--- a/configure.in	Sun Nov 17 22:53:08 2002 +0000
+++ b/configure.in	Mon Nov 18 06:53:08 2002 +0000
@@ -53,6 +53,14 @@
 dnl autoconf system), so quote them like this: [[foo]]
 
 AC_PREREQ(2.13)dnl
+
+dnl #### Doesn't work currently.  it would be really nice if we could
+dnl get this working, because many autoconfs v2.5 come with support for
+dnl v2.1 source files but get snafued by our nasty configure.ac kludge.
+dnl
+dnl m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]), 2.5), -1,
+dnl       [m4_fatal([Autoconf version 2.5 or higher not supported])])
+
 dnl Redefine some standard autoconf macros
 dnl here is how XEmacs is different:
 dnl - no cache file
@@ -346,6 +354,7 @@
 with_prefix='yes'
 with_site_lisp='no'
 with_site_modules='yes'
+need_modules_common=''
 with_menubars=''
 with_scrollbars=''
 with_widgets=''
@@ -533,6 +542,7 @@
 	compiler	| \
 	xemacs_compiler	| \
 	cflags		| \
+        cflags_warning  | \
 	cpp		| \
 	cppflags	| \
 	libs		| \
@@ -1646,6 +1656,11 @@
   else cflags_specified=no;
 fi
 
+if test "${cflags_warning-unset}" != unset
+  then cflags_warning_specified=yes;
+  else cflags_warning_specified=no;
+fi
+
 xe_save_CFLAGS="$CFLAGS"
 
 AC_PROG_CC dnl Autoconf has its own magic for compiler autodetection
@@ -1931,37 +1946,67 @@
   dnl Following values of CFLAGS are known to work well.
   dnl Should we take debugging options into consideration?
   if   test "$GCC" = "yes"; then
-    CFLAGS="-g -O3 -Wall -Wno-switch -Winline -Wmissing-prototypes"
+    CFLAGS="-g -O3"
+    dnl I'm not convinced this is a good idea any more. -sb
+    dnl test "$opsys $machine" = "linux intel386" && \
+    dnl CFLAGS="$CFLAGS -fno-strength-reduce -malign-loops=2 -malign-jumps=2 -malign-functions=2"
+  elif test "$__SUNPRO_C" = "yes"; then
+    case "$opsys" in
+      sol2    ) CFLAGS="-xO4" ;;
+      sunos4* ) CFLAGS="-xO2" ;;
+    esac
+  elif test "$__DECC" = "yes"; then
+    CFLAGS="-O3"
+  elif test "$CC" = "xlc"; then
+    CFLAGS="-g -O3 -qstrict -qnoansialias -qlibansi -qro -qmaxmem=20000"
+  dnl ### Add optimal CFLAGS support for other compilers HERE!
+  else
+    CFLAGS="-O" ;dnl The only POSIX-approved flag
+  fi
+fi
+
+dnl Calculate warning flags.  We now separate the flags for warnings from
+dnl the other flags because we really really want the warnings to be seen
+dnl by everyone.
+
+if test "$cflags_warning_specified" = "no"; then
+  dnl Following warning flags are known to work well.
+  if   test "$GCC" = "yes"; then
+    cflags_warning="-Wall -Wno-switch -Winline -Wmissing-prototypes"
     dnl Yuck, bad compares have been worth at least 3 crashes!
-    CFLAGS="$CFLAGS -Wsign-compare"
+    cflags_warning="$cflags_warning -Wsign-compare"
+    dnl NOTE: The following three, as well as -Wmissing-declarations and
+    dnl -Weffc++ below, have been recently added.  If you are getting
+    dnl grief from them, please notify ben@xemacs.org!
+    cflags_warning="$cflags_warning -Wundef -Wstrict-prototypes -Wpacked"
     dnl With g++, -Wshadow produces five zillion utterly random warnings --
     dnl a local var named `buffer' conflicts with `struct buffer' for
     dnl example.  Even with gcc, -Wshadow is questionable because of its
     dnl complaints about parameters with the same names as global functions.
     if test "$xemacs_compiler" != "g++"; then
-      CFLAGS="$CFLAGS -Wshadow"
+    dnl no -Wmissing-declarations under g++.
+      cflags_warning="$cflags_warning -Wshadow -Wmissing-declarations"
+    else
+      cflags_warning="$cflags_warning -Weffc++"
     fi
     dnl glibc is intentionally not `-Wpointer-arith'-clean.
     dnl Ulrich Drepper has rejected patches to fix the glibc header files.
-    test "$have_glibc" != "yes" && CFLAGS="$CFLAGS -Wpointer-arith"
-    dnl I'm not convinced this is a good idea any more. -sb
-    dnl test "$opsys $machine" = "linux intel386" && \
-    dnl CFLAGS="$CFLAGS -fno-strength-reduce -malign-loops=2 -malign-jumps=2 -malign-functions=2"
+    test "$have_glibc" != "yes" && \
+      cflags_warning="$cflags_warning -Wpointer-arith"
   elif test "$__SUNPRO_C" = "yes"; then
     case "$opsys" in
-      sol2    ) CFLAGS="-v -xO4" ;;
-      sunos4* ) CFLAGS="-xO2";;
+      sol2    ) cflags_warning="-v" ;;
     esac
-  elif test "$__DECC" = "yes"; then
-    CFLAGS="-O3"
   elif test "$CC" = "xlc"; then
-    CFLAGS="-g -O3 -qstrict -qnoansialias -qlibansi -qinfo -qro -qmaxmem=20000"
-  dnl ### Add optimal CFLAGS support for other compilers HERE!
-  else
-    CFLAGS="-O" ;dnl The only POSIX-approved flag
+    cflags_warning="-qinfo"
+  dnl ### Add optimal cflags_warning support for other compilers HERE!
   fi
 fi
 
+dnl Now combine all C flags.  Put the warning flags first so that
+dnl user-specified flags will override.
+CFLAGS="$cflags_warning $CFLAGS"
+
 dnl Search for GCC specific build problems we know about
 if test "$GCC" = "yes"; then
 AC_MSG_CHECKING(for buggy gcc versions)
@@ -3065,6 +3110,19 @@
 dnl offix.c, so that the thing is dumped after lastfile.o
 AC_SUBST(dnd_objs)
 
+dnl Support for using a different compiler for xemacs itself.
+dnl Useful for building XEmacs with a C++ compiler.
+dnl For example, `configure --compiler=gcc --xemacs-compiler=g++
+
+dnl The compiler used to build xemacs, as opposed to the compiler
+dnl used by configure and lib-src, is determined from the following
+dnl sources, in order of priority:
+dnl o --xemacs-compiler configure flag
+dnl o XEMACS_CC environment variable
+dnl o same as the regular compiler, (determined previously)
+test -n "$xemacs_compiler" && XEMACS_CC="$xemacs_compiler"
+: ${XEMACS_CC:="$CC"}
+
 dnl Autodetect dll support
 dnl This must come before the detection code for anything that is in a module
 if test "$with_modules" != "no"; then
@@ -3121,7 +3179,7 @@
       echo "    No module support."
     fi
     with_modules=no
-    MOD_CC=${CC}
+    MOD_CC="$XEMACS_CC"
     MODCFLAGS="\$(CFLAGS) -I../../src -I\$(srcdir)/../../src"
     INSTALLPATH=""
     MOD_INSTALL_PROGRAM="true"
@@ -3270,6 +3328,7 @@
   AC_CHECK_FUNCS(ldap_set_option ldap_get_lderrno ldap_result2error ldap_parse_result)
   LIBS="$save_LIBS"
   XE_APPEND(modules/ldap, MAKE_SUBDIR)
+  need_modules_common=yes
   if test "$with_modules" = "yes"; then
     XE_APPEND(modules/ldap, INSTALL_ARCH_DEP_SUBDIR)
   fi
@@ -3304,6 +3363,7 @@
     AC_DEFINE_UNQUOTED(LIBPQ_FE_H_FILE, "$libpq_fe_h_file")
     XE_PREPEND(-lpq, postgresql_libs)
     XE_APPEND(modules/postgresql, MAKE_SUBDIR)
+    need_modules_common=yes
     if test "$with_modules" = "yes"; then
       XE_APPEND(modules/postgresql, INSTALL_ARCH_DEP_SUBDIR)
     fi
@@ -3888,7 +3948,7 @@
 dnl Check for POSIX functions.
 dnl ----------------------------------------------------------------
 
-AC_CHECK_FUNCS(cbrt closedir dup2 eaccess fmod fpathconf frexp ftime getaddrinfo gethostname getnameinfo getpagesize gettimeofday getcwd getwd link logb lrand48 matherr mkdir mktime perror poll random readlink rename res_init rint rmdir select setitimer setpgid setlocale setsid sigblock sighold sigprocmask snprintf stpcpy strerror symlink tzset ulimit usleep waitpid vsnprintf fsync ftruncate umask)
+AC_CHECK_FUNCS(cbrt closedir dup2 eaccess fmod fpathconf frexp ftime getaddrinfo gethostname getnameinfo getpagesize gettimeofday getcwd getwd link logb lrand48 matherr mkdir mktime perror poll random readlink rename res_init rint rmdir select setitimer setpgid setlocale setsid sigblock sighold sigprocmask snprintf stpcpy strerror symlink tzset ulimit usleep waitpid vsnprintf fsync ftruncate umask wcslen wcscmp)
 
 dnl getaddrinfo() is borked under hpux11
 if test "$ac_cv_func_getaddrinfo" != "no" ; then
@@ -4568,7 +4628,7 @@
 AC_SUBST(MAKE_SUBDIR)
 AC_SUBST(SUBDIR_MAKEFILES)
 
-dnl Make s&m symlinks in the src directory, for config.h
+dnl Make s&m symlinks in the src directory, for config.h.
 for dir in src/s src/m; do
   if test ! -d "$dir" ; then
     echo Making symbolic link to "$srcdir/$dir"
@@ -4576,6 +4636,16 @@
   fi
 done
 
+dnl Also make modules/common link if needed for the module Makefiles.
+if test "$need_modules_common" = "yes"; then
+  for dir in modules/common; do
+    if test ! -d "$dir" ; then
+      echo Making symbolic link to "$srcdir/$dir"
+      ${LN_S} "$srcdir/$dir" "$dir"
+    fi
+  done
+fi
+
 if test "$extra_verbose" = "yes"; then
   echo ""
   PRINT_VAR(extra_objs
@@ -4806,18 +4876,6 @@
 AC_SUBST(RANLIB)
 AC_SUBST(dynodump_arch)
 
-dnl Support for using a different compiler for xemacs itself.
-dnl Useful for building XEmacs with a C++ compiler.
-dnl For example, `configure --compiler=gcc --xemacs-compiler=g++
-
-dnl The compiler used to build xemacs, as opposed to the compiler
-dnl used by configure and lib-src, is determined from the following
-dnl sources, in order of priority:
-dnl o --xemacs-compiler configure flag
-dnl o XEMACS_CC environment variable
-dnl o same as the regular compiler, (determined previously)
-test -n "$xemacs_compiler" && XEMACS_CC="$xemacs_compiler"
-: ${XEMACS_CC:="$CC"}
 AC_SUBST(XEMACS_CC)
 
 dnl The default is yes
@@ -4928,7 +4986,7 @@
 else echo "  Not using any machine description file"
 fi
 
-echo "  Compiler:                          $CC $CFLAGS"
+echo "  Compiler:                          $XEMACS_CC $CFLAGS"
 echo "  Relocating allocator for buffers:  $rel_alloc"
 echo "  GNU version of malloc:             ${GNU_MALLOC}${GNU_MALLOC_reason}"
 case "$ld_switch_site" in
@@ -5115,10 +5173,15 @@
 
 dnl Build Makefile.in's from Makefile.in.in's
 dnl except ./Makefile from $srcdir/Makefile.in
+dnl src/Makefile.in will have src/depend appended to it;
+dnl module Makefiles will have the common text in
+dnl modules/common/Makefile.common appended.
 
 for file in $internal_makefile_list; do
-  test "$file" = src/Makefile.in && \
-    file="src/Makefile.in:src/Makefile.in.in:src/depend"
+  case $file in
+    src/Makefile.in ) file="src/Makefile.in:src/Makefile.in.in:src/depend" ;;
+    modules/* ) file="${file}:${file}.in:modules/common/Makefile.common" ;;
+  esac
   XE_APPEND($file, ac_output_files)
 done
 ac_output_files="$ac_output_files src/paths.h lib-src/config.values"