blob: 77975c6e083a29fa01a890e94bcf591a87940d14 [file] [log] [blame]
/* go-panic.c -- support for the go panic function.
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 <stdio.h>
#include <stdlib.h>
#include "runtime.h"
#include "arch.h"
#include "malloc.h"
#include "go-alloc.h"
#include "go-defer.h"
#include "go-panic.h"
#include "interface.h"
/* Print the panic stack. This is used when there is no recover. */
static void
__printpanics (struct __go_panic_stack *p)
if (p->__next != NULL)
__printpanics (p->__next);
runtime_printf ("\t");
runtime_printf ("panic: ");
runtime_printany (p->__arg);
if (p->__was_recovered)
runtime_printf (" [recovered]");
runtime_printf ("\n");
/* This implements __go_panic which is used for the panic
function. */
__go_panic (struct __go_empty_interface arg)
G *g;
struct __go_panic_stack *n;
g = runtime_g ();
n = (struct __go_panic_stack *) __go_alloc (sizeof (struct __go_panic_stack));
n->__arg = arg;
n->__next = g->panic;
g->panic = n;
/* Run all the defer functions. */
while (1)
struct __go_defer_stack *d;
void (*pfn) (void *);
d = g->defer;
if (d == NULL)
pfn = d->__pfn;
d->__pfn = NULL;
if (pfn != NULL)
(*pfn) (d->__arg);
if (n->__was_recovered)
/* Some defer function called recover. That means that
we should stop running this panic. */
g->panic = n->__next;
__go_free (n);
/* Now unwind the stack by throwing an exception. The
compiler has arranged to create exception handlers in
each function which uses a defer statement. These
exception handlers will check whether the entry on
the top of the defer stack is from the current
function. If it is, we have unwound the stack far
enough. */
__go_unwind_stack ();
/* __go_unwind_stack should not return. */
abort ();
/* Because we executed that defer function by a panic, and
it did not call recover, we know that we are not
returning from the calling function--we are panicing
through it. */
*d->__frame = 0;
g->defer = d->__next;
/* This may be called by a cgo callback routine to defer the
call to syscall.CgocallBackDone, in which case we will not
have a memory context. Don't try to free anything in that
case--the GC will release it later. */
if (runtime_m () != NULL)
runtime_freedefer (d);
/* The panic was not recovered. */
runtime_startpanic ();
__printpanics (g->panic);
runtime_dopanic (0);