[Flang][OpenMP] Skip component symbols when creating extended values (#79657)

The `map` clause in OpenMP allows structure components to be specified
(unlike other clauses). Structure components do get their own symbols,
but these are not meant to be instantiated.

When a component reference is passed as an argument to the omp.target
op, it gets a corresponding parameter in the target op's entry block.
The original symbols are then bound to the same kind of an extended
value as before, but the value is now based on the parameters.

To handle structure components more gracefully, put their symbols on the
list of mapped objects, but skip them when creating extended values.

Fixes #79478.

Author: kparzysz

flang/lib/Lower/OpenMP.cpp

@@ -58,6 +58,9 @@ getOmpObjectSymbol(const Fortran::parser::OmpObject &ompObject) {
                     Fortran::parser::Unwrap<Fortran::parser::ArrayElement>(
                         designator)) {
               sym = GetFirstName(arrayEle->base).symbol;
+            } else if (auto *structComp = Fortran::parser::Unwrap<
+                           Fortran::parser::StructureComponent>(designator)) {
+              sym = structComp->component.symbol;
             } else if (const Fortran::parser::Name *name =
                            Fortran::semantics::getDesignatorNameIfDataRef(
                                designator)) {
@@ -2743,6 +2746,9 @@ static void genBodyOfTargetOp(
     const mlir::BlockArgument &arg = region.getArgument(argIndex);
     // Avoid capture of a reference to a structured binding.
     const Fortran::semantics::Symbol *sym = argSymbol;
+    // Structure component symbols don't have bindings.
+    if (sym->owner().IsDerivedType())
+      continue;
     fir::ExtendedValue extVal = converter.getSymbolExtendedValue(*sym);
     extVal.match(
         [&](const fir::BoxValue &v) {

flang/test/Lower/OpenMP/FIR/map-component-ref.f90

@@ -0,0 +1,33 @@
+! RUN: %flang_fc1 -emit-fir -fopenmp %s -o - | FileCheck %s
+! RUN: bbc -fopenmp -emit-fir %s -o - | FileCheck %s
+
+! CHECK: %[[V0:[0-9]+]] = fir.alloca !fir.type<_QFfooTt0{a0:i32,a1:i32}> {bindc_name = "a", uniq_name = "_QFfooEa"}
+! CHECK: %[[V1:[0-9]+]] = fir.declare %[[V0]] {uniq_name = "_QFfooEa"} : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) -> !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>
+! CHECK: %[[V2:[0-9]+]] = fir.field_index a1, !fir.type<_QFfooTt0{a0:i32,a1:i32}>
+! CHECK: %[[V3:[0-9]+]] = fir.coordinate_of %[[V1]], %[[V2]] : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>, !fir.field) -> !fir.ref<i32>
+! CHECK: %[[V4:[0-9]+]] = omp.map_info var_ptr(%[[V3]] : !fir.ref<i32>, i32) map_clauses(tofrom) capture(ByRef) -> !fir.ref<i32> {name = "a%a1"}
+! CHECK: %[[V5:[0-9]+]] = omp.map_info var_ptr(%[[V1]] : !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>, !fir.type<_QFfooTt0{a0:i32,a1:i32}>) map_clauses(implicit, tofrom) capture(ByRef) -> !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>> {name = "a"}
+! CHECK: omp.target map_entries(%[[V4]] -> %arg0, %[[V5]] -> %arg1 : !fir.ref<i32>, !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) {
+! CHECK: ^bb0(%arg0: !fir.ref<i32>, %arg1: !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>):
+! CHECK:   %c0_i32 = arith.constant 0 : i32
+! CHECK:   %[[V6:[0-9]+]] = fir.declare %arg1 {uniq_name = "_QFfooEa"} : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) -> !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>
+! CHECK:   %[[V7:[0-9]+]] = fir.field_index a1, !fir.type<_QFfooTt0{a0:i32,a1:i32}>
+! CHECK:   %[[V8:[0-9]+]] = fir.coordinate_of %[[V6]], %[[V7]] : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>, !fir.field) -> !fir.ref<i32>
+! CHECK:   fir.store %c0_i32 to %[[V8]] : !fir.ref<i32>
+! CHECK:   omp.terminator
+! CHECK: }
+
+subroutine foo()
+  implicit none
+
+  type t0
+    integer :: a0, a1
+  end type
+
+  type(t0) :: a
+
+  !$omp target map(a%a1)
+  a%a1 = 0
+  !$omp end target
+end
+

flang/test/Lower/OpenMP/map-component-ref.f90

@@ -0,0 +1,31 @@
+! RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
+! RUN: bbc -fopenmp -emit-hlfir %s -o - | FileCheck %s
+
+! CHECK: %[[V0:[0-9]+]] = fir.alloca !fir.type<_QFfooTt0{a0:i32,a1:i32}> {bindc_name = "a", uniq_name = "_QFfooEa"}
+! CHECK: %[[V1:[0-9]+]]:2 = hlfir.declare %[[V0]] {uniq_name = "_QFfooEa"} : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) -> (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>, !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>)
+! CHECK: %[[V2:[0-9]+]] = hlfir.designate %[[V1]]#0{"a1"}   : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) -> !fir.ref<i32>
+! CHECK: %[[V3:[0-9]+]] = omp.map_info var_ptr(%[[V2]] : !fir.ref<i32>, i32) map_clauses(tofrom) capture(ByRef) -> !fir.ref<i32> {name = "a%a1"}
+! CHECK: %[[V4:[0-9]+]] = omp.map_info var_ptr(%[[V1]]#1 : !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>, !fir.type<_QFfooTt0{a0:i32,a1:i32}>) map_clauses(implicit, tofrom) capture(ByRef) -> !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>> {name = "a"}
+! CHECK: omp.target map_entries(%[[V3]] -> %arg0, %[[V4]] -> %arg1 : !fir.ref<i32>, !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) {
+! CHECK: ^bb0(%arg0: !fir.ref<i32>, %arg1: !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>):
+! CHECK:   %[[V5:[0-9]+]]:2 = hlfir.declare %arg1 {uniq_name = "_QFfooEa"} : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) -> (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>, !fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>)
+! CHECK:   %c0_i32 = arith.constant 0 : i32
+! CHECK:   %[[V6:[0-9]+]] = hlfir.designate %[[V5]]#0{"a1"}   : (!fir.ref<!fir.type<_QFfooTt0{a0:i32,a1:i32}>>) -> !fir.ref<i32>
+! CHECK:   hlfir.assign %c0_i32 to %[[V6]] : i32, !fir.ref<i32>
+! CHECK:   omp.terminator
+! CHECK: }
+
+subroutine foo()
+  implicit none
+
+  type t0
+    integer :: a0, a1
+  end type
+
+  type(t0) :: a
+
+  !$omp target map(a%a1)
+  a%a1 = 0
+  !$omp end target
+end
+