[flang] Change more pointers into references

Remove unused interface

Respond to review comments

Original-commit: flang-compiler/f18@7fdfe7b
Reviewed-on: flang-compiler/f18#809

flang/lib/evaluate/characteristics.h

@@ -85,10 +85,6 @@ class TypeAndShape {
       const semantics::DeclTypeSpec &);
   static std::optional<TypeAndShape> Characterize(
       const Expr<SomeType> &, FoldingContext &);
-  template<typename A>
-  static std::optional<TypeAndShape> Characterize(const A *p) {
-    return p ? Characterize(*p) : std::nullopt;
-  }
 
   DynamicType type() const { return type_; }
   TypeAndShape &set_type(DynamicType t) {

flang/lib/semantics/mod-file.cc

@@ -246,8 +246,8 @@ void ModFileWriter::PutSymbol(
           [&](const CommonBlockDetails &x) {
             decls_ << "common/" << symbol.name();
             char sep = '/';
-            for (const auto *object : x.objects()) {
-              decls_ << sep << DEREF(object).name();
+            for (const Symbol &object : x.objects()) {
+              decls_ << sep << object.name();
               sep = ',';
             }
             decls_ << '\n';
@@ -889,8 +889,8 @@ void SubprogramSymbolCollector::DoSymbol(
             }
           },
           [this](const CommonBlockDetails &details) {
-            for (const Symbol *object : details.objects()) {
-              DoSymbol(*object);
+            for (const Symbol &object : details.objects()) {
+              DoSymbol(object);
             }
           },
           [](const auto &) {},

flang/lib/semantics/resolve-names.cc

@@ -1105,7 +1105,7 @@ class OmpVisitor : public virtual DeclarationVisitor {
   static constexpr Symbol::Flags ompFlagsRequireMark{
       Symbol::Flag::OmpThreadprivate};
 
-  void AddDataSharingAttributeObject(const Symbol *object) {
+  void AddDataSharingAttributeObject(SymbolRef object) {
     dataSharingAttributeObjects_.insert(object);
   }
   void ClearDataSharingAttributeObjects() {
@@ -1126,11 +1126,11 @@ class OmpVisitor : public virtual DeclarationVisitor {
   void CheckMultipleAppearances(
       const parser::Name &, const Symbol &, Symbol::Flag);
 
-  std::set<const Symbol *> dataSharingAttributeObjects_;  // on one directive
+  SymbolSet dataSharingAttributeObjects_;  // on one directive
 };
 
 bool OmpVisitor::HasDataSharingAttributeObject(const Symbol &object) {
-  auto it{dataSharingAttributeObjects_.find(&object)};
+  auto it{dataSharingAttributeObjects_.find(object)};
   return it != dataSharingAttributeObjects_.end();
 }
 
@@ -1190,9 +1190,10 @@ void OmpVisitor::ResolveOmpObject(
               // 2.15.3 When a named common block appears in a list, it has the
               // same meaning as if every explicit member of the common block
               // appeared in the list
-              for (Symbol *object :
+              for (const Symbol &object :
                   symbol->get<CommonBlockDetails>().objects()) {
-                ResolveOmp(*object, ompFlag);
+                Symbol &mutableObject{const_cast<Symbol &>(object)};
+                ResolveOmp(mutableObject, ompFlag);
               }
             } else {
               Say(name.source,  // 2.15.3
@@ -1288,7 +1289,7 @@ void OmpVisitor::CheckMultipleAppearances(
         "on the same OpenMP directive"_err_en_US,
         name.ToString());
   } else {
-    AddDataSharingAttributeObject(target);
+    AddDataSharingAttributeObject(*target);
   }
 }
 
@@ -1867,10 +1868,10 @@ void ScopeHandler::SayLocalMustBeVariable(
 
 void ScopeHandler::SayDerivedType(
     const SourceName &name, MessageFixedText &&msg, const Scope &type) {
-  const Symbol *typeSymbol{type.GetSymbol()};
-  Say(name, std::move(msg), name, DEREF(typeSymbol).name())
-      .Attach(typeSymbol->name(), "Declaration of derived type '%s'"_en_US,
-          typeSymbol->name());
+  const Symbol &typeSymbol{DEREF(type.GetSymbol())};
+  Say(name, std::move(msg), name, typeSymbol.name())
+      .Attach(typeSymbol.name(), "Declaration of derived type '%s'"_en_US,
+          typeSymbol.name());
 }
 void ScopeHandler::Say2(const SourceName &name1, MessageFixedText &&msg1,
     const SourceName &name2, MessageFixedText &&msg2) {
@@ -4184,8 +4185,9 @@ void DeclarationVisitor::CheckSaveStmts() {
               " common block name '%s'"_err_en_US);
         }
       } else {
-        for (Symbol *object : symbol->get<CommonBlockDetails>().objects()) {
-          SetSaveAttr(*object);
+        for (const Symbol &object :
+            symbol->get<CommonBlockDetails>().objects()) {
+          SetSaveAttr(*const_cast<Symbol *>(&object));
         }
       }
     }

flang/lib/semantics/symbol.cc

@@ -447,8 +447,8 @@ std::ostream &operator<<(std::ostream &os, const Details &details) {
           },
           [&](const CommonBlockDetails &x) {
             os << ':';
-            for (const auto *object : x.objects()) {
-              os << ' ' << object->name();
+            for (const Symbol &object : x.objects()) {
+              os << ' ' << object.name();
             }
           },
           [&](const FinalProcDetails &) {},

flang/lib/semantics/symbol.h

@@ -263,11 +263,11 @@ class DerivedTypeDetails {
 
 class ProcBindingDetails : public WithPassArg {
 public:
-  explicit ProcBindingDetails(const Symbol &symbol) : symbol_{&symbol} {}
-  const Symbol &symbol() const { return *symbol_; }
+  explicit ProcBindingDetails(const Symbol &symbol) : symbol_{symbol} {}
+  const Symbol &symbol() const { return symbol_; }
 
 private:
-  const Symbol *symbol_;  // procedure bound to; may be forward
+  SymbolRef symbol_;  // procedure bound to; may be forward
 };
 
 ENUM_CLASS(GenericKind,  // Kinds of generic-spec
@@ -304,14 +304,13 @@ class NamelistDetails {
 
 class CommonBlockDetails {
 public:
-  std::list<Symbol *> &objects() { return objects_; }
-  const std::list<Symbol *> &objects() const { return objects_; }
-  void add_object(Symbol &object) { objects_.push_back(&object); }
+  const SymbolVector &objects() const { return objects_; }
+  void add_object(const Symbol &object) { objects_.emplace_back(object); }
   MaybeExpr bindName() const { return bindName_; }
   void set_bindName(MaybeExpr &&expr) { bindName_ = std::move(expr); }
 
 private:
-  std::list<Symbol *> objects_;
+  SymbolVector objects_;
   MaybeExpr bindName_;
 };
 
@@ -352,14 +351,14 @@ class TypeParamDetails {
 class UseDetails {
 public:
   UseDetails(const SourceName &location, const Symbol &symbol)
-    : location_{location}, symbol_{&symbol} {}
+    : location_{location}, symbol_{symbol} {}
   const SourceName &location() const { return location_; }
-  const Symbol &symbol() const { return *symbol_; }
+  const Symbol &symbol() const { return symbol_; }
   const Symbol &module() const;
 
 private:
   SourceName location_;
-  const Symbol *symbol_;
+  SymbolRef symbol_;
 };
 
 // A symbol with ambiguous use-associations. Record where they were so
@@ -378,11 +377,11 @@ class UseErrorDetails {
 // A symbol host-associated from an enclosing scope.
 class HostAssocDetails {
 public:
-  HostAssocDetails(const Symbol &symbol) : symbol_{&symbol} {}
-  const Symbol &symbol() const { return *symbol_; }
+  HostAssocDetails(const Symbol &symbol) : symbol_{symbol} {}
+  const Symbol &symbol() const { return symbol_; }
 
 private:
-  const Symbol *symbol_;
+  SymbolRef symbol_;
 };
 
 class GenericDetails {

flang/lib/semantics/tools.cc

@@ -88,7 +88,7 @@ bool IsGenericDefinedOp(const Symbol &symbol) {
 
 bool IsCommonBlockContaining(const Symbol &block, const Symbol &object) {
   const auto &objects{block.get<CommonBlockDetails>().objects()};
-  auto found{std::find(objects.begin(), objects.end(), &object)};
+  auto found{std::find(objects.begin(), objects.end(), object)};
   return found != objects.end();
 }