Handle review comments.

Added isSpecialSymbol to check for symbols which don't require debug info.

Author: abidh

flang/include/flang/Optimizer/Support/InternalNames.h

@@ -184,6 +184,10 @@ struct NameUniquer {
 
   static std::string replaceSpecialSymbols(const std::string &name);
 
+  /// Returns true if the passed name denotes a special symbol (e.g. global
+  /// symbol generated for derived type description).
+  static bool isSpecialSymbol(llvm::StringRef name);
+
 private:
   static std::string intAsString(std::int64_t i);
   static std::string doKind(std::int64_t kind);

flang/lib/Optimizer/Support/InternalNames.cpp

@@ -411,3 +411,7 @@ fir::NameUniquer::dropTypeConversionMarkers(llvm::StringRef mangledTypeName) {
 std::string fir::NameUniquer::replaceSpecialSymbols(const std::string &name) {
   return std::regex_replace(name, std::regex{"\\."}, "X");
 }
+
+bool fir::NameUniquer::isSpecialSymbol(llvm::StringRef name) {
+  return !name.empty() && (name[0] == '.' || name[0] == 'X');
+}

flang/lib/Optimizer/Transforms/AddDebugInfo.cpp

@@ -211,13 +211,7 @@ void AddDebugInfoPass::handleGlobalOp(fir::GlobalOp globalOp,
   if (result.first != fir::NameUniquer::NameKind::VARIABLE)
     return;
 
-  // Discard entries that describe a derived type. They start with either '.' or
-  // 'X'. We filter both of them out. Note that NameUniquer makes the name lower
-  // case so user variables should be safe. It would be better if result of the
-  // deconstruct had a flag for such values so that we dont have to look at
-  // string values.
-  if (!result.second.name.empty() &&
-      (result.second.name[0] == '.' || result.second.name[0] == 'X'))
+  if (fir::NameUniquer::isSpecialSymbol(result.second.name))
     return;
 
   unsigned line = getLineFromLoc(globalOp.getLoc());

flang/test/Integration/debug-extra-global-2.f90

@@ -1,8 +1,8 @@
 ! RUN: %flang_fc1 -emit-llvm -debug-info-kind=standalone %s -o - | FileCheck  %s
 
 module m
-integer XcX
+  integer XcX
 end
 
 ! Test that global starting with 'X' don't get filtered.
-CHECK: !DIGlobalVariable(name: "xcx", linkageName: "_QMmExcx"{{.*}})
+! CHECK: !DIGlobalVariable(name: "xcx", linkageName: "_QMmExcx"{{.*}})