xref: /openbsd-src/gnu/llvm/llvm/include/llvm/Support/Compiler.h (revision d415bd752c734aee168c4ee86ff32e8cc249eb16)
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 #if __has_attribute(visibility) &&                                             \
117     (!(defined(_WIN32) || defined(__CYGWIN__)) ||                              \
118      (defined(__MINGW32__) && defined(__clang__)))
119 #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden")))
120 #if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS)
121 #define LLVM_EXTERNAL_VISIBILITY __attribute__((visibility("default")))
122 #else
123 #define LLVM_EXTERNAL_VISIBILITY
124 #endif
125 #else
126 #define LLVM_LIBRARY_VISIBILITY
127 #define LLVM_EXTERNAL_VISIBILITY
128 #endif
129 
130 #if defined(__GNUC__)
131 #define LLVM_PREFETCH(addr, rw, locality) __builtin_prefetch(addr, rw, locality)
132 #else
133 #define LLVM_PREFETCH(addr, rw, locality)
134 #endif
135 
136 #if __has_attribute(used)
137 #define LLVM_ATTRIBUTE_USED __attribute__((__used__))
138 #else
139 #define LLVM_ATTRIBUTE_USED
140 #endif
141 
142 #if defined(__clang__)
143 #define LLVM_DEPRECATED(MSG, FIX) __attribute__((deprecated(MSG, FIX)))
144 #else
145 #define LLVM_DEPRECATED(MSG, FIX) [[deprecated(MSG)]]
146 #endif
147 
148 // Indicate that a non-static, non-const C++ member function reinitializes
149 // the entire object to a known state, independent of the previous state of
150 // the object.
151 //
152 // The clang-tidy check bugprone-use-after-move recognizes this attribute as a
153 // marker that a moved-from object has left the indeterminate state and can be
154 // reused.
155 #if LLVM_HAS_CPP_ATTRIBUTE(clang::reinitializes)
156 #define LLVM_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
157 #else
158 #define LLVM_ATTRIBUTE_REINITIALIZES
159 #endif
160 
161 // Some compilers warn about unused functions. When a function is sometimes
162 // used or not depending on build settings (e.g. a function only called from
163 // within "assert"), this attribute can be used to suppress such warnings.
164 //
165 // However, it shouldn't be used for unused *variables*, as those have a much
166 // more portable solution:
167 //   (void)unused_var_name;
168 // Prefer cast-to-void wherever it is sufficient.
169 #if __has_attribute(unused)
170 #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__))
171 #else
172 #define LLVM_ATTRIBUTE_UNUSED
173 #endif
174 
175 // FIXME: Provide this for PE/COFF targets.
176 #if __has_attribute(weak) && !defined(__MINGW32__) && !defined(__CYGWIN__) &&  \
177     !defined(_WIN32)
178 #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__))
179 #else
180 #define LLVM_ATTRIBUTE_WEAK
181 #endif
182 
183 // Prior to clang 3.2, clang did not accept any spelling of
184 // __has_attribute(const), so assume it is supported.
185 #if defined(__clang__) || defined(__GNUC__)
186 // aka 'CONST' but following LLVM Conventions.
187 #define LLVM_READNONE __attribute__((__const__))
188 #else
189 #define LLVM_READNONE
190 #endif
191 
192 #if __has_attribute(pure) || defined(__GNUC__)
193 // aka 'PURE' but following LLVM Conventions.
194 #define LLVM_READONLY __attribute__((__pure__))
195 #else
196 #define LLVM_READONLY
197 #endif
198 
199 #if __has_attribute(minsize)
200 #define LLVM_ATTRIBUTE_MINSIZE __attribute__((minsize))
201 #else
202 #define LLVM_ATTRIBUTE_MINSIZE
203 #endif
204 
205 #if __has_builtin(__builtin_expect) || defined(__GNUC__)
206 #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true)
207 #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false)
208 #else
209 #define LLVM_LIKELY(EXPR) (EXPR)
210 #define LLVM_UNLIKELY(EXPR) (EXPR)
211 #endif
212 
213 /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so,
214 /// mark a method "not for inlining".
215 #if __has_attribute(noinline)
216 #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
217 #elif defined(_MSC_VER)
218 #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
219 #else
220 #define LLVM_ATTRIBUTE_NOINLINE
221 #endif
222 
223 /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do
224 /// so, mark a method "always inline" because it is performance sensitive.
225 #if __has_attribute(always_inline)
226 #define LLVM_ATTRIBUTE_ALWAYS_INLINE inline __attribute__((always_inline))
227 #elif defined(_MSC_VER)
228 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline
229 #else
230 #define LLVM_ATTRIBUTE_ALWAYS_INLINE inline
231 #endif
232 
233 /// LLVM_ATTRIBUTE_NO_DEBUG - On compilers where we have a directive to do
234 /// so, mark a method "no debug" because debug info makes the debugger
235 /// experience worse.
236 #if __has_attribute(nodebug)
237 #define LLVM_ATTRIBUTE_NODEBUG __attribute__((nodebug))
238 #else
239 #define LLVM_ATTRIBUTE_NODEBUG
240 #endif
241 
242 #if __has_attribute(returns_nonnull)
243 #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull))
244 #elif defined(_MSC_VER)
245 #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_
246 #else
247 #define LLVM_ATTRIBUTE_RETURNS_NONNULL
248 #endif
249 
250 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a
251 /// pointer that does not alias any other valid pointer.
252 #ifdef __GNUC__
253 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__))
254 #elif defined(_MSC_VER)
255 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict)
256 #else
257 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS
258 #endif
259 
260 /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
261 #if defined(__cplusplus) && __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(fallthrough)
262 #define LLVM_FALLTHROUGH [[fallthrough]]
263 #elif LLVM_HAS_CPP_ATTRIBUTE(gnu::fallthrough)
264 #define LLVM_FALLTHROUGH [[gnu::fallthrough]]
265 #elif __has_attribute(fallthrough)
266 #define LLVM_FALLTHROUGH __attribute__((fallthrough))
267 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::fallthrough)
268 #define LLVM_FALLTHROUGH [[clang::fallthrough]]
269 #else
270 #define LLVM_FALLTHROUGH
271 #endif
272 
273 /// LLVM_REQUIRE_CONSTANT_INITIALIZATION - Apply this to globals to ensure that
274 /// they are constant initialized.
275 #if LLVM_HAS_CPP_ATTRIBUTE(clang::require_constant_initialization)
276 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION                                   \
277   [[clang::require_constant_initialization]]
278 #else
279 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION
280 #endif
281 
282 /// LLVM_GSL_OWNER - Apply this to owning classes like SmallVector to enable
283 /// lifetime warnings.
284 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Owner)
285 #define LLVM_GSL_OWNER [[gsl::Owner]]
286 #else
287 #define LLVM_GSL_OWNER
288 #endif
289 
290 /// LLVM_GSL_POINTER - Apply this to non-owning classes like
291 /// StringRef to enable lifetime warnings.
292 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Pointer)
293 #define LLVM_GSL_POINTER [[gsl::Pointer]]
294 #else
295 #define LLVM_GSL_POINTER
296 #endif
297 
298 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
299 /// pedantic diagnostics.
300 #ifdef __GNUC__
301 #define LLVM_EXTENSION __extension__
302 #else
303 #define LLVM_EXTENSION
304 #endif
305 
306 /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands
307 /// to an expression which states that it is undefined behavior for the
308 /// compiler to reach this point.  Otherwise is not defined.
309 ///
310 /// '#else' is intentionally left out so that other macro logic (e.g.,
311 /// LLVM_ASSUME_ALIGNED and llvm_unreachable()) can detect whether
312 /// LLVM_BUILTIN_UNREACHABLE has a definition.
313 #if __has_builtin(__builtin_unreachable) || defined(__GNUC__)
314 # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
315 #elif defined(_MSC_VER)
316 # define LLVM_BUILTIN_UNREACHABLE __assume(false)
317 #endif
318 
319 /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression
320 /// which causes the program to exit abnormally.
321 #if __has_builtin(__builtin_trap) || defined(__GNUC__)
322 # define LLVM_BUILTIN_TRAP __builtin_trap()
323 #elif defined(_MSC_VER)
324 // The __debugbreak intrinsic is supported by MSVC, does not require forward
325 // declarations involving platform-specific typedefs (unlike RaiseException),
326 // results in a call to vectored exception handlers, and encodes to a short
327 // instruction that still causes the trapping behavior we want.
328 # define LLVM_BUILTIN_TRAP __debugbreak()
329 #else
330 # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0
331 #endif
332 
333 /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to
334 /// an expression which causes the program to break while running
335 /// under a debugger.
336 #if __has_builtin(__builtin_debugtrap)
337 # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap()
338 #elif defined(_MSC_VER)
339 // The __debugbreak intrinsic is supported by MSVC and breaks while
340 // running under the debugger, and also supports invoking a debugger
341 // when the OS is configured appropriately.
342 # define LLVM_BUILTIN_DEBUGTRAP __debugbreak()
343 #else
344 // Just continue execution when built with compilers that have no
345 // support. This is a debugging aid and not intended to force the
346 // program to abort if encountered.
347 # define LLVM_BUILTIN_DEBUGTRAP
348 #endif
349 
350 /// \macro LLVM_ASSUME_ALIGNED
351 /// Returns a pointer with an assumed alignment.
352 #if __has_builtin(__builtin_assume_aligned) || defined(__GNUC__)
353 # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a)
354 #elif defined(LLVM_BUILTIN_UNREACHABLE)
355 # define LLVM_ASSUME_ALIGNED(p, a) \
356            (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p)))
357 #else
358 # define LLVM_ASSUME_ALIGNED(p, a) (p)
359 #endif
360 
361 /// \macro LLVM_PACKED
362 /// Used to specify a packed structure.
363 /// LLVM_PACKED(
364 ///    struct A {
365 ///      int i;
366 ///      int j;
367 ///      int k;
368 ///      long long l;
369 ///   });
370 ///
371 /// LLVM_PACKED_START
372 /// struct B {
373 ///   int i;
374 ///   int j;
375 ///   int k;
376 ///   long long l;
377 /// };
378 /// LLVM_PACKED_END
379 #ifdef _MSC_VER
380 # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop))
381 # define LLVM_PACKED_START __pragma(pack(push, 1))
382 # define LLVM_PACKED_END   __pragma(pack(pop))
383 #else
384 # define LLVM_PACKED(d) d __attribute__((packed))
385 # define LLVM_PACKED_START _Pragma("pack(push, 1)")
386 # define LLVM_PACKED_END   _Pragma("pack(pop)")
387 #endif
388 
389 /// \macro LLVM_MEMORY_SANITIZER_BUILD
390 /// Whether LLVM itself is built with MemorySanitizer instrumentation.
391 #if __has_feature(memory_sanitizer)
392 # define LLVM_MEMORY_SANITIZER_BUILD 1
393 # include <sanitizer/msan_interface.h>
394 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE __attribute__((no_sanitize_memory))
395 #else
396 # define LLVM_MEMORY_SANITIZER_BUILD 0
397 # define __msan_allocated_memory(p, size)
398 # define __msan_unpoison(p, size)
399 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE
400 #endif
401 
402 /// \macro LLVM_ADDRESS_SANITIZER_BUILD
403 /// Whether LLVM itself is built with AddressSanitizer instrumentation.
404 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
405 # define LLVM_ADDRESS_SANITIZER_BUILD 1
406 #if __has_include(<sanitizer/asan_interface.h>)
407 # include <sanitizer/asan_interface.h>
408 #else
409 // These declarations exist to support ASan with MSVC. If MSVC eventually ships
410 // asan_interface.h in their headers, then we can remove this.
411 #ifdef __cplusplus
412 extern "C" {
413 #endif
414 void __asan_poison_memory_region(void const volatile *addr, size_t size);
415 void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
416 #ifdef __cplusplus
417 } // extern "C"
418 #endif
419 #endif
420 #else
421 # define LLVM_ADDRESS_SANITIZER_BUILD 0
422 # define __asan_poison_memory_region(p, size)
423 # define __asan_unpoison_memory_region(p, size)
424 #endif
425 
426 /// \macro LLVM_HWADDRESS_SANITIZER_BUILD
427 /// Whether LLVM itself is built with HWAddressSanitizer instrumentation.
428 #if __has_feature(hwaddress_sanitizer)
429 #define LLVM_HWADDRESS_SANITIZER_BUILD 1
430 #else
431 #define LLVM_HWADDRESS_SANITIZER_BUILD 0
432 #endif
433 
434 /// \macro LLVM_THREAD_SANITIZER_BUILD
435 /// Whether LLVM itself is built with ThreadSanitizer instrumentation.
436 #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
437 # define LLVM_THREAD_SANITIZER_BUILD 1
438 #else
439 # define LLVM_THREAD_SANITIZER_BUILD 0
440 #endif
441 
442 #if LLVM_THREAD_SANITIZER_BUILD
443 // Thread Sanitizer is a tool that finds races in code.
444 // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations .
445 // tsan detects these exact functions by name.
446 #ifdef __cplusplus
447 extern "C" {
448 #endif
449 void AnnotateHappensAfter(const char *file, int line, const volatile void *cv);
450 void AnnotateHappensBefore(const char *file, int line, const volatile void *cv);
451 void AnnotateIgnoreWritesBegin(const char *file, int line);
452 void AnnotateIgnoreWritesEnd(const char *file, int line);
453 #ifdef __cplusplus
454 }
455 #endif
456 
457 // This marker is used to define a happens-before arc. The race detector will
458 // infer an arc from the begin to the end when they share the same pointer
459 // argument.
460 # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv)
461 
462 // This marker defines the destination of a happens-before arc.
463 # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv)
464 
465 // Ignore any races on writes between here and the next TsanIgnoreWritesEnd.
466 # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
467 
468 // Resume checking for racy writes.
469 # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
470 #else
471 # define TsanHappensBefore(cv)
472 # define TsanHappensAfter(cv)
473 # define TsanIgnoreWritesBegin()
474 # define TsanIgnoreWritesEnd()
475 #endif
476 
477 /// \macro LLVM_NO_SANITIZE
478 /// Disable a particular sanitizer for a function.
479 #if __has_attribute(no_sanitize)
480 #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND)))
481 #else
482 #define LLVM_NO_SANITIZE(KIND)
483 #endif
484 
485 /// Mark debug helper function definitions like dump() that should not be
486 /// stripped from debug builds.
487 /// Note that you should also surround dump() functions with
488 /// `#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` so they do always
489 /// get stripped in release builds.
490 // FIXME: Move this to a private config.h as it's not usable in public headers.
491 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
492 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
493 #else
494 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
495 #endif
496 
497 /// \macro LLVM_PRETTY_FUNCTION
498 /// Gets a user-friendly looking function signature for the current scope
499 /// using the best available method on each platform.  The exact format of the
500 /// resulting string is implementation specific and non-portable, so this should
501 /// only be used, for example, for logging or diagnostics.
502 #if defined(_MSC_VER)
503 #define LLVM_PRETTY_FUNCTION __FUNCSIG__
504 #elif defined(__GNUC__) || defined(__clang__)
505 #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__
506 #else
507 #define LLVM_PRETTY_FUNCTION __func__
508 #endif
509 
510 /// \macro LLVM_THREAD_LOCAL
511 /// A thread-local storage specifier which can be used with globals,
512 /// extern globals, and static globals.
513 ///
514 /// This is essentially an extremely restricted analog to C++11's thread_local
515 /// support. It uses thread_local if available, falling back on gcc __thread
516 /// if not. __thread doesn't support many of the C++11 thread_local's
517 /// features. You should only use this for PODs that you can statically
518 /// initialize to some constant value. In almost all circumstances this is most
519 /// appropriate for use with a pointer, integer, or small aggregation of
520 /// pointers and integers.
521 #if LLVM_ENABLE_THREADS
522 #if __has_feature(cxx_thread_local) || defined(_MSC_VER)
523 #define LLVM_THREAD_LOCAL thread_local
524 #else
525 // Clang, GCC, and other compatible compilers used __thread prior to C++11 and
526 // we only need the restricted functionality that provides.
527 #define LLVM_THREAD_LOCAL __thread
528 #endif
529 #else // !LLVM_ENABLE_THREADS
530 // If threading is disabled entirely, this compiles to nothing and you get
531 // a normal global variable.
532 #define LLVM_THREAD_LOCAL
533 #endif
534 
535 /// \macro LLVM_ENABLE_EXCEPTIONS
536 /// Whether LLVM is built with exception support.
537 #if __has_feature(cxx_exceptions)
538 #define LLVM_ENABLE_EXCEPTIONS 1
539 #elif defined(__GNUC__) && defined(__EXCEPTIONS)
540 #define LLVM_ENABLE_EXCEPTIONS 1
541 #elif defined(_MSC_VER) && defined(_CPPUNWIND)
542 #define LLVM_ENABLE_EXCEPTIONS 1
543 #endif
544 
545 /// \macro LLVM_NO_PROFILE_INSTRUMENT_FUNCTION
546 /// Disable the profile instrument for a function.
547 #if __has_attribute(no_profile_instrument_function)
548 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION                                    \
549   __attribute__((no_profile_instrument_function))
550 #else
551 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION
552 #endif
553 
554 #endif
555