Don't look for lto-wrapper, liblto_plugin.so.0 nor collect2 if -E/-S/-c

Hi!

In Fedora (but several other distros do the same) we ship cpp
as a separate package, unfortunately the lto plugin support means (IMHO
unnecessarily) that the plugin needs to be included in the cpp package
rather than gcc, because the driver looks for the plugin and complains
if not found even when the driver is cpp (or for gcc -E/-S/-c).
I think we only need it when actually linking, so this patch should save
some unnecessary syscalls on every -E/-S/-c preprocessing/compilation
as well as make /usr/bin/cpp only need cc1 and no other files.
have_c is a variable used in a couple of places earlier.

2012-02-07  Jakub Jelinek  <jakub@redhat.com>

	* gcc.c (main): Don't look for lto-wrapper or lto-wrapper
	or LTOPLUGINSONAME if have_c.


	Jakub

On Tue, Feb 7, 2012 at 10:11 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> In Fedora (but several other distros do the same) we ship cpp
> as a separate package, unfortunately the lto plugin support means (IMHO
> unnecessarily) that the plugin needs to be included in the cpp package
> rather than gcc, because the driver looks for the plugin and complains
> if not found even when the driver is cpp (or for gcc -E/-S/-c).
> I think we only need it when actually linking, so this patch should save
> some unnecessary syscalls on every -E/-S/-c preprocessing/compilation
> as well as make /usr/bin/cpp only need cc1 and no other files.
> have_c is a variable used in a couple of places earlier.

Ok.

Thanks,
Richard.

> 2012-02-07  Jakub Jelinek  <jakub@redhat.com>
>
>        * gcc.c (main): Don't look for lto-wrapper or lto-wrapper
>        or LTOPLUGINSONAME if have_c.
>
> --- gcc/gcc.c.jj        2012-01-30 00:10:01.000000000 +0100
> +++ gcc/gcc.c   2012-02-07 10:03:44.777138464 +0100
> @@ -6447,7 +6447,11 @@ main (int argc, char **argv)
>
>   /* Set up to remember the pathname of the lto wrapper. */
>
> -  lto_wrapper_file = find_a_file (&exec_prefixes, "lto-wrapper", X_OK, false);
> +  if (have_c)
> +    lto_wrapper_file = NULL;
> +  else
> +    lto_wrapper_file = find_a_file (&exec_prefixes, "lto-wrapper",
> +                                   X_OK, false);
>   if (lto_wrapper_file)
>     {
>       lto_wrapper_spec = lto_wrapper_file;
> @@ -6821,39 +6825,46 @@ warranty; not even for MERCHANTABILITY o
>   if (num_linker_inputs > 0 && !seen_error () && print_subprocess_help < 2)
>     {
>       int tmp = execution_count;
> +
> +      if (! have_c)
> +       {
>  #if HAVE_LTO_PLUGIN > 0
>  #if HAVE_LTO_PLUGIN == 2
> -      const char *fno_use_linker_plugin = "fno-use-linker-plugin";
> +         const char *fno_use_linker_plugin = "fno-use-linker-plugin";
>  #else
> -      const char *fuse_linker_plugin = "fuse-linker-plugin";
> +         const char *fuse_linker_plugin = "fuse-linker-plugin";
>  #endif
>  #endif
>
> -      /* We'll use ld if we can't find collect2.  */
> -      if (! strcmp (linker_name_spec, "collect2"))
> -       {
> -         char *s = find_a_file (&exec_prefixes, "collect2", X_OK, false);
> -         if (s == NULL)
> -           linker_name_spec = "ld";
> -       }
> +         /* We'll use ld if we can't find collect2.  */
> +         if (! strcmp (linker_name_spec, "collect2"))
> +           {
> +             char *s = find_a_file (&exec_prefixes, "collect2", X_OK, false);
> +             if (s == NULL)
> +               linker_name_spec = "ld";
> +           }
>
>  #if HAVE_LTO_PLUGIN > 0
>  #if HAVE_LTO_PLUGIN == 2
> -      if (!switch_matches (fno_use_linker_plugin,
> -                          fno_use_linker_plugin + strlen (fno_use_linker_plugin), 0))
> +         if (!switch_matches (fno_use_linker_plugin,
> +                              fno_use_linker_plugin
> +                              + strlen (fno_use_linker_plugin), 0))
>  #else
> -      if (switch_matches (fuse_linker_plugin,
> -                         fuse_linker_plugin + strlen (fuse_linker_plugin), 0))
> +         if (switch_matches (fuse_linker_plugin,
> +                             fuse_linker_plugin
> +                             + strlen (fuse_linker_plugin), 0))
>  #endif
> -       {
> -         linker_plugin_file_spec = find_a_file (&exec_prefixes,
> -                                                LTOPLUGINSONAME, R_OK,
> -                                                false);
> -         if (!linker_plugin_file_spec)
> -           fatal_error ("-fuse-linker-plugin, but %s not found", LTOPLUGINSONAME);
> -       }
> +           {
> +             linker_plugin_file_spec = find_a_file (&exec_prefixes,
> +                                                    LTOPLUGINSONAME, R_OK,
> +                                                    false);
> +             if (!linker_plugin_file_spec)
> +               fatal_error ("-fuse-linker-plugin, but %s not found",
> +                            LTOPLUGINSONAME);
> +           }
>  #endif
> -      lto_gcc_spec = argv[0];
> +         lto_gcc_spec = argv[0];
> +       }
>
>       /* Rebuild the COMPILER_PATH and LIBRARY_PATH environment variables
>         for collect.  */
>
>        Jakub