On Mon, Apr 29, 2024 at 1:27 AM Peter0x44 <peter0...@disroot.org> wrote:
>
> 29 Apr 2024 12:16:26 am Peter Damianov <peter0...@disroot.org>:
>
> > This commit adds a new option to the driver that truncates one file
> > after
> > linking.
> >
> > Tested likeso:
> >
> > $ gcc hello.c -c
> > $ du -h hello.o
> > 4.0K hello.o
> > $ gcc hello.o -truncate hello.o
> > $ ./a.out
> > Hello world
> > $ du -h hello.o
> > $ 0 hello.o
> >
> > $ gcc hello.o -truncate
> > gcc: error: missing filename after '-truncate'
> >
> > The motivation for adding this is PR110710. It is used by lto-wrapper
> > to
> > truncate files in a shell-independent manner.
> >
> > Signed-off-by: Peter Damianov <peter0...@disroot.org>
> > ---
> > gcc/common.opt | 6 ++++++
> > gcc/gcc.cc | 14 ++++++++++++++
> > 2 files changed, 20 insertions(+)
> >
> > diff --git a/gcc/common.opt b/gcc/common.opt
> > index ad348844775..40cab3cb36a 100644
> > --- a/gcc/common.opt
> > +++ b/gcc/common.opt
> > @@ -422,6 +422,12 @@ Display target specific command line options
> > (including assembler and linker opt
> > -time
> > Driver Alias(time)
> >
> > +;; Truncate the file specified after linking.
> > +;; This option is used by lto-wrapper to reduce the peak disk-usage
> > when
> > +;; linking with many .LTRANS units.
> > +truncate
> > +Driver Separate Undocumented MissingArgError(missing filename after
> > %qs)
> > +
> > -verbose
> > Driver Alias(v)
> >
> > diff --git a/gcc/gcc.cc b/gcc/gcc.cc
> > index 728332b8153..830a4700a87 100644
> > --- a/gcc/gcc.cc
> > +++ b/gcc/gcc.cc
> > @@ -2138,6 +2138,10 @@ static int have_E = 0;
> > /* Pointer to output file name passed in with -o. */
> > static const char *output_file = 0;
> >
> > +/* Pointer to input file name passed in with -truncate.
> > + This file should be truncated after linking. */
> > +static const char *totruncate_file = 0;
> > +
> > /* This is the list of suffixes and codes (%g/%u/%U/%j) and the
> > associated
> > temp file. If the HOST_BIT_BUCKET is used for %j, no entry is made
> > for
> > it here. */
> > @@ -4538,6 +4542,11 @@ driver_handle_option (struct gcc_options *opts,
> > do_save = false;
> > break;
> >
> > + case OPT_truncate:
> > + totruncate_file = arg;
> > + do_save = false;
> > + break;
> > +
> > case OPT____:
> > /* "-###"
> > This is similar to -v except that there is no execution
> > @@ -9286,6 +9295,11 @@ driver::final_actions () const
> > delete_failure_queue ();
> > delete_temp_files ();
> >
> > + if (totruncate_file != NULL && !seen_error ())
> > + /* Truncate file specified by -truncate.
> > + Used by lto-wrapper to reduce temporary disk-space usage. */
> > + truncate(totruncate_file, 0);
> > +
> > if (print_help_list)
> > {
> > printf (("\nFor bug reporting instructions, please see:\n"));
> > --
> > 2.39.2
> I resubmitted the patch because the previous one had a mistake.
>
> It didn't set "do_save" to false, so it resulted in problems like this:
>
> ./gcc/xgcc -truncate
> xgcc: error: missing filename after ‘-truncate’
> xgcc: fatal error: no input files
>
> ./gcc/xgcc -truncate ??
> xgcc: error: unrecognized command-line option ‘-truncate’
> xgcc: fatal error: no input files
>
> Therefore regressing some tests, and not working properly.
> After fixing this, I ran all of the LTO tests again and observed no
> failures.
>
> I'm not sure how I ever observed it working before, but I'm reasonably
> confident this is correct now.
The series is still OK. I suppose you do not have git write access so
I am testing the series with a LTO bootstrap and will push it once
that's successful.
Thanks,
Richard.
