s := recover()
		if s == nil {
			t.Fatal("did not panic")
		}
		if s.(string) != "callback panic" {
			t.Fatal("wrong panic:", s)
		}
		if !lockedOSThread() {
			t.Fatal("lost lock on OS thread after panic")
		}
	}()
	nestedCall(func() { panic("callback panic") })
	panic("nestedCall returned")
}

// Callback with zero arguments used to make the stack misaligned,

Austin Clements <******@****.***> 1683224724 -0400

			fchown(fd, uid, gid, callback) { callback(enosys()); },
			fstat(fd, callback) { callback(enosys()); },
			fsync(fd, callback) { callback(null); },
			ftruncate(fd, length, callback) { callback(enosys()); },
			lchown(path, uid, gid, callback) { callback(enosys()); },
			link(path, link, callback) { callback(enosys()); },
			lstat(path, callback) { callback(enosys()); },
			mkdir(path, perm, callback) { callback(enosys()); },

package main

import (
	"fmt"
	"os"
)

func main() {
	if len(os.Args) != 2 {
		fatal("usage: callback testname")
	}
	switch os.Args[1] {
	default:
		fatal("unknown test %q", os.Args[1])
	case "Call":
		testCall()
	case "Callback":
		testCallback()
	}
	println("OK")
}

func fatal(f string, args ...any) {
	fmt.Fprintln(os.Stderr, fmt.Sprintf(f, args...))

	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")
	t.Run("lto", func(t *testing.T) { run(t, "testdata/callback", true, "Callback") })
}

Go 1.20 introduced automatic seeding of the
[`math/rand`](/pkg/math/rand) global random number generator,
controlled by the [`randautoseed` setting](/pkg/math/rand/#Seed).

Go 1.20 introduced the concept of fallback roots for use during certificate verification,
controlled by the [`x509usefallbackroots` setting](/pkg/crypto/x509/#SetFallbackRoots).

Go 1.20 removed the preinstalled `.a` files for the standard library

// Copyright 2011 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.

#include <string.h>

#include "_cgo_export.h"

void
callback(void *f)
{
	// use some stack space
	volatile char data[64*1024];

	data[0] = 0;
	goCallback(f);
        data[sizeof(data)-1] = 0;
}

void
callGoFoo(void)
{
	extern void goFoo(void);

	}
	// Only frames in the test package are checked.
	want := []string{
		"test._Cfunc_backtrace",
		"test.testCallbackCallersSEH.func1.1",
		"test.testCallbackCallersSEH.func1",
		"test.goCallback",
		"test._Cfunc_callback",
		"test.nestedCall.func1",
		"test.nestedCall",
		"test.testCallbackCallersSEH",
		"test.TestCallbackCallersSEH",
	}
	pc := make([]uintptr, 100)
	n := 0
	nestedCall(func() {

	{"fofofofofoofofoffofoobarfoo", "foobars", -1},
	{"foofyfoobarfoobar", "y", 4},
	{"oooooooooooooooooooooo", "r", -1},
	{"oxoxoxoxoxoxoxoxoxoxoxoy", "oy", 22},
	{"oxoxoxoxoxoxoxoxoxoxoxox", "oy", -1},
	// test fallback to Rabin-Karp.
	{"000000000000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000001", 5},
}

var lastIndexTests = []BinOpTest{
	{"", "", 0},

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

class Callback {
public:
	virtual ~Callback() { }
	virtual std::string run() { return "Callback::run"; }
};

class Caller {
private:
	Callback *callback_;
public:
	Caller(): callback_(0) { }
	~Caller() { delCallback(); }
	void delCallback() { delete callback_; callback_ = 0; }
	void setCallback(Callback *cb) { delCallback(); callback_ = cb; }
	std::string call();