Before, picking a symbol name for a Code object when generating
assembly required adding a placeholder entry in the Dwarf object,
because the Dwarf object separately used a SnapshotTextObjectNamer
to determine the appropriate symbol name to use in relocations.
Instead, now the ImageWriter subclasses are entirely responsible for
creating the symbol name for a given Code object, and that name is
passed when adding the Code object to the Dwarf object.
For Elf output, we eagerly create symbols for sections and Code objects
again in the appropriate symbol table, and so looking up the start of a
given section or Code object can be done simply by asking for the
corresponding symbol's address, removing special case methods and other
workarounds.
We also clean up the generated static and dynamic symbol tables by
only generating local symbols for Code objects and BSS sections (these
are local in assembly output also), and only adding global symbols to
the dynamic symbol table.
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-debug-simarm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-mac-debug-x64-try,vm-kernel-win-debug-x64-try,vm-kernel-precomp-win-release-x64-try
Change-Id: Ie40c0c836681e98f345483136bb6860e5588ef30
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166002
Reviewed-by: Martin Kustermann <kustermann@google.com>
For proper crashpad integration, we need to generate a build ID, as the
build ID generated by crashpad if there is not one will be a simple XOR
of the first text page, which rarely changes for Dart snapshots.
Assembly snapshots already have a build ID included by the assembler, so
we currently only do this for ELF snapshots.
Currently the build ID is a 128-bit hash value that is four separate
32-bit hash values concatenated together. Those hash values come from
the contents of the VM and isolate .text and .rodata sections.
This change also contains work to separate out the concepts of sections
and segments in the ELF builder. Now, consecutive allocated sections
with the same write and execute flags are combined into a single PT_LOAD
segment when possible, which reduces the padding needed to ensure that
segments start on page boundaries in ELF snapshots.
Bug: https://github.com/dart-lang/sdk/issues/42020
Change-Id: I42a837dae665a3902d881b8d151b49ede87d6c67
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm_x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150625
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Introduce an internal StreamingWriteStream wrapper and use that instead.
Also add more ELF-defined constants and use those appropriately.
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-simarm_x64-try,vm-kernel-precomp-linux-product-x64-try
Change-Id: I2bd34ebac60e789aea82c8f064c59351e2c55dd3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149291
Reviewed-by: Clement Skau <cskau@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
Removes an unnecessary change to the names of type testing stubs that
allowed name collisions to happen.
Old commit message:
The flag can be used when creating AOT snapshots. The resulting file can be
used with package:vm/dwarf/convert.dart to convert DWARF-based stack traces
to stack traces with function, file, and line number information.
Currently the saved file will be an ELF file with DWARF debugging information,
but this is subject to change in the future. To avoid being affected by any
changes in format, read the DWARF information from the file using
Dwarf.fromFile() in package:vm/dwarf/dwarf.dart.
Also adds --dwarf-stack-traces to the VM global flag list, so its value at
compilation will be read out of snapshots by the precompiled runtime.
Fixes https://github.com/dart-lang/sdk/issues/39512, which was due to
a missing compiler::target:: prefix for Instructions::HeaderSize() in
BlobImageWriter::WriteText().
Exposes the information suggested in
https://github.com/dart-lang/sdk/issues/39490 so that package:vm/dwarf
can appropriately convert absolute PC addresses to the correct virtual
address for a given DWARF line number program.
Bug: https://github.com/dart-lang/sdk/issues/35851
Change-Id: I6723449dceb0b89c054a1f1e70e7acd7749baf14
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128730
Reviewed-by: Martin Kustermann <kustermann@google.com>
REASON: the first commit in the chain contains a change that breaks internal
Flutter roll due to duplicated symbols for type testing stubs in assembly
snapshots.
Revert "[vm/compiler] Add --save-debugging-info flag to gen_snapshot."
This reverts commit c2b6c2e1db.
Revert "[vm] De-obfuscate function and file names in DWARF sections."
This reverts commit 4b8fd3c412.
Revert "[vm] Add docs for DWARF stack traces and related tools/libraries."
This reverts commit 5543e5ceb8.
Revert "[vm] Weaken dwarf_stack_trace expected stack trace."
This reverts commit 5824d3ed53.
Change-Id: I95ecd16fe493f61ae761dabfdd91a6ec0c2f0ca3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/128776
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
The flag can be used when creating AOT snapshots. The resulting file can be
used with package:vm/dwarf/convert.dart to convert DWARF-based stack traces
to stack traces with function, file, and line number information.
Currently the saved file will be an ELF file with DWARF debugging information,
but this is subject to change in the future. To avoid being affected by any
changes in format, read the DWARF information from the file using
Dwarf.fromFile() in package:vm/dwarf/dwarf.dart.
Also adds --dwarf-stack-traces to the VM global flag list, so its value at
compilation will be read out of snapshots by the precompiled runtime.
Fixes https://github.com/dart-lang/sdk/issues/39512, which was due to
a missing compiler::target:: prefix for Instructions::HeaderSize() in
BlobImageWriter::WriteText().
Exposes the information suggested in
https://github.com/dart-lang/sdk/issues/39490 so that package:vm/dwarf
can appropriately convert absolute PC addresses to the correct virtual
address for a given DWARF line number program.
Bug: https://github.com/dart-lang/sdk/issues/35851
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-precomp-mac-release-simarm_x64-try,vm-kernel-precomp-win-release-x64-try
Change-Id: I80d900fd9e5f1e2399ad3f2fd25c85131a7ea43c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121857
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Also switch some CQ bots using blobs to ELF. Once all embedders have migrated, we will remove blobs
support entirely.
Change-Id: Ie5e8c1187ad6c1af362b5715daafd3641bc8cc0e
Cq-Include-Trybots:luci.dart.try:vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-linux-release-simarm-try,vm-kernel-precomp-linux-release-simarm64-try,vm-kernel-precomp-bare-linux-release-simarm-try,vm-kernel-precomp-mac-debug-simarm_x64-try,vm-kernel-precomp-mac-release-simarm64-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-precomp-android-release-arm-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/116620
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Tess Strickland