Re: [PATCH] AIX SONAME emulation, simplified implementation

Hi Daniel,

(I'm not a libtool maintainer, but the author of current --with-aix-soname impl)

On 06/24/2015 03:34 PM, Daniel Ruoso (BLOOMBERG/ 731 LEX) wrote:
> This patch offers a simplified implementation of a SONAME-like behavior emulation.

I've tried this variant of soname-emulation too, but discovered the one using
the "lib.so.v(shr.o,shr.imp)" archive (=svr4) as the more reasonable compromise.

Is there a specific reason you need/want this simplified implementation?

> This is different in the sense that it doesn't add archives disguised as .so files,

Yeah, instead it does provide plain text files disguised as .so files.

Besides that, there's potential for more different confusion:
*) Linking with "/path/to/lib.so" produces different result than 
   linking with "/path/to/lib.so.v" (difference is in the runpath).
*) dlopen("lib.so") fails, while dlopen("lib.so.v") does work.
*) Provides two distinct files, instead of one single file with symlinks.

> and instead relies on the fact that the AIX linker will take an import file when
> looking for -l<foo>, and will record what the import file says.

This very detail isn't anything different compared to aix-soname=svr4.

Leaving alone different confusion, this version of the patch has some real problems:

*) Please post patches as plain-text.
*) Breaks test cases in build setups that should be unaffected by this patch
   (I'm using https://github.com/haubi/libtool-testing/ for the different build
   setups to run the testsuite in and compare the results).
*) Why do you change archive_expsym_cmds for $host_cpu = ia64 ?
*) Seems you haven't used 'make distcheck': Tells to not use '==' with 'test'.
*) Prohibits the AIX-style of multilib (multiple shared objects in one archive).
*) Existing site setups using LDFLAGS=-Wl,-brtl will break, as their existing
   binaries depend on the unversioned .so files, which will be replaced by
   plain text files.
   At least something like --with-aix-soname=simple would be necessary.

Thanks for your interest on this topic!
/haubi/