[Bug bootstrap/45053] New: libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[Bug bootstrap/45053] New: libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[gcc-bugzilla at gcc dot gnu dot org]

        [I know this is a duplicate of 43810, but the information there is
        partly misleading, so I decided to file a new report.]
        If GCC is configured for powerpc with --enable-target-optspace,
        libgcc_s objects get compiled with -Os, and this causes libgcc_s
        to contain undefined symbols _savegpr_* and _restgpr_*.
        This is probably due to this commit:
        http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=151729
        (The use of those symbols might also depend on --with-float=soft,
        I didn't test with a different float option.)
        Those symbols _savegpr_* and _restgpr_* are defined in
        crtsavgpr_s.o and crtresgpr_s.o, respectively.  But those objects
        are not linked into libgcc_s.
        The problem also occurs with gcc-4.5.1-RC-20100722 and with
        gcc-4.4.4, if the patch for pr41175 is applied.

Environment:
System: Linux sonnet 2.6.24-28-generic #1 SMP Fri Jun 18 14:18:04 UTC 2010
x86_64 GNU/Linux


host: x86_64-unknown-linux-gnu
build: x86_64-unknown-linux-gnu
target: powerpc-none-linux-gnu
configured with: /work2/build/cross-own/src/gcc-4.5.0/configure
--target=powerpc-none-linux-gnu --prefix=/work2/build/cross-own/ppc-own-tmp
--disable-threads --disable-nls --disable-multilib --disable-libgomp
--disable-libssp --disable-libmudflap --enable-decimal-float=no
--disable-libssp --enable-shared --enable-languages=c --enable-checking=yes
--enable-symvers=gnu --enable-target-optspace --with-float=soft
--with-local-prefix=/work2/build/cross-own/ppc-own/sys-root
--with-build-sysroot=/work2/build/cross-own/ppc-own/sys-root
--with-sysroot=/work2/build/cross-own/ppc-own/sys-root

How-To-Repeat:
        configure for powerpc and --enable-target-optspace (and possibly
--with-float=soft)


------- Comment #1 from dv at vollmann dot ch  2010-07-24 12:42 -------
Fix:
        The workaround is not to use --enable-target-optspace.
        The correct fix would be to link libgcc_s against crtsavgpr_s.o
        and crtresgpr_s.o, but I don't know the build system of GCC well
        enough to figure out how to do that.


-- 
           Summary: libgcc_s link command misses crtsavgpr_s and crtresgpr_s
                    for powerpc
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dv at vollmann dot ch
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: powerpc-none-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[mikpe at it dot uu dot se]

------- Comment #2 from mikpe at it dot uu dot se  2010-07-24 13:22 -------
The build on some targets including powerpc is supposed to create libgcc_s.so
as a linker script that inputs BOTH the real shared libgcc_s.so and the static
libgcc.a, as some symbols are only defined in the static libgcc.  Please make
sure that you're preserving this linker script when installing gcc.

If you want to backport PR41175 to 4.4 then you also need to backport
config.gcc changes related to the powerpc linker script from r151568.

(ARM has the same issue.  No I'm not responsible for this misdesign.)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[dv at vollmann dot ch]

------- Comment #3 from dv at vollmann dot ch  2010-07-24 13:35 -------
Subject: Re:  libgcc_s link command misses crtsavgpr_s
 and crtresgpr_s for powerpc

On 07/24/10 15:22, mikpe at it dot uu dot se wrote:
> ------- Comment #2 from mikpe at it dot uu dot se  2010-07-24 13:22 -------
> The build on some targets including powerpc is supposed to create libgcc_s.so
> as a linker script that inputs BOTH the real shared libgcc_s.so and the static
> libgcc.a, as some symbols are only defined in the static libgcc.  Please make
> sure that you're preserving this linker script when installing gcc.
> 
> If you want to backport PR41175 to 4.4 then you also need to backport
> config.gcc changes related to the powerpc linker script from r151568.
> 
> (ARM has the same issue.  No I'm not responsible for this misdesign.)
> 
> 
This is not an issue of the linker script, as the linker script
doesn't give a DSO (correctly) access to hidden symbols in another
library of the same group.
You relly need to link those objects into libgcc_s, as those symbols
aren't fit for calling through dynamic symbol lookup.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[mikpe at it dot uu dot se]

------- Comment #4 from mikpe at it dot uu dot se  2010-07-24 19:36 -------
Attempting to bootstrap 4.5.1-RC on powerpc-linux with --enable-target-optspace
fails near the end of stage1 while configuring libgomp:

configure:3658: checking for C compiler default output file name
configure:3680: /home/mikpe/objdir/./gcc/xgcc -B/home/mikpe/objdir/./gcc/
-B/tmp/install/powerpc-unknown-linux-gnu/bin/
-B/tmp/install/powerpc-unknown-linux-gnu/lib/ -isystem
/tmp/install/powerpc-unknown-linux-gnu/include -isystem
/tmp/install/powerpc-unknown-linux-gnu/sys-include    -g -Os   conftest.c  >&5
/home/mikpe/objdir/./gcc/crtend.o: In function `__do_global_ctors_aux':
crtstuff.c:(.text+0xc): undefined reference to `_savegpr_31'
collect2: ld returned 1 exit status

libgcc.a was built and does define _savegpr_31, and libgcc_s.so is the expected
linker script, and both files are available in the build directory.

So yes, --enable-target-optspace appears broken.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[paolo dot carlini at oracle dot com]

------- Comment #5 from paolo dot carlini at oracle dot com  2010-08-05 14:38 -------
Ian, is this a libgcc issue? Can you suggest the best wa to triage it? Thanks.


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ian at airs dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[ian at airs dot com]

------- Comment #6 from ian at airs dot com  2010-08-11 04:28 -------
Yes, this is a libgcc issue.  This kind of target-specific issue is normally
handled by the relevant backend maintainers.

I'm surprised that it doesn't work, as libgcc/config/rs6000/t-ppccomm includes
crtsavgpr.S and crtresgpr.S in LIB2ADD_ST.  I would expect that to include the
required functions.  But I haven't tried it, and apparently something goes
wrong.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[paolo dot carlini at oracle dot com]

------- Comment #7 from paolo dot carlini at oracle dot com  2010-08-11 07:26 -------
Thanks for your feedback Ian. Now, I'm not sure which target maintainer to
suggest for powerpc-linux... David Edelsohn?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[paolo dot carlini at oracle dot com]

-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-08-11 07:30:59
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[dv at vollmann dot ch]

------- Comment #8 from dv at vollmann dot ch  2010-08-11 10:56 -------
Subject: Re:  libgcc_s link command misses crtsavgpr_s
 and crtresgpr_s for powerpc

@Ian:
> I'm surprised that it doesn't work, as libgcc/config/rs6000/t-ppccomm includes
> crtsavgpr.S and crtresgpr.S in LIB2ADD_ST.  I would expect that to include the
> required functions.
Maybe the problem is that the functions are only referenced if you use
-Os.  So if there's some automatism going on that collects all the
required symbols, this automatism needs to use -Os for target-optspace.
But I have no real idea how the build process works, so this is just
guessing.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

[Bug bootstrap/45053] libgcc_s link command misses crtsavgpr_s and crtresgpr_s for powerpc

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45053

--- Comment #9 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-25 10:21:25 UTC ---
*** Bug 48278 has been marked as a duplicate of this bug. ***