4 files changed, 32 insertions, 15 deletions
diff --git a/src/pkg/go/build/build.go b/src/pkg/go/build/build.go
index 50d2fb4ae..412abea3a 100644
--- a/src/pkg/go/build/build.go
+++ b/src/pkg/go/build/build.go
@@ -292,10 +292,10 @@ func defaultContext() Context {
 	// say "+build go1.x", and code that should only be built before Go 1.x
 	// (perhaps it is the stub to use in that case) should say "+build !go1.x".
 	//
-	// When we reach Go 1.3 the line will read
-	//	c.ReleaseTags = []string{"go1.1", "go1.2", "go1.3"}
+	// When we reach Go 1.4 the line will read
+	//	c.ReleaseTags = []string{"go1.1", "go1.2", "go1.3", "go1.4"}
 	// and so on.
-	c.ReleaseTags = []string{"go1.1", "go1.2"}
+	c.ReleaseTags = []string{"go1.1", "go1.2", "go1.3"}
 
 	switch os.Getenv("CGO_ENABLED") {
 	case "1":
@@ -303,8 +303,7 @@ func defaultContext() Context {
 	case "0":
 		c.CgoEnabled = false
 	default:
-		// golang.org/issue/5141
-		// cgo should be disabled for cross compilation builds
+		// cgo must be explicitly enabled for cross compilation builds
 		if runtime.GOARCH == c.GOARCH && runtime.GOOS == c.GOOS {
 			c.CgoEnabled = cgoEnabled[c.GOOS+"/"+c.GOARCH]
 			break
@@ -358,6 +357,7 @@ type Package struct {
 	IgnoredGoFiles []string // .go source files ignored for this build
 	CFiles         []string // .c source files
 	CXXFiles       []string // .cc, .cpp and .cxx source files
+	MFiles         []string // .m (Objective-C) source files
 	HFiles         []string // .h, .hh, .hpp and .hxx source files
 	SFiles         []string // .s source files
 	SwigFiles      []string // .swig files
@@ -622,6 +622,9 @@ Found:
 		case ".cc", ".cpp", ".cxx":
 			p.CXXFiles = append(p.CXXFiles, name)
 			continue
+		case ".m":
+			p.MFiles = append(p.MFiles, name)
+			continue
 		case ".h", ".hh", ".hpp", ".hxx":
 			p.HFiles = append(p.HFiles, name)
 			continue
@@ -789,7 +792,7 @@ func (ctxt *Context) matchFile(dir, name string, returnImports bool, allTags map
 	}
 
 	switch ext {
-	case ".go", ".c", ".cc", ".cxx", ".cpp", ".s", ".h", ".hh", ".hpp", ".hxx", ".S", ".swig", ".swigcxx":
+	case ".go", ".c", ".cc", ".cxx", ".cpp", ".m", ".s", ".h", ".hh", ".hpp", ".hxx", ".S", ".swig", ".swigcxx":
 		// tentatively okay - read to make sure
 	case ".syso":
 		// binary, no reading
@@ -1207,7 +1210,7 @@ func ArchChar(goarch string) (string, error) {
 	switch goarch {
 	case "386":
 		return "8", nil
-	case "amd64":
+	case "amd64", "amd64p32":
 		return "6", nil
 	case "arm":
 		return "5", nil
diff --git a/src/pkg/go/build/deps_test.go b/src/pkg/go/build/deps_test.go
index dd162c7db..7421e144f 100644
--- a/src/pkg/go/build/deps_test.go
+++ b/src/pkg/go/build/deps_test.go
@@ -8,6 +8,7 @@
 package build
 
 import (
+	"runtime"
 	"sort"
 	"testing"
 )
@@ -29,7 +30,7 @@ var pkgDeps = map[string][]string{
 	"errors":      {},
 	"io":          {"errors", "sync"},
 	"runtime":     {"unsafe"},
-	"sync":        {"sync/atomic", "unsafe"},
+	"sync":        {"runtime", "sync/atomic", "unsafe"},
 	"sync/atomic": {"unsafe"},
 	"unsafe":      {},
 
@@ -125,7 +126,7 @@ var pkgDeps = map[string][]string{
 	"os":            {"L1", "os", "syscall", "time"},
 	"path/filepath": {"L2", "os", "syscall"},
 	"io/ioutil":     {"L2", "os", "path/filepath", "time"},
-	"os/exec":       {"L2", "os", "syscall"},
+	"os/exec":       {"L2", "os", "path/filepath", "syscall"},
 	"os/signal":     {"L2", "os", "syscall"},
 
 	// OS enables basic operating system functionality,
@@ -301,7 +302,7 @@ var pkgDeps = map[string][]string{
 	// SSL/TLS.
 	"crypto/tls": {
 		"L4", "CRYPTO-MATH", "CGO", "OS",
-		"crypto/x509", "encoding/pem", "net", "syscall",
+		"container/list", "crypto/x509", "encoding/pem", "net", "syscall",
 	},
 	"crypto/x509": {
 		"L4", "CRYPTO-MATH", "OS", "CGO",
@@ -359,7 +360,7 @@ func allowed(pkg string) map[string]bool {
 }
 
 var bools = []bool{false, true}
-var geese = []string{"darwin", "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "plan9", "windows"}
+var geese = []string{"darwin", "dragonfly", "freebsd", "linux", "nacl", "netbsd", "openbsd", "plan9", "solaris", "windows"}
 var goarches = []string{"386", "amd64", "arm"}
 
 type osPkg struct {
@@ -374,6 +375,11 @@ var allowedErrors = map[osPkg]bool{
 }
 
 func TestDependencies(t *testing.T) {
+	if runtime.GOOS == "nacl" {
+		// NaCl tests run in a limited file system and we do not
+		// provide access to every source file.
+		t.Skip("skipping on NaCl")
+	}
 	var all []string
 
 	for k := range pkgDeps {
@@ -387,6 +393,9 @@ func TestDependencies(t *testing.T) {
 			if isMacro(pkg) {
 				continue
 			}
+			if pkg == "runtime/cgo" && !ctxt.CgoEnabled {
+				continue
+			}
 			p, err := ctxt.Import(pkg, "", 0)
 			if err != nil {
 				if allowedErrors[osPkg{ctxt.GOOS, pkg}] {
diff --git a/src/pkg/go/build/doc.go b/src/pkg/go/build/doc.go
index b2f04ea45..f17f76ccc 100644
--- a/src/pkg/go/build/doc.go
+++ b/src/pkg/go/build/doc.go
@@ -57,11 +57,15 @@
 //
 // Build Constraints
 //
-// A build constraint is a line comment beginning with the directive +build
+// A build constraint, also known as a build tag, is a line comment that begins
+//
+//	// +build
+//
 // that lists the conditions under which a file should be included in the package.
 // Constraints may appear in any kind of source file (not just Go), but
 // they must appear near the top of the file, preceded
-// only by blank lines and other line comments.
+// only by blank lines and other line comments. These rules mean that in Go
+// files a build constraint must appear before the package clause.
 //
 // To distinguish build constraints from package documentation, a series of
 // build constraints must be followed by a blank line.
@@ -95,6 +99,7 @@
 //	- "cgo", if ctxt.CgoEnabled is true
 //	- "go1.1", from Go version 1.1 onward
 //	- "go1.2", from Go version 1.2 onward
+//	- "go1.3", from Go version 1.3 onward
 //	- any additional words listed in ctxt.BuildTags
 //
 // If a file's name, after stripping the extension and a possible _test suffix,
diff --git a/src/pkg/go/build/syslist.go b/src/pkg/go/build/syslist.go
index e1fbf6330..5c42b946b 100644
--- a/src/pkg/go/build/syslist.go
+++ b/src/pkg/go/build/syslist.go
@@ -4,5 +4,5 @@
 
 package build
 
-const goosList = "darwin dragonfly freebsd linux netbsd openbsd plan9 windows "
-const goarchList = "386 amd64 arm "
+const goosList = "darwin dragonfly freebsd linux nacl netbsd openbsd plan9 solaris windows "
+const goarchList = "386 amd64 amd64p32 arm "