[Clang] Use range loops and autos in utils/TableGen/ClangAttrEmitter.cpp

[Eugene.Zelenko]

Summary

I fixed Clang-tidy modernize-loop-convert and modernize-use-auto. Autos are also used for pointer variables assigned via casts. Patch includes other minor cleanups.

Fixes are in both source and generated code.

Build and regressions were finr on RHEL 6.

[aaron.ballman]

A few small nits, but mostly looks good. Thank you for this!

utils/TableGen/ClangAttrEmitter.cpp

2404

I don't think this is the correct change (a const std::foo<bar>::iterator is often different than a std::foo<bar>::const_iterator). I would drop the const since the original is an iterator instead of a const_iterator anyway.

2518

Same here.

2581

And here.

[Eugene.Zelenko]

Replaced const auto with auto as suggested by Aaron.

[aaron.ballman]

LGTM, thank you!

utils/TableGen/ClangAttrEmitter.cpp

     std::vector<std::string> uniques;
     std::set<std::string> unique_set(enums.begin(), enums.end());
     for (const auto &i : enums) {
-      std::set<std::string>::iterator set_i = unique_set.find(i);
+      auto set_i = unique_set.find(i);
       if (set_i != unique_set.end()) {
         uniques.push_back(i);
         unique_set.erase(set_i);

       OS << type << " " << getUpperName();
     }
     void writeDeclarations(raw_ostream &OS) const override {
-      std::vector<std::string>::const_iterator i = uniques.begin(),
-                                               e = uniques.end();
+      auto i = uniques.cbegin(), e = uniques.cend();
       // The last one needs to not have a comma.
       --e;
 

     bool isVariadicEnumArg() const override { return true; }
     
     void writeDeclarations(raw_ostream &OS) const override {
-      std::vector<std::string>::const_iterator i = uniques.begin(),
-                                               e = uniques.end();
+      auto i = uniques.cbegin(), e = uniques.cend();
       // The last one needs to not have a comma.
       --e;
 

     }
 
     void writeTemplateInstantiation(raw_ostream &OS) const override {
-      OS << "      " << getType() << " *tempInst" << getUpperName()
+      OS << "      auto *tempInst" << getUpperName()
          << " = new (C, 16) " << getType()
          << "[A->" << getLowerName() << "_size()];\n";
       OS << "      {\n";

       }
       OS << ", SourceRange Loc = SourceRange()";
       OS << ") {\n";
-      OS << "    " << R.getName() << "Attr *A = new (Ctx) " << R.getName();
+      OS << "    auto *A = new (Ctx) " << R.getName();
       OS << "Attr(Loc, Ctx, ";
       for (auto const &ai : Args) {
         if (ai->isFake() && !emitFake) continue;

     OS << "};\n\n";
   }
 
-  OS << "#endif\n";
+  OS << "#endif // LLVM_CLANG_ATTR_CLASSES_INC\n";
 }
 
 // Emits the class method definitions for attributes.

 
 static void EmitAttrList(raw_ostream &OS, StringRef Class,
                          const std::vector<Record*> &AttrList) {
-  std::vector<Record*>::const_iterator i = AttrList.begin(), e = AttrList.end();
+  auto i = AttrList.cbegin(), e = AttrList.cend();
 
   if (i != e) {
     // Move the end iterator back to emit the last attribute.

     OS << "  case attr::" << R.getName() << ": {\n";
     Args = R.getValueAsListOfDefs("Args");
     if (R.isSubClassOf(InhClass) || !Args.empty())
-      OS << "    const " << R.getName() << "Attr *SA = cast<" << R.getName()
+      OS << "    const auto *SA = cast<" << R.getName()
          << "Attr>(A);\n";
     if (R.isSubClassOf(InhClass))
       OS << "    Record.push_back(SA->isInherited());\n";

   GenerateHasAttrSpellingStringSwitch(Pragma, OS, "Pragma");
   OS << "case AttrSyntax::CXX: {\n";
   // C++11-style attributes are further split out based on the Scope.
-  for (std::map<std::string, std::vector<Record *>>::iterator I = CXX.begin(),
-                                                              E = CXX.end();
-       I != E; ++I) {
+  for (auto I = CXX.cbegin(), E = CXX.cend(); I != E; ++I) {
     if (I != CXX.begin())
       OS << " else ";
     if (I->first.empty())

       continue;
     }
 
-    OS << "      const " << R.getName() << "Attr *A = cast<"
+    OS << "      const auto *A = cast<"
        << R.getName() << "Attr>(At);\n";
     bool TDependent = R.getValueAsBit("TemplateDependent");
 

   // If this code has already been generated, simply return the previous
   // instance of it.
   static std::set<std::string> CustomSubjectSet;
-  std::set<std::string>::iterator I = CustomSubjectSet.find(FnName);
+  const auto I = CustomSubjectSet.find(FnName);
   if (I != CustomSubjectSet.end())
     return *I;
 

   }
 
   OS << "static bool " << FnName << "(const Decl *D) {\n";
-  OS << "  if (const " << GetSubjectWithSuffix(Base) << " *S = dyn_cast<";
+  OS << "  if (const auto *S = dyn_cast<";
   OS << GetSubjectWithSuffix(Base);
   OS << ">(D))\n";
   OS << "    return " << Subject.getValueAsString("CheckCode") << ";\n";

   // If this code has already been generated, simply return the previous
   // instance of it.
   static std::set<std::string> CustomLangOptsSet;
-  std::set<std::string>::iterator I = CustomLangOptsSet.find(FnName);
+  const auto I = CustomLangOptsSet.find(FnName);
   if (I != CustomLangOptsSet.end())
     return *I;
 

   // If this code has already been generated, simply return the previous
   // instance of it.
   static std::set<std::string> CustomTargetSet;
-  std::set<std::string>::iterator I = CustomTargetSet.find(FnName);
+  const auto I = CustomTargetSet.find(FnName);
   if (I != CustomTargetSet.end())
     return *I;
 

 
     Args = R.getValueAsListOfDefs("Args");
     if (!Args.empty()) {
-      OS << "    const " << R.getName() << "Attr *SA = cast<" << R.getName()
+      OS << "    const auto *SA = cast<" << R.getName()
          << "Attr>(A);\n";
       for (const auto *Arg : Args)
         createArgument(*Arg, R.getName())->writeDump(OS);
 
-      for (auto AI = Args.begin(), AE = Args.end(); AI != AE; ++AI)
-        createArgument(**AI, R.getName())->writeDumpChildren(OS);
+      for (const auto *AI : Args)
+        createArgument(*AI, R.getName())->writeDumpChildren(OS);
     }
     OS <<
       "    break;\n"