[clang-query] Add option to print matcher expression

[steveire]

Summary

This is useful if using clang-query -f with a file containing multiple
matchers.

[aaron.ballman]

LGTM!

clang-query/Query.h

struct QuitQuery : Query {
   QuitQuery() : Query(QK_Quit) {}
   bool run(llvm::raw_ostream &OS, QuerySession &QS) const override;
 
   static bool classof(const Query *Q) { return Q->Kind == QK_Quit; }
 };
 
 /// Query for "match MATCHER".
 struct MatchQuery : Query {
-  MatchQuery(const ast_matchers::dynamic::DynTypedMatcher &Matcher)
-      : Query(QK_Match), Matcher(Matcher) {}
+  MatchQuery(StringRef Source,
+             const ast_matchers::dynamic::DynTypedMatcher &Matcher)
+      : Query(QK_Match), Matcher(Matcher), Source(Source) {}
   bool run(llvm::raw_ostream &OS, QuerySession &QS) const override;
 
   ast_matchers::dynamic::DynTypedMatcher Matcher;
 
+  StringRef Source;
+
   static bool classof(const Query *Q) { return Q->Kind == QK_Match; }
 };
 
 struct LetQuery : Query {
   LetQuery(StringRef Name, const ast_matchers::dynamic::VariantValue &Value)
       : Query(QK_Let), Name(Name), Value(Value) {}
   bool run(llvm::raw_ostream &OS, QuerySession &QS) const override;
 

clang-query/Query.cpp

for (auto &AST : QS.ASTs) {
     }
     CollectBoundNodes Collect(Matches);
     if (!Finder.addDynamicMatcher(MaybeBoundMatcher, &Collect)) {
       OS << "Not a valid top-level matcher.\n";
       return false;
     }
     Finder.matchAST(AST->getASTContext());
 
+    if (QS.MatcherOutput) {
+      std::string prefixText = "Matcher: ";
+      OS << "\n  " << prefixText << Source << "\n";
+      OS << "  " << std::string(prefixText.size() + Source.size(), '=') << '\n';
+    }
+
     for (auto MI = Matches.begin(), ME = Matches.end(); MI != ME; ++MI) {
       OS << "\nMatch #" << ++MatchCount << ":\n\n";
 
       for (auto BI = MI->getMap().begin(), BE = MI->getMap().end(); BI != BE;
            ++BI) {
         if (QS.DiagOutput) {
           clang::SourceRange R = BI->second.getSourceRange();
           if (R.isValid()) {

clang-query/QueryParser.cpp

 };
 
 enum ParsedQueryVariable {
   PQV_Invalid,
   PQV_Output,
   PQV_BindRoot,
   PQV_DumpOutput,
   PQV_DiagOutput,
-  PQV_PrintOutput
+  PQV_PrintOutput,
+  PQV_MatcherOutput
 };
 
 QueryRef makeInvalidQueryFromDiagnostics(const Diagnostics &Diag) {
   std::string ErrStr;
   llvm::raw_string_ostream OS(ErrStr);
   Diag.printToStreamFull(OS);
   return new InvalidQuery(OS.str());
 }
case PQK_Let: {
     return new LetQuery(Name, Value);
   }
 
   case PQK_Match: {
     if (CompletionPos)
       return completeMatcherExpression();
 
     Diagnostics Diag;
+    auto MatcherSource = StringRef(Begin, End - Begin).trim();
     Optional<DynTypedMatcher> Matcher = Parser::parseMatcherExpression(
-        StringRef(Begin, End - Begin), nullptr, &QS.NamedValues, &Diag);
+        MatcherSource, nullptr, &QS.NamedValues, &Diag);
     if (!Matcher) {
       return makeInvalidQueryFromDiagnostics(Diag);
     }
-    return new MatchQuery(*Matcher);
+    return new MatchQuery(MatcherSource, *Matcher);
   }
 
   case PQK_Set: {
     StringRef VarStr;
     ParsedQueryVariable Var =
         LexOrCompleteWord<ParsedQueryVariable>(this, VarStr)
             .Case("output", PQV_Output)
             .Case("bind-root", PQV_BindRoot)
             .Case("dump-output", PQV_DumpOutput)
             .Case("diag-output", PQV_DiagOutput)
             .Case("print-output", PQV_PrintOutput)
+            .Case("matcher-output", PQV_MatcherOutput)
             .Default(PQV_Invalid);
     if (VarStr.empty())
       return new InvalidQuery("expected variable name");
     if (Var == PQV_Invalid)
       return new InvalidQuery("unknown variable: '" + VarStr + "'");
 
     QueryRef Q;
     switch (Var) {
     case PQV_Output:
       Q = parseSetOutputKind();
       break;
     case PQV_BindRoot:
       Q = parseSetBool(&QuerySession::BindRoot);
       break;
     case PQV_DumpOutput:
       Q = parseSetBool(&QuerySession::DumpOutput);
       break;
     case PQV_DiagOutput:
       Q = parseSetBool(&QuerySession::DiagOutput);
       break;
     case PQV_PrintOutput:
       Q = parseSetBool(&QuerySession::PrintOutput);
       break;
+    case PQV_MatcherOutput:
+      Q = parseSetBool(&QuerySession::MatcherOutput);
+      break;
     case PQV_Invalid:
       llvm_unreachable("Invalid query kind");
     }
 
     return endQuery(Q);
   }
 
   case PQK_Unlet: {

clang-query/QuerySession.h

 
 namespace query {
 
 /// Represents the state for a particular clang-query session.
 class QuerySession {
 public:
   QuerySession(llvm::ArrayRef<std::unique_ptr<ASTUnit>> ASTs)
       : ASTs(ASTs), BindRoot(true), DiagOutput(true), DumpOutput(false),
-        PrintOutput(false), Terminate(false) {}
+        PrintOutput(false), MatcherOutput(false), Terminate(false) {}
 
   llvm::ArrayRef<std::unique_ptr<ASTUnit>> ASTs;
   bool BindRoot;
   bool DiagOutput;
   bool DumpOutput;
   bool PrintOutput;
+  bool MatcherOutput;
   bool Terminate;
   llvm::StringMap<ast_matchers::dynamic::VariantValue> NamedValues;
 };
 
 } // namespace query
 } // namespace clang
 
 #endif

unittests/clang-query/QueryEngineTest.cpp

protected:
   QuerySession S;
 
   std::string Str;
   llvm::raw_string_ostream OS;
 };
 
 TEST_F(QueryEngineTest, Deprecated) {
   DynTypedMatcher FooMatcher = functionDecl(hasName("foo1"));
+  std::string FooMatcherString = "functionDecl(hasName(\"foo1\"))";
 
   EXPECT_TRUE(SetOutputQuery(&QuerySession::PrintOutput).run(OS, S));
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
 
   EXPECT_TRUE(OS.str().find("Binding for \"root\":\nvoid foo1()") !=
               std::string::npos);
 
   Str.clear();
 
   EXPECT_TRUE(SetOutputQuery(&QuerySession::DumpOutput).run(OS, S));
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
   EXPECT_TRUE(OS.str().find("FunctionDecl") != std::string::npos);
 
   Str.clear();
 }
 
 TEST_F(QueryEngineTest, Basic) {
   DynTypedMatcher FnMatcher = functionDecl();
   DynTypedMatcher FooMatcher = functionDecl(hasName("foo1"));
 
+  std::string FooMatcherString = "functionDecl(hasName(\"foo1\"))";
+
   EXPECT_TRUE(NoOpQuery().run(OS, S));
 
   EXPECT_EQ("", OS.str());
 
   Str.clear();
 
   EXPECT_FALSE(InvalidQuery("Parse error").run(OS, S));
 
   EXPECT_EQ("Parse error\n", OS.str());
 
   Str.clear();
 
   EXPECT_TRUE(HelpQuery().run(OS, S));
 
   EXPECT_TRUE(OS.str().find("Available commands:") != std::string::npos);
 
   Str.clear();
 
-  EXPECT_TRUE(MatchQuery(FnMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery("functionDecl()", FnMatcher).run(OS, S));
 
   EXPECT_TRUE(OS.str().find("foo.cc:1:1: note: \"root\" binds here") !=
               std::string::npos);
   EXPECT_TRUE(OS.str().find("foo.cc:2:1: note: \"root\" binds here") !=
               std::string::npos);
   EXPECT_TRUE(OS.str().find("bar.cc:1:1: note: \"root\" binds here") !=
               std::string::npos);
   EXPECT_TRUE(OS.str().find("bar.cc:2:1: note: \"root\" binds here") !=
               std::string::npos);
   EXPECT_TRUE(OS.str().find("4 matches.") != std::string::npos);
 
   Str.clear();
 
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
 
   EXPECT_TRUE(OS.str().find("foo.cc:1:1: note: \"root\" binds here") !=
               std::string::npos);
   EXPECT_TRUE(OS.str().find("1 match.") != std::string::npos);
 
   Str.clear();
 
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::DiagOutput, false).run(OS, S));
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::PrintOutput, true).run(OS, S));
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
 
   EXPECT_TRUE(OS.str().find("Binding for \"root\":\nvoid foo1()") !=
               std::string::npos);
 
   Str.clear();
 
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::PrintOutput, false).run(OS, S));
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::DumpOutput, true).run(OS, S));
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
 
   EXPECT_TRUE(OS.str().find("FunctionDecl") != std::string::npos);
 
   Str.clear();
 
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::DiagOutput, true).run(OS, S));
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::DumpOutput, true).run(OS, S));
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(SetQuery<bool>(&QuerySession::MatcherOutput, true).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
 
   {
     auto Output = OS.str();
+    EXPECT_TRUE(Output.find(FooMatcherString) != std::string::npos);
     EXPECT_TRUE(Output.find("FunctionDecl") != std::string::npos);
     EXPECT_TRUE(Output.find("foo.cc:1:1: note: \"root\" binds here") !=
                 std::string::npos);
   }
 
   Str.clear();
 
   EXPECT_TRUE(SetQuery<bool>(&QuerySession::BindRoot, false).run(OS, S));
-  EXPECT_TRUE(MatchQuery(FooMatcher).run(OS, S));
+  EXPECT_TRUE(MatchQuery(FooMatcherString, FooMatcher).run(OS, S));
 
   EXPECT_TRUE(OS.str().find("No bindings.") != std::string::npos);
 
   Str.clear();
 
-  EXPECT_FALSE(MatchQuery(isMain()).run(OS, S));
+  EXPECT_FALSE(MatchQuery("isMain()", isMain()).run(OS, S));
 
   EXPECT_EQ("Not a valid top-level matcher.\n", OS.str());
 }
 
 TEST_F(QueryEngineTest, LetAndMatch) {
   EXPECT_TRUE(QueryParser::parse("let x \"foo1\"", S)->run(OS, S));
   EXPECT_EQ("", OS.str());
   Str.clear();