// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Issue 8047.  Stack copier shouldn't crash if there
// is a nil defer.

package main

func stackit(n int) {
	if n == 0 {
		return
	}
	stackit(n - 1)
}

func main() {
	defer func() {
		// catch & ignore panic from nil defer below
		err := recover()
		if err == nil {

static void*
threadentry(void *v)
{
	ThreadStart ts;
	stack_t ss;

	ts = *(ThreadStart*)v;
	free(v);

	// On NetBSD, a new thread inherits the signal stack of the
	// creating thread. That confuses minit, so we remove that
	// signal stack here before calling the regular mstart. It's
	// a bit baroque to remove a signal stack here only to add one
	// in minit, but it's a simple change that keeps NetBSD

	// morestack on g0 crash.
	if (g->stacklo >= g->stackhi) {
		fatalf("bad stack bounds: lo=%p hi=%p", (void*)(g->stacklo), (void*)(g->stackhi));
	}
}

void
_cgo_sys_thread_start(ThreadStart *ts)
{
	pthread_attr_t attr;
	sigset_t ign, oset;
	pthread_t p;
	void *base;
	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);

	//
	// Functions that need frames <= StackSmall can perform the stack check
	// using a single comparison directly between the stack guard and the SP
	// because we ensure that StackSmall bytes of stack space are available
	// beyond the stack guard.
	StackSmall = 128

	// Functions that need frames <= StackBig can assume that neither
	// SP-framesize nor stackGuard-StackSmall will underflow, and thus use a

type Xmmreg C.struct__libc_xmmreg
type Fpstate C.struct__libc_fpstate
type Fpxreg1 C.struct__fpxreg
type Xmmreg1 C.struct__xmmreg
type Fpstate1 C.struct__fpstate
type Fpreg1 C.struct__fpreg
type StackT C.stack_t
type Mcontext C.mcontext_t
type Ucontext C.ucontext_t

)

type Usigset C.__sigset_t

// types used in sigcontext
type Ptregs C.struct_pt_regs
type Gregset C.elf_gregset_t
type FPregset C.elf_fpregset_t
type Vreg C.elf_vrreg_t

type StackT C.stack_t

// PPC64 uses sigcontext in place of mcontext in ucontext.
// see https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/include/uapi/asm/ucontext.h
type Sigcontext C.struct_sigcontext

)

type sigset C.sigset_t
type siginfo C.siginfo_t
type timespec C.struct_timespec
type timestruc C.struct_timestruc_t
type timeval C.struct_timeval
type itimerval C.struct_itimerval

type stackt C.stack_t
type sigcontext C.struct_sigcontext
type ucontext C.ucontext_t
type _Ctype_struct___extctx uint64 // ucontext use a pointer to this structure but it shouldn't be used
type jmpbuf C.struct___jmpbuf

	size_t size;
	int err;

	SIGFILLSET(ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);

	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {
		fatalf("pthread_create failed: %s", strerror(err));

	size_t size;
	int err;

	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	pthread_attr_init(&attr);
	pthread_attr_getstacksize(&attr, &size);

	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {
		fatalf("pthread_create failed: %s", strerror(err));

	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	size = pthread_get_stacksize_np(pthread_self());
	pthread_attr_init(&attr);
	pthread_attr_setstacksize(&attr, size);
	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
	ts->g->stackhi = size;
	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

	pthread_sigmask(SIG_SETMASK, &oset, nil);

	if (err != 0) {