openacc: Fortran derived-type mapping fix

Fix a bug with mapping Fortran components which themselves have derived
types in the OpenACC 2.5+ manual deep-copy support.

2020-07-09  Julian Brown  <julian@codesourcery.com>

gcc/fortran/
	* trans-openmp.c (gfc_trans_omp_clauses): Use 'inner' not 'decl' for
	derived type members which themselves have derived types.

gcc/testsuite/
	* gfortran.dg/goacc/mapping-tests-3.f90: New test.
	* gfortran.dg/goacc/mapping-tests-4.f90: New test.

(cherry picked from commit ac8996edb14eef0a15cd0ce850fde2be5e227e69)

gcc/fortran/trans-openmp.c

@@ -2750,9 +2750,9 @@ gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			}
 		      else
 			{
-			  OMP_CLAUSE_DECL (node) = decl;
+			  OMP_CLAUSE_DECL (node) = inner;
 			  OMP_CLAUSE_SIZE (node)
-			    = TYPE_SIZE_UNIT (TREE_TYPE (decl));
+			    = TYPE_SIZE_UNIT (TREE_TYPE (inner));
 			}
 		    }
 		  else if (lastcomp->next

gcc/testsuite/gfortran.dg/goacc/mapping-tests-3.f90

+! { dg-additional-options "-fdump-tree-gimple" }
+
+subroutine foo
+  type one
+    integer i, j
+  end type
+  type two
+    type(one) A, B
+  end type
+
+  type(two) x
+
+  !$acc enter data copyin(x%A)
+! { dg-final { scan-tree-dump-times "omp target oacc_enter_exit_data map\\(struct:x \\\[len: 1\\\]\\) map\\(to:x.a \\\[len: \[0-9\]+\\\]\\)" 1 "gimple" } }
+end

gcc/testsuite/gfortran.dg/goacc/mapping-tests-4.f90

+subroutine foo
+  type one
+    integer i, j
+  end type
+  type two
+    type(one) A, B
+  end type
+
+  type(two) x
+
+! This is accepted at present, although it represents a probably-unintentional
+! overlapping subcopy.
+  !$acc enter data copyin(x%A, x%A%i)
+! But this raises an error.
+  !$acc enter data copyin(x%A, x%A%i, x%A%i)
+! { dg-error ".x.a.i. appears more than once in map clauses" "" { target *-*-* } .-1 }
+end