var i I = p;  // this should be possible even though p is nil: we still know the type
	i.M();  // should be possible since we know the type, and don't ever use the receiver
}


/*
throw: ifaces2i: nil pointer
SIGSEGV: segmentation violation
Faulting address: 0x0
pc: 0x1b7d

0x1b7d?zi
	throw(30409, 0, 0, ...)
	throw(0x76c9, 0x0, 0x0, ...)
0x207f?zi
	sys·ifaces2i(31440, 0, 31480, ...)
	sys·ifaces2i(0x7ad0, 0x7af8, 0x0, ...)

	register("SegvInCgo", SegvInCgo)
}

func SegvInCgo() {
	c := make(chan bool)
	go func() {
		close(c)
		for {
			C.nop()
		}
	}()

	<-c

	syscall.Kill(syscall.Getpid(), syscall.SIGSEGV)

	// Wait for the OS to deliver the signal.
	C.pause()

}

func TgkillSegvInCgo() {
	c := make(chan bool)
	go func() {
		close(c)
		for {
			C.nop()
		}
	}()

	<-c

	syscall.Tgkill(syscall.Getpid(), syscall.Gettid(), syscall.SIGSEGV)

	// Wait for the OS to deliver the signal.
	C.pause()

	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGEMT    = C.SIGEMT
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGBUS    = C.SIGBUS
	SIGSEGV   = C.SIGSEGV
	SIGSYS    = C.SIGSYS
	SIGPIPE   = C.SIGPIPE
	SIGALRM   = C.SIGALRM
	SIGTERM   = C.SIGTERM
	SIGURG    = C.SIGURG
	SIGSTOP   = C.SIGSTOP
	SIGTSTP   = C.SIGTSTP
	SIGCONT   = C.SIGCONT

	SIGINT    = C.SIGINT
	SIGQUIT   = C.SIGQUIT
	SIGILL    = C.SIGILL
	SIGTRAP   = C.SIGTRAP
	SIGABRT   = C.SIGABRT
	SIGEMT    = C.SIGEMT
	SIGFPE    = C.SIGFPE
	SIGKILL   = C.SIGKILL
	SIGBUS    = C.SIGBUS
	SIGSEGV   = C.SIGSEGV
	SIGSYS    = C.SIGSYS
	SIGPIPE   = C.SIGPIPE
	SIGALRM   = C.SIGALRM
	SIGTERM   = C.SIGTERM
	SIGURG    = C.SIGURG
	SIGSTOP   = C.SIGSTOP
	SIGTSTP   = C.SIGTSTP
	SIGCONT   = C.SIGCONT

#include "funcdata.h"
#include "textflag.h"

// We have to resort to TLS variable to save g(R10).
// One reason is that external code might trigger
// SIGSEGV, and our runtime.sigtramp don't even know we
// are in external code, and will continue to use R10,
// this might as well result in another SIGSEGV.
// Note: both functions will clobber R0 and R11 and
// can be called from 5c ABI code.

// On android, runtime.tls_g is a normal variable.

rm $WORK/gopath/pkg/mod/cache/download/golang.org/x/text/
go mod tidy -e
stderr '^go: rsc.io/sampler@v1.3.0 requires\n\tgolang.org/x/text@.*: reading file://.*/pkg/mod/cache/download/golang.org/x/text/.*'
! stderr 'signal SIGSEGV: segmentation violation'

-- $WORK/x/go.mod --
module example.com/mod

go 1.17

require rsc.io/quote v1.5.2

require (
	golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c // indirect

}

void registerSegvFowarder() {
	struct sigaction sa;
	memset(&sa, 0, sizeof(sa));
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
	sa.sa_sigaction = forwardSignal;

	if (sigaction(SIGSEGV, &sa, &prev_sa) != 0) {
		perror("failed to register SEGV forwarder");
		exit(EXIT_FAILURE);
	}
}
*/
import "C"

func main() {
	C.registerSegvFowarder()

	defer func() {
		recover()
	}()

// 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.

package main

// This program failed with SIGSEGV when run under the C/C++ ThreadSanitizer.
// The Go runtime had re-registered the C handler with the wrong flags due to a
// typo, resulting in null pointers being passed for the info and context
// parameters to the handler.

/*

	/* 8 */ {_SigPanic + _SigUnblock, "SIGFPE: floating-point exception"},
	/* 9 */ {0, "SIGKILL: kill"},
	/* 10 */ {_SigPanic + _SigUnblock, "SIGBUS: bus error"},
	/* 11 */ {_SigPanic + _SigUnblock, "SIGSEGV: segmentation violation"},
	/* 12 */ {_SigNotify, "SIGSYS: bad system call"}, // see golang.org/issues/15204
	/* 13 */ {_SigNotify, "SIGPIPE: write to broken pipe"},
	/* 14 */ {_SigNotify, "SIGALRM: alarm clock"},