xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/crtbegin.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 //===-- crtbegin.c - Start of constructors and destructors ----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include <stddef.h>
10 
11 __attribute__((visibility("hidden"))) void *__dso_handle = &__dso_handle;
12 
13 #ifdef EH_USE_FRAME_REGISTRY
14 __extension__ static void *__EH_FRAME_LIST__[]
15     __attribute__((section(".eh_frame"), aligned(sizeof(void *)))) = {};
16 
17 extern void __register_frame_info(const void *, void *) __attribute__((weak));
18 extern void *__deregister_frame_info(const void *) __attribute__((weak));
19 #endif
20 
21 #ifndef CRT_HAS_INITFINI_ARRAY
22 typedef void (*fp)(void);
23 
24 static fp __CTOR_LIST__[]
25     __attribute__((section(".ctors"), aligned(sizeof(fp)))) = {(fp)-1};
26 extern fp __CTOR_LIST_END__[];
27 #endif
28 
29 extern void __cxa_finalize(void *) __attribute__((weak));
30 
__do_init(void)31 static void __attribute__((used)) __do_init(void) {
32   static _Bool __initialized;
33   if (__builtin_expect(__initialized, 0))
34     return;
35   __initialized = 1;
36 
37 #ifdef EH_USE_FRAME_REGISTRY
38   static struct { void *p[8]; } __object;
39   if (__register_frame_info)
40     __register_frame_info(__EH_FRAME_LIST__, &__object);
41 #endif
42 #ifndef CRT_HAS_INITFINI_ARRAY
43   const size_t n = __CTOR_LIST_END__ - __CTOR_LIST__ - 1;
44   for (size_t i = n; i >= 1; i--) __CTOR_LIST__[i]();
45 #endif
46 }
47 
48 #ifdef CRT_HAS_INITFINI_ARRAY
49 __attribute__((section(".init_array"),
50                used)) static void (*__init)(void) = __do_init;
51 #elif defined(__i386__) || defined(__x86_64__)
52 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
53         "call __do_init\n\t"
54         ".popsection");
55 #elif defined(__riscv)
56 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
57         "call __do_init\n\t"
58         ".popsection");
59 #elif defined(__arm__) || defined(__aarch64__)
60 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
61         "bl __do_init\n\t"
62         ".popsection");
63 #elif defined(__mips__)
64 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
65         "jal __do_init\n\t"
66         ".popsection");
67 #elif defined(__powerpc__) || defined(__powerpc64__)
68 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
69         "bl __do_init\n\t"
70         "nop\n\t"
71         ".popsection");
72 #elif defined(__sparc__)
73 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
74         "call __do_init\n\t"
75         ".popsection");
76 #else
77 #error "crtbegin without .init_fini array unimplemented for this architecture"
78 #endif // CRT_HAS_INITFINI_ARRAY
79 
80 #ifndef CRT_HAS_INITFINI_ARRAY
81 static fp __DTOR_LIST__[]
82     __attribute__((section(".dtors"), aligned(sizeof(fp)))) = {(fp)-1};
83 extern fp __DTOR_LIST_END__[];
84 #endif
85 
__do_fini(void)86 static void __attribute__((used)) __do_fini(void) {
87   static _Bool __finalized;
88   if (__builtin_expect(__finalized, 0))
89     return;
90   __finalized = 1;
91 
92   if (__cxa_finalize)
93     __cxa_finalize(__dso_handle);
94 
95 #ifndef CRT_HAS_INITFINI_ARRAY
96   const size_t n = __DTOR_LIST_END__ - __DTOR_LIST__ - 1;
97   for (size_t i = 1; i <= n; i++) __DTOR_LIST__[i]();
98 #endif
99 #ifdef EH_USE_FRAME_REGISTRY
100   if (__deregister_frame_info)
101     __deregister_frame_info(__EH_FRAME_LIST__);
102 #endif
103 }
104 
105 #ifdef CRT_HAS_INITFINI_ARRAY
106 __attribute__((section(".fini_array"),
107                used)) static void (*__fini)(void) = __do_fini;
108 #elif defined(__i386__) || defined(__x86_64__)
109 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
110         "call __do_fini\n\t"
111         ".popsection");
112 #elif defined(__arm__) || defined(__aarch64__)
113 __asm__(".pushsection .fini,\"ax\",%progbits\n\t"
114         "bl __do_fini\n\t"
115         ".popsection");
116 #elif defined(__mips__)
117 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
118         "jal __do_fini\n\t"
119         ".popsection");
120 #elif defined(__powerpc__) || defined(__powerpc64__)
121 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
122         "bl __do_fini\n\t"
123         "nop\n\t"
124         ".popsection");
125 #elif defined(__riscv)
126 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
127         "call __do_fini\n\t"
128         ".popsection");
129 #elif defined(__sparc__)
130 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
131         "call __do_fini\n\t"
132         ".popsection");
133 #else
134 #error "crtbegin without .init_fini array unimplemented for this architecture"
135 #endif  // CRT_HAS_INIT_FINI_ARRAY
136