minor cleanups to configure.ac to reduce autoconf-2.70 warnings a bit.

configure output is practically unchanged. there are still lots of
AC_TRY_COMPILE/AC_TRY_LINK replacements needed to really eliminate
the warnings, but that's for another time.

acinclude/alsa.m4

@@ -1,4 +1,3 @@
-##############################################################################
 dnl Configure Paths for Alsa
 dnl Some modifications by Richard Boulton <richard-alsa@tartarus.org>
 dnl Christopher Lansdown <lansdoct@cs.alfred.edu>
@@ -7,12 +6,13 @@ dnl Last modification: alsa.m4,v 1.23 2004/01/16 18:14:22 tiwai Exp
 dnl AM_PATH_ALSA([MINIMUM-VERSION [, ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]]])
 dnl Test for libasound, and define ALSA_CFLAGS and ALSA_LIBS as appropriate.
 dnl enables arguments --with-alsa-prefix=
-dnl                   --with-alsa-enc-prefix=
+dnl                   --with-alsa-inc-prefix=
 dnl                   --disable-alsatest
 dnl
 dnl For backwards compatibility, if ACTION_IF_NOT_FOUND is not specified,
 dnl and the alsa libraries are not found, a fatal AC_MSG_ERROR() will result.
 dnl
+
 AC_DEFUN([AM_PATH_ALSA],
 [dnl Save the original CFLAGS, LDFLAGS, and LIBS
 alsa_save_CFLAGS="$CFLAGS"

acinclude/esd.m4

@@ -1,7 +1,3 @@
-##############################################################################
-#
-# --- esd.m4 ---
-#
 # Configure paths for ESD
 # Manish Singh    98-9-30
 # stolen back from Frank Belew

configure

@@ -2769,6 +2769,7 @@ ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
+
 ac_config_headers="$ac_config_headers include/SDL_config.h"
 
 ac_aux_dir=
@@ -11738,7 +11739,6 @@ LT_AGE=`expr $SDL_BINARY_AGE - $SDL_INTERFACE_AGE`
 
 
 
-
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -15866,7 +15866,6 @@ fi
 
 
 
-
 if test "x$ac_cv_env_PKG_CONFIG_set" != "xset"; then
 	if test -n "$ac_tool_prefix"; then
   # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.

configure.ac

@@ -1,6 +1,7 @@
 dnl Process this file with autoconf to produce a configure script.
-AC_INIT(README.txt)
+AC_INIT
-AC_CONFIG_HEADER(include/SDL_config.h)
+AC_CONFIG_SRCDIR(README.txt)
+AC_CONFIG_HEADERS(include/SDL_config.h)
 AC_CONFIG_AUX_DIR(build-scripts)
 AC_CONFIG_MACRO_DIR([acinclude])
 
@@ -51,12 +52,10 @@ dnl Detect the canonical build and host environments
 dnl AC_CANONICAL_HOST
 
 dnl Check for tools
-AC_PROG_LIBTOOL
 AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_INSTALL
 AC_PROG_MAKE_SET
-AC_LIBTOOL_RC
 PKG_PROG_PKG_CONFIG
 
 dnl Make sure that srcdir is a full pathname
@@ -1320,7 +1319,7 @@ dnl Check for ARM instruction support using gas syntax
 CheckARM()
 {
     AC_ARG_ENABLE(arm-simd,
-AC_HELP_STRING([--enable-arm-simd], [use SIMD assembly blitters on ARM [[default=no]]]),
+AS_HELP_STRING([--enable-arm-simd], [use SIMD assembly blitters on ARM [[default=no]]]),
                   enable_arm_simd=$enableval, enable_arm_simd=no)
     if test x$enable_video = xyes -a x$enable_assembly = xyes -a x$enable_arm_simd = xyes; then
         save_CFLAGS="$CFLAGS"
@@ -1357,7 +1356,7 @@ dnl Check for ARM NEON instruction support using gas syntax
 CheckNEON()
 {
     AC_ARG_ENABLE(arm-neon,
-AC_HELP_STRING([--enable-arm-neon], [use NEON assembly blitters on ARM [[default=no]]]),
+AS_HELP_STRING([--enable-arm-neon], [use NEON assembly blitters on ARM [[default=no]]]),
                   enable_arm_neon=$enableval, enable_arm_neon=no)
     if test x$enable_video = xyes -a x$enable_assembly = xyes -a x$enable_arm_neon = xyes; then
         save_CFLAGS="$CFLAGS"
@@ -2142,7 +2141,7 @@ AS_HELP_STRING([--enable-video-cocoa], [use Cocoa video driver [[default=yes]]])
 CheckMETAL()
 {
     AC_ARG_ENABLE(video-metal,
-AC_HELP_STRING([--enable-video-metal], [include Metal support [[default=yes]]]),
+AS_HELP_STRING([--enable-video-metal], [include Metal support [[default=yes]]]),
               , enable_video_metal=yes)
     AC_ARG_ENABLE(render-metal,
 AS_HELP_STRING([--enable-render-metal], [enable the Metal render driver [[default=yes]]]),

test/configure

@@ -1919,6 +1919,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
+
 ac_aux_dir=
 for ac_dir in $srcdir/../build-scripts; do
   if test -f "$ac_dir/install-sh"; then
@@ -2020,7 +2021,6 @@ case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
 
-
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -2812,7 +2812,6 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for an ANSI C-conforming const" >&5
 $as_echo_n "checking for an ANSI C-conforming const... " >&6; }
 if ${ac_cv_c_const+:} false; then :

test/configure.ac

@@ -1,16 +1,15 @@
 dnl Process this file with autoconf to produce a configure script.
-AC_INIT(README)
+AC_INIT
+AC_CONFIG_SRCDIR([README])
 
 dnl Detect the canonical build and host environments
 AC_CONFIG_AUX_DIRS($srcdir/../build-scripts)
 AC_CANONICAL_HOST
 
 dnl Check for tools
-
 AC_PROG_CC
 
 dnl Check for compiler environment
-
 AC_C_CONST
 
 dnl We only care about this for building testnative at the moment, so these
@@ -42,7 +41,7 @@ case "$host" in
     *-*-aix*)
         ISUNIX="true"
         EXE=""
-        if test x$ac_cv_prog_gcc = xyes; then
+        if test x$ac_cv_c_compiler_gnu = xyes; then
             CFLAGS="-mthreads"
         fi
         SYS_GL_LIBS=""
@@ -201,4 +200,5 @@ fi
 AC_SUBST(SDL_TTF_LIB)
 
 dnl Finally create all the generated files
-AC_OUTPUT([Makefile])
+AC_CONFIG_FILES([Makefile])
+AC_OUTPUT