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// Copyright 2009 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 "runtime.h"
extern int32 debug;
extern uint8 end;
void
traceback(byte *pc0, byte *sp, G *g)
{
Stktop *stk;
uint64 pc;
int32 i, n;
Func *f;
pc = (uint64)pc0;
// If the PC is zero, it's likely a nil function call.
// Start in the caller's frame.
if(pc == 0) {
pc = *(uint64*)sp;
sp += 8;
}
stk = (Stktop*)g->stackbase;
for(n=0; n<100; n++) {
while(pc == (uint64)retfromnewstack) {
// pop to earlier stack block
sp = stk->oldsp;
stk = (Stktop*)stk->oldbase;
pc = *(uint64*)(sp+8);
sp += 16; // two irrelevant calls on stack: morestack plus its call
}
f = findfunc(pc);
if(f == nil) {
printf("%p unknown pc\n", pc);
return;
}
if(f->frame < 8) // assembly funcs say 0 but lie
sp += 8;
else
sp += f->frame;
// print this frame
// main+0xf /home/rsc/go/src/runtime/x.go:23
// main(0x1, 0x2, 0x3)
printf("%S", f->name);
if(pc > f->entry)
printf("+%X", pc - f->entry);
printf(" %S:%d\n", f->src, funcline(f, pc-1)); // -1 to get to CALL instr.
printf("\t%S(", f->name);
for(i = 0; i < f->args; i++) {
if(i != 0)
prints(", ");
sys·printhex(((uint32*)sp)[i]);
if(i >= 4) {
prints(", ...");
break;
}
}
prints(")\n");
pc = *(uint64*)(sp-8);
if(pc <= 0x1000)
return;
}
prints("...\n");
}
// func caller(n int) (pc uint64, file string, line int, ok bool)
void
sys·caller(int32 n, uint64 retpc, string retfile, int32 retline, bool retbool)
{
uint64 pc;
byte *sp;
Stktop *stk;
Func *f;
// our caller's pc, sp.
sp = (byte*)&n;
pc = *(uint64*)(sp-8);
if((f = findfunc(pc)) == nil) {
error:
retpc = 0;
retline = 0;
retfile = nil;
retbool = false;
FLUSH(&retpc);
FLUSH(&retfile);
FLUSH(&retline);
FLUSH(&retbool);
return;
}
// now unwind n levels
stk = (Stktop*)g->stackbase;
while(n-- > 0) {
while(pc == (uint64)retfromnewstack) {
sp = stk->oldsp;
stk = (Stktop*)stk->oldbase;
pc = *(uint64*)(sp+8);
sp += 16;
}
if(f->frame < 8) // assembly functions lie
sp += 8;
else
sp += f->frame;
pc = *(uint64*)(sp-8);
if(pc <= 0x1000 || (f = findfunc(pc)) == nil)
goto error;
}
retpc = pc;
retfile = f->src;
retline = funcline(f, pc-1);
retbool = true;
FLUSH(&retpc);
FLUSH(&retfile);
FLUSH(&retline);
FLUSH(&retbool);
}
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