Fortran: reject NULL actual argument without explicit interface [PR107576]
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Dear all,
one cannot pass a NULL actual argument to a procedure without an
explicit interface. This is detected and reported by NAG and Intel.
(Cray accepts this silently, and some other brands ICE.)
The testcase by Gerhard even tricked gfortran into inconsistent
behavior which could lead to an ICE with -fallow-argument-mismatch,
or silently accepting invalid code.
The solution is to reject such code, see attached patch.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
As this is marked as a regression which started at v7,
OK for backports to open branches?
Thanks,
Harald
Comments
Le 17/11/2022 à 21:48, Harald Anlauf via Fortran a écrit :
> Dear all,
>
> one cannot pass a NULL actual argument to a procedure without an
> explicit interface. This is detected and reported by NAG and Intel.
> (Cray accepts this silently, and some other brands ICE.)
>
> The testcase by Gerhard even tricked gfortran into inconsistent
> behavior which could lead to an ICE with -fallow-argument-mismatch,
> or silently accepting invalid code.
>
> The solution is to reject such code, see attached patch.
>
> Regtested on x86_64-pc-linux-gnu. OK for mainline?
>
OK.
> As this is marked as a regression which started at v7,
> OK for backports to open branches?
>
OK.
From c6b19d662f51b1e2d2691e81cfeb68ad953a4c09 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Thu, 17 Nov 2022 21:36:49 +0100
Subject: [PATCH] Fortran: reject NULL actual argument without explicit
interface [PR107576]
gcc/fortran/ChangeLog:
PR fortran/107576
* interface.cc (gfc_procedure_use): Reject NULL as actual argument
when there is no explicit procedure interface.
gcc/testsuite/ChangeLog:
PR fortran/107576
* gfortran.dg/null_actual_3.f90: New test.
---
gcc/fortran/interface.cc | 8 ++++++++
gcc/testsuite/gfortran.dg/null_actual_3.f90 | 18 ++++++++++++++++++
2 files changed, 26 insertions(+)
create mode 100644 gcc/testsuite/gfortran.dg/null_actual_3.f90
@@ -4162,6 +4162,14 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where)
return false;
}
+ if (a->expr && a->expr->expr_type == EXPR_NULL)
+ {
+ gfc_error ("Passing intrinsic NULL as actual argument at %L "
+ "requires an explicit interface", &a->expr->where);
+ a->expr->error = 1;
+ return false;
+ }
+
/* TS 29113, C407b. */
if (a->expr && a->expr->expr_type == EXPR_VARIABLE
&& symbol_rank (a->expr->symtree->n.sym) == -1)
new file mode 100644
@@ -0,0 +1,18 @@
+! { dg-do compile }
+! { dg-options "-fallow-argument-mismatch -w" }
+! PR fortran/107576
+! Contributed by G.Steinmetz
+
+program p
+ implicit none
+ interface
+ subroutine r(y)
+ integer, pointer :: y(:)
+ end subroutine r
+ end interface
+ integer, pointer :: z(:) => null()
+ call r(z)
+ call s(z)
+ call r(null(z))
+ call s(null(z)) ! { dg-error "requires an explicit interface" }
+end
--
2.35.3