# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
# vim: set filetype=python:
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.


@depends(build_project, "--enable-smoosh")
def cbindgen_is_needed(build_project, js_enable_smoosh):
    if build_project != "js":
        # cbindgen is needed by the style system build and webrender.
        return True

    # cbindgen is needed by SmooshMonkey.
    return js_enable_smoosh


option(env="CBINDGEN", nargs=1, when=cbindgen_is_needed, help="Path to cbindgen")


@imports(_from="textwrap", _import="dedent")
def check_cbindgen_version(cbindgen, fatal=False):
    log.debug("trying cbindgen: %s" % cbindgen)

    cbindgen_min_version = Version("0.16.0")

    # cbindgen x.y.z
    version = Version(check_cmd_output(cbindgen, "--version").strip().split(" ")[1])
    log.debug("%s has version %s" % (cbindgen, version))
    if version >= cbindgen_min_version:
        return True
    if not fatal:
        return False

    die(
        dedent(
            """\
    cbindgen version {} is too old. At least version {} is required.

    Please update using 'cargo install cbindgen --force' or running
    './mach bootstrap', after removing the existing executable located at
    {}.
    """.format(
                version, cbindgen_min_version, cbindgen
            )
        )
    )


@depends_if(
    "CBINDGEN",
    bootstrap_search_path("cbindgen"),
    rust_search_path,
    when=cbindgen_is_needed,
)
@checking("for cbindgen")
@imports(_from="textwrap", _import="dedent")
def cbindgen(cbindgen_override, bootstrap_search_path, rust_search_path):
    if cbindgen_override:
        check_cbindgen_version(cbindgen_override[0], fatal=True)
        return cbindgen_override[0]

    candidates = []
    for path in bootstrap_search_path + rust_search_path:
        candidate = find_program("cbindgen", [path])
        if not candidate:
            continue
        if check_cbindgen_version(candidate):
            return candidate
        candidates.append(candidate)

    if not candidates:
        raise FatalCheckError(
            dedent(
                """\
        Cannot find cbindgen. Please run `mach bootstrap`,
        `cargo install cbindgen`, ensure that `cbindgen` is on your PATH,
        or point at an executable with `CBINDGEN`.
        """
            )
        )
    check_cbindgen_version(candidates[0], fatal=True)


set_config("CBINDGEN", cbindgen)

# Bindgen can use rustfmt to format Rust file, but it's not required.
option(env="RUSTFMT", nargs=1, help="Path to the rustfmt program")

rustfmt = check_prog(
    "RUSTFMT",
    ["rustfmt"],
    paths=rust_search_path,
    input="RUSTFMT",
    allow_missing=True,
)


option(
    "--with-libclang-path",
    nargs=1,
    help="Absolute path to a directory containing Clang/LLVM libraries for bindgen (version 3.9.x or above)",
)
option(
    "--with-clang-path",
    nargs=1,
    help="Absolute path to a Clang binary for bindgen (version 3.9.x or above)",
)


@depends(
    "--with-clang-path",
    c_compiler,
    cxx_compiler,
    clang_search_path,
    target,
    macos_sdk,
)
@checking("for clang for bindgen", lambda x: x.path if x else "not found")
def bindgen_clang_compiler(
    clang_path, c_compiler, cxx_compiler, clang_search_path, target, macos_sdk
):
    # When the target compiler is clang, use that, including flags.
    if cxx_compiler.type == "clang":
        if clang_path and clang_path[0] not in (
            c_compiler.compiler,
            cxx_compiler.compiler,
        ):
            die(
                "--with-clang-path is not valid when the target compiler is %s",
                cxx_compiler.type,
            )
        return namespace(
            path=cxx_compiler.compiler,
            flags=cxx_compiler.flags,
        )
    # When the target compiler is clang-cl, use clang in the same directory,
    # and figure the right flags to use.
    if cxx_compiler.type == "clang-cl":
        if clang_path and os.path.dirname(clang_path[0]) != os.path.dirname(
            cxx_compiler.compiler
        ):
            die(
                "--with-clang-path must point to clang in the same directory "
                "as the target compiler"
            )
        if not clang_path:
            clang_path = [os.path.join(os.path.dirname(cxx_compiler.compiler), "clang")]

    clang_path = find_program(
        clang_path[0] if clang_path else "clang++", clang_search_path
    )
    if not clang_path:
        return
    # Hack before bug 1617793: if the compiler is clang-cl, hack the target
    if cxx_compiler.type == "clang-cl":
        target = split_triplet("%s-pc-windows-msvc" % target.raw_cpu, allow_msvc=True)
    flags = prepare_flags(target, macos_sdk)
    info = check_compiler([clang_path] + flags, "C++", target)
    return namespace(
        path=clang_path,
        flags=flags + info.flags,
    )


@depends("--with-libclang-path", bindgen_clang_compiler, host_library_name_info, host)
@checking("for libclang for bindgen", lambda x: x if x else "not found")
@imports("glob")
@imports(_from="os", _import="pathsep")
@imports(_from="os.path", _import="split", _as="pathsplit")
@imports("re")
def bindgen_libclang_path(libclang_path, clang, library_name_info, host):
    if not clang:
        if libclang_path:
            die(
                "--with-libclang-path is not valid without a clang compiler "
                "for bindgen"
            )
        return

    # Try to ensure that the clang shared library that bindgen is going
    # to look for is actually present.  The files that we search for
    # mirror the logic in clang-sys/build.rs.
    libclang_choices = []
    if host.os == "WINNT":
        libclang_choices.append("libclang.dll")
    libclang_choices.append(
        "%sclang%s" % (library_name_info.dll.prefix, library_name_info.dll.suffix)
    )
    if host.kernel == "Linux":
        libclang_choices.append("libclang.so.*")

    if host.os == "OpenBSD":
        libclang_choices.append("libclang.so.*.*")

    candidates = []
    if not libclang_path:
        # Try to find libclang_path based on clang search dirs.
        clang_search_dirs = check_cmd_output(clang.path, "-print-search-dirs")
        for line in clang_search_dirs.splitlines():
            name, _, value = line.partition(": =")
            if host.os == "WINNT" and name == "programs":
                # On Windows, libclang.dll is in bin/ rather than lib/,
                # so scan the programs search dirs.
                # To make matters complicated, clang before version 9 uses `:`
                # separate between paths (and `;` in newer versions)
                if pathsep in value:
                    candidates.extend(value.split(pathsep))
                else:
                    for part in value.split(":"):
                        # Assume that if previous "candidate" was of length 1,
                        # it's a drive letter and the current part is the rest of
                        # the corresponding full path.
                        if candidates and len(candidates[-1]) == 1:
                            candidates[-1] += ":" + part
                        else:
                            candidates.append(part)
            elif host.os != "WINNT" and name == "libraries":
                # On other platforms, use the directories from the libraries
                # search dirs that looks like $something/clang/$version.
                for dir in value.split(pathsep):
                    dir, version = pathsplit(dir)
                    if re.match(r"[0-9.]+", version):
                        dir, name = pathsplit(dir)
                        if name == "clang":
                            candidates.append(dir)
    else:
        candidates.append(libclang_path[0])

    for dir in candidates:
        for pattern in libclang_choices:
            log.debug('Trying "%s" in "%s"', pattern, dir)
            libs = glob.glob(os.path.join(dir, pattern))
            if libs:
                return libs[0]


@depends(bindgen_clang_compiler, bindgen_libclang_path, build_project)
def bindgen_config_paths(clang, libclang, build_project):
    # XXX: we want this code to be run for both Gecko and JS, but we don't
    # necessarily want to force a bindgen/Rust dependency on JS just yet.
    # Actually, we don't want to force an error if we're not building the
    # browser generally.  We therefore whitelist the projects that require
    # bindgen facilities at this point and leave it at that.
    if build_project in ("browser", "mobile/android"):
        if not clang:
            die(
                "Could not find clang to generate run bindings for C/C++. "
                "Please install the necessary packages, run `mach bootstrap`, "
                "or use --with-clang-path to give the location of clang."
            )

        if not libclang:
            die(
                "Could not find libclang to generate rust bindings for C/C++. "
                "Please install the necessary packages, run `mach bootstrap`, "
                "or use --with-libclang-path to give the path containing it."
            )

    if clang and libclang:
        return namespace(
            libclang=libclang,
            libclang_path=os.path.dirname(libclang),
            clang_path=clang.path,
            clang_flags=clang.flags,
        )


@depends(bindgen_config_paths.libclang, when=bindgen_config_paths)
@checking("that libclang is new enough", lambda s: "yes" if s else "no")
@imports(_from="ctypes", _import="CDLL")
@imports(_from="textwrap", _import="dedent")
def min_libclang_version(libclang):
    try:
        lib = CDLL(libclang)
        # We want at least 5.0. The API we test below is enough for that.
        # Just accessing it should throw if not found.
        fun = lib.clang_getAddressSpace
        return True
    except:
        die(
            dedent(
                """\
        The libclang located at {} is too old (need at least 5.0).

        Please make sure to update it or point to a newer libclang using
        --with-libclang-path.
        """.format(
                    libclang
                )
            )
        )
        return False


set_config("MOZ_LIBCLANG_PATH", bindgen_config_paths.libclang_path)
set_config("MOZ_CLANG_PATH", bindgen_config_paths.clang_path)


@depends(
    target,
    target_is_unix,
    cxx_compiler,
    bindgen_cflags_android,
    bindgen_config_paths.clang_flags,
)
def basic_bindgen_cflags(target, is_unix, compiler_info, android_cflags, clang_flags):
    args = [
        "-x",
        "c++",
        "-fno-sized-deallocation",
        "-fno-aligned-new",
        "-DTRACING=1",
        "-DIMPL_LIBXUL",
        "-DMOZILLA_INTERNAL_API",
        "-DRUST_BINDGEN",
    ]

    if is_unix:
        args += ["-DOS_POSIX=1"]

    if target.os == "Android":
        args += android_cflags

    args += {
        "Android": ["-DOS_ANDROID=1"],
        "DragonFly": ["-DOS_BSD=1", "-DOS_DRAGONFLY=1"],
        "FreeBSD": ["-DOS_BSD=1", "-DOS_FREEBSD=1"],
        "GNU": ["-DOS_LINUX=1"],
        "NetBSD": ["-DOS_BSD=1", "-DOS_NETBSD=1"],
        "OpenBSD": ["-DOS_BSD=1", "-DOS_OPENBSD=1"],
        "OSX": ["-DOS_MACOSX=1", "-stdlib=libc++"],
        "SunOS": ["-DOS_SOLARIS=1"],
        "WINNT": [
            "-DOS_WIN=1",
            "-DWIN32=1",
        ],
    }.get(target.os, [])

    if compiler_info.type == "clang-cl":
        args += [
            # To enable the builtin __builtin_offsetof so that CRT wouldn't
            # use reinterpret_cast in offsetof() which is not allowed inside
            # static_assert().
            "-D_CRT_USE_BUILTIN_OFFSETOF",
            # Enable hidden attribute (which is not supported by MSVC and
            # thus not enabled by default with a MSVC-compatibile build)
            # to exclude hidden symbols from the generated file.
            "-DHAVE_VISIBILITY_HIDDEN_ATTRIBUTE=1",
        ]

    return args + (clang_flags or [])


option(
    env="BINDGEN_CFLAGS",
    nargs=1,
    help="Options bindgen should pass to the C/C++ parser",
)


@depends(basic_bindgen_cflags, "BINDGEN_CFLAGS")
@checking("bindgen cflags", lambda s: s if s else "no")
def bindgen_cflags(base_flags, extra_flags):
    flags = base_flags
    if extra_flags and len(extra_flags):
        flags += extra_flags[0].split()
    return " ".join(flags)


add_old_configure_assignment("_BINDGEN_CFLAGS", bindgen_cflags)