Ben Barham ce70727e6f [Deserialization] Output a diagnostic for invalid decls or types ...

47b068d445 output a diagnostic if a
deserialized decl was invalid (checking `Decl::isInvalid`). It had two
major issues:
  1. It incorrectly output diagnostics for valid modules
  2. It did not catch call invalid declarations

(1) is caused by `isInvalid` falling back to checking the storage for
accessors when the interface type hasn't already been computed (a
fallback to prevent a cycle due to `SimpleDidSetRequest` typechecking
the body). Since the `VarDecl` hasn't finished deserializing, it returns
`true` for its `isInvalid` check (even though it would later return
`false`).

For (2), only `ValueDecl`s would ever be invalid, since other
declarations use a bit in `Decl` to check for validity. As that's not
serialized, those would always be valid in deserialization.

To avoid both these issues, instead output a flag for each declaration
representing whether it is invalid (or not). Read that during
deserialization and output a diagnostic if it is invalid. To be extra
sure that a diagnostic is always output on an error, also output one
when deserializing any `ErrorType`. This ensures that SILGen does not
run when allowing errors (and an error is present), as it is likely to
crash when presented with an invalid AST.

Resolves rdar://74541834

2021-03-03 12:12:20 +10:00

64 KiB

Raw Blame History

View Raw