// the runtime manually, though any memory obtained from freed arenas must
// not be accessed once that happens. An Arena is automatically freed once
// it is no longer referenced, so it must be kept alive (see runtime.KeepAlive)
// until any memory allocated from it is no longer needed.
//
// An Arena must never be used concurrently by multiple goroutines.
type Arena struct {
	a unsafe.Pointer
}

	swigOnce sync.Once
	haveSwig bool
)

func mustHaveSwig(t *testing.T) {
	swigOnce.Do(func() {
		mustHaveSwigOnce(t)
		haveSwig = true
	})
	// The first call will skip t with a nice message. On later calls, we just skip.
	if !haveSwig {
		t.Skip("swig not found")
	}
}

func mustHaveSwigOnce(t *testing.T) {
	swig, err := exec.LookPath("swig")
	if err != nil {
		t.Skipf("swig not in PATH: %s", err)
	}

// Copyright 2017 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.

// This file is here just to cause problems.
// main.swig turns into a file also named main.go.
// Make sure cmd/go keeps them separate
// when both are passed to cgo.

package main

//int F(void) { return 1; }
import "C"
import (
	"fmt"
	"os"
)

// Copyright 2018 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.

// Failed to resolve typedefs consistently.
// No runtime test; just make sure it compiles.
// In separate directory to isolate #pragma GCC diagnostic.

package issue27340

// We use the #pragma to avoid a compiler warning about incompatible

		for i := len(b) - 1; i >= 0; i-- {
			b[i] = byte(x)
			x >>= 8
		}
		b[0] |= 0x80 // Highest bit indicates binary format
		return
	}

	f.formatOctal(b, 0) // Last resort, just write zero
	f.err = ErrFieldTooLong
}

func (p *parser) parseOctal(b []byte) int64 {
	// Because unused fields are filled with NULs, we need
	// to skip leading NULs. Fields may also be padded with

// See the [ZIP specification] for details.
//
// [ZIP specification]: https://support.pkware.com/pkzip/appnote
type FileHeader struct {
	// Name is the name of the file.
	//
	// It must be a relative path, not start with a drive letter (such as "C:"),
	// and must use forward slashes instead of back slashes. A trailing slash
	// indicates that this file is a directory and should have no data.
	Name string

// large to fit in the [Scanner.Buffer]. When a scan stops, the reader may have
// advanced arbitrarily far past the last token. Programs that need more
// control over error handling or large tokens, or must run sequential scans
// on a reader, should use [bufio.Reader] instead.
type Scanner struct {
	r            io.Reader // The reader provided by the client.
	split        SplitFunc // The function to split the tokens.

	if err != nil {
		t.Fatalf("go tool addr2line %v: %v\n%s", os.Args[0], err, string(out))
	}
	f := strings.Split(string(out), "\n")
	if len(f) < 3 && f[2] == "" {
		t.Fatal("addr2line output must have 2 lines")
	}
	funcname = f[0]
	pathAndLineNo := f[1]
	f = strings.Split(pathAndLineNo, ":")
	if runtime.GOOS == "windows" && len(f) == 3 {
		// Reattach drive letter.
		f = []string{f[0] + ":" + f[1], f[2]}
	}

//
// In most cases, new([Buffer]) (or just declaring a [Buffer] variable) is
// sufficient to initialize a [Buffer].
func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} }

// NewBufferString creates and initializes a new [Buffer] using string s as its
// initial contents. It is intended to prepare a buffer to read an existing
// string.
//
// In most cases, new([Buffer]) (or just declaring a [Buffer] variable) is

			"A",
		),
		"1234.\n",
	},
	{
		"define without value",
		"#define A",
		"",
	},
	{
		"macro without arguments",
		"#define A() 1234\n" + "A()\n",
		"1234.\n",
	},
	{
		"macro with just parens as body",
		"#define A () \n" + "A\n",
		"(.).\n",
	},
	{
		"macro with parens but no arguments",
		"#define A (x) \n" + "A\n",
		"(.x.).\n",
	},
	{
		"macro with arguments",