Re: configure can't detect proper pthread flags

On Fri, Mar 20, 2015 at 05:15:51AM +0300, Max Filippov wrote:
> On Fri, Mar 20, 2015 at 5:09 AM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> > On Fri, Mar 20, 2015 at 04:51:55AM +0300, Max Filippov wrote:
> >> xtensa-linux-gcc -o conftest -Wall -Wmissing-prototypes
> >> -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels
> >> -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing
> >> -fwrapv -fexcess-precision=standard -D_LARGEFILE_SOURCE
> >> -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -mlongcalls
> >> -mtext-section-literals -Os -pthread -D_LARGEFILE_SOURCE
> >> -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE conftest.c
> >> -lssl -lcrypto -lz -lreadline -lrt -lcrypt -ldl -lm
> >>
> >> and if I drop irrelevant libraries from that command its stdout+stderr
> >> will probably be empty.
> >>
> >> But I was curious why this test is written *that* way.
> >
> > Threading compiles are different for every platform so the code just
> > tries everything --- we didn't anticipate that adding a useless library
> > would actually cause a failure.
>
> Sorry, I must be not clear enough: why checking compiler/linker output
> instead of checking their exit code or presence of produced object/
> executable files?

Oh, uh, I don't rember the answer to that one. I think the code is in
config/acx_pthread.m4 and I assume we are just checking using the
configure macros that are provided.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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