[dev.boringcrypto] all: merge master into dev.boringcrypto

Change-Id: I1aa33cabd0c55fe64994b08f8a3f7b6bbfb3282c

.github/SUPPORT.md

@@ -11,4 +11,4 @@ For asking questions, see:
 
 * [Stack Overflow](https://stackoverflow.com/questions/tagged/go) with questions tagged "go"
 
-* **IRC** channel #go-nuts on Freenode
+* **IRC** channel #go-nuts on Libera

AUTHORS

@@ -817,6 +817,7 @@ Lehner Florian <dev@der-flo.net>
 Leigh McCulloch <leighmcc@gmail.com>
 Leo Antunes <leo@costela.net>
 Leon Klingele <git@leonklingele.de>
+Leonard Wang <wangdeyu0907@gmail.com> <wangdeyu@golangcn.org>
 Leonel Quinteros <leonel.quinteros@gmail.com>
 Lev Shamardin <shamardin@gmail.com>
 Lewin Bormann <lewin.bormann@gmail.com>
@@ -1015,6 +1016,7 @@ Nathan Youngman <git@nathany.com>
 Nathaniel Cook <nvcook42@gmail.com>
 Naveen Kumar Sangi <naveenkumarsangi@protonmail.com>
 Neelesh Chandola <neelesh.c98@gmail.com>
+Neil Alexander <neilalexander@neilalexander.dev>
 Neil Lyons <nwjlyons@googlemail.com>
 Netflix, Inc.
 Neuman Vong <neuman.vong@gmail.com>
@@ -1479,6 +1481,7 @@ Zheng Dayu <davidzheng23@gmail.com>
 Zhongtao Chen <chenzhongtao@126.com>
 Zhou Peng <p@ctriple.cn>
 Ziad Hatahet <hatahet@gmail.com>
+Zizhao Zhang <btw515wolf2@gmail.com>
 Zorion Arrizabalaga <zorionk@gmail.com>
 Максим Федосеев <max.faceless.frei@gmail.com>
 Роман Хавроненко <hagen1778@gmail.com>

CONTRIBUTORS

@@ -1109,7 +1109,6 @@ Ian Lance Taylor <iant@golang.org>
 Ian Leue <ian@appboy.com>
 Ian Mckay <iann0036@gmail.com>
 Ian Tay <iantay@google.com>
-Ian Woolf <btw515wolf2@gmail.com>
 Ian Zapolsky <ianzapolsky@gmail.com>
 Ibrahim AshShohail <ibra.sho@gmail.com>
 Icarus Sparry <golang@icarus.freeuk.com>
@@ -1570,7 +1569,7 @@ Leigh McCulloch <leighmcc@gmail.com>
 Leo Antunes <leo@costela.net>
 Leo Rudberg <ljr@google.com>
 Leon Klingele <git@leonklingele.de>
-Leonard Wang <wangdeyu0907@gmail.com>
+Leonard Wang <wangdeyu0907@gmail.com> <wangdeyu@golangcn.org>
 Leonardo Comelli <leonardo.comelli@gmail.com>
 Leonel Quinteros <leonel.quinteros@gmail.com>
 Lev Shamardin <shamardin@gmail.com>
@@ -1902,6 +1901,7 @@ Naveen Kumar Sangi <naveenkumarsangi@protonmail.com>
 Neeilan Selvalingam <neeilan96@gmail.com>
 Neelesh Chandola <neelesh.c98@gmail.com>
 Nehal J Wani <nehaljw.kkd1@gmail.com>
+Neil Alexander <neilalexander@neilalexander.dev>
 Neil Lyons <nwjlyons@googlemail.com>
 Neuman Vong <neuman.vong@gmail.com>
 Neven Sajko <nsajko@gmail.com>
@@ -2749,6 +2749,7 @@ Zhongwei Yao <zhongwei.yao@arm.com>
 Zhou Peng <p@ctriple.cn>
 Ziad Hatahet <hatahet@gmail.com>
 Ziheng Liu <lzhfromustc@gmail.com>
+Zizhao Zhang <btw515wolf2@gmail.com>
 Zorion Arrizabalaga <zorionk@gmail.com>
 Zvonimir Pavlinovic <zpavlinovic@google.com>
 Zyad A. Ali <zyad.ali.me@gmail.com>

README.md

@@ -32,7 +32,7 @@ for source installation instructions.
 
 Go is the work of thousands of contributors. We appreciate your help!
 
-To contribute, please read the contribution guidelines at https://golang.org/doc/contribute.html.
+To contribute, please read the contribution guidelines at https://golang.org/doc/contribute.
 
 Note that the Go project uses the issue tracker for bug reports and
 proposals only. See https://golang.org/wiki/Questions for a list of

api/except.txt

@@ -492,6 +492,7 @@ pkg syscall (windows-amd64), type CertRevocationInfo struct, OidSpecificInfo uin
 pkg syscall (windows-amd64), type CertSimpleChain struct, TrustListInfo uintptr
 pkg syscall (windows-amd64), type RawSockaddrAny struct, Pad [96]int8
 pkg testing, func MainStart(func(string, string) (bool, error), []InternalTest, []InternalBenchmark, []InternalExample) *M
+pkg testing, func MainStart(testDeps, []InternalTest, []InternalBenchmark, []InternalExample) *M
 pkg testing, func RegisterCover(Cover)
 pkg text/scanner, const GoTokens = 1012
 pkg text/template/parse, type DotNode bool

api/go1.1.txt

@@ -2603,7 +2603,34 @@ pkg runtime/debug, type GCStats struct, Pause []time.Duration
 pkg runtime/debug, type GCStats struct, PauseQuantiles []time.Duration
 pkg runtime/debug, type GCStats struct, PauseTotal time.Duration
 pkg sort, func Reverse(Interface) Interface
-pkg strconv, const IntSize = 64
+pkg strconv (darwin-amd64), const IntSize = 64
+pkg strconv (darwin-amd64-cgo), const IntSize = 64
+pkg strconv (freebsd-386), const IntSize = 32
+pkg strconv (freebsd-386-cgo), const IntSize = 32
+pkg strconv (freebsd-amd64), const IntSize = 64
+pkg strconv (freebsd-amd64-cgo), const IntSize = 64
+pkg strconv (freebsd-arm), const IntSize = 32
+pkg strconv (freebsd-arm-cgo), const IntSize = 32
+pkg strconv (linux-386), const IntSize = 32
+pkg strconv (linux-386-cgo), const IntSize = 32
+pkg strconv (linux-amd64), const IntSize = 64
+pkg strconv (linux-amd64-cgo), const IntSize = 64
+pkg strconv (linux-arm), const IntSize = 32
+pkg strconv (linux-arm-cgo), const IntSize = 32
+pkg strconv (netbsd-386), const IntSize = 32
+pkg strconv (netbsd-386-cgo), const IntSize = 32
+pkg strconv (netbsd-amd64), const IntSize = 64
+pkg strconv (netbsd-amd64-cgo), const IntSize = 64
+pkg strconv (netbsd-arm), const IntSize = 32
+pkg strconv (netbsd-arm-cgo), const IntSize = 32
+pkg strconv (netbsd-arm64), const IntSize = 64
+pkg strconv (netbsd-arm64-cgo), const IntSize = 64
+pkg strconv (openbsd-386), const IntSize = 32
+pkg strconv (openbsd-386-cgo), const IntSize = 32
+pkg strconv (openbsd-amd64), const IntSize = 64
+pkg strconv (openbsd-amd64-cgo), const IntSize = 64
+pkg strconv (windows-386), const IntSize = 32
+pkg strconv (windows-amd64), const IntSize = 64
 pkg strings, func TrimPrefix(string, string) string
 pkg strings, func TrimSuffix(string, string) string
 pkg strings, method (*Reader) WriteTo(io.Writer) (int64, error)
@@ -49366,7 +49393,7 @@ pkg syscall (windows-386), const IP_MULTICAST_TTL = 10
 pkg syscall (windows-386), const IP_TOS = 3
 pkg syscall (windows-386), const IP_TTL = 4
 pkg syscall (windows-386), const ImplementsGetwd = true
-pkg syscall (windows-386), const InvalidHandle = 18446744073709551615
+pkg syscall (windows-386), const InvalidHandle = 4294967295
 pkg syscall (windows-386), const KEY_ALL_ACCESS = 983103
 pkg syscall (windows-386), const KEY_CREATE_LINK = 32
 pkg syscall (windows-386), const KEY_CREATE_SUB_KEY = 4

api/go1.17.txt

@@ -63,12 +63,93 @@ pkg image/draw, type RGBA64Image interface, RGBA64At(int, int) color.RGBA64
 pkg image/draw, type RGBA64Image interface, Set(int, int, color.Color)
 pkg image/draw, type RGBA64Image interface, SetRGBA64(int, int, color.RGBA64)
 pkg io/fs, func FileInfoToDirEntry(FileInfo) DirEntry
+pkg math (darwin-amd64), const MaxInt = 9223372036854775807
+pkg math (darwin-amd64), const MaxUint = 18446744073709551615
+pkg math (darwin-amd64), const MinInt = -9223372036854775808
+pkg math (darwin-amd64-cgo), const MaxInt = 9223372036854775807
+pkg math (darwin-amd64-cgo), const MaxUint = 18446744073709551615
+pkg math (darwin-amd64-cgo), const MinInt = -9223372036854775808
+pkg math (freebsd-386), const MaxInt = 2147483647
+pkg math (freebsd-386), const MaxUint = 4294967295
+pkg math (freebsd-386), const MinInt = -2147483648
+pkg math (freebsd-386-cgo), const MaxInt = 2147483647
+pkg math (freebsd-386-cgo), const MaxUint = 4294967295
+pkg math (freebsd-386-cgo), const MinInt = -2147483648
+pkg math (freebsd-amd64), const MaxInt = 9223372036854775807
+pkg math (freebsd-amd64), const MaxUint = 18446744073709551615
+pkg math (freebsd-amd64), const MinInt = -9223372036854775808
+pkg math (freebsd-amd64-cgo), const MaxInt = 9223372036854775807
+pkg math (freebsd-amd64-cgo), const MaxUint = 18446744073709551615
+pkg math (freebsd-amd64-cgo), const MinInt = -9223372036854775808
+pkg math (freebsd-arm), const MaxInt = 2147483647
+pkg math (freebsd-arm), const MaxUint = 4294967295
+pkg math (freebsd-arm), const MinInt = -2147483648
+pkg math (freebsd-arm-cgo), const MaxInt = 2147483647
+pkg math (freebsd-arm-cgo), const MaxUint = 4294967295
+pkg math (freebsd-arm-cgo), const MinInt = -2147483648
+pkg math (linux-386), const MaxInt = 2147483647
+pkg math (linux-386), const MaxUint = 4294967295
+pkg math (linux-386), const MinInt = -2147483648
+pkg math (linux-386-cgo), const MaxInt = 2147483647
+pkg math (linux-386-cgo), const MaxUint = 4294967295
+pkg math (linux-386-cgo), const MinInt = -2147483648
+pkg math (linux-amd64), const MaxInt = 9223372036854775807
+pkg math (linux-amd64), const MaxUint = 18446744073709551615
+pkg math (linux-amd64), const MinInt = -9223372036854775808
+pkg math (linux-amd64-cgo), const MaxInt = 9223372036854775807
+pkg math (linux-amd64-cgo), const MaxUint = 18446744073709551615
+pkg math (linux-amd64-cgo), const MinInt = -9223372036854775808
+pkg math (linux-arm), const MaxInt = 2147483647
+pkg math (linux-arm), const MaxUint = 4294967295
+pkg math (linux-arm), const MinInt = -2147483648
+pkg math (linux-arm-cgo), const MaxInt = 2147483647
+pkg math (linux-arm-cgo), const MaxUint = 4294967295
+pkg math (linux-arm-cgo), const MinInt = -2147483648
+pkg math (netbsd-386), const MaxInt = 2147483647
+pkg math (netbsd-386), const MaxUint = 4294967295
+pkg math (netbsd-386), const MinInt = -2147483648
+pkg math (netbsd-386-cgo), const MaxInt = 2147483647
+pkg math (netbsd-386-cgo), const MaxUint = 4294967295
+pkg math (netbsd-386-cgo), const MinInt = -2147483648
+pkg math (netbsd-amd64), const MaxInt = 9223372036854775807
+pkg math (netbsd-amd64), const MaxUint = 18446744073709551615
+pkg math (netbsd-amd64), const MinInt = -9223372036854775808
+pkg math (netbsd-amd64-cgo), const MaxInt = 9223372036854775807
+pkg math (netbsd-amd64-cgo), const MaxUint = 18446744073709551615
+pkg math (netbsd-amd64-cgo), const MinInt = -9223372036854775808
+pkg math (netbsd-arm), const MaxInt = 2147483647
+pkg math (netbsd-arm), const MaxUint = 4294967295
+pkg math (netbsd-arm), const MinInt = -2147483648
+pkg math (netbsd-arm-cgo), const MaxInt = 2147483647
+pkg math (netbsd-arm-cgo), const MaxUint = 4294967295
+pkg math (netbsd-arm-cgo), const MinInt = -2147483648
+pkg math (netbsd-arm64), const MaxInt = 9223372036854775807
+pkg math (netbsd-arm64), const MaxUint = 18446744073709551615
+pkg math (netbsd-arm64), const MinInt = -9223372036854775808
+pkg math (netbsd-arm64-cgo), const MaxInt = 9223372036854775807
+pkg math (netbsd-arm64-cgo), const MaxUint = 18446744073709551615
+pkg math (netbsd-arm64-cgo), const MinInt = -9223372036854775808
+pkg math (openbsd-386), const MaxInt = 2147483647
+pkg math (openbsd-386), const MaxUint = 4294967295
+pkg math (openbsd-386), const MinInt = -2147483648
+pkg math (openbsd-386-cgo), const MaxInt = 2147483647
+pkg math (openbsd-386-cgo), const MaxUint = 4294967295
+pkg math (openbsd-386-cgo), const MinInt = -2147483648
+pkg math (openbsd-amd64), const MaxInt = 9223372036854775807
+pkg math (openbsd-amd64), const MaxUint = 18446744073709551615
+pkg math (openbsd-amd64), const MinInt = -9223372036854775808
+pkg math (openbsd-amd64-cgo), const MaxInt = 9223372036854775807
+pkg math (openbsd-amd64-cgo), const MaxUint = 18446744073709551615
+pkg math (openbsd-amd64-cgo), const MinInt = -9223372036854775808
+pkg math (windows-386), const MaxInt = 2147483647
+pkg math (windows-386), const MaxUint = 4294967295
+pkg math (windows-386), const MinInt = -2147483648
+pkg math (windows-amd64), const MaxInt = 9223372036854775807
+pkg math (windows-amd64), const MaxUint = 18446744073709551615
+pkg math (windows-amd64), const MinInt = -9223372036854775808
 pkg math, const MaxFloat64 = 1.79769e+308  // 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368
-pkg math, const MaxInt = 9223372036854775807
 pkg math, const MaxInt ideal-int
-pkg math, const MaxUint = 18446744073709551615
 pkg math, const MaxUint ideal-int
-pkg math, const MinInt = -9223372036854775808
 pkg math, const MinInt ideal-int
 pkg math, const SmallestNonzeroFloat32 = 1.4013e-45  // 1/713623846352979940529142984724747568191373312
 pkg math, const SmallestNonzeroFloat64 = 4.94066e-324  // 1/202402253307310618352495346718917307049556649764142118356901358027430339567995346891960383701437124495187077864316811911389808737385793476867013399940738509921517424276566361364466907742093216341239767678472745068562007483424692698618103355649159556340810056512358769552333414615230502532186327508646006263307707741093494784

api/go1.9.txt

@@ -50,7 +50,34 @@ pkg image/png, type EncoderBufferPool interface, Put(*EncoderBuffer)
 pkg math/big, method (*Int) IsInt64() bool
 pkg math/big, method (*Int) IsUint64() bool
 pkg math/big, type Word uint
-pkg math/bits, const UintSize = 64
+pkg math/bits (darwin-amd64), const UintSize = 64
+pkg math/bits (darwin-amd64-cgo), const UintSize = 64
+pkg math/bits (freebsd-386), const UintSize = 32
+pkg math/bits (freebsd-386-cgo), const UintSize = 32
+pkg math/bits (freebsd-amd64), const UintSize = 64
+pkg math/bits (freebsd-amd64-cgo), const UintSize = 64
+pkg math/bits (freebsd-arm), const UintSize = 32
+pkg math/bits (freebsd-arm-cgo), const UintSize = 32
+pkg math/bits (linux-386), const UintSize = 32
+pkg math/bits (linux-386-cgo), const UintSize = 32
+pkg math/bits (linux-amd64), const UintSize = 64
+pkg math/bits (linux-amd64-cgo), const UintSize = 64
+pkg math/bits (linux-arm), const UintSize = 32
+pkg math/bits (linux-arm-cgo), const UintSize = 32
+pkg math/bits (netbsd-386), const UintSize = 32
+pkg math/bits (netbsd-386-cgo), const UintSize = 32
+pkg math/bits (netbsd-amd64), const UintSize = 64
+pkg math/bits (netbsd-amd64-cgo), const UintSize = 64
+pkg math/bits (netbsd-arm), const UintSize = 32
+pkg math/bits (netbsd-arm-cgo), const UintSize = 32
+pkg math/bits (netbsd-arm64), const UintSize = 64
+pkg math/bits (netbsd-arm64-cgo), const UintSize = 64
+pkg math/bits (openbsd-386), const UintSize = 32
+pkg math/bits (openbsd-386-cgo), const UintSize = 32
+pkg math/bits (openbsd-amd64), const UintSize = 64
+pkg math/bits (openbsd-amd64-cgo), const UintSize = 64
+pkg math/bits (windows-386), const UintSize = 32
+pkg math/bits (windows-amd64), const UintSize = 64
 pkg math/bits, const UintSize ideal-int
 pkg math/bits, func LeadingZeros(uint) int
 pkg math/bits, func LeadingZeros16(uint16) int

api/next.txt

@@ -0,0 +1,47 @@
+pkg debug/buildinfo, func Read(io.ReaderAt) (*debug.BuildInfo, error)
+pkg debug/buildinfo, func ReadFile(string) (*debug.BuildInfo, error)
+pkg debug/buildinfo, type BuildInfo = debug.BuildInfo
+pkg runtime/debug, method (*BuildInfo) MarshalText() ([]byte, error)
+pkg runtime/debug, method (*BuildInfo) UnmarshalText() ([]byte, error)
+pkg runtime/debug, type BuildInfo struct, GoVersion string
+pkg runtime/debug, type BuildInfo struct, Settings []BuildSetting
+pkg runtime/debug, type BuildSetting struct
+pkg runtime/debug, type BuildSetting struct, Key string
+pkg runtime/debug, type BuildSetting struct, Value string
+pkg testing, func Fuzz(func(*F)) FuzzResult
+pkg testing, func MainStart(testDeps, []InternalTest, []InternalBenchmark, []InternalFuzzTarget, []InternalExample) *M
+pkg testing, func RunFuzzTargets(func(string, string) (bool, error), []InternalFuzzTarget) bool
+pkg testing, func RunFuzzing(func(string, string) (bool, error), []InternalFuzzTarget) bool
+pkg testing, method (*B) Setenv(string, string)
+pkg testing, method (*F) Add(...interface{})
+pkg testing, method (*F) Cleanup(func())
+pkg testing, method (*F) Error(...interface{})
+pkg testing, method (*F) Errorf(string, ...interface{})
+pkg testing, method (*F) Fail()
+pkg testing, method (*F) FailNow()
+pkg testing, method (*F) Failed() bool
+pkg testing, method (*F) Fatal(...interface{})
+pkg testing, method (*F) Fatalf(string, ...interface{})
+pkg testing, method (*F) Fuzz(interface{})
+pkg testing, method (*F) Helper()
+pkg testing, method (*F) Log(...interface{})
+pkg testing, method (*F) Logf(string, ...interface{})
+pkg testing, method (*F) Name() string
+pkg testing, method (*F) Setenv(string, string)
+pkg testing, method (*F) Skip(...interface{})
+pkg testing, method (*F) SkipNow()
+pkg testing, method (*F) Skipf(string, ...interface{})
+pkg testing, method (*F) Skipped() bool
+pkg testing, method (*F) TempDir() string
+pkg testing, method (*T) Setenv(string, string)
+pkg testing, method (FuzzResult) String() string
+pkg testing, type F struct
+pkg testing, type FuzzResult struct
+pkg testing, type FuzzResult struct, Crasher entry
+pkg testing, type FuzzResult struct, Error error
+pkg testing, type FuzzResult struct, N int
+pkg testing, type FuzzResult struct, T time.Duration
+pkg testing, type InternalFuzzTarget struct
+pkg testing, type InternalFuzzTarget struct, Fn func(*F)
+pkg testing, type InternalFuzzTarget struct, Name string
+pkg net/http, method (*Cookie) Valid() error

doc/asm.html

@@ -125,8 +125,8 @@ it is a distinct program, so there are some differences.
 One is in constant evaluation.
 Constant expressions in the assembler are parsed using Go's operator
 precedence, not the C-like precedence of the original.
-Thus <code>3&amp;1<<2</code> is 4, not 0—it parses as <code>(3&amp;1)<<2</code>
+Thus <code>3&amp;1&lt;&lt;2</code> is 4, not 0—it parses as <code>(3&amp;1)&lt;&lt;2</code>
-not <code>3&amp;(1<<2)</code>.
+not <code>3&amp;(1&lt;&lt;2)</code>.
 Also, constants are always evaluated as 64-bit unsigned integers.
 Thus <code>-2</code> is not the integer value minus two,
 but the unsigned 64-bit integer with the same bit pattern.
@@ -914,8 +914,6 @@ This assembler is used by GOARCH values ppc64 and ppc64le.
 Reference: <a href="/pkg/cmd/internal/obj/ppc64">Go PPC64 Assembly Instructions Reference Manual</a>
 </p>
 
-</ul>
-
 <h3 id="s390x">IBM z/Architecture, a.k.a. s390x</h3>
 
 <p>

doc/go1.18.html

@@ -0,0 +1,242 @@
+<!--{
+	"Title": "Go 1.18 Release Notes",
+	"Path":  "/doc/go1.18"
+}-->
+
+<!--
+NOTE: In this document and others in this directory, the convention is to
+set fixed-width phrases with non-fixed-width spaces, as in
+<code>hello</code> <code>world</code>.
+Do not send CLs removing the interior tags from such phrases.
+-->
+
+<style>
+  main ul li { margin: 0.5em 0; }
+</style>
+
+<h2 id="introduction">DRAFT RELEASE NOTES — Introduction to Go 1.18</h2>
+
+<p>
+  <strong>
+    Go 1.18 is not yet released. These are work-in-progress
+    release notes. Go 1.18 is expected to be released in February 2022.
+  </strong>
+</p>
+
+<h2 id="language">Changes to the language</h2>
+
+<p>
+  TODO: complete this section
+</p>
+
+<h2 id="ports">Ports</h2>
+
+<p id="freebsd">
+  Go 1.18 is the last release that is supported on FreeBSD 11.x, which has
+  already reached end-of-life. Go 1.19 will require FreeBSD 12.2+ or FreeBSD
+  13.0+.
+  FreeBSD 13.0+ will require a kernel with the COMPAT_FREEBSD12 option set (this is the default).
+</p>
+
+<h2 id="tools">Tools</h2>
+
+<p>
+  TODO: complete this section, or delete if not needed
+</p>
+
+<h3 id="go-command">Go command</h3>
+
+<p><!-- golang.org/issue/43684 -->
+  <code>go</code> <code>get</code> no longer builds or installs packages in
+  module-aware mode. <code>go</code> <code>get</code> is now dedicated to
+  adjusting dependencies in <code>go.mod</code>. Effectively, the
+  <code>-d</code> flag is always enabled. To install the latest version
+  of an executable outside the context of the current module, use
+  <a href="https://golang.org/ref/mod#go-install"><code>go</code>
+  <code>install</code> <code>example.com/cmd@latest</code></a>. Any
+  <a href="https://golang.org/ref/mod#version-queries">version query</a>
+  may be used instead of <code>latest</code>. This form of <code>go</code>
+  <code>install</code> was added in Go 1.16, so projects supporting older
+  versions may need to provide install instructions for both <code>go</code>
+  <code>install</code> and <code>go</code> <code>get</code>. <code>go</code>
+  <code>get</code> now reports an error when used outside a module, since there
+  is no <code>go.mod</code> file to update. In GOPATH mode (with
+  <code>GO111MODULE=off</code>), <code>go</code> <code>get</code> still builds
+  and installs packages, as before.
+</p>
+
+<p><!-- golang.org/issue/37475 -->
+  The <code>go</code> command now embeds version control information in
+  binaries including the currently checked-out revision, commit time, and a
+  flag indicating whether edited or untracked files are present. Version
+  control information is embedded if the <code>go</code> command is invoked in
+  a directory within a Git, Mercurial, Fossil, or Bazaar repository, and the
+  <code>main</code> package and its containing main module are in the same
+  repository. This information may be omitted using the flag
+  <code>-buildvcs=false</code>.
+</p>
+
+<p><!-- golang.org/issue/37475 -->
+  Additionally, the <code>go</code> command embeds information about the build
+  including build and tool tags (set with <code>-tags</code>), compiler,
+  assembler, and linker flags (like <code>-gcflags</code>), whether cgo was
+  enabled, and if it was, the values of the cgo environment variables
+  (like <code>CGO_CFLAGS</code>). This information may be omitted using the
+  flag <code>-buildinfo=false</code>. Both VCS and build information may be
+  read together with module information using <code>go</code>
+  <code>version</code> <code>-m</code> <code>file</code> or
+  <code>runtime/debug.ReadBuildInfo</code> (for the currently running binary)
+  or the new <a href="#debug/buildinfo"><code>debug/buildinfo</code></a>
+  package.
+</p>
+
+<p><!-- https://golang.org/issue/44435 -->
+  If the main module's <code>go.mod</code> file
+  specifies <a href="/ref/mod#go-mod-file-go"><code>go</code> <code>1.17</code></a>
+  or higher, <code>go</code> <code>mod</code> <code>download</code> without
+  arguments now downloads source code for only the modules
+  explicitly <a href="/ref/mod#go-mod-file-require">required</a> in the main
+  module's <code>go.mod</code> file. (In a <code>go</code> <code>1.17</code> or
+  higher module, that set already includes all dependencies needed to build the
+  packages and tests in the main module.)
+  To also download source code for transitive dependencies, use
+  <code>go</code> <code>mod</code> <code>download</code> <code>all</code>.
+</p>
+
+<p>
+  TODO: complete this section, or delete if not needed
+</p>
+
+<h3 id="gofmt"><code>gofmt</code></h3>
+
+<p><!-- https://golang.org/issue/43566 -->
+  <code>gofmt</code> now reads and formats input files concurrently, with a
+  memory limit proportional to <code>GOMAXPROCS</code>. On a machine with
+  multiple CPUs, <code>gofmt</code> should now be significantly faster.
+</p>
+
+
+<h2 id="runtime">Runtime</h2>
+
+<p>
+  TODO: complete this section, or delete if not needed
+</p>
+
+<h2 id="compiler">Compiler</h2>
+
+<p>
+  TODO: complete this section, or delete if not needed
+</p>
+
+<h2 id="linker">Linker</h2>
+
+<p>
+  TODO: complete this section, or delete if not needed
+</p>
+
+<h2 id="library">Core library</h2>
+
+<h3>TODO</h3>
+<p>
+  TODO: complete this section
+</p>
+
+<h3 id="netip">New <code>net/netip</code> package</h3>
+<p>
+  The new <a href="/pkg/net/netip/"><code>net/netip</code></a>
+  package defines a new IP address type, <a href="/pkg/net/netip/#Addr"><code>Addr</code></a>.
+  Compared to the existing
+  <a href="/pkg/net/#IP"><code>net.IP</code></a> type, the <code>netip.Addr</code> type takes less
+  memory, is immutable, and is comparable so it supports <code>==</code>
+  and can be used as a map key.
+</p>
+<p>
+  In addition to <code>Addr</code>, the package defines
+  <a href="/pkg/net/netip/#AddrPort"><code>AddrPort</code></a>, representing
+  an IP and port, and
+  <a href="/pkg/net/netip/#Prefix"><code>Prefix</code></a>, representing
+  a network CIDR prefix.
+</p>
+<p>
+  The <code>net</code> package now has methods to send and receive UDP packets
+  using <code>netip.Addr</code> values instead of the relatively heavy
+  <code>*net.UDPAddr</code> values.
+</p>
+
+<h3 id="minor_library_changes">Minor changes to the library</h3>
+
+<p>
+  As always, there are various minor changes and updates to the library,
+  made with the Go 1 <a href="/doc/go1compat">promise of compatibility</a>
+  in mind.
+</p>
+
+<p>
+  TODO: complete this section
+</p>
+
+<dl id="debug/buildinfo"><dt><a href="/pkg/debug/buildinfo">debug/buildinfo</a></dt>
+  <dd>
+    <p><!-- golang.org/issue/39301 -->
+      This new package provides access to module versions, version control
+      information, and build flags embedded in executable files built by
+      the <code>go</code> command. The same information is also available via
+      <a href="/pkg/runtime/debug#ReadBuildInfo"><code>runtime/debug.ReadBuildInfo</code></a>
+      for the currently running binary and via <code>go</code>
+      <code>version</code> <code>-m</code> on the command line.
+    </p>
+  </dd>
+</dl>
+
+<dl id="image/draw"><dt><a href="/pkg/image/draw/">image/draw</a></dt>
+  <dd>
+    <p><!-- CL 340049 -->
+      The <code>Draw</code> and <code>DrawMask</code> fallback implementations
+      (used when the arguments are not the most common image types) are now
+      faster when those arguments implement the optional
+      <a href="/pkg/image/draw/#RGBA64Image"><code>draw.RGBA64Image</code></a>
+      and <a href="/pkg/image/#RGBA64Image"><code>image.RGBA64Image</code></a>
+      interfaces that were added in Go 1.17.
+    </p>
+  </dd>
+</dl><!-- image/draw -->
+
+<dl id="reflect"><dt><a href="/pkg/reflect/">reflect</a></dt>
+  <dd>
+    <p><!-- CL 356049, 320929 -->
+      The new
+      <a href="/pkg/reflect/#Value.SetIterKey"><code>Value.SetIterKey</code></a>
+      and <a href="/pkg/reflect/#Value.SetIterValue"><code>Value.SetIterValue</code></a>
+      methods set a Value using a map iterator as the source. They are equivalent to
+      <code>Value.Set(iter.Key())</code> and <code>Value.Set(iter.Value())</code> but
+      do fewer allocations.
+    </p>
+  </dd>
+  <dd>
+    <p><!-- CL 350691 -->
+      The new
+      <a href="/pkg/reflect/#Value.UnsafePointer"><code>Value.UnsafePointer</code></a>
+      method returns the Value's value as an <a href="/pkg/unsafe/#Pointer"><code>unsafe.Pointer</code></a>.
+      This allows callers to migrate from <a href="/pkg/reflect/#Value.UnsafeAddr"><code>Value.UnsafeAddr</code></a>
+      and <a href="/pkg/reflect/#Value.Pointer"><code>Value.Pointer</code></a>
+      to eliminate the need to perform uintptr to unsafe.Pointer conversions at the callsite (as unsafe.Pointer rules require).
+    </p>
+  </dd>
+</dl><!-- reflect -->
+
+<dl id="syscall"><dt><a href="/pkg/syscall/">syscall</a></dt>
+  <dd>
+    <p><!-- CL 336550 -->
+      The new function <a href="/pkg/syscall/?GOOS=windows#SyscallN"><code>SyscallN</code></a>
+      has been introduced for Windows, allowing for calls with arbitrary number
+      of arguments. As a result,
+      <a href="/pkg/syscall/?GOOS=windows#Syscall"><code>Syscall</code></a>,
+      <a href="/pkg/syscall/?GOOS=windows#Syscall6"><code>Syscall6</code></a>,
+      <a href="/pkg/syscall/?GOOS=windows#Syscall9"><code>Syscall9</code></a>,
+      <a href="/pkg/syscall/?GOOS=windows#Syscall12"><code>Syscall12</code></a>,
+      <a href="/pkg/syscall/?GOOS=windows#Syscall15"><code>Syscall15</code></a>, and
+      <a href="/pkg/syscall/?GOOS=windows#Syscall18"><code>Syscall18</code></a> are
+      deprecated in favor of <a href="/pkg/syscall/?GOOS=windows#SyscallN"><code>SyscallN</code></a>.
+    </p>
+  </dd>
+</dl><!-- syscall -->

doc/go_spec.html

@@ -1,6 +1,6 @@
 <!--{
 	"Title": "The Go Programming Language Specification",
-	"Subtitle": "Version of Jul 26, 2021",
+	"Subtitle": "Version of Oct 15, 2021",
 	"Path": "/ref/spec"
 }-->
 
@@ -3000,6 +3000,18 @@ method value; the saved copy is then used as the receiver in any calls,
 which may be executed later.
 </p>
 
+<pre>
+type S struct { *T }
+type T int
+func (t T) M() { print(t) }
+
+t := new(T)
+s := S{T: t}
+f := t.M                    // receiver *t is evaluated and stored in f
+g := s.M                    // receiver *(s.T) is evaluated and stored in g
+*t = 42                     // does not affect stored receivers in f and g
+</pre>
+
 <p>
 The type <code>T</code> may be an interface or non-interface type.
 </p>
@@ -3602,7 +3614,7 @@ var i = 1&lt;&lt;s                   // 1 has type int
 var j int32 = 1&lt;&lt;s             // 1 has type int32; j == 0
 var k = uint64(1&lt;&lt;s)           // 1 has type uint64; k == 1&lt;&lt;33
 var m int = 1.0&lt;&lt;s             // 1.0 has type int; m == 1&lt;&lt;33
-var n = 1.0&lt;&lt;s == j            // 1.0 has type int; n == true
+var n = 1.0&lt;&lt;s == j            // 1.0 has type int32; n == true
 var o = 1&lt;&lt;s == 2&lt;&lt;s           // 1 and 2 have type int; o == false
 var p = 1&lt;&lt;s == 1&lt;&lt;33          // 1 has type int; p == true
 var u = 1.0&lt;&lt;s                 // illegal: 1.0 has type float64, cannot shift
@@ -4338,7 +4350,7 @@ t0 := (*[0]string)(t)    // t0 == nil
 t1 := (*[1]string)(t)    // panics: len([1]string) > len(t)
 
 u := make([]byte, 0)
-u0 = (*[0]byte)(u)       // u0 != nil
+u0 := (*[0]byte)(u)      // u0 != nil
 </pre>
 
 <h3 id="Constant_expressions">Constant expressions</h3>
@@ -4549,9 +4561,8 @@ SimpleStmt = EmptyStmt | ExpressionStmt | SendStmt | IncDecStmt | Assignment | S
 <h3 id="Terminating_statements">Terminating statements</h3>
 
 <p>
-A <i>terminating statement</i> prevents execution of all statements that lexically
+A <i>terminating statement</i> interrupts the regular flow of control in
-appear after it in the same <a href="#Blocks">block</a>. The following statements
+a <a href="#Blocks">block</a>. The following statements are terminating:
-are terminating:
 </p>
 
 <ol>
@@ -4587,7 +4598,8 @@ are terminating:
 	A <a href="#For_statements">"for" statement</a> in which:
 	<ul>
 	<li>there are no "break" statements referring to the "for" statement, and</li>
-	<li>the loop condition is absent.</li>
+	<li>the loop condition is absent, and</li>
+	<li>the "for" statement does not use a range clause.</li>
 	</ul>
 </li>
 

misc/cgo/errors/errors_test.go

@@ -36,14 +36,13 @@ func check(t *testing.T, file string) {
 				continue
 			}
 
-			frags := bytes.SplitAfterN(line, []byte("ERROR HERE: "), 2)
+			_, frag, ok := bytes.Cut(line, []byte("ERROR HERE: "))
-			if len(frags) == 1 {
+			if !ok {
 				continue
 			}
-			frag := fmt.Sprintf(":%d:.*%s", i+1, frags[1])
+			re, err := regexp.Compile(fmt.Sprintf(":%d:.*%s", i+1, frag))
-			re, err := regexp.Compile(frag)
 			if err != nil {
-				t.Errorf("Invalid regexp after `ERROR HERE: `: %#q", frags[1])
+				t.Errorf("Invalid regexp after `ERROR HERE: `: %#q", frag)
 				continue
 			}
 			errors = append(errors, re)

misc/cgo/test/cgo_test.go

@@ -59,6 +59,7 @@ func Test28896(t *testing.T)                 { test28896(t) }
 func Test30065(t *testing.T)                 { test30065(t) }
 func Test32579(t *testing.T)                 { test32579(t) }
 func Test31891(t *testing.T)                 { test31891(t) }
+func Test42018(t *testing.T)                 { test42018(t) }
 func Test45451(t *testing.T)                 { test45451(t) }
 func TestAlign(t *testing.T)                 { testAlign(t) }
 func TestAtol(t *testing.T)                  { testAtol(t) }

misc/cgo/test/issue42018.go

@@ -0,0 +1,14 @@
+// Copyright 2021 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.
+
+//go:build !windows
+// +build !windows
+
+package cgotest
+
+import "testing"
+
+func test42018(t *testing.T) {
+	t.Skip("skipping Windows-only test")
+}

misc/cgo/test/issue42018_windows.go

@@ -0,0 +1,46 @@
+// Copyright 2021 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 cgotest
+
+/*
+typedef void *HANDLE;
+
+struct HWND__{int unused;}; typedef struct HWND__ *HWND;
+*/
+import "C"
+
+import (
+	"testing"
+	"unsafe"
+)
+
+func test42018(t *testing.T) {
+	// Test that Windows handles are marked go:notinheap, by growing the
+	// stack and checking for pointer adjustments. Trick from
+	// test/fixedbugs/issue40954.go.
+	var i int
+	handle := C.HANDLE(unsafe.Pointer(uintptr(unsafe.Pointer(&i))))
+	recurseHANDLE(100, handle, uintptr(unsafe.Pointer(&i)))
+	hwnd := C.HWND(unsafe.Pointer(uintptr(unsafe.Pointer(&i))))
+	recurseHWND(400, hwnd, uintptr(unsafe.Pointer(&i)))
+}
+
+func recurseHANDLE(n int, p C.HANDLE, v uintptr) {
+	if n > 0 {
+		recurseHANDLE(n-1, p, v)
+	}
+	if uintptr(unsafe.Pointer(p)) != v {
+		panic("adjusted notinheap pointer")
+	}
+}
+
+func recurseHWND(n int, p C.HWND, v uintptr) {
+	if n > 0 {
+		recurseHWND(n-1, p, v)
+	}
+	if uintptr(unsafe.Pointer(p)) != v {
+		panic("adjusted notinheap pointer")
+	}
+}

misc/cgo/test/testdata/issue43639.go

@@ -0,0 +1,9 @@
+// Copyright 2021 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 cgotest
+
+// Issue 43639: No runtime test needed, make sure package cgotest/issue43639 compiles well.
+
+import _ "cgotest/issue43639"

misc/cgo/test/testdata/issue43639/a.go

@@ -0,0 +1,8 @@
+// Copyright 2021 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 issue43639
+
+// #cgo CFLAGS: -W -Wall -Werror
+import "C"

misc/cgo/test/typeparam.go

@@ -0,0 +1,17 @@
+// Copyright 2021 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 cgotest
+
+// #include <stddef.h>
+import "C"
+
+func generic[T, U any](t T, u U) {}
+
+func useGeneric() {
+	const zero C.size_t = 0
+
+	generic(zero, zero)
+	generic[C.size_t, C.size_t](0, 0)
+}

misc/cgo/testcarchive/carchive_test.go

@@ -931,3 +931,55 @@ func TestManyCalls(t *testing.T) {
 		t.Error(err)
 	}
 }
+
+// Issue 49288.
+func TestPreemption(t *testing.T) {
+	if runtime.Compiler == "gccgo" {
+		t.Skip("skipping asynchronous preemption test with gccgo")
+	}
+
+	t.Parallel()
+
+	if !testWork {
+		defer func() {
+			os.Remove("testp8" + exeSuffix)
+			os.Remove("libgo8.a")
+			os.Remove("libgo8.h")
+		}()
+	}
+
+	cmd := exec.Command("go", "build", "-buildmode=c-archive", "-o", "libgo8.a", "./libgo8")
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+	checkLineComments(t, "libgo8.h")
+
+	ccArgs := append(cc, "-o", "testp8"+exeSuffix, "main8.c", "libgo8.a")
+	if out, err := exec.Command(ccArgs[0], ccArgs[1:]...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	argv := cmdToRun("./testp8")
+	cmd = exec.Command(argv[0], argv[1:]...)
+	var sb strings.Builder
+	cmd.Stdout = &sb
+	cmd.Stderr = &sb
+	if err := cmd.Start(); err != nil {
+		t.Fatal(err)
+	}
+
+	timer := time.AfterFunc(time.Minute,
+		func() {
+			t.Error("test program timed out")
+			cmd.Process.Kill()
+		},
+	)
+	defer timer.Stop()
+
+	if err := cmd.Wait(); err != nil {
+		t.Log(sb.String())
+		t.Error(err)
+	}
+}

misc/cgo/testcarchive/testdata/libgo8/a.go

@@ -0,0 +1,36 @@
+// Copyright 2021 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 main
+
+import "C"
+
+import (
+	"os"
+	"runtime"
+	"sync/atomic"
+)
+
+var started int32
+
+// Start a goroutine that loops forever.
+func init() {
+	runtime.GOMAXPROCS(1)
+	go func() {
+		for {
+			atomic.StoreInt32(&started, 1)
+		}
+	}()
+}
+
+//export GoFunction8
+func GoFunction8() {
+	for atomic.LoadInt32(&started) == 0 {
+		runtime.Gosched()
+	}
+	os.Exit(0)
+}
+
+func main() {
+}

misc/cgo/testcarchive/testdata/main8.c

@@ -0,0 +1,16 @@
+// Copyright 2021 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.
+
+// Test preemption.
+
+#include <stdlib.h>
+
+#include "libgo8.h"
+
+int main() {
+	GoFunction8();
+
+	// That should have exited the program.
+	abort();
+}

misc/cgo/testcshared/cshared_test.go

@@ -200,7 +200,7 @@ func adbRun(t *testing.T, env []string, adbargs ...string) string {
 	args := append(adbCmd(), "exec-out")
 	// Propagate LD_LIBRARY_PATH to the adb shell invocation.
 	for _, e := range env {
-		if strings.Index(e, "LD_LIBRARY_PATH=") != -1 {
+		if strings.Contains(e, "LD_LIBRARY_PATH=") {
 			adbargs = append([]string{e}, adbargs...)
 			break
 		}
@@ -326,7 +326,7 @@ func createHeaders() error {
 			base, name := filepath.Split(args[0])
 			args[0] = filepath.Join(base, "llvm-dlltool")
 			var machine string
-			switch strings.SplitN(name, "-", 2)[0] {
+			switch prefix, _, _ := strings.Cut(name, "-"); prefix {
 			case "i686":
 				machine = "i386"
 			case "x86_64":

misc/cgo/testcshared/testdata/libgo2/dup2.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux,!arm64 netbsd openbsd
+// +build darwin dragonfly freebsd linux,!arm64,!riscv64 netbsd openbsd
 
 package main
 

misc/cgo/testcshared/testdata/libgo2/dup3.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,arm64
+// +build linux,arm64 linux,riscv64
 
 package main
 

misc/cgo/testgodefs/testdata/issue48396.go

@@ -0,0 +1,18 @@
+// Copyright 2021 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.
+//
+// +build ignore
+
+package main
+
+/*
+// from <linux/kcm.h>
+struct issue48396 {
+	int fd;
+	int bpf_fd;
+};
+*/
+import "C"
+
+type Issue48396 C.struct_issue48396

misc/cgo/testgodefs/testdata/main.go

@@ -28,6 +28,9 @@ var v7 = S{}
 // Test that #define'd type is fully defined
 var _ = issue38649{X: 0}
 
+// Test that prefixes do not cause duplicate field names.
+var _ = Issue48396{Fd: 1, Bpf_fd: 2}
+
 func main() {
 	pass := true
 

misc/cgo/testgodefs/testgodefs_test.go

@@ -25,6 +25,7 @@ var filePrefixes = []string{
 	"issue37621",
 	"issue38649",
 	"issue39534",
+	"issue48396",
 }
 
 func TestGoDefs(t *testing.T) {

misc/cgo/testsanitizers/asan_test.go

@@ -0,0 +1,66 @@
+// Copyright 2021 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 sanitizers_test
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestASAN(t *testing.T) {
+	goos, err := goEnv("GOOS")
+	if err != nil {
+		t.Fatal(err)
+	}
+	goarch, err := goEnv("GOARCH")
+	if err != nil {
+		t.Fatal(err)
+	}
+	// The asan tests require support for the -asan option.
+	if !aSanSupported(goos, goarch) {
+		t.Skipf("skipping on %s/%s; -asan option is not supported.", goos, goarch)
+	}
+
+	t.Parallel()
+	requireOvercommit(t)
+	config := configure("address")
+	config.skipIfCSanitizerBroken(t)
+
+	mustRun(t, config.goCmd("build", "std"))
+
+	cases := []struct {
+		src               string
+		memoryAccessError string
+	}{
+		{src: "asan1_fail.go", memoryAccessError: "heap-use-after-free"},
+		{src: "asan2_fail.go", memoryAccessError: "heap-buffer-overflow"},
+		{src: "asan3_fail.go", memoryAccessError: "use-after-poison"},
+		{src: "asan4_fail.go", memoryAccessError: "use-after-poison"},
+		{src: "asan_useAfterReturn.go"},
+	}
+	for _, tc := range cases {
+		tc := tc
+		name := strings.TrimSuffix(tc.src, ".go")
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			dir := newTempDir(t)
+			defer dir.RemoveAll(t)
+
+			outPath := dir.Join(name)
+			mustRun(t, config.goCmd("build", "-o", outPath, srcPath(tc.src)))
+
+			cmd := hangProneCmd(outPath)
+			if tc.memoryAccessError != "" {
+				out, err := cmd.CombinedOutput()
+				if err != nil && strings.Contains(string(out), tc.memoryAccessError) {
+					return
+				}
+				t.Fatalf("%#q exited without expected memory access error\n%s; got failure\n%s", strings.Join(cmd.Args, " "), tc.memoryAccessError, out)
+			}
+			mustRun(t, cmd)
+		})
+	}
+}

misc/cgo/testsanitizers/cc_test.go

@@ -267,6 +267,9 @@ func configure(sanitizer string) *config {
 			c.ldFlags = append(c.ldFlags, "-fPIC", "-static-libtsan")
 		}
 
+	case "address":
+		c.goFlags = append(c.goFlags, "-asan")
+
 	default:
 		panic(fmt.Sprintf("unrecognized sanitizer: %q", sanitizer))
 	}
@@ -344,7 +347,7 @@ func (c *config) checkCSanitizer() (skip bool, err error) {
 		if os.IsNotExist(err) {
 			return true, fmt.Errorf("%#q failed to produce executable: %v", strings.Join(cmd.Args, " "), err)
 		}
-		snippet := bytes.SplitN(out, []byte{'\n'}, 2)[0]
+		snippet, _, _ := bytes.Cut(out, []byte("\n"))
 		return true, fmt.Errorf("%#q generated broken executable: %v\n%s", strings.Join(cmd.Args, " "), err, snippet)
 	}
 
@@ -450,3 +453,14 @@ func mSanSupported(goos, goarch string) bool {
 		return false
 	}
 }
+
+// aSanSupported is a copy of the function cmd/internal/sys.ASanSupported,
+// because the internal pacakage can't be used here.
+func aSanSupported(goos, goarch string) bool {
+	switch goos {
+	case "linux":
+		return goarch == "amd64" || goarch == "arm64"
+	default:
+		return false
+	}
+}

misc/cgo/testsanitizers/testdata/asan1_fail.go

@@ -0,0 +1,28 @@
+// Copyright 2021 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 main
+
+/*
+#include <stdlib.h>
+#include <stdio.h>
+
+int *p;
+int* test() {
+ p = (int *)malloc(2 * sizeof(int));
+ free(p);
+ return p;
+}
+*/
+import "C"
+import "fmt"
+
+func main() {
+	// C passes Go an invalid pointer.
+	a := C.test()
+	// Use after free
+	*a = 2
+	// We shouldn't get here; asan should stop us first.
+	fmt.Println(*a)
+}

misc/cgo/testsanitizers/testdata/asan2_fail.go

@@ -0,0 +1,34 @@
+// Copyright 2021 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 main
+
+/*
+#include <stdlib.h>
+#include <stdio.h>
+
+int *p;
+int* f() {
+  int i;
+  p = (int *)malloc(5*sizeof(int));
+  for (i = 0; i < 5; i++) {
+    p[i] = i+10;
+  }
+  return p;
+}
+*/
+import "C"
+import (
+	"fmt"
+	"unsafe"
+)
+
+func main() {
+	a := C.f()
+	q5 := (*C.int)(unsafe.Add(unsafe.Pointer(a), 4*5))
+	// Access to C pointer out of bounds.
+	*q5 = 100
+	// We shouldn't get here; asan should stop us first.
+	fmt.Printf("q5: %d, %x\n", *q5, q5)
+}

misc/cgo/testsanitizers/testdata/asan3_fail.go

@@ -0,0 +1,23 @@
+// Copyright 2021 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 main
+
+/*
+#include <stdlib.h>
+#include <stdio.h>
+
+void test(int *a) {
+	// Access Go pointer out of bounds.
+	int c = a[5];        // BOOM
+	// We shouldn't get here; asan should stop us first.
+	printf("a[5]=%d\n", c);
+}
+*/
+import "C"
+
+func main() {
+	cIntSlice := []C.int{200, 201, 203, 203, 204}
+	C.test(&cIntSlice[0])
+}

misc/cgo/testsanitizers/testdata/asan4_fail.go

@@ -0,0 +1,22 @@
+// Copyright 2021 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 main
+
+/*
+#include <stdlib.h>
+#include <stdio.h>
+
+void test(int* a) {
+	// Access Go pointer out of bounds.
+	a[3] = 300;          // BOOM
+	// We shouldn't get here; asan should stop us first.
+	printf("a[3]=%d\n", a[3]);
+}*/
+import "C"
+
+func main() {
+	var cIntArray [2]C.int
+	C.test(&cIntArray[0]) // cIntArray is moved to heap.
+}

misc/cgo/testsanitizers/testdata/asan_useAfterReturn.go

@@ -0,0 +1,26 @@
+// Copyright 2021 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 main
+
+// The -fsanitize=address option of C compier can detect stack-use-after-return bugs.
+// In the following program, the local variable 'local' was moved to heap by the Go
+// compiler because foo() is returning the reference to 'local', and return stack of
+// foo() will be invalid. Thus for main() to use the reference to 'local', the 'local'
+// must be available even after foo() has finished. Therefore, Go has no such issue.
+
+import "fmt"
+
+var ptr *int
+
+func main() {
+	foo()
+	fmt.Printf("ptr=%x, %v", *ptr, ptr)
+}
+
+func foo() {
+	var local int
+	local = 1
+	ptr = &local // local is moved to heap.
+}

misc/cgo/testshared/shared_test.go

@@ -1033,7 +1033,7 @@ func TestGlobal(t *testing.T) {
 // Run a test using -linkshared of an installed shared package.
 // Issue 26400.
 func TestTestInstalledShared(t *testing.T) {
-	goCmd(nil, "test", "-linkshared", "-test.short", "sync/atomic")
+	goCmd(t, "test", "-linkshared", "-test.short", "sync/atomic")
 }
 
 // Test generated pointer method with -linkshared.
@@ -1045,8 +1045,8 @@ func TestGeneratedMethod(t *testing.T) {
 // Test use of shared library struct with generated hash function.
 // Issue 30768.
 func TestGeneratedHash(t *testing.T) {
-	goCmd(nil, "install", "-buildmode=shared", "-linkshared", "./issue30768/issue30768lib")
+	goCmd(t, "install", "-buildmode=shared", "-linkshared", "./issue30768/issue30768lib")
-	goCmd(nil, "test", "-linkshared", "./issue30768")
+	goCmd(t, "test", "-linkshared", "./issue30768")
 }
 
 // Test that packages can be added not in dependency order (here a depends on b, and a adds
@@ -1070,3 +1070,11 @@ func TestIssue44031(t *testing.T) {
 	goCmd(t, "install", "-buildmode=shared", "-linkshared", "./issue44031/b")
 	goCmd(t, "run", "-linkshared", "./issue44031/main")
 }
+
+// Test that we use a variable from shared libraries (which implement an
+// interface in shared libraries.). A weak reference is used in the itab
+// in main process. It can cause unreacheble panic. See issue 47873.
+func TestIssue47873(t *testing.T) {
+	goCmd(t, "install", "-buildmode=shared", "-linkshared", "./issue47837/a")
+	goCmd(t, "run", "-linkshared", "./issue47837/main")
+}

misc/cgo/testshared/testdata/issue47837/a/a.go

@@ -0,0 +1,19 @@
+// Copyright 2021 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 A interface {
+	M()
+}
+
+//go:noinline
+func TheFuncWithArgA(a A) {
+	a.M()
+}
+
+type ImplA struct{}
+
+//go:noinline
+func (A *ImplA) M() {}

misc/cgo/testshared/testdata/issue47837/main/main.go

@@ -0,0 +1,14 @@
+// Copyright 2021 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 main
+
+import (
+	"testshared/issue47837/a"
+)
+
+func main() {
+	var vara a.ImplA
+	a.TheFuncWithArgA(&vara)
+}

misc/go.mod

@@ -8,4 +8,4 @@
 // directory.)
 module misc
 
-go 1.12
+go 1.18

misc/ios/go_ios_exec.go

@@ -148,9 +148,8 @@ func runOnDevice(appdir string) error {
 	// Device IDs as listed with ios-deploy -c.
 	deviceID = os.Getenv("GOIOS_DEVICE_ID")
 
-	parts := strings.SplitN(appID, ".", 2)
+	if _, id, ok := strings.Cut(appID, "."); ok {
-	if len(parts) == 2 {
+		bundleID = id
-		bundleID = parts[1]
 	}
 
 	if err := signApp(appdir); err != nil {
@@ -291,11 +290,10 @@ func findDevImage() (string, error) {
 	var iosVer, buildVer string
 	lines := bytes.Split(out, []byte("\n"))
 	for _, line := range lines {
-		spl := bytes.SplitN(line, []byte(": "), 2)
+		key, val, ok := strings.Cut(string(line), ": ")
-		if len(spl) != 2 {
+		if !ok {
 			continue
 		}
-		key, val := string(spl[0]), string(spl[1])
 		switch key {
 		case "ProductVersion":
 			iosVer = val

misc/linkcheck/linkcheck.go

@@ -81,10 +81,8 @@ func crawl(url string, sourceURL string) {
 	}
 	mu.Lock()
 	defer mu.Unlock()
-	var frag string
+	if u, frag, ok := strings.Cut(url, "#"); ok {
-	if i := strings.Index(url, "#"); i >= 0 {
+		url = u
-		frag = url[i+1:]
-		url = url[:i]
 		if frag != "" {
 			uf := urlFrag{url, frag}
 			neededFrags[uf] = append(neededFrags[uf], sourceURL)

misc/wasm/go_js_wasm_exec

@@ -11,4 +11,4 @@ while [ -h "$SOURCE" ]; do
 done
 DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
 
-exec node "$DIR/wasm_exec.js" "$@"
+exec node "$DIR/wasm_exec_node.js" "$@"

misc/wasm/wasm_exec.js

@@ -2,47 +2,18 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+"use strict";
+
 (() => {
-	// Map multiple JavaScript environments to a single common API,
-	// preferring web standards over Node.js API.
-	//
-	// Environments considered:
-	// - Browsers
-	// - Node.js
-	// - Electron
-	// - Parcel
-	// - Webpack
-
-	if (typeof global !== "undefined") {
-		// global already exists
-	} else if (typeof window !== "undefined") {
-		window.global = window;
-	} else if (typeof self !== "undefined") {
-		self.global = self;
-	} else {
-		throw new Error("cannot export Go (neither global, window nor self is defined)");
-	}
-
-	if (!global.require && typeof require !== "undefined") {
-		global.require = require;
-	}
-
-	if (!global.fs && global.require) {
-		const fs = require("fs");
-		if (typeof fs === "object" && fs !== null && Object.keys(fs).length !== 0) {
-			global.fs = fs;
-		}
-	}
-
 	const enosys = () => {
 		const err = new Error("not implemented");
 		err.code = "ENOSYS";
 		return err;
 	};
 
-	if (!global.fs) {
+	if (!globalThis.fs) {
 		let outputBuf = "";
-		global.fs = {
+		globalThis.fs = {
 			constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused
 			writeSync(fd, buf) {
 				outputBuf += decoder.decode(buf);
@@ -87,8 +58,8 @@
 		};
 	}
 
-	if (!global.process) {
+	if (!globalThis.process) {
-		global.process = {
+		globalThis.process = {
 			getuid() { return -1; },
 			getgid() { return -1; },
 			geteuid() { return -1; },
@@ -102,47 +73,26 @@
 		}
 	}
 
-	if (!global.crypto && global.require) {
+	if (!globalThis.crypto) {
-		const nodeCrypto = require("crypto");
+		throw new Error("globalThis.crypto is not available, polyfill required (crypto.getRandomValues only)");
-		global.crypto = {
-			getRandomValues(b) {
-				nodeCrypto.randomFillSync(b);
-			},
-		};
-	}
-	if (!global.crypto) {
-		throw new Error("global.crypto is not available, polyfill required (getRandomValues only)");
 	}
 
-	if (!global.performance) {
+	if (!globalThis.performance) {
-		global.performance = {
+		throw new Error("globalThis.performance is not available, polyfill required (performance.now only)");
-			now() {
-				const [sec, nsec] = process.hrtime();
-				return sec * 1000 + nsec / 1000000;
-			},
-		};
 	}
 
-	if (!global.TextEncoder && global.require) {
+	if (!globalThis.TextEncoder) {
-		global.TextEncoder = require("util").TextEncoder;
+		throw new Error("globalThis.TextEncoder is not available, polyfill required");
-	}
-	if (!global.TextEncoder) {
-		throw new Error("global.TextEncoder is not available, polyfill required");
 	}
 
-	if (!global.TextDecoder && global.require) {
+	if (!globalThis.TextDecoder) {
-		global.TextDecoder = require("util").TextDecoder;
+		throw new Error("globalThis.TextDecoder is not available, polyfill required");
 	}
-	if (!global.TextDecoder) {
-		throw new Error("global.TextDecoder is not available, polyfill required");
-	}
-
-	// End of polyfills for common API.
 
 	const encoder = new TextEncoder("utf-8");
 	const decoder = new TextDecoder("utf-8");
 
-	global.Go = class {
+	globalThis.Go = class {
 		constructor() {
 			this.argv = ["js"];
 			this.env = {};
@@ -517,7 +467,7 @@
 				null,
 				true,
 				false,
-				global,
+				globalThis,
 				this,
 			];
 			this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id
@@ -526,7 +476,7 @@
 				[null, 2],
 				[true, 3],
 				[false, 4],
-				[global, 5],
+				[globalThis, 5],
 				[this, 6],
 			]);
 			this._idPool = [];   // unused ids that have been garbage collected
@@ -567,6 +517,13 @@
 				offset += 8;
 			});
 
+			// The linker guarantees global data starts from at least wasmMinDataAddr.
+			// Keep in sync with cmd/link/internal/ld/data.go:wasmMinDataAddr.
+			const wasmMinDataAddr = 4096 + 8192;
+			if (offset >= wasmMinDataAddr) {
+				throw new Error("total length of command line and environment variables exceeds limit");
+			}
+
 			this._inst.exports.run(argc, argv);
 			if (this.exited) {
 				this._resolveExitPromise();
@@ -594,36 +551,4 @@
 			};
 		}
 	}
-
-	if (
-		typeof module !== "undefined" &&
-		global.require &&
-		global.require.main === module &&
-		global.process &&
-		global.process.versions &&
-		!global.process.versions.electron
-	) {
-		if (process.argv.length < 3) {
-			console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
-			process.exit(1);
-		}
-
-		const go = new Go();
-		go.argv = process.argv.slice(2);
-		go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
-		go.exit = process.exit;
-		WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
-			process.on("exit", (code) => { // Node.js exits if no event handler is pending
-				if (code === 0 && !go.exited) {
-					// deadlock, make Go print error and stack traces
-					go._pendingEvent = { id: 0 };
-					go._resume();
-				}
-			});
-			return go.run(result.instance);
-		}).catch((err) => {
-			console.error(err);
-			process.exit(1);
-		});
-	}
 })();

misc/wasm/wasm_exec_node.js

@@ -0,0 +1,49 @@
+// Copyright 2021 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.
+
+"use strict";
+
+if (process.argv.length < 3) {
+	console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
+	process.exit(1);
+}
+
+globalThis.require = require;
+globalThis.fs = require("fs");
+globalThis.TextEncoder = require("util").TextEncoder;
+globalThis.TextDecoder = require("util").TextDecoder;
+
+globalThis.performance = {
+	now() {
+		const [sec, nsec] = process.hrtime();
+		return sec * 1000 + nsec / 1000000;
+	},
+};
+
+const crypto = require("crypto");
+globalThis.crypto = {
+	getRandomValues(b) {
+		crypto.randomFillSync(b);
+	},
+};
+
+require("./wasm_exec");
+
+const go = new Go();
+go.argv = process.argv.slice(2);
+go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
+go.exit = process.exit;
+WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
+	process.on("exit", (code) => { // Node.js exits if no event handler is pending
+		if (code === 0 && !go.exited) {
+			// deadlock, make Go print error and stack traces
+			go._pendingEvent = { id: 0 };
+			go._resume();
+		}
+	});
+	return go.run(result.instance);
+}).catch((err) => {
+	console.error(err);
+	process.exit(1);
+});

src/archive/tar/common.go

@@ -316,10 +316,10 @@ func invertSparseEntries(src []sparseEntry, size int64) []sparseEntry {
 // fileState tracks the number of logical (includes sparse holes) and physical
 // (actual in tar archive) bytes remaining for the current file.
 //
-// Invariant: LogicalRemaining >= PhysicalRemaining
+// Invariant: logicalRemaining >= physicalRemaining
 type fileState interface {
-	LogicalRemaining() int64
+	logicalRemaining() int64
-	PhysicalRemaining() int64
+	physicalRemaining() int64
 }
 
 // allowedFormats determines which formats can be used.
@@ -413,22 +413,22 @@ func (h Header) allowedFormats() (format Format, paxHdrs map[string]string, err
 
 	// Check basic fields.
 	var blk block
-	v7 := blk.V7()
+	v7 := blk.toV7()
-	ustar := blk.USTAR()
+	ustar := blk.toUSTAR()
-	gnu := blk.GNU()
+	gnu := blk.toGNU()
-	verifyString(h.Name, len(v7.Name()), "Name", paxPath)
+	verifyString(h.Name, len(v7.name()), "Name", paxPath)
-	verifyString(h.Linkname, len(v7.LinkName()), "Linkname", paxLinkpath)
+	verifyString(h.Linkname, len(v7.linkName()), "Linkname", paxLinkpath)
-	verifyString(h.Uname, len(ustar.UserName()), "Uname", paxUname)
+	verifyString(h.Uname, len(ustar.userName()), "Uname", paxUname)
-	verifyString(h.Gname, len(ustar.GroupName()), "Gname", paxGname)
+	verifyString(h.Gname, len(ustar.groupName()), "Gname", paxGname)
-	verifyNumeric(h.Mode, len(v7.Mode()), "Mode", paxNone)
+	verifyNumeric(h.Mode, len(v7.mode()), "Mode", paxNone)
-	verifyNumeric(int64(h.Uid), len(v7.UID()), "Uid", paxUid)
+	verifyNumeric(int64(h.Uid), len(v7.uid()), "Uid", paxUid)
-	verifyNumeric(int64(h.Gid), len(v7.GID()), "Gid", paxGid)
+	verifyNumeric(int64(h.Gid), len(v7.gid()), "Gid", paxGid)
-	verifyNumeric(h.Size, len(v7.Size()), "Size", paxSize)
+	verifyNumeric(h.Size, len(v7.size()), "Size", paxSize)
-	verifyNumeric(h.Devmajor, len(ustar.DevMajor()), "Devmajor", paxNone)
+	verifyNumeric(h.Devmajor, len(ustar.devMajor()), "Devmajor", paxNone)
-	verifyNumeric(h.Devminor, len(ustar.DevMinor()), "Devminor", paxNone)
+	verifyNumeric(h.Devminor, len(ustar.devMinor()), "Devminor", paxNone)
-	verifyTime(h.ModTime, len(v7.ModTime()), "ModTime", paxMtime)
+	verifyTime(h.ModTime, len(v7.modTime()), "ModTime", paxMtime)
-	verifyTime(h.AccessTime, len(gnu.AccessTime()), "AccessTime", paxAtime)
+	verifyTime(h.AccessTime, len(gnu.accessTime()), "AccessTime", paxAtime)
-	verifyTime(h.ChangeTime, len(gnu.ChangeTime()), "ChangeTime", paxCtime)
+	verifyTime(h.ChangeTime, len(gnu.changeTime()), "ChangeTime", paxCtime)
 
 	// Check for header-only types.
 	var whyOnlyPAX, whyOnlyGNU string

src/archive/tar/format.go

@@ -156,28 +156,28 @@ var zeroBlock block
 type block [blockSize]byte
 
 // Convert block to any number of formats.
-func (b *block) V7() *headerV7       { return (*headerV7)(b) }
+func (b *block) toV7() *headerV7       { return (*headerV7)(b) }
-func (b *block) GNU() *headerGNU     { return (*headerGNU)(b) }
+func (b *block) toGNU() *headerGNU     { return (*headerGNU)(b) }
-func (b *block) STAR() *headerSTAR   { return (*headerSTAR)(b) }
+func (b *block) toSTAR() *headerSTAR   { return (*headerSTAR)(b) }
-func (b *block) USTAR() *headerUSTAR { return (*headerUSTAR)(b) }
+func (b *block) toUSTAR() *headerUSTAR { return (*headerUSTAR)(b) }
-func (b *block) Sparse() sparseArray { return sparseArray(b[:]) }
+func (b *block) toSparse() sparseArray { return sparseArray(b[:]) }
 
 // GetFormat checks that the block is a valid tar header based on the checksum.
 // It then attempts to guess the specific format based on magic values.
 // If the checksum fails, then FormatUnknown is returned.
-func (b *block) GetFormat() Format {
+func (b *block) getFormat() Format {
 	// Verify checksum.
 	var p parser
-	value := p.parseOctal(b.V7().Chksum())
+	value := p.parseOctal(b.toV7().chksum())
-	chksum1, chksum2 := b.ComputeChecksum()
+	chksum1, chksum2 := b.computeChecksum()
 	if p.err != nil || (value != chksum1 && value != chksum2) {
 		return FormatUnknown
 	}
 
 	// Guess the magic values.
-	magic := string(b.USTAR().Magic())
+	magic := string(b.toUSTAR().magic())
-	version := string(b.USTAR().Version())
+	version := string(b.toUSTAR().version())
-	trailer := string(b.STAR().Trailer())
+	trailer := string(b.toSTAR().trailer())
 	switch {
 	case magic == magicUSTAR && trailer == trailerSTAR:
 		return formatSTAR
@@ -190,23 +190,23 @@ func (b *block) GetFormat() Format {
 	}
 }
 
-// SetFormat writes the magic values necessary for specified format
+// setFormat writes the magic values necessary for specified format
 // and then updates the checksum accordingly.
-func (b *block) SetFormat(format Format) {
+func (b *block) setFormat(format Format) {
 	// Set the magic values.
 	switch {
 	case format.has(formatV7):
 		// Do nothing.
 	case format.has(FormatGNU):
-		copy(b.GNU().Magic(), magicGNU)
+		copy(b.toGNU().magic(), magicGNU)
-		copy(b.GNU().Version(), versionGNU)
+		copy(b.toGNU().version(), versionGNU)
 	case format.has(formatSTAR):
-		copy(b.STAR().Magic(), magicUSTAR)
+		copy(b.toSTAR().magic(), magicUSTAR)
-		copy(b.STAR().Version(), versionUSTAR)
+		copy(b.toSTAR().version(), versionUSTAR)
-		copy(b.STAR().Trailer(), trailerSTAR)
+		copy(b.toSTAR().trailer(), trailerSTAR)
 	case format.has(FormatUSTAR | FormatPAX):
-		copy(b.USTAR().Magic(), magicUSTAR)
+		copy(b.toUSTAR().magic(), magicUSTAR)
-		copy(b.USTAR().Version(), versionUSTAR)
+		copy(b.toUSTAR().version(), versionUSTAR)
 	default:
 		panic("invalid format")
 	}
@@ -214,17 +214,17 @@ func (b *block) SetFormat(format Format) {
 	// Update checksum.
 	// This field is special in that it is terminated by a NULL then space.
 	var f formatter
-	field := b.V7().Chksum()
+	field := b.toV7().chksum()
-	chksum, _ := b.ComputeChecksum() // Possible values are 256..128776
+	chksum, _ := b.computeChecksum() // Possible values are 256..128776
 	f.formatOctal(field[:7], chksum) // Never fails since 128776 < 262143
 	field[7] = ' '
 }
 
-// ComputeChecksum computes the checksum for the header block.
+// computeChecksum computes the checksum for the header block.
 // POSIX specifies a sum of the unsigned byte values, but the Sun tar used
 // signed byte values.
 // We compute and return both.
-func (b *block) ComputeChecksum() (unsigned, signed int64) {
+func (b *block) computeChecksum() (unsigned, signed int64) {
 	for i, c := range b {
 		if 148 <= i && i < 156 {
 			c = ' ' // Treat the checksum field itself as all spaces.
@@ -236,68 +236,68 @@ func (b *block) ComputeChecksum() (unsigned, signed int64) {
 }
 
 // Reset clears the block with all zeros.
-func (b *block) Reset() {
+func (b *block) reset() {
 	*b = block{}
 }
 
 type headerV7 [blockSize]byte
 
-func (h *headerV7) Name() []byte     { return h[000:][:100] }
+func (h *headerV7) name() []byte     { return h[000:][:100] }
-func (h *headerV7) Mode() []byte     { return h[100:][:8] }
+func (h *headerV7) mode() []byte     { return h[100:][:8] }
-func (h *headerV7) UID() []byte      { return h[108:][:8] }
+func (h *headerV7) uid() []byte      { return h[108:][:8] }
-func (h *headerV7) GID() []byte      { return h[116:][:8] }
+func (h *headerV7) gid() []byte      { return h[116:][:8] }
-func (h *headerV7) Size() []byte     { return h[124:][:12] }
+func (h *headerV7) size() []byte     { return h[124:][:12] }
-func (h *headerV7) ModTime() []byte  { return h[136:][:12] }
+func (h *headerV7) modTime() []byte  { return h[136:][:12] }
-func (h *headerV7) Chksum() []byte   { return h[148:][:8] }
+func (h *headerV7) chksum() []byte   { return h[148:][:8] }
-func (h *headerV7) TypeFlag() []byte { return h[156:][:1] }
+func (h *headerV7) typeFlag() []byte { return h[156:][:1] }
-func (h *headerV7) LinkName() []byte { return h[157:][:100] }
+func (h *headerV7) linkName() []byte { return h[157:][:100] }
 
 type headerGNU [blockSize]byte
 
-func (h *headerGNU) V7() *headerV7       { return (*headerV7)(h) }
+func (h *headerGNU) v7() *headerV7       { return (*headerV7)(h) }
-func (h *headerGNU) Magic() []byte       { return h[257:][:6] }
+func (h *headerGNU) magic() []byte       { return h[257:][:6] }
-func (h *headerGNU) Version() []byte     { return h[263:][:2] }
+func (h *headerGNU) version() []byte     { return h[263:][:2] }
-func (h *headerGNU) UserName() []byte    { return h[265:][:32] }
+func (h *headerGNU) userName() []byte    { return h[265:][:32] }
-func (h *headerGNU) GroupName() []byte   { return h[297:][:32] }
+func (h *headerGNU) groupName() []byte   { return h[297:][:32] }
-func (h *headerGNU) DevMajor() []byte    { return h[329:][:8] }
+func (h *headerGNU) devMajor() []byte    { return h[329:][:8] }
-func (h *headerGNU) DevMinor() []byte    { return h[337:][:8] }
+func (h *headerGNU) devMinor() []byte    { return h[337:][:8] }
-func (h *headerGNU) AccessTime() []byte  { return h[345:][:12] }
+func (h *headerGNU) accessTime() []byte  { return h[345:][:12] }
-func (h *headerGNU) ChangeTime() []byte  { return h[357:][:12] }
+func (h *headerGNU) changeTime() []byte  { return h[357:][:12] }
-func (h *headerGNU) Sparse() sparseArray { return sparseArray(h[386:][:24*4+1]) }
+func (h *headerGNU) sparse() sparseArray { return sparseArray(h[386:][:24*4+1]) }
-func (h *headerGNU) RealSize() []byte    { return h[483:][:12] }
+func (h *headerGNU) realSize() []byte    { return h[483:][:12] }
 
 type headerSTAR [blockSize]byte
 
-func (h *headerSTAR) V7() *headerV7      { return (*headerV7)(h) }
+func (h *headerSTAR) v7() *headerV7      { return (*headerV7)(h) }
-func (h *headerSTAR) Magic() []byte      { return h[257:][:6] }
+func (h *headerSTAR) magic() []byte      { return h[257:][:6] }
-func (h *headerSTAR) Version() []byte    { return h[263:][:2] }
+func (h *headerSTAR) version() []byte    { return h[263:][:2] }
-func (h *headerSTAR) UserName() []byte   { return h[265:][:32] }
+func (h *headerSTAR) userName() []byte   { return h[265:][:32] }
-func (h *headerSTAR) GroupName() []byte  { return h[297:][:32] }
+func (h *headerSTAR) groupName() []byte  { return h[297:][:32] }
-func (h *headerSTAR) DevMajor() []byte   { return h[329:][:8] }
+func (h *headerSTAR) devMajor() []byte   { return h[329:][:8] }
-func (h *headerSTAR) DevMinor() []byte   { return h[337:][:8] }
+func (h *headerSTAR) devMinor() []byte   { return h[337:][:8] }
-func (h *headerSTAR) Prefix() []byte     { return h[345:][:131] }
+func (h *headerSTAR) prefix() []byte     { return h[345:][:131] }
-func (h *headerSTAR) AccessTime() []byte { return h[476:][:12] }
+func (h *headerSTAR) accessTime() []byte { return h[476:][:12] }
-func (h *headerSTAR) ChangeTime() []byte { return h[488:][:12] }
+func (h *headerSTAR) changeTime() []byte { return h[488:][:12] }
-func (h *headerSTAR) Trailer() []byte    { return h[508:][:4] }
+func (h *headerSTAR) trailer() []byte    { return h[508:][:4] }
 
 type headerUSTAR [blockSize]byte
 
-func (h *headerUSTAR) V7() *headerV7     { return (*headerV7)(h) }
+func (h *headerUSTAR) v7() *headerV7     { return (*headerV7)(h) }
-func (h *headerUSTAR) Magic() []byte     { return h[257:][:6] }
+func (h *headerUSTAR) magic() []byte     { return h[257:][:6] }
-func (h *headerUSTAR) Version() []byte   { return h[263:][:2] }
+func (h *headerUSTAR) version() []byte   { return h[263:][:2] }
-func (h *headerUSTAR) UserName() []byte  { return h[265:][:32] }
+func (h *headerUSTAR) userName() []byte  { return h[265:][:32] }
-func (h *headerUSTAR) GroupName() []byte { return h[297:][:32] }
+func (h *headerUSTAR) groupName() []byte { return h[297:][:32] }
-func (h *headerUSTAR) DevMajor() []byte  { return h[329:][:8] }
+func (h *headerUSTAR) devMajor() []byte  { return h[329:][:8] }
-func (h *headerUSTAR) DevMinor() []byte  { return h[337:][:8] }
+func (h *headerUSTAR) devMinor() []byte  { return h[337:][:8] }
-func (h *headerUSTAR) Prefix() []byte    { return h[345:][:155] }
+func (h *headerUSTAR) prefix() []byte    { return h[345:][:155] }
 
 type sparseArray []byte
 
-func (s sparseArray) Entry(i int) sparseElem { return sparseElem(s[i*24:]) }
+func (s sparseArray) entry(i int) sparseElem { return sparseElem(s[i*24:]) }
-func (s sparseArray) IsExtended() []byte     { return s[24*s.MaxEntries():][:1] }
+func (s sparseArray) isExtended() []byte     { return s[24*s.maxEntries():][:1] }
-func (s sparseArray) MaxEntries() int        { return len(s) / 24 }
+func (s sparseArray) maxEntries() int        { return len(s) / 24 }
 
 type sparseElem []byte
 
-func (s sparseElem) Offset() []byte { return s[00:][:12] }
+func (s sparseElem) offset() []byte { return s[00:][:12] }
-func (s sparseElem) Length() []byte { return s[12:][:12] }
+func (s sparseElem) length() []byte { return s[12:][:12] }

src/archive/tar/reader.go

@@ -65,7 +65,7 @@ func (tr *Reader) next() (*Header, error) {
 	format := FormatUSTAR | FormatPAX | FormatGNU
 	for {
 		// Discard the remainder of the file and any padding.
-		if err := discard(tr.r, tr.curr.PhysicalRemaining()); err != nil {
+		if err := discard(tr.r, tr.curr.physicalRemaining()); err != nil {
 			return nil, err
 		}
 		if _, err := tryReadFull(tr.r, tr.blk[:tr.pad]); err != nil {
@@ -355,7 +355,7 @@ func (tr *Reader) readHeader() (*Header, *block, error) {
 	}
 
 	// Verify the header matches a known format.
-	format := tr.blk.GetFormat()
+	format := tr.blk.getFormat()
 	if format == FormatUnknown {
 		return nil, nil, ErrHeader
 	}
@@ -364,30 +364,30 @@ func (tr *Reader) readHeader() (*Header, *block, error) {
 	hdr := new(Header)
 
 	// Unpack the V7 header.
-	v7 := tr.blk.V7()
+	v7 := tr.blk.toV7()
-	hdr.Typeflag = v7.TypeFlag()[0]
+	hdr.Typeflag = v7.typeFlag()[0]
-	hdr.Name = p.parseString(v7.Name())
+	hdr.Name = p.parseString(v7.name())
-	hdr.Linkname = p.parseString(v7.LinkName())
+	hdr.Linkname = p.parseString(v7.linkName())
-	hdr.Size = p.parseNumeric(v7.Size())
+	hdr.Size = p.parseNumeric(v7.size())
-	hdr.Mode = p.parseNumeric(v7.Mode())
+	hdr.Mode = p.parseNumeric(v7.mode())
-	hdr.Uid = int(p.parseNumeric(v7.UID()))
+	hdr.Uid = int(p.parseNumeric(v7.uid()))
-	hdr.Gid = int(p.parseNumeric(v7.GID()))
+	hdr.Gid = int(p.parseNumeric(v7.gid()))
-	hdr.ModTime = time.Unix(p.parseNumeric(v7.ModTime()), 0)
+	hdr.ModTime = time.Unix(p.parseNumeric(v7.modTime()), 0)
 
 	// Unpack format specific fields.
 	if format > formatV7 {
-		ustar := tr.blk.USTAR()
+		ustar := tr.blk.toUSTAR()
-		hdr.Uname = p.parseString(ustar.UserName())
+		hdr.Uname = p.parseString(ustar.userName())
-		hdr.Gname = p.parseString(ustar.GroupName())
+		hdr.Gname = p.parseString(ustar.groupName())
-		hdr.Devmajor = p.parseNumeric(ustar.DevMajor())
+		hdr.Devmajor = p.parseNumeric(ustar.devMajor())
-		hdr.Devminor = p.parseNumeric(ustar.DevMinor())
+		hdr.Devminor = p.parseNumeric(ustar.devMinor())
 
 		var prefix string
 		switch {
 		case format.has(FormatUSTAR | FormatPAX):
 			hdr.Format = format
-			ustar := tr.blk.USTAR()
+			ustar := tr.blk.toUSTAR()
-			prefix = p.parseString(ustar.Prefix())
+			prefix = p.parseString(ustar.prefix())
 
 			// For Format detection, check if block is properly formatted since
 			// the parser is more liberal than what USTAR actually permits.
@@ -396,23 +396,23 @@ func (tr *Reader) readHeader() (*Header, *block, error) {
 				hdr.Format = FormatUnknown // Non-ASCII characters in block.
 			}
 			nul := func(b []byte) bool { return int(b[len(b)-1]) == 0 }
-			if !(nul(v7.Size()) && nul(v7.Mode()) && nul(v7.UID()) && nul(v7.GID()) &&
+			if !(nul(v7.size()) && nul(v7.mode()) && nul(v7.uid()) && nul(v7.gid()) &&
-				nul(v7.ModTime()) && nul(ustar.DevMajor()) && nul(ustar.DevMinor())) {
+				nul(v7.modTime()) && nul(ustar.devMajor()) && nul(ustar.devMinor())) {
 				hdr.Format = FormatUnknown // Numeric fields must end in NUL
 			}
 		case format.has(formatSTAR):
-			star := tr.blk.STAR()
+			star := tr.blk.toSTAR()
-			prefix = p.parseString(star.Prefix())
+			prefix = p.parseString(star.prefix())
-			hdr.AccessTime = time.Unix(p.parseNumeric(star.AccessTime()), 0)
+			hdr.AccessTime = time.Unix(p.parseNumeric(star.accessTime()), 0)
-			hdr.ChangeTime = time.Unix(p.parseNumeric(star.ChangeTime()), 0)
+			hdr.ChangeTime = time.Unix(p.parseNumeric(star.changeTime()), 0)
 		case format.has(FormatGNU):
 			hdr.Format = format
 			var p2 parser
-			gnu := tr.blk.GNU()
+			gnu := tr.blk.toGNU()
-			if b := gnu.AccessTime(); b[0] != 0 {
+			if b := gnu.accessTime(); b[0] != 0 {
 				hdr.AccessTime = time.Unix(p2.parseNumeric(b), 0)
 			}
-			if b := gnu.ChangeTime(); b[0] != 0 {
+			if b := gnu.changeTime(); b[0] != 0 {
 				hdr.ChangeTime = time.Unix(p2.parseNumeric(b), 0)
 			}
 
@@ -439,8 +439,8 @@ func (tr *Reader) readHeader() (*Header, *block, error) {
 			// See https://golang.org/issues/21005
 			if p2.err != nil {
 				hdr.AccessTime, hdr.ChangeTime = time.Time{}, time.Time{}
-				ustar := tr.blk.USTAR()
+				ustar := tr.blk.toUSTAR()
-				if s := p.parseString(ustar.Prefix()); isASCII(s) {
+				if s := p.parseString(ustar.prefix()); isASCII(s) {
 					prefix = s
 				}
 				hdr.Format = FormatUnknown // Buggy file is not GNU
@@ -465,38 +465,38 @@ func (tr *Reader) readOldGNUSparseMap(hdr *Header, blk *block) (sparseDatas, err
 	// Make sure that the input format is GNU.
 	// Unfortunately, the STAR format also has a sparse header format that uses
 	// the same type flag but has a completely different layout.
-	if blk.GetFormat() != FormatGNU {
+	if blk.getFormat() != FormatGNU {
 		return nil, ErrHeader
 	}
 	hdr.Format.mayOnlyBe(FormatGNU)
 
 	var p parser
-	hdr.Size = p.parseNumeric(blk.GNU().RealSize())
+	hdr.Size = p.parseNumeric(blk.toGNU().realSize())
 	if p.err != nil {
 		return nil, p.err
 	}
-	s := blk.GNU().Sparse()
+	s := blk.toGNU().sparse()
-	spd := make(sparseDatas, 0, s.MaxEntries())
+	spd := make(sparseDatas, 0, s.maxEntries())
 	for {
-		for i := 0; i < s.MaxEntries(); i++ {
+		for i := 0; i < s.maxEntries(); i++ {
 			// This termination condition is identical to GNU and BSD tar.
-			if s.Entry(i).Offset()[0] == 0x00 {
+			if s.entry(i).offset()[0] == 0x00 {
 				break // Don't return, need to process extended headers (even if empty)
 			}
-			offset := p.parseNumeric(s.Entry(i).Offset())
+			offset := p.parseNumeric(s.entry(i).offset())
-			length := p.parseNumeric(s.Entry(i).Length())
+			length := p.parseNumeric(s.entry(i).length())
 			if p.err != nil {
 				return nil, p.err
 			}
 			spd = append(spd, sparseEntry{Offset: offset, Length: length})
 		}
 
-		if s.IsExtended()[0] > 0 {
+		if s.isExtended()[0] > 0 {
 			// There are more entries. Read an extension header and parse its entries.
 			if _, err := mustReadFull(tr.r, blk[:]); err != nil {
 				return nil, err
 			}
-			s = blk.Sparse()
+			s = blk.toSparse()
 			continue
 		}
 		return spd, nil // Done
@@ -678,11 +678,13 @@ func (fr *regFileReader) WriteTo(w io.Writer) (int64, error) {
 	return io.Copy(w, struct{ io.Reader }{fr})
 }
 
-func (fr regFileReader) LogicalRemaining() int64 {
+// logicalRemaining implements fileState.logicalRemaining.
+func (fr regFileReader) logicalRemaining() int64 {
 	return fr.nb
 }
 
-func (fr regFileReader) PhysicalRemaining() int64 {
+// logicalRemaining implements fileState.physicalRemaining.
+func (fr regFileReader) physicalRemaining() int64 {
 	return fr.nb
 }
 
@@ -694,9 +696,9 @@ type sparseFileReader struct {
 }
 
 func (sr *sparseFileReader) Read(b []byte) (n int, err error) {
-	finished := int64(len(b)) >= sr.LogicalRemaining()
+	finished := int64(len(b)) >= sr.logicalRemaining()
 	if finished {
-		b = b[:sr.LogicalRemaining()]
+		b = b[:sr.logicalRemaining()]
 	}
 
 	b0 := b
@@ -724,7 +726,7 @@ func (sr *sparseFileReader) Read(b []byte) (n int, err error) {
 		return n, errMissData // Less data in dense file than sparse file
 	case err != nil:
 		return n, err
-	case sr.LogicalRemaining() == 0 && sr.PhysicalRemaining() > 0:
+	case sr.logicalRemaining() == 0 && sr.physicalRemaining() > 0:
 		return n, errUnrefData // More data in dense file than sparse file
 	case finished:
 		return n, io.EOF
@@ -746,7 +748,7 @@ func (sr *sparseFileReader) WriteTo(w io.Writer) (n int64, err error) {
 
 	var writeLastByte bool
 	pos0 := sr.pos
-	for sr.LogicalRemaining() > 0 && !writeLastByte && err == nil {
+	for sr.logicalRemaining() > 0 && !writeLastByte && err == nil {
 		var nf int64 // Size of fragment
 		holeStart, holeEnd := sr.sp[0].Offset, sr.sp[0].endOffset()
 		if sr.pos < holeStart { // In a data fragment
@@ -754,7 +756,7 @@ func (sr *sparseFileReader) WriteTo(w io.Writer) (n int64, err error) {
 			nf, err = io.CopyN(ws, sr.fr, nf)
 		} else { // In a hole fragment
 			nf = holeEnd - sr.pos
-			if sr.PhysicalRemaining() == 0 {
+			if sr.physicalRemaining() == 0 {
 				writeLastByte = true
 				nf--
 			}
@@ -779,18 +781,18 @@ func (sr *sparseFileReader) WriteTo(w io.Writer) (n int64, err error) {
 		return n, errMissData // Less data in dense file than sparse file
 	case err != nil:
 		return n, err
-	case sr.LogicalRemaining() == 0 && sr.PhysicalRemaining() > 0:
+	case sr.logicalRemaining() == 0 && sr.physicalRemaining() > 0:
 		return n, errUnrefData // More data in dense file than sparse file
 	default:
 		return n, nil
 	}
 }
 
-func (sr sparseFileReader) LogicalRemaining() int64 {
+func (sr sparseFileReader) logicalRemaining() int64 {
 	return sr.sp[len(sr.sp)-1].endOffset() - sr.pos
 }
-func (sr sparseFileReader) PhysicalRemaining() int64 {
+func (sr sparseFileReader) physicalRemaining() int64 {
-	return sr.fr.PhysicalRemaining()
+	return sr.fr.physicalRemaining()
 }
 
 type zeroReader struct{}

src/archive/tar/reader_test.go

@@ -1021,12 +1021,12 @@ func TestParsePAX(t *testing.T) {
 
 func TestReadOldGNUSparseMap(t *testing.T) {
 	populateSparseMap := func(sa sparseArray, sps []string) []string {
-		for i := 0; len(sps) > 0 && i < sa.MaxEntries(); i++ {
+		for i := 0; len(sps) > 0 && i < sa.maxEntries(); i++ {
-			copy(sa.Entry(i), sps[0])
+			copy(sa.entry(i), sps[0])
 			sps = sps[1:]
 		}
 		if len(sps) > 0 {
-			copy(sa.IsExtended(), "\x80")
+			copy(sa.isExtended(), "\x80")
 		}
 		return sps
 	}
@@ -1034,19 +1034,19 @@ func TestReadOldGNUSparseMap(t *testing.T) {
 	makeInput := func(format Format, size string, sps ...string) (out []byte) {
 		// Write the initial GNU header.
 		var blk block
-		gnu := blk.GNU()
+		gnu := blk.toGNU()
-		sparse := gnu.Sparse()
+		sparse := gnu.sparse()
-		copy(gnu.RealSize(), size)
+		copy(gnu.realSize(), size)
 		sps = populateSparseMap(sparse, sps)
 		if format != FormatUnknown {
-			blk.SetFormat(format)
+			blk.setFormat(format)
 		}
 		out = append(out, blk[:]...)
 
 		// Write extended sparse blocks.
 		for len(sps) > 0 {
 			var blk block
-			sps = populateSparseMap(blk.Sparse(), sps)
+			sps = populateSparseMap(blk.toSparse(), sps)
 			out = append(out, blk[:]...)
 		}
 		return out
@@ -1359,7 +1359,7 @@ func TestFileReader(t *testing.T) {
 			wantCnt int64
 			wantErr error
 		}
-		testRemaining struct { // LogicalRemaining() == wantLCnt, PhysicalRemaining() == wantPCnt
+		testRemaining struct { // logicalRemaining() == wantLCnt, physicalRemaining() == wantPCnt
 			wantLCnt int64
 			wantPCnt int64
 		}
@@ -1596,11 +1596,11 @@ func TestFileReader(t *testing.T) {
 					t.Errorf("test %d.%d, expected %d more operations", i, j, len(f.ops))
 				}
 			case testRemaining:
-				if got := fr.LogicalRemaining(); got != tf.wantLCnt {
+				if got := fr.logicalRemaining(); got != tf.wantLCnt {
-					t.Errorf("test %d.%d, LogicalRemaining() = %d, want %d", i, j, got, tf.wantLCnt)
+					t.Errorf("test %d.%d, logicalRemaining() = %d, want %d", i, j, got, tf.wantLCnt)
 				}
-				if got := fr.PhysicalRemaining(); got != tf.wantPCnt {
+				if got := fr.physicalRemaining(); got != tf.wantPCnt {
-					t.Errorf("test %d.%d, PhysicalRemaining() = %d, want %d", i, j, got, tf.wantPCnt)
+					t.Errorf("test %d.%d, physicalRemaining() = %d, want %d", i, j, got, tf.wantPCnt)
 				}
 			default:
 				t.Fatalf("test %d.%d, unknown test operation: %T", i, j, tf)

src/archive/tar/stat_actime1.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || linux || dragonfly || openbsd || solaris
-// +build aix linux dragonfly openbsd solaris
 
 package tar
 

src/archive/tar/stat_actime2.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build darwin || freebsd || netbsd
-// +build darwin freebsd netbsd
 
 package tar
 

src/archive/tar/stat_unix.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || linux || darwin || dragonfly || freebsd || openbsd || netbsd || solaris
-// +build aix linux darwin dragonfly freebsd openbsd netbsd solaris
 
 package tar
 

src/archive/tar/strconv.go

@@ -14,7 +14,7 @@ import (
 
 // hasNUL reports whether the NUL character exists within s.
 func hasNUL(s string) bool {
-	return strings.IndexByte(s, 0) >= 0
+	return strings.Contains(s, "\x00")
 }
 
 // isASCII reports whether the input is an ASCII C-style string.
@@ -201,10 +201,7 @@ func parsePAXTime(s string) (time.Time, error) {
 	const maxNanoSecondDigits = 9
 
 	// Split string into seconds and sub-seconds parts.
-	ss, sn := s, ""
+	ss, sn, _ := strings.Cut(s, ".")
-	if pos := strings.IndexByte(s, '.'); pos >= 0 {
-		ss, sn = s[:pos], s[pos+1:]
-	}
 
 	// Parse the seconds.
 	secs, err := strconv.ParseInt(ss, 10, 64)
@@ -254,48 +251,32 @@ func formatPAXTime(ts time.Time) (s string) {
 // return the remainder as r.
 func parsePAXRecord(s string) (k, v, r string, err error) {
 	// The size field ends at the first space.
-	sp := strings.IndexByte(s, ' ')
+	nStr, rest, ok := strings.Cut(s, " ")
-	if sp == -1 {
+	if !ok {
 		return "", "", s, ErrHeader
 	}
 
 	// Parse the first token as a decimal integer.
-	n, perr := strconv.ParseInt(s[:sp], 10, 0) // Intentionally parse as native int
+	n, perr := strconv.ParseInt(nStr, 10, 0) // Intentionally parse as native int
-	if perr != nil || n < 5 || int64(len(s)) < n {
+	if perr != nil || n < 5 || n > int64(len(s)) {
 		return "", "", s, ErrHeader
 	}
-
+	n -= int64(len(nStr) + 1) // convert from index in s to index in rest
-	afterSpace := int64(sp + 1)
+	if n <= 0 {
-	beforeLastNewLine := n - 1
-	// In some cases, "length" was perhaps padded/malformed, and
-	// trying to index past where the space supposedly is goes past
-	// the end of the actual record.
-	// For example:
-	//    "0000000000000000000000000000000030 mtime=1432668921.098285006\n30 ctime=2147483649.15163319"
-	//                                  ^     ^
-	//                                  |     |
-	//                                  |  afterSpace=35
-	//                                  |
-	//                          beforeLastNewLine=29
-	// yet indexOf(firstSpace) MUST BE before endOfRecord.
-	//
-	// See https://golang.org/issues/40196.
-	if afterSpace >= beforeLastNewLine {
 		return "", "", s, ErrHeader
 	}
 
 	// Extract everything between the space and the final newline.
-	rec, nl, rem := s[afterSpace:beforeLastNewLine], s[beforeLastNewLine:n], s[n:]
+	rec, nl, rem := rest[:n-1], rest[n-1:n], rest[n:]
 	if nl != "\n" {
 		return "", "", s, ErrHeader
 	}
 
 	// The first equals separates the key from the value.
-	eq := strings.IndexByte(rec, '=')
+	k, v, ok = strings.Cut(rec, "=")
-	if eq == -1 {
+	if !ok {
 		return "", "", s, ErrHeader
 	}
-	k, v = rec[:eq], rec[eq+1:]
 
 	if !validPAXRecord(k, v) {
 		return "", "", s, ErrHeader
@@ -333,7 +314,7 @@ func formatPAXRecord(k, v string) (string, error) {
 // for the PAX version of the USTAR string fields.
 // The key must not contain an '=' character.
 func validPAXRecord(k, v string) bool {
-	if k == "" || strings.IndexByte(k, '=') >= 0 {
+	if k == "" || strings.Contains(k, "=") {
 		return false
 	}
 	switch k {

src/archive/tar/writer.go

@@ -50,7 +50,7 @@ func (tw *Writer) Flush() error {
 	if tw.err != nil {
 		return tw.err
 	}
-	if nb := tw.curr.LogicalRemaining(); nb > 0 {
+	if nb := tw.curr.logicalRemaining(); nb > 0 {
 		return fmt.Errorf("archive/tar: missed writing %d bytes", nb)
 	}
 	if _, tw.err = tw.w.Write(zeroBlock[:tw.pad]); tw.err != nil {
@@ -117,8 +117,8 @@ func (tw *Writer) writeUSTARHeader(hdr *Header) error {
 	// Pack the main header.
 	var f formatter
 	blk := tw.templateV7Plus(hdr, f.formatString, f.formatOctal)
-	f.formatString(blk.USTAR().Prefix(), namePrefix)
+	f.formatString(blk.toUSTAR().prefix(), namePrefix)
-	blk.SetFormat(FormatUSTAR)
+	blk.setFormat(FormatUSTAR)
 	if f.err != nil {
 		return f.err // Should never happen since header is validated
 	}
@@ -208,7 +208,7 @@ func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error {
 	var f formatter // Ignore errors since they are expected
 	fmtStr := func(b []byte, s string) { f.formatString(b, toASCII(s)) }
 	blk := tw.templateV7Plus(hdr, fmtStr, f.formatOctal)
-	blk.SetFormat(FormatPAX)
+	blk.setFormat(FormatPAX)
 	if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil {
 		return err
 	}
@@ -250,10 +250,10 @@ func (tw *Writer) writeGNUHeader(hdr *Header) error {
 	var spb []byte
 	blk := tw.templateV7Plus(hdr, f.formatString, f.formatNumeric)
 	if !hdr.AccessTime.IsZero() {
-		f.formatNumeric(blk.GNU().AccessTime(), hdr.AccessTime.Unix())
+		f.formatNumeric(blk.toGNU().accessTime(), hdr.AccessTime.Unix())
 	}
 	if !hdr.ChangeTime.IsZero() {
-		f.formatNumeric(blk.GNU().ChangeTime(), hdr.ChangeTime.Unix())
+		f.formatNumeric(blk.toGNU().changeTime(), hdr.ChangeTime.Unix())
 	}
 	// TODO(dsnet): Re-enable this when adding sparse support.
 	// See https://golang.org/issue/22735
@@ -293,7 +293,7 @@ func (tw *Writer) writeGNUHeader(hdr *Header) error {
 			f.formatNumeric(blk.GNU().RealSize(), realSize)
 		}
 	*/
-	blk.SetFormat(FormatGNU)
+	blk.setFormat(FormatGNU)
 	if err := tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag); err != nil {
 		return err
 	}
@@ -321,28 +321,28 @@ type (
 // The block returned is only valid until the next call to
 // templateV7Plus or writeRawFile.
 func (tw *Writer) templateV7Plus(hdr *Header, fmtStr stringFormatter, fmtNum numberFormatter) *block {
-	tw.blk.Reset()
+	tw.blk.reset()
 
 	modTime := hdr.ModTime
 	if modTime.IsZero() {
 		modTime = time.Unix(0, 0)
 	}
 
-	v7 := tw.blk.V7()
+	v7 := tw.blk.toV7()
-	v7.TypeFlag()[0] = hdr.Typeflag
+	v7.typeFlag()[0] = hdr.Typeflag
-	fmtStr(v7.Name(), hdr.Name)
+	fmtStr(v7.name(), hdr.Name)
-	fmtStr(v7.LinkName(), hdr.Linkname)
+	fmtStr(v7.linkName(), hdr.Linkname)
-	fmtNum(v7.Mode(), hdr.Mode)
+	fmtNum(v7.mode(), hdr.Mode)
-	fmtNum(v7.UID(), int64(hdr.Uid))
+	fmtNum(v7.uid(), int64(hdr.Uid))
-	fmtNum(v7.GID(), int64(hdr.Gid))
+	fmtNum(v7.gid(), int64(hdr.Gid))
-	fmtNum(v7.Size(), hdr.Size)
+	fmtNum(v7.size(), hdr.Size)
-	fmtNum(v7.ModTime(), modTime.Unix())
+	fmtNum(v7.modTime(), modTime.Unix())
 
-	ustar := tw.blk.USTAR()
+	ustar := tw.blk.toUSTAR()
-	fmtStr(ustar.UserName(), hdr.Uname)
+	fmtStr(ustar.userName(), hdr.Uname)
-	fmtStr(ustar.GroupName(), hdr.Gname)
+	fmtStr(ustar.groupName(), hdr.Gname)
-	fmtNum(ustar.DevMajor(), hdr.Devmajor)
+	fmtNum(ustar.devMajor(), hdr.Devmajor)
-	fmtNum(ustar.DevMinor(), hdr.Devminor)
+	fmtNum(ustar.devMinor(), hdr.Devminor)
 
 	return &tw.blk
 }
@@ -351,7 +351,7 @@ func (tw *Writer) templateV7Plus(hdr *Header, fmtStr stringFormatter, fmtNum num
 // It uses format to encode the header format and will write data as the body.
 // It uses default values for all of the other fields (as BSD and GNU tar does).
 func (tw *Writer) writeRawFile(name, data string, flag byte, format Format) error {
-	tw.blk.Reset()
+	tw.blk.reset()
 
 	// Best effort for the filename.
 	name = toASCII(name)
@@ -361,15 +361,15 @@ func (tw *Writer) writeRawFile(name, data string, flag byte, format Format) erro
 	name = strings.TrimRight(name, "/")
 
 	var f formatter
-	v7 := tw.blk.V7()
+	v7 := tw.blk.toV7()
-	v7.TypeFlag()[0] = flag
+	v7.typeFlag()[0] = flag
-	f.formatString(v7.Name(), name)
+	f.formatString(v7.name(), name)
-	f.formatOctal(v7.Mode(), 0)
+	f.formatOctal(v7.mode(), 0)
-	f.formatOctal(v7.UID(), 0)
+	f.formatOctal(v7.uid(), 0)
-	f.formatOctal(v7.GID(), 0)
+	f.formatOctal(v7.gid(), 0)
-	f.formatOctal(v7.Size(), int64(len(data))) // Must be < 8GiB
+	f.formatOctal(v7.size(), int64(len(data))) // Must be < 8GiB
-	f.formatOctal(v7.ModTime(), 0)
+	f.formatOctal(v7.modTime(), 0)
-	tw.blk.SetFormat(format)
+	tw.blk.setFormat(format)
 	if f.err != nil {
 		return f.err // Only occurs if size condition is violated
 	}
@@ -511,10 +511,13 @@ func (fw *regFileWriter) ReadFrom(r io.Reader) (int64, error) {
 	return io.Copy(struct{ io.Writer }{fw}, r)
 }
 
-func (fw regFileWriter) LogicalRemaining() int64 {
+// logicalRemaining implements fileState.logicalRemaining.
+func (fw regFileWriter) logicalRemaining() int64 {
 	return fw.nb
 }
-func (fw regFileWriter) PhysicalRemaining() int64 {
+
+// logicalRemaining implements fileState.physicalRemaining.
+func (fw regFileWriter) physicalRemaining() int64 {
 	return fw.nb
 }
 
@@ -526,9 +529,9 @@ type sparseFileWriter struct {
 }
 
 func (sw *sparseFileWriter) Write(b []byte) (n int, err error) {
-	overwrite := int64(len(b)) > sw.LogicalRemaining()
+	overwrite := int64(len(b)) > sw.logicalRemaining()
 	if overwrite {
-		b = b[:sw.LogicalRemaining()]
+		b = b[:sw.logicalRemaining()]
 	}
 
 	b0 := b
@@ -556,7 +559,7 @@ func (sw *sparseFileWriter) Write(b []byte) (n int, err error) {
 		return n, errMissData // Not possible; implies bug in validation logic
 	case err != nil:
 		return n, err
-	case sw.LogicalRemaining() == 0 && sw.PhysicalRemaining() > 0:
+	case sw.logicalRemaining() == 0 && sw.physicalRemaining() > 0:
 		return n, errUnrefData // Not possible; implies bug in validation logic
 	case overwrite:
 		return n, ErrWriteTooLong
@@ -578,12 +581,12 @@ func (sw *sparseFileWriter) ReadFrom(r io.Reader) (n int64, err error) {
 
 	var readLastByte bool
 	pos0 := sw.pos
-	for sw.LogicalRemaining() > 0 && !readLastByte && err == nil {
+	for sw.logicalRemaining() > 0 && !readLastByte && err == nil {
 		var nf int64 // Size of fragment
 		dataStart, dataEnd := sw.sp[0].Offset, sw.sp[0].endOffset()
 		if sw.pos < dataStart { // In a hole fragment
 			nf = dataStart - sw.pos
-			if sw.PhysicalRemaining() == 0 {
+			if sw.physicalRemaining() == 0 {
 				readLastByte = true
 				nf--
 			}
@@ -613,18 +616,18 @@ func (sw *sparseFileWriter) ReadFrom(r io.Reader) (n int64, err error) {
 		return n, errMissData // Not possible; implies bug in validation logic
 	case err != nil:
 		return n, err
-	case sw.LogicalRemaining() == 0 && sw.PhysicalRemaining() > 0:
+	case sw.logicalRemaining() == 0 && sw.physicalRemaining() > 0:
 		return n, errUnrefData // Not possible; implies bug in validation logic
 	default:
 		return n, ensureEOF(rs)
 	}
 }
 
-func (sw sparseFileWriter) LogicalRemaining() int64 {
+func (sw sparseFileWriter) logicalRemaining() int64 {
 	return sw.sp[len(sw.sp)-1].endOffset() - sw.pos
 }
-func (sw sparseFileWriter) PhysicalRemaining() int64 {
+func (sw sparseFileWriter) physicalRemaining() int64 {
-	return sw.fw.PhysicalRemaining()
+	return sw.fw.physicalRemaining()
 }
 
 // zeroWriter may only be written with NULs, otherwise it returns errWriteHole.

src/archive/tar/writer_test.go

@@ -987,11 +987,9 @@ func TestIssue12594(t *testing.T) {
 		// The prefix field should never appear in the GNU format.
 		var blk block
 		copy(blk[:], b.Bytes())
-		prefix := string(blk.USTAR().Prefix())
+		prefix := string(blk.toUSTAR().prefix())
-		if i := strings.IndexByte(prefix, 0); i >= 0 {
+		prefix, _, _ = strings.Cut(prefix, "\x00") // Truncate at the NUL terminator
-			prefix = prefix[:i] // Truncate at the NUL terminator
+		if blk.getFormat() == FormatGNU && len(prefix) > 0 && strings.HasPrefix(name, prefix) {
-		}
-		if blk.GetFormat() == FormatGNU && len(prefix) > 0 && strings.HasPrefix(name, prefix) {
 			t.Errorf("test %d, found prefix in GNU format: %s", i, prefix)
 		}
 
@@ -1029,7 +1027,7 @@ func TestFileWriter(t *testing.T) {
 			wantCnt int64
 			wantErr error
 		}
-		testRemaining struct { // LogicalRemaining() == wantLCnt, PhysicalRemaining() == wantPCnt
+		testRemaining struct { // logicalRemaining() == wantLCnt, physicalRemaining() == wantPCnt
 			wantLCnt int64
 			wantPCnt int64
 		}
@@ -1292,11 +1290,11 @@ func TestFileWriter(t *testing.T) {
 					t.Errorf("test %d.%d, expected %d more operations", i, j, len(f.ops))
 				}
 			case testRemaining:
-				if got := fw.LogicalRemaining(); got != tf.wantLCnt {
+				if got := fw.logicalRemaining(); got != tf.wantLCnt {
-					t.Errorf("test %d.%d, LogicalRemaining() = %d, want %d", i, j, got, tf.wantLCnt)
+					t.Errorf("test %d.%d, logicalRemaining() = %d, want %d", i, j, got, tf.wantLCnt)
 				}
-				if got := fw.PhysicalRemaining(); got != tf.wantPCnt {
+				if got := fw.physicalRemaining(); got != tf.wantPCnt {
-					t.Errorf("test %d.%d, PhysicalRemaining() = %d, want %d", i, j, got, tf.wantPCnt)
+					t.Errorf("test %d.%d, physicalRemaining() = %d, want %d", i, j, got, tf.wantPCnt)
 				}
 			default:
 				t.Fatalf("test %d.%d, unknown test operation: %T", i, j, tf)

src/archive/zip/reader.go

@@ -102,7 +102,7 @@ func (z *Reader) init(r io.ReaderAt, size int64) error {
 	// indicate it contains up to 1 << 128 - 1 files. Since each file has a
 	// header which will be _at least_ 30 bytes we can safely preallocate
 	// if (data size / 30) >= end.directoryRecords.
-	if (uint64(size)-end.directorySize)/30 >= end.directoryRecords {
+	if end.directorySize < uint64(size) && (uint64(size)-end.directorySize)/30 >= end.directoryRecords {
 		z.File = make([]*File, 0, end.directoryRecords)
 	}
 	z.Comment = end.comment
@@ -741,6 +741,9 @@ func (r *Reader) initFileList() {
 		for _, file := range r.File {
 			isDir := len(file.Name) > 0 && file.Name[len(file.Name)-1] == '/'
 			name := toValidName(file.Name)
+			if name == "" {
+				continue
+			}
 			for dir := path.Dir(name); dir != "."; dir = path.Dir(dir) {
 				dirs[dir] = true
 			}
@@ -782,8 +785,11 @@ func fileEntryLess(x, y string) bool {
 func (r *Reader) Open(name string) (fs.File, error) {
 	r.initFileList()
 
+	if !fs.ValidPath(name) {
+		return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrInvalid}
+	}
 	e := r.openLookup(name)
-	if e == nil || !fs.ValidPath(name) {
+	if e == nil {
 		return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrNotExist}
 	}
 	if e.isDir {
@@ -797,7 +803,7 @@ func (r *Reader) Open(name string) (fs.File, error) {
 }
 
 func split(name string) (dir, elem string, isDir bool) {
-	if name[len(name)-1] == '/' {
+	if len(name) > 0 && name[len(name)-1] == '/' {
 		isDir = true
 		name = name[:len(name)-1]
 	}

src/archive/zip/reader_test.go

@@ -13,6 +13,7 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"reflect"
 	"regexp"
 	"strings"
 	"testing"
@@ -1202,6 +1203,15 @@ func TestCVE202127919(t *testing.T) {
 	if err != nil {
 		t.Errorf("Error reading file: %v", err)
 	}
+	if len(r.File) != 1 {
+		t.Fatalf("No entries in the file list")
+	}
+	if r.File[0].Name != "../test.txt" {
+		t.Errorf("Unexpected entry name: %s", r.File[0].Name)
+	}
+	if _, err := r.File[0].Open(); err != nil {
+		t.Errorf("Error opening file: %v", err)
+	}
 }
 
 func TestReadDataDescriptor(t *testing.T) {
@@ -1384,3 +1394,139 @@ func TestCVE202133196(t *testing.T) {
 		t.Errorf("Archive has unexpected number of files, got %d, want 5", len(r.File))
 	}
 }
+
+func TestCVE202139293(t *testing.T) {
+	// directory size is so large, that the check in Reader.init
+	// overflows when subtracting from the archive size, causing
+	// the pre-allocation check to be bypassed.
+	data := []byte{
+		0x50, 0x4b, 0x06, 0x06, 0x05, 0x06, 0x31, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x4b,
+		0x06, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+		0x00, 0x00, 0x50, 0x4b, 0x05, 0x06, 0x00, 0x1a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x4b,
+		0x06, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+		0x00, 0x00, 0x00, 0x50, 0x4b, 0x05, 0x06, 0x00, 0x31, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
+		0xff, 0x50, 0xfe, 0x00, 0xff, 0x00, 0x3a, 0x00, 0x00, 0x00, 0xff,
+	}
+	_, err := NewReader(bytes.NewReader(data), int64(len(data)))
+	if err != ErrFormat {
+		t.Fatalf("unexpected error, got: %v, want: %v", err, ErrFormat)
+	}
+}
+
+func TestCVE202141772(t *testing.T) {
+	// Archive contains a file whose name is exclusively made up of '/', '\'
+	// characters, or "../", "..\" paths, which would previously cause a panic.
+	//
+	//  Length   Method    Size  Cmpr    Date    Time   CRC-32   Name
+	// --------  ------  ------- ---- ---------- ----- --------  ----
+	//        0  Stored        0   0% 08-05-2021 18:32 00000000  /
+	//        0  Stored        0   0% 09-14-2021 12:59 00000000  //
+	//        0  Stored        0   0% 09-14-2021 12:59 00000000  \
+	//       11  Stored       11   0% 09-14-2021 13:04 0d4a1185  /test.txt
+	// --------          -------  ---                            -------
+	//       11               11   0%                            4 files
+	data := []byte{
+		0x50, 0x4b, 0x03, 0x04, 0x0a, 0x00, 0x00, 0x08,
+		0x00, 0x00, 0x06, 0x94, 0x05, 0x53, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x2f, 0x50,
+		0x4b, 0x03, 0x04, 0x0a, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x78, 0x67, 0x2e, 0x53, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x02, 0x00, 0x00, 0x00, 0x2f, 0x2f, 0x50,
+		0x4b, 0x03, 0x04, 0x0a, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x78, 0x67, 0x2e, 0x53, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x01, 0x00, 0x00, 0x00, 0x5c, 0x50, 0x4b,
+		0x03, 0x04, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x91, 0x68, 0x2e, 0x53, 0x85, 0x11, 0x4a, 0x0d,
+		0x0b, 0x00, 0x00, 0x00, 0x0b, 0x00, 0x00, 0x00,
+		0x09, 0x00, 0x00, 0x00, 0x2f, 0x74, 0x65, 0x73,
+		0x74, 0x2e, 0x74, 0x78, 0x74, 0x68, 0x65, 0x6c,
+		0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64,
+		0x50, 0x4b, 0x01, 0x02, 0x14, 0x03, 0x0a, 0x00,
+		0x00, 0x08, 0x00, 0x00, 0x06, 0x94, 0x05, 0x53,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
+		0xed, 0x41, 0x00, 0x00, 0x00, 0x00, 0x2f, 0x50,
+		0x4b, 0x01, 0x02, 0x3f, 0x00, 0x0a, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x78, 0x67, 0x2e, 0x53, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x02, 0x00, 0x24, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00,
+		0x00, 0x1f, 0x00, 0x00, 0x00, 0x2f, 0x2f, 0x0a,
+		0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+		0x00, 0x18, 0x00, 0x93, 0x98, 0x25, 0x57, 0x25,
+		0xa9, 0xd7, 0x01, 0x93, 0x98, 0x25, 0x57, 0x25,
+		0xa9, 0xd7, 0x01, 0x93, 0x98, 0x25, 0x57, 0x25,
+		0xa9, 0xd7, 0x01, 0x50, 0x4b, 0x01, 0x02, 0x3f,
+		0x00, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x78,
+		0x67, 0x2e, 0x53, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+		0x00, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x20, 0x00, 0x00, 0x00, 0x3f, 0x00, 0x00,
+		0x00, 0x5c, 0x0a, 0x00, 0x20, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x01, 0x00, 0x18, 0x00, 0x93, 0x98,
+		0x25, 0x57, 0x25, 0xa9, 0xd7, 0x01, 0x93, 0x98,
+		0x25, 0x57, 0x25, 0xa9, 0xd7, 0x01, 0x93, 0x98,
+		0x25, 0x57, 0x25, 0xa9, 0xd7, 0x01, 0x50, 0x4b,
+		0x01, 0x02, 0x3f, 0x00, 0x0a, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x91, 0x68, 0x2e, 0x53, 0x85, 0x11,
+		0x4a, 0x0d, 0x0b, 0x00, 0x00, 0x00, 0x0b, 0x00,
+		0x00, 0x00, 0x09, 0x00, 0x24, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00,
+		0x5e, 0x00, 0x00, 0x00, 0x2f, 0x74, 0x65, 0x73,
+		0x74, 0x2e, 0x74, 0x78, 0x74, 0x0a, 0x00, 0x20,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x18,
+		0x00, 0xa9, 0x80, 0x51, 0x01, 0x26, 0xa9, 0xd7,
+		0x01, 0x31, 0xd1, 0x57, 0x01, 0x26, 0xa9, 0xd7,
+		0x01, 0xdf, 0x48, 0x85, 0xf9, 0x25, 0xa9, 0xd7,
+		0x01, 0x50, 0x4b, 0x05, 0x06, 0x00, 0x00, 0x00,
+		0x00, 0x04, 0x00, 0x04, 0x00, 0x31, 0x01, 0x00,
+		0x00, 0x90, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}
+	r, err := NewReader(bytes.NewReader([]byte(data)), int64(len(data)))
+	if err != nil {
+		t.Fatalf("Error reading the archive: %v", err)
+	}
+	entryNames := []string{`/`, `//`, `\`, `/test.txt`}
+	var names []string
+	for _, f := range r.File {
+		names = append(names, f.Name)
+		if _, err := f.Open(); err != nil {
+			t.Errorf("Error opening %q: %v", f.Name, err)
+		}
+		if _, err := r.Open(f.Name); err == nil {
+			t.Errorf("Opening %q with fs.FS API succeeded", f.Name)
+		}
+	}
+	if !reflect.DeepEqual(names, entryNames) {
+		t.Errorf("Unexpected file entries: %q", names)
+	}
+	if _, err := r.Open(""); err == nil {
+		t.Errorf("Opening %q with fs.FS API succeeded", "")
+	}
+	if _, err := r.Open("test.txt"); err != nil {
+		t.Errorf("Error opening %q with fs.FS API: %v", "test.txt", err)
+	}
+	dirEntries, err := fs.ReadDir(r, ".")
+	if err != nil {
+		t.Fatalf("Error reading the root directory: %v", err)
+	}
+	if len(dirEntries) != 1 || dirEntries[0].Name() != "test.txt" {
+		t.Errorf("Unexpected directory entries")
+		for _, dirEntry := range dirEntries {
+			_, err := r.Open(dirEntry.Name())
+			t.Logf("%q (Open error: %v)", dirEntry.Name(), err)
+		}
+		t.FailNow()
+	}
+	info, err := dirEntries[0].Info()
+	if err != nil {
+		t.Fatalf("Error reading info entry: %v", err)
+	}
+	if name := info.Name(); name != "test.txt" {
+		t.Errorf("Inconsistent name in info entry: %v", name)
+	}
+}

src/archive/zip/writer_test.go

@@ -362,7 +362,7 @@ func TestWriterDirAttributes(t *testing.T) {
 	}
 
 	binary.LittleEndian.PutUint32(sig[:], uint32(dataDescriptorSignature))
-	if bytes.Index(b, sig[:]) != -1 {
+	if bytes.Contains(b, sig[:]) {
 		t.Error("there should be no data descriptor")
 	}
 }

src/bufio/bufio.go

@@ -68,7 +68,12 @@ func (b *Reader) Size() int { return len(b.buf) }
 
 // Reset discards any buffered data, resets all state, and switches
 // the buffered reader to read from r.
+// Calling Reset on the zero value of Reader initializes the internal buffer
+// to the default size.
 func (b *Reader) Reset(r io.Reader) {
+	if b.buf == nil {
+		b.buf = make([]byte, defaultBufSize)
+	}
 	b.reset(b.buf, r)
 }
 
@@ -168,6 +173,10 @@ func (b *Reader) Discard(n int) (discarded int, err error) {
 	if n == 0 {
 		return
 	}
+
+	b.lastByte = -1
+	b.lastRuneSize = -1
+
 	remain := n
 	for {
 		skip := b.Buffered()
@@ -261,8 +270,8 @@ func (b *Reader) ReadByte() (byte, error) {
 // UnreadByte unreads the last byte. Only the most recently read byte can be unread.
 //
 // UnreadByte returns an error if the most recent method called on the
-// Reader was not a read operation. Notably, Peek is not considered a
+// Reader was not a read operation. Notably, Peek, Discard, and WriteTo are not
-// read operation.
+// considered read operations.
 func (b *Reader) UnreadByte() error {
 	if b.lastByte < 0 || b.r == 0 && b.w > 0 {
 		return ErrInvalidUnreadByte
@@ -497,6 +506,9 @@ func (b *Reader) ReadString(delim byte) (string, error) {
 // If the underlying reader supports the WriteTo method,
 // this calls the underlying WriteTo without buffering.
 func (b *Reader) WriteTo(w io.Writer) (n int64, err error) {
+	b.lastByte = -1
+	b.lastRuneSize = -1
+
 	n, err = b.writeBuf(w)
 	if err != nil {
 		return
@@ -590,7 +602,12 @@ func (b *Writer) Size() int { return len(b.buf) }
 
 // Reset discards any unflushed buffered data, clears any error, and
 // resets b to write its output to w.
+// Calling Reset on the zero value of Writer initializes the internal buffer
+// to the default size.
 func (b *Writer) Reset(w io.Writer) {
+	if b.buf == nil {
+		b.buf = make([]byte, defaultBufSize)
+	}
 	b.err = nil
 	b.n = 0
 	b.wr = w
@@ -623,6 +640,14 @@ func (b *Writer) Flush() error {
 // Available returns how many bytes are unused in the buffer.
 func (b *Writer) Available() int { return len(b.buf) - b.n }
 
+// AvailableBuffer returns an empty buffer with b.Available() capacity.
+// This buffer is intended to be appended to and
+// passed to an immediately succeeding Write call.
+// The buffer is only valid until the next write operation on b.
+func (b *Writer) AvailableBuffer() []byte {
+	return b.buf[b.n:][:0]
+}
+
 // Buffered returns the number of bytes that have been written into the current buffer.
 func (b *Writer) Buffered() int { return b.n }
 
@@ -720,19 +745,14 @@ func (b *Writer) WriteString(s string) (int, error) {
 }
 
 // ReadFrom implements io.ReaderFrom. If the underlying writer
-// supports the ReadFrom method, and b has no buffered data yet,
+// supports the ReadFrom method, this calls the underlying ReadFrom.
-// this calls the underlying ReadFrom without buffering.
+// If there is buffered data and an underlying ReadFrom, this fills
+// the buffer and writes it before calling ReadFrom.
 func (b *Writer) ReadFrom(r io.Reader) (n int64, err error) {
 	if b.err != nil {
 		return 0, b.err
 	}
-	if b.Buffered() == 0 {
+	readerFrom, readerFromOK := b.wr.(io.ReaderFrom)
-		if w, ok := b.wr.(io.ReaderFrom); ok {
-			n, err = w.ReadFrom(r)
-			b.err = err
-			return n, err
-		}
-	}
 	var m int
 	for {
 		if b.Available() == 0 {
@@ -740,6 +760,12 @@ func (b *Writer) ReadFrom(r io.Reader) (n int64, err error) {
 				return n, err1
 			}
 		}
+		if readerFromOK && b.Buffered() == 0 {
+			nn, err := readerFrom.ReadFrom(r)
+			b.err = err
+			n += nn
+			return n, err
+		}
 		nr := 0
 		for nr < maxConsecutiveEmptyReads {
 			m, err = r.Read(b.buf[b.n:])

src/bufio/bufio_test.go

@@ -10,6 +10,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math/rand"
+	"strconv"
 	"strings"
 	"testing"
 	"testing/iotest"
@@ -302,6 +304,40 @@ func TestNoUnreadByteAfterPeek(t *testing.T) {
 	}
 }
 
+func TestNoUnreadRuneAfterDiscard(t *testing.T) {
+	br := NewReader(strings.NewReader("example"))
+	br.ReadRune()
+	br.Discard(1)
+	if err := br.UnreadRune(); err == nil {
+		t.Error("UnreadRune didn't fail after Discard")
+	}
+}
+
+func TestNoUnreadByteAfterDiscard(t *testing.T) {
+	br := NewReader(strings.NewReader("example"))
+	br.ReadByte()
+	br.Discard(1)
+	if err := br.UnreadByte(); err == nil {
+		t.Error("UnreadByte didn't fail after Discard")
+	}
+}
+
+func TestNoUnreadRuneAfterWriteTo(t *testing.T) {
+	br := NewReader(strings.NewReader("example"))
+	br.WriteTo(io.Discard)
+	if err := br.UnreadRune(); err == nil {
+		t.Error("UnreadRune didn't fail after WriteTo")
+	}
+}
+
+func TestNoUnreadByteAfterWriteTo(t *testing.T) {
+	br := NewReader(strings.NewReader("example"))
+	br.WriteTo(io.Discard)
+	if err := br.UnreadByte(); err == nil {
+		t.Error("UnreadByte didn't fail after WriteTo")
+	}
+}
+
 func TestUnreadByte(t *testing.T) {
 	segments := []string{"Hello, ", "world"}
 	r := NewReader(&StringReader{data: segments})
@@ -608,6 +644,37 @@ func TestWriter(t *testing.T) {
 	}
 }
 
+func TestWriterAppend(t *testing.T) {
+	got := new(bytes.Buffer)
+	var want []byte
+	rn := rand.New(rand.NewSource(0))
+	w := NewWriterSize(got, 64)
+	for i := 0; i < 100; i++ {
+		// Obtain a buffer to append to.
+		b := w.AvailableBuffer()
+		if w.Available() != cap(b) {
+			t.Fatalf("Available() = %v, want %v", w.Available(), cap(b))
+		}
+
+		// While not recommended, it is valid to append to a shifted buffer.
+		// This forces Write to copy the the input.
+		if rn.Intn(8) == 0 && cap(b) > 0 {
+			b = b[1:1:cap(b)]
+		}
+
+		// Append a random integer of varying width.
+		n := int64(rn.Intn(1 << rn.Intn(30)))
+		want = append(strconv.AppendInt(want, n, 10), ' ')
+		b = append(strconv.AppendInt(b, n, 10), ' ')
+		w.Write(b)
+	}
+	w.Flush()
+
+	if !bytes.Equal(got.Bytes(), want) {
+		t.Errorf("output mismatch:\ngot  %s\nwant %s", got.Bytes(), want)
+	}
+}
+
 // Check that write errors are returned properly.
 
 type errorWriterTest struct {
@@ -1284,6 +1351,54 @@ func TestWriterReadFromErrNoProgress(t *testing.T) {
 	}
 }
 
+type readFromWriter struct {
+	buf           []byte
+	writeBytes    int
+	readFromBytes int
+}
+
+func (w *readFromWriter) Write(p []byte) (int, error) {
+	w.buf = append(w.buf, p...)
+	w.writeBytes += len(p)
+	return len(p), nil
+}
+
+func (w *readFromWriter) ReadFrom(r io.Reader) (int64, error) {
+	b, err := io.ReadAll(r)
+	w.buf = append(w.buf, b...)
+	w.readFromBytes += len(b)
+	return int64(len(b)), err
+}
+
+// Test that calling (*Writer).ReadFrom with a partially-filled buffer
+// fills the buffer before switching over to ReadFrom.
+func TestWriterReadFromWithBufferedData(t *testing.T) {
+	const bufsize = 16
+
+	input := createTestInput(64)
+	rfw := &readFromWriter{}
+	w := NewWriterSize(rfw, bufsize)
+
+	const writeSize = 8
+	if n, err := w.Write(input[:writeSize]); n != writeSize || err != nil {
+		t.Errorf("w.Write(%v bytes) = %v, %v; want %v, nil", writeSize, n, err, writeSize)
+	}
+	n, err := w.ReadFrom(bytes.NewReader(input[writeSize:]))
+	if wantn := len(input[writeSize:]); int(n) != wantn || err != nil {
+		t.Errorf("io.Copy(w, %v bytes) = %v, %v; want %v, nil", wantn, n, err, wantn)
+	}
+	if err := w.Flush(); err != nil {
+		t.Errorf("w.Flush() = %v, want nil", err)
+	}
+
+	if got, want := rfw.writeBytes, bufsize; got != want {
+		t.Errorf("wrote %v bytes with Write, want %v", got, want)
+	}
+	if got, want := rfw.readFromBytes, len(input)-bufsize; got != want {
+		t.Errorf("wrote %v bytes with ReadFrom, want %v", got, want)
+	}
+}
+
 func TestReadZero(t *testing.T) {
 	for _, size := range []int{100, 2} {
 		t.Run(fmt.Sprintf("bufsize=%d", size), func(t *testing.T) {
@@ -1312,6 +1427,7 @@ func TestReaderReset(t *testing.T) {
 	if string(buf) != "foo" {
 		t.Errorf("buf = %q; want foo", buf)
 	}
+
 	r.Reset(strings.NewReader("bar bar"))
 	all, err := io.ReadAll(r)
 	if err != nil {
@@ -1320,12 +1436,23 @@ func TestReaderReset(t *testing.T) {
 	if string(all) != "bar bar" {
 		t.Errorf("ReadAll = %q; want bar bar", all)
 	}
+
+	*r = Reader{} // zero out the Reader
+	r.Reset(strings.NewReader("bar bar"))
+	all, err = io.ReadAll(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(all) != "bar bar" {
+		t.Errorf("ReadAll = %q; want bar bar", all)
+	}
 }
 
 func TestWriterReset(t *testing.T) {
-	var buf1, buf2 bytes.Buffer
+	var buf1, buf2, buf3 bytes.Buffer
 	w := NewWriter(&buf1)
 	w.WriteString("foo")
+
 	w.Reset(&buf2) // and not flushed
 	w.WriteString("bar")
 	w.Flush()
@@ -1335,6 +1462,17 @@ func TestWriterReset(t *testing.T) {
 	if buf2.String() != "bar" {
 		t.Errorf("buf2 = %q; want bar", buf2.String())
 	}
+
+	*w = Writer{}  // zero out the Writer
+	w.Reset(&buf3) // and not flushed
+	w.WriteString("bar")
+	w.Flush()
+	if buf1.String() != "" {
+		t.Errorf("buf1 = %q; want empty", buf1.String())
+	}
+	if buf3.String() != "bar" {
+		t.Errorf("buf3 = %q; want bar", buf3.String())
+	}
 }
 
 func TestReaderDiscard(t *testing.T) {

src/bufio/example_test.go

@@ -20,6 +20,18 @@ func ExampleWriter() {
 	// Output: Hello, world!
 }
 
+func ExampleWriter_AvailableBuffer() {
+	w := bufio.NewWriter(os.Stdout)
+	for _, i := range []int64{1, 2, 3, 4} {
+		b := w.AvailableBuffer()
+		b = strconv.AppendInt(b, i, 10)
+		b = append(b, ' ')
+		w.Write(b)
+	}
+	w.Flush()
+	// Output: 1 2 3 4
+}
+
 // The simplest use of a Scanner, to read standard input as a set of lines.
 func ExampleScanner_lines() {
 	scanner := bufio.NewScanner(os.Stdin)

src/bytes/boundary_test.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 //
 //go:build linux
-// +build linux
 
 package bytes_test
 
@@ -66,7 +65,11 @@ func TestIndexByteNearPageBoundary(t *testing.T) {
 
 func TestIndexNearPageBoundary(t *testing.T) {
 	t.Parallel()
-	var q [64]byte
+	q := dangerousSlice(t)
+	if len(q) > 64 {
+		// Only worry about when we're near the end of a page.
+		q = q[len(q)-64:]
+	}
 	b := dangerousSlice(t)
 	if len(b) > 256 {
 		// Only worry about when we're near the end of a page.
@@ -82,4 +85,16 @@ func TestIndexNearPageBoundary(t *testing.T) {
 		}
 		q[j-1] = 0
 	}
+
+	// Test differing alignments and sizes of q which always end on a page boundary.
+	q[len(q)-1] = 1 // difference is only found on the last byte
+	for j := 0; j < len(q); j++ {
+		for i := range b {
+			idx := Index(b[i:], q[j:])
+			if idx != -1 {
+				t.Fatalf("Index(b[%d:], q[%d:])=%d, want -1\n", i, j, idx)
+			}
+		}
+	}
+	q[len(q)-1] = 0
 }

src/bytes/bytes.go

@@ -21,7 +21,7 @@ func Equal(a, b []byte) bool {
 }
 
 // Compare returns an integer comparing two byte slices lexicographically.
-// The result will be 0 if a==b, -1 if a < b, and +1 if a > b.
+// The result will be 0 if a == b, -1 if a < b, and +1 if a > b.
 // A nil argument is equivalent to an empty slice.
 func Compare(a, b []byte) int {
 	return bytealg.Compare(a, b)
@@ -699,7 +699,7 @@ func ToValidUTF8(s, replacement []byte) []byte {
 		if c < utf8.RuneSelf {
 			i++
 			invalid = false
-			b = append(b, byte(c))
+			b = append(b, c)
 			continue
 		}
 		_, wid := utf8.DecodeRune(s[i:])
@@ -867,6 +867,8 @@ func lastIndexFunc(s []byte, f func(r rune) bool, truth bool) int {
 // most-significant bit of the highest word, map to the full range of all
 // 128 ASCII characters. The 128-bits of the upper 16 bytes will be zeroed,
 // ensuring that any non-ASCII character will be reported as not in the set.
+// This allocates a total of 32 bytes even though the upper half
+// is unused to avoid bounds checks in asciiSet.contains.
 type asciiSet [8]uint32
 
 // makeASCIISet creates a set of ASCII characters and reports whether all
@@ -877,53 +879,133 @@ func makeASCIISet(chars string) (as asciiSet, ok bool) {
 		if c >= utf8.RuneSelf {
 			return as, false
 		}
-		as[c>>5] |= 1 << uint(c&31)
+		as[c/32] |= 1 << (c % 32)
 	}
 	return as, true
 }
 
 // contains reports whether c is inside the set.
 func (as *asciiSet) contains(c byte) bool {
-	return (as[c>>5] & (1 << uint(c&31))) != 0
+	return (as[c/32] & (1 << (c % 32))) != 0
 }
 
-func makeCutsetFunc(cutset string) func(r rune) bool {
+// containsRune is a simplified version of strings.ContainsRune
-	if len(cutset) == 1 && cutset[0] < utf8.RuneSelf {
+// to avoid importing the strings package.
-		return func(r rune) bool {
+// We avoid bytes.ContainsRune to avoid allocating a temporary copy of s.
-			return r == rune(cutset[0])
+func containsRune(s string, r rune) bool {
+	for _, c := range s {
+		if c == r {
+			return true
 		}
 	}
-	if as, isASCII := makeASCIISet(cutset); isASCII {
+	return false
-		return func(r rune) bool {
-			return r < utf8.RuneSelf && as.contains(byte(r))
-		}
-	}
-	return func(r rune) bool {
-		for _, c := range cutset {
-			if c == r {
-				return true
-			}
-		}
-		return false
-	}
 }
 
 // Trim returns a subslice of s by slicing off all leading and
 // trailing UTF-8-encoded code points contained in cutset.
 func Trim(s []byte, cutset string) []byte {
-	return TrimFunc(s, makeCutsetFunc(cutset))
+	if len(s) == 0 || cutset == "" {
+		return s
+	}
+	if len(cutset) == 1 && cutset[0] < utf8.RuneSelf {
+		return trimLeftByte(trimRightByte(s, cutset[0]), cutset[0])
+	}
+	if as, ok := makeASCIISet(cutset); ok {
+		return trimLeftASCII(trimRightASCII(s, &as), &as)
+	}
+	return trimLeftUnicode(trimRightUnicode(s, cutset), cutset)
 }
 
 // TrimLeft returns a subslice of s by slicing off all leading
 // UTF-8-encoded code points contained in cutset.
 func TrimLeft(s []byte, cutset string) []byte {
-	return TrimLeftFunc(s, makeCutsetFunc(cutset))
+	if len(s) == 0 || cutset == "" {
+		return s
+	}
+	if len(cutset) == 1 && cutset[0] < utf8.RuneSelf {
+		return trimLeftByte(s, cutset[0])
+	}
+	if as, ok := makeASCIISet(cutset); ok {
+		return trimLeftASCII(s, &as)
+	}
+	return trimLeftUnicode(s, cutset)
+}
+
+func trimLeftByte(s []byte, c byte) []byte {
+	for len(s) > 0 && s[0] == c {
+		s = s[1:]
+	}
+	return s
+}
+
+func trimLeftASCII(s []byte, as *asciiSet) []byte {
+	for len(s) > 0 {
+		if !as.contains(s[0]) {
+			break
+		}
+		s = s[1:]
+	}
+	return s
+}
+
+func trimLeftUnicode(s []byte, cutset string) []byte {
+	for len(s) > 0 {
+		r, n := rune(s[0]), 1
+		if r >= utf8.RuneSelf {
+			r, n = utf8.DecodeRune(s)
+		}
+		if !containsRune(cutset, r) {
+			break
+		}
+		s = s[n:]
+	}
+	return s
 }
 
 // TrimRight returns a subslice of s by slicing off all trailing
 // UTF-8-encoded code points that are contained in cutset.
 func TrimRight(s []byte, cutset string) []byte {
-	return TrimRightFunc(s, makeCutsetFunc(cutset))
+	if len(s) == 0 || cutset == "" {
+		return s
+	}
+	if len(cutset) == 1 && cutset[0] < utf8.RuneSelf {
+		return trimRightByte(s, cutset[0])
+	}
+	if as, ok := makeASCIISet(cutset); ok {
+		return trimRightASCII(s, &as)
+	}
+	return trimRightUnicode(s, cutset)
+}
+
+func trimRightByte(s []byte, c byte) []byte {
+	for len(s) > 0 && s[len(s)-1] == c {
+		s = s[:len(s)-1]
+	}
+	return s
+}
+
+func trimRightASCII(s []byte, as *asciiSet) []byte {
+	for len(s) > 0 {
+		if !as.contains(s[len(s)-1]) {
+			break
+		}
+		s = s[:len(s)-1]
+	}
+	return s
+}
+
+func trimRightUnicode(s []byte, cutset string) []byte {
+	for len(s) > 0 {
+		r, n := rune(s[len(s)-1]), 1
+		if r >= utf8.RuneSelf {
+			r, n = utf8.DecodeLastRune(s)
+		}
+		if !containsRune(cutset, r) {
+			break
+		}
+		s = s[:len(s)-n]
+	}
+	return s
 }
 
 // TrimSpace returns a subslice of s by slicing off all leading and
@@ -1174,3 +1256,16 @@ func Index(s, sep []byte) int {
 	}
 	return -1
 }
+
+// Cut slices s around the first instance of sep,
+// returning the text before and after sep.
+// The found result reports whether sep appears in s.
+// If sep does not appear in s, cut returns s, nil, false.
+//
+// Cut returns slices of the original slice s, not copies.
+func Cut(s, sep []byte) (before, after []byte, found bool) {
+	if i := Index(s, sep); i >= 0 {
+		return s[:i], s[i+len(sep):], true
+	}
+	return s, nil, false
+}

src/bytes/bytes_test.go

@@ -1251,7 +1251,9 @@ var trimTests = []TrimTest{
 	{"TrimLeft", "abba", "ab", ""},
 	{"TrimRight", "abba", "ab", ""},
 	{"TrimLeft", "abba", "a", "bba"},
+	{"TrimLeft", "abba", "b", "abba"},
 	{"TrimRight", "abba", "a", "abb"},
+	{"TrimRight", "abba", "b", "abba"},
 	{"Trim", "<tag>", "<>", "tag"},
 	{"Trim", "* listitem", " *", "listitem"},
 	{"Trim", `"quote"`, `"`, "quote"},
@@ -1565,6 +1567,29 @@ func TestEqualFold(t *testing.T) {
 	}
 }
 
+var cutTests = []struct {
+	s, sep        string
+	before, after string
+	found         bool
+}{
+	{"abc", "b", "a", "c", true},
+	{"abc", "a", "", "bc", true},
+	{"abc", "c", "ab", "", true},
+	{"abc", "abc", "", "", true},
+	{"abc", "", "", "abc", true},
+	{"abc", "d", "abc", "", false},
+	{"", "d", "", "", false},
+	{"", "", "", "", true},
+}
+
+func TestCut(t *testing.T) {
+	for _, tt := range cutTests {
+		if before, after, found := Cut([]byte(tt.s), []byte(tt.sep)); string(before) != tt.before || string(after) != tt.after || found != tt.found {
+			t.Errorf("Cut(%q, %q) = %q, %q, %v, want %q, %q, %v", tt.s, tt.sep, before, after, found, tt.before, tt.after, tt.found)
+		}
+	}
+}
+
 func TestBufferGrowNegative(t *testing.T) {
 	defer func() {
 		if err := recover(); err == nil {
@@ -1963,6 +1988,13 @@ func BenchmarkTrimASCII(b *testing.B) {
 	}
 }
 
+func BenchmarkTrimByte(b *testing.B) {
+	x := []byte("  the quick brown fox   ")
+	for i := 0; i < b.N; i++ {
+		Trim(x, " ")
+	}
+}
+
 func BenchmarkIndexPeriodic(b *testing.B) {
 	key := []byte{1, 1}
 	for _, skip := range [...]int{2, 4, 8, 16, 32, 64} {

src/bytes/example_test.go

@@ -54,6 +54,19 @@ func ExampleBuffer_Len() {
 	// Output: 5
 }
 
+func ExampleBuffer_Next() {
+	var b bytes.Buffer
+	b.Grow(64)
+	b.Write([]byte("abcde"))
+	fmt.Printf("%s\n", string(b.Next(2)))
+	fmt.Printf("%s\n", string(b.Next(2)))
+	fmt.Printf("%s", string(b.Next(2)))
+	// Output:
+	// ab
+	// cd
+	// e
+}
+
 func ExampleCompare() {
 	// Interpret Compare's result by comparing it to zero.
 	var a, b []byte
@@ -92,36 +105,6 @@ func ExampleCompare_search() {
 	}
 }
 
-func ExampleTrimSuffix() {
-	var b = []byte("Hello, goodbye, etc!")
-	b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
-	b = bytes.TrimSuffix(b, []byte("gopher"))
-	b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
-	os.Stdout.Write(b)
-	// Output: Hello, world!
-}
-
-func ExampleTrimPrefix() {
-	var b = []byte("Goodbye,, world!")
-	b = bytes.TrimPrefix(b, []byte("Goodbye,"))
-	b = bytes.TrimPrefix(b, []byte("See ya,"))
-	fmt.Printf("Hello%s", b)
-	// Output: Hello, world!
-}
-
-func ExampleFields() {
-	fmt.Printf("Fields are: %q", bytes.Fields([]byte("  foo bar  baz   ")))
-	// Output: Fields are: ["foo" "bar" "baz"]
-}
-
-func ExampleFieldsFunc() {
-	f := func(c rune) bool {
-		return !unicode.IsLetter(c) && !unicode.IsNumber(c)
-	}
-	fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte("  foo1;bar2,baz3..."), f))
-	// Output: Fields are: ["foo1" "bar2" "baz3"]
-}
-
 func ExampleContains() {
 	fmt.Println(bytes.Contains([]byte("seafood"), []byte("foo")))
 	fmt.Println(bytes.Contains([]byte("seafood"), []byte("bar")))
@@ -168,6 +151,22 @@ func ExampleCount() {
 	// 5
 }
 
+func ExampleCut() {
+	show := func(s, sep string) {
+		before, after, found := bytes.Cut([]byte(s), []byte(sep))
+		fmt.Printf("Cut(%q, %q) = %q, %q, %v\n", s, sep, before, after, found)
+	}
+	show("Gopher", "Go")
+	show("Gopher", "ph")
+	show("Gopher", "er")
+	show("Gopher", "Badger")
+	// Output:
+	// Cut("Gopher", "Go") = "", "pher", true
+	// Cut("Gopher", "ph") = "Go", "er", true
+	// Cut("Gopher", "er") = "Goph", "", true
+	// Cut("Gopher", "Badger") = "Gopher", "", false
+}
+
 func ExampleEqual() {
 	fmt.Println(bytes.Equal([]byte("Go"), []byte("Go")))
 	fmt.Println(bytes.Equal([]byte("Go"), []byte("C++")))
@@ -181,6 +180,19 @@ func ExampleEqualFold() {
 	// Output: true
 }
 
+func ExampleFields() {
+	fmt.Printf("Fields are: %q", bytes.Fields([]byte("  foo bar  baz   ")))
+	// Output: Fields are: ["foo" "bar" "baz"]
+}
+
+func ExampleFieldsFunc() {
+	f := func(c rune) bool {
+		return !unicode.IsLetter(c) && !unicode.IsNumber(c)
+	}
+	fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte("  foo1;bar2,baz3..."), f))
+	// Output: Fields are: ["foo1" "bar2" "baz3"]
+}
+
 func ExampleHasPrefix() {
 	fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("Go")))
 	fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("C")))
@@ -246,6 +258,12 @@ func ExampleIndexRune() {
 	// -1
 }
 
+func ExampleJoin() {
+	s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
+	fmt.Printf("%s", bytes.Join(s, []byte(", ")))
+	// Output: foo, bar, baz
+}
+
 func ExampleLastIndex() {
 	fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
 	fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
@@ -286,10 +304,12 @@ func ExampleLastIndexFunc() {
 	// -1
 }
 
-func ExampleJoin() {
+func ExampleReader_Len() {
-	s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
+	fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
-	fmt.Printf("%s", bytes.Join(s, []byte(", ")))
+	fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
-	// Output: foo, bar, baz
+	// Output:
+	// 3
+	// 16
 }
 
 func ExampleRepeat() {
@@ -399,20 +419,6 @@ func ExampleTrimFunc() {
 	// go-gopher!
 }
 
-func ExampleMap() {
-	rot13 := func(r rune) rune {
-		switch {
-		case r >= 'A' && r <= 'Z':
-			return 'A' + (r-'A'+13)%26
-		case r >= 'a' && r <= 'z':
-			return 'a' + (r-'a'+13)%26
-		}
-		return r
-	}
-	fmt.Printf("%s", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
-	// Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
-}
-
 func ExampleTrimLeft() {
 	fmt.Print(string(bytes.TrimLeft([]byte("453gopher8257"), "0123456789")))
 	// Output:
@@ -429,11 +435,28 @@ func ExampleTrimLeftFunc() {
 	// go-gopher!567
 }
 
+func ExampleTrimPrefix() {
+	var b = []byte("Goodbye,, world!")
+	b = bytes.TrimPrefix(b, []byte("Goodbye,"))
+	b = bytes.TrimPrefix(b, []byte("See ya,"))
+	fmt.Printf("Hello%s", b)
+	// Output: Hello, world!
+}
+
 func ExampleTrimSpace() {
 	fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
 	// Output: a lone gopher
 }
 
+func ExampleTrimSuffix() {
+	var b = []byte("Hello, goodbye, etc!")
+	b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
+	b = bytes.TrimSuffix(b, []byte("gopher"))
+	b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
+	os.Stdout.Write(b)
+	// Output: Hello, world!
+}
+
 func ExampleTrimRight() {
 	fmt.Print(string(bytes.TrimRight([]byte("453gopher8257"), "0123456789")))
 	// Output:
@@ -450,21 +473,6 @@ func ExampleTrimRightFunc() {
 	// 1234go-gopher!
 }
 
-func ExampleToUpper() {
-	fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
-	// Output: GOPHER
-}
-
-func ExampleToUpperSpecial() {
-	str := []byte("ahoj vývojári golang")
-	totitle := bytes.ToUpperSpecial(unicode.AzeriCase, str)
-	fmt.Println("Original : " + string(str))
-	fmt.Println("ToUpper : " + string(totitle))
-	// Output:
-	// Original : ahoj vývojári golang
-	// ToUpper : AHOJ VÝVOJÁRİ GOLANG
-}
-
 func ExampleToLower() {
 	fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
 	// Output: gopher
@@ -480,10 +488,17 @@ func ExampleToLowerSpecial() {
 	// ToLower : ahoj vývojári golang
 }
 
-func ExampleReader_Len() {
+func ExampleToUpper() {
-	fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
+	fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
-	fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
+	// Output: GOPHER
-	// Output:
+}
-	// 3
+
-	// 16
+func ExampleToUpperSpecial() {
+	str := []byte("ahoj vývojári golang")
+	totitle := bytes.ToUpperSpecial(unicode.AzeriCase, str)
+	fmt.Println("Original : " + string(str))
+	fmt.Println("ToUpper : " + string(totitle))
+	// Output:
+	// Original : ahoj vývojári golang
+	// ToUpper : AHOJ VÝVOJÁRİ GOLANG
 }

src/cmd/api/goapi.go

@@ -653,10 +653,15 @@ func (w *Walker) ImportFrom(fromPath, fromDir string, mode types.ImportMode) (*t
 	}
 
 	// Type-check package files.
+	var sizes types.Sizes
+	if w.context != nil {
+		sizes = types.SizesFor(w.context.Compiler, w.context.GOARCH)
+	}
 	conf := types.Config{
 		IgnoreFuncBodies: true,
 		FakeImportC:      true,
 		Importer:         w,
+		Sizes:            sizes,
 	}
 	pkg, err = conf.Check(name, fset, files, nil)
 	if err != nil {
@@ -701,6 +706,36 @@ func sortedMethodNames(typ *types.Interface) []string {
 	return list
 }
 
+// sortedEmbeddeds returns constraint types embedded in an
+// interface. It does not include embedded interface types or methods.
+func (w *Walker) sortedEmbeddeds(typ *types.Interface) []string {
+	n := typ.NumEmbeddeds()
+	list := make([]string, 0, n)
+	for i := 0; i < n; i++ {
+		emb := typ.EmbeddedType(i)
+		switch emb := emb.(type) {
+		case *types.Interface:
+			list = append(list, w.sortedEmbeddeds(emb)...)
+		case *types.Union:
+			var buf bytes.Buffer
+			nu := emb.Len()
+			for i := 0; i < nu; i++ {
+				if i > 0 {
+					buf.WriteString(" | ")
+				}
+				term := emb.Term(i)
+				if term.Tilde() {
+					buf.WriteByte('~')
+				}
+				w.writeType(&buf, term.Type())
+			}
+			list = append(list, buf.String())
+		}
+	}
+	sort.Strings(list)
+	return list
+}
+
 func (w *Walker) writeType(buf *bytes.Buffer, typ types.Type) {
 	switch typ := typ.(type) {
 	case *types.Basic:
@@ -758,9 +793,16 @@ func (w *Walker) writeType(buf *bytes.Buffer, typ types.Type) {
 
 	case *types.Interface:
 		buf.WriteString("interface{")
-		if typ.NumMethods() > 0 {
+		if typ.NumMethods() > 0 || typ.NumEmbeddeds() > 0 {
 			buf.WriteByte(' ')
+		}
+		if typ.NumMethods() > 0 {
 			buf.WriteString(strings.Join(sortedMethodNames(typ), ", "))
+		}
+		if typ.NumEmbeddeds() > 0 {
+			buf.WriteString(strings.Join(w.sortedEmbeddeds(typ), ", "))
+		}
+		if typ.NumMethods() > 0 || typ.NumEmbeddeds() > 0 {
 			buf.WriteByte(' ')
 		}
 		buf.WriteString("}")
@@ -795,12 +837,19 @@ func (w *Walker) writeType(buf *bytes.Buffer, typ types.Type) {
 		}
 		buf.WriteString(typ.Obj().Name())
 
+	case *types.TypeParam:
+		// Type parameter names may change, so use a placeholder instead.
+		fmt.Fprintf(buf, "$%d", typ.Index())
+
 	default:
 		panic(fmt.Sprintf("unknown type %T", typ))
 	}
 }
 
 func (w *Walker) writeSignature(buf *bytes.Buffer, sig *types.Signature) {
+	if tparams := sig.TypeParams(); tparams != nil {
+		w.writeTypeParams(buf, tparams, true)
+	}
 	w.writeParams(buf, sig.Params(), sig.Variadic())
 	switch res := sig.Results(); res.Len() {
 	case 0:
@@ -814,6 +863,23 @@ func (w *Walker) writeSignature(buf *bytes.Buffer, sig *types.Signature) {
 	}
 }
 
+func (w *Walker) writeTypeParams(buf *bytes.Buffer, tparams *types.TypeParamList, withConstraints bool) {
+	buf.WriteByte('[')
+	c := tparams.Len()
+	for i := 0; i < c; i++ {
+		if i > 0 {
+			buf.WriteString(", ")
+		}
+		tp := tparams.At(i)
+		w.writeType(buf, tp)
+		if withConstraints {
+			buf.WriteByte(' ')
+			w.writeType(buf, tp.Constraint())
+		}
+	}
+	buf.WriteByte(']')
+}
+
 func (w *Walker) writeParams(buf *bytes.Buffer, t *types.Tuple, variadic bool) {
 	buf.WriteByte('(')
 	for i, n := 0, t.Len(); i < n; i++ {
@@ -867,6 +933,12 @@ func (w *Walker) emitObj(obj types.Object) {
 
 func (w *Walker) emitType(obj *types.TypeName) {
 	name := obj.Name()
+	if tparams := obj.Type().(*types.Named).TypeParams(); tparams != nil {
+		var buf bytes.Buffer
+		buf.WriteString(name)
+		w.writeTypeParams(&buf, tparams, true)
+		name = buf.String()
+	}
 	typ := obj.Type()
 	if obj.IsAlias() {
 		w.emitf("type %s = %s", name, w.typeString(typ))
@@ -990,7 +1062,13 @@ func (w *Walker) emitMethod(m *types.Selection) {
 			log.Fatalf("exported method with unexported receiver base type: %s", m)
 		}
 	}
-	w.emitf("method (%s) %s%s", w.typeString(recv), m.Obj().Name(), w.signatureString(sig))
+	tps := ""
+	if rtp := sig.RecvTypeParams(); rtp != nil {
+		var buf bytes.Buffer
+		w.writeTypeParams(&buf, rtp, false)
+		tps = buf.String()
+	}
+	w.emitf("method (%s%s) %s%s", w.typeString(recv), tps, m.Obj().Name(), w.signatureString(sig))
 }
 
 func (w *Walker) emitf(format string, args ...interface{}) {

src/cmd/api/run.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 // The run program is invoked via the dist tool.
 // To invoke manually: go tool dist test -run api --no-rebuild

src/cmd/api/testdata/src/pkg/p4/golden.txt

@@ -0,0 +1,5 @@
+pkg p4, func NewPair[$0 interface{ M }, $1 interface{ ~int }]($0, $1) Pair
+pkg p4, method (Pair[$0, $1]) Second() $1
+pkg p4, method (Pair[$0, $1]) First() $0
+pkg p4, type Pair[$0 interface{ M }, $1 interface{ ~int }] struct
+pkg p4, func Clone[$0 interface{ ~[]$1 }, $1 interface{}]($0) $0

src/cmd/api/testdata/src/pkg/p4/p4.go

@@ -0,0 +1,26 @@
+// Copyright 2021 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 p4
+
+type Pair[T1 interface { M() }, T2 ~int] struct {
+	f1 T1
+	f2 T2
+}
+
+func NewPair[T1 interface { M() }, T2 ~int](v1 T1, v2 T2) Pair[T1, T2] {
+	return Pair[T1, T2]{f1: v1, f2: v2}
+}
+
+func (p Pair[X1, _]) First() X1 {
+	return p.f1
+}
+
+func (p Pair[_, X2]) Second() X2 {
+	return p.f2
+}
+
+func Clone[S ~[]T, T any](s S) S {
+	return append(S(nil), s...)
+}

src/cmd/asm/internal/arch/arch.go

@@ -50,7 +50,7 @@ func nilRegisterNumber(name string, n int16) (int16, bool) {
 
 // Set configures the architecture specified by GOARCH and returns its representation.
 // It returns nil if GOARCH is not recognized.
-func Set(GOARCH string) *Arch {
+func Set(GOARCH string, shared bool) *Arch {
 	switch GOARCH {
 	case "386":
 		return archX86(&x86.Link386)
@@ -73,7 +73,7 @@ func Set(GOARCH string) *Arch {
 	case "ppc64le":
 		return archPPC64(&ppc64.Linkppc64le)
 	case "riscv64":
-		return archRISCV64()
+		return archRISCV64(shared)
 	case "s390x":
 		return archS390x()
 	case "wasm":
@@ -178,6 +178,10 @@ func archX86(linkArch *obj.LinkArch) *Arch {
 	instructions["PSLLDQ"] = x86.APSLLO
 	instructions["PSRLDQ"] = x86.APSRLO
 	instructions["PADDD"] = x86.APADDL
+	// Spellings originally used in CL 97235.
+	instructions["MOVBELL"] = x86.AMOVBEL
+	instructions["MOVBEQQ"] = x86.AMOVBEQ
+	instructions["MOVBEWW"] = x86.AMOVBEW
 
 	return &Arch{
 		LinkArch:       linkArch,
@@ -374,6 +378,9 @@ func archPPC64(linkArch *obj.LinkArch) *Arch {
 	for i := ppc64.REG_MSR; i <= ppc64.REG_CR; i++ {
 		register[obj.Rconv(i)] = int16(i)
 	}
+	for i := ppc64.REG_CR0LT; i <= ppc64.REG_CR7SO; i++ {
+		register[obj.Rconv(i)] = int16(i)
+	}
 	register["CR"] = ppc64.REG_CR
 	register["XER"] = ppc64.REG_XER
 	register["LR"] = ppc64.REG_LR
@@ -534,12 +541,18 @@ func archMips64(linkArch *obj.LinkArch) *Arch {
 	}
 }
 
-func archRISCV64() *Arch {
+func archRISCV64(shared bool) *Arch {
 	register := make(map[string]int16)
 
 	// Standard register names.
 	for i := riscv.REG_X0; i <= riscv.REG_X31; i++ {
-		if i == riscv.REG_G {
+		// Disallow X3 in shared mode, as this will likely be used as the
+		// GP register, which could result in problems in non-Go code,
+		// including signal handlers.
+		if shared && i == riscv.REG_GP {
+			continue
+		}
+		if i == riscv.REG_TP || i == riscv.REG_G {
 			continue
 		}
 		name := fmt.Sprintf("X%d", i-riscv.REG_X0)

src/cmd/asm/internal/arch/arm64.go

@@ -165,27 +165,21 @@ func ARM64RegisterExtension(a *obj.Addr, ext string, reg, num int16, isAmount, i
 		}
 	}
 	if reg <= arm64.REG_R31 && reg >= arm64.REG_R0 {
+		if !isAmount {
+			return errors.New("invalid register extension")
+		}
 		switch ext {
 		case "UXTB":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			if a.Type == obj.TYPE_MEM {
 				return errors.New("invalid shift for the register offset addressing mode")
 			}
 			a.Reg = arm64.REG_UXTB + Rnum
 		case "UXTH":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			if a.Type == obj.TYPE_MEM {
 				return errors.New("invalid shift for the register offset addressing mode")
 			}
 			a.Reg = arm64.REG_UXTH + Rnum
 		case "UXTW":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			// effective address of memory is a base register value and an offset register value.
 			if a.Type == obj.TYPE_MEM {
 				a.Index = arm64.REG_UXTW + Rnum
@@ -193,48 +187,33 @@ func ARM64RegisterExtension(a *obj.Addr, ext string, reg, num int16, isAmount, i
 				a.Reg = arm64.REG_UXTW + Rnum
 			}
 		case "UXTX":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			if a.Type == obj.TYPE_MEM {
 				return errors.New("invalid shift for the register offset addressing mode")
 			}
 			a.Reg = arm64.REG_UXTX + Rnum
 		case "SXTB":
-			if !isAmount {
+			if a.Type == obj.TYPE_MEM {
-				return errors.New("invalid register extension")
+				return errors.New("invalid shift for the register offset addressing mode")
 			}
 			a.Reg = arm64.REG_SXTB + Rnum
 		case "SXTH":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			if a.Type == obj.TYPE_MEM {
 				return errors.New("invalid shift for the register offset addressing mode")
 			}
 			a.Reg = arm64.REG_SXTH + Rnum
 		case "SXTW":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			if a.Type == obj.TYPE_MEM {
 				a.Index = arm64.REG_SXTW + Rnum
 			} else {
 				a.Reg = arm64.REG_SXTW + Rnum
 			}
 		case "SXTX":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			if a.Type == obj.TYPE_MEM {
 				a.Index = arm64.REG_SXTX + Rnum
 			} else {
 				a.Reg = arm64.REG_SXTX + Rnum
 			}
 		case "LSL":
-			if !isAmount {
-				return errors.New("invalid register extension")
-			}
 			a.Index = arm64.REG_LSL + Rnum
 		default:
 			return errors.New("unsupported general register extension type: " + ext)

src/cmd/asm/internal/asm/asm.go

@@ -793,6 +793,13 @@ func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
 				return
 			}
 		}
+		if p.arch.Family == sys.RISCV64 {
+			prog.From = a[0]
+			prog.Reg = p.getRegister(prog, op, &a[1])
+			prog.SetRestArgs([]obj.Addr{a[2]})
+			prog.To = a[3]
+			break
+		}
 		if p.arch.Family == sys.S390X {
 			if a[1].Type != obj.TYPE_REG {
 				p.errorf("second operand must be a register in %s instruction", op)

src/cmd/asm/internal/asm/operand_test.go

@@ -19,7 +19,7 @@ import (
 func setArch(goarch string) (*arch.Arch, *obj.Link) {
 	buildcfg.GOOS = "linux" // obj can handle this OS for all architectures.
 	buildcfg.GOARCH = goarch
-	architecture := arch.Set(goarch)
+	architecture := arch.Set(goarch, false)
 	if architecture == nil {
 		panic("asm: unrecognized architecture " + goarch)
 	}

src/cmd/asm/internal/asm/testdata/amd64enc.s

@@ -2495,30 +2495,30 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	MOVAPS X11, (BX)                        // 440f291b
 	MOVAPS X2, (R11)                        // 410f2913
 	MOVAPS X11, (R11)                       // 450f291b
-	MOVBEWW DX, (BX)                        // 660f38f113
+	MOVBEW DX, (BX)                         // 660f38f113
-	MOVBEWW R11, (BX)                       // 66440f38f11b
+	MOVBEW R11, (BX)                        // 66440f38f11b
-	MOVBEWW DX, (R11)                       // 66410f38f113
+	MOVBEW DX, (R11)                        // 66410f38f113
-	MOVBEWW R11, (R11)                      // 66450f38f11b
+	MOVBEW R11, (R11)                       // 66450f38f11b
-	MOVBEWW (BX), DX                        // 660f38f013
+	MOVBEW (BX), DX                         // 660f38f013
-	MOVBEWW (R11), DX                       // 66410f38f013
+	MOVBEW (R11), DX                        // 66410f38f013
-	MOVBEWW (BX), R11                       // 66440f38f01b
+	MOVBEW (BX), R11                        // 66440f38f01b
-	MOVBEWW (R11), R11                      // 66450f38f01b
+	MOVBEW (R11), R11                       // 66450f38f01b
-	MOVBELL DX, (BX)                        // 0f38f113
+	MOVBEL DX, (BX)                         // 0f38f113
-	MOVBELL R11, (BX)                       // 440f38f11b
+	MOVBEL R11, (BX)                        // 440f38f11b
-	MOVBELL DX, (R11)                       // 410f38f113
+	MOVBEL DX, (R11)                        // 410f38f113
-	MOVBELL R11, (R11)                      // 450f38f11b
+	MOVBEL R11, (R11)                       // 450f38f11b
-	MOVBELL (BX), DX                        // 0f38f013
+	MOVBEL (BX), DX                         // 0f38f013
-	MOVBELL (R11), DX                       // 410f38f013
+	MOVBEL (R11), DX                        // 410f38f013
-	MOVBELL (BX), R11                       // 440f38f01b
+	MOVBEL (BX), R11                        // 440f38f01b
-	MOVBELL (R11), R11                      // 450f38f01b
+	MOVBEL (R11), R11                       // 450f38f01b
-	MOVBEQQ DX, (BX)                        // 480f38f113
+	MOVBEQ DX, (BX)                         // 480f38f113
-	MOVBEQQ R11, (BX)                       // 4c0f38f11b
+	MOVBEQ R11, (BX)                        // 4c0f38f11b
-	MOVBEQQ DX, (R11)                       // 490f38f113
+	MOVBEQ DX, (R11)                        // 490f38f113
-	MOVBEQQ R11, (R11)                      // 4d0f38f11b
+	MOVBEQ R11, (R11)                       // 4d0f38f11b
-	MOVBEQQ (BX), DX                        // 480f38f013
+	MOVBEQ (BX), DX                         // 480f38f013
-	MOVBEQQ (R11), DX                       // 490f38f013
+	MOVBEQ (R11), DX                        // 490f38f013
-	MOVBEQQ (BX), R11                       // 4c0f38f01b
+	MOVBEQ (BX), R11                        // 4c0f38f01b
-	MOVBEQQ (R11), R11                      // 4d0f38f01b
+	MOVBEQ (R11), R11                       // 4d0f38f01b
 	MOVQ (BX), M2                           // 0f6e13 or 0f6f13 or 480f6e13
 	MOVQ (R11), M2                          // 410f6e13 or 410f6f13 or 490f6e13
 	MOVQ DX, M2                             // 0f6ed2 or 480f6ed2

src/cmd/asm/internal/asm/testdata/arm64.s

@@ -334,6 +334,8 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	EONW	$0x6006000060060, R5                // EONW	$1689262177517664, R5           // 1b0c8052db00a072a5003b4a
 	ORNW	$0x6006000060060, R5                // ORNW	$1689262177517664, R5           // 1b0c8052db00a072a5003b2a
 	BICSW	$0x6006000060060, R5                // BICSW	$1689262177517664, R5           // 1b0c8052db00a072a5003b6a
+	AND	$1, ZR                              // fb0340b2ff031b8a
+	ANDW	$1, ZR                              // fb030032ff031b0a
 	// TODO: this could have better encoding
 	ANDW	$-1, R10                            // 1b0080124a011b0a
 	AND	$8, R0, RSP                         // 1f007d92
@@ -369,9 +371,9 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	MOVD	$-1, R1                       // 01008092
 	MOVD	$0x210000, R0                 // MOVD	$2162688, R0                // 2004a0d2
 	MOVD	$0xffffffffffffaaaa, R1       // MOVD	$-21846, R1                 // a1aa8a92
-	MOVW	$1, ZR
+	MOVW	$1, ZR                        // 3f008052
 	MOVW	$1, R1
-	MOVD	$1, ZR
+	MOVD	$1, ZR                        // 3f0080d2
 	MOVD	$1, R1
 	MOVK	$1, R1
 	MOVD	$0x1000100010001000, RSP      // MOVD	$1152939097061330944, RSP   // ff8304b2
@@ -386,10 +388,10 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	VMOVQ	$0x8040201008040202, $0x7040201008040201, V20         // VMOVQ	$-9205322385119247870, $8088500183983456769, V20
 
 // mov(to/from sp)
-	MOVD	$0x1002(RSP), R1              // MOVD	$4098(RSP), R1              // fb074091610b0091
+	MOVD	$0x1002(RSP), R1              // MOVD	$4098(RSP), R1              // e107409121080091
-	MOVD	$0x1708(RSP), RSP             // MOVD	$5896(RSP), RSP             // fb0740917f231c91
+	MOVD	$0x1708(RSP), RSP             // MOVD	$5896(RSP), RSP             // ff074091ff231c91
-	MOVD	$0x2001(R7), R1               // MOVD	$8193(R7), R1               // fb08409161070091
+	MOVD	$0x2001(R7), R1               // MOVD	$8193(R7), R1               // e108409121040091
-	MOVD	$0xffffff(R7), R1             // MOVD	$16777215(R7), R1           // fbfc7f9161ff3f91
+	MOVD	$0xffffff(R7), R1             // MOVD	$16777215(R7), R1           // e1fc7f9121fc3f91
 	MOVD	$-0x1(R7), R1                 // MOVD	$-1(R7), R1                 // e10400d1
 	MOVD	$-0x30(R7), R1                // MOVD	$-48(R7), R1                // e1c000d1
 	MOVD	$-0x708(R7), R1               // MOVD	$-1800(R7), R1              // e1201cd1

src/cmd/asm/internal/asm/testdata/arm64error.s

@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 TEXT errors(SB),$0
-	AND	$1, RSP                                          // ERROR "illegal combination"
+	AND	$1, RSP                                          // ERROR "illegal source register"
 	ANDS	$1, R0, RSP                                      // ERROR "illegal combination"
 	ADDSW	R7->32, R14, R13                                 // ERROR "shift amount out of range 0 to 31"
 	ADD	R1.UXTB<<5, R2, R3                               // ERROR "shift amount out of range 0 to 4"
@@ -406,12 +406,12 @@ TEXT errors(SB),$0
 	VBIF	V0.D2, V1.D2, V2.D2                              // ERROR "invalid arrangement"
 	VUADDW	V9.B8, V12.H8, V14.B8                            // ERROR "invalid arrangement"
 	VUADDW2	V9.B8, V12.S4, V14.S4                            // ERROR "operand mismatch"
-	VUMAX   V1.D2, V2.D2, V3.D2                              // ERROR "invalid arrangement"
+	VUMAX	V1.D2, V2.D2, V3.D2                              // ERROR "invalid arrangement"
-	VUMIN   V1.D2, V2.D2, V3.D2                              // ERROR "invalid arrangement"
+	VUMIN	V1.D2, V2.D2, V3.D2                              // ERROR "invalid arrangement"
 	VUMAX	V1.B8, V2.B8, V3.B16                             // ERROR "operand mismatch"
 	VUMIN	V1.H4, V2.S4, V3.H4                              // ERROR "operand mismatch"
 	VSLI	$64, V7.D2, V8.D2                                // ERROR "shift out of range"
-	VUSRA   $0, V7.D2, V8.D2                                 // ERROR "shift out of range"
+	VUSRA	$0, V7.D2, V8.D2                                 // ERROR "shift out of range"
 	CASPD	(R3, R4), (R2), (R8, R9)                         // ERROR "source register pair must start from even register"
 	CASPD	(R2, R3), (R2), (R9, R10)                        // ERROR "destination register pair must start from even register"
 	CASPD	(R2, R4), (R2), (R8, R9)                         // ERROR "source register pair must be contiguous"
@@ -419,4 +419,17 @@ TEXT errors(SB),$0
 	ADD	R1>>2, RSP, R3                                   // ERROR "illegal combination"
 	ADDS	R2<<3, R3, RSP                                   // ERROR "unexpected SP reference"
 	CMP	R1<<5, RSP                                       // ERROR "the left shift amount out of range 0 to 4"
+	MOVD.P	y+8(FP), R1                                      // ERROR "illegal combination"
+	MOVD.W	x-8(SP), R1                                      // ERROR "illegal combination"
+	LDP.P	x+8(FP), (R0, R1)                                // ERROR "illegal combination"
+	LDP.W	x+8(SP), (R0, R1)                                // ERROR "illegal combination"
+	ADD	$0x1234567, R27, R3                              // ERROR "cannot use REGTMP as source"
+	ADD	$0x3fffffffc000, R27, R5                         // ERROR "cannot use REGTMP as source"
+	AND	$0x22220000, R27, R4                             // ERROR "cannot use REGTMP as source"
+	ANDW	$0x6006000060060, R27, R5                        // ERROR "cannot use REGTMP as source"
+	STP	(R3, R4), 0x1234567(R27)                         // ERROR "REGTMP used in large offset store"
+	LDP	0x1234567(R27), (R3, R4)                         // ERROR "REGTMP used in large offset load"
+	STP	(R26, R27), 700(R2)                              // ERROR "cannot use REGTMP as source"
+	MOVK	$0, R10                                          // ERROR "zero shifts cannot be handled correctly"
+	MOVK	$(0<<32), R10                                    // ERROR "zero shifts cannot be handled correctly"
 	RET

src/cmd/asm/internal/asm/testdata/ppc64.s

@@ -342,14 +342,14 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	NOP F2
 	NOP $4
 
-	CRAND CR1, CR2, CR3             // 4c620a02
+	CRAND CR0GT, CR0EQ, CR0SO       // 4c620a02
-	CRANDN CR1, CR2, CR3            // 4c620902
+	CRANDN CR0GT, CR0EQ, CR0SO      // 4c620902
-	CREQV CR1, CR2, CR3             // 4c620a42
+	CREQV CR0GT, CR0EQ, CR0SO       // 4c620a42
-	CRNAND CR1, CR2, CR3            // 4c6209c2
+	CRNAND CR0GT, CR0EQ, CR0SO      // 4c6209c2
-	CRNOR CR1, CR2, CR3             // 4c620842
+	CRNOR CR0GT, CR0EQ, CR0SO       // 4c620842
-	CROR CR1, CR2, CR3              // 4c620b82
+	CROR CR0GT, CR0EQ, CR0SO        // 4c620b82
-	CRORN CR1, CR2, CR3             // 4c620b42
+	CRORN CR0GT, CR0EQ, CR0SO       // 4c620b42
-	CRXOR CR1, CR2, CR3             // 4c620982
+	CRXOR CR0GT, CR0EQ, CR0SO       // 4c620982
 
 	ISEL $1, R3, R4, R5             // 7ca3205e
 	ISEL $0, R3, R4, R5             // 7ca3201e
@@ -649,6 +649,8 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	LXVB16X (R3)(R4), VS1           // 7c241ed8
 	LXVW4X (R3)(R4), VS1            // 7c241e18
 	LXV 16(R3), VS1                 // f4230011
+	LXV 16(R3), VS33                // f4230019
+	LXV 16(R3), V1                  // f4230019
 	LXVL R3, R4, VS1                // 7c23221a
 	LXVLL R3, R4, VS1               // 7c23225a
 	LXVX R3, R4, VS1                // 7c232218
@@ -668,8 +670,13 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	MTFPRD R3, F0                   // 7c030166
 	MFVRD V0, R3                    // 7c030067
 	MFVSRLD VS63,R4                 // 7fe40267
+	MFVSRLD V31,R4                  // 7fe40267
 	MFVSRWZ VS33,R4                 // 7c2400e7
+	MFVSRWZ V1,R4                   // 7c2400e7
 	MTVSRD R3, VS1                  // 7c230166
+	MTVSRDD R3, R4, VS1             // 7c232366
+	MTVSRDD R3, R4, VS33            // 7c232367
+	MTVSRDD R3, R4, V1              // 7c232367
 	MTVRD R3, V13                   // 7da30167
 	MTVSRWA R4, VS31                // 7fe401a6
 	MTVSRWS R4, VS32                // 7c040327
@@ -678,6 +685,8 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	XXBRW VS1, VS2                  // f04f0f6c
 	XXBRH VS2, VS3                  // f067176c
 	XXLAND VS1, VS2, VS3            // f0611410
+	XXLAND V1, V2, V3               // f0611417
+	XXLAND VS33, VS34, VS35         // f0611417
 	XXLANDC VS1, VS2, VS3           // f0611450
 	XXLEQV VS0, VS1, VS2            // f0400dd0
 	XXLNAND VS0, VS1, VS2           // f0400d90
@@ -687,11 +696,17 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	XXLORQ VS1, VS2, VS3            // f0611490
 	XXLXOR VS1, VS2, VS3            // f06114d0
 	XXSEL VS1, VS2, VS3, VS4        // f08110f0
+	XXSEL VS33, VS34, VS35, VS36    // f08110ff
+	XXSEL V1, V2, V3, V4            // f08110ff
 	XXMRGHW VS1, VS2, VS3           // f0611090
 	XXMRGLW VS1, VS2, VS3           // f0611190
 	XXSPLTW VS1, $1, VS2            // f0410a90
+	XXSPLTW VS33, $1, VS34          // f0410a93
+	XXSPLTW V1, $1, V2              // f0410a93
 	XXPERM VS1, VS2, VS3            // f06110d0
 	XXSLDWI VS1, VS2, $1, VS3       // f0611110
+	XXSLDWI V1, V2, $1, V3          // f0611117
+	XXSLDWI VS33, VS34, $1, VS35    // f0611117
 	XSCVDPSP VS1, VS2               // f0400c24
 	XVCVDPSP VS1, VS2               // f0400e24
 	XSCVSXDDP VS1, VS2              // f0400de0
@@ -736,4 +751,17 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	MOVD XER, R3                    // 7c6102a6
 	MOVFL CR3, CR1                  // 4c8c0000
 
+	MOVW CR0, R1			// 7c380026
+	MOVW CR7, R1			// 7c301026
+	MOVW CR, R1			// 7c200026
+
+	MOVW R1, CR			// 7c2ff120
+	MOVFL R1, CR			// 7c2ff120
+	MOVW R1, CR2			// 7c320120
+	MOVFL R1, CR2			// 7c320120
+	MOVFL R1, $255			// 7c2ff120
+	MOVFL R1, $1			// 7c301120
+	MOVFL R1, $128			// 7c380120
+	MOVFL R1, $3			// 7c203120
+
 	RET

src/cmd/asm/internal/asm/testdata/riscv64.s

@@ -10,20 +10,35 @@ start:
 
 	// 2.4: Integer Computational Instructions
 
-	ADDI	$2047, X5, X6				// 1383f27f
-	ADDI	$-2048, X5, X6				// 13830280
 	ADDI	$2047, X5				// 9382f27f
 	ADDI	$-2048, X5				// 93820280
+	ADDI	$2048, X5				// 9382024093820240
+	ADDI	$-2049, X5				// 938202c09382f2bf
+	ADDI	$4094, X5				// 9382f27f9382f27f
+	ADDI	$-4096, X5				// 9382028093820280
+	ADDI	$4095, X5				// b71f00009b8fffffb382f201
+	ADDI	$-4097, X5				// b7ffffff9b8fffffb382f201
+	ADDI	$2047, X5, X6				// 1383f27f
+	ADDI	$-2048, X5, X6				// 13830280
+	ADDI	$2048, X5, X6				// 1383024013030340
+	ADDI	$-2049, X5, X6				// 138302c01303f3bf
+	ADDI	$4094, X5, X6				// 1383f27f1303f37f
+	ADDI	$-4096, X5, X6				// 1383028013030380
+	ADDI	$4095, X5, X6				// b71f00009b8fffff3383f201
+	ADDI	$-4097, X5, X6				// b7ffffff9b8fffff3383f201
 
 	SLTI	$55, X5, X7				// 93a37203
 	SLTIU	$55, X5, X7				// 93b37203
 
 	ANDI	$1, X5, X6				// 13f31200
 	ANDI	$1, X5					// 93f21200
+	ANDI	$2048, X5				// b71f00009b8f0f80b3f2f201
 	ORI	$1, X5, X6				// 13e31200
 	ORI	$1, X5					// 93e21200
+	ORI	$2048, X5				// b71f00009b8f0f80b3e2f201
 	XORI	$1, X5, X6				// 13c31200
 	XORI	$1, X5					// 93c21200
+	XORI	$2048, X5				// b71f00009b8f0f80b3c2f201
 
 	SLLI	$1, X5, X6				// 13931200
 	SLLI	$1, X5					// 93921200
@@ -86,20 +101,15 @@ start:
 	SRA	$1, X5					// 93d21240
 
 	// 2.5: Control Transfer Instructions
-
+	JAL	X5, 2(PC)				// ef028000
-	// These jumps and branches get printed as a jump or branch
-	// to 2 because they transfer control to the second instruction
-	// in the function (the first instruction being an invisible
-	// stack pointer adjustment).
-	JAL	X5, start	// JAL	X5, 2		// eff25ff0
 	JALR	X6, (X5)				// 67830200
 	JALR	X6, 4(X5)				// 67834200
-	BEQ	X5, X6, start	// BEQ	X5, X6, 2	// e38c62ee
+	BEQ	X5, X6, 2(PC)				// 63846200
-	BNE	X5, X6, start	// BNE	X5, X6, 2	// e39a62ee
+	BNE	X5, X6, 2(PC)				// 63946200
-	BLT	X5, X6, start	// BLT	X5, X6, 2	// e3c862ee
+	BLT	X5, X6, 2(PC)				// 63c46200
-	BLTU	X5, X6, start	// BLTU	X5, X6, 2	// e3e662ee
+	BLTU	X5, X6, 2(PC)				// 63e46200
-	BGE	X5, X6, start	// BGE	X5, X6, 2	// e3d462ee
+	BGE	X5, X6, 2(PC)				// 63d46200
-	BGEU	X5, X6, start	// BGEU	X5, X6, 2	// e3f262ee
+	BGEU	X5, X6, 2(PC)				// 63f46200
 
 	// 2.6: Load and Store Instructions
 	LW	(X5), X6				// 03a30200
@@ -219,6 +229,10 @@ start:
 	FMVSX	X5, F0					// 538002f0
 	FMVXW	F0, X5					// d30200e0
 	FMVWX	X5, F0					// 538002f0
+	FMADDS	F1, F2, F3, F4				// 43822018
+	FMSUBS	F1, F2, F3, F4				// 47822018
+	FNMSUBS	F1, F2, F3, F4				// 4b822018
+	FNMADDS	F1, F2, F3, F4				// 4f822018
 
 	// 11.8: Single-Precision Floating-Point Compare Instructions
 	FEQS	F0, F1, X7				// d3a300a0
@@ -259,6 +273,10 @@ start:
 	FSGNJXD	F1, F0, F2				// 53211022
 	FMVXD	F0, X5					// d30200e2
 	FMVDX	X5, F0					// 538002f2
+	FMADDD	F1, F2, F3, F4				// 4382201a
+	FMSUBD	F1, F2, F3, F4				// 4782201a
+	FNMSUBD	F1, F2, F3, F4				// 4b82201a
+	FNMADDD	F1, F2, F3, F4				// 4f82201a
 
 	// 12.6: Double-Precision Floating-Point Classify Instruction
 	FCLASSD	F0, X5					// d31200e2
@@ -277,11 +295,17 @@ start:
 
 	// MOV pseudo-instructions
 	MOV	X5, X6					// 13830200
-	MOV	$2047, X5				// 9b02f07f
+	MOV	$2047, X5				// 9302f07f
-	MOV	$-2048, X5				// 9b020080
+	MOV	$-2048, X5				// 93020080
+	MOV	$2048, X5				// b71200009b820280
+	MOV	$-2049, X5				// b7f2ffff9b82f27f
+	MOV	$4096, X5				// b7120000
+	MOV	$2147479552, X5				// b7f2ff7f
+	MOV	$2147483647, X5				// b70200809b82f2ff
+	MOV	$-2147483647, X5			// b70200809b821200
 
-	// Converted to load of symbol.
+	// Converted to load of symbol (AUIPC + LD)
-	MOV	$4294967296, X5				// 97020000
+	MOV	$4294967296, X5				// 9702000083b20200
 
 	MOV	(X5), X6				// 03b30200
 	MOV	4(X5), X6				// 03b34200
@@ -325,42 +349,44 @@ start:
 	NEGW	X5					// bb025040
 	NEGW	X5, X6					// 3b035040
 
-	// These jumps can get printed as jumps to 2 because they go to the
+	// This jumps to the second instruction in the function (the
-	// second instruction in the function (the first instruction is an
+	// first instruction is an invisible stack pointer adjustment).
-	// invisible stack pointer adjustment).
+	JMP	start					// JMP	2
-	JMP	start		// JMP	2		// 6ff01fc2
+
+	JMP	2(PC)					// 6f008000
 	JMP	(X5)					// 67800200
 	JMP	4(X5)					// 67804200
 
-	// JMP and CALL to symbol are encoded as:
+	// CALL and JMP to symbol are encoded as JAL (using LR or ZERO
-	//	AUIPC $0, TMP
+	// respectively), with a R_RISCV_CALL relocation. The linker resolves
-	//	JALR $0, TMP
+	// the real address and updates the immediate, using a trampoline in
-	// with a R_RISCV_PCREL_ITYPE relocation - the linker resolves the
+	// the case where the address is not directly reachable.
-	// real address and updates the immediates for both instructions.
+	CALL	asmtest(SB)				// ef000000
-	CALL	asmtest(SB)				// 970f0000
+	JMP	asmtest(SB)				// 6f000000
-	JMP	asmtest(SB)				// 970f0000
 
 	// Branch pseudo-instructions
-	BEQZ	X5, start	// BEQZ	X5, 2		// e38202c0
+	BEQZ	X5, 2(PC)				// 63840200
-	BGEZ	X5, start	// BGEZ	X5, 2		// e3d002c0
+	BGEZ	X5, 2(PC)				// 63d40200
-	BGT	X5, X6, start	// BGT	X5, X6, 2	// e34e53be
+	BGT	X5, X6, 2(PC)				// 63445300
-	BGTU	X5, X6, start	// BGTU	X5, X6, 2	// e36c53be
+	BGTU	X5, X6, 2(PC)				// 63645300
-	BGTZ	X5, start	// BGTZ	X5, 2		// e34a50be
+	BGTZ	X5, 2(PC)				// 63445000
-	BLE	X5, X6, start	// BLE	X5, X6, 2	// e35853be
+	BLE	X5, X6, 2(PC)				// 63545300
-	BLEU	X5, X6, start	// BLEU	X5, X6, 2	// e37653be
+	BLEU	X5, X6, 2(PC)				// 63745300
-	BLEZ	X5, start	// BLEZ	X5, 2		// e35450be
+	BLEZ	X5, 2(PC)				// 63545000
-	BLTZ	X5, start	// BLTZ	X5, 2		// e3c202be
+	BLTZ	X5, 2(PC)				// 63c40200
-	BNEZ	X5, start	// BNEZ	X5, 2		// e39002be
+	BNEZ	X5, 2(PC)				// 63940200
 
 	// Set pseudo-instructions
 	SEQZ	X15, X15				// 93b71700
 	SNEZ	X15, X15				// b337f000
 
 	// F extension
+	FABSS	F0, F1					// d3200020
 	FNEGS	F0, F1					// d3100020
 	FNES	F0, F1, X7				// d3a300a093c31300
 
 	// D extension
+	FABSD	F0, F1					// d3200022
 	FNEGD	F0, F1					// d3100022
 	FNED	F0, F1, X5				// d3a200a293c21200
 	FLTD	F0, F1, X5				// d39200a2

src/cmd/asm/internal/asm/testdata/riscv64error.s

@@ -3,6 +3,14 @@
 // license that can be found in the LICENSE file.
 
 TEXT errors(SB),$0
+	MOV	$errors(SB), (X5)		// ERROR "address load must target register"
+	MOV	$8(SP), (X5)			// ERROR "address load must target register"
+	MOVB	$8(SP), X5			// ERROR "unsupported address load"
+	MOVH	$8(SP), X5			// ERROR "unsupported address load"
+	MOVW	$8(SP), X5			// ERROR "unsupported address load"
+	MOVF	$8(SP), X5			// ERROR "unsupported address load"
+	MOV	$1234, 0(SP)			// ERROR "constant load must target register"
+	MOV	$1234, 8(SP)			// ERROR "constant load must target register"
 	MOV	$0, 0(SP)			// ERROR "constant load must target register"
 	MOV	$0, 8(SP)			// ERROR "constant load must target register"
 	MOV	$1234, 0(SP)			// ERROR "constant load must target register"
@@ -11,4 +19,8 @@ TEXT errors(SB),$0
 	MOVH	$1, X5				// ERROR "unsupported constant load"
 	MOVW	$1, X5				// ERROR "unsupported constant load"
 	MOVF	$1, X5				// ERROR "unsupported constant load"
+	MOVBU	X5, (X6)			// ERROR "unsupported unsigned store"
+	MOVHU	X5, (X6)			// ERROR "unsupported unsigned store"
+	MOVWU	X5, (X6)			// ERROR "unsupported unsigned store"
+
 	RET

src/cmd/asm/internal/flags/flags.go

@@ -28,6 +28,10 @@ var (
 	CompilingRuntime = flag.Bool("compiling-runtime", false, "source to be compiled is part of the Go runtime")
 )
 
+var DebugFlags struct {
+	MayMoreStack string `help:"call named function before all stack growth checks"`
+}
+
 var (
 	D        MultiFlag
 	I        MultiFlag
@@ -39,6 +43,7 @@ func init() {
 	flag.Var(&D, "D", "predefined symbol with optional simple value -D=identifier=value; can be set multiple times")
 	flag.Var(&I, "I", "include directory; can be set multiple times")
 	flag.BoolVar(&DebugV, "v", false, "print debug output")
+	flag.Var(objabi.NewDebugFlag(&DebugFlags, nil), "d", "enable debugging settings; try -d help")
 	objabi.AddVersionFlag() // -V
 	objabi.Flagcount("S", "print assembly and machine code", &PrintOut)
 }

src/cmd/asm/main.go

@@ -29,19 +29,20 @@ func main() {
 	buildcfg.Check()
 	GOARCH := buildcfg.GOARCH
 
-	architecture := arch.Set(GOARCH)
+	flags.Parse()
+
+	architecture := arch.Set(GOARCH, *flags.Shared || *flags.Dynlink)
 	if architecture == nil {
 		log.Fatalf("unrecognized architecture %s", GOARCH)
 	}
 
-	flags.Parse()
-
 	ctxt := obj.Linknew(architecture.LinkArch)
 	ctxt.Debugasm = flags.PrintOut
 	ctxt.Debugvlog = flags.DebugV
 	ctxt.Flag_dynlink = *flags.Dynlink
 	ctxt.Flag_linkshared = *flags.Linkshared
 	ctxt.Flag_shared = *flags.Shared || *flags.Dynlink
+	ctxt.Flag_maymorestack = flags.DebugFlags.MayMoreStack
 	ctxt.IsAsm = true
 	ctxt.Pkgpath = *flags.Importpath
 	switch *flags.Spectre {

src/cmd/cgo/ast.go

@@ -338,8 +338,7 @@ func (f *File) walk(x interface{}, context astContext, visit func(*File, interfa
 
 	// everything else just recurs
 	default:
-		error_(token.NoPos, "unexpected type %T in walk", x)
+		f.walkUnexpected(x, context, visit)
-		panic("unexpected type")
 
 	case nil:
 

src/cmd/cgo/ast_go1.go

@@ -0,0 +1,17 @@
+// Copyright 2021 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.
+
+//go:build compiler_bootstrap
+// +build compiler_bootstrap
+
+package main
+
+import (
+	"go/token"
+)
+
+func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
+	error_(token.NoPos, "unexpected type %T in walk", x)
+	panic("unexpected type")
+}

src/cmd/cgo/ast_go118.go

@@ -0,0 +1,25 @@
+// Copyright 2021 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.
+
+//go:build !compiler_bootstrap
+// +build !compiler_bootstrap
+
+package main
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
+	switch n := x.(type) {
+	default:
+		error_(token.NoPos, "unexpected type %T in walk", x)
+		panic("unexpected type")
+
+	case *ast.IndexListExpr:
+		f.walk(&n.X, ctxExpr, visit)
+		f.walk(n.Indices, ctxExpr, visit)
+	}
+}

src/cmd/cgo/gcc.go

@@ -23,10 +23,13 @@ import (
 	"internal/xcoff"
 	"math"
 	"os"
+	"os/exec"
 	"strconv"
 	"strings"
 	"unicode"
 	"unicode/utf8"
+
+	"cmd/internal/quoted"
 )
 
 var debugDefine = flag.Bool("debug-define", false, "print relevant #defines")
@@ -382,7 +385,7 @@ func (p *Package) guessKinds(f *File) []*Name {
 		stderr = p.gccErrors(b.Bytes())
 	}
 	if stderr == "" {
-		fatalf("%s produced no output\non input:\n%s", p.gccBaseCmd()[0], b.Bytes())
+		fatalf("%s produced no output\non input:\n%s", gccBaseCmd[0], b.Bytes())
 	}
 
 	completed := false
@@ -457,7 +460,7 @@ func (p *Package) guessKinds(f *File) []*Name {
 	}
 
 	if !completed {
-		fatalf("%s did not produce error at completed:1\non input:\n%s\nfull error output:\n%s", p.gccBaseCmd()[0], b.Bytes(), stderr)
+		fatalf("%s did not produce error at completed:1\non input:\n%s\nfull error output:\n%s", gccBaseCmd[0], b.Bytes(), stderr)
 	}
 
 	for i, n := range names {
@@ -488,7 +491,7 @@ func (p *Package) guessKinds(f *File) []*Name {
 		// to users debugging preamble mistakes. See issue 8442.
 		preambleErrors := p.gccErrors([]byte(f.Preamble))
 		if len(preambleErrors) > 0 {
-			error_(token.NoPos, "\n%s errors for preamble:\n%s", p.gccBaseCmd()[0], preambleErrors)
+			error_(token.NoPos, "\n%s errors for preamble:\n%s", gccBaseCmd[0], preambleErrors)
 		}
 
 		fatalf("unresolved names")
@@ -1503,7 +1506,7 @@ func (p *Package) rewriteName(f *File, r *Ref, addPosition bool) ast.Expr {
 				Args: []ast.Expr{getNewIdent(name.Mangle)},
 			}
 		case "type":
-			// Okay - might be new(T)
+			// Okay - might be new(T), T(x), Generic[T], etc.
 			if r.Name.Type == nil {
 				error_(r.Pos(), "expression C.%s: undefined C type '%s'", fixGo(r.Name.Go), r.Name.C)
 			}
@@ -1545,20 +1548,37 @@ func gofmtPos(n ast.Expr, pos token.Pos) string {
 	return fmt.Sprintf("/*line :%d:%d*/%s", p.Line, p.Column, s)
 }
 
-// gccBaseCmd returns the start of the compiler command line.
+// checkGCCBaseCmd returns the start of the compiler command line.
 // It uses $CC if set, or else $GCC, or else the compiler recorded
 // during the initial build as defaultCC.
 // defaultCC is defined in zdefaultcc.go, written by cmd/dist.
-func (p *Package) gccBaseCmd() []string {
+//
+// The compiler command line is split into arguments on whitespace. Quotes
+// are understood, so arguments may contain whitespace.
+//
+// checkGCCBaseCmd confirms that the compiler exists in PATH, returning
+// an error if it does not.
+func checkGCCBaseCmd() ([]string, error) {
 	// Use $CC if set, since that's what the build uses.
-	if ret := strings.Fields(os.Getenv("CC")); len(ret) > 0 {
+	value := os.Getenv("CC")
-		return ret
+	if value == "" {
+		// Try $GCC if set, since that's what we used to use.
+		value = os.Getenv("GCC")
 	}
-	// Try $GCC if set, since that's what we used to use.
+	if value == "" {
-	if ret := strings.Fields(os.Getenv("GCC")); len(ret) > 0 {
+		value = defaultCC(goos, goarch)
-		return ret
 	}
-	return strings.Fields(defaultCC(goos, goarch))
+	args, err := quoted.Split(value)
+	if err != nil {
+		return nil, err
+	}
+	if len(args) == 0 {
+		return nil, errors.New("CC not set and no default found")
+	}
+	if _, err := exec.LookPath(args[0]); err != nil {
+		return nil, fmt.Errorf("C compiler %q not found: %v", args[0], err)
+	}
+	return args[:len(args):len(args)], nil
 }
 
 // gccMachine returns the gcc -m flag to use, either "-m32", "-m64" or "-marm".
@@ -1604,7 +1624,7 @@ func gccTmp() string {
 // gccCmd returns the gcc command line to use for compiling
 // the input.
 func (p *Package) gccCmd() []string {
-	c := append(p.gccBaseCmd(),
+	c := append(gccBaseCmd,
 		"-w",          // no warnings
 		"-Wno-error",  // warnings are not errors
 		"-o"+gccTmp(), // write object to tmp
@@ -2005,7 +2025,7 @@ func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int6
 // #defines that gcc encountered while processing the input
 // and its included files.
 func (p *Package) gccDefines(stdin []byte) string {
-	base := append(p.gccBaseCmd(), "-E", "-dM", "-xc")
+	base := append(gccBaseCmd, "-E", "-dM", "-xc")
 	base = append(base, p.gccMachine()...)
 	stdout, _ := runGcc(stdin, append(append(base, p.GccOptions...), "-"))
 	return stdout
@@ -2086,6 +2106,9 @@ type typeConv struct {
 	// Type names X for which there exists an XGetTypeID function with type func() CFTypeID.
 	getTypeIDs map[string]bool
 
+	// badStructs contains C structs that should be marked NotInHeap.
+	notInHeapStructs map[string]bool
+
 	// Predeclared types.
 	bool                                   ast.Expr
 	byte                                   ast.Expr // denotes padding
@@ -2097,6 +2120,7 @@ type typeConv struct {
 	string                                 ast.Expr
 	goVoid                                 ast.Expr // _Ctype_void, denotes C's void
 	goVoidPtr                              ast.Expr // unsafe.Pointer or *byte
+	goVoidPtrNoHeap                        ast.Expr // *_Ctype_void_notinheap, like goVoidPtr but marked NotInHeap
 
 	ptrSize int64
 	intSize int64
@@ -2120,6 +2144,7 @@ func (c *typeConv) Init(ptrSize, intSize int64) {
 	c.m = make(map[string]*Type)
 	c.ptrs = make(map[string][]*Type)
 	c.getTypeIDs = make(map[string]bool)
+	c.notInHeapStructs = make(map[string]bool)
 	c.bool = c.Ident("bool")
 	c.byte = c.Ident("byte")
 	c.int8 = c.Ident("int8")
@@ -2138,6 +2163,7 @@ func (c *typeConv) Init(ptrSize, intSize int64) {
 	c.void = c.Ident("void")
 	c.string = c.Ident("string")
 	c.goVoid = c.Ident("_Ctype_void")
+	c.goVoidPtrNoHeap = c.Ident("*_Ctype_void_notinheap")
 
 	// Normally cgo translates void* to unsafe.Pointer,
 	// but for historical reasons -godefs uses *byte instead.
@@ -2518,6 +2544,7 @@ func (c *typeConv) loadType(dtype dwarf.Type, pos token.Pos, parent string) *Typ
 				tt.C = &TypeRepr{"struct %s", []interface{}{tag}}
 			}
 			tt.Go = g
+			tt.NotInHeap = c.notInHeapStructs[tag]
 			typedef[name.Name] = &tt
 		}
 
@@ -2561,6 +2588,30 @@ func (c *typeConv) loadType(dtype dwarf.Type, pos token.Pos, parent string) *Typ
 				oldType.BadPointer = true
 			}
 		}
+		if c.badVoidPointerTypedef(dt) {
+			// Treat this typedef as a pointer to a NotInHeap void.
+			s := *sub
+			s.Go = c.goVoidPtrNoHeap
+			sub = &s
+			// Make sure we update any previously computed type.
+			if oldType := typedef[name.Name]; oldType != nil {
+				oldType.Go = sub.Go
+			}
+		}
+		// Check for non-pointer "struct <tag>{...}; typedef struct <tag> *<name>"
+		// typedefs that should be marked NotInHeap.
+		if ptr, ok := dt.Type.(*dwarf.PtrType); ok {
+			if strct, ok := ptr.Type.(*dwarf.StructType); ok {
+				if c.badStructPointerTypedef(dt.Name, strct) {
+					c.notInHeapStructs[strct.StructName] = true
+					// Make sure we update any previously computed type.
+					name := "_Ctype_struct_" + strct.StructName
+					if oldType := typedef[name]; oldType != nil {
+						oldType.NotInHeap = true
+					}
+				}
+			}
+		}
 		t.Go = name
 		t.BadPointer = sub.BadPointer
 		t.NotInHeap = sub.NotInHeap
@@ -3010,6 +3061,31 @@ func upper(s string) string {
 // so that all fields are exported.
 func godefsFields(fld []*ast.Field) {
 	prefix := fieldPrefix(fld)
+
+	// Issue 48396: check for duplicate field names.
+	if prefix != "" {
+		names := make(map[string]bool)
+	fldLoop:
+		for _, f := range fld {
+			for _, n := range f.Names {
+				name := n.Name
+				if name == "_" {
+					continue
+				}
+				if name != prefix {
+					name = strings.TrimPrefix(n.Name, prefix)
+				}
+				name = upper(name)
+				if names[name] {
+					// Field name conflict: don't remove prefix.
+					prefix = ""
+					break fldLoop
+				}
+				names[name] = true
+			}
+		}
+	}
+
 	npad := 0
 	for _, f := range fld {
 		for _, n := range f.Names {
@@ -3087,6 +3163,48 @@ func (c *typeConv) badPointerTypedef(dt *dwarf.TypedefType) bool {
 	return false
 }
 
+// badVoidPointerTypedef is like badPointerTypeDef, but for "void *" typedefs that should be NotInHeap.
+func (c *typeConv) badVoidPointerTypedef(dt *dwarf.TypedefType) bool {
+	// Match the Windows HANDLE type (#42018).
+	if goos != "windows" || dt.Name != "HANDLE" {
+		return false
+	}
+	// Check that the typedef is "typedef void *<name>".
+	if ptr, ok := dt.Type.(*dwarf.PtrType); ok {
+		if _, ok := ptr.Type.(*dwarf.VoidType); ok {
+			return true
+		}
+	}
+	return false
+}
+
+// badStructPointerTypedef is like badVoidPointerTypedefs but for structs.
+func (c *typeConv) badStructPointerTypedef(name string, dt *dwarf.StructType) bool {
+	// Windows handle types can all potentially contain non-pointers.
+	// badVoidPointerTypedef handles the "void *" HANDLE type, but other
+	// handles are defined as
+	//
+	// struct <name>__{int unused;}; typedef struct <name>__ *name;
+	//
+	// by the DECLARE_HANDLE macro in STRICT mode. The macro is declared in
+	// the Windows ntdef.h header,
+	//
+	// https://github.com/tpn/winsdk-10/blob/master/Include/10.0.16299.0/shared/ntdef.h#L779
+	if goos != "windows" {
+		return false
+	}
+	if len(dt.Field) != 1 {
+		return false
+	}
+	if dt.StructName != name+"__" {
+		return false
+	}
+	if f := dt.Field[0]; f.Name != "unused" || f.Type.Common().Name != "int" {
+		return false
+	}
+	return true
+}
+
 // baseBadPointerTypedef reports whether the base of a chain of typedefs is a bad typedef
 // as badPointerTypedef reports.
 func (c *typeConv) baseBadPointerTypedef(dt *dwarf.TypedefType) bool {

src/cmd/cgo/main.go

@@ -21,7 +21,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"reflect"
 	"runtime"
@@ -248,6 +247,7 @@ var importSyscall = flag.Bool("import_syscall", true, "import syscall in generat
 var trimpath = flag.String("trimpath", "", "applies supplied rewrites or trims prefixes to recorded source file paths")
 
 var goarch, goos, gomips, gomips64 string
+var gccBaseCmd []string
 
 func main() {
 	objabi.AddVersionFlag() // -V
@@ -305,10 +305,10 @@ func main() {
 	p := newPackage(args[:i])
 
 	// We need a C compiler to be available. Check this.
-	gccName := p.gccBaseCmd()[0]
+	var err error
-	_, err := exec.LookPath(gccName)
+	gccBaseCmd, err = checkGCCBaseCmd()
 	if err != nil {
-		fatalf("C compiler %q not found: %v", gccName, err)
+		fatalf("%v", err)
 		os.Exit(2)
 	}
 

src/cmd/cgo/out.go

@@ -59,9 +59,9 @@ func (p *Package) writeDefs() {
 	// Write C main file for using gcc to resolve imports.
 	fmt.Fprintf(fm, "int main() { return 0; }\n")
 	if *importRuntimeCgo {
-		fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*), void *a, int c, __SIZE_TYPE__ ctxt) { }\n")
+		fmt.Fprintf(fm, "void crosscall2(void(*fn)(void*) __attribute__((unused)), void *a __attribute__((unused)), int c __attribute__((unused)), __SIZE_TYPE__ ctxt __attribute__((unused))) { }\n")
 		fmt.Fprintf(fm, "__SIZE_TYPE__ _cgo_wait_runtime_init_done(void) { return 0; }\n")
-		fmt.Fprintf(fm, "void _cgo_release_context(__SIZE_TYPE__ ctxt) { }\n")
+		fmt.Fprintf(fm, "void _cgo_release_context(__SIZE_TYPE__ ctxt __attribute__((unused))) { }\n")
 		fmt.Fprintf(fm, "char* _cgo_topofstack(void) { return (char*)0; }\n")
 	} else {
 		// If we're not importing runtime/cgo, we *are* runtime/cgo,
@@ -70,8 +70,8 @@ func (p *Package) writeDefs() {
 		fmt.Fprintf(fm, "__SIZE_TYPE__ _cgo_wait_runtime_init_done(void);\n")
 		fmt.Fprintf(fm, "void _cgo_release_context(__SIZE_TYPE__);\n")
 	}
-	fmt.Fprintf(fm, "void _cgo_allocate(void *a, int c) { }\n")
+	fmt.Fprintf(fm, "void _cgo_allocate(void *a __attribute__((unused)), int c __attribute__((unused))) { }\n")
-	fmt.Fprintf(fm, "void _cgo_panic(void *a, int c) { }\n")
+	fmt.Fprintf(fm, "void _cgo_panic(void *a __attribute__((unused)), int c __attribute__((unused))) { }\n")
 	fmt.Fprintf(fm, "void _cgo_reginit(void) { }\n")
 
 	// Write second Go output: definitions of _C_xxx.
@@ -135,6 +135,7 @@ func (p *Package) writeDefs() {
 		fmt.Fprintf(fgo2, "%s", buf.Bytes())
 		fmt.Fprintf(fgo2, "\n\n")
 	}
+	fmt.Fprintf(fgo2, "//go:notinheap\ntype _Ctype_void_notinheap struct{}\n\n")
 	if *gccgo {
 		fmt.Fprintf(fgo2, "type _Ctype_void byte\n")
 	} else {
@@ -1054,9 +1055,10 @@ func (p *Package) writeExports(fgo2, fm, fgcc, fgcch io.Writer) {
 
 		fmt.Fprintf(fm, "void _cgoexp%s_%s(void* p){}\n", cPrefix, exp.ExpName)
 
+		fmt.Fprintf(fgo2, "\t")
+
 		if gccResult != "void" {
 			// Write results back to frame.
-			fmt.Fprintf(fgo2, "\t")
 			forFieldList(fntype.Results,
 				func(i int, aname string, atype ast.Expr) {
 					if i > 0 {
@@ -1458,10 +1460,10 @@ const gccProlog = `
   (have a negative array count) and an inscrutable error will come
   out of the compiler and hopefully mention "name".
 */
-#define __cgo_compile_assert_eq(x, y, name) typedef char name[(x-y)*(x-y)*-2+1];
+#define __cgo_compile_assert_eq(x, y, name) typedef char name[(x-y)*(x-y)*-2UL+1UL];
 
 /* Check at compile time that the sizes we use match our expectations. */
-#define __cgo_size_assert(t, n) __cgo_compile_assert_eq(sizeof(t), n, _cgo_sizeof_##t##_is_not_##n)
+#define __cgo_size_assert(t, n) __cgo_compile_assert_eq(sizeof(t), (size_t)n, _cgo_sizeof_##t##_is_not_##n)
 
 __cgo_size_assert(char, 1)
 __cgo_size_assert(short, 2)

src/cmd/compile/abi-internal.md

@@ -627,6 +627,105 @@ modifying or saving the FPCR.
 Functions are allowed to modify it between calls (as long as they
 restore it), but as of this writing Go code never does.
 
+### ppc64 architecture
+
+The ppc64 architecture uses R3 – R10 and R14 – R17 for integer arguments
+and results.
+
+It uses F1 – F12 for floating-point arguments and results.
+
+Register R31 is a permanent scratch register in Go.
+
+Special-purpose registers used within Go generated code and Go
+assembly code are as follows:
+
+| Register | Call meaning | Return meaning | Body meaning |
+| --- | --- | --- | --- |
+| R0  | Zero value | Same | Same |
+| R1  | Stack pointer | Same | Same |
+| R2  | TOC register | Same | Same |
+| R11 | Closure context pointer | Scratch | Scratch |
+| R12 | Function address on indirect calls | Scratch | Scratch |
+| R13 | TLS pointer | Same | Same |
+| R20,R21 | Scratch | Scratch | Used by duffcopy, duffzero |
+| R30 | Current goroutine | Same | Same |
+| R31 | Scratch | Scratch | Scratch |
+| LR  | Link register | Link register | Scratch |
+*Rationale*: These register meanings are compatible with Go’s
+stack-based calling convention.
+
+The link register, LR, holds the function return
+address at the function entry and is set to the correct return
+address before exiting the function. It is also used
+in some cases as the function address when doing an indirect call.
+
+The register R2 contains the address of the TOC (table of contents) which
+contains data or code addresses used when generating position independent
+code. Non-Go code generated when using cgo contains TOC-relative addresses
+which depend on R2 holding a valid TOC. Go code compiled with -shared or
+-dynlink initializes and maintains R2 and uses it in some cases for
+function calls; Go code compiled without these options does not modify R2.
+
+When making a function call R12 contains the function address for use by the
+code to generate R2 at the beginning of the function. R12 can be used for
+other purposes within the body of the function, such as trampoline generation.
+
+R20 and R21 are used in duffcopy and duffzero which could be generated
+before arguments are saved so should not be used for register arguments.
+
+The Count register CTR can be used as the call target for some branch instructions.
+It holds the return address when preemption has occurred.
+
+On PPC64 when a float32 is loaded it becomes a float64 in the register, which is
+different from other platforms and that needs to be recognized by the internal
+implementation of reflection so that float32 arguments are passed correctly.
+
+Registers R18 - R29 and F13 - F31 are considered scratch registers.
+
+#### Stack layout
+
+The stack pointer, R1, grows down and is aligned to 8 bytes in Go, but changed
+to 16 bytes when calling cgo.
+
+A function's stack frame, after the frame is created, is laid out as
+follows:
+
+    +------------------------------+
+    | ... locals ...               |
+    | ... outgoing arguments ...   |
+    | 24  TOC register R2 save     | When compiled with -shared/-dynlink
+    | 16  Unused in Go             | Not used in Go
+    |  8  CR save                  | nonvolatile CR fields
+    |  0  return PC                | ← R1 points to
+    +------------------------------+ ↓ lower addresses
+
+The "return PC" is loaded to the link register, LR, as part of the
+ppc64 `BL` operations.
+
+On entry to a non-leaf function, the stack frame size is subtracted from R1 to
+create its stack frame, and saves the value of LR at the bottom of the frame.
+
+A leaf function that does not require any stack space does not modify R1 and
+does not save LR.
+
+*NOTE*: We might need to save the frame pointer on the stack as
+in the PPC64 ELF v2 ABI so Go can inter-operate with platform debuggers
+and profilers.
+
+This stack layout is used by both register-based (ABIInternal) and
+stack-based (ABI0) calling conventions.
+
+#### Flags
+
+The condition register consists of 8 condition code register fields
+CR0-CR7. Go generated code only sets and uses CR0, commonly set by
+compare functions and use to determine the target of a conditional
+branch. The generated code does not set or use CR1-CR7.
+
+The floating point status and control register (FPSCR) is initialized
+to 0 by the kernel at startup of the Go program and not changed by
+the Go generated code.
+
 ## Future directions
 
 ### Spill path improvements

src/cmd/compile/doc.go

@@ -44,6 +44,8 @@ Flags:
 		Print compiler version and exit.
 	-asmhdr file
 		Write assembly header to file.
+	-asan
+		Insert calls to C/C++ address sanitizer.
 	-buildid id
 		Record id as the build id in the export metadata.
 	-blockprofile file

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

@@ -144,7 +144,7 @@ func (pa *ABIParamAssignment) RegisterTypesAndOffsets() ([]*types.Type, []int64)
 }
 
 func appendParamTypes(rts []*types.Type, t *types.Type) []*types.Type {
-	w := t.Width
+	w := t.Size()
 	if w == 0 {
 		return rts
 	}
@@ -193,12 +193,12 @@ func appendParamTypes(rts []*types.Type, t *types.Type) []*types.Type {
 // to input offsets, and returns the longer slice and the next unused offset.
 func appendParamOffsets(offsets []int64, at int64, t *types.Type) ([]int64, int64) {
 	at = align(at, t)
-	w := t.Width
+	w := t.Size()
 	if w == 0 {
 		return offsets, at
 	}
 	if t.IsScalar() || t.IsPtrShaped() {
-		if t.IsComplex() || int(t.Width) > types.RegSize { // complex and *int64 on 32-bit
+		if t.IsComplex() || int(t.Size()) > types.RegSize { // complex and *int64 on 32-bit
 			s := w / 2
 			return append(offsets, at, at+s), at + w
 		} else {
@@ -214,7 +214,7 @@ func appendParamOffsets(offsets []int64, at int64, t *types.Type) ([]int64, int6
 		case types.TSTRUCT:
 			for i, f := range t.FieldSlice() {
 				offsets, at = appendParamOffsets(offsets, at, f.Type)
-				if f.Type.Width == 0 && i == t.NumFields()-1 {
+				if f.Type.Size() == 0 && i == t.NumFields()-1 {
 					at++ // last field has zero width
 				}
 			}
@@ -531,7 +531,7 @@ type assignState struct {
 
 // align returns a rounded up to t's alignment
 func align(a int64, t *types.Type) int64 {
-	return alignTo(a, int(t.Align))
+	return alignTo(a, int(uint8(t.Alignment())))
 }
 
 // alignTo returns a rounded up to t, where t must be 0 or a power of 2.
@@ -546,7 +546,7 @@ func alignTo(a int64, t int) int64 {
 // specified type.
 func (state *assignState) stackSlot(t *types.Type) int64 {
 	rv := align(state.stackOffset, t)
-	state.stackOffset = rv + t.Width
+	state.stackOffset = rv + t.Size()
 	return rv
 }
 
@@ -554,7 +554,7 @@ func (state *assignState) stackSlot(t *types.Type) int64 {
 // that we've just determined to be register-assignable. The number of registers
 // needed is assumed to be stored in state.pUsed.
 func (state *assignState) allocateRegs(regs []RegIndex, t *types.Type) []RegIndex {
-	if t.Width == 0 {
+	if t.Size() == 0 {
 		return regs
 	}
 	ri := state.rUsed.intRegs
@@ -647,7 +647,7 @@ func (state *assignState) floatUsed() int {
 // can register allocate, FALSE otherwise (and updates state
 // accordingly).
 func (state *assignState) regassignIntegral(t *types.Type) bool {
-	regsNeeded := int(types.Rnd(t.Width, int64(types.PtrSize)) / int64(types.PtrSize))
+	regsNeeded := int(types.Rnd(t.Size(), int64(types.PtrSize)) / int64(types.PtrSize))
 	if t.IsComplex() {
 		regsNeeded = 2
 	}
@@ -722,14 +722,17 @@ func setup() {
 			types.NewField(nxp, fname("len"), ui),
 			types.NewField(nxp, fname("cap"), ui),
 		})
+		types.CalcStructSize(synthSlice)
 		synthString = types.NewStruct(types.NoPkg, []*types.Field{
 			types.NewField(nxp, fname("data"), unsp),
 			types.NewField(nxp, fname("len"), ui),
 		})
+		types.CalcStructSize(synthString)
 		synthIface = types.NewStruct(types.NoPkg, []*types.Field{
 			types.NewField(nxp, fname("f1"), unsp),
 			types.NewField(nxp, fname("f2"), unsp),
 		})
+		types.CalcStructSize(synthIface)
 	})
 }
 
@@ -764,10 +767,10 @@ func (state *assignState) regassign(pt *types.Type) bool {
 // ABIParamResultInfo held in 'state'.
 func (state *assignState) assignParamOrReturn(pt *types.Type, n types.Object, isReturn bool) ABIParamAssignment {
 	state.pUsed = RegAmounts{}
-	if pt.Width == types.BADWIDTH {
+	if pt.Size() == types.BADWIDTH {
 		base.Fatalf("should never happen")
 		panic("unreachable")
-	} else if pt.Width == 0 {
+	} else if pt.Size() == 0 {
 		return state.stackAllocate(pt, n)
 	} else if state.regassign(pt) {
 		return state.regAllocate(pt, n, isReturn)
@@ -777,11 +780,11 @@ func (state *assignState) assignParamOrReturn(pt *types.Type, n types.Object, is
 }
 
 // ComputePadding returns a list of "post element" padding values in
-// the case where we have a structure being passed in registers. Give
+// the case where we have a structure being passed in registers. Given
-// a param assignment corresponding to a struct, it returns a list of
+// a param assignment corresponding to a struct, it returns a list
-// contaning padding values for each field, e.g. the Kth element in
+// containing padding values for each field, e.g. the Kth element in
 // the list is the amount of padding between field K and the following
-// field. For things that are not struct (or structs without padding)
+// field. For things that are not structs (or structs without padding)
 // it returns a list of zeros. Example:
 //
 // type small struct {
@@ -793,8 +796,8 @@ func (state *assignState) assignParamOrReturn(pt *types.Type, n types.Object, is
 //
 // For this struct we would return a list [0, 1, 0, 0], meaning that
 // we have one byte of padding after the second field, and no bytes of
-// padding after any of the other fields. Input parameter "storage"
+// padding after any of the other fields. Input parameter "storage" is
-// is with enough capacity to accommodate padding elements for
+// a slice with enough capacity to accommodate padding elements for
 // the architected register set in question.
 func (pa *ABIParamAssignment) ComputePadding(storage []uint64) []uint64 {
 	nr := len(pa.Registers)

src/cmd/compile/internal/amd64/ssa.go

@@ -263,6 +263,24 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Reg = lo
 		p.SetFrom3Reg(hi)
 
+	case ssa.OpAMD64BLSIQ, ssa.OpAMD64BLSIL,
+		ssa.OpAMD64BLSMSKQ, ssa.OpAMD64BLSMSKL,
+		ssa.OpAMD64BLSRQ, ssa.OpAMD64BLSRL,
+		ssa.OpAMD64TZCNTQ, ssa.OpAMD64TZCNTL:
+		p := s.Prog(v.Op.Asm())
+		p.From.Type = obj.TYPE_REG
+		p.From.Reg = v.Args[0].Reg()
+		p.To.Type = obj.TYPE_REG
+		p.To.Reg = v.Reg()
+
+	case ssa.OpAMD64ANDNQ, ssa.OpAMD64ANDNL:
+		p := s.Prog(v.Op.Asm())
+		p.From.Type = obj.TYPE_REG
+		p.From.Reg = v.Args[0].Reg()
+		p.To.Type = obj.TYPE_REG
+		p.To.Reg = v.Reg()
+		p.SetFrom3Reg(v.Args[1].Reg())
+
 	case ssa.OpAMD64DIVQU, ssa.OpAMD64DIVLU, ssa.OpAMD64DIVWU:
 		// Arg[0] (the dividend) is in AX.
 		// Arg[1] (the divisor) can be in any other register.
@@ -600,8 +618,21 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Reg = r
 		p.SetFrom3Reg(v.Args[0].Reg())
 
+	case ssa.OpAMD64ANDQconst:
+		asm := v.Op.Asm()
+		// If the constant is positive and fits into 32 bits, use ANDL.
+		// This saves a few bytes of encoding.
+		if 0 <= v.AuxInt && v.AuxInt <= (1<<32-1) {
+			asm = x86.AANDL
+		}
+		p := s.Prog(asm)
+		p.From.Type = obj.TYPE_CONST
+		p.From.Offset = v.AuxInt
+		p.To.Type = obj.TYPE_REG
+		p.To.Reg = v.Reg()
+
 	case ssa.OpAMD64SUBQconst, ssa.OpAMD64SUBLconst,
-		ssa.OpAMD64ANDQconst, ssa.OpAMD64ANDLconst,
+		ssa.OpAMD64ANDLconst,
 		ssa.OpAMD64ORQconst, ssa.OpAMD64ORLconst,
 		ssa.OpAMD64XORQconst, ssa.OpAMD64XORLconst,
 		ssa.OpAMD64SHLQconst, ssa.OpAMD64SHLLconst,
@@ -741,7 +772,9 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Val = math.Float64frombits(uint64(v.AuxInt))
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = x
-	case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload, ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVWQSXload, ssa.OpAMD64MOVLQSXload, ssa.OpAMD64MOVOload:
+	case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload, ssa.OpAMD64MOVOload,
+		ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVWQSXload, ssa.OpAMD64MOVLQSXload,
+		ssa.OpAMD64MOVBEQload, ssa.OpAMD64MOVBELload:
 		p := s.Prog(v.Op.Asm())
 		p.From.Type = obj.TYPE_MEM
 		p.From.Reg = v.Args[0].Reg()
@@ -757,7 +790,8 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Reg = v.Reg()
 	case ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore, ssa.OpAMD64MOVOstore,
 		ssa.OpAMD64ADDQmodify, ssa.OpAMD64SUBQmodify, ssa.OpAMD64ANDQmodify, ssa.OpAMD64ORQmodify, ssa.OpAMD64XORQmodify,
-		ssa.OpAMD64ADDLmodify, ssa.OpAMD64SUBLmodify, ssa.OpAMD64ANDLmodify, ssa.OpAMD64ORLmodify, ssa.OpAMD64XORLmodify:
+		ssa.OpAMD64ADDLmodify, ssa.OpAMD64SUBLmodify, ssa.OpAMD64ANDLmodify, ssa.OpAMD64ORLmodify, ssa.OpAMD64XORLmodify,
+		ssa.OpAMD64MOVBEQstore, ssa.OpAMD64MOVBELstore:
 		p := s.Prog(v.Op.Asm())
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = v.Args[1].Reg()
@@ -822,7 +856,12 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Type = obj.TYPE_MEM
 		p.To.Reg = v.Args[0].Reg()
 		ssagen.AddAux2(&p.To, v, sc.Off64())
-	case ssa.OpAMD64MOVOstorezero:
+	case ssa.OpAMD64MOVOstoreconst:
+		sc := v.AuxValAndOff()
+		if sc.Val() != 0 {
+			v.Fatalf("MOVO for non zero constants not implemented: %s", v.LongString())
+		}
+
 		if s.ABI != obj.ABIInternal {
 			// zero X15 manually
 			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
@@ -832,7 +871,8 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Reg = x86.REG_X15
 		p.To.Type = obj.TYPE_MEM
 		p.To.Reg = v.Args[0].Reg()
-		ssagen.AddAux(&p.To, v)
+		ssagen.AddAux2(&p.To, v, sc.Off64())
+
 	case ssa.OpAMD64MOVQstoreconstidx1, ssa.OpAMD64MOVQstoreconstidx8, ssa.OpAMD64MOVLstoreconstidx1, ssa.OpAMD64MOVLstoreconstidx4, ssa.OpAMD64MOVWstoreconstidx1, ssa.OpAMD64MOVWstoreconstidx2, ssa.OpAMD64MOVBstoreconstidx1,
 		ssa.OpAMD64ADDLconstmodifyidx1, ssa.OpAMD64ADDLconstmodifyidx4, ssa.OpAMD64ADDLconstmodifyidx8, ssa.OpAMD64ADDQconstmodifyidx1, ssa.OpAMD64ADDQconstmodifyidx8,
 		ssa.OpAMD64ANDLconstmodifyidx1, ssa.OpAMD64ANDLconstmodifyidx4, ssa.OpAMD64ANDLconstmodifyidx8, ssa.OpAMD64ANDQconstmodifyidx1, ssa.OpAMD64ANDQconstmodifyidx8,
@@ -1002,7 +1042,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		}
 		r := v.Reg()
 		getgFromTLS(s, r)
-	case ssa.OpAMD64CALLstatic:
+	case ssa.OpAMD64CALLstatic, ssa.OpAMD64CALLtail:
 		if s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
 			// zeroing X15 when entering ABIInternal from ABI0
 			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
@@ -1011,6 +1051,10 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
+		if v.Op == ssa.OpAMD64CALLtail {
+			s.TailCall(v)
+			break
+		}
 		s.Call(v)
 		if s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
 			// zeroing X15 when entering ABIInternal from ABI0
@@ -1097,7 +1141,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		if v.Args[0].Reg() != v.Reg() {
 			// POPCNT on Intel has a false dependency on the destination register.
 			// Xor register with itself to break the dependency.
-			p := s.Prog(x86.AXORQ)
+			p := s.Prog(x86.AXORL)
 			p.From.Type = obj.TYPE_REG
 			p.From.Reg = v.Reg()
 			p.To.Type = obj.TYPE_REG
@@ -1225,6 +1269,10 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Type = obj.TYPE_MEM
 		p.To.Reg = v.Args[0].Reg()
 		ssagen.AddAux(&p.To, v)
+	case ssa.OpAMD64PrefetchT0, ssa.OpAMD64PrefetchNTA:
+		p := s.Prog(v.Op.Asm())
+		p.From.Type = obj.TYPE_MEM
+		p.From.Reg = v.Args[0].Reg()
 	case ssa.OpClobber:
 		p := s.Prog(x86.AMOVL)
 		p.From.Type = obj.TYPE_CONST
@@ -1304,22 +1352,9 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 			p.To.Type = obj.TYPE_BRANCH
 			s.Branches = append(s.Branches, ssagen.Branch{P: p, B: b.Succs[0].Block()})
 		}
-	case ssa.BlockExit:
+	case ssa.BlockExit, ssa.BlockRetJmp:
 	case ssa.BlockRet:
 		s.Prog(obj.ARET)
-	case ssa.BlockRetJmp:
-		if s.ABI == obj.ABI0 && b.Aux.(*obj.LSym).ABI() == obj.ABIInternal {
-			// zeroing X15 when entering ABIInternal from ABI0
-			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
-				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
-			}
-			// set G register from TLS
-			getgFromTLS(s, x86.REG_R14)
-		}
-		p := s.Prog(obj.ARET)
-		p.To.Type = obj.TYPE_MEM
-		p.To.Name = obj.NAME_EXTERN
-		p.To.Sym = b.Aux.(*obj.LSym)
 
 	case ssa.BlockAMD64EQF:
 		s.CombJump(b, next, &eqfJumps)

src/cmd/compile/internal/amd64/versions_test.go

@@ -0,0 +1,383 @@
+// Copyright 2021 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 amd64_test
+
+import (
+	"bufio"
+	"debug/elf"
+	"debug/macho"
+	"fmt"
+	"internal/testenv"
+	"io"
+	"math"
+	"math/bits"
+	"os"
+	"os/exec"
+	"regexp"
+	"runtime"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+// Test to make sure that when building for GOAMD64=v1, we don't
+// use any >v1 instructions.
+func TestGoAMD64v1(t *testing.T) {
+	if runtime.GOARCH != "amd64" {
+		t.Skip("amd64-only test")
+	}
+	if runtime.GOOS != "linux" && runtime.GOOS != "darwin" {
+		t.Skip("test only works on elf or macho platforms")
+	}
+	if v := os.Getenv("GOAMD64"); v != "" && v != "v1" {
+		// Test runs only on v1 (which is the default).
+		// TODO: use build tags from #45454 instead.
+		t.Skip("GOAMD64 already set")
+	}
+	if os.Getenv("TESTGOAMD64V1") != "" {
+		t.Skip("recursive call")
+	}
+
+	// Make a binary which will be a modified version of the
+	// currently running binary.
+	dst, err := os.CreateTemp("", "TestGoAMD64v1")
+	if err != nil {
+		t.Fatalf("failed to create temp file: %v", err)
+	}
+	defer os.Remove(dst.Name())
+	dst.Chmod(0500) // make executable
+
+	// Clobber all the non-v1 opcodes.
+	opcodes := map[string]bool{}
+	var features []string
+	for feature, opcodeList := range featureToOpcodes {
+		if runtimeFeatures[feature] {
+			features = append(features, fmt.Sprintf("cpu.%s=off", feature))
+		}
+		for _, op := range opcodeList {
+			opcodes[op] = true
+		}
+	}
+	clobber(t, os.Args[0], dst, opcodes)
+	if err = dst.Close(); err != nil {
+		t.Fatalf("can't close binary: %v", err)
+	}
+
+	// Run the resulting binary.
+	cmd := exec.Command(dst.Name())
+	testenv.CleanCmdEnv(cmd)
+	cmd.Env = append(cmd.Env, "TESTGOAMD64V1=yes")
+	cmd.Env = append(cmd.Env, fmt.Sprintf("GODEBUG=%s", strings.Join(features, ",")))
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("couldn't execute test: %s", err)
+	}
+	if string(out) != "PASS\n" {
+		t.Fatalf("test reported error: %s", string(out))
+	}
+}
+
+// Clobber copies the binary src to dst, replacing all the instructions in opcodes with
+// faulting instructions.
+func clobber(t *testing.T, src string, dst *os.File, opcodes map[string]bool) {
+	// Run objdump to get disassembly.
+	var re *regexp.Regexp
+	var disasm io.Reader
+	if false {
+		// TODO: go tool objdump doesn't disassemble the bmi1 instructions
+		// in question correctly. See issue 48584.
+		cmd := exec.Command("go", "tool", "objdump", src)
+		var err error
+		disasm, err = cmd.StdoutPipe()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := cmd.Start(); err != nil {
+			t.Fatal(err)
+		}
+		re = regexp.MustCompile(`^[^:]*:[-0-9]+\s+0x([0-9a-f]+)\s+([0-9a-f]+)\s+([A-Z]+)`)
+	} else {
+		// TODO: we're depending on platform-native objdump here. Hence the Skipf
+		// below if it doesn't run for some reason.
+		cmd := exec.Command("objdump", "-d", src)
+		var err error
+		disasm, err = cmd.StdoutPipe()
+		if err != nil {
+			t.Skipf("can't run test due to missing objdump: %s", err)
+		}
+		if err := cmd.Start(); err != nil {
+			t.Fatal(err)
+		}
+		re = regexp.MustCompile(`^\s*([0-9a-f]+):\s*((?:[0-9a-f][0-9a-f] )+)\s*([a-z0-9]+)`)
+	}
+
+	// Find all the instruction addresses we need to edit.
+	virtualEdits := map[uint64]bool{}
+	scanner := bufio.NewScanner(disasm)
+	for scanner.Scan() {
+		line := scanner.Text()
+		parts := re.FindStringSubmatch(line)
+		if len(parts) == 0 {
+			continue
+		}
+		addr, err := strconv.ParseUint(parts[1], 16, 64)
+		if err != nil {
+			continue // not a hex address
+		}
+		opcode := strings.ToLower(parts[3])
+		if !opcodes[opcode] {
+			continue
+		}
+		t.Logf("clobbering instruction %s", line)
+		n := (len(parts[2]) - strings.Count(parts[2], " ")) / 2 // number of bytes in instruction encoding
+		for i := 0; i < n; i++ {
+			// Only really need to make the first byte faulting, but might
+			// as well make all the bytes faulting.
+			virtualEdits[addr+uint64(i)] = true
+		}
+	}
+
+	// Figure out where in the binary the edits must be done.
+	physicalEdits := map[uint64]bool{}
+	if e, err := elf.Open(src); err == nil {
+		for _, sec := range e.Sections {
+			vaddr := sec.Addr
+			paddr := sec.Offset
+			size := sec.Size
+			for a := range virtualEdits {
+				if a >= vaddr && a < vaddr+size {
+					physicalEdits[paddr+(a-vaddr)] = true
+				}
+			}
+		}
+	} else if m, err2 := macho.Open(src); err2 == nil {
+		for _, sec := range m.Sections {
+			vaddr := sec.Addr
+			paddr := uint64(sec.Offset)
+			size := sec.Size
+			for a := range virtualEdits {
+				if a >= vaddr && a < vaddr+size {
+					physicalEdits[paddr+(a-vaddr)] = true
+				}
+			}
+		}
+	} else {
+		t.Log(err)
+		t.Log(err2)
+		t.Fatal("executable format not elf or macho")
+	}
+	if len(virtualEdits) != len(physicalEdits) {
+		t.Fatal("couldn't find an instruction in text sections")
+	}
+
+	// Copy source to destination, making edits along the way.
+	f, err := os.Open(src)
+	if err != nil {
+		t.Fatal(err)
+	}
+	r := bufio.NewReader(f)
+	w := bufio.NewWriter(dst)
+	a := uint64(0)
+	done := 0
+	for {
+		b, err := r.ReadByte()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatal("can't read")
+		}
+		if physicalEdits[a] {
+			b = 0xcc // INT3 opcode
+			done++
+		}
+		err = w.WriteByte(b)
+		if err != nil {
+			t.Fatal("can't write")
+		}
+		a++
+	}
+	if done != len(physicalEdits) {
+		t.Fatal("physical edits remaining")
+	}
+	w.Flush()
+	f.Close()
+}
+
+func setOf(keys ...string) map[string]bool {
+	m := make(map[string]bool, len(keys))
+	for _, key := range keys {
+		m[key] = true
+	}
+	return m
+}
+
+var runtimeFeatures = setOf(
+	"adx", "aes", "avx", "avx2", "bmi1", "bmi2", "erms", "fma",
+	"pclmulqdq", "popcnt", "rdtscp", "sse3", "sse41", "sse42", "ssse3",
+)
+
+var featureToOpcodes = map[string][]string{
+	// Note: we include *q, *l, and plain opcodes here.
+	// go tool objdump doesn't include a [QL] on popcnt instructions, until CL 351889
+	// native objdump doesn't include [QL] on linux.
+	"popcnt": {"popcntq", "popcntl", "popcnt"},
+	"bmi1":   {"andnq", "andnl", "andn", "blsiq", "blsil", "blsi", "blsmskq", "blsmskl", "blsmsk", "blsrq", "blsrl", "blsr", "tzcntq", "tzcntl", "tzcnt"},
+	"sse41":  {"roundsd"},
+	"fma":    {"vfmadd231sd"},
+	"movbe":  {"movbeqq", "movbeq", "movbell", "movbel", "movbe"},
+}
+
+// Test to use POPCNT instruction, if available
+func TestPopCnt(t *testing.T) {
+	for _, tt := range []struct {
+		x    uint64
+		want int
+	}{
+		{0b00001111, 4},
+		{0b00001110, 3},
+		{0b00001100, 2},
+		{0b00000000, 0},
+	} {
+		if got := bits.OnesCount64(tt.x); got != tt.want {
+			t.Errorf("OnesCount64(%#x) = %d, want %d", tt.x, got, tt.want)
+		}
+		if got := bits.OnesCount32(uint32(tt.x)); got != tt.want {
+			t.Errorf("OnesCount32(%#x) = %d, want %d", tt.x, got, tt.want)
+		}
+	}
+}
+
+// Test to use ANDN, if available
+func TestAndNot(t *testing.T) {
+	for _, tt := range []struct {
+		x, y, want uint64
+	}{
+		{0b00001111, 0b00000011, 0b1100},
+		{0b00001111, 0b00001100, 0b0011},
+		{0b00000000, 0b00000000, 0b0000},
+	} {
+		if got := tt.x &^ tt.y; got != tt.want {
+			t.Errorf("%#x &^ %#x = %#x, want %#x", tt.x, tt.y, got, tt.want)
+		}
+		if got := uint32(tt.x) &^ uint32(tt.y); got != uint32(tt.want) {
+			t.Errorf("%#x &^ %#x = %#x, want %#x", tt.x, tt.y, got, tt.want)
+		}
+	}
+}
+
+// Test to use BLSI, if available
+func TestBLSI(t *testing.T) {
+	for _, tt := range []struct {
+		x, want uint64
+	}{
+		{0b00001111, 0b001},
+		{0b00001110, 0b010},
+		{0b00001100, 0b100},
+		{0b11000110, 0b010},
+		{0b00000000, 0b000},
+	} {
+		if got := tt.x & -tt.x; got != tt.want {
+			t.Errorf("%#x & (-%#x) = %#x, want %#x", tt.x, tt.x, got, tt.want)
+		}
+		if got := uint32(tt.x) & -uint32(tt.x); got != uint32(tt.want) {
+			t.Errorf("%#x & (-%#x) = %#x, want %#x", tt.x, tt.x, got, tt.want)
+		}
+	}
+}
+
+// Test to use BLSMSK, if available
+func TestBLSMSK(t *testing.T) {
+	for _, tt := range []struct {
+		x, want uint64
+	}{
+		{0b00001111, 0b001},
+		{0b00001110, 0b011},
+		{0b00001100, 0b111},
+		{0b11000110, 0b011},
+		{0b00000000, 1<<64 - 1},
+	} {
+		if got := tt.x ^ (tt.x - 1); got != tt.want {
+			t.Errorf("%#x ^ (%#x-1) = %#x, want %#x", tt.x, tt.x, got, tt.want)
+		}
+		if got := uint32(tt.x) ^ (uint32(tt.x) - 1); got != uint32(tt.want) {
+			t.Errorf("%#x ^ (%#x-1) = %#x, want %#x", tt.x, tt.x, got, uint32(tt.want))
+		}
+	}
+}
+
+// Test to use BLSR, if available
+func TestBLSR(t *testing.T) {
+	for _, tt := range []struct {
+		x, want uint64
+	}{
+		{0b00001111, 0b00001110},
+		{0b00001110, 0b00001100},
+		{0b00001100, 0b00001000},
+		{0b11000110, 0b11000100},
+		{0b00000000, 0b00000000},
+	} {
+		if got := tt.x & (tt.x - 1); got != tt.want {
+			t.Errorf("%#x & (%#x-1) = %#x, want %#x", tt.x, tt.x, got, tt.want)
+		}
+		if got := uint32(tt.x) & (uint32(tt.x) - 1); got != uint32(tt.want) {
+			t.Errorf("%#x & (%#x-1) = %#x, want %#x", tt.x, tt.x, got, tt.want)
+		}
+	}
+}
+
+func TestTrailingZeros(t *testing.T) {
+	for _, tt := range []struct {
+		x    uint64
+		want int
+	}{
+		{0b00001111, 0},
+		{0b00001110, 1},
+		{0b00001100, 2},
+		{0b00001000, 3},
+		{0b00000000, 64},
+	} {
+		if got := bits.TrailingZeros64(tt.x); got != tt.want {
+			t.Errorf("TrailingZeros64(%#x) = %d, want %d", tt.x, got, tt.want)
+		}
+		want := tt.want
+		if want == 64 {
+			want = 32
+		}
+		if got := bits.TrailingZeros32(uint32(tt.x)); got != want {
+			t.Errorf("TrailingZeros64(%#x) = %d, want %d", tt.x, got, want)
+		}
+	}
+}
+
+func TestRound(t *testing.T) {
+	for _, tt := range []struct {
+		x, want float64
+	}{
+		{1.4, 1},
+		{1.5, 2},
+		{1.6, 2},
+		{2.4, 2},
+		{2.5, 2},
+		{2.6, 3},
+	} {
+		if got := math.RoundToEven(tt.x); got != tt.want {
+			t.Errorf("RoundToEven(%f) = %f, want %f", tt.x, got, tt.want)
+		}
+	}
+}
+
+func TestFMA(t *testing.T) {
+	for _, tt := range []struct {
+		x, y, z, want float64
+	}{
+		{2, 3, 4, 10},
+		{3, 4, 5, 17},
+	} {
+		if got := math.FMA(tt.x, tt.y, tt.z); got != tt.want {
+			t.Errorf("FMA(%f,%f,%f) = %f, want %f", tt.x, tt.y, tt.z, got, tt.want)
+		}
+	}
+}

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

@@ -88,15 +88,18 @@ func (v shift) String() string {
 }
 
 // makeshift encodes a register shifted by a constant
-func makeshift(reg int16, typ int64, s int64) shift {
+func makeshift(v *ssa.Value, reg int16, typ int64, s int64) shift {
+	if s < 0 || s >= 32 {
+		v.Fatalf("shift out of range: %d", s)
+	}
 	return shift(int64(reg&0xf) | typ | (s&31)<<7)
 }
 
 // genshift generates a Prog for r = r0 op (r1 shifted by n)
-func genshift(s *ssagen.State, as obj.As, r0, r1, r int16, typ int64, n int64) *obj.Prog {
+func genshift(s *ssagen.State, v *ssa.Value, as obj.As, r0, r1, r int16, typ int64, n int64) *obj.Prog {
 	p := s.Prog(as)
 	p.From.Type = obj.TYPE_SHIFT
-	p.From.Offset = int64(makeshift(r1, typ, n))
+	p.From.Offset = int64(makeshift(v, r1, typ, n))
 	p.Reg = r0
 	if r != 0 {
 		p.To.Type = obj.TYPE_REG
@@ -335,7 +338,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = v.Reg0()
 	case ssa.OpARMSRRconst:
-		genshift(s, arm.AMOVW, 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_RR, v.AuxInt)
+		genshift(s, v, arm.AMOVW, 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_RR, v.AuxInt)
 	case ssa.OpARMADDshiftLL,
 		ssa.OpARMADCshiftLL,
 		ssa.OpARMSUBshiftLL,
@@ -346,11 +349,11 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		ssa.OpARMORshiftLL,
 		ssa.OpARMXORshiftLL,
 		ssa.OpARMBICshiftLL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_LL, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_LL, v.AuxInt)
 	case ssa.OpARMADDSshiftLL,
 		ssa.OpARMSUBSshiftLL,
 		ssa.OpARMRSBSshiftLL:
-		p := genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg0(), arm.SHIFT_LL, v.AuxInt)
+		p := genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg0(), arm.SHIFT_LL, v.AuxInt)
 		p.Scond = arm.C_SBIT
 	case ssa.OpARMADDshiftRL,
 		ssa.OpARMADCshiftRL,
@@ -362,11 +365,11 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		ssa.OpARMORshiftRL,
 		ssa.OpARMXORshiftRL,
 		ssa.OpARMBICshiftRL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_LR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_LR, v.AuxInt)
 	case ssa.OpARMADDSshiftRL,
 		ssa.OpARMSUBSshiftRL,
 		ssa.OpARMRSBSshiftRL:
-		p := genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg0(), arm.SHIFT_LR, v.AuxInt)
+		p := genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg0(), arm.SHIFT_LR, v.AuxInt)
 		p.Scond = arm.C_SBIT
 	case ssa.OpARMADDshiftRA,
 		ssa.OpARMADCshiftRA,
@@ -378,20 +381,20 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		ssa.OpARMORshiftRA,
 		ssa.OpARMXORshiftRA,
 		ssa.OpARMBICshiftRA:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_AR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_AR, v.AuxInt)
 	case ssa.OpARMADDSshiftRA,
 		ssa.OpARMSUBSshiftRA,
 		ssa.OpARMRSBSshiftRA:
-		p := genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg0(), arm.SHIFT_AR, v.AuxInt)
+		p := genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg0(), arm.SHIFT_AR, v.AuxInt)
 		p.Scond = arm.C_SBIT
 	case ssa.OpARMXORshiftRR:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_RR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_RR, v.AuxInt)
 	case ssa.OpARMMVNshiftLL:
-		genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_LL, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_LL, v.AuxInt)
 	case ssa.OpARMMVNshiftRL:
-		genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_LR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_LR, v.AuxInt)
 	case ssa.OpARMMVNshiftRA:
-		genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_AR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_AR, v.AuxInt)
 	case ssa.OpARMMVNshiftLLreg:
 		genregshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm.SHIFT_LL)
 	case ssa.OpARMMVNshiftRLreg:
@@ -513,11 +516,11 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = v.Args[0].Reg()
 	case ssa.OpARMCMPshiftLL, ssa.OpARMCMNshiftLL, ssa.OpARMTSTshiftLL, ssa.OpARMTEQshiftLL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm.SHIFT_LL, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm.SHIFT_LL, v.AuxInt)
 	case ssa.OpARMCMPshiftRL, ssa.OpARMCMNshiftRL, ssa.OpARMTSTshiftRL, ssa.OpARMTEQshiftRL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm.SHIFT_LR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm.SHIFT_LR, v.AuxInt)
 	case ssa.OpARMCMPshiftRA, ssa.OpARMCMNshiftRA, ssa.OpARMTSTshiftRA, ssa.OpARMTEQshiftRA:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm.SHIFT_AR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm.SHIFT_AR, v.AuxInt)
 	case ssa.OpARMCMPshiftLLreg, ssa.OpARMCMNshiftLLreg, ssa.OpARMTSTshiftLLreg, ssa.OpARMTEQshiftLLreg:
 		genregshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Args[2].Reg(), 0, arm.SHIFT_LL)
 	case ssa.OpARMCMPshiftRLreg, ssa.OpARMCMNshiftRLreg, ssa.OpARMTSTshiftRLreg, ssa.OpARMTEQshiftRLreg:
@@ -583,13 +586,13 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		// this is just shift 0 bits
 		fallthrough
 	case ssa.OpARMMOVWloadshiftLL:
-		p := genshift(s, v.Op.Asm(), 0, v.Args[1].Reg(), v.Reg(), arm.SHIFT_LL, v.AuxInt)
+		p := genshift(s, v, v.Op.Asm(), 0, v.Args[1].Reg(), v.Reg(), arm.SHIFT_LL, v.AuxInt)
 		p.From.Reg = v.Args[0].Reg()
 	case ssa.OpARMMOVWloadshiftRL:
-		p := genshift(s, v.Op.Asm(), 0, v.Args[1].Reg(), v.Reg(), arm.SHIFT_LR, v.AuxInt)
+		p := genshift(s, v, v.Op.Asm(), 0, v.Args[1].Reg(), v.Reg(), arm.SHIFT_LR, v.AuxInt)
 		p.From.Reg = v.Args[0].Reg()
 	case ssa.OpARMMOVWloadshiftRA:
-		p := genshift(s, v.Op.Asm(), 0, v.Args[1].Reg(), v.Reg(), arm.SHIFT_AR, v.AuxInt)
+		p := genshift(s, v, v.Op.Asm(), 0, v.Args[1].Reg(), v.Reg(), arm.SHIFT_AR, v.AuxInt)
 		p.From.Reg = v.Args[0].Reg()
 	case ssa.OpARMMOVWstoreidx, ssa.OpARMMOVBstoreidx, ssa.OpARMMOVHstoreidx:
 		// this is just shift 0 bits
@@ -600,21 +603,21 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Reg = v.Args[2].Reg()
 		p.To.Type = obj.TYPE_SHIFT
 		p.To.Reg = v.Args[0].Reg()
-		p.To.Offset = int64(makeshift(v.Args[1].Reg(), arm.SHIFT_LL, v.AuxInt))
+		p.To.Offset = int64(makeshift(v, v.Args[1].Reg(), arm.SHIFT_LL, v.AuxInt))
 	case ssa.OpARMMOVWstoreshiftRL:
 		p := s.Prog(v.Op.Asm())
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = v.Args[2].Reg()
 		p.To.Type = obj.TYPE_SHIFT
 		p.To.Reg = v.Args[0].Reg()
-		p.To.Offset = int64(makeshift(v.Args[1].Reg(), arm.SHIFT_LR, v.AuxInt))
+		p.To.Offset = int64(makeshift(v, v.Args[1].Reg(), arm.SHIFT_LR, v.AuxInt))
 	case ssa.OpARMMOVWstoreshiftRA:
 		p := s.Prog(v.Op.Asm())
 		p.From.Type = obj.TYPE_REG
 		p.From.Reg = v.Args[2].Reg()
 		p.To.Type = obj.TYPE_SHIFT
 		p.To.Reg = v.Args[0].Reg()
-		p.To.Offset = int64(makeshift(v.Args[1].Reg(), arm.SHIFT_AR, v.AuxInt))
+		p.To.Offset = int64(makeshift(v, v.Args[1].Reg(), arm.SHIFT_AR, v.AuxInt))
 	case ssa.OpARMMOVBreg,
 		ssa.OpARMMOVBUreg,
 		ssa.OpARMMOVHreg,
@@ -645,7 +648,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		}
 		if buildcfg.GOARM >= 6 {
 			// generate more efficient "MOVB/MOVBU/MOVH/MOVHU Reg@>0, Reg" on ARMv6 & ARMv7
-			genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_RR, 0)
+			genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm.SHIFT_RR, 0)
 			return
 		}
 		fallthrough
@@ -696,6 +699,8 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Reg = v.Reg()
 	case ssa.OpARMCALLstatic, ssa.OpARMCALLclosure, ssa.OpARMCALLinter:
 		s.Call(v)
+	case ssa.OpARMCALLtail:
+		s.TailCall(v)
 	case ssa.OpARMCALLudiv:
 		p := s.Prog(obj.ACALL)
 		p.To.Type = obj.TYPE_MEM
@@ -936,17 +941,11 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 			s.Branches = append(s.Branches, ssagen.Branch{P: p, B: b.Succs[0].Block()})
 		}
 
-	case ssa.BlockExit:
+	case ssa.BlockExit, ssa.BlockRetJmp:
 
 	case ssa.BlockRet:
 		s.Prog(obj.ARET)
 
-	case ssa.BlockRetJmp:
-		p := s.Prog(obj.ARET)
-		p.To.Type = obj.TYPE_MEM
-		p.To.Name = obj.NAME_EXTERN
-		p.To.Sym = b.Aux.(*obj.LSym)
-
 	case ssa.BlockARMEQ, ssa.BlockARMNE,
 		ssa.BlockARMLT, ssa.BlockARMGE,
 		ssa.BlockARMLE, ssa.BlockARMGT,

src/cmd/compile/internal/arm64/ssa.go

@@ -79,15 +79,18 @@ func storeByType(t *types.Type) obj.As {
 }
 
 // makeshift encodes a register shifted by a constant, used as an Offset in Prog
-func makeshift(reg int16, typ int64, s int64) int64 {
+func makeshift(v *ssa.Value, reg int16, typ int64, s int64) int64 {
+	if s < 0 || s >= 64 {
+		v.Fatalf("shift out of range: %d", s)
+	}
 	return int64(reg&31)<<16 | typ | (s&63)<<10
 }
 
 // genshift generates a Prog for r = r0 op (r1 shifted by n)
-func genshift(s *ssagen.State, as obj.As, r0, r1, r int16, typ int64, n int64) *obj.Prog {
+func genshift(s *ssagen.State, v *ssa.Value, as obj.As, r0, r1, r int16, typ int64, n int64) *obj.Prog {
 	p := s.Prog(as)
 	p.From.Type = obj.TYPE_SHIFT
-	p.From.Offset = makeshift(r1, typ, n)
+	p.From.Offset = makeshift(v, r1, typ, n)
 	p.Reg = r0
 	if r != 0 {
 		p.To.Type = obj.TYPE_REG
@@ -310,11 +313,13 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = v.Reg()
 	case ssa.OpARM64MVNshiftLL, ssa.OpARM64NEGshiftLL:
-		genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_LL, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_LL, v.AuxInt)
 	case ssa.OpARM64MVNshiftRL, ssa.OpARM64NEGshiftRL:
-		genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_LR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_LR, v.AuxInt)
 	case ssa.OpARM64MVNshiftRA, ssa.OpARM64NEGshiftRA:
-		genshift(s, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_AR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_AR, v.AuxInt)
+	case ssa.OpARM64MVNshiftRO:
+		genshift(s, v, v.Op.Asm(), 0, v.Args[0].Reg(), v.Reg(), arm64.SHIFT_ROR, v.AuxInt)
 	case ssa.OpARM64ADDshiftLL,
 		ssa.OpARM64SUBshiftLL,
 		ssa.OpARM64ANDshiftLL,
@@ -323,7 +328,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		ssa.OpARM64EONshiftLL,
 		ssa.OpARM64ORNshiftLL,
 		ssa.OpARM64BICshiftLL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_LL, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_LL, v.AuxInt)
 	case ssa.OpARM64ADDshiftRL,
 		ssa.OpARM64SUBshiftRL,
 		ssa.OpARM64ANDshiftRL,
@@ -332,7 +337,7 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		ssa.OpARM64EONshiftRL,
 		ssa.OpARM64ORNshiftRL,
 		ssa.OpARM64BICshiftRL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_LR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_LR, v.AuxInt)
 	case ssa.OpARM64ADDshiftRA,
 		ssa.OpARM64SUBshiftRA,
 		ssa.OpARM64ANDshiftRA,
@@ -341,7 +346,14 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		ssa.OpARM64EONshiftRA,
 		ssa.OpARM64ORNshiftRA,
 		ssa.OpARM64BICshiftRA:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_AR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_AR, v.AuxInt)
+	case ssa.OpARM64ANDshiftRO,
+		ssa.OpARM64ORshiftRO,
+		ssa.OpARM64XORshiftRO,
+		ssa.OpARM64EONshiftRO,
+		ssa.OpARM64ORNshiftRO,
+		ssa.OpARM64BICshiftRO:
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), v.Reg(), arm64.SHIFT_ROR, v.AuxInt)
 	case ssa.OpARM64MOVDconst:
 		p := s.Prog(v.Op.Asm())
 		p.From.Type = obj.TYPE_CONST
@@ -384,11 +396,13 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Offset = v.AuxInt
 		p.Reg = v.Args[0].Reg()
 	case ssa.OpARM64CMPshiftLL, ssa.OpARM64CMNshiftLL, ssa.OpARM64TSTshiftLL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_LL, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_LL, v.AuxInt)
 	case ssa.OpARM64CMPshiftRL, ssa.OpARM64CMNshiftRL, ssa.OpARM64TSTshiftRL:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_LR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_LR, v.AuxInt)
 	case ssa.OpARM64CMPshiftRA, ssa.OpARM64CMNshiftRA, ssa.OpARM64TSTshiftRA:
-		genshift(s, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_AR, v.AuxInt)
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_AR, v.AuxInt)
+	case ssa.OpARM64TSTshiftRO:
+		genshift(s, v, v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg(), 0, arm64.SHIFT_ROR, v.AuxInt)
 	case ssa.OpARM64MOVDaddr:
 		p := s.Prog(arm64.AMOVD)
 		p.From.Type = obj.TYPE_ADDR
@@ -1046,6 +1060,8 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p4.To.SetTarget(p)
 	case ssa.OpARM64CALLstatic, ssa.OpARM64CALLclosure, ssa.OpARM64CALLinter:
 		s.Call(v)
+	case ssa.OpARM64CALLtail:
+		s.TailCall(v)
 	case ssa.OpARM64LoweredWB:
 		p := s.Prog(obj.ACALL)
 		p.To.Type = obj.TYPE_MEM
@@ -1095,6 +1111,12 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.From.Reg = condBits[v.Op]
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = v.Reg()
+	case ssa.OpARM64PRFM:
+		p := s.Prog(v.Op.Asm())
+		p.From.Type = obj.TYPE_MEM
+		p.From.Reg = v.Args[0].Reg()
+		p.To.Type = obj.TYPE_CONST
+		p.To.Offset = v.AuxInt
 	case ssa.OpARM64LoweredGetClosurePtr:
 		// Closure pointer is R26 (arm64.REGCTXT).
 		ssagen.CheckLoweredGetClosurePtr(v)
@@ -1110,6 +1132,10 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p := s.Prog(obj.AGETCALLERPC)
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = v.Reg()
+	case ssa.OpARM64DMB:
+		p := s.Prog(v.Op.Asm())
+		p.From.Type = obj.TYPE_CONST
+		p.From.Offset = v.AuxInt
 	case ssa.OpARM64FlagConstant:
 		v.Fatalf("FlagConstant op should never make it to codegen %v", v.LongString())
 	case ssa.OpARM64InvertFlags:
@@ -1235,17 +1261,11 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 			s.Branches = append(s.Branches, ssagen.Branch{P: p, B: b.Succs[0].Block()})
 		}
 
-	case ssa.BlockExit:
+	case ssa.BlockExit, ssa.BlockRetJmp:
 
 	case ssa.BlockRet:
 		s.Prog(obj.ARET)
 
-	case ssa.BlockRetJmp:
-		p := s.Prog(obj.ARET)
-		p.To.Type = obj.TYPE_MEM
-		p.To.Name = obj.NAME_EXTERN
-		p.To.Sym = b.Aux.(*obj.LSym)
-
 	case ssa.BlockARM64EQ, ssa.BlockARM64NE,
 		ssa.BlockARM64LT, ssa.BlockARM64GE,
 		ssa.BlockARM64LE, ssa.BlockARM64GT,

src/cmd/compile/internal/base/base.go

@@ -67,6 +67,7 @@ var NoInstrumentPkgs = []string{
 	"runtime",
 	"runtime/race",
 	"runtime/msan",
+	"runtime/asan",
 	"internal/cpu",
 }
 

src/cmd/compile/internal/base/debug.go

@@ -6,15 +6,6 @@
 
 package base
 
-import (
-	"fmt"
-	"log"
-	"os"
-	"reflect"
-	"strconv"
-	"strings"
-)
-
 // Debug holds the parsed debugging configuration values.
 var Debug DebugFlags
 
@@ -26,7 +17,7 @@ var Debug DebugFlags
 // Each setting is name=value; for ints, name is short for name=1.
 type DebugFlags struct {
 	Append               int    `help:"print information about append compilation"`
-	Checkptr             int    `help:"instrument unsafe pointer conversions"`
+	Checkptr             int    `help:"instrument unsafe pointer conversions\n0: instrumentation disabled\n1: conversions involving unsafe.Pointer are instrumented\n2: conversions to unsafe.Pointer force heap allocation"`
 	Closure              int    `help:"print information about closure compilation"`
 	DclStack             int    `help:"run internal dclstack check"`
 	Defer                int    `help:"print information about defer compilation"`
@@ -40,7 +31,7 @@ type DebugFlags struct {
 	LocationLists        int    `help:"print information about DWARF location list creation"`
 	Nil                  int    `help:"print information about nil checks"`
 	NoOpenDefer          int    `help:"disable open-coded defers"`
-	PCTab                string `help:"print named pc-value table"`
+	PCTab                string `help:"print named pc-value table\nOne of: pctospadj, pctofile, pctoline, pctoinline, pctopcdata"`
 	Panic                int    `help:"show all compiler panics"`
 	Slice                int    `help:"print information about slice compilation"`
 	SoftFloat            int    `help:"force compiler to emit soft-float code"`
@@ -51,142 +42,12 @@ type DebugFlags struct {
 	UnifiedQuirks        int    `help:"enable unified IR construction's quirks mode"`
 	WB                   int    `help:"print information about write barriers"`
 	ABIWrap              int    `help:"print information about ABI wrapper generation"`
+	MayMoreStack         string `help:"call named function before all stack growth checks"`
 
-	any bool // set when any of the values have been set
+	Any bool // set when any of the debug flags have been set
-}
-
-// Any reports whether any of the debug flags have been set.
-func (d *DebugFlags) Any() bool { return d.any }
-
-type debugField struct {
-	name string
-	help string
-	val  interface{} // *int or *string
-}
-
-var debugTab []debugField
-
-func init() {
-	v := reflect.ValueOf(&Debug).Elem()
-	t := v.Type()
-	for i := 0; i < t.NumField(); i++ {
-		f := t.Field(i)
-		if f.Name == "any" {
-			continue
-		}
-		name := strings.ToLower(f.Name)
-		help := f.Tag.Get("help")
-		if help == "" {
-			panic(fmt.Sprintf("base.Debug.%s is missing help text", f.Name))
-		}
-		ptr := v.Field(i).Addr().Interface()
-		switch ptr.(type) {
-		default:
-			panic(fmt.Sprintf("base.Debug.%s has invalid type %v (must be int or string)", f.Name, f.Type))
-		case *int, *string:
-			// ok
-		}
-		debugTab = append(debugTab, debugField{name, help, ptr})
-	}
 }
 
 // DebugSSA is called to set a -d ssa/... option.
 // If nil, those options are reported as invalid options.
 // If DebugSSA returns a non-empty string, that text is reported as a compiler error.
 var DebugSSA func(phase, flag string, val int, valString string) string
-
-// parseDebug parses the -d debug string argument.
-func parseDebug(debugstr string) {
-	// parse -d argument
-	if debugstr == "" {
-		return
-	}
-	Debug.any = true
-Split:
-	for _, name := range strings.Split(debugstr, ",") {
-		if name == "" {
-			continue
-		}
-		// display help about the -d option itself and quit
-		if name == "help" {
-			fmt.Print(debugHelpHeader)
-			maxLen := len("ssa/help")
-			for _, t := range debugTab {
-				if len(t.name) > maxLen {
-					maxLen = len(t.name)
-				}
-			}
-			for _, t := range debugTab {
-				fmt.Printf("\t%-*s\t%s\n", maxLen, t.name, t.help)
-			}
-			// ssa options have their own help
-			fmt.Printf("\t%-*s\t%s\n", maxLen, "ssa/help", "print help about SSA debugging")
-			fmt.Print(debugHelpFooter)
-			os.Exit(0)
-		}
-		val, valstring, haveInt := 1, "", true
-		if i := strings.IndexAny(name, "=:"); i >= 0 {
-			var err error
-			name, valstring = name[:i], name[i+1:]
-			val, err = strconv.Atoi(valstring)
-			if err != nil {
-				val, haveInt = 1, false
-			}
-		}
-		for _, t := range debugTab {
-			if t.name != name {
-				continue
-			}
-			switch vp := t.val.(type) {
-			case nil:
-				// Ignore
-			case *string:
-				*vp = valstring
-			case *int:
-				if !haveInt {
-					log.Fatalf("invalid debug value %v", name)
-				}
-				*vp = val
-			default:
-				panic("bad debugtab type")
-			}
-			continue Split
-		}
-		// special case for ssa for now
-		if DebugSSA != nil && strings.HasPrefix(name, "ssa/") {
-			// expect form ssa/phase/flag
-			// e.g. -d=ssa/generic_cse/time
-			// _ in phase name also matches space
-			phase := name[4:]
-			flag := "debug" // default flag is debug
-			if i := strings.Index(phase, "/"); i >= 0 {
-				flag = phase[i+1:]
-				phase = phase[:i]
-			}
-			err := DebugSSA(phase, flag, val, valstring)
-			if err != "" {
-				log.Fatalf(err)
-			}
-			continue Split
-		}
-		log.Fatalf("unknown debug key -d %s\n", name)
-	}
-}
-
-const debugHelpHeader = `usage: -d arg[,arg]* and arg is <key>[=<value>]
-
-<key> is one of:
-
-`
-
-const debugHelpFooter = `
-<value> is key-specific.
-
-Key "checkptr" supports values:
-	"0": instrumentation disabled
-	"1": conversions involving unsafe.Pointer are instrumented
-	"2": conversions to unsafe.Pointer force heap allocation
-
-Key "pctab" supports values:
-	"pctospadj", "pctofile", "pctoline", "pctoinline", "pctopcdata"
-`

src/cmd/compile/internal/base/flag.go

@@ -64,19 +64,19 @@ type CmdFlags struct {
 	// V is added by objabi.AddVersionFlag
 	W CountFlag "help:\"debug parse tree after type checking\""
 
-	LowerC int          "help:\"concurrency during compilation (1 means no concurrency)\""
+	LowerC int        "help:\"concurrency during compilation (1 means no concurrency)\""
-	LowerD func(string) "help:\"enable debugging settings; try -d help\""
+	LowerD flag.Value "help:\"enable debugging settings; try -d help\""
-	LowerE CountFlag    "help:\"no limit on number of errors reported\""
+	LowerE CountFlag  "help:\"no limit on number of errors reported\""
-	LowerH CountFlag    "help:\"halt on error\""
+	LowerH CountFlag  "help:\"halt on error\""
-	LowerJ CountFlag    "help:\"debug runtime-initialized variables\""
+	LowerJ CountFlag  "help:\"debug runtime-initialized variables\""
-	LowerL CountFlag    "help:\"disable inlining\""
+	LowerL CountFlag  "help:\"disable inlining\""
-	LowerM CountFlag    "help:\"print optimization decisions\""
+	LowerM CountFlag  "help:\"print optimization decisions\""
-	LowerO string       "help:\"write output to `file`\""
+	LowerO string     "help:\"write output to `file`\""
-	LowerP *string      "help:\"set expected package import `path`\"" // &Ctxt.Pkgpath, set below
+	LowerP *string    "help:\"set expected package import `path`\"" // &Ctxt.Pkgpath, set below
-	LowerR CountFlag    "help:\"debug generated wrappers\""
+	LowerR CountFlag  "help:\"debug generated wrappers\""
-	LowerT bool         "help:\"enable tracing for debugging the compiler\""
+	LowerT bool       "help:\"enable tracing for debugging the compiler\""
-	LowerW CountFlag    "help:\"debug type checking\""
+	LowerW CountFlag  "help:\"debug type checking\""
-	LowerV *bool        "help:\"increase debug verbosity\""
+	LowerV *bool      "help:\"increase debug verbosity\""
 
 	// Special characters
 	Percent          int  "flag:\"%\" help:\"debug non-static initializers\""
@@ -84,6 +84,7 @@ type CmdFlags struct {
 
 	// Longer names
 	AsmHdr             string       "help:\"write assembly header to `file`\""
+	ASan               bool         "help:\"build code compatible with C/C++ address sanitizer\""
 	Bench              string       "help:\"append benchmark times to `file`\""
 	BlockProfile       string       "help:\"write block profile to `file`\""
 	BuildID            string       "help:\"record `id` as the build id in the export metadata\""
@@ -108,7 +109,7 @@ type CmdFlags struct {
 	Live               CountFlag    "help:\"debug liveness analysis\""
 	MSan               bool         "help:\"build code compatible with C/C++ memory sanitizer\""
 	MemProfile         string       "help:\"write memory profile to `file`\""
-	MemProfileRate     int64        "help:\"set runtime.MemProfileRate to `rate`\""
+	MemProfileRate     int          "help:\"set runtime.MemProfileRate to `rate`\""
 	MutexProfile       string       "help:\"write mutex profile to `file`\""
 	NoLocalImports     bool         "help:\"reject local (relative) imports\""
 	Pack               bool         "help:\"write to file.a instead of file.o\""
@@ -140,10 +141,11 @@ type CmdFlags struct {
 
 // ParseFlags parses the command-line flags into Flag.
 func ParseFlags() {
+	Flag.G = 3
 	Flag.I = addImportDir
 
 	Flag.LowerC = 1
-	Flag.LowerD = parseDebug
+	Flag.LowerD = objabi.NewDebugFlag(&Debug, DebugSSA)
 	Flag.LowerP = &Ctxt.Pkgpath
 	Flag.LowerV = &Ctxt.Debugvlog
 
@@ -176,6 +178,9 @@ func ParseFlags() {
 	if Flag.MSan && !sys.MSanSupported(buildcfg.GOOS, buildcfg.GOARCH) {
 		log.Fatalf("%s/%s does not support -msan", buildcfg.GOOS, buildcfg.GOARCH)
 	}
+	if Flag.ASan && !sys.ASanSupported(buildcfg.GOOS, buildcfg.GOARCH) {
+		log.Fatalf("%s/%s does not support -asan", buildcfg.GOOS, buildcfg.GOARCH)
+	}
 	if Flag.Race && !sys.RaceDetectorSupported(buildcfg.GOOS, buildcfg.GOARCH) {
 		log.Fatalf("%s/%s does not support -race", buildcfg.GOOS, buildcfg.GOARCH)
 	}
@@ -187,6 +192,7 @@ func ParseFlags() {
 	Ctxt.Flag_shared = Ctxt.Flag_dynlink || Ctxt.Flag_shared
 	Ctxt.Flag_optimize = Flag.N == 0
 	Ctxt.Debugasm = int(Flag.S)
+	Ctxt.Flag_maymorestack = Debug.MayMoreStack
 
 	if flag.NArg() < 1 {
 		usage()
@@ -216,12 +222,16 @@ func ParseFlags() {
 		}
 		Flag.LowerO = p + suffix
 	}
-
+	switch {
-	if Flag.Race && Flag.MSan {
+	case Flag.Race && Flag.MSan:
 		log.Fatal("cannot use both -race and -msan")
+	case Flag.Race && Flag.ASan:
+		log.Fatal("cannot use both -race and -asan")
+	case Flag.MSan && Flag.ASan:
+		log.Fatal("cannot use both -msan and -asan")
 	}
-	if Flag.Race || Flag.MSan {
+	if Flag.Race || Flag.MSan || Flag.ASan {
-		// -race and -msan imply -d=checkptr for now.
+		// -race, -msan and -asan imply -d=checkptr for now.
 		if Debug.Checkptr == -1 { // if not set explicitly
 			Debug.Checkptr = 1
 		}
@@ -321,6 +331,12 @@ func registerFlags() {
 		case funcType:
 			f := v.Field(i).Interface().(func(string))
 			objabi.Flagfn1(name, help, f)
+		default:
+			if val, ok := v.Field(i).Interface().(flag.Value); ok {
+				flag.Var(val, name, help)
+			} else {
+				panic(fmt.Sprintf("base.Flag.%s has unexpected type %s", f.Name, f.Type))
+			}
 		}
 	}
 }
@@ -348,7 +364,7 @@ func concurrentBackendAllowed() bool {
 	// while writing the object file, and that is non-concurrent.
 	// Adding Debug_vlog, however, causes Debug.S to also print
 	// while flushing the plist, which happens concurrently.
-	if Ctxt.Debugvlog || Debug.Any() || Flag.Live > 0 {
+	if Ctxt.Debugvlog || Debug.Any || Flag.Live > 0 {
 		return false
 	}
 	// TODO: Test and delete this condition.
@@ -356,7 +372,7 @@ func concurrentBackendAllowed() bool {
 		return false
 	}
 	// TODO: fix races and enable the following flags
-	if Ctxt.Flag_shared || Ctxt.Flag_dynlink || Flag.Race {
+	if Ctxt.Flag_dynlink || Flag.Race {
 		return false
 	}
 	return true

src/cmd/compile/internal/bitvec/bv.go

@@ -128,10 +128,21 @@ func (bv BitVec) IsEmpty() bool {
 	return true
 }
 
+func (bv BitVec) Count() int {
+	n := 0
+	for _, x := range bv.B {
+		n += bits.OnesCount32(x)
+	}
+	return n
+}
+
 func (bv BitVec) Not() {
 	for i, x := range bv.B {
 		bv.B[i] = ^x
 	}
+	if bv.N%wordBits != 0 {
+		bv.B[len(bv.B)-1] &= 1<<uint(bv.N%wordBits) - 1 // clear bits past N in the last word
+	}
 }
 
 // union

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

@@ -38,6 +38,7 @@ func Func(fn *ir.Func) {
 		}
 	}
 
+	ir.VisitList(fn.Body, markHiddenClosureDead)
 	fn.Body = []ir.Node{ir.NewBlockStmt(base.Pos, nil)}
 }
 
@@ -62,9 +63,11 @@ func stmts(nn *ir.Nodes) {
 			if ir.IsConst(n.Cond, constant.Bool) {
 				var body ir.Nodes
 				if ir.BoolVal(n.Cond) {
+					ir.VisitList(n.Else, markHiddenClosureDead)
 					n.Else = ir.Nodes{}
 					body = n.Body
 				} else {
+					ir.VisitList(n.Body, markHiddenClosureDead)
 					n.Body = ir.Nodes{}
 					body = n.Else
 				}
@@ -114,6 +117,7 @@ func stmts(nn *ir.Nodes) {
 		}
 
 		if cut {
+			ir.VisitList((*nn)[i+1:len(*nn)], markHiddenClosureDead)
 			*nn = (*nn)[:i+1]
 			break
 		}
@@ -150,3 +154,13 @@ func expr(n ir.Node) ir.Node {
 	}
 	return n
 }
+
+func markHiddenClosureDead(n ir.Node) {
+	if n.Op() != ir.OCLOSURE {
+		return
+	}
+	clo := n.(*ir.ClosureExpr)
+	if clo.Func.IsHiddenClosure() {
+		clo.Func.SetIsDeadcodeClosure(true)
+	}
+}

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

@@ -214,9 +214,10 @@ func createDwarfVars(fnsym *obj.LSym, complexOK bool, fn *ir.Func, apDecls []*ir
 			Type:          base.Ctxt.Lookup(typename),
 			DeclFile:      declpos.RelFilename(),
 			DeclLine:      declpos.RelLine(),
-			DeclCol:       declpos.Col(),
+			DeclCol:       declpos.RelCol(),
 			InlIndex:      int32(inlIndex),
 			ChildIndex:    -1,
+			DictIndex:     n.DictIndex,
 		})
 		// Record go type of to insure that it gets emitted by the linker.
 		fnsym.Func().RecordAutoType(reflectdata.TypeLinksym(n.Type()))
@@ -371,9 +372,10 @@ func createSimpleVar(fnsym *obj.LSym, n *ir.Name) *dwarf.Var {
 		Type:          base.Ctxt.Lookup(typename),
 		DeclFile:      declpos.RelFilename(),
 		DeclLine:      declpos.RelLine(),
-		DeclCol:       declpos.Col(),
+		DeclCol:       declpos.RelCol(),
 		InlIndex:      int32(inlIndex),
 		ChildIndex:    -1,
+		DictIndex:     n.DictIndex,
 	}
 }
 
@@ -475,9 +477,10 @@ func createComplexVar(fnsym *obj.LSym, fn *ir.Func, varID ssa.VarID) *dwarf.Var
 		StackOffset: ssagen.StackOffset(debug.Slots[debug.VarSlots[varID][0]]),
 		DeclFile:    declpos.RelFilename(),
 		DeclLine:    declpos.RelLine(),
-		DeclCol:     declpos.Col(),
+		DeclCol:     declpos.RelCol(),
 		InlIndex:    int32(inlIndex),
 		ChildIndex:  -1,
+		DictIndex:   n.DictIndex,
 	}
 	list := debug.LocationLists[varID]
 	if len(list) != 0 {