This CL adds features to pack/unpack map words.
Currently V8 cannot store extra metadata in object headers -- because V8
objects do not have a proper header, but only a map pointer at the start
of the object. To store per-object metadata like marking data, a side
table is required as the per-object metadata storage.
This CL enables V8 to use higher unused bits in a 64-bit map word as
per-object metadata storage. Map pointer stores come with an extra step
to encode the metadata into the pointer (we call it "map packing").
Map pointer loads will also remove the metadata bits as well (we call it
"map packing").
Since the map word is no longer a valid pointer after packing, we also
change the tag of the packed map word to make it looks like a Smi. This
helps various GC and barrier code to correctly skip them instead of
blindly dereferencing this invalid pointer.
A ninja flag `v8_enable_map_packing` is provided to turn this
map-packing feature on and off. It is disabled by default.
* Only works on x64 platform, with `v8_enable_pointer_compression`
set to `false`
Bug: v8:11624
Change-Id: Ia2bdf79553945e5fc0b0874c87803d2cc733e073
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2247561
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73915}
This is a reland of 19b62d0b4e
Fixing the misalignment issue founded in usban build by doing four-byte
comparison: compressing the "expected" values such as script.name() and
passing them to CheckProp as type Tagged_t
Original change's description:
> [v8windbg] Add more items in the Locals pane
>
> Add more items in the Locals pane representing the JS function name,
> source file name, and character offset within the source file, so
> that the user doesn’t need to dig through the shared_function_info to
> find them.
>
> Change-Id: I5d42b3c9542885a72e81613503d1d5abf51870b5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2712310
> Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
> Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#73282}
Change-Id: Idd77f61905651fbcfae5f5b590094639bc205834
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2744959
Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#73359}
This is a reland of 80f5dfda01. A condition
in pipeline.cc was inverted, which lead to a CSA verifier error.
Original change's description:
> [no-wasm] Exclude src/wasm from compilation
>
> This is the biggest chunk, including
> - all of src/wasm,
> - torque file for wasm objects,
> - torque file for wasm builtins,
> - wasm builtins,
> - wasm runtime functions,
> - int64 lowering,
> - simd scala lowering,
> - WasmGraphBuilder (TF graph construction for wasm),
> - wasm frame types,
> - wasm interrupts,
> - the JSWasmCall opcode,
> - wasm backing store allocation.
>
> Those components are all recursively entangled, so I found no way to
> split this change up further.
>
> Some includes that were recursively included by wasm headers needed to
> be added explicitly now.
>
> backing-store-unittest.cc is renamed to wasm-backing-store-unittest.cc
> because it only tests wasm backing stores. This file is excluded from
> no-wasm builds then.
>
> R=jkummerow@chromium.org, jgruber@chromium.org, mlippautz@chromium.org, petermarshall@chromium.org
>
> Bug: v8:11238
> Change-Id: I7558f2d12d2dd6c65128c4de7b79173668c80b2b
> Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2742955
> Commit-Queue: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73344}
TBR=jgruber@chromium.org
Bug: v8:11238
Change-Id: I20bd2847a59c68738b5a336cd42582b7b1499585
Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
Cq-Include-Trybots: luci.v8.try:v8_linux_verify_csa_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_verify_csa_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2752867
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73348}
This reverts commit 80f5dfda01.
Reason for revert: Fails CSA verification: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux%20-%20verify%20csa/21766/overview
Original change's description:
> [no-wasm] Exclude src/wasm from compilation
>
> This is the biggest chunk, including
> - all of src/wasm,
> - torque file for wasm objects,
> - torque file for wasm builtins,
> - wasm builtins,
> - wasm runtime functions,
> - int64 lowering,
> - simd scala lowering,
> - WasmGraphBuilder (TF graph construction for wasm),
> - wasm frame types,
> - wasm interrupts,
> - the JSWasmCall opcode,
> - wasm backing store allocation.
>
> Those components are all recursively entangled, so I found no way to
> split this change up further.
>
> Some includes that were recursively included by wasm headers needed to
> be added explicitly now.
>
> backing-store-unittest.cc is renamed to wasm-backing-store-unittest.cc
> because it only tests wasm backing stores. This file is excluded from
> no-wasm builds then.
>
> R=jkummerow@chromium.org, jgruber@chromium.org, mlippautz@chromium.org, petermarshall@chromium.org
>
> Bug: v8:11238
> Change-Id: I7558f2d12d2dd6c65128c4de7b79173668c80b2b
> Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2742955
> Commit-Queue: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73344}
Bug: v8:11238
Change-Id: I93672002c1faa36bb0bb5b4a9cc2032ee2ccd814
Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2752866
Auto-Submit: Clemens Backes <clemensb@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@{#73346}
This is the biggest chunk, including
- all of src/wasm,
- torque file for wasm objects,
- torque file for wasm builtins,
- wasm builtins,
- wasm runtime functions,
- int64 lowering,
- simd scala lowering,
- WasmGraphBuilder (TF graph construction for wasm),
- wasm frame types,
- wasm interrupts,
- the JSWasmCall opcode,
- wasm backing store allocation.
Those components are all recursively entangled, so I found no way to
split this change up further.
Some includes that were recursively included by wasm headers needed to
be added explicitly now.
backing-store-unittest.cc is renamed to wasm-backing-store-unittest.cc
because it only tests wasm backing stores. This file is excluded from
no-wasm builds then.
R=jkummerow@chromium.org, jgruber@chromium.org, mlippautz@chromium.org, petermarshall@chromium.org
Bug: v8:11238
Change-Id: I7558f2d12d2dd6c65128c4de7b79173668c80b2b
Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2742955
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73344}
This reverts commit 19b62d0b4e.
Reason for revert: Undefined behavior
https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20UBSan/15449
Original change's description:
> [v8windbg] Add more items in the Locals pane
>
> Add more items in the Locals pane representing the JS function name,
> source file name, and character offset within the source file, so
> that the user doesn’t need to dig through the shared_function_info to
> find them.
>
> Change-Id: I5d42b3c9542885a72e81613503d1d5abf51870b5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2712310
> Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
> Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#73282}
Change-Id: I616cd642379b97dff5fb0c66aeb6488e2f9b298b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2744420
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73284}
Add more items in the Locals pane representing the JS function name,
source file name, and character offset within the source file, so
that the user doesn’t need to dig through the shared_function_info to
find them.
Change-Id: I5d42b3c9542885a72e81613503d1d5abf51870b5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2712310
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#73282}
Docs: https://docs.google.com/document/d/13n1qaB6A-gvgWc9NDhWm-UPuOqow_Y0DNgCeTbtIotI
Modify that C++ backend so that it can emit either runtime C++ or
postmortem debugging code. When in postmortem debugging mode, the
overall code structure would look similar with some difference:
1. Instead of passing an Isolate* everywhere, we pass a MemoryAccessor.
2. Instead of runtime class names like String, we use uintptr_t
3. When loading data from objects, instead of TaggedField<T>::load or
Object::ReadField (which read from the current process), we use the
MemoryAccessor and read data from the debuggee process.
4. Return values should be wrapped in the Value struct.
Implement the debug accessors for complex length expressions and add
test for such class (SmallOrderedHashSet).
Change-Id: I34107c92b31ed4e07bb628ae58c84487e41ba648
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2477921
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#72148}
This CL
* renames Name::hash_field field to raw_hash_field.
* all local variables that store raw_hash_field value are also renamed
to raw_hash_field where possible.
Bug: chromium:1133527, v8:11074
Change-Id: I17313f386110b33a64f629cc2b9d4afd1e06c6c0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2471999
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71114}
For js frame, we want to display currently executing function.
Change-Id: If33b04279dafdf6e4834bfb6c7240e8e7e799fc7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2411483
Reviewed-by: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#70018}
This reverts commit f78d69fa5d.
With https://chromium-review.googlesource.com/c/v8/v8/+/2243216,
incorrect MemoryChunk::FromHeapObject uses are now fixed.
Original change's description:
> Revert "[heap] Make ReadOnlySpace use bump pointer allocation"
>
> This reverts commit 81c34968a7 and also
> 490f3580a3 which depends on the former.
>
> Reason for revert: Break CFI tests in chromium https://ci.chromium.org/p/chromium/builders/ci/Linux%20CFI/17438
> Original change's description:
> > [heap] Make ReadOnlySpace use bump pointer allocation
> >
> > This changes ReadOnlySpace to no longer be a PagedSpace but instead it
> > is now a BaseSpace. BasicSpace is a new base class that Space inherits
> > from and which has no allocation methods and does not dictate how the
> > pages should be held.
> >
> > ReadOnlySpace unlike Space holds its pages as a
> > std::vector<ReadOnlyPage>, where ReadOnlyPage directly subclasses
> > BasicMemoryChunk, meaning they do not have prev_ and next_ pointers and
> > cannot be held in a heap::List. This is desirable since with pointer
> > compression we would like to remap these pages to different memory
> > addresses which would be impossible with a heap::List.
> >
> > Since ReadOnlySpace no longer uses most of the code from the other
> > Spaces it makes sense to simplify its memory allocation to use a simple
> > bump pointer and always allocate a new page whenever an allocation
> > exceeds the remaining space on the final page.
> >
> > Change-Id: Iee6d9f96cfb174b4026ee671ee4f897909b38418
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2209060
> > Commit-Queue: Dan Elphick <delphick@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#68137}
>
> TBR=ulan@chromium.org,delphick@chromium.org
>
> # Not skipping CQ checks because original CL landed > 1 day ago.
>
> Change-Id: I68c9834872e55eb833be081f8ff99b786bfa9894
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2232552
> Commit-Queue: Dan Elphick <delphick@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68211}
TBR=ulan@chromium.org,delphick@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: Id5b3cce41b5dec1dca816c05848d183790b1cc05
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2250254
Reviewed-by: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68407}
This reverts commit 81c34968a7 and also
490f3580a3 which depends on the former.
Reason for revert: Break CFI tests in chromium https://ci.chromium.org/p/chromium/builders/ci/Linux%20CFI/17438
Original change's description:
> [heap] Make ReadOnlySpace use bump pointer allocation
>
> This changes ReadOnlySpace to no longer be a PagedSpace but instead it
> is now a BaseSpace. BasicSpace is a new base class that Space inherits
> from and which has no allocation methods and does not dictate how the
> pages should be held.
>
> ReadOnlySpace unlike Space holds its pages as a
> std::vector<ReadOnlyPage>, where ReadOnlyPage directly subclasses
> BasicMemoryChunk, meaning they do not have prev_ and next_ pointers and
> cannot be held in a heap::List. This is desirable since with pointer
> compression we would like to remap these pages to different memory
> addresses which would be impossible with a heap::List.
>
> Since ReadOnlySpace no longer uses most of the code from the other
> Spaces it makes sense to simplify its memory allocation to use a simple
> bump pointer and always allocate a new page whenever an allocation
> exceeds the remaining space on the final page.
>
> Change-Id: Iee6d9f96cfb174b4026ee671ee4f897909b38418
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2209060
> Commit-Queue: Dan Elphick <delphick@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68137}
TBR=ulan@chromium.org,delphick@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: I68c9834872e55eb833be081f8ff99b786bfa9894
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2232552
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68211}
This changes ReadOnlySpace to no longer be a PagedSpace but instead it
is now a BaseSpace. BasicSpace is a new base class that Space inherits
from and which has no allocation methods and does not dictate how the
pages should be held.
ReadOnlySpace unlike Space holds its pages as a
std::vector<ReadOnlyPage>, where ReadOnlyPage directly subclasses
BasicMemoryChunk, meaning they do not have prev_ and next_ pointers and
cannot be held in a heap::List. This is desirable since with pointer
compression we would like to remap these pages to different memory
addresses which would be impossible with a heap::List.
Since ReadOnlySpace no longer uses most of the code from the other
Spaces it makes sense to simplify its memory allocation to use a simple
bump pointer and always allocate a new page whenever an allocation
exceeds the remaining space on the final page.
Change-Id: Iee6d9f96cfb174b4026ee671ee4f897909b38418
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2209060
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68137}
Moves ReadOnlyPage, ReadOnlyArtifacts, ReadOnlySpace and
SharedReadOnlySpace out of spaces.h and into read-only-spaces.h, as well
as creating a corresponding .cc file.
Bug: v8:10473
Change-Id: I9d8b49d61ed643fd6e16919d571a909ab6fce407
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2171197
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67531}
Bill kindly pointed out to me that v8windbg was not handling bit_field2
correctly. The issue was that the constexpr type for ElementsKind was,
somewhat unsurprisingly, "ElementsKind", but v8windbg expected a fully-
qualified type name like "v8::internal::ElementsKind". This change
addresses the problem in two ways:
1. Update v8windbg's type resolution logic to resolve type names as if
they were used in the v8::internal namespace. This makes it more
consistent with how those type names are used in other generated
Torque code, reducing surprises and the number of times we have to
write `v8::internal::` in .tq files.
2. Add compile-time verification that any constexpr type name used as a
string in class-debug-readers-tq.cc can also resolve as a type name.
Bug: v8:9376
Change-Id: I349cd6ab586fd8345a1fa8bfc3989bb8e6376ab8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2063769
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#66633}
This reverts commit 4dc1fb4e04.
Reason for revert: the regression from the original change was likely due to unlucky factors like code alignment.
Original change's description:
> Revert "[torque] Support bitfield structs stored within Smis"
>
> This reverts commit e5e4ea962e.
>
> Reason for revert: mysterious performance regression chromium:1052756
>
> Original change's description:
> > [torque] Support bitfield structs stored within Smis
> >
> > This change moves the definition of the bits stored in DebugInfo::flags
> > to Torque, and updates the only Torque usage of that field to use more
> > natural syntax. This is intended as an example of common patterns found
> > in various other classes. Several supporting changes are required:
> >
> > 1. Add a new type representing a bitfield struct stored within a Smi. It
> > is currently called SmiTagged, but I'm open to suggestions.
> > 2. Add an enum-style output for Torque bitfield structs whose bitfields
> > occupy only one bit each.
> > 3. Add a new case to MachineOperatorReducer that makes the generated
> > code for IncBlockCounter match with what was generated before this
> > change.
> > 4. Add support for reporting these bitfields in the postmortem debugging
> > API. The format matches existing bitfields but with an offset value
> > that includes the SMI shift size.
> >
> > Bug: v8:7793
> > Change-Id: Icaecbe4a162da55d2d9a3a35a8ea85b285b2f1b7
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2028832
> > Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> > Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> > Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#66182}
>
> Bug: chromium:1052756, v8:7793
> Change-Id: I9e2897efbb6321124bf4952cf09de2f179f7310d
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2062569
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66349}
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: chromium:1052756, v8:7793
Change-Id: I6087928aa14c8551ebd294513bd8d6ffa402a0d4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2070635
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#66465}
This reverts commit e5e4ea962e.
Reason for revert: mysterious performance regression chromium:1052756
Original change's description:
> [torque] Support bitfield structs stored within Smis
>
> This change moves the definition of the bits stored in DebugInfo::flags
> to Torque, and updates the only Torque usage of that field to use more
> natural syntax. This is intended as an example of common patterns found
> in various other classes. Several supporting changes are required:
>
> 1. Add a new type representing a bitfield struct stored within a Smi. It
> is currently called SmiTagged, but I'm open to suggestions.
> 2. Add an enum-style output for Torque bitfield structs whose bitfields
> occupy only one bit each.
> 3. Add a new case to MachineOperatorReducer that makes the generated
> code for IncBlockCounter match with what was generated before this
> change.
> 4. Add support for reporting these bitfields in the postmortem debugging
> API. The format matches existing bitfields but with an offset value
> that includes the SMI shift size.
>
> Bug: v8:7793
> Change-Id: Icaecbe4a162da55d2d9a3a35a8ea85b285b2f1b7
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2028832
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66182}
Bug: chromium:1052756, v8:7793
Change-Id: I9e2897efbb6321124bf4952cf09de2f179f7310d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2062569
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66349}
This change moves the definition of the bits stored in DebugInfo::flags
to Torque, and updates the only Torque usage of that field to use more
natural syntax. This is intended as an example of common patterns found
in various other classes. Several supporting changes are required:
1. Add a new type representing a bitfield struct stored within a Smi. It
is currently called SmiTagged, but I'm open to suggestions.
2. Add an enum-style output for Torque bitfield structs whose bitfields
occupy only one bit each.
3. Add a new case to MachineOperatorReducer that makes the generated
code for IncBlockCounter match with what was generated before this
change.
4. Add support for reporting these bitfields in the postmortem debugging
API. The format matches existing bitfields but with an offset value
that includes the SMI shift size.
Bug: v8:7793
Change-Id: Icaecbe4a162da55d2d9a3a35a8ea85b285b2f1b7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2028832
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66182}
This change adds support for the postmortem inspection library to show
the content of cached external strings if that content is available. It
also fixes a minor annoyance where strings with unavailable data would
show up as "...". Now, if fetching the very first character fails, we
omit the literal value from the output.
Bug: v8:9376
Change-Id: Id694a774c231ab3467fb59b1c149284729acfb20
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1987922
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#65961}
This change updates GetObjectProperties to list all of the bitfields
within a class field, if that class field's type is a bitfield struct.
The representation of bitfields in the GetObjectProperties response is
very similar to the representation of struct fields, but with two extra
bytes of data specifying the shift and size of the bitfield.
Bug: v8:9376
Change-Id: I40a22169f3d01652a7f2db8cface43c2a1e30cfe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1960835
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#65610}
Part of the GetObjectProperties test case is for verifying the human-
readable brief object description string that GetObjectProperties
returns. That string might look something like this:
"xy" (0x28f038d5 <v8::internal::SeqOneByteString>)
GetObjectProperties also tries to detect known immortal objects by
recognizing their addresses, which is useful in crash dumps with limited
memory. The recognized object name, if it exists, is prepended to the
description string. In order to provide this data accurately (in builds
without pointer compression), GetObjectProperties relies on the caller
to provide the addresses of the first pages in read-only space, map
space, and old space. If the caller doesn't provide those addresses,
then GetObjectProperties does the best it can with limited information
and reports possible matches based on an object's offset within the heap
page that contains it. So the result string might look like this, if the
object happened to get allocated at a lucky offset within its page:
maybe LoadHandler3Map "xy" (0x28f038d5 <v8::internal::SeqOneByteString>)
As a result, when testing these descriptions, we should generally check
that they contain the interesting data rather than that they start with
it, because some incorrect "maybe" match with a known object might be
included at the beginning.
Bug: v8:10034
Change-Id: I0cf5afd67793a239614aba3665ef57cd2d663a47
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1950233
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#65432}
Until now, the in-object properties on JSObject have been invisible to
tools using the postmortem debugging library. With this change, those
tools will get enough information to show a flat list of property
values. This is still less powerful than the runtime printers, which can
show the corresponding key for each value, but it's a big step up from
manually inspecting memory.
This change basically requires a reimplementation of
Map::GetInObjectProperties for postmortem debugging. I'm not
enthusiastic about duplicating this logic, but it's pretty small and I
don't see any good alternatives.
As a drive-by cleanup, I moved some inline string literals into a batch
of constexpr char arrays.
Bug: v8:9376
Change-Id: Ia24c05f6e823086babaa07882d0d320ab9a225db
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1930174
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#65183}
This change defines a way that v8_debug_helper can describe object
fields which are packed structs, and uses it for the "descriptors" field
in DescriptorArray.
In more detail:
- debug-helper.h (the public interface for v8_debug_helper) adds a size
and an optional list of struct properties to ObjectProperty.
- debug-helper-internal.h mirrors those changes to the internal class
hierarchy which maintains proper unique_ptr ownership.
- In src/torque/class-debug-reader-generator.cc,
- Some existing logic is moved into smaller functions.
- New logic is added to generate the field list for structs. Example
output is included in a comment above the function
GenerateGetPropsChunkForField.
Bug: v8:9376
Change-Id: I531acac039ccb42050641448a4cbaec26186a7bc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1894362
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65079}
This change extends v8_debug_helper to export a new method that returns
a list of all known heap object types.
Why? We can substantially improve the user experience in our work-in-
progress WinDbg extension if we register handlers not only for
v8::internal::Object but for every specific HeapObject type. This has
two benefits:
- You save a click: if you're expanding a local variable of a more
specific type than Object, you can see properties immediately rather
than first needing to expand a sub-item that casts the variable to
Object.
- You retain the type hint: GetObjectProperties accepts a type hint
string, and it's super important to pass it when working in a crash
dump because the object's Map is probably inaccessible. If we have to
cast to Object first, we lose this data.
Bug: v8:9376
Change-Id: I4d635a1826574a3d08ac657e848e1fe7b83849fe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1822859
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#64331}
If we can read an object's Map pointer but not any data from the Map
itself, we may still be able to accurately describe the object's type if
the Map pointer matches one of the known Maps from the snapshot.
GetObjectProperties uses that data in one of two ways:
- If it is sure that the Map pointer matches a known Map, then it uses
the type from that Map and continues as if it read the type normally.
- If the Map pointer is at the right offset within a heap page to match
a known Map, but the caller didn't provide the addresses of the first
pages in Map space or read-only space, then the type of that Map is
just a guess and gets returned in a separate array. This gives the
caller the opportunity to present guessed types to the user, and
perhaps call again using the guessed type as the type hint.
Bug: v8:9376
Change-Id: I187f67b77e76699863a14534a9d635b79f654124
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1787986
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63908}
v8_debug_helper attempts to flag known object pointers when it can
recognize them, even if the memory pointed to is not available in the
crash dump. In ptr-compr builds, the first pages of the map space,
read-only space, and old space are always at the same offsets within the
heap reservation region, so we can more easily detect known objects.
Bug: v8:9376
Change-Id: I04e0d2357143d753f575f556e94f8fd42ce9d811
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1783729
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63624}
This change provides a quick way to see string contents in postmortem
debugging sessions, without digging through a (possibly very large, in
the case of ConsString) tree of properties. As well as being convenient
for inspecting String objects, this functionality will also be necessary
for displaying property names on JSReceiver objects. In order to support
custom behaviors for specific classes, this change extends the existing
generated debug reader classes with a visitor pattern.
Bug: v8:9376
Change-Id: I70eab9ea4e74ca0fab39bf5998d6a602716a4202
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1771939
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#63485}
This change adds the indexed field for the characters in the definition
of sequential string types, and introduces support for recognizing the
various specific string types in v8_debug_helper. In an attempt to
avoid duplicating info about string instance types, it also refactors
String::Get so that StringShape (a simple class usable by postmortem
tools) can dispatch using a class that defines behaviors for each
concrete type.
Bug: v8:9376
Change-Id: Id0653040f6decddc004c73f8fe93d2187828c2c6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1735795
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63352}
This is a reland of 517ab73fd7
Updates since original: now compressed pointers passed to the function
GetObjectProperties are required to be sign-extended. Previously, the
function allowed zero-extended values, but that led to ambiguity on
pointers like 0x88044919: is it compressed or is the heap range actually
centered on 0x100000000?
Original change's description:
> Add postmortem debugging helper library
>
> This change begins to implement the functionality described in
> https://docs.google.com/document/d/1evHnb1uLlSbvHAAsmOXyc25x3uh1DjgNa8u1RHvwVhk/edit#
> for investigating V8 state in crash dumps.
>
> This change adds a new library, v8_debug_helper, for providing platform-
> agnostic assistance with postmortem debugging. This library can be used
> by extensions built for debuggers such as WinDbg or lldb. Its public API
> is described by debug-helper.h; currently the only method it exposes is
> GetObjectProperties, but we'd like to add more functionality over time.
> The API surface is restricted to plain C-style structs and pointers, so
> that it's easy to link from a debugger extension built with a different
> toolchain.
>
> This change also adds a new cctest file to exercise some basic
> interaction with the new library.
>
> The API function GetObjectProperties takes an object pointer (which
> could be compressed, or weak, or a SMI), and returns a string
> description of the object and a list of properties the object contains.
> For now, the list of properties is entirely based on Torque object
> definitions, but we expect to add custom properties in future updates so
> that it can be easier to make sense of complex data structures such as
> dictionaries.
>
> GetObjectProperties does several things that are intended to generate
> somewhat useful results even in cases where memory may be corrupt or
> unavailable:
> - The caller may optionally provide a type string which will be used if
> the memory for the object's Map is inaccessible.
> - All object pointers are compared against the list of known objects
> generated by mkgrokdump. The caller may optionally provide the
> pointers for the first pages of various heap spaces, to avoid spurious
> matches. If those pointers are not provided, then any matches are
> prefixed with "maybe" in the resulting description string, such as
> "maybe UndefinedValue (0x4288000341 <Oddball>)".
>
> Bug: v8:9376
>
> Change-Id: Iebf3cc2dea3133c7811bcefcdf38d9458b02fded
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628012
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62882}
Bug: v8:9376
Change-Id: I866a1cc9d4c34bfe10c7b98462451fe69763cf3f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1717090
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#63008}
This reverts commit 517ab73fd7.
Reason for revert: Test failures https://bugs.chromium.org/p/v8/issues/detail?id=9538
Original change's description:
> Add postmortem debugging helper library
>
> This change begins to implement the functionality described in
> https://docs.google.com/document/d/1evHnb1uLlSbvHAAsmOXyc25x3uh1DjgNa8u1RHvwVhk/edit#
> for investigating V8 state in crash dumps.
>
> This change adds a new library, v8_debug_helper, for providing platform-
> agnostic assistance with postmortem debugging. This library can be used
> by extensions built for debuggers such as WinDbg or lldb. Its public API
> is described by debug-helper.h; currently the only method it exposes is
> GetObjectProperties, but we'd like to add more functionality over time.
> The API surface is restricted to plain C-style structs and pointers, so
> that it's easy to link from a debugger extension built with a different
> toolchain.
>
> This change also adds a new cctest file to exercise some basic
> interaction with the new library.
>
> The API function GetObjectProperties takes an object pointer (which
> could be compressed, or weak, or a SMI), and returns a string
> description of the object and a list of properties the object contains.
> For now, the list of properties is entirely based on Torque object
> definitions, but we expect to add custom properties in future updates so
> that it can be easier to make sense of complex data structures such as
> dictionaries.
>
> GetObjectProperties does several things that are intended to generate
> somewhat useful results even in cases where memory may be corrupt or
> unavailable:
> - The caller may optionally provide a type string which will be used if
> the memory for the object's Map is inaccessible.
> - All object pointers are compared against the list of known objects
> generated by mkgrokdump. The caller may optionally provide the
> pointers for the first pages of various heap spaces, to avoid spurious
> matches. If those pointers are not provided, then any matches are
> prefixed with "maybe" in the resulting description string, such as
> "maybe UndefinedValue (0x4288000341 <Oddball>)".
>
> Bug: v8:9376
>
> Change-Id: Iebf3cc2dea3133c7811bcefcdf38d9458b02fded
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628012
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#62882}
TBR=yangguo@chromium.org,mvstanton@chromium.org,jgruber@chromium.org,tebbi@chromium.org,seth.brenith@microsoft.com
Change-Id: Ia078f2e8d101d2375b5db88021b2d65d28f1b075
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9376
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1716033
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62899}
This change begins to implement the functionality described in
https://docs.google.com/document/d/1evHnb1uLlSbvHAAsmOXyc25x3uh1DjgNa8u1RHvwVhk/edit#
for investigating V8 state in crash dumps.
This change adds a new library, v8_debug_helper, for providing platform-
agnostic assistance with postmortem debugging. This library can be used
by extensions built for debuggers such as WinDbg or lldb. Its public API
is described by debug-helper.h; currently the only method it exposes is
GetObjectProperties, but we'd like to add more functionality over time.
The API surface is restricted to plain C-style structs and pointers, so
that it's easy to link from a debugger extension built with a different
toolchain.
This change also adds a new cctest file to exercise some basic
interaction with the new library.
The API function GetObjectProperties takes an object pointer (which
could be compressed, or weak, or a SMI), and returns a string
description of the object and a list of properties the object contains.
For now, the list of properties is entirely based on Torque object
definitions, but we expect to add custom properties in future updates so
that it can be easier to make sense of complex data structures such as
dictionaries.
GetObjectProperties does several things that are intended to generate
somewhat useful results even in cases where memory may be corrupt or
unavailable:
- The caller may optionally provide a type string which will be used if
the memory for the object's Map is inaccessible.
- All object pointers are compared against the list of known objects
generated by mkgrokdump. The caller may optionally provide the
pointers for the first pages of various heap spaces, to avoid spurious
matches. If those pointers are not provided, then any matches are
prefixed with "maybe" in the resulting description string, such as
"maybe UndefinedValue (0x4288000341 <Oddball>)".
Bug: v8:9376
Change-Id: Iebf3cc2dea3133c7811bcefcdf38d9458b02fded
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1628012
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62882}
