code review 106380043: cmd/go, cmd/ld, runtime, os/user: TLS emultion for android

src/cmd/go/build.go

 // Copyright 2011 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 (
         "bufio"
         "bytes"
         "container/heap"
@@ skipping 1723 matching lines @@
                 }
         }
         if !extld {
                 var compiler []string
                 if cxx {
                         compiler = envList("CXX", defaultCXX)
                 } else {
                         compiler = envList("CC", defaultCC)
                 }
                 ldflags = append(ldflags, "-extld="+compiler[0])
+                if goos == "android" {
+                        compiler = append(compiler, "-llog")

[minux, 2014/07/02 04:21:14]

put -llog as a #cgo LDFLAGS in runtime/cgo/cgo.go so that
we don't need to modify cmd/go for this.

[dave_cheney.net, 2014/07/02 04:33:05]

yup, good idea

[crawshaw, 2014/07/02 14:57:21]

Done.

+                }
                 if len(compiler) > 1 {
                         extldflags := false
                         add := strings.Join(compiler[1:], " ")
                         for i, f := range ldflags {
                                 if f == "-extldflags" && i+1 < len(ldflags) {
                                         ldflags[i+1] = add + " " + ldflags[i+1]
                                         extldflags = true
                                         break
                                 } else if strings.HasPrefix(f, "-extldflags=") {
                                         ldflags[i] = "-extldflags=" + add + " " + ldflags[i][len("-extldflags="):]
@@ skipping 501 matching lines @@
                 ofile := obj + cgoRe.ReplaceAllString(file, "_") + ".o"
                 if err := b.gcc(p, ofile, cflags, file); err != nil {
                         return nil, nil, err
                 }
                 linkobj = append(linkobj, ofile)
                 outObj = append(outObj, ofile)
         }
 
         linkobj = append(linkobj, p.SysoFiles...)
         dynobj := obj + "_cgo_.o"
-        if goarch == "arm" && goos == "linux" { // we need to use -pie for Linux/ARM to get accurate imported sym
+        if goos == "android" {
+                cgoLDFLAGS = append(cgoLDFLAGS, "-llog")
+        }
+        if goarch == "arm" && (goos == "linux" || goos == "android") { // we need to use -pie for Linux/ARM to get accurate imported sym
                 cgoLDFLAGS = append(cgoLDFLAGS, "-pie")
         }
         if err := b.gccld(p, dynobj, cgoLDFLAGS, linkobj); err != nil {
                 return nil, nil, err
         }
         if goarch == "arm" && goos == "linux" { // but we don't need -pie for normal cgo programs
                 cgoLDFLAGS = cgoLDFLAGS[0 : len(cgoLDFLAGS)-1]
         }
 
         if _, ok := buildToolchain.(gccgoToolchain); ok {
@@ skipping 299 matching lines @@
 func defaultSuffix() string {
         switch runtime.GOOS {
         case "windows":
                 return ".bat"
         case "plan9":
                 return ".rc"
         default:
                 return ".bash"
         }
 }