[Rehashing a thread from 3 years ago] 28.01.2013 11:48, Denys Vlasenko wrote: > On Monday 28 January 2013 00:17, Abdoulaye Walsimou GAYE wrote:
>>>>> diff --git a/archival/libarchive/Kbuild.src >>>>> b/archival/libarchive/Kbuild.src >>>>> index 58457fc..87e1ab9 100644 >>>>> --- a/archival/libarchive/Kbuild.src >>>>> +++ b/archival/libarchive/Kbuild.src >>>>> -lib-$(CONFIG_TAR) += get_header_tar.o >>>>> +lib-$(CONFIG_TAR) += get_header_tar.o >>>>> decompress_uncompress.o >> >> /home/walsimou/embtoolkit.git/build/packages_build-mipsel-linux-mips32/busybox-1.20.2/archival/tar.c:1065: >> undefined reference to `unpack_Z_stream' >> /home/walsimou/embtoolkit.git/build/packages_build-mipsel-linux-mips32/busybox-1.20.2/archival/tar.c:1065: >> undefined reference to `unpack_Z_stream' >> /home/walsimou/embtoolkit.git/tools-mipsel-linux-mips32/bin/mipsisa32el-unknown-linux-uclibc-ld: >> busybox_unstripped: hidden symbol `unpack_Z_stream' isn't defined >> /home/walsimou/embtoolkit.git/tools-mipsel-linux-mips32/bin/mipsisa32el-unknown-linux-uclibc-ld: >> final link failed: Bad value >> mipsisa32el-unknown-linux-uclibc-clang: error: linker command failed with >> exit code 1 (use -v to see invocation) > > > I was able to build busybox-1.20.2 with this .config > without errors. > > Looks like your compiler did not optimize this out: > > if (opt & OPT_COMPRESS) > USE_FOR_MMU(xformer = unpack_Z_stream;) > USE_FOR_NOMMU(xformer_prog = "uncompress";) > > > even though OPT_COMPRESS is a constant zero. The same prob exists with clang, apparently, Here's a bugreport filed against debian package of busybox: http://bugs.debian.org/789499 . The proposed fix is to apply the above patch only if building with clang :) Basically, I'm not sure relying on dead code elimination like this is a good idea. I mean, the code is eliminated, there's no if() statement in the generated code, so it is okay, but it looks like clang still records symbols referenced in the eliminated code. Sometimes it is actually a good idea to keep ref symbols, eg when you build an executable which can load modules, so that modules will use symbols in that executable. Thanks, /mjt _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox
