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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_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# define V8_HAS_ATTRIBUTE_OPTNONE (__has_attribute(optnone))
375// Support for the "preserve_most" attribute is limited:
376// - 32-bit platforms do not implement it,
377// - component builds fail because _dl_runtime_resolve clobbers registers,
378// - we see crashes on arm64 on Windows (https://crbug.com/1409934), which can
379// hopefully be fixed in the future.
380// Additionally, the initial implementation in clang <= 16 overwrote the return
381// register(s) in the epilogue of a preserve_most function, so we only use
382// preserve_most in clang >= 17 (see https://reviews.llvm.org/D143425).
383#if (defined(_M_X64) || defined(__x86_64__) /* x64 (everywhere) */ \
384 || ((defined(__AARCH64EL__) || defined(_M_ARM64)) /* arm64, but ... */ \
385 && !defined(_WIN32))) /* not on windows */ \
386 && !defined(COMPONENT_BUILD) /* no component build */\
387 && __clang_major__ >= 17 /* clang >= 17 */
388# define V8_HAS_ATTRIBUTE_PRESERVE_MOST (__has_attribute(preserve_most))
389#endif
390# define V8_HAS_ATTRIBUTE_VISIBILITY (__has_attribute(visibility))
391# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT \
392 (__has_attribute(warn_unused_result))
393# define V8_HAS_ATTRIBUTE_WEAK (__has_attribute(weak))
394
395# define V8_HAS_CPP_ATTRIBUTE_NODISCARD (V8_HAS_CPP_ATTRIBUTE(nodiscard))
396#if defined(V8_CC_MSVC)
397# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \
398 (V8_HAS_CPP_ATTRIBUTE(msvc::no_unique_address) || \
399 V8_HAS_CPP_ATTRIBUTE(no_unique_address))
400#else
401# define V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS \
402 (V8_HAS_CPP_ATTRIBUTE(no_unique_address))
403#endif
404
405# define V8_HAS_BUILTIN_ADD_OVERFLOW (__has_builtin(__builtin_add_overflow))
406# define V8_HAS_BUILTIN_ASSUME (__has_builtin(__builtin_assume))
407# define V8_HAS_BUILTIN_ASSUME_ALIGNED (__has_builtin(__builtin_assume_aligned))
408# define V8_HAS_BUILTIN_BIT_CAST (__has_builtin(__builtin_bit_cast))
409# define V8_HAS_BUILTIN_BSWAP16 (__has_builtin(__builtin_bswap16))
410# define V8_HAS_BUILTIN_BSWAP32 (__has_builtin(__builtin_bswap32))
411# define V8_HAS_BUILTIN_BSWAP64 (__has_builtin(__builtin_bswap64))
412# define V8_HAS_BUILTIN_CLZ (__has_builtin(__builtin_clz))
413# define V8_HAS_BUILTIN_CTZ (__has_builtin(__builtin_ctz))
414# define V8_HAS_BUILTIN_EXPECT (__has_builtin(__builtin_expect))
415# define V8_HAS_BUILTIN_FRAME_ADDRESS (__has_builtin(__builtin_frame_address))
416# define V8_HAS_BUILTIN_MUL_OVERFLOW (__has_builtin(__builtin_mul_overflow))
417# define V8_HAS_BUILTIN_POPCOUNT (__has_builtin(__builtin_popcount))
418# define V8_HAS_BUILTIN_SADD_OVERFLOW (__has_builtin(__builtin_sadd_overflow))
419# define V8_HAS_BUILTIN_SMUL_OVERFLOW (__has_builtin(__builtin_smul_overflow))
420# define V8_HAS_BUILTIN_SSUB_OVERFLOW (__has_builtin(__builtin_ssub_overflow))
421# define V8_HAS_BUILTIN_SUB_OVERFLOW (__has_builtin(__builtin_sub_overflow))
422# define V8_HAS_BUILTIN_UADD_OVERFLOW (__has_builtin(__builtin_uadd_overflow))
423# define V8_HAS_BUILTIN_UNREACHABLE (__has_builtin(__builtin_unreachable))
424
425// Clang has no __has_feature for computed gotos.
426// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
427# define V8_HAS_COMPUTED_GOTO 1
428
429#elif defined(__GNUC__)
430
431# define V8_CC_GNU 1
432# if defined(__INTEL_COMPILER) // Intel C++ also masquerades as GCC 3.2.0
433# define V8_CC_INTEL 1
434# endif
435# if defined(__MINGW32__)
436# define V8_CC_MINGW32 1
437# endif
438# if defined(__MINGW64__)
439# define V8_CC_MINGW64 1
440# endif
441# define V8_CC_MINGW (V8_CC_MINGW32 || V8_CC_MINGW64)
442
443// FYI: __has_builtin is only available with GCC 10 and later, so explicitly
444// check GCC version numbers to enable features. TODO(leszeks): Merge feature
445// enabling for GCC 10 and later into the Clang section above, and leave this
446// section for GCC 9 and earlier.
447
448// always_inline is available in gcc 4.0 but not very reliable until 4.4.
449// Works around "sorry, unimplemented: inlining failed" build errors with
450// older compilers.
451# define V8_HAS_ATTRIBUTE_ALWAYS_INLINE 1
452# define V8_HAS_ATTRIBUTE_NOINLINE 1
453# define V8_HAS_ATTRIBUTE_UNUSED 1
454# define V8_HAS_ATTRIBUTE_VISIBILITY 1
455# define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT (!V8_CC_INTEL)
456# define V8_HAS_ATTRIBUTE_WEAK 1
457
458// [[nodiscard]] does not work together with with
459// __attribute__((visibility(""))) on GCC 7.4 which is why there is no define
460// for V8_HAS_CPP_ATTRIBUTE_NODISCARD. See https://crbug.com/v8/11707.
461
462# define V8_HAS_BUILTIN_ASSUME_ALIGNED 1
463# if __GNUC__ >= 11
464# define V8_HAS_BUILTIN_BIT_CAST 1
465# endif
466# define V8_HAS_BUILTIN_CLZ 1
467# define V8_HAS_BUILTIN_CTZ 1
468# define V8_HAS_BUILTIN_EXPECT 1
469# define V8_HAS_BUILTIN_FRAME_ADDRESS 1
470# define V8_HAS_BUILTIN_POPCOUNT 1
471# define V8_HAS_BUILTIN_UNREACHABLE 1
472
473// GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
474#define V8_HAS_COMPUTED_GOTO 1
475
476#endif
477
478#if defined(_MSC_VER)
479# define V8_CC_MSVC 1
480
481# define V8_HAS_DECLSPEC_NOINLINE 1
482# define V8_HAS_DECLSPEC_SELECTANY 1
483
484# define V8_HAS___FORCEINLINE 1
485
486#endif
487
488
489// -----------------------------------------------------------------------------
490// Helper macros
491
492// A macro used to make better inlining. Don't bother for debug builds.
493// Use like:
494// V8_INLINE int GetZero() { return 0; }
495#if !defined(DEBUG) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
496# define V8_INLINE inline __attribute__((always_inline))
497#elif !defined(DEBUG) && V8_HAS___FORCEINLINE
498# define V8_INLINE __forceinline
499#else
500# define V8_INLINE inline
501#endif
502
503// A macro to force better inlining of calls in a statement. Don't bother for
504// debug builds.
505// Use like:
506// V8_INLINE_STATEMENT foo = bar(); // Will force inlining the bar() call.
507#if !defined(DEBUG) && defined(__clang__) && V8_HAS_ATTRIBUTE_ALWAYS_INLINE
508# define V8_INLINE_STATEMENT [[clang::always_inline]]
509#else
510# define V8_INLINE_STATEMENT
511#endif
512
513#if V8_HAS_BUILTIN_ASSUME
514#ifdef DEBUG
515// In debug mode, check assumptions in addition to adding annotations.
516// This helps GCC (and maybe other compilers) figure out that certain
517// situations are unreachable.
518# define V8_ASSUME(condition) \
519 do { \
520 DCHECK(condition); \
521 __builtin_assume(condition); \
522 } while (false)
523#else // DEBUG
524# define V8_ASSUME __builtin_assume
525#endif // DEBUG
526#elif V8_HAS_BUILTIN_UNREACHABLE
527# define V8_ASSUME(condition) \
528 do { \
529 DCHECK(condition); \
530 if (!(condition)) __builtin_unreachable(); \
531 } while (false)
532#else
533# define V8_ASSUME USE
534#endif
535
536// Prefer c++20 std::assume_aligned. Don't use it on MSVC though, because it's
537// not happy with our large 4GB alignment values.
538#if __cplusplus >= 202002L && defined(__cpp_lib_assume_aligned) && !V8_CC_MSVC
539# define V8_ASSUME_ALIGNED(ptr, alignment) \
540 std::assume_aligned<(alignment)>(ptr)
541#elif V8_HAS_BUILTIN_ASSUME_ALIGNED
542# define V8_ASSUME_ALIGNED(ptr, alignment) \
543 __builtin_assume_aligned((ptr), (alignment))
544#else
545# define V8_ASSUME_ALIGNED(ptr, alignment) (ptr)
546#endif
547
548// A macro to mark functions whose values don't change (e.g. across calls)
549// and thereby compiler is free to hoist and fold multiple calls together.
550// Use like:
551// V8_CONST int foo() { ... }
552#if V8_HAS_ATTRIBUTE_CONST
553# define V8_CONST __attribute__((const))
554#else
555# define V8_CONST
556#endif
557
558// A macro to mark a declaration as requiring constant initialization.
559// Use like:
560// int* foo V8_CONSTINIT;
561#if V8_HAS_ATTRIBUTE_CONSTINIT
562# define V8_CONSTINIT __attribute__((require_constant_initialization))
563#else
564# define V8_CONSTINIT
565#endif
566
567
568// A macro to mark specific arguments as non-null.
569// Use like:
570// int add(int* x, int y, int* z) V8_NONNULL(1, 3) { return *x + y + *z; }
571#if V8_HAS_ATTRIBUTE_NONNULL
572# define V8_NONNULL(...) __attribute__((nonnull(__VA_ARGS__)))
573#else
574# define V8_NONNULL(...) /* NOT SUPPORTED */
575#endif
576
577
578// A macro used to tell the compiler to never inline a particular function.
579// Use like:
580// V8_NOINLINE int GetMinusOne() { return -1; }
581#if V8_HAS_ATTRIBUTE_NOINLINE
582# define V8_NOINLINE __attribute__((noinline))
583#elif V8_HAS_DECLSPEC_NOINLINE
584# define V8_NOINLINE __declspec(noinline)
585#else
586# define V8_NOINLINE /* NOT SUPPORTED */
587#endif
588
589
590// A macro used to change the calling conventions to preserve all registers (no
591// caller-saved registers). Use this for cold functions called from hot
592// functions.
593// Use like:
594// V8_NOINLINE V8_PRESERVE_MOST void UnlikelyMethod();
595#if V8_HAS_ATTRIBUTE_PRESERVE_MOST
596# define V8_PRESERVE_MOST __attribute__((preserve_most))
597#else
598# define V8_PRESERVE_MOST /* NOT SUPPORTED */
599#endif
600
601
602// A macro (V8_DEPRECATED) to mark classes or functions as deprecated.
603#if defined(V8_DEPRECATION_WARNINGS)
604# define V8_DEPRECATED(message) [[deprecated(message)]]
605#else
606# define V8_DEPRECATED(message)
607#endif
608
609
610// A macro (V8_DEPRECATE_SOON) to make it easier to see what will be deprecated.
611#if defined(V8_IMMINENT_DEPRECATION_WARNINGS)
612# define V8_DEPRECATE_SOON(message) [[deprecated(message)]]
613#else
614# define V8_DEPRECATE_SOON(message)
615#endif
616
617
618#if defined(V8_IMMINENT_DEPRECATION_WARNINGS) || \
619 defined(V8_DEPRECATION_WARNINGS)
620#if defined(V8_CC_MSVC)
621# define START_ALLOW_USE_DEPRECATED() \
622 __pragma(warning(push)) \
623 __pragma(warning(disable : 4996))
624# define END_ALLOW_USE_DEPRECATED() __pragma(warning(pop))
625#else // !defined(V8_CC_MSVC)
626# define START_ALLOW_USE_DEPRECATED() \
627 _Pragma("GCC diagnostic push") \
628 _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
629#define END_ALLOW_USE_DEPRECATED() _Pragma("GCC diagnostic pop")
630#endif // !defined(V8_CC_MSVC)
631#else // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
632 // defined(V8_DEPRECATION_WARNINGS))
633#define START_ALLOW_USE_DEPRECATED()
634#define END_ALLOW_USE_DEPRECATED()
635#endif // !(defined(V8_IMMINENT_DEPRECATION_WARNINGS) ||
636 // defined(V8_DEPRECATION_WARNINGS))
637#define ALLOW_COPY_AND_MOVE_WITH_DEPRECATED_FIELDS(ClassName) \
638 START_ALLOW_USE_DEPRECATED() \
639 ClassName(const ClassName&) = default; \
640 ClassName(ClassName&&) = default; \
641 ClassName& operator=(const ClassName&) = default; \
642 ClassName& operator=(ClassName&&) = default; \
643 END_ALLOW_USE_DEPRECATED()
644
645
646#if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 6)
647# define V8_ENUM_DEPRECATED(message)
648# define V8_ENUM_DEPRECATE_SOON(message)
649#else
650# define V8_ENUM_DEPRECATED(message) V8_DEPRECATED(message)
651# define V8_ENUM_DEPRECATE_SOON(message) V8_DEPRECATE_SOON(message)
652#endif
653
654
655// A macro to provide the compiler with branch prediction information.
656#if V8_HAS_BUILTIN_EXPECT
657# define V8_UNLIKELY(condition) (__builtin_expect(!!(condition), 0))
658# define V8_LIKELY(condition) (__builtin_expect(!!(condition), 1))
659#else
660# define V8_UNLIKELY(condition) (condition)
661# define V8_LIKELY(condition) (condition)
662#endif
663
664
665// Annotate a function indicating the caller must examine the return value.
666// Use like:
667// int foo() V8_WARN_UNUSED_RESULT;
668#if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
669#define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
670#else
671#define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
672#endif
673
674
675// Annotate functions/variables as weak to allow overriding the symbol.
676#if V8_HAS_ATTRIBUTE_WEAK
677#define V8_WEAK __attribute__((weak))
678#else
679#define V8_WEAK /* NOT SUPPORTED */
680#endif
681
682
683// Annotate a class or constructor indicating the caller must assign the
684// constructed instances.
685// Apply to the whole class like:
686// class V8_NODISCARD Foo() { ... };
687// or apply to just one constructor like:
688// V8_NODISCARD Foo() { ... };
689// [[nodiscard]] comes in C++17 but supported in clang with -std >= c++11.
690#if V8_HAS_CPP_ATTRIBUTE_NODISCARD
691#define V8_NODISCARD [[nodiscard]]
692#else
693#define V8_NODISCARD /* NOT SUPPORTED */
694#endif
695
696// The no_unique_address attribute allows tail padding in a non-static data
697// member to overlap other members of the enclosing class (and in the special
698// case when the type is empty, permits it to fully overlap other members). The
699// field is laid out as if a base class were encountered at the corresponding
700// point within the class (except that it does not share a vptr with the
701// enclosing object).
702//
703// Apply to a data member like:
704//
705// class Foo {
706// V8_NO_UNIQUE_ADDRESS Bar bar_;
707// };
708//
709// [[no_unique_address]] comes in C++20 but supported in clang with
710// -std >= c++11.
711#if V8_HAS_CPP_ATTRIBUTE_NO_UNIQUE_ADDRESS
712#if defined(V8_CC_MSVC) && V8_HAS_CPP_ATTRIBUTE(msvc::no_unique_address)
713// Unfortunately MSVC ignores [[no_unique_address]] (see
714// https://devblogs.microsoft.com/cppblog/msvc-cpp20-and-the-std-cpp20-switch/#msvc-extensions-and-abi),
715// and clang-cl matches it for ABI compatibility reasons. We need to prefer
716// [[msvc::no_unique_address]] when available if we actually want any effect.
717#define V8_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
718#else
719#define V8_NO_UNIQUE_ADDRESS [[no_unique_address]]
720#endif
721#else
722#define V8_NO_UNIQUE_ADDRESS /* NOT SUPPORTED */
723#endif
724
725// Marks a type as being eligible for the "trivial" ABI despite having a
726// non-trivial destructor or copy/move constructor. Such types can be relocated
727// after construction by simply copying their memory, which makes them eligible
728// to be passed in registers. The canonical example is std::unique_ptr.
729//
730// Use with caution; this has some subtle effects on constructor/destructor
731// ordering and will be very incorrect if the type relies on its address
732// remaining constant. When used as a function argument (by value), the value
733// may be constructed in the caller's stack frame, passed in a register, and
734// then used and destructed in the callee's stack frame. A similar thing can
735// occur when values are returned.
736//
737// TRIVIAL_ABI is not needed for types which have a trivial destructor and
738// copy/move constructors, since those are automatically trivial by the ABI
739// spec.
740//
741// It is also not likely to be effective on types too large to be passed in one
742// or two registers on typical target ABIs.
743//
744// See also:
745// https://clang.llvm.org/docs/AttributeReference.html#trivial-abi
746// https://libcxx.llvm.org/docs/DesignDocs/UniquePtrTrivialAbi.html
747#if defined(__clang__) && defined(__has_attribute)
748#if __has_attribute(trivial_abi)
749#define V8_TRIVIAL_ABI [[clang::trivial_abi]]
750#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 1
751#endif // __has_attribute(trivial_abi)
752#endif // defined(__clang__) && defined(__has_attribute)
753#if !defined(V8_TRIVIAL_ABI)
754#define V8_TRIVIAL_ABI
755#define V8_HAS_ATTRIBUTE_TRIVIAL_ABI 0
756#endif
757
758// Helper macro to define no_sanitize attributes only with clang.
759#if defined(__clang__) && defined(__has_attribute)
760#if __has_attribute(no_sanitize)
761#define V8_CLANG_NO_SANITIZE(what) __attribute__((no_sanitize(what)))
762#endif
763#endif
764#if !defined(V8_CLANG_NO_SANITIZE)
765#define V8_CLANG_NO_SANITIZE(what)
766#endif
767
768// Exposing private symbols requires exposing public symbols too.
769#ifdef BUILDING_V8_SHARED_PRIVATE
770#define BUILDING_V8_SHARED
771#endif
772
773#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
774#error Inconsistent build configuration: To build the V8 shared library \
775set BUILDING_V8_SHARED, to include its headers for linking against the \
776V8 shared library set USING_V8_SHARED.
777#endif
778
779#ifdef V8_OS_WIN
780
781// Setup for Windows DLL export/import. When building the V8 DLL the
782// BUILDING_V8_SHARED needs to be defined. When building a program which uses
783// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
784// static library or building a program which uses the V8 static library neither
785// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
786#ifdef BUILDING_V8_SHARED
787# define V8_EXPORT __declspec(dllexport)
788#elif USING_V8_SHARED
789# define V8_EXPORT __declspec(dllimport)
790#else
791# define V8_EXPORT
792#endif // BUILDING_V8_SHARED
793
794#else // V8_OS_WIN
795
796// Setup for Linux shared library export.
797#if V8_HAS_ATTRIBUTE_VISIBILITY && (defined(BUILDING_V8_SHARED) || USING_V8_SHARED)
798# define V8_EXPORT __attribute__((visibility("default")))
799#else
800# define V8_EXPORT
801# endif // V8_HAS_ATTRIBUTE_VISIBILITY && ...
802
803#endif // V8_OS_WIN
804
805// clang-format on
806
807// Processor architecture detection. For more info on what's defined, see:
808// http://msdn.microsoft.com/en-us/library/b0084kay.aspx
809// http://www.agner.org/optimize/calling_conventions.pdf
810// or with gcc, run: "echo | gcc -E -dM -"
811// The V8_HOST_ARCH_* macros correspond to the architecture on which V8, as a
812// virtual machine and compiler, runs. Don't confuse this with the architecture
813// on which V8 is built.
814#if defined(_M_X64) || defined(__x86_64__)
815#define V8_HOST_ARCH_X64 1
816#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4 // Check for x32.
817#define V8_HOST_ARCH_32_BIT 1
818#else
819#define V8_HOST_ARCH_64_BIT 1
820#endif
821#elif defined(_M_IX86) || defined(__i386__)
822#define V8_HOST_ARCH_IA32 1
823#define V8_HOST_ARCH_32_BIT 1
824#elif defined(__AARCH64EL__) || defined(_M_ARM64)
825#define V8_HOST_ARCH_ARM64 1
826#define V8_HOST_ARCH_64_BIT 1
827#elif defined(__ARMEL__)
828#define V8_HOST_ARCH_ARM 1
829#define V8_HOST_ARCH_32_BIT 1
830#elif defined(__mips64)
831#define V8_HOST_ARCH_MIPS64 1
832#define V8_HOST_ARCH_64_BIT 1
833#elif defined(__loongarch_lp64)
834#define V8_HOST_ARCH_LOONG64 1
835#define V8_HOST_ARCH_64_BIT 1
836#elif defined(__PPC64__) || defined(_ARCH_PPC64)
837#define V8_HOST_ARCH_PPC64 1
838#define V8_HOST_ARCH_64_BIT 1
839#elif defined(__s390x__)
840#define V8_HOST_ARCH_S390X 1
841#define V8_HOST_ARCH_64_BIT 1
842#elif defined(__riscv) || defined(__riscv__)
843#if __riscv_xlen == 64
844#define V8_HOST_ARCH_RISCV64 1
845#define V8_HOST_ARCH_64_BIT 1
846#elif __riscv_xlen == 32
847#define V8_HOST_ARCH_RISCV32 1
848#define V8_HOST_ARCH_32_BIT 1
849#else
850#error "Cannot detect Riscv's bitwidth"
851#endif
852#else
853#error "Host architecture was not detected as supported by v8"
854#endif
855
856// Target architecture detection. This corresponds to the architecture for which
857// V8's JIT will generate code (the last stage of the canadian cross-compiler).
858// The macros may be set externally. If not, detect in the same way as the host
859// architecture, that is, target the native environment as presented by the
860// compiler.
861#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && \
862 !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 && \
863 !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390X && \
864 !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64 && \
865 !V8_TARGET_ARCH_RISCV32
866#if defined(_M_X64) || defined(__x86_64__)
867#define V8_TARGET_ARCH_X64 1
868#elif defined(_M_IX86) || defined(__i386__)
869#define V8_TARGET_ARCH_IA32 1
870#elif defined(__AARCH64EL__) || defined(_M_ARM64)
871#define V8_TARGET_ARCH_ARM64 1
872#elif defined(__ARMEL__)
873#define V8_TARGET_ARCH_ARM 1
874#elif defined(__mips64)
875#define V8_TARGET_ARCH_MIPS64 1
876#elif defined(__loongarch_lp64)
877#define V8_TARGET_ARCH_LOONG64 1
878#elif defined(_ARCH_PPC64)
879#define V8_TARGET_ARCH_PPC64 1
880#elif defined(__s390x__)
881#define V8_TARGET_ARCH_S390X 1
882#elif defined(__riscv) || defined(__riscv__)
883#if __riscv_xlen == 64
884#define V8_TARGET_ARCH_RISCV64 1
885#elif __riscv_xlen == 32
886#define V8_TARGET_ARCH_RISCV32 1
887#endif
888#else
889#error Target architecture was not detected as supported by v8
890#endif
891#endif
892
893// Determine architecture pointer size.
894#if V8_TARGET_ARCH_IA32
895#define V8_TARGET_ARCH_32_BIT 1
896#elif V8_TARGET_ARCH_X64
897#if !V8_TARGET_ARCH_32_BIT && !V8_TARGET_ARCH_64_BIT
898#if defined(__x86_64__) && __SIZEOF_POINTER__ == 4 // Check for x32.
899#define V8_TARGET_ARCH_32_BIT 1
900#else
901#define V8_TARGET_ARCH_64_BIT 1
902#endif
903#endif
904#elif V8_TARGET_ARCH_ARM
905#define V8_TARGET_ARCH_32_BIT 1
906#elif V8_TARGET_ARCH_ARM64
907#define V8_TARGET_ARCH_64_BIT 1
908#elif V8_TARGET_ARCH_MIPS
909#define V8_TARGET_ARCH_32_BIT 1
910#elif V8_TARGET_ARCH_MIPS64
911#define V8_TARGET_ARCH_64_BIT 1
912#elif V8_TARGET_ARCH_LOONG64
913#define V8_TARGET_ARCH_64_BIT 1
914#elif V8_TARGET_ARCH_PPC64
915#define V8_TARGET_ARCH_64_BIT 1
916#elif V8_TARGET_ARCH_S390X
917#define V8_TARGET_ARCH_64_BIT 1
918#elif V8_TARGET_ARCH_RISCV64
919#define V8_TARGET_ARCH_64_BIT 1
920#elif V8_TARGET_ARCH_RISCV32
921#define V8_TARGET_ARCH_32_BIT 1
922#else
923#error Unknown target architecture pointer size
924#endif
925
926// Check for supported combinations of host and target architectures.
927#if V8_TARGET_ARCH_IA32 && !V8_HOST_ARCH_IA32
928#error Target architecture ia32 is only supported on ia32 host
929#endif
930#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_64_BIT && \
931 !((V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64) && V8_HOST_ARCH_64_BIT))
932#error Target architecture x64 is only supported on x64 and arm64 host
933#endif
934#if (V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT && \
935 !(V8_HOST_ARCH_X64 && V8_HOST_ARCH_32_BIT))
936#error Target architecture x32 is only supported on x64 host with x32 support
937#endif
938#if (V8_TARGET_ARCH_ARM && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_ARM))
939#error Target architecture arm is only supported on arm and ia32 host
940#endif
941#if (V8_TARGET_ARCH_ARM64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_ARM64))
942#error Target architecture arm64 is only supported on arm64 and x64 host
943#endif
944#if (V8_TARGET_ARCH_MIPS64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_MIPS64))
945#error Target architecture mips64 is only supported on mips64 and x64 host
946#endif
947#if (V8_TARGET_ARCH_RISCV64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_RISCV64))
948#error Target architecture riscv64 is only supported on riscv64 and x64 host
949#endif
950#if (V8_TARGET_ARCH_RISCV32 && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_RISCV32))
951#error Target architecture riscv32 is only supported on riscv32 and ia32 host
952#endif
953#if (V8_TARGET_ARCH_LOONG64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_LOONG64))
954#error Target architecture loong64 is only supported on loong64 and x64 host
955#endif
956
957// Determine architecture endianness.
958#if V8_TARGET_ARCH_IA32
959#define V8_TARGET_LITTLE_ENDIAN 1
960#elif V8_TARGET_ARCH_X64
961#define V8_TARGET_LITTLE_ENDIAN 1
962#elif V8_TARGET_ARCH_ARM
963#define V8_TARGET_LITTLE_ENDIAN 1
964#elif V8_TARGET_ARCH_ARM64
965#define V8_TARGET_LITTLE_ENDIAN 1
966#elif V8_TARGET_ARCH_LOONG64
967#define V8_TARGET_LITTLE_ENDIAN 1
968#elif V8_TARGET_ARCH_MIPS64
969#if defined(__MIPSEB__) || defined(V8_TARGET_ARCH_MIPS64_BE)
970#define V8_TARGET_BIG_ENDIAN 1
971#else
972#define V8_TARGET_LITTLE_ENDIAN 1
973#endif
974#elif V8_TARGET_ARCH_PPC64
975#if V8_OS_AIX
976#define V8_TARGET_BIG_ENDIAN 1
977#else
978#define V8_TARGET_LITTLE_ENDIAN 1
979#endif
980#elif V8_TARGET_ARCH_S390X
981#if V8_TARGET_ARCH_S390X_LE_SIM
982#define V8_TARGET_LITTLE_ENDIAN 1
983#else
984#define V8_TARGET_BIG_ENDIAN 1
985#endif
986#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
987#define V8_TARGET_LITTLE_ENDIAN 1
988#elif defined(__BYTE_ORDER__)
989#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
990#define V8_TARGET_BIG_ENDIAN 1
991#else
992#define V8_TARGET_LITTLE_ENDIAN 1
993#endif
994#else
995#error Unknown target architecture endianness
996#endif
997
998#undef V8_HAS_CPP_ATTRIBUTE
999
1000#if !defined(V8_STATIC_ROOTS)
1001#define V8_STATIC_ROOTS_BOOL false
1002#else
1003#define V8_STATIC_ROOTS_BOOL true
1004#endif
1005#ifdef V8_TARGET_BIG_ENDIAN
1006#define V8_TARGET_BIG_ENDIAN_BOOL true
1007#else
1008#define V8_TARGET_BIG_ENDIAN_BOOL false
1009#endif
1010
1011#endif // V8CONFIG_H_