[clang-query] Add comment token handling

Summary:
It is possible to pass a file of commands to clang-query using the
command line option -f or --preload.  Make it possible to write comments
in such files.

Reviewers: aaron.ballman

Reviewed By: aaron.ballman

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D52752

llvm-svn: 343666

clang-tools-extra/clang-query/QueryParser.cpp

@@ -37,6 +37,11 @@ StringRef QueryParser::lexWord() {
     ++Begin;
   }
 
+  if (*Begin == '#') {
+    End = Begin;
+    return StringRef();
+  }
+
   const char *WordBegin = Begin;
 
   while (true) {
@@ -127,6 +132,7 @@ namespace {
 
 enum ParsedQueryKind {
   PQK_Invalid,
+  PQK_Comment,
   PQK_NoOp,
   PQK_Help,
   PQK_Let,
@@ -161,6 +167,7 @@ QueryRef QueryParser::doParse() {
   StringRef CommandStr;
   ParsedQueryKind QKind = LexOrCompleteWord<ParsedQueryKind>(this, CommandStr)
                               .Case("", PQK_NoOp)
+                              .Case("#", PQK_Comment, /*IsCompletion=*/false)
                               .Case("help", PQK_Help)
                               .Case("l", PQK_Let, /*IsCompletion=*/false)
                               .Case("let", PQK_Let)
@@ -173,6 +180,7 @@ QueryRef QueryParser::doParse() {
                               .Default(PQK_Invalid);
 
   switch (QKind) {
+  case PQK_Comment:
   case PQK_NoOp:
     return new NoOpQuery;
 

clang-tools-extra/unittests/clang-query/QueryParserTest.cpp

@@ -146,6 +146,17 @@ TEST_F(QueryParserTest, LetUnlet) {
             cast<InvalidQuery>(Q)->ErrStr);
 }
 
+TEST_F(QueryParserTest, Comment) {
+  QueryRef Q = parse("# let foo decl()");
+  ASSERT_TRUE(isa<NoOpQuery>(Q));
+
+  Q = parse("let foo decl() # creates a decl() matcher called foo");
+  ASSERT_TRUE(isa<LetQuery>(Q));
+
+  Q = parse("set bind-root false # reduce noise");
+  ASSERT_TRUE(isa<SetQuery<bool>>(Q));
+}
+
 TEST_F(QueryParserTest, Complete) {
   std::vector<llvm::LineEditor::Completion> Comps =
       QueryParser::complete("", 0, QS);