cmd/dist: added support for GOARCH=mips64{,le}

Change-Id: I22ea3352ad0794fc611334c2f2ec5f1e894985ce
Reviewed-on: https://go-review.googlesource.com/14460Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

src/cmd/dist/build.go

@@ -54,6 +54,8 @@ var okgoarch = []string{
 	"amd64p32",
 	"arm",
 	"arm64",
+	"mips64",
+	"mips64le",
 	"ppc64",
 	"ppc64le",
 }

src/cmd/dist/buildtool.go

@@ -34,12 +34,14 @@ var bootstrapDirs = []string{
 	"compile/internal/arm64",
 	"compile/internal/big",
 	"compile/internal/gc",
+	"compile/internal/mips64",
 	"compile/internal/ppc64",
 	"compile/internal/x86",
 	"internal/gcprog",
 	"internal/obj",
 	"internal/obj/arm",
 	"internal/obj/arm64",
+	"internal/obj/mips",
 	"internal/obj/ppc64",
 	"internal/obj/x86",
 	"link",
@@ -47,6 +49,7 @@ var bootstrapDirs = []string{
 	"link/internal/arm",
 	"link/internal/arm64",
 	"link/internal/ld",
+	"link/internal/mips64",
 	"link/internal/ppc64",
 	"link/internal/x86",
 }

src/cmd/dist/test.go

@@ -745,6 +745,10 @@ func (t *tester) cgoTestSOSupported() bool {
 		// External linking not implemented on ppc64 (issue #8912).
 		return false
 	}
+	if t.goarch == "mips64le" || t.goarch == "mips64" {
+		// External linking not implemented on mips64.
+		return false
+	}
 	return true
 }
 

src/cmd/dist/util.go

@@ -6,6 +6,8 @@ package main
 
 import (
 	"bytes"
+	"debug/elf"
+	"encoding/binary"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -438,6 +440,16 @@ func main() {
 			gohostarch = "ppc64le"
 		case strings.Contains(out, "ppc64"):
 			gohostarch = "ppc64"
+		case strings.Contains(out, "mips64"):
+			file, err := elf.Open(os.Args[0])
+			if err != nil {
+				fatal("failed to open %s to determine endianness: %v", os.Args[0], err)
+			}
+			if file.FileHeader.ByteOrder == binary.BigEndian {
+				gohostarch = "mips64"
+			} else {
+				gohostarch = "mips64le"
+			}
 		case gohostos == "darwin":
 			if strings.Contains(run("", CheckExit, "uname", "-v"), "RELEASE_ARM_") {
 				gohostarch = "arm"