# The name, version, and maintainer of this package
AC_INIT([freedom-metal], [m4_esyscmd_s([./scripts/git-version])], [https://github.com/sifive/freedom-metal/issues], [freedom-metal], [https://github.com/sifive/freedom-metal])

# Initializes automake, enabling maintainer mode by default (which should be
# disabled by the archive generated by "make dist").
AM_INIT_AUTOMAKE([foreign subdir-objects])
AM_MAINTAINER_MODE([disable])
AC_CONFIG_MACRO_DIRS([m4])

# This library is actually an integral part of the toolchain build process on
# METAL toolchains as it's necessary to link any program.  To prevent this from
# causing every autoconf test failing we instead place some weak symbols in
# confdefs.h to trick the toolchain into linking.
#
#AC_CANONICAL_HOST -- for now don't canonicalize the host because the *-metal
#                     tuples aren't upstream in config.*
case "${host_alias}" in
*-metal)
    AS_ECHO("long metal_segment_stack_end __attribute__((weak));") >> confdefs.h
    AS_ECHO("long metal_segment_data_source_start __attribute__((weak));") >> confdefs.h
    AS_ECHO("long metal_segment_data_source_end __attribute__((weak));") >> confdefs.h
    AS_ECHO("long metal_segment_data_target_start __attribute__((weak));") >> confdefs.h
    AS_ECHO("long metal_segment_data_target_end __attribute__((weak));") >> confdefs.h
    AS_ECHO("long metal_segment_bss_target_start __attribute__((weak));") >> confdefs.h
    AS_ECHO("long metal_segment_bss_target_end __attribute__((weak));") >> confdefs.h
    AS_ECHO("void metal_shutdown(void) __attribute__((weak)); void metal_shutdown(void) {}") >> confdefs.h
    ;;
esac

# Probe for tools that we need in order to build.
AC_PROG_CC
AC_PROG_RANLIB
AM_PROG_AR
AM_PROG_AS

# autoconf tries very hard to avoid failing, so it'll even go ahead and try to
# build the project using "gcc" if it can't find a suitable C compiler prefixed
# by the host system.  This doesn't work when cross compiling, but it's a
# common error for users so we explicitly check for this right here to quickly
# provide an error message.
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[
#ifndef __riscv
# error "A RISC-V compiler is required to build the Freedom MBI"
#endif
])], [], [AC_MSG_FAILURE([The C compiler doesn't define __riscv, which means it's probably not a RISC-V compiler.  You should specify something like --host=riscv64-sifive-elf when building this, as it will only work on RISC-V systems.])])

########################################################
# Generic Options
########################################################

# Allows users to specify some device tree information.
AC_ARG_WITH([machine-name],
    [AS_HELP_STRING([--with-machine-name=NAME], [Install this machine with a particular name])],
    [],
    [with_machine_name="no"]
)

AS_IF([test "x$with_machine_name" != "xno"],
    [AC_SUBST([MACHINE_NAME], "$with_machine_name")],
    [AC_MSG_FAILURE([--with-machine-name is required])]
)

AC_ARG_WITH([preconfigured],
    [AS_HELP_STRING([--with-preconfigured], [Use pre-configured machine support files instead of generating them during the build])],
    [with_preconfigured="yes"],
    [with_preconfigured="no"]
)

AC_ARG_WITH([builtin-libgloss],
    [AS_HELP_STRING([--with-bultin-libgloss], [Build libgloss along with the METAL])],
    [with_builtin_libgloss="yes"],
    [with_builtin_libgloss="no"]
)

AM_CONDITIONAL([WITH_BUILTIN_LIBGLOSS], [test "x$with_builtin_libgloss" = "xyes"])

########################################################
# Preconfigured Options (--with-preconfigured)
########################################################

AC_ARG_WITH([machine-header],
    [AS_HELP_STRING([--with-machine-header=PATH], [Path to the machine header file])],
    [],
    [with_machine_header="no"]
)

AC_ARG_WITH([machine-inline],
    [AS_HELP_STRING([--with-machine-inline=PATH], [Path to the machine inline file])],
    [],
    [with_machine_inline="no"]
)

AC_ARG_WITH([platform-header],
    [AS_HELP_STRING([--with-platform-header=PATH], [Path to the platform header file])],
    [],
    [with_platform_header="no"]
)

AC_ARG_WITH([machine-ldscript],
    [AS_HELP_STRING([--with-machine-ldscript=PATH], [Path to the machine ldscript])],
    [],
    [with_machine_ldscript="no"]
)

########################################################
# Configuration Options (--without-preconfigured)
########################################################

AC_ARG_WITH([machine-dts],
    [AS_HELP_STRING([--with-machine-dts=PATH], [The full path to the device tree])],
    [],
    [with_machine_dts="no"]
)

# Allows users to specify a path to DTC
AC_ARG_WITH([dtc],
    [AS_HELP_STRING([--with-dtc=PATH], [Use the given path to the device tree compiler])],
    [],
    [with_dtc=check]
)

AC_ARG_VAR(DTC, [The absolute path to dtc])

# Allows users to specify a path to freedom-metal_header-generator, which
# generates METAL paramaterization headers from the device tree.
AC_ARG_WITH([metal-header-generator],
    [AS_HELP_STRING([--with-metal-header-generator=PATH], [Use the given path to freedom-metal_header-generator])],
    [],
    [with_metal_header_generator=check]
)

AC_ARG_VAR(METAL_HEADER_GENERATOR, [The absolute path of the freedom-metal_header-generator])

AC_ARG_WITH([platform-header-generator],
    [AS_HELP_STRING([--with-platform-header-generator=PATH], [Use the given path to freedom-platform_header-generator])],
    [],
    [with_platform_header_generator=check]
)

AC_ARG_VAR(BARE_HEADER_GENERATOR, [The absolute path of the freedom-platform_header-generator])

# Allows users to specify a path to freedom-ldscript-generator, which generates
# linker scripts that are more suitable for embedded development than the
# default linker script is.  This allows the tests to link using the actual
# linker script.
AC_ARG_WITH([ldscript-generator],
    [AS_HELP_STRING([--with-ldscript-generator=PATH], [Use the given path to freedom-ldscript-generator])],
    [],
    [with_ldscript_generator=check]
)

AC_ARG_VAR(LDSCRIPT_GENERATOR, [The absolute path of the freedom-ldscript-generator])

# Allows users to specify a path to freedom-makeattributes-generator, which
# generates makefile fragments that help set up the various CFLAGS that are
# required to target a machine.
AC_ARG_WITH([makeattributes-generator],
    [AS_HELP_STRING([--with-makeattributes-generator=PATH], [Use the given path to freedom-makeattributes-generator])],
    [],
    [with_makeattributes_generator=check]
)

AC_ARG_VAR(MAKEATTRIBUTES_GENERATOR, [The absolute path of the freedom-makeattributes-generator])

# Allows users to specify a path to freedom-metal_specs-generator, which
# generates GCC spec files to control the compilation of METAL based targets.
AC_ARG_WITH([metal_specs-generator],
    [AS_HELP_STRING([--with-metal_specs-generator=PATH], [Use the given path to freedom-metal_specs-generator])],
    [],
    [with_metal_specs_generator=check]
)

AC_ARG_VAR(SPECS_GENERATOR, [The absolute path of the freedom-metal_specs-generator])

########################################################
# Process the Preconfigured or Configured options
########################################################


AM_CONDITIONAL([PRECONFIGURED], [test "x$with_preconfigured" = "xyes"])

AS_IF([test "x$with_preconfigured" = "xyes"],
[
    # Configure the build system to pass in the preconfigured machine support files
    AS_IF([test "x$with_machine_header" != "xno"],
        [AC_SUBST([MACHINE_HEADER], "$with_machine_header")],
        [AC_MSG_FAILURE([--with-machine-header is required with the --with-preconfigured option])]
    )

    AS_IF([test "x$with_machine_inline" != "xno"],
        [AC_SUBST([MACHINE_INLINE], "$with_machine_inline")],
        [AC_MSG_FAILURE([--with-machine-inline is required with the --with-preconfigured option])]
    )

    AS_IF([test "x$with_platform_header" != "xno"],
        [AC_SUBST([PLATFORM_HEADER], "$with_platform_header")],
        [AC_MSG_FAILURE([--with-platform-header is required with the --with-preconfigured option])]
    )

    AS_IF([test "x$with_machine_ldscript" != "xno"],
        [AC_SUBST([MACHINE_LDSCRIPT], "$with_machine_ldscript")],
        [AC_MSG_FAILURE([--with-machine-ldscript is required with the --with-preconfigured option])]
    )

    AC_SUBST([MAKEATTRIBUTES_GENERATOR], [false])
    AC_SUBST([SPECS_GENERATOR], [false])
], [
    # Configure the build system to generate the machine support files during build
    AS_IF([test "x$with_machine_dts" != "xno"],
        [AC_SUBST([MACHINE_DTS], "$with_machine_dts")],
        [AC_MSG_FAILURE([--with-machine-dts is required])]
    )

    AS_IF([test "x$with_dtc" == "xcheck"],
        [AC_PATH_PROG(DTC, dtc, [no])],
        [DTC="$with_dtc"]
    )
    AS_IF([test "x$DTC" != "xno"],
        [AC_SUBST([DTC], "$DTC")],
        [AC_MSG_ERROR([Unable to find dtc, either place it in PATH or try the --with-dtc argument.])]
    )

    AS_IF([test "x$with_metal_header_generator" == "xcheck"],
        [AC_PATH_PROG(METAL_HEADER_GENERATOR, freedom-metal_header-generator, [no])],
        [METAL_HEADER_GENERATOR=$with_metal_header_generator]
    )
    AS_IF([test "x$METAL_HEADER_GENERATOR" != "xno"],
        [AC_SUBST([METAL_HEADER_GENERATOR], "$METAL_HEADER_GENERATOR")],
        [AC_MSG_ERROR([Unable to find freedom-metal_header-generator, either place it in PATH or try the --with-metal-header-generator argument.])]
    )

    AS_IF([test "x$with_ldscript_generator" == "xcheck"],
        [AC_PATH_PROG(LDSCRIPT_GENERATOR, freedom-ldscript-generator, [no])],
        [LDSCRIPT_GENERATOR=$with_ldscript_generator]
    )
    AS_IF([test "x$LDSCRIPT_GENERATOR" != "xno"],
        [AC_SUBST([LDSCRIPT_GENERATOR], "$LDSCRIPT_GENERATOR")],
        [AC_MSG_ERROR([Unable to find freedom-ldscript-generator, either place it in PATH or try the --with-ldscript-generator argument.])]
    )

    AS_IF([test "x$with_makeattributes_generator" == "xcheck"],
        [AC_PATH_PROG(MAKEATTRIBUTES_GENERATOR, freedom-makeattributes-generator, [no])],
        [MAKEATTRIBUTES_GENERATOR=$with_makeattributes_generator]
    )
    AS_IF([test "x$MAKEATTRIBUTES_GENERATOR" != "xno"],
        [AC_SUBST([MAKEATTRIBUTES_GENERATOR], "$MAKEATTRIBUTES_GENERATOR")],
        [AC_MSG_ERROR([Unable to find freedom-makeattributes-generator, either place it in PATH or try the --with-makeattributes-generator argument.])]
    )

    AS_IF([test "x$with_metal_specs_generator" == "xcheck"],
        [AC_PATH_PROG(SPECS_GENERATOR, freedom-metal_specs-generator, [no])],
        [SPECS_GENERATOR=$with_metal_specs_generator]
    )
    AS_IF([test "x$SPECS_GENERATOR" != "xno"],
        [AC_SUBST([SPECS_GENERATOR], "$SPECS_GENERATOR")],
        [AC_MSG_ERROR([Unable to find freedom-metal_specs-generator, either place it in PATH or try the --with-metal_specs-generator argument.])]
    )
])

# Check for the additional compiler flags provided by the METAL toolchains,
# directly substituting in the relevant 
AX_CHECK_COMPILE_FLAG([mmachine=$machine_name],
    [mmachine_machine_name="-mmachine=$machine_name"],
)

AC_SUBST([MMACHINE_MACHINE_NAME], "$mmachine_machine_name")

AX_CHECK_COMPILE_FLAG([menv=metal],
    [menv_metal="-menv=metal"],
    [menv_metal="-lriscv_metal_$machine_name"]
)

AC_SUBST([MENV_METAL], "$menv_metal")

# Generates the remainder of the build system.
AC_CONFIG_FILES([Makefile])
AC_OUTPUT