Those are not safe in combination with the sandbox as they are stored as
raw pointers. Instead of turning them into ExternalPointers (which use
the ExternalPointerTable indirection), this CL simply turns them into
on-heap ByteArrays which is cheaper and should be unproblematic
security-wise as their contents can be corrupted without causing memory
corruption outside the sandbox address space (just incorrect behaviour
and/or further memory corruption *inside* the sandbox, which is fine).
Bug: chromium:1335046
Change-Id: Id2b901a58b7d6c91dd7596fca553d7c76cbc61ec
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3845636
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82765}
This is a reland of commit 491de34bcc
co-authors: Ji Qiu <qiuji@iscas.ac.cn>
Alvise De Faveri Tron <elvisilde@gmail.com>
Usman Zain <uszain@gmail.com>
Zheng Quan <vitalyankh@gmail.com>
Original change's description:
> [riscv32] Add RISCV32 backend
>
> This very large changeset adds support for RISCV32.
>
> Bug: v8:13025
> Change-Id: Ieacc857131e6620f0fcfd7daa88a0f8d77056aa9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3736732
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
> Reviewed-by: ji qiu <qiuji@iscas.ac.cn>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#82053}
Bug: v8:13025
Change-Id: I220fae4b8e2679bdc111724e08817b079b373bd5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3807124
Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: ji qiu <qiuji@iscas.ac.cn>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82198}
This very large changeset adds support for RISCV32.
Bug: v8:13025
Change-Id: Ieacc857131e6620f0fcfd7daa88a0f8d77056aa9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3736732
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
Reviewed-by: ji qiu <qiuji@iscas.ac.cn>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82053}
The implicit copy constructor triggers a deprecation warning if the
struct contains a deprecated field. We can fix this by explicitly
declaring the copy and move constructors and assignment operators
with the deprecation warning disabled.
This CL also adds a test to check that we can indeed call the
constructors and assignment operators, which did not work before.
R=leszeks@chromium.org
Bug: v8:13092
Change-Id: Ia63ff9375de13fc6e5b5a8d59d827a742c99fb39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3785145
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81962}
Provide a V8_ASSUME implementation for GCC which has the same effect as
using __builtin_assume on clang.
R=cbruni@chromium.org
Change-Id: Ia6ab56995d9ecac1015eab8bacc7e3115da7004f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3779691
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81901}
The stack offsets of cache slots are always positive, but the compiler
does not know that. The lack of this knowledge makes division by the
system pointer size significantly more expensive.
One solution would be to rewrite the division to be an actual right
shift. Another solution is to teach the compiler that offsets are
positive. This CL does the latter.
This reduces the overall Liftoff compile time of the reproducer in the
linked issue by nearly 25%.
R=jkummerow@chromium.org, cbruni@chromium.org
Bug: v8:13063
Change-Id: Ib55b35d407e9909c792ae095a6767aaa03faebdc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3760453
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81778}
This patch fixes machine detection on nodejs where the build
pipeline may not use gn and as a result certain macros
will not get set.
More details can be found in this comment:
https://github.com/nodejs/node-v8/issues/223#issuecomment-1180505313
Change-Id: I0cbfc736b28bc130acbdc2cf2e27bbf687be463c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3757944
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#81667}
Since v8config.h already defines the related logic for OS detection, it
should be fine to move arch detection also there. The CL also makes
Oilpan use one of those macros to avoid discrepancy between the compiler
and custom macros (the discrepancy occurs for host tools, e.g. mksnapshot).
Bug: chromium:1336222
Change-Id: Ibe7d9116d27c3e816f4778fd4c149d8142d0f7a9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3726208
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81397}
This is more consistent with similar features, for example
V8_ENABLE_WEBASSEMBLY or V8_ENABLE_MAGLEV.
Drive-by: remove V8_SANDBOX_IS_AVAILABLE as it's no longer needed.
Bug: v8:10391
Change-Id: I8658c5b0c331a4c73892737083b2c2f9b8f84056
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3647355
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Auto-Submit: Samuel Groß <saelo@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80530}
Previously, V8_OS_MACOSX was, somewhat confusingly, also used for iOS.
With this CL, V8_OS_DARWIN will be set on both macOS and iOS,
V8_OS_MACOS only on macOS, and V8_OS_IOS only on iOS.
This CL also renames V8_TARGET_OS_MACOSX to V8_TARGET_OS_MACOS and
renames platform-xnu.cc to platform-darwin.cc.
Change-Id: I4bcafc7c337586662114144f6c7ccf47d978da1f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3468577
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79167}
The external pointer table is now managed by the GC, which marks entries
that are alive during major GC, then sweeps the table afterwards to free
all dead entries and build a free list from them. For now, only major GCs
are supported, Scavenger GCs do not interact with the external pointer table.
In more detail, garbage collection of the external pointer table works
as follows:
1. The external pointer table now reserves a large region of virtual
address space for its backing buffer and is then never reallocated,
only grown in place until the maximum size is reached.
2. When the GC's marking visitor marks a HeapObject with an external
pointer as alive, it also marks the corresponding external pointer
table entry as alive. This can happen on a background thread.
3. For that, it uses the MSB of each entry in the table to indicate
whether the entry has been marked or not. This works because the MSB
is always cleared during the AND-based type check performed when
accessing an external pointer.
4. After marking, the external pointer table is swept while the mutator
is stopped. This builds an inline, singly-linked freelist of all
newly-dead and previously-free entries.
5. When allocating an entry from the table, the first entry on the
freelist is used. If the freelist is empty, the table grows,
populating the freelist with the new entries.
6. Every newly-allocated entry is marked as alive, and every store to an
existing entry also automatically marks that entry as alive (by also
setting the MSB). This simplifies the design of the table GC with
regards to concurrency (See ExternalPointerTable::Mark).
Bug: v8:10391
Change-Id: I8877fdf5576af3761bde65298951bb09e601bd14
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3359625
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78708}
This CL renames a number of things related to the V8 sandbox.
Mainly, what used to be under V8_HEAP_SANDBOX is now under
V8_SANDBOXED_EXTERNAL_POINTERS, while the previous V8 VirtualMemoryCage
is now simply the V8 Sandbox:
V8_VIRTUAL_MEMORY_CAGE => V8_SANDBOX
V8_HEAP_SANDBOX => V8_SANDBOXED_EXTERNAL_POINTERS
V8_CAGED_POINTERS => V8_SANDBOXED_POINTERS
V8VirtualMemoryCage => Sandbox
CagedPointer => SandboxedPointer
fake cage => partially reserved sandbox
src/security => src/sandbox
This naming scheme should simplify things: the sandbox is now the large
region of virtual address space inside which V8 mainly operates and
which should be considered untrusted. Mechanisms like sandboxed pointers
are then used to attempt to prevent escapes from the sandbox (i.e.
corruption of memory outside of it). Furthermore, the new naming scheme
avoids the confusion with the various other "cages" in V8, in
particular, the VirtualMemoryCage class, by dropping that name entirely.
Future sandbox features are developed under their own V8_SANDBOX_X flag,
and will, once final, be merged into V8_SANDBOX. Current future features
are sandboxed external pointers (using the external pointer table), and
sandboxed pointers (pointers guaranteed to point into the sandbox, e.g.
because they are encoded as offsets). This CL then also introduces a new
build flag, v8_enable_sandbox_future, which enables all future features.
Bug: v8:10391
Change-Id: I5174ea8f5ab40fb96a04af10853da735ad775c96
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3322981
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78384}
It's deprecated in C++17 and not needed (it was needed for static const,
but not for constexpr). It's needed in C++14, but can trigger
deprecation errors in C++17, so include it conditionally on __cplusplus.
Bug: chromium:1274247
Change-Id: I92524f377bb92ac2aa008f15830920786a1c1432
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3308795
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78157}
This reverts commit d7c3f1cd8a.
Reason for revert: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Android%20Arm64%20-%20debug%20builder/22043/overview
Original change's description:
> Reland "[fastcall] Enable float support on arm64 simulator"
>
> This is a reland of b9ddcbc86f
>
> The original CL was reverted due to an MSAN issue, that is fixed by
> moving the signature mapping onto the Isolate (instead of having
> per-thread storage, which got invalid on multithreaded compilation).
>
> This CL also contains fixes for the Bazel config and for a data race
> when obtaining the PerIsolateSimulatorData.
>
> Original change's description:
> > [fastcall] Enable float support on arm64 simulator
> >
> > This CL adds support for handling calls to C functions with arbitrary
> > signatures on the arm64 simulator. It adds infrastructure for
> > encoding the signature data from CallDescriptor and FunctionInfo
> > classes into a compact representation, stored in the simulator and
> > called EncodedCSignature.
> >
> > Design doc:
> > https://docs.google.com/document/d/1ZxOF3GSyNmtU0C0YJvrsydPJj35W_tTJZymeXwfDxoI/edit
> >
> > This CL is a follow up on the native support added in
> > https://chromium-review.googlesource.com/c/v8/v8/+/3182232
> > and is partially based on the previous attempt:
> > https://chromium-review.googlesource.com/c/v8/v8/+/2343072
> >
> > Bug: chromium:1052746
> > Change-Id: I0991b47bd644b2fc2244c5eb923b085261f04765
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3060486
> > Commit-Queue: Maya Lekova <mslekova@chromium.org>
> > Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> > Cr-Commit-Position: refs/heads/main@{#77744}
>
> Bug: chromium:1052746, chromium:1267854
> Change-Id: I89bbd01e33fb1080543d98bcfd4c2d17b5c76861
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3270541
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Commit-Queue: Maya Lekova <mslekova@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#78018}
Bug: chromium:1052746, chromium:1267854
Change-Id: Ia8f10d085d13990b331f306957f95ecf3e003cfd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3295453
Owners-Override: Nico Hartmann <nicohartmann@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78019}
This is a reland of b9ddcbc86f
The original CL was reverted due to an MSAN issue, that is fixed by
moving the signature mapping onto the Isolate (instead of having
per-thread storage, which got invalid on multithreaded compilation).
This CL also contains fixes for the Bazel config and for a data race
when obtaining the PerIsolateSimulatorData.
Original change's description:
> [fastcall] Enable float support on arm64 simulator
>
> This CL adds support for handling calls to C functions with arbitrary
> signatures on the arm64 simulator. It adds infrastructure for
> encoding the signature data from CallDescriptor and FunctionInfo
> classes into a compact representation, stored in the simulator and
> called EncodedCSignature.
>
> Design doc:
> https://docs.google.com/document/d/1ZxOF3GSyNmtU0C0YJvrsydPJj35W_tTJZymeXwfDxoI/edit
>
> This CL is a follow up on the native support added in
> https://chromium-review.googlesource.com/c/v8/v8/+/3182232
> and is partially based on the previous attempt:
> https://chromium-review.googlesource.com/c/v8/v8/+/2343072
>
> Bug: chromium:1052746
> Change-Id: I0991b47bd644b2fc2244c5eb923b085261f04765
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3060486
> Commit-Queue: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Camillo Bruni <cbruni@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#77744}
Bug: chromium:1052746, chromium:1267854
Change-Id: I89bbd01e33fb1080543d98bcfd4c2d17b5c76861
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3270541
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78018}
This CL adds an Allocator to SmallVector to control how dynamic
storage is managed. The default value uses the plain old C++
std::allocator<T>, i.e. acts like malloc/free.
For use with zone memory, one can pass a ZoneAllocator as follows:
// Allocates in zone memory.
base::SmallVector<int, kInitialSize, ZoneAllocator<int>>
xs(ZoneAllocator<int>(zone));
Note: this is a follow-up to crrev.com/c/3240823.
Drive-by: hide the internal `reset` function. It doesn't free the
dynamic backing store; that's a surprise and should not be exposed to
external use.
Change-Id: I1f92f184924541e2269493fb52c30f2fdec032be
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3257711
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77755}
A CagedPointer is guaranteed to point into the Virtual Memory Cage and
will for example be used for ArrayBuffer backing stores when the heap
sandbox is enabled. In the current implementation, CagedPointers are
stored as offsets from the cage base, shifted to the left. Because the
cage base address is usually available in a register, accessing a
CagedPointer is very efficient, requiring only an additional shift and
add operation.
Bug: chromium:1218005
Change-Id: Ifc8c088e3862400672051a8c52840514dee2911f
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3123417
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77614}
This is a reland of 1ea76c1397
Disabled the failing test on Fuchsia until its PageAllocator
respects allocation hints.
Original change's description:
> Implement a fake virtual memory cage mechanism
>
> On operating systems where reserving virtual address space is expensive,
> notably Windows pre 8.1, it is not possible to create a proper virtual
> memory cage. In order to still be able to reference caged objects
> through offsets from the cage base on these systems, this CL introduces
> a fake cage mechanism. When the fake cage is used, most of the virtual
> memory for the cage is not actually reserved. Instead, the cage's page
> allocator simply relies on hints to the OS to obtain pages inside the
> cage. This does, however, not provide the same security benefits as a
> real cage as unrelated allocations might end up inside the cage.
>
> Bug: chromium:1218005
> Change-Id: Ie5314be23966ed0042a017917b63595481b5e7e3
> Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3217200
> Commit-Queue: Samuel Groß <saelo@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#77367}
Bug: chromium:1218005
Change-Id: I2ed95d121db164679c38085115e8fa92690c057e
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3220151
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77378}
This reverts commit 1ea76c1397.
Reason for revert: The unit test added fails on the Fuchsia bot https://ci.chromium.org/p/v8/builders/ci/V8%20Fuchsia/25976?
Original change's description:
> Implement a fake virtual memory cage mechanism
>
> On operating systems where reserving virtual address space is expensive,
> notably Windows pre 8.1, it is not possible to create a proper virtual
> memory cage. In order to still be able to reference caged objects
> through offsets from the cage base on these systems, this CL introduces
> a fake cage mechanism. When the fake cage is used, most of the virtual
> memory for the cage is not actually reserved. Instead, the cage's page
> allocator simply relies on hints to the OS to obtain pages inside the
> cage. This does, however, not provide the same security benefits as a
> real cage as unrelated allocations might end up inside the cage.
>
> Bug: chromium:1218005
> Change-Id: Ie5314be23966ed0042a017917b63595481b5e7e3
> Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3217200
> Commit-Queue: Samuel Groß <saelo@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#77367}
Bug: chromium:1218005
Change-Id: I541bb9656ab2a6a080c2a30d372226fcc5c95391
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3219086
Auto-Submit: Deepti Gandluri <gdeepti@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Owners-Override: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77368}
On operating systems where reserving virtual address space is expensive,
notably Windows pre 8.1, it is not possible to create a proper virtual
memory cage. In order to still be able to reference caged objects
through offsets from the cage base on these systems, this CL introduces
a fake cage mechanism. When the fake cage is used, most of the virtual
memory for the cage is not actually reserved. Instead, the cage's page
allocator simply relies on hints to the OS to obtain pages inside the
cage. This does, however, not provide the same security benefits as a
real cage as unrelated allocations might end up inside the cage.
Bug: chromium:1218005
Change-Id: Ie5314be23966ed0042a017917b63595481b5e7e3
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3217200
Commit-Queue: Samuel Groß <saelo@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77367}
This cannot be defined in v8config.h because target architecture
detection is not done in that file.
This CL moves the logic to set V8_HAS_PTHREAD_JIT_WRITE_PROTECT to
src/base/build_config.h, which also defines the V8_TARGET_ARCH* macros.
R=jkummerow@chromium.org, mlippautz@chromium.org
Bug: chromium:1238029
Change-Id: I2a688dad32b83df1d26bf23b15bf4485d78c8cc6
Cq-Include-Trybots: luci.v8.try:v8_mac_arm64_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3085271
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76198}
pthread_jit_write_protect* functions are only available on arm64 Mac,
not on iOS (which also sets V8_{TARGET_,}OS_MACOSX).
This CL refactors the logic to detect whether pthread_jit_write_protect
and MAP_JIT are available and defines a global preprocessor macro which
can subsequently be used instead of the existing complex condition.
R=jkummerow@chromium.org, mlippautz@chromium.org
Change-Id: I63894f42df35406d6eee90a4ce5070c2fde7b566
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3077154
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Auto-Submit: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76143}
This reverts commit 92bfb63cac.
Reason for revert: Broke build https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux%20-%20shared/43249/overview
Original change's description:
> [build] Separate out inspector as a shared library
>
> This makes src/inspector:inspector into a v8_component producing a
> shared library in component builds. To enable this, all of its exported
> are now marked with V8_INSPECTOR_EXPORT.
>
> This also inverts the dependency between src/inspector:inspector and
> :v8_base_without_compiler, and instead makes d8 and some tests depend on
> inspector rather than getting it via v8.
>
> As a result, the no_check_targets exclusions list in .gn is reduced.
>
> Ultimately embedders like chromium should depend on :v8 and optionally
> src/inspector:inspector, but to allow that transition to occur, this
> renames :v8 to :v8_lib and introduces a new :v8 which depends on v8 and
> inspector. Once all embedders have changed to reflect the new structure,
> this part can be reverted.
>
> Bug: v8:11917
> Change-Id: Ia8b15f07fb15acc5e1f111b1a80248def4285fd0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2999088
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Commit-Queue: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#75532}
Bug: v8:11917
Change-Id: I0ed27ed95211d13b8b3438a8c0a42d577806c475
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3003452
Auto-Submit: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#75533}
This makes src/inspector:inspector into a v8_component producing a
shared library in component builds. To enable this, all of its exported
are now marked with V8_INSPECTOR_EXPORT.
This also inverts the dependency between src/inspector:inspector and
:v8_base_without_compiler, and instead makes d8 and some tests depend on
inspector rather than getting it via v8.
As a result, the no_check_targets exclusions list in .gn is reduced.
Ultimately embedders like chromium should depend on :v8 and optionally
src/inspector:inspector, but to allow that transition to occur, this
renames :v8 to :v8_lib and introduces a new :v8 which depends on v8 and
inspector. Once all embedders have changed to reflect the new structure,
this part can be reverted.
Bug: v8:11917
Change-Id: Ia8b15f07fb15acc5e1f111b1a80248def4285fd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2999088
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75532}
After updating our bots to use GCC 7.4, we do not need to support
incomplete C++14 support any more. In particular, we can assume
complete c++14 constexpr support now.
This CL removes the V8_HAS_CXX14_CONSTEXPR and CONSTEXPR_DCHECK macros.
The CONSTEXPR_DCHECKs are replaced by DCHECK and friend, or
STATIC_ASSERT where possible.
R=jgruber@chromium.org, leszeks@chromium.org, mlippautz@chromium.org
Bug: v8:9686, v8:11384
Change-Id: I3a8769a0f54da7eb2cacc37ee23e5c97092e3051
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2876847
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74486}
GCC 7.4 has problems with combining [[nodiscard]] with
__attribute__((visibility(""))). Disable as there's enough compilation
coverage for clang to find issues.
Bug: v8:11707
Change-Id: I9e61463c4d11dbc3b03d458e2810206fb93de108
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2854737
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74262}
Adds a v8-gn.h file containing defines that are used in the
externally-visible headers files like v8.h. This must be included by
include/v8config.h which includes it if the GN flag
v8_generate_external_defines_header is on. (Currently off by default).
To enable the v8config.h file to be included without the other v8
headers (as required by cppgc), this moves it into its own header set
which sets up the include path correctly.
Also updates some headers to ensure v8config.h is included before using
externally-visible defines.
Bug: v8:11292
Change-Id: I5be634f4adfbef144bf684071461d64f1cb30899
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2608212
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72140}
This allows us to assert at compile time that a class instance is
assigned, which is particularly useful for Guard classes.
Change-Id: Id16b2bb70d29573566e821c908c1169d49ec57af
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2552415
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71397}
Switch the current bool* parameter to a structure that contains
the boolean fallback flag and is forward compatible, if we decide
to add more options to the fallback call.
Fly-by refactoring: moved V8_ENABLE_FP_PARAMS_IN_C_LINKAGE out of
a public V8 header file.
Bug: chromium:1052746
Change-Id: I844db24cc687c58b3c3bbd84b4d61bb4759bcfc7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2474775
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70642}
This CL also adds some unit tests, locally tested under x64.
The double support is based on this original CL by Gus Caplan
(snek@chromium.org):
https://chromium-review.googlesource.com/c/v8/v8/+/2264612
Bug: chromium:1052746
Change-Id: Ibdf631689b01ab619a72005226bfc015b4737dde
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2416028
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Auto-Submit: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70168}
Starboard is the platform abstraction for Cobalt.
This CL introduces all Cobalt changes in src/base/platform.
The review was conducted mostly on:
https://chromium-review.googlesource.com/c/v8/v8/+/2247918
See b/156155426 for background
Tbr: mlippautz@chromium.org
Change-Id: I6cd092304ba6485acd38e82aa2dc4505d7dfb0aa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2346090
Commit-Queue: John Xu <johnx@google.com>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69530}
This is a reland of e0c1a349ea
The issue was passing SentinelPointer (== +1) through T*.
The fix is disabling cfi unrelated cast diagnostic for the bottlenecks
(Get()). This means that nullptr is treated the same as
kSentinelPointer.
The alternative would be a DCHECK that Get() does not return
kSentinelPointer and adjusting all Member and Persistent logic that
uses Get() to work on void*. This is quite intrusive as it involves
Swap(), heterogeneous assignments, comparisons, etc.
Original change's description:
> cppgc: Properly clear (Weak)Peristent and WeakMember pointers
>
> The CL addresses two issues with (Weak)Persistent and WeakMember:
> 1. (Weak)Persistent pointers are cleared on heap teardown. Before this
> CL the pointers would contain stale values which could lead to UAF.
> 2. WeakPersistent and WeakMember are cleared using a combination of
> internal clearing methods and mutable fields which avoids the use
> of const_cast<>.
>
> Bug: chromium:1056170
> Change-Id: Ibf2b0f0856771b4f6906608cde13a6d43ebf81f3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2248190
> Reviewed-by: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68394}
Bug: chromium:1056170
Change-Id: I3d74b43464c2973df1956f51b1419d755dd9f519
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2250240
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68426}
This CL adds 2 new values to the EmbedderStackState enum with more
explicit names. The old values are updated as aliases to the new
values and marked as soon to be deprecated. This CL also moves the
enum to v8-platform.h so that it can be reused by cppgc.
Depracating individual values in an enum is supported by GCC only
since version 6. Thus new macros were needed for the deprecation
(which delegate to the existing macros when supported). GCC versions
older than 6 are still used by the CQ bots.
Bug: chromium:1056170
Change-Id: Id1ea73edfbbae282b0d8a3bb103dbbbf8ebd417e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2188971
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67744}
- Introduces a API to set top of the stack through
EmbedderHeapTracer::SetStackTop.
- Introduces a new API to inform V8 about an empty embedder stack.
- Switch internal representation of TracedReference
for on-stack handles to a proper stack that considers all
contained handles as roots.
- Handle garbage is avoided by cleaning up on handle creation or
GC.
Design doc: https://bit.ly/on-stack-traced-reference
Bug: chromium:1040038
Change-Id: I927ef0abb268fdb5853c9e17b1bc96e2491cf101
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1993973
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65757}
We still set a lot of macros depending on specific gcc versions. All
these old versions are unsupported by now anyways, so we can also just
define these macros as 1.
If this CL sticks for a while, we can start actually cleaning up all
code relying on these macros, as most of them should be 1 now on all
platforms.
R=ulan@chromium.org
Bug: v8:9810
Change-Id: I2f9c55170091f8c263deeddfb7ff89e5b2a0bb12
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1862564
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64413}
DCHECKs are not really special, they just create a non-constexpr path
within an otherwise constexpr function. Since C++14, this is allowed.
Unfortunately, gcc only supports this since version 6, but we still
need to support gcc 5.
R=ulan@chromium.org
Change-Id: If74486144abafa5bbdcdbb9a567ee9295ac4cfc7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1862568
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64310}
The V8_HAS_DECLSPEC_NORETURN macro is unused since
https://crrev.com/c/529072, where we switched to the standard
[[noreturn]] attribute.
R=ulan@chromium.org
Bug: v8:9810
Change-Id: Ifd76c967df1da7bb71369e61cd0adc1807b62d44
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1847365
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64175}
Since C++14, there is a spec'ed attribute for deprecation of methods,
functions, types, aliases or anything else.
This CL switches from the GCC __attribute__ to this standard attribute.
This allows to use the V8_DEPRECATED and V8_DEPRECATE_SOON macros on
anything where the standard attribute can be used (including {using}
statements that were not working before). It also avoids the need to
nest the whole declaration in the macro, making the code more readable.
R=adamk@chromium.org
Bug: v8:9810
Change-Id: I7adab7694af75423fb31ade2fc982dbf9c9bc699
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1847361
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64174}
This CL allows us to distinguish between the host- and target OS. The
host OS is defined by V8_OS_ macros (e.g. V8_OS_WIN). The target OS is
defined by V8_TARGET_OS_ macros (e.g. V8_TARGET_OS_WIN).
V8_TARGET_OS_ macros are defined by gn, based on the `target_os` gn
variable. If a V8_TARGET_OS_ is set, we also define V8_HAVE_TARGET_OS
(this determines fall-back behavior in V8; if it is not defined, we set
V8_TARGET_OS_ to equal the equivalent V8_OS_ define).
Besides adding the defines, this CL also adds logic to consider the
target OS in codegen. Specifically, x64 builds now look at the
V8_TARGET_OS_WIN define instead of V8_OS_WIN or _WIN64. This
effectively makes cross-compilation to x64 Windows in mksnapshot
possible.
In future work, we could add similar support for cross-compiling to
other platforms such as ia32 Windows.
Bug: v8:9736,chromium:803591
Change-Id: I689f3de8c206b743c4bef703f5ade0bba32ce995
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1809374
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63892}
This is an unmodified reland of
60624b5692. Nosnap bots do not block
LKGR any more: https://crbug.com/v8/9737#c10.
Original change's description:
> Disallow nullptr arguments for {CopyChars}
>
> This allows to remove special casing for the {count == 0} case, which
> was needed because {memmove} does not accept {nullptr} arguments even
> if the {count} is zero.
>
> R=leszeks@chromium.org
>
> Bug: v8:9396
> Change-Id: Iaef3cdbbffa74c2ba1c4e4501dafd943282cbcd9
> Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1807366
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63838}
TBR=leszeks@chromium.org
Bug: v8:9396
Change-Id: I6ab13575f13df060b450ff105e4b9db516671dcf
Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1809365
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63863}
This reverts commits 9febc505bd
(along with followup commit 60624b5692).
Reason for revert: Breaks win32 nosnap shared, blocking lkgr & roll:
https://ci.chromium.org/p/v8/builders/ci/V8%20Win32%20-%20nosnap%20-%20shared/35145
nosnap bots may be deprecated, but as long as they're in LKGR
we need to mind them.
Original change's description:
> Reland "Remove all custom CopyCharsUnsigned implementations"
>
> This is a reland of 5d8c489000
>
> Original change's description:
> > Remove all custom CopyCharsUnsigned implementations
> >
> > It's unclear whether the custom implementation have any advantage over
> > the standard library one's.
> > Since we update our toolchain and standard library regularly, it might
> > well be the case that the custom implementations are slower by now.
> >
> > Thus this CL removes all {CopyCharsUnsigned} implementations and
> > implements {CopyChars} generically using {std::copy_n}.
> >
> > Note that this does not touch the {MemMove} and {MemCopy} functions
> > yet, as we have seen regressions when trying to remove them before
> > (https://crbug.com/v8/8675#c5).
> >
> > R=leszeks@chromium.org
> >
> > Bug: v8:9396
> > Change-Id: I97a183afebcccd2fbb567bdba02e827331475608
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1800577
> > Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> > Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#63808}
>
> Bug: v8:9396
> Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng
> Change-Id: I9cd754ebe6b802bb4aabd6d2a448de41da040874
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1807357
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#63823}
TBR=leszeks@chromium.org,clemensh@chromium.org
Change-Id: Ic53ab2293d5dc7722a1121d1aa1159328a6ed8f5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9396
Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1808035
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63854}
This allows to remove special casing for the {count == 0} case, which
was needed because {memmove} does not accept {nullptr} arguments even
if the {count} is zero.
R=leszeks@chromium.org
Bug: v8:9396
Change-Id: Iaef3cdbbffa74c2ba1c4e4501dafd943282cbcd9
Cq-Include-Trybots: luci.v8.try:v8_linux64_ubsan_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1807366
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63838}
... to let C++ compiler know that isolate root is 4Gb aligned and give
it a chance to generate a better code.
Bug: v8:9353
Change-Id: Ibd23c14cc44107c722a446a84dd14ca66f3bccfe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1776079
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63445}
This CL changes the dispatch technique in the regex interpreter to
token-threaded dispatch, if computed gotos are supported by the
compiler. Otherwise old switch-based dispatch is still used
(e.g. for MSVC).
With computed gotos, less jumps will be emitted (no extra jump to
single branch point/begin of switch) and branch prediction will
be better because of no single branch point.
This CL improves performance on the RexBench Benchmark suite by ~10%.
Bug: v8:9575
Change-Id: I585ad824ff1cc595a5dfa8831ad66d6810d0119b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1733073
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Patrick Thier <pthier@google.com>
Cr-Commit-Position: refs/heads/master@{#63126}
