Summary:
1. Previously, in 'BuildGraphOfConvertedClosureFunction', the VM was unable to
correctly forward parameters to converted closure functions when
they were captured in the converted function's body. This could happen when, for
example, a closure was introduced into it by async conversion.
Now, this is fixed by an approach that mirrors the technique in
'BuildGraphOfFunction'.
2. Previously, local variables declared inside loop bodies were being saved in
the loop's enclosing context, so closures within the loop would see new
values initialized to the variable in subsequent iterations.
Now, this is fixed by creating nested contexts for all loops, regardless of
whether the loop variables are captured.
3. Previously, arity checks were not being performed on converted closures, so
they could be called with too few or too many arguments. In the former case, the
missing arguments would be filled in with garbage on the stack.
Now, the assembly generation in 'CompileGraph' inserts argument count checks
for converted closures as well as regular closures.
Test Plan:
Introduced new tests in the closure conversion suite to test each bug:
1. syncstart.dart
2. loop2.dart, blocks.dart, updated for_in_closure.dart
3. arity.dart
With these changes, closure conversion passes all co19 tests in non-checked mode, except those that are not passed without it:
python tools/test.py -m release -c dartk --vm-options "--reify --reify_generic_functions" co19
BUG=
R=dmitryas@google.com
Review-Url: https://codereview.chromium.org/3000333002 .
Samir Jindel
7b53e209c5