all: use "noopt" build tag for checking optimization disabled

Fixes #49390

Change-Id: Ie5a5e097635c9fdcf4509455007283009a7d3021
Reviewed-on: https://go-review.googlesource.com/c/go/+/423256
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/cmd/dist/build.go

@@ -55,6 +55,7 @@ var (
 
 	rebuildall   bool
 	defaultclang bool
+	noOpt        bool
 
 	vflag int // verbosity
 )
@@ -1325,6 +1326,7 @@ func cmdbootstrap() {
 	}
 
 	gogcflags = os.Getenv("GO_GCFLAGS") // we were using $BOOT_GO_GCFLAGS until now
+	setNoOpt()
 	goldflags = os.Getenv("GO_LDFLAGS") // we were using $BOOT_GO_LDFLAGS until now
 	goBootstrap := pathf("%s/go_bootstrap", tooldir)
 	cmdGo := pathf("%s/go", gorootBin)
@@ -1510,6 +1512,9 @@ func appendCompilerFlags(args []string) []string {
 
 func goCmd(goBinary string, cmd string, args ...string) {
 	goCmd := []string{goBinary, cmd}
+	if noOpt {
+		goCmd = append(goCmd, "-tags=noopt")
+	}
 	goCmd = appendCompilerFlags(goCmd)
 	if vflag > 0 {
 		goCmd = append(goCmd, "-v")
@@ -1525,6 +1530,9 @@ func goCmd(goBinary string, cmd string, args ...string) {
 
 func checkNotStale(goBinary string, targets ...string) {
 	goCmd := []string{goBinary, "list"}
+	if noOpt {
+		goCmd = append(goCmd, "-tags=noopt")
+	}
 	goCmd = appendCompilerFlags(goCmd)
 	goCmd = append(goCmd, "-f={{if .Stale}}\tSTALE {{.ImportPath}}: {{.StaleReason}}{{end}}")
 
@@ -1800,3 +1808,12 @@ func IsRuntimePackagePath(pkgpath string) bool {
 	}
 	return rval
 }
+
+func setNoOpt() {
+	for _, gcflag := range strings.Split(gogcflags, " ") {
+		if gcflag == "-N" || gcflag == "-l" {
+			noOpt = true
+			break
+		}
+	}
+}

src/cmd/dist/test.go

@@ -25,6 +25,7 @@ import (
 
 func cmdtest() {
 	gogcflags = os.Getenv("GO_GCFLAGS")
+	setNoOpt()
 
 	var t tester
 
@@ -325,10 +326,17 @@ func (t *tester) goTest() []string {
 }
 
 func (t *tester) tags() string {
-	if t.iOS() {
+	ios := t.iOS()
+	switch {
+	case ios && noOpt:
+		return "-tags=lldb,noopt"
+	case ios:
 		return "-tags=lldb"
+	case noOpt:
+		return "-tags=noopt"
+	default:
+		return "-tags="
 	}
-	return "-tags="
 }
 
 // timeoutDuration converts the provided number of seconds into a

src/internal/testenv/noopt.go

@@ -0,0 +1,12 @@
+// Copyright 2022 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.
+
+//go:build noopt
+
+package testenv
+
+// OptimizationOff reports whether optimization is disabled.
+func OptimizationOff() bool {
+	return true
+}

src/internal/testenv/opt.go

@@ -0,0 +1,12 @@
+// Copyright 2022 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.
+
+//go:build !noopt
+
+package testenv
+
+// OptimizationOff reports whether optimization is disabled.
+func OptimizationOff() bool {
+	return false
+}

src/internal/testenv/testenv.go

@@ -412,15 +412,10 @@ func SkipIfShortAndSlow(t testing.TB) {
 func SkipIfOptimizationOff(t testing.TB) {
 	if OptimizationOff() {
 		t.Helper()
-		t.Skip("skipping test with optimization disabled on builder")
+		t.Skip("skipping test with optimization disabled")
 	}
 }
 
-// OptimizationOff reports whether optimization is disabled.
-func OptimizationOff() bool {
-	return strings.HasSuffix(Builder(), "-noopt")
-}
-
 // RunWithTimeout runs cmd and returns its combined output. If the
 // subprocess exits with a non-zero status, it will log that status
 // and return a non-nil error, but this is not considered fatal.