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
27#include <stdio.h>
28
29#include "py/mpstate.h"
30#include "py/gc.h"
31#include "lib/utils/gchelper.h"
32
33#if MICROPY_ENABLE_GC
34
35// Even if we have specific support for an architecture, it is
36// possible to force use of setjmp-based implementation.
37#if !MICROPY_GCREGS_SETJMP
38
39// We capture here callee-save registers, i.e. ones which may contain
40// interesting values held there by our callers. It doesn't make sense
41// to capture caller-saved registers, because they, well, put on the
42// stack already by the caller.
43#if defined(__x86_64__)
44
45STATIC void gc_helper_get_regs(gc_helper_regs_t arr) {
46 register long rbx asm ("rbx");
47 register long rbp asm ("rbp");
48 register long r12 asm ("r12");
49 register long r13 asm ("r13");
50 register long r14 asm ("r14");
51 register long r15 asm ("r15");
52 #ifdef __clang__
53 // TODO:
54 // This is dirty workaround for Clang. It tries to get around
55 // uncompliant (wrt to GCC) behavior of handling register variables.
56 // Application of this patch here is random, and done only to unbreak
57 // MacOS build. Better, cross-arch ways to deal with Clang issues should
58 // be found.
59 asm ("" : "=r" (rbx));
60 asm ("" : "=r" (rbp));
61 asm ("" : "=r" (r12));
62 asm ("" : "=r" (r13));
63 asm ("" : "=r" (r14));
64 asm ("" : "=r" (r15));
65 #endif
66 arr[0] = rbx;
67 arr[1] = rbp;
68 arr[2] = r12;
69 arr[3] = r13;
70 arr[4] = r14;
71 arr[5] = r15;
72}
73
74#elif defined(__i386__)
75
76STATIC void gc_helper_get_regs(gc_helper_regs_t arr) {
77 register long ebx asm ("ebx");
78 register long esi asm ("esi");
79 register long edi asm ("edi");
80 register long ebp asm ("ebp");
81 #ifdef __clang__
82 // TODO:
83 // This is dirty workaround for Clang. It tries to get around
84 // uncompliant (wrt to GCC) behavior of handling register variables.
85 // Application of this patch here is random, and done only to unbreak
86 // MacOS build. Better, cross-arch ways to deal with Clang issues should
87 // be found.
88 asm ("" : "=r" (ebx));
89 asm ("" : "=r" (esi));
90 asm ("" : "=r" (edi));
91 asm ("" : "=r" (ebp));
92 #endif
93 arr[0] = ebx;
94 arr[1] = esi;
95 arr[2] = edi;
96 arr[3] = ebp;
97}
98
99#elif defined(__thumb2__) || defined(__thumb__) || defined(__arm__)
100
101// Fallback implementation, prefer gchelper_m0.s or gchelper_m3.s
102
103STATIC void gc_helper_get_regs(gc_helper_regs_t arr) {
104 register long r4 asm ("r4");
105 register long r5 asm ("r5");
106 register long r6 asm ("r6");
107 register long r7 asm ("r7");
108 register long r8 asm ("r8");
109 register long r9 asm ("r9");
110 register long r10 asm ("r10");
111 register long r11 asm ("r11");
112 register long r12 asm ("r12");
113 register long r13 asm ("r13");
114 arr[0] = r4;
115 arr[1] = r5;
116 arr[2] = r6;
117 arr[3] = r7;
118 arr[4] = r8;
119 arr[5] = r9;
120 arr[6] = r10;
121 arr[7] = r11;
122 arr[8] = r12;
123 arr[9] = r13;
124}
125
126#elif defined(__aarch64__)
127
128STATIC void gc_helper_get_regs(gc_helper_regs_t arr) {
129 const register long x19 asm ("x19");
130 const register long x20 asm ("x20");
131 const register long x21 asm ("x21");
132 const register long x22 asm ("x22");
133 const register long x23 asm ("x23");
134 const register long x24 asm ("x24");
135 const register long x25 asm ("x25");
136 const register long x26 asm ("x26");
137 const register long x27 asm ("x27");
138 const register long x28 asm ("x28");
139 const register long x29 asm ("x29");
140 arr[0] = x19;
141 arr[1] = x20;
142 arr[2] = x21;
143 arr[3] = x22;
144 arr[4] = x23;
145 arr[5] = x24;
146 arr[6] = x25;
147 arr[7] = x26;
148 arr[8] = x27;
149 arr[9] = x28;
150 arr[10] = x29;
151}
152
153#else
154
155#error "Architecture not supported for gc_helper_get_regs. Set MICROPY_GCREGS_SETJMP to use the fallback implementation."
156
157#endif
158
159#else // !MICROPY_GCREGS_SETJMP
160
161// Even if we have specific support for an architecture, it is
162// possible to force use of setjmp-based implementation.
163
164STATIC void gc_helper_get_regs(gc_helper_regs_t arr) {
165 setjmp(arr);
166}
167
168#endif // MICROPY_GCREGS_SETJMP
169
170// Explicitly mark this as noinline to make sure the regs variable
171// is effectively at the top of the stack: otherwise, in builds where
172// LTO is enabled and a lot of inlining takes place we risk a stack
173// layout where regs is lower on the stack than pointers which have
174// just been allocated but not yet marked, and get incorrectly sweeped.
175MP_NOINLINE void gc_helper_collect_regs_and_stack(void) {
176 gc_helper_regs_t regs;
177 gc_helper_get_regs(regs);
178 // GC stack (and regs because we captured them)
179 void **regs_ptr = (void **)(void *)&regs;
180 gc_collect_root(regs_ptr, ((uintptr_t)MP_STATE_THREAD(stack_top) - (uintptr_t)&regs) / sizeof(uintptr_t));
181}
182
183#endif // MICROPY_ENABLE_GC
184