cmd/compile: rework TestPGOHash to not rebuild dependencies

TestPGOHash may rebuild dependencies as we pass -trimpath to the
go command. This CL makes it pass -trimpath compiler flag to only
the current package instead, as we only need the current package
to have a stable source file path.

Also refactor buildPGOInliningTest to only take compiler flags,
not go flags, to avoid accidental rebuild.

Should fix #63733.

Change-Id: Iec6c4e90cf659790e21083ee2e697f518234c5b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/535915
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Bryan Mills <bcmills@google.com>

diff --git a/src/cmd/compile/internal/test/pgo_inl_test.go b/src/cmd/compile/internal/test/pgo_inl_test.go
index 7aabf8b01061420c4a0b70ea0dcf5896e5223f73..da6c4a53d362288bb3b1b4f7f919d92b5e00b9b3 100644 (file)
--- a/src/cmd/compile/internal/test/pgo_inl_test.go
+++ b/src/cmd/compile/internal/test/pgo_inl_test.go
@@ -18,7 +18,7 @@ import (
        "testing"
 )
 
-func buildPGOInliningTest(t *testing.T, dir string, flags ...string) []byte {
+func buildPGOInliningTest(t *testing.T, dir string, gcflag string) []byte {
        const pkg = "example.com/pgo/inline"
 
        // Add a go.mod so we have a consistent symbol names in this temp dir.
@@ -30,10 +30,11 @@ go 1.19
        }
 
        exe := filepath.Join(dir, "test.exe")
-       args := []string{"test", "-c", "-o", exe}
-       args = append(args, flags...)
-       cmd := testenv.CleanCmdEnv(testenv.Command(t, testenv.GoToolPath(t), args...))
+       args := []string{"test", "-c", "-o", exe, "-gcflags=" + gcflag}
+       cmd := testenv.Command(t, testenv.GoToolPath(t), args...)
        cmd.Dir = dir
+       cmd = testenv.CleanCmdEnv(cmd)
+       t.Log(cmd)
        out, err := cmd.CombinedOutput()
        if err != nil {
                t.Fatalf("build failed: %v, output:\n%s", err, out)
@@ -86,7 +87,7 @@ func testPGOIntendedInlining(t *testing.T, dir string) {
        // Build the test with the profile. Use a smaller threshold to test.
        // TODO: maybe adjust the test to work with default threshold.
        pprof := filepath.Join(dir, "inline_hot.pprof")
-       gcflag := fmt.Sprintf("-gcflags=-m -m -pgoprofile=%s -d=pgoinlinebudget=160,pgoinlinecdfthreshold=90", pprof)
+       gcflag := fmt.Sprintf("-m -m -pgoprofile=%s -d=pgoinlinebudget=160,pgoinlinecdfthreshold=90", pprof)
        out := buildPGOInliningTest(t, dir, gcflag)
 
        scanner := bufio.NewScanner(bytes.NewReader(out))
@@ -300,6 +301,8 @@ func TestPGOHash(t *testing.T) {
        testenv.MustHaveGoRun(t)
        t.Parallel()
 
+       const pkg = "example.com/pgo/inline"
+
        wd, err := os.Getwd()
        if err != nil {
                t.Fatalf("error getting wd: %v", err)
@@ -316,7 +319,9 @@ func TestPGOHash(t *testing.T) {
        }
 
        pprof := filepath.Join(dir, "inline_hot.pprof")
-       gcflag0 := fmt.Sprintf("-gcflags=-pgoprofile=%s -d=pgoinlinebudget=160,pgoinlinecdfthreshold=90,pgodebug=1,", pprof)
+       // build with -trimpath so the source location (thus the hash)
+       // does not depend on the temporary directory path.
+       gcflag0 := fmt.Sprintf("-pgoprofile=%s -trimpath %s=>%s -d=pgoinlinebudget=160,pgoinlinecdfthreshold=90,pgodebug=1", pprof, dir, pkg)
 
        // Check that a hash match allows PGO inlining.
        const srcPos = "example.com/pgo/inline/inline_hot.go:81:19"
@@ -324,9 +329,7 @@ func TestPGOHash(t *testing.T) {
        pgoDebugRE := regexp.MustCompile(`hot-budget check allows inlining for call .* at ` + strings.ReplaceAll(srcPos, ".", "\\."))
        hash := "v1" // 1 matches srcPos, v for verbose (print source location)
        gcflag := gcflag0 + ",pgohash=" + hash
-       // build with -trimpath so the source location (thus the hash)
-       // does not depend on the temporary directory path.
-       out := buildPGOInliningTest(t, dir, gcflag, "-trimpath")
+       out := buildPGOInliningTest(t, dir, gcflag)
        if !bytes.Contains(out, []byte(hashMatch)) || !pgoDebugRE.Match(out) {
                t.Errorf("output does not contain expected source line, out:\n%s", out)
        }
@@ -334,7 +337,7 @@ func TestPGOHash(t *testing.T) {
        // Check that a hash mismatch turns off PGO inlining.
        hash = "v0" // 0 should not match srcPos
        gcflag = gcflag0 + ",pgohash=" + hash
-       out = buildPGOInliningTest(t, dir, gcflag, "-trimpath")
+       out = buildPGOInliningTest(t, dir, gcflag)
        if bytes.Contains(out, []byte(hashMatch)) || pgoDebugRE.Match(out) {
                t.Errorf("output contains unexpected source line, out:\n%s", out)
        }