1 // Copyright 2013 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
8 // Platform headers for feature detection below.
9 #if defined(__ANDROID__)
10 # include <sys/cdefs.h>
11 #elif defined(__APPLE__)
12 # include <TargetConditionals.h>
13 #elif defined(__linux__)
14 # include <features.h>
18 // This macro allows to test for the version of the GNU C library (or
19 // a compatible C library that masquerades as glibc). It evaluates to
20 // 0 if libc is not GNU libc or compatible.
22 // #if V8_GLIBC_PREREQ(2, 3)
25 #if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
26 # define V8_GLIBC_PREREQ(major, minor) \
27 ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
29 # define V8_GLIBC_PREREQ(major, minor) 0
33 // This macro allows to test for the version of the GNU C++ compiler.
34 // Note that this also applies to compilers that masquerade as GCC,
35 // for example clang and the Intel C++ compiler for Linux.
37 // #if V8_GNUC_PREREQ(4, 3, 1)
40 #if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
41 # define V8_GNUC_PREREQ(major, minor, patchlevel) \
42 ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >= \
43 ((major) * 10000 + (minor) * 100 + (patchlevel)))
44 #elif defined(__GNUC__) && defined(__GNUC_MINOR__)
45 # define V8_GNUC_PREREQ(major, minor, patchlevel) \
46 ((__GNUC__ * 10000 + __GNUC_MINOR__) >= \
47 ((major) * 10000 + (minor) * 100 + (patchlevel)))
49 # define V8_GNUC_PREREQ(major, minor, patchlevel) 0
54 // -----------------------------------------------------------------------------
55 // Operating system detection
57 // V8_OS_ANDROID - Android
58 // V8_OS_BSD - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
59 // V8_OS_CYGWIN - Cygwin
60 // V8_OS_DRAGONFLYBSD - DragonFlyBSD
61 // V8_OS_FREEBSD - FreeBSD
62 // V8_OS_LINUX - Linux
63 // V8_OS_MACOSX - Mac OS X
64 // V8_OS_NACL - Native Client
65 // V8_OS_NETBSD - NetBSD
66 // V8_OS_OPENBSD - OpenBSD
67 // V8_OS_POSIX - POSIX compatible (mostly everything except Windows)
68 // V8_OS_QNX - QNX Neutrino
69 // V8_OS_SOLARIS - Sun Solaris and OpenSolaris
71 // V8_OS_WIN - Microsoft Windows
73 #if defined(__ANDROID__)
74 # define V8_OS_ANDROID 1
75 # define V8_OS_LINUX 1
76 # define V8_OS_POSIX 1
77 #elif defined(__APPLE__)
79 # define V8_OS_MACOSX 1
80 # define V8_OS_POSIX 1
81 #elif defined(__native_client__)
83 # define V8_OS_POSIX 1
84 #elif defined(__CYGWIN__)
85 # define V8_OS_CYGWIN 1
86 # define V8_OS_POSIX 1
87 #elif defined(__linux__)
88 # define V8_OS_LINUX 1
89 # define V8_OS_POSIX 1
91 # define V8_OS_POSIX 1
92 # define V8_OS_SOLARIS 1
96 #elif defined(__FreeBSD__)
98 # define V8_OS_FREEBSD 1
99 # define V8_OS_POSIX 1
100 #elif defined(__DragonFly__)
102 # define V8_OS_DRAGONFLYBSD 1
103 # define V8_OS_POSIX 1
104 #elif defined(__NetBSD__)
106 # define V8_OS_NETBSD 1
107 # define V8_OS_POSIX 1
108 #elif defined(__OpenBSD__)
110 # define V8_OS_OPENBSD 1
111 # define V8_OS_POSIX 1
112 #elif defined(__QNXNTO__)
113 # define V8_OS_POSIX 1
115 #elif defined(_WIN32)
120 // -----------------------------------------------------------------------------
121 // C library detection
123 // V8_LIBC_MSVCRT - MSVC libc
124 // V8_LIBC_BIONIC - Bionic libc
125 // V8_LIBC_BSD - BSD libc derivate
126 // V8_LIBC_GLIBC - GNU C library
127 // V8_LIBC_UCLIBC - uClibc
129 // Note that testing for libc must be done using #if not #ifdef. For example,
130 // to test for the GNU C library, use:
135 #if defined (_MSC_VER)
136 # define V8_LIBC_MSVCRT 1
137 #elif defined(__BIONIC__)
138 # define V8_LIBC_BIONIC 1
139 # define V8_LIBC_BSD 1
140 #elif defined(__UCLIBC__)
141 // Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
142 # define V8_LIBC_UCLIBC 1
143 #elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
144 # define V8_LIBC_GLIBC 1
146 # define V8_LIBC_BSD V8_OS_BSD
150 // -----------------------------------------------------------------------------
151 // Compiler detection
153 // V8_CC_GNU - GCC, or clang in gcc mode
154 // V8_CC_INTEL - Intel C++
155 // V8_CC_MINGW - Minimalist GNU for Windows
156 // V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
157 // V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
158 // V8_CC_MSVC - Microsoft Visual C/C++, or clang in cl.exe mode
160 // C++11 feature detection
162 // V8_HAS_CXX11_ALIGNAS - alignas specifier supported
163 // V8_HAS_CXX11_ALIGNOF - alignof(type) operator supported
164 // V8_HAS_CXX11_STATIC_ASSERT - static_assert() supported
165 // V8_HAS_CXX11_DELETE - deleted functions supported
166 // V8_HAS_CXX11_FINAL - final marker supported
167 // V8_HAS_CXX11_OVERRIDE - override marker supported
169 // Compiler-specific feature detection
171 // V8_HAS___ALIGNOF - __alignof(type) operator supported
172 // V8_HAS___ALIGNOF__ - __alignof__(type) operator supported
173 // V8_HAS_ATTRIBUTE_ALIGNED - __attribute__((aligned(n))) supported
174 // V8_HAS_ATTRIBUTE_ALWAYS_INLINE - __attribute__((always_inline))
176 // V8_HAS_ATTRIBUTE_DEPRECATED - __attribute__((deprecated)) supported
177 // V8_HAS_ATTRIBUTE_NOINLINE - __attribute__((noinline)) supported
178 // V8_HAS_ATTRIBUTE_UNUSED - __attribute__((unused)) supported
179 // V8_HAS_ATTRIBUTE_VISIBILITY - __attribute__((visibility)) supported
180 // V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
182 // V8_HAS_BUILTIN_CLZ - __builtin_clz() supported
183 // V8_HAS_BUILTIN_CTZ - __builtin_ctz() supported
184 // V8_HAS_BUILTIN_EXPECT - __builtin_expect() supported
185 // V8_HAS_BUILTIN_FRAME_ADDRESS - __builtin_frame_address() supported
186 // V8_HAS_BUILTIN_POPCOUNT - __builtin_popcount() supported
187 // V8_HAS_BUILTIN_SADD_OVERFLOW - __builtin_sadd_overflow() supported
188 // V8_HAS_BUILTIN_SSUB_OVERFLOW - __builtin_ssub_overflow() supported
189 // V8_HAS_DECLSPEC_ALIGN - __declspec(align(n)) supported
190 // V8_HAS_DECLSPEC_DEPRECATED - __declspec(deprecated) supported
191 // V8_HAS_DECLSPEC_NOINLINE - __declspec(noinline) supported
192 // V8_HAS_DECLSPEC_SELECTANY - __declspec(selectany) supported
193 // V8_HAS___FINAL - __final supported in non-C++11 mode
194 // V8_HAS___FORCEINLINE - __forceinline supported
196 // Note that testing for compilers and/or features must be done using #if
197 // not #ifdef. For example, to test for Intel C++ Compiler, use:
202 #if defined(__clang__)
204 #if defined(__GNUC__) // Clang in gcc mode.
206 #elif defined(_MSC_VER) // Clang in cl mode.
207 # define V8_CC_MSVC 1
210 // Clang defines __alignof__ as alias for __alignof
211 # define V8_HAS___ALIGNOF 1
212 # define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
214 # define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
215 # define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
216 # define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
217 # define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
218 # define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
219 # define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
220 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
221 (__has_attribute(warn_unused_result))
223 # define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
224 # define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
225 # define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
226 # define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
227 # define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
228 # define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
229 # define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
231 # define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
232 # define V8_HAS_CXX11_STATIC_ASSERT (__has_feature(cxx_static_assert))
233 # define V8_HAS_CXX11_DELETE (__has_feature(cxx_deleted_functions))
234 # define V8_HAS_CXX11_FINAL (__has_feature(cxx_override_control))
235 # define V8_HAS_CXX11_OVERRIDE (__has_feature(cxx_override_control))
237 #elif defined(__GNUC__)
240 // Intel C++ also masquerades as GCC 3.2.0
241 # define V8_CC_INTEL (defined(__INTEL_COMPILER))
242 # define V8_CC_MINGW32 (defined(__MINGW32__))
243 # define V8_CC_MINGW64 (defined(__MINGW64__))
244 # define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
246 # define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
248 # define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
249 // always_inline is available in gcc 4.0 but not very reliable until 4.4.
250 // Works around "sorry, unimplemented: inlining failed" build errors with
252 # define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
253 # define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
254 # define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
255 # define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
256 # define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
257 # define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
258 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
259 (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
261 # define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
262 # define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
263 # define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
264 # define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
265 # define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
267 // g++ requires -std=c++0x or -std=gnu++0x to support C++11 functionality
268 // without warnings (functionality used by the macros below). These modes
269 // are detectable by checking whether __GXX_EXPERIMENTAL_CXX0X__ is defined or,
270 // more standardly, by checking whether __cplusplus has a C++11 or greater
271 // value. Current versions of g++ do not correctly set __cplusplus, so we check
272 // both for forward compatibility.
273 # if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
274 # define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
275 # define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
276 # define V8_HAS_CXX11_STATIC_ASSERT (V8_GNUC_PREREQ(4, 3, 0))
277 # define V8_HAS_CXX11_DELETE (V8_GNUC_PREREQ(4, 4, 0))
278 # define V8_HAS_CXX11_OVERRIDE (V8_GNUC_PREREQ(4, 7, 0))
279 # define V8_HAS_CXX11_FINAL (V8_GNUC_PREREQ(4, 7, 0))
281 // '__final' is a non-C++11 GCC synonym for 'final', per GCC r176655.
282 # define V8_HAS___FINAL (V8_GNUC_PREREQ(4, 7, 0))
285 #elif defined(_MSC_VER)
287 # define V8_CC_MSVC 1
289 # define V8_HAS___ALIGNOF 1
291 # define V8_HAS_CXX11_FINAL 1
292 # define V8_HAS_CXX11_OVERRIDE 1
294 # define V8_HAS_DECLSPEC_ALIGN 1
295 # define V8_HAS_DECLSPEC_DEPRECATED 1
296 # define V8_HAS_DECLSPEC_NOINLINE 1
297 # define V8_HAS_DECLSPEC_SELECTANY 1
299 # define V8_HAS___FORCEINLINE 1
304 // -----------------------------------------------------------------------------
307 // A macro used to make better inlining. Don't bother for debug builds.
309 // V8_INLINE int GetZero() { return 0; }
310 #if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
311 # define V8_INLINE inline __attribute__((always_inline))
312 #elif !defined(DEBUG) && V8_HAS___FORCEINLINE
313 # define V8_INLINE __forceinline
315 # define V8_INLINE inline
319 // A macro used to tell the compiler to never inline a particular function.
320 // Don't bother for debug builds.
322 // V8_NOINLINE int GetMinusOne() { return -1; }
323 #if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
324 # define V8_NOINLINE __attribute__((noinline))
325 #elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
326 # define V8_NOINLINE __declspec(noinline)
328 # define V8_NOINLINE /* NOT SUPPORTED */
332 // A macro to mark classes or functions as deprecated.
333 #if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
334 # define V8_DEPRECATED(message, declarator) \
335 declarator __attribute__((deprecated(message)))
336 #elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
337 # define V8_DEPRECATED(message, declarator) \
338 declarator __attribute__((deprecated))
339 #elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
340 # define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
342 # define V8_DEPRECATED(message, declarator) declarator
346 // A macro to provide the compiler with branch prediction information.
347 #if V8_HAS_BUILTIN_EXPECT
348 # define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
349 # define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
351 # define V8_UNLIKELY(condition) (condition)
352 # define V8_LIKELY(condition) (condition)
356 // A macro to specify that a method is deleted from the corresponding class.
357 // Any attempt to use the method will always produce an error at compile time
358 // when this macro can be implemented (i.e. if the compiler supports C++11).
359 // If the current compiler does not support C++11, use of the annotated method
360 // will still cause an error, but the error will most likely occur at link time
361 // rather than at compile time. As a backstop, method declarations using this
362 // macro should be private.
366 // A(const A& other) V8_DELETE;
367 // A& operator=(const A& other) V8_DELETE;
369 #if V8_HAS_CXX11_DELETE
370 # define V8_DELETE = delete
372 # define V8_DELETE /* NOT SUPPORTED */
376 // This macro allows to specify memory alignment for structs, classes, etc.
378 // class V8_ALIGNED(16) MyClass { ... };
379 // V8_ALIGNED(32) int array[42];
380 #if V8_HAS_CXX11_ALIGNAS
381 # define V8_ALIGNED(n) alignas(n)
382 #elif V8_HAS_ATTRIBUTE_ALIGNED
383 # define V8_ALIGNED(n) __attribute__((aligned(n)))
384 #elif V8_HAS_DECLSPEC_ALIGN
385 # define V8_ALIGNED(n) __declspec(align(n))
387 # define V8_ALIGNED(n) /* NOT SUPPORTED */
391 // This macro is similar to V8_ALIGNED(), but takes a type instead of size
392 // in bytes. If the compiler does not supports using the alignment of the
393 // |type|, it will align according to the |alignment| instead. For example,
394 // Visual Studio C++ cannot combine __declspec(align) and __alignof. The
395 // |alignment| must be a literal that is used as a kind of worst-case fallback
398 // struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
399 // V8_ALIGNAS(double, 8) int array[100];
400 #if V8_HAS_CXX11_ALIGNAS
401 # define V8_ALIGNAS(type, alignment) alignas(type)
402 #elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
403 # define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
405 # define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
409 // This macro returns alignment in bytes (an integer power of two) required for
410 // any instance of the given type, which is either complete type, an array type,
411 // or a reference type.
413 // size_t alignment = V8_ALIGNOF(double);
414 #if V8_HAS_CXX11_ALIGNOF
415 # define V8_ALIGNOF(type) alignof(type)
416 #elif V8_HAS___ALIGNOF
417 # define V8_ALIGNOF(type) __alignof(type)
418 #elif V8_HAS___ALIGNOF__
419 # define V8_ALIGNOF(type) __alignof__(type)
421 // Note that alignment of a type within a struct can be less than the
422 // alignment of the type stand-alone (because of ancient ABIs), so this
423 // should only be used as a last resort.
424 namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
425 # define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
428 #endif // V8CONFIG_H_