot use %s as %s value in %s", x, T, context)
+			if reason != "" {
+				check.errorf(x, "cannot use %s as %s value in %s: %s", x, T, context, reason)
+			} else {
+				check.errorf(x, "cannot use %s as %s value in %s", x, T, context)
+			}
 		}
 		x.mode = invalid
 	}
diff --git a/src/cmd/compile/internal/types2/builtins.go b/src/cmd/compile/internal/types2/builtins.go
index 6ad84f4354..43da6a1529 100644
--- a/src/cmd/compile/internal/types2/builtins.go
+++ b/src/cmd/compile/internal/types2/builtins.go
@@ -281,7 +281,7 @@ func (check *Checker) builtin(x *operand, call *syntax.CallExpr, id builtinId) (
 
 		// both argument types must be identical
 		if !check.identical(x.typ, y.typ) {
-			check.invalidArgf(x, "mismatched types %s and %s", x.typ, y.typ)
+			check.invalidOpf(x, "%s (mismatched types %s and %s)", call, x.typ, y.typ)
 			return
 		}
 
diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go
index ff37d85c6f..c7bfd3fd7b 100644
--- a/src/cmd/compile/internal/types2/decl.go
+++ b/src/cmd/compile/internal/types2/decl.go
@@ -792,7 +792,11 @@ func (check *Checker) collectMethods(obj *TypeName) {
 			case *Var:
 				check.errorf(m.pos, "field and method with the same name %s", m.name)
 			case *Func:
-				check.errorf(m.pos, "method %s already declared for %s", m.name, obj)
+				if check.conf.CompilerErrorMessages {
+					check.errorf(m.pos, "%s.%s redeclared in this block", obj.Name(), m.name)
+				} else {
+					check.errorf(m.pos, "method %s already declared for %s", m.name, obj)
+				}
 			default:
 				unreachable()
 			}
diff --git a/src/cmd/compile/internal/types2/expr.go b/src/cmd/compile/internal/types2/expr.go
index cb92143f93..3c9540783a 100644
--- a/src/cmd/compile/internal/types2/expr.go
+++ b/src/cmd/compile/internal/types2/expr.go
@@ -736,7 +736,8 @@ func (check *Checker) comparison(x, y *operand, op syntax.Operator) {
 	}
 
 	if err != "" {
-		check.errorf(x, "cannot compare %s %s %s (%s)", x.expr, op, y.expr, err)
+		// TODO(gri) better error message for cases where one can only compare against nil
+		check.invalidOpf(x, "cannot compare %s %s %s (%s)", x.expr, op, y.expr, err)
 		x.mode = invalid
 		return
 	}
@@ -1174,6 +1175,9 @@ func (check *Checker) exprInternal(x *operand, e syntax.Expr, hint Type) exprKin
 		goto Error
 
 	case *syntax.BasicLit:
+		if e.Bad {
+			goto Error // error was reported before
+		}
 		x.setConst(e.Kind, e.Value)
 		if x.mode == invalid {
 			// The parser already establishes syntactic correctness.
@@ -1624,7 +1628,7 @@ func (check *Checker) exprInternal(x *operand, e syntax.Expr, hint Type) exprKin
 			valid = true
 			length = typ.len
 			if x.mode != variable {
-				check.invalidOpf(x, "cannot slice %s (value not addressable)", x)
+				check.invalidOpf(x, "%s (slice of unaddressable value)", x)
 				goto Error
 			}
 			x.typ = &Slice{elem: typ.elem}
diff --git a/src/cmd/compile/internal/types2/exprstring.go b/src/cmd/compile/internal/types2/exprstring.go
index e187d050e6..0ec5d1338f 100644
--- a/src/cmd/compile/internal/types2/exprstring.go
+++ b/src/cmd/compile/internal/types2/exprstring.go
@@ -50,14 +50,20 @@ func WriteExpr(buf *bytes.Buffer, x syntax.Expr) {
 		buf.WriteString(x.Value)
 
 	case *syntax.FuncLit:
-		buf.WriteByte('(')
 		WriteExpr(buf, x.Type)
-		buf.WriteString(" literal)") // shortened
+		if x.Body != nil && len(x.Body.List) > 0 {
+			buf.WriteString(" {…}") // shortened
+		} else {
+			buf.WriteString(" {}")
+		}
 
 	case *syntax.CompositeLit:
-		buf.WriteByte('(')
 		WriteExpr(buf, x.Type)
-		buf.WriteString(" literal)") // shortened
+		if len(x.ElemList) > 0 {
+			buf.WriteString("{…}") // shortened
+		} else {
+			buf.WriteString("{}")
+		}
 
 	case *syntax.ParenExpr:
 		buf.WriteByte('(')
diff --git a/src/cmd/compile/internal/types2/exprstring_test.go b/src/cmd/compile/internal/types2/exprstring_test.go
index d7b9d5b2ef..efb7c308b7 100644
--- a/src/cmd/compile/internal/types2/exprstring_test.go
+++ b/src/cmd/compile/internal/types2/exprstring_test.go
@@ -24,9 +24,9 @@ var testExprs = []testEntry{
 	dup("`bar`"),
 
 	// func and composite literals
-	{"func(){}", "(func() literal)"},
-	{"func(x int) complex128 {}", "(func(x int) complex128 literal)"},
-	{"[]int{1, 2, 3}", "([]int literal)"},
+	{"func(){}", "func() {}"},
+	{"func(x int) complex128 {}", "func(x int) complex128 {}"},
+	{"[]int{1, 2, 3}", "[]int{…}"},
 
 	// non-type expressions
 	dup("(x)"),
diff --git a/src/cmd/compile/internal/types2/testdata/decls3.src b/src/cmd/compile/internal/types2/testdata/decls3.src
index 745175c710..d7a0c444da 100644
--- a/src/cmd/compile/internal/types2/testdata/decls3.src
+++ b/src/cmd/compile/internal/types2/testdata/decls3.src
@@ -221,16 +221,16 @@ func _() {
 	_ = S2{}.B
 	_ = S2{}.C
 	_ = S2{}.D /* ERROR "no field or method" */
-	_ = S3{}.S1 /* ERROR "ambiguous selector \(S3 literal\).S1" */
+	_ = S3{}.S1 /* ERROR "ambiguous selector S3\{\}.S1" */
 	_ = S3{}.A
-	_ = S3{}.B /* ERROR "ambiguous selector" \(S3 literal\).B */
+	_ = S3{}.B /* ERROR "ambiguous selector" S3\{\}.B */
 	_ = S3{}.D
 	_ = S3{}.E
 	_ = S4{}.A
 	_ = S4{}.B /* ERROR "no field or method" */
-	_ = S5{}.X /* ERROR "ambiguous selector \(S5 literal\).X" */
+	_ = S5{}.X /* ERROR "ambiguous selector S5\{\}.X" */
 	_ = S5{}.Y
-	_ = S10{}.X /* ERROR "ambiguous selector \(S10 literal\).X" */
+	_ = S10{}.X /* ERROR "ambiguous selector S10\{\}.X" */
 	_ = S10{}.Y
 }
 
@@ -306,4 +306,4 @@ type R22 R21
 type R23 R21
 type R24 R21
 
-var _ = R0{}.X /* ERROR "ambiguous selector \(R0 literal\).X" */
\ No newline at end of file
+var _ = R0{}.X /* ERROR "ambiguous selector R0\{\}.X" */
\ No newline at end of file
diff --git a/src/cmd/compile/internal/types2/testdata/decls4.src b/src/cmd/compile/internal/types2/testdata/decls4.src
index 140bbfd31f..eb08421bee 100644
--- a/src/cmd/compile/internal/types2/testdata/decls4.src
+++ b/src/cmd/compile/internal/types2/testdata/decls4.src
@@ -190,8 +190,8 @@ type eD struct {
 }
 
 var (
-	_ = eD{}.xf /* ERROR ambiguous selector \(eD literal\).xf */
-	_ = eD{}.xm /* ERROR ambiguous selector \(eD literal\).xm */
+	_ = eD{}.xf /* ERROR ambiguous selector eD\{\}.xf */
+	_ = eD{}.xm /* ERROR ambiguous selector eD\{\}.xm */
 )
 
 var (
diff --git a/src/cmd/compile/internal/types2/testdata/issue28251.src b/src/cmd/compile/internal/types2/testdata/issue28251.src
index cd79e0e8b5..ef5e61df47 100644
--- a/src/cmd/compile/internal/types2/testdata/issue28251.src
+++ b/src/cmd/compile/internal/types2/testdata/issue28251.src
@@ -60,6 +60,6 @@ type (
         T11 = T
 )
 
-func (T9 /* ERROR invalid receiver \*\*T */ ) m9() {}
+func (T9 /* ERROR invalid receiver type \*\*T */ ) m9() {}
 func _() { (T{}).m9 /* ERROR has no field or method m9 */ () }
 func _() { (&T{}).m9 /* ERROR has no field or method m9 */ () }
diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go
index 1adf967859..0c27e5e04b 100644
--- a/src/cmd/compile/internal/types2/typexpr.go
+++ b/src/cmd/compile/internal/types2/typexpr.go
@@ -384,6 +384,10 @@ func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams []
 				// as the method."
 				if T.obj.pkg != check.pkg {
 					err = "type not defined in this package"
+					if check.conf.CompilerErrorMessages {
+						check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
+						err = ""
+					}
 				} else {
 					switch u := optype(T.Under()).(type) {
 					case *Basic:
@@ -395,11 +399,17 @@ func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams []
 						err = "pointer or interface type"
 					}
 				}
-			} else {
+			} else if T := t.Basic(); T != nil {
 				err = "basic or unnamed type"
+				if check.conf.CompilerErrorMessages {
+					check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ)
+					err = ""
+				}
+			} else {
+				check.errorf(recv.pos, "invalid receiver type %s", recv.typ)
 			}
 			if err != "" {
-				check.errorf(recv.pos, "invalid receiver %s (%s)", recv.typ, err)
+				check.errorf(recv.pos, "invalid receiver type %s (%s)", recv.typ, err)
 				// ok to continue
 			}
 		}