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Hi devs, |
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while there is the appreciated multiple ABI portage support going on, |
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a thought on the intentions of the multilib profiles. |
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Some background: |
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I do have to support building an older, but still maintained large |
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application software, that simply does not work when built as 64bit. |
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As it does not have the need itself for >32bit pointers, and all |
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the 64bit target platforms do support 32bit binaries too, the plan |
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to fix the code for 64bits has been cancelled. |
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I'm using gcc to build the application on all the target unices, |
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as well as autotools for build management. |
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As I'm building the toolchain myself too, I configure it with the |
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32bit host triplet on each platform, usually disabling multilib. |
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This simply works for ppc-aix, hppa-hpux, ia64-hpux, sparc-solaris, |
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x86-solaris, even if the underlying OS/kernel is 64bit. |
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It isn't even necessary to explicitly use --{build,host} at all, |
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as config.guess tells the 32bit triplet on these platforms. |
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Additionally, even their default compiler output is 32bit. |
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|
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But Linux "is not Unix": |
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Configuring both binutils and gcc needs to be done with: |
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$ CC="gcc -m32" /path/to/configure --{build,host}=i686-pc-linux-gnu ... |
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This works on 64bit RHEL as well as on 64bit SLES (both have 32bit in /lib, |
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64bit in /lib64, no /lib32), but breaks on amd64+multilib Gentoo Linux. |
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|
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Problem is that, as x86-linux isn't a multilib target, both ld and gcc |
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search for 32bit libs&objects in /usr/lib:/lib, as they don't know about |
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/usr/lib32:/lib32. The error when bootstrapping gcc is: |
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/usr/lib/crti.o: file not recognized: File format not recognized |
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While it is possible to patch binutils[1] and gcc[2] to search in |
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/usr/lib32:/lib32 even with this otherways non-multilib target, |
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it doesn't feel like the "right thing" to enable multilib for |
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just one multilib option. |
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Isn't the intention of multilib to have a new (64bit) system |
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be compatible with the corresponding old (32bit) system? |
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Please comment, thank you! |
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/haubi/ |
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|
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[1] http://overlays.gentoo.org/proj/alt/changeset/51324 |
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[2] http://overlays.gentoo.org/proj/alt/changeset/51325 |
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