do not delay template parsing (needed on Windows)

Author: andrurogerz

Sources/idt/idt.cc

@@ -618,8 +618,17 @@ class consumer : public clang::ASTConsumer {
 
 struct action : clang::ASTFrontendAction {
   void ExecuteAction() override {
+    clang::CompilerInstance &CI = getCompilerInstance();
     if (!include_header.empty())
-      installPPCallbacks();
+      installPPCallbacks(CI);
+
+    // Setting DelayedTemplateParsing to false is equivalent invoking Clang with
+    // the -fno-delayed-template-parsing option. On Windows, Clang defaults to
+    // -fdelayed-template-parsing behavior to more closely match MSVC behavior.
+    // We do not want this behavior because it causes us to miss some expression
+    // nodes in template functions.
+    CI.getInvocation().getLangOpts().DelayedTemplateParsing = false;
+
     clang::ASTFrontendAction::ExecuteAction();
   }
 
@@ -632,10 +641,9 @@ struct action : clang::ASTFrontendAction {
   // Install a callback that will be invoked on every preprocessor include
   // statement. This is done so we can determine if a user-specified custom
   // include statment needs to be added if any annotations are added.
-  void installPPCallbacks() {
-    clang::CompilerInstance &compiler_instance = getCompilerInstance();
-    clang::Preprocessor &preprocessor = compiler_instance.getPreprocessor();
-    clang::SourceManager &source_manager = compiler_instance.getSourceManager();
+  void installPPCallbacks(clang::CompilerInstance &CI) {
+    clang::Preprocessor &preprocessor = CI.getPreprocessor();
+    clang::SourceManager &source_manager = CI.getSourceManager();
     preprocessor.addPPCallbacks(
         std::make_unique<PPCallbacks>(source_manager, file_includes_));
   }