Merge remote-tracking branch 'upstream/master' into regexp_examples_l…

…ongest_findsubmatchindex_findallindex

api/go1.13.txt

@@ -39,6 +39,8 @@ pkg debug/dwarf, method (*UnsupportedType) String() string
 pkg debug/dwarf, type UnsupportedType struct
 pkg debug/dwarf, type UnsupportedType struct, embedded CommonType
 pkg debug/dwarf, type UnsupportedType struct, Tag Tag
+pkg debug/elf, type Symbol struct, Library string
+pkg debug/elf, type Symbol struct, Version string
 pkg encoding/csv, method (*ParseError) Unwrap() error
 pkg encoding/json, method (*MarshalerError) Unwrap() error
 pkg errors, func As(error, interface{}) bool

doc/articles/race_detector.html

@@ -377,8 +377,11 @@ <h3 id="Primitive_unprotected_variable">Primitive unprotected variable</h3>
 <h2 id="Supported_Systems">Supported Systems</h2>
 
 <p>
-The race detector runs on <code>darwin/amd64</code>, <code>freebsd/amd64</code>,
-<code>linux/amd64</code>, and <code>windows/amd64</code>.
+  The race detector runs on
+  <code>linux/amd64</code>, <code>linux/ppc64le</code>,
+  <code>linux/arm64</code>, <code>freebsd/amd64</code>,
+  <code>netbsd/amd64</code>, <code>darwin/amd64</code>,
+  and <code>windows/amd64</code>.
 </p>
 
 <h2 id="Runtime_Overheads">Runtime Overhead</h2>

doc/asm.html

@@ -590,27 +590,37 @@ <h3 id="x86">32-bit Intel 386</h3>
 <p>
 The runtime pointer to the <code>g</code> structure is maintained
 through the value of an otherwise unused (as far as Go is concerned) register in the MMU.
-A OS-dependent macro <code>get_tls</code> is defined for the assembler if the source includes
-a special header, <code>go_asm.h</code>:
+An OS-dependent macro <code>get_tls</code> is defined for the assembler if the source is
+in the <code>runtime</code> package and includes a special header, <code>go_tls.h</code>:
 </p>
 
 <pre>
-#include "go_asm.h"
+#include "go_tls.h"
 </pre>
 
 <p>
 Within the runtime, the <code>get_tls</code> macro loads its argument register
 with a pointer to the <code>g</code> pointer, and the <code>g</code> struct
 contains the <code>m</code> pointer.
+There's another special header containing the offsets for each
+element of <code>g</code>, called <code>go_asm.h</code>.
 The sequence to load <code>g</code> and <code>m</code> using <code>CX</code> looks like this:
 </p>
 
 <pre>
+#include "go_tls.h"
+#include "go_asm.h"
+...
 get_tls(CX)
 MOVL	g(CX), AX     // Move g into AX.
 MOVL	g_m(AX), BX   // Move g.m into BX.
 </pre>
 
+<p>
+Note: The code above works only in the <code>runtime</code> package, while <code>go_tls.h</code> also
+applies to <a href="#arm">arm</a>, <a href="#amd64">amd64</a> and amd64p32, and <code>go_asm.h</code> applies to all architectures.
+</p>
+
 <p>
 Addressing modes:
 </p>

doc/go1.13.html

@@ -525,6 +525,37 @@ <h3 id="crypto/ed25519"><a href="/pkg/crypto/ed25519/">crypto/ed25519</a></h3>
   <code>crypto/ed25519</code> when used with Go 1.13+.
 </p>
 
+<h3 id="error_wrapping">Error wrapping</h3>
+
+<p><!-- CL 163558, 176998 -->
+  Go 1.13 contains support for error wrapping, as first proposed in
+  the <a href="https://go.googlesource.com/proposal/+/master/design/29934-error-values.md">
+  Error Values proposal</a> and discussed on <a href="https://golang.org/issue/29934">the
+  associated issue</a>.
+</p>
+<p>
+  An error <code>e</code> can <em>wrap</em> another error <code>w</code> by providing
+  an <code>Unwrap</code> method that returns <code>w</code>. Both <code>e</code>
+  and <code>w</code> are available to programs, allowing <code>e</code> to provide
+  additional context to <code>w</code> or to reinterpret it while still allowing
+  programs to make decisions based on <code>w</code>.
+</p>
+<p>
+  To support wrapping, <a href="#fmt"><code>fmt.Errorf</code></a> now has a <code>%w</code>
+  verb for creating wrapped errors, and three new functions in
+  the <a href="#errors"><code>errors</code></a> package (
+  <a href="/pkg/errors#Unwrap"><code>errors.Unwrap</code></a>,
+  <a href="/pkg/errors#Is"><code>errors.Is</code></a> and
+  <a href="/pkg/errors#As"><code>errors.As</code></a>) simplify unwrapping
+  and inspecting wrapped errors.
+</p>
+<p>
+  For more information, read the <a href="/pkg/errors/"><code>errors</code> package
+  documentation</a>, or see
+  the <a href="https://golang.org/wiki/ErrorValueFAQ">Error Value FAQ</a>.
+  There will soon be a blog post as well.
+</p>
+
 <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 <p>
@@ -612,7 +643,8 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
   <dd>
     <!-- CL 163558 -->
     <p>
-      The new function <a href="/pkg/errors/#As"><code>As</code></a> finds the first error in a given error’s chain
+      The new function <a href="/pkg/errors/#As"><code>As</code></a> finds the first
+      error in a given error’s chain (sequence of wrapped errors)
       that matches a given target’s type, and if so, sets the target to that error value.
     </p>
     <p>
@@ -860,6 +892,14 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 <dl id="sync"><dt><a href="/pkg/sync/">sync</a></dt>
   <dd>
+    <p><!-- CL 148958, CL 148959, CL 152697, CL 152698 -->
+      The fast paths of <a href="/pkg/sync/#Mutex.Lock"><code>Mutex.Lock</code></a>, <a href="/pkg/sync/#Mutex.Unlock"><code>Mutex.Unlock</code></a>,
+      <a href="/pkg/sync/#RWMutex.Lock"><code>RWMutex.Lock</code></a>, <a href="/pkg/sync/#Mutex.RUnlock"><code>RWMutex.RUnlock</code></a>, and
+      <a href="/pkg/sync/#Once.Do"><code>Once.Do</code></a> are now inlined in their callers.
+      For the uncontended cases on amd64, these changes make <a href="/pkg/sync/#Once.Do"><code>Once.Do</code></a> twice as fast, and the
+      <a href="/pkg/sync/#Mutex"><code>Mutex</code></a>/<a href="/pkg/sync/#RWMutex"><code>RWMutex</code></a> methods up to 10% faster.
+    </p>
+
     <p><!-- CL 166960 -->
       Large <a href="/pkg/sync/#Pool"><code>Pool</code></a> no longer increase stop-the-world pause times.
     </p>
@@ -960,3 +1000,13 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 </dl><!-- time -->
 
+<dl id="unicode"><dt><a href="/pkg/unicode/">unicode</a></dt>
+  <dd>
+    <p>
+      The <a href="/pkg/unicode/"><code>unicode</code></a> package and associated
+      support throughout the system has been upgraded from Unicode 10.0 to
+      <a href="http://www.unicode.org/versions/Unicode11.0.0/">Unicode 11.0</a>,
+      which adds 684 new characters, including seven new scripts, and 66 new emoji.
+    </p>
+
+</dl><!-- unicode -->

doc/install-source.html

@@ -33,7 +33,7 @@ <h2 id="introduction">Introduction</h2>
 </p>
 
 <p>
-The Go compilers support eight instruction sets.
+The Go compilers support nine instruction sets.
 There are important differences in the quality of the compilers for the different
 architectures.
 </p>
@@ -87,6 +87,12 @@ <h2 id="introduction">Introduction</h2>
 <dd>
 	Supports Linux binaries. New in 1.7 and not as well exercised as other ports.
 </dd>
+<dt>
+	<code>wasm</code> (WebAssembly)
+</dt>
+<dd>
+	Targets the WebAssembly platform. New in 1.11 and not as well exercised as other ports.
+</dd>
 </dl>
 
 <p>
@@ -134,12 +140,16 @@ <h2 id="go14">Install Go compiler binaries</h2>
 the <code>go</code> command binary for the bootstrap toolchain.
 </p>
 
+<h3 id="bootstrapFromBinaryRelease">Bootstrap toolchain from binary release</h3>
+
 <p>
 To use a binary release as a bootstrap toolchain, see
 <a href="/dl/">the downloads page</a> or use any other
 packaged Go distribution.
 </p>
 
+<h3 id="bootstrapFromSource">Bootstrap toolchain from source</h3>
+
 <p>
 To build a bootstrap toolchain from source, use
 either the git branch <code>release-branch.go1.4</code> or
@@ -153,6 +163,17 @@ <h2 id="go14">Install Go compiler binaries</h2>
 on Windows, <code>make.bat</code>).
 </p>
 
+<p>
+Once the Go 1.4 source has been unpacked into your GOROOT_BOOTSTRAP directory,
+you must keep this git clone instance checked out to branch
+<code>release-branch.go1.4</code>.  Specifically, do not attempt to reuse
+this git clone in the later step named "Fetch the repository."  The go1.4
+bootstrap toolchain <b>must be able</b> to properly traverse the go1.4 sources
+that it assumes are present under this repository root.
+</p>
+
+<h3 id="bootstrapFromCrosscompiledSource">Bootstrap toolchain from cross-compiled source</h3>
+
 <p>
 To cross-compile a bootstrap toolchain from source, which is
 necessary on systems Go 1.4 did not target (for
@@ -175,6 +196,8 @@ <h2 id="go14">Install Go compiler binaries</h2>
 and used as <code>GOROOT_BOOTSTRAP</code> to bootstrap a local build.
 </p>
 
+<h3 id="bootstrapFromGccgo">Bootstrap toolchain using gccgo</h3>
+
 <p>
 To use gccgo as the bootstrap toolchain, you need to arrange
 for <code>$GOROOT_BOOTSTRAP/bin/go</code> to be the go tool that comes
@@ -240,6 +263,11 @@ <h2 id="fetch">Fetch the repository</h2>
 the default location of <code>$GOPATH</code>.
 See <a href="#gopath"><code>GOPATH</code></a> below.</p>
 
+Reminder: If you opted to also compile the bootstrap binaries from source (in an
+earlier section), you still need to <code>git clone</code> again at this point
+(to checkout the latest <code>&lt;tag&gt;</code>), because you must keep your
+go1.4 repository distinct.
+
 <h2 id="head">(Optional) Switch to the master branch</h2>
 
 <p>If you intend to modify the go source code, and
@@ -493,25 +521,45 @@ <h2 id="environment">Optional environment variables</h2>
 
 <p>
 Choices for <code>$GOOS</code> are
-<code>darwin</code> (macOS 10.10 and above and iOS), <code>dragonfly</code>, <code>freebsd</code>,
+<code>android</code>, <code>darwin</code> (macOS 10.11 and above and iOS),
+<code>dragonfly</code>, <code>freebsd</code>, <code>illumos</code>, <code>js</code>,
 <code>linux</code>, <code>netbsd</code>, <code>openbsd</code>,
 <code>plan9</code>, <code>solaris</code> and <code>windows</code>.
+</p>
+
+<p>
 Choices for <code>$GOARCH</code> are
 <code>amd64</code> (64-bit x86, the most mature port),
 <code>386</code> (32-bit x86), <code>arm</code> (32-bit ARM), <code>arm64</code> (64-bit ARM),
 <code>ppc64le</code> (PowerPC 64-bit, little-endian), <code>ppc64</code> (PowerPC 64-bit, big-endian),
 <code>mips64le</code> (MIPS 64-bit, little-endian), <code>mips64</code> (MIPS 64-bit, big-endian),
-<code>mipsle</code> (MIPS 32-bit, little-endian), <code>mips</code> (MIPS 32-bit, big-endian), and
-<code>s390x</code> (IBM System z 64-bit, big-endian).
+<code>mipsle</code> (MIPS 32-bit, little-endian), <code>mips</code> (MIPS 32-bit, big-endian),
+<code>s390x</code> (IBM System z 64-bit, big-endian), and
+<code>wasm</code> (WebAssembly 32-bit).
+</p>
+
+<p>
 The valid combinations of <code>$GOOS</code> and <code>$GOARCH</code> are:
 <table cellpadding="0">
 <tr>
 <th width="50"></th><th align="left" width="100"><code>$GOOS</code></th> <th align="left" width="100"><code>$GOARCH</code></th>
 </tr>
 <tr>
+<td></td><td><code>aix</code></td> <td><code>ppc64</code></td>
+</tr>
+<tr>
+<td></td><td><code>android</code></td> <td><code>386</code></td>
+</tr>
+<tr>
+<td></td><td><code>android</code></td> <td><code>amd64</code></td>
+</tr>
+<tr>
 <td></td><td><code>android</code></td> <td><code>arm</code></td>
 </tr>
 <tr>
+<td></td><td><code>android</code></td> <td><code>arm64</code></td>
+</tr>
+<tr>
 <td></td><td><code>darwin</code></td> <td><code>386</code></td>
 </tr>
 <tr>
@@ -536,6 +584,12 @@ <h2 id="environment">Optional environment variables</h2>
 <td></td><td><code>freebsd</code></td> <td><code>arm</code></td>
 </tr>
 <tr>
+<td></td><td><code>illumos</code></td> <td><code>amd64</code></td>
+</tr>
+<tr>
+<td></td><td><code>js</code></td> <td><code>wasm</code></td>
+</tr>
+<tr>
 <td></td><td><code>linux</code></td> <td><code>386</code></td>
 </tr>
 <tr>
@@ -587,12 +641,18 @@ <h2 id="environment">Optional environment variables</h2>
 <td></td><td><code>openbsd</code></td> <td><code>arm</code></td>
 </tr>
 <tr>
+<td></td><td><code>openbsd</code></td> <td><code>arm64</code></td>
+</tr>
+<tr>
 <td></td><td><code>plan9</code></td> <td><code>386</code></td>
 </tr>
 <tr>
 <td></td><td><code>plan9</code></td> <td><code>amd64</code></td>
 </tr>
 <tr>
+<td></td><td><code>plan9</code></td> <td><code>arm</code></td>
+</tr>
+<tr>
 <td></td><td><code>solaris</code></td> <td><code>amd64</code></td>
 </tr>
 <tr>

src/cmd/go.sum

@@ -7,11 +7,13 @@ golang.org/x/arch v0.0.0-20181203225421-5a4828bb7045/go.mod h1:cYlCBUl1MsqxdiKgm
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c h1:Vj5n4GlwjmQteupaxJ9+0FNOmBrHfq7vN4btdGoDZgI=
 golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82 h1:vsphBvatvfbhlb4PO1BYSr9dzugGxJ/SQHoNufZJq1w=
 golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190611154301-25a4f137592f h1:6awn5JC4pwVI5HiBqs7MDtRxnwV9PpO5iSA9v6P09pA=
 golang.org/x/tools v0.0.0-20190611154301-25a4f137592f/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=

src/cmd/go/internal/list/list.go

@@ -390,7 +390,7 @@ func runList(cmd *base.Command, args []string) {
 		if !*listE {
 			for _, m := range mods {
 				if m.Error != nil {
-					base.Errorf("go list -m %s: %v", m.Path, m.Error.Err)
+					base.Errorf("go list -m: %v", m.Error.Err)
 				}
 			}
 			base.ExitIfErrors()

src/cmd/go/internal/load/pkg.go

@@ -653,7 +653,7 @@ func loadPackageData(path, parentPath, parentDir, parentRoot string, parentIsStd
 			}
 		} else if r.err != nil {
 			data.p = new(build.Package)
-			data.err = fmt.Errorf("unknown import path %q: %v", r.path, r.err)
+			data.err = r.err
 		} else if cfg.ModulesEnabled && path != "unsafe" {
 			data.p = new(build.Package)
 			data.err = fmt.Errorf("unknown import path %q: internal error: module loader did not resolve import", r.path)

src/cmd/go/internal/modcmd/download.go

@@ -89,14 +89,19 @@ func runDownload(cmd *base.Command, args []string) {
 		if info.Replace != nil {
 			info = info.Replace
 		}
-		if info.Version == "" {
+		if info.Version == "" && info.Error == nil {
+			// main module
 			continue
 		}
 		m := &moduleJSON{
 			Path:    info.Path,
 			Version: info.Version,
 		}
 		mods = append(mods, m)
+		if info.Error != nil {
+			m.Error = info.Error.Err
+			continue
+		}
 		work.Add(m)
 	}
 
@@ -110,12 +115,17 @@ func runDownload(cmd *base.Command, args []string) {
 		// downloading the modules.
 		var latestArgs []string
 		for _, m := range mods {
+			if m.Error != "" {
+				continue
+			}
 			latestArgs = append(latestArgs, m.Path+"@latest")
 		}
 
-		for _, info := range modload.ListModules(latestArgs, listU, listVersions) {
-			if info.Version != "" {
-				latest[info.Path] = info.Version
+		if len(latestArgs) > 0 {
+			for _, info := range modload.ListModules(latestArgs, listU, listVersions) {
+				if info.Version != "" {
+					latest[info.Path] = info.Version
+				}
 			}
 		}
 	}
@@ -169,7 +179,7 @@ func runDownload(cmd *base.Command, args []string) {
 	} else {
 		for _, m := range mods {
 			if m.Error != "" {
-				base.Errorf("%s@%s: %s\n", m.Path, m.Version, m.Error)
+				base.Errorf("%s", m.Error)
 			}
 		}
 		base.ExitIfErrors()

src/cmd/go/internal/modfetch/repo.go

@@ -240,7 +240,7 @@ func lookup(proxy, path string) (r Repo, err error) {
 
 var (
 	errModVendor       = errors.New("module lookup disabled by -mod=vendor")
-	errProxyOff        = errors.New("module lookup disabled by GOPROXY=off")
+	errProxyOff        = notExistError("module lookup disabled by GOPROXY=off")
 	errNoproxy   error = notExistError("disabled by GOPRIVATE/GONOPROXY")
 	errUseProxy  error = notExistError("path does not match GOPRIVATE/GONOPROXY")
 )