}
		return q
	}

	ret := []cfg.EnvVar{
		// Note: Update the switch in runEnv below when adding to this list.
		{Name: "CGO_CFLAGS", Value: join(cflags)},
		{Name: "CGO_CPPFLAGS", Value: join(cppflags)},
		{Name: "CGO_CXXFLAGS", Value: join(cxxflags)},
		{Name: "CGO_FFLAGS", Value: join(fflags)},
		{Name: "CGO_LDFLAGS", Value: join(ldflags)},
		{Name: "PKG_CONFIG", Value: b.PkgconfigCmd()},

	cgoCflags := os.Getenv("CGO_CFLAGS")
	if cgoCflags != "" {
		cgoCflags += " "
	}
	cgoCflags += "-I" + tmpdir

	cgoLdflags := os.Getenv("CGO_LDFLAGS")
	if cgoLdflags != "" {
		cgoLdflags += " "
	}
	cgoLdflags += "-L" + tmpdir + " -ltestgo2c2go"

	goenv := []string{"CGO_CFLAGS=" + cgoCflags, "CGO_LDFLAGS=" + cgoLdflags}

env GOSUMDB=nodefault
env GOPROXY=nodefault
env GO111MODULE=auto
env CGO_CFLAGS=nodefault
env CGO_CPPFLAGS=nodefault

go env -changed
# linux output like GOTOOLCHAIN='local'
# windows output like GOTOOLCHAIN=local
stdout 'GOTOOLCHAIN=''?local''?'
stdout 'GOSUMDB=''?nodefault''?'
stdout 'GOPROXY=''?nodefault''?'
stdout 'GO111MODULE=''?auto''?'
stdout 'CGO_CFLAGS=''?nodefault''?'
stdout 'CGO_CPPFLAGS=''?nodefault''?'

# golang.org/issue/46347: a stale runtime/cgo should only force a single rebuild

[!cgo] skip
[short] skip


# If we set a unique CGO_CFLAGS, the installed copy of runtime/cgo
# should be reported as stale.

env CGO_CFLAGS=-DTestScript_cgo_stale=true
stale runtime/cgo


# If we then build a package that uses cgo, runtime/cgo should be rebuilt and
# cached with the new flag, but not installed to GOROOT.

# Explicitly rebuild it to ensure that it is cached.
# (See https://go.dev/issue/50892.)
#
# If running in non-short mode, explicitly vary CGO_CFLAGS
# as a control case (to ensure that our regexps do catch rebuilds).

[!short] env GOCACHE=$WORK/cache
[!short] env CGO_CFLAGS=-DTestScript_cgo_stale_precompiled=true
go build -x runtime/cgo
[!short] stderr '[/\\]cgo'$GOEXE'["]? .* -importpath runtime/cgo'

# Tests golang.org/issue/36000

[!cgo] skip

# go env with CGO flags should not make NUL file

		}
		args = append(args, strings.Fields(string(out))...)
	}
	args = append(args, "-I", tmpdir)
	args = append(args, strings.Fields(os.Getenv("CGO_CFLAGS"))...)
	args = append(args, bp.CgoCFLAGS...)
	args = append(args, bp.CgoFiles...)

	cmd := exec.Command(args[0], args[1:]...)
	cmd.Dir = bp.Dir
	if err := cmd.Run(); err != nil {
		return nil, fmt.Errorf("go tool cgo: %w", err)

#
# Verifies golang.org/issue/53345
#
# Note, older gcc/clang may accept this option, but
# ignore it if binutils does not support the relocs.
[!compiler:gc] skip
[!cgo] skip
[!GOARCH:ppc64le] skip

env CGO_CFLAGS='-fno-plt -O2 -g'

go build -ldflags='-linkmode=internal'
exec ./noplttest
stdout helloworld

-- go.mod --
module noplttest

-- noplttest.go --
package main

/*
#include <stdio.h>

// Copyright 2016 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.

// Issue 14669: test that fails when build with CGO_CFLAGS selecting
// optimization.

package p

/*
const int E = 1;

typedef struct s {
	int       c;
} s;
*/
import "C"

func F() {
	_ = C.s{
		c: C.E,
	}

rm $WORK/log.txt

# TODO(#41400, #43078): when CC is set explicitly, it should be allowed to
# contain spaces separating arguments, and it should be possible to quote
# arguments with spaces (including the path), as in CGO_CFLAGS and other
# variables. For now, this doesn't work.
[!GOOS:windows] env CC=$WORK/'program files'/gcc
[GOOS:windows] env CC=$WORK\'program files'\gcc.bat
! go build -x
! exists $WORK/log.txt

-- go.mod --
module m