Loading...
Searching...
No Matches
v8config.h
Go to the documentation of this file.
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// gcc 10 defines __cplusplus to "an unspecified value strictly larger than
9// 201703L" for its experimental -std=gnu++2a config.
10// TODO(leszeks): Change to `__cplusplus <= 202002L` once we only support
11// compilers with full C++20 support.
12#if __cplusplus <= 201703L
13#error "C++20 or later required."
14#endif
15
16#ifdef V8_GN_HEADER
17#if !__has_include("v8-gn.h")
18#error Missing v8-gn.h. The configuration for v8 is missing from the include \
19path. Add it with -I<path> to the command line
20#endif
21#include "v8-gn.h" // NOLINT(build/include_directory)
22#endif
23
24#include <memory>
25// clang-format off
26
27// Platform headers for feature detection below.
28#if defined(__ANDROID__)
29# include <sys/cdefs.h>
30#elif defined(__APPLE__)
31# include <TargetConditionals.h>
32#elif defined(__linux__)
33# include <features.h>
34#elif defined(__MVS__)
35# include "zos-base.h"
36#endif
37
38
39// This macro allows to test for the version of the GNU C library (or
40// a compatible C library that masquerades as glibc). It evaluates to
41// 0 if libc is not GNU libc or compatible.
42// Use like:
43// #if V8_GLIBC_PREREQ(2, 3)
44// ...
45// #endif
46#if defined(__GLIBC__) && defined(__GLIBC_MINOR__)
47# define V8_GLIBC_PREREQ(major, minor) \
48 ((__GLIBC__ * 100 + __GLIBC_MINOR__) >= ((major) * 100 + (minor)))
49#else
50# define V8_GLIBC_PREREQ(major, minor) 0
51#endif
52
53
54// This macro allows to test for the version of the GNU C++ compiler.
55// Note that this also applies to compilers that masquerade as GCC,
56// for example clang and the Intel C++ compiler for Linux.
57// Use like:
58// #if V8_GNUC_PREREQ(4, 3, 1)
59// ...
60// #endif
61#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
62# define V8_GNUC_PREREQ(major, minor, patchlevel) \
63 ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >= \
64 ((major) * 10000 + (minor) * 100 + (patchlevel)))
65#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
66# define V8_GNUC_PREREQ(major, minor, patchlevel) \
67 ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >= \
68 ((major) * 10000 + (minor) * 100 + (patchlevel)))
69#else
70# define V8_GNUC_PREREQ(major, minor, patchlevel) 0
71#endif
72
73
74
75// -----------------------------------------------------------------------------
76// Operating system detection (host)
77//
78// V8_OS_ANDROID - Android
79// V8_OS_BSD - BSDish (macOS, Net/Free/Open/DragonFlyBSD)
80// V8_OS_CYGWIN - Cygwin
81// V8_OS_DRAGONFLYBSD - DragonFlyBSD
82// V8_OS_FREEBSD - FreeBSD
83// V8_OS_FUCHSIA - Fuchsia
84// V8_OS_LINUX - Linux (Android, ChromeOS, Linux, ...)
85// V8_OS_DARWIN - Darwin (macOS, iOS)
86// V8_OS_MACOS - macOS
87// V8_OS_IOS - iOS
88// V8_OS_NETBSD - NetBSD
89// V8_OS_OPENBSD - OpenBSD
90// V8_OS_POSIX - POSIX compatible (mostly everything except Windows)
91// V8_OS_QNX - QNX Neutrino
92// V8_OS_SOLARIS - Sun Solaris and OpenSolaris
93// V8_OS_STARBOARD - Starboard (platform abstraction for Cobalt)
94// V8_OS_AIX - AIX
95// V8_OS_WIN - Microsoft Windows
96// V8_OS_ZOS - z/OS
97
98#if defined(__ANDROID__)
99# define V8_OS_ANDROID 1
100# define V8_OS_LINUX 1
101# define V8_OS_POSIX 1
102# define V8_OS_STRING "android"
103
104#elif defined(__APPLE__)
105# define V8_OS_POSIX 1
106# define V8_OS_BSD 1
107# define V8_OS_DARWIN 1
108# if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
109# define V8_OS_IOS 1
110# define V8_OS_STRING "ios"
111# else
112# define V8_OS_MACOS 1
113# define V8_OS_STRING "macos"
114# endif // defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
115
116#elif defined(__CYGWIN__)
117# define V8_OS_CYGWIN 1
118# define V8_OS_POSIX 1
119# define V8_OS_STRING "cygwin"
120
121#elif defined(__linux__)
122# define V8_OS_LINUX 1
123# define V8_OS_POSIX 1
124# define V8_OS_STRING "linux"
125
126#elif defined(__sun)
127# define V8_OS_POSIX 1
128# define V8_OS_SOLARIS 1
129# define V8_OS_STRING "sun"
130
131#elif defined(STARBOARD)
132# define V8_OS_STARBOARD 1
133# define V8_OS_STRING "starboard"
134
135#elif defined(_AIX)
136# define V8_OS_POSIX 1
137# define V8_OS_AIX 1
138# define V8_OS_STRING "aix"
139
140#elif defined(__FreeBSD__)
141# define V8_OS_BSD 1
142# define V8_OS_FREEBSD 1
143# define V8_OS_POSIX 1
144# define V8_OS_STRING "freebsd"
145
146#elif defined(__Fuchsia__)
147# define V8_OS_FUCHSIA 1
148# define V8_OS_POSIX 1
149# define V8_OS_STRING "fuchsia"
150
151#elif defined(__DragonFly__)
152# define V8_OS_BSD 1
153# define V8_OS_DRAGONFLYBSD 1
154# define V8_OS_POSIX 1
155# define V8_OS_STRING "dragonflybsd"
156
157#elif defined(__NetBSD__)
158# define V8_OS_BSD 1
159# define V8_OS_NETBSD 1
160# define V8_OS_POSIX 1
161# define V8_OS_STRING "netbsd"
162
163#elif defined(__OpenBSD__)
164# define V8_OS_BSD 1
165# define V8_OS_OPENBSD 1
166# define V8_OS_POSIX 1
167# define V8_OS_STRING "openbsd"
168
169#elif defined(__QNXNTO__)
170# define V8_OS_POSIX 1
171# define V8_OS_QNX 1
172# define V8_OS_STRING "qnx"
173
174#elif defined(_WIN32)
175# define V8_OS_WIN 1
176# define V8_OS_STRING "windows"
177
178#elif defined(__MVS__)
179# define V8_OS_POSIX 1
180# define V8_OS_ZOS 1
181# define V8_OS_STRING "zos"
182#endif
183
184// -----------------------------------------------------------------------------
185// Operating system detection (target)
186//
187// V8_TARGET_OS_ANDROID
188// V8_TARGET_OS_FUCHSIA
189// V8_TARGET_OS_IOS
190// V8_TARGET_OS_LINUX
191// V8_TARGET_OS_MACOS
192// V8_TARGET_OS_WIN
193// V8_TARGET_OS_CHROMEOS
194//
195// If not set explicitly, these fall back to corresponding V8_OS_ values.
196
197#ifdef V8_HAVE_TARGET_OS
198
199// The target OS is provided, just check that at least one known value is set.
200# if !defined(V8_TARGET_OS_ANDROID) \
201 && !defined(V8_TARGET_OS_FUCHSIA) \
202 && !defined(V8_TARGET_OS_IOS) \
203 && !defined(V8_TARGET_OS_LINUX) \
204 && !defined(V8_TARGET_OS_MACOS) \
205 && !defined(V8_TARGET_OS_WIN) \
206 && !defined(V8_TARGET_OS_CHROMEOS)
207# error No known target OS defined.
208# endif
209
210#else // V8_HAVE_TARGET_OS
211
212# if defined(V8_TARGET_OS_ANDROID) \
213 || defined(V8_TARGET_OS_FUCHSIA) \
214 || defined(V8_TARGET_OS_IOS) \
215 || defined(V8_TARGET_OS_LINUX) \
216 || defined(V8_TARGET_OS_MACOS) \
217 || defined(V8_TARGET_OS_WIN) \
218 || defined(V8_TARGET_OS_CHROMEOS)
219# error A target OS is defined but V8_HAVE_TARGET_OS is unset.
220# endif
221
222// Fall back to the detected host OS.
223#ifdef V8_OS_ANDROID
224# define V8_TARGET_OS_ANDROID
225#endif
226
227#ifdef V8_OS_FUCHSIA
228# define V8_TARGET_OS_FUCHSIA
229#endif
230
231#ifdef V8_OS_IOS
232# define V8_TARGET_OS_IOS
233#endif
234
235#ifdef V8_OS_LINUX
236# define V8_TARGET_OS_LINUX
237#endif
238
239#ifdef V8_OS_MACOS
240# define V8_TARGET_OS_MACOS
241#endif
242
243#ifdef V8_OS_WIN
244# define V8_TARGET_OS_WIN
245#endif
246
247#endif // V8_HAVE_TARGET_OS
248
249#if defined(V8_TARGET_OS_ANDROID)
250# define V8_TARGET_OS_STRING "android"
251#elif defined(V8_TARGET_OS_FUCHSIA)
252# define V8_TARGET_OS_STRING "fuchsia"
253#elif defined(V8_TARGET_OS_IOS)
254# define V8_TARGET_OS_STRING "ios"
255#elif defined(V8_TARGET_OS_LINUX)
256# define V8_TARGET_OS_STRING "linux"
257#elif defined(V8_TARGET_OS_MACOS)
258# define V8_TARGET_OS_STRING "macos"
259#elif defined(V8_TARGET_OS_WINDOWS)
260# define V8_TARGET_OS_STRING "windows"
261#else
262# define V8_TARGET_OS_STRING "unknown"
263#endif
264
265// -----------------------------------------------------------------------------
266// C library detection
267//
268// V8_LIBC_MSVCRT - MSVC libc
269// V8_LIBC_BIONIC - Bionic libc
270// V8_LIBC_BSD - BSD libc derivate
271// V8_LIBC_GLIBC - GNU C library
272// V8_LIBC_UCLIBC - uClibc
273//
274// Note that testing for libc must be done using #if not #ifdef. For example,
275// to test for the GNU C library, use:
276// #if V8_LIBC_GLIBC
277// ...
278// #endif
279
280#if defined (_MSC_VER)
281# define V8_LIBC_MSVCRT 1
282#elif defined(__BIONIC__)
283# define V8_LIBC_BIONIC 1
284# define V8_LIBC_BSD 1
285#elif defined(__UCLIBC__)
286// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
287# define V8_LIBC_UCLIBC 1
288#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
289# define V8_LIBC_GLIBC 1
290#else
291# define V8_LIBC_BSD V8_OS_BSD
292#endif
293
294
295// -----------------------------------------------------------------------------
296// Compiler detection
297//
298// V8_CC_GNU - GCC, or clang in gcc mode
299// V8_CC_INTEL - Intel C++
300// V8_CC_MINGW - Minimalist GNU for Windows
301// V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
302// V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
303// V8_CC_MSVC - Microsoft Visual C/C++, or clang in cl.exe mode
304//
305// C++11 feature detection
306//
307// Compiler-specific feature detection
308//
309// V8_HAS_ATTRIBUTE_ALWAYS_INLINE - __attribute__((always_inline))
310// supported
311// V8_HAS_ATTRIBUTE_CONSTINIT - __attribute__((require_constant_
312// initialization))
313// supported
314// V8_HAS_ATTRIBUTE_NONNULL - __attribute__((nonnull)) supported
315// V8_HAS_ATTRIBUTE_NOINLINE - __attribute__((noinline)) supported
316// V8_HAS_ATTRIBUTE_UNUSED - __attribute__((unused)) supported
317// V8_HAS_ATTRIBUTE_USED - __attribute__((used)) supported
318// V8_HAS_ATTRIBUTE_RETAIN - __attribute__((retain)) supported
319// V8_HAS_ATTRIBUTE_VISIBILITY - __attribute__((visibility)) supported
320// V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
321// supported
322// V8_HAS_CPP_ATTRIBUTE_NODISCARD - [[nodiscard]] supported
323// V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
324// - [[no_unique_address]] supported
325// V8_HAS_BUILTIN_ADD_OVERFLOW - __builtin_add_overflow() supported
326// V8_HAS_BUILTIN_BIT_CAST - __builtin_bit_cast() supported
327// V8_HAS_BUILTIN_BSWAP16 - __builtin_bswap16() supported
328// V8_HAS_BUILTIN_BSWAP32 - __builtin_bswap32() supported
329// V8_HAS_BUILTIN_BSWAP64 - __builtin_bswap64() supported
330// V8_HAS_BUILTIN_CLZ - __builtin_clz() supported
331// V8_HAS_BUILTIN_CTZ - __builtin_ctz() supported
332// V8_HAS_BUILTIN_EXPECT - __builtin_expect() supported
333// V8_HAS_BUILTIN_FRAME_ADDRESS - __builtin_frame_address() supported
334// V8_HAS_BUILTIN_MUL_OVERFLOW - __builtin_mul_overflow() supported
335// V8_HAS_BUILTIN_POPCOUNT - __builtin_popcount() supported
336// V8_HAS_BUILTIN_SADD_OVERFLOW - __builtin_sadd_overflow() supported
337// V8_HAS_BUILTIN_SMUL_OVERFLOW - __builtin_smul_overflow() supported
338// V8_HAS_BUILTIN_SSUB_OVERFLOW - __builtin_ssub_overflow() supported
339// V8_HAS_BUILTIN_SUB_OVERFLOW - __builtin_sub_overflow() supported
340// V8_HAS_BUILTIN_UADD_OVERFLOW - __builtin_uadd_overflow() supported
341// V8_HAS_COMPUTED_GOTO - computed goto/labels as values
342// supported
343// V8_HAS_DECLSPEC_NOINLINE - __declspec(noinline) supported
344// V8_HAS_DECLSPEC_SELECTANY - __declspec(selectany) supported
345// V8_HAS___FORCEINLINE - __forceinline supported
346//
347// Note that testing for compilers and/or features must be done using #if
348// not #ifdef. For example, to test for Intel C++ Compiler, use:
349// #if V8_CC_INTEL
350// ...
351// #endif
352
353#if defined(__has_cpp_attribute)
354#define V8_HAS_CPP_ATTRIBUTE(FEATURE) __has_cpp_attribute(FEATURE)
355#else
356#define V8_HAS_CPP_ATTRIBUTE(FEATURE) 0
357#endif
358
359#if defined(__clang__)
360
361#if defined(__GNUC__) // Clang in gcc mode.
362# define V8_CC_GNU 1
363#endif
364
365# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
366# define V8_HAS_ATTRIBUTE_CONSTINIT \
367 (__has_attribute(require_constant_initialization))
368# define V8_HAS_ATTRIBUTE_CONST (__has_attribute(const))
369# define V8_HAS_ATTRIBUTE_NONNULL (__has_attribute(nonnull))
370# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
371# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
372# define V8_HAS_ATTRIBUTE_USED (__has_attribute(used))
373# define V8_HAS_ATTRIBUTE_RETAIN (__has_attribute(retain))
374// Support for the "preserve_most" attribute is limited:
375// - 32-bit platforms do not implement it,
376// - component builds fail because _dl_runtime_resolve clobbers registers,
377// - we see crashes on arm64 on Windows (https://crbug.com/1409934), which can
378// hopefully be fixed in the future.
379// Additionally, the initial implementation in clang <= 16 overwrote the return
380// register(s) in the epilogue of a preserve_most function, so we only use
381// preserve_most in clang >= 17 (see https://reviews.llvm.org/D143425).
382#if (defined(_M_X64) || defined(__x86_64__) /* x64 (everywhere) */ \
383 || ((defined(__AARCH64EL__) || defined(_M_ARM64)) /* arm64, but ... */ \
384 && !defined(_WIN32))) /* not on windows */ \
385 && !defined(COMPONENT_BUILD) /* no component build */\
386 && __clang_major__ >= 17 /* clang >= 17 */
387# define V8_HAS_ATTRIBUTE_PRESERVE_MOST (__has_attribute(preserve_most))
388#endif
389# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
390# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
391 (__has_attribute(warn_unused_result))
392# define V8_HAS_ATTRIBUTE_WEAK (__has_attribute(weak))
393
394# define V8_HAS_CPP_ATTRIBUTE_NODISCARD (V8_HAS_CPP_ATTRIBUTE(nodiscard))
395# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \
396 (V8_HAS_CPP_ATTRIBUTE(no_unique_address))
397
398# define V8_HAS_BUILTIN_ADD_OVERFLOW (__has_builtin(__builtin_add_overflow))
399# define V8_HAS_BUILTIN_ASSUME (__has_builtin(__builtin_assume))
400# define V8_HAS_BUILTIN_ASSUME_ALIGNED (__has_builtin(__builtin_assume_aligned))
401# define V8_HAS_BUILTIN_BIT_CAST (__has_builtin(__builtin_bit_cast))
402# define V8_HAS_BUILTIN_BSWAP16 (__has_builtin(__builtin_bswap16))
403# define V8_HAS_BUILTIN_BSWAP32 (__has_builtin(__builtin_bswap32))
404# define V8_HAS_BUILTIN_BSWAP64 (__has_builtin(__builtin_bswap64))
405# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
406# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
407# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
408# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
409# define V8_HAS_BUILTIN_MUL_OVERFLOW (__has_builtin(__builtin_mul_overflow))
410# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
411# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
412# define V8_HAS_BUILTIN_SMUL_OVERFLOW (__has_builtin(__builtin_smul_overflow))
413# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
414# define V8_HAS_BUILTIN_SUB_OVERFLOW (__has_builtin(__builtin_sub_overflow))
415# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
416# define V8_HAS_BUILTIN_UNREACHABLE (__has_builtin(__builtin_unreachable))
417
418// Clang has no __has_feature for computed gotos.
419// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
420# define V8_HAS_COMPUTED_GOTO 1
421
422#elif defined(__GNUC__)
423
424# define V8_CC_GNU 1
425# if defined(__INTEL_COMPILER) // Intel C++ also masquerades as GCC 3.2.0
426# define V8_CC_INTEL 1
427# endif
428# if defined(__MINGW32__)
429# define V8_CC_MINGW32 1
430# endif
431# if defined(__MINGW64__)
432# define V8_CC_MINGW64 1
433# endif
434# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
435
436// FYI: __has_builtin is only available with GCC 10 and later, so explicitly
437// check GCC version numbers to enable features. TODO(leszeks): Merge feature
438// enabling for GCC 10 and later into the Clang section above, and leave this
439// section for GCC 9 and earlier.
440
441// always_inline is available in gcc 4.0 but not very reliable until 4.4.
442// Works around "sorry, unimplemented: inlining failed" build errors with
443// older compilers.
444# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE 1
445# define V8_HAS_ATTRIBUTE_NOINLINE 1
446# define V8_HAS_ATTRIBUTE_UNUSED 1
447# define V8_HAS_ATTRIBUTE_VISIBILITY 1
448# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT (!V8_CC_INTEL)
449# define V8_HAS_ATTRIBUTE_WEAK 1
450
451// [[nodiscard]] does not work together with with
452// __attribute__((visibility(""))) on GCC 7.4 which is why there is no define
453// for V8_HAS_CPP_ATTRIBUTE_NODISCARD. See https://crbug.com/v8/11707.
454
455# define V8_HAS_BUILTIN_ASSUME_ALIGNED 1
456# if __GNUC__ >= 11
457# define V8_HAS_BUILTIN_BIT_CAST 1
458# endif
459# define V8_HAS_BUILTIN_CLZ 1
460# define V8_HAS_BUILTIN_CTZ 1
461# define V8_HAS_BUILTIN_EXPECT 1
462# define V8_HAS_BUILTIN_FRAME_ADDRESS 1
463# define V8_HAS_BUILTIN_POPCOUNT 1
464# define V8_HAS_BUILTIN_UNREACHABLE 1
465
466// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
467#define V8_HAS_COMPUTED_GOTO 1
468
469#endif
470
471#if defined(_MSC_VER)
472# define V8_CC_MSVC 1
473
474# define V8_HAS_DECLSPEC_NOINLINE 1
475# define V8_HAS_DECLSPEC_SELECTANY 1
476
477# define V8_HAS___FORCEINLINE 1
478
479#endif
480
481
482// -----------------------------------------------------------------------------
483// Helper macros
484
485// A macro used to make better inlining. Don't bother for debug builds.
486// Use like:
487// V8_INLINE int GetZero() { return 0; }
488#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
489# define V8_INLINE inline __attribute__((always_inline))
490#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
491# define V8_INLINE __forceinline
492#else
493# define V8_INLINE inline
494#endif
495
496#if V8_HAS_BUILTIN_ASSUME
497#ifdef DEBUG
498// In debug mode, check assumptions in addition to adding annotations.
499// This helps GCC (and maybe other compilers) figure out that certain
500// situations are unreachable.
501# define V8_ASSUME(condition) \
502 do { \
503 DCHECK(condition); \
504 __builtin_assume(condition); \
505 } while (false)
506#else // DEBUG
507# define V8_ASSUME __builtin_assume
508#endif // DEBUG
509#elif V8_HAS_BUILTIN_UNREACHABLE
510# define V8_ASSUME(condition) \
511 do { \
512 DCHECK(condition); \
513 if (!(condition)) __builtin_unreachable(); \
514 } while (false)
515#else
516# define V8_ASSUME USE
517#endif
518
519// Prefer c++20 std::assume_aligned. Don't use it on MSVC though, because it's
520// not happy with our large 4GB alignment values.
521#if __cplusplus >= 202002L && defined(__cpp_lib_assume_aligned) && !V8_CC_MSVC
522# define V8_ASSUME_ALIGNED(ptr, alignment) \
523 std::assume_aligned<(alignment)>(ptr)
524#elif V8_HAS_BUILTIN_ASSUME_ALIGNED
525# define V8_ASSUME_ALIGNED(ptr, alignment) \
526 __builtin_assume_aligned((ptr), (alignment))
527#else
528# define V8_ASSUME_ALIGNED(ptr, alignment) (ptr)
529#endif
530
531// A macro to mark functions whose values don't change (e.g. across calls)
532// and thereby compiler is free to hoist and fold multiple calls together.
533// Use like:
534// V8_CONST int foo() { ... }
535#if V8_HAS_ATTRIBUTE_CONST
536# define V8_CONST __attribute__((const))
537#else
538# define V8_CONST
539#endif
540
541// A macro to mark a declaration as requiring constant initialization.
542// Use like:
543// int* foo V8_CONSTINIT;
544#if V8_HAS_ATTRIBUTE_CONSTINIT
545# define V8_CONSTINIT __attribute__((require_constant_initialization))
546#else
547# define V8_CONSTINIT
548#endif
549
550
551// A macro to mark specific arguments as non-null.
552// Use like:
553// int add(int* x, int y, int* z) V8_NONNULL(1, 3) { return *x + y + *z; }
554#if V8_HAS_ATTRIBUTE_NONNULL
555# define V8_NONNULL(...) __attribute__((nonnull(__VA_ARGS__)))
556#else
557# define V8_NONNULL(...) /* NOT SUPPORTED */
558#endif
559
560
561// A macro used to tell the compiler to never inline a particular function.
562// Use like:
563// V8_NOINLINE int GetMinusOne() { return -1; }
564#if V8_HAS_ATTRIBUTE_NOINLINE
565# define V8_NOINLINE __attribute__((noinline))
566#elif V8_HAS_DECLSPEC_NOINLINE
567# define V8_NOINLINE __declspec(noinline)
568#else
569# define V8_NOINLINE /* NOT SUPPORTED */
570#endif
571
572
573// A macro used to change the calling conventions to preserve all registers (no
574// caller-saved registers). Use this for cold functions called from hot
575// functions.
576// Use like:
577// V8_NOINLINE V8_PRESERVE_MOST void UnlikelyMethod();
578#if V8_HAS_ATTRIBUTE_PRESERVE_MOST
579# define V8_PRESERVE_MOST __attribute__((preserve_most))
580#else
581# define V8_PRESERVE_MOST /* NOT SUPPORTED */
582#endif
583
584
585// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
586#if defined(V8_DEPRECATION_WARNINGS)
587# define V8_DEPRECATED(message) [[deprecated(message)]]
588#else
589# define V8_DEPRECATED(message)
590#endif
591
592
593// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
594#if defined(V8_IMMINENT_DEPRECATION_WARNINGS)
595# define V8_DEPRECATE_SOON(message) [[deprecated(message)]]
596#else
597# define V8_DEPRECATE_SOON(message)
598#endif
599
600
601#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) || \
602 defined(V8_DEPRECATION_WARNINGS)
603#if defined(V8_CC_MSVC)
604# define START_ALLOW_USE_DEPRECATED() \
605 __pragma(warning(push)) \
606 __pragma(warning(disable : 4996))
607# define END_ALLOW_USE_DEPRECATED() __pragma(warning(pop))
608#else // !defined(V8_CC_MSVC)
609# define START_ALLOW_USE_DEPRECATED() \
610 _Pragma("GCC diagnostic push") \
611 _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
612#define END_ALLOW_USE_DEPRECATED() _Pragma("GCC diagnostic pop")
613#endif // !defined(V8_CC_MSVC)
614#else // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
615 // defined(V8_DEPRECATION_WARNINGS))
616#define START_ALLOW_USE_DEPRECATED()
617#define END_ALLOW_USE_DEPRECATED()
618#endif // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
619 // defined(V8_DEPRECATION_WARNINGS))
620#define ALLOW_COPY_AND_MOVE_WITH_DEPRECATED_FIELDS(ClassName) \
621 START_ALLOW_USE_DEPRECATED() \
622 ClassName(const ClassName&) = default; \
623 ClassName(ClassName&&) = default; \
624 ClassName& operator=(const ClassName&) = default; \
625 ClassName& operator=(ClassName&&) = default; \
626 END_ALLOW_USE_DEPRECATED()
627
628
629#if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 6)
630# define V8_ENUM_DEPRECATED(message)
631# define V8_ENUM_DEPRECATE_SOON(message)
632#else
633# define V8_ENUM_DEPRECATED(message) V8_DEPRECATED(message)
634# define V8_ENUM_DEPRECATE_SOON(message) V8_DEPRECATE_SOON(message)
635#endif
636
637
638// A macro to provide the compiler with branch prediction information.
639#if V8_HAS_BUILTIN_EXPECT
640# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
641# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
642#else
643# define V8_UNLIKELY(condition) (condition)
644# define V8_LIKELY(condition) (condition)
645#endif
646
647
648// Annotate a function indicating the caller must examine the return value.
649// Use like:
650// int foo() V8_WARN_UNUSED_RESULT;
651#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
652#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
653#else
654#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
655#endif
656
657
658// Annotate functions/variables as weak to allow overriding the symbol.
659#if V8_HAS_ATTRIBUTE_WEAK
660#define V8_WEAK __attribute__((weak))
661#else
662#define V8_WEAK /* NOT SUPPORTED */
663#endif
664
665
666// Annotate a class or constructor indicating the caller must assign the
667// constructed instances.
668// Apply to the whole class like:
669// class V8_NODISCARD Foo() { ... };
670// or apply to just one constructor like:
671// V8_NODISCARD Foo() { ... };
672// [[nodiscard]] comes in C++17 but supported in clang with -std >= c++11.
673#if V8_HAS_CPP_ATTRIBUTE_NODISCARD
674#define V8_NODISCARD [[nodiscard]]
675#else
676#define V8_NODISCARD /* NOT SUPPORTED */
677#endif
678
679// The no_unique_address attribute allows tail padding in a non-static data
680// member to overlap other members of the enclosing class (and in the special
681// case when the type is empty, permits it to fully overlap other members). The
682// field is laid out as if a base class were encountered at the corresponding
683// point within the class (except that it does not share a vptr with the
684// enclosing object).
685//
686// Apply to a data member like:
687//
688// class Foo {
689// V8_NO_UNIQUE_ADDRESS Bar bar_;
690// };
691//
692// [[no_unique_address]] comes in C++20 but supported in clang with
693// -std >= c++11.
694#if V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
695#define V8_NO_UNIQUE_ADDRESS [[no_unique_address]]
696#else
697#define V8_NO_UNIQUE_ADDRESS /* NOT SUPPORTED */
698#endif
699
700// Marks a type as being eligible for the "trivial" ABI despite having a
701// non-trivial destructor or copy/move constructor. Such types can be relocated
702// after construction by simply copying their memory, which makes them eligible
703// to be passed in registers. The canonical example is std::unique_ptr.
704//
705// Use with caution; this has some subtle effects on constructor/destructor
706// ordering and will be very incorrect if the type relies on its address
707// remaining constant. When used as a function argument (by value), the value
708// may be constructed in the caller's stack frame, passed in a register, and
709// then used and destructed in the callee's stack frame. A similar thing can
710// occur when values are returned.
711//
712// TRIVIAL_ABI is not needed for types which have a trivial destructor and
713// copy/move constructors, since those are automatically trivial by the ABI
714// spec.
715//
716// It is also not likely to be effective on types too large to be passed in one
717// or two registers on typical target ABIs.
718//
719// See also:
720// https://clang.llvm.org/docs/AttributeReference.html#trivial-abi
721// https://libcxx.llvm.org/docs/DesignDocs/UniquePtrTrivialAbi.html
722#if defined(__clang__) && defined(__has_attribute)
723#if __has_attribute(trivial_abi)
724#define V8_TRIVIAL_ABI [[clang::trivial_abi]]
725#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 1
726#endif // __has_attribute(trivial_abi)
727#endif // defined(__clang__) && defined(__has_attribute)
728#if !defined(V8_TRIVIAL_ABI)
729#define V8_TRIVIAL_ABI
730#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 0
731#endif
732
733// Helper macro to define no_sanitize attributes only with clang.
734#if defined(__clang__) && defined(__has_attribute)
735#if __has_attribute(no_sanitize)
736#define V8_CLANG_NO_SANITIZE(what) __attribute__((no_sanitize(what)))
737#endif
738#endif
739#if !defined(V8_CLANG_NO_SANITIZE)
740#define V8_CLANG_NO_SANITIZE(what)
741#endif
742
743// Exposing private symbols requires exposing public symbols too.
744#ifdef BUILDING_V8_SHARED_PRIVATE
745#define BUILDING_V8_SHARED
746#endif
747
748#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
749#error Inconsistent build configuration: To build the V8 shared library \
750set BUILDING_V8_SHARED, to include its headers for linking against the \
751V8 shared library set USING_V8_SHARED.
752#endif
753
754#ifdef V8_OS_WIN
755
756// Setup for Windows DLL export/import. When building the V8 DLL the
757// BUILDING_V8_SHARED needs to be defined. When building a program which uses
758// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
759// static library or building a program which uses the V8 static library neither
760// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
761#ifdef BUILDING_V8_SHARED
762# define V8_EXPORT __declspec(dllexport)
763#elif USING_V8_SHARED
764# define V8_EXPORT __declspec(dllimport)
765#else
766# define V8_EXPORT
767#endif // BUILDING_V8_SHARED
768
769#else // V8_OS_WIN
770
771// Setup for Linux shared library export.
772#if V8_HAS_ATTRIBUTE_VISIBILITY
773# ifdef BUILDING_V8_SHARED
774# define V8_EXPORT __attribute__ ((visibility("default")))
775# else
776# define V8_EXPORT
777# endif
778#else
779# define V8_EXPORT
780#endif
781
782#endif // V8_OS_WIN
783
784// clang-format on
785
786// Processor architecture detection. For more info on what's defined, see:
787// http://msdn.microsoft.com/en-us/library/b0084kay.aspx
788// http://www.agner.org/optimize/calling_conventions.pdf
789// or with gcc, run: "echo | gcc -E -dM -"
790// The V8_HOST_ARCH_* macros correspond to the architecture on which V8, as a
791// virtual machine and compiler, runs. Don't confuse this with the architecture
792// on which V8 is built.
793#if defined(_M_X64) || defined(__x86_64__)
794#define V8_HOST_ARCH_X64 1
795#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4 // Check for x32.
796#define V8_HOST_ARCH_32_BIT 1
797#else
798#define V8_HOST_ARCH_64_BIT 1
799#endif
800#elif defined(_M_IX86) || defined(__i386__)
801#define V8_HOST_ARCH_IA32 1
802#define V8_HOST_ARCH_32_BIT 1
803#elif defined(__AARCH64EL__) || defined(_M_ARM64)
804#define V8_HOST_ARCH_ARM64 1
805#define V8_HOST_ARCH_64_BIT 1
806#elif defined(__ARMEL__)
807#define V8_HOST_ARCH_ARM 1
808#define V8_HOST_ARCH_32_BIT 1
809#elif defined(__mips64)
810#define V8_HOST_ARCH_MIPS64 1
811#define V8_HOST_ARCH_64_BIT 1
812#elif defined(__loongarch_lp64)
813#define V8_HOST_ARCH_LOONG64 1
814#define V8_HOST_ARCH_64_BIT 1
815#elif defined(__PPC64__) || defined(_ARCH_PPC64)
816#define V8_HOST_ARCH_PPC64 1
817#define V8_HOST_ARCH_64_BIT 1
818#elif defined(__PPC__) || defined(_ARCH_PPC)
819#define V8_HOST_ARCH_PPC 1
820#define V8_HOST_ARCH_32_BIT 1
821#elif defined(__s390__) || defined(__s390x__)
822#define V8_HOST_ARCH_S390 1
823#if defined(__s390x__)
824#define V8_HOST_ARCH_64_BIT 1
825#else
826#define V8_HOST_ARCH_32_BIT 1
827#endif
828#elif defined(__riscv) || defined(__riscv__)
829#if __riscv_xlen == 64
830#define V8_HOST_ARCH_RISCV64 1
831#define V8_HOST_ARCH_64_BIT 1
832#elif __riscv_xlen == 32
833#define V8_HOST_ARCH_RISCV32 1
834#define V8_HOST_ARCH_32_BIT 1
835#else
836#error "Cannot detect Riscv's bitwidth"
837#endif
838#else
839#error "Host architecture was not detected as supported by v8"
840#endif
841
842// Target architecture detection. This corresponds to the architecture for which
843// V8's JIT will generate code (the last stage of the canadian cross-compiler).
844// The macros may be set externally. If not, detect in the same way as the host
845// architecture, that is, target the native environment as presented by the
846// compiler.
847#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && \
848 !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_PPC && \
849 !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390 && \
850 !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64 && \
851 !V8_TARGET_ARCH_RISCV32
852#if defined(_M_X64) || defined(__x86_64__)
853#define V8_TARGET_ARCH_X64 1
854#elif defined(_M_IX86) || defined(__i386__)
855#define V8_TARGET_ARCH_IA32 1
856#elif defined(__AARCH64EL__) || defined(_M_ARM64)
857#define V8_TARGET_ARCH_ARM64 1
858#elif defined(__ARMEL__)
859#define V8_TARGET_ARCH_ARM 1
860#elif defined(__mips64)
861#define V8_TARGET_ARCH_MIPS64 1
862#elif defined(__loongarch_lp64)
863#define V8_TARGET_ARCH_LOONG64 1
864#elif defined(_ARCH_PPC64)
865#define V8_TARGET_ARCH_PPC64 1
866#elif defined(_ARCH_PPC)
867#define V8_TARGET_ARCH_PPC 1
868#elif defined(__s390__)
869#define V8_TARGET_ARCH_S390 1
870#if defined(__s390x__)
871#define V8_TARGET_ARCH_S390X 1
872#endif
873#elif defined(__riscv) || defined(__riscv__)
874#if __riscv_xlen == 64
875#define V8_TARGET_ARCH_RISCV64 1
876#elif __riscv_xlen == 32
877#define V8_TARGET_ARCH_RISCV32 1
878#endif
879#else
880#error Target architecture was not detected as supported by v8
881#endif
882#endif
883
884// Determine architecture pointer size.
885#if V8_TARGET_ARCH_IA32
886#define V8_TARGET_ARCH_32_BIT 1
887#elif V8_TARGET_ARCH_X64
888#if !V8_TARGET_ARCH_32_BIT && !V8_TARGET_ARCH_64_BIT
889#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4 // Check for x32.
890#define V8_TARGET_ARCH_32_BIT 1
891#else
892#define V8_TARGET_ARCH_64_BIT 1
893#endif
894#endif
895#elif V8_TARGET_ARCH_ARM
896#define V8_TARGET_ARCH_32_BIT 1
897#elif V8_TARGET_ARCH_ARM64
898#define V8_TARGET_ARCH_64_BIT 1
899#elif V8_TARGET_ARCH_MIPS
900#define V8_TARGET_ARCH_32_BIT 1
901#elif V8_TARGET_ARCH_MIPS64
902#define V8_TARGET_ARCH_64_BIT 1
903#elif V8_TARGET_ARCH_LOONG64
904#define V8_TARGET_ARCH_64_BIT 1
905#elif V8_TARGET_ARCH_PPC
906#define V8_TARGET_ARCH_32_BIT 1
907#elif V8_TARGET_ARCH_PPC64
908#define V8_TARGET_ARCH_64_BIT 1
909#elif V8_TARGET_ARCH_S390
910#if V8_TARGET_ARCH_S390X
911#define V8_TARGET_ARCH_64_BIT 1
912#else
913#define V8_TARGET_ARCH_32_BIT 1
914#endif
915#elif V8_TARGET_ARCH_RISCV64
916#define V8_TARGET_ARCH_64_BIT 1
917#elif V8_TARGET_ARCH_RISCV32
918#define V8_TARGET_ARCH_32_BIT 1
919#else
920#error Unknown target architecture pointer size
921#endif
922
923// Check for supported combinations of host and target architectures.
924#if V8_TARGET_ARCH_IA32 && !V8_HOST_ARCH_IA32
925#error Target architecture ia32 is only supported on ia32 host
926#endif
927#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT && \
928 !((V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64) && V8_HOST_ARCH_64_BIT))
929#error Target architecture x64 is only supported on x64 and arm64 host
930#endif
931#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT && \
932 !(V8_HOST_ARCH_X64 && V8_HOST_ARCH_32_BIT))
933#error Target architecture x32 is only supported on x64 host with x32 support
934#endif
935#if (V8_TARGET_ARCH_ARM && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_ARM))
936#error Target architecture arm is only supported on arm and ia32 host
937#endif
938#if (V8_TARGET_ARCH_ARM64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64))
939#error Target architecture arm64 is only supported on arm64 and x64 host
940#endif
941#if (V8_TARGET_ARCH_MIPS64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_MIPS64))
942#error Target architecture mips64 is only supported on mips64 and x64 host
943#endif
944#if (V8_TARGET_ARCH_RISCV64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_RISCV64))
945#error Target architecture riscv64 is only supported on riscv64 and x64 host
946#endif
947#if (V8_TARGET_ARCH_RISCV32 && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_RISCV32))
948#error Target architecture riscv32 is only supported on riscv32 and ia32 host
949#endif
950#if (V8_TARGET_ARCH_LOONG64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_LOONG64))
951#error Target architecture loong64 is only supported on loong64 and x64 host
952#endif
953
954// Determine architecture endianness.
955#if V8_TARGET_ARCH_IA32
956#define V8_TARGET_LITTLE_ENDIAN 1
957#elif V8_TARGET_ARCH_X64
958#define V8_TARGET_LITTLE_ENDIAN 1
959#elif V8_TARGET_ARCH_ARM
960#define V8_TARGET_LITTLE_ENDIAN 1
961#elif V8_TARGET_ARCH_ARM64
962#define V8_TARGET_LITTLE_ENDIAN 1
963#elif V8_TARGET_ARCH_LOONG64
964#define V8_TARGET_LITTLE_ENDIAN 1
965#elif V8_TARGET_ARCH_MIPS64
966#if defined(__MIPSEB__) || defined(V8_TARGET_ARCH_MIPS64_BE)
967#define V8_TARGET_BIG_ENDIAN 1
968#else
969#define V8_TARGET_LITTLE_ENDIAN 1
970#endif
971#elif defined(__BIG_ENDIAN__) // FOR PPCGR on AIX
972#define V8_TARGET_BIG_ENDIAN 1
973#elif V8_TARGET_ARCH_PPC_LE
974#define V8_TARGET_LITTLE_ENDIAN 1
975#elif V8_TARGET_ARCH_PPC_BE
976#define V8_TARGET_BIG_ENDIAN 1
977#elif V8_TARGET_ARCH_S390
978#if V8_TARGET_ARCH_S390_LE_SIM
979#define V8_TARGET_LITTLE_ENDIAN 1
980#else
981#define V8_TARGET_BIG_ENDIAN 1
982#endif
983#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
984#define V8_TARGET_LITTLE_ENDIAN 1
985#elif defined(__BYTE_ORDER__)
986#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
987#define V8_TARGET_BIG_ENDIAN 1
988#else
989#define V8_TARGET_LITTLE_ENDIAN 1
990#endif
991#else
992#error Unknown target architecture endianness
993#endif
994
995#undef V8_HAS_CPP_ATTRIBUTE
996
997#if !defined(V8_STATIC_ROOTS)
998#define V8_STATIC_ROOTS_BOOL false
999#else
1000#define V8_STATIC_ROOTS_BOOL true
1001#endif
1002
1003#endif // V8CONFIG_H_