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| 1 | +/* |
| 2 | + * This file is part of the MicroPython project, http://micropython.org/ |
| 3 | + * |
| 4 | + * The MIT License (MIT) |
| 5 | + * |
| 6 | + * Copyright (c) 2013-2017 Damien P. George |
| 7 | + * |
| 8 | + * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 9 | + * of this software and associated documentation files (the "Software"), to deal |
| 10 | + * in the Software without restriction, including without limitation the rights |
| 11 | + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 12 | + * copies of the Software, and to permit persons to whom the Software is |
| 13 | + * furnished to do so, subject to the following conditions: |
| 14 | + * |
| 15 | + * The above copyright notice and this permission notice shall be included in |
| 16 | + * all copies or substantial portions of the Software. |
| 17 | + * |
| 18 | + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 19 | + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 20 | + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 21 | + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 22 | + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 23 | + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 24 | + * THE SOFTWARE. |
| 25 | + */ |
| 26 | + |
| 27 | +#include "py/mpstate.h" |
| 28 | +#include "py/nlr.h" |
| 29 | + |
| 30 | +#if !MICROPY_NLR_SETJMP && defined(__i386__) |
| 31 | + |
| 32 | +#undef nlr_push |
| 33 | + |
| 34 | +// For reference, x86 callee save regs are: |
| 35 | +// ebx, esi, edi, ebp, esp, eip |
| 36 | + |
| 37 | +#define NLR_OS_WINDOWS (defined(_WIN32) || defined(__CYGWIN__)) |
| 38 | + |
| 39 | +#if NLR_OS_WINDOWS |
| 40 | +unsigned int nlr_push_tail(nlr_buf_t *nlr) asm("nlr_push_tail"); |
| 41 | +#else |
| 42 | +__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr); |
| 43 | +#endif |
| 44 | + |
| 45 | +unsigned int nlr_push(nlr_buf_t *nlr) { |
| 46 | + (void)nlr; |
| 47 | + |
| 48 | + __asm volatile ( |
| 49 | + "pop %ebp \n" // undo function's prelude |
| 50 | + "mov 4(%esp), %edx \n" // load nlr_buf |
| 51 | + "mov (%esp), %eax \n" // load return %eip |
| 52 | + "mov %eax, 8(%edx) \n" // store %eip into nlr_buf |
| 53 | + "mov %ebp, 12(%edx) \n" // store %ebp into nlr_buf |
| 54 | + "mov %esp, 16(%edx) \n" // store %esp into nlr_buf |
| 55 | + "mov %ebx, 20(%edx) \n" // store %ebx into nlr_buf |
| 56 | + "mov %edi, 24(%edx) \n" // store %edi into nlr_buf |
| 57 | + "mov %esi, 28(%edx) \n" // store %esi into nlr_buf |
| 58 | + "jmp nlr_push_tail \n" // do the rest in C |
| 59 | + ); |
| 60 | + |
| 61 | + return 0; // needed to silence compiler warning |
| 62 | +} |
| 63 | + |
| 64 | +__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr) { |
| 65 | + nlr_buf_t **top = &MP_STATE_THREAD(nlr_top); |
| 66 | + nlr->prev = *top; |
| 67 | + *top = nlr; |
| 68 | + return 0; // normal return |
| 69 | +} |
| 70 | + |
| 71 | +void nlr_pop(void) { |
| 72 | + nlr_buf_t **top = &MP_STATE_THREAD(nlr_top); |
| 73 | + *top = (*top)->prev; |
| 74 | +} |
| 75 | + |
| 76 | +NORETURN void nlr_jump(void *val) { |
| 77 | + nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top); |
| 78 | + nlr_buf_t *top = *top_ptr; |
| 79 | + if (top == NULL) { |
| 80 | + nlr_jump_fail(val); |
| 81 | + } |
| 82 | + |
| 83 | + top->ret_val = val; |
| 84 | + *top_ptr = top->prev; |
| 85 | + |
| 86 | + __asm volatile ( |
| 87 | + "mov %0, %%edx \n" // %edx points to nlr_buf |
| 88 | + "mov 28(%%edx), %%esi \n" // load saved %esi |
| 89 | + "mov 24(%%edx), %%edi \n" // load saved %edi |
| 90 | + "mov 20(%%edx), %%ebx \n" // load saved %ebx |
| 91 | + "mov 16(%%edx), %%esp \n" // load saved %esp |
| 92 | + "mov 12(%%edx), %%ebp \n" // load saved %ebp |
| 93 | + "mov 8(%%edx), %%eax \n" // load saved %eip |
| 94 | + "mov %%eax, (%%esp) \n" // store saved %eip to stack |
| 95 | + "xor %%eax, %%eax \n" // clear return register |
| 96 | + "inc %%al \n" // increase to make 1, non-local return |
| 97 | + "ret \n" // return |
| 98 | + : // output operands |
| 99 | + : "r"(top) // input operands |
| 100 | + : // clobbered registers |
| 101 | + ); |
| 102 | + |
| 103 | + for (;;); // needed to silence compiler warning |
| 104 | +} |
| 105 | + |
| 106 | +#endif // !MICROPY_NLR_SETJMP && defined(__i386__) |
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