[PATCH, committed] Fortran: improve checking of FINAL subroutine arguments [PR104572]

[Harald Anlauf via Fortran]

Dear all,

I've committed the attached simple patch after discussion with
Steve (see PR).  We need to reject alternate return arguments
of FINAL subroutines.

Regtested on x86_64-pc-linux-gnu.

Thanks,
Harald

From 3e791f45ded89626bc1f9f8013728f6e035801b2 Mon Sep 17 00:00:00 2001
From: Harald Anlauf 
Date: Wed, 22 Mar 2023 19:20:41 +0100
Subject: [PATCH] Fortran: improve checking of FINAL subroutine arguments
 [PR104572]

gcc/fortran/ChangeLog:

	PR fortran/104572
	* resolve.cc (gfc_resolve_finalizers): Argument of a FINAL subroutine
	cannot be an alternate return.

gcc/testsuite/ChangeLog:

	PR fortran/104572
	* gfortran.dg/pr104572.f90: New test.

Co-authored-by: Steven G. Kargl 
---
 gcc/fortran/resolve.cc |  7 +++
 gcc/testsuite/gfortran.dg/pr104572.f90 | 14 ++
 2 files changed, 21 insertions(+)
 create mode 100644 gcc/testsuite/gfortran.dg/pr104572.f90

diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 1a03e458d99..f6ec76acb0b 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -13986,6 +13986,13 @@ gfc_resolve_finalizers (gfc_symbol* derived, bool *finalizable)
 	}
   arg = dummy_args->sym;

+  if (!arg)
+	{
+	  gfc_error ("Argument of FINAL procedure at %L must be of type %qs",
+		 >proc_sym->declared_at, derived->name);
+	  goto error;
+	}
+
   if (arg->as && arg->as->type == AS_ASSUMED_RANK
 	  && ((list != derived->f2k_derived->finalizers) || list->next))
 	{
diff --git a/gcc/testsuite/gfortran.dg/pr104572.f90 b/gcc/testsuite/gfortran.dg/pr104572.f90
new file mode 100644
index 000..59fd688d798
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr104572.f90
@@ -0,0 +1,14 @@
+! { dg-do compile }
+! { dg-additional-options "-w" }
+! PR fortran/104572 - ICE in gfc_resolve_finalizers
+! Contributed by G. Steinmetz
+
+module m
+  type t
+   contains
+ final :: s
+  end type
+contains
+  subroutine s(*) ! { dg-error "Argument of FINAL procedure" }
+  end
+end
--
2.35.3

Re: [PATCH][stage1] Remove conditionals around free()

[Eric Gallager via Fortran]

On 3/4/23, Janne Blomqvist via Gcc-patches  wrote:
> On Wed, Mar 1, 2023 at 11:31 PM Bernhard Reutner-Fischer via Fortran
>  wrote:
>>
>> Hi!
>>
>> Mere cosmetics.
>>
>> - if (foo != NULL)
>> free (foo);
>>
>> With the caveat that coccinelle ruins replacement whitespace or i'm
>> uneducated enough to be unable to _not_ run the diff through
>>  sed -e 's/^+\([[:space:]]*\)free(/+\1free (/'
>> at least. If anybody knows how to improve replacement whitespace,
>> i'd be interrested but didn't look nor ask. ISTM that leading
>> whitespace is somewhat ruined, too, so beware (8 spaces versus tab as
>> far as i have spot-checked).
>>
>> Would touch
>>  gcc/ada/rtinit.c |3 +--
>>  intl/bindtextdom.c   |3 +--
>>  intl/loadmsgcat.c|6 ++
>>  intl/localcharset.c  |3 +--
>>  libbacktrace/xztest.c|9 +++--
>>  libbacktrace/zstdtest.c  |9 +++--
>>  libbacktrace/ztest.c |9 +++--
>>  libgfortran/caf/single.c |6 ++
>>  libgfortran/io/async.c   |6 ++
>>  libgfortran/io/format.c  |3 +--
>>  libgfortran/io/transfer.c|6 ++
>>  libgfortran/io/unix.c|3 +--
>>  libgo/runtime/go-setenv.c|6 ++
>>  libgo/runtime/go-unsetenv.c  |3 +--
>>  libgomp/target.c |3 +--
>>  libiberty/concat.c   |3 +--
>>  zlib/contrib/minizip/unzip.c |2 +-
>>  zlib/contrib/minizip/zip.c   |2 +-
>>  zlib/examples/enough.c   |6 ++
>>  zlib/examples/gun.c  |2 +-
>>  zlib/examples/gzjoin.c   |3 +--
>>  zlib/examples/gzlog.c|6 ++
>>
>> coccinelle script and invocation inline.
>> Would need to be split for the respective maintainers and run through
>> mklog with subject changelog and should of course be compiled and
>> tested before that.
>>
>> Remarks:
>> 1) We should do this in if-conversion (?) on our own.
>>I suppose. Independently of -fdelete-null-pointer-checks
>> 2) Maybe not silently, but raise language awareness nowadays.
>>By now it's been a long time since this was first mandated.
>> 3) fallout from looking at something completely different
>> 4) i most likely will not remember to split it apart and send proper
>>patches, tested patches, in stage 1 to maintainers proper, so if
>>anyone feels like pursuing this, be my guest. I thought i'd just
>>mention it.
>>
>> cheers,
>
> Back in 2011 Jim Meyering applied a patch doing this, see
> https://gcc.gnu.org/legacy-ml/gcc-patches/2011-03/msg00403.html , and
> the gcc/README.Portability snippet added then which is still there.
>
> Per analysis done then, it seems SunOS 4 was the last system where
> free() of a NULL pointer didn't behave per the spec.
>
> Also in Jim's patch intl/ and zlib/ directories were not touched as
> those are imported from other upstreams.
>

Speaking of which, this reminded me that I opened bug 80528 to catch
code like this as a compiler warning:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80528

> --
> Janne Blomqvist
>