[flang] Set func.func arg attributes for procedure designators (#68420)

Currently, if the first usage of a procedure not defined in the file was
inside a procedure designator reference (not a call to it), the lowered
func.func lacked the argument attributes if any.

Fix this by using `CallInterface<T>::declare` too in SignatureBuilder to
create a new func.func instead of using custom code.

Note: this problem was made worse by the fact that module variables
fir.global are currently lowered before the module procedures func.func
are created. I will try to fix that in a later patch (the debug location
may still be wrong in certain cases) because there is quite some test
fallout when changing the order of globals/funcop in the output.

1 files changed, 4 insertions, 4 deletions

diff --git a/flang/lib/Lower/ConvertProcedureDesignator.cpp b/flang/lib/Lower/ConvertProcedureDesignator.cpp
index aa5a7fe..20ade1a 100644
--- a/flang/lib/Lower/ConvertProcedureDesignator.cpp
+++ b/flang/lib/Lower/ConvertProcedureDesignator.cpp
@@ -62,11 +62,11 @@ fir::ExtendedValue Fortran::lower::convertProcedureDesignator(
       std::tie(funcPtr, funcPtrResultLength) =
           fir::factory::extractCharacterProcedureTuple(builder, loc, funcPtr);
   } else {
-    std::string name = converter.mangleName(*symbol);
     mlir::func::FuncOp func =
-        Fortran::lower::getOrDeclareFunction(name, proc, converter);
-    funcPtr = builder.create<fir::AddrOfOp>(loc, func.getFunctionType(),
-                                            builder.getSymbolRefAttr(name));
+        Fortran::lower::getOrDeclareFunction(proc, converter);
+    mlir::SymbolRefAttr nameAttr = builder.getSymbolRefAttr(func.getSymName());
+    funcPtr =
+        builder.create<fir::AddrOfOp>(loc, func.getFunctionType(), nameAttr);
   }
   if (Fortran::lower::mustPassLengthWithDummyProcedure(proc, converter)) {
     // The result length, if available here, must be propagated along the