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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// 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_TVOS - tvOS (also sets V8_OS_IOS)
89// V8_OS_NETBSD - NetBSD
90// V8_OS_OPENBSD - OpenBSD
91// V8_OS_POSIX - POSIX compatible (mostly everything except Windows)
92// V8_OS_QNX - QNX Neutrino
93// V8_OS_SOLARIS - Sun Solaris and OpenSolaris
94// V8_OS_STARBOARD - Starboard (platform abstraction for Cobalt)
95// V8_OS_AIX - AIX
96// V8_OS_WIN - Microsoft Windows
97// V8_OS_ZOS - z/OS
98
99#if defined(__ANDROID__)
100# define V8_OS_ANDROID 1
101# define V8_OS_LINUX 1
102# define V8_OS_POSIX 1
103# define V8_OS_STRING "android"
104
105#elif defined(__APPLE__)
106# define V8_OS_POSIX 1
107# define V8_OS_BSD 1
108# define V8_OS_DARWIN 1
109# if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
110# define V8_OS_IOS 1
111# define V8_OS_STRING "ios"
112# if defined(TARGET_OS_TV) && TARGET_OS_TV
113# define V8_OS_TVOS 1
114# endif
115# else
116# define V8_OS_MACOS 1
117# define V8_OS_STRING "macos"
118# endif // defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
119
120#elif defined(__CYGWIN__)
121# define V8_OS_CYGWIN 1
122# define V8_OS_POSIX 1
123# define V8_OS_STRING "cygwin"
124
125#elif defined(__linux__)
126# define V8_OS_LINUX 1
127# define V8_OS_POSIX 1
128# define V8_OS_STRING "linux"
129
130#elif defined(__sun)
131# define V8_OS_POSIX 1
132# define V8_OS_SOLARIS 1
133# define V8_OS_STRING "sun"
134
135#elif defined(STARBOARD)
136# define V8_OS_STARBOARD 1
137# define V8_OS_STRING "starboard"
138
139#elif defined(_AIX)
140# define V8_OS_POSIX 1
141# define V8_OS_AIX 1
142# define V8_OS_STRING "aix"
143
144#elif defined(__FreeBSD__)
145# define V8_OS_BSD 1
146# define V8_OS_FREEBSD 1
147# define V8_OS_POSIX 1
148# define V8_OS_STRING "freebsd"
149
150#elif defined(__Fuchsia__)
151# define V8_OS_FUCHSIA 1
152# define V8_OS_POSIX 1
153# define V8_OS_STRING "fuchsia"
154
155#elif defined(__DragonFly__)
156# define V8_OS_BSD 1
157# define V8_OS_DRAGONFLYBSD 1
158# define V8_OS_POSIX 1
159# define V8_OS_STRING "dragonflybsd"
160
161#elif defined(__NetBSD__)
162# define V8_OS_BSD 1
163# define V8_OS_NETBSD 1
164# define V8_OS_POSIX 1
165# define V8_OS_STRING "netbsd"
166
167#elif defined(__OpenBSD__)
168# define V8_OS_BSD 1
169# define V8_OS_OPENBSD 1
170# define V8_OS_POSIX 1
171# define V8_OS_STRING "openbsd"
172
173#elif defined(__QNXNTO__)
174# define V8_OS_POSIX 1
175# define V8_OS_QNX 1
176# define V8_OS_STRING "qnx"
177
178#elif defined(_WIN32)
179# define V8_OS_WIN 1
180# define V8_OS_STRING "windows"
181
182#elif defined(__MVS__)
183# define V8_OS_POSIX 1
184# define V8_OS_ZOS 1
185# define V8_OS_STRING "zos"
186#endif
187
188// -----------------------------------------------------------------------------
189// Operating system detection (target)
190//
191// V8_TARGET_OS_ANDROID
192// V8_TARGET_OS_FUCHSIA
193// V8_TARGET_OS_IOS
194// V8_TARGET_OS_TVOS (also sets V8_TARGET_OS_IOS)
195// V8_TARGET_OS_LINUX
196// V8_TARGET_OS_MACOS
197// V8_TARGET_OS_WIN
198// V8_TARGET_OS_CHROMEOS
199//
200// If not set explicitly, these fall back to corresponding V8_OS_ values.
201
202#ifdef V8_HAVE_TARGET_OS
203
204// The target OS is provided, just check that at least one known value is set.
205# if !defined(V8_TARGET_OS_ANDROID) \
206 && !defined(V8_TARGET_OS_FUCHSIA) \
207 && !defined(V8_TARGET_OS_IOS) \
208 && !defined(V8_TARGET_OS_TVOS) \
209 && !defined(V8_TARGET_OS_LINUX) \
210 && !defined(V8_TARGET_OS_MACOS) \
211 && !defined(V8_TARGET_OS_WIN) \
212 && !defined(V8_TARGET_OS_CHROMEOS)
213# error No known target OS defined.
214# endif
215
216#else // V8_HAVE_TARGET_OS
217
218# if defined(V8_TARGET_OS_ANDROID) \
219 || defined(V8_TARGET_OS_FUCHSIA) \
220 || defined(V8_TARGET_OS_IOS) \
221 || defined(V8_TARGET_OS_TVOS) \
222 || defined(V8_TARGET_OS_LINUX) \
223 || defined(V8_TARGET_OS_MACOS) \
224 || defined(V8_TARGET_OS_WIN) \
225 || defined(V8_TARGET_OS_CHROMEOS)
226# error A target OS is defined but V8_HAVE_TARGET_OS is unset.
227# endif
228
229// Fall back to the detected host OS.
230#ifdef V8_OS_ANDROID
231# define V8_TARGET_OS_ANDROID
232#endif
233
234#ifdef V8_OS_FUCHSIA
235# define V8_TARGET_OS_FUCHSIA
236#endif
237
238#ifdef V8_OS_IOS
239# define V8_TARGET_OS_IOS
240#endif
241
242#ifdef V8_OS_TVOS
243# define V8_TARGET_OS_TVOS
244#endif
245
246#ifdef V8_OS_LINUX
247# define V8_TARGET_OS_LINUX
248#endif
249
250#ifdef V8_OS_MACOS
251# define V8_TARGET_OS_MACOS
252#endif
253
254#ifdef V8_OS_WIN
255# define V8_TARGET_OS_WIN
256#endif
257
258#endif // V8_HAVE_TARGET_OS
259
260#if defined(V8_TARGET_OS_ANDROID)
261# define V8_TARGET_OS_STRING "android"
262#elif defined(V8_TARGET_OS_FUCHSIA)
263# define V8_TARGET_OS_STRING "fuchsia"
264#elif defined(V8_TARGET_OS_IOS)
265# define V8_TARGET_OS_STRING "ios"
266#elif defined(V8_TARGET_OS_LINUX)
267# define V8_TARGET_OS_STRING "linux"
268#elif defined(V8_TARGET_OS_MACOS)
269# define V8_TARGET_OS_STRING "macos"
270#elif defined(V8_TARGET_OS_WINDOWS)
271# define V8_TARGET_OS_STRING "windows"
272#else
273# define V8_TARGET_OS_STRING "unknown"
274#endif
275
276// -----------------------------------------------------------------------------
277// C library detection
278//
279// V8_LIBC_MSVCRT - MSVC libc
280// V8_LIBC_BIONIC - Bionic libc
281// V8_LIBC_BSD - BSD libc derivate
282// V8_LIBC_GLIBC - GNU C library
283// V8_LIBC_UCLIBC - uClibc
284//
285// Note that testing for libc must be done using #if not #ifdef. For example,
286// to test for the GNU C library, use:
287// #if V8_LIBC_GLIBC
288// ...
289// #endif
290
291#if defined (_MSC_VER)
292# define V8_LIBC_MSVCRT 1
293#elif defined(__BIONIC__)
294# define V8_LIBC_BIONIC 1
295# define V8_LIBC_BSD 1
296#elif defined(__UCLIBC__)
297// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
298# define V8_LIBC_UCLIBC 1
299#elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
300# define V8_LIBC_GLIBC 1
301#else
302# define V8_LIBC_BSD V8_OS_BSD
303#endif
304
305
306// -----------------------------------------------------------------------------
307// Compiler detection
308//
309// V8_CC_GNU - GCC, or clang in gcc mode
310// V8_CC_INTEL - Intel C++
311// V8_CC_MINGW - Minimalist GNU for Windows
312// V8_CC_MINGW32 - Minimalist GNU for Windows (mingw32)
313// V8_CC_MINGW64 - Minimalist GNU for Windows (mingw-w64)
314// V8_CC_MSVC - Microsoft Visual C/C++, or clang in cl.exe mode
315//
316// C++11 feature detection
317//
318// Compiler-specific feature detection
319//
320// V8_HAS_ATTRIBUTE_ALWAYS_INLINE - __attribute__((always_inline))
321// supported
322// V8_HAS_ATTRIBUTE_CONSTINIT - __attribute__((require_constant_
323// initialization))
324// supported
325// V8_HAS_ATTRIBUTE_NONNULL - __attribute__((nonnull)) supported
326// V8_HAS_ATTRIBUTE_NOINLINE - __attribute__((noinline)) supported
327// V8_HAS_ATTRIBUTE_UNUSED - __attribute__((unused)) supported
328// V8_HAS_ATTRIBUTE_USED - __attribute__((used)) supported
329// V8_HAS_ATTRIBUTE_RETAIN - __attribute__((retain)) supported
330// V8_HAS_ATTRIBUTE_VISIBILITY - __attribute__((visibility)) supported
331// V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT - __attribute__((warn_unused_result))
332// supported
333// V8_HAS_CPP_ATTRIBUTE_NODISCARD - [[nodiscard]] supported
334// V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
335// - [[no_unique_address]] supported
336// V8_HAS_BUILTIN_ADD_OVERFLOW - __builtin_add_overflow() supported
337// V8_HAS_BUILTIN_BIT_CAST - __builtin_bit_cast() supported
338// V8_HAS_BUILTIN_BSWAP16 - __builtin_bswap16() supported
339// V8_HAS_BUILTIN_BSWAP32 - __builtin_bswap32() supported
340// V8_HAS_BUILTIN_BSWAP64 - __builtin_bswap64() supported
341// V8_HAS_BUILTIN_CLZ - __builtin_clz() supported
342// V8_HAS_BUILTIN_CTZ - __builtin_ctz() supported
343// V8_HAS_BUILTIN_EXPECT - __builtin_expect() supported
344// V8_HAS_BUILTIN_FRAME_ADDRESS - __builtin_frame_address() supported
345// V8_HAS_BUILTIN_MUL_OVERFLOW - __builtin_mul_overflow() supported
346// V8_HAS_BUILTIN_POPCOUNT - __builtin_popcount() supported
347// V8_HAS_BUILTIN_SADD_OVERFLOW - __builtin_sadd_overflow() supported
348// V8_HAS_BUILTIN_SMUL_OVERFLOW - __builtin_smul_overflow() supported
349// V8_HAS_BUILTIN_SSUB_OVERFLOW - __builtin_ssub_overflow() supported
350// V8_HAS_BUILTIN_SUB_OVERFLOW - __builtin_sub_overflow() supported
351// V8_HAS_BUILTIN_UADD_OVERFLOW - __builtin_uadd_overflow() supported
352// V8_HAS_COMPUTED_GOTO - computed goto/labels as values
353// supported
354// V8_HAS_DECLSPEC_NOINLINE - __declspec(noinline) supported
355// V8_HAS_DECLSPEC_SELECTANY - __declspec(selectany) supported
356// V8_HAS___FORCEINLINE - __forceinline supported
357//
358// Note that testing for compilers and/or features must be done using #if
359// not #ifdef. For example, to test for Intel C++ Compiler, use:
360// #if V8_CC_INTEL
361// ...
362// #endif
363
364#if defined(__has_cpp_attribute)
365#define V8_HAS_CPP_ATTRIBUTE(FEATURE) __has_cpp_attribute(FEATURE)
366#else
367#define V8_HAS_CPP_ATTRIBUTE(FEATURE) 0
368#endif
369
370#if defined(__clang__)
371
372#if defined(__GNUC__) // Clang in gcc mode.
373# define V8_CC_GNU 1
374#endif
375
376# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE (__has_attribute(always_inline))
377# define V8_HAS_ATTRIBUTE_CONSTINIT \
378 (__has_attribute(require_constant_initialization))
379# define V8_HAS_ATTRIBUTE_CONST (__has_attribute(const))
380# define V8_HAS_ATTRIBUTE_NONNULL (__has_attribute(nonnull))
381# define V8_HAS_ATTRIBUTE_NOINLINE (__has_attribute(noinline))
382# define V8_HAS_ATTRIBUTE_UNUSED (__has_attribute(unused))
383# define V8_HAS_ATTRIBUTE_USED (__has_attribute(used))
384# define V8_HAS_ATTRIBUTE_RETAIN (__has_attribute(retain))
385# define V8_HAS_ATTRIBUTE_OPTNONE (__has_attribute(optnone))
386// Support for the "preserve_most" attribute is limited:
387// - 32-bit platforms do not implement it,
388// - component builds fail because _dl_runtime_resolve clobbers registers,
389// - we see crashes on arm64 on Windows (https://crbug.com/1409934), which can
390// hopefully be fixed in the future.
391// Additionally, the initial implementation in clang <= 16 overwrote the return
392// register(s) in the epilogue of a preserve_most function, so we only use
393// preserve_most in clang >= 17 (see https://reviews.llvm.org/D143425).
394#if (defined(_M_X64) || defined(__x86_64__) /* x64 (everywhere) */ \
395 || ((defined(__AARCH64EL__) || defined(_M_ARM64)) /* arm64, but ... */ \
396 && !defined(_WIN32))) /* not on windows */ \
397 && !defined(COMPONENT_BUILD) /* no component build */\
398 && __clang_major__ >= 17 /* clang >= 17 */
399# define V8_HAS_ATTRIBUTE_PRESERVE_MOST (__has_attribute(preserve_most))
400#endif
401# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
402# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
403 (__has_attribute(warn_unused_result))
404# define V8_HAS_ATTRIBUTE_WEAK (__has_attribute(weak))
405
406# define V8_HAS_CPP_ATTRIBUTE_NODISCARD (V8_HAS_CPP_ATTRIBUTE(nodiscard))
407#if defined(V8_CC_MSVC)
408# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \
409 (V8_HAS_CPP_ATTRIBUTE(msvc::no_unique_address) || \
410 V8_HAS_CPP_ATTRIBUTE(no_unique_address))
411#else
412# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \
413 (V8_HAS_CPP_ATTRIBUTE(no_unique_address))
414#endif
415
416# define V8_HAS_BUILTIN_ADD_OVERFLOW (__has_builtin(__builtin_add_overflow))
417# define V8_HAS_BUILTIN_ASSUME (__has_builtin(__builtin_assume))
418# define V8_HAS_BUILTIN_ASSUME_ALIGNED (__has_builtin(__builtin_assume_aligned))
419# define V8_HAS_BUILTIN_BIT_CAST (__has_builtin(__builtin_bit_cast))
420# define V8_HAS_BUILTIN_BSWAP16 (__has_builtin(__builtin_bswap16))
421# define V8_HAS_BUILTIN_BSWAP32 (__has_builtin(__builtin_bswap32))
422# define V8_HAS_BUILTIN_BSWAP64 (__has_builtin(__builtin_bswap64))
423# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
424# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
425# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
426# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
427# define V8_HAS_BUILTIN_MUL_OVERFLOW (__has_builtin(__builtin_mul_overflow))
428# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
429# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
430# define V8_HAS_BUILTIN_SMUL_OVERFLOW (__has_builtin(__builtin_smul_overflow))
431# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
432# define V8_HAS_BUILTIN_SUB_OVERFLOW (__has_builtin(__builtin_sub_overflow))
433# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
434# define V8_HAS_BUILTIN_UNREACHABLE (__has_builtin(__builtin_unreachable))
435
436// Clang has no __has_feature for computed gotos.
437// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
438# define V8_HAS_COMPUTED_GOTO 1
439
440#elif defined(__GNUC__)
441
442# define V8_CC_GNU 1
443# if defined(__INTEL_COMPILER) // Intel C++ also masquerades as GCC 3.2.0
444# define V8_CC_INTEL 1
445# endif
446# if defined(__MINGW32__)
447# define V8_CC_MINGW32 1
448# endif
449# if defined(__MINGW64__)
450# define V8_CC_MINGW64 1
451# endif
452# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
453
454// FYI: __has_builtin is only available with GCC 10 and later, so explicitly
455// check GCC version numbers to enable features. TODO(leszeks): Merge feature
456// enabling for GCC 10 and later into the Clang section above, and leave this
457// section for GCC 9 and earlier.
458
459// always_inline is available in gcc 4.0 but not very reliable until 4.4.
460// Works around "sorry, unimplemented: inlining failed" build errors with
461// older compilers.
462# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE 1
463# define V8_HAS_ATTRIBUTE_NOINLINE 1
464# define V8_HAS_ATTRIBUTE_UNUSED 1
465# define V8_HAS_ATTRIBUTE_VISIBILITY 1
466# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT (!V8_CC_INTEL)
467# define V8_HAS_ATTRIBUTE_WEAK 1
468
469// [[nodiscard]] does not work together with with
470// __attribute__((visibility(""))) on GCC 7.4 which is why there is no define
471// for V8_HAS_CPP_ATTRIBUTE_NODISCARD. See https://crbug.com/v8/11707.
472
473# define V8_HAS_BUILTIN_ASSUME_ALIGNED 1
474# if __GNUC__ >= 11
475# define V8_HAS_BUILTIN_BIT_CAST 1
476# endif
477# define V8_HAS_BUILTIN_CLZ 1
478# define V8_HAS_BUILTIN_CTZ 1
479# define V8_HAS_BUILTIN_EXPECT 1
480# define V8_HAS_BUILTIN_FRAME_ADDRESS 1
481# define V8_HAS_BUILTIN_POPCOUNT 1
482# define V8_HAS_BUILTIN_UNREACHABLE 1
483
484// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
485#define V8_HAS_COMPUTED_GOTO 1
486
487#endif
488
489#if defined(_MSC_VER)
490# define V8_CC_MSVC 1
491
492# define V8_HAS_DECLSPEC_NOINLINE 1
493# define V8_HAS_DECLSPEC_SELECTANY 1
494
495# define V8_HAS___FORCEINLINE 1
496
497#endif
498
499
500// -----------------------------------------------------------------------------
501// Helper macros
502
503// A macro used to make better inlining. Don't bother for debug builds.
504// Use like:
505// V8_INLINE int GetZero() { return 0; }
506#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
507# define V8_INLINE inline __attribute__((always_inline))
508#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
509# define V8_INLINE __forceinline
510#else
511# define V8_INLINE inline
512#endif
513
514// A macro to force better inlining of calls in a statement. Don't bother for
515// debug builds.
516// Use like:
517// V8_INLINE_STATEMENT foo = bar(); // Will force inlining the bar() call.
518#if !defined(DEBUG) && defined(__clang__) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
519# define V8_INLINE_STATEMENT [[clang::always_inline]]
520#else
521# define V8_INLINE_STATEMENT
522#endif
523
524#if V8_HAS_BUILTIN_ASSUME
525#ifdef DEBUG
526// In debug mode, check assumptions in addition to adding annotations.
527// This helps GCC (and maybe other compilers) figure out that certain
528// situations are unreachable.
529# define V8_ASSUME(condition) \
530 do { \
531 DCHECK(condition); \
532 __builtin_assume(condition); \
533 } while (false)
534#else // DEBUG
535# define V8_ASSUME __builtin_assume
536#endif // DEBUG
537#elif V8_HAS_BUILTIN_UNREACHABLE
538# define V8_ASSUME(condition) \
539 do { \
540 DCHECK(condition); \
541 if (!(condition)) __builtin_unreachable(); \
542 } while (false)
543#else
544# define V8_ASSUME USE
545#endif
546
547// Prefer c++20 std::assume_aligned. Don't use it on MSVC though, because it's
548// not happy with our large 4GB alignment values.
549#if __cplusplus >= 202002L && defined(__cpp_lib_assume_aligned) && !V8_CC_MSVC
550# define V8_ASSUME_ALIGNED(ptr, alignment) \
551 std::assume_aligned<(alignment)>(ptr)
552#elif V8_HAS_BUILTIN_ASSUME_ALIGNED
553# define V8_ASSUME_ALIGNED(ptr, alignment) \
554 __builtin_assume_aligned((ptr), (alignment))
555#else
556# define V8_ASSUME_ALIGNED(ptr, alignment) (ptr)
557#endif
558
559// A macro to mark functions whose values don't change (e.g. across calls)
560// and thereby compiler is free to hoist and fold multiple calls together.
561// Use like:
562// V8_CONST int foo() { ... }
563#if V8_HAS_ATTRIBUTE_CONST
564# define V8_CONST __attribute__((const))
565#else
566# define V8_CONST
567#endif
568
569// A macro to mark a declaration as requiring constant initialization.
570// Use like:
571// int* foo V8_CONSTINIT;
572#if V8_HAS_ATTRIBUTE_CONSTINIT
573# define V8_CONSTINIT __attribute__((require_constant_initialization))
574#else
575# define V8_CONSTINIT
576#endif
577
578
579// A macro to mark specific arguments as non-null.
580// Use like:
581// int add(int* x, int y, int* z) V8_NONNULL(1, 3) { return *x + y + *z; }
582#if V8_HAS_ATTRIBUTE_NONNULL
583# define V8_NONNULL(...) __attribute__((nonnull(__VA_ARGS__)))
584#else
585# define V8_NONNULL(...) /* NOT SUPPORTED */
586#endif
587
588
589// A macro used to tell the compiler to never inline a particular function.
590// Use like:
591// V8_NOINLINE int GetMinusOne() { return -1; }
592#if V8_HAS_ATTRIBUTE_NOINLINE
593# define V8_NOINLINE __attribute__((noinline))
594#elif V8_HAS_DECLSPEC_NOINLINE
595# define V8_NOINLINE __declspec(noinline)
596#else
597# define V8_NOINLINE /* NOT SUPPORTED */
598#endif
599
600
601// A macro used to change the calling conventions to preserve all registers (no
602// caller-saved registers). Use this for cold functions called from hot
603// functions.
604// Use like:
605// V8_NOINLINE V8_PRESERVE_MOST void UnlikelyMethod();
606#if V8_HAS_ATTRIBUTE_PRESERVE_MOST
607# define V8_PRESERVE_MOST __attribute__((preserve_most))
608#else
609# define V8_PRESERVE_MOST /* NOT SUPPORTED */
610#endif
611
612
613// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
614#if defined(V8_DEPRECATION_WARNINGS)
615# define V8_DEPRECATED(message) [[deprecated(message)]]
616#else
617# define V8_DEPRECATED(message)
618#endif
619
620
621// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
622#if defined(V8_IMMINENT_DEPRECATION_WARNINGS)
623# define V8_DEPRECATE_SOON(message) [[deprecated(message)]]
624#else
625# define V8_DEPRECATE_SOON(message)
626#endif
627
628
629#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) || \
630 defined(V8_DEPRECATION_WARNINGS)
631#if defined(V8_CC_MSVC)
632# define START_ALLOW_USE_DEPRECATED() \
633 __pragma(warning(push)) \
634 __pragma(warning(disable : 4996))
635# define END_ALLOW_USE_DEPRECATED() __pragma(warning(pop))
636#else // !defined(V8_CC_MSVC)
637# define START_ALLOW_USE_DEPRECATED() \
638 _Pragma("GCC diagnostic push") \
639 _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
640#define END_ALLOW_USE_DEPRECATED() _Pragma("GCC diagnostic pop")
641#endif // !defined(V8_CC_MSVC)
642#else // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
643 // defined(V8_DEPRECATION_WARNINGS))
644#define START_ALLOW_USE_DEPRECATED()
645#define END_ALLOW_USE_DEPRECATED()
646#endif // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
647 // defined(V8_DEPRECATION_WARNINGS))
648#define ALLOW_COPY_AND_MOVE_WITH_DEPRECATED_FIELDS(ClassName) \
649 START_ALLOW_USE_DEPRECATED() \
650 ClassName(const ClassName&) = default; \
651 ClassName(ClassName&&) = default; \
652 ClassName& operator=(const ClassName&) = default; \
653 ClassName& operator=(ClassName&&) = default; \
654 END_ALLOW_USE_DEPRECATED()
655
656
657#if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 6)
658# define V8_ENUM_DEPRECATED(message)
659# define V8_ENUM_DEPRECATE_SOON(message)
660#else
661# define V8_ENUM_DEPRECATED(message) V8_DEPRECATED(message)
662# define V8_ENUM_DEPRECATE_SOON(message) V8_DEPRECATE_SOON(message)
663#endif
664
665
666// A macro to provide the compiler with branch prediction information.
667#if V8_HAS_BUILTIN_EXPECT
668# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
669# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
670#else
671# define V8_UNLIKELY(condition) (condition)
672# define V8_LIKELY(condition) (condition)
673#endif
674
675
676// Annotate a function indicating the caller must examine the return value.
677// Use like:
678// int foo() V8_WARN_UNUSED_RESULT;
679#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
680#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
681#else
682#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
683#endif
684
685
686// Annotate functions/variables as weak to allow overriding the symbol.
687#if V8_HAS_ATTRIBUTE_WEAK
688#define V8_WEAK __attribute__((weak))
689#else
690#define V8_WEAK /* NOT SUPPORTED */
691#endif
692
693
694// Annotate a class or constructor indicating the caller must assign the
695// constructed instances.
696// Apply to the whole class like:
697// class V8_NODISCARD Foo() { ... };
698// or apply to just one constructor like:
699// V8_NODISCARD Foo() { ... };
700// [[nodiscard]] comes in C++17 but supported in clang with -std >= c++11.
701#if V8_HAS_CPP_ATTRIBUTE_NODISCARD
702#define V8_NODISCARD [[nodiscard]]
703#else
704#define V8_NODISCARD /* NOT SUPPORTED */
705#endif
706
707// The no_unique_address attribute allows tail padding in a non-static data
708// member to overlap other members of the enclosing class (and in the special
709// case when the type is empty, permits it to fully overlap other members). The
710// field is laid out as if a base class were encountered at the corresponding
711// point within the class (except that it does not share a vptr with the
712// enclosing object).
713//
714// Apply to a data member like:
715//
716// class Foo {
717// V8_NO_UNIQUE_ADDRESS Bar bar_;
718// };
719//
720// [[no_unique_address]] comes in C++20 but supported in clang with
721// -std >= c++11.
722#if V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
723#if defined(V8_CC_MSVC) && V8_HAS_CPP_ATTRIBUTE(msvc::no_unique_address)
724// Unfortunately MSVC ignores [[no_unique_address]] (see
725// https://devblogs.microsoft.com/cppblog/msvc-cpp20-and-the-std-cpp20-switch/#msvc-extensions-and-abi),
726// and clang-cl matches it for ABI compatibility reasons. We need to prefer
727// [[msvc::no_unique_address]] when available if we actually want any effect.
728#define V8_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
729#else
730#define V8_NO_UNIQUE_ADDRESS [[no_unique_address]]
731#endif
732#else
733#define V8_NO_UNIQUE_ADDRESS /* NOT SUPPORTED */
734#endif
735
736// Marks a type as being eligible for the "trivial" ABI despite having a
737// non-trivial destructor or copy/move constructor. Such types can be relocated
738// after construction by simply copying their memory, which makes them eligible
739// to be passed in registers. The canonical example is std::unique_ptr.
740//
741// Use with caution; this has some subtle effects on constructor/destructor
742// ordering and will be very incorrect if the type relies on its address
743// remaining constant. When used as a function argument (by value), the value
744// may be constructed in the caller's stack frame, passed in a register, and
745// then used and destructed in the callee's stack frame. A similar thing can
746// occur when values are returned.
747//
748// TRIVIAL_ABI is not needed for types which have a trivial destructor and
749// copy/move constructors, since those are automatically trivial by the ABI
750// spec.
751//
752// It is also not likely to be effective on types too large to be passed in one
753// or two registers on typical target ABIs.
754//
755// See also:
756// https://clang.llvm.org/docs/AttributeReference.html#trivial-abi
757// https://libcxx.llvm.org/docs/DesignDocs/UniquePtrTrivialAbi.html
758#if defined(__clang__) && defined(__has_attribute)
759#if __has_attribute(trivial_abi)
760#define V8_TRIVIAL_ABI [[clang::trivial_abi]]
761#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 1
762#endif // __has_attribute(trivial_abi)
763#endif // defined(__clang__) && defined(__has_attribute)
764#if !defined(V8_TRIVIAL_ABI)
765#define V8_TRIVIAL_ABI
766#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 0
767#endif
768
769// Helper macro to define no_sanitize attributes only with clang.
770#if defined(__clang__) && defined(__has_attribute)
771#if __has_attribute(no_sanitize)
772#define V8_CLANG_NO_SANITIZE(what) __attribute__((no_sanitize(what)))
773#endif
774#endif
775#if !defined(V8_CLANG_NO_SANITIZE)
776#define V8_CLANG_NO_SANITIZE(what)
777#endif
778
779// Exposing private symbols requires exposing public symbols too.
780#ifdef BUILDING_V8_SHARED_PRIVATE
781#define BUILDING_V8_SHARED
782#endif
783
784#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
785#error Inconsistent build configuration: To build the V8 shared library \
786set BUILDING_V8_SHARED, to include its headers for linking against the \
787V8 shared library set USING_V8_SHARED.
788#endif
789
790#ifdef V8_OS_WIN
791
792// Setup for Windows DLL export/import. When building the V8 DLL the
793// BUILDING_V8_SHARED needs to be defined. When building a program which uses
794// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
795// static library or building a program which uses the V8 static library neither
796// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
797#ifdef BUILDING_V8_SHARED
798# define V8_EXPORT __declspec(dllexport)
799#elif USING_V8_SHARED
800# define V8_EXPORT __declspec(dllimport)
801#else
802# define V8_EXPORT
803#endif // BUILDING_V8_SHARED
804
805#else // V8_OS_WIN
806
807// Setup for Linux shared library export.
808#if (V8_HAS_ATTRIBUTE_VISIBILITY && \
809 (defined(BUILDING_V8_SHARED) || USING_V8_SHARED))
810# define V8_EXPORT __attribute__((visibility("default")))
811#else
812# define V8_EXPORT
813# endif // V8_HAS_ATTRIBUTE_VISIBILITY && ...
814
815#endif // V8_OS_WIN
816
817// clang-format on
818
819// Processor architecture detection. For more info on what's defined, see:
820// http://msdn.microsoft.com/en-us/library/b0084kay.aspx
821// http://www.agner.org/optimize/calling_conventions.pdf
822// or with gcc, run: "echo | gcc -E -dM -"
823// The V8_HOST_ARCH_* macros correspond to the architecture on which V8, as a
824// virtual machine and compiler, runs. Don't confuse this with the architecture
825// on which V8 is built.
826#if defined(_M_X64) || defined(__x86_64__)
827#define V8_HOST_ARCH_X64 1
828#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4 // Check for x32.
829#define V8_HOST_ARCH_32_BIT 1
830#else
831#define V8_HOST_ARCH_64_BIT 1
832#endif
833#elif defined(_M_IX86) || defined(__i386__)
834#define V8_HOST_ARCH_IA32 1
835#define V8_HOST_ARCH_32_BIT 1
836#elif defined(__AARCH64EL__) || defined(_M_ARM64)
837#define V8_HOST_ARCH_ARM64 1
838#define V8_HOST_ARCH_64_BIT 1
839#elif defined(__ARMEL__)
840#define V8_HOST_ARCH_ARM 1
841#define V8_HOST_ARCH_32_BIT 1
842#elif defined(__mips64)
843#define V8_HOST_ARCH_MIPS64 1
844#define V8_HOST_ARCH_64_BIT 1
845#elif defined(__loongarch_lp64)
846#define V8_HOST_ARCH_LOONG64 1
847#define V8_HOST_ARCH_64_BIT 1
848#elif defined(__PPC64__) || defined(_ARCH_PPC64)
849#define V8_HOST_ARCH_PPC64 1
850#define V8_HOST_ARCH_64_BIT 1
851#elif defined(__s390x__)
852#define V8_HOST_ARCH_S390X 1
853#define V8_HOST_ARCH_64_BIT 1
854#elif defined(__riscv) || defined(__riscv__)
855#if __riscv_xlen == 64
856#define V8_HOST_ARCH_RISCV64 1
857#define V8_HOST_ARCH_64_BIT 1
858#elif __riscv_xlen == 32
859#define V8_HOST_ARCH_RISCV32 1
860#define V8_HOST_ARCH_32_BIT 1
861#else
862#error "Cannot detect Riscv's bitwidth"
863#endif
864#else
865#error "Host architecture was not detected as supported by v8"
866#endif
867
868// Target architecture detection. This corresponds to the architecture for which
869// V8's JIT will generate code (the last stage of the canadian cross-compiler).
870// The macros may be set externally. If not, detect in the same way as the host
871// architecture, that is, target the native environment as presented by the
872// compiler.
873#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && \
874 !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 && \
875 !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390X && \
876 !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64 && \
877 !V8_TARGET_ARCH_RISCV32
878#if defined(_M_X64) || defined(__x86_64__)
879#define V8_TARGET_ARCH_X64 1
880#elif defined(_M_IX86) || defined(__i386__)
881#define V8_TARGET_ARCH_IA32 1
882#elif defined(__AARCH64EL__) || defined(_M_ARM64)
883#define V8_TARGET_ARCH_ARM64 1
884#elif defined(__ARMEL__)
885#define V8_TARGET_ARCH_ARM 1
886#elif defined(__mips64)
887#define V8_TARGET_ARCH_MIPS64 1
888#elif defined(__loongarch_lp64)
889#define V8_TARGET_ARCH_LOONG64 1
890#elif defined(_ARCH_PPC64)
891#define V8_TARGET_ARCH_PPC64 1
892#elif defined(__s390x__)
893#define V8_TARGET_ARCH_S390X 1
894#elif defined(__riscv) || defined(__riscv__)
895#if __riscv_xlen == 64
896#define V8_TARGET_ARCH_RISCV64 1
897#elif __riscv_xlen == 32
898#define V8_TARGET_ARCH_RISCV32 1
899#endif
900#else
901#error Target architecture was not detected as supported by v8
902#endif
903#endif
904
905// Determine architecture pointer size.
906#if V8_TARGET_ARCH_IA32
907#define V8_TARGET_ARCH_32_BIT 1
908#elif V8_TARGET_ARCH_X64
909#if !V8_TARGET_ARCH_32_BIT && !V8_TARGET_ARCH_64_BIT
910#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4 // Check for x32.
911#define V8_TARGET_ARCH_32_BIT 1
912#else
913#define V8_TARGET_ARCH_64_BIT 1
914#endif
915#endif
916#elif V8_TARGET_ARCH_ARM
917#define V8_TARGET_ARCH_32_BIT 1
918#elif V8_TARGET_ARCH_ARM64
919#define V8_TARGET_ARCH_64_BIT 1
920#elif V8_TARGET_ARCH_MIPS64
921#define V8_TARGET_ARCH_64_BIT 1
922#elif V8_TARGET_ARCH_LOONG64
923#define V8_TARGET_ARCH_64_BIT 1
924#elif V8_TARGET_ARCH_PPC64
925#define V8_TARGET_ARCH_64_BIT 1
926#elif V8_TARGET_ARCH_S390X
927#define V8_TARGET_ARCH_64_BIT 1
928#elif V8_TARGET_ARCH_RISCV64
929#define V8_TARGET_ARCH_64_BIT 1
930#elif V8_TARGET_ARCH_RISCV32
931#define V8_TARGET_ARCH_32_BIT 1
932#else
933#error Unknown target architecture pointer size
934#endif
935
936// Check for supported combinations of host and target architectures.
937#if V8_TARGET_ARCH_IA32 && !V8_HOST_ARCH_IA32
938#error Target architecture ia32 is only supported on ia32 host
939#endif
940#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT && \
941 !((V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64) && V8_HOST_ARCH_64_BIT))
942#error Target architecture x64 is only supported on x64 and arm64 host
943#endif
944#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT && \
945 !(V8_HOST_ARCH_X64 && V8_HOST_ARCH_32_BIT))
946#error Target architecture x32 is only supported on x64 host with x32 support
947#endif
948#if (V8_TARGET_ARCH_ARM && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_ARM))
949#error Target architecture arm is only supported on arm and ia32 host
950#endif
951#if (V8_TARGET_ARCH_ARM64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64))
952#error Target architecture arm64 is only supported on arm64 and x64 host
953#endif
954#if (V8_TARGET_ARCH_MIPS64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_MIPS64))
955#error Target architecture mips64 is only supported on mips64 and x64 host
956#endif
957#if (V8_TARGET_ARCH_RISCV64 && \
958 !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64 || V8_HOST_ARCH_RISCV64))
959#error Target architecture riscv64 is only supported on riscv64, x64, and \
960arm64 host
961#endif
962#if (V8_TARGET_ARCH_RISCV32 && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_RISCV32))
963#error Target architecture riscv32 is only supported on riscv32 and ia32 host
964#endif
965#if (V8_TARGET_ARCH_LOONG64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_LOONG64))
966#error Target architecture loong64 is only supported on loong64 and x64 host
967#endif
968
969// Determine architecture endianness.
970#if V8_TARGET_ARCH_IA32
971#define V8_TARGET_LITTLE_ENDIAN 1
972#elif V8_TARGET_ARCH_X64
973#define V8_TARGET_LITTLE_ENDIAN 1
974#elif V8_TARGET_ARCH_ARM
975#define V8_TARGET_LITTLE_ENDIAN 1
976#elif V8_TARGET_ARCH_ARM64
977#define V8_TARGET_LITTLE_ENDIAN 1
978#elif V8_TARGET_ARCH_LOONG64
979#define V8_TARGET_LITTLE_ENDIAN 1
980#elif V8_TARGET_ARCH_MIPS64
981#if defined(__MIPSEB__) || defined(V8_TARGET_ARCH_MIPS64_BE)
982#define V8_TARGET_BIG_ENDIAN 1
983#else
984#define V8_TARGET_LITTLE_ENDIAN 1
985#endif
986#elif V8_TARGET_ARCH_PPC64
987#if V8_OS_AIX
988#define V8_TARGET_BIG_ENDIAN 1
989#else
990#define V8_TARGET_LITTLE_ENDIAN 1
991#endif
992#elif V8_TARGET_ARCH_S390X
993#if V8_TARGET_ARCH_S390X_LE_SIM
994#define V8_TARGET_LITTLE_ENDIAN 1
995#else
996#define V8_TARGET_BIG_ENDIAN 1
997#endif
998#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
999#define V8_TARGET_LITTLE_ENDIAN 1
1000#elif defined(__BYTE_ORDER__)
1001#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
1002#define V8_TARGET_BIG_ENDIAN 1
1003#else
1004#define V8_TARGET_LITTLE_ENDIAN 1
1005#endif
1006#else
1007#error Unknown target architecture endianness
1008#endif
1009
1010#undef V8_HAS_CPP_ATTRIBUTE
1011
1012#if !defined(V8_STATIC_ROOTS)
1013#define V8_STATIC_ROOTS_BOOL false
1014#else
1015#define V8_STATIC_ROOTS_BOOL true
1016#endif
1017#ifdef V8_TARGET_BIG_ENDIAN
1018#define V8_TARGET_BIG_ENDIAN_BOOL true
1019#else
1020#define V8_TARGET_BIG_ENDIAN_BOOL false
1021#endif
1022
1023#endif // V8CONFIG_H_