[PATCH v2 2/9] fortran: Fix invalid function decl clobber ICE [PR105012]

[Mikael Morin <mikael@gcc.gnu.org>]

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.
---
 gcc/fortran/trans-expr.cc                   |  3 ++-
 gcc/testsuite/gfortran.dg/intent_out_15.f90 | 27 +++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/intent_out_15.f90

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 7902b941c2d..76c587e3d9f 100644
--- 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
index 00000000000..64334e6f038
--- /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" } }
-- 
2.35.1