In order to support causal-async-stacks, the following synthetic calls
are inserted: _asyncStackTraceHelper, _setAsyncThreadStackTrace and
_clearAsyncThreadStackTrace.
_asyncStackTraceHelper is always generated in the async transformation.
_setAsyncThreadStackTrace and _clearAsyncThreadStackTrace are inserted
during bytecode generation (or in the flow graph builder in case of AST
pipeline). If bytecode generation options are set inconsistently with
--causal-async-stacks VM option, then it was possible that
_asyncStackTraceHelper was generated but other calls were not generated,
causing incorrect (full, non-truncated) async stack traces. This also
causes performance regression as collecting full stack traces takes
much more time.
This change makes generation of all these calls more consistent: if
causal async stacks are disabled during bytecode generation, then all
three calls are omitted. Also, in case these calls were generated and
present in bytecode, but VM option --causal-async-stacks is disabled,
then bytecode flow graph builder turns all these three calls into no-ops.
Change-Id: I93eb1d83c675ee093799bb8e37ca3d60a3c5c19d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120927
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Alexander Markov
62ee78eeec