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(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 " __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
  82 static void __attribute__((used)) __do_fini(void) {
  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