libgo: update to Go 1.10.2 release

    
    Reviewed-on: https://go-review.googlesource.com/115196

From-SVN: r261041

39 files changed, 853 insertions, 158 deletions

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 8500b37..618004c 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-9731580e76c065b76e3a103356bb8920da05a685
+79eca4fd642724d89e9bec8f79889451f6632a46
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/libgo/MERGE b/libgo/MERGE
index b715f06..6f31fab 100644
--- a/libgo/MERGE
+++ b/libgo/MERGE
@@ -1,4 +1,4 @@
-bf86aec25972f3a100c3aa58a6abcbcc35bdea49
+71bdbf431b79dff61944f22c25c7e085ccfc25d5
 
 The first line of this file holds the git revision number of the
 last merge done from the master library sources.
diff --git a/libgo/VERSION b/libgo/VERSION
index 95ec39e..98736c7 100644
--- a/libgo/VERSION
+++ b/libgo/VERSION
@@ -1 +1 @@
-go1.10
+go1.10.2
diff --git a/libgo/check-packages.txt b/libgo/check-packages.txt
index 8ede851..82a08c6 100644
--- a/libgo/check-packages.txt
+++ b/libgo/check-packages.txt
@@ -122,6 +122,7 @@ net/http/httptest
 net/http/httptrace
 net/http/httputil
 net/http/internal
+net/http/pprof
 net/internal/socktest
 net/mail
 net/rpc
diff --git a/libgo/go/archive/zip/reader.go b/libgo/go/archive/zip/reader.go
index 1563e74..2444106 100644
--- a/libgo/go/archive/zip/reader.go
+++ b/libgo/go/archive/zip/reader.go
@@ -366,7 +366,7 @@ parseExtras:
 				epoch := time.Date(1601, time.January, 1, 0, 0, 0, 0, time.UTC)
 				modified = time.Unix(epoch.Unix()+secs, nsecs)
 			}
-		case unixExtraID:
+		case unixExtraID, infoZipUnixExtraID:
 			if len(fieldBuf) < 8 {
 				continue parseExtras
 			}
@@ -379,12 +379,6 @@ parseExtras:
 			}
 			ts := int64(fieldBuf.uint32()) // ModTime since Unix epoch
 			modified = time.Unix(ts, 0)
-		case infoZipUnixExtraID:
-			if len(fieldBuf) < 4 {
-				continue parseExtras
-			}
-			ts := int64(fieldBuf.uint32()) // ModTime since Unix epoch
-			modified = time.Unix(ts, 0)
 		}
 	}
 
diff --git a/libgo/go/archive/zip/reader_test.go b/libgo/go/archive/zip/reader_test.go
index 0d9040f..1e58b26 100644
--- a/libgo/go/archive/zip/reader_test.go
+++ b/libgo/go/archive/zip/reader_test.go
@@ -414,7 +414,7 @@ var tests = []ZipTest{
 				Name:     "test.txt",
 				Content:  []byte{},
 				Size:     1<<32 - 1,
-				Modified: time.Date(2017, 10, 31, 21, 17, 27, 0, timeZone(-7*time.Hour)),
+				Modified: time.Date(2017, 10, 31, 21, 11, 57, 0, timeZone(-7*time.Hour)),
 				Mode:     0644,
 			},
 		},
diff --git a/libgo/go/cmd/go/go_test.go b/libgo/go/cmd/go/go_test.go
index 2945418..f6d6f42 100644
--- a/libgo/go/cmd/go/go_test.go
+++ b/libgo/go/cmd/go/go_test.go
@@ -3265,6 +3265,20 @@ func TestGoVetWithOnlyTestFiles(t *testing.T) {
 	tg.run("vet", "p")
 }
 
+// Issue 24193.
+func TestVetWithOnlyCgoFiles(t *testing.T) {
+	if !canCgo {
+		t.Skip("skipping because cgo not enabled")
+	}
+
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.parallel()
+	tg.tempFile("src/p/p.go", "package p; import \"C\"; func F() {}")
+	tg.setenv("GOPATH", tg.path("."))
+	tg.run("vet", "p")
+}
+
 // Issue 9767, 19769.
 func TestGoGetDotSlashDownload(t *testing.T) {
 	testenv.MustHaveExternalNetwork(t)
@@ -5099,6 +5113,28 @@ func TestCacheOutput(t *testing.T) {
 	}
 }
 
+func TestCacheListStale(t *testing.T) {
+	tooSlow(t)
+	if strings.Contains(os.Getenv("GODEBUG"), "gocacheverify") {
+		t.Skip("GODEBUG gocacheverify")
+	}
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.parallel()
+	tg.makeTempdir()
+	tg.setenv("GOCACHE", tg.path("cache"))
+	tg.tempFile("gopath/src/p/p.go", "package p; import _ \"q\"; func F(){}\n")
+	tg.tempFile("gopath/src/q/q.go", "package q; func F(){}\n")
+	tg.tempFile("gopath/src/m/m.go", "package main; import _ \"q\"; func main(){}\n")
+
+	tg.setenv("GOPATH", tg.path("gopath"))
+	tg.run("install", "p", "m")
+	tg.run("list", "-f={{.ImportPath}} {{.Stale}}", "m", "q", "p")
+	tg.grepStdout("^m false", "m should not be stale")
+	tg.grepStdout("^q true", "q should be stale")
+	tg.grepStdout("^p false", "p should not be stale")
+}
+
 func TestCacheCoverage(t *testing.T) {
 	tooSlow(t)
 
@@ -5792,6 +5828,22 @@ func TestAtomicCoverpkgAll(t *testing.T) {
 	}
 }
 
+// Issue 23882.
+func TestCoverpkgAllRuntime(t *testing.T) {
+	skipIfGccgo(t, "gccgo has no cover tool")
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.parallel()
+
+	tg.tempFile("src/x/x.go", `package x; import _ "runtime"; func F() {}`)
+	tg.tempFile("src/x/x_test.go", `package x; import "testing"; func TestF(t *testing.T) { F() }`)
+	tg.setenv("GOPATH", tg.path("."))
+	tg.run("test", "-coverpkg=all", "x")
+	if canRace {
+		tg.run("test", "-coverpkg=all", "-race", "x")
+	}
+}
+
 func TestBadCommandLines(t *testing.T) {
 	tg := testgo(t)
 	defer tg.cleanup()
@@ -5949,3 +6001,36 @@ func TestBadCgoDirectives(t *testing.T) {
 	tg.run("build", "-n", "x")
 	tg.grepStderr("-D@foo", "did not find -D@foo in commands")
 }
+
+func TestTwoPkgConfigs(t *testing.T) {
+	if !canCgo {
+		t.Skip("no cgo")
+	}
+	if runtime.GOOS == "windows" || runtime.GOOS == "plan9" {
+		t.Skipf("no shell scripts on %s", runtime.GOOS)
+	}
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.parallel()
+	tg.tempFile("src/x/a.go", `package x
+		// #cgo pkg-config: --static a
+		import "C"
+	`)
+	tg.tempFile("src/x/b.go", `package x
+		// #cgo pkg-config: --static a
+		import "C"
+	`)
+	tg.tempFile("pkg-config.sh", `#!/bin/sh
+echo $* >>`+tg.path("pkg-config.out"))
+	tg.must(os.Chmod(tg.path("pkg-config.sh"), 0755))
+	tg.setenv("GOPATH", tg.path("."))
+	tg.setenv("PKG_CONFIG", tg.path("pkg-config.sh"))
+	tg.run("build", "x")
+	out, err := ioutil.ReadFile(tg.path("pkg-config.out"))
+	tg.must(err)
+	out = bytes.TrimSpace(out)
+	want := "--cflags --static --static -- a a\n--libs --static --static -- a a"
+	if !bytes.Equal(out, []byte(want)) {
+		t.Errorf("got %q want %q", out, want)
+	}
+}
diff --git a/libgo/go/cmd/go/internal/get/vcs.go b/libgo/go/cmd/go/internal/get/vcs.go
index 26693b1..0b2a04e 100644
--- a/libgo/go/cmd/go/internal/get/vcs.go
+++ b/libgo/go/cmd/go/internal/get/vcs.go
@@ -809,8 +809,8 @@ func repoRootForImportDynamic(importPath string, security web.SecurityMode) (*re
 		}
 	}
 
-	if !strings.Contains(mmi.RepoRoot, "://") {
-		return nil, fmt.Errorf("%s: invalid repo root %q; no scheme", urlStr, mmi.RepoRoot)
+	if err := validateRepoRootScheme(mmi.RepoRoot); err != nil {
+		return nil, fmt.Errorf("%s: invalid repo root %q: %v", urlStr, mmi.RepoRoot, err)
 	}
 	rr := &repoRoot{
 		vcs:      vcsByCmd(mmi.VCS),
@@ -824,6 +824,36 @@ func repoRootForImportDynamic(importPath string, security web.SecurityMode) (*re
 	return rr, nil
 }
 
+// validateRepoRootScheme returns an error if repoRoot does not seem
+// to have a valid URL scheme. At this point we permit things that
+// aren't valid URLs, although later, if not using -insecure, we will
+// restrict repoRoots to be valid URLs. This is only because we've
+// historically permitted them, and people may depend on that.
+func validateRepoRootScheme(repoRoot string) error {
+	end := strings.Index(repoRoot, "://")
+	if end <= 0 {
+		return errors.New("no scheme")
+	}
+
+	// RFC 3986 section 3.1.
+	for i := 0; i < end; i++ {
+		c := repoRoot[i]
+		switch {
+		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z':
+			// OK.
+		case '0' <= c && c <= '9' || c == '+' || c == '-' || c == '.':
+			// OK except at start.
+			if i == 0 {
+				return errors.New("invalid scheme")
+			}
+		default:
+			return errors.New("invalid scheme")
+		}
+	}
+
+	return nil
+}
+
 var fetchGroup singleflight.Group
 var (
 	fetchCacheMu sync.Mutex
diff --git a/libgo/go/cmd/go/internal/get/vcs_test.go b/libgo/go/cmd/go/internal/get/vcs_test.go
index e29338a..a6f8642 100644
--- a/libgo/go/cmd/go/internal/get/vcs_test.go
+++ b/libgo/go/cmd/go/internal/get/vcs_test.go
@@ -408,3 +408,46 @@ func TestMatchGoImport(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateRepoRootScheme(t *testing.T) {
+	tests := []struct {
+		root string
+		err  string
+	}{
+		{
+			root: "",
+			err:  "no scheme",
+		},
+		{
+			root: "http://",
+			err:  "",
+		},
+		{
+			root: "a://",
+			err:  "",
+		},
+		{
+			root: "a#://",
+			err:  "invalid scheme",
+		},
+		{
+			root: "-config://",
+			err:  "invalid scheme",
+		},
+	}
+
+	for _, test := range tests {
+		err := validateRepoRootScheme(test.root)
+		if err == nil {
+			if test.err != "" {
+				t.Errorf("validateRepoRootScheme(%q) = nil, want %q", test.root, test.err)
+			}
+		} else if test.err == "" {
+			if err != nil {
+				t.Errorf("validateRepoRootScheme(%q) = %q, want nil", test.root, test.err)
+			}
+		} else if err.Error() != test.err {
+			t.Errorf("validateRepoRootScheme(%q) = %q, want %q", test.root, err, test.err)
+		}
+	}
+}
diff --git a/libgo/go/cmd/go/internal/test/test.go b/libgo/go/cmd/go/internal/test/test.go
index dbf6eea..72415cc 100644
--- a/libgo/go/cmd/go/internal/test/test.go
+++ b/libgo/go/cmd/go/internal/test/test.go
@@ -673,6 +673,14 @@ func runTest(cmd *base.Command, args []string) {
 				continue
 			}
 
+			// If using the race detector, silently ignore
+			// attempts to run coverage on the runtime
+			// packages. It will cause the race detector
+			// to be invoked before it has been initialized.
+			if cfg.BuildRace && p.Standard && (p.ImportPath == "runtime" || strings.HasPrefix(p.ImportPath, "runtime/internal")) {
+				continue
+			}
+
 			if haveMatch {
 				testCoverPkgs = append(testCoverPkgs, p)
 			}
diff --git a/libgo/go/cmd/go/internal/vet/vet.go b/libgo/go/cmd/go/internal/vet/vet.go
index 07eed89..a737ebd 100644
--- a/libgo/go/cmd/go/internal/vet/vet.go
+++ b/libgo/go/cmd/go/internal/vet/vet.go
@@ -62,11 +62,11 @@ func runVet(cmd *base.Command, args []string) {
 			base.Errorf("%v", err)
 			continue
 		}
-		if len(ptest.GoFiles) == 0 && pxtest == nil {
+		if len(ptest.GoFiles) == 0 && len(ptest.CgoFiles) == 0 && pxtest == nil {
 			base.Errorf("go vet %s: no Go files in %s", p.ImportPath, p.Dir)
 			continue
 		}
-		if len(ptest.GoFiles) > 0 {
+		if len(ptest.GoFiles) > 0 || len(ptest.CgoFiles) > 0 {
 			root.Deps = append(root.Deps, b.VetAction(work.ModeBuild, work.ModeBuild, ptest))
 		}
 		if pxtest != nil {
diff --git a/libgo/go/cmd/go/internal/work/buildid.go b/libgo/go/cmd/go/internal/work/buildid.go
index 6150bbb..733938e 100644
--- a/libgo/go/cmd/go/internal/work/buildid.go
+++ b/libgo/go/cmd/go/internal/work/buildid.go
@@ -461,15 +461,7 @@ func (b *Builder) useCache(a *Action, p *load.Package, actionHash cache.ActionID
 	// If so, it's up to date and we can reuse it instead of rebuilding it.
 	var buildID string
 	if target != "" && !cfg.BuildA {
-		var err error
-		buildID, err = buildid.ReadFile(target)
-		if err != nil && b.ComputeStaleOnly {
-			if p != nil && !p.Stale {
-				p.Stale = true
-				p.StaleReason = "target missing"
-			}
-			return true
-		}
+		buildID, _ = buildid.ReadFile(target)
 		if strings.HasPrefix(buildID, actionID+buildIDSeparator) {
 			a.buildID = buildID
 			a.built = target
@@ -546,7 +538,10 @@ func (b *Builder) useCache(a *Action, p *load.Package, actionHash cache.ActionID
 				}
 			}
 		}
-		return true
+
+		// Fall through to update a.buildID from the build artifact cache,
+		// which will affect the computation of buildIDs for targets
+		// higher up in the dependency graph.
 	}
 
 	// Check the build artifact cache.
@@ -574,6 +569,10 @@ func (b *Builder) useCache(a *Action, p *load.Package, actionHash cache.ActionID
 						a.built = file
 						a.Target = "DO NOT USE - using cache"
 						a.buildID = buildID
+						if p := a.Package; p != nil {
+							// Clearer than explaining that something else is stale.
+							p.StaleReason = "not installed but available in build cache"
+						}
 						return true
 					}
 				}
@@ -584,6 +583,10 @@ func (b *Builder) useCache(a *Action, p *load.Package, actionHash cache.ActionID
 		a.output = []byte{}
 	}
 
+	if b.ComputeStaleOnly {
+		return true
+	}
+
 	return false
 }
 
diff --git a/libgo/go/cmd/go/internal/work/exec.go b/libgo/go/cmd/go/internal/work/exec.go
index 837ffb5..5994dbc 100644
--- a/libgo/go/cmd/go/internal/work/exec.go
+++ b/libgo/go/cmd/go/internal/work/exec.go
@@ -956,11 +956,19 @@ func splitPkgConfigOutput(out []byte) []string {
 
 // Calls pkg-config if needed and returns the cflags/ldflags needed to build the package.
 func (b *Builder) getPkgConfigFlags(p *load.Package) (cflags, ldflags []string, err error) {
-	if pkgs := p.CgoPkgConfig; len(pkgs) > 0 {
+	if pcargs := p.CgoPkgConfig; len(pcargs) > 0 {
+		// pkg-config permits arguments to appear anywhere in
+		// the command line. Move them all to the front, before --.
 		var pcflags []string
-		for len(pkgs) > 0 && strings.HasPrefix(pkgs[0], "--") {
-			pcflags = append(pcflags, pkgs[0])
-			pkgs = pkgs[1:]
+		var pkgs []string
+		for _, pcarg := range pcargs {
+			if pcarg == "--" {
+				// We're going to add our own "--" argument.
+			} else if strings.HasPrefix(pcarg, "--") {
+				pcflags = append(pcflags, pcarg)
+			} else {
+				pkgs = append(pkgs, pcarg)
+			}
 		}
 		for _, pkg := range pkgs {
 			if !load.SafeArg(pkg) {
@@ -1107,7 +1115,7 @@ func BuildInstallFunc(b *Builder, a *Action) (err error) {
 		// We want to hide that awful detail as much as possible, so don't
 		// advertise it by touching the mtimes (usually the libraries are up
 		// to date).
-		if !a.buggyInstall {
+		if !a.buggyInstall && !b.ComputeStaleOnly {
 			now := time.Now()
 			os.Chtimes(a.Target, now, now)
 		}
diff --git a/libgo/go/cmd/go/internal/work/security.go b/libgo/go/cmd/go/internal/work/security.go
index 54fd6b9..5c67aa9 100644
--- a/libgo/go/cmd/go/internal/work/security.go
+++ b/libgo/go/cmd/go/internal/work/security.go
@@ -46,12 +46,19 @@ var validCompilerFlags = []*regexp.Regexp{
 	re(`-O([^@\-].*)`),
 	re(`-W`),
 	re(`-W([^@,]+)`), // -Wall but not -Wa,-foo.
+	re(`-Wa,-mbig-obj`),
+	re(`-ansi`),
 	re(`-f(no-)?blocks`),
 	re(`-f(no-)?common`),
 	re(`-f(no-)?constant-cfstrings`),
+	re(`-fdiagnostics-show-note-include-stack`),
 	re(`-f(no-)?exceptions`),
+	re(`-f(no-)?inline-functions`),
 	re(`-finput-charset=([^@\-].*)`),
+	re(`-f(no-)?fat-lto-objects`),
 	re(`-f(no-)?lto`),
+	re(`-fmacro-backtrace-limit=(.+)`),
+	re(`-fmessage-length=(.+)`),
 	re(`-f(no-)?modules`),
 	re(`-f(no-)?objc-arc`),
 	re(`-f(no-)?omit-frame-pointer`),
@@ -62,27 +69,42 @@ var validCompilerFlags = []*regexp.Regexp{
 	re(`-f(no-)?split-stack`),
 	re(`-f(no-)?stack-(.+)`),
 	re(`-f(no-)?strict-aliasing`),
+	re(`-f(un)signed-char`),
+	re(`-f(no-)?use-linker-plugin`), // safe if -B is not used; we don't permit -B
 	re(`-fsanitize=(.+)`),
+	re(`-ftemplate-depth-(.+)`),
+	re(`-fvisibility=(.+)`),
 	re(`-g([^@\-].*)?`),
+	re(`-m32`),
+	re(`-m64`),
 	re(`-m(arch|cpu|fpu|tune)=([^@\-].*)`),
 	re(`-m(no-)?avx[0-9a-z.]*`),
 	re(`-m(no-)?ms-bitfields`),
 	re(`-m(no-)?stack-(.+)`),
 	re(`-mmacosx-(.+)`),
+	re(`-mios-simulator-version-min=(.+)`),
+	re(`-miphoneos-version-min=(.+)`),
 	re(`-mnop-fun-dllimport`),
 	re(`-m(no-)?sse[0-9.]*`),
+	re(`-mwindows`),
 	re(`-pedantic(-errors)?`),
 	re(`-pipe`),
 	re(`-pthread`),
 	re(`-?-std=([^@\-].*)`),
+	re(`-?-stdlib=([^@\-].*)`),
+	re(`-w`),
 	re(`-x([^@\-].*)`),
 }
 
 var validCompilerFlagsWithNextArg = []string{
+	"-arch",
 	"-D",
 	"-I",
-	"-isystem",
 	"-framework",
+	"-isysroot",
+	"-isystem",
+	"--sysroot",
+	"-target",
 	"-x",
 }
 
@@ -90,43 +112,65 @@ var validLinkerFlags = []*regexp.Regexp{
 	re(`-F([^@\-].*)`),
 	re(`-l([^@\-].*)`),
 	re(`-L([^@\-].*)`),
+	re(`-O`),
+	re(`-O([^@\-].*)`),
 	re(`-f(no-)?(pic|PIC|pie|PIE)`),
 	re(`-fsanitize=([^@\-].*)`),
 	re(`-g([^@\-].*)?`),
 	re(`-m(arch|cpu|fpu|tune)=([^@\-].*)`),
+	re(`-mmacosx-(.+)`),
+	re(`-mios-simulator-version-min=(.+)`),
+	re(`-miphoneos-version-min=(.+)`),
+	re(`-mwindows`),
 	re(`-(pic|PIC|pie|PIE)`),
 	re(`-pthread`),
+	re(`-shared`),
 	re(`-?-static([-a-z0-9+]*)`),
+	re(`-?-stdlib=([^@\-].*)`),
 
 	// Note that any wildcards in -Wl need to exclude comma,
 	// since -Wl splits its argument at commas and passes
 	// them all to the linker uninterpreted. Allowing comma
 	// in a wildcard would allow tunnelling arbitrary additional
 	// linker arguments through one of these.
+	re(`-Wl,--(no-)?allow-multiple-definition`),
 	re(`-Wl,--(no-)?as-needed`),
 	re(`-Wl,-Bdynamic`),
 	re(`-Wl,-Bstatic`),
+	re(`-Wl,-d[ny]`),
 	re(`-Wl,--disable-new-dtags`),
 	re(`-Wl,--enable-new-dtags`),
 	re(`-Wl,--end-group`),
 	re(`-Wl,-framework,[^,@\-][^,]+`),
 	re(`-Wl,-headerpad_max_install_names`),
 	re(`-Wl,--no-undefined`),
-	re(`-Wl,-rpath,([^,@\-][^,]+)`),
+	re(`-Wl,-rpath[=,]([^,@\-][^,]+)`),
 	re(`-Wl,-search_paths_first`),
+	re(`-Wl,-sectcreate,([^,@\-][^,]+),([^,@\-][^,]+),([^,@\-][^,]+)`),
 	re(`-Wl,--start-group`),
+	re(`-Wl,-?-static`),
+	re(`-Wl,--subsystem,(native|windows|console|posix|xbox)`),
+	re(`-Wl,-undefined[=,]([^,@\-][^,]+)`),
 	re(`-Wl,-?-unresolved-symbols=[^,]+`),
 	re(`-Wl,--(no-)?warn-([^,]+)`),
+	re(`-Wl,-z,(no)?execstack`),
+	re(`-Wl,-z,relro`),
 
 	re(`[a-zA-Z0-9_/].*\.(a|o|obj|dll|dylib|so)`), // direct linker inputs: x.o or libfoo.so (but not -foo.o or @foo.o)
 }
 
 var validLinkerFlagsWithNextArg = []string{
+	"-arch",
 	"-F",
 	"-l",
 	"-L",
 	"-framework",
+	"-isysroot",
+	"--sysroot",
+	"-target",
 	"-Wl,-framework",
+	"-Wl,-rpath",
+	"-Wl,-undefined",
 }
 
 func checkCompilerFlags(name, source string, list []string) error {
diff --git a/libgo/go/cmd/go/internal/work/security_test.go b/libgo/go/cmd/go/internal/work/security_test.go
index 976501b..bd898c9 100644
--- a/libgo/go/cmd/go/internal/work/security_test.go
+++ b/libgo/go/cmd/go/internal/work/security_test.go
@@ -140,9 +140,6 @@ var goodLinkerFlags = [][]string{
 var badLinkerFlags = [][]string{
 	{"-DFOO"},
 	{"-Dfoo=bar"},
-	{"-O"},
-	{"-O2"},
-	{"-Osmall"},
 	{"-W"},
 	{"-Wall"},
 	{"-fobjc-arc"},
@@ -155,7 +152,6 @@ var badLinkerFlags = [][]string{
 	{"-fno-stack-xxx"},
 	{"-mstack-overflow"},
 	{"-mno-stack-overflow"},
-	{"-mmacosx-version"},
 	{"-mnop-fun-dllimport"},
 	{"-std=c99"},
 	{"-xc"},
diff --git a/libgo/go/cmd/internal/objabi/funcid.go b/libgo/go/cmd/internal/objabi/funcid.go
new file mode 100644
index 0000000..55f1328
--- /dev/null
+++ b/libgo/go/cmd/internal/objabi/funcid.go
@@ -0,0 +1,34 @@
+// Copyright 2018 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 objabi
+
+// A FuncID identifies particular functions that need to be treated
+// specially by the runtime.
+// Note that in some situations involving plugins, there may be multiple
+// copies of a particular special runtime function.
+// Note: this list must match the list in runtime/symtab.go.
+type FuncID uint32
+
+const (
+	FuncID_normal FuncID = iota // not a special function
+	FuncID_goexit
+	FuncID_jmpdefer
+	FuncID_mcall
+	FuncID_morestack
+	FuncID_mstart
+	FuncID_rt0_go
+	FuncID_asmcgocall
+	FuncID_sigpanic
+	FuncID_runfinq
+	FuncID_bgsweep
+	FuncID_forcegchelper
+	FuncID_timerproc
+	FuncID_gcBgMarkWorker
+	FuncID_systemstack_switch
+	FuncID_systemstack
+	FuncID_cgocallback_gofunc
+	FuncID_gogo
+	FuncID_externalthreadhandler
+)
diff --git a/libgo/go/crypto/x509/name_constraints_test.go b/libgo/go/crypto/x509/name_constraints_test.go
index 10cc348..bad488f 100644
--- a/libgo/go/crypto/x509/name_constraints_test.go
+++ b/libgo/go/crypto/x509/name_constraints_test.go
@@ -11,6 +11,7 @@ import (
 	"crypto/rand"
 	"crypto/x509/pkix"
 	"encoding/asn1"
+	"encoding/hex"
 	"encoding/pem"
 	"fmt"
 	"io/ioutil"
@@ -42,6 +43,7 @@ type nameConstraintsTest struct {
 	roots         []constraintsSpec
 	intermediates [][]constraintsSpec
 	leaf          leafSpec
+	requestedEKUs []ExtKeyUsage
 	expectedError string
 	noOpenSSL     bool
 }
@@ -1444,6 +1446,118 @@ var nameConstraintsTests = []nameConstraintsTest{
 		},
 		expectedError: "\"https://example.com/test\" is excluded",
 	},
+
+	// #75: While serverAuth in a CA certificate permits clientAuth in a leaf,
+	// serverAuth in a leaf shouldn't permit clientAuth when requested in
+	// VerifyOptions.
+	nameConstraintsTest{
+		roots: []constraintsSpec{
+			constraintsSpec{},
+		},
+		intermediates: [][]constraintsSpec{
+			[]constraintsSpec{
+				constraintsSpec{},
+			},
+		},
+		leaf: leafSpec{
+			sans: []string{"dns:example.com"},
+			ekus: []string{"serverAuth"},
+		},
+		requestedEKUs: []ExtKeyUsage{ExtKeyUsageClientAuth},
+		expectedError: "incompatible key usage",
+	},
+
+	// #76: However, MSSGC in a leaf should match a request for serverAuth.
+	nameConstraintsTest{
+		roots: []constraintsSpec{
+			constraintsSpec{},
+		},
+		intermediates: [][]constraintsSpec{
+			[]constraintsSpec{
+				constraintsSpec{},
+			},
+		},
+		leaf: leafSpec{
+			sans: []string{"dns:example.com"},
+			ekus: []string{"msSGC"},
+		},
+		requestedEKUs: []ExtKeyUsage{ExtKeyUsageServerAuth},
+	},
+
+	// An invalid DNS SAN should be detected only at validation time so
+	// that we can process CA certificates in the wild that have invalid SANs.
+	// See https://github.com/golang/go/issues/23995
+
+	// #77: an invalid DNS or mail SAN will not be detected if name constaint
+	// checking is not triggered.
+	nameConstraintsTest{
+		roots: []constraintsSpec{
+			constraintsSpec{},
+		},
+		intermediates: [][]constraintsSpec{
+			[]constraintsSpec{
+				constraintsSpec{},
+			},
+		},
+		leaf: leafSpec{
+			sans: []string{"dns:this is invalid", "email:this @ is invalid"},
+		},
+	},
+
+	// #78: an invalid DNS SAN will be detected if any name constraint checking
+	// is triggered.
+	nameConstraintsTest{
+		roots: []constraintsSpec{
+			constraintsSpec{
+				bad: []string{"uri:"},
+			},
+		},
+		intermediates: [][]constraintsSpec{
+			[]constraintsSpec{
+				constraintsSpec{},
+			},
+		},
+		leaf: leafSpec{
+			sans: []string{"dns:this is invalid"},
+		},
+		expectedError: "cannot parse dnsName",
+	},
+
+	// #79: an invalid email SAN will be detected if any name constraint
+	// checking is triggered.
+	nameConstraintsTest{
+		roots: []constraintsSpec{
+			constraintsSpec{
+				bad: []string{"uri:"},
+			},
+		},
+		intermediates: [][]constraintsSpec{
+			[]constraintsSpec{
+				constraintsSpec{},
+			},
+		},
+		leaf: leafSpec{
+			sans: []string{"email:this @ is invalid"},
+		},
+		expectedError: "cannot parse rfc822Name",
+	},
+
+	// #80: if several EKUs are requested, satisfying any of them is sufficient.
+	nameConstraintsTest{
+		roots: []constraintsSpec{
+			constraintsSpec{},
+		},
+		intermediates: [][]constraintsSpec{
+			[]constraintsSpec{
+				constraintsSpec{},
+			},
+		},
+		leaf: leafSpec{
+			sans: []string{"dns:example.com"},
+			ekus: []string{"email"},
+		},
+		requestedEKUs: []ExtKeyUsage{ExtKeyUsageClientAuth, ExtKeyUsageEmailProtection},
+	},
 }
 
 func makeConstraintsCACert(constraints constraintsSpec, name string, key *ecdsa.PrivateKey, parent *Certificate, parentKey *ecdsa.PrivateKey) (*Certificate, error) {
@@ -1459,7 +1573,7 @@ func makeConstraintsCACert(constraints constraintsSpec, name string, key *ecdsa.
 		NotAfter:              time.Unix(2000, 0),
 		KeyUsage:              KeyUsageCertSign,
 		BasicConstraintsValid: true,
-		IsCA: true,
+		IsCA:                  true,
 	}
 
 	if err := addConstraintsToTemplate(constraints, template); err != nil {
@@ -1497,7 +1611,7 @@ func makeConstraintsLeafCert(leaf leafSpec, key *ecdsa.PrivateKey, parent *Certi
 		NotAfter:              time.Unix(2000, 0),
 		KeyUsage:              KeyUsageDigitalSignature,
 		BasicConstraintsValid: true,
-		IsCA: false,
+		IsCA:                  false,
 	}
 
 	for _, name := range leaf.sans {
@@ -1512,6 +1626,13 @@ func makeConstraintsLeafCert(leaf leafSpec, key *ecdsa.PrivateKey, parent *Certi
 			}
 			template.IPAddresses = append(template.IPAddresses, ip)
 
+		case strings.HasPrefix(name, "invalidip:"):
+			ipBytes, err := hex.DecodeString(name[10:])
+			if err != nil {
+				return nil, fmt.Errorf("cannot parse invalid IP: %s", err)
+			}
+			template.IPAddresses = append(template.IPAddresses, net.IP(ipBytes))
+
 		case strings.HasPrefix(name, "email:"):
 			template.EmailAddresses = append(template.EmailAddresses, name[6:])
 
@@ -1781,6 +1902,7 @@ func TestConstraintCases(t *testing.T) {
 			Roots:         rootPool,
 			Intermediates: intermediatePool,
 			CurrentTime:   time.Unix(1500, 0),
+			KeyUsages:     test.requestedEKUs,
 		}
 		_, err = leafCert.Verify(verifyOpts)
 
@@ -1972,12 +2094,13 @@ func TestBadNamesInConstraints(t *testing.T) {
 }
 
 func TestBadNamesInSANs(t *testing.T) {
-	// Bad names in SANs should not parse.
+	// Bad names in URI and IP SANs should not parse. Bad DNS and email SANs
+	// will parse and are tested in name constraint tests at the top of this
+	// file.
 	badNames := []string{
-		"dns:foo.com.",
-		"email:abc@foo.com.",
-		"email:foo.com.",
 		"uri:https://example.com./dsf",
+		"invalidip:0102",
+		"invalidip:0102030405",
 	}
 
 	priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
diff --git a/libgo/go/crypto/x509/verify.go b/libgo/go/crypto/x509/verify.go
index 9477e85..0ea214b 100644
--- a/libgo/go/crypto/x509/verify.go
+++ b/libgo/go/crypto/x509/verify.go
@@ -6,12 +6,14 @@ package x509
 
 import (
 	"bytes"
+	"encoding/asn1"
 	"errors"
 	"fmt"
 	"net"
 	"net/url"
 	"reflect"
 	"runtime"
+	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -178,10 +180,14 @@ type VerifyOptions struct {
 	Intermediates *CertPool
 	Roots         *CertPool // if nil, the system roots are used
 	CurrentTime   time.Time // if zero, the current time is used
-	// KeyUsage specifies which Extended Key Usage values are acceptable.
-	// An empty list means ExtKeyUsageServerAuth. Key usage is considered a
-	// constraint down the chain which mirrors Windows CryptoAPI behavior,
-	// but not the spec. To accept any key usage, include ExtKeyUsageAny.
+	// KeyUsage specifies which Extended Key Usage values are acceptable. A leaf
+	// certificate is accepted if it contains any of the listed values. An empty
+	// list means ExtKeyUsageServerAuth. To accept any key usage, include
+	// ExtKeyUsageAny.
+	//
+	// Certificate chains are required to nest extended key usage values,
+	// irrespective of this value. This matches the Windows CryptoAPI behavior,
+	// but not the spec.
 	KeyUsages []ExtKeyUsage
 	// MaxConstraintComparisions is the maximum number of comparisons to
 	// perform when checking a given certificate's name constraints. If
@@ -543,11 +549,16 @@ func (c *Certificate) checkNameConstraints(count *int,
 	return nil
 }
 
+const (
+	checkingAgainstIssuerCert = iota
+	checkingAgainstLeafCert
+)
+
 // ekuPermittedBy returns true iff the given extended key usage is permitted by
 // the given EKU from a certificate. Normally, this would be a simple
 // comparison plus a special case for the “any” EKU. But, in order to support
 // existing certificates, some exceptions are made.
-func ekuPermittedBy(eku, certEKU ExtKeyUsage) bool {
+func ekuPermittedBy(eku, certEKU ExtKeyUsage, context int) bool {
 	if certEKU == ExtKeyUsageAny || eku == certEKU {
 		return true
 	}
@@ -564,18 +575,23 @@ func ekuPermittedBy(eku, certEKU ExtKeyUsage) bool {
 	eku = mapServerAuthEKUs(eku)
 	certEKU = mapServerAuthEKUs(certEKU)
 
-	if eku == certEKU ||
-		// ServerAuth in a CA permits ClientAuth in the leaf.
-		(eku == ExtKeyUsageClientAuth && certEKU == ExtKeyUsageServerAuth) ||
+	if eku == certEKU {
+		return true
+	}
+
+	// If checking a requested EKU against the list in a leaf certificate there
+	// are fewer exceptions.
+	if context == checkingAgainstLeafCert {
+		return false
+	}
+
+	// ServerAuth in a CA permits ClientAuth in the leaf.
+	return (eku == ExtKeyUsageClientAuth && certEKU == ExtKeyUsageServerAuth) ||
 		// Any CA may issue an OCSP responder certificate.
 		eku == ExtKeyUsageOCSPSigning ||
 		// Code-signing CAs can use Microsoft's commercial and
 		// kernel-mode EKUs.
-		((eku == ExtKeyUsageMicrosoftCommercialCodeSigning || eku == ExtKeyUsageMicrosoftKernelCodeSigning) && certEKU == ExtKeyUsageCodeSigning) {
-		return true
-	}
-
-	return false
+		(eku == ExtKeyUsageMicrosoftCommercialCodeSigning || eku == ExtKeyUsageMicrosoftKernelCodeSigning) && certEKU == ExtKeyUsageCodeSigning
 }
 
 // isValid performs validity checks on c given that it is a candidate to append
@@ -630,8 +646,7 @@ func (c *Certificate) isValid(certType int, currentChain []*Certificate, opts *V
 				name := string(data)
 				mailbox, ok := parseRFC2821Mailbox(name)
 				if !ok {
-					// This certificate should not have parsed.
-					return errors.New("x509: internal error: rfc822Name SAN failed to parse")
+					return fmt.Errorf("x509: cannot parse rfc822Name %q", mailbox)
 				}
 
 				if err := c.checkNameConstraints(&comparisonCount, maxConstraintComparisons, "email address", name, mailbox,
@@ -643,6 +658,10 @@ func (c *Certificate) isValid(certType int, currentChain []*Certificate, opts *V
 
 			case nameTypeDNS:
 				name := string(data)
+				if _, ok := domainToReverseLabels(name); !ok {
+					return fmt.Errorf("x509: cannot parse dnsName %q", name)
+				}
+
 				if err := c.checkNameConstraints(&comparisonCount, maxConstraintComparisons, "DNS name", name, name,
 					func(parsedName, constraint interface{}) (bool, error) {
 						return matchDomainConstraint(parsedName.(string), constraint.(string))
@@ -716,7 +735,7 @@ func (c *Certificate) isValid(certType int, currentChain []*Certificate, opts *V
 
 			for _, caEKU := range c.ExtKeyUsage {
 				comparisonCount++
-				if ekuPermittedBy(eku, caEKU) {
+				if ekuPermittedBy(eku, caEKU, checkingAgainstIssuerCert) {
 					continue NextEKU
 				}
 			}
@@ -773,6 +792,18 @@ func (c *Certificate) isValid(certType int, currentChain []*Certificate, opts *V
 	return nil
 }
 
+// formatOID formats an ASN.1 OBJECT IDENTIFER in the common, dotted style.
+func formatOID(oid asn1.ObjectIdentifier) string {
+	ret := ""
+	for i, v := range oid {
+		if i > 0 {
+			ret += "."
+		}
+		ret += strconv.Itoa(v)
+	}
+	return ret
+}
+
 // Verify attempts to verify c by building one or more chains from c to a
 // certificate in opts.Roots, using certificates in opts.Intermediates if
 // needed. If successful, it returns one or more chains where the first
@@ -847,16 +878,33 @@ func (c *Certificate) Verify(opts VerifyOptions) (chains [][]*Certificate, err e
 	}
 
 	if checkEKU {
+		foundMatch := false
 	NextUsage:
 		for _, eku := range requestedKeyUsages {
 			for _, leafEKU := range c.ExtKeyUsage {
-				if ekuPermittedBy(eku, leafEKU) {
-					continue NextUsage
+				if ekuPermittedBy(eku, leafEKU, checkingAgainstLeafCert) {
+					foundMatch = true
+					break NextUsage
 				}
 			}
+		}
 
-			oid, _ := oidFromExtKeyUsage(eku)
-			return nil, CertificateInvalidError{c, IncompatibleUsage, fmt.Sprintf("%#v", oid)}
+		if !foundMatch {
+			msg := "leaf contains the following, recognized EKUs: "
+
+			for i, leafEKU := range c.ExtKeyUsage {
+				oid, ok := oidFromExtKeyUsage(leafEKU)
+				if !ok {
+					continue
+				}
+
+				if i > 0 {
+					msg += ", "
+				}
+				msg += formatOID(oid)
+			}
+
+			return nil, CertificateInvalidError{c, IncompatibleUsage, msg}
 		}
 	}
 
diff --git a/libgo/go/crypto/x509/x509.go b/libgo/go/crypto/x509/x509.go
index 86d9e82..ee08dd9 100644
--- a/libgo/go/crypto/x509/x509.go
+++ b/libgo/go/crypto/x509/x509.go
@@ -706,7 +706,9 @@ type Certificate struct {
 	OCSPServer            []string
 	IssuingCertificateURL []string
 
-	// Subject Alternate Name values
+	// Subject Alternate Name values. (Note that these values may not be valid
+	// if invalid values were contained within a parsed certificate. For
+	// example, an element of DNSNames may not be a valid DNS domain name.)
 	DNSNames       []string
 	EmailAddresses []string
 	IPAddresses    []net.IP
@@ -1126,17 +1128,9 @@ func parseSANExtension(value []byte) (dnsNames, emailAddresses []string, ipAddre
 	err = forEachSAN(value, func(tag int, data []byte) error {
 		switch tag {
 		case nameTypeEmail:
-			mailbox := string(data)
-			if _, ok := parseRFC2821Mailbox(mailbox); !ok {
-				return fmt.Errorf("x509: cannot parse rfc822Name %q", mailbox)
-			}
-			emailAddresses = append(emailAddresses, mailbox)
+			emailAddresses = append(emailAddresses, string(data))
 		case nameTypeDNS:
-			domain := string(data)
-			if _, ok := domainToReverseLabels(domain); !ok {
-				return fmt.Errorf("x509: cannot parse dnsName %q", string(data))
-			}
-			dnsNames = append(dnsNames, domain)
+			dnsNames = append(dnsNames, string(data))
 		case nameTypeURI:
 			uri, err := url.Parse(string(data))
 			if err != nil {
@@ -1153,7 +1147,7 @@ func parseSANExtension(value []byte) (dnsNames, emailAddresses []string, ipAddre
 			case net.IPv4len, net.IPv6len:
 				ipAddresses = append(ipAddresses, data)
 			default:
-				return errors.New("x509: certificate contained IP address of length " + strconv.Itoa(len(data)))
+				return errors.New("x509: cannot parse IP address of length " + strconv.Itoa(len(data)))
 			}
 		}
 
@@ -2543,7 +2537,7 @@ func ParseCertificateRequest(asn1Data []byte) (*CertificateRequest, error) {
 
 func parseCertificateRequest(in *certificateRequest) (*CertificateRequest, error) {
 	out := &CertificateRequest{
-		Raw: in.Raw,
+		Raw:                      in.Raw,
 		RawTBSCertificateRequest: in.TBSCSR.Raw,
 		RawSubjectPublicKeyInfo:  in.TBSCSR.PublicKey.Raw,
 		RawSubject:               in.TBSCSR.Subject.FullBytes,
diff --git a/libgo/go/encoding/json/decode.go b/libgo/go/encoding/json/decode.go
index 536f25d..730fb92 100644
--- a/libgo/go/encoding/json/decode.go
+++ b/libgo/go/encoding/json/decode.go
@@ -443,10 +443,25 @@ func (d *decodeState) valueQuoted() interface{} {
 // if it encounters an Unmarshaler, indirect stops and returns that.
 // if decodingNull is true, indirect stops at the last pointer so it can be set to nil.
 func (d *decodeState) indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnmarshaler, reflect.Value) {
+	// Issue #24153 indicates that it is generally not a guaranteed property
+	// that you may round-trip a reflect.Value by calling Value.Addr().Elem()
+	// and expect the value to still be settable for values derived from
+	// unexported embedded struct fields.
+	//
+	// The logic below effectively does this when it first addresses the value
+	// (to satisfy possible pointer methods) and continues to dereference
+	// subsequent pointers as necessary.
+	//
+	// After the first round-trip, we set v back to the original value to
+	// preserve the original RW flags contained in reflect.Value.
+	v0 := v
+	haveAddr := false
+
 	// If v is a named type and is addressable,
 	// start with its address, so that if the type has pointer methods,
 	// we find them.
 	if v.Kind() != reflect.Ptr && v.Type().Name() != "" && v.CanAddr() {
+		haveAddr = true
 		v = v.Addr()
 	}
 	for {
@@ -455,6 +470,7 @@ func (d *decodeState) indirect(v reflect.Value, decodingNull bool) (Unmarshaler,
 		if v.Kind() == reflect.Interface && !v.IsNil() {
 			e := v.Elem()
 			if e.Kind() == reflect.Ptr && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Ptr) {
+				haveAddr = false
 				v = e
 				continue
 			}
@@ -480,7 +496,13 @@ func (d *decodeState) indirect(v reflect.Value, decodingNull bool) (Unmarshaler,
 				}
 			}
 		}
-		v = v.Elem()
+
+		if haveAddr {
+			v = v0 // restore original value after round-trip Value.Addr().Elem()
+			haveAddr = false
+		} else {
+			v = v.Elem()
+		}
 	}
 	return nil, nil, v
 }
diff --git a/libgo/go/encoding/json/decode_test.go b/libgo/go/encoding/json/decode_test.go
index 34b7ec6..fa1531f 100644
--- a/libgo/go/encoding/json/decode_test.go
+++ b/libgo/go/encoding/json/decode_test.go
@@ -615,9 +615,9 @@ var unmarshalTests = []unmarshalTest{
 		out: S5{S8: S8{S9: S9{Y: 2}}},
 	},
 	{
-		in:  `{"X": 1,"Y":2}`,
-		ptr: new(S5),
-		err: fmt.Errorf("json: unknown field \"X\""),
+		in:                    `{"X": 1,"Y":2}`,
+		ptr:                   new(S5),
+		err:                   fmt.Errorf("json: unknown field \"X\""),
 		disallowUnknownFields: true,
 	},
 	{
@@ -626,9 +626,9 @@ var unmarshalTests = []unmarshalTest{
 		out: S10{S13: S13{S8: S8{S9: S9{Y: 2}}}},
 	},
 	{
-		in:  `{"X": 1,"Y":2}`,
-		ptr: new(S10),
-		err: fmt.Errorf("json: unknown field \"X\""),
+		in:                    `{"X": 1,"Y":2}`,
+		ptr:                   new(S10),
+		err:                   fmt.Errorf("json: unknown field \"X\""),
 		disallowUnknownFields: true,
 	},
 
@@ -835,8 +835,8 @@ var unmarshalTests = []unmarshalTest{
 			"Q": 18,
 			"extra": true
 		}`,
-		ptr: new(Top),
-		err: fmt.Errorf("json: unknown field \"extra\""),
+		ptr:                   new(Top),
+		err:                   fmt.Errorf("json: unknown field \"extra\""),
 		disallowUnknownFields: true,
 	},
 	{
@@ -862,8 +862,8 @@ var unmarshalTests = []unmarshalTest{
 			"Z": 17,
 			"Q": 18
 		}`,
-		ptr: new(Top),
-		err: fmt.Errorf("json: unknown field \"extra\""),
+		ptr:                   new(Top),
+		err:                   fmt.Errorf("json: unknown field \"extra\""),
 		disallowUnknownFields: true,
 	},
 }
@@ -2089,10 +2089,14 @@ func TestInvalidStringOption(t *testing.T) {
 	}
 }
 
-// Test unmarshal behavior with regards to embedded pointers to unexported structs.
-// If unallocated, this returns an error because unmarshal cannot set the field.
-// Issue 21357.
-func TestUnmarshalEmbeddedPointerUnexported(t *testing.T) {
+// Test unmarshal behavior with regards to embedded unexported structs.
+//
+// (Issue 21357) If the embedded struct is a pointer and is unallocated,
+// this returns an error because unmarshal cannot set the field.
+//
+// (Issue 24152) If the embedded struct is given an explicit name,
+// ensure that the normal unmarshal logic does not panic in reflect.
+func TestUnmarshalEmbeddedUnexported(t *testing.T) {
 	type (
 		embed1 struct{ Q int }
 		embed2 struct{ Q int }
@@ -2119,6 +2123,18 @@ func TestUnmarshalEmbeddedPointerUnexported(t *testing.T) {
 			*embed3
 			R int
 		}
+		S6 struct {
+			embed1 `json:"embed1"`
+		}
+		S7 struct {
+			embed1 `json:"embed1"`
+			embed2
+		}
+		S8 struct {
+			embed1 `json:"embed1"`
+			embed2 `json:"embed2"`
+			Q      int
+		}
 	)
 
 	tests := []struct {
@@ -2154,6 +2170,32 @@ func TestUnmarshalEmbeddedPointerUnexported(t *testing.T) {
 		ptr: new(S5),
 		out: &S5{R: 2},
 		err: fmt.Errorf("json: cannot set embedded pointer to unexported struct: json.embed3"),
+	}, {
+		// Issue 24152, ensure decodeState.indirect does not panic.
+		in:  `{"embed1": {"Q": 1}}`,
+		ptr: new(S6),
+		out: &S6{embed1{1}},
+	}, {
+		// Issue 24153, check that we can still set forwarded fields even in
+		// the presence of a name conflict.
+		//
+		// This relies on obscure behavior of reflect where it is possible
+		// to set a forwarded exported field on an unexported embedded struct
+		// even though there is a name conflict, even when it would have been
+		// impossible to do so according to Go visibility rules.
+		// Go forbids this because it is ambiguous whether S7.Q refers to
+		// S7.embed1.Q or S7.embed2.Q. Since embed1 and embed2 are unexported,
+		// it should be impossible for an external package to set either Q.
+		//
+		// It is probably okay for a future reflect change to break this.
+		in:  `{"embed1": {"Q": 1}, "Q": 2}`,
+		ptr: new(S7),
+		out: &S7{embed1{1}, embed2{2}},
+	}, {
+		// Issue 24153, similar to the S7 case.
+		in:  `{"embed1": {"Q": 1}, "embed2": {"Q": 2}, "Q": 3}`,
+		ptr: new(S8),
+		out: &S8{embed1{1}, embed2{2}, 3},
 	}}
 
 	for i, tt := range tests {
diff --git a/libgo/go/go/internal/srcimporter/srcimporter.go b/libgo/go/go/internal/srcimporter/srcimporter.go
index b0dc8ab..9ed7e5e 100644
--- a/libgo/go/go/internal/srcimporter/srcimporter.go
+++ b/libgo/go/go/internal/srcimporter/srcimporter.go
@@ -44,9 +44,9 @@ func New(ctxt *build.Context, fset *token.FileSet, packages map[string]*types.Pa
 // for a package that is in the process of being imported.
 var importing types.Package
 
-// Import(path) is a shortcut for ImportFrom(path, "", 0).
+// Import(path) is a shortcut for ImportFrom(path, ".", 0).
 func (p *Importer) Import(path string) (*types.Package, error) {
-	return p.ImportFrom(path, "", 0)
+	return p.ImportFrom(path, ".", 0) // use "." rather than "" (see issue #24441)
 }
 
 // ImportFrom imports the package with the given import path resolved from the given srcDir,
@@ -60,23 +60,10 @@ func (p *Importer) ImportFrom(path, srcDir string, mode types.ImportMode) (*type
 		panic("non-zero import mode")
 	}
 
-	// determine package path (do vendor resolution)
-	var bp *build.Package
-	var err error
-	switch {
-	default:
-		if abs, err := p.absPath(srcDir); err == nil { // see issue #14282
-			srcDir = abs
-		}
-		bp, err = p.ctxt.Import(path, srcDir, build.FindOnly)
-
-	case build.IsLocalImport(path):
-		// "./x" -> "srcDir/x"
-		bp, err = p.ctxt.ImportDir(filepath.Join(srcDir, path), build.FindOnly)
-
-	case p.isAbsPath(path):
-		return nil, fmt.Errorf("invalid absolute import path %q", path)
+	if abs, err := p.absPath(srcDir); err == nil { // see issue #14282
+		srcDir = abs
 	}
+	bp, err := p.ctxt.Import(path, srcDir, 0)
 	if err != nil {
 		return nil, err // err may be *build.NoGoError - return as is
 	}
@@ -113,11 +100,6 @@ func (p *Importer) ImportFrom(path, srcDir string, mode types.ImportMode) (*type
 		}
 	}()
 
-	// collect package files
-	bp, err = p.ctxt.ImportDir(bp.Dir, 0)
-	if err != nil {
-		return nil, err // err may be *build.NoGoError - return as is
-	}
 	var filenames []string
 	filenames = append(filenames, bp.GoFiles...)
 	filenames = append(filenames, bp.CgoFiles...)
diff --git a/libgo/go/go/internal/srcimporter/srcimporter_test.go b/libgo/go/go/internal/srcimporter/srcimporter_test.go
index 356e71d..dd4d56a 100644
--- a/libgo/go/go/internal/srcimporter/srcimporter_test.go
+++ b/libgo/go/go/internal/srcimporter/srcimporter_test.go
@@ -10,6 +10,7 @@ import (
 	"go/types"
 	"internal/testenv"
 	"io/ioutil"
+	"path"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -162,3 +163,34 @@ func TestIssue20855(t *testing.T) {
 		t.Error("got no package despite no hard errors")
 	}
 }
+
+func testImportPath(t *testing.T, pkgPath string) {
+	if !testenv.HasSrc() {
+		t.Skip("no source code available")
+	}
+
+	pkgName := path.Base(pkgPath)
+
+	pkg, err := importer.Import(pkgPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if pkg.Name() != pkgName {
+		t.Errorf("got %q; want %q", pkg.Name(), pkgName)
+	}
+
+	if pkg.Path() != pkgPath {
+		t.Errorf("got %q; want %q", pkg.Path(), pkgPath)
+	}
+}
+
+// TestIssue23092 tests relative imports.
+func TestIssue23092(t *testing.T) {
+	testImportPath(t, "./testdata/issue23092")
+}
+
+// TestIssue24392 tests imports against a path containing 'testdata'.
+func TestIssue24392(t *testing.T) {
+	testImportPath(t, "go/internal/srcimporter/testdata/issue24392")
+}
diff --git a/libgo/go/go/internal/srcimporter/testdata/issue23092/issue23092.go b/libgo/go/go/internal/srcimporter/testdata/issue23092/issue23092.go
new file mode 100644
index 0000000..608698b
--- /dev/null
+++ b/libgo/go/go/internal/srcimporter/testdata/issue23092/issue23092.go
@@ -0,0 +1,5 @@
+// Copyright 2018 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 issue23092
diff --git a/libgo/go/go/internal/srcimporter/testdata/issue24392/issue24392.go b/libgo/go/go/internal/srcimporter/testdata/issue24392/issue24392.go
new file mode 100644
index 0000000..8ad5221
--- /dev/null
+++ b/libgo/go/go/internal/srcimporter/testdata/issue24392/issue24392.go
@@ -0,0 +1,5 @@
+// Copyright 2018 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 issue24392
diff --git a/libgo/go/internal/singleflight/singleflight.go b/libgo/go/internal/singleflight/singleflight.go
index 1e9960d..b2d82e2 100644
--- a/libgo/go/internal/singleflight/singleflight.go
+++ b/libgo/go/internal/singleflight/singleflight.go
@@ -103,11 +103,21 @@ func (g *Group) doCall(c *call, key string, fn func() (interface{}, error)) {
 	g.mu.Unlock()
 }
 
-// Forget tells the singleflight to forget about a key.  Future calls
-// to Do for this key will call the function rather than waiting for
-// an earlier call to complete.
-func (g *Group) Forget(key string) {
+// ForgetUnshared tells the singleflight to forget about a key if it is not
+// shared with any other goroutines. Future calls to Do for a forgotten key
+// will call the function rather than waiting for an earlier call to complete.
+// Returns whether the key was forgotten or unknown--that is, whether no
+// other goroutines are waiting for the result.
+func (g *Group) ForgetUnshared(key string) bool {
 	g.mu.Lock()
-	delete(g.m, key)
-	g.mu.Unlock()
+	defer g.mu.Unlock()
+	c, ok := g.m[key]
+	if !ok {
+		return true
+	}
+	if c.dups == 0 {
+		delete(g.m, key)
+		return true
+	}
+	return false
 }
diff --git a/libgo/go/net/http/pprof/pprof.go b/libgo/go/net/http/pprof/pprof.go
index 21992d6..77e0bcd 100644
--- a/libgo/go/net/http/pprof/pprof.go
+++ b/libgo/go/net/http/pprof/pprof.go
@@ -80,6 +80,7 @@ func init() {
 // command line, with arguments separated by NUL bytes.
 // The package initialization registers it as /debug/pprof/cmdline.
 func Cmdline(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	fmt.Fprintf(w, strings.Join(os.Args, "\x00"))
 }
@@ -100,33 +101,36 @@ func durationExceedsWriteTimeout(r *http.Request, seconds float64) bool {
 	return ok && srv.WriteTimeout != 0 && seconds >= srv.WriteTimeout.Seconds()
 }
 
+func serveError(w http.ResponseWriter, status int, txt string) {
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.Header().Set("X-Go-Pprof", "1")
+	w.Header().Del("Content-Disposition")
+	w.WriteHeader(status)
+	fmt.Fprintln(w, txt)
+}
+
 // Profile responds with the pprof-formatted cpu profile.
 // The package initialization registers it as /debug/pprof/profile.
 func Profile(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	sec, _ := strconv.ParseInt(r.FormValue("seconds"), 10, 64)
 	if sec == 0 {
 		sec = 30
 	}
 
 	if durationExceedsWriteTimeout(r, float64(sec)) {
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusBadRequest)
-		fmt.Fprintln(w, "profile duration exceeds server's WriteTimeout")
+		serveError(w, http.StatusBadRequest, "profile duration exceeds server's WriteTimeout")
 		return
 	}
 
 	// Set Content Type assuming StartCPUProfile will work,
 	// because if it does it starts writing.
 	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Disposition", `attachment; filename="profile"`)
 	if err := pprof.StartCPUProfile(w); err != nil {
 		// StartCPUProfile failed, so no writes yet.
-		// Can change header back to text content
-		// and send error code.
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusInternalServerError)
-		fmt.Fprintf(w, "Could not enable CPU profiling: %s\n", err)
+		serveError(w, http.StatusInternalServerError,
+			fmt.Sprintf("Could not enable CPU profiling: %s", err))
 		return
 	}
 	sleep(w, time.Duration(sec)*time.Second)
@@ -137,29 +141,25 @@ func Profile(w http.ResponseWriter, r *http.Request) {
 // Tracing lasts for duration specified in seconds GET parameter, or for 1 second if not specified.
 // The package initialization registers it as /debug/pprof/trace.
 func Trace(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	sec, err := strconv.ParseFloat(r.FormValue("seconds"), 64)
 	if sec <= 0 || err != nil {
 		sec = 1
 	}
 
 	if durationExceedsWriteTimeout(r, sec) {
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusBadRequest)
-		fmt.Fprintln(w, "profile duration exceeds server's WriteTimeout")
+		serveError(w, http.StatusBadRequest, "profile duration exceeds server's WriteTimeout")
 		return
 	}
 
 	// Set Content Type assuming trace.Start will work,
 	// because if it does it starts writing.
 	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Disposition", `attachment; filename="trace"`)
 	if err := trace.Start(w); err != nil {
 		// trace.Start failed, so no writes yet.
-		// Can change header back to text content and send error code.
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		w.Header().Set("X-Go-Pprof", "1")
-		w.WriteHeader(http.StatusInternalServerError)
-		fmt.Fprintf(w, "Could not enable tracing: %s\n", err)
+		serveError(w, http.StatusInternalServerError,
+			fmt.Sprintf("Could not enable tracing: %s", err))
 		return
 	}
 	sleep(w, time.Duration(sec*float64(time.Second)))
@@ -170,6 +170,7 @@ func Trace(w http.ResponseWriter, r *http.Request) {
 // responding with a table mapping program counters to function names.
 // The package initialization registers it as /debug/pprof/symbol.
 func Symbol(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 
 	// We have to read the whole POST body before
@@ -222,18 +223,23 @@ func Handler(name string) http.Handler {
 type handler string
 
 func (name handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-	debug, _ := strconv.Atoi(r.FormValue("debug"))
+	w.Header().Set("X-Content-Type-Options", "nosniff")
 	p := pprof.Lookup(string(name))
 	if p == nil {
-		w.WriteHeader(404)
-		fmt.Fprintf(w, "Unknown profile: %s\n", name)
+		serveError(w, http.StatusNotFound, "Unknown profile")
 		return
 	}
 	gc, _ := strconv.Atoi(r.FormValue("gc"))
 	if name == "heap" && gc > 0 {
 		runtime.GC()
 	}
+	debug, _ := strconv.Atoi(r.FormValue("debug"))
+	if debug != 0 {
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	} else {
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, name))
+	}
 	p.WriteTo(w, debug)
 }
 
diff --git a/libgo/go/net/http/pprof/pprof_test.go b/libgo/go/net/http/pprof/pprof_test.go
new file mode 100644
index 0000000..47dd35b
--- /dev/null
+++ b/libgo/go/net/http/pprof/pprof_test.go
@@ -0,0 +1,69 @@
+// Copyright 2018 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 pprof
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHandlers(t *testing.T) {
+	testCases := []struct {
+		path               string
+		handler            http.HandlerFunc
+		statusCode         int
+		contentType        string
+		contentDisposition string
+		resp               []byte
+	}{
+		{"/debug/pprof/<script>scripty<script>", Index, http.StatusNotFound, "text/plain; charset=utf-8", "", []byte("Unknown profile\n")},
+		{"/debug/pprof/heap", Index, http.StatusOK, "application/octet-stream", `attachment; filename="heap"`, nil},
+		{"/debug/pprof/heap?debug=1", Index, http.StatusOK, "text/plain; charset=utf-8", "", nil},
+		{"/debug/pprof/cmdline", Cmdline, http.StatusOK, "text/plain; charset=utf-8", "", nil},
+		{"/debug/pprof/profile?seconds=1", Profile, http.StatusOK, "application/octet-stream", `attachment; filename="profile"`, nil},
+		{"/debug/pprof/symbol", Symbol, http.StatusOK, "text/plain; charset=utf-8", "", nil},
+		{"/debug/pprof/trace", Trace, http.StatusOK, "application/octet-stream", `attachment; filename="trace"`, nil},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.path, func(t *testing.T) {
+			req := httptest.NewRequest("GET", "http://example.com"+tc.path, nil)
+			w := httptest.NewRecorder()
+			tc.handler(w, req)
+
+			resp := w.Result()
+			if got, want := resp.StatusCode, tc.statusCode; got != want {
+				t.Errorf("status code: got %d; want %d", got, want)
+			}
+
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				t.Errorf("when reading response body, expected non-nil err; got %v", err)
+			}
+			if got, want := resp.Header.Get("X-Content-Type-Options"), "nosniff"; got != want {
+				t.Errorf("X-Content-Type-Options: got %q; want %q", got, want)
+			}
+			if got, want := resp.Header.Get("Content-Type"), tc.contentType; got != want {
+				t.Errorf("Content-Type: got %q; want %q", got, want)
+			}
+			if got, want := resp.Header.Get("Content-Disposition"), tc.contentDisposition; got != want {
+				t.Errorf("Content-Disposition: got %q; want %q", got, want)
+			}
+
+			if resp.StatusCode == http.StatusOK {
+				return
+			}
+			if got, want := resp.Header.Get("X-Go-Pprof"), "1"; got != want {
+				t.Errorf("X-Go-Pprof: got %q; want %q", got, want)
+			}
+			if !bytes.Equal(body, tc.resp) {
+				t.Errorf("response: got %q; want %q", body, tc.resp)
+			}
+		})
+	}
+
+}
diff --git a/libgo/go/net/lookup.go b/libgo/go/net/lookup.go
index 85e4729..a65b735 100644
--- a/libgo/go/net/lookup.go
+++ b/libgo/go/net/lookup.go
@@ -194,10 +194,16 @@ func (r *Resolver) LookupIPAddr(ctx context.Context, host string) ([]IPAddr, err
 		resolverFunc = alt
 	}
 
+	// We don't want a cancelation of ctx to affect the
+	// lookupGroup operation. Otherwise if our context gets
+	// canceled it might cause an error to be returned to a lookup
+	// using a completely different context.
+	lookupGroupCtx, lookupGroupCancel := context.WithCancel(context.Background())
+
 	dnsWaitGroup.Add(1)
 	ch, called := lookupGroup.DoChan(host, func() (interface{}, error) {
 		defer dnsWaitGroup.Done()
-		return testHookLookupIP(ctx, resolverFunc, host)
+		return testHookLookupIP(lookupGroupCtx, resolverFunc, host)
 	})
 	if !called {
 		dnsWaitGroup.Done()
@@ -205,20 +211,28 @@ func (r *Resolver) LookupIPAddr(ctx context.Context, host string) ([]IPAddr, err
 
 	select {
 	case <-ctx.Done():
-		// If the DNS lookup timed out for some reason, force
-		// future requests to start the DNS lookup again
-		// rather than waiting for the current lookup to
-		// complete. See issue 8602.
-		ctxErr := ctx.Err()
-		if ctxErr == context.DeadlineExceeded {
-			lookupGroup.Forget(host)
+		// Our context was canceled. If we are the only
+		// goroutine looking up this key, then drop the key
+		// from the lookupGroup and cancel the lookup.
+		// If there are other goroutines looking up this key,
+		// let the lookup continue uncanceled, and let later
+		// lookups with the same key share the result.
+		// See issues 8602, 20703, 22724.
+		if lookupGroup.ForgetUnshared(host) {
+			lookupGroupCancel()
+		} else {
+			go func() {
+				<-ch
+				lookupGroupCancel()
+			}()
 		}
-		err := mapErr(ctxErr)
+		err := mapErr(ctx.Err())
 		if trace != nil && trace.DNSDone != nil {
 			trace.DNSDone(nil, false, err)
 		}
 		return nil, err
 	case r := <-ch:
+		lookupGroupCancel()
 		if trace != nil && trace.DNSDone != nil {
 			addrs, _ := r.Val.([]IPAddr)
 			trace.DNSDone(ipAddrsEface(addrs), r.Shared, r.Err)
diff --git a/libgo/go/net/lookup_test.go b/libgo/go/net/lookup_test.go
index bfb8725..24787cc 100644
--- a/libgo/go/net/lookup_test.go
+++ b/libgo/go/net/lookup_test.go
@@ -791,3 +791,28 @@ func TestLookupNonLDH(t *testing.T) {
 		t.Fatalf("lookup error = %v, want %v", err, errNoSuchHost)
 	}
 }
+
+func TestLookupContextCancel(t *testing.T) {
+	if testenv.Builder() == "" {
+		testenv.MustHaveExternalNetwork(t)
+	}
+	if runtime.GOOS == "nacl" {
+		t.Skip("skip on nacl")
+	}
+
+	defer dnsWaitGroup.Wait()
+
+	ctx, ctxCancel := context.WithCancel(context.Background())
+	ctxCancel()
+	_, err := DefaultResolver.LookupIPAddr(ctx, "google.com")
+	if err != errCanceled {
+		testenv.SkipFlakyNet(t)
+		t.Fatal(err)
+	}
+	ctx = context.Background()
+	_, err = DefaultResolver.LookupIPAddr(ctx, "google.com")
+	if err != nil {
+		testenv.SkipFlakyNet(t)
+		t.Fatal(err)
+	}
+}
diff --git a/libgo/go/net/tcpsock_unix_test.go b/libgo/go/net/tcpsock_unix_test.go
index 3af1834..95c02d2 100644
--- a/libgo/go/net/tcpsock_unix_test.go
+++ b/libgo/go/net/tcpsock_unix_test.go
@@ -87,6 +87,7 @@ func TestTCPSpuriousConnSetupCompletionWithCancel(t *testing.T) {
 	if testenv.Builder() == "" {
 		testenv.MustHaveExternalNetwork(t)
 	}
+	defer dnsWaitGroup.Wait()
 	t.Parallel()
 	const tries = 10000
 	var wg sync.WaitGroup
diff --git a/libgo/go/runtime/error.go b/libgo/go/runtime/error.go
index 34b7d37..1a038cf 100644
--- a/libgo/go/runtime/error.go
+++ b/libgo/go/runtime/error.go
@@ -139,14 +139,12 @@ func typestring(x interface{}) string {
 }
 
 // printany prints an argument passed to panic.
+// If panic is called with a value that has a String or Error method,
+// it has already been converted into a string by preprintpanics.
 func printany(i interface{}) {
 	switch v := i.(type) {
 	case nil:
 		print("nil")
-	case stringer:
-		print(v.String())
-	case error:
-		print(v.Error())
 	case bool:
 		print(v)
 	case int:
diff --git a/libgo/go/runtime/panic.go b/libgo/go/runtime/panic.go
index fbdb17e..6b490b7 100644
--- a/libgo/go/runtime/panic.go
+++ b/libgo/go/runtime/panic.go
@@ -384,7 +384,6 @@ func Goexit() {
 
 // Call all Error and String methods before freezing the world.
 // Used when crashing with panicking.
-// This must match types handled by printany.
 func preprintpanics(p *_panic) {
 	defer func() {
 		if recover() != nil {
@@ -410,8 +409,6 @@ func printpanics(p *_panic) {
 		print("\t")
 	}
 	print("panic: ")
-	// Because of preprintpanics, p.arg cannot be an error or
-	// stringer, so this won't call into user code.
 	printany(p.arg)
 	if p.recovered {
 		print(" [recovered]")
diff --git a/libgo/go/runtime/proc.go b/libgo/go/runtime/proc.go
index 20fa0ad..a6746c9 100644
--- a/libgo/go/runtime/proc.go
+++ b/libgo/go/runtime/proc.go
@@ -423,6 +423,12 @@ func releaseSudog(s *sudog) {
 
 // funcPC returns the entry PC of the function f.
 // It assumes that f is a func value. Otherwise the behavior is undefined.
+// CAREFUL: In programs with plugins, funcPC can return different values
+// for the same function (because there are actually multiple copies of
+// the same function in the address space). To be safe, don't use the
+// results of this function in any == expression. It is only safe to
+// use the result as an address at which to start executing code.
+//
 // For gccgo note that this differs from the gc implementation; the gc
 // implementation adds sys.PtrSize to the address of the interface
 // value, but GCC's alias analysis decides that that can not be a
diff --git a/libgo/go/runtime/symtab.go b/libgo/go/runtime/symtab.go
index 3d15fc8..12dc672 100644
--- a/libgo/go/runtime/symtab.go
+++ b/libgo/go/runtime/symtab.go
@@ -115,6 +115,35 @@ type Func struct {
 	entry uintptr
 }
 
+// A FuncID identifies particular functions that need to be treated
+// specially by the runtime.
+// Note that in some situations involving plugins, there may be multiple
+// copies of a particular special runtime function.
+// Note: this list must match the list in cmd/internal/objabi/funcid.go.
+type funcID uint32
+
+const (
+	funcID_normal funcID = iota // not a special function
+	funcID_goexit
+	funcID_jmpdefer
+	funcID_mcall
+	funcID_morestack
+	funcID_mstart
+	funcID_rt0_go
+	funcID_asmcgocall
+	funcID_sigpanic
+	funcID_runfinq
+	funcID_bgsweep
+	funcID_forcegchelper
+	funcID_timerproc
+	funcID_gcBgMarkWorker
+	funcID_systemstack_switch
+	funcID_systemstack
+	funcID_cgocallback_gofunc
+	funcID_gogo
+	funcID_externalthreadhandler
+)
+
 // FuncForPC returns a *Func describing the function that contains the
 // given program counter address, or else nil.
 //
diff --git a/libgo/misc/cgo/testplugin/src/issue24351/main.go b/libgo/misc/cgo/testplugin/src/issue24351/main.go
new file mode 100644
index 0000000..4107adf
--- /dev/null
+++ b/libgo/misc/cgo/testplugin/src/issue24351/main.go
@@ -0,0 +1,21 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "plugin"
+
+func main() {
+	p, err := plugin.Open("issue24351.so")
+	if err != nil {
+		panic(err)
+	}
+	f, err := p.Lookup("B")
+	if err != nil {
+		panic(err)
+	}
+	c := make(chan bool)
+	f.(func(chan bool))(c)
+	<-c
+}
diff --git a/libgo/misc/cgo/testplugin/src/issue24351/plugin.go b/libgo/misc/cgo/testplugin/src/issue24351/plugin.go
new file mode 100644
index 0000000..db17e0a
--- /dev/null
+++ b/libgo/misc/cgo/testplugin/src/issue24351/plugin.go
@@ -0,0 +1,14 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "fmt"
+
+func B(c chan bool) {
+	go func() {
+		fmt.Println(1.5)
+		c <- true
+	}()
+}
diff --git a/libgo/misc/cgo/testplugin/test.bash b/libgo/misc/cgo/testplugin/test.bash
index 18e3803..df38204 100644
--- a/libgo/misc/cgo/testplugin/test.bash
+++ b/libgo/misc/cgo/testplugin/test.bash
@@ -85,3 +85,8 @@ GOPATH=$(pwd) go build -gcflags "$GO_GCFLAGS" -o issue22175 src/issue22175/main.
 GOPATH=$(pwd) go build -gcflags "$GO_GCFLAGS" -buildmode=plugin -o issue.22295.so issue22295.pkg
 GOPATH=$(pwd) go build -gcflags "$GO_GCFLAGS" -o issue22295 src/issue22295.pkg/main.go
 ./issue22295
+
+# Test for issue 24351
+GOPATH=$(pwd) go build -gcflags "$GO_GCFLAGS" -buildmode=plugin -o issue24351.so src/issue24351/plugin.go
+GOPATH=$(pwd) go build -gcflags "$GO_GCFLAGS" -o issue24351 src/issue24351/main.go
+./issue24351
diff --git a/libgo/misc/cgo/testshared/shared_test.go b/libgo/misc/cgo/testshared/shared_test.go
index cf049ec..a296005 100644
--- a/libgo/misc/cgo/testshared/shared_test.go
+++ b/libgo/misc/cgo/testshared/shared_test.go
@@ -790,6 +790,7 @@ func TestRebuilding(t *testing.T) {
 	// If the .a file is newer than the .so, the .so is rebuilt (but not the .a)
 	t.Run("newarchive", func(t *testing.T) {
 		resetFileStamps()
+		AssertNotRebuilt(t, "new .a file before build", filepath.Join(gopathInstallDir, "depBase.a"))
 		goCmd(t, "list", "-linkshared", "-f={{.ImportPath}} {{.Stale}} {{.StaleReason}} {{.Target}}", "depBase")
 		AssertNotRebuilt(t, "new .a file before build", filepath.Join(gopathInstallDir, "depBase.a"))
 		cleanup := touch(t, filepath.Join(gopathInstallDir, "depBase.a"))