godot/platform/javascript/detect.py
Rémi Verschelde d52b70fb5e SCons: Always use env.Prepend for CPPPATH
Include paths are processed from left to right, so we use Prepend to
ensure that paths to bundled thirdparty files will have precedence over
system paths (e.g. `/usr/include` should have lowest priority).
2019-04-30 13:12:06 +02:00

138 lines
4.8 KiB
Python

import os
def is_active():
return True
def get_name():
return 'JavaScript'
def can_build():
return 'EM_CONFIG' in os.environ or os.path.exists(os.path.expanduser('~/.emscripten'))
def get_opts():
from SCons.Variables import BoolVariable
return [
# eval() can be a security concern, so it can be disabled.
BoolVariable('javascript_eval', 'Enable JavaScript eval interface', True),
]
def get_flags():
return [
('tools', False),
# Disabling the mbedtls module reduces file size.
# The module has little use due to the limited networking functionality
# in this platform. For the available networking methods, the browser
# manages TLS.
('module_mbedtls_enabled', False),
]
def configure(env):
## Build type
if env['target'] != 'debug':
# Use -Os to prioritize optimizing for reduced file size. This is
# particularly valuable for the web platform because it directly
# decreases download time.
# -Os reduces file size by around 5 MiB over -O3. -Oz only saves about
# 100 KiB over -Os, which does not justify the negative impact on
# run-time performance.
env.Append(CCFLAGS=['-Os'])
env.Append(LINKFLAGS=['-Os'])
if env['target'] == 'release_debug':
env.Append(CPPDEFINES=['DEBUG_ENABLED'])
# Retain function names for backtraces at the cost of file size.
env.Append(LINKFLAGS=['--profiling-funcs'])
else:
env.Append(CPPDEFINES=['DEBUG_ENABLED'])
env.Append(CCFLAGS=['-O1', '-g'])
env.Append(LINKFLAGS=['-O1', '-g'])
env.Append(LINKFLAGS=['-s', 'ASSERTIONS=1'])
## Compiler configuration
env['ENV'] = os.environ
em_config_file = os.getenv('EM_CONFIG') or os.path.expanduser('~/.emscripten')
if not os.path.exists(em_config_file):
raise RuntimeError("Emscripten configuration file '%s' does not exist" % em_config_file)
with open(em_config_file) as f:
em_config = {}
try:
# Emscripten configuration file is a Python file with simple assignments.
exec(f.read(), em_config)
except StandardError as e:
raise RuntimeError("Emscripten configuration file '%s' is invalid:\n%s" % (em_config_file, e))
if 'EMSCRIPTEN_ROOT' not in em_config:
raise RuntimeError("'EMSCRIPTEN_ROOT' missing in Emscripten configuration file '%s'" % em_config_file)
env.PrependENVPath('PATH', em_config['EMSCRIPTEN_ROOT'])
env['CC'] = 'emcc'
env['CXX'] = 'em++'
env['LINK'] = 'emcc'
# Emscripten's ar has issues with duplicate file names, so use cc.
env['AR'] = 'emcc'
env['ARFLAGS'] = '-o'
# emranlib is a noop, so it's safe to use with AR=emcc.
env['RANLIB'] = 'emranlib'
# Use TempFileMunge since some AR invocations are too long for cmd.exe.
# Use POSIX-style paths, required with TempFileMunge.
env['ARCOM_POSIX'] = env['ARCOM'].replace(
'$TARGET', '$TARGET.posix').replace(
'$SOURCES', '$SOURCES.posix')
env['ARCOM'] = '${TEMPFILE(ARCOM_POSIX)}'
# All intermediate files are just LLVM bitcode.
env['OBJPREFIX'] = ''
env['OBJSUFFIX'] = '.bc'
env['PROGPREFIX'] = ''
# Program() output consists of multiple files, so specify suffixes manually at builder.
env['PROGSUFFIX'] = ''
env['LIBPREFIX'] = 'lib'
env['LIBSUFFIX'] = '.bc'
env['LIBPREFIXES'] = ['$LIBPREFIX']
env['LIBSUFFIXES'] = ['$LIBSUFFIX']
## Compile flags
env.Prepend(CPPPATH=['#platform/javascript'])
env.Append(CPPDEFINES=['JAVASCRIPT_ENABLED', 'UNIX_ENABLED'])
# No multi-threading (SharedArrayBuffer) available yet,
# once feasible also consider memory buffer size issues.
env.Append(CPPDEFINES=['NO_THREADS'])
# These flags help keep the file size down.
env.Append(CCFLAGS=['-fno-exceptions', '-fno-rtti'])
# Don't use dynamic_cast, necessary with no-rtti.
env.Append(CPPDEFINES=['NO_SAFE_CAST'])
if env['javascript_eval']:
env.Append(CPPDEFINES=['JAVASCRIPT_EVAL_ENABLED'])
## Link flags
env.Append(LINKFLAGS=['-s', 'BINARYEN=1'])
env.Append(LINKFLAGS=['-s', 'BINARYEN_TRAP_MODE=\'clamp\''])
# Allow increasing memory buffer size during runtime. This is efficient
# when using WebAssembly (in comparison to asm.js) and works well for
# us since we don't know requirements at compile-time.
env.Append(LINKFLAGS=['-s', 'ALLOW_MEMORY_GROWTH=1'])
# This setting just makes WebGL 2 APIs available, it does NOT disable WebGL 1.
env.Append(LINKFLAGS=['-s', 'USE_WEBGL2=1'])
env.Append(LINKFLAGS=['-s', 'INVOKE_RUN=0'])
# TODO: Reevaluate usage of this setting now that engine.js manages engine runtime.
env.Append(LINKFLAGS=['-s', 'NO_EXIT_RUNTIME=1'])