[PATCH] buildsys: clean up libubacktrace linker script handling

[Khem Raj]

On Fri, Jun 15, 2012 at 7:37 AM, Bernhard Reutner-Fischer
<rep.dot.nop at gmail.com> wrote:
> On 15 June 2012 04:54, Kevin Cernekee <cernekee at gmail.com> wrote:
>> On Wed, Jun 13, 2012 at 12:58 AM, Bernhard Reutner-Fischer
>> <rep.dot.nop at gmail.com> wrote:
>>> On Tue, Jun 12, 2012 at 04:52:21PM +0100, Carmelo AMOROSO wrote:
>>>>On 07/06/2012 19.32, Kevin Cernekee wrote:
>>>>> Move the AS_NEEDED insertion into libc/Makefile.in, and add a case to
>>>>> the HARDWIRED_ABSPATH substitution command so libubacktrace is handled
>>>>> the same way as the other libraries listed in the script.
>>>>
>>>>Looks fine to me.
>>>>
>>>
>>> Applied, thanks!
>>
>> Unfortunately it looks like this could cause some problems when
>> bootstrapping a new toolchain.  If the libc.so script references
>> libubacktrace, but libubacktrace.so.0 is not yet installed anywhere,
>> gcc will throw an error during the final link on the other shared
>> libraries:
>>
>> rm -f lib/libdl.so lib/libdl.so.0 lib/libdl-0.9.32.1.so
>> arm-linux-uclibcgnueabi-gcc -Wl,-EL -shared -Wl,--warn-common
>> -Wl,--warn-once -Wl,-z,combreloc -Wl,-z,relro -Wl,-z,defs
>> -Wl,-fini,dl_cleanup  -Wl,-soname=libdl.so.0 -nostdlib -o
>> lib/libdl-0.9.32.1.so  -Wl,--whole-archive ldso/libdl/libdl_so.a
>> -Wl,--no-whole-archive ./lib/interp.os -L./lib ./lib/libc.so
>> ./lib/ld-uClibc.so.0
>> /ssd/test/bin/../lib/gcc/arm-linux-uclibcgnueabi/4.5.3/libgcc.a
>> /ssd/test/bin/../lib/gcc/arm-linux-uclibcgnueabi/4.5.3/libgcc_eh.a
>> /ssd/test/bin/../lib/gcc/arm-linux-uclibcgnueabi/4.5.3/../../../../arm-linux-uclibcgnueabi/bin/ld:
>> cannot find libubacktrace.so.0
>> collect2: ld returned 1 exit status
>> make[1]: *** [lib/libdl.so] Error 1
>>
>>
>> I did not see this earlier because -nostdlib doesn't actually keep gcc
>> from passing ld "-L" arguments pointing into the sysroot directories.
>> So it saw my existing libubacktrace.so.0 from the installed sysroot
>> and did not complain that libubacktrace.so.0 was missing from the
>> uClibc build tree.
>>
>> Maybe we will need to revert back to this technique, at least in some form?
>>
>> -# Add the AS_NEEDED entry for libubacktrace.so
>> -       if [ -f $(top_builddir)lib/libc.so -a -f
>> $(PREFIX)$(RUNTIME_PREFIX)$(MULTILIB_DIR)/$(SHARED_LIBNAME) ] ; then \
>> -               echo "GROUP ( $(UBACKTRACE_ASNEEDED) )" >>
>> $(PREFIX)$(DEVEL_PREFIX)$(MULTILIB_DIR)/libc.so; \
>> -       fi
>> -endif
>>
>> I would appreciate any feedback/suggestions.
>
> What a mess. Carmelo, can you suggest a proper fix please (as
> quick-fix i put the static lib into the libc script just to make it
> link).
> TIA,


This quick fix is wrong since now it will try to ask for static
version of libubacktrace when linking shared libs and PIC binaries and
libubacktrace.a is not PIC