circuitpython/py/nlrx86.c
Damien George c97607db5c py/nlrx86: Use naked attribute on nlr_push for gcc 8.0 and higher.
gcc 8.0 supports the naked attribute for x86 systems so it can now be used
here.  And in fact it is necessary to use this for nlr_push because gcc 8.0
no longer generates a prelude for this function (even without the naked
attribute).
2018-05-15 11:17:28 +10:00

107 lines
3.7 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2017 Damien P. George
*
* 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 "py/mpstate.h"
#if MICROPY_NLR_X86
#undef nlr_push
// For reference, x86 callee save regs are:
// ebx, esi, edi, ebp, esp, eip
#if MICROPY_NLR_OS_WINDOWS
unsigned int nlr_push_tail(nlr_buf_t *nlr) asm("nlr_push_tail");
#else
__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr);
#endif
#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 8
// Since gcc 8.0 the naked attribute is supported
#define USE_NAKED (1)
#define UNDO_PRELUDE (0)
#elif defined(__ZEPHYR__) || defined(__ANDROID__)
// Zephyr and Android use a different calling convention by default
#define USE_NAKED (0)
#define UNDO_PRELUDE (0)
#else
#define USE_NAKED (0)
#define UNDO_PRELUDE (1)
#endif
#if USE_NAKED
__attribute__((naked))
#endif
unsigned int nlr_push(nlr_buf_t *nlr) {
#if !USE_NAKED
(void)nlr;
#endif
__asm volatile (
#if UNDO_PRELUDE
"pop %ebp \n" // undo function's prelude
#endif
"mov 4(%esp), %edx \n" // load nlr_buf
"mov (%esp), %eax \n" // load return %eip
"mov %eax, 8(%edx) \n" // store %eip into nlr_buf
"mov %ebp, 12(%edx) \n" // store %ebp into nlr_buf
"mov %esp, 16(%edx) \n" // store %esp into nlr_buf
"mov %ebx, 20(%edx) \n" // store %ebx into nlr_buf
"mov %edi, 24(%edx) \n" // store %edi into nlr_buf
"mov %esi, 28(%edx) \n" // store %esi into nlr_buf
"jmp nlr_push_tail \n" // do the rest in C
);
#if !USE_NAKED
return 0; // needed to silence compiler warning
#endif
}
NORETURN void nlr_jump(void *val) {
MP_NLR_JUMP_HEAD(val, top)
__asm volatile (
"mov %0, %%edx \n" // %edx points to nlr_buf
"mov 28(%%edx), %%esi \n" // load saved %esi
"mov 24(%%edx), %%edi \n" // load saved %edi
"mov 20(%%edx), %%ebx \n" // load saved %ebx
"mov 16(%%edx), %%esp \n" // load saved %esp
"mov 12(%%edx), %%ebp \n" // load saved %ebp
"mov 8(%%edx), %%eax \n" // load saved %eip
"mov %%eax, (%%esp) \n" // store saved %eip to stack
"xor %%eax, %%eax \n" // clear return register
"inc %%al \n" // increase to make 1, non-local return
"ret \n" // return
: // output operands
: "r"(top) // input operands
: // clobbered registers
);
for (;;); // needed to silence compiler warning
}
#endif // MICROPY_NLR_X86