I created a second copy of each test where the output changes
after disabling parser lookup. The primary copy now explicitly
calls the frontend with -disable-parser-lookup and expects the
new diagnostics; the *_parser_lookup.swift version calls the
frontend with -enable-parser-lookup and has the old expectations.
This allows us to turn parser lookup on and off by default
without disturbing tests. Once parser lookup is completely
removed we can remove the *_parser_lookup.swift variants.
Use ExtensionDecl::getExtendedNominal() to wire up extensions to their
nominal types early in type checking (the bindExtensions()) operation,
rather than going through type validation to do so.
The parser was using an AST-level name lookup operation to provide a
slightly improved diagnostic (suggesting "self." if there was a member
of that name in the enclosing type context). This is a fairly unfortunate
layering violation: name lookup cannot produce correct results at this
point. Remove the custom diagnostic and the lookup; this can come back
when all lookup moves out of the parser.
...and collapse StaticVar/ClassVar and StaticLet/ClassLet into
StaticProperty/ClassProperty.
"var" and "let" aren't great nouns to use in diagnostics to begin with,
especially alongside semantic terms like "instance method". Focus on
the type vs. non-type aspect instead with "property", which better
matches how people talk about member vars (and lets) anyway.
This crash happens because shouldAddSelfFixit (a check for the expected_self_before_reference diagnotic) performs name lookup inside the parser, which causes a search for extensions, which triggers the mangler, which can get confused if we are in an unfinished declaration (a PatternBindingInitilizer in this case).
A cleaner fix would be to move that logic inside Sema, but it would require much more refactoring that I don’t feel comfortable doing. Instead, this band-aid checks if the innermost type is inside a local context. If that’s the case, we can ignore the search for extensions.
This fixit checks if a decl with the identical name can be found in the parent type
context; if can, we add "self." to try to resolve the issue. rdar://25389852
