compiler-rt/lib/builtins/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 #ifndef __has_feature
  12 # define __has_feature(x) 0
  13 #endif
  14
  15 #if __has_feature(ptrauth_init_fini)
  16 #include <ptrauth.h>
  17 #endif
  18
  19 __attribute__((visibility("hidden"))) void *__dso_handle = &__dso_handle;
  20
  21 #ifdef EH_USE_FRAME_REGISTRY
  22 __extension__ static void *__EH_FRAME_LIST__[]
  23     __attribute__((section(".eh_frame"), aligned(sizeof(void *)))) = {};
  24
  25 extern void __register_frame_info(const void *, void *) __attribute__((weak));
  26 extern void *__deregister_frame_info(const void *) __attribute__((weak));
  27 #endif
  28
  29 #ifndef CRT_HAS_INITFINI_ARRAY
  30 typedef void (*fp)(void);
  31
  32 static fp __CTOR_LIST__[]
  33     __attribute__((section(".ctors"), aligned(sizeof(fp)))) = {(fp)-1};
  34 extern fp __CTOR_LIST_END__[];
  35 #endif
  36
  37 extern void __cxa_finalize(void *) __attribute__((weak));
  38
  39 static void __attribute__((used)) __do_init(void) {
  40   static _Bool __initialized;
  41   if (__builtin_expect(__initialized, 0))
  42     return;
  43   __initialized = 1;
  44
  45 #ifdef EH_USE_FRAME_REGISTRY
  46   static struct { void *p[8]; } __object;
  47   if (__register_frame_info)
  48     __register_frame_info(__EH_FRAME_LIST__, &__object);
  49 #endif
  50 #ifndef CRT_HAS_INITFINI_ARRAY
  51   const size_t n = __CTOR_LIST_END__ - __CTOR_LIST__ - 1;
  52   for (size_t i = n; i >= 1; i--) __CTOR_LIST__[i]();
  53 #endif
  54 }
  55
  56 #ifdef CRT_HAS_INITFINI_ARRAY
  57 #if __has_feature(ptrauth_init_fini)
  58 // TODO: use __ptrauth-qualified pointers when they are supported on clang side
  59 #if __has_feature(ptrauth_init_fini_address_discrimination)
  60 __attribute__((section(".init_array"), used)) static void *__init =
  61     ptrauth_sign_constant(&__do_init, ptrauth_key_init_fini_pointer,
  62                           ptrauth_blend_discriminator(
  63                               &__init, __ptrauth_init_fini_discriminator));
  64 #else
  65 __attribute__((section(".init_array"), used)) static void *__init =
  66     ptrauth_sign_constant(&__do_init, ptrauth_key_init_fini_pointer,
  67                           __ptrauth_init_fini_discriminator);
  68 #endif
  69 #else
  70 __attribute__((section(".init_array"),
  71                used)) static void (*__init)(void) = __do_init;
  72 #endif
  73 #elif defined(__i386__) || defined(__x86_64__)
  74 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
  75         "call __do_init\n\t"
  76         ".popsection");
  77 #elif defined(__riscv)
  78 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
  79         "call __do_init\n\t"
  80         ".popsection");
  81 #elif defined(__arm__) || defined(__aarch64__)
  82 __asm__(".pushsection .init,\"ax\",%progbits\n\t"
  83         "bl __do_init\n\t"
  84         ".popsection");
  85 #elif defined(__mips__)
  86 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
  87         "jal __do_init\n\t"
  88         ".popsection");
  89 #elif defined(__powerpc__) || defined(__powerpc64__)
  90 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
  91         "bl __do_init\n\t"
  92         "nop\n\t"
  93         ".popsection");
  94 #elif defined(__sparc__)
  95 __asm__(".pushsection .init,\"ax\",@progbits\n\t"
  96         "call __do_init\n\t"
  97         ".popsection");
  98 #else
  99 #error "crtbegin without .init_fini array unimplemented for this architecture"
 100 #endif // CRT_HAS_INITFINI_ARRAY
 101
 102 #ifndef CRT_HAS_INITFINI_ARRAY
 103 static fp __DTOR_LIST__[]
 104     __attribute__((section(".dtors"), aligned(sizeof(fp)))) = {(fp)-1};
 105 extern fp __DTOR_LIST_END__[];
 106 #endif
 107
 108 static void __attribute__((used)) __do_fini(void) {
 109   static _Bool __finalized;
 110   if (__builtin_expect(__finalized, 0))
 111     return;
 112   __finalized = 1;
 113
 114   if (__cxa_finalize)
 115     __cxa_finalize(__dso_handle);
 116
 117 #ifndef CRT_HAS_INITFINI_ARRAY
 118   const size_t n = __DTOR_LIST_END__ - __DTOR_LIST__ - 1;
 119   for (size_t i = 1; i <= n; i++) __DTOR_LIST__[i]();
 120 #endif
 121 #ifdef EH_USE_FRAME_REGISTRY
 122   if (__deregister_frame_info)
 123     __deregister_frame_info(__EH_FRAME_LIST__);
 124 #endif
 125 }
 126
 127 #ifdef CRT_HAS_INITFINI_ARRAY
 128 #if __has_feature(ptrauth_init_fini)
 129 // TODO: use __ptrauth-qualified pointers when they are supported on clang side
 130 #if __has_feature(ptrauth_init_fini_address_discrimination)
 131 __attribute__((section(".fini_array"), used)) static void *__fini =
 132     ptrauth_sign_constant(&__do_fini, ptrauth_key_init_fini_pointer,
 133                           ptrauth_blend_discriminator(
 134                               &__fini, __ptrauth_init_fini_discriminator));
 135 #else
 136 __attribute__((section(".fini_array"), used)) static void *__fini =
 137     ptrauth_sign_constant(&__do_fini, ptrauth_key_init_fini_pointer,
 138                           __ptrauth_init_fini_discriminator);
 139 #endif
 140 #else
 141 __attribute__((section(".fini_array"),
 142                used)) static void (*__fini)(void) = __do_fini;
 143 #endif
 144 #elif defined(__i386__) || defined(__x86_64__)
 145 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
 146         "call __do_fini\n\t"
 147         ".popsection");
 148 #elif defined(__arm__) || defined(__aarch64__)
 149 __asm__(".pushsection .fini,\"ax\",%progbits\n\t"
 150         "bl __do_fini\n\t"
 151         ".popsection");
 152 #elif defined(__mips__)
 153 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
 154         "jal __do_fini\n\t"
 155         ".popsection");
 156 #elif defined(__powerpc__) || defined(__powerpc64__)
 157 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
 158         "bl __do_fini\n\t"
 159         "nop\n\t"
 160         ".popsection");
 161 #elif defined(__riscv)
 162 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
 163         "call __do_fini\n\t"
 164         ".popsection");
 165 #elif defined(__sparc__)
 166 __asm__(".pushsection .fini,\"ax\",@progbits\n\t"
 167         "call __do_fini\n\t"
 168         ".popsection");
 169 #else
 170 #error "crtbegin without .init_fini array unimplemented for this architecture"
 171 #endif  // CRT_HAS_INIT_FINI_ARRAY