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 #ifdef __cplusplus 21 #include <new> 22 #endif 23 #include <stddef.h> 24 25 #if defined(_MSC_VER) 26 #include <sal.h> 27 #endif 28 29 #ifndef __has_feature 30 # define __has_feature(x) 0 31 #endif 32 33 #ifndef __has_extension 34 # define __has_extension(x) 0 35 #endif 36 37 #ifndef __has_attribute 38 # define __has_attribute(x) 0 39 #endif 40 41 #ifndef __has_builtin 42 # define __has_builtin(x) 0 43 #endif 44 45 // Only use __has_cpp_attribute in C++ mode. GCC defines __has_cpp_attribute in 46 // C mode, but the :: in __has_cpp_attribute(scoped::attribute) is invalid. 47 #ifndef LLVM_HAS_CPP_ATTRIBUTE 48 #if defined(__cplusplus) && defined(__has_cpp_attribute) 49 # define LLVM_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) 50 #else 51 # define LLVM_HAS_CPP_ATTRIBUTE(x) 0 52 #endif 53 #endif 54 55 /// \macro LLVM_GNUC_PREREQ 56 /// Extend the default __GNUC_PREREQ even if glibc's features.h isn't 57 /// available. 58 #ifndef LLVM_GNUC_PREREQ 59 # if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__) 60 # define LLVM_GNUC_PREREQ(maj, min, patch) \ 61 ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \ 62 ((maj) << 20) + ((min) << 10) + (patch)) 63 # elif defined(__GNUC__) && defined(__GNUC_MINOR__) 64 # define LLVM_GNUC_PREREQ(maj, min, patch) \ 65 ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10)) 66 # else 67 # define LLVM_GNUC_PREREQ(maj, min, patch) 0 68 # endif 69 #endif 70 71 /// \macro LLVM_MSC_PREREQ 72 /// Is the compiler MSVC of at least the specified version? 73 /// The common \param version values to check for are: 74 /// * 1910: VS2017, version 15.1 & 15.2 75 /// * 1911: VS2017, version 15.3 & 15.4 76 /// * 1912: VS2017, version 15.5 77 /// * 1913: VS2017, version 15.6 78 /// * 1914: VS2017, version 15.7 79 /// * 1915: VS2017, version 15.8 80 /// * 1916: VS2017, version 15.9 81 /// * 1920: VS2019, version 16.0 82 /// * 1921: VS2019, version 16.1 83 #ifdef _MSC_VER 84 #define LLVM_MSC_PREREQ(version) (_MSC_VER >= (version)) 85 86 // We require at least MSVC 2017. 87 #if !LLVM_MSC_PREREQ(1910) 88 #error LLVM requires at least MSVC 2017. 89 #endif 90 91 #else 92 #define LLVM_MSC_PREREQ(version) 0 93 #endif 94 95 /// Does the compiler support ref-qualifiers for *this? 96 /// 97 /// Sadly, this is separate from just rvalue reference support because GCC 98 /// and MSVC implemented this later than everything else. This appears to be 99 /// corrected in MSVC 2019 but not MSVC 2017. 100 #if __has_feature(cxx_rvalue_references) || LLVM_GNUC_PREREQ(4, 8, 1) 101 #define LLVM_HAS_RVALUE_REFERENCE_THIS 1 102 #else 103 #define LLVM_HAS_RVALUE_REFERENCE_THIS 0 104 #endif 105 106 /// Expands to '&' if ref-qualifiers for *this are supported. 107 /// 108 /// This can be used to provide lvalue/rvalue overrides of member functions. 109 /// The rvalue override should be guarded by LLVM_HAS_RVALUE_REFERENCE_THIS 110 #if LLVM_HAS_RVALUE_REFERENCE_THIS 111 #define LLVM_LVALUE_FUNCTION & 112 #else 113 #define LLVM_LVALUE_FUNCTION 114 #endif 115 116 /// LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked 117 /// into a shared library, then the class should be private to the library and 118 /// not accessible from outside it. Can also be used to mark variables and 119 /// functions, making them private to any shared library they are linked into. 120 /// On PE/COFF targets, library visibility is the default, so this isn't needed. 121 /// 122 /// LLVM_EXTERNAL_VISIBILITY - classes, functions, and variables marked with 123 /// this attribute will be made public and visible outside of any shared library 124 /// they are linked in to. 125 #if (__has_attribute(visibility) || LLVM_GNUC_PREREQ(4, 0, 0)) && \ 126 !defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_WIN32) 127 #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden"))) 128 #define LLVM_EXTERNAL_VISIBILITY __attribute__ ((visibility("default"))) 129 #else 130 #define LLVM_LIBRARY_VISIBILITY 131 #define LLVM_EXTERNAL_VISIBILITY 132 #endif 133 134 #if defined(__GNUC__) 135 #define LLVM_PREFETCH(addr, rw, locality) __builtin_prefetch(addr, rw, locality) 136 #else 137 #define LLVM_PREFETCH(addr, rw, locality) 138 #endif 139 140 #if __has_attribute(used) || LLVM_GNUC_PREREQ(3, 1, 0) 141 #define LLVM_ATTRIBUTE_USED __attribute__((__used__)) 142 #else 143 #define LLVM_ATTRIBUTE_USED 144 #endif 145 146 /// LLVM_NODISCARD - Warn if a type or return value is discarded. 147 148 // Use the 'nodiscard' attribute in C++17 or newer mode. 149 #if __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(nodiscard) 150 #define LLVM_NODISCARD [[nodiscard]] 151 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::warn_unused_result) 152 #define LLVM_NODISCARD [[clang::warn_unused_result]] 153 // Clang in C++14 mode claims that it has the 'nodiscard' attribute, but also 154 // warns in the pedantic mode that 'nodiscard' is a C++17 extension (PR33518). 155 // Use the 'nodiscard' attribute in C++14 mode only with GCC. 156 // TODO: remove this workaround when PR33518 is resolved. 157 #elif defined(__GNUC__) && LLVM_HAS_CPP_ATTRIBUTE(nodiscard) 158 #define LLVM_NODISCARD [[nodiscard]] 159 #else 160 #define LLVM_NODISCARD 161 #endif 162 163 // Indicate that a non-static, non-const C++ member function reinitializes 164 // the entire object to a known state, independent of the previous state of 165 // the object. 166 // 167 // The clang-tidy check bugprone-use-after-move recognizes this attribute as a 168 // marker that a moved-from object has left the indeterminate state and can be 169 // reused. 170 #if LLVM_HAS_CPP_ATTRIBUTE(clang::reinitializes) 171 #define LLVM_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]] 172 #else 173 #define LLVM_ATTRIBUTE_REINITIALIZES 174 #endif 175 176 // Some compilers warn about unused functions. When a function is sometimes 177 // used or not depending on build settings (e.g. a function only called from 178 // within "assert"), this attribute can be used to suppress such warnings. 179 // 180 // However, it shouldn't be used for unused *variables*, as those have a much 181 // more portable solution: 182 // (void)unused_var_name; 183 // Prefer cast-to-void wherever it is sufficient. 184 #if __has_attribute(unused) || LLVM_GNUC_PREREQ(3, 1, 0) 185 #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__)) 186 #else 187 #define LLVM_ATTRIBUTE_UNUSED 188 #endif 189 190 // FIXME: Provide this for PE/COFF targets. 191 #if (__has_attribute(weak) || LLVM_GNUC_PREREQ(4, 0, 0)) && \ 192 (!defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_WIN32)) 193 #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__)) 194 #else 195 #define LLVM_ATTRIBUTE_WEAK 196 #endif 197 198 // Prior to clang 3.2, clang did not accept any spelling of 199 // __has_attribute(const), so assume it is supported. 200 #if defined(__clang__) || defined(__GNUC__) 201 // aka 'CONST' but following LLVM Conventions. 202 #define LLVM_READNONE __attribute__((__const__)) 203 #else 204 #define LLVM_READNONE 205 #endif 206 207 #if __has_attribute(pure) || defined(__GNUC__) 208 // aka 'PURE' but following LLVM Conventions. 209 #define LLVM_READONLY __attribute__((__pure__)) 210 #else 211 #define LLVM_READONLY 212 #endif 213 214 #if __has_builtin(__builtin_expect) || LLVM_GNUC_PREREQ(4, 0, 0) 215 #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true) 216 #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false) 217 #else 218 #define LLVM_LIKELY(EXPR) (EXPR) 219 #define LLVM_UNLIKELY(EXPR) (EXPR) 220 #endif 221 222 /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so, 223 /// mark a method "not for inlining". 224 #if __has_attribute(noinline) || LLVM_GNUC_PREREQ(3, 4, 0) 225 #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline)) 226 #elif defined(_MSC_VER) 227 #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline) 228 #else 229 #define LLVM_ATTRIBUTE_NOINLINE 230 #endif 231 232 /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do 233 /// so, mark a method "always inline" because it is performance sensitive. GCC 234 /// 3.4 supported this but is buggy in various cases and produces unimplemented 235 /// errors, just use it in GCC 4.0 and later. 236 #if __has_attribute(always_inline) || LLVM_GNUC_PREREQ(4, 0, 0) 237 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline)) 238 #elif defined(_MSC_VER) 239 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline 240 #else 241 #define LLVM_ATTRIBUTE_ALWAYS_INLINE 242 #endif 243 244 #ifdef __GNUC__ 245 #define LLVM_ATTRIBUTE_NORETURN __attribute__((noreturn)) 246 #elif defined(_MSC_VER) 247 #define LLVM_ATTRIBUTE_NORETURN __declspec(noreturn) 248 #else 249 #define LLVM_ATTRIBUTE_NORETURN 250 #endif 251 252 #if __has_attribute(returns_nonnull) || LLVM_GNUC_PREREQ(4, 9, 0) 253 #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull)) 254 #elif defined(_MSC_VER) 255 #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_ 256 #else 257 #define LLVM_ATTRIBUTE_RETURNS_NONNULL 258 #endif 259 260 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a 261 /// pointer that does not alias any other valid pointer. 262 #ifdef __GNUC__ 263 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__)) 264 #elif defined(_MSC_VER) 265 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict) 266 #else 267 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS 268 #endif 269 270 /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements. 271 #if __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(fallthrough) 272 #define LLVM_FALLTHROUGH [[fallthrough]] 273 #elif LLVM_HAS_CPP_ATTRIBUTE(gnu::fallthrough) 274 #define LLVM_FALLTHROUGH [[gnu::fallthrough]] 275 #elif __has_attribute(fallthrough) 276 #define LLVM_FALLTHROUGH __attribute__((fallthrough)) 277 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::fallthrough) 278 #define LLVM_FALLTHROUGH [[clang::fallthrough]] 279 #else 280 #define LLVM_FALLTHROUGH 281 #endif 282 283 /// LLVM_REQUIRE_CONSTANT_INITIALIZATION - Apply this to globals to ensure that 284 /// they are constant initialized. 285 #if LLVM_HAS_CPP_ATTRIBUTE(clang::require_constant_initialization) 286 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION \ 287 [[clang::require_constant_initialization]] 288 #else 289 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION 290 #endif 291 292 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress 293 /// pedantic diagnostics. 294 #ifdef __GNUC__ 295 #define LLVM_EXTENSION __extension__ 296 #else 297 #define LLVM_EXTENSION 298 #endif 299 300 // LLVM_ATTRIBUTE_DEPRECATED(decl, "message") 301 #if __has_feature(attribute_deprecated_with_message) 302 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ 303 decl __attribute__((deprecated(message))) 304 #elif defined(__GNUC__) 305 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ 306 decl __attribute__((deprecated)) 307 #elif defined(_MSC_VER) 308 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ 309 __declspec(deprecated(message)) decl 310 #else 311 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ 312 decl 313 #endif 314 315 /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands 316 /// to an expression which states that it is undefined behavior for the 317 /// compiler to reach this point. Otherwise is not defined. 318 #if __has_builtin(__builtin_unreachable) || LLVM_GNUC_PREREQ(4, 5, 0) 319 # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable() 320 #elif defined(_MSC_VER) 321 # define LLVM_BUILTIN_UNREACHABLE __assume(false) 322 #endif 323 324 /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression 325 /// which causes the program to exit abnormally. 326 #if __has_builtin(__builtin_trap) || LLVM_GNUC_PREREQ(4, 3, 0) 327 # define LLVM_BUILTIN_TRAP __builtin_trap() 328 #elif defined(_MSC_VER) 329 // The __debugbreak intrinsic is supported by MSVC, does not require forward 330 // declarations involving platform-specific typedefs (unlike RaiseException), 331 // results in a call to vectored exception handlers, and encodes to a short 332 // instruction that still causes the trapping behavior we want. 333 # define LLVM_BUILTIN_TRAP __debugbreak() 334 #else 335 # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0 336 #endif 337 338 /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to 339 /// an expression which causes the program to break while running 340 /// under a debugger. 341 #if __has_builtin(__builtin_debugtrap) 342 # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap() 343 #elif defined(_MSC_VER) 344 // The __debugbreak intrinsic is supported by MSVC and breaks while 345 // running under the debugger, and also supports invoking a debugger 346 // when the OS is configured appropriately. 347 # define LLVM_BUILTIN_DEBUGTRAP __debugbreak() 348 #else 349 // Just continue execution when built with compilers that have no 350 // support. This is a debugging aid and not intended to force the 351 // program to abort if encountered. 352 # define LLVM_BUILTIN_DEBUGTRAP 353 #endif 354 355 /// \macro LLVM_ASSUME_ALIGNED 356 /// Returns a pointer with an assumed alignment. 357 #if __has_builtin(__builtin_assume_aligned) || LLVM_GNUC_PREREQ(4, 7, 0) 358 # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a) 359 #elif defined(LLVM_BUILTIN_UNREACHABLE) 360 // As of today, clang does not support __builtin_assume_aligned. 361 # define LLVM_ASSUME_ALIGNED(p, a) \ 362 (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p))) 363 #else 364 # define LLVM_ASSUME_ALIGNED(p, a) (p) 365 #endif 366 367 /// \macro LLVM_PACKED 368 /// Used to specify a packed structure. 369 /// LLVM_PACKED( 370 /// struct A { 371 /// int i; 372 /// int j; 373 /// int k; 374 /// long long l; 375 /// }); 376 /// 377 /// LLVM_PACKED_START 378 /// struct B { 379 /// int i; 380 /// int j; 381 /// int k; 382 /// long long l; 383 /// }; 384 /// LLVM_PACKED_END 385 #ifdef _MSC_VER 386 # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop)) 387 # define LLVM_PACKED_START __pragma(pack(push, 1)) 388 # define LLVM_PACKED_END __pragma(pack(pop)) 389 #else 390 # define LLVM_PACKED(d) d __attribute__((packed)) 391 # define LLVM_PACKED_START _Pragma("pack(push, 1)") 392 # define LLVM_PACKED_END _Pragma("pack(pop)") 393 #endif 394 395 /// \macro LLVM_PTR_SIZE 396 /// A constant integer equivalent to the value of sizeof(void*). 397 /// Generally used in combination with alignas or when doing computation in the 398 /// preprocessor. 399 #ifdef __SIZEOF_POINTER__ 400 # define LLVM_PTR_SIZE __SIZEOF_POINTER__ 401 #elif defined(_WIN64) 402 # define LLVM_PTR_SIZE 8 403 #elif defined(_WIN32) 404 # define LLVM_PTR_SIZE 4 405 #elif defined(_MSC_VER) 406 # error "could not determine LLVM_PTR_SIZE as a constant int for MSVC" 407 #else 408 # define LLVM_PTR_SIZE sizeof(void *) 409 #endif 410 411 /// \macro LLVM_MEMORY_SANITIZER_BUILD 412 /// Whether LLVM itself is built with MemorySanitizer instrumentation. 413 #if __has_feature(memory_sanitizer) 414 # define LLVM_MEMORY_SANITIZER_BUILD 1 415 # include <sanitizer/msan_interface.h> 416 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE __attribute__((no_sanitize_memory)) 417 #else 418 # define LLVM_MEMORY_SANITIZER_BUILD 0 419 # define __msan_allocated_memory(p, size) 420 # define __msan_unpoison(p, size) 421 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE 422 #endif 423 424 /// \macro LLVM_ADDRESS_SANITIZER_BUILD 425 /// Whether LLVM itself is built with AddressSanitizer instrumentation. 426 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) 427 # define LLVM_ADDRESS_SANITIZER_BUILD 1 428 # include <sanitizer/asan_interface.h> 429 #else 430 # define LLVM_ADDRESS_SANITIZER_BUILD 0 431 # define __asan_poison_memory_region(p, size) 432 # define __asan_unpoison_memory_region(p, size) 433 #endif 434 435 /// \macro LLVM_THREAD_SANITIZER_BUILD 436 /// Whether LLVM itself is built with ThreadSanitizer instrumentation. 437 #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__) 438 # define LLVM_THREAD_SANITIZER_BUILD 1 439 #else 440 # define LLVM_THREAD_SANITIZER_BUILD 0 441 #endif 442 443 #if LLVM_THREAD_SANITIZER_BUILD 444 // Thread Sanitizer is a tool that finds races in code. 445 // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations . 446 // tsan detects these exact functions by name. 447 #ifdef __cplusplus 448 extern "C" { 449 #endif 450 void AnnotateHappensAfter(const char *file, int line, const volatile void *cv); 451 void AnnotateHappensBefore(const char *file, int line, const volatile void *cv); 452 void AnnotateIgnoreWritesBegin(const char *file, int line); 453 void AnnotateIgnoreWritesEnd(const char *file, int line); 454 #ifdef __cplusplus 455 } 456 #endif 457 458 // This marker is used to define a happens-before arc. The race detector will 459 // infer an arc from the begin to the end when they share the same pointer 460 // argument. 461 # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv) 462 463 // This marker defines the destination of a happens-before arc. 464 # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv) 465 466 // Ignore any races on writes between here and the next TsanIgnoreWritesEnd. 467 # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__) 468 469 // Resume checking for racy writes. 470 # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__) 471 #else 472 # define TsanHappensBefore(cv) 473 # define TsanHappensAfter(cv) 474 # define TsanIgnoreWritesBegin() 475 # define TsanIgnoreWritesEnd() 476 #endif 477 478 /// \macro LLVM_NO_SANITIZE 479 /// Disable a particular sanitizer for a function. 480 #if __has_attribute(no_sanitize) 481 #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND))) 482 #else 483 #define LLVM_NO_SANITIZE(KIND) 484 #endif 485 486 /// Mark debug helper function definitions like dump() that should not be 487 /// stripped from debug builds. 488 /// Note that you should also surround dump() functions with 489 /// `#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` so they do always 490 /// get stripped in release builds. 491 // FIXME: Move this to a private config.h as it's not usable in public headers. 492 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 493 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED 494 #else 495 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE 496 #endif 497 498 /// \macro LLVM_PRETTY_FUNCTION 499 /// Gets a user-friendly looking function signature for the current scope 500 /// using the best available method on each platform. The exact format of the 501 /// resulting string is implementation specific and non-portable, so this should 502 /// only be used, for example, for logging or diagnostics. 503 #if defined(_MSC_VER) 504 #define LLVM_PRETTY_FUNCTION __FUNCSIG__ 505 #elif defined(__GNUC__) || defined(__clang__) 506 #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__ 507 #else 508 #define LLVM_PRETTY_FUNCTION __func__ 509 #endif 510 511 /// \macro LLVM_THREAD_LOCAL 512 /// A thread-local storage specifier which can be used with globals, 513 /// extern globals, and static globals. 514 /// 515 /// This is essentially an extremely restricted analog to C++11's thread_local 516 /// support. It uses thread_local if available, falling back on gcc __thread 517 /// if not. __thread doesn't support many of the C++11 thread_local's 518 /// features. You should only use this for PODs that you can statically 519 /// initialize to some constant value. In almost all circumstances this is most 520 /// appropriate for use with a pointer, integer, or small aggregation of 521 /// pointers and integers. 522 #if LLVM_ENABLE_THREADS 523 #if __has_feature(cxx_thread_local) || defined(_MSC_VER) 524 #define LLVM_THREAD_LOCAL thread_local 525 #else 526 // Clang, GCC, and other compatible compilers used __thread prior to C++11 and 527 // we only need the restricted functionality that provides. 528 #define LLVM_THREAD_LOCAL __thread 529 #endif 530 #else // !LLVM_ENABLE_THREADS 531 // If threading is disabled entirely, this compiles to nothing and you get 532 // a normal global variable. 533 #define LLVM_THREAD_LOCAL 534 #endif 535 536 /// \macro LLVM_ENABLE_EXCEPTIONS 537 /// Whether LLVM is built with exception support. 538 #if __has_feature(cxx_exceptions) 539 #define LLVM_ENABLE_EXCEPTIONS 1 540 #elif defined(__GNUC__) && defined(__EXCEPTIONS) 541 #define LLVM_ENABLE_EXCEPTIONS 1 542 #elif defined(_MSC_VER) && defined(_CPPUNWIND) 543 #define LLVM_ENABLE_EXCEPTIONS 1 544 #endif 545 546 #ifdef __cplusplus 547 namespace llvm { 548 549 /// Allocate a buffer of memory with the given size and alignment. 550 /// 551 /// When the compiler supports aligned operator new, this will use it to to 552 /// handle even over-aligned allocations. 553 /// 554 /// However, this doesn't make any attempt to leverage the fancier techniques 555 /// like posix_memalign due to portability. It is mostly intended to allow 556 /// compatibility with platforms that, after aligned allocation was added, use 557 /// reduced default alignment. 558 inline void *allocate_buffer(size_t Size, size_t Alignment) { 559 return ::operator new(Size 560 #ifdef __cpp_aligned_new 561 , 562 std::align_val_t(Alignment) 563 #endif 564 ); 565 } 566 567 /// Deallocate a buffer of memory with the given size and alignment. 568 /// 569 /// If supported, this will used the sized delete operator. Also if supported, 570 /// this will pass the alignment to the delete operator. 571 /// 572 /// The pointer must have been allocated with the corresponding new operator, 573 /// most likely using the above helper. 574 inline void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment) { 575 ::operator delete(Ptr 576 #ifdef __cpp_sized_deallocation 577 , 578 Size 579 #endif 580 #ifdef __cpp_aligned_new 581 , 582 std::align_val_t(Alignment) 583 #endif 584 ); 585 } 586 587 } // End namespace llvm 588 589 #endif // __cplusplus 590 #endif 591