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 // clang-format off
9 
10 // Platform headers for feature detection below.
11 #if defined(__ANDROID__)
12 # include <sys/cdefs.h>
13 #elif defined(__APPLE__)
14 # include <TargetConditionals.h>
15 #elif defined(__linux__)
16 # include <features.h>
17 #endif
18 
19 
20 // This macro allows to test for the version of the GNU C library (or
21 // a compatible C library that masquerades as glibc). It evaluates to
22 // 0 if libc is not GNU libc or compatible.
23 // Use like:
24 //  #if V8_GLIBC_PREREQ(2, 3)
25 //   ...
26 //  #endif
27 #if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
28 # define V8_GLIBC_PREREQ(major, minor)                                    \
29     ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
30 #else
31 # define V8_GLIBC_PREREQ(major, minor) 0
32 #endif
33 
34 
35 // This macro allows to test for the version of the GNU C++ compiler.
36 // Note that this also applies to compilers that masquerade as GCC,
37 // for example clang and the Intel C++ compiler for Linux.
38 // Use like:
39 //  #if V8_GNUC_PREREQ(4, 3, 1)
40 //   ...
41 //  #endif
42 #if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
43 # define V8_GNUC_PREREQ(major, minor, patchlevel)                         \
44     ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \
45      ((major) * 10000 + (minor) * 100 + (patchlevel)))
46 #elif defined(__GNUC__) && defined(__GNUC_MINOR__)
47 # define V8_GNUC_PREREQ(major, minor, patchlevel)      \
48     ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \
49      ((major) * 10000 + (minor) * 100 + (patchlevel)))
50 #else
51 # define V8_GNUC_PREREQ(major, minor, patchlevel) 0
52 #endif
53 
54 
55 
56 // -----------------------------------------------------------------------------
57 // Operating system detection
58 //
59 //  V8_OS_ANDROID       - Android
60 //  V8_OS_BSD           - BSDish (Mac OS X, Net/Free/Open/DragonFlyBSD)
61 //  V8_OS_CYGWIN        - Cygwin
62 //  V8_OS_DRAGONFLYBSD  - DragonFlyBSD
63 //  V8_OS_FREEBSD       - FreeBSD
64 //  V8_OS_LINUX         - Linux
65 //  V8_OS_MACOSX        - Mac OS X
66 //  V8_OS_NACL          - Native Client
67 //  V8_OS_NETBSD        - NetBSD
68 //  V8_OS_OPENBSD       - OpenBSD
69 //  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)
70 //  V8_OS_QNX           - QNX Neutrino
71 //  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris
72 //  V8_OS_AIX           - AIX
73 //  V8_OS_WIN           - Microsoft Windows
74 
75 #if defined(__ANDROID__)
76 # define V8_OS_ANDROID 1
77 # define V8_OS_LINUX 1
78 # define V8_OS_POSIX 1
79 #elif defined(__APPLE__)
80 # define V8_OS_BSD 1
81 # define V8_OS_MACOSX 1
82 # define V8_OS_POSIX 1
83 #elif defined(__native_client__)
84 # define V8_OS_NACL 1
85 # define V8_OS_POSIX 1
86 #elif defined(__CYGWIN__)
87 # define V8_OS_CYGWIN 1
88 # define V8_OS_POSIX 1
89 #elif defined(__linux__)
90 # define V8_OS_LINUX 1
91 # define V8_OS_POSIX 1
92 #elif defined(__sun)
93 # define V8_OS_POSIX 1
94 # define V8_OS_SOLARIS 1
95 #elif defined(_AIX)
96 #define V8_OS_POSIX 1
97 #define V8_OS_AIX 1
98 #elif defined(__FreeBSD__)
99 # define V8_OS_BSD 1
100 # define V8_OS_FREEBSD 1
101 # define V8_OS_POSIX 1
102 #elif defined(__DragonFly__)
103 # define V8_OS_BSD 1
104 # define V8_OS_DRAGONFLYBSD 1
105 # define V8_OS_POSIX 1
106 #elif defined(__NetBSD__)
107 # define V8_OS_BSD 1
108 # define V8_OS_NETBSD 1
109 # define V8_OS_POSIX 1
110 #elif defined(__OpenBSD__)
111 # define V8_OS_BSD 1
112 # define V8_OS_OPENBSD 1
113 # define V8_OS_POSIX 1
114 #elif defined(__QNXNTO__)
115 # define V8_OS_POSIX 1
116 # define V8_OS_QNX 1
117 #elif defined(_WIN32)
118 # define V8_OS_WIN 1
119 #endif
120 
121 
122 // -----------------------------------------------------------------------------
123 // C library detection
124 //
125 //  V8_LIBC_MSVCRT  - MSVC libc
126 //  V8_LIBC_BIONIC  - Bionic libc
127 //  V8_LIBC_BSD     - BSD libc derivate
128 //  V8_LIBC_GLIBC   - GNU C library
129 //  V8_LIBC_UCLIBC  - uClibc
130 //
131 // Note that testing for libc must be done using #if not #ifdef. For example,
132 // to test for the GNU C library, use:
133 //  #if V8_LIBC_GLIBC
134 //   ...
135 //  #endif
136 
137 #if defined (_MSC_VER)
138 # define V8_LIBC_MSVCRT 1
139 #elif defined(__BIONIC__)
140 # define V8_LIBC_BIONIC 1
141 # define V8_LIBC_BSD 1
142 #elif defined(__UCLIBC__)
143 // Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
144 # define V8_LIBC_UCLIBC 1
145 #elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
146 # define V8_LIBC_GLIBC 1
147 #else
148 # define V8_LIBC_BSD V8_OS_BSD
149 #endif
150 
151 
152 // -----------------------------------------------------------------------------
153 // Compiler detection
154 //
155 //  V8_CC_GNU     - GCC, or clang in gcc mode
156 //  V8_CC_INTEL   - Intel C++
157 //  V8_CC_MINGW   - Minimalist GNU for Windows
158 //  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
159 //  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
160 //  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode
161 //
162 // C++11 feature detection
163 //
164 //  V8_HAS_CXX11_ALIGNAS        - alignas specifier supported
165 //  V8_HAS_CXX11_ALIGNOF        - alignof(type) operator supported
166 //
167 // Compiler-specific feature detection
168 //
169 //  V8_HAS___ALIGNOF                    - __alignof(type) operator supported
170 //  V8_HAS___ALIGNOF__                  - __alignof__(type) operator supported
171 //  V8_HAS_ATTRIBUTE_ALIGNED            - __attribute__((aligned(n))) supported
172 //  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))
173 //                                        supported
174 //  V8_HAS_ATTRIBUTE_DEPRECATED         - __attribute__((deprecated)) supported
175 //  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported
176 //  V8_HAS_ATTRIBUTE_NORETURN           - __attribute__((noreturn)) supported
177 //  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported
178 //  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported
179 //  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
180 //                                        supported
181 //  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported
182 //  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported
183 //  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported
184 //  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported
185 //  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported
186 //  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported
187 //  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported
188 //  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_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_DECLSPEC_NORETURN            - __declspec(noreturn) supported
194 //  V8_HAS___FORCEINLINE                - __forceinline supported
195 //
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:
198 //  #if V8_CC_INTEL
199 //   ...
200 //  #endif
201 
202 #if defined(__clang__)
203 
204 #if defined(__GNUC__)  // Clang in gcc mode.
205 # define V8_CC_GNU 1
206 #endif
207 
208 // Clang defines __alignof__ as alias for __alignof
209 # define V8_HAS___ALIGNOF 1
210 # define V8_HAS___ALIGNOF__ V8_HAS___ALIGNOF
211 
212 # define V8_HAS_ATTRIBUTE_ALIGNED (__has_attribute(aligned))
213 # define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
214 # define V8_HAS_ATTRIBUTE_DEPRECATED (__has_attribute(deprecated))
215 # define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
216 # define V8_HAS_ATTRIBUTE_NORETURN (__has_attribute(noreturn))
217 # define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
218 # define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
219 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
220     (__has_attribute(warn_unused_result))
221 
222 # define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
223 # define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
224 # define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
225 # define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
226 # define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
227 # define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
228 # define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
229 # define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
230 
231 # define V8_HAS_CXX11_ALIGNAS (__has_feature(cxx_alignas))
232 
233 #elif defined(__GNUC__)
234 
235 # define V8_CC_GNU 1
236 # if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0
237 #  define V8_CC_INTEL 1
238 # endif
239 # if defined(__MINGW32__)
240 #  define V8_CC_MINGW32 1
241 # endif
242 # if defined(__MINGW64__)
243 #  define V8_CC_MINGW64 1
244 # endif
245 # define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
246 
247 # define V8_HAS___ALIGNOF__ (V8_GNUC_PREREQ(4, 3, 0))
248 
249 # define V8_HAS_ATTRIBUTE_ALIGNED (V8_GNUC_PREREQ(2, 95, 0))
250 // always_inline is available in gcc 4.0 but not very reliable until 4.4.
251 // Works around "sorry, unimplemented: inlining failed" build errors with
252 // older compilers.
253 # define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (V8_GNUC_PREREQ(4, 4, 0))
254 # define V8_HAS_ATTRIBUTE_DEPRECATED (V8_GNUC_PREREQ(3, 4, 0))
255 # define V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE (V8_GNUC_PREREQ(4, 5, 0))
256 # define V8_HAS_ATTRIBUTE_NOINLINE (V8_GNUC_PREREQ(3, 4, 0))
257 # define V8_HAS_ATTRIBUTE_NORETURN (V8_GNUC_PREREQ(2, 5, 0))
258 # define V8_HAS_ATTRIBUTE_UNUSED (V8_GNUC_PREREQ(2, 95, 0))
259 # define V8_HAS_ATTRIBUTE_VISIBILITY (V8_GNUC_PREREQ(4, 3, 0))
260 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
261     (!V8_CC_INTEL && V8_GNUC_PREREQ(4, 1, 0))
262 
263 # define V8_HAS_BUILTIN_CLZ (V8_GNUC_PREREQ(3, 4, 0))
264 # define V8_HAS_BUILTIN_CTZ (V8_GNUC_PREREQ(3, 4, 0))
265 # define V8_HAS_BUILTIN_EXPECT (V8_GNUC_PREREQ(2, 96, 0))
266 # define V8_HAS_BUILTIN_FRAME_ADDRESS (V8_GNUC_PREREQ(2, 96, 0))
267 # define V8_HAS_BUILTIN_POPCOUNT (V8_GNUC_PREREQ(3, 4, 0))
268 
269 // g++ requires -std=c++0x or -std=gnu++0x to support C++11 functionality
270 // without warnings (functionality used by the macros below).  These modes
271 // are detectable by checking whether __GXX_EXPERIMENTAL_CXX0X__ is defined or,
272 // more standardly, by checking whether __cplusplus has a C++11 or greater
273 // value. Current versions of g++ do not correctly set __cplusplus, so we check
274 // both for forward compatibility.
275 # if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
276 #  define V8_HAS_CXX11_ALIGNAS (V8_GNUC_PREREQ(4, 8, 0))
277 #  define V8_HAS_CXX11_ALIGNOF (V8_GNUC_PREREQ(4, 8, 0))
278 # endif
279 #endif
280 
281 #if defined(_MSC_VER)
282 # define V8_CC_MSVC 1
283 # define V8_HAS___ALIGNOF 1
284 
285 # define V8_HAS_DECLSPEC_ALIGN 1
286 # define V8_HAS_DECLSPEC_DEPRECATED 1
287 # define V8_HAS_DECLSPEC_NOINLINE 1
288 # define V8_HAS_DECLSPEC_SELECTANY 1
289 # define V8_HAS_DECLSPEC_NORETURN 1
290 
291 # define V8_HAS___FORCEINLINE 1
292 
293 #endif
294 
295 
296 // -----------------------------------------------------------------------------
297 // Helper macros
298 
299 // A macro used to make better inlining. Don't bother for debug builds.
300 // Use like:
301 //   V8_INLINE int GetZero() { return 0; }
302 #if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
303 # define V8_INLINE inline __attribute__((always_inline))
304 #elif !defined(DEBUG) && V8_HAS___FORCEINLINE
305 # define V8_INLINE __forceinline
306 #else
307 # define V8_INLINE inline
308 #endif
309 
310 
311 // A macro used to tell the compiler to never inline a particular function.
312 // Don't bother for debug builds.
313 // Use like:
314 //   V8_NOINLINE int GetMinusOne() { return -1; }
315 #if !defined(DEBUG) && V8_HAS_ATTRIBUTE_NOINLINE
316 # define V8_NOINLINE __attribute__((noinline))
317 #elif !defined(DEBUG) && V8_HAS_DECLSPEC_NOINLINE
318 # define V8_NOINLINE __declspec(noinline)
319 #else
320 # define V8_NOINLINE /* NOT SUPPORTED */
321 #endif
322 
323 
324 // A macro used to tell the compiler that a particular function never returns.
325 // Use like:
326 //   V8_NORETURN void MyAbort() { abort(); }
327 #if V8_HAS_ATTRIBUTE_NORETURN
328 # define V8_NORETURN __attribute__((noreturn))
329 #elif HAS_DECLSPEC_NORETURN
330 # define V8_NORETURN __declspec(noreturn)
331 #else
332 # define V8_NORETURN /* NOT SUPPORTED */
333 #endif
334 
335 
336 // A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
337 #if defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
338 #define V8_DEPRECATED(message, declarator) \
339   declarator __attribute__((deprecated(message)))
340 #elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
341 #define V8_DEPRECATED(message, declarator) \
342   declarator __attribute__((deprecated))
343 #elif defined(V8_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
344 #define V8_DEPRECATED(message, declarator) __declspec(deprecated) declarator
345 #else
346 #define V8_DEPRECATED(message, declarator) declarator
347 #endif
348 
349 
350 // A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
351 #if defined(V8_IMMINENT_DEPRECATION_WARNINGS) && \
352     V8_HAS_ATTRIBUTE_DEPRECATED_MESSAGE
353 #define V8_DEPRECATE_SOON(message, declarator) \
354   declarator __attribute__((deprecated(message)))
355 #elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_ATTRIBUTE_DEPRECATED
356 #define V8_DEPRECATE_SOON(message, declarator) \
357   declarator __attribute__((deprecated))
358 #elif defined(V8_IMMINENT_DEPRECATION_WARNINGS) && V8_HAS_DECLSPEC_DEPRECATED
359 #define V8_DEPRECATE_SOON(message, declarator) __declspec(deprecated) declarator
360 #else
361 #define V8_DEPRECATE_SOON(message, declarator) declarator
362 #endif
363 
364 
365 // A macro to provide the compiler with branch prediction information.
366 #if V8_HAS_BUILTIN_EXPECT
367 # define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
368 # define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
369 #else
370 # define V8_UNLIKELY(condition) (condition)
371 # define V8_LIKELY(condition) (condition)
372 #endif
373 
374 
375 // This macro allows to specify memory alignment for structs, classes, etc.
376 // Use like:
377 //   class V8_ALIGNED(16) MyClass { ... };
378 //   V8_ALIGNED(32) int array[42];
379 #if V8_HAS_CXX11_ALIGNAS
380 # define V8_ALIGNED(n) alignas(n)
381 #elif V8_HAS_ATTRIBUTE_ALIGNED
382 # define V8_ALIGNED(n) __attribute__((aligned(n)))
383 #elif V8_HAS_DECLSPEC_ALIGN
384 # define V8_ALIGNED(n) __declspec(align(n))
385 #else
386 # define V8_ALIGNED(n) /* NOT SUPPORTED */
387 #endif
388 
389 
390 // This macro is similar to V8_ALIGNED(), but takes a type instead of size
391 // in bytes. If the compiler does not supports using the alignment of the
392 // |type|, it will align according to the |alignment| instead. For example,
393 // Visual Studio C++ cannot combine __declspec(align) and __alignof. The
394 // |alignment| must be a literal that is used as a kind of worst-case fallback
395 // alignment.
396 // Use like:
397 //   struct V8_ALIGNAS(AnotherClass, 16) NewClass { ... };
398 //   V8_ALIGNAS(double, 8) int array[100];
399 #if V8_HAS_CXX11_ALIGNAS
400 # define V8_ALIGNAS(type, alignment) alignas(type)
401 #elif V8_HAS___ALIGNOF__ && V8_HAS_ATTRIBUTE_ALIGNED
402 # define V8_ALIGNAS(type, alignment) __attribute__((aligned(__alignof__(type))))
403 #else
404 # define V8_ALIGNAS(type, alignment) V8_ALIGNED(alignment)
405 #endif
406 
407 
408 // This macro returns alignment in bytes (an integer power of two) required for
409 // any instance of the given type, which is either complete type, an array type,
410 // or a reference type.
411 // Use like:
412 //   size_t alignment = V8_ALIGNOF(double);
413 #if V8_HAS_CXX11_ALIGNOF
414 # define V8_ALIGNOF(type) alignof(type)
415 #elif V8_HAS___ALIGNOF
416 # define V8_ALIGNOF(type) __alignof(type)
417 #elif V8_HAS___ALIGNOF__
418 # define V8_ALIGNOF(type) __alignof__(type)
419 #else
420 // Note that alignment of a type within a struct can be less than the
421 // alignment of the type stand-alone (because of ancient ABIs), so this
422 // should only be used as a last resort.
423 namespace v8 { template <typename T> class AlignOfHelper { char c; T t; }; }
424 # define V8_ALIGNOF(type) (sizeof(::v8::AlignOfHelper<type>) - sizeof(type))
425 #endif
426 
427 // Annotate a function indicating the caller must examine the return value.
428 // Use like:
429 //   int foo() WARN_UNUSED_RESULT;
430 #if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
431 #define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
432 #else
433 #define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
434 #endif
435 
436 // clang-format on
437 
438 #endif  // V8CONFIG_H_
439