Hi, Am Mittwoch, den 04.01.2012, 20:50 +0100 schrieb Axel Simon:
On 04.01.2012, at 17:50, Joachim Breitner wrote:
BTW, Is there a way to get the linker to create two independent copies of a library in one program space? Maybe if it is compiled as PIC (random name dropping here)? That would seem to be an elegant solution, as it makes the distro packers happy and you would not have to maintain a code copy.
In the past, I've linked a C++ library that used gmpxx against a Haskell program by renaming all symbols starting with gmp to mygmp using objcopy. Unfortunately, this is not portable and completely broke down on Mac OS when Apple moved to fat binaries (Intel and PowerPC) since their objcopy version was crippled (there doesn't even seem to be an objcopy anymore on later OS X versions). Thus, renaming symbols after compilation is non-portable and sometimes not possible without writing your own tool.
let me pick up this idea again. It was pointed out that it is mostly Linux and BSD based distributions that dislike code copies. For these, the objcopy-way might work. It does not work on MacOS, but that target does not have the code copy requirements.. So would it be possible to * use objcopy at GHC build-time to take the system libgmp shared library, rename the symbols, and install the modified library with ghc on architectures that support it, * have a code copy for those who don’t? For the distros this has the nice effect that if there is a bugfix in libgmp, they just have to rebuild ghc without any changes to the sources to benefit from it. (But I am really wondering why the linker cannot do something that has the same effect as objcopy --prefix-symbols, but on the fly.) Greetings, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata@debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata@joachim-breitner.de | http://people.debian.org/~nomeata