dnl
dnl Configuration script for PDFio
dnl
dnl Copyright © 2023 by Michael R Sweet
dnl
dnl Licensed under Apache License v2.0.  See the file "LICENSE" for more
dnl information.
dnl

dnl ***********************************************************************
dnl
dnl Note: Using autoheader or automake on this project will break the PDFio
dnl build system.  Use "autoconf -f" to regenerate the configure script if
dnl you make changes to this file.
dnl
dnl ***********************************************************************


dnl We need at least autoconf 2.70 for --runstatedir...
AC_PREREQ([2.70])


dnl Package name and version...
AC_INIT([pdfio], [1.2.0], [https://github.com/michaelrsweet/pdfio/issues], [pdfio], [https://www.msweet.org/pdfio])

PDFIO_VERSION="AC_PACKAGE_VERSION"
PDFIO_VERSION_MAJOR="`echo AC_PACKAGE_VERSION | awk -F. '{print $1}'`"
PDFIO_VERSION_MINOR="`echo AC_PACKAGE_VERSION | awk -F. '{printf("%d\n",$2);}'`"
AC_SUBST([PDFIO_VERSION])
AC_SUBST([PDFIO_VERSION_MAJOR])
AC_SUBST([PDFIO_VERSION_MINOR])


dnl This line is provided to ensure that you don't run the autoheader program
dnl against this project.  Doing so is completely unsupported and WILL cause
dnl problems!
AH_TOP([#error "Somebody ran autoheader on this project which is unsupported and WILL cause problems."])


dnl Get the build and host platforms and split the host_os value
AC_CANONICAL_BUILD
AC_CANONICAL_HOST

[host_os_name="$(echo $host_os | sed -e '1,$s/[0-9.]*$//g')"]
[host_os_version="$(echo $host_os | sed -e '1,$s/^[^0-9.]*//g' | awk -F. '{print $1 $2}')"]
# Linux often does not yield an OS version we can use...
AS_IF([test "x$host_os_version" = x], [
    host_os_version="0"
])


dnl Compiler options...
CFLAGS="${CFLAGS:=}"
CPPFLAGS="${CPPFLAGS:=}"
DSOFLAGS="${DSOFLAGS:=}"
LDFLAGS="${LDFLAGS:=}"
LIBS="${LIBS:=}"
OPTIM="${OPTIM:=}"

AC_SUBST([DSOFLAGS])
AC_SUBST([OPTIM])


dnl Standard programs...
AC_PROG_CC
AC_PROG_RANLIB
AC_PATH_PROG([AR], [ar])
AC_PATH_PROGS([CODE_SIGN], [codesign true])
AC_PATH_PROG([MKDIR], [mkdir])
AC_PATH_PROG([RM], [rm])
AC_PATH_PROG([RMDIR], [rmdir])
AC_PATH_PROG([LN], [ln])


dnl Figure out the correct "ar" command flags...
AS_IF([test "$ac_cv_prog_ranlib" = ":"], [
    ARFLAGS="crs"
], [
    ARFLAGS="cr"
])
AC_SUBST([ARFLAGS])


dnl install-sh
AC_MSG_CHECKING([for install-sh script])
INSTALL="$(pwd)/install-sh"
AC_SUBST([INSTALL])
AC_MSG_RESULT([using $INSTALL])


dnl Check for pkg-config, which is used for some other tests later on...
AC_PATH_TOOL([PKGCONFIG], [pkg-config])

PKGCONFIG_CFLAGS="-I\${includedir}"
PKGCONFIG_LIBS="-L\${libdir} -lpdfio"
PKGCONFIG_LIBS_PRIVATE="-lm"
PKGCONFIG_REQUIRES="zlib"
AC_SUBST([PKGCONFIG_CFLAGS])
AC_SUBST([PKGCONFIG_LIBS])
AC_SUBST([PKGCONFIG_LIBS_PRIVATE])
AC_SUBST([PKGCONFIG_REQUIRES])


dnl ZLIB
AC_MSG_CHECKING([for zlib via pkg-config])
AS_IF([$PKCONFIG --exists zlib], [
    AC_MSG_RESULT([yes])
    LIBS="$($PKGCONFIG --libs zlib) $LIBS"
    CPPFLAGS="$($PKGCONFIG --cflags zlib) $CPPFLAGS"
],[
    AC_MSG_RESULT([no])
    AC_CHECK_HEADER([zlib.h])
    AC_CHECK_LIB([z], [inflateCopy])

    AS_IF([test x$ac_cv_header_zlib_h != xyes -o x$ac_cv_lib_z_inflateCopy != xyes], [
	AC_MSG_ERROR([Sorry, this software requires zlib 1.1 or higher.])
    ])

    PKGCONFIG_LIBS_PRIVATE="-lz $PKGCONFIG_LIBS_PRIVATE"
])


dnl Library target...
AC_ARG_ENABLE([static], AS_HELP_STRING([--disable-static], [do not install static library]))
AC_ARG_ENABLE([shared], AS_HELP_STRING([--enable-shared], [install shared library]))

AS_IF([test x$enable_shared = xyes], [
    AS_IF([test "$host_os_name" = darwin], [
	LIBPDFIO="libpdfio.1.dylib"
    ], [
	LIBPDFIO="libpdfio.so.1"
    ])

    AS_IF([test x$enable_static != xno], [
        LIBPDFIO_STATIC="libpdfio.a"
    ], [
	LIBPDFIO_STATIC=""
    ])
], [
    LIBPDFIO="libpdfio.a"
    LIBPDFIO_STATIC=""
    PKGCONFIG_LIBS="$PKGCONFIG_LIBS $PKGCONFIG_LIBS_PRIVATE"
    PKGCONFIG_LIBS_PRIVATE=""
])

AC_SUBST([LIBPDFIO])
AC_SUBST([LIBPDFIO_STATIC])


dnl Extra compiler options...
AC_ARG_ENABLE([debug], AS_HELP_STRING([--enable-debug], [turn on debugging, default=no]))
AC_ARG_ENABLE([maintainer], AS_HELP_STRING([--enable-maintainer], [turn on maintainer mode, default=no]))
AC_ARG_ENABLE([sanitizer], AS_HELP_STRING([--enable-sanitizer], [build with AddressSanitizer, default=no]))

AS_IF([test x$enable_debug = xyes], [
    OPTIM="$OPTIM -g"
    CSFLAGS=""
], [
    OPTIM="$OPTIM -g -Os"
    CSFLAGS="-o runtime"
])

AC_SUBST([CSFLAGS])

WARNINGS=""
AC_SUBST([WARNINGS])

AS_IF([test -n "$GCC"], [
    AS_IF([test x$enable_sanitizer = xyes], [
	# Use -fsanitize=address with debugging...
	OPTIM="$OPTIM -fsanitize=address"
    ], [
	# Otherwise use the Fortify enhancements to catch any unbounded
	# string operations...
	CPPFLAGS="$CPPFLAGS -D_FORTIFY_SOURCE=2"
    ])

    dnl Show all standard warnings + unused variables when compiling...
    WARNINGS="-Wall -Wunused"

    dnl Drop some not-useful/unreliable warnings...
    for warning in char-subscripts format-truncation format-y2k switch unused-result; do
	AC_MSG_CHECKING([whether compiler supports -Wno-$warning])

	OLDCFLAGS="$CFLAGS"
	CFLAGS="$CFLAGS -Wno-$warning -Werror"

	AC_COMPILE_IFELSE([AC_LANG_PROGRAM()], [
	    AC_MSG_RESULT(yes)
	    WARNINGS="$WARNINGS -Wno-$warning"
        ], [
	    AC_MSG_RESULT(no)
	])

	CFLAGS="$OLDCFLAGS"
    done

    dnl Maintainer mode enables -Werror...
    AS_IF([test x$enable_maintainer = xyes], [
	WARNINGS="$WARNINGS -Werror -Wno-error=deprecated"
    ])

    dnl See if PIE options are supported...
    AC_MSG_CHECKING(whether compiler supports -fPIE)
    OLDCFLAGS="$CFLAGS"
    AS_CASE(["$host_os_name"],
    [darwin*], [
	CFLAGS="$CFLAGS -fPIC -fPIE -Wl,-pie"
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[
	    OLDCFLAGS="-fPIC $OLDCFLAGS"
	    LDFLAGS="-fPIE -Wl,-pie $LDFLAGS"
	    AC_MSG_RESULT(yes)
	],[
	    AC_MSG_RESULT(no)
	])
    ], [*], [
	CFLAGS="$CFLAGS -fPIC -fPIE -pie"
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[
	    OLDCFLAGS="-fPIC $OLDCFLAGS"
	    LDFLAGS="-fPIE -pie $LDFLAGS"
	    AC_MSG_RESULT(yes)
	],[
	    AC_MSG_RESULT(no)
	])
    ])
    CFLAGS="$OLDCFLAGS"

    dnl OS-specific compiler options...
    AC_MSG_CHECKING([for OS-specific compiler options])
    AS_CASE(["$host_os_name"], [linux*], [
    	# Make sure we get the full set of 64-bit Linux APIs from the headers...
	CPPFLAGS="$CPPFLAGS -D__USE_MISC -D_GNU_SOURCE -D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64"

	# Mark read-only sections as relocatable to random addresses...
	LDFLAGS="$LDFLAGS -Wl,-z,relro,-z,now"

        AC_MSG_RESULT([-D__USE_MISC -D_GNU_SOURCE -D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64 -Wl,-z,relro,-z,now])
    ], [darwin*], [
        # When not building for debug, target macOS 11 or later, "universal"
        # binaries when possible...
        AS_IF([echo "$CPPFLAGS $CFLAGS $LDFLAGS $OPTIM" | grep -q "\\-arch "], [
            # Don't add architecture/min-version flags if they are already present
            AC_MSG_RESULT([none])
        ], [echo "$CPPFLAGS $CFLAGS $LDFLAGS $OPTIM" | grep -q "\\-mmacosx-version-"], [
            # Don't add architecture/min-version flags if they are already present
            AC_MSG_RESULT([none])
        ], [test "$host_os_version" -ge 200 -a x$enable_debug != xyes], [
	    # macOS 11.0 and higher support the Apple Silicon (arm64) CPUs
	    OPTIM="$OPTIM -mmacosx-version-min=11.0 -arch x86_64 -arch arm64"
            AC_MSG_RESULT([-mmacosx-version-min=11.0 -arch x86_64 -arch arm64])
	], [
	    # Don't add architecture/min-version flags if debug enabled
            AC_MSG_RESULT([none])
	])
    ], [*], [
        AC_MSG_RESULT([none])
    ])
])


dnl Extra linker options...
AC_ARG_WITH([dsoflags], AS_HELP_STRING([--with-dsoflags=...], [Specify additional DSOFLAGS]), [
    DSOFLAGS="$withval $DSOFLAGS"
])
AC_ARG_WITH([ldflags], AS_HELP_STRING([--with-ldflags=...], [Specify additional LDFLAGS]), [
    LDFLAGS="$withval $LDFLAGS"
])


dnl Generate the Makefile and pkg-config file...
AC_CONFIG_FILES([Makefile pdfio.pc])
AC_OUTPUT