[flang][openacc] Fix crash with array section in acc declare in function

[clementval]

Summary

getSymbolFromAccObject was hitting the fatal error when
trying to retrieve the symbol on array section

[razvanlupusoru]

Looks OK! Thank you!

flang/lib/Lower/OpenACC.cpp

 
 Fortran::semantics::Symbol &
 getSymbolFromAccObject(const Fortran::parser::AccObject &accObject) {
   if (const auto *designator =
           std::get_if<Fortran::parser::Designator>(&accObject.u)) {
     if (const auto *name =
             Fortran::semantics::getDesignatorNameIfDataRef(*designator))
       return *name->symbol;
+    if (const auto *arrayElement =
+            Fortran::parser::Unwrap<Fortran::parser::ArrayElement>(
+                *designator)) {
+      const Fortran::parser::Name &name =
+          Fortran::parser::GetLastName(arrayElement->base);
+      return *name.symbol;
+    }
   } else if (const auto *name =
                  std::get_if<Fortran::parser::Name>(&accObject.u)) {
     return *name->symbol;
   }
   llvm::report_fatal_error("Could not find symbol");
 }
 
 template <typename Op>

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

 ! CHECK: acc.declare dataOperands(%[[COPYIN]], %[[CREATE]] : !fir.ref<!fir.array<100xi32>>, !fir.ref<!fir.array<100xi32>>) {
 ! CHECK: %{{.*}}:{{.*}} = fir.do_loop %{{.*}} = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%{{.*}} = %{{.*}}) -> (index, i32) {
         
 ! CHECK: acc.terminator
 ! CHECK: }
 ! CHECK: acc.copyout accPtr(%[[CREATE]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) to varPtr(%[[ARG1]] : !fir.ref<!fir.array<100xi32>>) {name = "b"}
 ! CHECK: acc.copyout accPtr(%[[COPYIN]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) to varPtr(%[[ARG0]] : !fir.ref<!fir.array<100xi32>>) {dataClause = #acc<data_clause acc_copy>, name = "a"}
 
+  subroutine acc_declare_array_section(a)
+    integer :: a(:)
+    !$acc declare copy(a(1:10))
+
+    do i = 1, 100
+      a(i) = i
+    end do
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMacc_declarePacc_declare_array_section(
+! CHECK-SAME:    %[[ARG0:.*]]: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "a"}) {
+! CHECK: %[[BOX_ADDR:.*]] = fir.box_addr %arg0 {acc.declare = #acc.declare<dataClause =  acc_copy>} : (!fir.box<!fir.array<?xi32>>) -> !fir.ref<!fir.array<?xi32>>
+! CHECK: %[[COPYIN:.*]] = acc.copyin varPtr(%[[BOX_ADDR]] : !fir.ref<!fir.array<?xi32>>) bounds(%{{.*}}) -> !fir.ref<!fir.array<?xi32>> {dataClause = #acc<data_clause acc_copy>, name = "a(1:10)"}
+! CHECK: acc.declare dataOperands(%4 : !fir.ref<!fir.array<?xi32>>) {
+! CHECK:   acc.terminator
+! CHECK: }
+! CHECK: acc.copyout accPtr(%[[COPYIN]] : !fir.ref<!fir.array<?xi32>>) bounds(%{{.*}}) to varPtr(%[[BOX_ADDR]] : !fir.ref<!fir.array<?xi32>>) {dataClause = #acc<data_clause acc_copy>, name = "a(1:10)"}
+
 end module
 
 module acc_declare_allocatable_test
  integer, allocatable :: data1(:)
  !$acc declare create(data1)
 end module
 
 ! CHECK-LABEL: acc.global_ctor @_QMacc_declare_allocatable_testEdata1_acc_ctor {