LLVM  8.0.0svn
Compiler.h
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1 //===-- llvm/Support/Compiler.h - Compiler abstraction support --*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines several macros, based on the current compiler. This allows
11 // use of compiler-specific features in a way that remains portable.
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 <new>
21 #include <stddef.h>
22 
23 #if defined(_MSC_VER)
24 #include <sal.h>
25 #endif
26 
27 #ifndef __has_feature
28 # define __has_feature(x) 0
29 #endif
30 
31 #ifndef __has_extension
32 # define __has_extension(x) 0
33 #endif
34 
35 #ifndef __has_attribute
36 # define __has_attribute(x) 0
37 #endif
38 
39 #ifndef __has_cpp_attribute
40 # define __has_cpp_attribute(x) 0
41 #endif
42 
43 #ifndef __has_builtin
44 # define __has_builtin(x) 0
45 #endif
46 
47 /// \macro LLVM_GNUC_PREREQ
48 /// Extend the default __GNUC_PREREQ even if glibc's features.h isn't
49 /// available.
50 #ifndef LLVM_GNUC_PREREQ
51 # if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
52 # define LLVM_GNUC_PREREQ(maj, min, patch) \
53  ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \
54  ((maj) << 20) + ((min) << 10) + (patch))
55 # elif defined(__GNUC__) && defined(__GNUC_MINOR__)
56 # define LLVM_GNUC_PREREQ(maj, min, patch) \
57  ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10))
58 # else
59 # define LLVM_GNUC_PREREQ(maj, min, patch) 0
60 # endif
61 #endif
62 
63 /// \macro LLVM_MSC_PREREQ
64 /// Is the compiler MSVC of at least the specified version?
65 /// The common \param version values to check for are:
66 /// * 1900: Microsoft Visual Studio 2015 / 14.0
67 #ifdef _MSC_VER
68 #define LLVM_MSC_PREREQ(version) (_MSC_VER >= (version))
69 
70 // We require at least MSVC 2015.
71 #if !LLVM_MSC_PREREQ(1900)
72 #error LLVM requires at least MSVC 2015.
73 #endif
74 
75 #else
76 #define LLVM_MSC_PREREQ(version) 0
77 #endif
78 
79 /// Does the compiler support ref-qualifiers for *this?
80 ///
81 /// Sadly, this is separate from just rvalue reference support because GCC
82 /// and MSVC implemented this later than everything else.
83 #if __has_feature(cxx_rvalue_references) || LLVM_GNUC_PREREQ(4, 8, 1)
84 #define LLVM_HAS_RVALUE_REFERENCE_THIS 1
85 #else
86 #define LLVM_HAS_RVALUE_REFERENCE_THIS 0
87 #endif
88 
89 /// Expands to '&' if ref-qualifiers for *this are supported.
90 ///
91 /// This can be used to provide lvalue/rvalue overrides of member functions.
92 /// The rvalue override should be guarded by LLVM_HAS_RVALUE_REFERENCE_THIS
93 #if LLVM_HAS_RVALUE_REFERENCE_THIS
94 #define LLVM_LVALUE_FUNCTION &
95 #else
96 #define LLVM_LVALUE_FUNCTION
97 #endif
98 
99 /// LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked
100 /// into a shared library, then the class should be private to the library and
101 /// not accessible from outside it. Can also be used to mark variables and
102 /// functions, making them private to any shared library they are linked into.
103 /// On PE/COFF targets, library visibility is the default, so this isn't needed.
104 #if (__has_attribute(visibility) || LLVM_GNUC_PREREQ(4, 0, 0)) && \
105  !defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_WIN32)
106 #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden")))
107 #else
108 #define LLVM_LIBRARY_VISIBILITY
109 #endif
110 
111 #if defined(__GNUC__)
112 #define LLVM_PREFETCH(addr, rw, locality) __builtin_prefetch(addr, rw, locality)
113 #else
114 #define LLVM_PREFETCH(addr, rw, locality)
115 #endif
116 
117 #if __has_attribute(used) || LLVM_GNUC_PREREQ(3, 1, 0)
118 #define LLVM_ATTRIBUTE_USED __attribute__((__used__))
119 #else
120 #define LLVM_ATTRIBUTE_USED
121 #endif
122 
123 /// LLVM_NODISCARD - Warn if a type or return value is discarded.
124 #if __cplusplus > 201402L && __has_cpp_attribute(nodiscard)
125 #define LLVM_NODISCARD [[nodiscard]]
126 #elif !__cplusplus
127 // Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious
128 // error when __has_cpp_attribute is given a scoped attribute in C mode.
129 #define LLVM_NODISCARD
130 #elif __has_cpp_attribute(clang::warn_unused_result)
131 #define LLVM_NODISCARD [[clang::warn_unused_result]]
132 #else
133 #define LLVM_NODISCARD
134 #endif
135 
136 // Indicate that a non-static, non-const C++ member function reinitializes
137 // the entire object to a known state, independent of the previous state of
138 // the object.
139 //
140 // The clang-tidy check bugprone-use-after-move recognizes this attribute as a
141 // marker that a moved-from object has left the indeterminate state and can be
142 // reused.
143 #if __has_cpp_attribute(clang::reinitializes)
144 #define LLVM_ATTRIBUTE_REINITIALIZES [[clang::reinitializes]]
145 #else
146 #define LLVM_ATTRIBUTE_REINITIALIZES
147 #endif
148 
149 // Some compilers warn about unused functions. When a function is sometimes
150 // used or not depending on build settings (e.g. a function only called from
151 // within "assert"), this attribute can be used to suppress such warnings.
152 //
153 // However, it shouldn't be used for unused *variables*, as those have a much
154 // more portable solution:
155 // (void)unused_var_name;
156 // Prefer cast-to-void wherever it is sufficient.
157 #if __has_attribute(unused) || LLVM_GNUC_PREREQ(3, 1, 0)
158 #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__))
159 #else
160 #define LLVM_ATTRIBUTE_UNUSED
161 #endif
162 
163 // FIXME: Provide this for PE/COFF targets.
164 #if (__has_attribute(weak) || LLVM_GNUC_PREREQ(4, 0, 0)) && \
165  (!defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(_WIN32))
166 #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__))
167 #else
168 #define LLVM_ATTRIBUTE_WEAK
169 #endif
170 
171 // Prior to clang 3.2, clang did not accept any spelling of
172 // __has_attribute(const), so assume it is supported.
173 #if defined(__clang__) || defined(__GNUC__)
174 // aka 'CONST' but following LLVM Conventions.
175 #define LLVM_READNONE __attribute__((__const__))
176 #else
177 #define LLVM_READNONE
178 #endif
179 
180 #if __has_attribute(pure) || defined(__GNUC__)
181 // aka 'PURE' but following LLVM Conventions.
182 #define LLVM_READONLY __attribute__((__pure__))
183 #else
184 #define LLVM_READONLY
185 #endif
186 
187 #if __has_builtin(__builtin_expect) || LLVM_GNUC_PREREQ(4, 0, 0)
188 #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true)
189 #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false)
190 #else
191 #define LLVM_LIKELY(EXPR) (EXPR)
192 #define LLVM_UNLIKELY(EXPR) (EXPR)
193 #endif
194 
195 /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so,
196 /// mark a method "not for inlining".
197 #if __has_attribute(noinline) || LLVM_GNUC_PREREQ(3, 4, 0)
198 #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
199 #elif defined(_MSC_VER)
200 #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
201 #else
202 #define LLVM_ATTRIBUTE_NOINLINE
203 #endif
204 
205 /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do
206 /// so, mark a method "always inline" because it is performance sensitive. GCC
207 /// 3.4 supported this but is buggy in various cases and produces unimplemented
208 /// errors, just use it in GCC 4.0 and later.
209 #if __has_attribute(always_inline) || LLVM_GNUC_PREREQ(4, 0, 0)
210 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline))
211 #elif defined(_MSC_VER)
212 #define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline
213 #else
214 #define LLVM_ATTRIBUTE_ALWAYS_INLINE
215 #endif
216 
217 #ifdef __GNUC__
218 #define LLVM_ATTRIBUTE_NORETURN __attribute__((noreturn))
219 #elif defined(_MSC_VER)
220 #define LLVM_ATTRIBUTE_NORETURN __declspec(noreturn)
221 #else
222 #define LLVM_ATTRIBUTE_NORETURN
223 #endif
224 
225 #if __has_attribute(returns_nonnull) || LLVM_GNUC_PREREQ(4, 9, 0)
226 #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull))
227 #elif defined(_MSC_VER)
228 #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_
229 #else
230 #define LLVM_ATTRIBUTE_RETURNS_NONNULL
231 #endif
232 
233 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a
234 /// pointer that does not alias any other valid pointer.
235 #ifdef __GNUC__
236 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__))
237 #elif defined(_MSC_VER)
238 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict)
239 #else
240 #define LLVM_ATTRIBUTE_RETURNS_NOALIAS
241 #endif
242 
243 /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements.
244 #if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
245 #define LLVM_FALLTHROUGH [[fallthrough]]
246 #elif __has_cpp_attribute(gnu::fallthrough)
247 #define LLVM_FALLTHROUGH [[gnu::fallthrough]]
248 #elif !__cplusplus
249 // Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious
250 // error when __has_cpp_attribute is given a scoped attribute in C mode.
251 #define LLVM_FALLTHROUGH
252 #elif __has_cpp_attribute(clang::fallthrough)
253 #define LLVM_FALLTHROUGH [[clang::fallthrough]]
254 #else
255 #define LLVM_FALLTHROUGH
256 #endif
257 
258 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
259 /// pedantic diagnostics.
260 #ifdef __GNUC__
261 #define LLVM_EXTENSION __extension__
262 #else
263 #define LLVM_EXTENSION
264 #endif
265 
266 // LLVM_ATTRIBUTE_DEPRECATED(decl, "message")
267 #if __has_feature(attribute_deprecated_with_message)
268 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
269  decl __attribute__((deprecated(message)))
270 #elif defined(__GNUC__)
271 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
272  decl __attribute__((deprecated))
273 #elif defined(_MSC_VER)
274 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
275  __declspec(deprecated(message)) decl
276 #else
277 # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
278  decl
279 #endif
280 
281 /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands
282 /// to an expression which states that it is undefined behavior for the
283 /// compiler to reach this point. Otherwise is not defined.
284 #if __has_builtin(__builtin_unreachable) || LLVM_GNUC_PREREQ(4, 5, 0)
285 # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
286 #elif defined(_MSC_VER)
287 # define LLVM_BUILTIN_UNREACHABLE __assume(false)
288 #endif
289 
290 /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression
291 /// which causes the program to exit abnormally.
292 #if __has_builtin(__builtin_trap) || LLVM_GNUC_PREREQ(4, 3, 0)
293 # define LLVM_BUILTIN_TRAP __builtin_trap()
294 #elif defined(_MSC_VER)
295 // The __debugbreak intrinsic is supported by MSVC, does not require forward
296 // declarations involving platform-specific typedefs (unlike RaiseException),
297 // results in a call to vectored exception handlers, and encodes to a short
298 // instruction that still causes the trapping behavior we want.
299 # define LLVM_BUILTIN_TRAP __debugbreak()
300 #else
301 # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0
302 #endif
303 
304 /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to
305 /// an expression which causes the program to break while running
306 /// under a debugger.
307 #if __has_builtin(__builtin_debugtrap)
308 # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap()
309 #elif defined(_MSC_VER)
310 // The __debugbreak intrinsic is supported by MSVC and breaks while
311 // running under the debugger, and also supports invoking a debugger
312 // when the OS is configured appropriately.
313 # define LLVM_BUILTIN_DEBUGTRAP __debugbreak()
314 #else
315 // Just continue execution when built with compilers that have no
316 // support. This is a debugging aid and not intended to force the
317 // program to abort if encountered.
318 # define LLVM_BUILTIN_DEBUGTRAP
319 #endif
320 
321 /// \macro LLVM_ASSUME_ALIGNED
322 /// Returns a pointer with an assumed alignment.
323 #if __has_builtin(__builtin_assume_aligned) || LLVM_GNUC_PREREQ(4, 7, 0)
324 # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a)
325 #elif defined(LLVM_BUILTIN_UNREACHABLE)
326 // As of today, clang does not support __builtin_assume_aligned.
327 # define LLVM_ASSUME_ALIGNED(p, a) \
328  (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p)))
329 #else
330 # define LLVM_ASSUME_ALIGNED(p, a) (p)
331 #endif
332 
333 /// \macro LLVM_ALIGNAS
334 /// Used to specify a minimum alignment for a structure or variable.
335 #if __GNUC__ && !__has_feature(cxx_alignas) && !LLVM_GNUC_PREREQ(4, 8, 1)
336 # define LLVM_ALIGNAS(x) __attribute__((aligned(x)))
337 #else
338 # define LLVM_ALIGNAS(x) alignas(x)
339 #endif
340 
341 /// \macro LLVM_PACKED
342 /// Used to specify a packed structure.
343 /// LLVM_PACKED(
344 /// struct A {
345 /// int i;
346 /// int j;
347 /// int k;
348 /// long long l;
349 /// });
350 ///
351 /// LLVM_PACKED_START
352 /// struct B {
353 /// int i;
354 /// int j;
355 /// int k;
356 /// long long l;
357 /// };
358 /// LLVM_PACKED_END
359 #ifdef _MSC_VER
360 # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop))
361 # define LLVM_PACKED_START __pragma(pack(push, 1))
362 # define LLVM_PACKED_END __pragma(pack(pop))
363 #else
364 # define LLVM_PACKED(d) d __attribute__((packed))
365 # define LLVM_PACKED_START _Pragma("pack(push, 1)")
366 # define LLVM_PACKED_END _Pragma("pack(pop)")
367 #endif
368 
369 /// \macro LLVM_PTR_SIZE
370 /// A constant integer equivalent to the value of sizeof(void*).
371 /// Generally used in combination with LLVM_ALIGNAS or when doing computation in
372 /// the preprocessor.
373 #ifdef __SIZEOF_POINTER__
374 # define LLVM_PTR_SIZE __SIZEOF_POINTER__
375 #elif defined(_WIN64)
376 # define LLVM_PTR_SIZE 8
377 #elif defined(_WIN32)
378 # define LLVM_PTR_SIZE 4
379 #elif defined(_MSC_VER)
380 # error "could not determine LLVM_PTR_SIZE as a constant int for MSVC"
381 #else
382 # define LLVM_PTR_SIZE sizeof(void *)
383 #endif
384 
385 /// \macro LLVM_MEMORY_SANITIZER_BUILD
386 /// Whether LLVM itself is built with MemorySanitizer instrumentation.
387 #if __has_feature(memory_sanitizer)
388 # define LLVM_MEMORY_SANITIZER_BUILD 1
389 # include <sanitizer/msan_interface.h>
390 #else
391 # define LLVM_MEMORY_SANITIZER_BUILD 0
392 # define __msan_allocated_memory(p, size)
393 # define __msan_unpoison(p, size)
394 #endif
395 
396 /// \macro LLVM_ADDRESS_SANITIZER_BUILD
397 /// Whether LLVM itself is built with AddressSanitizer instrumentation.
398 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
399 # define LLVM_ADDRESS_SANITIZER_BUILD 1
400 # include <sanitizer/asan_interface.h>
401 #else
402 # define LLVM_ADDRESS_SANITIZER_BUILD 0
403 # define __asan_poison_memory_region(p, size)
404 # define __asan_unpoison_memory_region(p, size)
405 #endif
406 
407 /// \macro LLVM_THREAD_SANITIZER_BUILD
408 /// Whether LLVM itself is built with ThreadSanitizer instrumentation.
409 #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
410 # define LLVM_THREAD_SANITIZER_BUILD 1
411 #else
412 # define LLVM_THREAD_SANITIZER_BUILD 0
413 #endif
414 
415 #if LLVM_THREAD_SANITIZER_BUILD
416 // Thread Sanitizer is a tool that finds races in code.
417 // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations .
418 // tsan detects these exact functions by name.
419 #ifdef __cplusplus
420 extern "C" {
421 #endif
422 void AnnotateHappensAfter(const char *file, int line, const volatile void *cv);
423 void AnnotateHappensBefore(const char *file, int line, const volatile void *cv);
424 void AnnotateIgnoreWritesBegin(const char *file, int line);
425 void AnnotateIgnoreWritesEnd(const char *file, int line);
426 #ifdef __cplusplus
427 }
428 #endif
429 
430 // This marker is used to define a happens-before arc. The race detector will
431 // infer an arc from the begin to the end when they share the same pointer
432 // argument.
433 # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv)
434 
435 // This marker defines the destination of a happens-before arc.
436 # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv)
437 
438 // Ignore any races on writes between here and the next TsanIgnoreWritesEnd.
439 # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
440 
441 // Resume checking for racy writes.
442 # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
443 #else
444 # define TsanHappensBefore(cv)
445 # define TsanHappensAfter(cv)
446 # define TsanIgnoreWritesBegin()
447 # define TsanIgnoreWritesEnd()
448 #endif
449 
450 /// \macro LLVM_NO_SANITIZE
451 /// Disable a particular sanitizer for a function.
452 #if __has_attribute(no_sanitize)
453 #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND)))
454 #else
455 #define LLVM_NO_SANITIZE(KIND)
456 #endif
457 
458 /// Mark debug helper function definitions like dump() that should not be
459 /// stripped from debug builds.
460 /// Note that you should also surround dump() functions with
461 /// `#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` so they do always
462 /// get stripped in release builds.
463 // FIXME: Move this to a private config.h as it's not usable in public headers.
464 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
465 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
466 #else
467 #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
468 #endif
469 
470 /// \macro LLVM_PRETTY_FUNCTION
471 /// Gets a user-friendly looking function signature for the current scope
472 /// using the best available method on each platform. The exact format of the
473 /// resulting string is implementation specific and non-portable, so this should
474 /// only be used, for example, for logging or diagnostics.
475 #if defined(_MSC_VER)
476 #define LLVM_PRETTY_FUNCTION __FUNCSIG__
477 #elif defined(__GNUC__) || defined(__clang__)
478 #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__
479 #else
480 #define LLVM_PRETTY_FUNCTION __func__
481 #endif
482 
483 /// \macro LLVM_THREAD_LOCAL
484 /// A thread-local storage specifier which can be used with globals,
485 /// extern globals, and static globals.
486 ///
487 /// This is essentially an extremely restricted analog to C++11's thread_local
488 /// support, and uses that when available. However, it falls back on
489 /// platform-specific or vendor-provided extensions when necessary. These
490 /// extensions don't support many of the C++11 thread_local's features. You
491 /// should only use this for PODs that you can statically initialize to
492 /// some constant value. In almost all circumstances this is most appropriate
493 /// for use with a pointer, integer, or small aggregation of pointers and
494 /// integers.
495 #if LLVM_ENABLE_THREADS
496 #if __has_feature(cxx_thread_local)
497 #define LLVM_THREAD_LOCAL thread_local
498 #elif defined(_MSC_VER)
499 // MSVC supports this with a __declspec.
500 #define LLVM_THREAD_LOCAL __declspec(thread)
501 #else
502 // Clang, GCC, and other compatible compilers used __thread prior to C++11 and
503 // we only need the restricted functionality that provides.
504 #define LLVM_THREAD_LOCAL __thread
505 #endif
506 #else // !LLVM_ENABLE_THREADS
507 // If threading is disabled entirely, this compiles to nothing and you get
508 // a normal global variable.
509 #define LLVM_THREAD_LOCAL
510 #endif
511 
512 /// \macro LLVM_ENABLE_EXCEPTIONS
513 /// Whether LLVM is built with exception support.
514 #if __has_feature(cxx_exceptions)
515 #define LLVM_ENABLE_EXCEPTIONS 1
516 #elif defined(__GNUC__) && defined(__EXCEPTIONS)
517 #define LLVM_ENABLE_EXCEPTIONS 1
518 #elif defined(_MSC_VER) && defined(_CPPUNWIND)
519 #define LLVM_ENABLE_EXCEPTIONS 1
520 #endif
521 
522 namespace llvm {
523 
524 /// Allocate a buffer of memory with the given size and alignment.
525 ///
526 /// When the compiler supports aligned operator new, this will use it to to
527 /// handle even over-aligned allocations.
528 ///
529 /// However, this doesn't make any attempt to leverage the fancier techniques
530 /// like posix_memalign due to portability. It is mostly intended to allow
531 /// compatibility with platforms that, after aligned allocation was added, use
532 /// reduced default alignment.
533 inline void *allocate_buffer(size_t Size, size_t Alignment) {
534  return ::operator new(Size
535 #ifdef __cpp_aligned_new
536  ,
537  std::align_val_t(Alignment)
538 #endif
539  );
540 }
541 
542 /// Deallocate a buffer of memory with the given size and alignment.
543 ///
544 /// If supported, this will used the sized delete operator. Also if supported,
545 /// this will pass the alignment to the delete operator.
546 ///
547 /// The pointer must have been allocated with the corresponding new operator,
548 /// most likely using the above helper.
549 inline void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment) {
550  ::operator delete(Ptr
551 #ifdef __cpp_sized_deallocation
552  ,
553  Size
554 #endif
555 #ifdef __cpp_aligned_new
556  ,
557  std::align_val_t(Alignment)
558 #endif
559  );
560 }
561 
562 } // End namespace llvm
563 
564 #endif
*ViewGraph Emit a dot run run gv on the postscript file
Definition: GraphWriter.h:363
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
void * allocate_buffer(size_t Size, size_t Alignment)
Allocate a buffer of memory with the given size and alignment.
Definition: Compiler.h:533
void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment)
Deallocate a buffer of memory with the given size and alignment.
Definition: Compiler.h:549
uint32_t Size
Definition: Profile.cpp:47