if gp.m.libcallsp != 0 {
		// We're in C code somewhere, traceback from the saved position.
		traceback1(gp.m.libcallpc, gp.m.libcallsp, 0, gp.m.libcallg.ptr(), 0)
		return
	}
	traceback1(pc, sp, lr, gp, unwindTrap)
}

func traceback1(pc, sp, lr uintptr, gp *g, flags unwindFlags) {
	// If the goroutine is in cgo, and we have a cgo traceback, print that.

package main

// This program will crash.
// We want the stack trace to include the C functions.
// We use a fake traceback, and a symbolizer that dumps a string we recognize.

/*
#cgo CFLAGS: -g -O0

// Defined in traceback_c.c.
extern int crashInGo;
int tracebackF1(void);
void cgoTraceback(void* parg);
void cgoSymbolizer(void* parg);
*/
import "C"

import (
	"runtime"
	"unsafe"
)

// The C definitions for traceback.go. That file uses //export so
// it can't put function definitions in the "C" import comment.

#include <stdint.h>

char *p;

int crashInGo;
extern void h1(void);

int tracebackF3(void) {
	if (crashInGo)
		h1();
	else
		*p = 0;
	return 0;
}

int tracebackF2(void) {
	return tracebackF3();
}

int tracebackF1(void) {

		panic(fmt.Sprintf("bad f %v\n", f))
	}
	if !more {
		panic("traceback truncated after f")
	}
	f, more = iter.Next()
	if f.Function != "test/a.init" || !strings.HasSuffix(f.File, "a.go") || f.Line != 15 {
		panic(fmt.Sprintf("bad init %v\n", f))
	}
	if !more {
		panic("traceback truncated after init")
	}
	f, _ = iter.Next()
	if !strings.HasPrefix(f.Function, "runtime.") {

var asmsysvicall6x libcFunc // name to take addr of asmsysvicall6

func asmsysvicall6() // declared for vet; do NOT call

//go:nosplit
func sysvicall0(fn *libcFunc) uintptr {
	// Leave caller's PC/SP around for traceback.
	gp := getg()
	var mp *m
	if gp != nil {
		mp = gp.m
	}
	if mp != nil && mp.libcallsp == 0 {
		mp.libcallg.set(gp)
		mp.libcallpc = getcallerpc()

			}
			if t.Failed() {
				t.Logf("traceback diverged at frame %d", i)
				off := len(stack)
				if len(tb.frames) > 0 {
					off = tb.frames[0].off
				}
				t.Logf("traceback before error:\n%s", stack[:off])
				t.Logf("traceback after error:\n%s", stack[off:])
			}
		})
	}
}

// tteStack creates a stack of n logical frames and sends the traceback to

	// Send SIGQUIT.
	if err := cmd.Process.Signal(syscall.SIGQUIT); err != nil {
		t.Fatal("signaling subprocess: ", err)
	}

	// Get traceback.
	tb, err := io.ReadAll(pr)
	if err != nil {
		t.Fatal("reading traceback from pipe: ", err)
	}

	// Traceback should have two testPanicSystemstackInternal's
	// and two blockOnSystemStackInternal's.
	userFunc := "testPanicSystemstackInternal"

#define __has_feature(x) 0
#endif

#if __has_feature(memory_sanitizer)
#include <sanitizer/msan_interface.h>
#endif

// Call the user's traceback function and then call sigtramp.
// The runtime signal handler will jump to this code.
// We do it this way so that the user's traceback function will be called
// by a C function with proper unwind info.
void

		// Signal to TracebackAncestors that we are done recursing and starting goroutines.
		w <- struct{}{}
		<-w
		return
	}
	if goroutines == 0 {
		// Record which goroutine this is so we can ignore it
		// in the traceback if it hasn't finished exiting by
		// the time we printStack.
		if !main {
			ignoreGoroutines[goroutineID()] = true
		}

		// Start the next goroutine now that there are no more recursions left

	// FuncFlagSPWrite indicates a function that writes an arbitrary value to SP
	// (any write other than adding or subtracting a constant amount).
	// The traceback routines cannot encode such changes into the
	// pcsp tables, so the function traceback cannot safely unwind past
	// SPWrite functions. Stopping at an SPWrite function is considered
	// to be an incomplete unwinding of the stack. In certain contexts