Re: [PATCH] Fortran: fix rank/shape check in interface checking [PR124567]

From 70bdd15f47757ec5e6befd58289c4245248a9476 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <[email protected]>
Date: Tue, 24 Mar 2026 22:04:29 +0100
Subject: [PATCH] Fortran: fix rank/shape check in interface checking
 [PR124567]

	PR fortran/124567

gcc/fortran/ChangeLog:

	* interface.cc (gfc_check_dummy_characteristics): Split shape check
	into a separate check for rank and a check for shape, taking into
	account a corner case where the ambiguity between deferred shape
	and assumed shape has not been fully resolved at the time of
	checking.

gcc/testsuite/ChangeLog:

	* gfortran.dg/pr124567.f90: New test.
	* gfortran.dg/proc_decl_30.f90: Likewise.
---
 gcc/fortran/interface.cc                   | 11 +++-
 gcc/testsuite/gfortran.dg/pr124567.f90     | 62 ++++++++++++++++++++++
 gcc/testsuite/gfortran.dg/proc_decl_30.f90 | 53 ++++++++++++++++++
 3 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr124567.f90
 create mode 100644 gcc/testsuite/gfortran.dg/proc_decl_30.f90

diff --git a/gcc/fortran/interface.cc b/gcc/fortran/interface.cc
index d29cb3a3b82..8a19c14aa78 100644
--- a/gcc/fortran/interface.cc
+++ b/gcc/fortran/interface.cc
@@ -1554,6 +1554,13 @@ gfc_check_dummy_characteristics (gfc_symbol *s1, gfc_symbol *s2,
       int i, compval;
       gfc_expr *shape1, *shape2;
 
+      if (s1->as->rank != s2->as->rank)
+	{
+	  snprintf (errmsg, err_len, "Rank mismatch in argument '%s' (%i/%i)",
+		    s1->name, s1->as->rank, s2->as->rank);
+	  return false;
+	}
+
       /* Sometimes the ambiguity between deferred shape and assumed shape
 	 does not get resolved in module procedures, where the only explicit
 	 declaration of the dummy is in the interface.  */
@@ -1567,7 +1574,9 @@ gfc_check_dummy_characteristics (gfc_symbol *s1, gfc_symbol *s2,
 	      s2->as->lower[i] = gfc_copy_expr (s1->as->lower[i]);
 	}
 
-      if (s1->as->type != s2->as->type)
+      if (s1->as->type != s2->as->type
+	  && !(s1->as->type == AS_DEFERRED
+	       && s2->as->type == AS_ASSUMED_SHAPE))
 	{
 	  snprintf (errmsg, err_len, "Shape mismatch in argument '%s'",
 		    s1->name);
diff --git a/gcc/testsuite/gfortran.dg/pr124567.f90 b/gcc/testsuite/gfortran.dg/pr124567.f90
new file mode 100644
index 00000000000..feb00f22214
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr124567.f90
@@ -0,0 +1,62 @@
+! { dg-do compile }
+!
+! PR fortran/124567 - overriding method not resolved correctly
+!
+! Contributed by Salvatore Filippone 
+
+module psb_base_spm_mod
+  type  :: psb_base_spm
+  end type psb_base_spm
+end module psb_base_spm_mod
+
+module psb_r_base_spm_mod
+  use psb_base_spm_mod
+  type, extends(psb_base_spm) :: psb_r_base_spm
+  contains
+    procedure, pass(a) :: csgrw => psb_r_base_csgrw
+  end type psb_r_base_spm
+
+  interface
+    subroutine psb_r_base_csgrw(a,iren)
+      import
+      class(psb_r_base_spm), intent(in) :: a
+      integer, intent(in), optional     :: iren(:)
+    end subroutine psb_r_base_csgrw
+  end interface
+end module psb_r_base_spm_mod
+
+module psb_d_mf_mat_mod
+  use psb_r_base_spm_mod
+  type, extends(psb_r_base_spm) :: psb_d_mf_spm
+    procedure(d_mf_mv), pass(a), pointer :: var_csmv => null()
+  contains
+    procedure, pass(a) :: csgrw     => psb_d_mf_csgrw
+    procedure, pass(a) :: set_csmv  => d_mf_set_csmv
+  end type psb_d_mf_spm
+
+  interface
+    subroutine d_mf_mv(a,x,info)
+      import :: psb_d_mf_spm
+      class(psb_d_mf_spm), intent(in) :: a
+      real, intent(in)                :: x(:)
+      integer, intent(out)            :: info
+    end subroutine d_mf_mv
+  end interface
+
+  interface
+    subroutine psb_d_mf_csgrw(a,iren)
+      import
+      class(psb_d_mf_spm), intent(in) :: a
+      integer, intent(in), optional   :: iren(:)
+    end subroutine psb_d_mf_csgrw
+  end interface
+
+contains
+  subroutine  d_mf_set_csmv(func,a)
+    implicit none
+    class(psb_d_mf_spm), intent(inout) :: a
+    procedure(d_mf_mv)                 :: func
+    a%var_csmv => func
+    return
+  end subroutine d_mf_set_csmv
+end module psb_d_mf_mat_mod
diff --git a/gcc/testsuite/gfortran.dg/proc_decl_30.f90 b/gcc/testsuite/gfortran.dg/proc_decl_30.f90
new file mode 100644
index 00000000000..f54f0e2f36d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/proc_decl_30.f90
@@ -0,0 +1,53 @@
+! { dg-do compile }
+!
+! PR fortran/124567 - rank/shape check in interface checking
+!
+! Variation of gfortran.dg/proc_decl_26.f90
+
+program test
+  implicit none
+
+  interface
+    subroutine one(a)
+      integer a(:)
+    end subroutine
+    subroutine two(a)
+      integer a(..)
+    end subroutine
+  end interface
+
+  ! Assumed-shape vs. deferred
+  call foo(two)  ! { dg-error "Rank mismatch in argument 'a' \\(1/-1\\)" }
+  call bar(two)  ! { dg-error "Rank mismatch in argument 'a' \\(1/-1\\)" }
+
+  ! Reversed
+  call bas(one)  ! { dg-error "Rank mismatch in argument 'a' \\(-1/1\\)" }
+  call bla(one)  ! { dg-error "Rank mismatch in argument 'a' \\(-1/1\\)" }
+
+contains
+
+  subroutine foo(f1)
+    procedure(one) :: f1
+  end subroutine foo
+
+  subroutine bar(f2)
+    interface
+      subroutine f2(a)
+        integer a(:)
+      end subroutine
+    end interface
+  end subroutine bar
+
+  subroutine bas(f1)
+    procedure(two) :: f1
+  end subroutine bas
+
+  subroutine bla(f2)
+    interface
+      subroutine f2(a)
+        integer a(..)
+      end subroutine
+    end interface
+  end subroutine bla
+
+end program 
-- 
2.51.0