Remove the unused AX_CHECK_LIBRARY and REQUIRE_CANONICAL macros from m4/, and stop calling AC_CANONICAL_TARGET from configure.ac since this tree no longer needs target canonicalization.
Update m4/ax_pthread.m4 to the latest AX_PTHREAD macro from the autoconf archive, which brings the host-based canonicalization checks used by the current upstream macro.
The AX_PTHREAD macro has a check for side-effects of the pthread flag beyond the functions being available. It also checks for a particular macro being set when compiling the test file. When running the build through the scan-build static analysis, for some reason, the check value isn't set. The build fails. I commented the check out for now.
1. Updated to the most recent copy of ax_pthread.m4.
2. Removed the darwin-clang check m4.
3. Added a check to see if AX_PTHREAD added the flag `-Qunused-arguments` for clang and if so prepend `-Xcompiler` so libtool will use it. Otherwise when building on Sierra's clang you get "soft" warnings on the build of the dylib.
Brian Aker
Daniel Pouzzner
John Safranek
toddouska
toddouska