tree cef4c3794ebeb53c3d895309d845ff4335ff3dd9
parent a000a117151ae97c0401e74de4c7fce455dabdce
author Alexander Markov <alexmarkov@google.com> 1636129467 +0000
committer Alexander Thomas <athom@google.com> 1637145489 +0100

[vm/compiler] Fix handling of captured try_finally_return_value variable

In async/async* methods synthetic :try_finally_return_value variable
(which is used to hold return value across finally) could be
captured, so flow graph builder needs to have correct context_depth_
in order to access it using LoadLocal(finally_return_variable)
when building flow graph for return statement.

Previously, flow graph builder left context in an unspecified state
and depth after TranslateFinallyFinalizers(NULL, -1), which caused
incorrect code being generated for LoadLocal(finally_return_variable).

This change fixes this problem by
* passing correct target_context_depth to TranslateFinallyFinalizers
  so context is adjusted to a known depth regardless of context
  depth which is used by finally;
* setting context_depth_ for LoadLocal(finally_return_variable)
  and then restoring it (to be able to continue building flow graph
  for the enclosing AST nodes).

TEST=tests/language/async_star/regression_47610_test.dart
Fixes https://github.com/dart-lang/sdk/issues/47610

Change-Id: Id15ea719ddda892eaff0b06f6450b1a8de36e8da
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/219283
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>