Revert "Octave: disable optimization of tests for faster compiles/less memory usage"

This reverts commit 8e37bcf1a8.

Reverting a series of Octave commits for re-applying again without
incorrect whitespace changes.

Tools/config/ax_check_compile_flag.m4

@@ -1,74 +0,0 @@
-# ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
-#
-# DESCRIPTION
-#
-#   Check whether the given FLAG works with the current language's compiler
-#   or gives an error.  (Warnings, however, are ignored)
-#
-#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
-#   success/failure.
-#
-#   If EXTRA-FLAGS is defined, it is added to the current language's default
-#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
-#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
-#   force the compiler to issue an error when a bad flag is given.
-#
-#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
-#
-#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
-#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
-#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
-#
-#   This program is free software: you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-
-#serial 3
-
-AC_DEFUN([AX_CHECK_COMPILE_FLAG],
-[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX
-AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
-AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
-  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
-  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
-  AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
-    [AS_VAR_SET(CACHEVAR,[yes])],
-    [AS_VAR_SET(CACHEVAR,[no])])
-  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
-AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
-  [m4_default([$2], :)],
-  [m4_default([$3], :)])
-AS_VAR_POPDEF([CACHEVAR])dnl
-])dnl AX_CHECK_COMPILE_FLAGS

configure.ac

@@ -937,38 +937,25 @@ fi
 if test -n "$OCTAVE"; then
    AC_MSG_CHECKING([for Octave preprocessor flags])
    OCTAVE_CPPFLAGS=
-   for var in CPPFLAGS INCFLAGS ALL_CXXFLAGS; do
+   for n in CPPFLAGS INCFLAGS; do
-      for flag in `env - ${mkoctfile} -p ${var}`; do
+     OCTAVE_CPPFLAGS="${OCTAVE_CPPFLAGS} "`unset CPPFLAGS; ${mkoctfile} -p $n`
-         case ${flag} in
-            -D*|-I*) OCTAVE_CPPFLAGS="${OCTAVE_CPPFLAGS} ${flag}";;
-            *) ;;
-         esac
-      done
    done
    AC_MSG_RESULT([$OCTAVE_CPPFLAGS])
    AC_MSG_CHECKING([for Octave compiler flags])
    OCTAVE_CXXFLAGS=
-   for var in ALL_CXXFLAGS; do
+   for n in ALL_CXXFLAGS; do
-      for flag in `env - ${mkoctfile} -p ${var}`; do
+     OCTAVE_CXXFLAGS="${OCTAVE_CXXFLAGS} "`unset CXXFLAGS; ${mkoctfile} -p $n`
-         case ${flag} in
-            -g*|-W*) OCTAVE_CXXFLAGS="${OCTAVE_CXXFLAGS} ${flag}";;
-            *) ;;
-         esac
-      done
    done
    AC_MSG_RESULT([$OCTAVE_CXXFLAGS])
-   AC_LANG_PUSH([C++])
-   AX_CHECK_COMPILE_FLAG([-O0],[OCTAVE_CXXFLAGS="${OCTAVE_CXXFLAGS} -O0"],[],[-Werror])
-   AC_LANG_POP([C++])
    AC_MSG_CHECKING([for Octave linker flags])
    OCTAVE_LDFLAGS=
-   for var in RDYNAMIC_FLAG LFLAGS RLD_FLAG OCTAVE_LIBS LIBS; do
+   for n in RDYNAMIC_FLAG LFLAGS RLD_FLAG OCTAVE_LIBS LIBS; do
-     OCTAVE_LDFLAGS="${OCTAVE_LDFLAGS} "`env - ${mkoctfile} -p ${var}`
+     OCTAVE_LDFLAGS="${OCTAVE_LDFLAGS} "`${mkoctfile} -p $n`
    done
    AC_MSG_RESULT([$OCTAVE_LDFLAGS])
    for octave_opt in --silent --norc --no-history --no-window-system; do
       AC_MSG_CHECKING([if Octave option '${octave_opt}' is supported])
-      octave_out=`${OCTAVE} ${octave_opt} /dev/null 2>&1 | sed -n '1p' | sed -n '/unrecognized/p'`
+      octave_out=`${OCTAVE} ${octave_opt} /dev/null 2>&1 | sed -n '1{/unrecognized/p}'`
       AS_IF([test "x${octave_out}" = x],[
          AC_MSG_RESULT([yes])
          OCTAVE="${OCTAVE} ${octave_opt}"