cosmopolitan/libc/mem/defer.greg.c
2021-08-19 09:34:24 -07:00

69 lines
3.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/likely.h"
#include "libc/calls/calls.h"
#include "libc/mem/mem.h"
#include "libc/nexgen32e/gc.internal.h"
#include "libc/runtime/gc.internal.h"
#include "libc/runtime/runtime.h"
forceinline bool PointerNotOwnedByParentStackFrame(struct StackFrame *frame,
struct StackFrame *parent,
void *ptr) {
return !(((intptr_t)ptr > (intptr_t)frame) &&
((intptr_t)ptr < (intptr_t)parent));
}
void __deferer(struct StackFrame *frame, void *fn, void *arg) {
size_t n2;
struct Garbage *p2;
if (UNLIKELY(__garbage.i == __garbage.n)) {
n2 = __garbage.n + (__garbage.n >> 1);
p2 = malloc(n2 * sizeof(*__garbage.p));
memcpy(p2, __garbage.p, __garbage.n * sizeof(*__garbage.p));
if (__garbage.p != __garbage.initmem) free(__garbage.p);
__garbage.p = p2;
__garbage.n = n2;
}
__garbage.p[__garbage.i].frame = frame;
__garbage.p[__garbage.i].fn = (intptr_t)fn;
__garbage.p[__garbage.i].arg = (intptr_t)arg;
__garbage.p[__garbage.i].ret = frame->addr;
__garbage.i++;
frame->addr = (intptr_t)__gc;
}
/**
* Adds destructor to garbage shadow stack.
*
* @param frame is passed automatically by wrapper macro
* @param fn takes one argument
* @param arg is passed to fn(arg)
* @return arg
*/
void __defer(struct StackFrame *frame, void *fn, void *arg) {
struct StackFrame *f2;
if (!arg) return;
f2 = __builtin_frame_address(0);
assert(__garbage.n);
assert(f2->next == frame);
assert(PointerNotOwnedByParentStackFrame(f2, frame, arg));
__deferer(frame, fn, arg);
}