[flang] Emit "raw" name for procedure interface in module file

flang/include/flang/Semantics/symbol.h

@@ -417,8 +417,12 @@ class ProcEntityDetails : public EntityDetails, public WithPassArg {
   ProcEntityDetails(ProcEntityDetails &&) = default;
   ProcEntityDetails &operator=(const ProcEntityDetails &) = default;
 
+  const Symbol *rawProcInterface() const { return rawProcInterface_; }
   const Symbol *procInterface() const { return procInterface_; }
-  void set_procInterface(const Symbol &sym) { procInterface_ = &sym; }
+  void set_procInterfaces(const Symbol &raw, const Symbol &resolved) {
+    rawProcInterface_ = &raw;
+    procInterface_ = &resolved;
+  }
   inline bool HasExplicitInterface() const;
 
   // Be advised: !init().has_value() => uninitialized pointer,
@@ -430,6 +434,7 @@ class ProcEntityDetails : public EntityDetails, public WithPassArg {
   void set_isCUDAKernel(bool yes = true) { isCUDAKernel_ = yes; }
 
 private:
+  const Symbol *rawProcInterface_{nullptr};
   const Symbol *procInterface_{nullptr};
   std::optional<const Symbol *> init_;
   bool isCUDAKernel_{false};

flang/lib/Semantics/check-declarations.cpp

@@ -1195,9 +1195,7 @@ void CheckHelper::CheckArraySpec(
 void CheckHelper::CheckProcEntity(
     const Symbol &symbol, const ProcEntityDetails &details) {
   CheckSymbolType(symbol);
-  const Symbol *interface {
-    details.procInterface() ? &details.procInterface()->GetUltimate() : nullptr
-  };
+  const Symbol *interface{details.procInterface()};
   if (details.isDummy()) {
     if (!symbol.attrs().test(Attr::POINTER) && // C843
         (symbol.attrs().test(Attr::INTENT_IN) ||

flang/lib/Semantics/mod-file.cpp

@@ -924,8 +924,8 @@ void ModFileWriter::PutProcEntity(llvm::raw_ostream &os, const Symbol &symbol) {
       os, symbol,
       [&]() {
         os << "procedure(";
-        if (details.procInterface()) {
-          os << details.procInterface()->name();
+        if (details.rawProcInterface()) {
+          os << details.rawProcInterface()->name();
         } else if (details.type()) {
           PutType(os, *details.type());
         }
@@ -1622,8 +1622,8 @@ void SubprogramSymbolCollector::DoSymbol(
                       }
                     },
                     [this](const ProcEntityDetails &details) {
-                      if (details.procInterface()) {
-                        DoSymbol(*details.procInterface());
+                      if (details.rawProcInterface()) {
+                        DoSymbol(*details.rawProcInterface());
                       } else {
                         DoType(details.type());
                       }

flang/lib/Semantics/resolve-names-utils.cpp

@@ -845,8 +845,9 @@ void SymbolMapper::MapSymbolExprs(Symbol &symbol) {
                        },
           [&](ProcEntityDetails &proc) {
             if (const Symbol *
-                mappedSymbol{MapInterface(proc.procInterface())}) {
-              proc.set_procInterface(*mappedSymbol);
+                mappedSymbol{MapInterface(proc.rawProcInterface())}) {
+              proc.set_procInterfaces(
+                  *mappedSymbol, BypassGeneric(mappedSymbol->GetUltimate()));
             } else if (const DeclTypeSpec * mappedType{MapType(proc.type())}) {
               proc.set_type(*mappedType);
             }

flang/lib/Semantics/resolve-names.cpp

@@ -4983,7 +4983,8 @@ Symbol &DeclarationVisitor::DeclareProcEntity(
           "The interface for procedure '%s' has already been declared"_err_en_US);
       context().SetError(symbol);
     } else if (interface) {
-      details->set_procInterface(*interface);
+      details->set_procInterfaces(
+          *interface, BypassGeneric(interface->GetUltimate()));
       if (interface->test(Symbol::Flag::Function)) {
         symbol.set(Symbol::Flag::Function);
       } else if (interface->test(Symbol::Flag::Subroutine)) {
@@ -5658,10 +5659,10 @@ void DeclarationVisitor::Post(const parser::ProcInterface &x) {
 }
 void DeclarationVisitor::Post(const parser::ProcDecl &x) {
   const auto &name{std::get<parser::Name>(x.t)};
-  const Symbol *procInterface{nullptr};
-  if (interfaceName_ && interfaceName_->symbol) {
-    procInterface = &BypassGeneric(*interfaceName_->symbol);
-  }
+  // Don't use BypassGeneric or GetUltimate on this symbol, they can
+  // lead to unusable names in module files.
+  const Symbol *procInterface{
+      interfaceName_ ? interfaceName_->symbol : nullptr};
   auto attrs{HandleSaveName(name.source, GetAttrs())};
   DerivedTypeDetails *dtDetails{nullptr};
   if (Symbol * symbol{currScope().symbol()}) {
@@ -6624,10 +6625,9 @@ void DeclarationVisitor::CheckExplicitInterface(const parser::Name &name) {
   if (const Symbol * symbol{name.symbol}) {
     const Symbol &ultimate{symbol->GetUltimate()};
     if (!context().HasError(*symbol) && !context().HasError(ultimate) &&
-        !ultimate.HasExplicitInterface()) {
+        !BypassGeneric(ultimate).HasExplicitInterface()) {
       Say(name,
-          "'%s' must be an abstract interface or a procedure with "
-          "an explicit interface"_err_en_US,
+          "'%s' must be an abstract interface or a procedure with an explicit interface"_err_en_US,
           symbol->name());
     }
   }

flang/lib/Semantics/symbol.cpp

@@ -452,6 +452,9 @@ llvm::raw_ostream &operator<<(
 llvm::raw_ostream &operator<<(
     llvm::raw_ostream &os, const ProcEntityDetails &x) {
   if (x.procInterface_) {
+    if (x.rawProcInterface_ != x.procInterface_) {
+      os << ' ' << x.rawProcInterface_->name() << " ->";
+    }
     os << ' ' << x.procInterface_->name();
   } else {
     DumpType(os, x.type());

flang/lib/Semantics/tools.cpp

@@ -465,9 +465,7 @@ const Symbol *FindInterface(const Symbol &symbol) {
   return common::visit(
       common::visitors{
           [](const ProcEntityDetails &details) {
-            const Symbol *interface {
-              details.procInterface()
-            };
+            const Symbol *interface{details.procInterface()};
             return interface ? FindInterface(*interface) : nullptr;
           },
           [](const ProcBindingDetails &details) {

flang/test/Semantics/modfile64.f90

@@ -0,0 +1,29 @@
+! RUN: %python %S/test_modfile.py %s %flang_fc1
+module mod0
+  interface proc
+    module procedure proc
+  end interface
+ contains
+  subroutine proc
+  end
+end
+module mod1
+  use mod0,renamed_proc=>proc
+  procedure(renamed_proc),pointer :: p
+end module
+
+!Expect: mod0.mod
+!module mod0
+!interface proc
+!procedure::proc
+!end interface
+!contains
+!subroutine proc()
+!end
+!end
+
+!Expect: mod1.mod
+!module mod1
+!use mod0,only:renamed_proc=>proc
+!procedure(renamed_proc),pointer::p
+!end