source: icGREP/icgrep-devel/llvm-3.4.2.src/include/llvm/Support/Compiler.h @ 3913

Last change on this file since 3913 was 3913, checked in by cameron, 5 years ago

Distribute llvm as source rather than compiled libraries

File size: 13.7 KB
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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#ifndef __has_feature
21# define __has_feature(x) 0
22#endif
23
24#ifndef __has_attribute
25# define __has_attribute(x) 0
26#endif
27
28#ifndef __has_builtin
29# define __has_builtin(x) 0
30#endif
31
32/// \macro __GNUC_PREREQ
33/// \brief Defines __GNUC_PREREQ if glibc's features.h isn't available.
34#ifndef __GNUC_PREREQ
35# if defined(__GNUC__) && defined(__GNUC_MINOR__)
36#  define __GNUC_PREREQ(maj, min) \
37    ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
38# else
39#  define __GNUC_PREREQ(maj, min) 0
40# endif
41#endif
42
43/// \brief Does the compiler support r-value references?
44/// This implies that <utility> provides the one-argument std::move;  it
45/// does not imply the existence of any other C++ library features.
46#if (__has_feature(cxx_rvalue_references)   \
47     || defined(__GXX_EXPERIMENTAL_CXX0X__) \
48     || (defined(_MSC_VER) && _MSC_VER >= 1600))
49#define LLVM_HAS_RVALUE_REFERENCES 1
50#else
51#define LLVM_HAS_RVALUE_REFERENCES 0
52#endif
53
54/// \brief Does the compiler support r-value reference *this?
55///
56/// Sadly, this is separate from just r-value reference support because GCC
57/// implemented everything but this thus far. No release of GCC yet has support
58/// for this feature so it is enabled with Clang only.
59/// FIXME: This should change to a version check when GCC grows support for it.
60#if __has_feature(cxx_rvalue_references)
61#define LLVM_HAS_RVALUE_REFERENCE_THIS 1
62#else
63#define LLVM_HAS_RVALUE_REFERENCE_THIS 0
64#endif
65
66/// \macro LLVM_HAS_CXX11_TYPETRAITS
67/// \brief Does the compiler have the C++11 type traits.
68///
69/// #include <type_traits>
70///
71/// * enable_if
72/// * {true,false}_type
73/// * is_constructible
74/// * etc...
75#if defined(__GXX_EXPERIMENTAL_CXX0X__) \
76    || (defined(_MSC_VER) && _MSC_VER >= 1700)
77#define LLVM_HAS_CXX11_TYPETRAITS 1
78#else
79#define LLVM_HAS_CXX11_TYPETRAITS 0
80#endif
81
82/// \macro LLVM_HAS_CXX11_STDLIB
83/// \brief Does the compiler have the C++11 standard library.
84///
85/// Implies LLVM_HAS_RVALUE_REFERENCES, LLVM_HAS_CXX11_TYPETRAITS
86#if defined(__GXX_EXPERIMENTAL_CXX0X__) \
87    || (defined(_MSC_VER) && _MSC_VER >= 1700)
88#define LLVM_HAS_CXX11_STDLIB 1
89#else
90#define LLVM_HAS_CXX11_STDLIB 0
91#endif
92
93/// \macro LLVM_HAS_VARIADIC_TEMPLATES
94/// \brief Does this compiler support variadic templates.
95///
96/// Implies LLVM_HAS_RVALUE_REFERENCES and the existence of std::forward.
97#if __has_feature(cxx_variadic_templates)
98# define LLVM_HAS_VARIADIC_TEMPLATES 1
99#else
100# define LLVM_HAS_VARIADIC_TEMPLATES 0
101#endif
102
103/// llvm_move - Expands to ::std::move if the compiler supports
104/// r-value references; otherwise, expands to the argument.
105#if LLVM_HAS_RVALUE_REFERENCES
106#define llvm_move(value) (::std::move(value))
107#else
108#define llvm_move(value) (value)
109#endif
110
111/// Expands to '&' if r-value references are supported.
112///
113/// This can be used to provide l-value/r-value overrides of member functions.
114/// The r-value override should be guarded by LLVM_HAS_RVALUE_REFERENCE_THIS
115#if LLVM_HAS_RVALUE_REFERENCE_THIS
116#define LLVM_LVALUE_FUNCTION &
117#else
118#define LLVM_LVALUE_FUNCTION
119#endif
120
121/// LLVM_DELETED_FUNCTION - Expands to = delete if the compiler supports it.
122/// Use to mark functions as uncallable. Member functions with this should
123/// be declared private so that some behavior is kept in C++03 mode.
124///
125/// class DontCopy {
126/// private:
127///   DontCopy(const DontCopy&) LLVM_DELETED_FUNCTION;
128///   DontCopy &operator =(const DontCopy&) LLVM_DELETED_FUNCTION;
129/// public:
130///   ...
131/// };
132#if (__has_feature(cxx_deleted_functions) \
133     || defined(__GXX_EXPERIMENTAL_CXX0X__))
134     // No version of MSVC currently supports this.
135#define LLVM_DELETED_FUNCTION = delete
136#else
137#define LLVM_DELETED_FUNCTION
138#endif
139
140/// LLVM_FINAL - Expands to 'final' if the compiler supports it.
141/// Use to mark classes or virtual methods as final.
142#if __has_feature(cxx_override_control) \
143    || (defined(_MSC_VER) && _MSC_VER >= 1700)
144#define LLVM_FINAL final
145#else
146#define LLVM_FINAL
147#endif
148
149/// LLVM_OVERRIDE - Expands to 'override' if the compiler supports it.
150/// Use to mark virtual methods as overriding a base class method.
151#if __has_feature(cxx_override_control) \
152    || (defined(_MSC_VER) && _MSC_VER >= 1700)
153#define LLVM_OVERRIDE override
154#else
155#define LLVM_OVERRIDE
156#endif
157
158#if __has_feature(cxx_constexpr) || defined(__GXX_EXPERIMENTAL_CXX0X__)
159# define LLVM_CONSTEXPR constexpr
160#else
161# define LLVM_CONSTEXPR
162#endif
163
164/// LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked
165/// into a shared library, then the class should be private to the library and
166/// not accessible from outside it.  Can also be used to mark variables and
167/// functions, making them private to any shared library they are linked into.
168/// On PE/COFF targets, library visibility is the default, so this isn't needed.
169#if (__has_attribute(visibility) || __GNUC_PREREQ(4, 0)) &&                    \
170    !defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(LLVM_ON_WIN32)
171#define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden")))
172#else
173#define LLVM_LIBRARY_VISIBILITY
174#endif
175
176#if __has_attribute(used) || __GNUC_PREREQ(3, 1)
177#define LLVM_ATTRIBUTE_USED __attribute__((__used__))
178#else
179#define LLVM_ATTRIBUTE_USED
180#endif
181
182#if __has_attribute(warn_unused_result) || __GNUC_PREREQ(3, 4)
183#define LLVM_ATTRIBUTE_UNUSED_RESULT __attribute__((__warn_unused_result__))
184#else
185#define LLVM_ATTRIBUTE_UNUSED_RESULT
186#endif
187
188// Some compilers warn about unused functions. When a function is sometimes
189// used or not depending on build settings (e.g. a function only called from
190// within "assert"), this attribute can be used to suppress such warnings.
191//
192// However, it shouldn't be used for unused *variables*, as those have a much
193// more portable solution:
194//   (void)unused_var_name;
195// Prefer cast-to-void wherever it is sufficient.
196#if __has_attribute(unused) || __GNUC_PREREQ(3, 1)
197#define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__))
198#else
199#define LLVM_ATTRIBUTE_UNUSED
200#endif
201
202// FIXME: Provide this for PE/COFF targets.
203#if (__has_attribute(weak) || __GNUC_PREREQ(4, 0)) &&                          \
204    (!defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(LLVM_ON_WIN32))
205#define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__))
206#else
207#define LLVM_ATTRIBUTE_WEAK
208#endif
209
210// Prior to clang 3.2, clang did not accept any spelling of
211// __has_attribute(const), so assume it is supported.
212#if defined(__clang__) || defined(__GNUC__)
213// aka 'CONST' but following LLVM Conventions.
214#define LLVM_READNONE __attribute__((__const__))
215#else
216#define LLVM_READNONE
217#endif
218
219#if __has_attribute(pure) || defined(__GNUC__)
220// aka 'PURE' but following LLVM Conventions.
221#define LLVM_READONLY __attribute__((__pure__))
222#else
223#define LLVM_READONLY
224#endif
225
226#if __has_builtin(__builtin_expect) || __GNUC_PREREQ(4, 0)
227#define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true)
228#define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false)
229#else
230#define LLVM_LIKELY(EXPR) (EXPR)
231#define LLVM_UNLIKELY(EXPR) (EXPR)
232#endif
233
234// C++ doesn't support 'extern template' of template specializations.  GCC does,
235// but requires __extension__ before it.  In the header, use this:
236//   EXTERN_TEMPLATE_INSTANTIATION(class foo<bar>);
237// in the .cpp file, use this:
238//   TEMPLATE_INSTANTIATION(class foo<bar>);
239#ifdef __GNUC__
240#define EXTERN_TEMPLATE_INSTANTIATION(X) __extension__ extern template X
241#define TEMPLATE_INSTANTIATION(X) template X
242#else
243#define EXTERN_TEMPLATE_INSTANTIATION(X)
244#define TEMPLATE_INSTANTIATION(X)
245#endif
246
247/// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so,
248/// mark a method "not for inlining".
249#if __has_attribute(noinline) || __GNUC_PREREQ(3, 4)
250#define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
251#elif defined(_MSC_VER)
252#define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
253#else
254#define LLVM_ATTRIBUTE_NOINLINE
255#endif
256
257/// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do
258/// so, mark a method "always inline" because it is performance sensitive. GCC
259/// 3.4 supported this but is buggy in various cases and produces unimplemented
260/// errors, just use it in GCC 4.0 and later.
261#if __has_attribute(always_inline) || __GNUC_PREREQ(4, 0)
262#define LLVM_ATTRIBUTE_ALWAYS_INLINE inline __attribute__((always_inline))
263#elif defined(_MSC_VER)
264#define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline
265#else
266#define LLVM_ATTRIBUTE_ALWAYS_INLINE
267#endif
268
269#ifdef __GNUC__
270#define LLVM_ATTRIBUTE_NORETURN __attribute__((noreturn))
271#elif defined(_MSC_VER)
272#define LLVM_ATTRIBUTE_NORETURN __declspec(noreturn)
273#else
274#define LLVM_ATTRIBUTE_NORETURN
275#endif
276
277/// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
278/// pedantic diagnostics.
279#ifdef __GNUC__
280#define LLVM_EXTENSION __extension__
281#else
282#define LLVM_EXTENSION
283#endif
284
285// LLVM_ATTRIBUTE_DEPRECATED(decl, "message")
286#if __has_feature(attribute_deprecated_with_message)
287# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
288  decl __attribute__((deprecated(message)))
289#elif defined(__GNUC__)
290# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
291  decl __attribute__((deprecated))
292#elif defined(_MSC_VER)
293# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
294  __declspec(deprecated(message)) decl
295#else
296# define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \
297  decl
298#endif
299
300/// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands
301/// to an expression which states that it is undefined behavior for the
302/// compiler to reach this point.  Otherwise is not defined.
303#if __has_builtin(__builtin_unreachable) || __GNUC_PREREQ(4, 5)
304# define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
305#elif defined(_MSC_VER)
306# define LLVM_BUILTIN_UNREACHABLE __assume(false)
307#endif
308
309/// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression
310/// which causes the program to exit abnormally.
311#if __has_builtin(__builtin_trap) || __GNUC_PREREQ(4, 3)
312# define LLVM_BUILTIN_TRAP __builtin_trap()
313#else
314# define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0
315#endif
316
317/// \macro LLVM_ASSUME_ALIGNED
318/// \brief Returns a pointer with an assumed alignment.
319#if __has_builtin(__builtin_assume_aligned) && __GNUC_PREREQ(4, 7)
320# define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a)
321#elif defined(LLVM_BUILTIN_UNREACHABLE)
322// As of today, clang does not support __builtin_assume_aligned.
323# define LLVM_ASSUME_ALIGNED(p, a) \
324           (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p)))
325#else
326# define LLVM_ASSUME_ALIGNED(p, a) (p)
327#endif
328
329/// \macro LLVM_FUNCTION_NAME
330/// \brief Expands to __func__ on compilers which support it.  Otherwise,
331/// expands to a compiler-dependent replacement.
332#if defined(_MSC_VER)
333# define LLVM_FUNCTION_NAME __FUNCTION__
334#else
335# define LLVM_FUNCTION_NAME __func__
336#endif
337
338#if defined(HAVE_SANITIZER_MSAN_INTERFACE_H)
339# include <sanitizer/msan_interface.h>
340#else
341# define __msan_allocated_memory(p, size)
342# define __msan_unpoison(p, size)
343#endif
344
345/// \macro LLVM_MEMORY_SANITIZER_BUILD
346/// \brief Whether LLVM itself is built with MemorySanitizer instrumentation.
347#if __has_feature(memory_sanitizer)
348# define LLVM_MEMORY_SANITIZER_BUILD 1
349#else
350# define LLVM_MEMORY_SANITIZER_BUILD 0
351#endif
352
353/// \macro LLVM_ADDRESS_SANITIZER_BUILD
354/// \brief Whether LLVM itself is built with AddressSanitizer instrumentation.
355#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
356# define LLVM_ADDRESS_SANITIZER_BUILD 1
357#else
358# define LLVM_ADDRESS_SANITIZER_BUILD 0
359#endif
360
361/// \macro LLVM_IS_UNALIGNED_ACCESS_FAST
362/// \brief Is unaligned memory access fast on the host machine.
363///
364/// Don't specialize on alignment for platforms where unaligned memory accesses
365/// generates the same code as aligned memory accesses for common types.
366#if defined(_M_AMD64) || defined(_M_IX86) || defined(__amd64) || \
367    defined(__amd64__) || defined(__x86_64) || defined(__x86_64__) || \
368    defined(_X86_) || defined(__i386) || defined(__i386__)
369# define LLVM_IS_UNALIGNED_ACCESS_FAST 1
370#else
371# define LLVM_IS_UNALIGNED_ACCESS_FAST 0
372#endif
373
374/// \macro LLVM_EXPLICIT
375/// \brief Expands to explicit on compilers which support explicit conversion
376/// operators. Otherwise expands to nothing.
377#if (__has_feature(cxx_explicit_conversions) \
378     || defined(__GXX_EXPERIMENTAL_CXX0X__))
379#define LLVM_EXPLICIT explicit
380#else
381#define LLVM_EXPLICIT
382#endif
383
384/// \macro LLVM_STATIC_ASSERT
385/// \brief Expands to C/C++'s static_assert on compilers which support it.
386#if __has_feature(cxx_static_assert)
387# define LLVM_STATIC_ASSERT(expr, msg) static_assert(expr, msg)
388#elif __has_feature(c_static_assert)
389# define LLVM_STATIC_ASSERT(expr, msg) _Static_assert(expr, msg)
390#else
391# define LLVM_STATIC_ASSERT(expr, msg)
392#endif
393
394/// \macro LLVM_ENUM_INT_TYPE
395/// \brief Expands to colon followed by the given integral type on compilers
396/// which support C++11 strong enums.  This can be used to make enums unsigned
397/// with MSVC.
398#if __has_feature(cxx_strong_enums)
399# define LLVM_ENUM_INT_TYPE(intty) : intty
400#elif defined(_MSC_VER) && _MSC_VER >= 1600  // Added in MSVC 2010.
401# define LLVM_ENUM_INT_TYPE(intty) : intty
402#else
403# define LLVM_ENUM_INT_TYPE(intty)
404#endif
405
406/// \brief Does the compiler support generalized initializers (using braced
407/// lists and std::initializer_list).
408#if __has_feature(cxx_generalized_initializers)
409#define LLVM_HAS_INITIALIZER_LISTS 1
410#else
411#define LLVM_HAS_INITIALIZER_LISTS 0
412#endif
413
414#endif
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