configure should exit if compilers are missing

configure

@@ -2343,6 +2343,11 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
+if test "x${CC}" = "x" -o "x${CXX}" = "x" ; then
+  { { echo "$as_me:$LINENO: error: Could not find required compilers, aborting." >&5
+echo "$as_me: error: Could not find required compilers, aborting." >&2;}
+   { (exit 1); exit 1; }; }
+fi
 
 FLAGS=""
 INCLS=""
@@ -2628,6 +2633,7 @@ else
   RANLIB="$ac_cv_prog_RANLIB"
 fi
 
+
 # Extract the first word of "ar", so it can be a program name with args.
 set dummy ar; ac_word=$2
 echo "$as_me:$LINENO: checking for $ac_word" >&5
@@ -2667,6 +2673,12 @@ else
 echo "${ECHO_T}no" >&6
 fi
 
+if test "x${AR}" = "x:"; then
+  { { echo "$as_me:$LINENO: error: Could not find the library archiver, aborting." >&5
+echo "$as_me: error: Could not find the library archiver, aborting." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+AR="${AR} ruvs"
 
 
 
@@ -2731,13 +2743,6 @@ fi
 
 
 
-if test "x${AR}" = "x:"; then
-  { { echo "$as_me:$LINENO: error: Could not find the library archiver" >&5
-echo "$as_me: error: Could not find the library archiver" >&2;}
-   { (exit aborting.); exit aborting.; }; }
-fi
-AR="${AR} ruvs"
-
 GMSH_DIRS="Common DataStr Geo Mesh Numeric Parallel Parser Plugin"
 
 if test "x$enable_gui" != "xno"; then
@@ -3141,8 +3146,8 @@ fi
     echo "versions <= 1.1.1 have a bug in the singular value decomposition"
     echo "algorithm that will cause Gmsh to hang during mesh generation."
     echo "********************************************************************"
-    { { echo "$as_me:$LINENO: error: " >&5
-echo "$as_me: error: " >&2;}
+    { { echo "$as_me:$LINENO: error: Could not find GSL, aborting." >&5
+echo "$as_me: error: Could not find GSL, aborting." >&2;}
    { (exit 1); exit 1; }; }
   fi
 fi

configure.in

-dnl "$Id: configure.in,v 1.29 2003-03-01 04:07:04 geuzaine Exp $"
+dnl "$Id: configure.in,v 1.30 2003-03-01 20:49:38 geuzaine Exp $"
 dnl
 dnl Copyright (C) 1997 - 2003 C. Geuzaine, J.-F. Remacle
 dnl
@@ -69,6 +69,9 @@ fi
 dnl Check for default compilers
 AC_PROG_CC
 AC_PROG_CXX
+if test "x${CC}" = "x" -o "x${CXX}" = "x" ; then
+  AC_MSG_ERROR([Could not find required compilers, aborting.])
+fi
 
 dnl Set default flags
 FLAGS=""
@@ -78,7 +81,13 @@ OPTIM="${CXXFLAGS}"
 dnl Check for various programs
 AC_PROG_CPP
 AC_PROG_RANLIB
+
+dnl How to build static libraries?
 AC_PATH_PROG(AR, ar)
+if test "x${AR}" = "x:"; then
+  AC_MSG_ERROR([Could not find the library archiver, aborting.])
+fi
+AR="${AR} ruvs"
 
 dnl Check for standard math library
 AC_CHECK_LIB(m,main)
@@ -86,12 +95,6 @@ AC_CHECK_LIB(m,main)
 dnl See if we need a .exe extension on executables
 AC_EXEEXT
 
-dnl How to build static libraries?
-if test "x${AR}" = "x:"; then
-  AC_MSG_ERROR(Could not find the library archiver, aborting.)
-fi
-AR="${AR} ruvs"
-
 dnl Set default subdirectories and libraries
 GMSH_DIRS="Common DataStr Geo Mesh Numeric Parallel Parser Plugin"
 
@@ -111,7 +114,7 @@ if test "x$enable_gui" != "xno"; then
     AC_PATH_PROG(FLTKCONFIG,fltk-config)
   fi
   if test "x$FLTKCONFIG" = "x"; then
-    AC_MSG_ERROR(Could not find fltk-config. Try --with-fltk-prefix?)
+    AC_MSG_ERROR([Could not find fltk-config. Try --with-fltk-prefix?])
   fi
   GMSH_LIBS="${GMSH_LIBS} `$FLTKCONFIG --use-gl --use-images --ldflags`"
   INCLS="${INCLS} `$FLTKCONFIG --use-gl --use-images --cxxflags`"
@@ -214,7 +217,7 @@ if test "x${GSL}" != "xyes"; then
     echo "versions <= 1.1.1 have a bug in the singular value decomposition"
     echo "algorithm that will cause Gmsh to hang during mesh generation."
     echo "********************************************************************"
-    AC_MSG_ERROR()
+    AC_MSG_ERROR([Could not find GSL, aborting.])
   fi
 fi