Cleaned up configure code related to threading and the shared cache.

  * acinclude.m4:
      - detect incompatibilities between configure options at the
        beginning of MPFR_CONFIGS, forcing enable_thread_safe to
        "no" or "yes" when necessary, so that the subsequent code
        can rely on that;
      - check ISO C11 thread support and/or POSIX thread support
        only when necessary;
      - handle --enable-shared-cache early in MPFR_CONFIGS, because
        the use of POSIX threads (pthread) may need to change CC,
        CFLAGS, and LIBS (thus affecting other tests);
      - test $enable_shared_cache instead of $mpfr_want_shared_cache;
      - removed the now useless MPFR_CHECK_SHARED_CACHE function.
  * configure.ac: no longer set the mpfr_want_shared_cache variable,
    as enable_shared_cache (now used) already has the same usage.
Note: currently,
  ./configure --enable-shared-cache CFLAGS="-std=c99"
still succeeds and still makes the compilation fail. This seems to
be due to a limitation of AX_PTHREAD, which just tests linking, not
compilation.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@13392 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 1 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 7901ca3a2..412f85fb8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -188,7 +188,7 @@ AC_ARG_ENABLE(shared-cache,
                           for all MPFR constants.  It usually makes MPFR
                           dependent on PTHREAD [[default=no]]],
    [ case $enableval in
-      yes) mpfr_want_shared_cache=yes
+      yes)
          AC_DEFINE([MPFR_WANT_SHARED_CACHE],1,[Want shared cache]) ;;
       no)  ;;
       *) AC_MSG_ERROR([bad value for --enable-shared-cache: yes or no]) ;;