Shared cache: cleanup and various improvements / corrections.

  * acinclude.m4:
      - test $enable_shared_cache instead of $mpfr_want_shared_cache;
      - check ISO C11 thread support and/or POSIX thread support
        only when necessary;
      - when checking support for POSIX threads (pthread), also check
        that pthread_rwlock_t is supported, as it is needed by MPFR
        and conditionally defined in glibc's bits/pthreadtypes.h (via
        <pthread.h>);
      - with POSIX threads, also set CC="$PTHREAD_CC" as documented by
        ax_pthread (autoconf-archive). This is not guaranteed to work,
        but according to the ax_pthread.m4 source, in the cases where
        "$PTHREAD_CC" != "$CC", not setting it will probably not work
        either;
      - 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);
      - 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.
  * acinclude.m4, configure.ac: moved the compatibility test of the
    configure options even earlier, from acinclude.m4 to configure.ac,
    just after the code that defines them. Also added an associated
    AC_MSG_CHECKING message for better clarity.
  * src/mpfr-impl.h: added a comment about the cache-related types,
    which depend on the locking methods.
  * src/mpfr-thread.h: fixed the lock macros:
      - in case of failure, one must abort, otherwise this would
        generally be undefined behavior;
      - added missing "do {} while (0)" (currently not mandatory).
  * tests/tversion.c: update concerning the shared cache, to be
    consistent with the other mpfr_buildopt_*_p features:
      - check that mpfr_buildopt_sharedcache_p() and
        MPFR_WANT_SHARED_CACHE match;
      - for the output of the value, test mpfr_buildopt_sharedcache_p()
        instead of the macro.
  * NEWS: update.
(merged changesets r13032,13390-13396,13410,13412 from the trunk)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/4.0@13416 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 25 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 2f8ae8fd3..19f83b85d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -167,7 +167,7 @@ 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]) ;;
@@ -204,6 +204,30 @@ AC_ARG_ENABLE(tune-for-coverage,
       *)    AC_MSG_ERROR([bad value for --enable-tune-for-coverage]) ;;
      esac])
 
+dnl First, detect incompatibilities between the above configure options.
+AC_MSG_CHECKING([whether configure options are compatible])
+if test "$enable_logging" = yes; then
+  if test "$enable_thread_safe" = yes; then
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([enable either logging or thread-safe, not both])
+  fi
+dnl The following test is done only to output a specific error message,
+dnl as there would otherwise be an error due to enable_thread_safe=no.
+  if test "$enable_shared_cache" = yes; then
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([shared cache does not work with logging support])
+  fi
+  enable_thread_safe=no
+fi
+if test "$enable_shared_cache" = yes; then
+  if test "$enable_thread_safe" = no; then
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([shared cache needs thread-safe support])
+  fi
+  enable_thread_safe=yes
+fi
+AC_MSG_RESULT([yes])
+
 
 dnl
 dnl Setup CC and CFLAGS