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).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160078 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/include/clang/AST/CommentDiagnostic.h b/include/clang/AST/CommentDiagnostic.h
new file mode 100644
index 0000000000..6e89410579
--- /dev/null
+++ b/include/clang/AST/CommentDiagnostic.h
@@ -0,0 +1,29 @@
+//===--- CommentDiagnostic.h - Diagnostics for the AST library --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_COMMENTDIAGNOSTIC_H
+#define LLVM_CLANG_COMMENTDIAGNOSTIC_H
+
+#include "clang/Basic/Diagnostic.h"
+
+namespace clang {
+  namespace diag {
+    enum {
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,NOWERROR,SHOWINSYSHEADER,CATEGORY) ENUM,
+#define COMMENTSTART
+#include "clang/Basic/DiagnosticCommentKinds.inc"
+#undef DIAG
+      NUM_BUILTIN_COMMENT_DIAGNOSTICS
+    };
+  }  // end namespace diag
+}  // end namespace clang
+
+#endif
+