mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
65 lines
2.1 KiB
C
65 lines
2.1 KiB
C
/*
|
|
* QuickJS Javascript Engine
|
|
*
|
|
* Copyright (c) 2017-2021 Fabrice Bellard
|
|
* Copyright (c) 2017-2021 Charlie Gordon
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
#include "libc/intrin/likely.h"
|
|
#include "third_party/quickjs/leb128.h"
|
|
|
|
asm(".ident\t\"\\n\\n\
|
|
QuickJS (MIT License)\\n\
|
|
Copyright (c) 2017-2021 Fabrice Bellard\\n\
|
|
Copyright (c) 2017-2021 Charlie Gordon\"");
|
|
asm(".include \"libc/disclaimer.inc\"");
|
|
/* clang-format off */
|
|
|
|
int get_leb128(uint32_t *pval, const uint8_t *buf, const uint8_t *buf_end)
|
|
{
|
|
const uint8_t *ptr = buf;
|
|
uint32_t v, a, i;
|
|
v = 0;
|
|
for(i = 0; i < 5; i++) {
|
|
if (UNLIKELY(ptr >= buf_end))
|
|
break;
|
|
a = *ptr++;
|
|
v |= (a & 0x7f) << (i * 7);
|
|
if (!(a & 0x80)) {
|
|
*pval = v;
|
|
return ptr - buf;
|
|
}
|
|
}
|
|
*pval = 0;
|
|
return -1;
|
|
}
|
|
|
|
int get_sleb128(int32_t *pval, const uint8_t *buf, const uint8_t *buf_end)
|
|
{
|
|
int ret;
|
|
uint32_t val;
|
|
ret = get_leb128(&val, buf, buf_end);
|
|
if (ret < 0) {
|
|
*pval = 0;
|
|
return -1;
|
|
}
|
|
*pval = (val >> 1) ^ -(val & 1);
|
|
return ret;
|
|
}
|