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

[Janne Blomqvist <blomqvist.janne@gmail.com>]

On Wed, Mar 1, 2023 at 11:31 PM Bernhard Reutner-Fischer via Fortran
<fortran@gcc.gnu.org> 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.

-- 
Janne Blomqvist