diagnostics implemented -- see testcases.
I created a new TableGen file for comment diagnostics,
DiagnosticCommentKinds.td, because comment diagnostics don't logically
fit into AST diagnostics file. But I don't feel strongly about it.
This also implements support for self-closing HTML tags in comment
lexer and parser (for example, <br />).
In order to issue precise diagnostics CommentSema needs to know the
declaration the comment is attached to. There is no easy way to find a decl by
comment, so we match comments and decls in lockstep: after parsing one
declgroup we check if we have any new, not yet attached comments. If we do --
then we do the usual comment-finding process.
It is interesting that this automatically handles trailing comments.
We pick up not only comments that precede the declaration, but also
comments that *follow* the declaration -- thanks to the lookahead in
the lexer: after parsing the declgroup we've consumed the semicolon
and looked ahead through comments.
Added -Wdocumentation-html flag for semantic HTML errors to allow the user to
disable only HTML warnings (but not HTML parse errors, which we emit as
warnings in -Wdocumentation).
llvm-svn: 160078