contrib/llvm-project/compiler-rt/lib/crt/crtbegin.c

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