src/3rdparty/libtiff/m4/acinclude.m4
changeset 0 1918ee327afb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/3rdparty/libtiff/m4/acinclude.m4	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,669 @@
+dnl ---------------------------------------------------------------------------
+dnl Message output
+dnl ---------------------------------------------------------------------------
+AC_DEFUN([LOC_MSG],[echo "$1"])
+
+dnl ---------------------------------------------------------------------------
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://www.gnu.org/software/ac-archive/vl_prog_cc_warnings.html
+dnl ---------------------------------------------------------------------------
+
+dnl @synopsis VL_PROG_CC_WARNINGS([ANSI])
+dnl
+dnl Enables a reasonable set of warnings for the C compiler.
+dnl Optionally, if the first argument is nonempty, turns on flags which
+dnl enforce and/or enable proper ANSI C if such are known with the
+dnl compiler used.
+dnl
+dnl Currently this macro knows about GCC, Solaris C compiler, Digital
+dnl Unix C compiler, C for AIX Compiler, HP-UX C compiler, IRIX C
+dnl compiler, NEC SX-5 (Super-UX 10) C compiler, and Cray J90 (Unicos
+dnl 10.0.0.8) C compiler.
+dnl
+dnl @category C
+dnl @author Ville Laurikari <vl@iki.fi>
+dnl @version 2002-04-04
+dnl @license AllPermissive
+
+AC_DEFUN([VL_PROG_CC_WARNINGS], [
+  ansi=$1
+  if test -z "$ansi"; then
+    msg="for C compiler warning flags"
+  else
+    msg="for C compiler warning and ANSI conformance flags"
+  fi
+  AC_CACHE_CHECK($msg, vl_cv_prog_cc_warnings, [
+    if test -n "$CC"; then
+      cat > conftest.c <<EOF
+int main(int argc, char **argv) { return 0; }
+EOF
+
+      dnl GCC. -W option has been renamed in -wextra in latest gcc versions.
+      if test "$GCC" = "yes"; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-Wall -W"
+        else
+          vl_cv_prog_cc_warnings="-Wall -W -ansi -pedantic"
+        fi
+
+      dnl Most compilers print some kind of a version string with some command
+      dnl line options (often "-V").  The version string should be checked
+      dnl before doing a test compilation run with compiler-specific flags.
+      dnl This is because some compilers (like the Cray compiler) only
+      dnl produce a warning message for unknown flags instead of returning
+      dnl an error, resulting in a false positive.  Also, compilers may do
+      dnl erratic things when invoked with flags meant for a different
+      dnl compiler.
+
+      dnl Solaris C compiler
+      elif $CC -V 2>&1 | grep -i "WorkShop" > /dev/null 2>&1 &&
+           $CC -c -v -Xc conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-v"
+        else
+          vl_cv_prog_cc_warnings="-v -Xc"
+        fi
+
+      dnl Digital Unix C compiler
+      elif $CC -V 2>&1 | grep -i "Digital UNIX Compiler" > /dev/null 2>&1 &&
+           $CC -c -verbose -w0 -warnprotos -std1 conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-verbose -w0 -warnprotos"
+        else
+          vl_cv_prog_cc_warnings="-verbose -w0 -warnprotos -std1"
+        fi
+
+      dnl C for AIX Compiler
+      elif $CC 2>&1 | grep -i "C for AIX Compiler" > /dev/null 2>&1 &&
+           $CC -c -qlanglvl=ansi -qinfo=all conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-qsrcmsg -qinfo=all:noppt:noppc:noobs:nocnd"
+        else
+          vl_cv_prog_cc_warnings="-qsrcmsg -qinfo=all:noppt:noppc:noobs:nocnd -qlanglvl=ansi"
+        fi
+
+      dnl IRIX C compiler
+      elif $CC -version 2>&1 | grep -i "MIPSpro Compilers" > /dev/null 2>&1 &&
+           $CC -c -fullwarn -ansi -ansiE conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-fullwarn"
+        else
+          vl_cv_prog_cc_warnings="-fullwarn -ansi -ansiE"
+        fi
+
+      dnl HP-UX C compiler
+      elif what $CC 2>&1 | grep -i "HP C Compiler" > /dev/null 2>&1 &&
+           $CC -c -Aa +w1 conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="+w1"
+        else
+          vl_cv_prog_cc_warnings="+w1 -Aa"
+        fi
+
+      dnl The NEC SX-5 (Super-UX 10) C compiler
+      elif $CC -V 2>&1 | grep "/SX" > /dev/null 2>&1 &&
+           $CC -c -pvctl[,]fullmsg -Xc conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-pvctl[,]fullmsg"
+        else
+          vl_cv_prog_cc_warnings="-pvctl[,]fullmsg -Xc"
+        fi
+
+      dnl The Cray C compiler (Unicos)
+      elif $CC -V 2>&1 | grep -i "Cray" > /dev/null 2>&1 &&
+           $CC -c -h msglevel 2 conftest.c > /dev/null 2>&1 &&
+           test -f conftest.o; then
+        if test -z "$ansi"; then
+          vl_cv_prog_cc_warnings="-h msglevel 2"
+        else
+          vl_cv_prog_cc_warnings="-h msglevel 2 -h conform"
+        fi
+
+      fi
+      rm -f conftest.*
+    fi
+    if test -n "$vl_cv_prog_cc_warnings"; then
+      CFLAGS="$CFLAGS $vl_cv_prog_cc_warnings"
+    else
+      vl_cv_prog_cc_warnings="unknown"
+    fi
+  ])
+])dnl
+
+dnl ---------------------------------------------------------------------------
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://autoconf-archive.cryp.to/ax_lang_compiler_ms.html
+dnl ---------------------------------------------------------------------------
+
+dnl @synopsis AX_LANG_COMPILER_MS
+dnl
+dnl Check whether the compiler for the current language is Microsoft.
+dnl
+dnl This macro is modeled after _AC_LANG_COMPILER_GNU in the GNU
+dnl Autoconf implementation.
+dnl
+dnl @category InstalledPackages
+dnl @author Braden McDaniel <braden@endoframe.com>
+dnl @version 2004-11-15
+dnl @license AllPermissive
+
+AC_DEFUN([AX_LANG_COMPILER_MS],
+[AC_CACHE_CHECK([whether we are using the Microsoft _AC_LANG compiler],
+                [ax_cv_[]_AC_LANG_ABBREV[]_compiler_ms],
+[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [[#ifndef _MSC_VER
+       choke me
+#endif
+]])],
+                   [ax_compiler_ms=yes],
+                   [ax_compiler_ms=no])
+ax_cv_[]_AC_LANG_ABBREV[]_compiler_ms=$ax_compiler_ms
+])])
+
+dnl ---------------------------------------------------------------------------
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://www.gnu.org/software/ac-archive/ax_check_gl.html
+dnl ---------------------------------------------------------------------------
+
+dnl @synopsis AX_CHECK_GL
+dnl
+dnl Check for an OpenGL implementation. If GL is found, the required
+dnl compiler and linker flags are included in the output variables
+dnl "GL_CFLAGS" and "GL_LIBS", respectively. This macro adds the
+dnl configure option "--with-apple-opengl-framework", which users can
+dnl use to indicate that Apple's OpenGL framework should be used on Mac
+dnl OS X. If Apple's OpenGL framework is used, the symbol
+dnl "HAVE_APPLE_OPENGL_FRAMEWORK" is defined. If no GL implementation
+dnl is found, "no_gl" is set to "yes".
+dnl
+dnl @category InstalledPackages
+dnl @author Braden McDaniel <braden@endoframe.com>
+dnl @version 2004-11-15
+dnl @license AllPermissive
+
+AC_DEFUN([AX_CHECK_GL],
+[AC_REQUIRE([AC_PATH_X])dnl
+AC_REQUIRE([ACX_PTHREAD])dnl
+
+#
+# There isn't a reliable way to know we should use the Apple OpenGL framework
+# without a configure option.  A Mac OS X user may have installed an
+# alternative GL implementation (e.g., Mesa), which may or may not depend on X.
+#
+AC_ARG_WITH([apple-opengl-framework],
+            [AC_HELP_STRING([--with-apple-opengl-framework],
+                            [use Apple OpenGL framework (Mac OS X only)])])
+if test "X$with_apple_opengl_framework" = "Xyes"; then
+  AC_DEFINE([HAVE_APPLE_OPENGL_FRAMEWORK], [1],
+            [Use the Apple OpenGL framework.])
+  GL_LIBS="-framework OpenGL"
+else
+  AC_LANG_PUSH(C)
+
+  AX_LANG_COMPILER_MS
+  if test X$ax_compiler_ms = Xno; then
+    GL_CFLAGS="${PTHREAD_CFLAGS}"
+    GL_LIBS="${PTHREAD_LIBS} -lm"
+  fi
+
+  #
+  # Use x_includes and x_libraries if they have been set (presumably by
+  # AC_PATH_X).
+  #
+  if test "X$no_x" != "Xyes"; then
+    if test -n "$x_includes"; then
+      GL_CFLAGS="-I${x_includes} ${GL_CFLAGS}"
+    fi
+    if test -n "$x_libraries"; then
+      GL_LIBS="-L${x_libraries} -lX11 ${GL_LIBS}"
+    fi
+  fi
+
+  AC_CHECK_HEADERS([windows.h])
+
+  AC_CACHE_CHECK([for OpenGL library], [ax_cv_check_gl_libgl],
+  [ax_cv_check_gl_libgl="no"
+  ax_save_CPPFLAGS="${CPPFLAGS}"
+  CPPFLAGS="${GL_CFLAGS} ${CPPFLAGS}"
+  ax_save_LIBS="${LIBS}"
+  LIBS=""
+  ax_check_libs="-lopengl32 -lGL"
+  for ax_lib in ${ax_check_libs}; do
+    if test X$ax_compiler_ms = Xyes; then
+      ax_try_lib=`echo $ax_lib | sed -e 's/^-l//' -e 's/$/.lib/'`
+    else
+      ax_try_lib="${ax_lib}"
+    fi
+    LIBS="${ax_try_lib} ${GL_LIBS} ${ax_save_LIBS}"
+    AC_LINK_IFELSE(
+    [AC_LANG_PROGRAM([[
+# if HAVE_WINDOWS_H && defined(_WIN32)
+#   include <windows.h>
+# endif
+# include <GL/gl.h>]],
+                     [[glBegin(0)]])],
+    [ax_cv_check_gl_libgl="${ax_try_lib}"; break])
+  done
+  LIBS=${ax_save_LIBS}
+  CPPFLAGS=${ax_save_CPPFLAGS}])
+
+  if test "X${ax_cv_check_gl_libgl}" = "Xno"; then
+    no_gl="yes"
+    GL_CFLAGS=""
+    GL_LIBS=""
+  else
+    GL_LIBS="${ax_cv_check_gl_libgl} ${GL_LIBS}"
+  fi
+  AC_LANG_POP(C)
+fi
+
+AC_SUBST([GL_CFLAGS])
+AC_SUBST([GL_LIBS])
+])dnl
+
+dnl ---------------------------------------------------------------------------
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://www.gnu.org/software/ac-archive/ax_check_glu.html
+dnl ---------------------------------------------------------------------------
+
+dnl @synopsis AX_CHECK_GLU
+dnl
+dnl Check for GLU. If GLU is found, the required preprocessor and
+dnl linker flags are included in the output variables "GLU_CFLAGS" and
+dnl "GLU_LIBS", respectively. This macro adds the configure option
+dnl "--with-apple-opengl-framework", which users can use to indicate
+dnl that Apple's OpenGL framework should be used on Mac OS X. If
+dnl Apple's OpenGL framework is used, the symbol
+dnl "HAVE_APPLE_OPENGL_FRAMEWORK" is defined. If no GLU implementation
+dnl is found, "no_glu" is set to "yes".
+dnl
+dnl @category InstalledPackages
+dnl @author Braden McDaniel <braden@endoframe.com>
+dnl @version 2004-11-15
+dnl @license AllPermissive
+
+AC_DEFUN([AX_CHECK_GLU],
+[AC_REQUIRE([AX_CHECK_GL])dnl
+AC_REQUIRE([AC_PROG_CXX])dnl
+GLU_CFLAGS="${GL_CFLAGS}"
+if test "X${with_apple_opengl_framework}" != "Xyes"; then
+  AC_CACHE_CHECK([for OpenGL Utility library], [ax_cv_check_glu_libglu],
+  [ax_cv_check_glu_libglu="no"
+  ax_save_CPPFLAGS="${CPPFLAGS}"
+  CPPFLAGS="${GL_CFLAGS} ${CPPFLAGS}"
+  ax_save_LIBS="${LIBS}"
+  LIBS=""
+  ax_check_libs="-lglu32 -lGLU"
+  for ax_lib in ${ax_check_libs}; do
+    if test X$ax_compiler_ms = Xyes; then
+      ax_try_lib=`echo $ax_lib | sed -e 's/^-l//' -e 's/$/.lib/'`
+    else
+      ax_try_lib="${ax_lib}"
+    fi
+    LIBS="${ax_try_lib} ${GL_LIBS} ${ax_save_LIBS}"
+    #
+    # libGLU typically links with libstdc++ on POSIX platforms. However,
+    # setting the language to C++ means that test program source is named
+    # "conftest.cc"; and Microsoft cl doesn't know what to do with such a
+    # file.
+    #
+    AC_LANG_PUSH([C++])
+    if test X$ax_compiler_ms = Xyes; then
+      AC_LANG_PUSH([C])
+    fi
+    AC_LINK_IFELSE(
+    [AC_LANG_PROGRAM([[
+# if HAVE_WINDOWS_H && defined(_WIN32)
+#   include <windows.h>
+# endif
+# include <GL/glu.h>]],
+                     [[gluBeginCurve(0)]])],
+    [ax_cv_check_glu_libglu="${ax_try_lib}"; break])
+    if test X$ax_compiler_ms = Xyes; then
+      AC_LANG_POP([C])
+    fi
+    AC_LANG_POP([C++])
+  done
+  LIBS=${ax_save_LIBS}
+  CPPFLAGS=${ax_save_CPPFLAGS}])
+  if test "X${ax_cv_check_glu_libglu}" = "Xno"; then
+    no_glu="yes"
+    GLU_CFLAGS=""
+    GLU_LIBS=""
+  else
+    GLU_LIBS="${ax_cv_check_glu_libglu} ${GL_LIBS}"
+  fi
+fi
+AC_SUBST([GLU_CFLAGS])
+AC_SUBST([GLU_LIBS])
+])
+
+dnl ---------------------------------------------------------------------------
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://www.gnu.org/software/ac-archive/ax_check_glut.html
+dnl ---------------------------------------------------------------------------
+
+dnl @synopsis AX_CHECK_GLUT
+dnl
+dnl Check for GLUT. If GLUT is found, the required compiler and linker
+dnl flags are included in the output variables "GLUT_CFLAGS" and
+dnl "GLUT_LIBS", respectively. This macro adds the configure option
+dnl "--with-apple-opengl-framework", which users can use to indicate
+dnl that Apple's OpenGL framework should be used on Mac OS X. If
+dnl Apple's OpenGL framework is used, the symbol
+dnl "HAVE_APPLE_OPENGL_FRAMEWORK" is defined. If GLUT is not found,
+dnl "no_glut" is set to "yes".
+dnl
+dnl @category InstalledPackages
+dnl @author Braden McDaniel <braden@endoframe.com>
+dnl @version 2004-11-15
+dnl @license AllPermissive
+
+AC_DEFUN([AX_CHECK_GLUT],
+[AC_REQUIRE([AX_CHECK_GLU])dnl
+AC_REQUIRE([AC_PATH_XTRA])dnl
+
+if test "X$with_apple_opengl_framework" = "Xyes"; then
+  GLUT_CFLAGS="${GLU_CFLAGS}"
+  GLUT_LIBS="-framework GLUT -lobjc ${GL_LIBS}"
+else
+  GLUT_CFLAGS=${GLU_CFLAGS}
+  GLUT_LIBS=${GLU_LIBS}
+
+  #
+  # If X is present, assume GLUT depends on it.
+  #
+  if test "X${no_x}" != "Xyes"; then
+    GLUT_LIBS="${X_PRE_LIBS} -lXmu -lXi ${X_EXTRA_LIBS} ${GLUT_LIBS}"
+  fi
+
+  AC_LANG_PUSH(C)
+
+  ax_save_CPPFLAGS="${CPPFLAGS}"
+  CPPFLAGS="${GLUT_CFLAGS} ${CPPFLAGS}"
+
+  AC_CACHE_CHECK([for GLUT library], [ax_cv_check_glut_libglut],
+  [ax_cv_check_glut_libglut="no"
+  ax_save_LIBS="${LIBS}"
+  LIBS=""
+  ax_check_libs="-lglut32 -lglut"
+  for ax_lib in ${ax_check_libs}; do
+    if test X$ax_compiler_ms = Xyes; then
+      ax_try_lib=`echo $ax_lib | sed -e 's/^-l//' -e 's/$/.lib/'`
+    else
+      ax_try_lib="${ax_lib}"
+    fi
+    LIBS="${ax_try_lib} ${GLUT_LIBS} ${ax_save_LIBS}"
+    AC_LINK_IFELSE(
+    [AC_LANG_PROGRAM([[
+# if HAVE_WINDOWS_H && defined(_WIN32)
+#   include <windows.h>
+# endif
+# include <GL/glut.h>]],
+                     [[glutMainLoop()]])],
+    [ax_cv_check_glut_libglut="${ax_try_lib}"; break])
+
+  done
+  LIBS=${ax_save_LIBS}
+  ])
+  CPPFLAGS="${ax_save_CPPFLAGS}"
+  AC_LANG_POP(C)
+
+  if test "X${ax_cv_check_glut_libglut}" = "Xno"; then
+    no_glut="yes"
+    GLUT_CFLAGS=""
+    GLUT_LIBS=""
+  else
+    GLUT_LIBS="${ax_cv_check_glut_libglut} ${GLUT_LIBS}"
+  fi
+fi
+
+AC_SUBST([GLUT_CFLAGS])
+AC_SUBST([GLUT_LIBS])
+])dnl
+
+dnl ---------------------------------------------------------------------------
+dnl Available from the GNU Autoconf Macro Archive at:
+dnl http://www.gnu.org/software/ac-archive/acx_pthread.html
+dnl ---------------------------------------------------------------------------
+
+dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
+dnl
+dnl This macro figures out how to build C programs using POSIX threads.
+dnl It sets the PTHREAD_LIBS output variable to the threads library and
+dnl linker flags, and the PTHREAD_CFLAGS output variable to any special
+dnl C compiler flags that are needed. (The user can also force certain
+dnl compiler flags/libs to be tested by setting these environment
+dnl variables.)
+dnl
+dnl Also sets PTHREAD_CC to any special C compiler that is needed for
+dnl multi-threaded programs (defaults to the value of CC otherwise).
+dnl (This is necessary on AIX to use the special cc_r compiler alias.)
+dnl
+dnl NOTE: You are assumed to not only compile your program with these
+dnl flags, but also link it with them as well. e.g. you should link
+dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
+dnl $LIBS
+dnl
+dnl If you are only building threads programs, you may wish to use
+dnl these variables in your default LIBS, CFLAGS, and CC:
+dnl
+dnl        LIBS="$PTHREAD_LIBS $LIBS"
+dnl        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+dnl        CC="$PTHREAD_CC"
+dnl
+dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
+dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
+dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
+dnl
+dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
+dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to
+dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the
+dnl default action will define HAVE_PTHREAD.
+dnl
+dnl Please let the authors know if this macro fails on any platform, or
+dnl if you have any other suggestions or comments. This macro was based
+dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with
+dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros
+dnl posted by Alejandro Forero Cuervo to the autoconf macro repository.
+dnl We are also grateful for the helpful feedback of numerous users.
+dnl
+dnl @category InstalledPackages
+dnl @author Steven G. Johnson <stevenj@alum.mit.edu>
+dnl @version 2005-01-14
+dnl @license GPLWithACException
+
+AC_DEFUN([ACX_PTHREAD], [
+AC_REQUIRE([AC_CANONICAL_HOST])
+AC_LANG_SAVE
+AC_LANG_C
+acx_pthread_ok=no
+
+# We used to check for pthread.h first, but this fails if pthread.h
+# requires special compiler flags (e.g. on True64 or Sequent).
+# It gets checked for in the link test anyway.
+
+# First of all, check if the user has set any of the PTHREAD_LIBS,
+# etcetera environment variables, and if threads linking works using
+# them:
+if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
+        AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
+        AC_MSG_RESULT($acx_pthread_ok)
+        if test x"$acx_pthread_ok" = xno; then
+                PTHREAD_LIBS=""
+                PTHREAD_CFLAGS=""
+        fi
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+fi
+
+# We must check for the threads library under a number of different
+# names; the ordering is very important because some systems
+# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
+# libraries is broken (non-POSIX).
+
+# Create a list of thread flags to try.  Items starting with a "-" are
+# C compiler flags, and other items are library names, except for "none"
+# which indicates that we try without any flags at all, and "pthread-config"
+# which is a program returning the flags for the Pth emulation library.
+
+acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
+
+# The ordering *is* (sometimes) important.  Some notes on the
+# individual items follow:
+
+# pthreads: AIX (must check this before -lpthread)
+# none: in case threads are in libc; should be tried before -Kthread and
+#       other compiler flags to prevent continual compiler warnings
+# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
+# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
+# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
+# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
+# -pthreads: Solaris/gcc
+# -mthreads: Mingw32/gcc, Lynx/gcc
+# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
+#      doesn't hurt to check since this sometimes defines pthreads too;
+#      also defines -D_REENTRANT)
+# pthread: Linux, etcetera
+# --thread-safe: KAI C++
+# pthread-config: use pthread-config program (for GNU Pth library)
+
+case "${host_cpu}-${host_os}" in
+        *solaris*)
+
+        # On Solaris (at least, for some versions), libc contains stubbed
+        # (non-functional) versions of the pthreads routines, so link-based
+        # tests will erroneously succeed.  (We need to link with -pthread or
+        # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
+        # a function called by this macro, so we could check for that, but
+        # who knows whether they'll stub that too in a future libc.)  So,
+        # we'll just look for -pthreads and -lpthread first:
+
+        acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
+        ;;
+esac
+
+if test x"$acx_pthread_ok" = xno; then
+for flag in $acx_pthread_flags; do
+
+        case $flag in
+                none)
+                AC_MSG_CHECKING([whether pthreads work without any flags])
+                ;;
+
+                -*)
+                AC_MSG_CHECKING([whether pthreads work with $flag])
+                PTHREAD_CFLAGS="$flag"
+                ;;
+
+		pthread-config)
+		AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
+		if test x"$acx_pthread_config" = xno; then continue; fi
+		PTHREAD_CFLAGS="`pthread-config --cflags`"
+		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
+		;;
+
+                *)
+                AC_MSG_CHECKING([for the pthreads library -l$flag])
+                PTHREAD_LIBS="-l$flag"
+                ;;
+        esac
+
+        save_LIBS="$LIBS"
+        save_CFLAGS="$CFLAGS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Check for various functions.  We must include pthread.h,
+        # since some functions may be macros.  (On the Sequent, we
+        # need a special flag -Kthread to make this header compile.)
+        # We check for pthread_join because it is in -lpthread on IRIX
+        # while pthread_create is in libc.  We check for pthread_attr_init
+        # due to DEC craziness with -lpthreads.  We check for
+        # pthread_cleanup_push because it is one of the few pthread
+        # functions on Solaris that doesn't have a non-functional libc stub.
+        # We try pthread_create on general principles.
+        AC_TRY_LINK([#include <pthread.h>],
+                    [pthread_t th; pthread_join(th, 0);
+                     pthread_attr_init(0); pthread_cleanup_push(0, 0);
+                     pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
+                    [acx_pthread_ok=yes])
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        AC_MSG_RESULT($acx_pthread_ok)
+        if test "x$acx_pthread_ok" = xyes; then
+                break;
+        fi
+
+        PTHREAD_LIBS=""
+        PTHREAD_CFLAGS=""
+done
+fi
+
+# Various other checks:
+if test "x$acx_pthread_ok" = xyes; then
+        save_LIBS="$LIBS"
+        LIBS="$PTHREAD_LIBS $LIBS"
+        save_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+
+        # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
+	AC_MSG_CHECKING([for joinable pthread attribute])
+	attr_name=unknown
+	for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
+	    AC_TRY_LINK([#include <pthread.h>], [int attr=$attr;],
+                        [attr_name=$attr; break])
+	done
+        AC_MSG_RESULT($attr_name)
+        if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
+            AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
+                               [Define to necessary symbol if this constant
+                                uses a non-standard name on your system.])
+        fi
+
+        AC_MSG_CHECKING([if more special flags are required for pthreads])
+        flag=no
+        case "${host_cpu}-${host_os}" in
+            *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
+            *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
+        esac
+        AC_MSG_RESULT(${flag})
+        if test "x$flag" != xno; then
+            PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
+        fi
+
+        LIBS="$save_LIBS"
+        CFLAGS="$save_CFLAGS"
+
+        # More AIX lossage: must compile with cc_r
+        AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
+else
+        PTHREAD_CC="$CC"
+fi
+
+AC_SUBST(PTHREAD_LIBS)
+AC_SUBST(PTHREAD_CFLAGS)
+AC_SUBST(PTHREAD_CC)
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test x"$acx_pthread_ok" = xyes; then
+        ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
+        :
+else
+        acx_pthread_ok=no
+        $2
+fi
+AC_LANG_RESTORE
+])dnl ACX_PTHREAD