godot/SConstruct

#!/usr/bin/env python

EnsureSConsVersion(3, 0, 0)
EnsurePythonVersion(3, 5)

# System
import glob
import os
import pickle
import sys

# Local
import methods
import gles_builders
import version
from platform_methods import run_in_subprocess

# Scan possible build platforms

platform_list = []  # list of platforms
platform_opts = {}  # options for each platform
platform_flags = {}  # flags for each platform

active_platforms = []
active_platform_ids = []
platform_exporters = []
platform_apis = []

for x in sorted(glob.glob("platform/*")):
    if not os.path.isdir(x) or not os.path.exists(x + "/detect.py"):
        continue
    tmppath = "./" + x

    sys.path.insert(0, tmppath)
    import detect

    if os.path.exists(x + "/export/export.cpp"):
        platform_exporters.append(x[9:])
    if os.path.exists(x + "/api/api.cpp"):
        platform_apis.append(x[9:])
    if detect.is_active():
        active_platforms.append(detect.get_name())
        active_platform_ids.append(x)
    if detect.can_build():
        x = x.replace("platform/", "")  # rest of world
        x = x.replace("platform\\", "")  # win32
        platform_list += [x]
        platform_opts[x] = detect.get_opts()
        platform_flags[x] = detect.get_flags()
    sys.path.remove(tmppath)
    sys.modules.pop("detect")

module_list = methods.detect_modules()

methods.save_active_platforms(active_platforms, active_platform_ids)

custom_tools = ["default"]

platform_arg = ARGUMENTS.get("platform", ARGUMENTS.get("p", False))

if os.name == "nt" and (platform_arg == "android" or ARGUMENTS.get("use_mingw", False)):
    custom_tools = ["mingw"]
elif platform_arg == "javascript":
    # Use generic POSIX build toolchain for Emscripten.
    custom_tools = ["cc", "c++", "ar", "link", "textfile", "zip"]

env_base = Environment(tools=custom_tools)
if "TERM" in os.environ:
    env_base["ENV"]["TERM"] = os.environ["TERM"]
env_base.AppendENVPath("PATH", os.getenv("PATH"))
env_base.AppendENVPath("PKG_CONFIG_PATH", os.getenv("PKG_CONFIG_PATH"))
env_base.disabled_modules = []
env_base.use_ptrcall = False
env_base.module_version_string = ""
env_base.msvc = False
env_base.stable_release = version.status == "stable"

env_base.__class__.disable_module = methods.disable_module

env_base.__class__.add_module_version_string = methods.add_module_version_string

env_base.__class__.add_source_files = methods.add_source_files
env_base.__class__.use_windows_spawn_fix = methods.use_windows_spawn_fix

env_base.__class__.add_shared_library = methods.add_shared_library
env_base.__class__.add_library = methods.add_library
env_base.__class__.add_program = methods.add_program
env_base.__class__.CommandNoCache = methods.CommandNoCache
env_base.__class__.disable_warnings = methods.disable_warnings

env_base["x86_libtheora_opt_gcc"] = False
env_base["x86_libtheora_opt_vc"] = False

# avoid issues when building with different versions of python out of the same directory
env_base.SConsignFile(".sconsign{0}.dblite".format(pickle.HIGHEST_PROTOCOL))

# Build options

customs = ["custom.py"]

profile = ARGUMENTS.get("profile", False)
if profile:
    if os.path.isfile(profile):
        customs.append(profile)
    elif os.path.isfile(profile + ".py"):
        customs.append(profile + ".py")

opts = Variables(customs, ARGUMENTS)

# Target build options
opts.Add("arch", "Platform-dependent architecture (arm/arm64/x86/x64/mips/...)", "")
opts.Add(EnumVariable("bits", "Target platform bits", "default", ("default", "32", "64")))
opts.Add("p", "Platform (alias for 'platform')", "")
opts.Add("platform", "Target platform (%s)" % ("|".join(platform_list),), "")
opts.Add(EnumVariable("target", "Compilation target", "debug", ("debug", "release_debug", "release")))
opts.Add(EnumVariable("optimize", "Optimization type", "speed", ("speed", "size")))

opts.Add(BoolVariable("tools", "Build the tools (a.k.a. the Godot editor)", True))
opts.Add(BoolVariable("use_lto", "Use link-time optimization", False))
opts.Add(BoolVariable("use_precise_math_checks", "Math checks use very precise epsilon (debug option)", False))

# Components
opts.Add(BoolVariable("deprecated", "Enable deprecated features", True))
opts.Add(BoolVariable("minizip", "Enable ZIP archive support using minizip", True))
opts.Add(BoolVariable("xaudio2", "Enable the XAudio2 audio driver", False))

# Advanced options
opts.Add(BoolVariable("verbose", "Enable verbose output for the compilation", False))
opts.Add(BoolVariable("progress", "Show a progress indicator during compilation", True))
opts.Add(EnumVariable("warnings", "Level of compilation warnings", "all", ("extra", "all", "moderate", "no")))
opts.Add(BoolVariable("werror", "Treat compiler warnings as errors", not env_base.stable_release))
opts.Add(BoolVariable("dev", "If yes, alias for verbose=yes warnings=extra werror=yes", False))
opts.Add("extra_suffix", "Custom extra suffix added to the base filename of all generated binary files", "")
opts.Add(BoolVariable("vsproj", "Generate a Visual Studio solution", False))
opts.Add(EnumVariable("macports_clang", "Build using Clang from MacPorts", "no", ("no", "5.0", "devel")))
opts.Add(BoolVariable("disable_3d", "Disable 3D nodes for a smaller executable", False))
opts.Add(BoolVariable("disable_advanced_gui", "Disable advanced GUI nodes and behaviors", False))
opts.Add(BoolVariable("no_editor_splash", "Don't use the custom splash screen for the editor", False))
opts.Add("system_certs_path", "Use this path as SSL certificates default for editor (for package maintainers)", "")

# Thirdparty libraries
# opts.Add(BoolVariable('builtin_assimp', "Use the built-in Assimp library", True))
opts.Add(BoolVariable("builtin_bullet", "Use the built-in Bullet library", True))
opts.Add(BoolVariable("builtin_certs", "Use the built-in SSL certificates bundles", True))
opts.Add(BoolVariable("builtin_enet", "Use the built-in ENet library", True))
opts.Add(BoolVariable("builtin_freetype", "Use the built-in FreeType library", True))
opts.Add(BoolVariable("builtin_glslang", "Use the built-in glslang library", True))
opts.Add(BoolVariable("builtin_libogg", "Use the built-in libogg library", True))
opts.Add(BoolVariable("builtin_libpng", "Use the built-in libpng library", True))
opts.Add(BoolVariable("builtin_libtheora", "Use the built-in libtheora library", True))
opts.Add(BoolVariable("builtin_libvorbis", "Use the built-in libvorbis library", True))
opts.Add(BoolVariable("builtin_libvpx", "Use the built-in libvpx library", True))
opts.Add(BoolVariable("builtin_libwebp", "Use the built-in libwebp library", True))
opts.Add(BoolVariable("builtin_wslay", "Use the built-in wslay library", True))
opts.Add(BoolVariable("builtin_mbedtls", "Use the built-in mbedTLS library", True))
opts.Add(BoolVariable("builtin_miniupnpc", "Use the built-in miniupnpc library", True))
opts.Add(BoolVariable("builtin_opus", "Use the built-in Opus library", True))
opts.Add(BoolVariable("builtin_pcre2", "Use the built-in PCRE2 library", True))
opts.Add(BoolVariable("builtin_pcre2_with_jit", "Use JIT compiler for the built-in PCRE2 library", True))
opts.Add(BoolVariable("builtin_recast", "Use the built-in Recast library", True))
opts.Add(BoolVariable("builtin_rvo2", "Use the built-in RVO2 library", True))
opts.Add(BoolVariable("builtin_squish", "Use the built-in squish library", True))
opts.Add(BoolVariable("builtin_vulkan", "Use the built-in Vulkan loader library and headers", True))
opts.Add(BoolVariable("builtin_xatlas", "Use the built-in xatlas library", True))
opts.Add(BoolVariable("builtin_zlib", "Use the built-in zlib library", True))
opts.Add(BoolVariable("builtin_zstd", "Use the built-in Zstd library", True))

# Compilation environment setup
opts.Add("CXX", "C++ compiler")
opts.Add("CC", "C compiler")
opts.Add("LINK", "Linker")
opts.Add("CCFLAGS", "Custom flags for both the C and C++ compilers")
opts.Add("CFLAGS", "Custom flags for the C compiler")
opts.Add("CXXFLAGS", "Custom flags for the C++ compiler")
opts.Add("LINKFLAGS", "Custom flags for the linker")

# add platform specific options

for k in platform_opts.keys():
    opt_list = platform_opts[k]
    for o in opt_list:
        opts.Add(o)

for x in module_list:
    module_enabled = True
    tmppath = "./modules/" + x
    sys.path.insert(0, tmppath)
    import config

    enabled_attr = getattr(config, "is_enabled", None)
    if callable(enabled_attr) and not config.is_enabled():
        module_enabled = False
    sys.path.remove(tmppath)
    sys.modules.pop("config")
    opts.Add(BoolVariable("module_" + x + "_enabled", "Enable module '%s'" % (x,), module_enabled))

opts.Update(env_base)  # update environment
Help(opts.GenerateHelpText(env_base))  # generate help

# add default include paths

env_base.Prepend(CPPPATH=["#"])

# configure ENV for platform
env_base.platform_exporters = platform_exporters
env_base.platform_apis = platform_apis

if env_base["use_precise_math_checks"]:
    env_base.Append(CPPDEFINES=["PRECISE_MATH_CHECKS"])

if env_base["target"] == "debug":
    env_base.Append(CPPDEFINES=["DEBUG_MEMORY_ALLOC", "DISABLE_FORCED_INLINE"])

    # The two options below speed up incremental builds, but reduce the certainty that all files
    # will properly be rebuilt. As such, we only enable them for debug (dev) builds, not release.

    # To decide whether to rebuild a file, use the MD5 sum only if the timestamp has changed.
    # http://scons.org/doc/production/HTML/scons-user/ch06.html#idm139837621851792
    env_base.Decider("MD5-timestamp")
    # Use cached implicit dependencies by default. Can be overridden by specifying `--implicit-deps-changed` in the command line.
    # http://scons.org/doc/production/HTML/scons-user/ch06s04.html
    env_base.SetOption("implicit_cache", 1)

if env_base["no_editor_splash"]:
    env_base.Append(CPPDEFINES=["NO_EDITOR_SPLASH"])

if not env_base["deprecated"]:
    env_base.Append(CPPDEFINES=["DISABLE_DEPRECATED"])

env_base.platforms = {}

selected_platform = ""

if env_base["platform"] != "":
    selected_platform = env_base["platform"]
elif env_base["p"] != "":
    selected_platform = env_base["p"]
    env_base["platform"] = selected_platform
else:
    # Missing `platform` argument, try to detect platform automatically
    if sys.platform.startswith("linux"):
        selected_platform = "linuxbsd"
    elif sys.platform == "darwin":
        selected_platform = "osx"
    elif sys.platform == "win32":
        selected_platform = "windows"
    else:
        print("Could not detect platform automatically. Supported platforms:")
        for x in platform_list:
            print("\t" + x)
        print("\nPlease run SCons again and select a valid platform: platform=<string>")

    if selected_platform != "":
        print("Automatically detected platform: " + selected_platform)
        env_base["platform"] = selected_platform

if selected_platform in ["linux", "bsd", "x11"]:
    if selected_platform == "x11":
        # Deprecated alias kept for compatibility.
        print('Platform "x11" has been renamed to "linuxbsd" in Godot 4.0. Building for platform "linuxbsd".')
    # Alias for convenience.
    selected_platform = "linuxbsd"
    env_base["platform"] = selected_platform

if selected_platform in platform_list:
    tmppath = "./platform/" + selected_platform
    sys.path.insert(0, tmppath)
    import detect

    if "create" in dir(detect):
        env = detect.create(env_base)
    else:
        env = env_base.Clone()

    # Custom tools are loaded automatically by SCons from site_scons/site_tools,
    # but we want to use a different folder, so we register it manually.
    from SCons.Script.Main import _load_site_scons_dir

    _load_site_scons_dir(".", "misc/scons")

    env.Tool("compilation_db")
    env.Alias("compiledb", env.CompilationDatabase("compile_commands.json"))

    if env["dev"]:
        env["verbose"] = True
        env["warnings"] = "extra"
        env["werror"] = True

    if env["vsproj"]:
        env.vs_incs = []
        env.vs_srcs = []

        def AddToVSProject(sources):
            for x in sources:
                if type(x) == type(""):
                    fname = env.File(x).path
                else:
                    fname = env.File(x)[0].path
                pieces = fname.split(".")
                if len(pieces) > 0:
                    basename = pieces[0]
                    basename = basename.replace("\\\\", "/")
                    if os.path.isfile(basename + ".h"):
                        env.vs_incs = env.vs_incs + [basename + ".h"]
                    elif os.path.isfile(basename + ".hpp"):
                        env.vs_incs = env.vs_incs + [basename + ".hpp"]
                    if os.path.isfile(basename + ".c"):
                        env.vs_srcs = env.vs_srcs + [basename + ".c"]
                    elif os.path.isfile(basename + ".cpp"):
                        env.vs_srcs = env.vs_srcs + [basename + ".cpp"]

        env.AddToVSProject = AddToVSProject

    env.extra_suffix = ""

    if env["extra_suffix"] != "":
        env.extra_suffix += "." + env["extra_suffix"]

    # Environment flags
    CCFLAGS = env.get("CCFLAGS", "")
    env["CCFLAGS"] = ""
    env.Append(CCFLAGS=str(CCFLAGS).split())

    CFLAGS = env.get("CFLAGS", "")
    env["CFLAGS"] = ""
    env.Append(CFLAGS=str(CFLAGS).split())

    CXXFLAGS = env.get("CXXFLAGS", "")
    env["CXXFLAGS"] = ""
    env.Append(CXXFLAGS=str(CXXFLAGS).split())

    LINKFLAGS = env.get("LINKFLAGS", "")
    env["LINKFLAGS"] = ""
    env.Append(LINKFLAGS=str(LINKFLAGS).split())

    # Platform specific flags
    flag_list = platform_flags[selected_platform]
    for f in flag_list:
        if not (f[0] in ARGUMENTS):  # allow command line to override platform flags
            env[f[0]] = f[1]

    # Must happen after the flags definition, so that they can be used by platform detect
    detect.configure(env)

    # Set our C and C++ standard requirements.
    # C++17 is required as we need guaranteed copy elision as per GH-36436.
    # Prepending to make it possible to override.
    # This needs to come after `configure`, otherwise we don't have env.msvc.
    if not env.msvc:
        # Specifying GNU extensions support explicitly, which are supported by
        # both GCC and Clang. Both currently default to gnu11 and gnu++14.
        env.Prepend(CFLAGS=["-std=gnu11"])
        env.Prepend(CXXFLAGS=["-std=gnu++17"])
    else:
        # MSVC doesn't have clear C standard support, /std only covers C++.
        # We apply it to CCFLAGS (both C and C++ code) in case it impacts C features.
        env.Prepend(CCFLAGS=["/std:c++17"])

    # Enforce our minimal compiler version requirements
    cc_version = methods.get_compiler_version(env) or [-1, -1]
    cc_version_major = cc_version[0]
    cc_version_minor = cc_version[1]

    if methods.using_gcc(env):
        # GCC 8 before 8.4 has a regression in the support of guaranteed copy elision
        # which causes a build failure: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86521
        if cc_version_major == 8 and cc_version_minor < 4:
            print(
                "Detected GCC 8 version < 8.4, which is not supported due to a "
                "regression in its C++17 guaranteed copy elision support. Use a "
                'newer GCC version, or Clang 6 or later by passing "use_llvm=yes" '
                "to the SCons command line."
            )
            sys.exit(255)
        elif cc_version_major < 7:
            print(
                "Detected GCC version older than 7, which does not fully support "
                "C++17. Supported versions are GCC 7, 9 and later. Use a newer GCC "
                'version, or Clang 6 or later by passing "use_llvm=yes" to the '
                "SCons command line."
            )
            sys.exit(255)
    elif methods.using_clang(env):
        # Apple LLVM versions differ from upstream LLVM version \o/, compare
        # in https://en.wikipedia.org/wiki/Xcode#Toolchain_versions
        if env["platform"] == "osx" or env["platform"] == "iphone":
            vanilla = methods.is_vanilla_clang(env)
            if vanilla and cc_version_major < 6:
                print(
                    "Detected Clang version older than 6, which does not fully support "
                    "C++17. Supported versions are Clang 6 and later."
                )
                sys.exit(255)
            elif not vanilla and cc_version_major < 10:
                print(
                    "Detected Apple Clang version older than 10, which does not fully "
                    "support C++17. Supported versions are Apple Clang 10 and later."
                )
                sys.exit(255)
        elif cc_version_major < 6:
            print(
                "Detected Clang version older than 6, which does not fully support "
                "C++17. Supported versions are Clang 6 and later."
            )
            sys.exit(255)

    # Configure compiler warnings
    if env.msvc:
        # Truncations, narrowing conversions, signed/unsigned comparisons...
        disable_nonessential_warnings = ["/wd4267", "/wd4244", "/wd4305", "/wd4018", "/wd4800"]
        if env["warnings"] == "extra":
            env.Append(CCFLAGS=["/Wall"])  # Implies /W4
        elif env["warnings"] == "all":
            env.Append(CCFLAGS=["/W3"] + disable_nonessential_warnings)
        elif env["warnings"] == "moderate":
            env.Append(CCFLAGS=["/W2"] + disable_nonessential_warnings)
        else:  # 'no'
            env.Append(CCFLAGS=["/w"])
        # Set exception handling model to avoid warnings caused by Windows system headers.
        env.Append(CCFLAGS=["/EHsc"])
        if env["werror"]:
            env.Append(CCFLAGS=["/WX"])
        # Force to use Unicode encoding
        env.Append(MSVC_FLAGS=["/utf8"])
    else:  # Rest of the world
        shadow_local_warning = []
        all_plus_warnings = ["-Wwrite-strings"]

        if methods.using_gcc(env):
            if cc_version_major >= 7:
                shadow_local_warning = ["-Wshadow-local"]

        if env["warnings"] == "extra":
            env.Append(CCFLAGS=["-Wall", "-Wextra", "-Wno-unused-parameter"] + all_plus_warnings + shadow_local_warning)
            env.Append(CXXFLAGS=["-Wctor-dtor-privacy", "-Wnon-virtual-dtor"])
            if methods.using_gcc(env):
                env.Append(
                    CCFLAGS=[
                        "-Walloc-zero",
                        "-Wduplicated-branches",
                        "-Wduplicated-cond",
                        "-Wstringop-overflow=4",
                        "-Wlogical-op",
                    ]
                )
                # -Wnoexcept was removed temporarily due to GH-36325.
                env.Append(CXXFLAGS=["-Wplacement-new=1"])
                if cc_version_major >= 9:
                    env.Append(CCFLAGS=["-Wattribute-alias=2"])
            if methods.using_clang(env):
                env.Append(CCFLAGS=["-Wimplicit-fallthrough"])
        elif env["warnings"] == "all":
            env.Append(CCFLAGS=["-Wall"] + shadow_local_warning)
        elif env["warnings"] == "moderate":
            env.Append(CCFLAGS=["-Wall", "-Wno-unused"] + shadow_local_warning)
        else:  # 'no'
            env.Append(CCFLAGS=["-w"])
        if env["werror"]:
            env.Append(CCFLAGS=["-Werror"])
            # FIXME: Temporary workaround after the Vulkan merge, remove once warnings are fixed.
            if methods.using_gcc(env):
                env.Append(CXXFLAGS=["-Wno-error=cpp"])
                if cc_version_major == 7:  # Bogus warning fixed in 8+.
                    env.Append(CCFLAGS=["-Wno-error=strict-overflow"])
            else:
                env.Append(CXXFLAGS=["-Wno-error=#warnings"])
        else:  # always enable those errors
            env.Append(CCFLAGS=["-Werror=return-type"])

    if hasattr(detect, "get_program_suffix"):
        suffix = "." + detect.get_program_suffix()
    else:
        suffix = "." + selected_platform

    if env["target"] == "release":
        if env["tools"]:
            print("Tools can only be built with targets 'debug' and 'release_debug'.")
            sys.exit(255)
        suffix += ".opt"
        env.Append(CPPDEFINES=["NDEBUG"])

    elif env["target"] == "release_debug":
        if env["tools"]:
            suffix += ".opt.tools"
        else:
            suffix += ".opt.debug"
    else:
        if env["tools"]:
            suffix += ".tools"
        else:
            suffix += ".debug"

    if env["arch"] != "":
        suffix += "." + env["arch"]
    elif env["bits"] == "32":
        suffix += ".32"
    elif env["bits"] == "64":
        suffix += ".64"

    suffix += env.extra_suffix

    sys.path.remove(tmppath)
    sys.modules.pop("detect")

    env.module_list = []
    env.module_icons_paths = []
    env.doc_class_path = {}

    for x in sorted(module_list):
        if not env["module_" + x + "_enabled"]:
            continue
        tmppath = "./modules/" + x
        sys.path.insert(0, tmppath)
        env.current_module = x
        import config

        if config.can_build(env, selected_platform):
            config.configure(env)
            env.module_list.append(x)

            # Get doc classes paths (if present)
            try:
                doc_classes = config.get_doc_classes()
                doc_path = config.get_doc_path()
                for c in doc_classes:
                    env.doc_class_path[c] = "modules/" + x + "/" + doc_path
            except:
                pass
            # Get icon paths (if present)
            try:
                icons_path = config.get_icons_path()
                env.module_icons_paths.append("modules/" + x + "/" + icons_path)
            except:
                # Default path for module icons
                env.module_icons_paths.append("modules/" + x + "/" + "icons")

        sys.path.remove(tmppath)
        sys.modules.pop("config")

    methods.update_version(env.module_version_string)

    env["PROGSUFFIX"] = suffix + env.module_version_string + env["PROGSUFFIX"]
    env["OBJSUFFIX"] = suffix + env["OBJSUFFIX"]
    # (SH)LIBSUFFIX will be used for our own built libraries
    # LIBSUFFIXES contains LIBSUFFIX and SHLIBSUFFIX by default,
    # so we need to append the default suffixes to keep the ability
    # to link against thirdparty libraries (.a, .so, .lib, etc.).
    if os.name == "nt":
        # On Windows, only static libraries and import libraries can be
        # statically linked - both using .lib extension
        env["LIBSUFFIXES"] += [env["LIBSUFFIX"]]
    else:
        env["LIBSUFFIXES"] += [env["LIBSUFFIX"], env["SHLIBSUFFIX"]]
    env["LIBSUFFIX"] = suffix + env["LIBSUFFIX"]
    env["SHLIBSUFFIX"] = suffix + env["SHLIBSUFFIX"]

    if env.use_ptrcall:
        env.Append(CPPDEFINES=["PTRCALL_ENABLED"])
    if env["tools"]:
        env.Append(CPPDEFINES=["TOOLS_ENABLED"])
    if env["disable_3d"]:
        if env["tools"]:
            print(
                "Build option 'disable_3d=yes' cannot be used with 'tools=yes' (editor), "
                "only with 'tools=no' (export template)."
            )
            sys.exit(255)
        else:
            env.Append(CPPDEFINES=["_3D_DISABLED"])
    if env["disable_advanced_gui"]:
        if env["tools"]:
            print(
                "Build option 'disable_advanced_gui=yes' cannot be used with 'tools=yes' (editor), "
                "only with 'tools=no' (export template)."
            )
            sys.exit(255)
        else:
            env.Append(CPPDEFINES=["ADVANCED_GUI_DISABLED"])
    if env["minizip"]:
        env.Append(CPPDEFINES=["MINIZIP_ENABLED"])

    editor_module_list = ["regex"]
    for x in editor_module_list:
        if not env["module_" + x + "_enabled"]:
            if env["tools"]:
                print(
                    "Build option 'module_" + x + "_enabled=no' cannot be used with 'tools=yes' (editor), "
                    "only with 'tools=no' (export template)."
                )
                sys.exit(255)

    if not env["verbose"]:
        methods.no_verbose(sys, env)

    if not env["platform"] == "server":
        env.Append(
            BUILDERS={
                "GLES2_GLSL": env.Builder(
                    action=run_in_subprocess(gles_builders.build_gles2_headers), suffix="glsl.gen.h", src_suffix=".glsl"
                )
            }
        )
        env.Append(
            BUILDERS={
                "RD_GLSL": env.Builder(
                    action=run_in_subprocess(gles_builders.build_rd_headers), suffix="glsl.gen.h", src_suffix=".glsl"
                )
            }
        )
        env.Append(
            BUILDERS={
                "GLSL_HEADER": env.Builder(
                    action=run_in_subprocess(gles_builders.build_raw_headers), suffix="glsl.gen.h", src_suffix=".glsl"
                )
            }
        )

    scons_cache_path = os.environ.get("SCONS_CACHE")
    if scons_cache_path != None:
        CacheDir(scons_cache_path)
        print("Scons cache enabled... (path: '" + scons_cache_path + "')")

    Export("env")

    # build subdirs, the build order is dependent on link order.

    SConscript("core/SCsub")
    SConscript("servers/SCsub")
    SConscript("scene/SCsub")
    SConscript("editor/SCsub")
    SConscript("drivers/SCsub")

    SConscript("platform/SCsub")
    SConscript("modules/SCsub")
    SConscript("main/SCsub")

    SConscript("platform/" + selected_platform + "/SCsub")  # build selected platform

    # Microsoft Visual Studio Project Generation
    if env["vsproj"]:
        env["CPPPATH"] = [Dir(path) for path in env["CPPPATH"]]
        methods.generate_vs_project(env, GetOption("num_jobs"))
        methods.generate_cpp_hint_file("cpp.hint")

    # Check for the existence of headers
    conf = Configure(env)
    if "check_c_headers" in env:
        for header in env["check_c_headers"]:
            if conf.CheckCHeader(header[0]):
                env.AppendUnique(CPPDEFINES=[header[1]])

elif selected_platform != "":
    if selected_platform == "list":
        print("The following platforms are available:\n")
    else:
        print('Invalid target platform "' + selected_platform + '".')
        print("The following platforms were detected:\n")

    for x in platform_list:
        print("\t" + x)

    print("\nPlease run SCons again and select a valid platform: platform=<string>")

    if selected_platform == "list":
        # Exit early to suppress the rest of the built-in SCons messages
        sys.exit(0)
    else:
        sys.exit(255)

# The following only makes sense when the env is defined, and assumes it is
if "env" in locals():
    screen = sys.stdout
    # Progress reporting is not available in non-TTY environments since it
    # messes with the output (for example, when writing to a file)
    show_progress = env["progress"] and sys.stdout.isatty()
    node_count = 0
    node_count_max = 0
    node_count_interval = 1
    node_count_fname = str(env.Dir("#")) + "/.scons_node_count"

    import time, math

    class cache_progress:
        # The default is 1 GB cache and 12 hours half life
        def __init__(self, path=None, limit=1073741824, half_life=43200):
            self.path = path
            self.limit = limit
            self.exponent_scale = math.log(2) / half_life
            if env["verbose"] and path != None:
                screen.write(
                    "Current cache limit is {} (used: {})\n".format(
                        self.convert_size(limit), self.convert_size(self.get_size(path))
                    )
                )
            self.delete(self.file_list())

        def __call__(self, node, *args, **kw):
            global node_count, node_count_max, node_count_interval, node_count_fname, show_progress
            if show_progress:
                # Print the progress percentage
                node_count += node_count_interval
                if node_count_max > 0 and node_count <= node_count_max:
                    screen.write("\r[%3d%%] " % (node_count * 100 / node_count_max))
                    screen.flush()
                elif node_count_max > 0 and node_count > node_count_max:
                    screen.write("\r[100%] ")
                    screen.flush()
                else:
                    screen.write("\r[Initial build] ")
                    screen.flush()

        def delete(self, files):
            if len(files) == 0:
                return
            if env["verbose"]:
                # Utter something
                screen.write("\rPurging %d %s from cache...\n" % (len(files), len(files) > 1 and "files" or "file"))
            [os.remove(f) for f in files]

        def file_list(self):
            if self.path is None:
                # Nothing to do
                return []
            # Gather a list of (filename, (size, atime)) within the
            # cache directory
            file_stat = [(x, os.stat(x)[6:8]) for x in glob.glob(os.path.join(self.path, "*", "*"))]
            if file_stat == []:
                # Nothing to do
                return []
            # Weight the cache files by size (assumed to be roughly
            # proportional to the recompilation time) times an exponential
            # decay since the ctime, and return a list with the entries
            # (filename, size, weight).
            current_time = time.time()
            file_stat = [(x[0], x[1][0], (current_time - x[1][1])) for x in file_stat]
            # Sort by the most recently accessed files (most sensible to keep) first
            file_stat.sort(key=lambda x: x[2])
            # Search for the first entry where the storage limit is
            # reached
            sum, mark = 0, None
            for i, x in enumerate(file_stat):
                sum += x[1]
                if sum > self.limit:
                    mark = i
                    break
            if mark is None:
                return []
            else:
                return [x[0] for x in file_stat[mark:]]

        def convert_size(self, size_bytes):
            if size_bytes == 0:
                return "0 bytes"
            size_name = ("bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB")
            i = int(math.floor(math.log(size_bytes, 1024)))
            p = math.pow(1024, i)
            s = round(size_bytes / p, 2)
            return "%s %s" % (int(s) if i == 0 else s, size_name[i])

        def get_size(self, start_path="."):
            total_size = 0
            for dirpath, dirnames, filenames in os.walk(start_path):
                for f in filenames:
                    fp = os.path.join(dirpath, f)
                    total_size += os.path.getsize(fp)
            return total_size

    def progress_finish(target, source, env):
        global node_count, progressor
        with open(node_count_fname, "w") as f:
            f.write("%d\n" % node_count)
        progressor.delete(progressor.file_list())

    try:
        with open(node_count_fname) as f:
            node_count_max = int(f.readline())
    except:
        pass

    cache_directory = os.environ.get("SCONS_CACHE")
    # Simple cache pruning, attached to SCons' progress callback. Trim the
    # cache directory to a size not larger than cache_limit.
    cache_limit = float(os.getenv("SCONS_CACHE_LIMIT", 1024)) * 1024 * 1024
    progressor = cache_progress(cache_directory, cache_limit)
    Progress(progressor, interval=node_count_interval)

    progress_finish_command = Command("progress_finish", [], progress_finish)
    AlwaysBuild(progress_finish_command)