v8  3.28.71(node0.12.18)
V8 is Google's open source JavaScript engine
v8config.h
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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.
4 
5 #ifndef V8CONFIG_H_
6 #define V8CONFIG_H_
7 
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>
15 #endif
16 
17 
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.
21 // Use like:
22 // #if V8_GLIBC_PREREQ(2, 3)
23 // ...
24 // #endif
25 #if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
26 # define V8_GLIBC_PREREQ(major, minor)
27  ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
28 #else
29 # define V8_GLIBC_PREREQ(major, minor) 0
30 #endif
31 
32 
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.
36 // Use like:
37 // #if V8_GNUC_PREREQ(4, 3, 1)
38 // ...
39 // #endif
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)))
48 #else
49 # define V8_GNUC_PREREQ(major, minor, patchlevel) 0
50 #endif
51 
52 
53 
54 // -----------------------------------------------------------------------------
55 // Operating system detection
56 //
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
70 // V8_OS_WIN - Microsoft Windows
71 
72 #if defined(__ANDROID__)
73 # define V8_OS_ANDROID 1
74 # define V8_OS_LINUX 1
75 # define V8_OS_POSIX 1
76 #elif defined(__APPLE__)
77 # define V8_OS_BSD 1
78 # define V8_OS_MACOSX 1
79 # define V8_OS_POSIX 1
80 #elif defined(__native_client__)
81 # define V8_OS_NACL 1
82 # define V8_OS_POSIX 1
83 #elif defined(__CYGWIN__)
84 # define V8_OS_CYGWIN 1
85 # define V8_OS_POSIX 1
86 #elif defined(__linux__)
87 # define V8_OS_LINUX 1
88 # define V8_OS_POSIX 1
89 #elif defined(__sun)
90 # define V8_OS_POSIX 1
91 # define V8_OS_SOLARIS 1
92 #elif defined(__FreeBSD__)
93 # define V8_OS_BSD 1
94 # define V8_OS_FREEBSD 1
95 # define V8_OS_POSIX 1
96 #elif defined(__DragonFly__)
97 # define V8_OS_BSD 1
98 # define V8_OS_DRAGONFLYBSD 1
99 # define V8_OS_POSIX 1
100 #elif defined(__NetBSD__)
101 # define V8_OS_BSD 1
102 # define V8_OS_NETBSD 1
103 # define V8_OS_POSIX 1
104 #elif defined(__OpenBSD__)
105 # define V8_OS_BSD 1
106 # define V8_OS_OPENBSD 1
107 # define V8_OS_POSIX 1
108 #elif defined(__QNXNTO__)
109 # define V8_OS_POSIX 1
110 # define V8_OS_QNX 1
111 #elif defined(_WIN32)
112 # define V8_OS_WIN 1
113 #endif
114 
115 
116 // -----------------------------------------------------------------------------
117 // C library detection
118 //
119 // V8_LIBC_MSVCRT - MSVC libc
120 // V8_LIBC_BIONIC - Bionic libc
121 // V8_LIBC_BSD - BSD libc derivate
122 // V8_LIBC_GLIBC - GNU C library
123 // V8_LIBC_UCLIBC - uClibc
124 //
125 // Note that testing for libc must be done using #if not #ifdef. For example,
126 // to test for the GNU C library, use:
127 // #if V8_LIBC_GLIBC
128 // ...
129 // #endif
130 
131 #if defined (_MSC_VER)
132 # define V8_LIBC_MSVCRT 1
133 #elif defined(__BIONIC__)
134 # define V8_LIBC_BIONIC 1
135 # define V8_LIBC_BSD 1
136 #elif defined(__UCLIBC__)
137 # define V8_LIBC_UCLIBC 1
138 #elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
139 # define V8_LIBC_GLIBC 1
140 #else
141 # define V8_LIBC_BSD V8_OS_BSD
142 #endif
143 
144 
145 // -----------------------------------------------------------------------------
146 // Compiler detection
147 //
148 // V8_CC_CLANG - Clang
149 // V8_CC_GNU - GNU C++
150 // V8_CC_INTEL - Intel C++
151 // V8_CC_MINGW - Minimalist GNU for Windows
152 // V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
153 // V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
154 // V8_CC_MSVC - Microsoft Visual C/C++
155 //
156 // C++11 feature detection
157 //
158 // V8_HAS_CXX11_ALIGNAS - alignas specifier supported
159 // V8_HAS_CXX11_ALIGNOF - alignof(type) operator supported
160 // V8_HAS_CXX11_STATIC_ASSERT - static_assert() supported
161 // V8_HAS_CXX11_DELETE - deleted functions supported
162 // V8_HAS_CXX11_FINAL - final marker supported
163 // V8_HAS_CXX11_OVERRIDE - override marker supported
164 //
165 // Compiler-specific feature detection
166 //
167 // V8_HAS___ALIGNOF - __alignof(type) operator supported
168 // V8_HAS___ALIGNOF__ - __alignof__(type) operator supported
169 // V8_HAS_ATTRIBUTE_ALIGNED - __attribute__((aligned(n))) supported
170 // V8_HAS_ATTRIBUTE_ALWAYS_INLINE - __attribute__((always_inline))
171 // supported
172 // V8_HAS_ATTRIBUTE_DEPRECATED - __attribute__((deprecated)) supported
173 // V8_HAS_ATTRIBUTE_NOINLINE - __attribute__((noinline)) supported
174 // V8_HAS_ATTRIBUTE_UNUSED - __attribute__((unused)) supported
175 // V8_HAS_ATTRIBUTE_VISIBILITY - __attribute__((visibility)) supported
176 // V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
177 // supported
178 // V8_HAS_BUILTIN_EXPECT - __builtin_expect() supported
179 // V8_HAS_DECLSPEC_ALIGN - __declspec(align(n)) supported
180 // V8_HAS_DECLSPEC_DEPRECATED - __declspec(deprecated) supported
181 // V8_HAS_DECLSPEC_NOINLINE - __declspec(noinline) supported
182 // V8_HAS___FINAL - __final supported in non-C++11 mode
183 // V8_HAS___FORCEINLINE - __forceinline supported
184 // V8_HAS_SEALED - MSVC style sealed marker supported
185 //
186 // Note that testing for compilers and/or features must be done using #if
187 // not #ifdef. For example, to test for Intel C++ Compiler, use:
188 // #if V8_CC_INTEL
189 // ...
190 // #endif
191 
192 #if defined(__clang__)
193 
194 # define V8_CC_CLANG 1
195 
196 // Clang defines __alignof__ as alias for __alignof
197 # define V8_HAS___ALIGNOF 1
198 # define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
199 
200 # define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
201 # define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
202 # define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
203 # define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
204 # define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
205 # define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
206 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
207  (__has_attribute(warn_unused_result))
208 
209 # define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
210 
211 # define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
212 # define V8_HAS_CXX11_STATIC_ASSERT (__has_feature(cxx_static_assert))
213 # define V8_HAS_CXX11_DELETE (__has_feature(cxx_deleted_functions))
214 # define V8_HAS_CXX11_FINAL (__has_feature(cxx_override_control))
215 # define V8_HAS_CXX11_OVERRIDE (__has_feature(cxx_override_control))
216 
217 #elif defined(__GNUC__)
218 
219 # define V8_CC_GNU 1
220 // Intel C++ also masquerades as GCC 3.2.0
221 # define V8_CC_INTEL (defined(__INTEL_COMPILER))
222 # define V8_CC_MINGW32 (defined(__MINGW32__))
223 # define V8_CC_MINGW64 (defined(__MINGW64__))
224 # define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
225 
226 # define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
227 
228 # define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
229 // always_inline is available in gcc 4.0 but not very reliable until 4.4.
230 // Works around "sorry, unimplemented: inlining failed" build errors with
231 // older compilers.
232 # define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
233 # define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
234 # define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
235 # define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
236 # define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
237 # define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
238 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
239  (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
240 
241 # define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
242 
243 // g++ requires -std=c++0x or -std=gnu++0x to support C++11 functionality
244 // without warnings (functionality used by the macros below). These modes
245 // are detectable by checking whether __GXX_EXPERIMENTAL_CXX0X__ is defined or,
246 // more standardly, by checking whether __cplusplus has a C++11 or greater
247 // value. Current versions of g++ do not correctly set __cplusplus, so we check
248 // both for forward compatibility.
249 # if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
250 # define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
251 # define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
252 # define V8_HAS_CXX11_STATIC_ASSERT (V8_GNUC_PREREQ(4, 3, 0))
253 # define V8_HAS_CXX11_DELETE (V8_GNUC_PREREQ(4, 4, 0))
254 # define V8_HAS_CXX11_OVERRIDE (V8_GNUC_PREREQ(4, 7, 0))
255 # define V8_HAS_CXX11_FINAL (V8_GNUC_PREREQ(4, 7, 0))
256 # else
257 // '__final' is a non-C++11 GCC synonym for 'final', per GCC r176655.
258 # define V8_HAS___FINAL (V8_GNUC_PREREQ(4, 7, 0))
259 # endif
260 
261 #elif defined(_MSC_VER)
262 
263 # define V8_CC_MSVC 1
264 
265 # define V8_HAS___ALIGNOF 1
266 
267 // Override control was added with Visual Studio 2005, but
268 // Visual Studio 2010 and earlier spell "final" as "sealed".
269 # define V8_HAS_CXX11_FINAL (_MSC_VER >= 1700)
270 # define V8_HAS_CXX11_OVERRIDE (_MSC_VER >= 1400)
271 # define V8_HAS_SEALED (_MSC_VER >= 1400)
272 
273 # define V8_HAS_DECLSPEC_ALIGN 1
274 # define V8_HAS_DECLSPEC_DEPRECATED (_MSC_VER >= 1300)
275 # define V8_HAS_DECLSPEC_NOINLINE 1
276 
277 # define V8_HAS___FORCEINLINE 1
278 
279 #endif
280 
281 
282 // -----------------------------------------------------------------------------
283 // Helper macros
284 
285 // A macro used to make better inlining. Don't bother for debug builds.
286 // Use like:
287 // V8_INLINE int GetZero() { return 0; }
288 #if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
289 # define V8_INLINE inline __attribute__((always_inline))
290 #elif !defined(DEBUG) && V8_HAS___FORCEINLINE
291 # define V8_INLINE __forceinline
292 #else
293 # define V8_INLINE inline
294 #endif
295 
296 
297 // A macro used to tell the compiler to never inline a particular function.
298 // Don't bother for debug builds.
299 // Use like:
300 // V8_NOINLINE int GetMinusOne() { return -1; }
301 #if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
302 # define V8_NOINLINE __attribute__((noinline))
303 #elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
304 # define V8_NOINLINE __declspec(noinline)
305 #else
306 # define V8_NOINLINE /* NOT SUPPORTED */
307 #endif
308 
309 
310 // A macro to mark classes or functions as deprecated.
311 #if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
312 # define V8_DEPRECATED(message, declarator) declarator
313  __attribute__((deprecated(message)))
314 #elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
315 # define V8_DEPRECATED(message, declarator) declarator
316  __attribute__((deprecated))
317 #elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
318 # define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
319 #else
320 # define V8_DEPRECATED(message, declarator) declarator
321 #endif
322 
323 
324 // A macro to mark variables or types as unused, avoiding compiler warnings.
325 #if V8_HAS_ATTRIBUTE_UNUSED
326 # define V8_UNUSED __attribute__((unused))
327 #else
328 # define V8_UNUSED
329 #endif
330 
331 
332 // Annotate a function indicating the caller must examine the return value.
333 // Use like:
334 // int foo() V8_WARN_UNUSED_RESULT;
335 #if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
336 # define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
337 #else
338 # define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
339 #endif
340 
341 
342 // A macro to provide the compiler with branch prediction information.
343 #if V8_HAS_BUILTIN_EXPECT
344 # define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
345 # define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
346 #else
347 # define V8_UNLIKELY(condition) (condition)
348 # define V8_LIKELY(condition) (condition)
349 #endif
350 
351 
352 // A macro to specify that a method is deleted from the corresponding class.
353 // Any attempt to use the method will always produce an error at compile time
354 // when this macro can be implemented (i.e. if the compiler supports C++11).
355 // If the current compiler does not support C++11, use of the annotated method
356 // will still cause an error, but the error will most likely occur at link time
357 // rather than at compile time. As a backstop, method declarations using this
358 // macro should be private.
359 // Use like:
360 // class A {
361 // private:
362 // A(const A& other) V8_DELETE;
363 // A& operator=(const A& other) V8_DELETE;
364 // };
365 #if V8_HAS_CXX11_DELETE
366 # define V8_DELETE = delete
367 #else
368 # define V8_DELETE /* NOT SUPPORTED */
369 #endif
370 
371 
372 // Annotate a virtual method indicating it must be overriding a virtual
373 // method in the parent class.
374 // Use like:
375 // virtual void bar() V8_OVERRIDE;
376 #if V8_HAS_CXX11_OVERRIDE
377 # define V8_OVERRIDE override
378 #else
379 # define V8_OVERRIDE /* NOT SUPPORTED */
380 #endif
381 
382 
383 // Annotate a virtual method indicating that subclasses must not override it,
384 // or annotate a class to indicate that it cannot be subclassed.
385 // Use like:
386 // class B V8_FINAL : public A {};
387 // virtual void bar() V8_FINAL;
388 #if V8_HAS_CXX11_FINAL
389 # define V8_FINAL final
390 #elif V8_HAS___FINAL
391 # define V8_FINAL __final
392 #elif V8_HAS_SEALED
393 # define V8_FINAL sealed
394 #else
395 # define V8_FINAL /* NOT SUPPORTED */
396 #endif
397 
398 
399 // This macro allows to specify memory alignment for structs, classes, etc.
400 // Use like:
401 // class V8_ALIGNED(16) MyClass { ... };
402 // V8_ALIGNED(32) int array[42];
403 #if V8_HAS_CXX11_ALIGNAS
404 # define V8_ALIGNED(n) alignas(n)
405 #elif V8_HAS_ATTRIBUTE_ALIGNED
406 # define V8_ALIGNED(n) __attribute__((aligned(n)))
407 #elif V8_HAS_DECLSPEC_ALIGN
408 # define V8_ALIGNED(n) __declspec(align(n))
409 #else
410 # define V8_ALIGNED(n) /* NOT SUPPORTED */
411 #endif
412 
413 
414 // This macro is similar to V8_ALIGNED(), but takes a type instead of size
415 // in bytes. If the compiler does not supports using the alignment of the
416 // |type|, it will align according to the |alignment| instead. For example,
417 // Visual Studio C++ cannot combine __declspec(align) and __alignof. The
418 // |alignment| must be a literal that is used as a kind of worst-case fallback
419 // alignment.
420 // Use like:
421 // struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
422 // V8_ALIGNAS(double, 8) int array[100];
423 #if V8_HAS_CXX11_ALIGNAS
424 # define V8_ALIGNAS(type, alignment) alignas(type)
425 #elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
426 # define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
427 #else
428 # define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
429 #endif
430 
431 
432 // This macro returns alignment in bytes (an integer power of two) required for
433 // any instance of the given type, which is either complete type, an array type,
434 // or a reference type.
435 // Use like:
436 // size_t alignment = V8_ALIGNOF(double);
437 #if V8_HAS_CXX11_ALIGNOF
438 # define V8_ALIGNOF(type) alignof(type)
439 #elif V8_HAS___ALIGNOF
440 # define V8_ALIGNOF(type) __alignof(type)
441 #elif V8_HAS___ALIGNOF__
442 # define V8_ALIGNOF(type) __alignof__(type)
443 #else
444 // Note that alignment of a type within a struct can be less than the
445 // alignment of the type stand-alone (because of ancient ABIs), so this
446 // should only be used as a last resort.
447 namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
448 # define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
449 #endif
450 
451 #endif // V8CONFIG_H_