#!/usr/bin/env python3

# Copyright 2011 The Emscripten Authors. All rights reserved.

# Emscripten is available under two separate licenses, the MIT license and the

# University of Illinois/NCSA Open Source License. Both these licenses can be

# found in the LICENSE file.

"""emcc - compiler helper script

=============================

emcc is a drop-in replacement for a compiler like gcc or clang.

See emcc --help for details.

emcc can be influenced by a few environment variables:

EMCC_DEBUG - "1" will log out useful information during compilation, as well as

save each compiler step as an emcc-* file in the temp dir

(by default /tmp/emscripten_temp). "2" will save additional emcc-*

steps, that would normally not be separately produced (so this

slows down compilation).

"""

from tools.toolchain_profiler import ToolchainProfiler

import base64

import glob

import hashlib

import json

import logging

import os

import re

import shlex

import shutil

import stat

import sys

import time

import tarfile

from enum import Enum, unique, auto

from subprocess import PIPE

from urllib.parse import quote

import emscripten

from tools import shared, system_libs, utils, ports, filelock

from tools import colored_logger, diagnostics, building

from tools.shared import unsuffixed, unsuffixed_basename, WINDOWS, safe_copy

from tools.shared import run_process, read_and_preprocess, exit_with_error, DEBUG

from tools.shared import do_replace

from tools.response_file import substitute_response_files

from tools.minimal_runtime_shell import generate_minimal_runtime_html

import tools.line_endings

from tools import feature_matrix

from tools import js_manipulation

from tools import webassembly

from tools import config

from tools import cache

from tools.settings import default_setting, user_settings, settings, MEM_SIZE_SETTINGS, COMPILE_TIME_SETTINGS

from tools.utils import read_file, write_file, read_binary, delete_file, removeprefix

logger = logging.getLogger('emcc')

# endings = dot + a suffix, compare against result of shared.suffix()

C_ENDINGS = ['.c', '.i']

CXX_ENDINGS = ['.cppm', '.pcm', '.cpp', '.cxx', '.cc', '.c++', '.CPP', '.CXX', '.C', '.CC', '.C++', '.ii']

OBJC_ENDINGS = ['.m', '.mi']

PREPROCESSED_ENDINGS = ['.i', '.ii']

OBJCXX_ENDINGS = ['.mm', '.mii']

SPECIAL_ENDINGLESS_FILENAMES = [os.devnull]

C_ENDINGS += SPECIAL_ENDINGLESS_FILENAMES # consider the special endingless filenames like /dev/null to be C

SOURCE_ENDINGS = C_ENDINGS + CXX_ENDINGS + OBJC_ENDINGS + OBJCXX_ENDINGS + ['.ll', '.S']

EXECUTABLE_ENDINGS = ['.wasm', '.html', '.js', '.mjs', '.out', '']

DYNAMICLIB_ENDINGS = ['.dylib', '.so'] # Windows .dll suffix is not included in this list, since those are never linked to directly on the command line.

STATICLIB_ENDINGS = ['.a']

ASSEMBLY_ENDINGS = ['.s']

HEADER_ENDINGS = ['.h', '.hxx', '.hpp', '.hh', '.H', '.HXX', '.HPP', '.HH']

DEFAULT_SHELL_HTML = utils.path_from_root('src/shell.html')

# Supported LLD flags which we will pass through to the linker.

SUPPORTED_LINKER_FLAGS = (

'--start-group', '--end-group',

'-(', '-)',

'--whole-archive', '--no-whole-archive',

'-whole-archive', '-no-whole-archive'

)

# Unsupported LLD flags which we will ignore.

# Maps to true if the flag takes an argument.

UNSUPPORTED_LLD_FLAGS = {

# macOS-specific linker flag that libtool (ltmain.sh) will if macOS is detected.

'-bind_at_load': False,

# wasm-ld doesn't support soname or other dynamic linking flags (yet). Ignore them

# in order to aid build systems that want to pass these flags.

'-soname': True,

'-allow-shlib-undefined': False,

'-rpath': True,

'-rpath-link': True,

'-version-script': True,

'-install_name': True,

}

DEFAULT_ASYNCIFY_IMPORTS = [

'wasi_snapshot_preview1.fd_sync', '__wasi_fd_sync', '__asyncjs__*'

]

DEFAULT_ASYNCIFY_EXPORTS = [

'main',

'__main_argc_argv',

# Embind's async template wrapper functions. These functions are usually in

# the function pointer table and not called from exports, but we need to name

# them so the JSPI pass can find and convert them.

'_ZN10emscripten8internal5async*'

]

# Target options

final_js = None

UBSAN_SANITIZERS = {

'alignment',

'bool',

'builtin',

'bounds',

'enum',

'float-cast-overflow',

'float-divide-by-zero',

'function',

'implicit-unsigned-integer-truncation',

'implicit-signed-integer-truncation',

'implicit-integer-sign-change',

'integer-divide-by-zero',

'nonnull-attribute',

'null',

'nullability-arg',

'nullability-assign',

'nullability-return',

'object-size',

'pointer-overflow',

'return',

'returns-nonnull-attribute',

'shift',

'signed-integer-overflow',

'unreachable',

'unsigned-integer-overflow',

'vla-bound',

'vptr',

'undefined',

'undefined-trap',

'implicit-integer-truncation',

'implicit-integer-arithmetic-value-change',

'implicit-conversion',

'integer',

'nullability',

}

# These symbol names are allowed in INCOMING_MODULE_JS_API but are not part of the

# default set.

EXTRA_INCOMING_JS_API = [

'fetchSettings'

]

VALID_ENVIRONMENTS = ('web', 'webview', 'worker', 'node', 'shell')

SIMD_INTEL_FEATURE_TOWER = ['-msse', '-msse2', '-msse3', '-mssse3', '-msse4.1', '-msse4.2', '-msse4', '-mavx']

SIMD_NEON_FLAGS = ['-mfpu=neon']

COMPILE_ONLY_FLAGS = {'--default-obj-ext'}

LINK_ONLY_FLAGS = {

'--bind', '--closure', '--cpuprofiler', '--embed-file',

'--emit-symbol-map', '--emrun', '--exclude-file', '--extern-post-js',

'--extern-pre-js', '--ignore-dynamic-linking', '--js-library',

'--js-transform', '--memory-init-file', '--oformat', '--output_eol',

'--post-js', '--pre-js', '--preload-file', '--profiling-funcs',

'--proxy-to-worker', '--shell-file', '--source-map-base',

'--threadprofiler', '--use-preload-plugins'

}

# this function uses the global 'final' variable, which contains the current

# final output file. if a method alters final, and calls this method, then it

# must modify final globally (i.e. it can't receive final as a param and

# return it)

# TODO: refactor all this, a singleton that abstracts over the final output

# and saving of intermediates

def save_intermediate(name, suffix='js'):

if not DEBUG:

return

if not final_js:

logger.debug(f'(not saving intermediate {name} because not generating JS)')

return

building.save_intermediate(final_js, f'{name}.{suffix}')

def save_intermediate_with_wasm(name, wasm_binary):

if not DEBUG:

return

save_intermediate(name) # save the js

building.save_intermediate(wasm_binary, name + '.wasm')

def base64_encode(b):

b64 = base64.b64encode(b)

return b64.decode('ascii')

def align_to_wasm_page_boundary(address):

page_size = webassembly.WASM_PAGE_SIZE

return ((address + (page_size - 1)) // page_size) * page_size

@unique

class OFormat(Enum):

# Output a relocatable object file. We use this

# today for `-r` and `-shared`.

OBJECT = auto()

WASM = auto()

JS = auto()

MJS = auto()

HTML = auto()

BARE = auto()

@unique

class Mode(Enum):

PREPROCESS_ONLY = auto()

PCH = auto()

COMPILE_ONLY = auto()

POST_LINK_ONLY = auto()

COMPILE_AND_LINK = auto()

class EmccState:

def __init__(self, args):

self.mode = Mode.COMPILE_AND_LINK

# Using tuple here to prevent accidental mutation

self.orig_args = tuple(args)

self.has_dash_c = False

self.has_dash_E = False

self.has_dash_S = False

self.link_flags = []

self.lib_dirs = []

self.forced_stdlibs = []

def add_link_flag(state, i, f):

if f.startswith('-L'):

state.lib_dirs.append(f[2:])

state.link_flags.append((i, f))

class EmccOptions:

def __init__(self):

self.target = ''

self.output_file = None

self.no_minify = False

self.post_link = False

self.executable = False

self.compiler_wrapper = None

self.oformat = None

self.requested_debug = ''

self.emit_symbol_map = False

self.use_closure_compiler = None

self.closure_args = []

self.js_transform = None

self.pre_js = [] # before all js

self.post_js = [] # after all js

self.extern_pre_js = [] # before all js, external to optimized code

self.extern_post_js = [] # after all js, external to optimized code

self.preload_files = []

self.embed_files = []

self.exclude_files = []

self.ignore_dynamic_linking = False

self.shell_path = DEFAULT_SHELL_HTML

self.source_map_base = ''

self.embind_emit_tsd = ''

self.emrun = False

self.cpu_profiler = False

self.memory_profiler = False

self.memory_init_file = None

self.use_preload_cache = False

self.use_preload_plugins = False

self.default_object_extension = '.o'

self.valid_abspaths = []

# Specifies the line ending format to use for all generated text files.

# Defaults to using the native EOL on each platform (\r\n on Windows, \n on

# Linux & MacOS)

self.output_eol = os.linesep

self.no_entry = False

self.shared = False

self.relocatable = False

self.reproduce = None

def will_metadce():

# The metadce JS parsing code does not currently support the JS that gets generated

# when assertions are enabled.

if settings.ASSERTIONS:

return False

return settings.OPT_LEVEL >= 3 or settings.SHRINK_LEVEL >= 1

def create_reproduce_file(name, args):

def make_relative(filename):

filename = os.path.normpath(os.path.abspath(filename))

filename = os.path.splitdrive(filename)[1]

filename = filename[1:]

return filename

root = unsuffixed_basename(name)

with tarfile.open(name, 'w') as reproduce_file:

reproduce_file.add(shared.path_from_root('emscripten-version.txt'), os.path.join(root, 'version.txt'))

with shared.get_temp_files().get_file(suffix='.tar') as rsp_name:

with open(rsp_name, 'w') as rsp:

ignore_next = False

output_arg = None

for arg in args:

ignore = ignore_next

ignore_next = False

if arg.startswith('--reproduce='):

continue

if arg.startswith('-o='):

rsp.write('-o\n')

arg = arg[3:]

output_arg = True

ignore = True

if output_arg:

# If -o path contains directories, "emcc @response.txt" will likely

# fail because the archive we are creating doesn't contain empty

# directories for the output path (-o doesn't create directories).

# Strip directories to prevent the issue.

arg = os.path.basename(arg)

output_arg = False

if not arg.startswith('-') and not ignore:

relpath = make_relative(arg)

rsp.write(relpath + '\n')

reproduce_file.add(arg, os.path.join(root, relpath))

else:

rsp.write(arg + '\n')

if ignore:

continue

if arg in ('-MT', '-MF', '-MJ', '-MQ', '-D', '-U', '-o', '-x',

'-Xpreprocessor', '-include', '-imacros', '-idirafter',

'-iprefix', '-iwithprefix', '-iwithprefixbefore',

'-isysroot', '-imultilib', '-A', '-isystem', '-iquote',

'-install_name', '-compatibility_version',

'-current_version', '-I', '-L', '-include-pch',

'-Xlinker', '-Xclang'):

ignore_next = True

if arg == '-o':

output_arg = True

reproduce_file.add(rsp_name, os.path.join(root, 'response.txt'))

def setup_environment_settings():

# Environment setting based on user input

environments = settings.ENVIRONMENT.split(',')

if any([x for x in environments if x not in VALID_ENVIRONMENTS]):

exit_with_error(f'Invalid environment specified in "ENVIRONMENT": {settings.ENVIRONMENT}. Should be one of: {",".join(VALID_ENVIRONMENTS)}')

settings.ENVIRONMENT_MAY_BE_WEB = not settings.ENVIRONMENT or 'web' in environments

settings.ENVIRONMENT_MAY_BE_WEBVIEW = not settings.ENVIRONMENT or 'webview' in environments

settings.ENVIRONMENT_MAY_BE_NODE = not settings.ENVIRONMENT or 'node' in environments

settings.ENVIRONMENT_MAY_BE_SHELL = not settings.ENVIRONMENT or 'shell' in environments

# The worker case also includes Node.js workers when pthreads are

# enabled and Node.js is one of the supported environments for the build to

# run on. Node.js workers are detected as a combination of

# ENVIRONMENT_IS_WORKER and ENVIRONMENT_IS_NODE.

settings.ENVIRONMENT_MAY_BE_WORKER = \

not settings.ENVIRONMENT or \

'worker' in environments or \

(settings.ENVIRONMENT_MAY_BE_NODE and settings.PTHREADS)

if not settings.ENVIRONMENT_MAY_BE_WORKER and settings.PROXY_TO_WORKER:

exit_with_error('If you specify --proxy-to-worker and specify a "-sENVIRONMENT=" directive, it must include "worker" as a target! (Try e.g. -sENVIRONMENT=web,worker)')

if not settings.ENVIRONMENT_MAY_BE_WORKER and settings.SHARED_MEMORY:

exit_with_error('When building with multithreading enabled and a "-sENVIRONMENT=" directive is specified, it must include "worker" as a target! (Try e.g. -sENVIRONMENT=web,worker)')

def embed_memfile(options):

return (settings.SINGLE_FILE or

(settings.WASM2JS and not options.memory_init_file and

(not settings.MAIN_MODULE and

not settings.SIDE_MODULE and

not settings.GENERATE_SOURCE_MAP)))

def expand_byte_size_suffixes(value):

"""Given a string with KB/MB size suffixes, such as "32MB", computes how

many bytes that is and returns it as an integer.

"""

value = value.strip()

match = re.match(r'^(\d+)\s*([kmgt]?b)?$', value, re.I)

if not match:

exit_with_error("invalid byte size `%s`. Valid suffixes are: kb, mb, gb, tb" % value)

value, suffix = match.groups()

value = int(value)

if suffix:

size_suffixes = {suffix: 1024 ** i for i, suffix in enumerate(['b', 'kb', 'mb', 'gb', 'tb'])}

value *= size_suffixes[suffix.lower()]

return value

def apply_user_settings():

"""Take a map of users settings {NAME: VALUE} and apply them to the global

settings object.

"""

# Stash a copy of all available incoming APIs before the user can potentially override it

settings.ALL_INCOMING_MODULE_JS_API = settings.INCOMING_MODULE_JS_API + EXTRA_INCOMING_JS_API

for key, value in user_settings.items():

if key in settings.internal_settings:

exit_with_error('%s is an internal setting and cannot be set from command line', key)

# map legacy settings which have aliases to the new names

# but keep the original key so errors are correctly reported via the `setattr` below

user_key = key

if key in settings.legacy_settings and key in settings.alt_names:

key = settings.alt_names[key]

# In those settings fields that represent amount of memory, translate suffixes to multiples of 1024.

if key in MEM_SIZE_SETTINGS:

value = str(expand_byte_size_suffixes(value))

filename = None

if value and value[0] == '@':

filename = removeprefix(value, '@')

if not os.path.exists(filename):

exit_with_error('%s: file not found parsing argument: %s=%s' % (filename, key, value))

value = read_file(filename).strip()

else:

value = value.replace('\\', '\\\\')

expected_type = settings.types.get(key)

if filename and expected_type == list and value.strip()[0] != '[':

# Prefer simpler one-line-per value parser

value = parse_symbol_list_file(value)

else:

try:

value = parse_value(value, expected_type)

except Exception as e:

exit_with_error('a problem occurred in evaluating the content after a "-s", specifically "%s=%s": %s', key, value, str(e))

setattr(settings, user_key, value)

if key == 'EXPORTED_FUNCTIONS':

# used for warnings in emscripten.py

settings.USER_EXPORTED_FUNCTIONS = settings.EXPORTED_FUNCTIONS.copy()

# TODO(sbc): Remove this legacy way.

if key == 'WASM_OBJECT_FILES':

settings.LTO = 0 if value else 'full'

def is_ar_file_with_missing_index(archive_file):

# We parse the archive header outselves because llvm-nm --print-armap is slower and less

# reliable.

# See: https://github.com/emscripten-core/emscripten/issues/10195

archive_header = b'!<arch>\n'

file_header_size = 60

with open(archive_file, 'rb') as f:

header = f.read(len(archive_header))

if header != archive_header:

# This is not even an ar file

return False

file_header = f.read(file_header_size)

if len(file_header) != file_header_size:

# We don't have any file entires at all so we don't consider the index missing

return False

name = file_header[:16].strip()

# If '/' is the name of the first file we have an index

return name != b'/'

def ensure_archive_index(archive_file):

# Fastcomp linking works without archive indexes.

if not settings.AUTO_ARCHIVE_INDEXES:

return

if is_ar_file_with_missing_index(archive_file):

diagnostics.warning('emcc', '%s: archive is missing an index; Use emar when creating libraries to ensure an index is created', archive_file)

diagnostics.warning('emcc', '%s: adding index', archive_file)

run_process([shared.LLVM_RANLIB, archive_file])

def generate_js_sym_info():

# Runs the js compiler to generate a list of all symbols available in the JS

# libraries. This must be done separately for each linker invokation since the

# list of symbols depends on what settings are used.

# TODO(sbc): Find a way to optimize this. Potentially we could add a super-set

# mode of the js compiler that would generate a list of all possible symbols

# that could be checked in.

_, forwarded_data = emscripten.compile_javascript(symbols_only=True)

# When running in symbols_only mode compiler.js outputs a flat list of C symbols.

return json.loads(forwarded_data)

@ToolchainProfiler.profile_block('JS symbol generation')

def get_js_sym_info():

# Avoiding using the cache when generating struct info since

# this step is performed while the cache is locked.

if DEBUG or settings.BOOTSTRAPPING_STRUCT_INFO or config.FROZEN_CACHE:

return generate_js_sym_info()

# We define a cache hit as when the settings and `--js-library` contents are

# identical.

# Ignore certain settings that can are no relevant to library deps. Here we

# skip PRE_JS_FILES/POST_JS_FILES which don't effect the library symbol list

# and can contain full paths to temporary files.

skip_settings = {'PRE_JS_FILES', 'POST_JS_FILES'}

input_files = [json.dumps(settings.external_dict(skip_keys=skip_settings), sort_keys=True, indent=2)]

for jslib in sorted(glob.glob(utils.path_from_root('src') + '/library*.js')):

input_files.append(read_file(jslib))

for jslib in settings.JS_LIBRARIES:

if not os.path.isabs(jslib):

jslib = utils.path_from_root('src', jslib)

input_files.append(read_file(jslib))

content = '\n'.join(input_files)

content_hash = hashlib.sha1(content.encode('utf-8')).hexdigest()

def build_symbol_list(filename):

"""Only called when there is no existing symbol list for a given content hash.

"""

library_syms = generate_js_sym_info()

write_file(filename, json.dumps(library_syms, separators=(',', ':'), indent=2))

# We need to use a separate lock here for symbol lists because, unlike with system libraries,

# it's normally for these file to get pruned as part of normal operation. This means that it

# can be deleted between the `cache.get()` then the `read_file`.

with filelock.FileLock(cache.get_path(cache.get_path('symbol_lists.lock'))):

filename = cache.get(f'symbol_lists/{content_hash}.json', build_symbol_list)

library_syms = json.loads(read_file(filename))

# Limit of the overall size of the cache to 100 files.

# This code will get test coverage since a full test run of `other` or `core`

# generates ~1000 unique symbol lists.

cache_limit = 500

root = cache.get_path('symbol_lists')

if len(os.listdir(root)) > cache_limit:

files = []

for f in os.listdir(root):

f = os.path.join(root, f)

files.append((f, os.path.getmtime(f)))

files.sort(key=lambda x: x[1])

# Delete all but the newest N files

for f, _ in files[:-cache_limit]:

delete_file(f)

return library_syms

def filter_link_flags(flags, using_lld):

def is_supported(f):

if using_lld:

for flag, takes_arg in UNSUPPORTED_LLD_FLAGS.items():

# lld allows various flags to have either a single -foo or double --foo

if f.startswith(flag) or f.startswith('-' + flag):

diagnostics.warning('linkflags', 'ignoring unsupported linker flag: `%s`', f)

# Skip the next argument if this linker flag takes and argument and that

# argument was not specified as a separately (i.e. it was specified as

# single arg containing an `=` char.)

skip_next = takes_arg and '=' not in f

return False, skip_next

return True, False

else:

if f in SUPPORTED_LINKER_FLAGS:

return True, False

# Silently ignore -l/-L flags when not using lld. If using lld allow

# them to pass through the linker

if f.startswith('-l') or f.startswith('-L'):

return False, False

diagnostics.warning('linkflags', 'ignoring unsupported linker flag: `%s`', f)

return False, False

results = []

skip_next = False

for f in flags:

if skip_next:

skip_next = False

continue

keep, skip_next = is_supported(f[1])

if keep:

results.append(f)

return results

def fix_windows_newlines(text):

# Avoid duplicating \r\n to \r\r\n when writing out text.

if WINDOWS:

text = text.replace('\r\n', '\n')

return text

def read_js_files(files):

contents = '\n'.join(read_file(f) for f in files)

return fix_windows_newlines(contents)

def cxx_to_c_compiler(cxx):

# Convert C++ compiler name into C compiler name

dirname, basename = os.path.split(cxx)

basename = basename.replace('clang++', 'clang').replace('g++', 'gcc').replace('em++', 'emcc')

return os.path.join(dirname, basename)

def should_run_binaryen_optimizer():

# run the binaryen optimizer in -O2+. in -O0 we don't need it obviously, while

# in -O1 we don't run it as the LLVM optimizer has been run, and it does the

# great majority of the work; not running the binaryen optimizer in that case

# keeps -O1 mostly-optimized while compiling quickly and without rewriting

# DWARF etc.

return settings.OPT_LEVEL >= 2

def get_binaryen_passes():

passes = []

optimizing = should_run_binaryen_optimizer()

# safe heap must run before post-emscripten, so post-emscripten can apply the sbrk ptr

if settings.SAFE_HEAP:

passes += ['--safe-heap']

# sign-ext is enabled by default by llvm. If the target browser settings don't support

# this we lower it away here using a binaryen pass.

if not feature_matrix.caniuse(feature_matrix.Feature.SIGN_EXT):

logger.debug('lowering sign-ext feature due to incompatiable target browser engines')

passes += ['--signext-lowering']

if optimizing:

passes += ['--post-emscripten']

if settings.SIDE_MODULE:

passes += ['--pass-arg=post-emscripten-side-module']

if optimizing:

passes += [building.opt_level_to_str(settings.OPT_LEVEL, settings.SHRINK_LEVEL)]

# when optimizing, use the fact that low memory is never used (1024 is a

# hardcoded value in the binaryen pass)

if optimizing and settings.GLOBAL_BASE >= 1024:

passes += ['--low-memory-unused']

if settings.AUTODEBUG:

# adding '--flatten' here may make these even more effective

passes += ['--instrument-locals']

passes += ['--log-execution']

passes += ['--instrument-memory']

if settings.LEGALIZE_JS_FFI:

# legalize it again now, as the instrumentation may need it

passes += ['--legalize-js-interface']

passes += building.js_legalization_pass_flags()

if settings.EMULATE_FUNCTION_POINTER_CASTS:

# note that this pass must run before asyncify, as if it runs afterwards we only

# generate the byn$fpcast_emu functions after asyncify runs, and so we wouldn't

# be able to further process them.

passes += ['--fpcast-emu']

if settings.ASYNCIFY == 1:

passes += ['--asyncify']

if settings.MAIN_MODULE or settings.SIDE_MODULE:

passes += ['--pass-arg=asyncify-relocatable']

if settings.ASSERTIONS:

passes += ['--pass-arg=asyncify-asserts']

if settings.ASYNCIFY_ADVISE:

passes += ['--pass-arg=asyncify-verbose']

if settings.ASYNCIFY_IGNORE_INDIRECT:

passes += ['--pass-arg=asyncify-ignore-indirect']

passes += ['--pass-arg=asyncify-imports@%s' % ','.join(settings.ASYNCIFY_IMPORTS)]

# shell escaping can be confusing; try to emit useful warnings

def check_human_readable_list(items):

for item in items:

if item.count('(') != item.count(')'):

logger.warning('emcc: ASYNCIFY list contains an item without balanced parentheses ("(", ")"):')

logger.warning(' ' + item)

logger.warning('This may indicate improper escaping that led to splitting inside your names.')

logger.warning('Try using a response file. e.g: -sASYNCIFY_ONLY=@funcs.txt. The format is a simple')

logger.warning('text file, one line per function.')

break

if settings.ASYNCIFY_REMOVE:

check_human_readable_list(settings.ASYNCIFY_REMOVE)

passes += ['--pass-arg=asyncify-removelist@%s' % ','.join(settings.ASYNCIFY_REMOVE)]

if settings.ASYNCIFY_ADD:

check_human_readable_list(settings.ASYNCIFY_ADD)

passes += ['--pass-arg=asyncify-addlist@%s' % ','.join(settings.ASYNCIFY_ADD)]

if settings.ASYNCIFY_ONLY:

check_human_readable_list(settings.ASYNCIFY_ONLY)

passes += ['--pass-arg=asyncify-onlylist@%s' % ','.join(settings.ASYNCIFY_ONLY)]

elif settings.ASYNCIFY == 2:

passes += ['--jspi']

passes += ['--pass-arg=jspi-imports@%s' % ','.join(settings.ASYNCIFY_IMPORTS)]

passes += ['--pass-arg=jspi-exports@%s' % ','.join(settings.ASYNCIFY_EXPORTS)]

if settings.SPLIT_MODULE:

passes += ['--pass-arg=jspi-split-module']

if settings.MEMORY64 == 2:

passes += ['--memory64-lowering']

if settings.BINARYEN_IGNORE_IMPLICIT_TRAPS:

passes += ['--ignore-implicit-traps']

# normally we can assume the memory, if imported, has not been modified

# beforehand (in fact, in most cases the memory is not even imported anyhow,

# but it is still safe to pass the flag), and is therefore filled with zeros.

# the one exception is dynamic linking of a side module: the main module is ok

# as it is loaded first, but the side module may be assigned memory that was

# previously used.

if optimizing and not settings.SIDE_MODULE:

passes += ['--zero-filled-memory']

# LLVM output always has immutable initial table contents: the table is

# fixed and may only be appended to at runtime (that is true even in

# relocatable mode)

if optimizing:

passes += ['--pass-arg=directize-initial-contents-immutable']

if settings.BINARYEN_EXTRA_PASSES:

# BINARYEN_EXTRA_PASSES is comma-separated, and we support both '-'-prefixed and

# unprefixed pass names

extras = settings.BINARYEN_EXTRA_PASSES.split(',')

passes += [('--' + p) if p[0] != '-' else p for p in extras if p]

return passes

def make_js_executable(script):

src = read_file(script)

cmd = config.NODE_JS

if settings.MEMORY64 == 1:

cmd += shared.node_memory64_flags()

elif settings.WASM_BIGINT:

cmd += shared.node_bigint_flags()

if len(cmd) > 1 or not os.path.isabs(cmd[0]):

# Using -S (--split-string) here means that arguments to the executable are

# correctly parsed. We don't do this by default because old versions of env

# don't support -S.

cmd = '/usr/bin/env -S ' + shared.shlex_join(cmd)

else:

cmd = shared.shlex_join(cmd)

logger.debug('adding `#!` to JavaScript file: %s' % cmd)

# add shebang

with open(script, 'w') as f:

f.write('#!%s\n' % cmd)

f.write(src)

try:

os.chmod(script, stat.S_IMODE(os.stat(script).st_mode) | stat.S_IXUSR) # make executable

except OSError:

pass # can fail if e.g. writing the executable to /dev/null

def do_split_module(wasm_file, options):

os.rename(wasm_file, wasm_file + '.orig')

args = ['--instrument']

if options.requested_debug:

# Tell wasm-split to preserve function names.

args += ['-g']

building.run_binaryen_command('wasm-split', wasm_file + '.orig', outfile=wasm_file, args=args)

def is_dash_s_for_emcc(args, i):

# -s OPT=VALUE or -s OPT or -sOPT are all interpreted as emscripten flags.

# -s by itself is a linker option (alias for --strip-all)

if args[i] == '-s':

if len(args) <= i + 1:

return False

arg = args[i + 1]

else:

arg = removeprefix(args[i], '-s')

arg = arg.split('=')[0]

return arg.isidentifier() and arg.isupper()

def filter_out_dynamic_libs(options, inputs):

# Filters out "fake" dynamic libraries that are really just intermediate object files.

def check(input_file):

if get_file_suffix(input_file) in DYNAMICLIB_ENDINGS and not building.is_wasm_dylib(input_file):

if not options.ignore_dynamic_linking:

diagnostics.warning('emcc', 'ignoring dynamic library %s because not compiling to JS or HTML, remember to link it when compiling to JS or HTML at the end', os.path.basename(input_file))

return False

else:

return True

return [f for f in inputs if check(f)]

def filter_out_duplicate_dynamic_libs(inputs):

seen = set()

# Filter out duplicate "fake" shared libraries (intermediate object files).

# See test_core.py:test_redundant_link

def check(input_file):

if get_file_suffix(input_file) in DYNAMICLIB_ENDINGS and not building.is_wasm_dylib(input_file):

abspath = os.path.abspath(input_file)

if abspath in seen:

return False

seen.add(abspath)

return True

return [f for f in inputs if check(f)]

def process_dynamic_libs(dylibs, lib_dirs):

extras = []

seen = set()

to_process = dylibs.copy()

while to_process:

dylib = to_process.pop()

dylink = webassembly.parse_dylink_section(dylib)

for needed in dylink.needed:

if needed in seen:

continue

path = find_library(needed, lib_dirs)

if path:

extras.append(path)

seen.add(needed)

else:

exit_with_error(f'{os.path.normpath(dylib)}: shared library dependency not found: `{needed}`')

to_process.append(path)

dylibs += extras

for dylib in dylibs:

exports = webassembly.get_exports(dylib)

exports = set(e.name for e in exports)

# EM_JS function are exports with a special prefix. We need to strip

# this prefix to get the actaul symbol name. For the main module, this

# is handled by extract_metadata.py.

exports = [removeprefix(e, '__em_js__') for e in exports]

settings.SIDE_MODULE_EXPORTS.extend(sorted(exports))

imports = webassembly.get_imports(dylib)

imports = [i.field for i in imports if i.kind in (webassembly.ExternType.FUNC, webassembly.ExternType.GLOBAL, webassembly.ExternType.TAG)]

# For now we ignore `invoke_` functions imported by side modules and rely

# on the dynamic linker to create them on the fly.

# TODO(sbc): Integrate with metadata.invokeFuncs that comes from the

# main module to avoid creating new invoke functions at runtime.

imports = set(imports)

imports = set(i for i in imports if not i.startswith('invoke_'))

weak_imports = webassembly.get_weak_imports(dylib)

strong_imports = sorted(imports.difference(weak_imports))

logger.debug('Adding symbols requirements from `%s`: %s', dylib, imports)

mangled_imports = [shared.asmjs_mangle(e) for e in sorted(imports)]

mangled_strong_imports = [shared.asmjs_mangle(e) for e in strong_imports]

for sym in weak_imports:

mangled = shared.asmjs_mangle(sym)

if mangled not in settings.SIDE_MODULE_IMPORTS and mangled not in building.user_requested_exports:

settings.WEAK_IMPORTS.append(sym)

settings.SIDE_MODULE_IMPORTS.extend(mangled_imports)

settings.EXPORT_IF_DEFINED.extend(sorted(imports))

settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.extend(sorted(imports))

building.user_requested_exports.update(mangled_strong_imports)

def unmangle_symbols_from_cmdline(symbols):

def unmangle(x):

return x.replace('.', ' ').replace('#', '&').replace('?', ',')

if type(symbols) is list:

return [unmangle(x) for x in symbols]

return unmangle(symbols)

def parse_s_args(args):

settings_changes = []

for i in range(len(args)):

if args[i].startswith('-s'):

if is_dash_s_for_emcc(args, i):

if args[i] == '-s':

key = args[i + 1]

args[i + 1] = ''

else:

key = removeprefix(args[i], '-s')

args[i] = ''

# If not = is specified default to 1

if '=' not in key:

key += '=1'

# Special handling of browser version targets. A version -1 means that the specific version

# is not supported at all. Replace those with INT32_MAX to make it possible to compare e.g.

# #if MIN_FIREFOX_VERSION < 68

if re.match(r'MIN_.*_VERSION(=.*)?', key):

try:

if int(key.split('=')[1]) < 0:

key = key.split('=')[0] + '=0x7FFFFFFF'

except Exception:

pass

settings_changes.append(key)

newargs = [a for a in args if a]

return (settings_changes, newargs)

def emsdk_cflags(user_args):

cflags = ['--sysroot=' + cache.get_sysroot(absolute=True)]

def array_contains_any_of(hay, needles):

for n in needles:

if n in hay:

return True

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER) or array_contains_any_of(user_args, SIMD_NEON_FLAGS):

if '-msimd128' not in user_args and '-mrelaxed-simd' not in user_args:

exit_with_error('Passing any of ' + ', '.join(SIMD_INTEL_FEATURE_TOWER + SIMD_NEON_FLAGS) + ' flags also requires passing -msimd128 (or -mrelaxed-simd)!')

cflags += ['-D__SSE__=1']

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER[1:]):

cflags += ['-D__SSE2__=1']

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER[2:]):

cflags += ['-D__SSE3__=1']

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER[3:]):

cflags += ['-D__SSSE3__=1']

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER[4:]):

cflags += ['-D__SSE4_1__=1']

# Handle both -msse4.2 and its alias -msse4.

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER[5:]):

cflags += ['-D__SSE4_2__=1']

if array_contains_any_of(user_args, SIMD_INTEL_FEATURE_TOWER[7:]):

cflags += ['-D__AVX__=1']

if array_contains_any_of(user_args, SIMD_NEON_FLAGS):

cflags += ['-D__ARM_NEON__=1']

if not settings.USE_SDL:

cflags += ['-Xclang', '-iwithsysroot' + os.path.join('/include', 'fakesdl')]

return cflags + ['-Xclang', '-iwithsysroot' + os.path.join('/include', 'compat')]

def get_target_flags():

return ['-target', shared.get_llvm_target()]

def get_clang_flags(user_args):

flags = get_target_flags()

# if exception catching is disabled, we can prevent that code from being

# generated in the frontend

if settings.DISABLE_EXCEPTION_CATCHING and not settings.WASM_EXCEPTIONS:

flags.append('-fignore-exceptions')

if settings.INLINING_LIMIT:

flags.append('-fno-inline-functions')

if settings.RELOCATABLE and '-fPIC' not in user_args:

flags.append('-fPIC')

# We use default visiibilty=default in emscripten even though the upstream

# backend defaults visibility=hidden. This matched the expectations of C/C++

# code in the wild which expects undecorated symbols to be exported to other

# DSO's by default.

if not any(a.startswith('-fvisibility') for a in user_args):

flags.append('-fvisibility=default')

if settings.LTO:

if not any(a.startswith('-flto') for a in user_args):

flags.append('-flto=' + settings.LTO)

# setjmp/longjmp handling using Wasm EH

# For non-LTO, '-mllvm -wasm-enable-eh' added in

# building.llvm_backend_args() sets this feature in clang. But in LTO, the

# argument is added to wasm-ld instead, so clang needs to know that EH is

# enabled so that it can be added to the attributes in LLVM IR.

if settings.SUPPORT_LONGJMP == 'wasm':

flags.append('-mexception-handling')

else:

# In LTO mode these args get passed instead at link time when the backend runs.

for a in building.llvm_backend_args():

flags += ['-mllvm', a]

return flags

cflags = None

def get_cflags(user_args, is_cxx):

global cflags

if cflags:

return cflags

# Flags we pass to the compiler when building C/C++ code

# We add these to the user's flags (newargs), but not when building .s or .S assembly files

cflags = get_clang_flags(user_args)

if settings.EMSCRIPTEN_TRACING:

cflags.append('-D__EMSCRIPTEN_TRACING__=1')