From 2e32a12c04c72f692a7bd119fd3e4e5b74392c9d Mon Sep 17 00:00:00 2001
From: Mikael Morin <mikael@gcc.gnu.org>
Date: Sun, 29 Jan 2023 21:57:24 +0100
Subject: [PATCH] fortran: Set name for *LOC default BACK argument [PR108450]

This change fixes an ICE caused by the double resolution of MINLOC,
MAXLOC and FINDLOC expressions which get a default value for the BACK
argument at resolution time.  That argument  is added without name,
and argument reordering code is not prepared to handle unnamed arguments
coming after named ones, so the second resolution causes a NULL pointer
dereference.
The problem is fixed by explicitly setting the argument name.

	PR fortran/108450

gcc/fortran/ChangeLog:

	* check.cc (gfc_check_minloc_maxloc): Explicitly set argument name.
	(gfc_check_findloc): Ditto.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/minmaxloc_1.f90: New test.
---
 gcc/fortran/check.cc                           |  2 ++
 gcc/testsuite/gfortran.dg/gomp/minmaxloc_1.f90 | 32 ++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 gcc/testsuite/gfortran.dg/gomp/minmaxloc_1.f90

diff --git a/gcc/fortran/check.cc b/gcc/fortran/check.cc
index ebcb8f3..8c1ae8c 100644
--- a/gcc/fortran/check.cc
+++ b/gcc/fortran/check.cc
@@ -3888,6 +3888,7 @@ gfc_check_minloc_maxloc (gfc_actual_arglist *ap)
     {
       b = gfc_get_logical_expr (gfc_logical_4_kind, NULL, 0);
       ap->next->next->next->next->expr = b;
+      ap->next->next->next->next->name = gfc_get_string ("back");
     }
 
   if (m == NULL && d != NULL && d->ts.type == BT_LOGICAL
@@ -3969,6 +3970,7 @@ gfc_check_findloc (gfc_actual_arglist *ap)
     {
       b = gfc_get_logical_expr (gfc_logical_4_kind, NULL, 0);
       ap->next->next->next->next->next->expr = b;
+      ap->next->next->next->next->next->name = gfc_get_string ("back");
     }
 
   if (m == NULL && d != NULL && d->ts.type == BT_LOGICAL
diff --git a/gcc/testsuite/gfortran.dg/gomp/minmaxloc_1.f90 b/gcc/testsuite/gfortran.dg/gomp/minmaxloc_1.f90
new file mode 100644
index 0000000..b3691f7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/gomp/minmaxloc_1.f90
@@ -0,0 +1,32 @@
+! { dg-do compile }
+!
+! PR fortran/108450
+! This program used to cause an ICE because of the double resolution
+! of the maxloc expression and the addition of a hidden unnamed argument
+! during the first resolution.
+!
+! Original testcase from G. Steinmetz
+
+subroutine s1
+   integer :: a(8) = 0
+   integer :: l
+   integer :: n
+   !$omp atomic
+   n = maxloc(a, mask=l) ! { dg-error ".mask. argument of .maxloc. intrinsic at .1. must be LOGICAL" }
+end
+
+subroutine s2
+   integer :: a(8) = 0
+   integer :: l
+   integer :: n
+   !$omp atomic
+   n = minloc(a, mask=l) ! { dg-error ".mask. argument of .minloc. intrinsic at .1. must be LOGICAL" }
+end
+
+subroutine s3
+   integer :: a(8) = 0
+   integer :: l
+   integer :: n
+   !$omp atomic
+   n = findloc(a, 3, mask=l) ! { dg-error ".mask. argument of .findloc. intrinsic at .1. must be LOGICAL" }
+end
-- 
2.7.4