mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
33e8fc8687
You can now do epic things like this:
puts(_gc(xasprintf("%d", 123)));
The _gc() API is shorthand for _defer() which works like Go's keyword:
const char *s = xasprintf("%d", 123);
_defer(free, s);
puts(s);
Be sure to always use -fno-omit-frame-pointer which makes code fast too.
Enjoy! See also #114
69 lines
3.4 KiB
C
69 lines
3.4 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/assert.h"
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#include "libc/bits/likely.h"
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#include "libc/calls/calls.h"
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#include "libc/mem/mem.h"
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#include "libc/nexgen32e/gc.internal.h"
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#include "libc/runtime/gc.internal.h"
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#include "libc/runtime/runtime.h"
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forceinline bool PointerNotOwnedByParentStackFrame(struct StackFrame *frame,
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struct StackFrame *parent,
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void *ptr) {
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return !(((intptr_t)ptr > (intptr_t)frame) &&
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((intptr_t)ptr < (intptr_t)parent));
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}
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void __deferer(struct StackFrame *frame, void *fn, void *arg) {
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size_t n2;
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struct Garbage *p2;
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if (UNLIKELY(__garbage.i == __garbage.n)) {
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n2 = __garbage.n + (__garbage.n >> 1);
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p2 = malloc(n2 * sizeof(*__garbage.p));
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memcpy(p2, __garbage.p, __garbage.n * sizeof(*__garbage.p));
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if (__garbage.p != __garbage.initmem) free(__garbage.p);
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__garbage.p = p2;
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__garbage.n = n2;
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}
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__garbage.p[__garbage.i].frame = frame->next;
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__garbage.p[__garbage.i].fn = (intptr_t)fn;
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__garbage.p[__garbage.i].arg = (intptr_t)arg;
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__garbage.p[__garbage.i].ret = frame->addr;
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__garbage.i++;
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frame->addr = (intptr_t)__gc;
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}
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/**
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* Adds destructor to garbage shadow stack.
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*
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* @param frame is passed automatically by wrapper macro
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* @param fn takes one argument
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* @param arg is passed to fn(arg)
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* @return arg
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*/
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void __defer(struct StackFrame *frame, void *fn, void *arg) {
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struct StackFrame *f2;
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if (!arg) return;
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f2 = __builtin_frame_address(0);
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assert(__garbage.n);
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assert(f2->next == frame);
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assert(PointerNotOwnedByParentStackFrame(f2, frame, arg));
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__deferer(frame, fn, arg);
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}
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