[release-branch.go1.12] go1.12.5

Change-Id: Ib253d4aafab3ad65b4ba666f4eeb8b2f245997a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/175447
Run-TryBot: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

VERSION

@@ -0,0 +1 @@
+go1.12.5

doc/cmd.html

@@ -18,10 +18,8 @@ underlying binary with arguments appropriate to package-level processing.
 
 <p>
 The programs can also be run as stand-alone binaries, with unmodified arguments,
-using the go <code>tool</code> subcommand, such as <code>go tool vet</code>.
-This style of invocation allows, for instance, checking a single source file
-rather than an entire package: <code>go tool vet myprogram.go</code> as
-compared to <code>go vet mypackage</code>.
+using the go <code>tool</code> subcommand, such as <code>go tool cgo</code>.
+For most commands this is mainly useful for debugging.
 Some of the commands, such as <code>pprof</code>, are accessible only through
 the go <code>tool</code> subcommand.
 </p>
@@ -76,7 +74,7 @@ and rewrites them to use newer ones.</td>
 </tr>
 
 <tr>
-<td><a href="/cmd/go/">fmt</a></td>
+<td><a href="/cmd/gofmt/">fmt</a></td>
 <td>&nbsp;&nbsp;&nbsp;&nbsp;</td>
 <td>Fmt formats Go packages, it is also available as an independent <a href="/cmd/gofmt/">
 gofmt</a> command with more general options.</td>

doc/contrib.html

@@ -34,6 +34,7 @@ We encourage all Go users to subscribe to
 <p>A <a href="/doc/devel/release.html">summary</a> of the changes between Go releases. Notes for the major releases:</p>
 
 <ul>
+	<li><a href="/doc/go1.12">Go 1.12</a> <small>(February 2019)</small></li>
 	<li><a href="/doc/go1.11">Go 1.11</a> <small>(August 2018)</small></li>
 	<li><a href="/doc/go1.10">Go 1.10</a> <small>(February 2018)</small></li>
 	<li><a href="/doc/go1.9">Go 1.9</a> <small>(August 2017)</small></li>

doc/contribute.html

@@ -46,7 +46,8 @@ CLA (Contributor License Agreement).
 <li>
 <b>Step 2</b>: Configure authentication credentials for the Go Git repository.
 Visit <a href="https://go.googlesource.com/">go.googlesource.com</a>, click
-on "Generate Password" (top right), and follow the instructions.
+on the gear icon (top right), then on "Obtain password", and follow the
+instructions.
 </li>
 <li>
 <b>Step 3</b>: Register for Gerrit, the code review tool used by the Go team,

doc/devel/release.html

@@ -23,6 +23,52 @@ in supported releases as needed by issuing minor revisions
 (for example, Go 1.6.1, Go 1.6.2, and so on).
 </p>
 
+<h2 id="go1.12">go1.12 (released 2019/02/25)</h2>
+
+<p>
+Go 1.12 is a major release of Go.
+Read the <a href="/doc/go1.12">Go 1.12 Release Notes</a> for more information.
+</p>
+
+<h3 id="go1.12.minor">Minor revisions</h3>
+
+<p>
+go1.12.1 (released 2019/03/14) includes fixes to cgo, the compiler, the go
+command, and the <code>fmt</code>, <code>net/smtp</code>, <code>os</code>,
+<code>path/filepath</code>, <code>sync</code>, and <code>text/template</code>
+packages. See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.12.1">Go
+1.12.1 milestone</a> on our issue tracker for details.
+</p>
+
+<p>
+go1.12.2 (released 2019/04/05) includes fixes to the compiler, the go
+command, the runtime, and the <code>doc</code>, <code>net</code>,
+<code>net/http/httputil</code>, and <code>os</code> packages. See the
+<a href="https://github.com/golang/go/issues?q=milestone%3AGo1.12.2">Go
+1.12.2 milestone</a> on our issue tracker for details.
+</p>
+
+<p>
+go1.12.3 (released 2019/04/08) was accidentally released without its
+intended fix. It is identical to go1.12.2, except for its version
+number. The intended fix is in go1.12.4.
+</p>
+
+<p>
+go1.12.4 (released 2019/04/11) fixes an issue where using the prebuilt binary
+releases on older versions of GNU/Linux
+<a href="https://golang.org/issues/31293">led to failures</a>
+when linking programs that used cgo.
+Only Linux users who hit this issue need to update.
+</p>
+
+<p>
+go1.12.5 (released 2019/05/06) includes fixes to the compiler, the linker,
+the go command, the runtime, and the <code>os</code> package. See the
+<a href="https://github.com/golang/go/issues?q=milestone%3AGo1.12.5">Go
+1.12.5 milestone</a> on our issue tracker for details.
+</p>
+
 <h2 id="go1.11">go1.11 (released 2018/08/24)</h2>
 
 <p>
@@ -66,6 +112,48 @@ See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.11.4+labe
 1.11.4 milestone</a> on our issue tracker for details.
 </p>
 
+<p>
+go1.11.5 (released 2019/01/23) includes a security fix to the
+<code>crypto/elliptic</code> package.  See
+the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.11.5">Go
+1.11.5 milestone</a> on our issue tracker for details.
+</p>
+
+<p>
+go1.11.6 (released 2019/03/14) includes fixes to cgo, the compiler, linker,
+runtime, go command, and the <code>crypto/x509</code>, <code>encoding/json</code>,
+<code>net</code>, and <code>net/url</code> packages. See the
+<a href="https://github.com/golang/go/issues?q=milestone%3AGo1.11.6">Go
+1.11.6 milestone</a> on our issue tracker for details.
+</p>
+
+<p>
+go1.11.7 (released 2019/04/05) includes fixes to the runtime and the
+<code>net</code> packages. See the
+<a href="https://github.com/golang/go/issues?q=milestone%3AGo1.11.7">Go
+1.11.7 milestone</a> on our issue tracker for details.
+</p>
+
+<p>
+go1.11.8 (released 2019/04/08) was accidentally released without its
+intended fix. It is identical to go1.11.7, except for its version
+number. The intended fix is in go1.11.9.
+</p>
+
+<p>
+go1.11.9 (released 2019/04/11) fixes an issue where using the prebuilt binary
+releases on older versions of GNU/Linux
+<a href="https://golang.org/issues/31293">led to failures</a>
+when linking programs that used cgo.
+Only Linux users who hit this issue need to update.
+</p>
+
+<p>
+go1.11.10 (released 2019/05/06) includes fixes to the runtime and the linker.
+See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.11.10">Go
+1.11.10 milestone</a> on our issue tracker for details.
+</p>
+
 <h2 id="go1.10">go1.10 (released 2018/02/16)</h2>
 
 <p>
@@ -131,6 +219,13 @@ See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.10.7+labe
 Go 1.10.7 milestone</a> on our issue tracker for details.
 </p>
 
+<p>
+go1.10.8 (released 2019/01/23) includes a security fix to the
+<code>crypto/elliptic</code> package.  See
+the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.10.8">Go
+1.10.8 milestone</a> on our issue tracker for details.
+</p>
+
 <h2 id="go1.9">go1.9 (released 2017/08/24)</h2>
 
 <p>

doc/go1.12.html

@@ -15,14 +15,7 @@ Do not send CLs removing the interior tags from such phrases.
   ul li { margin: 0.5em 0; }
 </style>
 
-<h2 id="introduction">DRAFT RELEASE NOTES - Introduction to Go 1.12</h2>
-
-<p>
-  <strong>
-    Go 1.12 is not yet released. These are work-in-progress
-    release notes. Go 1.12 is expected to be released in February 2019.
-  </strong>
-</p>
+<h2 id="introduction">Introduction to Go 1.12</h2>
 
 <p>
   The latest Go release, version 1.12, arrives six months after <a href="go1.11">Go 1.11</a>.
@@ -109,7 +102,7 @@ Do not send CLs removing the interior tags from such phrases.
   is no longer available with <code>go vet</code>. Checking for
   variable shadowing may now be done using
 <pre>
-go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow
+go get -u golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow
 go vet -vettool=$(which shadow)
 </pre>
 </p>
@@ -121,7 +114,7 @@ The Go tour is no longer included in the main binary distribution. To
 run the tour locally, instead of running <code>go</code> <code>tool</code> <code>tour</code>,
 manually install it:
 <pre>
-go install golang.org/x/tour
+go get -u golang.org/x/tour
 tour
 </pre>
 </p>
@@ -192,6 +185,17 @@ tour
   that build fails.
 </p>
 
+<p><!-- CL 147282, 147281 -->
+  This changed use of the <code>go</code> directive means that if you
+  use Go 1.12 to build a module, thus recording <code>go 1.12</code>
+  in the <code>go.mod</code> file, you will get an error when
+  attempting to build the same module with Go 1.11 through Go 1.11.3.
+  Go 1.11.4 or later will work fine, as will releases older than Go 1.11.
+  If you must use Go 1.11 through 1.11.3, you can avoid the problem by
+  setting the language version to 1.11, using the Go 1.12 go tool,
+  via <code>go mod edit -go=1.11</code>.
+</p>
+
 <p><!-- CL 152739 -->
   When an import cannot be resolved using the active modules,
   the <code>go</code> command will now try to use the modules mentioned in the
@@ -303,7 +307,9 @@ for {
 <p>
   In Go 1.12, <code>godoc</code> no longer has a command-line interface and
   is only a web server. Users should use <code>go</code> <code>doc</code>
-  for command-line help output instead.
+  for command-line help output instead. Go 1.12 is the last release that will
+  include the <code>godoc</code> webserver; in Go 1.13 it will be available
+  via <code>go</code> <code>get</code>.
 </p>
 
 <p><!-- CL 141977 -->
@@ -493,8 +499,11 @@ for {
 <dl id="crypto/rc4"><dt><a href="/pkg/crypto/rc4/">crypto/rc4</a></dt>
   <dd>
     <p><!-- CL 130397 -->
-      This release removes the optimized assembly implementations. RC4 is insecure
-      and should only be used for compatibility with legacy systems.
+      This release removes the assembly implementations, leaving only
+      the pure Go version. The Go compiler generates code that is
+      either slightly better or slightly worse, depending on the exact
+      CPU. RC4 is insecure and should only be used for compatibility
+      with legacy systems.
     </p>
 
 </dl><!-- crypto/rc4 -->
@@ -602,17 +611,6 @@ for {
 
 </dl><!-- io -->
 
-<dl id="lib/time"><dt><a href="/pkg/lib/time/">lib/time</a></dt>
-  <dd>
-    <p><!-- CL 151299 -->
-      The time zone database in <code>$GOROOT/lib/time/zoneinfo.zip</code>
-      has been updated to version 2018i. Note that this ZIP file is
-      only used if a time zone database is not provided by the operating
-      system.
-    </p>
-
-</dl><!-- lib/time -->
-
 <dl id="math"><dt><a href="/pkg/math/">math</a></dt>
   <dd>
     <p><!-- CL 153059 -->
@@ -689,6 +687,20 @@ for {
 
 </dl><!-- net/http -->
 
+<dl id="net/url"><dt><a href="/pkg/net/url/">net/url</a></dt>
+  <dd>
+    <p><!-- CL 159157, CL 160178 -->
+      <a href="/pkg/net/url/#Parse"><code>Parse</code></a>,
+      <a href="/pkg/net/url/#ParseRequestURI"><code>ParseRequestURI</code></a>,
+      and
+      <a href="/pkg/net/url/#URL.Parse"><code>URL.Parse</code></a>
+      now return an
+      error for URLs containing ASCII control characters, which includes NULL,
+      tab, and newlines.
+    </p>
+
+</dl><!-- net/url -->
+
 <dl id="net/http/httputil"><dt><a href="/pkg/net/http/httputil/">net/http/httputil</a></dt>
   <dd>
     <p><!-- CL 146437 -->
@@ -779,7 +791,7 @@ for {
       A new <a href="/pkg/runtime/debug/#BuildInfo"><code>BuildInfo</code></a> type
       exposes the build information read from the running binary, available only in
       binaries built with module support. This includes the main package path, main
-      module information, and the module dependencies. This type is given though the
+      module information, and the module dependencies. This type is given through the
       <a href="/pkg/runtime/debug/#ReadBuildInfo"><code>ReadBuildInfo</code></a> function
       on <a href="/pkg/runtime/debug/#BuildInfo"><code>BuildInfo</code></a>.
     </p>
@@ -912,6 +924,17 @@ for {
     </p>
 </dl><!-- text/template -->
 
+<dl id="time"><dt><a href="/pkg/time/">time</a></dt>
+  <dd>
+    <p><!-- CL 151299 -->
+      The time zone database in <code>$GOROOT/lib/time/zoneinfo.zip</code>
+      has been updated to version 2018i. Note that this ZIP file is
+      only used if a time zone database is not provided by the operating
+      system.
+    </p>
+
+</dl><!-- time -->
+
 <dl id="unsafe"><dt><a href="/pkg/unsafe/">unsafe</a></dt>
   <dd>
     <p><!-- CL 146058 -->

doc/install-source.html

@@ -349,15 +349,7 @@ provides <b>essential setup instructions</b> for using the Go tools.
 <p>
 The source code for several Go tools (including <a href="/cmd/godoc/">godoc</a>)
 is kept in <a href="https://golang.org/x/tools">the go.tools repository</a>.
-To install all of them, run the <code>go</code> <code>get</code> command:
-</p>
-
-<pre>
-$ go get golang.org/x/tools/cmd/...
-</pre>
-
-<p>
-Or if you just want to install a specific command (<code>godoc</code> in this case):
+To install one of the tools (<code>godoc</code> in this case):
 </p>
 
 <pre>
@@ -374,16 +366,6 @@ You must also have a workspace (<code>GOPATH</code>) set up;
 see <a href="/doc/code.html">How to Write Go Code</a> for the details.
 </p>
 
-<p>
-<b>Note</b>: The <code>go</code> command will install the <code>godoc</code>
-binary to <code>$GOROOT/bin</code> (or <code>$GOBIN</code>) and the
-<code>cover</code> and <code>vet</code> binaries to
-<code>$GOROOT/pkg/tool/$GOOS_$GOARCH</code>.
-You can access the latter commands with
-"<code>go</code> <code>tool</code> <code>cover</code>" and
-"<code>go</code> <code>tool</code> <code>vet</code>".
-</p>
-
 <h2 id="community">Community resources</h2>
 
 <p>

misc/cgo/test/testdata/issue30527.go

@@ -0,0 +1,14 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 30527: function call rewriting casts untyped
+// constants to int because of ":=" usage.
+
+package cgotest
+
+import "cgotest/issue30527"
+
+func issue30527G() {
+	issue30527.G(nil)
+}

misc/cgo/test/testdata/issue30527/a.go

@@ -0,0 +1,19 @@
+// Copyright 2019 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 issue30527
+
+import "math"
+
+/*
+#include <inttypes.h>
+
+static void issue30527F(char **p, uint64_t mod, uint32_t unused) {}
+*/
+import "C"
+
+func G(p **C.char) {
+	C.issue30527F(p, math.MaxUint64, 1)
+	C.issue30527F(p, 1<<64-1, Z)
+}

misc/cgo/test/testdata/issue30527/b.go

@@ -0,0 +1,11 @@
+// Copyright 2019 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 issue30527
+
+const (
+	X = 1 << iota
+	Y
+	Z
+)

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

@@ -261,6 +261,18 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	ORRW	$0x1b000, R2, R3                    // ORRW	$110592, R2, R3                 // 1b0096523b00a07243001b2a
 	TSTW	$0x500000, R1                       // TSTW	$5242880, R1                    // 1b0aa0523f001b6a
 	TSTW	$0xff00ff, R1                       // TSTW	$16711935, R1                   // 3f9c0072
+	TSTW	$0x60060, R5                        // TSTW	$393312, R5                     // 1b0c8052db00a072bf001b6a
+	TSTW	$0x6006000060060, R5                // TSTW	$1689262177517664, R5           // 1b0c8052db00a072bf001b6a
+	ANDW	$0x6006000060060, R5                // ANDW	$1689262177517664, R5           // 1b0c8052db00a072a5001b0a
+	ANDSW	$0x6006000060060, R5                // ANDSW	$1689262177517664, R5           // 1b0c8052db00a072a5001b6a
+	EORW	$0x6006000060060, R5                // EORW	$1689262177517664, R5           // 1b0c8052db00a072a5001b4a
+	ORRW	$0x6006000060060, R5                // ORRW	$1689262177517664, R5           // 1b0c8052db00a072a5001b2a
+	BICW	$0x6006000060060, R5                // BICW	$1689262177517664, R5           // 1b0c8052db00a072a5003b0a
+	EONW	$0x6006000060060, R5                // EONW	$1689262177517664, R5           // 1b0c8052db00a072a5003b4a
+	ORNW	$0x6006000060060, R5                // ORNW	$1689262177517664, R5           // 1b0c8052db00a072a5003b2a
+	BICSW	$0x6006000060060, R5                // BICSW	$1689262177517664, R5           // 1b0c8052db00a072a5003b6a
+	ADDW	$0x60060, R2                        // ADDW	$393312, R2                     // 4280011142804111
+	CMPW	$0x60060, R2                        // CMPW	$393312, R2                     // 1b0c8052db00a0725f001b6b
 
 	AND	$8, R0, RSP // 1f007d92
 	ORR	$8, R0, RSP // 1f007db2

src/cmd/cgo/ast.go

@@ -200,18 +200,6 @@ func (f *File) saveExprs(x interface{}, context astContext) {
 		}
 	case *ast.CallExpr:
 		f.saveCall(x, context)
-	case *ast.GenDecl:
-		if x.Tok == token.CONST {
-			for _, spec := range x.Specs {
-				vs := spec.(*ast.ValueSpec)
-				if vs.Type == nil {
-					for _, name := range spec.(*ast.ValueSpec).Names {
-						consts[name.Name] = true
-					}
-				}
-			}
-		}
-
 	}
 }
 

src/cmd/cgo/gcc.go

@@ -897,21 +897,16 @@ func (p *Package) rewriteCall(f *File, call *Call) (string, bool) {
 			needsUnsafe = true
 		}
 
-		// Explicitly convert untyped constants to the
-		// parameter type, to avoid a type mismatch.
-		if p.isConst(f, arg) {
-			ptype := p.rewriteUnsafe(param.Go)
+		// Use "var x T = ..." syntax to explicitly convert untyped
+		// constants to the parameter type, to avoid a type mismatch.
+		ptype := p.rewriteUnsafe(param.Go)
+
+		if !p.needsPointerCheck(f, param.Go, args[i]) || param.BadPointer {
 			if ptype != param.Go {
 				needsUnsafe = true
 			}
-			arg = &ast.CallExpr{
-				Fun:  ptype,
-				Args: []ast.Expr{arg},
-			}
-		}
-
-		if !p.needsPointerCheck(f, param.Go, args[i]) {
-			fmt.Fprintf(&sb, "_cgo%d := %s; ", i, gofmtPos(arg, origArg.Pos()))
+			fmt.Fprintf(&sb, "var _cgo%d %s = %s; ", i,
+				gofmtLine(ptype), gofmtPos(arg, origArg.Pos()))
 			continue
 		}
 
@@ -1254,47 +1249,6 @@ func (p *Package) isType(t ast.Expr) bool {
 	return false
 }
 
-// isConst reports whether x is an untyped constant expression.
-func (p *Package) isConst(f *File, x ast.Expr) bool {
-	switch x := x.(type) {
-	case *ast.BasicLit:
-		return true
-	case *ast.SelectorExpr:
-		id, ok := x.X.(*ast.Ident)
-		if !ok || id.Name != "C" {
-			return false
-		}
-		name := f.Name[x.Sel.Name]
-		if name != nil {
-			return name.IsConst()
-		}
-	case *ast.Ident:
-		return x.Name == "nil" ||
-			strings.HasPrefix(x.Name, "_Ciconst_") ||
-			strings.HasPrefix(x.Name, "_Cfconst_") ||
-			strings.HasPrefix(x.Name, "_Csconst_") ||
-			consts[x.Name]
-	case *ast.UnaryExpr:
-		return p.isConst(f, x.X)
-	case *ast.BinaryExpr:
-		return p.isConst(f, x.X) && p.isConst(f, x.Y)
-	case *ast.ParenExpr:
-		return p.isConst(f, x.X)
-	case *ast.CallExpr:
-		// Calling the builtin function complex on two untyped
-		// constants returns an untyped constant.
-		// TODO: It's possible to construct a case that will
-		// erroneously succeed if there is a local function
-		// named "complex", shadowing the builtin, that returns
-		// a numeric type. I can't think of any cases that will
-		// erroneously fail.
-		if id, ok := x.Fun.(*ast.Ident); ok && id.Name == "complex" && len(x.Args) == 2 {
-			return p.isConst(f, x.Args[0]) && p.isConst(f, x.Args[1])
-		}
-	}
-	return false
-}
-
 // isVariable reports whether x is a variable, possibly with field references.
 func (p *Package) isVariable(x ast.Expr) bool {
 	switch x := x.(type) {
@@ -2511,13 +2465,16 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 			// Treat this typedef as a uintptr.
 			s := *sub
 			s.Go = c.uintptr
+			s.BadPointer = true
 			sub = &s
 			// Make sure we update any previously computed type.
 			if oldType := typedef[name.Name]; oldType != nil {
 				oldType.Go = sub.Go
+				oldType.BadPointer = true
 			}
 		}
 		t.Go = name
+		t.BadPointer = sub.BadPointer
 		if unionWithPointer[sub.Go] {
 			unionWithPointer[t.Go] = true
 		}
@@ -2527,6 +2484,7 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		if oldType == nil {
 			tt := *t
 			tt.Go = sub.Go
+			tt.BadPointer = sub.BadPointer
 			typedef[name.Name] = &tt
 		}
 

src/cmd/cgo/main.go

@@ -71,9 +71,6 @@ type File struct {
 	Edit     *edit.Buffer
 }
 
-// Untyped constants in the current package.
-var consts = make(map[string]bool)
-
 func (f *File) offset(p token.Pos) int {
 	return fset.Position(p).Offset
 }
@@ -154,6 +151,7 @@ type Type struct {
 	Go         ast.Expr
 	EnumValues map[string]int64
 	Typedef    string
+	BadPointer bool
 }
 
 // A FuncType collects information about a function type in both the C and Go worlds.

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

@@ -24,6 +24,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue

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

@@ -19,6 +19,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = func(s *gc.SSAGenState, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue

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

@@ -19,6 +19,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = func(s *gc.SSAGenState, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue

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

@@ -127,7 +127,7 @@ func assembleInlines(fnsym *obj.LSym, dwVars []*dwarf.Var) dwarf.InlCalls {
 				DeclLine: v.DeclLine,
 				DeclCol:  v.DeclCol,
 			}
-			synthesized := strings.HasPrefix(v.Name, "~r") || canonName == "_"
+			synthesized := strings.HasPrefix(v.Name, "~r") || canonName == "_" || strings.HasPrefix(v.Name, "~b")
 			if idx, found := m[vp]; found {
 				v.ChildIndex = int32(idx)
 				v.IsInAbstract = !synthesized

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

@@ -2105,6 +2105,16 @@ func (e *EscState) escwalkBody(level Level, dst *Node, src *Node, step *EscStep,
 				step.describe(src)
 			}
 			extraloopdepth = modSrcLoopdepth
+			if src.Op == OCONVIFACE {
+				lt := src.Left.Type
+				if !lt.IsInterface() && !isdirectiface(lt) && types.Haspointers(lt) {
+					// We're converting from a non-direct interface type.
+					// The interface will hold a heap copy of the data
+					// (by calling convT2I or friend). Flow the data to heap.
+					// See issue 29353.
+					e.escwalk(level, &e.theSink, src.Left, e.stepWalk(dst, src.Left, "interface-converted", step))
+				}
+			}
 		}
 
 	case ODOT,

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

@@ -255,9 +255,10 @@ type Arch struct {
 	Use387    bool // should 386 backend use 387 FP instructions instead of sse2.
 	SoftFloat bool
 
-	PadFrame  func(int64) int64
-	ZeroRange func(*Progs, *obj.Prog, int64, int64, *uint32) *obj.Prog
-	Ginsnop   func(*Progs) *obj.Prog
+	PadFrame     func(int64) int64
+	ZeroRange    func(*Progs, *obj.Prog, int64, int64, *uint32) *obj.Prog
+	Ginsnop      func(*Progs) *obj.Prog
+	Ginsnopdefer func(*Progs) *obj.Prog // special ginsnop for deferreturn
 
 	// SSAMarkMoves marks any MOVXconst ops that need to avoid clobbering flags.
 	SSAMarkMoves func(*SSAGenState, *ssa.Block)

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

@@ -287,7 +287,7 @@ func addGCLocals() {
 			}
 		}
 		if x := s.Func.StackObjects; x != nil {
-			ggloblsym(x, int32(len(x.P)), obj.RODATA|obj.LOCAL)
+			ggloblsym(x, int32(len(x.P)), obj.RODATA|obj.DUPOK)
 		}
 	}
 }

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

@@ -1108,10 +1108,10 @@ func (o *Order) expr(n, lhs *Node) *Node {
 		if n.Left.Type.IsInterface() {
 			break
 		}
-		if _, needsaddr := convFuncName(n.Left.Type, n.Type); needsaddr || consttype(n.Left) > 0 {
+		if _, needsaddr := convFuncName(n.Left.Type, n.Type); needsaddr || isStaticCompositeLiteral(n.Left) {
 			// Need a temp if we need to pass the address to the conversion function.
-			// We also process constants here, making a named static global whose
-			// address we can put directly in an interface (see OCONVIFACE case in walk).
+			// We also process static composite literal node here, making a named static global
+			// whose address we can put directly in an interface (see OCONVIFACE case in walk).
 			n.Left = o.addrTemp(n.Left)
 		}
 
@@ -1130,14 +1130,40 @@ func (o *Order) expr(n, lhs *Node) *Node {
 		}
 
 	case OANDAND, OOROR:
-		mark := o.markTemp()
-		n.Left = o.expr(n.Left, nil)
+		// ... = LHS && RHS
+		//
+		// var r bool
+		// r = LHS
+		// if r {       // or !r, for OROR
+		//     r = RHS
+		// }
+		// ... = r
 
-		// Clean temporaries from first branch at beginning of second.
-		// Leave them on the stack so that they can be killed in the outer
-		// context in case the short circuit is taken.
-		n.Right = addinit(n.Right, o.cleanTempNoPop(mark))
-		n.Right = o.exprInPlace(n.Right)
+		r := o.newTemp(n.Type, false)
+
+		// Evaluate left-hand side.
+		lhs := o.expr(n.Left, nil)
+		o.out = append(o.out, typecheck(nod(OAS, r, lhs), ctxStmt))
+
+		// Evaluate right-hand side, save generated code.
+		saveout := o.out
+		o.out = nil
+		t := o.markTemp()
+		rhs := o.expr(n.Right, nil)
+		o.out = append(o.out, typecheck(nod(OAS, r, rhs), ctxStmt))
+		o.cleanTemp(t)
+		gen := o.out
+		o.out = saveout
+
+		// If left-hand side doesn't cause a short-circuit, issue right-hand side.
+		nif := nod(OIF, r, nil)
+		if n.Op == OANDAND {
+			nif.Nbody.Set(gen)
+		} else {
+			nif.Rlist.Set(gen)
+		}
+		o.out = append(o.out, nif)
+		n = r
 
 	case OCALLFUNC,
 		OCALLINTER,

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

@@ -267,7 +267,7 @@ func compile(fn *Node) {
 					// Also make sure we allocate a linker symbol
 					// for the stack object data, for the same reason.
 					if fn.Func.lsym.Func.StackObjects == nil {
-						fn.Func.lsym.Func.StackObjects = lookup(fmt.Sprintf("%s.stkobj", fn.funcname())).Linksym()
+						fn.Func.lsym.Func.StackObjects = Ctxt.Lookup(fn.Func.lsym.Name + ".stkobj")
 					}
 				}
 			}
@@ -597,8 +597,22 @@ func createDwarfVars(fnsym *obj.LSym, fn *Func, automDecls []*Node) ([]*Node, []
 		typename := dwarf.InfoPrefix + typesymname(n.Type)
 		decls = append(decls, n)
 		abbrev := dwarf.DW_ABRV_AUTO_LOCLIST
+		isReturnValue := (n.Class() == PPARAMOUT)
 		if n.Class() == PPARAM || n.Class() == PPARAMOUT {
 			abbrev = dwarf.DW_ABRV_PARAM_LOCLIST
+		} else if n.Class() == PAUTOHEAP {
+			// If dcl in question has been promoted to heap, do a bit
+			// of extra work to recover original class (auto or param);
+			// see issue 30908. This insures that we get the proper
+			// signature in the abstract function DIE, but leaves a
+			// misleading location for the param (we want pointer-to-heap
+			// and not stack).
+			// TODO(thanm): generate a better location expression
+			stackcopy := n.Name.Param.Stackcopy
+			if stackcopy != nil && (stackcopy.Class() == PPARAM || stackcopy.Class() == PPARAMOUT) {
+				abbrev = dwarf.DW_ABRV_PARAM_LOCLIST
+				isReturnValue = (stackcopy.Class() == PPARAMOUT)
+			}
 		}
 		inlIndex := 0
 		if genDwarfInline > 1 {
@@ -612,7 +626,7 @@ func createDwarfVars(fnsym *obj.LSym, fn *Func, automDecls []*Node) ([]*Node, []
 		declpos := Ctxt.InnermostPos(n.Pos)
 		vars = append(vars, &dwarf.Var{
 			Name:          n.Sym.Name,
-			IsReturnValue: n.Class() == PPARAMOUT,
+			IsReturnValue: isReturnValue,
 			Abbrev:        abbrev,
 			StackOffset:   int32(n.Xoffset),
 			Type:          Ctxt.Lookup(typename),

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

@@ -993,26 +993,32 @@ func (s *state) stmt(n *Node) {
 		s.assign(n.Left, r, deref, skip)
 
 	case OIF:
-		bThen := s.f.NewBlock(ssa.BlockPlain)
 		bEnd := s.f.NewBlock(ssa.BlockPlain)
-		var bElse *ssa.Block
 		var likely int8
 		if n.Likely() {
 			likely = 1
 		}
+		var bThen *ssa.Block
+		if n.Nbody.Len() != 0 {
+			bThen = s.f.NewBlock(ssa.BlockPlain)
+		} else {
+			bThen = bEnd
+		}
+		var bElse *ssa.Block
 		if n.Rlist.Len() != 0 {
 			bElse = s.f.NewBlock(ssa.BlockPlain)
-			s.condBranch(n.Left, bThen, bElse, likely)
 		} else {
-			s.condBranch(n.Left, bThen, bEnd, likely)
+			bElse = bEnd
 		}
+		s.condBranch(n.Left, bThen, bElse, likely)
 
-		s.startBlock(bThen)
-		s.stmtList(n.Nbody)
-		if b := s.endBlock(); b != nil {
-			b.AddEdgeTo(bEnd)
+		if n.Nbody.Len() != 0 {
+			s.startBlock(bThen)
+			s.stmtList(n.Nbody)
+			if b := s.endBlock(); b != nil {
+				b.AddEdgeTo(bEnd)
+			}
 		}
-
 		if n.Rlist.Len() != 0 {
 			s.startBlock(bElse)
 			s.stmtList(n.Rlist)
@@ -5597,7 +5603,7 @@ func (s *SSAGenState) PrepareCall(v *ssa.Value) {
 		// insert an actual hardware NOP that will have the right line number.
 		// This is different from obj.ANOP, which is a virtual no-op
 		// that doesn't make it into the instruction stream.
-		thearch.Ginsnop(s.pp)
+		thearch.Ginsnopdefer(s.pp)
 	}
 
 	if sym, ok := v.Aux.(*obj.LSym); ok {

src/cmd/compile/internal/mips/galign.go

@@ -22,6 +22,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 	arch.SSAMarkMoves = func(s *gc.SSAGenState, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue
 	arch.SSAGenBlock = ssaGenBlock

src/cmd/compile/internal/mips64/galign.go

@@ -22,6 +22,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = func(s *gc.SSAGenState, b *ssa.Block) {}
 	arch.SSAGenValue = ssaGenValue

src/cmd/compile/internal/ppc64/galign.go

@@ -20,7 +20,8 @@ func Init(arch *gc.Arch) {
 
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
-	arch.Ginsnop = ginsnop2
+	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop2
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue

src/cmd/compile/internal/s390x/galign.go

@@ -17,6 +17,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue

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

@@ -1220,6 +1220,13 @@ func (s *regAllocState) regalloc(f *Func) {
 					// This forces later liveness analysis to make the
 					// value live at this point.
 					v.SetArg(0, s.makeSpill(a, b))
+				} else if _, ok := a.Aux.(GCNode); ok && vi.rematerializeable {
+					// Rematerializeable value with a gc.Node. This is the address of
+					// a stack object (e.g. an LEAQ). Keep the object live.
+					// Change it to VarLive, which is what plive expects for locals.
+					v.Op = OpVarLive
+					v.SetArgs1(v.Args[1])
+					v.Aux = a.Aux
 				} else {
 					// In-register and rematerializeable values are already live.
 					// These are typically rematerializeable constants like nil,

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

@@ -1141,7 +1141,7 @@ func symIsRO(sym interface{}) bool {
 // read8 reads one byte from the read-only global sym at offset off.
 func read8(sym interface{}, off int64) uint8 {
 	lsym := sym.(*obj.LSym)
-	if off >= int64(len(lsym.P)) {
+	if off >= int64(len(lsym.P)) || off < 0 {
 		// Invalid index into the global sym.
 		// This can happen in dead code, so we don't want to panic.
 		// Just return any value, it will eventually get ignored.
@@ -1154,7 +1154,7 @@ func read8(sym interface{}, off int64) uint8 {
 // read16 reads two bytes from the read-only global sym at offset off.
 func read16(sym interface{}, off int64, bigEndian bool) uint16 {
 	lsym := sym.(*obj.LSym)
-	if off >= int64(len(lsym.P))-1 {
+	if off >= int64(len(lsym.P))-1 || off < 0 {
 		return 0
 	}
 	if bigEndian {
@@ -1167,7 +1167,7 @@ func read16(sym interface{}, off int64, bigEndian bool) uint16 {
 // read32 reads four bytes from the read-only global sym at offset off.
 func read32(sym interface{}, off int64, bigEndian bool) uint32 {
 	lsym := sym.(*obj.LSym)
-	if off >= int64(len(lsym.P))-3 {
+	if off >= int64(len(lsym.P))-3 || off < 0 {
 		return 0
 	}
 	if bigEndian {
@@ -1180,7 +1180,7 @@ func read32(sym interface{}, off int64, bigEndian bool) uint32 {
 // read64 reads eight bytes from the read-only global sym at offset off.
 func read64(sym interface{}, off int64, bigEndian bool) uint64 {
 	lsym := sym.(*obj.LSym)
-	if off >= int64(len(lsym.P))-7 {
+	if off >= int64(len(lsym.P))-7 || off < 0 {
 		return 0
 	}
 	if bigEndian {

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

@@ -196,6 +196,43 @@ func writebarrier(f *Func) {
 		// and simple store version to bElse
 		memThen := mem
 		memElse := mem
+
+		// If the source of a MoveWB is volatile (will be clobbered by a
+		// function call), we need to copy it to a temporary location, as
+		// marshaling the args of typedmemmove might clobber the value we're
+		// trying to move.
+		// Look for volatile source, copy it to temporary before we emit any
+		// call.
+		// It is unlikely to have more than one of them. Just do a linear
+		// search instead of using a map.
+		type volatileCopy struct {
+			src *Value // address of original volatile value
+			tmp *Value // address of temporary we've copied the volatile value into
+		}
+		var volatiles []volatileCopy
+	copyLoop:
+		for _, w := range stores {
+			if w.Op == OpMoveWB {
+				val := w.Args[1]
+				if isVolatile(val) {
+					for _, c := range volatiles {
+						if val == c.src {
+							continue copyLoop // already copied
+						}
+					}
+
+					t := val.Type.Elem()
+					tmp := f.fe.Auto(w.Pos, t)
+					memThen = bThen.NewValue1A(w.Pos, OpVarDef, types.TypeMem, tmp, memThen)
+					tmpaddr := bThen.NewValue2A(w.Pos, OpLocalAddr, t.PtrTo(), tmp, sp, memThen)
+					siz := t.Size()
+					memThen = bThen.NewValue3I(w.Pos, OpMove, types.TypeMem, siz, tmpaddr, val, memThen)
+					memThen.Aux = t
+					volatiles = append(volatiles, volatileCopy{val, tmpaddr})
+				}
+			}
+		}
+
 		for _, w := range stores {
 			ptr := w.Args[0]
 			pos := w.Pos
@@ -222,11 +259,19 @@ func writebarrier(f *Func) {
 			// then block: emit write barrier call
 			switch w.Op {
 			case OpStoreWB, OpMoveWB, OpZeroWB:
-				volatile := w.Op == OpMoveWB && isVolatile(val)
 				if w.Op == OpStoreWB {
 					memThen = bThen.NewValue3A(pos, OpWB, types.TypeMem, gcWriteBarrier, ptr, val, memThen)
 				} else {
-					memThen = wbcall(pos, bThen, fn, typ, ptr, val, memThen, sp, sb, volatile)
+					srcval := val
+					if w.Op == OpMoveWB && isVolatile(srcval) {
+						for _, c := range volatiles {
+							if srcval == c.src {
+								srcval = c.tmp
+								break
+							}
+						}
+					}
+					memThen = wbcall(pos, bThen, fn, typ, ptr, srcval, memThen, sp, sb)
 				}
 				// Note that we set up a writebarrier function call.
 				f.fe.SetWBPos(pos)
@@ -249,6 +294,12 @@ func writebarrier(f *Func) {
 			}
 		}
 
+		// mark volatile temps dead
+		for _, c := range volatiles {
+			tmpNode := c.tmp.Aux
+			memThen = bThen.NewValue1A(memThen.Pos, OpVarKill, types.TypeMem, tmpNode, memThen)
+		}
+
 		// merge memory
 		// Splice memory Phi into the last memory of the original sequence,
 		// which may be used in subsequent blocks. Other memories in the
@@ -302,25 +353,9 @@ func writebarrier(f *Func) {
 }
 
 // wbcall emits write barrier runtime call in b, returns memory.
-// if valIsVolatile, it moves val into temp space before making the call.
-func wbcall(pos src.XPos, b *Block, fn, typ *obj.LSym, ptr, val, mem, sp, sb *Value, valIsVolatile bool) *Value {
+func wbcall(pos src.XPos, b *Block, fn, typ *obj.LSym, ptr, val, mem, sp, sb *Value) *Value {
 	config := b.Func.Config
 
-	var tmp GCNode
-	if valIsVolatile {
-		// Copy to temp location if the source is volatile (will be clobbered by
-		// a function call). Marshaling the args to typedmemmove might clobber the
-		// value we're trying to move.
-		t := val.Type.Elem()
-		tmp = b.Func.fe.Auto(val.Pos, t)
-		mem = b.NewValue1A(pos, OpVarDef, types.TypeMem, tmp, mem)
-		tmpaddr := b.NewValue2A(pos, OpLocalAddr, t.PtrTo(), tmp, sp, mem)
-		siz := t.Size()
-		mem = b.NewValue3I(pos, OpMove, types.TypeMem, siz, tmpaddr, val, mem)
-		mem.Aux = t
-		val = tmpaddr
-	}
-
 	// put arguments on stack
 	off := config.ctxt.FixedFrameSize()
 
@@ -348,11 +383,6 @@ func wbcall(pos src.XPos, b *Block, fn, typ *obj.LSym, ptr, val, mem, sp, sb *Va
 	// issue call
 	mem = b.NewValue1A(pos, OpStaticCall, types.TypeMem, fn, mem)
 	mem.AuxInt = off - config.ctxt.FixedFrameSize()
-
-	if valIsVolatile {
-		mem = b.NewValue1A(pos, OpVarKill, types.TypeMem, tmp, mem) // mark temp dead
-	}
-
 	return mem
 }
 

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

@@ -20,6 +20,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zeroRange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 	arch.SSAGenValue = ssaGenValue

src/cmd/compile/internal/x86/galign.go

@@ -32,6 +32,7 @@ func Init(arch *gc.Arch) {
 	arch.ZeroRange = zerorange
 	arch.ZeroAuto = zeroAuto
 	arch.Ginsnop = ginsnop
+	arch.Ginsnopdefer = ginsnop
 
 	arch.SSAMarkMoves = ssaMarkMoves
 }

src/cmd/go/internal/cache/default.go

@@ -37,7 +37,7 @@ See golang.org to learn more about Go.
 // the first time Default is called.
 func initDefaultCache() {
 	dir := DefaultDir()
-	if dir == "off" || dir == "" {
+	if dir == "off" {
 		if defaultDirErr != nil {
 			base.Fatalf("build cache is required, but could not be located: %v", defaultDirErr)
 		}
@@ -74,7 +74,12 @@ func DefaultDir() string {
 
 	defaultDirOnce.Do(func() {
 		defaultDir = os.Getenv("GOCACHE")
+		if filepath.IsAbs(defaultDir) || defaultDir == "off" {
+			return
+		}
 		if defaultDir != "" {
+			defaultDir = "off"
+			defaultDirErr = fmt.Errorf("GOCACHE is not an absolute path")
 			return
 		}
 

src/cmd/go/internal/get/vcs.go

@@ -424,8 +424,8 @@ func (v *vcsCmd) run1(dir string, cmdline string, keyval []string, verbose bool)
 	cmd.Dir = dir
 	cmd.Env = base.EnvForDir(cmd.Dir, os.Environ())
 	if cfg.BuildX {
-		fmt.Printf("cd %s\n", dir)
-		fmt.Printf("%s %s\n", v.cmd, strings.Join(args, " "))
+		fmt.Fprintf(os.Stderr, "cd %s\n", dir)
+		fmt.Fprintf(os.Stderr, "%s %s\n", v.cmd, strings.Join(args, " "))
 	}
 	out, err := cmd.Output()
 	if err != nil {

src/cmd/go/internal/imports/scan.go

@@ -26,7 +26,7 @@ func ScanDir(dir string, tags map[string]bool) ([]string, []string, error) {
 		// If the directory entry is a symlink, stat it to obtain the info for the
 		// link target instead of the link itself.
 		if info.Mode()&os.ModeSymlink != 0 {
-			info, err = os.Stat(name)
+			info, err = os.Stat(filepath.Join(dir, name))
 			if err != nil {
 				continue // Ignore broken symlinks.
 			}

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

@@ -1178,6 +1178,36 @@ var cgoSyscallExclude = map[string]bool{
 
 var foldPath = make(map[string]string)
 
+// DefaultExecName returns the default executable name
+// for a package with the import path importPath.
+//
+// The default executable name is the last element of the import path.
+// In module-aware mode, an additional rule is used. If the last element
+// is a vN path element specifying the major version, then the second last
+// element of the import path is used instead.
+func DefaultExecName(importPath string) string {
+	_, elem := pathpkg.Split(importPath)
+	if cfg.ModulesEnabled {
+		// If this is example.com/mycmd/v2, it's more useful to install it as mycmd than as v2.
+		// See golang.org/issue/24667.
+		isVersion := func(v string) bool {
+			if len(v) < 2 || v[0] != 'v' || v[1] < '1' || '9' < v[1] {
+				return false
+			}
+			for i := 2; i < len(v); i++ {
+				if c := v[i]; c < '0' || '9' < c {
+					return false
+				}
+			}
+			return true
+		}
+		if isVersion(elem) {
+			_, elem = pathpkg.Split(pathpkg.Dir(importPath))
+		}
+	}
+	return elem
+}
+
 // load populates p using information from bp, err, which should
 // be the result of calling build.Context.Import.
 func (p *Package) load(stk *ImportStack, bp *build.Package, err error) {
@@ -1220,7 +1250,7 @@ func (p *Package) load(stk *ImportStack, bp *build.Package, err error) {
 		}
 		_, elem := filepath.Split(p.Dir)
 		if cfg.ModulesEnabled {
-			// NOTE(rsc): Using p.ImportPath instead of p.Dir
+			// NOTE(rsc,dmitshur): Using p.ImportPath instead of p.Dir
 			// makes sure we install a package in the root of a
 			// cached module directory as that package name
 			// not name@v1.2.3.
@@ -1229,26 +1259,9 @@ func (p *Package) load(stk *ImportStack, bp *build.Package, err error) {
 			// even for non-module-enabled code,
 			// but I'm not brave enough to change the
 			// non-module behavior this late in the
-			// release cycle. Maybe for Go 1.12.
+			// release cycle. Can be done for Go 1.13.
 			// See golang.org/issue/26869.
-			_, elem = pathpkg.Split(p.ImportPath)
-
-			// If this is example.com/mycmd/v2, it's more useful to install it as mycmd than as v2.
-			// See golang.org/issue/24667.
-			isVersion := func(v string) bool {
-				if len(v) < 2 || v[0] != 'v' || v[1] < '1' || '9' < v[1] {
-					return false
-				}
-				for i := 2; i < len(v); i++ {
-					if c := v[i]; c < '0' || '9' < c {
-						return false
-					}
-				}
-				return true
-			}
-			if isVersion(elem) {
-				_, elem = pathpkg.Split(pathpkg.Dir(p.ImportPath))
-			}
+			elem = DefaultExecName(p.ImportPath)
 		}
 		full := cfg.BuildContext.GOOS + "_" + cfg.BuildContext.GOARCH + "/" + elem
 		if cfg.BuildContext.GOOS != base.ToolGOOS || cfg.BuildContext.GOARCH != base.ToolGOARCH {

src/cmd/go/internal/load/test.go

@@ -129,6 +129,7 @@ func TestPackagesFor(p *Package, cover *TestCover) (pmain, ptest, pxtest *Packag
 		ptest.Internal.Imports = append(imports, p.Internal.Imports...)
 		ptest.Internal.RawImports = str.StringList(rawTestImports, p.Internal.RawImports)
 		ptest.Internal.ForceLibrary = true
+		ptest.Internal.BuildInfo = ""
 		ptest.Internal.Build = new(build.Package)
 		*ptest.Internal.Build = *p.Internal.Build
 		m := map[string][]token.Position{}
@@ -186,6 +187,7 @@ func TestPackagesFor(p *Package, cover *TestCover) (pmain, ptest, pxtest *Packag
 		},
 		Internal: PackageInternal{
 			Build:      &build.Package{Name: "main"},
+			BuildInfo:  p.Internal.BuildInfo,
 			Asmflags:   p.Internal.Asmflags,
 			Gcflags:    p.Internal.Gcflags,
 			Ldflags:    p.Internal.Ldflags,
@@ -266,17 +268,8 @@ func TestPackagesFor(p *Package, cover *TestCover) (pmain, ptest, pxtest *Packag
 	pmain.Imports = pmain.Imports[:w]
 	pmain.Internal.RawImports = str.StringList(pmain.Imports)
 
-	if ptest != p {
-		// We have made modifications to the package p being tested
-		// and are rebuilding p (as ptest).
-		// Arrange to rebuild all packages q such that
-		// the test depends on q and q depends on p.
-		// This makes sure that q sees the modifications to p.
-		// Strictly speaking, the rebuild is only necessary if the
-		// modifications to p change its export metadata, but
-		// determining that is a bit tricky, so we rebuild always.
-		recompileForTest(pmain, p, ptest, pxtest)
-	}
+	// Replace pmain's transitive dependencies with test copies, as necessary.
+	recompileForTest(pmain, p, ptest, pxtest)
 
 	// Should we apply coverage analysis locally,
 	// only for this package and only for this test?
@@ -323,6 +316,14 @@ Search:
 	return stk
 }
 
+// recompileForTest copies and replaces certain packages in pmain's dependency
+// graph. This is necessary for two reasons. First, if ptest is different than
+// preal, packages that import the package under test should get ptest instead
+// of preal. This is particularly important if pxtest depends on functionality
+// exposed in test sources in ptest. Second, if there is a main package
+// (other than pmain) anywhere, we need to clear p.Internal.BuildInfo in
+// the test copy to prevent link conflicts. This may happen if both -coverpkg
+// and the command line patterns include multiple main packages.
 func recompileForTest(pmain, preal, ptest, pxtest *Package) {
 	// The "test copy" of preal is ptest.
 	// For each package that depends on preal, make a "test copy"
@@ -352,6 +353,7 @@ func recompileForTest(pmain, preal, ptest, pxtest *Package) {
 			copy(p1.Imports, p.Imports)
 			p = p1
 			p.Target = ""
+			p.Internal.BuildInfo = ""
 		}
 
 		// Update p.Internal.Imports to use test copies.
@@ -361,6 +363,13 @@ func recompileForTest(pmain, preal, ptest, pxtest *Package) {
 				p.Internal.Imports[i] = p1
 			}
 		}
+
+		// Don't compile build info from a main package. This can happen
+		// if -coverpkg patterns include main packages, since those packages
+		// are imported by pmain. See golang.org/issue/30907.
+		if p.Internal.BuildInfo != "" && p != pmain {
+			split()
+		}
 	}
 }
 

src/cmd/go/internal/modfetch/coderepo.go

@@ -23,55 +23,99 @@ import (
 type codeRepo struct {
 	modPath string
 
-	code     codehost.Repo
+	// code is the repository containing this module.
+	code codehost.Repo
+	// codeRoot is the import path at the root of code.
 	codeRoot string
-	codeDir  string
+	// codeDir is the directory (relative to root) at which we expect to find the module.
+	// If pathMajor is non-empty and codeRoot is not the full modPath,
+	// then we look in both codeDir and codeDir+modPath
+	codeDir string
 
-	path        string
-	pathPrefix  string
-	pathMajor   string
+	// pathMajor is the suffix of modPath that indicates its major version,
+	// or the empty string if modPath is at major version 0 or 1.
+	//
+	// pathMajor is typically of the form "/vN", but possibly ".vN", or
+	// ".vN-unstable" for modules resolved using gopkg.in.
+	pathMajor string
+	// pathPrefix is the prefix of modPath that excludes pathMajor.
+	// It is used only for logging.
+	pathPrefix string
+
+	// pseudoMajor is the major version prefix to use when generating
+	// pseudo-versions for this module, derived from the module path.
+	//
+	// TODO(golang.org/issue/29262): We can't distinguish v0 from v1 using the
+	// path alone: we have to compute it by examining the tags at a particular
+	// revision.
 	pseudoMajor string
 }
 
-func newCodeRepo(code codehost.Repo, root, path string) (Repo, error) {
-	if !hasPathPrefix(path, root) {
-		return nil, fmt.Errorf("mismatched repo: found %s for %s", root, path)
+// newCodeRepo returns a Repo that reads the source code for the module with the
+// given path, from the repo stored in code, with the root of the repo
+// containing the path given by codeRoot.
+func newCodeRepo(code codehost.Repo, codeRoot, path string) (Repo, error) {
+	if !hasPathPrefix(path, codeRoot) {
+		return nil, fmt.Errorf("mismatched repo: found %s for %s", codeRoot, path)
 	}
 	pathPrefix, pathMajor, ok := module.SplitPathVersion(path)
 	if !ok {
 		return nil, fmt.Errorf("invalid module path %q", path)
 	}
+	if codeRoot == path {
+		pathPrefix = path
+	}
 	pseudoMajor := "v0"
 	if pathMajor != "" {
 		pseudoMajor = pathMajor[1:]
 	}
 
+	// Compute codeDir = bar, the subdirectory within the repo
+	// corresponding to the module root.
+	//
 	// At this point we might have:
-	//	codeRoot = github.com/rsc/foo
 	//	path = github.com/rsc/foo/bar/v2
+	//	codeRoot = github.com/rsc/foo
 	//	pathPrefix = github.com/rsc/foo/bar
 	//	pathMajor = /v2
 	//	pseudoMajor = v2
 	//
-	// Compute codeDir = bar, the subdirectory within the repo
-	// corresponding to the module root.
-	codeDir := strings.Trim(strings.TrimPrefix(pathPrefix, root), "/")
-	if strings.HasPrefix(path, "gopkg.in/") {
-		// But gopkg.in is a special legacy case, in which pathPrefix does not start with codeRoot.
-		// For example we might have:
-		//	codeRoot = gopkg.in/yaml.v2
-		//	pathPrefix = gopkg.in/yaml
-		//	pathMajor = .v2
-		//	pseudoMajor = v2
-		//	codeDir = pathPrefix (because codeRoot is not a prefix of pathPrefix)
-		// Clear codeDir - the module root is the repo root for gopkg.in repos.
-		codeDir = ""
+	// which gives
+	//	codeDir = bar
+	//
+	// We know that pathPrefix is a prefix of path, and codeRoot is a prefix of
+	// path, but codeRoot may or may not be a prefix of pathPrefix, because
+	// codeRoot may be the entire path (in which case codeDir should be empty).
+	// That occurs in two situations.
+	//
+	// One is when a go-import meta tag resolves the complete module path,
+	// including the pathMajor suffix:
+	//	path = nanomsg.org/go/mangos/v2
+	//	codeRoot = nanomsg.org/go/mangos/v2
+	//	pathPrefix = nanomsg.org/go/mangos
+	//	pathMajor = /v2
+	//	pseudoMajor = v2
+	//
+	// The other is similar: for gopkg.in only, the major version is encoded
+	// with a dot rather than a slash, and thus can't be in a subdirectory.
+	//	path = gopkg.in/yaml.v2
+	//	codeRoot = gopkg.in/yaml.v2
+	//	pathPrefix = gopkg.in/yaml
+	//	pathMajor = .v2
+	//	pseudoMajor = v2
+	//
+	codeDir := ""
+	if codeRoot != path {
+		if !hasPathPrefix(pathPrefix, codeRoot) {
+			return nil, fmt.Errorf("repository rooted at %s cannot contain module %s", codeRoot, path)
+		}
+		codeDir = strings.Trim(pathPrefix[len(codeRoot):], "/")
 	}
 
 	r := &codeRepo{
 		modPath:     path,
 		code:        code,
-		codeRoot:    root,
+		codeRoot:    codeRoot,
 		codeDir:     codeDir,
 		pathPrefix:  pathPrefix,
 		pathMajor:   pathMajor,
@@ -149,9 +193,6 @@ func (r *codeRepo) Stat(rev string) (*RevInfo, error) {
 		return r.Latest()
 	}
 	codeRev := r.revToRev(rev)
-	if semver.IsValid(codeRev) && r.codeDir != "" {
-		codeRev = r.codeDir + "/" + codeRev
-	}
 	info, err := r.code.Stat(codeRev)
 	if err != nil {
 		return nil, err
@@ -290,7 +331,7 @@ func (r *codeRepo) findDir(version string) (rev, dir string, gomod []byte, err e
 	found1 := err1 == nil && isMajor(mpath1, r.pathMajor)
 
 	var file2 string
-	if r.pathMajor != "" && !strings.HasPrefix(r.pathMajor, ".") {
+	if r.pathMajor != "" && r.codeRoot != r.modPath && !strings.HasPrefix(r.pathMajor, ".") {
 		// Suppose pathMajor is "/v2".
 		// Either go.mod should claim v2 and v2/go.mod should not exist,
 		// or v2/go.mod should exist and claim v2. Not both.
@@ -298,6 +339,9 @@ func (r *codeRepo) findDir(version string) (rev, dir string, gomod []byte, err e
 		// because of replacement modules. This might be a fork of
 		// the real module, found at a different path, usable only in
 		// a replace directive.
+		//
+		// TODO(bcmills): This doesn't seem right. Investigate futher.
+		// (Notably: why can't we replace foo/v2 with fork-of-foo/v3?)
 		dir2 := path.Join(r.codeDir, r.pathMajor[1:])
 		file2 = path.Join(dir2, "go.mod")
 		gomod2, err2 := r.code.ReadFile(rev, file2, codehost.MaxGoMod)
@@ -418,7 +462,7 @@ func (r *codeRepo) Zip(dst io.Writer, version string) error {
 	}
 	defer dl.Close()
 	if actualDir != "" && !hasPathPrefix(dir, actualDir) {
-		return fmt.Errorf("internal error: downloading %v %v: dir=%q but actualDir=%q", r.path, rev, dir, actualDir)
+		return fmt.Errorf("internal error: downloading %v %v: dir=%q but actualDir=%q", r.modPath, rev, dir, actualDir)
 	}
 	subdir := strings.Trim(strings.TrimPrefix(dir, actualDir), "/")
 

src/cmd/go/internal/modfetch/coderepo_test.go

@@ -323,6 +323,15 @@ var codeRepoTests = []struct {
 		time:    time.Date(2017, 5, 31, 16, 3, 50, 0, time.UTC),
 		gomod:   "module gopkg.in/natefinch/lumberjack.v2\n",
 	},
+	{
+		path:    "nanomsg.org/go/mangos/v2",
+		rev:     "v2.0.2",
+		version: "v2.0.2",
+		name:    "63f66a65137b9a648ac9f7bf0160b4a4d17d7999",
+		short:   "63f66a65137b",
+		time:    time.Date(2018, 12, 1, 15, 7, 40, 0, time.UTC),
+		gomod:   "module nanomsg.org/go/mangos/v2\n\nrequire (\n\tgithub.com/Microsoft/go-winio v0.4.11\n\tgithub.com/droundy/goopt v0.0.0-20170604162106-0b8effe182da\n\tgithub.com/gopherjs/gopherjs v0.0.0-20181103185306-d547d1d9531e // indirect\n\tgithub.com/gorilla/websocket v1.4.0\n\tgithub.com/jtolds/gls v4.2.1+incompatible // indirect\n\tgithub.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d // indirect\n\tgithub.com/smartystreets/goconvey v0.0.0-20181108003508-044398e4856c\n\tgolang.org/x/sys v0.0.0-20181128092732-4ed8d59d0b35 // indirect\n)\n",
+	},
 }
 
 func TestCodeRepo(t *testing.T) {

src/cmd/go/internal/test/test.go

@@ -805,7 +805,7 @@ func builderTest(b *work.Builder, p *load.Package) (buildAction, runAction, prin
 	if p.ImportPath == "command-line-arguments" {
 		elem = p.Name
 	} else {
-		_, elem = path.Split(p.ImportPath)
+		elem = load.DefaultExecName(p.ImportPath)
 	}
 	testBinary := elem + ".test"
 

src/cmd/go/internal/work/build.go

@@ -10,7 +10,6 @@ import (
 	"go/build"
 	"os"
 	"os/exec"
-	"path"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -285,7 +284,7 @@ func runBuild(cmd *base.Command, args []string) {
 	pkgs := load.PackagesForBuild(args)
 
 	if len(pkgs) == 1 && pkgs[0].Name == "main" && cfg.BuildO == "" {
-		_, cfg.BuildO = path.Split(pkgs[0].ImportPath)
+		cfg.BuildO = load.DefaultExecName(pkgs[0].ImportPath)
 		cfg.BuildO += cfg.ExeSuffix
 	}
 
@@ -518,7 +517,7 @@ func InstallPackages(patterns []string, pkgs []*load.Package) {
 	if len(patterns) == 0 && len(pkgs) == 1 && pkgs[0].Name == "main" {
 		// Compute file 'go build' would have created.
 		// If it exists and is an executable file, remove it.
-		_, targ := filepath.Split(pkgs[0].ImportPath)
+		targ := load.DefaultExecName(pkgs[0].ImportPath)
 		targ += cfg.ExeSuffix
 		if filepath.Join(pkgs[0].Dir, targ) != pkgs[0].Target { // maybe $GOBIN is the current directory
 			fi, err := os.Stat(targ)

src/cmd/go/internal/work/exec.go

@@ -214,6 +214,7 @@ func (b *Builder) buildActionID(a *Action) cache.ActionID {
 	if p.Internal.CoverMode != "" {
 		fmt.Fprintf(h, "cover %q %q\n", p.Internal.CoverMode, b.toolID("cover"))
 	}
+	fmt.Fprintf(h, "modinfo %q\n", p.Internal.BuildInfo)
 
 	// Configuration specific to compiler toolchain.
 	switch cfg.BuildToolchainName {
@@ -655,7 +656,7 @@ func (b *Builder) build(a *Action) (err error) {
 	if len(out) > 0 {
 		output := b.processOutput(out)
 		if p.Module != nil && !allowedVersion(p.Module.GoVersion) {
-			output += "note: module requires Go " + p.Module.GoVersion
+			output += "note: module requires Go " + p.Module.GoVersion + "\n"
 		}
 		b.showOutput(a, a.Package.Dir, a.Package.Desc(), output)
 		if err != nil {

src/cmd/go/testdata/mod/rsc.io_fortune_v2_v2.0.0.txt

@@ -13,3 +13,9 @@ import "rsc.io/quote"
 func main() {
 	println(quote.Hello())
 }
+-- fortune_test.go --
+package main
+
+import "testing"
+
+func TestFortuneV2(t *testing.T) {}

src/cmd/go/testdata/script/build_nocache.txt

@@ -10,6 +10,11 @@ env HOME=
 ! go build -o triv triv.go
 stderr 'build cache is required, but could not be located: GOCACHE is not defined and .*'
 
+# If GOCACHE is set but is not an absolute path, and we cannot build.
+env GOCACHE=test
+! go build -o triv triv.go
+stderr 'build cache is required, but could not be located: GOCACHE is not an absolute path'
+
 # An explicit GOCACHE=off also disables builds.
 env GOCACHE=off
 ! go build -o triv triv.go

src/cmd/go/testdata/script/cover_pkgall_multiple_mains.txt

@@ -0,0 +1,43 @@
+# This test checks that multiple main packages can be tested
+# with -coverpkg=all without duplicate symbol errors.
+# Verifies golang.org/issue/30374.
+
+env GO111MODULE=on
+
+[short] skip
+
+go test -coverpkg=all ./...
+
+-- go.mod --
+module example.com/cov
+
+-- mainonly/mainonly.go --
+package main
+
+func main() {}
+
+-- mainwithtest/mainwithtest.go --
+package main
+
+func main() {}
+
+func Foo() {}
+
+-- mainwithtest/mainwithtest_test.go --
+package main
+
+import "testing"
+
+func TestFoo(t *testing.T) {
+  Foo()
+}
+
+-- xtest/x.go --
+package x
+
+-- xtest/x_test.go --
+package x_test
+
+import "testing"
+
+func TestX(t *testing.T) {}

src/cmd/go/testdata/script/mod_build_versioned.txt

@@ -0,0 +1,16 @@
+env GO111MODULE=on
+
+go get -m rsc.io/fortune/v2
+
+# The default executable name shouldn't be v2$exe
+go build rsc.io/fortune/v2
+! exists v2$exe
+exists fortune$exe
+
+# The default test binary name shouldn't be v2.test$exe
+go test -c rsc.io/fortune/v2
+! exists v2.test$exe
+exists fortune.test$exe
+
+-- go.mod --
+module scratch

src/cmd/go/testdata/script/mod_symlink.txt

@@ -2,16 +2,31 @@ env GO111MODULE=on
 [!symlink] skip
 
 # 'go list' should resolve modules of imported packages.
-go list -deps -f '{{.Module}}'
+go list -deps -f '{{.Module}}' .
 stdout golang.org/x/text
 
-# They should continue to resolve if the importing file is a symlink.
-mkdir links
-cd links
-symlink go.mod -> ../go.mod
-symlink issue.go -> ../issue.go
+go list -deps -f '{{.Module}}' ./subpkg
+stdout golang.org/x/text
 
-go list -deps -f '{{.Module}}'
+# Create a copy of the module using symlinks in src/links.
+mkdir links
+symlink links/go.mod -> $GOPATH/src/go.mod
+symlink links/issue.go -> $GOPATH/src/issue.go
+mkdir links/subpkg
+symlink links/subpkg/issue.go -> $GOPATH/src/subpkg/issue.go
+
+# We should see the copy as a valid module root.
+cd links
+go env GOMOD
+stdout links[/\\]go.mod
+go list -m
+stdout golang.org/issue/28107
+
+# The symlink-based copy should contain the same packages
+# and have the same dependencies as the original.
+go list -deps -f '{{.Module}}' .
+stdout golang.org/x/text
+go list -deps -f '{{.Module}}' ./subpkg
 stdout golang.org/x/text
 
 -- go.mod --
@@ -21,3 +36,7 @@ module golang.org/issue/28107
 package issue
 
 import _ "golang.org/x/text/language"
+-- subpkg/issue.go --
+package issue
+
+import _ "golang.org/x/text/language"

src/cmd/internal/obj/arm64/asm7.go

@@ -2986,7 +2986,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		num := uint8(0)
 		cls := oclass(&p.From)
 		if isADDWop(p.As) {
-			if (cls != C_LCON) && (cls != C_ADDCON2) {
+			if !cmp(C_LCON, cls) {
 				c.ctxt.Diag("illegal combination: %v", p)
 			}
 			num = c.omovlconst(AMOVW, p, &p.From, REGTMP, os[:])
@@ -3271,7 +3271,7 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 		num := uint8(0)
 		cls := oclass(&p.From)
 		if isANDWop(p.As) {
-			if (cls != C_LCON) && (cls != C_ADDCON) {
+			if !cmp(C_LCON, cls) {
 				c.ctxt.Diag("illegal combination: %v", p)
 			}
 			num = c.omovlconst(AMOVW, p, &p.From, REGTMP, os[:])

src/cmd/link/elf_test.go

@@ -0,0 +1,113 @@
+// Copyright 2019 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 dragonfly freebsd linux netbsd openbsd
+
+package main
+
+import (
+	"internal/testenv"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+var asmSource = `
+	.section .text1,"ax"
+s1:
+	.byte 0
+	.section .text2,"ax"
+s2:
+	.byte 0
+`
+
+var goSource = `
+package main
+func main() {}
+`
+
+// The linker used to crash if an ELF input file had multiple text sections
+// with the same name.
+func TestSectionsWithSameName(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	testenv.MustHaveCGO(t)
+	t.Parallel()
+
+	objcopy, err := exec.LookPath("objcopy")
+	if err != nil {
+		t.Skipf("can't find objcopy: %v", err)
+	}
+
+	dir, err := ioutil.TempDir("", "go-link-TestSectionsWithSameName")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	gopath := filepath.Join(dir, "GOPATH")
+	env := append(os.Environ(), "GOPATH="+gopath)
+
+	if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), []byte("module elf_test\n"), 0666); err != nil {
+		t.Fatal(err)
+	}
+
+	asmFile := filepath.Join(dir, "x.s")
+	if err := ioutil.WriteFile(asmFile, []byte(asmSource), 0444); err != nil {
+		t.Fatal(err)
+	}
+
+	goTool := testenv.GoToolPath(t)
+	cmd := exec.Command(goTool, "env", "CC")
+	cmd.Env = env
+	ccb, err := cmd.Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cc := strings.TrimSpace(string(ccb))
+
+	cmd = exec.Command(goTool, "env", "GOGCCFLAGS")
+	cmd.Env = env
+	cflagsb, err := cmd.Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cflags := strings.Fields(string(cflagsb))
+
+	asmObj := filepath.Join(dir, "x.o")
+	t.Logf("%s %v -c -o %s %s", cc, cflags, asmObj, asmFile)
+	if out, err := exec.Command(cc, append(cflags, "-c", "-o", asmObj, asmFile)...).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	asm2Obj := filepath.Join(dir, "x2.syso")
+	t.Logf("%s --rename-section .text2=.text1 %s %s", objcopy, asmObj, asm2Obj)
+	if out, err := exec.Command(objcopy, "--rename-section", ".text2=.text1", asmObj, asm2Obj).CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+
+	for _, s := range []string{asmFile, asmObj} {
+		if err := os.Remove(s); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	goFile := filepath.Join(dir, "main.go")
+	if err := ioutil.WriteFile(goFile, []byte(goSource), 0444); err != nil {
+		t.Fatal(err)
+	}
+
+	cmd = exec.Command(goTool, "build")
+	cmd.Dir = dir
+	cmd.Env = env
+	t.Logf("%s build", goTool)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Logf("%s", out)
+		t.Fatal(err)
+	}
+}

src/cmd/link/internal/loadelf/ldelf.go

@@ -678,6 +678,8 @@ func Load(arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length i
 	// as well use one large chunk.
 
 	// create symbols for elfmapped sections
+	sectsymNames := make(map[string]bool)
+	counter := 0
 	for i := 0; uint(i) < elfobj.nsect; i++ {
 		sect = &elfobj.sect[i]
 		if sect.type_ == SHT_ARM_ATTRIBUTES && sect.name == ".ARM.attributes" {
@@ -709,6 +711,12 @@ func Load(arch *sys.Arch, syms *sym.Symbols, f *bio.Reader, pkg string, length i
 		}
 
 		name := fmt.Sprintf("%s(%s)", pkg, sect.name)
+		for sectsymNames[name] {
+			counter++
+			name = fmt.Sprintf("%s(%s%d)", pkg, sect.name, counter)
+		}
+		sectsymNames[name] = true
+
 		s := syms.Lookup(name, localSymVersion)
 
 		switch int(sect.flags) & (ElfSectFlagAlloc | ElfSectFlagWrite | ElfSectFlagExec) {

src/cmd/vendor/golang.org/x/tools/go/analysis/analysis.go

@@ -87,6 +87,7 @@ type Pass struct {
 	OtherFiles []string       // names of non-Go files of this package
 	Pkg        *types.Package // type information about the package
 	TypesInfo  *types.Info    // type information about the syntax trees
+	TypesSizes types.Sizes    // function for computing sizes of types
 
 	// Report reports a Diagnostic, a finding about a specific location
 	// in the analyzed source code such as a potential mistake.

src/cmd/vendor/golang.org/x/tools/go/analysis/doc.go

@@ -246,7 +246,7 @@ An Analyzer that uses facts must declare their types:
 
 	var Analyzer = &analysis.Analyzer{
 		Name:       "printf",
-		FactTypes: []reflect.Type{reflect.TypeOf(new(isWrapper))},
+		FactTypes: []analysis.Fact{new(isWrapper)},
 		...
 	}
 

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go

@@ -114,7 +114,8 @@ func init() {
 			// library we cannot assume types.SizesFor is consistent with arches.
 			// For now, assume 64-bit norms and print a warning.
 			// But this warning should really be deferred until we attempt to use
-			// arch, which is very unlikely.
+			// arch, which is very unlikely. Better would be
+			// to defer size computation until we have Pass.TypesSizes.
 			arch.sizes = types.SizesFor("gc", "amd64")
 			log.Printf("unknown architecture %s", arch.name)
 		}

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/cgocall/cgocall.go

@@ -9,7 +9,6 @@ package cgocall
 import (
 	"fmt"
 	"go/ast"
-	"go/build"
 	"go/format"
 	"go/parser"
 	"go/token"
@@ -45,7 +44,7 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		return nil, nil // doesn't use cgo
 	}
 
-	cgofiles, info, err := typeCheckCgoSourceFiles(pass.Fset, pass.Pkg, pass.Files, pass.TypesInfo)
+	cgofiles, info, err := typeCheckCgoSourceFiles(pass.Fset, pass.Pkg, pass.Files, pass.TypesInfo, pass.TypesSizes)
 	if err != nil {
 		return nil, err
 	}
@@ -171,7 +170,7 @@ func checkCgo(fset *token.FileSet, f *ast.File, info *types.Info, reportf func(t
 // limited ourselves here to preserving function bodies and initializer
 // expressions since that is all that the cgocall analyzer needs.
 //
-func typeCheckCgoSourceFiles(fset *token.FileSet, pkg *types.Package, files []*ast.File, info *types.Info) ([]*ast.File, *types.Info, error) {
+func typeCheckCgoSourceFiles(fset *token.FileSet, pkg *types.Package, files []*ast.File, info *types.Info, sizes types.Sizes) ([]*ast.File, *types.Info, error) {
 	const thispkg = "·this·"
 
 	// Which files are cgo files?
@@ -269,8 +268,7 @@ func typeCheckCgoSourceFiles(fset *token.FileSet, pkg *types.Package, files []*a
 		Importer: importerFunc(func(path string) (*types.Package, error) {
 			return importMap[path], nil
 		}),
-		// TODO(adonovan): Sizes should probably be provided by analysis.Pass.
-		Sizes: types.SizesFor("gc", build.Default.GOARCH),
+		Sizes: sizes,
 		Error: func(error) {}, // ignore errors (e.g. unused import)
 	}
 

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/composite/composite.go

@@ -21,7 +21,16 @@ const Doc = `check for unkeyed composite literals
 This analyzer reports a diagnostic for composite literals of struct
 types imported from another package that do not use the field-keyed
 syntax. Such literals are fragile because the addition of a new field
-(even if unexported) to the struct will cause compilation to fail.`
+(even if unexported) to the struct will cause compilation to fail.
+
+As an example,
+
+	err = &net.DNSConfigError{err}
+
+should be replaced by:
+
+	err = &net.DNSConfigError{Err: err}
+`
 
 var Analyzer = &analysis.Analyzer{
 	Name:             "composites",

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/inspect/inspect.go

@@ -8,7 +8,11 @@
 //
 // Example of use in another analysis:
 //
-//	import "golang.org/x/tools/go/analysis/passes/inspect"
+//	import (
+//		"golang.org/x/tools/go/analysis"
+//		"golang.org/x/tools/go/analysis/passes/inspect"
+//		"golang.org/x/tools/go/ast/inspector"
+//	)
 //
 //	var Analyzer = &analysis.Analyzer{
 //		...

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go

@@ -453,15 +453,23 @@ func printfNameAndKind(pass *analysis.Pass, call *ast.CallExpr) (fn *types.Func,
 }
 
 // isFormatter reports whether t satisfies fmt.Formatter.
-// Unlike fmt.Stringer, it's impossible to satisfy fmt.Formatter without importing fmt.
-func isFormatter(pass *analysis.Pass, t types.Type) bool {
-	for _, imp := range pass.Pkg.Imports() {
-		if imp.Path() == "fmt" {
-			formatter := imp.Scope().Lookup("Formatter").Type().Underlying().(*types.Interface)
-			return types.Implements(t, formatter)
-		}
+// The only interface method to look for is "Format(State, rune)".
+func isFormatter(typ types.Type) bool {
+	obj, _, _ := types.LookupFieldOrMethod(typ, false, nil, "Format")
+	fn, ok := obj.(*types.Func)
+	if !ok {
+		return false
 	}
-	return false
+	sig := fn.Type().(*types.Signature)
+	return sig.Params().Len() == 2 &&
+		sig.Results().Len() == 0 &&
+		isNamed(sig.Params().At(0).Type(), "fmt", "State") &&
+		types.Identical(sig.Params().At(1).Type(), types.Typ[types.Rune])
+}
+
+func isNamed(T types.Type, pkgpath, name string) bool {
+	named, ok := T.(*types.Named)
+	return ok && named.Obj().Pkg().Path() == pkgpath && named.Obj().Name() == name
 }
 
 // formatState holds the parsed representation of a printf directive such as "%3.*[4]d".
@@ -753,7 +761,7 @@ func okPrintfArg(pass *analysis.Pass, call *ast.CallExpr, state *formatState) (o
 	formatter := false
 	if state.argNum < len(call.Args) {
 		if tv, ok := pass.TypesInfo.Types[call.Args[state.argNum]]; ok {
-			formatter = isFormatter(pass, tv.Type)
+			formatter = isFormatter(tv.Type)
 		}
 	}
 
@@ -831,7 +839,7 @@ func recursiveStringer(pass *analysis.Pass, e ast.Expr) bool {
 	typ := pass.TypesInfo.Types[e].Type
 
 	// It's unlikely to be a recursive stringer if it has a Format method.
-	if isFormatter(pass, typ) {
+	if isFormatter(typ) {
 		return false
 	}
 

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/types.go

@@ -2,7 +2,6 @@ package printf
 
 import (
 	"go/ast"
-	"go/build"
 	"go/types"
 
 	"golang.org/x/tools/go/analysis"
@@ -39,7 +38,7 @@ func matchArgTypeInternal(pass *analysis.Pass, t printfArgType, typ types.Type,
 		}
 	}
 	// If the type implements fmt.Formatter, we have nothing to check.
-	if isFormatter(pass, typ) {
+	if isFormatter(typ) {
 		return true
 	}
 	// If we can use a string, might arg (dynamically) implement the Stringer or Error interface?
@@ -235,5 +234,3 @@ func matchStructArgType(pass *analysis.Pass, t printfArgType, typ *types.Struct,
 	}
 	return true
 }
-
-var archSizes = types.SizesFor("gc", build.Default.GOARCH)

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/shift/shift.go

@@ -12,10 +12,8 @@ package shift
 
 import (
 	"go/ast"
-	"go/build"
 	"go/constant"
 	"go/token"
-	"go/types"
 
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/passes/inspect"
@@ -93,36 +91,9 @@ func checkLongShift(pass *analysis.Pass, node ast.Node, x, y ast.Expr) {
 	if t == nil {
 		return
 	}
-	b, ok := t.Underlying().(*types.Basic)
-	if !ok {
-		return
-	}
-	var size int64
-	switch b.Kind() {
-	case types.Uint8, types.Int8:
-		size = 8
-	case types.Uint16, types.Int16:
-		size = 16
-	case types.Uint32, types.Int32:
-		size = 32
-	case types.Uint64, types.Int64:
-		size = 64
-	case types.Int, types.Uint:
-		size = uintBitSize
-	case types.Uintptr:
-		size = uintptrBitSize
-	default:
-		return
-	}
+	size := 8 * pass.TypesSizes.Sizeof(t)
 	if amt >= size {
 		ident := analysisutil.Format(pass.Fset, x)
 		pass.Reportf(node.Pos(), "%s (%d bits) too small for shift of %d", ident, size, amt)
 	}
 }
-
-var (
-	uintBitSize    = 8 * archSizes.Sizeof(types.Typ[types.Uint])
-	uintptrBitSize = 8 * archSizes.Sizeof(types.Typ[types.Uintptr])
-)
-
-var archSizes = types.SizesFor("gc", build.Default.GOARCH)

src/cmd/vendor/golang.org/x/tools/go/analysis/passes/structtag/structtag.go

@@ -96,6 +96,11 @@ func checkTagDuplicates(pass *analysis.Pass, tag, key string, nearest, field *ty
 	}
 	if val == "" || val[0] == ',' {
 		if field.Anonymous() {
+			// Disable this check enhancement in Go 1.12.1; some
+			// false positives were spotted in the initial 1.12
+			// release. See https://golang.org/issues/30465.
+			return
+
 			typ, ok := field.Type().Underlying().(*types.Struct)
 			if !ok {
 				return

src/cmd/vendor/golang.org/x/tools/go/analysis/unitchecker/unitchecker.go

@@ -329,6 +329,7 @@ func run(fset *token.FileSet, cfg *Config, analyzers []*analysis.Analyzer) ([]re
 				OtherFiles:        cfg.NonGoFiles,
 				Pkg:               pkg,
 				TypesInfo:         info,
+				TypesSizes:        tc.Sizes,
 				ResultOf:          inputs,
 				Report:            func(d analysis.Diagnostic) { act.diagnostics = append(act.diagnostics, d) },
 				ImportObjectFact:  facts.ImportObjectFact,

src/cmd/vendor/golang.org/x/tools/go/ast/inspector/inspector.go

@@ -14,7 +14,7 @@
 // Experiments suggest the inspector's traversals are about 2.5x faster
 // than ast.Inspect, but it may take around 5 traversals for this
 // benefit to amortize the inspector's construction cost.
-// If efficiency is the primary concern, do not use use Inspector for
+// If efficiency is the primary concern, do not use Inspector for
 // one-off traversals.
 package inspector
 

src/cmd/vet/testdata/src/print2/big.go

@@ -0,0 +1,17 @@
+// Copyright 2019 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 print2
+
+import ( // NOTE: Does not import "fmt"
+	"log"
+	"math/big"
+)
+
+var fmt int
+
+func f() {
+	log.Printf("%d", new(big.Int))
+	log.Printf("%d", 1.0) // ERROR "Printf format %d has arg 1.0 of wrong type float64"
+}

src/cmd/vet/testdata/src/structtag/structtag.go

@@ -6,6 +6,20 @@
 
 package structtag
 
+import "encoding/json"
+
 type StructTagTest struct {
 	A int "hello" // ERROR "`hello` not compatible with reflect.StructTag.Get: bad syntax for struct tag pair"
 }
+
+func Issue30465() {
+	type T1 struct {
+		X string `json:"x"`
+	}
+	type T2 struct {
+		T1
+		X string `json:"x"`
+	}
+	var t2 T2
+	json.Marshal(&t2)
+}

src/cmd/vet/vet_test.go

@@ -88,6 +88,7 @@ func TestVet(t *testing.T) {
 		"method",
 		"nilfunc",
 		"print",
+		"print2",
 		"rangeloop",
 		"shift",
 		"structtag",

src/crypto/rc4/rc4.go

@@ -45,8 +45,10 @@ func NewCipher(key []byte) (*Cipher, error) {
 	return &c, nil
 }
 
-// Reset zeros the key data so that it will no longer appear in the
-// process's memory.
+// Reset zeros the key data and makes the Cipher unusable.
+//
+// Deprecated: Reset can't guarantee that the key will be entirely removed from
+// the process's memory.
 func (c *Cipher) Reset() {
 	for i := range c.s {
 		c.s[i] = 0

src/crypto/tls/handshake_client.go

@@ -573,7 +573,7 @@ func (hs *clientHandshakeState) doFullHandshake() error {
 			return fmt.Errorf("tls: client certificate private key of type %T does not implement crypto.Signer", chainToSend.PrivateKey)
 		}
 
-		signatureAlgorithm, sigType, hashFunc, err := pickSignatureAlgorithm(key.Public(), certReq.supportedSignatureAlgorithms, hs.hello.supportedSignatureAlgorithms, c.vers)
+		signatureAlgorithm, sigType, hashFunc, err := pickSignatureAlgorithm(key.Public(), certReq.supportedSignatureAlgorithms, supportedSignatureAlgorithmsTLS12, c.vers)
 		if err != nil {
 			c.sendAlert(alertInternalError)
 			return err

src/crypto/tls/handshake_client_test.go

@@ -873,10 +873,41 @@ func TestHandshakeClientCertPSSDisabled(t *testing.T) {
 	supportedSignatureAlgorithmsTLS12 = savedSupportedSignatureAlgorithmsTLS12
 
 	// Use t.Run to ensure the defer runs after all parallel tests end.
-	t.Run("", func(t *testing.T) {
+	t.Run("1024", func(t *testing.T) {
 		runClientTestTLS12(t, test)
 		runClientTestTLS13(t, test)
 	})
+
+	// Use a 512-bit key to check that the TLS 1.2 handshake is actually using
+	// PKCS#1 v1.5. PSS would be failing here.
+	cert, err := X509KeyPair([]byte(`-----BEGIN CERTIFICATE-----
+MIIBcTCCARugAwIBAgIQGjQnkCFlUqaFlt6ixyz/tDANBgkqhkiG9w0BAQsFADAS
+MRAwDgYDVQQKEwdBY21lIENvMB4XDTE5MDExODIzMjMyOFoXDTIwMDExODIzMjMy
+OFowEjEQMA4GA1UEChMHQWNtZSBDbzBcMA0GCSqGSIb3DQEBAQUAA0sAMEgCQQDd
+ez1rFUDwax2HTxbcnFUP9AhcgEGMHVV2nn4VVEWFJB6I8C/Nkx0XyyQlrmFYBzEQ
+nIPhKls4T0hFoLvjJnXpAgMBAAGjTTBLMA4GA1UdDwEB/wQEAwIFoDATBgNVHSUE
+DDAKBggrBgEFBQcDATAMBgNVHRMBAf8EAjAAMBYGA1UdEQQPMA2CC2V4YW1wbGUu
+Y29tMA0GCSqGSIb3DQEBCwUAA0EAxDuUS+BrrS3c+h+k+fQPOmOScy6yTX9mHw0Q
+KbucGamXYEy0URIwOdO0tQ3LHPc1YGvYSPwkDjkjqECs2Vm/AA==
+-----END CERTIFICATE-----`), []byte(`-----BEGIN RSA PRIVATE KEY-----
+MIIBOgIBAAJBAN17PWsVQPBrHYdPFtycVQ/0CFyAQYwdVXaefhVURYUkHojwL82T
+HRfLJCWuYVgHMRCcg+EqWzhPSEWgu+MmdekCAwEAAQJBALjQYNTdXF4CFBbXwUz/
+yt9QFDYT9B5WT/12jeGAe653gtYS6OOi/+eAkGmzg1GlRnw6fOfn+HYNFDORST7z
+4j0CIQDn2xz9hVWQEu9ee3vecNT3f60huDGTNoRhtqgweQGX0wIhAPSLj1VcRZEz
+nKpbtU22+PbIMSJ+e80fmY9LIPx5N4HTAiAthGSimMR9bloz0EY3GyuUEyqoDgMd
+hXxjuno2WesoJQIgemilbcALXpxsLmZLgcQ2KSmaVr7jb5ECx9R+hYKTw1sCIG4s
+T+E0J8wlH24pgwQHzy7Ko2qLwn1b5PW8ecrlvP1g
+-----END RSA PRIVATE KEY-----`))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	test.name = "ClientCert-RSA-PSS-Disabled-512"
+	config.Certificates = []Certificate{cert}
+
+	t.Run("512", func(t *testing.T) {
+		runClientTestTLS12(t, test)
+	})
 }
 
 func TestClientKeyUpdate(t *testing.T) {

src/crypto/tls/testdata/Client-TLSv12-ClientCert-RSA-PSS-Disabled

@@ -16,11 +16,11 @@
 000000e0  a3 47 cd 62 43 15 28 da  ac 5f bb 29 07 30 ff f6  |.G.bC.(.._.).0..|
 000000f0  84 af c4 cf c2 ed 90 99  5f 58 cb 3b 74           |........_X.;t|
 >>> Flow 2 (server to client)
-00000000  16 03 03 00 59 02 00 00  55 03 03 33 ad 8d f8 90  |....Y...U..3....|
-00000010  d1 72 5d ef e8 94 0f d7  58 15 59 9f 0b f9 ec 73  |.r].....X.Y....s|
-00000020  99 53 f7 03 81 53 1a aa  05 f0 17 20 55 a1 9e 4e  |.S...S..... U..N|
-00000030  98 26 6b b8 d5 bc 2c 3e  ca f6 a0 d9 bb f2 3b dd  |.&k...,>......;.|
-00000040  be 99 f1 35 de 1c f6 51  5b 19 4f 55 c0 2f 00 00  |...5...Q[.OU./..|
+00000000  16 03 03 00 59 02 00 00  55 03 03 05 c1 62 2b 2f  |....Y...U....b+/|
+00000010  12 46 4d c5 47 61 bd 43  6d bb 3a 60 42 c1 cf da  |.FM.Ga.Cm.:`B...|
+00000020  47 96 0a 11 35 f0 71 d8  f6 39 69 20 0f 9c c1 3f  |G...5.q..9i ...?|
+00000030  9c 68 e7 86 13 7c 1f 83  6b 56 39 ee 0d c0 82 0b  |.h...|..kV9.....|
+00000040  24 1b 8a 39 a6 dc bf 57  79 27 02 e4 c0 2f 00 00  |$..9...Wy'.../..|
 00000050  0d ff 01 00 01 00 00 0b  00 04 03 00 01 02 16 03  |................|
 00000060  03 02 59 0b 00 02 55 00  02 52 00 02 4f 30 82 02  |..Y...U..R..O0..|
 00000070  4b 30 82 01 b4 a0 03 02  01 02 02 09 00 e8 f0 9d  |K0..............|
@@ -60,17 +60,17 @@
 00000290  77 8d 0c 1c f1 0f a1 d8  40 83 61 c9 4c 72 2b 9d  |w.......@.a.Lr+.|
 000002a0  ae db 46 06 06 4d f4 c1  b3 3e c0 d1 bd 42 d4 db  |..F..M...>...B..|
 000002b0  fe 3d 13 60 84 5c 21 d3  3b e9 fa e7 16 03 03 00  |.=.`.\!.;.......|
-000002c0  ac 0c 00 00 a8 03 00 1d  20 2d c8 0c d2 27 fc f9  |........ -...'..|
-000002d0  79 71 c4 17 ea 45 ec 0b  dd 66 ce af ec 49 96 7d  |yq...E...f...I.}|
-000002e0  43 ff 88 68 b1 a8 bb e1  38 08 04 00 80 5a ab 5b  |C..h....8....Z.[|
-000002f0  e6 b3 32 e2 98 ae c3 ed  7c f9 90 c4 a4 ea dd 70  |..2.....|......p|
-00000300  fc a4 f8 ef d1 15 0d b7  ad b8 e3 1f 3e c0 e4 40  |............>..@|
-00000310  0d 7b 50 36 8f 88 cb 88  59 7c 20 63 d1 7f 36 9e  |.{P6....Y| c..6.|
-00000320  de a7 cb 6a 49 fd 65 32  36 0b 10 6a df 58 ef fd  |...jI.e26..j.X..|
-00000330  f6 fc e6 65 e7 81 0e 73  25 87 c7 89 dc ec ae 7c  |...e...s%......||
-00000340  e4 81 79 79 a2 b9 12 28  ab 3b d0 2e 5e 81 47 2a  |..yy...(.;..^.G*|
-00000350  79 1e 16 21 fa 64 78 24  33 24 f7 ac f1 11 a7 15  |y..!.dx$3$......|
-00000360  98 f6 24 52 14 7c 1f 28  0c 24 b1 a9 8a 16 03 03  |..$R.|.(.$......|
+000002c0  ac 0c 00 00 a8 03 00 1d  20 94 54 54 4c 52 a7 a5  |........ .TTLR..|
+000002d0  c0 01 ed 59 bf 46 03 59  25 3b 57 f8 24 99 1b dc  |...Y.F.Y%;W.$...|
+000002e0  f6 f4 1d 42 0e 2e c3 7c  02 08 04 00 80 5a 42 35  |...B...|.....ZB5|
+000002f0  78 c8 a9 37 6f 61 a4 ef  3a a3 12 03 f7 ee 44 be  |x..7oa..:.....D.|
+00000300  8b c9 52 4f de db f5 1e  9c c8 33 32 3c 0a 9e d6  |..RO......32<...|
+00000310  32 bf 2e 12 f7 b0 9b 15  dc eb 24 6e d6 f2 ad 5d  |2.........$n...]|
+00000320  9e 77 c4 a7 7a a1 a0 13  0b 90 b4 aa 3e 51 a1 3d  |.w..z.......>Q.=|
+00000330  71 09 15 84 1c c5 98 bb  12 db 11 e2 4c 2c d1 a9  |q...........L,..|
+00000340  5a ed 8e fb c6 ae ec d5  6d ec d8 d8 2a a7 23 ae  |Z.......m...*.#.|
+00000350  d7 d2 03 d0 23 8a 21 ac  7e 56 b4 23 7f c6 2a 72  |....#.!.~V.#..*r|
+00000360  85 0b 6d 6c 9d 6f ad ee  15 20 d9 2b b9 16 03 03  |..ml.o... .+....|
 00000370  00 3a 0d 00 00 36 03 01  02 40 00 2e 04 03 05 03  |.:...6...@......|
 00000380  06 03 08 07 08 08 08 09  08 0a 08 0b 08 04 08 05  |................|
 00000390  08 06 04 01 05 01 06 01  03 03 02 03 03 01 02 01  |................|
@@ -112,26 +112,26 @@
 00000200  e5 35 16 03 03 00 25 10  00 00 21 20 2f e5 7d a3  |.5....%...! /.}.|
 00000210  47 cd 62 43 15 28 da ac  5f bb 29 07 30 ff f6 84  |G.bC.(.._.).0...|
 00000220  af c4 cf c2 ed 90 99 5f  58 cb 3b 74 16 03 03 00  |......._X.;t....|
-00000230  88 0f 00 00 84 08 04 00  80 8b ad 4b 9a 7a 53 b8  |...........K.zS.|
-00000240  6a 0a e7 71 6a 9b 8b 89  7d 3a 49 c9 af ce 3f e2  |j..qj...}:I...?.|
-00000250  3e cc 0b da 57 9b 8c 2f  58 0f a9 05 4d e9 de 83  |>...W../X...M...|
-00000260  60 e8 1c 77 ef 23 e4 aa  6b c3 15 64 98 f8 b1 72  |`..w.#..k..d...r|
-00000270  b2 8a 9e a3 19 3d 73 84  05 53 59 e1 bb e1 db 51  |.....=s..SY....Q|
-00000280  49 38 cf 8b ee 3c b6 05  0d ba 62 02 b3 36 dc c1  |I8...<....b..6..|
-00000290  e1 52 4d bd 6a c1 3e 55  ff 82 5f e3 7c 84 1c 65  |.RM.j.>U.._.|..e|
-000002a0  45 53 b9 c0 56 99 ac 56  d7 4a fa 72 3e 63 36 06  |ES..V..V.J.r>c6.|
-000002b0  d3 60 ef 34 05 3f 57 20  79 14 03 03 00 01 01 16  |.`.4.?W y.......|
-000002c0  03 03 00 28 00 00 00 00  00 00 00 00 00 26 b7 73  |...(.........&.s|
-000002d0  b5 e9 b3 8a 63 00 9b 36  a0 cf 2a 60 0f 8a 59 75  |....c..6..*`..Yu|
-000002e0  08 71 97 dc 66 73 15 04  08 b4 d3 91              |.q..fs......|
+00000230  88 0f 00 00 84 04 01 00  80 61 11 ba 1a fe 08 7c  |.........a.....||
+00000240  40 68 88 01 a4 3a 46 bf  f6 e9 bb b6 08 92 20 f0  |@h...:F....... .|
+00000250  13 90 c2 4b 53 83 a1 12  c2 d5 8d e6 67 82 df 80  |...KS.......g...|
+00000260  85 a5 b4 e0 cf 1b d6 3a  46 1e 62 e5 7f 21 bc 91  |.......:F.b..!..|
+00000270  4a 8c c0 79 16 64 5f 7e  40 c5 fb 7a 52 5b bf db  |J..y.d_~@..zR[..|
+00000280  cc 31 f8 b8 37 ef df dc  5f 96 30 ad dd 0b 8a 87  |.1..7..._.0.....|
+00000290  af 4d c6 5c a5 5e d7 2e  fa c7 72 68 85 71 c3 0e  |.M.\.^....rh.q..|
+000002a0  1b 26 87 ff 46 47 4a 1b  ce b7 a5 aa 13 d2 5a e3  |.&..FGJ.......Z.|
+000002b0  36 02 35 df 68 d9 bf 3f  24 14 03 03 00 01 01 16  |6.5.h..?$.......|
+000002c0  03 03 00 28 00 00 00 00  00 00 00 00 e3 8e cc e5  |...(............|
+000002d0  2e ab 40 fa 3d 47 c1 4f  3f de 97 a9 3d 96 73 ba  |..@.=G.O?...=.s.|
+000002e0  eb a0 ce 67 f6 d1 14 b8  7e cd 1f 85              |...g....~...|
 >>> Flow 4 (server to client)
-00000000  14 03 03 00 01 01 16 03  03 00 28 d2 b2 3f a8 43  |..........(..?.C|
-00000010  41 1a 85 20 9f ee 21 6a  c5 96 cf 7c 01 8e f6 3a  |A.. ..!j...|...:|
-00000020  e3 29 14 68 ea 74 a3 ef  85 04 78 33 db c7 d4 c9  |.).h.t....x3....|
-00000030  a2 fd 6a                                          |..j|
+00000000  14 03 03 00 01 01 16 03  03 00 28 6a 0a 74 70 75  |..........(j.tpu|
+00000010  0b 39 33 a5 15 0d 7c 7f  f8 13 de 0e 0a 8f 13 3b  |.93...|........;|
+00000020  62 4f 8a 0b bd 0a aa 9b  5a 52 d5 e6 9f e5 b9 3f  |bO......ZR.....?|
+00000030  bd d8 3b                                          |..;|
 >>> Flow 5 (client to server)
-00000000  17 03 03 00 1e 00 00 00  00 00 00 00 01 c3 3b 68  |..............;h|
-00000010  b5 e9 4d 75 22 92 fb 19  85 88 38 97 12 3f ce ca  |..Mu".....8..?..|
-00000020  36 c0 d6 15 03 03 00 1a  00 00 00 00 00 00 00 02  |6...............|
-00000030  c1 a9 03 81 61 04 7c 86  24 e9 90 22 59 6f c7 bc  |....a.|.$.."Yo..|
-00000040  c2 a1                                             |..|
+00000000  17 03 03 00 1e 00 00 00  00 00 00 00 01 0e 4d 62  |..............Mb|
+00000010  d3 ac cd 11 15 6d 24 c7  00 fa f9 d2 91 ba eb 06  |.....m$.........|
+00000020  f2 44 f1 15 03 03 00 1a  00 00 00 00 00 00 00 02  |.D..............|
+00000030  d1 5a 58 ba ae 65 15 67  79 1f 52 f1 1a da 50 99  |.ZX..e.gy.R...P.|
+00000040  e8 50                                             |.P|

src/crypto/tls/testdata/Client-TLSv12-ClientCert-RSA-PSS-Disabled-512

@@ -0,0 +1,125 @@
+>>> Flow 1 (client to server)
+00000000  16 03 01 00 f8 01 00 00  f4 03 03 00 00 00 00 00  |................|
+00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+00000020  00 00 00 00 00 00 00 00  00 00 00 20 00 00 00 00  |........... ....|
+00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
+00000040  00 00 00 00 00 00 00 00  00 00 00 00 00 32 cc a8  |.............2..|
+00000050  cc a9 c0 2f c0 2b c0 30  c0 2c c0 27 c0 13 c0 23  |.../.+.0.,.'...#|
+00000060  c0 09 c0 14 c0 0a 00 9c  00 9d 00 3c 00 2f 00 35  |...........<./.5|
+00000070  c0 12 00 0a 00 05 c0 11  c0 07 13 01 13 03 13 02  |................|
+00000080  01 00 00 79 00 05 00 05  01 00 00 00 00 00 0a 00  |...y............|
+00000090  0a 00 08 00 1d 00 17 00  18 00 19 00 0b 00 02 01  |................|
+000000a0  00 00 0d 00 18 00 16 08  04 08 05 08 06 04 01 04  |................|
+000000b0  03 05 01 05 03 06 01 06  03 02 01 02 03 ff 01 00  |................|
+000000c0  01 00 00 12 00 00 00 2b  00 09 08 03 04 03 03 03  |.......+........|
+000000d0  02 03 01 00 33 00 26 00  24 00 1d 00 20 2f e5 7d  |....3.&.$... /.}|
+000000e0  a3 47 cd 62 43 15 28 da  ac 5f bb 29 07 30 ff f6  |.G.bC.(.._.).0..|
+000000f0  84 af c4 cf c2 ed 90 99  5f 58 cb 3b 74           |........_X.;t|
+>>> Flow 2 (server to client)
+00000000  16 03 03 00 59 02 00 00  55 03 03 68 11 23 f1 8d  |....Y...U..h.#..|
+00000010  2b a0 71 8f 6e ad 9f ae  43 58 c2 93 2e f5 01 3d  |+.q.n...CX.....=|
+00000020  15 b6 d6 0d f5 42 25 ca  b7 b4 96 20 00 c7 86 06  |.....B%.... ....|
+00000030  ed d1 23 99 dd e3 c4 f5  f9 31 42 51 a3 51 5a 40  |..#......1BQ.QZ@|
+00000040  11 f6 07 90 51 04 f8 a2  f6 66 c1 f7 c0 2f 00 00  |....Q....f.../..|
+00000050  0d ff 01 00 01 00 00 0b  00 04 03 00 01 02 16 03  |................|
+00000060  03 02 59 0b 00 02 55 00  02 52 00 02 4f 30 82 02  |..Y...U..R..O0..|
+00000070  4b 30 82 01 b4 a0 03 02  01 02 02 09 00 e8 f0 9d  |K0..............|
+00000080  3f e2 5b ea a6 30 0d 06  09 2a 86 48 86 f7 0d 01  |?.[..0...*.H....|
+00000090  01 0b 05 00 30 1f 31 0b  30 09 06 03 55 04 0a 13  |....0.1.0...U...|
+000000a0  02 47 6f 31 10 30 0e 06  03 55 04 03 13 07 47 6f  |.Go1.0...U....Go|
+000000b0  20 52 6f 6f 74 30 1e 17  0d 31 36 30 31 30 31 30  | Root0...1601010|
+000000c0  30 30 30 30 30 5a 17 0d  32 35 30 31 30 31 30 30  |00000Z..25010100|
+000000d0  30 30 30 30 5a 30 1a 31  0b 30 09 06 03 55 04 0a  |0000Z0.1.0...U..|
+000000e0  13 02 47 6f 31 0b 30 09  06 03 55 04 03 13 02 47  |..Go1.0...U....G|
+000000f0  6f 30 81 9f 30 0d 06 09  2a 86 48 86 f7 0d 01 01  |o0..0...*.H.....|
+00000100  01 05 00 03 81 8d 00 30  81 89 02 81 81 00 db 46  |.......0.......F|
+00000110  7d 93 2e 12 27 06 48 bc  06 28 21 ab 7e c4 b6 a2  |}...'.H..(!.~...|
+00000120  5d fe 1e 52 45 88 7a 36  47 a5 08 0d 92 42 5b c2  |]..RE.z6G....B[.|
+00000130  81 c0 be 97 79 98 40 fb  4f 6d 14 fd 2b 13 8b c2  |....y.@.Om..+...|
+00000140  a5 2e 67 d8 d4 09 9e d6  22 38 b7 4a 0b 74 73 2b  |..g....."8.J.ts+|
+00000150  c2 34 f1 d1 93 e5 96 d9  74 7b f3 58 9f 6c 61 3c  |.4......t{.X.la<|
+00000160  c0 b0 41 d4 d9 2b 2b 24  23 77 5b 1c 3b bd 75 5d  |..A..++$#w[.;.u]|
+00000170  ce 20 54 cf a1 63 87 1d  1e 24 c4 f3 1d 1a 50 8b  |. T..c...$....P.|
+00000180  aa b6 14 43 ed 97 a7 75  62 f4 14 c8 52 d7 02 03  |...C...ub...R...|
+00000190  01 00 01 a3 81 93 30 81  90 30 0e 06 03 55 1d 0f  |......0..0...U..|
+000001a0  01 01 ff 04 04 03 02 05  a0 30 1d 06 03 55 1d 25  |.........0...U.%|
+000001b0  04 16 30 14 06 08 2b 06  01 05 05 07 03 01 06 08  |..0...+.........|
+000001c0  2b 06 01 05 05 07 03 02  30 0c 06 03 55 1d 13 01  |+.......0...U...|
+000001d0  01 ff 04 02 30 00 30 19  06 03 55 1d 0e 04 12 04  |....0.0...U.....|
+000001e0  10 9f 91 16 1f 43 43 3e  49 a6 de 6d b6 80 d7 9f  |.....CC>I..m....|
+000001f0  60 30 1b 06 03 55 1d 23  04 14 30 12 80 10 48 13  |`0...U.#..0...H.|
+00000200  49 4d 13 7e 16 31 bb a3  01 d5 ac ab 6e 7b 30 19  |IM.~.1......n{0.|
+00000210  06 03 55 1d 11 04 12 30  10 82 0e 65 78 61 6d 70  |..U....0...examp|
+00000220  6c 65 2e 67 6f 6c 61 6e  67 30 0d 06 09 2a 86 48  |le.golang0...*.H|
+00000230  86 f7 0d 01 01 0b 05 00  03 81 81 00 9d 30 cc 40  |.............0.@|
+00000240  2b 5b 50 a0 61 cb ba e5  53 58 e1 ed 83 28 a9 58  |+[P.a...SX...(.X|
+00000250  1a a9 38 a4 95 a1 ac 31  5a 1a 84 66 3d 43 d3 2d  |..8....1Z..f=C.-|
+00000260  d9 0b f2 97 df d3 20 64  38 92 24 3a 00 bc cf 9c  |...... d8.$:....|
+00000270  7d b7 40 20 01 5f aa d3  16 61 09 a2 76 fd 13 c3  |}.@ ._...a..v...|
+00000280  cc e1 0c 5c ee b1 87 82  f1 6c 04 ed 73 bb b3 43  |...\.....l..s..C|
+00000290  77 8d 0c 1c f1 0f a1 d8  40 83 61 c9 4c 72 2b 9d  |w.......@.a.Lr+.|
+000002a0  ae db 46 06 06 4d f4 c1  b3 3e c0 d1 bd 42 d4 db  |..F..M...>...B..|
+000002b0  fe 3d 13 60 84 5c 21 d3  3b e9 fa e7 16 03 03 00  |.=.`.\!.;.......|
+000002c0  ac 0c 00 00 a8 03 00 1d  20 fe 68 1c bf 2b d7 75  |........ .h..+.u|
+000002d0  c2 dd 96 03 5d 77 61 c1  7d dd 6f bc ea 3c aa 27  |....]wa.}.o..<.'|
+000002e0  ba cf 93 e2 8b d8 66 a1  1c 08 04 00 80 5e 16 b9  |......f......^..|
+000002f0  53 17 7d 8d bb 46 4b 1f  37 be cd fe e1 45 c3 10  |S.}..FK.7....E..|
+00000300  68 54 e4 61 20 a5 a5 98  4b df a7 5d 41 4a aa f8  |hT.a ...K..]AJ..|
+00000310  0e 36 c2 02 a6 56 a9 f1  aa 76 86 fd a7 86 fb 06  |.6...V...v......|
+00000320  94 55 56 bd eb 57 10 9a  d5 ba 70 59 46 75 e3 b3  |.UV..W....pYFu..|
+00000330  29 14 c2 65 0e 5c a1 47  e6 bf 12 9d 31 8f 65 4d  |)..e.\.G....1.eM|
+00000340  af dc 1b 6e d2 de d7 fb  85 e7 5a 42 4f de bf d8  |...n......ZBO...|
+00000350  d5 d8 5c 95 71 27 e7 04  af 58 0a d8 77 fb 3d 22  |..\.q'...X..w.="|
+00000360  84 f6 f6 53 c0 79 7a 72  01 6e 5c e1 a8 16 03 03  |...S.yzr.n\.....|
+00000370  00 3a 0d 00 00 36 03 01  02 40 00 2e 04 03 05 03  |.:...6...@......|
+00000380  06 03 08 07 08 08 08 09  08 0a 08 0b 08 04 08 05  |................|
+00000390  08 06 04 01 05 01 06 01  03 03 02 03 03 01 02 01  |................|
+000003a0  03 02 02 02 04 02 05 02  06 02 00 00 16 03 03 00  |................|
+000003b0  04 0e 00 00 00                                    |.....|
+>>> Flow 3 (client to server)
+00000000  16 03 03 01 7f 0b 00 01  7b 00 01 78 00 01 75 30  |........{..x..u0|
+00000010  82 01 71 30 82 01 1b a0  03 02 01 02 02 10 1a 34  |..q0...........4|
+00000020  27 90 21 65 52 a6 85 96  de a2 c7 2c ff b4 30 0d  |'.!eR......,..0.|
+00000030  06 09 2a 86 48 86 f7 0d  01 01 0b 05 00 30 12 31  |..*.H........0.1|
+00000040  10 30 0e 06 03 55 04 0a  13 07 41 63 6d 65 20 43  |.0...U....Acme C|
+00000050  6f 30 1e 17 0d 31 39 30  31 31 38 32 33 32 33 32  |o0...19011823232|
+00000060  38 5a 17 0d 32 30 30 31  31 38 32 33 32 33 32 38  |8Z..200118232328|
+00000070  5a 30 12 31 10 30 0e 06  03 55 04 0a 13 07 41 63  |Z0.1.0...U....Ac|
+00000080  6d 65 20 43 6f 30 5c 30  0d 06 09 2a 86 48 86 f7  |me Co0\0...*.H..|
+00000090  0d 01 01 01 05 00 03 4b  00 30 48 02 41 00 dd 7b  |.......K.0H.A..{|
+000000a0  3d 6b 15 40 f0 6b 1d 87  4f 16 dc 9c 55 0f f4 08  |=k.@.k..O...U...|
+000000b0  5c 80 41 8c 1d 55 76 9e  7e 15 54 45 85 24 1e 88  |\.A..Uv.~.TE.$..|
+000000c0  f0 2f cd 93 1d 17 cb 24  25 ae 61 58 07 31 10 9c  |./.....$%.aX.1..|
+000000d0  83 e1 2a 5b 38 4f 48 45  a0 bb e3 26 75 e9 02 03  |..*[8OHE...&u...|
+000000e0  01 00 01 a3 4d 30 4b 30  0e 06 03 55 1d 0f 01 01  |....M0K0...U....|
+000000f0  ff 04 04 03 02 05 a0 30  13 06 03 55 1d 25 04 0c  |.......0...U.%..|
+00000100  30 0a 06 08 2b 06 01 05  05 07 03 01 30 0c 06 03  |0...+.......0...|
+00000110  55 1d 13 01 01 ff 04 02  30 00 30 16 06 03 55 1d  |U.......0.0...U.|
+00000120  11 04 0f 30 0d 82 0b 65  78 61 6d 70 6c 65 2e 63  |...0...example.c|
+00000130  6f 6d 30 0d 06 09 2a 86  48 86 f7 0d 01 01 0b 05  |om0...*.H.......|
+00000140  00 03 41 00 c4 3b 94 4b  e0 6b ad 2d dc fa 1f a4  |..A..;.K.k.-....|
+00000150  f9 f4 0f 3a 63 92 73 2e  b2 4d 7f 66 1f 0d 10 29  |...:c.s..M.f...)|
+00000160  bb 9c 19 a9 97 60 4c b4  51 12 30 39 d3 b4 b5 0d  |.....`L.Q.09....|
+00000170  cb 1c f7 35 60 6b d8 48  fc 24 0e 39 23 a8 40 ac  |...5`k.H.$.9#.@.|
+00000180  d9 59 bf 00 16 03 03 00  25 10 00 00 21 20 2f e5  |.Y......%...! /.|
+00000190  7d a3 47 cd 62 43 15 28  da ac 5f bb 29 07 30 ff  |}.G.bC.(.._.).0.|
+000001a0  f6 84 af c4 cf c2 ed 90  99 5f 58 cb 3b 74 16 03  |........._X.;t..|
+000001b0  03 00 48 0f 00 00 44 04  01 00 40 15 33 b2 27 d6  |..H...D...@.3.'.|
+000001c0  ad 7f 45 86 df a0 83 5e  7c fb a7 0e 04 8e 3c a1  |..E....^|.....<.|
+000001d0  5b 9a 8f 98 04 cf 66 bb  cf 6a d4 63 d7 ff b2 a4  |[.....f..j.c....|
+000001e0  f1 08 27 f7 53 1c ec 76  35 b1 09 93 91 db 63 e3  |..'.S..v5.....c.|
+000001f0  a6 2b e5 55 da 06 5b 2f  c7 8d c3 14 03 03 00 01  |.+.U..[/........|
+00000200  01 16 03 03 00 28 00 00  00 00 00 00 00 00 98 d8  |.....(..........|
+00000210  99 fa 5a fb 79 57 1f 02  4e 07 51 d6 c6 32 9c e8  |..Z.yW..N.Q..2..|
+00000220  54 50 6c f9 63 fb 38 e2  ef 88 4b 7e 8d 7a        |TPl.c.8...K~.z|
+>>> Flow 4 (server to client)
+00000000  14 03 03 00 01 01 16 03  03 00 28 4c 6b f0 26 84  |..........(Lk.&.|
+00000010  97 e6 54 cf 1f 25 1c 91  5d 10 63 22 66 73 d2 ce  |..T..%..].c"fs..|
+00000020  0d 7c 0b 3d 7d 31 3c 0b  6c be 30 72 9e 04 c0 fb  |.|.=}1<.l.0r....|
+00000030  73 88 75                                          |s.u|
+>>> Flow 5 (client to server)
+00000000  17 03 03 00 1e 00 00 00  00 00 00 00 01 2a b2 2d  |.............*.-|
+00000010  7f 6e 12 2d d7 63 05 e8  c4 fd 81 de b6 65 2f 2b  |.n.-.c.......e/+|
+00000020  00 0e 13 15 03 03 00 1a  00 00 00 00 00 00 00 02  |................|
+00000030  9c c0 ae 5a b4 5f b5 4f  cd 3f 27 78 f9 b3 b5 b5  |...Z._.O.?'x....|
+00000040  57 f2                                             |W.|

src/crypto/tls/tls.go

@@ -4,6 +4,15 @@
 
 // Package tls partially implements TLS 1.2, as specified in RFC 5246,
 // and TLS 1.3, as specified in RFC 8446.
+//
+// TLS 1.3 is available only on an opt-in basis in Go 1.12. To enable
+// it, set the GODEBUG environment variable (comma-separated key=value
+// options) such that it includes "tls13=1". To enable it from within
+// the process, set the environment variable before any use of TLS:
+//
+//     func init() {
+//         os.Setenv("GODEBUG", os.Getenv("GODEBUG")+",tls13=1")
+//     }
 package tls
 
 // BUG(agl): The crypto/tls package only implements some countermeasures

src/database/sql/driver/driver.go

@@ -137,7 +137,7 @@ type Pinger interface {
 
 // Execer is an optional interface that may be implemented by a Conn.
 //
-// If a Conn implements neither ExecerContext nor Execer Execer,
+// If a Conn implements neither ExecerContext nor Execer,
 // the sql package's DB.Exec will first prepare a query, execute the statement,
 // and then close the statement.
 //

src/internal/fmtsort/sort.go

@@ -167,7 +167,7 @@ func compare(aVal, bVal reflect.Value) int {
 		if c, ok := nilCompare(aVal, bVal); ok {
 			return c
 		}
-		c := compare(reflect.ValueOf(aType), reflect.ValueOf(bType))
+		c := compare(reflect.ValueOf(aVal.Elem().Type()), reflect.ValueOf(bVal.Elem().Type()))
 		if c != 0 {
 			return c
 		}

src/internal/fmtsort/sort_test.go

@@ -126,10 +126,6 @@ var sortTests = []sortTest{
 		map[[2]int]string{{7, 2}: "72", {7, 1}: "71", {3, 4}: "34"},
 		"[3 4]:34 [7 1]:71 [7 2]:72",
 	},
-	{
-		map[interface{}]string{7: "7", 4: "4", 3: "3", nil: "nil"},
-		"<nil>:nil 3:3 4:4 7:7",
-	},
 }
 
 func sprint(data interface{}) string {
@@ -210,3 +206,41 @@ func TestOrder(t *testing.T) {
 		}
 	}
 }
+
+func TestInterface(t *testing.T) {
+	// A map containing multiple concrete types should be sorted by type,
+	// then value. However, the relative ordering of types is unspecified,
+	// so test this by checking the presence of sorted subgroups.
+	m := map[interface{}]string{
+		[2]int{1, 0}:             "",
+		[2]int{0, 1}:             "",
+		true:                     "",
+		false:                    "",
+		3.1:                      "",
+		2.1:                      "",
+		1.1:                      "",
+		math.NaN():               "",
+		3:                        "",
+		2:                        "",
+		1:                        "",
+		"c":                      "",
+		"b":                      "",
+		"a":                      "",
+		struct{ x, y int }{1, 0}: "",
+		struct{ x, y int }{0, 1}: "",
+	}
+	got := sprint(m)
+	typeGroups := []string{
+		"NaN: 1.1: 2.1: 3.1:", // float64
+		"false: true:",        // bool
+		"1: 2: 3:",            // int
+		"a: b: c:",            // string
+		"[0 1]: [1 0]:",       // [2]int
+		"{0 1}: {1 0}:",       // struct{ x int; y int }
+	}
+	for _, g := range typeGroups {
+		if !strings.Contains(got, g) {
+			t.Errorf("sorted map should contain %q", g)
+		}
+	}
+}

src/internal/poll/fd_windows.go

@@ -660,6 +660,10 @@ func (fd *FD) Write(buf []byte) (int, error) {
 		return 0, err
 	}
 	defer fd.writeUnlock()
+	if fd.isFile || fd.isDir || fd.isConsole {
+		fd.l.Lock()
+		defer fd.l.Unlock()
+	}
 
 	ntotal := 0
 	for len(buf) > 0 {
@@ -670,8 +674,6 @@ func (fd *FD) Write(buf []byte) (int, error) {
 		var n int
 		var err error
 		if fd.isFile || fd.isDir || fd.isConsole {
-			fd.l.Lock()
-			defer fd.l.Unlock()
 			if fd.isConsole {
 				n, err = fd.writeConsole(b)
 			} else {

src/net/http/httptrace/trace.go

@@ -152,7 +152,7 @@ type ClientTrace struct {
 	WroteHeaders func()
 
 	// Wait100Continue is called if the Request specified
-	// "Expected: 100-continue" and the Transport has written the
+	// "Expect: 100-continue" and the Transport has written the
 	// request headers but is waiting for "100 Continue" from the
 	// server before writing the request body.
 	Wait100Continue func()

src/net/http/httputil/reverseproxy.go

@@ -389,6 +389,11 @@ func (p *ReverseProxy) copyResponse(dst io.Writer, src io.Reader, flushInterval
 				latency: flushInterval,
 			}
 			defer mlw.stop()
+
+			// set up initial timer so headers get flushed even if body writes are delayed
+			mlw.flushPending = true
+			mlw.t = time.AfterFunc(flushInterval, mlw.delayedFlush)
+
 			dst = mlw
 		}
 	}

src/net/http/httputil/reverseproxy_test.go

@@ -9,6 +9,7 @@ package httputil
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -317,6 +318,47 @@ func TestReverseProxyFlushInterval(t *testing.T) {
 	}
 }
 
+func TestReverseProxyFlushIntervalHeaders(t *testing.T) {
+	const expected = "hi"
+	stopCh := make(chan struct{})
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("MyHeader", expected)
+		w.WriteHeader(200)
+		w.(http.Flusher).Flush()
+		<-stopCh
+	}))
+	defer backend.Close()
+	defer close(stopCh)
+
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	proxyHandler.FlushInterval = time.Microsecond
+
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+
+	req, _ := http.NewRequest("GET", frontend.URL, nil)
+	req.Close = true
+
+	ctx, cancel := context.WithTimeout(req.Context(), 10*time.Second)
+	defer cancel()
+	req = req.WithContext(ctx)
+
+	res, err := frontend.Client().Do(req)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	defer res.Body.Close()
+
+	if res.Header.Get("MyHeader") != expected {
+		t.Errorf("got header %q; expected %q", res.Header.Get("MyHeader"), expected)
+	}
+}
+
 func TestReverseProxyCancelation(t *testing.T) {
 	const backendResponse = "I am the backend"
 

src/net/lookup.go

@@ -262,8 +262,9 @@ func (r *Resolver) lookupIPAddr(ctx context.Context, network, host string) ([]IP
 	// only the values in context. See Issue 28600.
 	lookupGroupCtx, lookupGroupCancel := context.WithCancel(withUnexpiredValuesPreserved(ctx))
 
+	lookupKey := network + "\000" + host
 	dnsWaitGroup.Add(1)
-	ch, called := r.getLookupGroup().DoChan(host, func() (interface{}, error) {
+	ch, called := r.getLookupGroup().DoChan(lookupKey, func() (interface{}, error) {
 		defer dnsWaitGroup.Done()
 		return testHookLookupIP(lookupGroupCtx, resolverFunc, network, host)
 	})
@@ -280,7 +281,7 @@ func (r *Resolver) lookupIPAddr(ctx context.Context, network, host string) ([]IP
 		// let the lookup continue uncanceled, and let later
 		// lookups with the same key share the result.
 		// See issues 8602, 20703, 22724.
-		if r.getLookupGroup().ForgetUnshared(host) {
+		if r.getLookupGroup().ForgetUnshared(lookupKey) {
 			lookupGroupCancel()
 		} else {
 			go func() {

src/net/lookup_test.go

@@ -16,6 +16,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 )
@@ -253,14 +254,11 @@ func TestLookupGmailTXT(t *testing.T) {
 	}
 }
 
-var lookupGooglePublicDNSAddrTests = []struct {
-	addr, name string
-}{
-	{"8.8.8.8", ".google.com."},
-	{"8.8.4.4", ".google.com."},
-
-	{"2001:4860:4860::8888", ".google.com."},
-	{"2001:4860:4860::8844", ".google.com."},
+var lookupGooglePublicDNSAddrTests = []string{
+	"8.8.8.8",
+	"8.8.4.4",
+	"2001:4860:4860::8888",
+	"2001:4860:4860::8844",
 }
 
 func TestLookupGooglePublicDNSAddr(t *testing.T) {
@@ -272,8 +270,8 @@ func TestLookupGooglePublicDNSAddr(t *testing.T) {
 
 	defer dnsWaitGroup.Wait()
 
-	for _, tt := range lookupGooglePublicDNSAddrTests {
-		names, err := LookupAddr(tt.addr)
+	for _, ip := range lookupGooglePublicDNSAddrTests {
+		names, err := LookupAddr(ip)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -281,8 +279,8 @@ func TestLookupGooglePublicDNSAddr(t *testing.T) {
 			t.Error("got no record")
 		}
 		for _, name := range names {
-			if !strings.HasSuffix(name, tt.name) {
-				t.Errorf("got %s; want a record containing %s", name, tt.name)
+			if !strings.HasSuffix(name, ".google.com.") && !strings.HasSuffix(name, ".google.") {
+				t.Errorf("got %q; want a record ending in .google.com. or .google.", name)
 			}
 		}
 	}
@@ -658,8 +656,8 @@ func testDots(t *testing.T, mode string) {
 		t.Errorf("LookupAddr(8.8.8.8): %v (mode=%v)", err, mode)
 	} else {
 		for _, name := range names {
-			if !strings.HasSuffix(name, ".google.com.") {
-				t.Errorf("LookupAddr(8.8.8.8) = %v, want names ending in .google.com. with trailing dot (mode=%v)", names, mode)
+			if !strings.HasSuffix(name, ".google.com.") && !strings.HasSuffix(name, ".google.") {
+				t.Errorf("LookupAddr(8.8.8.8) = %v, want names ending in .google.com or .google with trailing dot (mode=%v)", names, mode)
 				break
 			}
 		}
@@ -1096,6 +1094,69 @@ func TestLookupIPAddrPreservesContextValues(t *testing.T) {
 	}
 }
 
+// Issue 30521: The lookup group should call the resolver for each network.
+func TestLookupIPAddrConcurrentCallsForNetworks(t *testing.T) {
+	origTestHookLookupIP := testHookLookupIP
+	defer func() { testHookLookupIP = origTestHookLookupIP }()
+
+	queries := [][]string{
+		{"udp", "golang.org"},
+		{"udp4", "golang.org"},
+		{"udp6", "golang.org"},
+		{"udp", "golang.org"},
+		{"udp", "golang.org"},
+	}
+	results := map[[2]string][]IPAddr{
+		{"udp", "golang.org"}: {
+			{IP: IPv4(127, 0, 0, 1)},
+			{IP: IPv6loopback},
+		},
+		{"udp4", "golang.org"}: {
+			{IP: IPv4(127, 0, 0, 1)},
+		},
+		{"udp6", "golang.org"}: {
+			{IP: IPv6loopback},
+		},
+	}
+	calls := int32(0)
+	waitCh := make(chan struct{})
+	testHookLookupIP = func(ctx context.Context, fn func(context.Context, string, string) ([]IPAddr, error), network, host string) ([]IPAddr, error) {
+		// We'll block until this is called one time for each different
+		// expected result. This will ensure that the lookup group would wait
+		// for the existing call if it was to be reused.
+		if atomic.AddInt32(&calls, 1) == int32(len(results)) {
+			close(waitCh)
+		}
+		select {
+		case <-waitCh:
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+		return results[[2]string{network, host}], nil
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	wg := sync.WaitGroup{}
+	for _, q := range queries {
+		network := q[0]
+		host := q[1]
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			gotIPs, err := DefaultResolver.lookupIPAddr(ctx, network, host)
+			if err != nil {
+				t.Errorf("lookupIPAddr(%v, %v): unexpected error: %v", network, host, err)
+			}
+			wantIPs := results[[2]string{network, host}]
+			if !reflect.DeepEqual(gotIPs, wantIPs) {
+				t.Errorf("lookupIPAddr(%v, %v): mismatched IPAddr results\n\tGot: %v\n\tWant: %v", network, host, gotIPs, wantIPs)
+			}
+		}()
+	}
+	wg.Wait()
+}
+
 func TestWithUnexpiredValuesPreserved(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 

src/os/export_unix_test.go

@@ -0,0 +1,9 @@
+// Copyright 2019 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 aix darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
+
+package os
+
+var SplitPath = splitPath

src/os/os_unix_test.go

@@ -281,3 +281,28 @@ func TestNewFileNonBlock(t *testing.T) {
 	t.Parallel()
 	newFileTest(t, false)
 }
+
+func TestSplitPath(t *testing.T) {
+	t.Parallel()
+	for _, tt := range []struct{ path, wantDir, wantBase string }{
+		{"a", ".", "a"},
+		{"a/", ".", "a"},
+		{"a//", ".", "a"},
+		{"a/b", "a", "b"},
+		{"a/b/", "a", "b"},
+		{"a/b/c", "a/b", "c"},
+		{"/a", "/", "a"},
+		{"/a/", "/", "a"},
+		{"/a/b", "/a", "b"},
+		{"/a/b/", "/a", "b"},
+		{"/a/b/c", "/a/b", "c"},
+		{"//a", "/", "a"},
+		{"//a/", "/", "a"},
+		{"///a", "/", "a"},
+		{"///a/", "/", "a"},
+	} {
+		if dir, base := SplitPath(tt.path); dir != tt.wantDir || base != tt.wantBase {
+			t.Errorf("splitPath(%q) = %q, %q, want %q, %q", tt.path, dir, base, tt.wantDir, tt.wantBase)
+		}
+	}
+}

src/os/path.go

@@ -62,6 +62,7 @@ func MkdirAll(path string, perm FileMode) error {
 // It removes everything it can but returns the first error
 // it encounters. If the path does not exist, RemoveAll
 // returns nil (no error).
+// If there is an error, it will be of type *PathError.
 func RemoveAll(path string) error {
 	return removeAll(path)
 }

src/os/path_unix.go

@@ -38,20 +38,30 @@ func basename(name string) string {
 func splitPath(path string) (string, string) {
 	// if no better parent is found, the path is relative from "here"
 	dirname := "."
-	// if no slashes in path, base is path
-	basename := path
+
+	// Remove all but one leading slash.
+	for len(path) > 1 && path[0] == '/' && path[1] == '/' {
+		path = path[1:]
+	}
 
 	i := len(path) - 1
 
-	// Remove trailing slashes
+	// Remove trailing slashes.
 	for ; i > 0 && path[i] == '/'; i-- {
 		path = path[:i]
 	}
 
+	// if no slashes in path, base is path
+	basename := path
+
 	// Remove leading directory path
 	for i--; i >= 0; i-- {
 		if path[i] == '/' {
-			dirname = path[:i+1]
+			if i == 0 {
+				dirname = path[:1]
+			} else {
+				dirname = path[:i]
+			}
 			basename = path[i+1:]
 			break
 		}

src/os/removeall_at.go

@@ -46,13 +46,20 @@ func removeAll(path string) error {
 	}
 	defer parent.Close()
 
-	return removeAllFrom(parent, base)
+	if err := removeAllFrom(parent, base); err != nil {
+		if pathErr, ok := err.(*PathError); ok {
+			pathErr.Path = parentDir + string(PathSeparator) + pathErr.Path
+			err = pathErr
+		}
+		return err
+	}
+	return nil
 }
 
-func removeAllFrom(parent *File, path string) error {
+func removeAllFrom(parent *File, base string) error {
 	parentFd := int(parent.Fd())
 	// Simple case: if Unlink (aka remove) works, we're done.
-	err := unix.Unlinkat(parentFd, path, 0)
+	err := unix.Unlinkat(parentFd, base, 0)
 	if err == nil || IsNotExist(err) {
 		return nil
 	}
@@ -64,18 +71,21 @@ func removeAllFrom(parent *File, path string) error {
 	// whose contents need to be removed.
 	// Otherwise just return the error.
 	if err != syscall.EISDIR && err != syscall.EPERM && err != syscall.EACCES {
-		return err
+		return &PathError{"unlinkat", base, err}
 	}
 
 	// Is this a directory we need to recurse into?
 	var statInfo syscall.Stat_t
-	statErr := unix.Fstatat(parentFd, path, &statInfo, unix.AT_SYMLINK_NOFOLLOW)
+	statErr := unix.Fstatat(parentFd, base, &statInfo, unix.AT_SYMLINK_NOFOLLOW)
 	if statErr != nil {
-		return statErr
+		if IsNotExist(statErr) {
+			return nil
+		}
+		return &PathError{"fstatat", base, statErr}
 	}
 	if statInfo.Mode&syscall.S_IFMT != syscall.S_IFDIR {
-		// Not a directory; return the error from the Remove.
-		return err
+		// Not a directory; return the error from the unix.Unlinkat.
+		return &PathError{"unlinkat", base, err}
 	}
 
 	// Remove the directory's entries.
@@ -84,12 +94,13 @@ func removeAllFrom(parent *File, path string) error {
 		const request = 1024
 
 		// Open the directory to recurse into
-		file, err := openFdAt(parentFd, path)
+		file, err := openFdAt(parentFd, base)
 		if err != nil {
 			if IsNotExist(err) {
 				return nil
 			}
-			return err
+			recurseErr = &PathError{"openfdat", base, err}
+			break
 		}
 
 		names, readErr := file.Readdirnames(request)
@@ -99,12 +110,15 @@ func removeAllFrom(parent *File, path string) error {
 			if IsNotExist(readErr) {
 				return nil
 			}
-			return readErr
+			return &PathError{"readdirnames", base, readErr}
 		}
 
 		for _, name := range names {
 			err := removeAllFrom(file, name)
 			if err != nil {
+				if pathErr, ok := err.(*PathError); ok {
+					pathErr.Path = base + string(PathSeparator) + pathErr.Path
+				}
 				recurseErr = err
 			}
 		}
@@ -123,7 +137,7 @@ func removeAllFrom(parent *File, path string) error {
 	}
 
 	// Remove the directory itself.
-	unlinkError := unix.Unlinkat(parentFd, path, unix.AT_REMOVEDIR)
+	unlinkError := unix.Unlinkat(parentFd, base, unix.AT_REMOVEDIR)
 	if unlinkError == nil || IsNotExist(unlinkError) {
 		return nil
 	}
@@ -131,7 +145,7 @@ func removeAllFrom(parent *File, path string) error {
 	if recurseErr != nil {
 		return recurseErr
 	}
-	return unlinkError
+	return &PathError{"unlinkat", base, unlinkError}
 }
 
 // openFdAt opens path relative to the directory in fd.
@@ -153,7 +167,7 @@ func openFdAt(dirfd int, name string) (*File, error) {
 			continue
 		}
 
-		return nil, &PathError{"openat", name, e}
+		return nil, e
 	}
 
 	if !supportsCloseOnExec {

src/os/removeall_test.go

@@ -294,7 +294,7 @@ func TestRemoveReadOnlyDir(t *testing.T) {
 }
 
 // Issue #29983.
-func TestRemoveAllButReadOnly(t *testing.T) {
+func TestRemoveAllButReadOnlyAndPathError(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "js", "windows":
 		t.Skipf("skipping test on %s", runtime.GOOS)
@@ -355,10 +355,21 @@ func TestRemoveAllButReadOnly(t *testing.T) {
 		defer Chmod(d, 0777)
 	}
 
-	if err := RemoveAll(tempDir); err == nil {
+	err = RemoveAll(tempDir)
+	if err == nil {
 		t.Fatal("RemoveAll succeeded unexpectedly")
 	}
 
+	// The error should be of type *PathError.
+	// see issue 30491 for details.
+	if pathErr, ok := err.(*PathError); ok {
+		if g, w := pathErr.Path, filepath.Join(tempDir, "b", "y"); g != w {
+			t.Errorf("got %q, expected pathErr.path %q", g, w)
+		}
+	} else {
+		t.Errorf("got %T, expected *os.PathError", err)
+	}
+
 	for _, dir := range dirs {
 		_, err := Stat(filepath.Join(tempDir, dir))
 		if inReadonly(dir) {
@@ -372,3 +383,33 @@ func TestRemoveAllButReadOnly(t *testing.T) {
 		}
 	}
 }
+
+func TestRemoveUnreadableDir(t *testing.T) {
+	switch runtime.GOOS {
+	case "nacl", "js", "windows":
+		t.Skipf("skipping test on %s", runtime.GOOS)
+	}
+
+	if Getuid() == 0 {
+		t.Skip("skipping test when running as root")
+	}
+
+	t.Parallel()
+
+	tempDir, err := ioutil.TempDir("", "TestRemoveAllButReadOnly-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer RemoveAll(tempDir)
+
+	target := filepath.Join(tempDir, "d0", "d1", "d2")
+	if err := MkdirAll(target, 0755); err != nil {
+		t.Fatal(err)
+	}
+	if err := Chmod(target, 0300); err != nil {
+		t.Fatal(err)
+	}
+	if err := RemoveAll(filepath.Join(tempDir, "d0")); err != nil {
+		t.Fatal(err)
+	}
+}

src/path/filepath/path.go

@@ -96,19 +96,14 @@ func Clean(path string) string {
 		}
 		return originalPath + "."
 	}
-
-	n := len(path)
-	if volLen > 2 && n == 1 && os.IsPathSeparator(path[0]) {
-		// UNC volume name with trailing slash.
-		return FromSlash(originalPath[:volLen])
-	}
 	rooted := os.IsPathSeparator(path[0])
 
 	// Invariants:
 	//	reading from path; r is index of next byte to process.
-	//	writing to out; w is index of next byte to write.
-	//	dotdot is index in out where .. must stop, either because
+	//	writing to buf; w is index of next byte to write.
+	//	dotdot is index in buf where .. must stop, either because
 	//		it is the leading slash or it is a leading ../../.. prefix.
+	n := len(path)
 	out := lazybuf{path: path, volAndPath: originalPath, volLen: volLen}
 	r, dotdot := 0, 0
 	if rooted {

src/path/filepath/path_test.go

@@ -93,9 +93,6 @@ var wincleantests = []PathTest{
 	{`//host/share/foo/../baz`, `\\host\share\baz`},
 	{`\\a\b\..\c`, `\\a\b\c`},
 	{`\\a\b`, `\\a\b`},
-	{`\\a\b\`, `\\a\b`},
-	{`\\folder\share\foo`, `\\folder\share\foo`},
-	{`\\folder\share\foo\`, `\\folder\share\foo`},
 }
 
 func TestClean(t *testing.T) {
@@ -1413,3 +1410,103 @@ func TestIssue29372(t *testing.T) {
 		}
 	}
 }
+
+// Issue 30520 part 1.
+func TestEvalSymlinksAboveRoot(t *testing.T) {
+	testenv.MustHaveSymlink(t)
+
+	t.Parallel()
+
+	tmpDir, err := ioutil.TempDir("", "TestEvalSymlinksAboveRoot")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	evalTmpDir, err := filepath.EvalSymlinks(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := os.Mkdir(filepath.Join(evalTmpDir, "a"), 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Symlink(filepath.Join(evalTmpDir, "a"), filepath.Join(evalTmpDir, "b")); err != nil {
+		t.Fatal(err)
+	}
+	if err := ioutil.WriteFile(filepath.Join(evalTmpDir, "a", "file"), nil, 0666); err != nil {
+		t.Fatal(err)
+	}
+
+	// Count the number of ".." elements to get to the root directory.
+	vol := filepath.VolumeName(evalTmpDir)
+	c := strings.Count(evalTmpDir[len(vol):], string(os.PathSeparator))
+	var dd []string
+	for i := 0; i < c+2; i++ {
+		dd = append(dd, "..")
+	}
+
+	wantSuffix := strings.Join([]string{"a", "file"}, string(os.PathSeparator))
+
+	// Try different numbers of "..".
+	for _, i := range []int{c, c + 1, c + 2} {
+		check := strings.Join([]string{evalTmpDir, strings.Join(dd[:i], string(os.PathSeparator)), evalTmpDir[len(vol)+1:], "b", "file"}, string(os.PathSeparator))
+		if resolved, err := filepath.EvalSymlinks(check); err != nil {
+			t.Errorf("EvalSymlinks(%q) failed: %v", check, err)
+		} else if !strings.HasSuffix(resolved, wantSuffix) {
+			t.Errorf("EvalSymlinks(%q) = %q does not end with %q", check, resolved, wantSuffix)
+		} else {
+			t.Logf("EvalSymlinks(%q) = %q", check, resolved)
+		}
+	}
+}
+
+// Issue 30520 part 2.
+func TestEvalSymlinksAboveRootChdir(t *testing.T) {
+	testenv.MustHaveSymlink(t)
+
+	tmpDir, err := ioutil.TempDir("", "TestEvalSymlinksAboveRootChdir")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	wd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Chdir(wd)
+
+	if err := os.Chdir(tmpDir); err != nil {
+		t.Fatal(err)
+	}
+
+	subdir := filepath.Join("a", "b")
+	if err := os.MkdirAll(subdir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Symlink(subdir, "c"); err != nil {
+		t.Fatal(err)
+	}
+	if err := ioutil.WriteFile(filepath.Join(subdir, "file"), nil, 0666); err != nil {
+		t.Fatal(err)
+	}
+
+	subdir = filepath.Join("d", "e", "f")
+	if err := os.MkdirAll(subdir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Chdir(subdir); err != nil {
+		t.Fatal(err)
+	}
+
+	check := filepath.Join("..", "..", "..", "c", "file")
+	wantSuffix := filepath.Join("a", "b", "file")
+	if resolved, err := filepath.EvalSymlinks(check); err != nil {
+		t.Errorf("EvalSymlinks(%q) failed: %v", check, err)
+	} else if !strings.HasSuffix(resolved, wantSuffix) {
+		t.Errorf("EvalSymlinks(%q) = %q does not end with %q", check, resolved, wantSuffix)
+	} else {
+		t.Logf("EvalSymlinks(%q) = %q", check, resolved)
+	}
+}

src/path/filepath/symlink.go

@@ -44,18 +44,26 @@ func walkSymlinks(path string) (string, error) {
 		} else if path[start:end] == ".." {
 			// Back up to previous component if possible.
 			// Note that volLen includes any leading slash.
+
+			// Set r to the index of the last slash in dest,
+			// after the volume.
 			var r int
 			for r = len(dest) - 1; r >= volLen; r-- {
 				if os.IsPathSeparator(dest[r]) {
 					break
 				}
 			}
-			if r < volLen {
+			if r < volLen || dest[r+1:] == ".." {
+				// Either path has no slashes
+				// (it's empty or just "C:")
+				// or it ends in a ".." we had to keep.
+				// Either way, keep this "..".
 				if len(dest) > volLen {
 					dest += pathSeparator
 				}
 				dest += ".."
 			} else {
+				// Discard everything since the last slash.
 				dest = dest[:r]
 			}
 			continue

src/runtime/asm_wasm.s

@@ -443,7 +443,7 @@ TEXT runtime·gcWriteBarrier(SB), NOSPLIT, $16
 	// Record value
 	MOVD R1, 0(R5)
 	// Record *slot
-	MOVD R0, 8(R5)
+	MOVD (R0), 8(R5)
 
 	// Increment wbBuf.next
 	Get R5

src/runtime/crash_test.go

@@ -728,3 +728,15 @@ func TestG0StackOverflow(t *testing.T) {
 
 	runtime.G0StackOverflow()
 }
+
+// Test that panic message is not clobbered.
+// See issue 30150.
+func TestDoublePanic(t *testing.T) {
+	output := runTestProg(t, "testprog", "DoublePanic", "GODEBUG=clobberfree=1")
+	wants := []string{"panic: XXX", "panic: YYY"}
+	for _, want := range wants {
+		if !strings.Contains(output, want) {
+			t.Errorf("output:\n%s\n\nwant output containing: %s", output, want)
+		}
+	}
+}

src/runtime/export_test.go

@@ -513,3 +513,116 @@ func MapTombstoneCheck(m map[int]int) {
 		}
 	}
 }
+
+// Span is a safe wrapper around an mspan, whose memory
+// is managed manually.
+type Span struct {
+	*mspan
+}
+
+func AllocSpan(base, npages uintptr) Span {
+	lock(&mheap_.lock)
+	s := (*mspan)(mheap_.spanalloc.alloc())
+	unlock(&mheap_.lock)
+	s.init(base, npages)
+	return Span{s}
+}
+
+func (s *Span) Free() {
+	lock(&mheap_.lock)
+	mheap_.spanalloc.free(unsafe.Pointer(s.mspan))
+	unlock(&mheap_.lock)
+	s.mspan = nil
+}
+
+func (s Span) Base() uintptr {
+	return s.mspan.base()
+}
+
+func (s Span) Pages() uintptr {
+	return s.mspan.npages
+}
+
+type TreapIter struct {
+	treapIter
+}
+
+func (t TreapIter) Span() Span {
+	return Span{t.span()}
+}
+
+func (t TreapIter) Valid() bool {
+	return t.valid()
+}
+
+func (t TreapIter) Next() TreapIter {
+	return TreapIter{t.next()}
+}
+
+func (t TreapIter) Prev() TreapIter {
+	return TreapIter{t.prev()}
+}
+
+// Treap is a safe wrapper around mTreap for testing.
+//
+// It must never be heap-allocated because mTreap is
+// notinheap.
+//
+//go:notinheap
+type Treap struct {
+	mTreap
+}
+
+func (t *Treap) Start() TreapIter {
+	return TreapIter{t.start()}
+}
+
+func (t *Treap) End() TreapIter {
+	return TreapIter{t.end()}
+}
+
+func (t *Treap) Insert(s Span) {
+	// mTreap uses a fixalloc in mheap_ for treapNode
+	// allocation which requires the mheap_ lock to manipulate.
+	// Locking here is safe because the treap itself never allocs
+	// or otherwise ends up grabbing this lock.
+	lock(&mheap_.lock)
+	t.insert(s.mspan)
+	unlock(&mheap_.lock)
+	t.CheckInvariants()
+}
+
+func (t *Treap) Find(npages uintptr) TreapIter {
+	return TreapIter{treapIter{t.find(npages)}}
+}
+
+func (t *Treap) Erase(i TreapIter) {
+	// mTreap uses a fixalloc in mheap_ for treapNode
+	// freeing which requires the mheap_ lock to manipulate.
+	// Locking here is safe because the treap itself never allocs
+	// or otherwise ends up grabbing this lock.
+	lock(&mheap_.lock)
+	t.erase(i.treapIter)
+	unlock(&mheap_.lock)
+	t.CheckInvariants()
+}
+
+func (t *Treap) RemoveSpan(s Span) {
+	// See Erase about locking.
+	lock(&mheap_.lock)
+	t.removeSpan(s.mspan)
+	unlock(&mheap_.lock)
+	t.CheckInvariants()
+}
+
+func (t *Treap) Size() int {
+	i := 0
+	t.mTreap.treap.walkTreap(func(t *treapNode) {
+		i++
+	})
+	return i
+}
+
+func (t *Treap) CheckInvariants() {
+	t.mTreap.treap.walkTreap(checkTreapNode)
+}

src/runtime/extern.go

@@ -27,6 +27,10 @@ It is a comma-separated list of name=val pairs setting these named variables:
 	allocfreetrace: setting allocfreetrace=1 causes every allocation to be
 	profiled and a stack trace printed on each object's allocation and free.
 
+	clobberfree: setting clobberfree=1 causes the garbage collector to
+	clobber the memory content of an object with bad content when it frees
+	the object.
+
 	cgocheck: setting cgocheck=0 disables all checks for packages
 	using cgo to incorrectly pass Go pointers to non-Go code.
 	Setting cgocheck=1 (the default) enables relatively cheap
@@ -123,7 +127,7 @@ It is a comma-separated list of name=val pairs setting these named variables:
 	IDs will refer to the ID of the goroutine at the time of creation; it's possible for this
 	ID to be reused for another goroutine. Setting N to 0 will report no ancestry information.
 
-The net and net/http packages also refer to debugging variables in GODEBUG.
+The net, net/http, and crypto/tls packages also refer to debugging variables in GODEBUG.
 See the documentation for those packages for details.
 
 The GOMAXPROCS variable limits the number of operating system threads that

src/runtime/mgclarge.go

@@ -134,16 +134,19 @@ func checkTreapNode(t *treapNode) {
 			return t.npagesKey < npages
 		}
 		// t.npagesKey == npages
-		return uintptr(unsafe.Pointer(t.spanKey)) < uintptr(unsafe.Pointer(s))
+		return t.spanKey.base() < s.base()
 	}
 
 	if t == nil {
 		return
 	}
-	if t.spanKey.npages != t.npagesKey || t.spanKey.next != nil {
+	if t.spanKey.next != nil || t.spanKey.prev != nil || t.spanKey.list != nil {
+		throw("span may be on an mSpanList while simultaneously in the treap")
+	}
+	if t.spanKey.npages != t.npagesKey {
 		println("runtime: checkTreapNode treapNode t=", t, "     t.npagesKey=", t.npagesKey,
 			"t.spanKey.npages=", t.spanKey.npages)
-		throw("why does span.npages and treap.ngagesKey do not match?")
+		throw("span.npages and treap.npagesKey do not match")
 	}
 	if t.left != nil && lessThan(t.left.npagesKey, t.left.spanKey) {
 		throw("t.lessThan(t.left.npagesKey, t.left.spanKey) is not false")
@@ -298,24 +301,30 @@ func (root *mTreap) removeNode(t *treapNode) {
 // find searches for, finds, and returns the treap node containing the
 // smallest span that can hold npages. If no span has at least npages
 // it returns nil.
-// This is slightly more complicated than a simple binary tree search
-// since if an exact match is not found the next larger node is
-// returned.
+// This is a simple binary tree search that tracks the best-fit node found
+// so far. The best-fit node is guaranteed to be on the path to a
+// (maybe non-existent) lowest-base exact match.
 func (root *mTreap) find(npages uintptr) *treapNode {
+	var best *treapNode
 	t := root.treap
 	for t != nil {
 		if t.spanKey == nil {
 			throw("treap node with nil spanKey found")
 		}
-		if t.npagesKey < npages {
-			t = t.right
-		} else if t.left != nil && t.left.npagesKey >= npages {
+		// If we found an exact match, try to go left anyway. There could be
+		// a span there with a lower base address.
+		//
+		// Don't bother checking nil-ness of left and right here; even if t
+		// becomes nil, we already know the other path had nothing better for
+		// us anyway.
+		if t.npagesKey >= npages {
+			best = t
 			t = t.left
 		} else {
-			return t
+			t = t.right
 		}
 	}
-	return nil
+	return best
 }
 
 // removeSpan searches for, finds, deletes span along with

src/runtime/mgcmark.go

@@ -709,7 +709,20 @@ func scanstack(gp *g, gcw *gcWork) {
 		return true
 	}
 	gentraceback(^uintptr(0), ^uintptr(0), 0, gp, 0, nil, 0x7fffffff, scanframe, nil, 0)
+
+	// Find additional pointers that point into the stack from the heap.
+	// Currently this includes defers and panics. See also function copystack.
 	tracebackdefers(gp, scanframe, nil)
+	for d := gp._defer; d != nil; d = d.link {
+		// tracebackdefers above does not scan the func value, which could
+		// be a stack allocated closure. See issue 30453.
+		if d.fn != nil {
+			scanblock(uintptr(unsafe.Pointer(&d.fn)), sys.PtrSize, &oneptrmask[0], gcw, &state)
+		}
+	}
+	if gp._panic != nil {
+		state.putPtr(uintptr(unsafe.Pointer(gp._panic)))
+	}
 
 	// Find and scan all reachable stack objects.
 	state.buildIndex()

src/runtime/mgcsweep.go

@@ -291,7 +291,7 @@ func (s *mspan) sweep(preserve bool) bool {
 		}
 	}
 
-	if debug.allocfreetrace != 0 || raceenabled || msanenabled {
+	if debug.allocfreetrace != 0 || debug.clobberfree != 0 || raceenabled || msanenabled {
 		// Find all newly freed objects. This doesn't have to
 		// efficient; allocfreetrace has massive overhead.
 		mbits := s.markBitsForBase()
@@ -302,6 +302,9 @@ func (s *mspan) sweep(preserve bool) bool {
 				if debug.allocfreetrace != 0 {
 					tracefree(unsafe.Pointer(x), size)
 				}
+				if debug.clobberfree != 0 {
+					clobberfree(unsafe.Pointer(x), size)
+				}
 				if raceenabled {
 					racefree(unsafe.Pointer(x), size)
 				}
@@ -446,3 +449,12 @@ retry:
 		traceGCSweepDone()
 	}
 }
+
+// clobberfree sets the memory content at x to bad content, for debugging
+// purposes.
+func clobberfree(x unsafe.Pointer, size uintptr) {
+	// size (span.elemsize) is always a multiple of 4.
+	for i := uintptr(0); i < size; i += 4 {
+		*(*uint32)(add(x, i)) = 0xdeadbeef
+	}
+}

src/runtime/mheap.go

@@ -1198,16 +1198,6 @@ HaveSpan:
 		// heap_released since we already did so earlier.
 		sysUsed(unsafe.Pointer(s.base()), s.npages<<_PageShift)
 		s.scavenged = false
-
-		// Since we allocated out of a scavenged span, we just
-		// grew the RSS. Mitigate this by scavenging enough free
-		// space to make up for it.
-		//
-		// Also, scavengeLargest may cause coalescing, so prevent
-		// coalescing with s by temporarily changing its state.
-		s.state = mSpanManual
-		h.scavengeLargest(s.npages * pageSize)
-		s.state = mSpanFree
 	}
 	s.unusedsince = 0
 

src/runtime/os_windows.go

@@ -29,6 +29,7 @@ const (
 //go:cgo_import_dynamic runtime._GetProcessAffinityMask GetProcessAffinityMask%3 "kernel32.dll"
 //go:cgo_import_dynamic runtime._GetQueuedCompletionStatus GetQueuedCompletionStatus%5 "kernel32.dll"
 //go:cgo_import_dynamic runtime._GetStdHandle GetStdHandle%1 "kernel32.dll"
+//go:cgo_import_dynamic runtime._GetSystemDirectoryA GetSystemDirectoryA%2 "kernel32.dll"
 //go:cgo_import_dynamic runtime._GetSystemInfo GetSystemInfo%1 "kernel32.dll"
 //go:cgo_import_dynamic runtime._GetThreadContext GetThreadContext%2 "kernel32.dll"
 //go:cgo_import_dynamic runtime._LoadLibraryW LoadLibraryW%1 "kernel32.dll"
@@ -47,12 +48,9 @@ const (
 //go:cgo_import_dynamic runtime._VirtualAlloc VirtualAlloc%4 "kernel32.dll"
 //go:cgo_import_dynamic runtime._VirtualFree VirtualFree%3 "kernel32.dll"
 //go:cgo_import_dynamic runtime._VirtualQuery VirtualQuery%3 "kernel32.dll"
-//go:cgo_import_dynamic runtime._WSAGetOverlappedResult WSAGetOverlappedResult%5 "ws2_32.dll"
 //go:cgo_import_dynamic runtime._WaitForSingleObject WaitForSingleObject%2 "kernel32.dll"
 //go:cgo_import_dynamic runtime._WriteConsoleW WriteConsoleW%5 "kernel32.dll"
 //go:cgo_import_dynamic runtime._WriteFile WriteFile%5 "kernel32.dll"
-//go:cgo_import_dynamic runtime._timeBeginPeriod timeBeginPeriod%1 "winmm.dll"
-//go:cgo_import_dynamic runtime._timeEndPeriod timeEndPeriod%1 "winmm.dll"
 
 type stdFunction unsafe.Pointer
 
@@ -75,6 +73,7 @@ var (
 	_GetProcessAffinityMask,
 	_GetQueuedCompletionStatus,
 	_GetStdHandle,
+	_GetSystemDirectoryA,
 	_GetSystemInfo,
 	_GetSystemTimeAsFileTime,
 	_GetThreadContext,
@@ -96,12 +95,9 @@ var (
 	_VirtualAlloc,
 	_VirtualFree,
 	_VirtualQuery,
-	_WSAGetOverlappedResult,
 	_WaitForSingleObject,
 	_WriteConsoleW,
 	_WriteFile,
-	_timeBeginPeriod,
-	_timeEndPeriod,
 	_ stdFunction
 
 	// Following syscalls are only available on some Windows PCs.
@@ -109,6 +105,7 @@ var (
 	_AddDllDirectory,
 	_AddVectoredContinueHandler,
 	_GetQueuedCompletionStatusEx,
+	_LoadLibraryExA,
 	_LoadLibraryExW,
 	_ stdFunction
 
@@ -126,6 +123,12 @@ var (
 	// links wrong printf function to cgo executable (see issue
 	// 12030 for details).
 	_NtWaitForSingleObject stdFunction
+
+	// These are from non-kernel32.dll, so we prefer to LoadLibraryEx them.
+	_timeBeginPeriod,
+	_timeEndPeriod,
+	_WSAGetOverlappedResult,
+	_ stdFunction
 )
 
 // Function to be called by windows CreateThread
@@ -173,6 +176,26 @@ func windowsFindfunc(lib uintptr, name []byte) stdFunction {
 	return stdFunction(unsafe.Pointer(f))
 }
 
+var sysDirectory [521]byte
+var sysDirectoryLen uintptr
+
+func windowsLoadSystemLib(name []byte) uintptr {
+	if useLoadLibraryEx {
+		return stdcall3(_LoadLibraryExA, uintptr(unsafe.Pointer(&name[0])), 0, _LOAD_LIBRARY_SEARCH_SYSTEM32)
+	} else {
+		if sysDirectoryLen == 0 {
+			l := stdcall2(_GetSystemDirectoryA, uintptr(unsafe.Pointer(&sysDirectory[0])), uintptr(len(sysDirectory)-1))
+			if l == 0 || l > uintptr(len(sysDirectory)-1) {
+				throw("Unable to determine system directory")
+			}
+			sysDirectory[l] = '\\'
+			sysDirectoryLen = l + 1
+		}
+		absName := append(sysDirectory[:sysDirectoryLen], name...)
+		return stdcall1(_LoadLibraryA, uintptr(unsafe.Pointer(&absName[0])))
+	}
+}
+
 func loadOptionalSyscalls() {
 	var kernel32dll = []byte("kernel32.dll\000")
 	k32 := stdcall1(_LoadLibraryA, uintptr(unsafe.Pointer(&kernel32dll[0])))
@@ -182,17 +205,19 @@ func loadOptionalSyscalls() {
 	_AddDllDirectory = windowsFindfunc(k32, []byte("AddDllDirectory\000"))
 	_AddVectoredContinueHandler = windowsFindfunc(k32, []byte("AddVectoredContinueHandler\000"))
 	_GetQueuedCompletionStatusEx = windowsFindfunc(k32, []byte("GetQueuedCompletionStatusEx\000"))
+	_LoadLibraryExA = windowsFindfunc(k32, []byte("LoadLibraryExA\000"))
 	_LoadLibraryExW = windowsFindfunc(k32, []byte("LoadLibraryExW\000"))
+	useLoadLibraryEx = (_LoadLibraryExW != nil && _LoadLibraryExA != nil && _AddDllDirectory != nil)
 
 	var advapi32dll = []byte("advapi32.dll\000")
-	a32 := stdcall1(_LoadLibraryA, uintptr(unsafe.Pointer(&advapi32dll[0])))
+	a32 := windowsLoadSystemLib(advapi32dll)
 	if a32 == 0 {
 		throw("advapi32.dll not found")
 	}
 	_RtlGenRandom = windowsFindfunc(a32, []byte("SystemFunction036\000"))
 
 	var ntdll = []byte("ntdll.dll\000")
-	n32 := stdcall1(_LoadLibraryA, uintptr(unsafe.Pointer(&ntdll[0])))
+	n32 := windowsLoadSystemLib(ntdll)
 	if n32 == 0 {
 		throw("ntdll.dll not found")
 	}
@@ -205,6 +230,27 @@ func loadOptionalSyscalls() {
 		}
 	}
 
+	var winmmdll = []byte("winmm.dll\000")
+	m32 := windowsLoadSystemLib(winmmdll)
+	if m32 == 0 {
+		throw("winmm.dll not found")
+	}
+	_timeBeginPeriod = windowsFindfunc(m32, []byte("timeBeginPeriod\000"))
+	_timeEndPeriod = windowsFindfunc(m32, []byte("timeEndPeriod\000"))
+	if _timeBeginPeriod == nil || _timeEndPeriod == nil {
+		throw("timeBegin/EndPeriod not found")
+	}
+
+	var ws232dll = []byte("ws2_32.dll\000")
+	ws232 := windowsLoadSystemLib(ws232dll)
+	if ws232 == 0 {
+		throw("ws2_32.dll not found")
+	}
+	_WSAGetOverlappedResult = windowsFindfunc(ws232, []byte("WSAGetOverlappedResult\000"))
+	if _WSAGetOverlappedResult == nil {
+		throw("WSAGetOverlappedResult not found")
+	}
+
 	if windowsFindfunc(n32, []byte("wine_get_version\000")) != nil {
 		// running on Wine
 		initWine(k32)
@@ -311,8 +357,6 @@ func osinit() {
 
 	loadOptionalSyscalls()
 
-	useLoadLibraryEx = (_LoadLibraryExW != nil && _AddDllDirectory != nil)
-
 	disableWER()
 
 	initExceptionHandler()

src/runtime/runtime-lldb_test.go

@@ -139,6 +139,7 @@ func TestLldbPython(t *testing.T) {
 	if final := os.Getenv("GOROOT_FINAL"); final != "" && runtime.GOROOT() != final {
 		t.Skip("gdb test can fail with GOROOT_FINAL pending")
 	}
+	testenv.SkipFlaky(t, 31188)
 
 	checkLldbPython(t)