go/build: accept spaces in cgo directives

Fixes #7906

Change-Id: Ibcf9cd670593241921ab3c426ff7357f799ebc3e
Reviewed-on: https://go-review.googlesource.com/43072Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/go/go_test.go

@@ -78,6 +78,8 @@ func init() {
 // (temp) directory.
 var testGOROOT string
 
+var testCC string
+
 // The TestMain function creates a go command for testing purposes and
 // deletes it after the tests have been run.
 func TestMain(m *testing.M) {
@@ -99,6 +101,13 @@ func TestMain(m *testing.M) {
 		}
 		testGOROOT = strings.TrimSpace(string(out))
 
+		out, err = exec.Command("go", "env", "CC").CombinedOutput()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "could not find testing CC: %v\n%s", err, out)
+			os.Exit(2)
+		}
+		testCC = strings.TrimSpace(string(out))
+
 		if out, err := exec.Command("./testgo"+exeSuffix, "env", "CGO_ENABLED").Output(); err != nil {
 			fmt.Fprintf(os.Stderr, "running testgo failed: %v\n", err)
 			canRun = false
@@ -4037,3 +4046,58 @@ func main() {}`)
 	tg.run("build", "-x", "-buildmode=c-archive", "-gcflags=-shared=false", tg.path("override.go"))
 	tg.grepStderr("compile .*-shared .*-shared=false", "user can not override code generation flag")
 }
+
+func TestCgoFlagContainsSpace(t *testing.T) {
+	if !canCgo {
+		t.Skip("skipping because cgo not enabled")
+	}
+
+	tg := testgo(t)
+	defer tg.cleanup()
+
+	tg.tempFile("src/cc/main.go", fmt.Sprintf(`package main
+		import (
+			"os"
+			"os/exec"
+		)
+
+		func main() {
+			var success bool
+			for _, arg := range os.Args {
+				switch arg {
+				case "-Ic flags":
+					if success {
+						panic("duplicate CFLAGS")
+					}
+					success = true
+				case "-Lld flags":
+					if success {
+						panic("duplicate LDFLAGS")
+					}
+					success = true
+				}
+			}
+			if !success {
+				panic("args should contains '-Ic flags' or '-Lld flags'")
+			}
+			cmd := exec.Command(%q, os.Args[1:]...)
+			cmd.Stdin = os.Stdin
+			cmd.Stdout = os.Stdout
+			err := cmd.Run()
+			if err != nil {
+				panic(err)
+			}
+		}
+	`, testCC))
+	tg.cd(tg.path("src/cc"))
+	tg.run("build")
+	tg.setenv("CC", tg.path("src/cc/cc"))
+	tg.tempFile("src/cgo/cgo.go", `package main
+		// #cgo CFLAGS: -I"c flags"
+		// #cgo LDFLAGS: -L"ld flags"
+		import "C"
+		func main() {}
+	`)
+	path := tg.path("src/cgo/cgo.go")
+	tg.run("run", path)
+}

src/go/build/build.go

@@ -1302,16 +1302,15 @@ func expandSrcDir(str string, srcdir string) (string, bool) {
 	// to "/" before starting (eg: on windows).
 	srcdir = filepath.ToSlash(srcdir)
 
-	// Spaces are tolerated in ${SRCDIR}, but not anywhere else.
 	chunks := strings.Split(str, "${SRCDIR}")
 	if len(chunks) < 2 {
-		return str, safeCgoName(str, false)
+		return str, safeCgoName(str)
 	}
 	ok := true
 	for _, chunk := range chunks {
-		ok = ok && (chunk == "" || safeCgoName(chunk, false))
+		ok = ok && (chunk == "" || safeCgoName(chunk))
 	}
-	ok = ok && (srcdir == "" || safeCgoName(srcdir, true))
+	ok = ok && (srcdir == "" || safeCgoName(srcdir))
 	res := strings.Join(chunks, srcdir)
 	return res, ok && res != ""
 }
@@ -1321,21 +1320,14 @@ func expandSrcDir(str string, srcdir string) (string, bool) {
 // See golang.org/issue/6038.
 // The @ is for OS X. See golang.org/issue/13720.
 // The % is for Jenkins. See golang.org/issue/16959.
-const safeString = "+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:$@%"
-const safeSpaces = " "
+const safeString = "+-.,/0123456789=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz:$@% "
 
-var safeBytes = []byte(safeSpaces + safeString)
-
-func safeCgoName(s string, spaces bool) bool {
+func safeCgoName(s string) bool {
 	if s == "" {
 		return false
 	}
-	safe := safeBytes
-	if !spaces {
-		safe = safe[len(safeSpaces):]
-	}
 	for i := 0; i < len(s); i++ {
-		if c := s[i]; c < utf8.RuneSelf && bytes.IndexByte(safe, c) < 0 {
+		if c := s[i]; c < utf8.RuneSelf && strings.IndexByte(safeString, c) < 0 {
 			return false
 		}
 	}

src/go/build/build_test.go

@@ -285,9 +285,11 @@ func TestShellSafety(t *testing.T) {
 		{"-I${SRCDIR}/../include", "/projects/src/issue 11868", "-I/projects/src/issue 11868/../include", true},
 		{"-I${SRCDIR}", "wtf$@%", "-Iwtf$@%", true},
 		{"-X${SRCDIR}/1,${SRCDIR}/2", "/projects/src/issue 11868", "-X/projects/src/issue 11868/1,/projects/src/issue 11868/2", true},
-		{"-I/tmp -I/tmp", "/tmp2", "-I/tmp -I/tmp", false},
+		{"-I/tmp -I/tmp", "/tmp2", "-I/tmp -I/tmp", true},
 		{"-I/tmp", "/tmp/[0]", "-I/tmp", true},
 		{"-I${SRCDIR}/dir", "/tmp/[0]", "-I/tmp/[0]/dir", false},
+		{"-I${SRCDIR}/dir", "/tmp/go go", "-I/tmp/go go/dir", true},
+		{"-I${SRCDIR}/dir dir", "/tmp/go", "-I/tmp/go/dir dir", true},
 	}
 	for _, test := range tests {
 		output, ok := expandSrcDir(test.input, test.srcdir)