Enable comment parsing and semantic analysis to emit diagnostics. A few

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

1 files changed, 13 insertions, 1 deletions

diff --git a/clang/lib/AST/CommentLexer.cpp b/clang/lib/AST/CommentLexer.cpp
index 55cd409a9ca..1f4955d1cf2 100644
--- a/clang/lib/AST/CommentLexer.cpp
+++ b/clang/lib/AST/CommentLexer.cpp
@@ -509,7 +509,7 @@ void Lexer::setupAndLexHTMLOpenTag(Token &T) {
 
   const char C = *BufferPtr;
   if (BufferPtr != CommentEnd &&
-      (C == '>' || isHTMLIdentifierStartingCharacter(C)))
+      (C == '>' || C == '/' || isHTMLIdentifierStartingCharacter(C)))
     State = LS_HTMLOpenTag;
 }
 
@@ -546,6 +546,18 @@ void Lexer::lexHTMLOpenTag(Token &T) {
       formTokenWithChars(T, TokenPtr, tok::html_greater);
       State = LS_Normal;
       return;
+    case '/':
+      TokenPtr++;
+      if (TokenPtr != CommentEnd && *TokenPtr == '>') {
+        TokenPtr++;
+        formTokenWithChars(T, TokenPtr, tok::html_slash_greater);
+      } else {
+        StringRef Text(BufferPtr, TokenPtr - BufferPtr);
+        formTokenWithChars(T, TokenPtr, tok::text);
+        T.setText(Text);
+      }
+      State = LS_Normal;
+      return;
     }
   }