[Bug bootstrap/39316] [lto] revision 144454 - Configure should check for elf support (similar to gmp/mpfr/PPL/CLooG)

[rob1weld at aol dot com]

------- Comment #6 from rob1weld at aol dot com  2009-10-04 10:25 -------
(In reply to comment #5)
> I see.  This particular issue should be fixed as libelf and the clone from
> elfutils use different SONAMEs and the configure test in GCC checks for the
> actual features it uses with a link test.  The only thing that may happen
> is that with broken installations (headers from one lib, shared library from
> the other) things will break and we'd need to run a test program to detect
> this weird case.

>> It is my Request for Enhancement that the 'Configury' detect if
>> there is enough elf support to build gcc - in a similar manner that
>> gmp, mpfr, PPL and CLooG are tested for. ...

I suggest that gmp, mpfr, PPL, CLooG and "LTOable ELF" all use "similar"
configury to check that each will work correctly with GCC _WHEN_ we
later get to the portion of the build that actually uses the feature.

The "similar configury" can each call a different snippet of code (obviously)
to test that _whatever_ the configure script thinks it has detected will
actually compile a program that will execute and produce an expected result.

Program code that can only be compiled (without warnings or errors) but are
not executable should be maked as compilable but not executable (for cross
compiling).

_IF_ we can not get whatever we thought we detected to compile we need to
signal this in the _FIRST_ configure script and _not_ leave it to be 
discovered by some configure script that get ran 3/4 though the build days
later, that is annoying and happens too frequently.

Richard, if you are closing this can you post the Changelog for this BR.

Thanks,
Rob


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39316