circuitpython/py/nlr.h
Damien George b25f92160b py/nlr: Factor out common NLR code to macro and generic funcs in nlr.c.
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, along with a helper macro in nlr.h.  This eliminates duplicated
code.
2017-12-28 16:46:30 +11:00

148 lines
4.7 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 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.
*/
#ifndef MICROPY_INCLUDED_PY_NLR_H
#define MICROPY_INCLUDED_PY_NLR_H
// non-local return
// exception handling, basically a stack of setjmp/longjmp buffers
#include <limits.h>
#include <assert.h>
#include "py/mpconfig.h"
// If MICROPY_NLR_SETJMP is not enabled then auto-detect the machine arch
#if !MICROPY_NLR_SETJMP
#if defined(__i386__)
#define MICROPY_NLR_X86 (1)
#define MICROPY_NLR_NUM_REGS (6)
#elif defined(__x86_64__)
#define MICROPY_NLR_X64 (1)
#if defined(__CYGWIN__)
#define MICROPY_NLR_NUM_REGS (12)
#else
#define MICROPY_NLR_NUM_REGS (8)
#endif
#elif defined(__thumb2__) || defined(__thumb__) || defined(__arm__)
#define MICROPY_NLR_THUMB (1)
#define MICROPY_NLR_NUM_REGS (10)
#elif defined(__xtensa__)
#define MICROPY_NLR_XTENSA (1)
#define MICROPY_NLR_NUM_REGS (10)
#else
#define MICROPY_NLR_SETJMP (1)
//#warning "No native NLR support for this arch, using setjmp implementation"
#endif
#endif
#if MICROPY_NLR_SETJMP
#include <setjmp.h>
#endif
typedef struct _nlr_buf_t nlr_buf_t;
struct _nlr_buf_t {
// the entries here must all be machine word size
nlr_buf_t *prev;
void *ret_val; // always a concrete object (an exception instance)
#if MICROPY_NLR_SETJMP
jmp_buf jmpbuf;
#else
void *regs[MICROPY_NLR_NUM_REGS];
#endif
#if MICROPY_ENABLE_PYSTACK
void *pystack;
#endif
};
// Helper macros to save/restore the pystack state
#if MICROPY_ENABLE_PYSTACK
#define MP_NLR_SAVE_PYSTACK(nlr_buf) (nlr_buf)->pystack = MP_STATE_THREAD(pystack_cur)
#define MP_NLR_RESTORE_PYSTACK(nlr_buf) MP_STATE_THREAD(pystack_cur) = (nlr_buf)->pystack
#else
#define MP_NLR_SAVE_PYSTACK(nlr_buf) (void)nlr_buf
#define MP_NLR_RESTORE_PYSTACK(nlr_buf) (void)nlr_buf
#endif
// Helper macro to use at the start of a specific nlr_jump implementation
#define MP_NLR_JUMP_HEAD(val, top) \
nlr_buf_t **_top_ptr = &MP_STATE_THREAD(nlr_top); \
nlr_buf_t *top = *_top_ptr; \
if (top == NULL) { \
nlr_jump_fail(val); \
} \
top->ret_val = val; \
MP_NLR_RESTORE_PYSTACK(top); \
*_top_ptr = top->prev; \
#if MICROPY_NLR_SETJMP
// nlr_push() must be defined as a macro, because "The stack context will be
// invalidated if the function which called setjmp() returns."
// For this case it is safe to call nlr_push_tail() first.
#define nlr_push(buf) (nlr_push_tail(buf), setjmp((buf)->jmpbuf))
#else
unsigned int nlr_push(nlr_buf_t *);
#endif
unsigned int nlr_push_tail(nlr_buf_t *top);
void nlr_pop(void);
NORETURN void nlr_jump(void *val);
// This must be implemented by a port. It's called by nlr_jump
// if no nlr buf has been pushed. It must not return, but rather
// should bail out with a fatal error.
NORETURN void nlr_jump_fail(void *val);
// use nlr_raise instead of nlr_jump so that debugging is easier
#ifndef MICROPY_DEBUG_NLR
#define nlr_raise(val) nlr_jump(MP_OBJ_TO_PTR(val))
#else
#include "mpstate.h"
#define nlr_raise(val) \
do { \
/*printf("nlr_raise: nlr_top=%p\n", MP_STATE_THREAD(nlr_top)); \
fflush(stdout);*/ \
void *_val = MP_OBJ_TO_PTR(val); \
assert(_val != NULL); \
assert(mp_obj_is_exception_instance(val)); \
nlr_jump(_val); \
} while (0)
#if !MICROPY_NLR_SETJMP
#define nlr_push(val) \
assert(MP_STATE_THREAD(nlr_top) != val),nlr_push(val)
/*
#define nlr_push(val) \
printf("nlr_push: before: nlr_top=%p, val=%p\n", MP_STATE_THREAD(nlr_top), val),assert(MP_STATE_THREAD(nlr_top) != val),nlr_push(val)
*/
#endif
#endif
#endif // MICROPY_INCLUDED_PY_NLR_H