[clang-query] Add check to prevent setting srcloc when no introspection is available.

[njames93]

Summary

Checks if introspection support is available set output kind parser.
If it isn't present the auto complete will not suggest srcloc and an error query will be reported if a user tries to access it.

[njames93]

Cleanup.

[njames93]

Fix up tests(probably, see what premerge says)

[steveire]

LGTM!

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

249 ↗

(On Diff #340902)

nit: I think HasIntrospection ? 4 : 3 would be clearer.

[njames93]

Nit.

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

 //===---- QueryParser.cpp - clang-query command parser --------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "QueryParser.h"
 #include "Query.h"
 #include "QuerySession.h"
 #include "clang/ASTMatchers/Dynamic/Parser.h"
 #include "clang/Basic/CharInfo.h"
+#include "clang/Tooling/NodeIntrospection.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include <set>
 
 using namespace llvm;
 using namespace clang::ast_matchers::dynamic;
 
 namespace clang {
QueryRef QueryParser::parseSetBool(bool QuerySession::*Var) {
   if (Value == ~0u) {
     return new InvalidQuery("expected 'true' or 'false', got '" + ValStr + "'");
   }
   return new SetQuery<bool>(Var, Value);
 }
 
 template <typename QueryType> QueryRef QueryParser::parseSetOutputKind() {
   StringRef ValStr;
-  unsigned OutKind = LexOrCompleteWord<unsigned>(this, ValStr)
-                         .Case("diag", OK_Diag)
-                         .Case("print", OK_Print)
-                         .Case("detailed-ast", OK_DetailedAST)
-                         .Case("srcloc", OK_SrcLoc)
-                         .Case("dump", OK_DetailedAST)
-                         .Default(~0u);
+  unsigned OutKind =
+      LexOrCompleteWord<unsigned>(this, ValStr)
+          .Case("srcloc", OK_SrcLoc,
+                /*IsCompletion=*/
+                tooling::NodeIntrospection::hasIntrospectionSupport())
   if (OutKind == ~0u) {
     return new InvalidQuery(
-        "expected 'diag', 'print', 'detailed-ast' or 'dump', got '" + ValStr +
-        "'");
+        "expected 'diag', 'print', 'detailed-ast'" +
+        StringRef(tooling::NodeIntrospection::hasIntrospectionSupport()
+                      ? ", 'srcloc'"
+                      : "") +
+        " or 'dump', got '" + ValStr + "'");
   }
 
   switch (OutKind) {
   case OK_DetailedAST:
     return new QueryType(&QuerySession::DetailedASTOutput);
   case OK_Diag:
     return new QueryType(&QuerySession::DiagOutput);
   case OK_Print:
     return new QueryType(&QuerySession::PrintOutput);
   case OK_SrcLoc:
+    if (tooling::NodeIntrospection::hasIntrospectionSupport())
       return new QueryType(&QuerySession::SrcLocOutput);
+    return new InvalidQuery("'srcloc' output support is not available.");
   }
 
   llvm_unreachable("Invalid output kind");
 }
 
 QueryRef QueryParser::parseSetTraversalKind(TraversalKind QuerySession::*Var) {
   StringRef ValStr;
   unsigned Value =