Update about CC / CFLAGS settings from GMP (__GMP_CC / __GMP_CFLAGS).

  * configure.ac: remove -pedantic unconditionally; since r7044, it was
    removed only when logging was enabled, as at that time only logging
    was using C extensions.
  * NEWS: added a line about this change.
  * INSTALL: updated the note about CC / CFLAGS, removing the obsolete
    reference to GMP 4.3.0 at the same time.
(merged changeset r13421 from the trunk)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/4.0@13422 280ebfd0-de03-0410-8827-d642c229c3f4

3 files changed, 15 insertions, 10 deletions

diff --git a/INSTALL b/INSTALL
index e092ba880..8c78c3034 100644
--- a/INSTALL
+++ b/INSTALL
@@ -238,13 +238,19 @@ specific architecture.
 
 [1] http://permalink.gmane.org/gmane.comp.gnu.libtool.patches/10111
 
-Note: By default, the configure script tries to set CC/CFLAGS to GMP's
-ones (this feature needs GMP 4.3.0 or later, or the --with-gmp-build
-option). However this is not guaranteed to work as the configure script
-does some compiler tests earlier, and the change may be too late. Also,
-the values obtained from GMP may be incorrect if GMP has been built
-on a different machine. In such a case, the user may need to specify
-CC/CFLAGS as explained below.
+Note: By default, the configure script tries to set CC / CFLAGS to GMP's
+ones from gmp.h (__GMP_CC / __GMP_CFLAGS) in order to ensure that MPFR is
+built with the same ABI as GMP. The reason is that when GMP is built, it
+may set CC / CFLAGS to select an ABI that is not the default one in order
+to have a better performance. The -pedantic option in GMP's CFLAGS, when
+present (which is the case by default), is removed, because the MPFR
+build system uses some C extensions (when this script detects that they
+are supported) and -pedantic yields too many useless warnings. However,
+this setting from GMP is not guaranteed to work as the configure script
+does some compiler tests earlier, and a conflict may arise. Also, the
+values obtained from GMP may be incorrect for the MPFR build if GMP has
+been built on a different machine; in such a case, the user may need to
+specify CC / CFLAGS, as explained below.
 
 Moreover, even without --with-gmp-build and --enable-gmp-internals,
 MPFR might use some GMP internals by mistake. This would be a bug,
diff --git a/NEWS b/NEWS
index e4f334270..4be59dd27 100644
--- a/NEWS
+++ b/NEWS
@@ -31,6 +31,7 @@ Changes from version 4.0.1 to version 4.0.2:
 Changes from version 4.0.0 to version 4.0.1:
 - Improved MPFR manual.
 - Improved __GMP_CC and __GMP_CFLAGS retrieval (in particular for MS Windows).
+- Option -pedantic is now always removed from __GMP_CFLAGS (see INSTALL).
 - Fixed a build failure on some platforms when --with-gmp-build is used.
 - Bug fixes (see ChangeLog file), in particular in mpfr_div_ui, which
   could yield an incorrectly rounded result to nearest when using
diff --git a/configure.ac b/configure.ac
index c535513bf..f4f682157 100644
--- a/configure.ac
+++ b/configure.ac
@@ -270,11 +270,9 @@ if test -z "$GMP_CC$GMP_CFLAGS" ; then
      # Get CFLAGS
      echo "#include \"gmp.h\"" >  conftest.c
      echo "MPFR_OPTION __GMP_CFLAGS" >> conftest.c
-     unset rmpedantic
-     [test "$enable_logging" = yes && rmpedantic='s/[ "]-pedantic[ "]/ /g;']
      $cpp $CPPFLAGS conftest.c 2> /dev/null > conftest.txt
      test $? -ne 0 && continue
-     GMP_CFLAGS=`$EGREP MPFR_OPTION conftest.txt | $SED -e "$rmpedantic"'s/MPFR_OPTION //g;s/ *" *//g'`
+     [GMP_CFLAGS=`$EGREP MPFR_OPTION conftest.txt | $SED -e 's/[ "]-pedantic[ "]/ /g;s/MPFR_OPTION //g;s/ *" *//g'`]
      break
    done
    rm -f conftest*