Addition to r21759 and r21764. Properly group flag-saving inside the AC_REQUIREd macro so that we don't get unexpected execution ordering. See comments on Trac ticket #1993 and Ralf W.'s post on the devel list: http://www.open-mpi.org/community/lists/devel/2009/08/6621.php

This commit was SVN r21803.

The following SVN revision numbers were found above:
  r21759 --> open-mpi/ompi@3eb2a3141a
  r21764 --> open-mpi/ompi@a82d957c46

config/ompi_setup_cxx.m4

@@ -13,7 +13,7 @@ dnl                         All rights reserved.
 dnl Copyright (c) 2006      Los Alamos National Security, LLC.  All rights
 dnl                         reserved. 
 dnl Copyright (c) 2007      Sun Microsystems, Inc.  All rights reserved.
-dnl Copyright (c) 2008-20009 Cisco Systems, Inc.  All rights reserved.
+dnl Copyright (c) 2008-2009 Cisco Systems, Inc.  All rights reserved.
 dnl $COPYRIGHT$
 dnl 
 dnl Additional copyrights may follow
@@ -26,6 +26,17 @@ AC_DEFUN([OMPI_SETUP_CXX_BANNER],[
     ompi_show_subtitle "C++ compiler and preprocessor" 
 ])
 
+# This macro is necessary because PROG_CXX* is REQUIREd by multiple
+# places in SETUP_CXX.
+AC_DEFUN([OMPI_PROG_CXX],[
+    OMPI_VAR_SCOPE_PUSH([ompi_cxxflags_save])
+    ompi_cxxflags_save="$CXXFLAGS"
+    AC_PROG_CXX
+    AC_PROG_CXXCPP
+    CXXFLAGS="$ompi_cxxflags_save"
+    OMPI_VAR_SCOPE_POP
+])
+
 # OMPI_SETUP_CXX()
 # ----------------
 # Do everything required to setup the C++ compiler.  Safe to AC_REQUIRE
@@ -66,11 +77,10 @@ AC_DEFUN([_OMPI_SETUP_CXX_COMPILER],[
     # both found a c++ compiler and want the C++ bindings (i.e., either
     # case #1 or #3)
 
-    ompi_cxxflags_save="$CXXFLAGS"
-    AC_REQUIRE([AC_PROG_CXX])
-    AC_REQUIRE([AC_PROG_CXXCPP])
+    # Must REQUIRE the PROG_CXX macro and not call it directly here for
+    # reasons well-described in the AC2.64 (and beyond) docs.
+    AC_REQUIRE([OMPI_PROG_CXX])
     BASECXX="`basename $CXX`"
-    CXXFLAGS="$ompi_cxxflags_save"
 
     AS_IF([test "x$CXX" = "x"], [CXX=none])
     set dummy $CXX

config/ompi_setup_f77.m4

@@ -41,7 +41,11 @@ AC_DEFUN([OMPI_SETUP_F77_BANNER],[
 # This macro is necessary because PROG_FC is REQUIREd by multiple
 # places in SETUP_F90.
 AC_DEFUN([OMPI_PROG_F77],[
+    OMPI_VAR_SCOPE_PUSH([ompi_fflags_save])
+    ompi_fflags_save="$FFLAGS"
     AC_PROG_F77([gfortran g77 f77 xlf frt ifort pgf77 fort77 fl32 af77])
+    FFLAGS="$ompi_fflags_save"
+    OMPI_VAR_SCOPE_POP
 ])
 
 AC_DEFUN([OMPI_SETUP_F77],[
@@ -58,11 +62,11 @@ AC_DEFUN([OMPI_SETUP_F77],[
 # Always run this test, even if fortran isn't wanted so that F77 has
 # value for the Fint tests
 #
-ompi_fflags_save="$FFLAGS"
-# Strangeness in AC2.64 forces us to require a macro that calls
-# PROG_FC instead of calling it directly.  Weird.
+
+# Must REQUIRE the PROG_F77 macro and not call it directly here for
+# reasons well-described in the AC2.64 (and beyond) docs.
 AC_REQUIRE([OMPI_PROG_F77])
-FFLAGS="$ompi_fflags_save"
+
 if test -z "$F77"; then
     AC_MSG_WARN([*** Fortran 77 bindings disabled (could not find compiler)])
     OMPI_WANT_F77_BINDINGS=0

config/ompi_setup_f90.m4

@@ -13,6 +13,7 @@ dnl                         All rights reserved.
 dnl Copyright (c) 2007      Los Alamos National Security, LLC.  All rights
 dnl                         reserved. 
 dnl Copyright (c) 2007      Sun Microsystems, Inc.  All rights reserved.
+dnl Copyright (c) 2009      Cisco Systems, Inc.  All rights reserved.
 dnl $COPYRIGHT$
 dnl 
 dnl Additional copyrights may follow
@@ -42,7 +43,11 @@ AC_DEFUN([OMPI_SETUP_F90_BANNER],[
 # This macro is necessary because PROG_FC is REQUIREd by multiple
 # places in SETUP_F90.
 AC_DEFUN([OMPI_PROG_FC],[
+    OMPI_VAR_SCOPE_PUSH([ompi_fcflags_save])
+    ompi_fcflags_save="$FCFLAGS"
     AC_PROG_FC([gfortran f95 fort xlf95 ifort ifc efc pgf95 lf95 f90 xlf90 pgf90 epcf90])
+    FCFLAGS="$ompi_fcflags_save"
+    OMPI_VAR_SCOPE_POP
 ])dnl
 
 AC_DEFUN([OMPI_SETUP_F90],[
@@ -86,11 +91,10 @@ else
     # list of 95 and 90 compilers and use it here.
     #
 
-    ompi_fcflags_save="$FCFLAGS"
-    # Strangeness in AC2.64 forces us to require a macro that calls
-    # PROG_FC instead of calling it directly.  Weird.
+    # Must REQUIRE the PROG_FC macro and not call it directly here for
+    # reasons well-described in the AC2.64 (and beyond) docs.
     AC_REQUIRE([OMPI_PROG_FC])
-    FCFLAGS="$ompi_fcflags_save"
+
     if test -z "$FC"; then
         AC_MSG_WARN([*** Fortran 90/95 bindings disabled (could not find compiler)])
         OMPI_WANT_F90_BINDINGS=0