gcc/libgo/runtime/go-panic.c
Ian Lance Taylor 75791bab05 runtime: use -fgo-c-header to build C header file
Use the new -fgo-c-header option to build a header file for the Go
    runtime code in libgo/go/runtime, and use the new header file in the C
    runtime code in libgo/runtime.  This will ensure that the Go code and C
    code share the same data structures as we convert the runtime from C to
    Go.
    
    The new file libgo/go/runtime/runtime2.go is copied from the Go 1.7
    release, and then edited to remove unnecessary data structures and
    modify others for use with libgo.
    
    The new file libgo/go/runtime/mcache.go is an initial version of the
    same files in the Go 1.7 release, and will be replaced by the Go 1.7
    file when we convert to the new memory allocator.
    
    The new file libgo/go/runtime/type.go describes the gccgo version of the
    reflection data structures, and replaces the Go 1.7 runtime file which
    describes the gc version of those structures.
    
    Using the new header file means changing a number of struct fields to
    use Go naming conventions (that is, no underscores) and to rename
    constants to have a leading underscore so that they are not exported
    from the Go package.  These names were updated in the C code.
    
    The C code was also changed to drop the thread-local variable m, as was
    done some time ago in the gc sources.  Now the m field is always
    accessed using g->m, where g is the single remaining thread-local
    variable.  This in turn required some adjustments to set g->m correctly
    in all cases.
    
    Also pass the new -fgo-compiling-runtime option when compiling the
    runtime package, although that option doesn't do anything yet.
    
    Reviewed-on: https://go-review.googlesource.com/28051

From-SVN: r239872
2016-08-30 21:07:47 +00:00

112 lines
2.5 KiB
C

/* 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-panic.h"
#include "interface.h"
/* Print the panic stack. This is used when there is no recover. */
static void
__printpanics (Panic *p)
{
if (p->next != NULL)
{
__printpanics (p->next);
runtime_printf ("\t");
}
runtime_printf ("panic: ");
runtime_printany (p->arg);
if (p->recovered)
runtime_printf (" [recovered]");
runtime_printf ("\n");
}
/* This implements __go_panic which is used for the panic
function. */
void
__go_panic (struct __go_empty_interface arg)
{
G *g;
Panic *n;
g = runtime_g ();
n = (Panic *) __go_alloc (sizeof (Panic));
n->arg = arg;
n->next = g->_panic;
g->_panic = n;
/* Run all the defer functions. */
while (1)
{
Defer *d;
void (*pfn) (void *);
d = g->_defer;
if (d == NULL)
break;
pfn = (void (*) (void *)) d->pfn;
d->pfn = 0;
if (pfn != NULL)
{
(*pfn) (d->arg);
if (n->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);
}