Red Hat Bugzilla – Bug 229703
RFE: use default hash-style=both instead of only gnu
Last modified: 2007-11-30 17:11:57 EST
Current binaries built on FC6 fail to execute on other systems due to using new gnu hash style. As it is possible to use both styles (gnu and sysv) on an executable, I suggest change gcc default options to build with both styles. Tests with kdebase.src.rpm show: i. 1.2% increase in uncompressed size: +2MB to 169MB (output of rpm2cpio | LANG=C wc -c) ii. 0.95% *decrease* in compressed size: -712KB from 73.2MB (size of kdebase-3.5.6-0.1.i386.rpm) Interestingly, most libraries and executables in kdebase, if bigger than 200KB, tend to compress better if compiled with hash-style=both than if compiled with hash-style=gnu. With this two interesting cases, and as hard-disks tend to be bigger and cheaper, removable storage slower, and compatibility is usually a benefit, I suggest that Fedora defaults to compile with both hash styles. Of course, I suggest further testing. It could be limited to kdebase and/or to my build system. I did the test by recompiling kdebase-3.5.6. The hash-style=both test was used with the following change to %build: %configure \ CC="${CC:-gcc} -Wl,--hash-style=both" \ CXX="${CXX:-g++} -Wl,--hash-style=both" \
Feel free to build your binaries that you want to reuse on other distributions with that option. All FC6+ rpms built with -Wl,--hash-style=gnu have rpm generated dependency on the proper glibc, so you can't mistakenly install them on older distributions. Generally, running binaries built for a newer distro on older doesn't work anyway (new symbols added to glibc and other symbol versioned libraries).
There were some instances of vendors shipping pre-compiled binaries that only worked in Fedora (like syslinux). For some cases, like that one, there's no dependency on newer glibc and other symbol versioned libraries. Only on the hash style. Without the sysv style, the executables die imediatly on startup with "Floating point exception". With it, they run fine. For most complex programs, however, the dependency on glibc versioned libraries will apply. But for the sake of the others, and for reducing the size of binary RPMs, hash style default of both would be nice. Anyway, it's only food for thought.