Barry Smith <bsmith at mcs.anl.gov> writes:
> On Wed, 14 Dec 2005, Matthew Knepley wrote:
>
>> Barry Smith <bsmith at mcs.anl.gov> writes:
>>
>> > Hmmm, why should you have a PIC test? Who cares if something
>> > has PIC or not? You only thing you care about is that you CAN
>> > do what you want to do with it? (In this case I think it is simply
>> > that you can build an executable using a shared library PLUS the
>> > given library you are testing.)
>> >
>> > Barry
>> >
>> > configure is suppose to be "can I ...?" not "is something ...?"
>>
>> Because the "can I" is VERY erratic. I can build some shared libraries, but
>> cannot build others.
>
> My understanding is that it can build a basic shared library (stand alone
> with a couple of symbols) BUT cannot build a shared library (and use it) in
> conjunction
> with the MPI libraries. So I fail to understand why you cannot just test
> this?????
This is not my understanding. The checkShared() from MPI.py DOES EXACTLY
build a shared
library (two in fact) linked to MPI. These succeed just fine.
> Make a new test that is, exactly the FIRST part of the test
>
> def checkShared(self, inclu....
>
> up to the code where
>
> if not checkLink(includes, body, cleanup = 0, codeBegin = codeBegin,
> codeEnd = codeEnd, shared = 1):
> if os.path.isfile(configObj.compilerObj):
> os.remove(configObj.compilerObj)
> self.setCompilers.LIBS = oldFlags
> raise RuntimeError('Could not complete shared library check\nCould not
> create a shared library using the currently configured shared
> linker.\nSuggest running with --with-shared=0 if you do not need shared
> libraries. Otherwise send configure.log to petsc-maint at mcs.anl.gov')
>
> but instead of throwing the silly exception you return 0 here. But if the
> link
> succeeds you continue the test until
This does succeed.
> ''' % (boolType, checkCode)
> if finiFunction:
> body += ' if (isInitialized) '+finiFunction+'();\n'
> body += ' return (int) isInitialized;\n'
> codeEnd = '\n}\n'
> if not checkLink(includes, body, cleanup = 0, codeBegin = codeBegin,
> codeEnd = codeEnd, shared = 1):
> if os.path.isfile(configObj.compilerObj):
> os.remove(configObj.compilerObj)
> self.setCompilers.LIBS = oldFlags
> raise RuntimeError('Could not complete shared library check\nCould not
> create a shared library using the currently configured shared
> linker.\nSuggest running with --with-shared=0 if you do not need shared
> libraries. Otherwise send configure.log to petsc-maint at mcs.anl.gov')
> return 0
>
> here instead of the exception return 1 or 0 based on whether the link
> succeeds.
> Do not do the rest of the test.
This also succeeds, unless I misunderstand greatly the error.
Matt
> I may be missing something but I don't understand why this has to be
> such a difficult thing. We know exactly where things go wrong (based on the
> log files)
> so we write a test specifically for that problem and report failure or
> success why
> make life more complicated.
>
> Barry
>
>>I do not understand the difference between these libraries
>> at the moment, however I DO know that absence of the PIC option causes the
>> error.
>> Furthermore, checking this option allows a precise error message rather than
>> a
>> guess. Lastly, this is in the configure spirit I believe, because we often
>> test
>> the "what" of things, like endianness or the size of void *.
>>
>> Matt
>>
>
>
>
--
"Failure has a thousand explanations. Success doesn't need one" -- Sir Alec
Guiness
