tree a49f29e8f41d77b172c86579b8f676f8c5ff6313
parent 79b85ae94409225d57e9bc78f54a566c896e1aa6
author Martin Kustermann <kustermann@google.com> 1542367102 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1542367102 +0000

[VM] Add @pragma annotations on Field, make @pragma annotations work generally

Currently the @pramga('vm:exact-result-type') annotation only works if
the function is a recognized method.  This change changes that to make
the VM just look if a function has the annotation (no matter if it's
also in the list of recognized methods or not).

Furthermore this CL adds a "has_pragma" bit to [Field] objects, similar
to how we have it on [Function]/[Class]es.  This allows annotating
fields with types, as we do with function return types.

Furthermore this CL lets the type propgagator use
@pragma('vm:exact-result-type') annotations to narrow the [CompileType]
set on [LoadFieldInstr]s.

Since the @pragma is a general feature, this CL moves the
`Function::FindPragma()` to `Library::FindPragma` (which is where any
other metadata lookup happens).  We also let the `FindPragma` accept any
of Class/Function/Field objects.

Furthermore this CL adds a bailout if we try to evaluate metadata in
the background compiler, since the background compiler is not allowed
to execute generated code. The bailout should trigger a re-compilation
on the mutator thread.

Furthermore the `FindPragma()` function is fixed to handle the case
when the evaluation of the metadata results in e.g. a language error.
In this case we simply claim to not have found a pragma annotation.

Issue https://github.com/dart-lang/sdk/issues/31954

Change-Id: I0900a80d5ae0f3e8d09baf13cba1b20dd974df31
Reviewed-on: https://dart-review.googlesource.com/c/84037
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>