From: Warren Young
Date: November 12 2010 9:31pm
Subject: Re: Link error when building mysql++-3.1.0 with --as-needed
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On 11/12/2010 2:03 PM, Adrian Cornish wrote:
> As far as I can determine all that matters is that  -lmysqlpp_ssqls2parse
> comes before -Wl,--as-needed.

If true, that's a screwy way for the GNU linker to implement that feature.

I assume Gentoo is adding this flag by diddling autoconf somehow, so it 
can inject this option into LDFLAGS.  There's no easy way that code can 
figure out that some -l flags refer to static helper libraries and 
others to dynamic ones, so it has to do something simple like prepend it 
blindly.

We *could* fix it in MySQL++ by doing without helper libraries entirely, 
rebuilding all the ssqls2parse modules separately for each program that 
used them so they just appear among *.o for that program's link command. 
  That's quite inefficient, however.

Andrew, you say Gentoo would reject a patch that removed --as-needed for 
MySQL++.  Unless there are serious penalties for doing that, I don't see 
why.  This sounds like a small tweak, a nice thing to have for programs 
that cope with it, but not something worth fighting over.

If you're right and they do reject such a patch, you could instead offer 
a patch that manually reorders the LDFLAGS=foo... line in the Makefile 
after the "configure" step.  That's more work for you, but there should 
be no way to argue against that.

Regardless, I retract my suggestion that we involve the Bakefile 
maintainer in this.  His code is doing the right thing already.