1 //===-- llvm/Support/Compiler.h - Compiler abstraction support --*- C++ -*-===// 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 several macros, based on the current compiler. This allows 10 // use of compiler-specific features in a way that remains portable. This header 11 // can be included from either C or C++. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_SUPPORT_COMPILER_H 16 #define LLVM_SUPPORT_COMPILER_H 17 18 #include "llvm/Config/llvm-config.h" 19 20 #include <stddef.h> 21 22 #if defined(_MSC_VER) 23 #include <sal.h> 24 #endif 25 26 #ifndef __has_feature 27 # define __has_feature(x) 0 28 #endif 29 30 #ifndef __has_extension 31 # define __has_extension(x) 0 32 #endif 33 34 #ifndef __has_attribute 35 # define __has_attribute(x) 0 36 #endif 37 38 #ifndef __has_builtin 39 # define __has_builtin(x) 0 40 #endif 41 42 #ifndef __has_include 43 # define __has_include(x) 0 44 #endif 45 46 // Only use __has_cpp_attribute in C++ mode. GCC defines __has_cpp_attribute in 47 // C mode, but the :: in __has_cpp_attribute(scoped::attribute) is invalid. 48 #ifndef LLVM_HAS_CPP_ATTRIBUTE 49 #if defined(__cplusplus) && defined(__has_cpp_attribute) 50 # define LLVM_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) 51 #else 52 # define LLVM_HAS_CPP_ATTRIBUTE(x) 0 53 #endif 54 #endif 55 56 /// \macro LLVM_GNUC_PREREQ 57 /// Extend the default __GNUC_PREREQ even if glibc's features.h isn't 58 /// available. 59 #ifndef LLVM_GNUC_PREREQ 60 # if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__) 61 # define LLVM_GNUC_PREREQ(maj, min, patch) \ 62 ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \ 63 ((maj) << 20) + ((min) << 10) + (patch)) 64 # elif defined(__GNUC__) && defined(__GNUC_MINOR__) 65 # define LLVM_GNUC_PREREQ(maj, min, patch) \ 66 ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10)) 67 # else 68 # define LLVM_GNUC_PREREQ(maj, min, patch) 0 69 # endif 70 #endif 71 72 /// \macro LLVM_MSC_PREREQ 73 /// Is the compiler MSVC of at least the specified version? 74 /// The common \param version values to check for are: 75 /// * 1910: VS2017, version 15.1 & 15.2 76 /// * 1911: VS2017, version 15.3 & 15.4 77 /// * 1912: VS2017, version 15.5 78 /// * 1913: VS2017, version 15.6 79 /// * 1914: VS2017, version 15.7 80 /// * 1915: VS2017, version 15.8 81 /// * 1916: VS2017, version 15.9 82 /// * 1920: VS2019, version 16.0 83 /// * 1921: VS2019, version 16.1 84 /// * 1922: VS2019, version 16.2 85 /// * 1923: VS2019, version 16.3 86 /// * 1924: VS2019, version 16.4 87 /// * 1925: VS2019, version 16.5 88 /// * 1926: VS2019, version 16.6 89 /// * 1927: VS2019, version 16.7 90 /// * 1928: VS2019, version 16.8 + 16.9 91 /// * 1929: VS2019, version 16.10 + 16.11 92 /// * 1930: VS2022, version 17.0 93 #ifdef _MSC_VER 94 #define LLVM_MSC_PREREQ(version) (_MSC_VER >= (version)) 95 96 // We require at least VS 2019. 97 #if !defined(LLVM_FORCE_USE_OLD_TOOLCHAIN) 98 #if !LLVM_MSC_PREREQ(1920) 99 #error LLVM requires at least VS 2019. 100 #endif 101 #endif 102 103 #else 104 #define LLVM_MSC_PREREQ(version) 0 105 #endif 106 107 /// LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked 108 /// into a shared library, then the class should be private to the library and 109 /// not accessible from outside it. Can also be used to mark variables and 110 /// functions, making them private to any shared library they are linked into. 111 /// On PE/COFF targets, library visibility is the default, so this isn't needed. 112 /// 113 /// LLVM_EXTERNAL_VISIBILITY - classes, functions, and variables marked with 114 /// this attribute will be made public and visible outside of any shared library 115 /// they are linked in to. 116 117 #if LLVM_HAS_CPP_ATTRIBUTE(gnu::visibility) 118 #define LLVM_ATTRIBUTE_VISIBILITY_HIDDEN [[gnu::visibility("hidden")]] 119 #define LLVM_ATTRIBUTE_VISIBILITY_DEFAULT [[gnu::visibility("default")]] 120 #elif __has_attribute(visibility) 121 #define LLVM_ATTRIBUTE_VISIBILITY_HIDDEN __attribute__((visibility("hidden"))) 122 #define LLVM_ATTRIBUTE_VISIBILITY_DEFAULT __attribute__((visibility("default"))) 123 #else 124 #define LLVM_ATTRIBUTE_VISIBILITY_HIDDEN 125 #define LLVM_ATTRIBUTE_VISIBILITY_DEFAULT 126 #endif 127 128 129 #if (!(defined(_WIN32) || defined(__CYGWIN__)) || \ 130 (defined(__MINGW32__) && defined(__clang__))) 131 #define LLVM_LIBRARY_VISIBILITY LLVM_ATTRIBUTE_VISIBILITY_HIDDEN 132 #if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS) 133 #define LLVM_EXTERNAL_VISIBILITY LLVM_ATTRIBUTE_VISIBILITY_DEFAULT 134 #else 135 #define LLVM_EXTERNAL_VISIBILITY 136 #endif 137 #else 138 #define LLVM_LIBRARY_VISIBILITY 139 #define LLVM_EXTERNAL_VISIBILITY 140 #endif 141 142 #if defined(__GNUC__) 143 #define LLVM_PREFETCH(addr, rw, locality) __builtin_prefetch(addr, rw, locality) 144 #else 145 #define LLVM_PREFETCH(addr, rw, locality) 146 #endif 147 148 #if __has_attribute(used) 149 #define LLVM_ATTRIBUTE_USED __attribute__((__used__)) 150 #else 151 #define LLVM_ATTRIBUTE_USED 152 #endif 153 154 #if defined(__clang__) 155 #define LLVM_DEPRECATED(MSG, FIX) __attribute__((deprecated(MSG, FIX))) 156 #else 157 #define LLVM_DEPRECATED(MSG, FIX) [[deprecated(MSG)]] 158 #endif 159 160 // Indicate that a non-static, non-const C++ member function reinitializes 161 // the entire object to a known state, independent of the previous state of 162 // the object. 163 // 164 // The clang-tidy check bugprone-use-after-move recognizes this attribute as a 165 // marker that a moved-from object has left the indeterminate state and can be 166 // reused. 167 #if LLVM_HAS_CPP_ATTRIBUTE(clang::reinitializes) 168 #define LLVM_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]] 169 #else 170 #define LLVM_ATTRIBUTE_REINITIALIZES 171 #endif 172 173 // Some compilers warn about unused functions. When a function is sometimes 174 // used or not depending on build settings (e.g. a function only called from 175 // within "assert"), this attribute can be used to suppress such warnings. 176 // 177 // However, it shouldn't be used for unused *variables*, as those have a much 178 // more portable solution: 179 // (void)unused_var_name; 180 // Prefer cast-to-void wherever it is sufficient. 181 #if __has_attribute(unused) 182 #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__)) 183 #else 184 #define LLVM_ATTRIBUTE_UNUSED 185 #endif 186 187 // FIXME: Provide this for PE/COFF targets. 188 #if __has_attribute(weak) && !defined(__MINGW32__) && !defined(__CYGWIN__) && \ 189 !defined(_WIN32) 190 #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__)) 191 #else 192 #define LLVM_ATTRIBUTE_WEAK 193 #endif 194 195 // Prior to clang 3.2, clang did not accept any spelling of 196 // __has_attribute(const), so assume it is supported. 197 #if defined(__clang__) || defined(__GNUC__) 198 // aka 'CONST' but following LLVM Conventions. 199 #define LLVM_READNONE __attribute__((__const__)) 200 #else 201 #define LLVM_READNONE 202 #endif 203 204 #if __has_attribute(pure) || defined(__GNUC__) 205 // aka 'PURE' but following LLVM Conventions. 206 #define LLVM_READONLY __attribute__((__pure__)) 207 #else 208 #define LLVM_READONLY 209 #endif 210 211 #if __has_attribute(minsize) 212 #define LLVM_ATTRIBUTE_MINSIZE __attribute__((minsize)) 213 #else 214 #define LLVM_ATTRIBUTE_MINSIZE 215 #endif 216 217 #if __has_builtin(__builtin_expect) || defined(__GNUC__) 218 #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true) 219 #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false) 220 #else 221 #define LLVM_LIKELY(EXPR) (EXPR) 222 #define LLVM_UNLIKELY(EXPR) (EXPR) 223 #endif 224 225 /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so, 226 /// mark a method "not for inlining". 227 #if __has_attribute(noinline) 228 #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline)) 229 #elif defined(_MSC_VER) 230 #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline) 231 #else 232 #define LLVM_ATTRIBUTE_NOINLINE 233 #endif 234 235 /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do 236 /// so, mark a method "always inline" because it is performance sensitive. 237 #if __has_attribute(always_inline) 238 #define LLVM_ATTRIBUTE_ALWAYS_INLINE inline __attribute__((always_inline)) 239 #elif defined(_MSC_VER) 240 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline 241 #else 242 #define LLVM_ATTRIBUTE_ALWAYS_INLINE inline 243 #endif 244 245 /// LLVM_ATTRIBUTE_NO_DEBUG - On compilers where we have a directive to do 246 /// so, mark a method "no debug" because debug info makes the debugger 247 /// experience worse. 248 #if __has_attribute(nodebug) 249 #define LLVM_ATTRIBUTE_NODEBUG __attribute__((nodebug)) 250 #else 251 #define LLVM_ATTRIBUTE_NODEBUG 252 #endif 253 254 #if __has_attribute(returns_nonnull) 255 #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull)) 256 #elif defined(_MSC_VER) 257 #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_ 258 #else 259 #define LLVM_ATTRIBUTE_RETURNS_NONNULL 260 #endif 261 262 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a 263 /// pointer that does not alias any other valid pointer. 264 #ifdef __GNUC__ 265 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__)) 266 #elif defined(_MSC_VER) 267 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict) 268 #else 269 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS 270 #endif 271 272 /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements. 273 #if defined(__cplusplus) && __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(fallthrough) 274 #define LLVM_FALLTHROUGH [[fallthrough]] 275 #elif LLVM_HAS_CPP_ATTRIBUTE(gnu::fallthrough) 276 #define LLVM_FALLTHROUGH [[gnu::fallthrough]] 277 #elif __has_attribute(fallthrough) 278 #define LLVM_FALLTHROUGH __attribute__((fallthrough)) 279 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::fallthrough) 280 #define LLVM_FALLTHROUGH [[clang::fallthrough]] 281 #else 282 #define LLVM_FALLTHROUGH 283 #endif 284 285 /// LLVM_REQUIRE_CONSTANT_INITIALIZATION - Apply this to globals to ensure that 286 /// they are constant initialized. 287 #if LLVM_HAS_CPP_ATTRIBUTE(clang::require_constant_initialization) 288 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION \ 289 [[clang::require_constant_initialization]] 290 #else 291 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION 292 #endif 293 294 /// LLVM_GSL_OWNER - Apply this to owning classes like SmallVector to enable 295 /// lifetime warnings. 296 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Owner) 297 #define LLVM_GSL_OWNER [[gsl::Owner]] 298 #else 299 #define LLVM_GSL_OWNER 300 #endif 301 302 /// LLVM_GSL_POINTER - Apply this to non-owning classes like 303 /// StringRef to enable lifetime warnings. 304 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Pointer) 305 #define LLVM_GSL_POINTER [[gsl::Pointer]] 306 #else 307 #define LLVM_GSL_POINTER 308 #endif 309 310 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress 311 /// pedantic diagnostics. 312 #ifdef __GNUC__ 313 #define LLVM_EXTENSION __extension__ 314 #else 315 #define LLVM_EXTENSION 316 #endif 317 318 /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands 319 /// to an expression which states that it is undefined behavior for the 320 /// compiler to reach this point. Otherwise is not defined. 321 /// 322 /// '#else' is intentionally left out so that other macro logic (e.g., 323 /// LLVM_ASSUME_ALIGNED and llvm_unreachable()) can detect whether 324 /// LLVM_BUILTIN_UNREACHABLE has a definition. 325 #if __has_builtin(__builtin_unreachable) || defined(__GNUC__) 326 # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable() 327 #elif defined(_MSC_VER) 328 # define LLVM_BUILTIN_UNREACHABLE __assume(false) 329 #endif 330 331 /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression 332 /// which causes the program to exit abnormally. 333 #if __has_builtin(__builtin_trap) || defined(__GNUC__) 334 # define LLVM_BUILTIN_TRAP __builtin_trap() 335 #elif defined(_MSC_VER) 336 // The __debugbreak intrinsic is supported by MSVC, does not require forward 337 // declarations involving platform-specific typedefs (unlike RaiseException), 338 // results in a call to vectored exception handlers, and encodes to a short 339 // instruction that still causes the trapping behavior we want. 340 # define LLVM_BUILTIN_TRAP __debugbreak() 341 #else 342 # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0 343 #endif 344 345 /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to 346 /// an expression which causes the program to break while running 347 /// under a debugger. 348 #if __has_builtin(__builtin_debugtrap) 349 # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap() 350 #elif defined(_MSC_VER) 351 // The __debugbreak intrinsic is supported by MSVC and breaks while 352 // running under the debugger, and also supports invoking a debugger 353 // when the OS is configured appropriately. 354 # define LLVM_BUILTIN_DEBUGTRAP __debugbreak() 355 #else 356 // Just continue execution when built with compilers that have no 357 // support. This is a debugging aid and not intended to force the 358 // program to abort if encountered. 359 # define LLVM_BUILTIN_DEBUGTRAP 360 #endif 361 362 /// \macro LLVM_ASSUME_ALIGNED 363 /// Returns a pointer with an assumed alignment. 364 #if __has_builtin(__builtin_assume_aligned) || defined(__GNUC__) 365 # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a) 366 #elif defined(LLVM_BUILTIN_UNREACHABLE) 367 # define LLVM_ASSUME_ALIGNED(p, a) \ 368 (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p))) 369 #else 370 # define LLVM_ASSUME_ALIGNED(p, a) (p) 371 #endif 372 373 /// \macro LLVM_PACKED 374 /// Used to specify a packed structure. 375 /// LLVM_PACKED( 376 /// struct A { 377 /// int i; 378 /// int j; 379 /// int k; 380 /// long long l; 381 /// }); 382 /// 383 /// LLVM_PACKED_START 384 /// struct B { 385 /// int i; 386 /// int j; 387 /// int k; 388 /// long long l; 389 /// }; 390 /// LLVM_PACKED_END 391 #ifdef _MSC_VER 392 # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop)) 393 # define LLVM_PACKED_START __pragma(pack(push, 1)) 394 # define LLVM_PACKED_END __pragma(pack(pop)) 395 #else 396 # define LLVM_PACKED(d) d __attribute__((packed)) 397 # define LLVM_PACKED_START _Pragma("pack(push, 1)") 398 # define LLVM_PACKED_END _Pragma("pack(pop)") 399 #endif 400 401 /// \macro LLVM_MEMORY_SANITIZER_BUILD 402 /// Whether LLVM itself is built with MemorySanitizer instrumentation. 403 #if __has_feature(memory_sanitizer) 404 # define LLVM_MEMORY_SANITIZER_BUILD 1 405 # include <sanitizer/msan_interface.h> 406 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE __attribute__((no_sanitize_memory)) 407 #else 408 # define LLVM_MEMORY_SANITIZER_BUILD 0 409 # define __msan_allocated_memory(p, size) 410 # define __msan_unpoison(p, size) 411 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE 412 #endif 413 414 /// \macro LLVM_ADDRESS_SANITIZER_BUILD 415 /// Whether LLVM itself is built with AddressSanitizer instrumentation. 416 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) 417 # define LLVM_ADDRESS_SANITIZER_BUILD 1 418 #if __has_include(<sanitizer/asan_interface.h>) 419 # include <sanitizer/asan_interface.h> 420 #else 421 // These declarations exist to support ASan with MSVC. If MSVC eventually ships 422 // asan_interface.h in their headers, then we can remove this. 423 #ifdef __cplusplus 424 extern "C" { 425 #endif 426 void __asan_poison_memory_region(void const volatile *addr, size_t size); 427 void __asan_unpoison_memory_region(void const volatile *addr, size_t size); 428 #ifdef __cplusplus 429 } // extern "C" 430 #endif 431 #endif 432 #else 433 # define LLVM_ADDRESS_SANITIZER_BUILD 0 434 # define __asan_poison_memory_region(p, size) 435 # define __asan_unpoison_memory_region(p, size) 436 #endif 437 438 /// \macro LLVM_HWADDRESS_SANITIZER_BUILD 439 /// Whether LLVM itself is built with HWAddressSanitizer instrumentation. 440 #if __has_feature(hwaddress_sanitizer) 441 #define LLVM_HWADDRESS_SANITIZER_BUILD 1 442 #else 443 #define LLVM_HWADDRESS_SANITIZER_BUILD 0 444 #endif 445 446 /// \macro LLVM_THREAD_SANITIZER_BUILD 447 /// Whether LLVM itself is built with ThreadSanitizer instrumentation. 448 #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__) 449 # define LLVM_THREAD_SANITIZER_BUILD 1 450 #else 451 # define LLVM_THREAD_SANITIZER_BUILD 0 452 #endif 453 454 #if LLVM_THREAD_SANITIZER_BUILD 455 // Thread Sanitizer is a tool that finds races in code. 456 // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations . 457 // tsan detects these exact functions by name. 458 #ifdef __cplusplus 459 extern "C" { 460 #endif 461 void AnnotateHappensAfter(const char *file, int line, const volatile void *cv); 462 void AnnotateHappensBefore(const char *file, int line, const volatile void *cv); 463 void AnnotateIgnoreWritesBegin(const char *file, int line); 464 void AnnotateIgnoreWritesEnd(const char *file, int line); 465 #ifdef __cplusplus 466 } 467 #endif 468 469 // This marker is used to define a happens-before arc. The race detector will 470 // infer an arc from the begin to the end when they share the same pointer 471 // argument. 472 # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv) 473 474 // This marker defines the destination of a happens-before arc. 475 # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv) 476 477 // Ignore any races on writes between here and the next TsanIgnoreWritesEnd. 478 # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__) 479 480 // Resume checking for racy writes. 481 # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__) 482 #else 483 # define TsanHappensBefore(cv) 484 # define TsanHappensAfter(cv) 485 # define TsanIgnoreWritesBegin() 486 # define TsanIgnoreWritesEnd() 487 #endif 488 489 /// \macro LLVM_NO_SANITIZE 490 /// Disable a particular sanitizer for a function. 491 #if __has_attribute(no_sanitize) 492 #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND))) 493 #else 494 #define LLVM_NO_SANITIZE(KIND) 495 #endif 496 497 /// Mark debug helper function definitions like dump() that should not be 498 /// stripped from debug builds. 499 /// Note that you should also surround dump() functions with 500 /// `#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` so they do always 501 /// get stripped in release builds. 502 // FIXME: Move this to a private config.h as it's not usable in public headers. 503 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 504 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED 505 #else 506 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE 507 #endif 508 509 /// \macro LLVM_PRETTY_FUNCTION 510 /// Gets a user-friendly looking function signature for the current scope 511 /// using the best available method on each platform. The exact format of the 512 /// resulting string is implementation specific and non-portable, so this should 513 /// only be used, for example, for logging or diagnostics. 514 #if defined(_MSC_VER) 515 #define LLVM_PRETTY_FUNCTION __FUNCSIG__ 516 #elif defined(__GNUC__) || defined(__clang__) 517 #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__ 518 #else 519 #define LLVM_PRETTY_FUNCTION __func__ 520 #endif 521 522 /// \macro LLVM_THREAD_LOCAL 523 /// A thread-local storage specifier which can be used with globals, 524 /// extern globals, and static globals. 525 /// 526 /// This is essentially an extremely restricted analog to C++11's thread_local 527 /// support. It uses thread_local if available, falling back on gcc __thread 528 /// if not. __thread doesn't support many of the C++11 thread_local's 529 /// features. You should only use this for PODs that you can statically 530 /// initialize to some constant value. In almost all circumstances this is most 531 /// appropriate for use with a pointer, integer, or small aggregation of 532 /// pointers and integers. 533 #if LLVM_ENABLE_THREADS 534 #if __has_feature(cxx_thread_local) || defined(_MSC_VER) 535 #define LLVM_THREAD_LOCAL thread_local 536 #else 537 // Clang, GCC, and other compatible compilers used __thread prior to C++11 and 538 // we only need the restricted functionality that provides. 539 #define LLVM_THREAD_LOCAL __thread 540 #endif 541 #else // !LLVM_ENABLE_THREADS 542 // If threading is disabled entirely, this compiles to nothing and you get 543 // a normal global variable. 544 #define LLVM_THREAD_LOCAL 545 #endif 546 547 /// \macro LLVM_ENABLE_EXCEPTIONS 548 /// Whether LLVM is built with exception support. 549 #if __has_feature(cxx_exceptions) 550 #define LLVM_ENABLE_EXCEPTIONS 1 551 #elif defined(__GNUC__) && defined(__EXCEPTIONS) 552 #define LLVM_ENABLE_EXCEPTIONS 1 553 #elif defined(_MSC_VER) && defined(_CPPUNWIND) 554 #define LLVM_ENABLE_EXCEPTIONS 1 555 #endif 556 557 /// \macro LLVM_NO_PROFILE_INSTRUMENT_FUNCTION 558 /// Disable the profile instrument for a function. 559 #if __has_attribute(no_profile_instrument_function) 560 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION \ 561 __attribute__((no_profile_instrument_function)) 562 #else 563 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION 564 #endif 565 566 #endif 567