but instead calls a Go helper function that wraps the C library malloc
but guarantees never to return nil. If C's malloc indicates out of memory,
the helper function crashes the program, like when Go itself runs out
of memory. Because C.malloc cannot fail, it has no two-result form
that returns errno.

# C references to Go

Go functions can be exported for use by C code in the following way:

	//export MyFunction

// license that can be found in the LICENSE file.

//go:build !darwin || !cgo || internal

package cgotest

import "testing"

func test21897(t *testing.T) {
	t.Skip("test runs only on darwin+cgo")

	}
	// disable LTO so we get an object whose symbols we can read
	c = append(c, "-fno-lto")
	c = append(c, "-") //read input from standard input
	return c
}

// gccDebug runs gcc -gdwarf-2 over the C program stdin and
// returns the corresponding DWARF data and, if present, debug data block.

	"internal/testenv"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
)

// TestMain executes the test binary as the addr2line command if
// GO_ADDR2LINETEST_IS_ADDR2LINE is set, and runs the tests otherwise.
func TestMain(m *testing.M) {
	if os.Getenv("GO_ADDR2LINETEST_IS_ADDR2LINE") != "" {
		main()
		os.Exit(0)
	}

	os.Setenv("GO_ADDR2LINETEST_IS_ADDR2LINE", "1") // Set for subprocesses to inherit.

# flag portability issues in builders named "misc-compile" or "all-compile".
# As of CL 464955, the build system uses make.bash -compile-only instead,
# so this script no longer runs in any automated fashion.
#
# Options:
#   -e: stop at first failure

if [ ! -f run.bash ]; then
	echo 'buildall.bash must be run from $GOROOT/src' 1>&2
	exit 1
fi

sete=false
if [ "$1" = "-e" ]; then

//
// Since the set of packages that exist depends on context, the result of
// loadImports also depends on context. However, to improve test running time
// the configuration for each environment is cached across runs.
func (w *Walker) loadImports() {
	if w.context == nil {
		return // test-only Walker; does not use the import map
	}

	name := contextName(w.context)

	imports, ok := listCache.Load(name)
	if !ok {

“Incorrect compilation” section below.
</p>

<h2 id="synchronization">Synchronization</h2>

<h3 id="init">Initialization</h3>

<p>
Program initialization runs in a single goroutine,
but that goroutine may create other goroutines,
which run concurrently.
</p>

<p class="rule">
If a package <code>p</code> imports package <code>q</code>, the completion of