gecko-dev/js/moz.configure

# -*- 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/.

# /!\ Use js_option() instead of option() in this file. /!\
# =========================================================

@depends(build_project)
def building_js(build_project):
    return build_project == 'js'

# Exception to the rule above: JS_STANDALONE is a special option that doesn't
# want the js_option treatment. When we're done merging js/src/configure and
# top-level configure, it can go away, although the JS_STANDALONE config
# will still need to be set depending on building_js above.
option(env='JS_STANDALONE', default=building_js,
       help='Reserved for internal use')

# Branding
# ==============================================================
js_option('--with-app-name', env='MOZ_APP_NAME', nargs=1,
          help='Used for e.g. the binary program file name. If not set, '
          'defaults to a lowercase form of MOZ_APP_BASENAME.')

@depends('--with-app-name', 'JS_STANDALONE', moz_app_basename)
def moz_app_name(value, js_standalone, moz_app_basename):
    if value:
        return value[0]
    if js_standalone:
        return 'js'
    return moz_app_basename.lower()

set_config('MOZ_APP_NAME', moz_app_name)

# SmooshMonkey (new frontend)
# ==================================================

# Define here in order to use the option from bindgen.configure.
js_option('--enable-smoosh', default=False,
          help='Enable SmooshMonkey (new JS engine frontend)')

@depends('--enable-smoosh')
def enable_smoosh(value):
    if value:
        return True

set_config('JS_ENABLE_SMOOSH', enable_smoosh)
set_define('JS_ENABLE_SMOOSH', enable_smoosh)

include('../build/moz.configure/nspr.configure',
        when='--enable-compile-environment')
include('../build/moz.configure/rust.configure',
        when='--enable-compile-environment')
include('../build/moz.configure/bindgen.configure',
        when='--enable-compile-environment')

@depends('JS_STANDALONE')
def js_standalone(value):
    if value:
        return True
set_config('JS_STANDALONE', js_standalone)
set_define('JS_STANDALONE', js_standalone)
add_old_configure_assignment('JS_STANDALONE', js_standalone)
js_option('--disable-js-shell', default=building_js,
          help='{Build|Do not build} the JS shell')

@depends('--disable-js-shell')
def js_disable_shell(value):
    if not value:
        return True

set_config('JS_DISABLE_SHELL', js_disable_shell)

set_define('JS_64BIT', depends(target)(lambda t: t.bitness == 64 or None))

set_define('JS_PUNBOX64', depends(target)(lambda t: t.bitness == 64 or None))
set_define('JS_NUNBOX32', depends(target)(lambda t: t.bitness == 32 or None))


# SpiderMonkey as a shared library, and how its symbols are exported
# ==================================================================
js_option('--disable-shared-js', when=js_standalone,
          help='{Create|Do not create} a shared library')

js_option('--disable-export-js', when=js_standalone,
          help='{Mark|Do not mark} JS symbols as DLL exported/visible')

@depends('--disable-shared-js', '--disable-export-js', when=js_standalone)
def shared_js(shared_js, export_js):
    if shared_js:
        if not export_js:
            die('Must export JS symbols when building a shared library.')
        return True

set_config('JS_SHARED_LIBRARY', shared_js)
add_old_configure_assignment('JS_SHARED_LIBRARY', shared_js)

@depends(shared_js, '--disable-export-js', when=js_standalone)
def exportable_js_api(shared_js, export_js):
    if not shared_js and export_js:
        return True

set_define('STATIC_EXPORTABLE_JS_API', exportable_js_api)

@depends(shared_js, exportable_js_api)
def static_js_api(shared_js, export_js):
    if not shared_js and not export_js:
        return True

set_define('STATIC_JS_API', static_js_api)

@depends(shared_js)
def static_js(value):
    if not value:
        return True

set_define('MOZ_STATIC_JS', static_js)


js_option(env='NO_RUST_PANIC_HOOK', when=js_standalone,
          help='Disable rust panic hook')

set_define('NO_RUST_PANIC_HOOK', True, when='NO_RUST_PANIC_HOOK')


# JIT support
# =======================================================
@depends(target)
def jit_default(target):
    if target.cpu in ('x86', 'x86_64', 'arm', 'aarch64', 'mips32', 'mips64'):
        return True
    return False

js_option('--enable-jit',
          default=jit_default,
          help='{Enable|Disable} use of the JITs')

@deprecated_option('--enable-ion')
def report_deprecated(value):
    if value:
        die('--enable-ion is deprecated, use --enable-jit instead')
    else:
        die('--disable-ion is deprecated, use --disable-jit instead')

# JIT code simulator for cross compiles
# =======================================================
js_option('--enable-simulator', choices=('arm', 'arm64', 'mips32', 'mips64'),
          nargs=1,
          help='Enable a JIT code simulator for the specified architecture')

@depends('--enable-jit', '--enable-simulator', target, '--help')
def simulator(jit_enabled, simulator_enabled, target, _):
    if not jit_enabled or not simulator_enabled:
        return

    sim_cpu = simulator_enabled[0]

    if sim_cpu in ('arm', 'mips32'):
        if target.cpu != 'x86':
            die('The %s simulator only works on x86.' % sim_cpu)

    if sim_cpu in ('arm64', 'mips64'):
        if target.cpu != 'x86_64':
            die('The %s simulator only works on x86-64.' % sim_cpu)

    return namespace(**{sim_cpu: True})

set_config('JS_SIMULATOR', depends_if(simulator)(lambda x: True))
set_config('JS_SIMULATOR_ARM', simulator.arm)
set_config('JS_SIMULATOR_ARM64', simulator.arm64)
set_config('JS_SIMULATOR_MIPS32', simulator.mips32)
set_config('JS_SIMULATOR_MIPS64', simulator.mips64)
set_define('JS_SIMULATOR', depends_if(simulator)(lambda x: True))
set_define('JS_SIMULATOR_ARM', simulator.arm)
set_define('JS_SIMULATOR_ARM64', simulator.arm64)
set_define('JS_SIMULATOR_MIPS32', simulator.mips32)
set_define('JS_SIMULATOR_MIPS64', simulator.mips64)

@depends('--enable-jit', simulator, target)
def jit_codegen(jit_enabled, simulator, target):
    if not jit_enabled:
        return namespace(none=True)

    if simulator:
        return simulator

    if target.cpu == 'aarch64':
        return namespace(arm64=True)
    elif target.cpu == 'x86_64':
        return namespace(x64=True)

    return namespace(**{str(target.cpu): True})

set_config('JS_CODEGEN_NONE', jit_codegen.none)
set_config('JS_CODEGEN_ARM', jit_codegen.arm)
set_config('JS_CODEGEN_ARM64', jit_codegen.arm64)
set_config('JS_CODEGEN_MIPS32', jit_codegen.mips32)
set_config('JS_CODEGEN_MIPS64', jit_codegen.mips64)
set_config('JS_CODEGEN_X86', jit_codegen.x86)
set_config('JS_CODEGEN_X64', jit_codegen.x64)
set_define('JS_CODEGEN_NONE', jit_codegen.none)
set_define('JS_CODEGEN_ARM', jit_codegen.arm)
set_define('JS_CODEGEN_ARM64', jit_codegen.arm64)
set_define('JS_CODEGEN_MIPS32', jit_codegen.mips32)
set_define('JS_CODEGEN_MIPS64', jit_codegen.mips64)
set_define('JS_CODEGEN_X86', jit_codegen.x86)
set_define('JS_CODEGEN_X64', jit_codegen.x64)

# Profiling
# =======================================================
js_option('--enable-instruments', env='MOZ_INSTRUMENTS',
          help='Enable instruments remote profiling')

@depends('--enable-instruments', target)
def instruments(value, target):
    if value and target.os != 'OSX':
        die('--enable-instruments cannot be used when targeting %s',
            target.os)
    if value:
        return True

set_config('MOZ_INSTRUMENTS', instruments)
set_define('MOZ_INSTRUMENTS', instruments)
add_old_configure_assignment('MOZ_INSTRUMENTS', instruments)
imply_option('--enable-profiling', instruments, reason='--enable-instruments')

js_option('--enable-callgrind', env='MOZ_CALLGRIND',
          help='Enable callgrind profiling')

@depends('--enable-callgrind')
def callgrind(value):
    if value:
        return True

set_define('MOZ_CALLGRIND', callgrind)
imply_option('--enable-profiling', callgrind)

@depends(milestone)
def enable_profiling(milestone):
    return milestone.is_nightly

js_option('--enable-profiling', env='MOZ_PROFILING', default=enable_profiling,
          help='{Set|Do not set} compile flags necessary for using sampling '
                'profilers (e.g. shark, perf)')

@depends('--enable-profiling')
def profiling(value):
    if value:
        return True

add_old_configure_assignment('MOZ_PROFILING', profiling)

with only_when('--enable-compile-environment'):
    imply_option('--enable-frame-pointers', True, when=profiling)


@depends(profiling, target)
def imply_vtune(value, target):
    ok_cpu    = target.cpu in ['x86', 'x86_64']
    ok_kernel = target.kernel == 'WINNT' or \
                (target.kernel == 'Linux' and target.os == 'GNU')

    if value and ok_cpu and ok_kernel:
        return True

set_config('MOZ_PROFILING', profiling)
set_define('MOZ_PROFILING', profiling)
imply_option('--enable-vtune', imply_vtune, reason='--enable-profiling')


js_option('--enable-vtune', env='MOZ_VTUNE', help='Enable VTune profiling')

@depends('--enable-vtune')
def vtune(value):
    if value:
        return True

set_config('MOZ_VTUNE', vtune)
set_define('MOZ_VTUNE', vtune)


js_option('--enable-gc-probes', env='JS_GC_PROBES',
          help='Turn on probes for allocation and finalization')

@depends('--enable-gc-probes')
def gc_probes(value):
    if value:
        return True

set_define('JS_GC_PROBES', gc_probes)


js_option('--enable-gczeal',
          default=depends(when=moz_debug)(lambda: True),
          help='{Enable|Disable} zealous GCing')

set_define('JS_GC_ZEAL',
           depends_if('--enable-gczeal')(lambda _: True))


# Use a smaller chunk size for GC chunks
# ========================================================
# Use large (1MB) chunks by default.  This option can be used to give
# smaller (currently 256K) chunks.
js_option('--enable-small-chunk-size',
          help='Allocate memory for JS GC things in smaller chunks')

set_define('JS_GC_SMALL_CHUNK_SIZE',
           depends(when='--enable-small-chunk-size')(lambda: True))


# Trace logging.
# =======================================================
@depends(milestone)
def default_trace_logging(milestone):
    return milestone.is_nightly


js_option('--enable-trace-logging',
          default=default_trace_logging,
          help='{Enable|Disable} trace logging')

set_config('ENABLE_TRACE_LOGGING',
           depends_if('--enable-trace-logging')(lambda x: True))
set_define('JS_TRACE_LOGGING',
           depends_if('--enable-trace-logging')(lambda x: True))


# Enable breakpoint for artificial OOMs
# =======================================================
js_option('--enable-oom-breakpoint',
          help='Enable a breakpoint function for artificial OOMs')

set_define('JS_OOM_BREAKPOINT',
           depends_if('--enable-oom-breakpoint')(lambda _: True))


js_option('--enable-perf', env='JS_ION_PERF',
          help='Enable Linux perf integration')

@depends('--enable-perf')
def ion_perf(value):
    if value:
        return True

set_define('JS_ION_PERF', ion_perf)


js_option('--enable-jitspew',
          default=depends(when=moz_debug)(lambda: True),
          help='{Enable|Disable} the Jit spew and IONFLAGS environment '
               'variable')

set_define('JS_JITSPEW',
           depends_if('--enable-jitspew')(lambda _: True))
set_config('JS_JITSPEW',
           depends_if('--enable-jitspew')(lambda _: True))

# Also enable the structured spewer
set_define('JS_STRUCTURED_SPEW',
           depends_if('--enable-jitspew')(lambda _: True))
set_config('JS_STRUCTURED_SPEW',
           depends_if('--enable-jitspew')(lambda _: True))

@depends('--enable-jit', '--enable-jitspew', simulator, target, moz_debug)
def jit_disasm_arm(jit_enabled, spew, simulator, target, debug):
    if not jit_enabled:
        return

    if simulator and (debug or spew):
        if getattr(simulator, 'arm', None):
            return True

    if target.cpu == 'arm' and (debug or spew):
        return True

set_config('JS_DISASM_ARM', jit_disasm_arm)
set_define('JS_DISASM_ARM', jit_disasm_arm)

@depends('--enable-jit', '--enable-jitspew', simulator, target, moz_debug)
def jit_disasm_arm64(jit_enabled, spew, simulator, target, debug):
    if not jit_enabled:
        return

    if simulator and (debug or spew):
        if getattr(simulator, 'arm64', None):
            return True

    if target.cpu == 'aarch64' and (debug or spew):
        return True

set_config('JS_DISASM_ARM64', jit_disasm_arm64)
set_define('JS_DISASM_ARM64', jit_disasm_arm64)

# When enabled, masm will generate assumeUnreachable calls that act as
# assertions in the generated code. This option is worth disabling when you
# have to track mutated values through the generated code, to avoid constantly
# dumping registers on and off the stack.
js_option('--enable-masm-verbose',
          default=depends(when=moz_debug)(lambda: True),
          help='{Enable|Disable} MacroAssembler verbosity of generated code.')
set_define('JS_MASM_VERBOSE',
           depends_if('--enable-masm-verbose')(lambda _: True))
set_config('JS_MASM_VERBOSE',
           depends_if('--enable-masm-verbose')(lambda _: True))


js_option('--enable-more-deterministic', env='JS_MORE_DETERMINISTIC',
          help='Enable changes that make the shell more deterministic')

@depends('--enable-more-deterministic')
def more_deterministic(value):
    if value:
        return True

set_define('JS_MORE_DETERMINISTIC', more_deterministic)


# CTypes
# =======================================================
@depends(building_js)
def ctypes_default(building_js):
    return not building_js

js_option('--enable-ctypes',
          default=ctypes_default,
          help='{Enable|Disable} js-ctypes')

build_ctypes = depends_if('--enable-ctypes')(lambda _: True)

set_config('BUILD_CTYPES', build_ctypes)
set_define('BUILD_CTYPES', build_ctypes)

@depends(build_ctypes, building_js)
def js_has_ctypes(ctypes, js):
    if ctypes and js:
        return True

set_config('JS_HAS_CTYPES', js_has_ctypes)
set_define('JS_HAS_CTYPES', js_has_ctypes)

@depends('--enable-ctypes', '--enable-compile-environment')
def ctypes_and_compile_environment(ctypes, compile_environment):
    return ctypes and compile_environment

include('ffi.configure', when=ctypes_and_compile_environment)


# Enable pipeline operator
# ===================================================
js_option('--enable-pipeline-operator', default=False, help='Enable pipeline operator')

@depends('--enable-pipeline-operator')
def enable_pipeline_operator(value):
    if value:
        return True

set_config('ENABLE_PIPELINE_OPERATOR', enable_pipeline_operator)
set_define('ENABLE_PIPELINE_OPERATOR', enable_pipeline_operator)


# SIMD acceleration for encoding_rs
# ==============================================================

js_option('--enable-rust-simd', env='MOZ_RUST_SIMD',
          help='Enable explicit SIMD in Rust code.')

@depends('--enable-rust-simd', target)
def rust_simd(value, target):
    # As of 2019-09-17, the simd-accel feature of encoding_rs has not
    # been properly set up outside aarch64, armv7, x86 and x86_64.
    if target.cpu in ('aarch64', 'arm', 'x86', 'x86_64') and value:
        return True

set_config('MOZ_RUST_SIMD', rust_simd)
set_define('MOZ_RUST_SIMD', rust_simd)


# Support for wasm code generation with Cranelift
# ==============================================================

@depends(milestone.is_nightly, target, simulator)
def cranelift_default(is_nightly, target, simulator):
    if is_nightly or target.cpu == 'aarch64' or (simulator is not None and simulator.arm64):
        return True

js_option('--enable-cranelift',
          default=cranelift_default,
          help='{Enable|Disable} Cranelift code generator for wasm')

set_config('ENABLE_WASM_CRANELIFT', depends_if('--enable-cranelift')(lambda x: True))
set_define('ENABLE_WASM_CRANELIFT', depends_if('--enable-cranelift')(lambda x: True))

# Telemetry to measure compile time and generated-code runtime
# ============================================================

js_option('--enable-spidermonkey-telemetry',
          default=milestone.is_nightly,
          help='{Enable|Disable} performance telemetry for SpiderMonkey (e.g. compile and run times)')

set_define('ENABLE_SPIDERMONKEY_TELEMETRY', depends_if('--enable-spidermonkey-telemetry')(lambda x: True))

# Support for debugging code generated by wasm backends
# =====================================================

js_option('--enable-wasm-codegen-debug',
          default=depends(when=moz_debug)(lambda: True),
          help='{Enable|Disable} debugging for wasm codegen')

set_config('WASM_CODEGEN_DEBUG', depends_if('--enable-wasm-codegen-debug')(lambda x: True))
set_define('WASM_CODEGEN_DEBUG', depends_if('--enable-wasm-codegen-debug')(lambda x: True))


# Support for typed objects.
# =====================================================

@depends(milestone.is_nightly)
def default_typed_objects(is_nightly):
    return is_nightly

js_option('--enable-typed-objects',
          default=default_typed_objects,
          help='{Enable|Disable} typed objects')

set_config('JS_HAS_TYPED_OBJECTS', depends_if('--enable-typed-objects')(lambda x: True))
set_define('JS_HAS_TYPED_OBJECTS', depends_if('--enable-typed-objects')(lambda x: True))


# Support for WebAssembly reference types.
# =====================================================

js_option('--disable-wasm-reftypes',
          help='Disable WebAssembly reference types')

@depends('--disable-wasm-reftypes')
def enable_wasm_reftypes(value):
    if value:
        return True

set_config('ENABLE_WASM_REFTYPES', enable_wasm_reftypes)
set_define('ENABLE_WASM_REFTYPES', enable_wasm_reftypes)


# Support for WebAssembly GC.
# ===========================

@depends(milestone.is_nightly, '--enable-wasm-reftypes', '--enable-typed-objects')
def default_wasm_gc(is_nightly, reftypes, typed_objects):
    if is_nightly and reftypes and typed_objects:
        return True

js_option('--enable-wasm-gc',
          default=default_wasm_gc,
          help='{Enable|Disable} WebAssembly GC')

@depends('--enable-wasm-gc', '--enable-wasm-reftypes', '--enable-typed-objects')
def wasm_gc(value, reftypes, typed_objects):
    if not value:
        return

    if reftypes and typed_objects:
        return True

    die('--enable-wasm-gc only possible with --enable-wasm-reftypes and --enable-typed-objects')

set_config('ENABLE_WASM_GC', wasm_gc)
set_define('ENABLE_WASM_GC', wasm_gc)


# Support for WebAssembly private ref types.
# Prevent (ref T) types from being exposed to JS content so that wasm need do
# no typechecking at the JS/wasm boundary
# ===========================================================================

@depends(milestone.is_nightly, '--enable-wasm-gc')
def default_wasm_private_reftypes(is_nightly, gc):
    if gc and is_nightly:
        return True

js_option('--enable-wasm-private-reftypes',
          default=default_wasm_private_reftypes,
          help='{Enable|Disable} WebAssembly private reference types')

set_config('WASM_PRIVATE_REFTYPES', depends_if('--enable-wasm-private-reftypes')(lambda x: True))
set_define('WASM_PRIVATE_REFTYPES', depends_if('--enable-wasm-private-reftypes')(lambda x: True))


# Support for the WebAssembly multi-value proposal.
# Do not remove until Cranelift supports multi-value.
# =====================================================

js_option('--disable-wasm-multi-value',
          help='Disable WebAssembly multi-value blocks and function calls')

@depends('--disable-wasm-multi-value')
def enable_wasm_multi_value(value):
    if value:
        return True

set_config('ENABLE_WASM_MULTI_VALUE', enable_wasm_multi_value)
set_define('ENABLE_WASM_MULTI_VALUE', enable_wasm_multi_value)


# Support for WebAssembly shared memory and atomics.
#
# This affects the JS shell only and here to allow the use of
# Cranelift in the shell.  Once Cranelift supports shared memory
# and atomics it can go away.
# =====================================================

js_option('--disable-shared-memory', help='Disable JS/WebAssembly shared memory and atomics')

@depends('--disable-shared-memory')
def enable_shared_memory(value):
    if value:
        return True

set_config('ENABLE_SHARED_MEMORY', enable_shared_memory)
set_define('ENABLE_SHARED_MEMORY', enable_shared_memory)


# Support for WebAssembly SIMD
# =====================================================

@depends('--enable-jit', '--enable-simulator', target)
def default_wasm_simd(jit_enabled, simulator, target):
    if not jit_enabled or simulator:
        return

    if target.cpu in ('x86_64', 'x86'):
        return True

js_option('--enable-wasm-simd',
          default=default_wasm_simd,
          help='{Enable|Disable} WebAssembly SIMD')

@depends('--enable-wasm-simd', '--enable-jit', '--enable-simulator', target)
def wasm_simd(value, jit_enabled, simulator, target):
    if not value:
        return

    if jit_enabled and not simulator:
        if target.cpu in ('x86_64', 'x86'):
            return True

    die('--enable-wasm-simd only possible when targeting the x86_64/x86 jit')

set_config('ENABLE_WASM_SIMD', wasm_simd)
set_define('ENABLE_WASM_SIMD', wasm_simd)


# Options for generating the shell as a script
# ============================================
js_option('--with-qemu-exe', nargs=1, help='Use path as an arm emulator on host platforms')
set_config('QEMU_EXE', depends_if('--with-qemu-exe')(lambda x: x))

js_option('--with-cross-lib', nargs=1, default=depends(target.alias)(lambda x: '/usr/%s' % x),
          help='Use dir as the location for arm libraries')
set_config('CROSS_LIB', depends_if('--with-cross-lib')(lambda x: x))

# Enable static checking using sixgill
# ====================================

js_option('--with-sixgill', nargs=1, help='Enable static checking of code using sixgill')

@depends_if('--with-sixgill')
@imports('os')
def sixgill(value):
    for f in ('bin/xdbfind', 'gcc/xgill.so', 'scripts/wrap_gcc/g++'):
        if not os.path.exists(os.path.join(value[0], f)):
            die('The sixgill plugin and binaries are not at the specified path')
    return value[0]

set_config('SIXGILL_PATH', sixgill)


# Support for readline
# =====================================================
@depends('--enable-js-shell', target_is_windows, compile_environment)
def editline(js_shell, is_windows, compile_environment):
    return js_shell and not is_windows and compile_environment

js_option('--enable-readline', help='Link js shell to system readline library',
          when=editline)

has_readline = check_symbol('readline', flags=['-lreadline'], when='--enable-readline',
                            onerror=lambda: die('No system readline library found'))

set_config('EDITLINE_LIBS', ['-lreadline'], when=has_readline)

@depends('--enable-readline', editline, when=editline)
def bundled_editline(readline, editline):
    return editline and not readline

set_config('JS_BUNDLED_EDITLINE', bundled_editline)

set_define('EDITLINE', True, when=editline)


# JIT observers
# =============

js_option('--with-jitreport-granularity', default='3', choices=('0', '1', '2', '3'),
          help='Default granularity at which to report JIT code to external tools '
               '(0 - no info, 1 - code ranges for while functions only, '
               '2 - per-line information, 3 - per-op information)')

set_define('JS_DEFAULT_JITREPORT_GRANULARITY',
           depends_if('--with-jitreport-granularity')(lambda value: value[0]))


# ECMAScript Internationalization API Support (uses ICU)
# ======================================================
js_option('--with-system-icu', help='Use system ICU')

system_icu = pkg_check_modules('MOZ_ICU', 'icu-i18n >= 67.1', when='--with-system-icu')

set_config('MOZ_SYSTEM_ICU', True, when=system_icu)
set_define('MOZ_SYSTEM_ICU', True, when=system_icu)

js_option('--without-intl-api', help='Disable ECMAScript Internationalization API')

@depends('--with-intl-api', building_js)
def check_intl_api(enabled, building_js):
    if not enabled and not building_js:
        die('--without-intl-api is not supported')

set_config('JS_HAS_INTL_API', True, when='--with-intl-api')
set_define('JS_HAS_INTL_API', True, when='--with-intl-api')

@depends(check_build_environment, when='--with-intl-api')
@imports(_from='__builtin__', _import='open')
@imports(_from='__builtin__', _import='ValueError')
def icu_version(build_env):
    path = os.path.join(build_env.topsrcdir, 'intl', 'icu', 'source', 'common',
                        'unicode', 'uvernum.h')
    with open(path, encoding='utf-8') as fh:
        for line in fh:
            if line.startswith('#define'):
                define = line.split(None, 3)
                if len(define) == 3 and define[1] == 'U_ICU_VERSION_MAJOR_NUM':
                    try:
                        return str(int(define[2]))
                    except ValueError:
                        pass
    die('Cannot determine ICU version number from uvernum.h header file')

set_config('MOZ_ICU_VERSION', icu_version)

# Source files that use ICU should have control over which parts of the ICU
# namespace they want to use.
set_define('U_USING_ICU_NAMESPACE', '0', when='--with-intl-api')

# We build ICU as a static library.
set_define('U_STATIC_IMPLEMENTATION', True, when=depends(system_icu)(lambda x: not x))

@depends(yasm, gnu_as, target, compile_environment)
def can_build_data_file(yasm, gnu_as, target, compile_environment):
    if not compile_environment or (target.kernel == 'WINNT' and target.cpu == 'aarch64'):
        return
    if not yasm and not gnu_as:
        die('Building ICU requires either yasm or a GNU assembler. If you do not have '
            'either of those available for this platform you must use --without-intl-api')