cb := NewCallback()

	c.SetCallback(cb)
	s := c.Call()
	if s != "Callback::run" {
		fatal("unexpected string from Call: %q", s)
	}
	c.DelCallback()
}

func testCallback() {
	c := NewCaller()
	cb := NewDirectorCallback(&GoCallback{})
	c.SetCallback(cb)
	s := c.Call()
	if s != "GoCallback.Run" {
		fatal("unexpected string from Call with callback: %q", s)
	}
	c.DelCallback()

file.
L4:
L5:@echo off
L6:
L7:setlocal
L8:
L9:if exist make.bat goto ok
L10:echo all.bat must be run from go\src
L11::: cannot exit: would kill parent command interpreter
L12:goto end
L13::ok
L14:
L15:call .\make.bat --no-banner --no-local
L16:if %GOBUILDFAIL%==1 goto end
L17:call .\run.bat --no-rebuild --no-local
L18:if %GOBUILDFAIL%==1 goto end
L19:"%GOTOOLDIR%/dist" banner
L20:
L21::end
L22:if x%GOBUILDEXIT%==x1 exit %GOBUILDFAIL%
...

		Context: context,
	})
}

// Save calls to C.xxx for later processing.
func (f *File) saveCall(call *ast.CallExpr, context astContext) {
	sel, ok := call.Fun.(*ast.SelectorExpr)
	if !ok {
		return
	}
	if l, ok := sel.X.(*ast.Ident); !ok || l.Name != "C" {
		return
	}
	c := &Call{Call: call, Deferred: context == ctxDefer}
	f.Calls = append(f.Calls, c)
}

	run(t, "testdata/stdio", false)
}

func TestCall(t *testing.T) {
	testenv.MustHaveCGO(t)
	mustHaveSwig(t)
	mustHaveCxx(t)
	run(t, "testdata/callback", false, "Call")
	t.Run("lto", func(t *testing.T) { run(t, "testdata/callback", true, "Call") })
}

func TestCallback(t *testing.T) {
	testenv.MustHaveCGO(t)
	mustHaveSwig(t)
	mustHaveCxx(t)
	run(t, "testdata/callback", false, "Callback")

	BEQ	R1, 2(PC)
	JAL	1(PC)		// CALL 1(PC)	// 0c00000f
	BEQ	R1, 2(PC)
	JAL	label0+0	// CALL 3	// 0c000007

//	LBRA addr
//	{
//		outcode(int($1), &nullgen, 0, &$2);
//	}
	BEQ	R1, 2(PC)
	JMP	0(R1)		// JMP (R1)	// 00200008
	BEQ	R1, 2(PC)
	JMP	foo+0(SB)	// JMP foo(SB)	// 08000019
	BEQ	R1, 2(PC)
	JAL	0(R1)		// CALL (R1)	// 0020f809
	BEQ	R1, 2(PC)
	JAL	foo+0(SB)	// CALL foo(SB)	// 0c000021

//
// BEQ/BNE

// Copyright 2009 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.

/*
Cgo enables the creation of Go packages that call C code.

# Using cgo with the go command

To use cgo write normal Go code that imports a pseudo-package "C".
The Go code can then refer to types such as C.size_t, variables such
as C.stdout, or functions such as C.putchar.

Use of this source code is governed by a BSD-style
L3::: license that can be found in the LICENSE file.
L4:
L5:@echo off
L6:
L7:setlocal
L8:
L9:set GOBUILDFAIL=0
L10:
L11:go tool dist env -w -p >env.bat
L12:if errorlevel 1 goto fail
L13:call .\env.bat
L14:del env.bat
L15:echo.
L16:
L17:if exist %GOTOOLDIR%\dist.exe goto distok
L18:echo cannot find %GOTOOLDIR%\dist; nothing to clean
L19:goto fail
L20::distok
L21:
L22:"%GOBIN%\go" clean -i std
L23:"%GOBIN%\go" tool dist clean
...

		"CMPBNE",
		"CMPUBEQ",
		"CMPUBGE",
		"CMPUBGT",
		"CMPUBLE",
		"CMPUBLT",
		"CMPUBNE",
		"CRJ",
		"CGRJ",
		"CLRJ",
		"CLGRJ",
		"CIJ",
		"CGIJ",
		"CLIJ",
		"CLGIJ",
		"CALL",
		"JMP":
		return true
	}
	return false
}

func s390xRegisterNumber(name string, n int16) (int16, bool) {
	switch name {
	case "AR":
		if 0 <= n && n <= 15 {
			return s390x.REG_AR0 + n, true
		}

import (
	"cmd/internal/obj"
	"cmd/internal/obj/ppc64"
)

func jumpPPC64(word string) bool {
	switch word {
	case "BC", "BCL", "BEQ", "BGE", "BGT", "BL", "BLE", "BLT", "BNE", "BR", "BVC", "BVS", "BDNZ", "BDZ", "CALL", "JMP":
		return true
	}
	return false
}

// IsPPC64CMP reports whether the op (as defined by an ppc64.A* constant) is
// one of the CMP instructions that require special handling.

		cmd.Stdout = buf
		cmd.Stderr = buf
		if err := cmd.Start(); err != nil {
			// We are starting so many processes that on
			// some systems (problem seen on Darwin,
			// Dragonfly, OpenBSD) the fork call will fail
			// with EAGAIN.
			if pe, ok := err.(*os.PathError); ok {
				err = pe.Err
			}
			if se, ok := err.(syscall.Errno); ok && (se == syscall.EAGAIN || se == syscall.EMFILE) {
				time.Sleep(time.Millisecond)