[clang] Skip implicit declarations when attaching doc comments

[sammccall]

Is there a motivating example that would make a good test?

[erik.pilkington]

It looks like this check is done already in getDeclLocForCommentSearch. Any reason to duplicate it?

[jkorous]

@erik.pilkington My bad - didn't check that.

clang/lib/AST/ASTContext.cpp

void ASTContext::attachCommentsToJustParsedDecls(ArrayRef<Decl *> Decls,
   //
   // Note that this way we pick up not only comments that precede the
   // declaration, but also comments that *follow* the declaration -- thanks to
   // the lookahead in the lexer: we've consumed the semicolon and looked
   // ahead through comments.
 
   for (const Decl *D : Decls) {
     assert(D);
-    if (D->isInvalidDecl())
+    if (D->isInvalidDecl() || D->isImplicit())
       continue;
 
     D = &adjustDeclToTemplate(*D);
 
     const SourceLocation DeclLoc = getDeclLocForCommentSearch(D, SourceMgr);
 
     if (DeclLoc.isInvalid() || !DeclLoc.isFileID())
       continue;