xref: /freebsd/contrib/llvm-project/llvm/include/llvm/Support/Compiler.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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 // clang-format off
161 #if defined(__clang__) || defined(__GNUC__)
162 #define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH                             \
163   _Pragma("GCC diagnostic push")                                               \
164   _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
165 #define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP                              \
166   _Pragma("GCC diagnostic pop")
167 #elif defined(_MSC_VER)
168 #define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH                             \
169   _Pragma("warning(push)")                                                     \
170   _Pragma("warning(disable : 4996)")
171 #define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP                              \
172   _Pragma("warning(pop)")
173 #else
174 #define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH
175 #define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP
176 #endif
177 // clang-format on
178 
179 // Indicate that a non-static, non-const C++ member function reinitializes
180 // the entire object to a known state, independent of the previous state of
181 // the object.
182 //
183 // The clang-tidy check bugprone-use-after-move recognizes this attribute as a
184 // marker that a moved-from object has left the indeterminate state and can be
185 // reused.
186 #if LLVM_HAS_CPP_ATTRIBUTE(clang::reinitializes)
187 #define LLVM_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
188 #else
189 #define LLVM_ATTRIBUTE_REINITIALIZES
190 #endif
191 
192 // Some compilers warn about unused functions. When a function is sometimes
193 // used or not depending on build settings (e.g. a function only called from
194 // within "assert"), this attribute can be used to suppress such warnings.
195 //
196 // However, it shouldn't be used for unused *variables*, as those have a much
197 // more portable solution:
198 //   (void)unused_var_name;
199 // Prefer cast-to-void wherever it is sufficient.
200 #if __has_attribute(unused)
201 #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__))
202 #else
203 #define LLVM_ATTRIBUTE_UNUSED
204 #endif
205 
206 // FIXME: Provide this for PE/COFF targets.
207 #if __has_attribute(weak) && !defined(__MINGW32__) && !defined(__CYGWIN__) &&  \
208     !defined(_WIN32)
209 #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__))
210 #else
211 #define LLVM_ATTRIBUTE_WEAK
212 #endif
213 
214 // Prior to clang 3.2, clang did not accept any spelling of
215 // __has_attribute(const), so assume it is supported.
216 #if defined(__clang__) || defined(__GNUC__)
217 // aka 'CONST' but following LLVM Conventions.
218 #define LLVM_READNONE __attribute__((__const__))
219 #else
220 #define LLVM_READNONE
221 #endif
222 
223 #if __has_attribute(pure) || defined(__GNUC__)
224 // aka 'PURE' but following LLVM Conventions.
225 #define LLVM_READONLY __attribute__((__pure__))
226 #else
227 #define LLVM_READONLY
228 #endif
229 
230 #if __has_attribute(minsize)
231 #define LLVM_ATTRIBUTE_MINSIZE __attribute__((minsize))
232 #else
233 #define LLVM_ATTRIBUTE_MINSIZE
234 #endif
235 
236 #if __has_builtin(__builtin_expect) || defined(__GNUC__)
237 #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true)
238 #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false)
239 #else
240 #define LLVM_LIKELY(EXPR) (EXPR)
241 #define LLVM_UNLIKELY(EXPR) (EXPR)
242 #endif
243 
244 /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so,
245 /// mark a method "not for inlining".
246 #if __has_attribute(noinline)
247 #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
248 #elif defined(_MSC_VER)
249 #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
250 #else
251 #define LLVM_ATTRIBUTE_NOINLINE
252 #endif
253 
254 /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do
255 /// so, mark a method "always inline" because it is performance sensitive.
256 #if __has_attribute(always_inline)
257 #define LLVM_ATTRIBUTE_ALWAYS_INLINE inline __attribute__((always_inline))
258 #elif defined(_MSC_VER)
259 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline
260 #else
261 #define LLVM_ATTRIBUTE_ALWAYS_INLINE inline
262 #endif
263 
264 /// LLVM_ATTRIBUTE_NO_DEBUG - On compilers where we have a directive to do
265 /// so, mark a method "no debug" because debug info makes the debugger
266 /// experience worse.
267 #if __has_attribute(nodebug)
268 #define LLVM_ATTRIBUTE_NODEBUG __attribute__((nodebug))
269 #else
270 #define LLVM_ATTRIBUTE_NODEBUG
271 #endif
272 
273 #if __has_attribute(returns_nonnull)
274 #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull))
275 #elif defined(_MSC_VER)
276 #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_
277 #else
278 #define LLVM_ATTRIBUTE_RETURNS_NONNULL
279 #endif
280 
281 /// LLVM_ATTRIBUTE_RESTRICT - Annotates a pointer to tell the compiler that
282 /// it is not aliased in the current scope.
283 #if defined(__clang__) || defined(__GNUC__) || defined(_MSC_VER)
284 #define LLVM_ATTRIBUTE_RESTRICT __restrict
285 #else
286 #define LLVM_ATTRIBUTE_RESTRICT
287 #endif
288 
289 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a
290 /// pointer that does not alias any other valid pointer.
291 #ifdef __GNUC__
292 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__))
293 #elif defined(_MSC_VER)
294 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict)
295 #else
296 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS
297 #endif
298 
299 /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
300 #if defined(__cplusplus) && __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(fallthrough)
301 #define LLVM_FALLTHROUGH [[fallthrough]]
302 #elif LLVM_HAS_CPP_ATTRIBUTE(gnu::fallthrough)
303 #define LLVM_FALLTHROUGH [[gnu::fallthrough]]
304 #elif __has_attribute(fallthrough)
305 #define LLVM_FALLTHROUGH __attribute__((fallthrough))
306 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::fallthrough)
307 #define LLVM_FALLTHROUGH [[clang::fallthrough]]
308 #else
309 #define LLVM_FALLTHROUGH
310 #endif
311 
312 /// LLVM_REQUIRE_CONSTANT_INITIALIZATION - Apply this to globals to ensure that
313 /// they are constant initialized.
314 #if LLVM_HAS_CPP_ATTRIBUTE(clang::require_constant_initialization)
315 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION                                   \
316   [[clang::require_constant_initialization]]
317 #else
318 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION
319 #endif
320 
321 /// LLVM_GSL_OWNER - Apply this to owning classes like SmallVector to enable
322 /// lifetime warnings.
323 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Owner)
324 #define LLVM_GSL_OWNER [[gsl::Owner]]
325 #else
326 #define LLVM_GSL_OWNER
327 #endif
328 
329 /// LLVM_GSL_POINTER - Apply this to non-owning classes like
330 /// StringRef to enable lifetime warnings.
331 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Pointer)
332 #define LLVM_GSL_POINTER [[gsl::Pointer]]
333 #else
334 #define LLVM_GSL_POINTER
335 #endif
336 
337 #if LLVM_HAS_CPP_ATTRIBUTE(nodiscard) >= 201907L
338 #define LLVM_CTOR_NODISCARD [[nodiscard]]
339 #else
340 #define LLVM_CTOR_NODISCARD
341 #endif
342 
343 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
344 /// pedantic diagnostics.
345 #ifdef __GNUC__
346 #define LLVM_EXTENSION __extension__
347 #else
348 #define LLVM_EXTENSION
349 #endif
350 
351 /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands
352 /// to an expression which states that it is undefined behavior for the
353 /// compiler to reach this point.  Otherwise is not defined.
354 ///
355 /// '#else' is intentionally left out so that other macro logic (e.g.,
356 /// LLVM_ASSUME_ALIGNED and llvm_unreachable()) can detect whether
357 /// LLVM_BUILTIN_UNREACHABLE has a definition.
358 #if __has_builtin(__builtin_unreachable) || defined(__GNUC__)
359 # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
360 #elif defined(_MSC_VER)
361 # define LLVM_BUILTIN_UNREACHABLE __assume(false)
362 #endif
363 
364 /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression
365 /// which causes the program to exit abnormally.
366 #if __has_builtin(__builtin_trap) || defined(__GNUC__)
367 # define LLVM_BUILTIN_TRAP __builtin_trap()
368 #elif defined(_MSC_VER)
369 // The __debugbreak intrinsic is supported by MSVC, does not require forward
370 // declarations involving platform-specific typedefs (unlike RaiseException),
371 // results in a call to vectored exception handlers, and encodes to a short
372 // instruction that still causes the trapping behavior we want.
373 # define LLVM_BUILTIN_TRAP __debugbreak()
374 #else
375 # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0
376 #endif
377 
378 /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to
379 /// an expression which causes the program to break while running
380 /// under a debugger.
381 #if __has_builtin(__builtin_debugtrap)
382 # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap()
383 #elif defined(_MSC_VER)
384 // The __debugbreak intrinsic is supported by MSVC and breaks while
385 // running under the debugger, and also supports invoking a debugger
386 // when the OS is configured appropriately.
387 # define LLVM_BUILTIN_DEBUGTRAP __debugbreak()
388 #else
389 // Just continue execution when built with compilers that have no
390 // support. This is a debugging aid and not intended to force the
391 // program to abort if encountered.
392 # define LLVM_BUILTIN_DEBUGTRAP
393 #endif
394 
395 /// \macro LLVM_ASSUME_ALIGNED
396 /// Returns a pointer with an assumed alignment.
397 #if __has_builtin(__builtin_assume_aligned) || defined(__GNUC__)
398 # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a)
399 #elif defined(LLVM_BUILTIN_UNREACHABLE)
400 # define LLVM_ASSUME_ALIGNED(p, a) \
401            (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p)))
402 #else
403 # define LLVM_ASSUME_ALIGNED(p, a) (p)
404 #endif
405 
406 /// \macro LLVM_PACKED
407 /// Used to specify a packed structure.
408 /// LLVM_PACKED(
409 ///    struct A {
410 ///      int i;
411 ///      int j;
412 ///      int k;
413 ///      long long l;
414 ///   });
415 ///
416 /// LLVM_PACKED_START
417 /// struct B {
418 ///   int i;
419 ///   int j;
420 ///   int k;
421 ///   long long l;
422 /// };
423 /// LLVM_PACKED_END
424 #ifdef _MSC_VER
425 # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop))
426 # define LLVM_PACKED_START __pragma(pack(push, 1))
427 # define LLVM_PACKED_END   __pragma(pack(pop))
428 #else
429 # define LLVM_PACKED(d) d __attribute__((packed))
430 # define LLVM_PACKED_START _Pragma("pack(push, 1)")
431 # define LLVM_PACKED_END   _Pragma("pack(pop)")
432 #endif
433 
434 /// \macro LLVM_MEMORY_SANITIZER_BUILD
435 /// Whether LLVM itself is built with MemorySanitizer instrumentation.
436 #if __has_feature(memory_sanitizer)
437 # define LLVM_MEMORY_SANITIZER_BUILD 1
438 # include <sanitizer/msan_interface.h>
439 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE __attribute__((no_sanitize_memory))
440 #else
441 # define LLVM_MEMORY_SANITIZER_BUILD 0
442 # define __msan_allocated_memory(p, size)
443 # define __msan_unpoison(p, size)
444 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE
445 #endif
446 
447 /// \macro LLVM_ADDRESS_SANITIZER_BUILD
448 /// Whether LLVM itself is built with AddressSanitizer instrumentation.
449 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
450 # define LLVM_ADDRESS_SANITIZER_BUILD 1
451 #if __has_include(<sanitizer/asan_interface.h>)
452 # include <sanitizer/asan_interface.h>
453 #else
454 // These declarations exist to support ASan with MSVC. If MSVC eventually ships
455 // asan_interface.h in their headers, then we can remove this.
456 #ifdef __cplusplus
457 extern "C" {
458 #endif
459 void __asan_poison_memory_region(void const volatile *addr, size_t size);
460 void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
461 #ifdef __cplusplus
462 } // extern "C"
463 #endif
464 #endif
465 #else
466 # define LLVM_ADDRESS_SANITIZER_BUILD 0
467 # define __asan_poison_memory_region(p, size)
468 # define __asan_unpoison_memory_region(p, size)
469 #endif
470 
471 /// \macro LLVM_HWADDRESS_SANITIZER_BUILD
472 /// Whether LLVM itself is built with HWAddressSanitizer instrumentation.
473 #if __has_feature(hwaddress_sanitizer)
474 #define LLVM_HWADDRESS_SANITIZER_BUILD 1
475 #else
476 #define LLVM_HWADDRESS_SANITIZER_BUILD 0
477 #endif
478 
479 /// \macro LLVM_THREAD_SANITIZER_BUILD
480 /// Whether LLVM itself is built with ThreadSanitizer instrumentation.
481 #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
482 # define LLVM_THREAD_SANITIZER_BUILD 1
483 #else
484 # define LLVM_THREAD_SANITIZER_BUILD 0
485 #endif
486 
487 #if LLVM_THREAD_SANITIZER_BUILD
488 // Thread Sanitizer is a tool that finds races in code.
489 // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations .
490 // tsan detects these exact functions by name.
491 #ifdef __cplusplus
492 extern "C" {
493 #endif
494 void AnnotateHappensAfter(const char *file, int line, const volatile void *cv);
495 void AnnotateHappensBefore(const char *file, int line, const volatile void *cv);
496 void AnnotateIgnoreWritesBegin(const char *file, int line);
497 void AnnotateIgnoreWritesEnd(const char *file, int line);
498 #ifdef __cplusplus
499 }
500 #endif
501 
502 // This marker is used to define a happens-before arc. The race detector will
503 // infer an arc from the begin to the end when they share the same pointer
504 // argument.
505 # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv)
506 
507 // This marker defines the destination of a happens-before arc.
508 # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv)
509 
510 // Ignore any races on writes between here and the next TsanIgnoreWritesEnd.
511 # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
512 
513 // Resume checking for racy writes.
514 # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
515 #else
516 # define TsanHappensBefore(cv)
517 # define TsanHappensAfter(cv)
518 # define TsanIgnoreWritesBegin()
519 # define TsanIgnoreWritesEnd()
520 #endif
521 
522 /// \macro LLVM_NO_SANITIZE
523 /// Disable a particular sanitizer for a function.
524 #if __has_attribute(no_sanitize)
525 #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND)))
526 #else
527 #define LLVM_NO_SANITIZE(KIND)
528 #endif
529 
530 /// Mark debug helper function definitions like dump() that should not be
531 /// stripped from debug builds.
532 /// Note that you should also surround dump() functions with
533 /// `#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` so they do always
534 /// get stripped in release builds.
535 // FIXME: Move this to a private config.h as it's not usable in public headers.
536 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
537 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
538 #else
539 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
540 #endif
541 
542 /// \macro LLVM_PRETTY_FUNCTION
543 /// Gets a user-friendly looking function signature for the current scope
544 /// using the best available method on each platform.  The exact format of the
545 /// resulting string is implementation specific and non-portable, so this should
546 /// only be used, for example, for logging or diagnostics.
547 #if defined(_MSC_VER)
548 #define LLVM_PRETTY_FUNCTION __FUNCSIG__
549 #elif defined(__GNUC__) || defined(__clang__)
550 #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__
551 #else
552 #define LLVM_PRETTY_FUNCTION __func__
553 #endif
554 
555 /// \macro LLVM_THREAD_LOCAL
556 /// A thread-local storage specifier which can be used with globals,
557 /// extern globals, and static globals.
558 ///
559 /// This is essentially an extremely restricted analog to C++11's thread_local
560 /// support. It uses thread_local if available, falling back on gcc __thread
561 /// if not. __thread doesn't support many of the C++11 thread_local's
562 /// features. You should only use this for PODs that you can statically
563 /// initialize to some constant value. In almost all circumstances this is most
564 /// appropriate for use with a pointer, integer, or small aggregation of
565 /// pointers and integers.
566 #if LLVM_ENABLE_THREADS
567 #if __has_feature(cxx_thread_local) || defined(_MSC_VER)
568 #define LLVM_THREAD_LOCAL thread_local
569 #else
570 // Clang, GCC, and other compatible compilers used __thread prior to C++11 and
571 // we only need the restricted functionality that provides.
572 #define LLVM_THREAD_LOCAL __thread
573 #endif
574 #else // !LLVM_ENABLE_THREADS
575 // If threading is disabled entirely, this compiles to nothing and you get
576 // a normal global variable.
577 #define LLVM_THREAD_LOCAL
578 #endif
579 
580 /// \macro LLVM_ENABLE_EXCEPTIONS
581 /// Whether LLVM is built with exception support.
582 #if __has_feature(cxx_exceptions)
583 #define LLVM_ENABLE_EXCEPTIONS 1
584 #elif defined(__GNUC__) && defined(__EXCEPTIONS)
585 #define LLVM_ENABLE_EXCEPTIONS 1
586 #elif defined(_MSC_VER) && defined(_CPPUNWIND)
587 #define LLVM_ENABLE_EXCEPTIONS 1
588 #endif
589 
590 /// \macro LLVM_NO_PROFILE_INSTRUMENT_FUNCTION
591 /// Disable the profile instrument for a function.
592 #if __has_attribute(no_profile_instrument_function)
593 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION                                    \
594   __attribute__((no_profile_instrument_function))
595 #else
596 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION
597 #endif
598 
599 /// \macro LLVM_PREFERRED_TYPE
600 /// Adjust type of bit-field in debug info.
601 #if __has_attribute(preferred_type)
602 #define LLVM_PREFERRED_TYPE(T) __attribute__((preferred_type(T)))
603 #else
604 #define LLVM_PREFERRED_TYPE(T)
605 #endif
606 
607 #endif
608