[project @ 2003-12-06 18:27:37 by panne]
[ghc-hetmet.git] / configure.ac
index 087924c..af3a1fa 100644 (file)
@@ -24,9 +24,9 @@ AC_PREREQ(2.52)
 dnl * Declare subdirectories that have a private configure script
 dnl
 dnl After the toplevel configuration is complete, the script will recurse into
-dnl these subdirectories (the use of cache values makes repeated checks cheap)
-dnl (We probably have to add hslibs/{OpenGL,GLUT} here later...)
-AC_CONFIG_SUBDIRS(ghc)
+dnl these subdirectories if they exist. The use of a cache file makes repeated
+dnl checks cheap.
+AC_CONFIG_SUBDIRS([ghc libraries])
 
 # -------------------------------------------------------------------------
 # Prepare to generate the following header files
@@ -105,6 +105,24 @@ alpha*-unknown-freebsd*)
         HostVendor_CPP='unknown'
         HostOS_CPP='freebsd'
         ;;
+arm*-linux*)
+        HostPlatform=arm-unknown-linux # hack again
+        TargetPlatform=arm-unknown-linux
+        BuildPlatform=arm-unknown-linux
+        HostPlatform_CPP='arm_unknown_linux'                 
+        HostArch_CPP='arm'
+        HostVendor_CPP='unknown'
+        HostOS_CPP='linux'
+        ;;
+hppa*-*-linux*)
+        HostPlatform=hppa-unknown-linux # hack again
+        TargetPlatform=hppa-unknown-linux
+        BuildPlatform=hppa-unknown-linux
+        HostPlatform_CPP='hppa_unknown_linux'                
+        HostArch_CPP='hppa'
+        HostVendor_CPP='unknown'                             
+        HostOS_CPP='linux'
+        ;;
 hppa1.1-hp-hpux*)
        HostPlatform=hppa1.1-hp-hpux  # canonicalise for our purposes (hack)
        TargetPlatform=hppa1.1-hp-hpux
@@ -206,6 +224,24 @@ ia64-*-linux*)
         HostVendor_CPP='unknown'
         HostOS_CPP='linux'
         ;;
+x86_64-*-linux*)
+        HostPlatform=x86_64-unknown-linux
+        TargetPlatform=x86_64-unknown-linux
+        BuildPlatform=x86_64-unknown-linux
+        HostPlatform_CPP='x86_64_unknown_linux'
+        HostArch_CPP='x86_64'
+        HostVendor_CPP='unknown'
+        HostOS_CPP='linux'
+       ;;
+m68k-*-linux*)
+        HostPlatform=m68k-unknown-linux # hack again
+        TargetPlatform=m68k-unknown-linux                    
+        BuildPlatform=m68k-unknown-linux
+        HostPlatform_CPP='m68k_unknown_linux'
+        HostArch_CPP='m68k'
+        HostVendor_CPP='unknown'
+        HostOS_CPP='linux'
+        ;;
 m68k-next-nextstep2)
         HostPlatform_CPP='m68k_next_nextstep2'
         HostArch_CPP='m68k'
@@ -236,13 +272,13 @@ m68k-*-openbsd*)
         HostVendor_CPP='unknown'
         HostOS_CPP='openbsd'
         ;;
-m68k-apple-netbsd*)
-       HostPlatform=m68k-apple-netbsd
-       TargetPlatform=m68k-apple-netbsd
-       BuildPlatform=m68k-apple-netbsd
-        HostPlatform_CPP='m68k_apple_netbsd'
+m68k-*-netbsd*)
+       HostPlatform=m68k-unknown-netbsd
+       TargetPlatform=m68k-unknown-netbsd
+       BuildPlatform=m68k-unknown-netbsd
+        HostPlatform_CPP='m68k_unknown_netbsd'
         HostArch_CPP='m68k'
-        HostVendor_CPP='apple'
+        HostVendor_CPP='unknown'
         HostOS_CPP='netbsd'
         ;;
 m68k-sun-sunos4*)
@@ -254,6 +290,15 @@ m68k-sun-sunos4*)
         HostVendor_CPP='sun'
         HostOS_CPP='sunos4'
         ;;
+mips-*-linux*)
+        HostPlatform=mips-unknown-linux # hack again
+        TargetPlatform=mips-unknown-linux
+        BuildPlatform=mips-unknown-linux
+        HostPlatform_CPP='mips_unknown_linux'
+        HostArch_CPP='mips'
+        HostVendor_CPP='unknown'
+        HostOS_CPP='linux'
+        ;;
 mips-dec-ultrix*)
         HostPlatform_CPP='mips_dec_ultrix'
         HostArch_CPP='mipsel'   # NB a little different
@@ -296,6 +341,24 @@ powerpc-apple-darwin*)
        HostVendor_CPP='apple'
        HostOS_CPP='darwin'
        ;;
+powerpc-unknown-linux*)
+        HostPlatform=powerpc-unknown-linux
+        TargetPlatform=powerpc-unknown-linux
+        BuildPlatform=powerpc-unknown-linux
+        HostPlatform_CPP='powerpc_unknown_linux'
+        HostArch_CPP='powerpc'
+        HostVendor_CPP='unknown'
+        HostOS_CPP='linux'
+        ;;
+s390-ibm-linux*)
+       HostPlatform=s390-ibm-linux
+       TargetPlatform=s390-ibm-linux #hack
+       BuildPlatform=s390-ibm-linux #hack
+        HostPlatform_CPP='s390_ibm_linux'
+        HostArch_CPP='s390'
+        HostVendor_CPP='ibm'
+        HostOS_CPP='linux'
+        ;;
 sparc-sun-sunos4*)
        HostPlatform=sparc-sun-sunos4
        TargetPlatform=sparc-sun-sunos4 #hack
@@ -351,27 +414,25 @@ TargetOS_CPP=$HostOS_CPP
 BuildVendor_CPP=$HostVendor_CPP
 TargetVendor_CPP=$HostVendor_CPP
 
-dnl Cannot afford all these SUBSTs (because of braindead seds w/ 99 cmd limits)
-dnl AC_SUBST(BuildPlatform)
-
+AC_SUBST(BuildPlatform)
 AC_SUBST(HostPlatform)
 AC_SUBST(TargetPlatform)
 AC_SUBST(HostPlatform_CPP)
-dnl AC_SUBST(BuildPlatform_CPP)
-dnl AC_SUBST(TargetPlatform_CPP)
+AC_SUBST(BuildPlatform_CPP)
+AC_SUBST(TargetPlatform_CPP)
 
 AC_SUBST(HostArch_CPP)
-dnl AC_SUBST(BuildArch_CPP)
-dnl AC_SUBST(TargetArch_CPP)
+AC_SUBST(BuildArch_CPP)
+AC_SUBST(TargetArch_CPP)
 
 AC_SUBST(HostOS_CPP)
 AC_SUBST(HostOS_Full)
-dnl AC_SUBST(BuildOS_CPP)
-dnl AC_SUBST(TargetOS_CPP)
+AC_SUBST(BuildOS_CPP)
+AC_SUBST(TargetOS_CPP)
 
 AC_SUBST(HostVendor_CPP)
-dnl AC_SUBST(BuildVendor_CPP)
-dnl AC_SUBST(TargetVendor_CPP)
+AC_SUBST(BuildVendor_CPP)
+AC_SUBST(TargetVendor_CPP)
 
 AC_SUBST(exeext)
 
@@ -558,27 +619,18 @@ AC_ARG_ENABLE(objectio,
 )
 AC_SUBST(GhcLibsWithObjectIO)
 
-dnl ** Enable the building of the OpenGL/GLUT binding in hslibs?
+dnl ** Enable the building of the OpenAL binding?
 dnl --------------------------------------------------------------
-AC_ARG_ENABLE(hopengl,
-[  --enable-hopengl
-        Build HOpenGL, a Haskell binding for OpenGL/GLUT.
-        On Mac OS X, use --enable-hopengl=x11 to use X11 instead
-        of the "native" libraries.
-],
-[GhcLibsWithHOpenGL=YES],
-[GhcLibsWithHOpenGL=NO]
-)
-UseQuartzOpenGL=NO
-if test x"$TargetOS_CPP" = x"darwin"; then
-  if test x"$enable_hopengl" != x"x11"; then
-    AC_DEFINE([USE_QUARTZ_OPENGL], [1],
-              [Define to 1 if native OpenGL should be used on Mac OS X])
-    UseQuartzOpenGL=YES
-  fi
-fi
+AC_ARG_ENABLE([openal],
+  AC_HELP_STRING([--enable-openal],
+                 [Build OpenAL binding [[default=autodetect]]]),
+  [GhcLibsWithOpenAL=$enableval],
+  [GhcLibsWithOpenAL=yes])
+
+# This is silly! Alas, "YES" and "NO" are currently our standard...
+GhcLibsWithOpenAL=`echo $GhcLibsWithOpenAL | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
 
-AC_SUBST(GhcLibsWithHOpenGL)
+AC_SUBST([GhcLibsWithOpenAL])
 
 dnl ** .NET interop support?
 dnl --------------------------------------------------------------
@@ -600,6 +652,16 @@ dnl --------------------------------------------------------------
 dnl * General configuration checks
 dnl --------------------------------------------------------------
 
+dnl ** Can the unix package be built?
+dnl --------------------------------------------------------------
+
+if test x"$TargetPlatform" = x"i386-unknown-mingw32"; then
+   GhcLibsWithUnix=NO
+else
+   GhcLibsWithUnix=YES
+fi
+AC_SUBST([GhcLibsWithUnix])
+
 dnl ** does #! work?
 AC_SYS_INTERPRETER()
 
@@ -645,19 +707,17 @@ AC_PROG_CPP
 dnl ** Without optimization some INLINE trickery fails for GHCi
 SRC_CC_OPTS="-O"
 
-dnl ** Try to add -mno-cygwin to the C compiler options for mingw32 targets
-if test x"$TargetOS_CPP" = x"mingw32"; then
-  FPTOOLS_CC_FLAG(-mno-cygwin,CC_SUPPORTS_MNO_CYGWIN)
-  SRC_CC_OPTS="$CC_SUPPORTS_MNO_CYGWIN $SRC_CC_OPTS"
-  CPPFLAGS="$CC_SUPPORTS_MNO_CYGWIN $CPPFLAGS"
-fi
+dnl ** Try to add -mno-cygwin to the C compiler options
+FP_CHECK_FLAG([-mno-cygwin], [
+SRC_CC_OPTS="-mno-cygwin $SRC_CC_OPTS"
+CPPFLAGS="-mno-cygwin $CPPFLAGS"])
 AC_SUBST(SRC_CC_OPTS)
 
 dnl ** figure out how to do context diffs
 FP_PROG_CONTEXT_DIFF
 
 dnl ** Find find command (for Win32's benefit)
-FPTOOLS_FIND_FIND
+FP_PROG_FIND
 
 dnl ** figure out how to do a BSD-ish install
 AC_PROG_INSTALL
@@ -683,9 +743,6 @@ dnl ** check for tar
 dnl   if GNU tar is named gtar, look for it first.
 AC_PATH_PROGS(TarCmd,gtar tar,tar)
 
-dnl ** check for gzip/compress
-AC_PATH_PROGS(CompressCmd,gzip compress,gzip)
-
 dnl ** check for jade/openjade & determine a working catalog
 AC_PATH_PROGS(JadeCmd,openjade jade,jade)
 FPTOOLS_DOCBOOK_CATALOG(Catalog, $JadeCmd, docs/fptools-both.dsl, 
@@ -709,15 +766,6 @@ case $Catalog in
 esac   
 AC_SUBST(Catalog)
 
-compress_nm=`basename $CompressCmd`
-if test x"$compress_nm" = xgzip; then
-  CompressCmd="$CompressCmd -d"
-  CompressSuffix="gz"
-else
-  CompressSuffix="Z"
-fi
-AC_SUBST(CompressCmd)
-AC_SUBST(CompressSuffix)
 
 dnl ** check for ghc-pkg command
 changequote(, )dnl
@@ -732,10 +780,10 @@ fi
 
 AC_ARG_WITH(greencard,
 [  --with-greencard=<greencard compiler>
-        Use a command different from 'green-card' to compile GreenCard files
+        Use a command different from 'greencard' to compile GreenCard files
 ],
 [
-GreencardCmd=$withval;
+GreenCardCmd=$withval;
 FPTOOLS_GREENCARD(3.00)
 ]
 )
@@ -799,13 +847,13 @@ AC_CHECK_HEADER(readline/readline.h, [HaveReadlineReadlineH=YES], [HaveReadlineR
 AC_CHECK_HEADER(readline/history.h, [HaveReadlineHistoryH=YES], [HaveReadlineHistoryH=NO])
 
 if test $HaveReadlineReadlineH = YES && test $HaveReadlineHistoryH = YES ; then
-  HaveReadlineHeaders=YES
+  GhcLibsWithReadline=YES
   AC_DEFINE([HAVE_READLINE_HEADERS], [1], [Define to 1 if readline/readline.h and readline/history.h exist.])
 else
-  HaveReadlineHeaders=NO
+  GhcLibsWithReadline=NO
   AC_DEFINE([HAVE_READLINE_HEADERS], [0], [Define to 1 if readline/readline.h and readline/history.h exist.])
 fi
-AC_SUBST(HaveReadlineHeaders)
+AC_SUBST(GhcLibsWithReadline)
 
 dnl ** check for DOS include files
 AC_CHECK_HEADERS(dos.h conio.h io.h std.h) 
@@ -813,12 +861,32 @@ AC_CHECK_HEADERS(dos.h conio.h io.h std.h)
 dnl ** check for Windows include files
 AC_CHECK_HEADERS(windows.h)
 
+dnl ** check for OpenGL/GLUT include paths and libraries
+FP_CHECK_GLUT
+
+if test x"$no_glu" = xyes; then
+  GhcLibsWithOpenGL=NO
+else
+  GhcLibsWithOpenGL=YES
+fi
+AC_SUBST([GhcLibsWithOpenGL])
+
+if test x"$no_glut" = xyes; then
+  GhcLibsWithGLUT=NO
+else
+  GhcLibsWithGLUT=YES
+fi
+AC_SUBST([GhcLibsWithGLUT])
+
 dnl ** check for OpenGL include files
-if test $UseQuartzOpenGL = YES ; then
-  AC_CHECK_HEADERS(OpenGL/gl.h)
+fp_save_cppflags="$CPPFLAGS"
+CPPFLAGS="$CPPFLAGS $X_CFLAGS"
+if test x"$use_quartz_opengl" = xyes; then
+  AC_CHECK_HEADERS([OpenGL/gl.h])
 else
-  AC_CHECK_HEADERS(GL/gl.h)
+  AC_CHECK_HEADERS([GL/gl.h])
 fi
+CPPFLAGS="$fp_save_cppflags"
 
 dnl ** check if it is safe to include both <time.h> and <sys/time.h>
 AC_HEADER_TIME
@@ -834,7 +902,7 @@ AC_CHECK_HEADER(malloc.h,[AC_CHECK_FUNCS(valloc)])
 
 dnl ** check for POSIX regex
 HavePosixRegex=NO
-AC_CHECK_HEADER(regex.h,[AC_CHECK_FUNC(regcomp, [HavePosixRegex=YES])])
+AC_CHECK_HEADERS(regex.h,[AC_CHECK_FUNC(regcomp, [HavePosixRegex=YES])])
 AC_SUBST(HavePosixRegex)
 
 dnl ** how do we get a timezone name, and UTC offset ?
@@ -936,9 +1004,10 @@ FPTOOLS_CHECK_HTYPE(blkcnt_t)
 FPTOOLS_CHECK_HTYPE(nlink_t)
 FPTOOLS_CHECK_HTYPE(ssize_t)
 FPTOOLS_CHECK_HTYPE(rlim_t)
+FPTOOLS_CHECK_HTYPE(wint_t)
 
 dnl ** Map OpenGL data types to Haskell types
-if test $GhcLibsWithHOpenGL = YES ; then
+if test $GhcLibsWithOpenGL = YES ; then
 FPTOOLS_CHECK_HTYPE(GLboolean)
 FPTOOLS_CHECK_HTYPE(GLbyte)
 FPTOOLS_CHECK_HTYPE(GLubyte)
@@ -955,10 +1024,11 @@ FPTOOLS_CHECK_HTYPE(GLdouble)
 FPTOOLS_CHECK_HTYPE(GLclampd)
 fi
 
-FPTOOLS_CHECK_CCONSTS(E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EADV EAFNOSUPPORT EAGAIN EALREADY EBADF EBADMSG EBADRPC EBUSY ECHILD ECOMM ECONNABORTED ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ EDIRTY EDOM EDQUOT EEXIST EFAULT EFBIG EFTYPE EHOSTDOWN EHOSTUNREACH EIDRM EILSEQ EINPROGRESS EINTR EINVAL EIO EISCONN EISDIR ELOOP EMFILE EMLINK EMSGSIZE EMULTIHOP ENAMETOOLONG ENETDOWN ENETRESET ENETUNREACH ENFILE ENOBUFS ENODATA ENODEV ENOENT ENOEXEC ENOLCK ENOLINK ENOMEM ENOMSG ENONET ENOPROTOOPT ENOSPC ENOSR ENOSTR ENOSYS ENOTBLK ENOTCONN ENOTDIR ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM EPFNOSUPPORT EPIPE EPROCLIM EPROCUNAVAIL EPROGMISMATCH EPROGUNAVAIL EPROTO EPROTONOSUPPORT EPROTOTYPE ERANGE EREMCHG EREMOTE EROFS ERPCMISMATCH ERREMOTE ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH ESRMNT ESTALE ETIME ETIMEDOUT ETOOMANYREFS ETXTBSY EUSERS EWOULDBLOCK EXDEV)
+FP_CHECK_CONSTS([E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EADV EAFNOSUPPORT EAGAIN EALREADY EBADF EBADMSG EBADRPC EBUSY ECHILD ECOMM ECONNABORTED ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ EDIRTY EDOM EDQUOT EEXIST EFAULT EFBIG EFTYPE EHOSTDOWN EHOSTUNREACH EIDRM EILSEQ EINPROGRESS EINTR EINVAL EIO EISCONN EISDIR ELOOP EMFILE EMLINK EMSGSIZE EMULTIHOP ENAMETOOLONG ENETDOWN ENETRESET ENETUNREACH ENFILE ENOBUFS ENODATA ENODEV ENOENT ENOEXEC ENOLCK ENOLINK ENOMEM ENOMSG ENONET ENOPROTOOPT ENOSPC ENOSR ENOSTR ENOSYS ENOTBLK ENOTCONN ENOTDIR ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM EPFNOSUPPORT EPIPE EPROCLIM EPROCUNAVAIL EPROGMISMATCH EPROGUNAVAIL EPROTO EPROTONOSUPPORT EPROTOTYPE ERANGE EREMCHG EREMOTE EROFS ERPCMISMATCH ERREMOTE ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH ESRMNT ESTALE ETIME ETIMEDOUT ETOOMANYREFS ETXTBSY EUSERS EWOULDBLOCK EXDEV], [#include <stdio.h>
+#include <errno.h>])
 
 dnl ** can we open files in binary mode?
-FPTOOLS_O_BINARY
+FP_CHECK_CONST([O_BINARY], [#include <fcntl.h>], [0])
 
 dnl ** check for GetModuleFileName and WinExec (windows only)
 dnl Old: AC_CHECK_FUNCS(WinExec GetModuleFileName)       dnl Windows
@@ -1034,7 +1104,7 @@ AC_CHECK_FUNCS(setenv unsetenv)
 
 
 dnl ** check for specific library functions that we are interested in
-AC_CHECK_FUNCS(access ftime getclock getpagesize getrusage gettimeofday mktime mprotect readlink setitimer stat lstat symlink sysconf timelocal times vadvise localtime_r gmtime_r readdir_r getgrgid_r getgrnam_r getpwuid_r getpwnam_r)
+AC_CHECK_FUNCS(access ftime getclock getpagesize getrusage gettimeofday mktime mprotect readlink setitimer stat lstat siginterrupt symlink sysconf timelocal times vadvise localtime_r gmtime_r readdir_r getgrgid_r getgrnam_r getpwuid_r getpwnam_r)
 
 dnl ** Solaris2 needs additionl flag for getpw*_r()
 case "$TargetPlatform" in
@@ -1075,8 +1145,8 @@ if test $HaveLibMingwEx = YES ; then
 fi
 
 if test "$HaveLibGmp" = "NO"; then
-if test "$HostArch_CPP" = "ia64"; then
-AC_MSG_ERROR([You need to install libgmp (the in-tree version does not work on IA64).])
+if test "$HostArch_CPP" = "ia64" -o "$HostArch_CPP" = "mipseb" ; then
+AC_MSG_ERROR([You need to install libgmp (the in-tree version does not work on IA64 or mips64).])
 fi;
 fi;
 
@@ -1086,7 +1156,11 @@ AC_CHECK_LIB(iberty, xmalloc)
 AC_CHECK_LIB(bfd,    bfd_init)
 
 dnl ** check for wide-char classifications
-AC_CHECK_HEADERS(wctype.h)
+dnl FreeBSD has an emtpy wctype.h, so test one of the affected
+dnl functions if it's really there.
+AC_CHECK_HEADERS(wctype.h,
+  [AC_CHECK_FUNCS(iswspace)]
+)
 
 dnl ** check for readline, for Hugs and hslibs' Readline
 dnl ncurses supersedes termcap and curses, but for compatibility,
@@ -1123,28 +1197,12 @@ else
 fi
 
 dnl ** check for math library
-FPTOOLS_CHECK_LIBM()
-AC_SUBST(LIBM)
+AC_CHECK_LIB([m], [main], [LIBM="-lm"], [LIBM=])
+AC_SUBST([LIBM])
 
 dnl ** check for X Window System
 AC_PATH_XTRA()
 
-dnl ** check for OpenGL/GLUT/GLX include paths and libraries
-if test $GhcLibsWithHOpenGL = YES ; then
-  if test $UseQuartzOpenGL = YES ; then
-    dnl Take a shortcut for Mac OS X native OpenGL:
-    dnl It's in a non-standard location, but it's always there
-    GL_CFLAGS=
-       GL_LIBS=
-       GLUT_LIBS=
-       AC_SUBST(GL_CFLAGS)
-       AC_SUBST(GL_LIBS)
-       AC_SUBST(GLUT_LIBS)
-  else
-    FPTOOLS_HAVE_OPENGL
-  fi
-fi
-
 dnl ################################################################
 dnl Check for libraries
 dnl ################################################################
@@ -1297,25 +1355,15 @@ dnl --------------------------------------------------
 dnl * test for GTK+
 dnl --------------------------------------------------
 
-AC_PATH_PROGS(GTK_CONFIG, gtk-config gtk12-config)
-if test "$GTK_CONFIG" != ""; then
-   AC_CACHE_CHECK([for version of GTK+], fptools_cv_gtk_version, [
-       fptools_cv_gtk_version=`$GTK_CONFIG --version`
-    ])
-    GTK_VERSION=$fptools_cv_gtk_version
-else
-    GTK_VERSION=
+AC_PATH_PROGS([GTK_CONFIG], [gtk-config gtk12-config])
+if test -n "$GTK_CONFIG"; then
+  AC_CACHE_CHECK([for version of GTK+], [fp_cv_gtk_version],
+    [fp_cv_gtk_version=`$GTK_CONFIG --version`])
+  FP_COMPARE_VERSIONS([$fp_cv_gtk_version], [-lt], [1.2],
+    [AC_MSG_WARN([GTK+ not usable, need at least version 1.2])
+     GTK_CONFIG=])
 fi
-
-case $fptools_cv_gtk_version in
-  1.[[23]].*) ;;
-  *) AC_MSG_WARN([GTK+ not usable; need at least version 1.2])
-     GTK_CONFIG=
-     ;;
-esac
-
-AC_SUBST(GTK_CONFIG)
-AC_SUBST(GTK_VERSION)
+AC_SUBST([GTK_CONFIG])
 
 dnl --------------------------------------------------
 dnl * Miscellaneous feature tests
@@ -1347,6 +1395,8 @@ esac
 AC_SUBST(LdCmd)
 FPTOOLS_LD_X
 
+FP_EMPTY_STRUCTS
+
 AC_MSG_CHECKING([for SIGPOLL])
 AC_EGREP_CPP(we_have_sigpoll,
 [#include <signal.h>