godot/platform/javascript/detect.py
Rémi Verschelde 6d6280dfa3 Emscripten: Re-add BINARYEN_TRAP_MODE='clamp' for fastcomp
The option is needed when using the 'fastcomp' backend (default before
1.39.0), and must not be defined when using 'upstream' (new default).
So we define it conditionally to support both backends.

Follow-up to #30751.
2019-12-03 13:33:35 +01:00

156 lines
5.9 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),
('builtin_pcre2_with_jit', 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 'BINARYEN_ROOT' in em_config and os.path.isdir(os.path.join(em_config.get('BINARYEN_ROOT'), 'emscripten')):
# New style, emscripten path as a subfolder of BINARYEN_ROOT
env.PrependENVPath('PATH', os.path.join(em_config.get('BINARYEN_ROOT'), 'emscripten'))
elif 'EMSCRIPTEN_ROOT' in em_config:
# Old style (but can be there as a result from previous activation, so do last)
env.PrependENVPath('PATH', em_config.get('EMSCRIPTEN_ROOT'))
else:
raise RuntimeError("'BINARYEN_ROOT' or 'EMSCRIPTEN_ROOT' missing in Emscripten configuration file '%s'" % em_config_file)
env['CC'] = 'emcc'
env['CXX'] = 'em++'
env['LINK'] = 'emcc'
env['AR'] = 'emar'
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'])
# Disable exceptions and rtti on non-tools (template) builds
if not env['tools']:
# 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
# We use IDBFS in javascript_main.cpp. Since Emscripten 1.39.1 it needs to
# be linked explicitly.
env.Append(LIBS=['idbfs.js'])
env.Append(LINKFLAGS=['-s', 'BINARYEN=1'])
# This needs to be defined for Emscripten using 'fastcomp' (default pre-1.39.0)
# and undefined if using 'upstream'. And to make things simple, earlier
# Emscripten versions didn't include 'fastcomp' in their path, so we check
# against the presence of 'upstream' to conditionally add the flag.
if not "upstream" in em_config['EMSCRIPTEN_ROOT']:
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'])
#adding flag due to issue with emscripten 1.38.41 callMain method https://github.com/emscripten-core/emscripten/blob/incoming/ChangeLog.md#v13841-08072019
env.Append(LINKFLAGS=['-s', 'EXTRA_EXPORTED_RUNTIME_METHODS=["callMain"]'])