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.
81 lines
3.1 KiB
C
81 lines
3.1 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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#if MICROPY_NLR_X86
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#undef nlr_push
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// For reference, x86 callee save regs are:
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// ebx, esi, edi, ebp, esp, eip
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unsigned int nlr_push(nlr_buf_t *nlr) {
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(void)nlr;
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__asm volatile (
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// Check for Zephyr, which uses a different calling convention
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// by default.
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// TODE: Better support for various x86 calling conventions
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// (unfortunately, __attribute__((naked)) is not supported on x86).
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#if !(defined(__ZEPHYR__) || defined(__ANDROID__))
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"pop %ebp \n" // undo function's prelude
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#endif
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"mov 4(%esp), %edx \n" // load nlr_buf
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"mov (%esp), %eax \n" // load return %eip
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"mov %eax, 8(%edx) \n" // store %eip into nlr_buf
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"mov %ebp, 12(%edx) \n" // store %ebp into nlr_buf
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"mov %esp, 16(%edx) \n" // store %esp into nlr_buf
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"mov %ebx, 20(%edx) \n" // store %ebx into nlr_buf
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"mov %edi, 24(%edx) \n" // store %edi into nlr_buf
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"mov %esi, 28(%edx) \n" // store %esi into nlr_buf
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"jmp nlr_push_tail \n" // do the rest in C
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);
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return 0; // needed to silence compiler warning
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}
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NORETURN void nlr_jump_tail(nlr_buf_t *top) {
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(void)top;
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__asm volatile (
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"mov 28(%edx), %esi \n" // load saved %esi
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"mov 24(%edx), %edi \n" // load saved %edi
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"mov 20(%edx), %ebx \n" // load saved %ebx
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"mov 16(%edx), %esp \n" // load saved %esp
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"mov 12(%edx), %ebp \n" // load saved %ebp
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"mov 8(%edx), %eax \n" // load saved %eip
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"mov %eax, (%esp) \n" // store saved %eip to stack
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"xor %eax, %eax \n" // clear return register
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"inc %al \n" // increase to make 1, non-local return
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"ret \n" // return
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);
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for (;;); // needed to silence compiler warning
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}
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#endif // MICROPY_NLR_X86
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