cmd/dist, cmd/compile: eliminate mergeEnvLists copies

This is now handled by os/exec.

Updates #12868

Change-Id: Ic21a6ff76a9b9517437ff1acf3a9195f9604bb45
Reviewed-on: https://go-review.googlesource.com/37698
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/compile/internal/gc/asm_test.go b/src/cmd/compile/internal/gc/asm_test.go
index 33e9f47b089f676b5097fa5ef7944873c8328938..e5c30c63fe610895a65cb284fadc53ddf20626fe 100644 (file)
--- a/src/cmd/compile/internal/gc/asm_test.go
+++ b/src/cmd/compile/internal/gc/asm_test.go
@@ -143,7 +143,7 @@ func (ats *asmTests) compileToAsm(t *testing.T, dir string) string {
 func (ats *asmTests) runGo(t *testing.T, args ...string) string {
        var stdout, stderr bytes.Buffer
        cmd := exec.Command(testenv.GoToolPath(t), args...)
-       cmd.Env = mergeEnvLists([]string{"GOARCH=" + ats.arch, "GOOS=" + ats.os}, os.Environ())
+       cmd.Env = append(os.Environ(), "GOARCH="+ats.arch, "GOOS="+ats.os)
        cmd.Stdout = &stdout
        cmd.Stderr = &stderr
 
@@ -790,25 +790,6 @@ var linuxARM64Tests = []*asmTest{
        },
 }
 
-// mergeEnvLists merges the two environment lists such that
-// variables with the same name in "in" replace those in "out".
-// This always returns a newly allocated slice.
-func mergeEnvLists(in, out []string) []string {
-       out = append([]string(nil), out...)
-NextVar:
-       for _, inkv := range in {
-               k := strings.SplitAfterN(inkv, "=", 2)[0]
-               for i, outkv := range out {
-                       if strings.HasPrefix(outkv, k) {
-                               out[i] = inkv
-                               continue NextVar
-                       }
-               }
-               out = append(out, inkv)
-       }
-       return out
-}
-
 // TestLineNumber checks to make sure the generated assembly has line numbers
 // see issue #16214
 func TestLineNumber(t *testing.T) {

diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index 227199ca220ab5da8dd34d6b27e880e888eaea32..73e99324db5c663f05e0eeca077a46f2b6da0f02 100644 (file)
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -426,7 +426,7 @@ func (t *tester) registerTests() {
                                cmd := t.addCmd(dt, "src", "go", "test", "-short", t.timeout(300), t.tags(), "runtime", "-cpu=1,2,4")
                                // We set GOMAXPROCS=2 in addition to -cpu=1,2,4 in order to test runtime bootstrap code,
                                // creation of first goroutines and first garbage collections in the parallel setting.
-                               cmd.Env = mergeEnvLists([]string{"GOMAXPROCS=2"}, os.Environ())
+                               cmd.Env = append(os.Environ(), "GOMAXPROCS=2")
                                return nil
                        },
                })
@@ -807,10 +807,9 @@ func (t *tester) registerHostTest(name, heading, dir, pkg string) {
 }
 
 func (t *tester) runHostTest(dir, pkg string) error {
-       env := mergeEnvLists([]string{"GOARCH=" + t.gohostarch, "GOOS=" + t.gohostos}, os.Environ())
        defer os.Remove(filepath.Join(t.goroot, dir, "test.test"))
        cmd := t.dirCmd(dir, "go", "test", t.tags(), "-c", "-o", "test.test", pkg)
-       cmd.Env = env
+       cmd.Env = append(os.Environ(), "GOARCH="+t.gohostarch, "GOOS="+t.gohostos)
        if err := cmd.Run(); err != nil {
                return err
        }
@@ -818,7 +817,7 @@ func (t *tester) runHostTest(dir, pkg string) error {
 }
 
 func (t *tester) cgoTest(dt *distTest) error {
-       env := mergeEnvLists([]string{"GOTRACEBACK=2"}, os.Environ())
+       env := append(os.Environ(), "GOTRACEBACK=2")
 
        cmd := t.addCmd(dt, "misc/cgo/test", "go", "test", t.tags(), "-ldflags", "-linkmode=auto", t.runFlag(""))
        cmd.Env = env
@@ -1053,12 +1052,12 @@ func (t *tester) cgoTestSO(dt *distTest, testpath string) error {
                if t.goos == "darwin" {
                        s = "DYLD_LIBRARY_PATH"
                }
-               cmd.Env = mergeEnvLists([]string{s + "=."}, os.Environ())
+               cmd.Env = append(os.Environ(), s+"=.")
 
                // On FreeBSD 64-bit architectures, the 32-bit linker looks for
                // different environment variables.
                if t.goos == "freebsd" && t.gohostarch == "386" {
-                       cmd.Env = mergeEnvLists([]string{"LD_32_LIBRARY_PATH=."}, cmd.Env)
+                       cmd.Env = append(cmd.Env, "LD_32_LIBRARY_PATH=.")
                }
        }
        return cmd.Run()
@@ -1097,9 +1096,8 @@ func (t *tester) raceTest(dt *distTest) error {
        // TODO(iant): Figure out how to catch this.
        // t.addCmd(dt, "src", "go", "test", "-race", "-run=TestParallelTest", "cmd/go")
        if t.cgoEnabled {
-               env := mergeEnvLists([]string{"GOTRACEBACK=2"}, os.Environ())
                cmd := t.addCmd(dt, "misc/cgo/test", "go", "test", "-race", "-short", t.runFlag(""))
-               cmd.Env = env
+               cmd.Env = append(os.Environ(), "GOTRACEBACK=2")
        }
        if t.extLink() {
                // Test with external linking; see issue 9133.
@@ -1118,7 +1116,7 @@ func (t *tester) testDirTest(dt *distTest, shard, shards int) error {
        runtest.Do(func() {
                const exe = "runtest.exe" // named exe for Windows, but harmless elsewhere
                cmd := t.dirCmd("test", "go", "build", "-o", exe, "run.go")
-               cmd.Env = mergeEnvLists([]string{"GOOS=" + t.gohostos, "GOARCH=" + t.gohostarch, "GOMAXPROCS="}, os.Environ())
+               cmd.Env = append(os.Environ(), "GOOS="+t.gohostos, "GOARCH="+t.gohostarch, "GOMAXPROCS=")
                runtest.exe = filepath.Join(cmd.Dir, exe)
                if err := cmd.Run(); err != nil {
                        runtest.err = err
@@ -1141,24 +1139,6 @@ func (t *tester) testDirTest(dt *distTest, shard, shards int) error {
        return nil
 }
 
-// mergeEnvLists merges the two environment lists such that
-// variables with the same name in "in" replace those in "out".
-// out may be mutated.
-func mergeEnvLists(in, out []string) []string {
-NextVar:
-       for _, inkv := range in {
-               k := strings.SplitAfterN(inkv, "=", 2)[0]
-               for i, outkv := range out {
-                       if strings.HasPrefix(outkv, k) {
-                               out[i] = inkv
-                               continue NextVar
-                       }
-               }
-               out = append(out, inkv)
-       }
-       return out
-}
-
 // cgoPackages is the standard packages that use cgo.
 var cgoPackages = []string{
        "crypto/x509",