LLVM  14.0.0git
Compiler.h
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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  LLVM_MSC_PREREQ(1920)
102 #define LLVM_HAS_RVALUE_REFERENCE_THIS 1
103 #else
104 #define LLVM_HAS_RVALUE_REFERENCE_THIS 0
105 #endif
106 
107 /// Expands to '&' if ref-qualifiers for *this are supported.
108 ///
109 /// This can be used to provide lvalue/rvalue overrides of member functions.
110 /// The rvalue override should be guarded by LLVM_HAS_RVALUE_REFERENCE_THIS
111 #if LLVM_HAS_RVALUE_REFERENCE_THIS
112 #define LLVM_LVALUE_FUNCTION &
113 #else
114 #define LLVM_LVALUE_FUNCTION
115 #endif
116 
117 /// LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked
118 /// into a shared library, then the class should be private to the library and
119 /// not accessible from outside it. Can also be used to mark variables and
120 /// functions, making them private to any shared library they are linked into.
121 /// On PE/COFF targets, library visibility is the default, so this isn't needed.
122 ///
123 /// LLVM_EXTERNAL_VISIBILITY - classes, functions, and variables marked with
124 /// this attribute will be made public and visible outside of any shared library
125 /// they are linked in to.
126 #if (__has_attribute(visibility) || LLVM_GNUC_PREREQ(4, 0, 0)) && \
127  !defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_WIN32)
128 #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden")))
129 #define LLVM_EXTERNAL_VISIBILITY __attribute__ ((visibility("default")))
130 #else
131 #define LLVM_LIBRARY_VISIBILITY
132 #define LLVM_EXTERNAL_VISIBILITY
133 #endif
134 
135 #if defined(__GNUC__)
136 #define LLVM_PREFETCH(addr, rw, locality) __builtin_prefetch(addr, rw, locality)
137 #else
138 #define LLVM_PREFETCH(addr, rw, locality)
139 #endif
140 
141 #if __has_attribute(used) || LLVM_GNUC_PREREQ(3, 1, 0)
142 #define LLVM_ATTRIBUTE_USED __attribute__((__used__))
143 #else
144 #define LLVM_ATTRIBUTE_USED
145 #endif
146 
147 /// LLVM_NODISCARD - Warn if a type or return value is discarded.
148 
149 // Use the 'nodiscard' attribute in C++17 or newer mode.
150 #if defined(__cplusplus) && __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(nodiscard)
151 #define LLVM_NODISCARD [[nodiscard]]
152 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::warn_unused_result)
153 #define LLVM_NODISCARD [[clang::warn_unused_result]]
154 // Clang in C++14 mode claims that it has the 'nodiscard' attribute, but also
155 // warns in the pedantic mode that 'nodiscard' is a C++17 extension (PR33518).
156 // Use the 'nodiscard' attribute in C++14 mode only with GCC.
157 // TODO: remove this workaround when PR33518 is resolved.
158 #elif defined(__GNUC__) && LLVM_HAS_CPP_ATTRIBUTE(nodiscard)
159 #define LLVM_NODISCARD [[nodiscard]]
160 #else
161 #define LLVM_NODISCARD
162 #endif
163 
164 // Indicate that a non-static, non-const C++ member function reinitializes
165 // the entire object to a known state, independent of the previous state of
166 // the object.
167 //
168 // The clang-tidy check bugprone-use-after-move recognizes this attribute as a
169 // marker that a moved-from object has left the indeterminate state and can be
170 // reused.
171 #if LLVM_HAS_CPP_ATTRIBUTE(clang::reinitializes)
172 #define LLVM_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
173 #else
174 #define LLVM_ATTRIBUTE_REINITIALIZES
175 #endif
176 
177 // Some compilers warn about unused functions. When a function is sometimes
178 // used or not depending on build settings (e.g. a function only called from
179 // within "assert"), this attribute can be used to suppress such warnings.
180 //
181 // However, it shouldn't be used for unused *variables*, as those have a much
182 // more portable solution:
183 // (void)unused_var_name;
184 // Prefer cast-to-void wherever it is sufficient.
185 #if __has_attribute(unused) || LLVM_GNUC_PREREQ(3, 1, 0)
186 #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__))
187 #else
188 #define LLVM_ATTRIBUTE_UNUSED
189 #endif
190 
191 // FIXME: Provide this for PE/COFF targets.
192 #if (__has_attribute(weak) || LLVM_GNUC_PREREQ(4, 0, 0)) && \
193  (!defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_WIN32))
194 #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__))
195 #else
196 #define LLVM_ATTRIBUTE_WEAK
197 #endif
198 
199 // Prior to clang 3.2, clang did not accept any spelling of
200 // __has_attribute(const), so assume it is supported.
201 #if defined(__clang__) || defined(__GNUC__)
202 // aka 'CONST' but following LLVM Conventions.
203 #define LLVM_READNONE __attribute__((__const__))
204 #else
205 #define LLVM_READNONE
206 #endif
207 
208 #if __has_attribute(pure) || defined(__GNUC__)
209 // aka 'PURE' but following LLVM Conventions.
210 #define LLVM_READONLY __attribute__((__pure__))
211 #else
212 #define LLVM_READONLY
213 #endif
214 
215 #if __has_builtin(__builtin_expect) || LLVM_GNUC_PREREQ(4, 0, 0)
216 #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true)
217 #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false)
218 #else
219 #define LLVM_LIKELY(EXPR) (EXPR)
220 #define LLVM_UNLIKELY(EXPR) (EXPR)
221 #endif
222 
223 /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so,
224 /// mark a method "not for inlining".
225 #if __has_attribute(noinline) || LLVM_GNUC_PREREQ(3, 4, 0)
226 #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
227 #elif defined(_MSC_VER)
228 #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
229 #else
230 #define LLVM_ATTRIBUTE_NOINLINE
231 #endif
232 
233 /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do
234 /// so, mark a method "always inline" because it is performance sensitive. GCC
235 /// 3.4 supported this but is buggy in various cases and produces unimplemented
236 /// errors, just use it in GCC 4.0 and later.
237 #if __has_attribute(always_inline) || LLVM_GNUC_PREREQ(4, 0, 0)
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 #if __has_attribute(returns_nonnull) || LLVM_GNUC_PREREQ(4, 9, 0)
246 #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull))
247 #elif defined(_MSC_VER)
248 #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_
249 #else
250 #define LLVM_ATTRIBUTE_RETURNS_NONNULL
251 #endif
252 
253 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a
254 /// pointer that does not alias any other valid pointer.
255 #ifdef __GNUC__
256 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__))
257 #elif defined(_MSC_VER)
258 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict)
259 #else
260 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS
261 #endif
262 
263 /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
264 #if defined(__cplusplus) && __cplusplus > 201402L && LLVM_HAS_CPP_ATTRIBUTE(fallthrough)
265 #define LLVM_FALLTHROUGH [[fallthrough]]
266 #elif LLVM_HAS_CPP_ATTRIBUTE(gnu::fallthrough)
267 #define LLVM_FALLTHROUGH [[gnu::fallthrough]]
268 #elif __has_attribute(fallthrough)
269 #define LLVM_FALLTHROUGH __attribute__((fallthrough))
270 #elif LLVM_HAS_CPP_ATTRIBUTE(clang::fallthrough)
271 #define LLVM_FALLTHROUGH [[clang::fallthrough]]
272 #else
273 #define LLVM_FALLTHROUGH
274 #endif
275 
276 /// LLVM_REQUIRE_CONSTANT_INITIALIZATION - Apply this to globals to ensure that
277 /// they are constant initialized.
278 #if LLVM_HAS_CPP_ATTRIBUTE(clang::require_constant_initialization)
279 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION \
280  [[clang::require_constant_initialization]]
281 #else
282 #define LLVM_REQUIRE_CONSTANT_INITIALIZATION
283 #endif
284 
285 /// LLVM_GSL_OWNER - Apply this to owning classes like SmallVector to enable
286 /// lifetime warnings.
287 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Owner)
288 #define LLVM_GSL_OWNER [[gsl::Owner]]
289 #else
290 #define LLVM_GSL_OWNER
291 #endif
292 
293 /// LLVM_GSL_POINTER - Apply this to non-owning classes like
294 /// StringRef to enable lifetime warnings.
295 #if LLVM_HAS_CPP_ATTRIBUTE(gsl::Pointer)
296 #define LLVM_GSL_POINTER [[gsl::Pointer]]
297 #else
298 #define LLVM_GSL_POINTER
299 #endif
300 
301 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
302 /// pedantic diagnostics.
303 #ifdef __GNUC__
304 #define LLVM_EXTENSION __extension__
305 #else
306 #define LLVM_EXTENSION
307 #endif
308 
309 // LLVM_ATTRIBUTE_DEPRECATED(decl, "message")
310 // This macro will be removed.
311 // Use C++14's attribute instead: [[deprecated("message")]]
312 #define LLVM_ATTRIBUTE_DEPRECATED(decl, message) [[deprecated(message)]] decl
313 
314 /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands
315 /// to an expression which states that it is undefined behavior for the
316 /// compiler to reach this point. Otherwise is not defined.
317 #if __has_builtin(__builtin_unreachable) || LLVM_GNUC_PREREQ(4, 5, 0)
318 # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
319 #elif defined(_MSC_VER)
320 # define LLVM_BUILTIN_UNREACHABLE __assume(false)
321 #endif
322 
323 /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression
324 /// which causes the program to exit abnormally.
325 #if __has_builtin(__builtin_trap) || LLVM_GNUC_PREREQ(4, 3, 0)
326 # define LLVM_BUILTIN_TRAP __builtin_trap()
327 #elif defined(_MSC_VER)
328 // The __debugbreak intrinsic is supported by MSVC, does not require forward
329 // declarations involving platform-specific typedefs (unlike RaiseException),
330 // results in a call to vectored exception handlers, and encodes to a short
331 // instruction that still causes the trapping behavior we want.
332 # define LLVM_BUILTIN_TRAP __debugbreak()
333 #else
334 # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0
335 #endif
336 
337 /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to
338 /// an expression which causes the program to break while running
339 /// under a debugger.
340 #if __has_builtin(__builtin_debugtrap)
341 # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap()
342 #elif defined(_MSC_VER)
343 // The __debugbreak intrinsic is supported by MSVC and breaks while
344 // running under the debugger, and also supports invoking a debugger
345 // when the OS is configured appropriately.
346 # define LLVM_BUILTIN_DEBUGTRAP __debugbreak()
347 #else
348 // Just continue execution when built with compilers that have no
349 // support. This is a debugging aid and not intended to force the
350 // program to abort if encountered.
351 # define LLVM_BUILTIN_DEBUGTRAP
352 #endif
353 
354 /// \macro LLVM_ASSUME_ALIGNED
355 /// Returns a pointer with an assumed alignment.
356 #if __has_builtin(__builtin_assume_aligned) || LLVM_GNUC_PREREQ(4, 7, 0)
357 # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a)
358 #elif defined(LLVM_BUILTIN_UNREACHABLE)
359 # define LLVM_ASSUME_ALIGNED(p, a) \
360  (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p)))
361 #else
362 # define LLVM_ASSUME_ALIGNED(p, a) (p)
363 #endif
364 
365 /// \macro LLVM_PACKED
366 /// Used to specify a packed structure.
367 /// LLVM_PACKED(
368 /// struct A {
369 /// int i;
370 /// int j;
371 /// int k;
372 /// long long l;
373 /// });
374 ///
375 /// LLVM_PACKED_START
376 /// struct B {
377 /// int i;
378 /// int j;
379 /// int k;
380 /// long long l;
381 /// };
382 /// LLVM_PACKED_END
383 #ifdef _MSC_VER
384 # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop))
385 # define LLVM_PACKED_START __pragma(pack(push, 1))
386 # define LLVM_PACKED_END __pragma(pack(pop))
387 #else
388 # define LLVM_PACKED(d) d __attribute__((packed))
389 # define LLVM_PACKED_START _Pragma("pack(push, 1)")
390 # define LLVM_PACKED_END _Pragma("pack(pop)")
391 #endif
392 
393 /// \macro LLVM_PTR_SIZE
394 /// A constant integer equivalent to the value of sizeof(void*).
395 /// Generally used in combination with alignas or when doing computation in the
396 /// preprocessor.
397 #ifdef __SIZEOF_POINTER__
398 # define LLVM_PTR_SIZE __SIZEOF_POINTER__
399 #elif defined(_WIN64)
400 # define LLVM_PTR_SIZE 8
401 #elif defined(_WIN32)
402 # define LLVM_PTR_SIZE 4
403 #elif defined(_MSC_VER)
404 # error "could not determine LLVM_PTR_SIZE as a constant int for MSVC"
405 #else
406 # define LLVM_PTR_SIZE sizeof(void *)
407 #endif
408 
409 /// \macro LLVM_MEMORY_SANITIZER_BUILD
410 /// Whether LLVM itself is built with MemorySanitizer instrumentation.
411 #if __has_feature(memory_sanitizer)
412 # define LLVM_MEMORY_SANITIZER_BUILD 1
413 # include <sanitizer/msan_interface.h>
414 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE __attribute__((no_sanitize_memory))
415 #else
416 # define LLVM_MEMORY_SANITIZER_BUILD 0
417 # define __msan_allocated_memory(p, size)
418 # define __msan_unpoison(p, size)
419 # define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE
420 #endif
421 
422 /// \macro LLVM_ADDRESS_SANITIZER_BUILD
423 /// Whether LLVM itself is built with AddressSanitizer instrumentation.
424 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
425 # define LLVM_ADDRESS_SANITIZER_BUILD 1
426 # include <sanitizer/asan_interface.h>
427 #else
428 # define LLVM_ADDRESS_SANITIZER_BUILD 0
429 # define __asan_poison_memory_region(p, size)
430 # define __asan_unpoison_memory_region(p, size)
431 #endif
432 
433 /// \macro LLVM_THREAD_SANITIZER_BUILD
434 /// Whether LLVM itself is built with ThreadSanitizer instrumentation.
435 #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
436 # define LLVM_THREAD_SANITIZER_BUILD 1
437 #else
438 # define LLVM_THREAD_SANITIZER_BUILD 0
439 #endif
440 
441 #if LLVM_THREAD_SANITIZER_BUILD
442 // Thread Sanitizer is a tool that finds races in code.
443 // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations .
444 // tsan detects these exact functions by name.
445 #ifdef __cplusplus
446 extern "C" {
447 #endif
448 void AnnotateHappensAfter(const char *file, int line, const volatile void *cv);
449 void AnnotateHappensBefore(const char *file, int line, const volatile void *cv);
450 void AnnotateIgnoreWritesBegin(const char *file, int line);
451 void AnnotateIgnoreWritesEnd(const char *file, int line);
452 #ifdef __cplusplus
453 }
454 #endif
455 
456 // This marker is used to define a happens-before arc. The race detector will
457 // infer an arc from the begin to the end when they share the same pointer
458 // argument.
459 # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv)
460 
461 // This marker defines the destination of a happens-before arc.
462 # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv)
463 
464 // Ignore any races on writes between here and the next TsanIgnoreWritesEnd.
465 # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
466 
467 // Resume checking for racy writes.
468 # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
469 #else
470 # define TsanHappensBefore(cv)
471 # define TsanHappensAfter(cv)
472 # define TsanIgnoreWritesBegin()
473 # define TsanIgnoreWritesEnd()
474 #endif
475 
476 /// \macro LLVM_NO_SANITIZE
477 /// Disable a particular sanitizer for a function.
478 #if __has_attribute(no_sanitize)
479 #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND)))
480 #else
481 #define LLVM_NO_SANITIZE(KIND)
482 #endif
483 
484 /// Mark debug helper function definitions like dump() that should not be
485 /// stripped from debug builds.
486 /// Note that you should also surround dump() functions with
487 /// `#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` so they do always
488 /// get stripped in release builds.
489 // FIXME: Move this to a private config.h as it's not usable in public headers.
490 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
491 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
492 #else
493 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
494 #endif
495 
496 /// \macro LLVM_PRETTY_FUNCTION
497 /// Gets a user-friendly looking function signature for the current scope
498 /// using the best available method on each platform. The exact format of the
499 /// resulting string is implementation specific and non-portable, so this should
500 /// only be used, for example, for logging or diagnostics.
501 #if defined(_MSC_VER)
502 #define LLVM_PRETTY_FUNCTION __FUNCSIG__
503 #elif defined(__GNUC__) || defined(__clang__)
504 #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__
505 #else
506 #define LLVM_PRETTY_FUNCTION __func__
507 #endif
508 
509 /// \macro LLVM_THREAD_LOCAL
510 /// A thread-local storage specifier which can be used with globals,
511 /// extern globals, and static globals.
512 ///
513 /// This is essentially an extremely restricted analog to C++11's thread_local
514 /// support. It uses thread_local if available, falling back on gcc __thread
515 /// if not. __thread doesn't support many of the C++11 thread_local's
516 /// features. You should only use this for PODs that you can statically
517 /// initialize to some constant value. In almost all circumstances this is most
518 /// appropriate for use with a pointer, integer, or small aggregation of
519 /// pointers and integers.
520 #if LLVM_ENABLE_THREADS
521 #if __has_feature(cxx_thread_local) || defined(_MSC_VER)
522 #define LLVM_THREAD_LOCAL thread_local
523 #else
524 // Clang, GCC, and other compatible compilers used __thread prior to C++11 and
525 // we only need the restricted functionality that provides.
526 #define LLVM_THREAD_LOCAL __thread
527 #endif
528 #else // !LLVM_ENABLE_THREADS
529 // If threading is disabled entirely, this compiles to nothing and you get
530 // a normal global variable.
531 #define LLVM_THREAD_LOCAL
532 #endif
533 
534 /// \macro LLVM_ENABLE_EXCEPTIONS
535 /// Whether LLVM is built with exception support.
536 #if __has_feature(cxx_exceptions)
537 #define LLVM_ENABLE_EXCEPTIONS 1
538 #elif defined(__GNUC__) && defined(__EXCEPTIONS)
539 #define LLVM_ENABLE_EXCEPTIONS 1
540 #elif defined(_MSC_VER) && defined(_CPPUNWIND)
541 #define LLVM_ENABLE_EXCEPTIONS 1
542 #endif
543 
544 #endif
file
dot regions Print regions of function to dot file(with no function bodies)"