fortran: Fix invalid function decl clobber ICE [PR105012]

The fortran frontend, as result symbol for a function without
declared result symbol, uses the function symbol itself.  This caused
an invalid clobber of a function decl to be emitted, leading to an
ICE, whereas the intended behaviour was to clobber the function result
variable.  This change fixes the problem by getting the decl from the
just-retrieved variable reference after the call to
gfc_conv_expr_reference, instead of copying it from the frontend symbol.

	PR fortran/105012

gcc/fortran/ChangeLog:

	* trans-expr.cc (gfc_conv_procedure_call): Retrieve variable
	from the just calculated variable reference.

gcc/testsuite/ChangeLog:

	* gfortran.dg/intent_out_15.f90: New test.

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 7cdab1cc9b4e1920a5e9d1771811e6d25d6585e6..8fb63359ba500c6c50c2b1f06c42b96584a618bc 100644 (file)
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -6528,7 +6528,8 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
                          tree var;
                          /* FIXME: This fails if var is passed by reference, see PR
                             41453.  */
-                         var = e->symtree->n.sym->backend_decl;
+                         var = build_fold_indirect_ref_loc (input_location,
+                                                            parmse.expr);
                          tree clobber = build_clobber (TREE_TYPE (var));
                          gfc_add_modify (&se->pre, var, clobber);
                        }

diff --git a/gcc/testsuite/gfortran.dg/intent_out_15.f90 b/gcc/testsuite/gfortran.dg/intent_out_15.f90
new file mode 100644 (file)
index 0000000..64334e6
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/intent_out_15.f90
@@ -0,0 +1,27 @@
+! { dg-do compile }
+! { dg-additional-options "-fdump-tree-original" }
+!
+! PR fortran/105012
+! The following case was triggering an ICE because of a clobber
+! on the DERFC function decl instead of its result.
+
+module error_function
+integer, parameter :: r8 = selected_real_kind(12) ! 8 byte real
+contains
+SUBROUTINE CALERF_r8(ARG, RESULT, JINT)
+   integer, parameter :: rk = r8
+   real(rk), intent(in)  :: arg
+   real(rk), intent(out) :: result
+   IF (Y .LE. THRESH) THEN
+   END IF
+end SUBROUTINE CALERF_r8
+FUNCTION DERFC(X)
+   integer, parameter :: rk = r8 ! 8 byte real
+   real(rk), intent(in) :: X
+   real(rk) :: DERFC
+   CALL CALERF_r8(X, DERFC, JINT)
+END FUNCTION DERFC
+end module error_function
+
+! { dg-final { scan-tree-dump-times "CLOBBER" 1 "original" } }
+! { dg-final { scan-tree-dump "__result_derfc = {CLOBBER};" "original" } }