[flang][openacc] Fix function name resolution in acc routine

When acc routine is in a function, the first symbol resolved
was the function result and not the function name itself. It was
then failing the deferred attachment because the mangled name
had the entity attach to it. This patch fix the name resolution
for the function name in acc routine directive.

Reviewed By: razvanlupusoru

Differential Revision: https://reviews.llvm.org/D158868

flang/lib/Semantics/resolve-directives.cpp

@@ -265,6 +265,7 @@ class AccAttributeVisitor : DirectiveAttributeVisitor<llvm::acc::Directive> {
   Symbol *ResolveAcc(const parser::Name &, Symbol::Flag, Scope &);
   Symbol *ResolveAcc(Symbol &, Symbol::Flag, Scope &);
   Symbol *ResolveName(const parser::Name &, bool parentScope = false);
+  Symbol *ResolveFctName(const parser::Name &);
   Symbol *ResolveAccCommonBlockName(const parser::Name *);
   Symbol *DeclareOrMarkOtherAccessEntity(const parser::Name &, Symbol::Flag);
   Symbol *DeclareOrMarkOtherAccessEntity(Symbol &, Symbol::Flag);
@@ -835,6 +836,17 @@ Symbol *AccAttributeVisitor::ResolveName(
   return prev;
 }
 
+Symbol *AccAttributeVisitor::ResolveFctName(const parser::Name &name) {
+  Symbol *prev{currScope().FindSymbol(name.source)};
+  if (!prev || (prev && prev->IsFuncResult())) {
+    prev = currScope().parent().FindSymbol(name.source);
+  }
+  if (prev != name.symbol) {
+    name.symbol = prev;
+  }
+  return prev;
+}
+
 template <typename T>
 common::IfNoLvalue<T, T> FoldExpr(
     evaluate::FoldingContext &foldingContext, T &&expr) {
@@ -907,7 +919,7 @@ void AccAttributeVisitor::AddRoutineInfoToSymbol(
 bool AccAttributeVisitor::Pre(const parser::OpenACCRoutineConstruct &x) {
   const auto &optName{std::get<std::optional<parser::Name>>(x.t)};
   if (optName) {
-    if (Symbol *sym = ResolveName(*optName, true)) {
+    if (Symbol *sym = ResolveFctName(*optName)) {
       Symbol &ultimate{sym->GetUltimate()};
       AddRoutineInfoToSymbol(ultimate, x);
     } else {

flang/test/Lower/OpenACC/acc-routine.f90

@@ -2,6 +2,7 @@
 
 ! RUN: bbc -fopenacc -emit-fir %s -o - | FileCheck %s
 
+! CHECK: acc.routine @acc_routine_9 func(@_QPacc_routine10) seq
 ! CHECK: acc.routine @acc_routine_8 func(@_QPacc_routine9) bind("_QPacc_routine9a")
 ! CHECK: acc.routine @acc_routine_7 func(@_QPacc_routine8) bind("routine8_")
 ! CHECK: acc.routine @acc_routine_6 func(@_QPacc_routine7) gang(dim = 1 : i32)
@@ -68,3 +69,9 @@ subroutine acc_routine9()
 end subroutine
 
 ! CHECK-LABEL: func.func @_QPacc_routine9() attributes {acc.routine_info = #acc.routine_info<[@acc_routine_8]>}
+
+function acc_routine10()
+  !$acc routine(acc_routine10) seq
+end function
+
+! CHECK-LABEL: func.func @_QPacc_routine10() -> f32 attributes {acc.routine_info = #acc.routine_info<[@acc_routine_9]>}