godot/platform/web/detect.py
Fabio Alessandrelli 7af8c494ab [Web] Force emcc to use "wasm" longjmp mode
SUPPORT_LONGJMP have changed since emscripten 3.1.32 to default to
"wasm" mode when exceptions are enabled, and "emscripten" mode when
disabled.

While we generally doesn't use exception in core, linked libraries may
need them, and emscripten don't plan to support WASM EH + Emscripten
SjLj in the long term.
2024-06-14 16:03:56 +02:00

300 lines
11 KiB
Python

import os
import sys
from typing import TYPE_CHECKING
from emscripten_helpers import (
add_js_externs,
add_js_libraries,
add_js_pre,
create_engine_file,
create_template_zip,
get_template_zip_path,
run_closure_compiler,
)
from SCons.Util import WhereIs
from methods import get_compiler_version, print_error, print_warning
if TYPE_CHECKING:
from SCons.Script.SConscript import SConsEnvironment
def get_name():
return "Web"
def can_build():
return WhereIs("emcc") is not None
def get_opts():
from SCons.Variables import BoolVariable
return [
("initial_memory", "Initial WASM memory (in MiB)", 32),
# Matches default values from before Emscripten 3.1.27. New defaults are too low for Godot.
("stack_size", "WASM stack size (in KiB)", 5120),
("default_pthread_stack_size", "WASM pthread default stack size (in KiB)", 2048),
BoolVariable("use_assertions", "Use Emscripten runtime assertions", False),
BoolVariable("use_ubsan", "Use Emscripten undefined behavior sanitizer (UBSAN)", False),
BoolVariable("use_asan", "Use Emscripten address sanitizer (ASAN)", False),
BoolVariable("use_lsan", "Use Emscripten leak sanitizer (LSAN)", False),
BoolVariable("use_safe_heap", "Use Emscripten SAFE_HEAP sanitizer", False),
# eval() can be a security concern, so it can be disabled.
BoolVariable("javascript_eval", "Enable JavaScript eval interface", True),
BoolVariable(
"dlink_enabled", "Enable WebAssembly dynamic linking (GDExtension support). Produces bigger binaries", False
),
BoolVariable("use_closure_compiler", "Use closure compiler to minimize JavaScript code", False),
BoolVariable(
"proxy_to_pthread",
"Use Emscripten PROXY_TO_PTHREAD option to run the main application code to a separate thread",
False,
),
]
def get_doc_classes():
return [
"EditorExportPlatformWeb",
]
def get_doc_path():
return "doc_classes"
def get_flags():
return {
"arch": "wasm32",
"target": "template_debug",
"builtin_pcre2_with_jit": False,
"vulkan": False,
# Embree is heavy and requires too much memory (GH-70621).
"module_raycast_enabled": False,
# 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.
"optimize": "size",
}
def configure(env: "SConsEnvironment"):
# Validate arch.
supported_arches = ["wasm32"]
if env["arch"] not in supported_arches:
print_error(
'Unsupported CPU architecture "%s" for Web. Supported architectures are: %s.'
% (env["arch"], ", ".join(supported_arches))
)
sys.exit(255)
try:
env["initial_memory"] = int(env["initial_memory"])
except Exception:
print_error("Initial memory must be a valid integer")
sys.exit(255)
## Build type
if env.debug_features:
# Retain function names for backtraces at the cost of file size.
env.Append(LINKFLAGS=["--profiling-funcs"])
else:
env["use_assertions"] = True
if env["use_assertions"]:
env.Append(LINKFLAGS=["-sASSERTIONS=1"])
if env.editor_build and env["initial_memory"] < 64:
print("Note: Forcing `initial_memory=64` as it is required for the web editor.")
env["initial_memory"] = 64
env.Append(LINKFLAGS=["-sINITIAL_MEMORY=%sMB" % env["initial_memory"]])
## Copy env variables.
env["ENV"] = os.environ
# LTO
if env["lto"] == "auto": # Full LTO for production.
env["lto"] = "full"
if env["lto"] != "none":
if env["lto"] == "thin":
env.Append(CCFLAGS=["-flto=thin"])
env.Append(LINKFLAGS=["-flto=thin"])
else:
env.Append(CCFLAGS=["-flto"])
env.Append(LINKFLAGS=["-flto"])
# Sanitizers
if env["use_ubsan"]:
env.Append(CCFLAGS=["-fsanitize=undefined"])
env.Append(LINKFLAGS=["-fsanitize=undefined"])
if env["use_asan"]:
env.Append(CCFLAGS=["-fsanitize=address"])
env.Append(LINKFLAGS=["-fsanitize=address"])
if env["use_lsan"]:
env.Append(CCFLAGS=["-fsanitize=leak"])
env.Append(LINKFLAGS=["-fsanitize=leak"])
if env["use_safe_heap"]:
env.Append(LINKFLAGS=["-sSAFE_HEAP=1"])
# Closure compiler
if env["use_closure_compiler"]:
# For emscripten support code.
env.Append(LINKFLAGS=["--closure", "1"])
# Register builder for our Engine files
jscc = env.Builder(generator=run_closure_compiler, suffix=".cc.js", src_suffix=".js")
env.Append(BUILDERS={"BuildJS": jscc})
# Add helper method for adding libraries, externs, pre-js.
env["JS_LIBS"] = []
env["JS_PRE"] = []
env["JS_EXTERNS"] = []
env.AddMethod(add_js_libraries, "AddJSLibraries")
env.AddMethod(add_js_pre, "AddJSPre")
env.AddMethod(add_js_externs, "AddJSExterns")
# Add method that joins/compiles our Engine files.
env.AddMethod(create_engine_file, "CreateEngineFile")
# Add method for getting the final zip path
env.AddMethod(get_template_zip_path, "GetTemplateZipPath")
# Add method for creating the final zip file
env.AddMethod(create_template_zip, "CreateTemplateZip")
# Closure compiler extern and support for ecmascript specs (const, let, etc).
env["ENV"]["EMCC_CLOSURE_ARGS"] = "--language_in ECMASCRIPT_2021"
env["CC"] = "emcc"
env["CXX"] = "em++"
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','$ARCOMSTR')}"
# All intermediate files are just object files.
env["OBJPREFIX"] = ""
env["OBJSUFFIX"] = ".o"
env["PROGPREFIX"] = ""
# Program() output consists of multiple files, so specify suffixes manually at builder.
env["PROGSUFFIX"] = ""
env["LIBPREFIX"] = "lib"
env["LIBSUFFIX"] = ".a"
env["LIBPREFIXES"] = ["$LIBPREFIX"]
env["LIBSUFFIXES"] = ["$LIBSUFFIX"]
# Get version info for checks below.
cc_version = get_compiler_version(env)
cc_semver = (cc_version["major"], cc_version["minor"], cc_version["patch"])
env.Prepend(CPPPATH=["#platform/web"])
env.Append(CPPDEFINES=["WEB_ENABLED", "UNIX_ENABLED"])
if env["opengl3"]:
env.AppendUnique(CPPDEFINES=["GLES3_ENABLED"])
# This setting just makes WebGL 2 APIs available, it does NOT disable WebGL 1.
env.Append(LINKFLAGS=["-sMAX_WEBGL_VERSION=2"])
# Allow use to take control of swapping WebGL buffers.
env.Append(LINKFLAGS=["-sOFFSCREEN_FRAMEBUFFER=1"])
# Breaking change since emscripten 3.1.51
# https://github.com/emscripten-core/emscripten/blob/main/ChangeLog.md#3151---121323
if cc_semver >= (3, 1, 51):
# Enables the use of *glGetProcAddress()
env.Append(LINKFLAGS=["-sGL_ENABLE_GET_PROC_ADDRESS=1"])
if env["javascript_eval"]:
env.Append(CPPDEFINES=["JAVASCRIPT_EVAL_ENABLED"])
stack_size_opt = "STACK_SIZE" if cc_semver >= (3, 1, 25) else "TOTAL_STACK"
env.Append(LINKFLAGS=["-s%s=%sKB" % (stack_size_opt, env["stack_size"])])
if env["threads"]:
# Thread support (via SharedArrayBuffer).
env.Append(CPPDEFINES=["PTHREAD_NO_RENAME"])
env.Append(CCFLAGS=["-sUSE_PTHREADS=1"])
env.Append(LINKFLAGS=["-sUSE_PTHREADS=1"])
env.Append(LINKFLAGS=["-sDEFAULT_PTHREAD_STACK_SIZE=%sKB" % env["default_pthread_stack_size"]])
env.Append(LINKFLAGS=["-sPTHREAD_POOL_SIZE=8"])
env.Append(LINKFLAGS=["-sWASM_MEM_MAX=2048MB"])
elif env["proxy_to_pthread"]:
print_warning('"threads=no" support requires "proxy_to_pthread=no", disabling proxy to pthread.')
env["proxy_to_pthread"] = False
if env["lto"] != "none":
# Workaround https://github.com/emscripten-core/emscripten/issues/19781.
if cc_semver >= (3, 1, 42) and cc_semver < (3, 1, 46):
env.Append(LINKFLAGS=["-Wl,-u,scalbnf"])
# Workaround https://github.com/emscripten-core/emscripten/issues/16836.
if cc_semver >= (3, 1, 47):
env.Append(LINKFLAGS=["-Wl,-u,_emscripten_run_callback_on_thread"])
if env["dlink_enabled"]:
if env["proxy_to_pthread"]:
print_warning("GDExtension support requires proxy_to_pthread=no, disabling proxy to pthread.")
env["proxy_to_pthread"] = False
if cc_semver < (3, 1, 14):
print_error("GDExtension support requires emscripten >= 3.1.14, detected: %s.%s.%s" % cc_semver)
sys.exit(255)
env.Append(CCFLAGS=["-sSIDE_MODULE=2"])
env.Append(LINKFLAGS=["-sSIDE_MODULE=2"])
env.Append(CCFLAGS=["-fvisibility=hidden"])
env.Append(LINKFLAGS=["-fvisibility=hidden"])
env.extra_suffix = ".dlink" + env.extra_suffix
# WASM_BIGINT is needed since emscripten ≥ 3.1.41
needs_wasm_bigint = cc_semver >= (3, 1, 41)
# Run the main application in a web worker
if env["proxy_to_pthread"]:
env.Append(LINKFLAGS=["-sPROXY_TO_PTHREAD=1"])
env.Append(CPPDEFINES=["PROXY_TO_PTHREAD_ENABLED"])
env.Append(LINKFLAGS=["-sEXPORTED_RUNTIME_METHODS=['_emscripten_proxy_main']"])
# https://github.com/emscripten-core/emscripten/issues/18034#issuecomment-1277561925
env.Append(LINKFLAGS=["-sTEXTDECODER=0"])
# BigInt support to pass object pointers between contexts
needs_wasm_bigint = True
if needs_wasm_bigint:
env.Append(LINKFLAGS=["-sWASM_BIGINT"])
# Reduce code size by generating less support code (e.g. skip NodeJS support).
env.Append(LINKFLAGS=["-sENVIRONMENT=web,worker"])
# Wrap the JavaScript support code around a closure named Godot.
env.Append(LINKFLAGS=["-sMODULARIZE=1", "-sEXPORT_NAME='Godot'"])
# Force long jump mode to 'wasm'
env.Append(CCFLAGS=["-sSUPPORT_LONGJMP='wasm'"])
env.Append(LINKFLAGS=["-sSUPPORT_LONGJMP='wasm'"])
# 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=["-sALLOW_MEMORY_GROWTH=1"])
# Do not call main immediately when the support code is ready.
env.Append(LINKFLAGS=["-sINVOKE_RUN=0"])
# callMain for manual start, cwrap for the mono version.
env.Append(LINKFLAGS=["-sEXPORTED_RUNTIME_METHODS=['callMain','cwrap']"])
# Add code that allow exiting runtime.
env.Append(LINKFLAGS=["-sEXIT_RUNTIME=1"])
# This workaround creates a closure that prevents the garbage collector from freeing the WebGL context.
# We also only use WebGL2, and changing context version is not widely supported anyway.
env.Append(LINKFLAGS=["-sGL_WORKAROUND_SAFARI_GETCONTEXT_BUG=0"])