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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()31 static void __attribute__((used)) __do_init() {
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 " __USER_LABEL_PREFIX__ "__do_init\n\t"
54     ".popsection");
55 #elif defined(__riscv)
56 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
57         "call " __USER_LABEL_PREFIX__ "__do_init\n\t"
58         ".popsection");
59 #elif defined(__arm__) || defined(__aarch64__)
60 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
61     "bl " __USER_LABEL_PREFIX__ "__do_init\n\t"
62     ".popsection");
63 #elif defined(__powerpc__) || defined(__powerpc64__)
64 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
65     "bl " __USER_LABEL_PREFIX__ "__do_init\n\t"
66     "nop\n\t"
67     ".popsection");
68 #elif defined(__sparc__)
69 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
70     "call " __USER_LABEL_PREFIX__ "__do_init\n\t"
71     ".popsection");
72 #else
73 #error "crtbegin without .init_fini array unimplemented for this architecture"
74 #endif // CRT_HAS_INITFINI_ARRAY
75 
76 #ifndef CRT_HAS_INITFINI_ARRAY
77 static fp __DTOR_LIST__[]
78     __attribute__((section(".dtors"), aligned(sizeof(fp)))) = {(fp)-1};
79 extern fp __DTOR_LIST_END__[];
80 #endif
81 
__do_fini()82 static void __attribute__((used)) __do_fini() {
83   static _Bool __finalized;
84   if (__builtin_expect(__finalized, 0))
85     return;
86   __finalized = 1;
87 
88   if (__cxa_finalize)
89     __cxa_finalize(__dso_handle);
90 
91 #ifndef CRT_HAS_INITFINI_ARRAY
92   const size_t n = __DTOR_LIST_END__ - __DTOR_LIST__ - 1;
93   for (size_t i = 1; i <= n; i++) __DTOR_LIST__[i]();
94 #endif
95 #ifdef EH_USE_FRAME_REGISTRY
96   if (__deregister_frame_info)
97     __deregister_frame_info(__EH_FRAME_LIST__);
98 #endif
99 }
100 
101 #ifdef CRT_HAS_INITFINI_ARRAY
102 __attribute__((section(".fini_array"),
103                used)) static void (*__fini)(void) = __do_fini;
104 #elif defined(__i386__) || defined(__x86_64__)
105 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
106     "call " __USER_LABEL_PREFIX__ "__do_fini\n\t"
107     ".popsection");
108 #elif defined(__arm__) || defined(__aarch64__)
109 __asm__(".pushsection .fini,\"ax\",%progbits\n\t"
110     "bl " __USER_LABEL_PREFIX__ "__do_fini\n\t"
111     ".popsection");
112 #elif defined(__powerpc__) || defined(__powerpc64__)
113 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
114     "bl " __USER_LABEL_PREFIX__ "__do_fini\n\t"
115     "nop\n\t"
116     ".popsection");
117 #elif defined(__riscv)
118 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
119         "call " __USER_LABEL_PREFIX__ "__do_fini\n\t"
120         ".popsection");
121 #elif defined(__sparc__)
122 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
123     "call " __USER_LABEL_PREFIX__ "__do_fini\n\t"
124     ".popsection");
125 #else
126 #error "crtbegin without .init_fini array unimplemented for this architecture"
127 #endif  // CRT_HAS_INIT_FINI_ARRAY
128