Fortran : ICE in generic_correspondence PR95584

Fortran : ICE in generic_correspondence PR95584

[Mark Eggleston]

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Please find attached fix for PR95584.  Original patch by Steve Kargl.

OK to commit and backport?

Commit message:

Fortran  : ICE in generic_correspondence PR95584

Output an error for ambiguous interfaces in generic interface
instead of ICE.

2020-06-25  Steven G. Kargl  <kargl@gcc.gnu.org>

gcc/fortran/

     PR fortran/95584
     * interface.c (generic_correspondence): Only use the pointer
     to a symbol if exists.

2020-06-25  Mark Eggleston <markeggleston@gcc.gnu.org>

gcc/testsuite/

     PR fortran/95584
     * gfortran.dg/pr95584.f90: New test.

-- 
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[-- Attachment #2: 0001-Fortran-ICE-in-generic_correspondence-PR95584.patch --]
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From 1205be65bd7c3aff52c2a9a00f298afa7aa0bf08 Mon Sep 17 00:00:00 2001
From: Mark Eggleston <markeggleston@gcc.gnu.org>
Date: Thu, 25 Jun 2020 05:16:50 +0100
Subject: [PATCH] Fortran  : ICE in generic_correspondence PR95584

Output an error for ambiguous interfaces in generic interface
instead of ICE.

2020-06-25  Steven G. Kargl  <kargl@gcc.gnu.org>

gcc/fortran/

	PR fortran/95584
	* interface.c (generic_correspondence): Only use the pointer
	to a symbol if exists.

2020-06-25  Mark Eggleston  <markeggleston@gcc.gnu.org>

gcc/testsuite/

	PR fortran/95584
	* gfortran.dg/pr95584.f90: New test.
---
 gcc/fortran/interface.c               |  2 +-
 gcc/testsuite/gfortran.dg/pr95584.f90 | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr95584.f90

diff --git a/gcc/fortran/interface.c b/gcc/fortran/interface.c
index b1a75a37b0e..0cc504f4e04 100644
--- a/gcc/fortran/interface.c
+++ b/gcc/fortran/interface.c
@@ -1257,7 +1257,7 @@ generic_correspondence (gfc_formal_arglist *f1, gfc_formal_arglist *f2,
 
   while (f1)
     {
-      if (f1->sym->attr.optional)
+      if (!f1->sym || f1->sym->attr.optional)
 	goto next;
 
       if (p1 && strcmp (f1->sym->name, p1) == 0)
diff --git a/gcc/testsuite/gfortran.dg/pr95584.f90 b/gcc/testsuite/gfortran.dg/pr95584.f90
new file mode 100644
index 00000000000..4504f7b500c
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr95584.f90
@@ -0,0 +1,16 @@
+! { dg-do compile }
+
+program p
+   interface s
+      subroutine g(x, *)
+      end
+      subroutine h(y, *)
+      end
+   end interface
+end
+
+! { dg-warning "Obsolescent feature: Alternate-return argument" " " { target *-*-* } 5 }
+! { dg-warning "Obsolescent feature: Alternate-return argument" " " { target *-*-* } 7 }
+! { dg-error ".1." " " { target *-*-* } 5 }
+! { dg-error "Ambiguous interfaces in generic interface" " " { target *-*-* } 7 }
+
-- 
2.11.0

Re: [PATCH] Fortran : ICE in generic_correspondence PR95584

[Mark Eggleston]

I forgot to use [PATCH] in the subject line. ping!

On 25/06/2020 07:33, Mark Eggleston wrote:
> Please find attached fix for PR95584.  Original patch by Steve Kargl.
>
> OK to commit and backport?
>
> Commit message:
>
> Fortran  : ICE in generic_correspondence PR95584
>
> Output an error for ambiguous interfaces in generic interface
> instead of ICE.
>
> 2020-06-25  Steven G. Kargl  <kargl@gcc.gnu.org>
>
> gcc/fortran/
>
>     PR fortran/95584
>     * interface.c (generic_correspondence): Only use the pointer
>     to a symbol if exists.
>
> 2020-06-25  Mark Eggleston <markeggleston@gcc.gnu.org>
>
> gcc/testsuite/
>
>     PR fortran/95584
>     * gfortran.dg/pr95584.f90: New test.
>
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Re: Fortran : ICE in generic_correspondence PR95584

[Thomas Koenig]

Hi Mark,


> OK to commit and backport?

OK, fixing such a NULL dererefence could also count as obvious
and simple (if it does the right thing :-)

Regarding backport:  I probably would not do it myself; it's
not a regression, and ICE does not have such a large impact.
However, if you want to do it, feel free.

Thanks for taking this on!

Regards

	Thomas