The former contents of the VM isolate are now included into each isolate group. This makes each isolate group's heap independent, and in particular allows each heap to be allocated to a separate pointer cage (not done in this CL).
The duplicated stubs that allowed PC relative calls are removed, since the originals can now be the target of PC relative calls.
The bootstrapping needing to load an AppJIT or AppAOT snapshot is reduced to allocating the oddballs. The code is entirely dropped in the AOT runtime, but the JIT runtime still has it to allow for flags to affect the compilation of the stub code. Further refactoring might be able to remove this for the JIT runtime too, with only gen_snapshot knowing how to bootstrap.
Class serialization no longer distinguishes predefined classes.
The page containing null is marked as never-evacuate. null, false and true must not move because the compiler relies on their low bits having certain patterns for some optimizations. (Previously, the entire VM isolate heap never moved.)
Compaction is disabled for IA32. Due to register pressure, some stub calls must not use a scratch register and embed the address of Code.
The page containing the call-through-safepoint stub is frozen when running with --write-protect-code and the stub is created at runtime (instead of loaded from an AppJIT or AppAOT snapshot). This stub must remain executable even during a safepoint, as a foreign call might during return during a safepoint and only block after the stub directs it to the runtime.
The snapshot symbols are renamed to kDartSnapshotData and kDartSnapshotText. There is no need to distinguish the VM isolate's snapshot, and snaphots are per isolate group not per isolate. Aliases with the old names are added to ease migration.
Some global flags that were automatically set based on the VM isolate's snapshot are now isolate group flags and automatically set by the isolate group's snapshot.
TEST=ci
Change-Id: Iee82016057d609112e9b021d178fc3d4d18b5044
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/500621
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
SLSA-Policy-Verified: SLSA Policy Verification Service <devtools-gerritcodereview-exitgate@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
This is a reland of commit 286326f834
Checking into https://github.com/flutter/flutter/issues/108378, it
looks like the stripped snapshot indeed is unchanged, but the .ipa
being benchmarked includes .dSYMs, which is why there was a size
regression in adding this extra debugging information.
If that changes, we can remove the flag, but for now, I've added the
flag back so these symbols are not added by default.
TEST=vm/dart{,_2}/readonly_data_symbols
Original change's description:
> [vm/compiler] Add symbols for read-only data when requested.
>
> Symbols for non-clustered objects in the read-only data section are
now added to the static symbol tables for unstripped snapshots and
separate debugging information.
>
> In DEBUG mode, the name for a non-String read-only data object also
includes the name of the parent object.
>
> TEST=vm/dart{,_2}/readonly_data_symbols
>
> Change-Id: I623b023138aeca0580bc76392882eac5686f8f50
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/251104
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Commit-Queue: Tess Strickland <sstrickl@google.com>
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Change-Id: I41be1c494c4324f1f3fae648d9832772c45bfbaf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/260522
Reviewed-by: Ryan Macnak <rmacnak@google.com>
This reverts commit 286326f834.
Reason for revert: Reverting for the regressions mentioned in https://github.com/flutter/flutter/issues/108378
Original change's description:
> [vm/compiler] Add symbols for read-only data when requested.
>
> Symbols for non-clustered objects in the read-only data section are
> now added to the static symbol tables for unstripped snapshots and
> separate debugging information.
>
> In DEBUG mode, the name for a non-String read-only data object also
> includes the name of the parent object.
>
> TEST=vm/dart{,_2}/readonly_data_symbols
>
> Change-Id: I623b023138aeca0580bc76392882eac5686f8f50
> Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/251104
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Commit-Queue: Tess Strickland <sstrickl@google.com>
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: I82bdabf07c137fbabe7b4c45bdf23011350c3d87
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252801
Reviewed-by: Tess Strickland <sstrickl@google.com>
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Zach Anderson <zra@google.com>
Symbols for non-clustered objects in the read-only data section are
now added to the static symbol tables for unstripped snapshots and
separate debugging information.
In DEBUG mode, the name for a non-String read-only data object also
includes the name of the parent object.
TEST=vm/dart{,_2}/readonly_data_symbols
Change-Id: I623b023138aeca0580bc76392882eac5686f8f50
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-precomp-nnbd-mac-release-arm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/251104
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
This ensures that the relocated addresses of sections with file contents
are contained in the loaded segment.
Fixes https://github.com/dart-lang/sdk/issues/47289
TEST=vm/dart{,_2}/use_save_debugging_info_flag
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Change-Id: I6f7f94900ab1f9f0cb5ead4b0dd63bd2402e5a19
Fixed: 47289
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/214800
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Instead of trying to lazily create artificial nodes when needed for
WeakSerializationReference (WSR) targets in all cases, create them
eagerly for targets in reachable WSRs, since those are guaranteed
to be needed.
Those for unreachable WSRs are still lazily created as needed, since the
WSR won't even be accessed by the clustered snapshot writer unless the
unreachable WSR is part of another unreachable object that has an
artificial node created.
This rework avoids some issues seen on upcoming CLs where the artificial
nodes for WSR targets weren't getting correctly generated.
-----
Also extend the v8 snapshot profile writer tests to check the sizes of
the text and data sections in ELF snapshots. That means the v8 snapshot
profile writer tests check up to three different measures, from most
precise to least precise, depending on the output mode:
* If writing an ELF snapshot directly: the sum of the sizes attributed
to the text and data section symbols are checked to be exactly the
same as the sum of the sizes of the objects in the profile.
* If writing an ELF snapshot either directly or via assembly: the sum
of the sizes of the text and data sections are checked to be the same
as the sum of the sizes of the objects in the profile. If using an
assembler that merges text and data sections, then account for the
padding between the sections using an approximate check.
* For all: Check that the size of the snapshot as a whole is
approximately equal to the sum of the sizes of the objects in the
profile, accounting both for possible padding and for the global
header information and non-data/non-text sections like the dynamic
symbol section.
TEST=vm/data{,_2}/v8_snapshot_profile_writer_test
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Change-Id: I66e0e7fdb5bb98045621bf516f150a4723e08147
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/198942
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Clement Skau <cskau@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Fixes the case where the Image name and type was not written
to the v8 snapshot profile in non-precompiled mode.
Adds core-jit snapshot tests to the v8 snapshot profile writer test.
In core-jit and app-aot-elf modes, verify that all bytes in the
snapshot sections are accounted for in the profile.
Bug: https://github.com/dart-lang/sdk/issues/45787
TEST=vm/dart{,_2}/v8_snapshot_profile_writer_test
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Change-Id: I88be309cdea6293d768e2fa458492387d70fde22
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/196323
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Ryan Macnak