6a3a742a6c
Each NLR implementation (Thumb, x86, x64, xtensa, setjmp) duplicates a lot of the NLR code, specifically that dealing with pushing and popping the NLR pointer to maintain the linked-list of NLR buffers. This patch factors all of that code out of the specific implementations into generic functions in nlr.c. This eliminates duplicated code. The factoring also allows to make the machine-specific NLR code pure assembler code, thus allowing nlrthumb.c to use naked function attributes in the correct way (naked functions can only have basic inline assembler code in them). There is a small overhead introduced (typically 1 machine instruction) because now the generic nlr_jump() must call nlr_jump_tail() rather than them being one combined function.
75 lines
2.6 KiB
C
75 lines
2.6 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2013-2017 Damien P. George
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "py/mpstate.h"
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// Helper macros to save/restore the pystack state
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#if MICROPY_ENABLE_PYSTACK
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#define MP_NLR_SAVE_PYSTACK(nlr_buf) (nlr_buf)->pystack = MP_STATE_THREAD(pystack_cur)
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#define MP_NLR_RESTORE_PYSTACK(nlr_buf) MP_STATE_THREAD(pystack_cur) = (nlr_buf)->pystack
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#else
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#define MP_NLR_SAVE_PYSTACK(nlr_buf) (void)nlr_buf
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#define MP_NLR_RESTORE_PYSTACK(nlr_buf) (void)nlr_buf
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#endif
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#if !MICROPY_NLR_SETJMP
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// When not using setjmp, nlr_push_tail is called from inline asm so needs special care
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#if MICROPY_NLR_X86 && (defined(_WIN32) || defined(__CYGWIN__))
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// On these 32-bit platforms make sure nlr_push_tail doesn't have a leading underscore
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unsigned int nlr_push_tail(nlr_buf_t *nlr) asm("nlr_push_tail");
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#else
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// LTO can't see inside inline asm functions so explicitly mark nlr_push_tail as used
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__attribute__((used)) unsigned int nlr_push_tail(nlr_buf_t *nlr);
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#endif
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#endif
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unsigned int nlr_push_tail(nlr_buf_t *nlr) {
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nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
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nlr->prev = *top;
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MP_NLR_SAVE_PYSTACK(nlr);
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*top = nlr;
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return 0; // normal return
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}
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void nlr_pop(void) {
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nlr_buf_t **top = &MP_STATE_THREAD(nlr_top);
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*top = (*top)->prev;
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}
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NORETURN void nlr_jump(void *val) {
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nlr_buf_t **top_ptr = &MP_STATE_THREAD(nlr_top);
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nlr_buf_t *top = *top_ptr;
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if (top == NULL) {
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nlr_jump_fail(val);
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}
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top->ret_val = val;
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MP_NLR_RESTORE_PYSTACK(top);
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*top_ptr = top->prev;
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nlr_jump_tail(top);
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}
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