[Bug other/109709] New: List of prerequisites should include that tar is required (not only for unpacking the source).

[Bug other/109709] New: List of prerequisites should include that tar is required (not only for unpacking the source).

[me at manueljacob dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

            Bug ID: 109709
           Summary: List of prerequisites should include that tar is
                    required (not only for unpacking the source).
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: me at manueljacob dot de
  Target Milestone: ---

When tar is not installed, building GCC under Linux will fail, at least with
the default configuration.


The documentation says

GNU tar version 1.14 (or later)

Necessary (only on some platforms) to untar the source code.  Many systems' tar
programs will also work, only try GNU tar if you have problems.


It could be argued that this prerequisite should be left implicit, similar to
how it is not mentioned that e.g. the "cp" and "file" commands should be
present.

[Bug other/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Huh, can you post how it fails?

[Bug other/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2023-05-03
     Ever confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Also the reason why it is listed explicitly for extraction is that the tar
files that are generated use gnu tar and use the gnu extensions for long file
names.

[Bug bootstrap/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[me at manueljacob dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

--- Comment #3 from Manuel Jacob <me at manueljacob dot de> ---
(In reply to Richard Biener from comment #1)
> Huh, can you post how it fails?

if [ -d ../prev-gcc ]; then \
  cd ../prev-gcc && \
  make real-install-headers-tar DESTDIR=`pwd`/../gcc/ \
    libsubdir=. ; \
else \
  set -e; for ml in `cat fixinc_list`; do \
    sysroot_headers_suffix=`echo ${ml} | sed -e 's/;.*$//'`; \
    multi_dir=`echo ${ml} | sed -e 's/^[^;]*;//'`; \
    fix_dir=include-fixed${multi_dir}; \
    if ! false && test ! -d `echo /usr/include | sed -e :a -e
's,[^/]*/\.\.\/,,' -e ta`; then \
      echo The directory that should contain system headers does not exist: >&2
; \
      echo "  `echo /usr/include | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`" >&2
; \
      tooldir_sysinc=`echo
"/usr/lib/gcc/x86_64-pc-linux-gnu/13.1.0/../../../../x86_64-pc-linux-gnu/sys-include"
| sed -e :a -e "s,[^/]*/\.\.\/,," -e ta`; \
      if test "x`echo /usr/include | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`" =
"x${tooldir_sysinc}"; \
      then sleep 1; else exit 1; fi; \
    fi; \
    /bin/sh /build/source/gcc-13.1.0/gcc/../mkinstalldirs ${fix_dir}; \
    chmod a+rx ${fix_dir} || true; \
    (TARGET_MACHINE='x86_64-pc-linux-gnu'; srcdir=`cd
/build/source/gcc-13.1.0/gcc; ${PWDCMD-pwd}`; \
      SHELL='/bin/sh'; MACRO_LIST=`${PWDCMD-pwd}`/macro_list ; \
      gcc_dir=`${PWDCMD-pwd}` ; \
      export TARGET_MACHINE srcdir SHELL MACRO_LIST && \
      cd ../build-x86_64-pc-linux-gnu/fixincludes && \
      /bin/sh ./fixinc.sh "${gcc_dir}/${fix_dir}" \
        `echo /usr/include | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`  ); \
  done; \
fi
make[4]: Entering directory '/build/build/prev-gcc'
(cd `${PWDCMD-pwd}`/include-fixed ; \
 tar -cf - .; exit 0) | (cd /build/build/prev-gcc/../gcc/./include-fixed; tar
xpf - )
/bin/sh: line 2: tar: command not found
/bin/sh: line 2: tar: command not found
make[4]: *** [Makefile:4028: real-install-headers-tar] Error 127
make[4]: Leaving directory '/build/build/prev-gcc'
make[3]: *** [Makefile:3309: stmp-fixinc] Error 2
make[3]: Leaving directory '/build/build/gcc'
make[2]: *** [Makefile:5013: all-stage2-gcc] Error 2
make[2]: Leaving directory '/build/build'
make[1]: *** [Makefile:27012: stage2-bubble] Error 2
make[1]: Leaving directory '/build/build'
make: *** [Makefile:1080: all] Error 2

[Bug bootstrap/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
gcc/Makefile.in has:

# Install the include directory using tar.
install-headers-tar: stmp-int-hdrs install-include-dir
# We use `pwd`/include instead of just include to problems with CDPATH
# Unless a full pathname is provided, some shells would print the new CWD,
# found in CDPATH, corrupting the output.  We could just redirect the
# output of `cd', but some shells lose on redirection within `()'s
        (cd `${PWD_COMMAND}`/include ; \
         tar -cf - .; exit 0) | (cd $(DESTDIR)$(libsubdir)/include; tar xpf - )
        (cd `${PWD_COMMAND}`/include-fixed ; \
         tar -cf - .; exit 0) | (cd $(DESTDIR)$(libsubdir)/include-fixed; tar
xpf - )
# /bin/sh on some systems returns the status of the first tar,
# and that can lose with GNU tar which always writes a full block.
# So use `exit 0' to ignore its exit status.


This doesn't require GNU tar though, just any tar, so I think I agree that it's
just like cp and file and sed which are part of any unix-like environment.

The prerequisites page is specifically saying that GNU tar is needed on some
systems, for the reason Andrew stated above.

[Bug bootstrap/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I suppose we could do something like:

--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -364,7 +364,9 @@ You must have GNU make installed to build GCC@.

 Necessary (only on some platforms) to untar the source code.  Many
 systems' @command{tar} programs will also work, only try GNU
-@command{tar} if you have problems.
+@command{tar} if you have problems. N.B. a @command{tar} program of some
+kind is always needed to build GCC, the GNU tar requirement is only
+for extracting the sources.

 @item Perl version between 5.6.1 and 5.6.24

[Bug bootstrap/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sjames at gcc dot gnu.org

--- Comment #6 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #5)
> I suppose we could do something like:
> 

lgtm, even if I think it's a little bit silly

[Bug bootstrap/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Maybe we should just say "a full set of POSIX shell utilities (ls, cp, find,
tar, sed, etc.) is expected to be available" and leave it at that.

[Bug bootstrap/109709] List of prerequisites should include that tar is required (not only for unpacking the source).

[me at manueljacob dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109709

--- Comment #8 from Manuel Jacob <me at manueljacob dot de> ---
As said in the original bug report, I’d understand if these prerequisites (like
tar and find) were left implicit (therefore this bug report could be closed
as-is), but the two suggestions by Jonathan Wakely seem reasonable to me.