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#ifdef V8_GN_HEADER
9#if __cplusplus >= 201703L && !__has_include("v8-gn.h")
10#error Missing v8-gn.h. The configuration for v8 is missing from the include \
11path. Add it with -I<path> to the command line
12#endif
13#include "v8-gn.h"  // NOLINT(build/include_directory)
14#endif
15
16// clang-format off
17
18// Platform headers for feature detection below.
19#if defined(__ANDROID__)
20# include <sys/cdefs.h>
21#elif defined(__APPLE__)
22# include <TargetConditionals.h>
23#elif defined(__linux__)
24# include <features.h>
25#endif
26
27
28// This macro allows to test for the version of the GNU C library (or
29// a compatible C library that masquerades as glibc). It evaluates to
30// 0 if libc is not GNU libc or compatible.
31// Use like:
32//  #if V8_GLIBC_PREREQ(2, 3)
33//   ...
34//  #endif
35#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
36# define V8_GLIBC_PREREQ(major, minor)                                    \
37    ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
38#else
39# define V8_GLIBC_PREREQ(major, minor) 0
40#endif
41
42
43// This macro allows to test for the version of the GNU C++ compiler.
44// Note that this also applies to compilers that masquerade as GCC,
45// for example clang and the Intel C++ compiler for Linux.
46// Use like:
47//  #if V8_GNUC_PREREQ(4, 3, 1)
48//   ...
49//  #endif
50#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
51# define V8_GNUC_PREREQ(major, minor, patchlevel)                         \
52    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >=   \
53     ((major) * 10000 + (minor) * 100 + (patchlevel)))
54#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
55# define V8_GNUC_PREREQ(major, minor, patchlevel)      \
56    ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >=      \
57     ((major) * 10000 + (minor) * 100 + (patchlevel)))
58#else
59# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
60#endif
61
62
63
64// -----------------------------------------------------------------------------
65// Operating system detection (host)
66//
67//  V8_OS_ANDROID       - Android
68//  V8_OS_BSD           - BSDish (macOS, Net/Free/Open/DragonFlyBSD)
69//  V8_OS_CYGWIN        - Cygwin
70//  V8_OS_DRAGONFLYBSD  - DragonFlyBSD
71//  V8_OS_FREEBSD       - FreeBSD
72//  V8_OS_FUCHSIA       - Fuchsia
73//  V8_OS_LINUX         - Linux (Android, ChromeOS, Linux, ...)
74//  V8_OS_DARWIN        - Darwin (macOS, iOS)
75//  V8_OS_MACOS         - macOS
76//  V8_OS_IOS           - iOS
77//  V8_OS_NETBSD        - NetBSD
78//  V8_OS_OPENBSD       - OpenBSD
79//  V8_OS_POSIX         - POSIX compatible (mostly everything except Windows)
80//  V8_OS_QNX           - QNX Neutrino
81//  V8_OS_SOLARIS       - Sun Solaris and OpenSolaris
82//  V8_OS_STARBOARD     - Starboard (platform abstraction for Cobalt)
83//  V8_OS_AIX           - AIX
84//  V8_OS_WIN           - Microsoft Windows
85
86#if defined(__ANDROID__)
87# define V8_OS_ANDROID 1
88# define V8_OS_LINUX 1
89# define V8_OS_POSIX 1
90# define V8_OS_STRING "android"
91
92#elif defined(__APPLE__)
93# define V8_OS_POSIX 1
94# define V8_OS_BSD 1
95# define V8_OS_DARWIN 1
96# if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
97#  define V8_OS_IOS 1
98#  define V8_OS_STRING "ios"
99# else
100#  define V8_OS_MACOS 1
101#  define V8_OS_STRING "macos"
102# endif  // defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
103
104#elif defined(__CYGWIN__)
105# define V8_OS_CYGWIN 1
106# define V8_OS_POSIX 1
107# define V8_OS_STRING "cygwin"
108
109#elif defined(__linux__)
110# define V8_OS_LINUX 1
111# define V8_OS_POSIX 1
112# define V8_OS_STRING "linux"
113
114#elif defined(__sun)
115# define V8_OS_POSIX 1
116# define V8_OS_SOLARIS 1
117# define V8_OS_STRING "sun"
118
119#elif defined(STARBOARD)
120# define V8_OS_STARBOARD 1
121# define V8_OS_STRING "starboard"
122
123#elif defined(_AIX)
124# define V8_OS_POSIX 1
125# define V8_OS_AIX 1
126# define V8_OS_STRING "aix"
127
128#elif defined(__FreeBSD__)
129# define V8_OS_BSD 1
130# define V8_OS_FREEBSD 1
131# define V8_OS_POSIX 1
132# define V8_OS_STRING "freebsd"
133
134#elif defined(__Fuchsia__)
135# define V8_OS_FUCHSIA 1
136# define V8_OS_POSIX 1
137# define V8_OS_STRING "fuchsia"
138
139#elif defined(__DragonFly__)
140# define V8_OS_BSD 1
141# define V8_OS_DRAGONFLYBSD 1
142# define V8_OS_POSIX 1
143# define V8_OS_STRING "dragonflybsd"
144
145#elif defined(__NetBSD__)
146# define V8_OS_BSD 1
147# define V8_OS_NETBSD 1
148# define V8_OS_POSIX 1
149# define V8_OS_STRING "netbsd"
150
151#elif defined(__OpenBSD__)
152# define V8_OS_BSD 1
153# define V8_OS_OPENBSD 1
154# define V8_OS_POSIX 1
155# define V8_OS_STRING "openbsd"
156
157#elif defined(__QNXNTO__)
158# define V8_OS_POSIX 1
159# define V8_OS_QNX 1
160# define V8_OS_STRING "qnx"
161
162#elif defined(_WIN32)
163# define V8_OS_WIN 1
164# define V8_OS_STRING "windows"
165#endif
166
167// -----------------------------------------------------------------------------
168// Operating system detection (target)
169//
170//  V8_TARGET_OS_ANDROID
171//  V8_TARGET_OS_FUCHSIA
172//  V8_TARGET_OS_IOS
173//  V8_TARGET_OS_LINUX
174//  V8_TARGET_OS_MACOS
175//  V8_TARGET_OS_WIN
176//  V8_TARGET_OS_CHROMEOS
177//
178// If not set explicitly, these fall back to corresponding V8_OS_ values.
179
180#ifdef V8_HAVE_TARGET_OS
181
182// The target OS is provided, just check that at least one known value is set.
183# if !defined(V8_TARGET_OS_ANDROID) \
184  && !defined(V8_TARGET_OS_FUCHSIA) \
185  && !defined(V8_TARGET_OS_IOS) \
186  && !defined(V8_TARGET_OS_LINUX) \
187  && !defined(V8_TARGET_OS_MACOS) \
188  && !defined(V8_TARGET_OS_WIN) \
189  && !defined(V8_TARGET_OS_CHROMEOS)
190#  error No known target OS defined.
191# endif
192
193#else  // V8_HAVE_TARGET_OS
194
195# if defined(V8_TARGET_OS_ANDROID) \
196  || defined(V8_TARGET_OS_FUCHSIA) \
197  || defined(V8_TARGET_OS_IOS) \
198  || defined(V8_TARGET_OS_LINUX) \
199  || defined(V8_TARGET_OS_MACOS) \
200  || defined(V8_TARGET_OS_WIN) \
201  || defined(V8_TARGET_OS_CHROMEOS)
202#  error A target OS is defined but V8_HAVE_TARGET_OS is unset.
203# endif
204
205// Fall back to the detected host OS.
206#ifdef V8_OS_ANDROID
207# define V8_TARGET_OS_ANDROID
208#endif
209
210#ifdef V8_OS_FUCHSIA
211# define V8_TARGET_OS_FUCHSIA
212#endif
213
214#ifdef V8_OS_IOS
215# define V8_TARGET_OS_IOS
216#endif
217
218#ifdef V8_OS_LINUX
219# define V8_TARGET_OS_LINUX
220#endif
221
222#ifdef V8_OS_MACOS
223# define V8_TARGET_OS_MACOS
224#endif
225
226#ifdef V8_OS_WIN
227# define V8_TARGET_OS_WIN
228#endif
229
230#endif  // V8_HAVE_TARGET_OS
231
232#if defined(V8_TARGET_OS_ANDROID)
233# define V8_TARGET_OS_STRING "android"
234#elif defined(V8_TARGET_OS_FUCHSIA)
235# define V8_TARGET_OS_STRING "fuchsia"
236#elif defined(V8_TARGET_OS_IOS)
237# define V8_TARGET_OS_STRING "ios"
238#elif defined(V8_TARGET_OS_LINUX)
239# define V8_TARGET_OS_STRING "linux"
240#elif defined(V8_TARGET_OS_MACOS)
241# define V8_TARGET_OS_STRING "macos"
242#elif defined(V8_TARGET_OS_WINDOWS)
243# define V8_TARGET_OS_STRING "windows"
244#else
245# define V8_TARGET_OS_STRING "unknown"
246#endif
247
248// -----------------------------------------------------------------------------
249// C library detection
250//
251//  V8_LIBC_MSVCRT  - MSVC libc
252//  V8_LIBC_BIONIC  - Bionic libc
253//  V8_LIBC_BSD     - BSD libc derivate
254//  V8_LIBC_GLIBC   - GNU C library
255//  V8_LIBC_UCLIBC  - uClibc
256//
257// Note that testing for libc must be done using #if not #ifdef. For example,
258// to test for the GNU C library, use:
259//  #if V8_LIBC_GLIBC
260//   ...
261//  #endif
262
263#if defined (_MSC_VER)
264# define V8_LIBC_MSVCRT 1
265#elif defined(__BIONIC__)
266# define V8_LIBC_BIONIC 1
267# define V8_LIBC_BSD 1
268#elif defined(__UCLIBC__)
269// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
270# define V8_LIBC_UCLIBC 1
271#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
272# define V8_LIBC_GLIBC 1
273#else
274# define V8_LIBC_BSD V8_OS_BSD
275#endif
276
277
278// -----------------------------------------------------------------------------
279// Compiler detection
280//
281//  V8_CC_GNU     - GCC, or clang in gcc mode
282//  V8_CC_INTEL   - Intel C++
283//  V8_CC_MINGW   - Minimalist GNU for Windows
284//  V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
285//  V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
286//  V8_CC_MSVC    - Microsoft Visual C/C++, or clang in cl.exe mode
287//
288// C++11 feature detection
289//
290// Compiler-specific feature detection
291//
292//  V8_HAS_ATTRIBUTE_ALWAYS_INLINE      - __attribute__((always_inline))
293//                                        supported
294//  V8_HAS_ATTRIBUTE_CONSTINIT          - __attribute__((require_constant_
295//                                                       initialization))
296//                                        supported
297//  V8_HAS_ATTRIBUTE_NONNULL            - __attribute__((nonnull)) supported
298//  V8_HAS_ATTRIBUTE_NOINLINE           - __attribute__((noinline)) supported
299//  V8_HAS_ATTRIBUTE_UNUSED             - __attribute__((unused)) supported
300//  V8_HAS_ATTRIBUTE_VISIBILITY         - __attribute__((visibility)) supported
301//  V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
302//                                        supported
303//  V8_HAS_CPP_ATTRIBUTE_NODISCARD      - [[nodiscard]] supported
304//  V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
305//                                      - [[no_unique_address]] supported
306//  V8_HAS_BUILTIN_BSWAP16              - __builtin_bswap16() supported
307//  V8_HAS_BUILTIN_BSWAP32              - __builtin_bswap32() supported
308//  V8_HAS_BUILTIN_BSWAP64              - __builtin_bswap64() supported
309//  V8_HAS_BUILTIN_CLZ                  - __builtin_clz() supported
310//  V8_HAS_BUILTIN_CTZ                  - __builtin_ctz() supported
311//  V8_HAS_BUILTIN_EXPECT               - __builtin_expect() supported
312//  V8_HAS_BUILTIN_FRAME_ADDRESS        - __builtin_frame_address() supported
313//  V8_HAS_BUILTIN_POPCOUNT             - __builtin_popcount() supported
314//  V8_HAS_BUILTIN_ADD_OVERFLOW         - __builtin_add_overflow() supported
315//  V8_HAS_BUILTIN_SUB_OVERFLOW         - __builtin_sub_overflow() supported
316//  V8_HAS_BUILTIN_MUL_OVERFLOW         - __builtin_mul_overflow() supported
317//  V8_HAS_BUILTIN_SADD_OVERFLOW        - __builtin_sadd_overflow() supported
318//  V8_HAS_BUILTIN_SSUB_OVERFLOW        - __builtin_ssub_overflow() supported
319//  V8_HAS_BUILTIN_UADD_OVERFLOW        - __builtin_uadd_overflow() supported
320//  V8_HAS_BUILTIN_SMUL_OVERFLOW        - __builtin_smul_overflow() supported
321//  V8_HAS_COMPUTED_GOTO                - computed goto/labels as values
322//                                        supported
323//  V8_HAS_DECLSPEC_NOINLINE            - __declspec(noinline) supported
324//  V8_HAS_DECLSPEC_SELECTANY           - __declspec(selectany) supported
325//  V8_HAS___FORCEINLINE                - __forceinline supported
326//
327// Note that testing for compilers and/or features must be done using #if
328// not #ifdef. For example, to test for Intel C++ Compiler, use:
329//  #if V8_CC_INTEL
330//   ...
331//  #endif
332
333#if defined(__has_cpp_attribute)
334#define V8_HAS_CPP_ATTRIBUTE(FEATURE) __has_cpp_attribute(FEATURE)
335#else
336#define V8_HAS_CPP_ATTRIBUTE(FEATURE) 0
337#endif
338
339#if defined(__clang__)
340
341#if defined(__GNUC__)  // Clang in gcc mode.
342# define V8_CC_GNU 1
343#endif
344
345# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
346# define V8_HAS_ATTRIBUTE_CONSTINIT \
347    (__has_attribute(require_constant_initialization))
348# define V8_HAS_ATTRIBUTE_CONST (__has_attribute(const))
349# define V8_HAS_ATTRIBUTE_NONNULL (__has_attribute(nonnull))
350# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
351# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
352// Support for the "preserve_most" attribute is limited:
353// - 32-bit platforms do not implement it,
354// - component builds fail because _dl_runtime_resolve clobbers registers,
355// - we see crashes on arm64 on Windows (https://crbug.com/1409934), which can
356//   hopefully be fixed in the future.
357// Additionally, the initial implementation in clang <= 16 overwrote the return
358// register(s) in the epilogue of a preserve_most function, so we only use
359// preserve_most in clang >= 17 (see https://reviews.llvm.org/D143425).
360#if (defined(_M_X64) || defined(__x86_64__)            /* x64 (everywhere) */  \
361     || ((defined(__AARCH64EL__) || defined(_M_ARM64)) /* arm64, but ... */    \
362         && !defined(_WIN32)))                         /* not on windows */    \
363     && !defined(COMPONENT_BUILD)                      /* no component build */\
364     && __clang_major__ >= 17                          /* clang >= 17 */
365# define V8_HAS_ATTRIBUTE_PRESERVE_MOST (__has_attribute(preserve_most))
366#endif
367# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
368# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
369    (__has_attribute(warn_unused_result))
370
371# define V8_HAS_CPP_ATTRIBUTE_NODISCARD (V8_HAS_CPP_ATTRIBUTE(nodiscard))
372# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \
373    (V8_HAS_CPP_ATTRIBUTE(no_unique_address))
374
375# define V8_HAS_BUILTIN_ASSUME (__has_builtin(__builtin_assume))
376# define V8_HAS_BUILTIN_ASSUME_ALIGNED (__has_builtin(__builtin_assume_aligned))
377# define V8_HAS_BUILTIN_BSWAP16 (__has_builtin(__builtin_bswap16))
378# define V8_HAS_BUILTIN_BSWAP32 (__has_builtin(__builtin_bswap32))
379# define V8_HAS_BUILTIN_BSWAP64 (__has_builtin(__builtin_bswap64))
380# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
381# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
382# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
383# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
384# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
385# define V8_HAS_BUILTIN_ADD_OVERFLOW (__has_builtin(__builtin_add_overflow))
386# define V8_HAS_BUILTIN_SUB_OVERFLOW (__has_builtin(__builtin_sub_overflow))
387# define V8_HAS_BUILTIN_MUL_OVERFLOW (__has_builtin(__builtin_mul_overflow))
388# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
389# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
390# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
391# define V8_HAS_BUILTIN_SMUL_OVERFLOW (__has_builtin(__builtin_smul_overflow))
392# define V8_HAS_BUILTIN_UNREACHABLE (__has_builtin(__builtin_unreachable))
393
394// Clang has no __has_feature for computed gotos.
395// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
396# define V8_HAS_COMPUTED_GOTO 1
397
398#elif defined(__GNUC__)
399
400# define V8_CC_GNU 1
401# if defined(__INTEL_COMPILER)  // Intel C++ also masquerades as GCC 3.2.0
402#  define V8_CC_INTEL 1
403# endif
404# if defined(__MINGW32__)
405#  define V8_CC_MINGW32 1
406# endif
407# if defined(__MINGW64__)
408#  define V8_CC_MINGW64 1
409# endif
410# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
411
412// always_inline is available in gcc 4.0 but not very reliable until 4.4.
413// Works around "sorry, unimplemented: inlining failed" build errors with
414// older compilers.
415# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE 1
416# define V8_HAS_ATTRIBUTE_NOINLINE 1
417# define V8_HAS_ATTRIBUTE_UNUSED 1
418# define V8_HAS_ATTRIBUTE_VISIBILITY 1
419# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT (!V8_CC_INTEL)
420
421// [[nodiscard]] does not work together with with
422// __attribute__((visibility(""))) on GCC 7.4 which is why there is no define
423// for V8_HAS_CPP_ATTRIBUTE_NODISCARD. See https://crbug.com/v8/11707.
424
425# define V8_HAS_BUILTIN_ASSUME_ALIGNED 1
426# define V8_HAS_BUILTIN_CLZ 1
427# define V8_HAS_BUILTIN_CTZ 1
428# define V8_HAS_BUILTIN_EXPECT 1
429# define V8_HAS_BUILTIN_FRAME_ADDRESS 1
430# define V8_HAS_BUILTIN_POPCOUNT 1
431# define V8_HAS_BUILTIN_UNREACHABLE 1
432
433// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
434#define V8_HAS_COMPUTED_GOTO 1
435
436#endif
437
438#if defined(_MSC_VER)
439# define V8_CC_MSVC 1
440
441# define V8_HAS_DECLSPEC_NOINLINE 1
442# define V8_HAS_DECLSPEC_SELECTANY 1
443
444# define V8_HAS___FORCEINLINE 1
445
446#endif
447
448
449// -----------------------------------------------------------------------------
450// Helper macros
451
452// A macro used to make better inlining. Don't bother for debug builds.
453// Use like:
454//   V8_INLINE int GetZero() { return 0; }
455#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
456# define V8_INLINE inline __attribute__((always_inline))
457#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
458# define V8_INLINE __forceinline
459#else
460# define V8_INLINE inline
461#endif
462
463#ifdef DEBUG
464// In debug mode, check assumptions instead of actually adding annotations.
465# define V8_ASSUME(condition) DCHECK(condition)
466#elif V8_HAS_BUILTIN_ASSUME
467# define V8_ASSUME(condition) __builtin_assume(condition)
468#elif V8_HAS_BUILTIN_UNREACHABLE
469# define V8_ASSUME(condition) \
470  do { if (!(condition)) __builtin_unreachable(); } while (false)
471#else
472# define V8_ASSUME(condition)
473#endif
474
475#if V8_HAS_BUILTIN_ASSUME_ALIGNED
476# define V8_ASSUME_ALIGNED(ptr, alignment) \
477  __builtin_assume_aligned((ptr), (alignment))
478#else
479# define V8_ASSUME_ALIGNED(ptr, alignment) (ptr)
480#endif
481
482
483// A macro to mark functions whose values don't change (e.g. across calls)
484// and thereby compiler is free to hoist and fold multiple calls together.
485// Use like:
486//   V8_CONST int foo() { ... }
487#if V8_HAS_ATTRIBUTE_CONST
488# define V8_CONST __attribute__((const))
489#else
490# define V8_CONST
491#endif
492
493// A macro to mark a declaration as requiring constant initialization.
494// Use like:
495//   int* foo V8_CONSTINIT;
496#if V8_HAS_ATTRIBUTE_CONSTINIT
497# define V8_CONSTINIT __attribute__((require_constant_initialization))
498#else
499# define V8_CONSTINIT
500#endif
501
502
503// A macro to mark specific arguments as non-null.
504// Use like:
505//   int add(int* x, int y, int* z) V8_NONNULL(1, 3) { return *x + y + *z; }
506#if V8_HAS_ATTRIBUTE_NONNULL
507# define V8_NONNULL(...) __attribute__((nonnull(__VA_ARGS__)))
508#else
509# define V8_NONNULL(...) /* NOT SUPPORTED */
510#endif
511
512
513// A macro used to tell the compiler to never inline a particular function.
514// Use like:
515//   V8_NOINLINE int GetMinusOne() { return -1; }
516#if V8_HAS_ATTRIBUTE_NOINLINE
517# define V8_NOINLINE __attribute__((noinline))
518#elif V8_HAS_DECLSPEC_NOINLINE
519# define V8_NOINLINE __declspec(noinline)
520#else
521# define V8_NOINLINE /* NOT SUPPORTED */
522#endif
523
524
525// A macro used to change the calling conventions to preserve all registers (no
526// caller-saved registers). Use this for cold functions called from hot
527// functions.
528// Note: The attribute is considered experimental, so apply with care. Also,
529// "preserve_most" is currently not handling the return value correctly, so only
530// use it for functions returning void (see https://reviews.llvm.org/D141020).
531// Use like:
532//   V8_NOINLINE V8_PRESERVE_MOST void UnlikelyMethod();
533#if V8_HAS_ATTRIBUTE_PRESERVE_MOST
534# define V8_PRESERVE_MOST __attribute__((preserve_most))
535#else
536# define V8_PRESERVE_MOST /* NOT SUPPORTED */
537#endif
538
539
540// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
541#if defined(V8_DEPRECATION_WARNINGS)
542# define V8_DEPRECATED(message) [[deprecated(message)]]
543#else
544# define V8_DEPRECATED(message)
545#endif
546
547
548// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
549#if defined(V8_IMMINENT_DEPRECATION_WARNINGS)
550# define V8_DEPRECATE_SOON(message) [[deprecated(message)]]
551#else
552# define V8_DEPRECATE_SOON(message)
553#endif
554
555
556#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) || \
557    defined(V8_DEPRECATION_WARNINGS)
558#if defined(V8_CC_MSVC)
559# define START_ALLOW_USE_DEPRECATED() \
560    __pragma(warning(push))           \
561    __pragma(warning(disable : 4996))
562# define END_ALLOW_USE_DEPRECATED() __pragma(warning(pop))
563#else  // !defined(V8_CC_MSVC)
564# define START_ALLOW_USE_DEPRECATED()                               \
565    _Pragma("GCC diagnostic push")                                  \
566    _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
567#define END_ALLOW_USE_DEPRECATED() _Pragma("GCC diagnostic pop")
568#endif  // !defined(V8_CC_MSVC)
569#else  // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
570       // defined(V8_DEPRECATION_WARNINGS))
571#define START_ALLOW_USE_DEPRECATED()
572#define END_ALLOW_USE_DEPRECATED()
573#endif  // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
574        // defined(V8_DEPRECATION_WARNINGS))
575#define ALLOW_COPY_AND_MOVE_WITH_DEPRECATED_FIELDS(ClassName) \
576  START_ALLOW_USE_DEPRECATED()                                \
577  ClassName(const ClassName&) = default;                      \
578  ClassName(ClassName&&) = default;                           \
579  ClassName& operator=(const ClassName&) = default;           \
580  ClassName& operator=(ClassName&&) = default;                \
581  END_ALLOW_USE_DEPRECATED()
582
583
584#if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 6)
585# define V8_ENUM_DEPRECATED(message)
586# define V8_ENUM_DEPRECATE_SOON(message)
587#else
588# define V8_ENUM_DEPRECATED(message) V8_DEPRECATED(message)
589# define V8_ENUM_DEPRECATE_SOON(message) V8_DEPRECATE_SOON(message)
590#endif
591
592
593// A macro to provide the compiler with branch prediction information.
594#if V8_HAS_BUILTIN_EXPECT
595# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
596# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
597#else
598# define V8_UNLIKELY(condition) (condition)
599# define V8_LIKELY(condition) (condition)
600#endif
601
602
603// Annotate a function indicating the caller must examine the return value.
604// Use like:
605//   int foo() V8_WARN_UNUSED_RESULT;
606#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
607#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
608#else
609#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
610#endif
611
612
613// Annotate a class or constructor indicating the caller must assign the
614// constructed instances.
615// Apply to the whole class like:
616//   class V8_NODISCARD Foo() { ... };
617// or apply to just one constructor like:
618//   V8_NODISCARD Foo() { ... };
619// [[nodiscard]] comes in C++17 but supported in clang with -std >= c++11.
620#if V8_HAS_CPP_ATTRIBUTE_NODISCARD
621#define V8_NODISCARD [[nodiscard]]
622#else
623#define V8_NODISCARD /* NOT SUPPORTED */
624#endif
625
626// The no_unique_address attribute allows tail padding in a non-static data
627// member to overlap other members of the enclosing class (and in the special
628// case when the type is empty, permits it to fully overlap other members). The
629// field is laid out as if a base class were encountered at the corresponding
630// point within the class (except that it does not share a vptr with the
631// enclosing object).
632//
633// Apply to a data member like:
634//
635//   class Foo {
636//    V8_NO_UNIQUE_ADDRESS Bar bar_;
637//   };
638//
639// [[no_unique_address]] comes in C++20 but supported in clang with
640// -std >= c++11.
641#if V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
642#define V8_NO_UNIQUE_ADDRESS [[no_unique_address]]
643#else
644#define V8_NO_UNIQUE_ADDRESS /* NOT SUPPORTED */
645#endif
646
647// Marks a type as being eligible for the "trivial" ABI despite having a
648// non-trivial destructor or copy/move constructor. Such types can be relocated
649// after construction by simply copying their memory, which makes them eligible
650// to be passed in registers. The canonical example is std::unique_ptr.
651//
652// Use with caution; this has some subtle effects on constructor/destructor
653// ordering and will be very incorrect if the type relies on its address
654// remaining constant. When used as a function argument (by value), the value
655// may be constructed in the caller's stack frame, passed in a register, and
656// then used and destructed in the callee's stack frame. A similar thing can
657// occur when values are returned.
658//
659// TRIVIAL_ABI is not needed for types which have a trivial destructor and
660// copy/move constructors, since those are automatically trivial by the ABI
661// spec.
662//
663// It is also not likely to be effective on types too large to be passed in one
664// or two registers on typical target ABIs.
665//
666// See also:
667//   https://clang.llvm.org/docs/AttributeReference.html#trivial-abi
668//   https://libcxx.llvm.org/docs/DesignDocs/UniquePtrTrivialAbi.html
669#if defined(__clang__) && defined(__has_attribute)
670#if __has_attribute(trivial_abi)
671#define V8_TRIVIAL_ABI [[clang::trivial_abi]]
672#endif // __has_attribute(trivial_abi)
673#endif // defined(__clang__) && defined(__has_attribute)
674#if !defined(V8_TRIVIAL_ABI)
675#define V8_TRIVIAL_ABI
676#endif //!defined(V8_TRIVIAL_ABI)
677
678// Helper macro to define no_sanitize attributes only with clang.
679#if defined(__clang__) && defined(__has_attribute)
680#if __has_attribute(no_sanitize)
681#define V8_CLANG_NO_SANITIZE(what) __attribute__((no_sanitize(what)))
682#endif
683#endif
684#if !defined(V8_CLANG_NO_SANITIZE)
685#define V8_CLANG_NO_SANITIZE(what)
686#endif
687
688#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
689#error Inconsistent build configuration: To build the V8 shared library \
690set BUILDING_V8_SHARED, to include its headers for linking against the \
691V8 shared library set USING_V8_SHARED.
692#endif
693
694#ifdef V8_OS_WIN
695
696// Setup for Windows DLL export/import. When building the V8 DLL the
697// BUILDING_V8_SHARED needs to be defined. When building a program which uses
698// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
699// static library or building a program which uses the V8 static library neither
700// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
701#ifdef BUILDING_V8_SHARED
702# define V8_EXPORT __declspec(dllexport)
703#elif USING_V8_SHARED
704# define V8_EXPORT __declspec(dllimport)
705#else
706# define V8_EXPORT
707#endif  // BUILDING_V8_SHARED
708
709#else  // V8_OS_WIN
710
711// Setup for Linux shared library export.
712#if V8_HAS_ATTRIBUTE_VISIBILITY
713# ifdef BUILDING_V8_SHARED
714#  define V8_EXPORT __attribute__ ((visibility("default")))
715# else
716#  define V8_EXPORT
717# endif
718#else
719# define V8_EXPORT
720#endif
721
722#endif  // V8_OS_WIN
723
724// clang-format on
725
726// Processor architecture detection.  For more info on what's defined, see:
727//   http://msdn.microsoft.com/en-us/library/b0084kay.aspx
728//   http://www.agner.org/optimize/calling_conventions.pdf
729//   or with gcc, run: "echo | gcc -E -dM -"
730// The V8_HOST_ARCH_* macros correspond to the architecture on which V8, as a
731// virtual machine and compiler, runs. Don't confuse this with the architecture
732// on which V8 is built.
733#if defined(_M_X64) || defined(__x86_64__)
734#define V8_HOST_ARCH_X64 1
735#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4  // Check for x32.
736#define V8_HOST_ARCH_32_BIT 1
737#else
738#define V8_HOST_ARCH_64_BIT 1
739#endif
740#elif defined(_M_IX86) || defined(__i386__)
741#define V8_HOST_ARCH_IA32 1
742#define V8_HOST_ARCH_32_BIT 1
743#elif defined(__AARCH64EL__) || defined(_M_ARM64)
744#define V8_HOST_ARCH_ARM64 1
745#define V8_HOST_ARCH_64_BIT 1
746#elif defined(__ARMEL__)
747#define V8_HOST_ARCH_ARM 1
748#define V8_HOST_ARCH_32_BIT 1
749#elif defined(__mips64)
750#define V8_HOST_ARCH_MIPS64 1
751#define V8_HOST_ARCH_64_BIT 1
752#elif defined(__loongarch64)
753#define V8_HOST_ARCH_LOONG64 1
754#define V8_HOST_ARCH_64_BIT 1
755#elif defined(__PPC64__) || defined(_ARCH_PPC64)
756#define V8_HOST_ARCH_PPC64 1
757#define V8_HOST_ARCH_64_BIT 1
758#elif defined(__PPC__) || defined(_ARCH_PPC)
759#define V8_HOST_ARCH_PPC 1
760#define V8_HOST_ARCH_32_BIT 1
761#elif defined(__s390__) || defined(__s390x__)
762#define V8_HOST_ARCH_S390 1
763#if defined(__s390x__)
764#define V8_HOST_ARCH_64_BIT 1
765#else
766#define V8_HOST_ARCH_32_BIT 1
767#endif
768#elif defined(__riscv) || defined(__riscv__)
769#if __riscv_xlen == 64
770#define V8_HOST_ARCH_RISCV64 1
771#define V8_HOST_ARCH_64_BIT 1
772#elif __riscv_xlen == 32
773#define V8_HOST_ARCH_RISCV32 1
774#define V8_HOST_ARCH_32_BIT 1
775#else
776#error "Cannot detect Riscv's bitwidth"
777#endif
778#else
779#error "Host architecture was not detected as supported by v8"
780#endif
781
782// Target architecture detection. This corresponds to the architecture for which
783// V8's JIT will generate code (the last stage of the canadian cross-compiler).
784// The macros may be set externally. If not, detect in the same way as the host
785// architecture, that is, target the native environment as presented by the
786// compiler.
787#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM &&     \
788    !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_PPC && \
789    !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390 &&                          \
790    !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64 &&                     \
791    !V8_TARGET_ARCH_RISCV32
792#if defined(_M_X64) || defined(__x86_64__)
793#define V8_TARGET_ARCH_X64 1
794#elif defined(_M_IX86) || defined(__i386__)
795#define V8_TARGET_ARCH_IA32 1
796#elif defined(__AARCH64EL__) || defined(_M_ARM64)
797#define V8_TARGET_ARCH_ARM64 1
798#elif defined(__ARMEL__)
799#define V8_TARGET_ARCH_ARM 1
800#elif defined(__mips64)
801#define V8_TARGET_ARCH_MIPS64 1
802#elif defined(__loongarch64)
803#define V8_TARGET_ARCH_LOONG64 1
804#elif defined(_ARCH_PPC64)
805#define V8_TARGET_ARCH_PPC64 1
806#elif defined(_ARCH_PPC)
807#define V8_TARGET_ARCH_PPC 1
808#elif defined(__s390__)
809#define V8_TARGET_ARCH_S390 1
810#if defined(__s390x__)
811#define V8_TARGET_ARCH_S390X 1
812#endif
813#elif defined(__riscv) || defined(__riscv__)
814#if __riscv_xlen == 64
815#define V8_TARGET_ARCH_RISCV64 1
816#elif __riscv_xlen == 32
817#define V8_TARGET_ARCH_RISCV32 1
818#endif
819#else
820#error Target architecture was not detected as supported by v8
821#endif
822#endif
823
824// Determine architecture pointer size.
825#if V8_TARGET_ARCH_IA32
826#define V8_TARGET_ARCH_32_BIT 1
827#elif V8_TARGET_ARCH_X64
828#if !V8_TARGET_ARCH_32_BIT && !V8_TARGET_ARCH_64_BIT
829#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4  // Check for x32.
830#define V8_TARGET_ARCH_32_BIT 1
831#else
832#define V8_TARGET_ARCH_64_BIT 1
833#endif
834#endif
835#elif V8_TARGET_ARCH_ARM
836#define V8_TARGET_ARCH_32_BIT 1
837#elif V8_TARGET_ARCH_ARM64
838#define V8_TARGET_ARCH_64_BIT 1
839#elif V8_TARGET_ARCH_MIPS
840#define V8_TARGET_ARCH_32_BIT 1
841#elif V8_TARGET_ARCH_MIPS64
842#define V8_TARGET_ARCH_64_BIT 1
843#elif V8_TARGET_ARCH_LOONG64
844#define V8_TARGET_ARCH_64_BIT 1
845#elif V8_TARGET_ARCH_PPC
846#define V8_TARGET_ARCH_32_BIT 1
847#elif V8_TARGET_ARCH_PPC64
848#define V8_TARGET_ARCH_64_BIT 1
849#elif V8_TARGET_ARCH_S390
850#if V8_TARGET_ARCH_S390X
851#define V8_TARGET_ARCH_64_BIT 1
852#else
853#define V8_TARGET_ARCH_32_BIT 1
854#endif
855#elif V8_TARGET_ARCH_RISCV64
856#define V8_TARGET_ARCH_64_BIT 1
857#elif V8_TARGET_ARCH_RISCV32
858#define V8_TARGET_ARCH_32_BIT 1
859#else
860#error Unknown target architecture pointer size
861#endif
862
863// Check for supported combinations of host and target architectures.
864#if V8_TARGET_ARCH_IA32 && !V8_HOST_ARCH_IA32
865#error Target architecture ia32 is only supported on ia32 host
866#endif
867#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT && \
868     !((V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64) && V8_HOST_ARCH_64_BIT))
869#error Target architecture x64 is only supported on x64 and arm64 host
870#endif
871#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT && \
872     !(V8_HOST_ARCH_X64 && V8_HOST_ARCH_32_BIT))
873#error Target architecture x32 is only supported on x64 host with x32 support
874#endif
875#if (V8_TARGET_ARCH_ARM && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_ARM))
876#error Target architecture arm is only supported on arm and ia32 host
877#endif
878#if (V8_TARGET_ARCH_ARM64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64))
879#error Target architecture arm64 is only supported on arm64 and x64 host
880#endif
881#if (V8_TARGET_ARCH_MIPS64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_MIPS64))
882#error Target architecture mips64 is only supported on mips64 and x64 host
883#endif
884#if (V8_TARGET_ARCH_RISCV64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_RISCV64))
885#error Target architecture riscv64 is only supported on riscv64 and x64 host
886#endif
887#if (V8_TARGET_ARCH_RISCV32 && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_RISCV32))
888#error Target architecture riscv32 is only supported on riscv32 and ia32 host
889#endif
890#if (V8_TARGET_ARCH_LOONG64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_LOONG64))
891#error Target architecture loong64 is only supported on loong64 and x64 host
892#endif
893
894// Determine architecture endianness.
895#if V8_TARGET_ARCH_IA32
896#define V8_TARGET_LITTLE_ENDIAN 1
897#elif V8_TARGET_ARCH_X64
898#define V8_TARGET_LITTLE_ENDIAN 1
899#elif V8_TARGET_ARCH_ARM
900#define V8_TARGET_LITTLE_ENDIAN 1
901#elif V8_TARGET_ARCH_ARM64
902#define V8_TARGET_LITTLE_ENDIAN 1
903#elif V8_TARGET_ARCH_LOONG64
904#define V8_TARGET_LITTLE_ENDIAN 1
905#elif V8_TARGET_ARCH_MIPS64
906#if defined(__MIPSEB__) || defined(V8_TARGET_ARCH_MIPS64_BE)
907#define V8_TARGET_BIG_ENDIAN 1
908#else
909#define V8_TARGET_LITTLE_ENDIAN 1
910#endif
911#elif defined(__BIG_ENDIAN__)  // FOR PPCGR on AIX
912#define V8_TARGET_BIG_ENDIAN 1
913#elif V8_TARGET_ARCH_PPC_LE
914#define V8_TARGET_LITTLE_ENDIAN 1
915#elif V8_TARGET_ARCH_PPC_BE
916#define V8_TARGET_BIG_ENDIAN 1
917#elif V8_TARGET_ARCH_S390
918#if V8_TARGET_ARCH_S390_LE_SIM
919#define V8_TARGET_LITTLE_ENDIAN 1
920#else
921#define V8_TARGET_BIG_ENDIAN 1
922#endif
923#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
924#define V8_TARGET_LITTLE_ENDIAN 1
925#elif defined(__BYTE_ORDER__)
926#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
927#define V8_TARGET_BIG_ENDIAN 1
928#else
929#define V8_TARGET_LITTLE_ENDIAN 1
930#endif
931#else
932#error Unknown target architecture endianness
933#endif
934
935#undef V8_HAS_CPP_ATTRIBUTE
936
937#if !defined(V8_STATIC_ROOTS)
938#define V8_STATIC_ROOTS_BOOL false
939#else
940#define V8_STATIC_ROOTS_BOOL true
941#endif
942
943#endif  // V8CONFIG_H_
944