[PATCH 2/2] Fortran: Fix memory leak in gfc_add_include_path [PR68800]

[Bernhard Reutner-Fischer]

On Sat, 6 Nov 2021 20:22:53 +0100
Harald Anlauf <anlauf@gmx.de> wrote:

> Hi Bernhard,
> 
> I cannot comment on the gcc/ parts, but
> 

> > diff --git a/gcc/fortran/cpp.c b/gcc/fortran/cpp.c
> > index e86386c8b17..04fe8fe460b 100644
> > --- a/gcc/fortran/cpp.c
> > +++ b/gcc/fortran/cpp.c
> > @@ -728,12 +728,20 @@ gfc_cpp_done (void)
> >     cpp_clear_file_cache (cpp_in);
> >   }  
> 
> why do you introduce a wrapper for something outside of fortran
> that is used only once,
> 
> > -/* PATH must be malloc-ed and NULL-terminated.  */
> > +/* Free all cpp include dirs.  */
> > +void
> > +gfc_cpp_free_cpp_dirs (void)
> > +{
> > +  free_cpp_dirs ();
> > +}

> > diff --git a/gcc/fortran/cpp.h b/gcc/fortran/cpp.h
> > index 44644a2a333..963b9a9c89e 100644
> > --- a/gcc/fortran/cpp.h
> > +++ b/gcc/fortran/cpp.h
> > @@ -46,6 +46,7 @@ void gfc_cpp_post_options (bool);
> >   bool gfc_cpp_preprocess (const char *source_file);
> >
> >   void gfc_cpp_done (void);
> > +void gfc_cpp_free_cpp_dirs (void);
> >
> >   void gfc_cpp_add_include_path (char *path, bool user_supplied);
> >   void gfc_cpp_add_include_path_after (char *path, bool user_supplied);
> > diff --git a/gcc/fortran/f95-lang.c b/gcc/fortran/f95-lang.c
> > index 58dcaf01d75..ec4c2cf01d9 100644
> > --- a/gcc/fortran/f95-lang.c
> > +++ b/gcc/fortran/f95-lang.c
> > @@ -275,7 +275,7 @@ gfc_finish (void)
> >     gfc_cpp_done ();
> >     gfc_done_1 ();
> >     gfc_release_include_path ();
> > -  return;  
> 
> namely here?
> 
> > +  gfc_cpp_free_cpp_dirs ();
> >   }  
> 
> Why not call free_cpp_dirs () here directly, omit all unnecessary
> stuff, and maybe only add a brief comment here?

cpp.c includes incpath.h, f95-lang.c does not and should not.
So the cleanest thing is to keep the cpp handling in cpp.[ch] and have
the language frontend call into it's cpp bits.

It would be rather rogue to
extern void free_cpp_dirs (void);
in f95-lang.c and directly call it in gfc_finish, i'd say?

thanks,