Commit Graph

957 Commits

Author SHA1 Message Date
Alexander Markov f49a95fec9 [vm] Reduce Class object size in JIT mode
The following fields in Class objects

  target_instance_size_in_words_
  target_type_arguments_field_offset_in_words_
  target_next_field_offset_in_words_

are only useful when cross-compiling.

This change removes these fields if DART_PRECOMPILER is not defined.

TEST=ci
Change-Id: I45e6e60ad6d0a738e2ac3afd45328209167393ff
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/196222
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2021-04-22 22:10:06 +00:00
Ryan Macnak 7e1d1963e5 [vm] Switch TypeArguments to compressed pointers.
TEST=ci
Change-Id: Ic3162ef1558fb803ab68749f1f1a4d820645ec7e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/194017
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Liam Appelbe <liama@google.com>
2021-04-21 00:06:58 +00:00
Vyacheslav Egorov f88ce677e1 [vm/debugger] Avoid treating a try/finally as a catch
There is a synthetic try/catch within a try/finally block.

When trying to assess whether an exception is caught, the debugger
should skip such generated try/catch blocks. Otherwise, it considers
that try/finally actually handles the exception, which is wrong.

Fixes https://github.com/dart-lang/sdk/issues/45684

TEST=runtime/observatory{,_2}/tests/service{,_2}/regress_45684_test.dart

Change-Id: I60e8837204cf97ee1ab02ffd03364e7f69857004
Fixed: 45684
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/196124
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
2021-04-20 23:14:38 +00:00
Alexander Markov 17c33d8d52 Reland "[vm] Reduce size of Class objects in AOT and PRODUCT modes"
This is a reland of 2852408881

Original change's description:
> [vm] Reduce size of Class objects in AOT and PRODUCT modes
>
> This change conditionally removes certain fields from Class objects
> in AOT and PRODUCT modes.
>
> Flutter gallery in release-sizeopt mode:
> Snapshot size -0.47% (arm64), -0.44% (arm)
> Heap size of snapshot objects -4.1% (arm64), -4.3% (arm)
>
> On a large Flutter application compiled in --dwarf-stack-traces mode:
> Heap size of Class objects -26%
> Heap size of all snapshot objects -3.6%
>
> TEST=ci
> Issue: https://github.com/dart-lang/sdk/issues/44020
> Change-Id: I795c625b71558cd2f336f92fc326c36fd339cd4b
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/195700
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TEST=ci
Change-Id: Ib473a959a2c610b7a0e6f4000b2101e5256c6119
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/196103
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-04-20 21:11:58 +00:00
Alexander Markov 867a95c50e Revert "[vm] Reduce size of Class objects in AOT and PRODUCT modes"
This reverts commit 2852408881.

Reason for revert: failures on Flutter engine tests.
Issue: https://github.com/flutter/flutter/issues/80801

Original change's description:
> [vm] Reduce size of Class objects in AOT and PRODUCT modes
>
> This change conditionally removes certain fields from Class objects
> in AOT and PRODUCT modes.
>
> Flutter gallery in release-sizeopt mode:
> Snapshot size -0.47% (arm64), -0.44% (arm)
> Heap size of snapshot objects -4.1% (arm64), -4.3% (arm)
>
> On a large Flutter application compiled in --dwarf-stack-traces mode:
> Heap size of Class objects -26%
> Heap size of all snapshot objects -3.6%
>
> TEST=ci
> Issue: https://github.com/dart-lang/sdk/issues/44020
> Change-Id: I795c625b71558cd2f336f92fc326c36fd339cd4b
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/195700
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TBR=vegorov@google.com,rmacnak@google.com,alexmarkov@google.com,sstrickl@google.com

Change-Id: I0dbf1d5fc139f3654ce52f185b799c09bba66de7
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Issue: https://github.com/dart-lang/sdk/issues/44020
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/196102
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2021-04-20 16:54:29 +00:00
Alexander Markov 2852408881 [vm] Reduce size of Class objects in AOT and PRODUCT modes
This change conditionally removes certain fields from Class objects
in AOT and PRODUCT modes.

Flutter gallery in release-sizeopt mode:
Snapshot size -0.47% (arm64), -0.44% (arm)
Heap size of snapshot objects -4.1% (arm64), -4.3% (arm)

On a large Flutter application compiled in --dwarf-stack-traces mode:
Heap size of Class objects -26%
Heap size of all snapshot objects -3.6%

TEST=ci
Issue: https://github.com/dart-lang/sdk/issues/44020
Change-Id: I795c625b71558cd2f336f92fc326c36fd339cd4b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/195700
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-04-20 00:45:38 +00:00
Ryan Macnak f54bb55244 Reland "[vm, service, observatory] Add ability to retrieve the set of all instances of a class, implementation hierarchy or interface hierarchy as an array."
Filter Class::direct_subclasses/implementors_ to remove tree-shaken classes.

TEST=ci, manual UI interaction
Bug: https://github.com/dart-lang/sdk/issues/45564
Change-Id: Ia2a46e9701745ce88dffa95a86b7756f3ab0921d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/194110
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
2021-04-14 19:40:20 +00:00
Alexander Markov 5129cff930 [vm/aot] Discard Code objects from the heap
While deserializing AOT snapshot, Code objects which do not contain
valuable information besides entry point and stack maps are discarded
and not allocated on the heap (they are replaced with
StubCode::UnknownDartCode()).

PC -> Code/CompressedStackMaps lookup is implemented using a separate
table (InstructionsTable).

Flutter gallery in release-sizeopt mode:
Heap size of snapshot objects: arm -26.89%, arm64 -27.68%

Large Flutter application in release mode with --dwarf-stack-traces:
Heap size of snapshot objects: -24.3%.
Discarded Code objects: 72.5% of all Code objects.

Issue: https://github.com/dart-lang/sdk/issues/44852.

TEST=existing tests; "--dwarf_stack_traces --no-retain_function_objects
--no-retain_code_objects" mode is enabled for a few tests.

Change-Id: I5fe3e283630c8e8f4442319d5dcae38d174dd0d8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/189560
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-04-13 02:36:16 +00:00
Ben Konyi 2a62fc49a3 [ VM / gen_snapshot ] Include resolved script URLs in non-PRODUCT AOT snapshots
Required for https://github.com/dart-lang/sdk/issues/37553

TEST=runtime/tests/vm/dart/gen_snapshot_include_resolved_urls_test.dart

Change-Id: I0a2f6293566e5e5436df92d21e6bd38bb58c7654
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193520
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
2021-04-06 22:30:48 +00:00
Ryan Macnak a6ffc74a4a [vm] Switch most Instances whose layout is determined in C++ to compressed pointers.
Instances whose layout must agree with a layout determined by Dart code are not switched: Array, GrowableObjectArray, Closure, LinkedHashMap.

TEST=ci
Change-Id: I19baf6473a29dd14f84aa1e087eee16b0e6e9d77
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193442
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Liam Appelbe <liama@google.com>
2021-04-05 17:43:16 +00:00
Alexander Aprelev abdca81fa0 Revert "[vm, service, observatory] Add ability to retrieve the set of all instances of a class, implementation hierarchy or interface hierarchy as an array."
This reverts commit 170bda2b74 as it breaks ffi test.

See https://github.com/dart-lang/sdk/issues/45564

TEST=rollback

Change-Id: Ie27cfa7c3bc093c1e8d46722942d1f2e5e3cb77e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193882
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
2021-04-02 16:46:11 +00:00
Ryan Macnak 170bda2b74 [vm, service, observatory] Add ability to retrieve the set of all instances of a class, implementation hierarchy or interface hierarchy as an array.
Allows developers to perform arbitrary filtering or analysis of instances, such as finding the largest strings, degreeses of duplication, histograms of various properties, etc.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/44479
Change-Id: I0b4005b5778038945e5f1b2d7858806c8e0dbbff
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176381
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Stephen Adams <sra@google.com>
2021-04-01 20:53:22 +00:00
Tess Strickland bf74cad477 [vm/compiler] Change when parents of local functions are retained.
Now they are only retained if one of the following is true:

* The parent is Future.wait or Future.timeout.
* The local function is a generated body of an async/async*/sync*
  function.
* Symbolic stack traces are enabled.

When a local closure's parent is dropped, the parent name will
be printed as `<optimized out>` in places like exceptions.

Changes in Flutter gallery in release-sizeopt mode:

* ARM7: ROData -1.41%, Isolate snapshot -2.35%, Total snapshot -0.54%,
        Isolate heap -1.38%, Total heap -1.38%
* ARM8: ROData -1.55%, Isolate snapshot -2.34%, Total snapshot -0.65%,
        Isolate heap -1.41%, Total heap -1.41%

TEST=Existing tests on CI.

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try, vm-kernel-precomp-dwarf-linux-product-x64-try
Change-Id: I9d05f9e0e30e9f428eff16a15b0f1eeb974419c8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/190023
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-03-25 13:47:03 +00:00
Tess Strickland 6d1ea68cc9 [build] Move from the C++11 to the C++17 standard.
Also includes some example changes using C++14/C++17 features.

TEST=vm/cc/BitField_Assert

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-win-release-x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-linux-release-x64-try,dart-sdk-win-try,vm-kernel-win-release-x64-try,vm-kernel-win-release-ia32-try,dart-sdk-mac-try,vm-kernel-mac-release-x64-try
Change-Id: Icf5c5267431daf9cea2e61b67131021557675f3c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/192183
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
2021-03-19 15:29:57 +00:00
Ryan Macnak 19e5899a02 [vm] Switch most non-Instances to compressed pointers.
The following are not compressed: Code, ObjectPool, Context, CallSiteData and subclasses.

Code::instructions_ is uncompressible because the VM doesn't control the address of Instructions when they are loaded via dynamic library.

Loads from the ObjectPool are a frequent occurrence in generated code, and shrinking ObjectPool entries would be offset by longer code sequences to decompress them. Also, some ObjectPool entries contain uncompressible pointers to C functions.

Context is not compressed based on reports from earlier work on compressed pointers that compressing them is disproporately bad for performance. The earlier work used a different, more-expensive compression scheme, so we should reinvestigate this.

CallSiteData et al. are on the hot path for unoptimized code but make up a comparatively small portion of the heap size.

TEST=ci
Change-Id: I9a425fa4e12113c9fd0b51999525d32a7e589a90
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/190600
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Liam Appelbe <liama@google.com>
2021-03-18 22:52:04 +00:00
Tess Strickland 901fed103b [vm] Use the cached number of parent type args in FunctionType.
Also ensure the number of parent type arguments is appropriately
adjusted in the returned FunctionType when partially instantiating
a FunctionType, and that free parent type arguments are _not_
included in types built while reading constants.

Since the number of parent type arguments is now cached there, we
no longer need to also cache them in ClosureData. We can also remove
the parent walking in Function::NumParentTypeArguments().

Previously, a FunctionType where the component types did not use
parent type parameters was considered instantiated. This CL changes
it so that FunctionType with free parent type parameters are never
considered instantiated. This is necessary because otherwise,
when instantiating the parent type parameters, a FunctionType that
does not use its parent type parameters will be used unchanged
instead of creating a copy with fewer parent type parameters.

Because of this, places where IsInstantiated was used to simply
check for generic parent functions (namely, for implicit closure
creation) has been appropriately weakened to check
!HasGenericParent() instead.

TEST=Existing tests on CI.

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try
Change-Id: Ifb4a0a1273d8d01908cdf4ffc3c4c28a1c33ffa0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/190021
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
2021-03-16 15:04:51 +00:00
Vyacheslav Egorov d42de4ed06 [vm] Crash on impossible GDT null errors
This CL adds code to detect situations when we hit
null error through GDT call with non-null receiver.

We achieve this by making receiver's cid part of the
GDT calling convention and checking this cid
in runtime entry responsible for throwing the null
error.

This CL is an attempt to narrow down b/179632636
and collapse various impossible crash reports
into a single native crash cluster by crashing VM
instead of throwing a null error.

TEST=tested manually

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try
Change-Id: If2ed4646c4c0f403016266e4e83e296a7b234cb5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/191141
Auto-Submit: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-03-15 15:35:10 +00:00
Ryan Macnak 927d45d013 [vm, gc] Remove data race updating TypedDataView::pointer_ during parallel scavenge.
TEST=tsan

Bug: https://github.com/dart-lang/sdk/issues/45217
Change-Id: I0045b793767b8397c62ce992cc775eff989e8642
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/189800
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-03-09 20:20:00 +00:00
Alexander Aprelev e4ab127fbc [vm/concurrency] Make Function::kind_tag_ concurrency-safe.
Fixes https://github.com/dart-lang/sdk/issues/45182.

TEST=flaky vm/dart_2/isolates/reload_many_isolates_test on tsan bot
Change-Id: Ie874e65643d1a1dc94a94446b3141a4fabb15adb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/189261
Commit-Queue: Alexander Aprelev <aam@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-03-08 19:29:21 +00:00
Vyacheslav Egorov ae37ff098a [vm] Compact serialization for canonical sets
This CL changes how canonical sets for some specific types are written
into the root snapshot: instead of writing canonical set as a separate
object we reorder objects within a canonical cluster in such a way that
the order matches order of elements in the backing store of a canonical
set and then we write canonical set layout out using differential
encoding (essentially writing gaps between elements instead of writing
absolute indices).

This significantly reduces the overhead of having canonical sets in the
snapshot while maintaining fast deserialisation: for example on build
microbenchmark this brings regression in the snapshot size from 4% to
.3%.

On sizeopt benchmarks:

  flutter_gallery_app_so_gzip_size   -1.5%
  flutter_gallery_app_so_size        -4.7%
  flutter_gallery_total_heap_size   -16.2%


TEST=ci

Change-Id: I2be7fd073668e9b52098e2acda9f11d128cfda95
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try,pkg-linux-release-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/185381
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2021-03-08 14:21:01 +00:00
Ryan Macnak dce0b514d4 [vm] Defer object pools and object pool entries.
This defers literals, to effectively split binary size for libraries that are more data than code, such as localizations.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: I506722037cc0247b90756959e6a6f12bb5021b5c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/183781
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2021-03-04 23:19:30 +00:00
Martin Kustermann 7fc9a1a14c [vm/compiler] Remove non-background optizable bit
The background compiler no longer has bailouts due to something that
cannot be done on BG compiler and has to be done on mutator (was
originally introduced in [0])

All optimizing compilations can happen on the BG thread. Class
finalization and other things no longer cause a bailout on BG
compiler.

If e.g. invalidated field guards cause a compilation to be discarded, it
can be retried on BG compiler.

[0] https://dart-review.googlesource.com/c/sdk/+/54886

Closes https://github.com/dart-lang/sdk/issues/45136

TEST=Fixes flaky hits of an assertion.

Change-Id: I50313dbedf96b8dec205acdb8c1ed5731d00433b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/187901
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2021-03-02 14:20:02 +00:00
Tess Strickland 960c944940 [vm/compiler] Get parameter names/counts from the closure signature.
Doing so removes some dependencies on the closure function itself,
making it easier to shake the function when possible in the future.

TEST=Existing tests that check dynamic closure invocations.

Bug: https://github.com/dart-lang/sdk/issues/41052
Bug: https://github.com/dart-lang/sdk/issues/44005

Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try
Change-Id: I88c4b37efff9a9894633db7f380ecc39da717e6e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/187081
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
2021-03-01 16:25:24 +00:00
Alexander Markov ddfc98337b Reland "[vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces"
This is a reland of b6dc4dad4d

TEST=ci

Original change's description:
> [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
>
> The following changes are done in preparation for the removal of Code
> objects in AOT with --dwarf-stack-traces:
>
> * Stack trace objects are extended to hold uword PCs (which may not
>   fit into Smi range).
>
> * Scanning stack frames in GC (StackFrame::VisitObjectPointers)
>   now avoids using Code objects.
>   In order to find CompressedStackMaps it now calls
>   ReversePc::FindCompressedStackMaps.
>
> * Singleton Code object (StubCode::UnknownDartCode()) is prepared as
>   a replacement for Code objects in stack traces. It has
>   PayloadStart() == 0 and Size() == kUwordMax so it includes
>   arbitrary PCs.
>
> * In --dwarf-stack-traces mode, most Code objects obtained from stack
>   frames are replaced with StubCode::UnknownDartCode().
>   This simulates future behavior of ReversePc::Lookup when Code objects
>   will be removed.
>
> Issue: https://github.com/dart-lang/sdk/issues/44852
> Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
> TEST=ci
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

Change-Id: Ia2fc4672a085cd963b7fc103369851df3603590c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/186202
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-02-22 10:46:28 +00:00
Alexander Markov fde0ed2e93 Revert "[vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces"
This reverts commit b6dc4dad4d.

Reason for revert: broke package:vm_snapshot_analysis in Flutter
(https://github.com/flutter/flutter/issues/76313).

Original change's description:
> [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
>
> The following changes are done in preparation for the removal of Code
> objects in AOT with --dwarf-stack-traces:
>
> * Stack trace objects are extended to hold uword PCs (which may not
>   fit into Smi range).
>
> * Scanning stack frames in GC (StackFrame::VisitObjectPointers)
>   now avoids using Code objects.
>   In order to find CompressedStackMaps it now calls
>   ReversePc::FindCompressedStackMaps.
>
> * Singleton Code object (StubCode::UnknownDartCode()) is prepared as
>   a replacement for Code objects in stack traces. It has
>   PayloadStart() == 0 and Size() == kUwordMax so it includes
>   arbitrary PCs.
>
> * In --dwarf-stack-traces mode, most Code objects obtained from stack
>   frames are replaced with StubCode::UnknownDartCode().
>   This simulates future behavior of ReversePc::Lookup when Code objects
>   will be removed.
>
> Issue: https://github.com/dart-lang/sdk/issues/44852
> Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
> TEST=ci
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I6f66171eecf1133363a7ce56193e782e43a20baf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/185488
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
2021-02-18 18:04:29 +00:00
Alexander Markov b6dc4dad4d [vm/aot] Avoid using most Code objects in stack traces with --dwarf-stack-traces
The following changes are done in preparation for the removal of Code
objects in AOT with --dwarf-stack-traces:

* Stack trace objects are extended to hold uword PCs (which may not
  fit into Smi range).

* Scanning stack frames in GC (StackFrame::VisitObjectPointers)
  now avoids using Code objects.
  In order to find CompressedStackMaps it now calls
  ReversePc::FindCompressedStackMaps.

* Singleton Code object (StubCode::UnknownDartCode()) is prepared as
  a replacement for Code objects in stack traces. It has
  PayloadStart() == 0 and Size() == kUwordMax so it includes
  arbitrary PCs.

* In --dwarf-stack-traces mode, most Code objects obtained from stack
  frames are replaced with StubCode::UnknownDartCode().
  This simulates future behavior of ReversePc::Lookup when Code objects
  will be removed.

Issue: https://github.com/dart-lang/sdk/issues/44852
Change-Id: I7cec7b8b9396c9cfeca3c256a412ba4e82a7e0c4
TEST=ci
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182720
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2021-02-17 20:12:32 +00:00
Martin Kustermann 5b4349de54 [vm/concurrency] Make main hot-reload implementation independent of current isolate
Since hot-reloading will affect all isolates within a group, there
should be nothing isolate-specific inside it. We therefore add a
NoActiveIsolateScope to the main part of the reloading
implementation.

Issue https://github.com/dart-lang/sdk/issues/36097

TEST=Refactoring of existing implementation.

Change-Id: I1c8db00e6a016c77c68c2c04448de056a76d42c5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/184782
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2021-02-17 09:38:29 +00:00
Ryan Macnak dd83f15826 [vm] Account for compressed pointers in pointer visitors.
TEST=ci
Change-Id: I033bb30e86dfc66ddeb7316a625e3f8925528a19
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/183784
Reviewed-by: Liam Appelbe <liama@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2021-02-16 18:27:39 +00:00
Alexander Aprelev 26c0de0acf [vm/deferred] Keep deferred library prefix status on isolate.
This is to ensure that deferred library status is per isolate, rather than per isolate-group.

TEST=deferred_isolate_test.dart

Issue dartbug.com/36097

Change-Id: I1fb8b8f1830aac688a078fe0a82b06c7daa856fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/184040
Commit-Queue: Alexander Aprelev <aam@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-02-11 18:00:59 +00:00
Ryan Macnak 25fd0200ef [vm] Replace recanonicalization in primary snapshots with weak constant tables.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: Icc4a3ebf861dca5172a0cfa2cd2eea266e814d0c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181480
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2021-02-10 01:21:07 +00:00
Alexander Markov 97e2f3ddc5 [vm/aot] Avoid retaining inlined functions with --dwarf_stack_traces
When --dwarf-stack-trace option is used, we don't use nor write inlined
functions information to the snapshot. However, we were retaining
Function objects corresponding to inlined functions.

On a large app, AOT-compiled in PRODUCT mode with
--dwarf-stack-traces on arm64:

Function objects in AOT snapshot -19.4%
Heap size used by objects in snapshot -4.45%
Total AOT snapshot size -2.35%

Flutter gallery AOT snapshot size
(release mode with --dwarf-stack-traces):
arm64 -1.1% (gzip -1.3%, brotli -1.4%)
arm -0.95% (gzip -1.2%, brotli -1.4%)

TEST=ci

Change-Id: Id2d7a2d6b6bff1a5929be97477b0e17a9afae475
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181700
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
2021-02-01 18:26:29 +00:00
asiva 27deca1457 Revert "[vm] Defer object pools." and
"[vm] Defer object pool entries in instructions bare mode."

This reverts commit 0bf8d38b3d and
             commit 63d17b0ad8.

Reason for revert : Performance regression, please see https://github.com/flutter/flutter/issues/73794

TEST=(none it is a revert).

Change-Id: I828734f00c55d5095f632b154d7f4ab27a184baf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/181542
Commit-Queue: Siva Annamalai <asiva@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
2021-01-28 21:13:35 +00:00
Ryan Macnak b1c09ecd8f [vm] Make naming more consistent when converting between handles, tagged and untagged pointers.
Currently we have things called XPtr which are not what you get from ptr().

Old world:
handle->raw() returns RawObject* (tagged)
raw_obj->ptr() returns RawObject* (untagged)

After 6fe15f6df9:
handle->raw() returns ObjectPtr
obj_ptr->ptr() returns ObjectLayout*

New world:
handle->ptr() returns ObjectPtr
obj_ptr->untag() returns UntaggedObject*

TEST=ci
Change-Id: I6c7f34014cf20737607caaf84979838300d12df2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149367
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2021-01-15 23:32:02 +00:00
Ryan Macnak 63d17b0ad8 [vm] Defer object pool entries in instructions bare mode.
dart2js+analyzer product X64 bare:
app.so            9289320 ->  8491864 (-8.58%)
app.so-2.part.so 12010936 -> 12315880 (2.53%)
app.so-3.part.so  7579704 ->  7847768 (3.53%)

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: I8e695966bc11c3912a01cd525ca69be6ef8e5ea2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/171102
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
2021-01-15 03:32:44 +00:00
Ryan Macnak 0bf8d38b3d [vm] Defer object pools.
This is a step toward deferring literals, to effectively split binary size for libraries that are more data than code, such as localizations. Bare instructions mode still has all constants in the root snapshot because it has one global ObjectPool.

dart2js+analyzer product X64 non-bare:
app.so           10072728 ->  8479824 (-15.8%)
app.so-2.part.so 14074512 -> 15016976 (6.69%)
app.so-3.part.so  9225936 ->  9888984 (7.18%)

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/41974
Change-Id: If61f6156e3fc2dd539331335b3bf0458102b7c75
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/168991
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
2021-01-08 22:11:03 +00:00
Regis Crelier b3bca1821c [VM/runtime] Decouple representation of function signatures from Function objects.
This fixes issue https://github.com/dart-lang/sdk/issues/43088

This CL improves on https://dart-review.googlesource.com/c/sdk/+/166920 by keeping the names of type parameters.

See go/dart-vm-signatures for motivation for this change.

TEST=existing suites

Change-Id: Ia82f1d322f72d07b2fb253cf914f9b868025c71e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176981
Reviewed-by: Ryan Macnak <rmacnak@google.com>
2021-01-07 23:45:37 +00:00
Tess Strickland 100e12b6cd [vm/compiler] Copy inlined IDs with token positions.
When creating new instructions that inherit a token position that
represents a source location from another instruction, the inheriting
instruction must also have the same inlining ID in order for the source
position represented by the token position to be looked up in the
correct script.

Force this by wrapping both in a single InstructionSource struct which
is taken by instructions which take token positions instead of just a
token position. That way, it's more work to manually transfer the token
position separately from the inlining ID of the instruction than doing
the right thing of transfering both at once.

To ensure this information is kept consistent, we pass InstructionSource
structs through the FlowGraphCompiler all the way down to the
CodeSourceMapBuilder.

This CL also makes the following changes:

* Cache the upper bound of source positions in scripts and use it to add
  a check for if a given real token position is valid for the script
  without iterating over the line starts data for each token position.

* Start inlining intervals appropriately when adding descriptor and
  null check information to the code source map.

Code size changes are minimal on Flutter gallery in release mode
(<0.05% decrease).

TEST=Existing tests on trybots, with manual checking with
--check-token-positions that previous errors are now removed.

Bug: https://github.com/dart-lang/sdk/issues/44436

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-release-x64-try,vm-kernel-nnbd-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-linux-release-simarm64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-ia32-try
Change-Id: I23ced262cb4e9fe9d81356f409e7e8d220d63ee0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/173967
Reviewed-by: Régis Crelier <regis@google.com>
2020-12-18 00:42:14 +00:00
Tess Strickland e2df4d30a0 [vm] Remove non-private uses of TokenPosition::value().
Instead, split each old use into the following cases:

* If the TokenPosition value is expected to be a real token position,
  then use TokenPosition::Pos().

* If the TokenPosition is being serialized in some way, then use
  TokenPosition::Serialize() and change the place where the
  TokenPosition is recreated to use TokenPosition::Deserialize().

* If the value of the TokenPosition is being printed for debugging
  purposes, then just use TokenPosition::ToCString() instead.

That is, we try to pin down when token positions are expected to
be real vs. when other types of token positions can be found.

Another source of possible error when using token positions is to
convert between synthetic and real token positions. In the past,
synthetic token positions may have been based off real token positions,
but that is no longer the case. Thus, all methods that allow
that conversion have been removed, and instead there is a new static
method for constructing synthetic tokens from valid nonces.

This CL also makes it so that Pos() and relational operators on token
positions are only defined on real token positions, to avoid any
assumptions about what the value encoded in synthetic positions mean. To
help with cases where non-real token positions may occur, four helper
methods are added:

* TokenPosition::Min(a, b): A static method that returns the smallest
  real token position provided. If neither `a` or `b` are real,
  returns `a`.

* TokenPosition::Max(a, b): A static method that returns the largest
  real token position provided. If neither `a` or `b` are real,
  returns `a`.

* TokenPosition::IsWithin(start, end): Determines whether `this` falls
  between `start` and `end` (inclusive). If `this` is non-real, then it
  must be either `start` or `end` if synthetic, otherwise false.
  Otherwise, we mimic the old style of range checking, which means that
  non-real starts and ends are treated as less than every real token.

* TokenPosition::CompareForSorting(other): Unlike the relational
  operators, provides a comparison between any types of token positions
  for purposes such as sorting.  Currently only used in the profiler.

It also changes TokenPosition::ToCString() to tag synthetic token
positions, so they can be distinguished from real ones at a glance.

TEST=Existing test suite on trybots, especially the observatory tests
which make heavy use of the debugger and the unit tests for the
profiler/source report modules.

Bug: https://github.com/dart-lang/sdk/issues/44436

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-nnbd-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-linux-debug-x64-try,vm-kernel-linux-release-x64-try,vm-kernel-nnbd-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try
Change-Id: Ic06aa0bc7a1f0fbac7257ed22ca5e7e0ccd7f3f2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174924
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
2020-12-16 08:27:32 +00:00
Ryan Macnak e2b88eea95 [vm] Fix gcc build.
TEST=local build
Change-Id: Ia4c28bda4b353e9f353ddbbf854df085adf831c1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/175562
Reviewed-by: Liam Appelbe <liama@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
2020-12-10 20:10:07 +00:00
Jens Johansen 6c19a8fc81 [VM] Read and report constant constructor coverage from dill (2nd try)
This CL makes use of the now included constant constructor coverage
in the dill file.

It works like this:
* When the CFE evaluates constants, every constant constructor
  invocation evaluated saves the reference to the constructor in the
  `Source` (from the Components uri to source table) for the callers
  Library.
* This data is loaded into the VM in a "raw" format.
* When a request for coverage comes in, the VM - on top of the normal
  coverage processing - goes through all scripts to find constant
  constructor coverage for the requested script and offset. Note that
  all scripts must be checked because library A can have evaluated a
  constructor from library B - so even if only coverage for library B
  was requested, library A has to be checked.
  For all constructors found the start and end position is reported as
  covered. Note that this does not mark any initializes and there are
  (at least currently) no good way of marking which initializes were
  evaluated (because it has to be stable across edits even when the
  `advanced invalidation feature` is enabled).
* Note that the reason for the coverage to work on references - as
  hinted above - is because we want it to be stable across hot reloads
  even if/when advanced invalidation is enabled. This means, that
  library A cannot record "positional coverage" for library B because
  library B might get (for instance) new comments that will make any old
  offsets invalid. By using references we always lookup in the current
  world and use the correct offsets.

https://github.com/dart-lang/sdk/issues/38934

TEST=Existing test suite, new tests for the new coverage added.

Change-Id: I29531247a4b91a99d9a459cfdefbb9798e9c948f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/175246
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
2020-12-08 10:47:43 +00:00
Ryan Macnak fc4726e1cb [vm, gc] Fix write-write race between array truncation and the concurrent sweeper.
TEST=tsan
Bug: https://github.com/dart-lang/sdk/issues/44091
Change-Id: I589b31c0b8664d6b10aa5aad5ed6079c55cfba0d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174843
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2020-12-07 20:05:38 +00:00
Ryan Macnak abbb51e1ff [vm] Clean up metadata tracking.
Remove the use of Fields, which have since the metadata mechanism was introduced come to require global registration.

Retain some sloppiness matching of declarations by name instead of identity for the sake of hot reload.

TEST=ci
Change-Id: Ifa4cc7724096c606f994b057b7838e124ceb3626
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/175141
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-12-07 19:43:48 +00:00
Ryan Macnak 28fe36c637 [vm, compiler] Recognize WeakProperty's accessors.
The layout of WeakProperty is defined in C++ instead of Dart. Add missing recognition of its accessors so the compiler can use direct field access instead of always going through natives. Compare LinkedHashMap.

Change the sentinel for WeakProperty lists to object null so that no special constructor is needed.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/44333
Change-Id: I8686383053c2c345c972b6615b514a1381e79fda
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/175001
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
2020-12-04 22:25:12 +00:00
Clement Skau c5eb666bcf Revert "[vm] Track metadata by identity instead of name."
This reverts commit bfd382820f.

Reason for revert: Breaks several lib_2/mirrors/ tests

Original change's description:
> [vm] Track metadata by identity instead of name.
>
> Remove the use of Fields, which have since the metadata mechanism was introduced come to require global registration.
>
> TEST=ci
> Change-Id: Ic2e0c4408557514507fd732e0cb19b022b2539c7
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/161631
> Commit-Queue: Ryan Macnak <rmacnak@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>

TBR=kustermann@google.com,aam@google.com,rmacnak@google.com

Change-Id: Icf75e91872d9c85ce9be29a9a178d72ca024c98b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174920
Reviewed-by: Clement Skau <cskau@google.com>
Commit-Queue: Clement Skau <cskau@google.com>
2020-12-03 08:03:11 +00:00
Ryan Macnak bfd382820f [vm] Track metadata by identity instead of name.
Remove the use of Fields, which have since the metadata mechanism was introduced come to require global registration.

TEST=ci
Change-Id: Ic2e0c4408557514507fd732e0cb19b022b2539c7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/161631
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-12-02 23:43:07 +00:00
Ryan Macnak ca5853779b [vm, gc] Route most heap reads through LoadPointer.
Provides a good point to apply a read barrier, pointer decompression, or TSAN annotations.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/44091
Change-Id: I4e6930264f8ef8399e261fd24fcab78731d6e29c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174484
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-12-02 21:08:58 +00:00
Jens Johansen 05bac41e39 Revert "[VM] Read and report constant constructor coverage from dill"
This reverts commit 5370c56c80.

Reason for revert: Failures on
dartk-android-product-arm
dartk-android-product-arm
dartkp-linux-release-arm-qemu

like this:

sizeof(ScriptLayout) got 64, Script_InstanceSize expected 56
../../runtime/vm/dart.cc: 160: error: CheckOffsets failed. Try updating offsets by running ./tools/run_offsets_extractor.sh

sizeof(ScriptLayout) got 64, AOT_Script_InstanceSize expected 56
../../runtime/vm/dart.cc: 160: error: CheckOffsets failed. Try updating offsets by running ./tools/run_offsets_extractor.sh


Original change's description:
> [VM] Read and report constant constructor coverage from dill
>
> This CL makes use of the now included constant constructor coverage
> in the dill file.
>
> It works like this:
> * When the CFE evaluates constants, every constant constructor
>   invocation evaluated saves the reference to the constructor in the
>   `Source` (from the Components uri to source table) for the callers
>   Library.
> * This data is loaded into the VM in a "raw" format.
> * When a request for coverage comes in, the VM - on top of the normal
>   coverage processing - goes through all scripts to find constant
>   constructor coverage for the requested script and offset. Note that
>   all scripts must be checked because library A can have evaluated a
>   constructor from library B - so even if only coverage for library B
>   was requested, library A has to be checked.
>   For all constructors found the start and end position is reported as
>   covered. Note that this does not mark any initializes and there are
>   (at least currently) no good way of marking which initializes were
>   evaluated (because it has to be stable across edits even when the
>   `advanced invalidation feature` is enabled).
> * Note that the reason for the coverage to work on references - as
>   hinted above - is because we want it to be stable across hot reloads
>   even if/when advanced invalidation is enabled. This means, that
>   library A cannot record "positional coverage" for library B because
>   library B might get (for instance) new comments that will make any old
>   offsets invalid. By using references we always lookup in the current
>   world and use the correct offsets.
>
> https://github.com/dart-lang/sdk/issues/38934
>
> TEST=Existing test suite, new tests for the new coverage added.
>
> Change-Id: I925963d1a9b9907efe621c72deb7348fa3be5ae8
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/171949
> Commit-Queue: Jens Johansen <jensj@google.com>
> Reviewed-by: Ben Konyi <bkonyi@google.com>
> Reviewed-by: Vyacheslav Egorov <vegorov@google.com>

TBR=vegorov@google.com,bkonyi@google.com,jensj@google.com

Change-Id: I5187e6749d59ded250ec0933a94db0536485b70a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174470
Reviewed-by: Jens Johansen <jensj@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
2020-12-01 14:12:16 +00:00
Jens Johansen 5370c56c80 [VM] Read and report constant constructor coverage from dill
This CL makes use of the now included constant constructor coverage
in the dill file.

It works like this:
* When the CFE evaluates constants, every constant constructor
  invocation evaluated saves the reference to the constructor in the
  `Source` (from the Components uri to source table) for the callers
  Library.
* This data is loaded into the VM in a "raw" format.
* When a request for coverage comes in, the VM - on top of the normal
  coverage processing - goes through all scripts to find constant
  constructor coverage for the requested script and offset. Note that
  all scripts must be checked because library A can have evaluated a
  constructor from library B - so even if only coverage for library B
  was requested, library A has to be checked.
  For all constructors found the start and end position is reported as
  covered. Note that this does not mark any initializes and there are
  (at least currently) no good way of marking which initializes were
  evaluated (because it has to be stable across edits even when the
  `advanced invalidation feature` is enabled).
* Note that the reason for the coverage to work on references - as
  hinted above - is because we want it to be stable across hot reloads
  even if/when advanced invalidation is enabled. This means, that
  library A cannot record "positional coverage" for library B because
  library B might get (for instance) new comments that will make any old
  offsets invalid. By using references we always lookup in the current
  world and use the correct offsets.

https://github.com/dart-lang/sdk/issues/38934

TEST=Existing test suite, new tests for the new coverage added.

Change-Id: I925963d1a9b9907efe621c72deb7348fa3be5ae8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/171949
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
2020-12-01 12:32:15 +00:00
Ryan Macnak d3d92e316b [vm, tsan] Consistently modify the object header as a full word.
An address containing an object header is sometimes interpreted as a object slot due to array truncation and concurrent marking/sweeping. Always accessing it as a word assuages TSAN that it won't be subject to tearing, and allows for the removal of TSAN suppressions from header access. In turn, this will allow TSAN to verify some acquire/release header accesses.

TEST=tsan
Bug: https://github.com/dart-lang/sdk/issues/44091
Change-Id: I7bf6449bf7dfeabd9db76e4bb37456e3be2d5124
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/172861
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-11-30 23:43:54 +00:00
Martin Kustermann dab1efeb5d [vm/concurrency] Make the IGs own the initial static field value table
As part of making lightweight isolates work in JIT, we will need to
ensure that whenever a new isolate is spawned it will get it's initial
global field table populated.

In order to achieve this we make the isolate groups initial field table
the authoritive place where we

  a) register initial static field values
  b) serializer reads them from, deserializer writes them to

This allows us to also remove the `FieldLayout::initial_saved_value_`
that was present for both static and non-static fields. In reality this
initial saved value is only meaningful for static fields though it was
kept in memory as well as (de)serialized even for non-static fields.

The one place where it was actually used for non-static fields was
incorrect and should instead use `null`.

The removal of this field results in net removal of code in this CL.

Issue https://github.com/dart-lang/sdk/issues/36097

TEST=Internal refactoring, relying on existing test coverage.

Change-Id: I088a87e2ea159bac7fa7f1f360da553d752e6569
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/173263
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2020-11-24 11:25:58 +00:00