# configure.ac

dnl Process this file with autoconf to produce a configure script.
dnl
dnl Minor upgrades (compatible ABI): increment the package version
dnl (third field in two places below) and set the PNGLIB_RELEASE
dnl variable.
dnl
dnl Major upgrades (incompatible ABI): increment the package major
dnl version (second field, or first if desired), set the minor
dnl to 0, set PNGLIB_MAJOR below *and* follow the instructions in
dnl Makefile.am to upgrade the package name.

dnl This is here to prevent earlier autoconf from being used, it
dnl should not be necessary to regenerate configure if the time
dnl stamps are correct
AC_PREREQ([2.68])

dnl Version number stuff here:

AC_INIT([libpng],[1.6.0beta19],[png-mng-implement@lists.sourceforge.net])
AC_CONFIG_MACRO_DIR([scripts])

# libpng does not follow GNU file name conventions (hence 'foreign')
# color-tests requires automake 1.11 or later
# silent-rules requires automake 1.11 or later
# dist-xz requires automake 1.11 or later
# 1.11.1 fixes a security issue in 1.11
AM_INIT_AUTOMAKE([1.11.1 foreign dist-xz dist-bzip2 color-tests silent-rules])
# was:
# AM_INIT_AUTOMAKE
AM_MAINTAINER_MODE

dnl configure.ac and Makefile.am expect automake 1.11.2 or a compatible later
dnl version; aclocal.m4 will generate a failure if you use a prior version of
dnl automake, so the following is not necessary (and is not defined anyway):
dnl AM_PREREQ([1.11.2])
dnl stop configure from automagically running automake

PNGLIB_VERSION=1.6.0beta19
PNGLIB_MAJOR=1
PNGLIB_MINOR=6
PNGLIB_RELEASE=0

dnl End of version number stuff

AC_CONFIG_SRCDIR([pngget.c])
AC_CONFIG_HEADERS([config.h])

# Checks for programs.
AC_LANG([C])
AC_PROG_CC
AM_PROG_AS
LT_PATH_LD
AC_PROG_CPP
AC_CHECK_TOOL(SED, sed, :)
AC_CHECK_TOOL(AWK, awk, :)
AC_PROG_INSTALL
AC_PROG_LN_S
AC_PROG_MAKE_SET

dnl libtool/libtoolize; version 2.4.2 is the tested version, this or any
dnl compatible later version may be used
LT_INIT([win32-dll])
LT_PREREQ([2.4.2])

# On Solaris 10 and 12 CPP gets set to cc -E, however this still
# does some input parsing.  We need strict ANSI-C style tokenization,
# check this:
AC_REQUIRE_CPP
AC_MSG_CHECKING([for a C preprocessor that does not parse its input])
AC_PREPROC_IFELSE([AC_LANG_SOURCE([[1.1.1 16BIT]])],
   [DFNCPP="$CPP"],
   [  DFNCPP=""
      sav_CPP="$CPP"
      for CPP in "${CC-cc} -E" "${CC-cc} -E -traditional-cpp" "/lib/cpp" "cpp"
      do
         AC_PREPROC_IFELSE([AC_LANG_SOURCE([[1.1.1 16BIT]])],
            [DFNCPP="$CPP"]
            [break],,)
      done
      CPP="$sav_CPP"
   ])
if test -n "$DFNCPP"; then
   AC_MSG_RESULT([$DFNCPP])
   AC_SUBST(DFNCPP)
else
   AC_MSG_FAILURE([not found], 1)
fi

# -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
# checks the compiler with a program that generates a warning), add the
# following option to deal with this
AC_ARG_VAR(PNG_COPTS,
   [additional flags for the C compiler, use this for options that would]
   [cause configure itself to fail])
AC_ARG_ENABLE(werror,
   AS_HELP_STRING([[[--enable-werror[=OPT]]]],
      [Pass -Werror or the given argument to the compiler if it is supported]),
   [test "$enable_werror" = "yes" && enable_werror="-Werror"
    if test "$enable_werror" != "no"; then
      sav_CFLAGS="$CFLAGS"
      CFLAGS="$enable_werror $CFLAGS"
      AC_MSG_CHECKING([if the compiler allows $enable_werror])
      AC_COMPILE_IFELSE(
         [AC_LANG_SOURCE([
            [int main(int argc, char **argv){]
            [return argv[argc-1][0];]
            [}]])],
         AC_MSG_RESULT(yes)
         PNG_COPTS="$PNG_COPTS $enable_werror",
         AC_MSG_RESULT(no))
      CFLAGS="$sav_CFLAGS"
    fi],)

# Checks for header files.
AC_HEADER_STDC
AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h])

# Checks for typedefs, structures, and compiler characteristics.
AC_C_CONST
AC_TYPE_SIZE_T
AC_STRUCT_TM
AC_C_RESTRICT

# Checks for library functions.
AC_FUNC_STRTOD
AC_CHECK_FUNCS([memset], , AC_MSG_ERROR(memset not found in libc))
AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_MSG_ERROR(cannot find pow)) )
AC_ARG_WITH(zlib-prefix,
   AS_HELP_STRING([[[--with-zlib-prefix]]],
      [prefix that may have been used in installed zlib]),
      [ZPREFIX=${withval}],
      [ZPREFIX='z_'])
AC_CHECK_LIB(z, zlibVersion, ,
    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))

# The following is for pngvalid, to ensure it catches FP errors even on
# platforms that don't enable FP exceptions, the function appears in the math
# library (typically), it's not an error if it is not found.
AC_CHECK_LIB([m], [feenableexcept])
AC_CHECK_FUNCS([feenableexcept])

AC_MSG_CHECKING([if using Solaris linker])
SLD=`$LD --version 2>&1 | grep Solaris`
if test "$SLD"; then
    have_solaris_ld=yes
    AC_MSG_RESULT(yes)
else
    have_solaris_ld=no
    AC_MSG_RESULT(no)
fi
AM_CONDITIONAL(HAVE_SOLARIS_LD, test "$have_solaris_ld" = "yes")

AC_MSG_CHECKING([if libraries can be versioned])
# Special case for PE/COFF platforms: ld reports
# support for version-script, but doesn't actually
# DO anything with it.
case $host in
*cygwin* | *mingw32* | *interix* )
    have_ld_version_script=no
    AC_MSG_RESULT(no)
;;
* )

if test "$have_solaris_ld" = "yes"; then
    GLD=`$LD --help < /dev/null 2>&1 | grep 'M mapfile'`
else
    GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
fi

if test "$GLD"; then
    have_ld_version_script=yes
    AC_MSG_RESULT(yes)
else
    have_ld_version_script=no
    AC_MSG_RESULT(no)
    AC_MSG_WARN(*** You have not enabled versioned symbols.)
fi
;;
esac

AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = "yes")

if test "$have_ld_version_script" = "yes"; then
    AC_MSG_CHECKING([for symbol prefix])
    SYMBOL_PREFIX=`echo "PREFIX=__USER_LABEL_PREFIX__" \
                   | ${CPP-${CC-gcc} -E} - 2>&1 \
                   | ${EGREP-grep} "^PREFIX=" \
                   | ${SED-sed} "s:^PREFIX=::"`
    AC_SUBST(SYMBOL_PREFIX)
    AC_MSG_RESULT($SYMBOL_PREFIX)
fi

# Substitutions for .in files
AC_SUBST(PNGLIB_VERSION)
AC_SUBST(PNGLIB_MAJOR)
AC_SUBST(PNGLIB_MINOR)
AC_SUBST(PNGLIB_RELEASE)

# Additional arguments (and substitutions)
# Allow the pkg-config directory to be set
AC_ARG_WITH(pkgconfigdir,
   AS_HELP_STRING([[[--with-pkgconfigdir]]],
      [Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
   [pkgconfigdir=${withval}],
   [pkgconfigdir='${libdir}/pkgconfig'])

AC_SUBST([pkgconfigdir])
AC_MSG_NOTICE([[pkgconfig directory is ${pkgconfigdir}]])

# Make the *-config binary config scripts optional
AC_ARG_WITH(binconfigs,
   AS_HELP_STRING([[[--with-binconfigs]]],
      [Generate shell libpng-config scripts as well as pkg-config data]
      [@<:@default=yes@:>@]),
   [if test "${withval}" = no; then
      binconfigs=
      AC_MSG_NOTICE([[libpng-config scripts will not be built]])
    else
      binconfigs='${binconfigs}'
    fi],
   [binconfigs='${binconfigs}'])
AC_SUBST([binconfigs])

# Support for prefixes to the API function names; this will generate defines
# at the start of the build to rename exported library functions
AC_ARG_WITH(libpng-prefix,
   AS_HELP_STRING([[[--with-libpng-prefix]]],
      [prefix libpng exported function (API) names with the given value]),
   [if test "${withval:-no}" != "no"; then
      AC_SUBST([PNG_PREFIX], [${withval}])
    fi])
AM_CONDITIONAL([DO_PNG_PREFIX], [test "${with_libpng_prefix:-no}" != "no"])

# Because GCC by default assembles code with an executable stack, even though it
# compiles C code with a non-executable stack, it is necessary to do a fixup
# here (this may by GCC specific)
AC_SUBST([AM_CCASFLAGS], [-Wa,--noexecstack])

AC_ARG_ENABLE([arm-neon],
   AS_HELP_STRING([[[--enable-arm-neon]]], [Enable ARM NEON optimizations]),
   [if test "${enableval}" = "yes"; then
      AC_DEFINE([PNG_ARM_NEON], [1], [Enable ARM NEON optimizations])
      AC_DEFINE([PNG_ALIGNED_MEMORY_SUPPORTED], [1], [Align row buffers])
    fi])
AM_CONDITIONAL([PNG_ARM_NEON], [test "${enable_arm_neon:-no}" = yes])

AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])

# Config files, substituting as above
AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
AC_CONFIG_FILES([libpng-config:libpng-config.in],
   [chmod +x libpng-config])

AC_OUTPUT