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Re: libstdc++ in a combined tree
On Fri, Apr 28, 2006 at 08:36:50PM -0400, DJ Delorie wrote:
>
> > Well, that sounds like an autoconf bug. If it refuses to work when
> > presented with a pile of compiler options, that just sounds bad.
>
> No, I think it's our bug - we do this:
>
> GCC_NO_EXECUTABLES
> GLIBCXX_ENABLE_SYMVERS([yes])
>
> You can't logically expect that to work, no matter how many compiler
> options we give it - we've told autoconf to not produce any
> executables, then asked it to test something that requires them.
Incorrect. Take a look at the implementation of GCC_NO_EXECUTABLES,
please:
AS_IF([AC_TRY_EVAL(ac_link)], [gcc_no_link=no], [gcc_no_link=yes])
It sets gcc_no_link based on a link test. If the link test succeeds,
then future link tests are allowed. If the link test fails, then
future link tests are a fatal error (instead of just reporting the
feature being tested for as missing).
So if you really have enough to link, then it ought to work fine.
What are you building here? A combined tree including newlib? If
so, I bet you aren't specifying --with-newlib; that turns off a bunch
of link tests. Newlib is special because we arrange to build
libstdc++-v3 before building newlib.
That we require the configure option is somewhat lame.
--
Daniel Jacobowitz
CodeSourcery