configure: add macro to set arbitrary make variables

[thirdparty/git.git] / configure.ac

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_PREREQ(2.59)
AC_INIT([git], [@@GIT_VERSION@@], [git@vger.kernel.org])

AC_CONFIG_SRCDIR([git.c])

config_file=config.mak.autogen
config_append=config.mak.append
config_in=config.mak.in

echo "# ${config_append}.  Generated by configure." > "${config_append}"


## Definitions of macros
# GIT_CONF_APPEND_LINE(LINE)
# --------------------------
# Append LINE to file ${config_append}
AC_DEFUN([GIT_CONF_APPEND_LINE],
[echo "$1" >> "${config_append}"])# GIT_CONF_APPEND_LINE
#
# GIT_ARG_SET_PATH(PROGRAM)
# -------------------------
# Provide --with-PROGRAM=PATH option to set PATH to PROGRAM
AC_DEFUN([GIT_ARG_SET_PATH],
[AC_ARG_WITH([$1],
 [AS_HELP_STRING([--with-$1=PATH],
                 [provide PATH to $1])],
 [GIT_CONF_APPEND_PATH($1)],[])
])# GIT_ARG_SET_PATH
#
# GIT_CONF_APPEND_PATH(PROGRAM)
# ------------------------------
# Parse --with-PROGRAM=PATH option to set PROGRAM_PATH=PATH
# Used by GIT_ARG_SET_PATH(PROGRAM)
AC_DEFUN([GIT_CONF_APPEND_PATH],
[PROGRAM=m4_toupper($1); \
if test "$withval" = "no"; then \
	AC_MSG_ERROR([You cannot use git without $1]); \
else \
	if test "$withval" = "yes"; then \
		AC_MSG_WARN([You should provide path for --with-$1=PATH]); \
	else \
		m4_toupper($1)_PATH=$withval; \
		AC_MSG_NOTICE([Setting m4_toupper($1)_PATH to $withval]); \
		GIT_CONF_APPEND_LINE(${PROGRAM}_PATH=$withval); \
	fi; \
fi; \
]) # GIT_CONF_APPEND_PATH
#
# GIT_PARSE_WITH(PACKAGE)
# -----------------------
# For use in AC_ARG_WITH action-if-found, for packages default ON.
# * Set NO_PACKAGE=YesPlease for --without-PACKAGE
# * Set PACKAGEDIR=PATH for --with-PACKAGE=PATH
# * Unset NO_PACKAGE for --with-PACKAGE without ARG
AC_DEFUN([GIT_PARSE_WITH],
[PACKAGE=m4_toupper($1); \
if test "$withval" = "no"; then \
	m4_toupper(NO_$1)=YesPlease; \
elif test "$withval" = "yes"; then \
	m4_toupper(NO_$1)=; \
else \
	m4_toupper(NO_$1)=; \
	m4_toupper($1)DIR=$withval; \
	AC_MSG_NOTICE([Setting m4_toupper($1)DIR to $withval]); \
	GIT_CONF_APPEND_LINE(${PACKAGE}DIR=$withval); \
fi \
])# GIT_PARSE_WITH
#
# GIT_PARSE_WITH_SET_MAKE_VAR(WITHNAME, VAR, HELP_TEXT)
# ---------------------
# Set VAR to the value specied by --with-WITHNAME.
# No verification of arguments is performed, but warnings are issued
# if either 'yes' or 'no' is specified.
# HELP_TEXT is presented when --help is called.
# This is a direct way to allow setting variables in the Makefile.
AC_DEFUN([GIT_PARSE_WITH_SET_MAKE_VAR],
[AC_ARG_WITH([$1],
 [AS_HELP_STRING([--with-$1=VALUE], $3)],
 if test -n "$withval"; then \
  if test "$withval" = "yes" -o "$withval" = "no"; then \
    AC_MSG_WARN([You likely do not want either 'yes' or 'no' as]
		     [a value for $1 ($2).  Maybe you do...?]); \
  fi; \
  \
  AC_MSG_NOTICE([Setting $2 to $withval]); \
  GIT_CONF_APPEND_LINE($2=$withval); \
 fi)])# GIT_PARSE_WITH_SET_MAKE_VAR

dnl
dnl GIT_CHECK_FUNC(FUNCTION, IFTRUE, IFFALSE)
dnl -----------------------------------------
dnl Similar to AC_CHECK_FUNC, but on systems that do not generate
dnl warnings for missing prototypes (e.g. FreeBSD when compiling without
dnl -Wall), it does not work.  By looking for function definition in
dnl libraries, this problem can be worked around.
AC_DEFUN([GIT_CHECK_FUNC],[AC_CHECK_FUNC([$1],[
  AC_SEARCH_LIBS([$1],,
  [$2],[$3])
],[$3])])

dnl
dnl GIT_STASH_FLAGS(BASEPATH_VAR)
dnl -----------------------------
dnl Allow for easy stashing of LDFLAGS and CPPFLAGS before running
dnl tests that may want to take user settings into account.
AC_DEFUN([GIT_STASH_FLAGS],[
if test -n "$1"; then
   old_CPPFLAGS="$CPPFLAGS"
   old_LDFLAGS="$LDFLAGS"
   CPPFLAGS="-I$1/include $CPPFLAGS"
   LDFLAGS="-L$1/$lib $LDFLAGS"
fi
])

dnl
dnl GIT_UNSTASH_FLAGS(BASEPATH_VAR)
dnl -----------------------------
dnl Restore the stashed *FLAGS values.
AC_DEFUN([GIT_UNSTASH_FLAGS],[
if test -n "$1"; then
   CPPFLAGS="$old_CPPFLAGS"
   LDFLAGS="$old_LDFLAGS"
fi
])

## Site configuration related to programs (before tests)
## --with-PACKAGE[=ARG] and --without-PACKAGE
#
# Set lib to alternative name of lib directory (e.g. lib64)
AC_ARG_WITH([lib],
 [AS_HELP_STRING([--with-lib=ARG],
                 [ARG specifies alternative name for lib directory])],
 [if test "$withval" = "no" || test "$withval" = "yes"; then \
	AC_MSG_WARN([You should provide name for --with-lib=ARG]); \
else \
	lib=$withval; \
	AC_MSG_NOTICE([Setting lib to '$lib']); \
	GIT_CONF_APPEND_LINE(lib=$withval); \
fi; \
],[])

if test -z "$lib"; then
   AC_MSG_NOTICE([Setting lib to 'lib' (the default)])
   lib=lib
fi

AC_ARG_ENABLE([pthreads],
 [AS_HELP_STRING([--enable-pthreads=FLAGS],
  [FLAGS is the value to pass to the compiler to enable POSIX Threads.]
  [The default if FLAGS is not specified is to try first -pthread]
  [and then -lpthread.]
  [--without-pthreads will disable threading.])],
[
if test "x$enableval" = "xyes"; then
   AC_MSG_NOTICE([Will try -pthread then -lpthread to enable POSIX Threads])
elif test "x$enableval" != "xno"; then
   PTHREAD_CFLAGS=$enableval
   AC_MSG_NOTICE([Setting '$PTHREAD_CFLAGS' as the FLAGS to enable POSIX Threads])
else
   AC_MSG_NOTICE([POSIX Threads will be disabled.])
   NO_PTHREADS=YesPlease
   USER_NOPTHREAD=1
fi],
[
   AC_MSG_NOTICE([Will try -pthread then -lpthread to enable POSIX Threads.])
])

## Site configuration (override autodetection)
## --with-PACKAGE[=ARG] and --without-PACKAGE
AC_MSG_NOTICE([CHECKS for site configuration])
#
# Define NO_SVN_TESTS if you want to skip time-consuming SVN interoperability
# tests.  These tests take up a significant amount of the total test time
# but are not needed unless you plan to talk to SVN repos.
#
# Define PPC_SHA1 environment variable when running make to make use of
# a bundled SHA1 routine optimized for PowerPC.
#
# Define NO_OPENSSL environment variable if you do not have OpenSSL.
# This also implies BLK_SHA1.
#
# Define OPENSSLDIR=/foo/bar if your openssl header and library files are in
# /foo/bar/include and /foo/bar/lib directories.
AC_ARG_WITH(openssl,
AS_HELP_STRING([--with-openssl],[use OpenSSL library (default is YES)])
AS_HELP_STRING([],              [ARG can be prefix for openssl library and headers]),\
GIT_PARSE_WITH(openssl))
#
# Define NO_CURL if you do not have curl installed.  git-http-pull and
# git-http-push are not built, and you cannot use http:// and https://
# transports.
#
# Define CURLDIR=/foo/bar if your curl header and library files are in
# /foo/bar/include and /foo/bar/lib directories.
AC_ARG_WITH(curl,
AS_HELP_STRING([--with-curl],[support http(s):// transports (default is YES)])
AS_HELP_STRING([],           [ARG can be also prefix for curl library and headers]),
GIT_PARSE_WITH(curl))
#
# Define NO_EXPAT if you do not have expat installed.  git-http-push is
# not built, and you cannot push using http:// and https:// transports.
#
# Define EXPATDIR=/foo/bar if your expat header and library files are in
# /foo/bar/include and /foo/bar/lib directories.
AC_ARG_WITH(expat,
AS_HELP_STRING([--with-expat],
[support git-push using http:// and https:// transports via WebDAV (default is YES)])
AS_HELP_STRING([],            [ARG can be also prefix for expat library and headers]),
GIT_PARSE_WITH(expat))
#
# Define NO_FINK if you are building on Darwin/Mac OS X, have Fink
# installed in /sw, but don't want GIT to link against any libraries
# installed there.  If defined you may specify your own (or Fink's)
# include directories and library directories by defining CFLAGS
# and LDFLAGS appropriately.
#
# Define NO_DARWIN_PORTS if you are building on Darwin/Mac OS X,
# have DarwinPorts installed in /opt/local, but don't want GIT to
# link against any libraries installed there.  If defined you may
# specify your own (or DarwinPort's) include directories and
# library directories by defining CFLAGS and LDFLAGS appropriately.
#
# Define NO_MMAP if you want to avoid mmap.
#
# Define NO_ICONV if your libc does not properly support iconv.
AC_ARG_WITH(iconv,
AS_HELP_STRING([--without-iconv],
[if your architecture doesn't properly support iconv])
AS_HELP_STRING([--with-iconv=PATH],
[PATH is prefix for libiconv library and headers])
AS_HELP_STRING([],
[used only if you need linking with libiconv]),
GIT_PARSE_WITH(iconv))

## --enable-FEATURE[=ARG] and --disable-FEATURE
#
# Define USE_NSEC below if you want git to care about sub-second file mtimes
# and ctimes. Note that you need recent glibc (at least 2.2.4) for this, and
# it will BREAK YOUR LOCAL DIFFS! show-diff and anything using it will likely
# randomly break unless your underlying filesystem supports those sub-second
# times (my ext3 doesn't).
#
# Define USE_STDEV below if you want git to care about the underlying device
# change being considered an inode change from the update-index perspective.

#
# Define SHELL_PATH to provide path to shell.
GIT_ARG_SET_PATH(shell)
#
# Define PERL_PATH to provide path to Perl.
GIT_ARG_SET_PATH(perl)
#
# Define ZLIB_PATH to provide path to zlib.
GIT_ARG_SET_PATH(zlib)
#
# Declare the with-tcltk/without-tcltk options.
AC_ARG_WITH(tcltk,
AS_HELP_STRING([--with-tcltk],[use Tcl/Tk GUI (default is YES)])
AS_HELP_STRING([],[ARG is the full path to the Tcl/Tk interpreter.])
AS_HELP_STRING([],[Bare --with-tcltk will make the GUI part only if])
AS_HELP_STRING([],[Tcl/Tk interpreter will be found in a system.]),\
GIT_PARSE_WITH(tcltk))
#


## Checks for programs.
AC_MSG_NOTICE([CHECKS for programs])
#
AC_PROG_CC([cc gcc])
# which switch to pass runtime path to dynamic libraries to the linker
AC_CACHE_CHECK([if linker supports -R], git_cv_ld_dashr, [
   SAVE_LDFLAGS="${LDFLAGS}"
   LDFLAGS="${SAVE_LDFLAGS} -R /"
   AC_LINK_IFELSE(AC_LANG_PROGRAM([], []), [git_cv_ld_dashr=yes], [git_cv_ld_dashr=no])
   LDFLAGS="${SAVE_LDFLAGS}"
])
if test "$git_cv_ld_dashr" = "yes"; then
   AC_SUBST(CC_LD_DYNPATH, [-R])
else
   AC_CACHE_CHECK([if linker supports -Wl,-rpath,], git_cv_ld_wl_rpath, [
      SAVE_LDFLAGS="${LDFLAGS}"
      LDFLAGS="${SAVE_LDFLAGS} -Wl,-rpath,/"
      AC_LINK_IFELSE(AC_LANG_PROGRAM([], []), [git_cv_ld_wl_rpath=yes], [git_cv_ld_wl_rpath=no])
      LDFLAGS="${SAVE_LDFLAGS}"
   ])
   if test "$git_cv_ld_wl_rpath" = "yes"; then
      AC_SUBST(CC_LD_DYNPATH, [-Wl,-rpath,])
   else
      AC_CACHE_CHECK([if linker supports -rpath], git_cv_ld_rpath, [
         SAVE_LDFLAGS="${LDFLAGS}"
         LDFLAGS="${SAVE_LDFLAGS} -rpath /"
         AC_LINK_IFELSE(AC_LANG_PROGRAM([], []), [git_cv_ld_rpath=yes], [git_cv_ld_rpath=no])
         LDFLAGS="${SAVE_LDFLAGS}"
      ])
      if test "$git_cv_ld_rpath" = "yes"; then
         AC_SUBST(CC_LD_DYNPATH, [-rpath])
      else
         AC_MSG_WARN([linker does not support runtime path to dynamic libraries])
      fi
   fi
fi
#AC_PROG_INSTALL		# needs install-sh or install.sh in sources
AC_CHECK_TOOLS(AR, [gar ar], :)
AC_CHECK_PROGS(TAR, [gtar tar])
# TCLTK_PATH will be set to some value if we want Tcl/Tk
# or will be empty otherwise.
if test -z "$NO_TCLTK"; then
  if test "$with_tcltk" = ""; then
  # No Tcl/Tk switches given. Do not check for Tcl/Tk, use bare 'wish'.
    TCLTK_PATH=wish
    AC_SUBST(TCLTK_PATH)
  elif test "$with_tcltk" = "yes"; then
  # Tcl/Tk check requested.
    AC_CHECK_PROGS(TCLTK_PATH, [wish], )
  else
    AC_MSG_RESULT([Using Tcl/Tk interpreter $with_tcltk])
    TCLTK_PATH="$with_tcltk"
    AC_SUBST(TCLTK_PATH)
  fi
fi
AC_CHECK_PROGS(ASCIIDOC, [asciidoc])
if test -n "$ASCIIDOC"; then
	AC_MSG_CHECKING([for asciidoc version])
	asciidoc_version=`$ASCIIDOC --version 2>/dev/null`
	case "${asciidoc_version}" in
	asciidoc' '8*)
		ASCIIDOC8=YesPlease
		AC_MSG_RESULT([${asciidoc_version} > 7])
		;;
	asciidoc' '7*)
		ASCIIDOC8=
		AC_MSG_RESULT([${asciidoc_version}])
		;;
	*)
		ASCIIDOC8=
		AC_MSG_RESULT([${asciidoc_version} (unknown)])
		;;
	esac
fi
AC_SUBST(ASCIIDOC8)


## Checks for libraries.
AC_MSG_NOTICE([CHECKS for libraries])
#
# Define NO_OPENSSL environment variable if you do not have OpenSSL.
# Define NEEDS_SSL_WITH_CRYPTO if you need -lcrypto with -lssl (Darwin).

GIT_STASH_FLAGS($OPENSSLDIR)

AC_CHECK_LIB([crypto], [SHA1_Init],
[NEEDS_SSL_WITH_CRYPTO=],
[AC_CHECK_LIB([ssl], [SHA1_Init],
 [NEEDS_SSL_WITH_CRYPTO=YesPlease],
 [NEEDS_SSL_WITH_CRYPTO= NO_OPENSSL=YesPlease])])

GIT_UNSTASH_FLAGS($OPENSSLDIR)

AC_SUBST(NEEDS_SSL_WITH_CRYPTO)
AC_SUBST(NO_OPENSSL)

#
# Define NO_CURL if you do not have libcurl installed.  git-http-pull and
# git-http-push are not built, and you cannot use http:// and https://
# transports.

GIT_STASH_FLAGS($CURLDIR)

AC_CHECK_LIB([curl], [curl_global_init],
[NO_CURL=],
[NO_CURL=YesPlease])

GIT_UNSTASH_FLAGS($CURLDIR)

AC_SUBST(NO_CURL)

#
# Define NO_EXPAT if you do not have expat installed.  git-http-push is
# not built, and you cannot push using http:// and https:// transports.

GIT_STASH_FLAGS($EXPATDIR)

AC_CHECK_LIB([expat], [XML_ParserCreate],
[NO_EXPAT=],
[NO_EXPAT=YesPlease])

GIT_UNSTASH_FLAGS($EXPATDIR)

AC_SUBST(NO_EXPAT)

#
# Define NEEDS_LIBICONV if linking with libc is not enough (Darwin and
# some Solaris installations).
# Define NO_ICONV if neither libc nor libiconv support iconv.

if test -z "$NO_ICONV"; then

GIT_STASH_FLAGS($ICONVDIR)

AC_DEFUN([ICONVTEST_SRC], [
#include <iconv.h>

int main(void)
{
	iconv_open("", "");
	return 0;
}
])

if test -n "$ICONVDIR"; then
   lib_order="-liconv -lc"
else
   lib_order="-lc -liconv"
fi

NO_ICONV=YesPlease

for l in $lib_order; do
    if test "$l" = "-liconv"; then
       NEEDS_LIBICONV=YesPlease
    else
       NEEDS_LIBICONV=
    fi

    old_LIBS="$LIBS"
    LIBS="$LIBS $l"
    AC_MSG_CHECKING([for iconv in $l])
    AC_LINK_IFELSE(ICONVTEST_SRC,
	[AC_MSG_RESULT([yes])
	NO_ICONV=
	break],
	[AC_MSG_RESULT([no])])
    LIBS="$old_LIBS"
done

#in case of break
LIBS="$old_LIBS"

GIT_UNSTASH_FLAGS($ICONVDIR)

AC_SUBST(NEEDS_LIBICONV)
AC_SUBST(NO_ICONV)

if test -n "$NO_ICONV"; then
    NEEDS_LIBICONV=
fi

fi

#
# Define NO_DEFLATE_BOUND if deflateBound is missing from zlib.

GIT_STASH_FLAGS($ZLIB_PATH)

AC_DEFUN([ZLIBTEST_SRC], [
#include <zlib.h>

int main(void)
{
	deflateBound(0, 0);
	return 0;
}
])
AC_MSG_CHECKING([for deflateBound in -lz])
old_LIBS="$LIBS"
LIBS="$LIBS -lz"
AC_LINK_IFELSE(ZLIBTEST_SRC,
	[AC_MSG_RESULT([yes])],
	[AC_MSG_RESULT([no])
	NO_DEFLATE_BOUND=yes])
LIBS="$old_LIBS"

GIT_UNSTASH_FLAGS($ZLIB_PATH)

AC_SUBST(NO_DEFLATE_BOUND)

#
# Define NEEDS_SOCKET if linking with libc is not enough (SunOS,
# Patrick Mauritz).
AC_CHECK_LIB([c], [socket],
[NEEDS_SOCKET=],
[NEEDS_SOCKET=YesPlease])
AC_SUBST(NEEDS_SOCKET)
test -n "$NEEDS_SOCKET" && LIBS="$LIBS -lsocket"

#
# Define NEEDS_RESOLV if linking with -lnsl and/or -lsocket is not enough.
# Notably on Solaris hstrerror resides in libresolv and on Solaris 7
# inet_ntop and inet_pton additionally reside there.
AC_CHECK_LIB([c], [hstrerror],
[NEEDS_RESOLV=],
[NEEDS_RESOLV=YesPlease])
AC_SUBST(NEEDS_RESOLV)
test -n "$NEEDS_RESOLV" && LIBS="$LIBS -lresolv"

AC_CHECK_LIB([c], [basename],
[NEEDS_LIBGEN=],
[NEEDS_LIBGEN=YesPlease])
AC_SUBST(NEEDS_LIBGEN)
test -n "$NEEDS_LIBGEN" && LIBS="$LIBS -lgen"

## Checks for header files.
AC_MSG_NOTICE([CHECKS for header files])
#
# Define NO_SYS_SELECT_H if you don't have sys/select.h.
AC_CHECK_HEADER([sys/select.h],
[NO_SYS_SELECT_H=],
[NO_SYS_SELECT_H=UnfortunatelyYes])
AC_SUBST(NO_SYS_SELECT_H)
#
# Define OLD_ICONV if your library has an old iconv(), where the second
# (input buffer pointer) parameter is declared with type (const char **).
AC_DEFUN([OLDICONVTEST_SRC], [[
#include <iconv.h>

extern size_t iconv(iconv_t cd,
		    char **inbuf, size_t *inbytesleft,
		    char **outbuf, size_t *outbytesleft);

int main(void)
{
	return 0;
}
]])

GIT_STASH_FLAGS($ICONVDIR)

AC_MSG_CHECKING([for old iconv()])
AC_COMPILE_IFELSE(OLDICONVTEST_SRC,
	[AC_MSG_RESULT([no])],
	[AC_MSG_RESULT([yes])
	OLD_ICONV=UnfortunatelyYes])

GIT_UNSTASH_FLAGS($ICONVDIR)

AC_SUBST(OLD_ICONV)

## Checks for typedefs, structures, and compiler characteristics.
AC_MSG_NOTICE([CHECKS for typedefs, structures, and compiler characteristics])
#
# Define NO_D_INO_IN_DIRENT if you don't have d_ino in your struct dirent.
AC_CHECK_MEMBER(struct dirent.d_ino,
[NO_D_INO_IN_DIRENT=],
[NO_D_INO_IN_DIRENT=YesPlease],
[#include <dirent.h>])
AC_SUBST(NO_D_INO_IN_DIRENT)
#
# Define NO_D_TYPE_IN_DIRENT if your platform defines DT_UNKNOWN but lacks
# d_type in struct dirent (latest Cygwin -- will be fixed soonish).
AC_CHECK_MEMBER(struct dirent.d_type,
[NO_D_TYPE_IN_DIRENT=],
[NO_D_TYPE_IN_DIRENT=YesPlease],
[#include <dirent.h>])
AC_SUBST(NO_D_TYPE_IN_DIRENT)
#
# Define NO_SOCKADDR_STORAGE if your platform does not have struct
# sockaddr_storage.
AC_CHECK_TYPE(struct sockaddr_storage,
[NO_SOCKADDR_STORAGE=],
[NO_SOCKADDR_STORAGE=YesPlease],[
#include <sys/types.h>
#include <sys/socket.h>
])
AC_SUBST(NO_SOCKADDR_STORAGE)
#
# Define NO_IPV6 if you lack IPv6 support and getaddrinfo().
AC_CHECK_TYPE([struct addrinfo],[
 GIT_CHECK_FUNC([getaddrinfo],
  [NO_IPV6=],
  [NO_IPV6=YesPlease])
],[NO_IPV6=YesPlease],[
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
])
AC_SUBST(NO_IPV6)
#
# Define NO_C99_FORMAT if your formatted IO functions (printf/scanf et.al.)
# do not support the 'size specifiers' introduced by C99, namely ll, hh,
# j, z, t. (representing long long int, char, intmax_t, size_t, ptrdiff_t).
# some C compilers supported these specifiers prior to C99 as an extension.
AC_CACHE_CHECK([whether formatted IO functions support C99 size specifiers],
 [ac_cv_c_c99_format],
[# Actually git uses only %z (%zu) in alloc.c, and %t (%td) in mktag.c
AC_RUN_IFELSE(
	[AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
		[[char buf[64];
		if (sprintf(buf, "%lld%hhd%jd%zd%td", (long long int)1, (char)2, (intmax_t)3, (size_t)4, (ptrdiff_t)5) != 5)
		  return 1;
		else if (strcmp(buf, "12345"))
		  return 2;]])],
	[ac_cv_c_c99_format=yes],
	[ac_cv_c_c99_format=no])
])
if test $ac_cv_c_c99_format = no; then
	NO_C99_FORMAT=YesPlease
else
	NO_C99_FORMAT=
fi
AC_SUBST(NO_C99_FORMAT)
#
# Define FREAD_READS_DIRECTORIES if your are on a system which succeeds
# when attempting to read from an fopen'ed directory.
AC_CACHE_CHECK([whether system succeeds to read fopen'ed directory],
 [ac_cv_fread_reads_directories],
[
AC_RUN_IFELSE(
	[AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT],
		[[char c;
		FILE *f = fopen(".", "r");
		return f && fread(&c, 1, 1, f)]])],
	[ac_cv_fread_reads_directories=no],
	[ac_cv_fread_reads_directories=yes])
])
if test $ac_cv_fread_reads_directories = yes; then
	FREAD_READS_DIRECTORIES=UnfortunatelyYes
else
	FREAD_READS_DIRECTORIES=
fi
AC_SUBST(FREAD_READS_DIRECTORIES)
#
# Define SNPRINTF_RETURNS_BOGUS if your are on a system which snprintf()
# or vsnprintf() return -1 instead of number of characters which would
# have been written to the final string if enough space had been available.
AC_CACHE_CHECK([whether snprintf() and/or vsnprintf() return bogus value],
 [ac_cv_snprintf_returns_bogus],
[
AC_RUN_IFELSE(
	[AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
		#include "stdarg.h"

		int test_vsnprintf(char *str, size_t maxsize, const char *format, ...)
		{
		  int ret;
		  va_list ap;
		  va_start(ap, format);
		  ret = vsnprintf(str, maxsize, format, ap);
		  va_end(ap);
		  return ret;
		}],
		[[char buf[6];
		  if (test_vsnprintf(buf, 3, "%s", "12345") != 5
		      || strcmp(buf, "12")) return 1;
		  if (snprintf(buf, 3, "%s", "12345") != 5
		      || strcmp(buf, "12")) return 1]])],
	[ac_cv_snprintf_returns_bogus=no],
	[ac_cv_snprintf_returns_bogus=yes])
])
if test $ac_cv_snprintf_returns_bogus = yes; then
	SNPRINTF_RETURNS_BOGUS=UnfortunatelyYes
else
	SNPRINTF_RETURNS_BOGUS=
fi
AC_SUBST(SNPRINTF_RETURNS_BOGUS)


## Checks for library functions.
## (in default C library and libraries checked by AC_CHECK_LIB)
AC_MSG_NOTICE([CHECKS for library functions])
#
# Define NO_LIBGEN_H if you don't have libgen.h.
AC_CHECK_HEADER([libgen.h],
[NO_LIBGEN_H=],
[NO_LIBGEN_H=YesPlease])
AC_SUBST(NO_LIBGEN_H)
#
# Define NO_STRCASESTR if you don't have strcasestr.
GIT_CHECK_FUNC(strcasestr,
[NO_STRCASESTR=],
[NO_STRCASESTR=YesPlease])
AC_SUBST(NO_STRCASESTR)
#
# Define NO_MEMMEM if you don't have memmem.
GIT_CHECK_FUNC(memmem,
[NO_MEMMEM=],
[NO_MEMMEM=YesPlease])
AC_SUBST(NO_MEMMEM)
#
# Define NO_STRLCPY if you don't have strlcpy.
GIT_CHECK_FUNC(strlcpy,
[NO_STRLCPY=],
[NO_STRLCPY=YesPlease])
AC_SUBST(NO_STRLCPY)
#
# Define NO_UINTMAX_T if your platform does not have uintmax_t
AC_CHECK_TYPE(uintmax_t,
[NO_UINTMAX_T=],
[NO_UINTMAX_T=YesPlease],[
#include <inttypes.h>
])
AC_SUBST(NO_UINTMAX_T)
#
# Define NO_STRTOUMAX if you don't have strtoumax in the C library.
GIT_CHECK_FUNC(strtoumax,
[NO_STRTOUMAX=],
[NO_STRTOUMAX=YesPlease])
AC_SUBST(NO_STRTOUMAX)
#
# Define NO_SETENV if you don't have setenv in the C library.
GIT_CHECK_FUNC(setenv,
[NO_SETENV=],
[NO_SETENV=YesPlease])
AC_SUBST(NO_SETENV)
#
# Define NO_UNSETENV if you don't have unsetenv in the C library.
GIT_CHECK_FUNC(unsetenv,
[NO_UNSETENV=],
[NO_UNSETENV=YesPlease])
AC_SUBST(NO_UNSETENV)
#
# Define NO_MKDTEMP if you don't have mkdtemp in the C library.
GIT_CHECK_FUNC(mkdtemp,
[NO_MKDTEMP=],
[NO_MKDTEMP=YesPlease])
AC_SUBST(NO_MKDTEMP)
#
# Define NO_MKSTEMPS if you don't have mkstemps in the C library.
GIT_CHECK_FUNC(mkstemps,
[NO_MKSTEMPS=],
[NO_MKSTEMPS=YesPlease])
AC_SUBST(NO_MKSTEMPS)
#
#
# Define NO_MMAP if you want to avoid mmap.
#
# Define NO_ICONV if your libc does not properly support iconv.


## Other checks.
# Define USE_PIC if you need the main git objects to be built with -fPIC
# in order to build and link perl/Git.so.  x86-64 seems to need this.
#
# Define NO_SYMLINK_HEAD if you never want .git/HEAD to be a symbolic link.
# Enable it on Windows.  By default, symrefs are still used.
#
# Define NO_PTHREADS if we do not have pthreads
#
# Define PTHREAD_LIBS to the linker flag used for Pthread support and define
# THREADED_DELTA_SEARCH if Pthreads are available.
AC_DEFUN([PTHREADTEST_SRC], [
#include <pthread.h>

int main(void)
{
	pthread_mutex_t test_mutex;
	return (0);
}
])

dnl AC_LANG_CONFTEST([AC_LANG_PROGRAM(
dnl   [[#include <pthread.h>]],
dnl   [[pthread_mutex_t test_mutex;]]
dnl )])

NO_PTHREADS=UnfortunatelyYes
THREADED_DELTA_SEARCH=
PTHREAD_LIBS=

if test -n "$USER_NOPTHREAD"; then
   AC_MSG_NOTICE([Skipping POSIX Threads at user request.])
# handle these separately since PTHREAD_CFLAGS could be '-lpthreads
# -D_REENTRANT' or some such.
elif test -z "$PTHREAD_CFLAGS"; then
  for opt in -pthread -lpthread; do
     old_CFLAGS="$CFLAGS"
     CFLAGS="$opt $CFLAGS"
     AC_MSG_CHECKING([Checking for POSIX Threads with '$opt'])
     AC_LINK_IFELSE(PTHREADTEST_SRC,
	[AC_MSG_RESULT([yes])
		NO_PTHREADS=
		PTHREAD_LIBS="$opt"
		THREADED_DELTA_SEARCH=YesPlease
		break
	],
	[AC_MSG_RESULT([no])])
      CFLAGS="$old_CFLAGS"
  done
else
  old_CFLAGS="$CFLAGS"
  CFLAGS="$PTHREAD_CFLAGS $CFLAGS"
  AC_MSG_CHECKING([Checking for POSIX Threads with '$PTHREAD_CFLAGS'])
  AC_LINK_IFELSE(PTHREADTEST_SRC,
	[AC_MSG_RESULT([yes])
		NO_PTHREADS=
		PTHREAD_LIBS="$PTHREAD_CFLAGS"
		THREADED_DELTA_SEARCH=YesPlease
	],
	[AC_MSG_RESULT([no])])

  CFLAGS="$old_CFLAGS"
fi

CFLAGS="$old_CFLAGS"

AC_SUBST(PTHREAD_LIBS)
AC_SUBST(NO_PTHREADS)
AC_SUBST(THREADED_DELTA_SEARCH)

## Output files
AC_CONFIG_FILES(["${config_file}":"${config_in}":"${config_append}"])
AC_OUTPUT


## Cleanup
rm -f "${config_append}"