libsanitizer/builtins/assembly.h

   1 //===-- assembly.h - compiler-rt assembler support macros -----------------===//
   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 // This file defines macros for use in compiler-rt assembler source.
  10 // This file is not part of the interface of this library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef COMPILERRT_ASSEMBLY_H
  15 #define COMPILERRT_ASSEMBLY_H
  16
  17 #if defined(__APPLE__) && defined(__aarch64__)
  18 #define SEPARATOR %%
  19 #else
  20 #define SEPARATOR ;
  21 #endif
  22
  23 #if defined(__APPLE__)
  24 #define HIDDEN(name) .private_extern name
  25 #define LOCAL_LABEL(name) L_##name
  26 // tell linker it can break up file at label boundaries
  27 #define FILE_LEVEL_DIRECTIVE .subsections_via_symbols
  28 #define SYMBOL_IS_FUNC(name)
  29 #define CONST_SECTION .const
  30
  31 #define NO_EXEC_STACK_DIRECTIVE
  32
  33 #elif defined(__ELF__)
  34
  35 #define HIDDEN(name) .hidden name
  36 #define LOCAL_LABEL(name) .L_##name
  37 #define FILE_LEVEL_DIRECTIVE
  38 #if defined(__arm__) || defined(__aarch64__)
  39 #define SYMBOL_IS_FUNC(name) .type name,%function
  40 #else
  41 #define SYMBOL_IS_FUNC(name) .type name,@function
  42 #endif
  43 #define CONST_SECTION .section .rodata
  44
  45 #if defined(__GNU__) || defined(__FreeBSD__) || defined(__Fuchsia__) ||        \
  46     defined(__linux__)
  47 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
  48 #else
  49 #define NO_EXEC_STACK_DIRECTIVE
  50 #endif
  51
  52 #else // !__APPLE__ && !__ELF__
  53
  54 #define HIDDEN(name)
  55 #define LOCAL_LABEL(name) .L ## name
  56 #define FILE_LEVEL_DIRECTIVE
  57 #define SYMBOL_IS_FUNC(name)                                                   \
  58   .def name SEPARATOR                                                          \
  59     .scl 2 SEPARATOR                                                           \
  60     .type 32 SEPARATOR                                                         \
  61   .endef
  62 #define CONST_SECTION .section .rdata,"rd"
  63
  64 #define NO_EXEC_STACK_DIRECTIVE
  65
  66 #endif
  67
  68 #if defined(__arm__) || defined(__aarch64__)
  69 #define FUNC_ALIGN                                                             \
  70   .text SEPARATOR                                                              \
  71   .balign 16 SEPARATOR
  72 #else
  73 #define FUNC_ALIGN
  74 #endif
  75
  76 // BTI and PAC gnu property note
  77 #define NT_GNU_PROPERTY_TYPE_0 5
  78 #define GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
  79 #define GNU_PROPERTY_AARCH64_FEATURE_1_BTI 1
  80 #define GNU_PROPERTY_AARCH64_FEATURE_1_PAC 2
  81
  82 #if defined(__ARM_FEATURE_BTI_DEFAULT)
  83 #define BTI_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  84 #else
  85 #define BTI_FLAG 0
  86 #endif
  87
  88 #if __ARM_FEATURE_PAC_DEFAULT & 3
  89 #define PAC_FLAG GNU_PROPERTY_AARCH64_FEATURE_1_PAC
  90 #else
  91 #define PAC_FLAG 0
  92 #endif
  93
  94 #define GNU_PROPERTY(type, value)                                              \
  95   .pushsection .note.gnu.property, "a" SEPARATOR                               \
  96   .p2align 3 SEPARATOR                                                         \
  97   .word 4 SEPARATOR                                                            \
  98   .word 16 SEPARATOR                                                           \
  99   .word NT_GNU_PROPERTY_TYPE_0 SEPARATOR                                       \
 100   .asciz "GNU" SEPARATOR                                                       \
 101   .word type SEPARATOR                                                         \
 102   .word 4 SEPARATOR                                                            \
 103   .word value SEPARATOR                                                        \
 104   .word 0 SEPARATOR                                                            \
 105   .popsection
 106
 107 #if BTI_FLAG != 0
 108 #define BTI_C hint #34
 109 #define BTI_J hint #36
 110 #else
 111 #define BTI_C
 112 #define BTI_J
 113 #endif
 114
 115 #if (BTI_FLAG | PAC_FLAG) != 0
 116 #define GNU_PROPERTY_BTI_PAC                                                   \
 117   GNU_PROPERTY(GNU_PROPERTY_AARCH64_FEATURE_1_AND, BTI_FLAG | PAC_FLAG)
 118 #else
 119 #define GNU_PROPERTY_BTI_PAC
 120 #endif
 121
 122 #if defined(__clang__) || defined(__GCC_HAVE_DWARF2_CFI_ASM)
 123 #define CFI_START .cfi_startproc
 124 #define CFI_END .cfi_endproc
 125 #else
 126 #define CFI_START
 127 #define CFI_END
 128 #endif
 129
 130 #if defined(__arm__)
 131
 132 // Determine actual [ARM][THUMB[1][2]] ISA using compiler predefined macros:
 133 // - for '-mthumb -march=armv6' compiler defines '__thumb__'
 134 // - for '-mthumb -march=armv7' compiler defines '__thumb__' and '__thumb2__'
 135 #if defined(__thumb2__) || defined(__thumb__)
 136 #define DEFINE_CODE_STATE .thumb SEPARATOR
 137 #define DECLARE_FUNC_ENCODING    .thumb_func SEPARATOR
 138 #if defined(__thumb2__)
 139 #define USE_THUMB_2
 140 #define IT(cond)  it cond
 141 #define ITT(cond) itt cond
 142 #define ITE(cond) ite cond
 143 #else
 144 #define USE_THUMB_1
 145 #define IT(cond)
 146 #define ITT(cond)
 147 #define ITE(cond)
 148 #endif // defined(__thumb__2)
 149 #else // !defined(__thumb2__) && !defined(__thumb__)
 150 #define DEFINE_CODE_STATE .arm SEPARATOR
 151 #define DECLARE_FUNC_ENCODING
 152 #define IT(cond)
 153 #define ITT(cond)
 154 #define ITE(cond)
 155 #endif
 156
 157 #if defined(USE_THUMB_1) && defined(USE_THUMB_2)
 158 #error "USE_THUMB_1 and USE_THUMB_2 can't be defined together."
 159 #endif
 160
 161 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
 162 #define ARM_HAS_BX
 163 #endif
 164 #if !defined(__ARM_FEATURE_CLZ) && !defined(USE_THUMB_1) &&  \
 165     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
 166 #define __ARM_FEATURE_CLZ
 167 #endif
 168
 169 #ifdef ARM_HAS_BX
 170 #define JMP(r) bx r
 171 #define JMPc(r, c) bx##c r
 172 #else
 173 #define JMP(r) mov pc, r
 174 #define JMPc(r, c) mov##c pc, r
 175 #endif
 176
 177 // pop {pc} can't switch Thumb mode on ARMv4T
 178 #if __ARM_ARCH >= 5
 179 #define POP_PC() pop {pc}
 180 #else
 181 #define POP_PC()                                                               \
 182   pop {ip};                                                                    \
 183   JMP(ip)
 184 #endif
 185
 186 #if defined(USE_THUMB_2)
 187 #define WIDE(op) op.w
 188 #else
 189 #define WIDE(op) op
 190 #endif
 191 #else // !defined(__arm)
 192 #define DECLARE_FUNC_ENCODING
 193 #define DEFINE_CODE_STATE
 194 #endif
 195
 196 #define GLUE2_(a, b) a##b
 197 #define GLUE(a, b) GLUE2_(a, b)
 198 #define GLUE2(a, b) GLUE2_(a, b)
 199 #define GLUE3_(a, b, c) a##b##c
 200 #define GLUE3(a, b, c) GLUE3_(a, b, c)
 201 #define GLUE4_(a, b, c, d) a##b##c##d
 202 #define GLUE4(a, b, c, d) GLUE4_(a, b, c, d)
 203
 204 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
 205
 206 #ifdef VISIBILITY_HIDDEN
 207 #define DECLARE_SYMBOL_VISIBILITY(name)                                        \
 208   HIDDEN(SYMBOL_NAME(name)) SEPARATOR
 209 #define DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name) \
 210   HIDDEN(name) SEPARATOR
 211 #else
 212 #define DECLARE_SYMBOL_VISIBILITY(name)
 213 #define DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name)
 214 #endif
 215
 216 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
 217   DEFINE_CODE_STATE                                                            \
 218   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
 219   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 220   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 221   DECLARE_SYMBOL_VISIBILITY(name)                                              \
 222   DECLARE_FUNC_ENCODING                                                        \
 223   SYMBOL_NAME(name):
 224
 225 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
 226   DEFINE_CODE_STATE                                                            \
 227   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
 228   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 229   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 230   DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR                                    \
 231   .thumb_func SEPARATOR                                                        \
 232   SYMBOL_NAME(name):
 233
 234 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
 235   DEFINE_CODE_STATE                                                            \
 236   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
 237   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 238   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 239   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
 240   DECLARE_FUNC_ENCODING                                                        \
 241   SYMBOL_NAME(name):
 242
 243 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
 244   DEFINE_CODE_STATE                                                            \
 245   .globl name SEPARATOR                                                        \
 246   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
 247   HIDDEN(name) SEPARATOR                                                       \
 248   DECLARE_FUNC_ENCODING                                                        \
 249   name:
 250
 251 #define DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(name)                     \
 252   DEFINE_CODE_STATE                                                            \
 253   FUNC_ALIGN                                                                   \
 254   .globl name SEPARATOR                                                        \
 255   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
 256   DECLARE_SYMBOL_VISIBILITY_UNMANGLED(name) SEPARATOR                          \
 257   CFI_START SEPARATOR                                                          \
 258   DECLARE_FUNC_ENCODING                                                        \
 259   name: SEPARATOR BTI_C
 260
 261 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
 262   .globl SYMBOL_NAME(name) SEPARATOR                                           \
 263   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
 264   DECLARE_SYMBOL_VISIBILITY(SYMBOL_NAME(name)) SEPARATOR                       \
 265   .set SYMBOL_NAME(name), SYMBOL_NAME(target) SEPARATOR
 266
 267 #if defined(__ARM_EABI__)
 268 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)                          \
 269   DEFINE_COMPILERRT_FUNCTION_ALIAS(aeabi_name, name)
 270 #else
 271 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)
 272 #endif
 273
 274 #ifdef __ELF__
 275 #define END_COMPILERRT_FUNCTION(name)                                          \
 276   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
 277 #define END_COMPILERRT_OUTLINE_FUNCTION(name)                                  \
 278   CFI_END SEPARATOR                                                            \
 279   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
 280 #else
 281 #define END_COMPILERRT_FUNCTION(name)
 282 #define END_COMPILERRT_OUTLINE_FUNCTION(name)                                  \
 283   CFI_END
 284 #endif
 285
 286 #endif // COMPILERRT_ASSEMBLY_H