extraLDFlags := ""
		if strings.Contains(testenv.Builder(), "clang") {
			extraLDFlags += " -fuse-ld=lld"
		}
		const cflags = "-flto -Wno-lto-type-mismatch -Wno-unknown-warning-option"
		cmd.Env = append(cmd.Environ(),
			"CGO_CFLAGS="+cflags,
			"CGO_CXXFLAGS="+cflags,
			"CGO_LDFLAGS="+cflags+extraLDFlags)
	}
	out, err := cmd.CombinedOutput()
	if string(out) != "OK\n" {
		t.Errorf("%s", string(out))
	}

}

func TestToleratesOptimizationFlag(t *testing.T) {
	for _, cflags := range []string{
		"",
		"-O",
	} {
		cflags := cflags
		t.Run(cflags, func(t *testing.T) {
			testenv.MustHaveGoBuild(t)
			testenv.MustHaveCGO(t)
			t.Parallel()

			cmd := exec.Command("go", "build", path("issue14669.go"))
			cmd.Env = append(os.Environ(), "CGO_CFLAGS="+cflags)
			out, err := cmd.CombinedOutput()
			if err != nil {

[!GOOS:darwin] skip
[!cgo] skip

! go build
stderr 'invalid flag in #cgo LDFLAGS: -lto_library'

-- go.mod --
module ldflag

-- main.go --
package main

// #cgo CFLAGS: -flto
// #cgo LDFLAGS: -lto_library bad.dylib
import "C"

		compiler, _ := compilerVersion()
		if compiler.name == "gcc" {
			c.cFlags = append(c.cFlags, "-fPIC")
			c.ldFlags = append(c.ldFlags, "-fPIC", "-static-libtsan")
		}

	case "address":
		c.goFlags = append(c.goFlags, "-asan")
		// Set the debug mode to print the C stack trace.
		c.cFlags = append(c.cFlags, "-g")

	case "fuzzer":

stdout success

go build -buildmode=pie -o abitest.pie -ldflags='-linkmode=internal'
exec ./abitest.pie
stdout success

-- go.mod --
module abitest

-- abitest.go --
package main

/*
#cgo CFLAGS: -Os

int foo_fpr() {
        asm volatile("":::"fr31","fr30","fr29","fr28");
}
int foo_gpr0() {
        asm volatile("":::"r30","r29","r28");
}
int foo_gpr1() {

ALL_OSVERSIONS.windows := 1809 ltsc2022
ALL_OS_ARCH.windows = $(foreach arch, $(ALL_ARCH.windows), $(foreach osversion, ${ALL_OSVERSIONS.windows}, windows-$(arch)-${osversion}))
ALL_OS_ARCH = $(foreach os, $(ALL_OS), ${ALL_OS_ARCH.${os}})

CFLAGS = -Os -Wall -Werror -static -DVERSION=v$(TAG)-$(REV)
KUBE_CROSS_IMAGE ?= registry.k8s.io/build-image/kube-cross
KUBE_CROSS_VERSION ?= $(shell cat ../build-image/cross/VERSION)

	}
	return args
}

// CFlags returns the flags to use when invoking the C, C++ or Fortran compilers, or cgo.
func (b *Builder) CFlags(p *load.Package) (cppflags, cflags, cxxflags, fflags, ldflags []string, err error) {
	if cppflags, err = buildFlags("CPPFLAGS", "", p.CgoCPPFLAGS, checkCompilerFlags); err != nil {
		return
	}
	if cflags, err = buildFlags("CFLAGS", DefaultCFlags, p.CgoCFLAGS, checkCompilerFlags); err != nil {

	defer func() {
		if err := b.Close(); err != nil {
			base.Fatal(err)
		}
	}()

	cppflags, cflags, cxxflags, fflags, ldflags, err := b.CFlags(&load.Package{})
	if err != nil {
		// Should not happen - b.CFlags was given an empty package.
		fmt.Fprintf(os.Stderr, "go: invalid cflags: %v\n", err)
		return nil
	}
	cmd := b.GccCmd(".", "")

	join := func(s []string) string {

curl -sS -L -O https://www.iana.org/time-zones/repository/releases/tzdata$DATA.tar.gz
tar xzf tzcode$CODE.tar.gz
tar xzf tzdata$DATA.tar.gz

if ! make CFLAGS=-DSTD_INSPIRED AWK=awk TZDIR=zoneinfo posix_only >make.out 2>&1; then
	cat make.out
	exit 2
fi

cd zoneinfo
../mkzip ../../zoneinfo.zip
cd ../..

files="update.bash zoneinfo.zip"
modified=true

			archivePath := dir.Join(name + ".a")
			mustRun(t, config.goCmd("build", "-buildmode=c-archive", "-o", archivePath, srcPath(tc.goSrc)))

			// build C code (if any) and link with Go code
			cmd, err := cc(config.cFlags...)
			if err != nil {
				t.Fatalf("error running cc: %v", err)
			}
			cmd.Args = append(cmd.Args, config.ldFlags...)
			cmd.Args = append(cmd.Args, "-o", outPath, "-I", dir.Base())
			if tc.cSrc != "" {