}
		f.walk(n.List, context, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.SwitchStmt:
		f.walk(n.Init, ctxStmt, visit)
		f.walk(&n.Tag, ctxExpr, visit)
		f.walk(n.Body, ctxSwitch, visit)
	case *ast.TypeSwitchStmt:
		f.walk(n.Init, ctxStmt, visit)
		f.walk(n.Assign, ctxStmt, visit)
		f.walk(n.Body, ctxTypeSwitch, visit)
	case *ast.CommClause:
		f.walk(n.Comm, ctxStmt, visit)

	VSUMQG	V19, V20, V21           // e75340003e67
	VSUMB	V7, V8, V9              // e79780000064
	VSUMH	V22, V23, V24           // e78670001e64

	RET
	RET	foo(SB)

TEXT main·init(SB),DUPOK|NOSPLIT,$0 // TEXT main.init(SB), DUPOK|NOSPLIT, $0
	RET

TEXT main·main(SB),DUPOK|NOSPLIT,$0 // TEXT main.main(SB), DUPOK|NOSPLIT, $0
	BL      main·foo(SB)    // CALL main.foo(SB)

threads and thread-local storage. The runtime package declares a few
variables:

	var (
		iscgo             bool
		_cgo_init         unsafe.Pointer
		_cgo_thread_start unsafe.Pointer
	)

Any package using cgo imports "runtime/cgo", which provides
initializations for these variables. It sets iscgo to true, _cgo_init
to a gcc-compiled function that can be called early during program

var testBytes []byte  // test data; same as testString but as a slice.

type negativeReader struct{}

func (r *negativeReader) Read([]byte) (int, error) { return -1, nil }

func init() {
	testBytes = make([]byte, N)
	for i := 0; i < N; i++ {
		testBytes[i] = 'a' + byte(i%26)
	}
	testString = string(testBytes)
}

// Verify that contents of buf match the string s.

	if size < 0 {
		return nil, errors.New("zip: size cannot be negative")
	}
	zr := new(Reader)
	var err error
	if err = zr.init(r, size); err != nil && err != ErrInsecurePath {
		return nil, err
	}
	return zr, err
}

func (r *Reader) init(rdr io.ReaderAt, size int64) error {
	end, baseOffset, err := readDirectoryEnd(rdr, size)
	if err != nil {
		return err
	}
	r.r = rdr

</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
<code>q</code>'s <code>init</code> functions happens before the start of any of <code>p</code>'s.
</p>

// result against a golden file.

func testEndToEnd(t *testing.T, goarch, file string) {
	input := filepath.Join("testdata", file+".s")
	architecture, ctxt := setArch(goarch)
	architecture.Init(ctxt)
	lexer := lex.NewLexer(input)
	parser := NewParser(ctxt, architecture, lexer)
	pList := new(obj.Plist)
	var ok bool
	testOut = new(strings.Builder) // The assembler writes test output to this buffer.