This commit makes a number of adjustments to how the diagnostic verifier handles source buffers and source locations. Specifically:
• Files named by `-verify-additional-file` are read as late as possible so that if some other component of the compiler has already loaded the file, even in some exotic way (e.g. ClangImporter’s source buffer mirroring), it will use the same buffer.
• Expectation source locations now ignore virtual files and other trickery; they are based on the source buffer and physical location in the file.
Hopefully this will make `-verify-additional-file` work better on Windows. As an unintended side effect, it also changes how expectations work in tests that use `#sourceLocation()`.
Parsing declaration list (e.g. member list of nominal decl) is very
different from comma separated list, because it's elements are separated with
new-line or semi-colon. There's no good reason to consolidate them.
Also, declaration list in 'extension' or inside of decl '#if' didn't
emit diagnostics for consecutive declarations on a line.
class C {
#if true
var value: Int = 42 func foo() {}
#endif
}
extension C {
func bar() {} subscript(i: Int) -> Int {
return 24
}
}
This change consolidates declaration list parsing for
members of nominal decls, extensions, and inside of '#if'.
In addition, removed unnecessary property 'TrailingSemiLoc' from decl.
If we found any error in a list, in most cases, we cannot expect that the
following tokens could construct a valid element. Skip them, instead of trying
to parse them as the next element. This significally reduces bogus diagnostics.
Bailout if seeing tok::eof or token that can never start a element, after
parsing an element. This silences superfluous "expected ',' separator" error,
or misleading expected declaration error. What we should emit is
"expected ')' in expression list, or "expected '}' in struct".
