"C", it will look for other non-Go files in the directory and compile
them as part of the Go package. Any .c, .s, .S or .sx files will be
compiled with the C compiler. Any .cc, .cpp, or .cxx files will be
compiled with the C++ compiler. Any .f, .F, .for or .f90 files will be
compiled with the fortran compiler. Any .h, .hh, .hpp, or .hxx files will
not be compiled separately, but, if these header files are changed,

## Compiler {#compiler}

## Assembler {#assembler}

// Copyright 2021 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 !compiler_bootstrap

package main

import (
	"go/ast"
	"go/token"
)

func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
	switch n := x.(type) {
	default:
		error_(token.NoPos, "unexpected type %T in walk", x)

	"sort"
	"strings"
	"sync"
	"testing"
)

var flagCheck = flag.Bool("check", false, "run API checks")

func TestMain(m *testing.M) {
	flag.Parse()
	for _, c := range contexts {
		c.Compiler = build.Default.Compiler
	}
	build.Default.GOROOT = testenv.GOROOT(nil)

	os.Exit(m.Run())
}

var (
	updateGolden = flag.Bool("updategolden", false, "update golden files")
)

func TestGolden(t *testing.T) {

Some of the details map precisely to the machine, but some do not.
This is because the compiler suite (see
<a href="https://9p.io/sys/doc/compiler.html">this description</a>)
needs no assembler pass in the usual pipeline.
Instead, the compiler operates on a kind of semi-abstract instruction set,
and instruction selection occurs partly after code generation.

		t.Fatalf("go env CXX failed: %s", err)
	}
	args, err := quoted.Split(string(cxx))
	if err != nil {
		t.Skipf("could not parse 'go env CXX' output %q: %s", string(cxx), err)
	}
	if len(args) == 0 {
		t.Skip("no C++ compiler")
	}
	testenv.MustHaveExecPath(t, string(args[0]))
}

var (
	swigOnce sync.Once
	haveSwig bool
)

func mustHaveSwig(t *testing.T) {
	swigOnce.Do(func() {
		mustHaveSwigOnce(t)

// Copyright 2021 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 compiler_bootstrap

package main

import (
	"go/ast"
	"go/token"
)

func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
	error_(token.NoPos, "unexpected type %T in walk", x)
	panic("unexpected type")
}

imported normally and vendored by the standard library.

Vendored packages are internally renamed with a "vendor/" prefix
to preserve the invariant that all packages have distinct paths.
This is necessary to avoid compiler and linker conflicts. Adding
a "vendor/" prefix also maintains the invariant that standard
library packages begin with a dotless path element.

The module requirements of std and cmd do not influence version

	ctxt.Pkgpath = *flags.Importpath
	switch *flags.Spectre {
	default:
		log.Printf("unknown setting -spectre=%s", *flags.Spectre)
		os.Exit(2)
	case "":
		// nothing
	case "index":
		// known to compiler; ignore here so people can use
		// the same list with -gcflags=-spectre=LIST and -asmflags=-spectrre=LIST
	case "all", "ret":
		ctxt.Retpoline = true
	}

	ctxt.Bso = bufio.NewWriter(os.Stdout)

Go on iOS
=========

To run the standard library tests, run all.bash as usual, but with the compiler
set to the clang wrapper that invokes clang for iOS. For example, this command runs
 all.bash on the iOS emulator:

	GOOS=ios GOARCH=amd64 CGO_ENABLED=1 CC_FOR_TARGET=$(pwd)/../misc/ios/clangwrap.sh ./all.bash

If CC_FOR_TARGET is not set when the toolchain is built (make.bash or all.bash), CC
can be set on the command line. For example,