1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2013, 2014 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#ifndef MICROPY_INCLUDED_PY_NLR_H
27#define MICROPY_INCLUDED_PY_NLR_H
28
29// non-local return
30// exception handling, basically a stack of setjmp/longjmp buffers
31
32#include <limits.h>
33#include <assert.h>
34
35#include "py/mpconfig.h"
36
37#define MICROPY_NLR_NUM_REGS_X86 (6)
38#define MICROPY_NLR_NUM_REGS_X64 (8)
39#define MICROPY_NLR_NUM_REGS_X64_WIN (10)
40#define MICROPY_NLR_NUM_REGS_ARM_THUMB (10)
41#define MICROPY_NLR_NUM_REGS_ARM_THUMB_FP (10 + 6)
42#define MICROPY_NLR_NUM_REGS_AARCH64 (13)
43#define MICROPY_NLR_NUM_REGS_XTENSA (10)
44#define MICROPY_NLR_NUM_REGS_XTENSAWIN (17)
45
46// *FORMAT-OFF*
47
48// If MICROPY_NLR_SETJMP is not enabled then auto-detect the machine arch
49#if !MICROPY_NLR_SETJMP
50// A lot of nlr-related things need different treatment on Windows
51#if defined(_WIN32) || defined(__CYGWIN__)
52#define MICROPY_NLR_OS_WINDOWS 1
53#else
54#define MICROPY_NLR_OS_WINDOWS 0
55#endif
56#if defined(__i386__)
57 #define MICROPY_NLR_X86 (1)
58 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_X86)
59#elif defined(__x86_64__)
60 #define MICROPY_NLR_X64 (1)
61 #if MICROPY_NLR_OS_WINDOWS
62 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_X64_WIN)
63 #else
64 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_X64)
65 #endif
66#elif defined(__thumb2__) || defined(__thumb__) || defined(__arm__)
67 #define MICROPY_NLR_THUMB (1)
68 #if defined(__SOFTFP__)
69 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_ARM_THUMB)
70 #else
71 // With hardware FP registers s16-s31 are callee save so in principle
72 // should be saved and restored by the NLR code. gcc only uses s16-s21
73 // so only save/restore those as an optimisation.
74 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_ARM_THUMB_FP)
75 #endif
76#elif defined(__aarch64__)
77 #define MICROPY_NLR_AARCH64 (1)
78 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_AARCH64)
79#elif defined(__xtensa__)
80 #define MICROPY_NLR_XTENSA (1)
81 #define MICROPY_NLR_NUM_REGS (MICROPY_NLR_NUM_REGS_XTENSA)
82#elif defined(__powerpc__)
83 #define MICROPY_NLR_POWERPC (1)
84 // this could be less but using 128 for safety
85 #define MICROPY_NLR_NUM_REGS (128)
86#else
87 #define MICROPY_NLR_SETJMP (1)
88 //#warning "No native NLR support for this arch, using setjmp implementation"
89#endif
90#endif
91
92// *FORMAT-ON*
93
94#if MICROPY_NLR_SETJMP
95#include <setjmp.h>
96#endif
97
98typedef struct _nlr_buf_t nlr_buf_t;
99struct _nlr_buf_t {
100 // the entries here must all be machine word size
101 nlr_buf_t *prev;
102 void *ret_val; // always a concrete object (an exception instance)
103
104 #if MICROPY_NLR_SETJMP
105 jmp_buf jmpbuf;
106 #else
107 void *regs[MICROPY_NLR_NUM_REGS];
108 #endif
109
110 #if MICROPY_ENABLE_PYSTACK
111 void *pystack;
112 #endif
113};
114
115// Helper macros to save/restore the pystack state
116#if MICROPY_ENABLE_PYSTACK
117#define MP_NLR_SAVE_PYSTACK(nlr_buf) (nlr_buf)->pystack = MP_STATE_THREAD(pystack_cur)
118#define MP_NLR_RESTORE_PYSTACK(nlr_buf) MP_STATE_THREAD(pystack_cur) = (nlr_buf)->pystack
119#else
120#define MP_NLR_SAVE_PYSTACK(nlr_buf) (void)nlr_buf
121#define MP_NLR_RESTORE_PYSTACK(nlr_buf) (void)nlr_buf
122#endif
123
124// Helper macro to use at the start of a specific nlr_jump implementation
125#define MP_NLR_JUMP_HEAD(val, top) \
126 nlr_buf_t **_top_ptr = &MP_STATE_THREAD(nlr_top); \
127 nlr_buf_t *top = *_top_ptr; \
128 if (top == NULL) { \
129 nlr_jump_fail(val); \
130 } \
131 top->ret_val = val; \
132 MP_NLR_RESTORE_PYSTACK(top); \
133 *_top_ptr = top->prev; \
134
135#if MICROPY_NLR_SETJMP
136// nlr_push() must be defined as a macro, because "The stack context will be
137// invalidated if the function which called setjmp() returns."
138// For this case it is safe to call nlr_push_tail() first.
139#define nlr_push(buf) (nlr_push_tail(buf), setjmp((buf)->jmpbuf))
140#else
141unsigned int nlr_push(nlr_buf_t *);
142#endif
143
144unsigned int nlr_push_tail(nlr_buf_t *top);
145void nlr_pop(void);
146NORETURN void nlr_jump(void *val);
147
148// This must be implemented by a port. It's called by nlr_jump
149// if no nlr buf has been pushed. It must not return, but rather
150// should bail out with a fatal error.
151NORETURN void nlr_jump_fail(void *val);
152
153// use nlr_raise instead of nlr_jump so that debugging is easier
154#ifndef MICROPY_DEBUG_NLR
155#define nlr_raise(val) nlr_jump(MP_OBJ_TO_PTR(val))
156#else
157#include "mpstate.h"
158#define nlr_raise(val) \
159 do { \
160 /*printf("nlr_raise: nlr_top=%p\n", MP_STATE_THREAD(nlr_top)); \
161 fflush(stdout);*/ \
162 void *_val = MP_OBJ_TO_PTR(val); \
163 assert(_val != NULL); \
164 assert(mp_obj_is_exception_instance(val)); \
165 nlr_jump(_val); \
166 } while (0)
167
168#if !MICROPY_NLR_SETJMP
169#define nlr_push(val) \
170 assert(MP_STATE_THREAD(nlr_top) != val),nlr_push(val)
171
172/*
173#define nlr_push(val) \
174 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)
175*/
176#endif
177
178#endif
179
180#endif // MICROPY_INCLUDED_PY_NLR_H
181