# 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. import base64 import json import logging import os import re import shlex import shutil import stat import time from subprocess import PIPE from urllib.parse import quote from . import ( building, cache, config, diagnostics, emscripten, extract_metadata, feature_matrix, js_manipulation, ports, shared, system_libs, utils, webassembly, ) from .cmdline import OFormat from .feature_matrix import Feature from .minimal_runtime_shell import generate_minimal_runtime_html from .settings import ( DEPRECATED_SETTINGS, EXPERIMENTAL_SETTINGS, INCOMPATIBLE_SETTINGS, JS_ONLY_SETTINGS, default_setting, settings, user_settings, ) from .shared import DEBUG, DYLIB_EXTENSIONS, do_replace, in_temp from .toolchain_profiler import ToolchainProfiler from .utils import ( WINDOWS, delete_file, exit_with_error, get_file_suffix, read_file, safe_copy, unsuffixed, unsuffixed_basename, write_file, ) logger = logging.getLogger('link') DEFAULT_SHELL_HTML = utils.path_from_root('src/shell.html') DEFAULT_ASYNCIFY_IMPORTS = ['__asyncjs__*'] DEFAULT_ASYNCIFY_EXPORTS = [ 'main', '__main_argc_argv', ] VALID_ENVIRONMENTS = ('web', 'webview', 'worker', 'node', 'shell') EXECUTABLE_EXTENSIONS = ['.wasm', '.html', '.js', '.mjs', '.out', ''] # 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', '-rpath', ) # 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. '-allow-shlib-undefined': False, '-rpath-link': True, '-version-script': True, '-install_name': True, } 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', } final_js = None # 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(filename): data = utils.read_binary(filename) b64 = base64.b64encode(data) 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 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 setup_environment_settings(): # The worker environment is automatically added if any of the pthread or Worker features are used. # Note: we need to actually modify ENVIRONMENTS variable here before the parsing, # because some JS code reads it back so modifying parsed info alone is not sufficient. maybe_web_worker = not settings.ENVIRONMENT or 'worker' in settings.ENVIRONMENT if settings.SHARED_MEMORY and settings.ENVIRONMENT: settings.ENVIRONMENT.append('worker') # Environment setting based on user input if any(x for x in settings.ENVIRONMENT 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 settings.ENVIRONMENT settings.ENVIRONMENT_MAY_BE_WEBVIEW = not settings.ENVIRONMENT or 'webview' in settings.ENVIRONMENT settings.ENVIRONMENT_MAY_BE_NODE = not settings.ENVIRONMENT or 'node' in settings.ENVIRONMENT settings.ENVIRONMENT_MAY_BE_SHELL = not settings.ENVIRONMENT or 'shell' in settings.ENVIRONMENT settings.ENVIRONMENT_MAY_BE_WORKER = not settings.ENVIRONMENT or 'worker' in settings.ENVIRONMENT if not settings.ENVIRONMENT_MAY_BE_NODE: if 'MIN_NODE_VERSION' in user_settings and settings.MIN_NODE_VERSION != feature_matrix.UNSUPPORTED: diagnostics.warning('unused-command-line-argument', 'ignoring MIN_NODE_VERSION because `node` environment is not enabled') settings.MIN_NODE_VERSION = feature_matrix.UNSUPPORTED if not (settings.ENVIRONMENT_MAY_BE_WEB or maybe_web_worker or settings.ENVIRONMENT_MAY_BE_WEBVIEW): for browser in ('FIREFOX', 'SAFARI', 'CHROME'): key = f'MIN_{browser}_VERSION' if key in user_settings and settings[key] != feature_matrix.UNSUPPORTED: diagnostics.warning('unused-command-line-argument', 'ignoring %s because `web`, `worker` and `webview` environments are not enabled', key) settings[key] = feature_matrix.UNSUPPORTED 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 invocation 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. """ output = emscripten.compile_javascript(symbols_only=True) # When running in symbols_only mode compiler.mjs outputs symbol metadata as JSON. return json.loads(output) @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() content_hash = emscripten.generate_js_compiler_input_hash(symbols_only=True) def generate_json(): library_syms = generate_js_sym_info() return json.dumps(library_syms, separators=(',', ':'), indent=2) # Limit of the overall size of the cache. # This code will get test coverage since a full test run of `other` or `core` # generates ~1000 unique symbol lists. file_content = emscripten.get_cached_file('symbol_lists', f'{content_hash}.json', generate_json, cache_limit=500) return json.loads(file_content) 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, '-' + 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 not f.startswith('-') or 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', '-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) 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 = [] for f in files: content = read_file(f) if content.startswith('#preprocess\n'): contents.append(building.read_and_preprocess(f, expand_macros=True)) else: contents.append(content) contents = '\n'.join(contents) return fix_windows_newlines(contents) 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_lowering_passes(): passes = [] # The following features are all enabled in llvm by default and therefore # enabled in the emscripten system libraries. This means that we need to # lower them away using binaryen passes, if they are not enabled in the # feature matrix. # This can happen if the feature is explicitly disabled on the command line, # or when targeting an VM/engine that does not support the feature. # List of [, , ] triples. features = [ [Feature.SIGN_EXT, '--signext-lowering', ['--enable-sign-ext']], [Feature.NON_TRAPPING_FPTOINT, '--llvm-nontrapping-fptoint-lowering', ['--enable-nontrapping-float-to-int']], [Feature.BULK_MEMORY, '--llvm-memory-copy-fill-lowering', ['--enable-bulk-memory', '--enable-bulk-memory-opt']], ] for feature, lowering_flag, feature_flags in features: if not feature_matrix.caniuse(feature): logger.debug(f'lowering {feature.name} feature due to incompatible target browser engines') for f in feature_flags: # Remove features from binaryen_features, otherwise future runs of binaryen # could re-introduce the feature. if f in building.binaryen_features: building.binaryen_features.remove(f) passes.append(lowering_flag) return passes def get_binaryen_passes(options): passes = get_binaryen_lowering_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'] if optimizing: # wasm-emscripten-finalize will strip the features section for us # automatically, but if we did not modify the wasm then we didn't run it, # and in an optimized build we strip it manually here. (note that in an # unoptimized build we might end up with the features section, if we neither # optimize nor run wasm-emscripten-finalize, but a few extra bytes in the # binary don't matter in an unoptimized build) passes += ['--strip-target-features'] passes += ['--post-emscripten'] if settings.SIDE_MODULE: passes += ['--pass-arg=post-emscripten-side-module'] 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). we also cannot do it when the stack # is first, as then the stack is in the low memory that should be unused. if settings.GLOBAL_BASE >= 1024 and not settings.STACK_FIRST: passes += ['--low-memory-unused'] if options.fast_math: passes += ['--fast-math'] 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: passes += ['--pass-arg=asyncify-export-globals'] elif settings.RELOCATABLE: passes += ['--pass-arg=asyncify-import-globals'] 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'] if settings.ASYNCIFY_PROPAGATE_ADD: passes += ['--pass-arg=asyncify-propagate-addlist'] 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)] if settings.MEMORY64 == 2: passes += ['--memory64-lowering', '--table64-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] # If we are going to run metadce then that means we will be running binaryen # tools after the main invocation, whose flags are determined here # (specifically we will run metadce and possibly also wasm-opt for import/ # export minification). And when we run such a tool it will "undo" any # StackIR optimizations (since the conversion to BinaryenIR undoes them as it # restructures the code). We could re-run those opts, but it is most efficient # to just not do them now if we'll invoke other tools later, and we'll do them # only in the very last invocation. if will_metadce(): passes += ['--no-stack-ir'] return passes def make_js_executable(script): src = read_file(script) cmd = config.NODE_JS 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 ' + shlex.join(cmd) else: cmd = 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.replace(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 get_worker_js_suffix(): return '.worker.mjs' if settings.EXPORT_ES6 else '.worker.js' def setup_pthreads(): # pthreads + dynamic linking has certain limitations if settings.MAIN_MODULE or settings.RELOCATABLE: diagnostics.warning('experimental', 'dynamic linking + pthreads is experimental') if settings.ALLOW_MEMORY_GROWTH and not settings.GROWABLE_ARRAYBUFFERS: diagnostics.warning('pthreads-mem-growth', '-pthread + ALLOW_MEMORY_GROWTH may run non-wasm code slowly, see https://github.com/WebAssembly/design/issues/1271') default_setting('DEFAULT_PTHREAD_STACK_SIZE', settings.STACK_SIZE) # Functions needs by runtime_pthread.js settings.REQUIRED_EXPORTS += [ '_emscripten_thread_free_data', '_emscripten_thread_crashed', ] if settings.MAIN_MODULE: settings.REQUIRED_EXPORTS += [ '_emscripten_dlsync_self', '_emscripten_dlsync_self_async', '_emscripten_proxy_dlsync', '_emscripten_proxy_dlsync_async', '__dl_seterr', ] # runtime_pthread.js depends on these library symbols settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += [ '$PThread', '$establishStackSpace', '$invokeEntryPoint', ] if settings.MINIMAL_RUNTIME: building.user_requested_exports.add('exit') def set_initial_memory(): user_specified_initial_heap = 'INITIAL_HEAP' in user_settings # INITIAL_HEAP cannot be used when the memory object is created in JS: we don't know # the size of static data here and thus the total initial memory size. if settings.IMPORTED_MEMORY: if user_specified_initial_heap: # Some of these could (and should) be implemented. exit_with_error('INITIAL_HEAP is currently not compatible with IMPORTED_MEMORY (which is enabled indirectly via SHARED_MEMORY, RELOCATABLE)') # The default for imported memory is to fall back to INITIAL_MEMORY. settings.INITIAL_HEAP = -1 if not user_specified_initial_heap: # For backwards compatibility, we will only use INITIAL_HEAP by default when the user # specified neither INITIAL_MEMORY nor MAXIMUM_MEMORY. Both place an upper bounds on # the overall initial linear memory (stack + static data + heap), and we do not know # the size of static data at this stage. Setting any non-zero initial heap value in # this scenario would risk pushing users over the limit they have set. user_specified_initial = settings.INITIAL_MEMORY != -1 user_specified_maximum = 'MAXIMUM_MEMORY' in user_settings or 'WASM_MEM_MAX' in user_settings or 'BINARYEN_MEM_MAX' in user_settings if user_specified_initial or user_specified_maximum: settings.INITIAL_HEAP = -1 # Apply the default if we are going with INITIAL_MEMORY. if settings.INITIAL_HEAP == -1 and settings.INITIAL_MEMORY == -1: default_setting('INITIAL_MEMORY', 16 * 1024 * 1024) def check_memory_setting(setting): if settings[setting] % webassembly.WASM_PAGE_SIZE != 0: exit_with_error(f'{setting} must be a multiple of WebAssembly page size (64KiB), was {settings[setting]}') if settings[setting] >= 2**53: exit_with_error(f'{setting} must be smaller than 2^53 bytes due to JS Numbers (doubles) being used to hold pointer addresses in JS side') # Due to the aforementioned lack of knowledge about the static data size, we delegate # checking the overall consistency of these settings to wasm-ld. if settings.INITIAL_HEAP != -1: check_memory_setting('INITIAL_HEAP') if settings.INITIAL_MEMORY != -1: check_memory_setting('INITIAL_MEMORY') if settings.INITIAL_MEMORY < settings.STACK_SIZE: exit_with_error(f'INITIAL_MEMORY must be larger than STACK_SIZE, was {settings.INITIAL_MEMORY} (STACK_SIZE={settings.STACK_SIZE})') check_memory_setting('MAXIMUM_MEMORY') if settings.MEMORY_GROWTH_LINEAR_STEP != -1: check_memory_setting('MEMORY_GROWTH_LINEAR_STEP') # Set an upper estimate of what MAXIMUM_MEMORY should be. Take note that this value # may not be precise, and is only an upper bound of the exact value calculated later # by the linker. def set_max_memory(): # With INITIAL_HEAP, we only know the lower bound on initial memory size. initial_memory_known = settings.INITIAL_MEMORY != -1 if not settings.ALLOW_MEMORY_GROWTH: if 'MAXIMUM_MEMORY' in user_settings: diagnostics.warning('unused-command-line-argument', 'MAXIMUM_MEMORY is only meaningful with ALLOW_MEMORY_GROWTH') # Optimization: lower the default maximum memory to initial memory if possible. if initial_memory_known: settings.MAXIMUM_MEMORY = settings.INITIAL_MEMORY # Automatically up the default maximum when the user requested a large minimum. if 'MAXIMUM_MEMORY' not in user_settings: if settings.ALLOW_MEMORY_GROWTH: if any([settings.INITIAL_HEAP != -1 and settings.INITIAL_HEAP >= 2 * 1024 * 1024 * 1024, initial_memory_known and settings.INITIAL_MEMORY > 2 * 1024 * 1024 * 1024]): settings.MAXIMUM_MEMORY = 4 * 1024 * 1024 * 1024 # INITIAL_MEMORY sets a lower bound for MAXIMUM_MEMORY if initial_memory_known and settings.INITIAL_MEMORY > settings.MAXIMUM_MEMORY: settings.MAXIMUM_MEMORY = settings.INITIAL_MEMORY # A similar check for INITIAL_HEAP would not be precise and so is delegated to wasm-ld. if initial_memory_known and settings.MAXIMUM_MEMORY < settings.INITIAL_MEMORY: exit_with_error('MAXIMUM_MEMORY cannot be less than INITIAL_MEMORY') def inc_initial_memory(delta): # Both INITIAL_HEAP and INITIAL_MEMORY can be set at the same time. Increment both. if settings.INITIAL_HEAP != -1: settings.INITIAL_HEAP += delta if settings.INITIAL_MEMORY != -1: settings.INITIAL_MEMORY += delta def check_browser_versions(): # Map of setting all VM version settings to the minimum version # we support. min_version_settings = { 'MIN_FIREFOX_VERSION': feature_matrix.OLDEST_SUPPORTED_FIREFOX, 'MIN_CHROME_VERSION': feature_matrix.OLDEST_SUPPORTED_CHROME, 'MIN_SAFARI_VERSION': feature_matrix.OLDEST_SUPPORTED_SAFARI, 'MIN_NODE_VERSION': feature_matrix.OLDEST_SUPPORTED_NODE, } if settings.LEGACY_VM_SUPPORT: # Default all browser versions to zero for key in min_version_settings: default_setting(key, 0) for key, oldest in min_version_settings.items(): if settings[key] != 0 and settings[key] < oldest: exit_with_error(f'{key} older than {oldest} is not supported') def add_system_js_lib(lib): lib = utils.path_from_root('src/lib', lib) assert os.path.exists(lib) settings.JS_LIBRARIES.append(lib) def check_settings(): for s, reason in DEPRECATED_SETTINGS.items(): if s in user_settings: diagnostics.warning('deprecated', f'{s} is deprecated ({reason}). Please open a bug if you have a continuing need for this setting') for name, msg in EXPERIMENTAL_SETTINGS.items(): if getattr(settings, name): diagnostics.warning('experimental', msg) for a, b, reason in INCOMPATIBLE_SETTINGS: invert_b = b.startswith('NO_') if invert_b: b = b[3:] b_val = getattr(settings, b) if invert_b: b_val = not b_val if getattr(settings, a) and b_val: msg = f'{a} is not compatible with {b}' if invert_b: msg += '=0' if reason: msg += f' ({reason})' exit_with_error(msg) @ToolchainProfiler.profile() def setup_sanitizers(options): assert(options.sanitize) if settings.WASM_WORKERS: exit_with_error('WASM_WORKERS is not currently compatible with `-fsanitize` tools') # These symbols are needed by `withBuiltinMalloc` which used to implement # the `__noleakcheck` attribute. However this dependency is not yet represented in the JS # symbol graph generated when we run the compiler with `--symbols-only`. settings.REQUIRED_EXPORTS += [ 'malloc', 'calloc', 'realloc', 'memalign', 'free', 'emscripten_builtin_malloc', 'emscripten_builtin_calloc', 'emscripten_builtin_realloc', 'emscripten_builtin_memalign', 'emscripten_builtin_free', ] if ('leak' in options.sanitize or 'address' in options.sanitize) and not settings.ALLOW_MEMORY_GROWTH: # Increase the minimum memory requirements to account for extra memory # that the sanitizers might need (in addition to the shadow memory # requirements handled below). # These values are designed be an over-estimate of the actual requirements and # are based on experimentation with different tests/programs under asan and # lsan. inc_initial_memory(50 * 1024 * 1024) if settings.PTHREADS: inc_initial_memory(50 * 1024 * 1024) if options.sanitize & UBSAN_SANITIZERS: if options.sanitize_minimal_runtime: settings.UBSAN_RUNTIME = 1 else: settings.UBSAN_RUNTIME = 2 if 'leak' in options.sanitize: settings.USE_LSAN = 1 default_setting('EXIT_RUNTIME', 1) if 'address' in options.sanitize: settings.USE_ASAN = 1 default_setting('EXIT_RUNTIME', 1) if not settings.UBSAN_RUNTIME: settings.UBSAN_RUNTIME = 2 settings.REQUIRED_EXPORTS += emscripten.ASAN_C_HELPERS if settings.ASYNCIFY and not settings.ASYNCIFY_ONLY: # we do not want asyncify to instrument these helpers - they just access # memory as small getters/setters, so they cannot pause anyhow, and also # we access them in the runtime as we prepare to rewind, which would hit # an asyncify assertion, if asyncify instrumented them. # # note that if ASYNCIFY_ONLY was set by the user then we do not need to # do anything (as the user's list won't contain these functions), and if # we did add them, the pass would assert on incompatible lists, hence the # condition in the above if. settings.ASYNCIFY_REMOVE.append("__asan_*") if settings.ASAN_SHADOW_SIZE != -1: diagnostics.warning('emcc', 'ASAN_SHADOW_SIZE is ignored and will be removed in a future release') if 'GLOBAL_BASE' in user_settings: exit_with_error("ASan does not support custom GLOBAL_BASE") # Increase the INITIAL_MEMORY and shift GLOBAL_BASE to account for # the ASan shadow region which starts at address zero. # The shadow region is 1/8th the size of the total memory and is # itself part of the total memory. # We use the following variables in this calculation: # - user_mem : memory usable/visible by the user program. # - shadow_size : memory used by asan for shadow memory. # - total_mem : the sum of the above. this is the size of the wasm memory (and must be aligned to WASM_PAGE_SIZE) user_mem = settings.MAXIMUM_MEMORY if not settings.ALLOW_MEMORY_GROWTH and settings.INITIAL_MEMORY != -1: user_mem = settings.INITIAL_MEMORY # Given the know value of user memory size we can work backwards # to find the total memory and the shadow size based on the fact # that the user memory is 7/8ths of the total memory. # (i.e. user_mem == total_mem * 7 / 8 # TODO-Bug?: this does not look to handle 4GB MAXIMUM_MEMORY correctly. total_mem = user_mem * 8 / 7 # But we might need to re-align to wasm page size total_mem = int(align_to_wasm_page_boundary(total_mem)) # The shadow size is 1/8th the resulting rounded up size shadow_size = total_mem // 8 # We start our global data after the shadow memory. # We don't need to worry about alignment here. wasm-ld will take care of that. settings.GLOBAL_BASE = shadow_size # Adjust INITIAL_MEMORY (if needed) to account for the shifted global base. if settings.INITIAL_MEMORY != -1: if settings.ALLOW_MEMORY_GROWTH: settings.INITIAL_MEMORY += align_to_wasm_page_boundary(shadow_size) else: settings.INITIAL_MEMORY = total_mem if settings.SAFE_HEAP: # SAFE_HEAP instruments ASan's shadow memory accesses. # Since the shadow memory starts at 0, the act of accessing the shadow memory is detected # by SAFE_HEAP as a null pointer dereference. exit_with_error('ASan does not work with SAFE_HEAP') if settings.MEMORY64: exit_with_error('MEMORY64 does not yet work with ASAN') if settings.GENERATE_SOURCE_MAP: settings.LOAD_SOURCE_MAP = 1 def get_dylibs(options, linker_args): """Find all the Wasm dynanamic libraries specified on the command line, either via `-lfoo` or via `libfoo.so` directly.""" dylibs = [] for arg in linker_args: if arg.startswith('-l'): for ext in DYLIB_EXTENSIONS: path = find_library('lib' + arg[2:] + ext, options.lib_dirs) if path and building.is_wasm_dylib(path): dylibs.append(path) elif building.is_wasm_dylib(arg): dylibs.append(arg) return dylibs @ToolchainProfiler.profile_block('linker_setup') def phase_linker_setup(options, linker_args): # noqa: C901, PLR0912, PLR0915 """Future modifications should consider refactoring to reduce complexity. * The McCabe cyclomatiic complexity is currently 244 vs 10 recommended. * There are currently 252 branches vs 12 recommended. * There are currently 563 statements vs 50 recommended. To revalidate these numbers, run `ruff check --select=C901,PLR091`. """ setup_environment_settings() apply_library_settings(linker_args) if settings.SIDE_MODULE or settings.MAIN_MODULE: default_setting('FAKE_DYLIBS', 0) if options.shared and not settings.FAKE_DYLIBS: default_setting('SIDE_MODULE', 1) default_setting('RELOCATABLE', 1) if not settings.FAKE_DYLIBS: options.dylibs = get_dylibs(options, linker_args) # If there are any dynamically linked libraries on the command line then # need to enable `MAIN_MODULE` in order to produce JS code that can load them. if not settings.MAIN_MODULE and not settings.SIDE_MODULE and options.dylibs: default_setting('MAIN_MODULE', 2) linker_args += calc_extra_ldflags(options) # We used to do this check during on startup during `check_sanity`, but # we now only do it when linking, in order to reduce the overhead when # only compiling. if not shared.SKIP_SUBPROCS: shared.check_llvm_version() autoconf = os.environ.get('EMMAKEN_JUST_CONFIGURE') or 'conftest.c' in options.input_files or 'conftest.cpp' in options.input_files if autoconf: # configure tests want a more shell-like style, where we emit return codes on exit() settings.EXIT_RUNTIME = 1 # use node.js raw filesystem access, to behave just like a native executable settings.NODERAWFS = 1 # Add `#!` line to output JS and make it executable. options.executable = True # autoconf declares functions without their proper signatures, and STRICT causes that to trip up by passing --fatal-warnings to the linker. if settings.STRICT: exit_with_error('autoconfiguring is not compatible with STRICT') if settings.OPT_LEVEL >= 1: default_setting('ASSERTIONS', 0) if options.emrun: options.pre_js.append(utils.path_from_root('src/emrun_prejs.js')) options.post_js.append(utils.path_from_root('src/emrun_postjs.js')) if settings.MINIMAL_RUNTIME: exit_with_error('--emrun is not compatible with MINIMAL_RUNTIME') # emrun mode waits on program exit if user_settings.get('EXIT_RUNTIME') == '0': exit_with_error('--emrun is not compatible with EXIT_RUNTIME=0') settings.EXIT_RUNTIME = 1 # emrun_postjs.js needs this library function. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$addOnExit'] if options.cpu_profiler: options.post_js.append(utils.path_from_root('src/cpuprofiler.js')) # Unless RUNTIME_DEBUG is explicitly set then we enable it when any of the # more specific debug settings are present. default_setting('RUNTIME_DEBUG', int(settings.LIBRARY_DEBUG or settings.GL_DEBUG or settings.DYLINK_DEBUG or settings.OPENAL_DEBUG or settings.SYSCALL_DEBUG or settings.WEBSOCKET_DEBUG or settings.SOCKET_DEBUG or settings.FETCH_DEBUG or settings.EXCEPTION_DEBUG or settings.PTHREADS_DEBUG or settings.ASYNCIFY_DEBUG)) if options.memory_profiler: settings.MEMORYPROFILER = 1 if settings.PTHREADS_PROFILING: options.post_js.append(utils.path_from_root('src/threadprofiler.js')) settings.REQUIRED_EXPORTS.append('emscripten_main_runtime_thread_id') # threadprofiler.js needs these library functions. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$addOnInit', '$addOnExit'] # TODO: support source maps with js_transform if options.js_transform and settings.GENERATE_SOURCE_MAP: logger.warning('disabling source maps because a js transform is being done') settings.GENERATE_SOURCE_MAP = 0 # options.output_file is the user-specified one, target is what we will generate if options.output_file: target = options.output_file # check for the existence of the output directory now, to avoid having # to do so repeatedly when each of the various output files (.mem, .wasm, # etc) are written. This gives a more useful error message than the # IOError and python backtrace that users would otherwise see. dirname = os.path.dirname(target) if dirname and not os.path.isdir(dirname): exit_with_error("specified output file (%s) is in a directory that does not exist" % target) elif autoconf: # Autoconf expects the executable output file to be called `a.out` target = 'a.out' elif settings.SIDE_MODULE: target = 'a.out.wasm' else: target = 'a.out.js' final_suffix = get_file_suffix(target) # Set the EXPORT_ES6 default early since it affects the setting of the # default oformat below. if settings.WASM_ESM_INTEGRATION or settings.SOURCE_PHASE_IMPORTS or settings.MODULARIZE == 'instance': default_setting('EXPORT_ES6', 1) # If no output format was specified we try to deduce the format based on # the output filename extension if not options.oformat and (options.relocatable or (options.shared and settings.FAKE_DYLIBS and not settings.SIDE_MODULE)): # With FAKE_DYLIBS we generate an normal object file rather than an shared object. # This is linked with `wasm-ld --relocatable` or (`llvm-link` in the case of LTO). if final_suffix in EXECUTABLE_EXTENSIONS: diagnostics.warning('emcc', '-shared/-r used with executable output suffix. This behaviour is deprecated. Please remove -shared/-r to build an executable or avoid the executable suffix (%s) when building object files.' % final_suffix) else: if options.shared and 'FAKE_DYLIBS' not in user_settings: diagnostics.warning('emcc', 'linking a library with `-shared` will emit a static object file (FAKE_DYLIBS defaults to true). If you want to build a runtime shared library use the SIDE_MODULE or FAKE_DYLIBS=0.') options.oformat = OFormat.OBJECT if not options.oformat: if settings.SIDE_MODULE or final_suffix == '.wasm': options.oformat = OFormat.WASM elif final_suffix == '.html': options.oformat = OFormat.HTML elif final_suffix == '.mjs' or settings.EXPORT_ES6: options.oformat = OFormat.MJS else: options.oformat = OFormat.JS if options.oformat in (OFormat.WASM, OFormat.OBJECT): for s in JS_ONLY_SETTINGS: if s in user_settings: diagnostics.warning('unused-command-line-argument', f'{s} is only valid when generating JavaScript output') if options.oformat == OFormat.MJS: default_setting('EXPORT_ES6', 1) settings.OUTPUT_FORMAT = options.oformat.name if settings.SUPPORT_BIG_ENDIAN and settings.WASM2JS: exit_with_error('WASMJ2S is currently not compatible with SUPPORT_BIG_ENDIAN') if settings.WASM_ESM_INTEGRATION: default_setting('MODULARIZE', 'instance') if not settings.EXPORT_ES6: exit_with_error('WASM_ESM_INTEGRATION requires EXPORT_ES6') if settings.MODULARIZE != 'instance': exit_with_error('WASM_ESM_INTEGRATION requires MODULARIZE=instance') if settings.RELOCATABLE: exit_with_error('WASM_ESM_INTEGRATION is not compatible with dynamic linking') if settings.ASYNCIFY: exit_with_error('WASM_ESM_INTEGRATION is not compatible with -sASYNCIFY') if settings.WASM_WORKERS: exit_with_error('WASM_ESM_INTEGRATION is not compatible with WASM_WORKERS') if not settings.WASM_ASYNC_COMPILATION: exit_with_error('WASM_ESM_INTEGRATION is not compatible with WASM_ASYNC_COMPILATION=0') if not settings.WASM: exit_with_error('WASM_ESM_INTEGRATION is not compatible with WASM2JS') if settings.ABORT_ON_WASM_EXCEPTIONS: exit_with_error('WASM_ESM_INTEGRATION is not compatible with ABORT_ON_WASM_EXCEPTIONS') if settings.MODULARIZE and settings.MODULARIZE not in [1, 'instance']: exit_with_error(f'Invalid setting "{settings.MODULARIZE}" for MODULARIZE.') def limit_incoming_module_api(): if options.oformat == OFormat.HTML and options.shell_path == DEFAULT_SHELL_HTML: # Out default shell.html file has minimal set of INCOMING_MODULE_JS_API elements that it expects default_setting('INCOMING_MODULE_JS_API', 'canvas,monitorRunDependencies,onAbort,onExit,print,setStatus'.split(',')) else: default_setting('INCOMING_MODULE_JS_API', []) if settings.ASYNCIFY == 1: # ASYNCIFY=1 wraps only wasm exports so we need to enable legacy # dyncalls via dynCall_xxx exports. # See: https://github.com/emscripten-core/emscripten/issues/12066 settings.DYNCALLS = 1 if settings.MODULARIZE == 'instance': diagnostics.warning('experimental', 'MODULARIZE=instance is still experimental. Many features may not work or will change.') if not settings.EXPORT_ES6: exit_with_error('MODULARIZE=instance requires EXPORT_ES6') if settings.MINIMAL_RUNTIME: exit_with_error('MODULARIZE=instance is not compatible with MINIMAL_RUNTIME') if options.use_preload_plugins or len(options.preload_files): exit_with_error('MODULARIZE=instance is not compatible with --embed-file/--preload-file') if settings.MINIMAL_RUNTIME and len(options.preload_files): exit_with_error('MINIMAL_RUNTIME is not compatible with --preload-file') if options.oformat in (OFormat.WASM, OFormat.BARE): if options.emit_tsd: exit_with_error('Wasm only output is not compatible with --emit-tsd') # If the user asks directly for a wasm file then this *is* the target wasm_target = target elif settings.SINGLE_FILE or settings.WASM == 0: # In SINGLE_FILE or WASM2JS mode the wasm file is not part of the output at # all so we generate it the temp directory. wasm_target = in_temp(utils.replace_suffix(target, '.wasm')) else: # Otherwise the wasm file is produced alongside the final target. wasm_target = get_secondary_target(target, '.wasm') if settings.SAFE_HEAP not in [0, 1, 2]: exit_with_error('SAFE_HEAP must be 0, 1 or 2') if not settings.WASM: # When the user requests non-wasm output, we enable wasm2js. that is, # we still compile to wasm normally, but we compile the final output # to js. settings.WASM = 1 settings.WASM2JS = 1 if settings.WASM == 2: # Requesting both Wasm and Wasm2JS support settings.WASM2JS = 1 if settings.WASM2JS: # Wasm bigint doesn't make sense with wasm2js, since it controls how the # wasm and JS interact. if user_settings.get('WASM_BIGINT') and settings.WASM_BIGINT: exit_with_error('WASM_BIGINT=1 is not compatible with wasm2js') settings.WASM_BIGINT = 0 feature_matrix.disable_feature(Feature.JS_BIGINT_INTEGRATION) if options.oformat == OFormat.WASM and not settings.SIDE_MODULE: # if the output is just a wasm file, it will normally be a standalone one, # as there is no JS. an exception are side modules, as we can't tell at # compile time whether JS will be involved or not - the main module may # have JS, and the side module is expected to link against that. # we also do not support standalone mode in fastcomp. settings.STANDALONE_WASM = 1 if settings.LZ4: settings.EXPORTED_RUNTIME_METHODS += ['LZ4'] if settings.PURE_WASI: settings.STANDALONE_WASM = 1 settings.WASM_BIGINT = 1 # WASI does not support Emscripten (JS-based) exception catching, which the # JS-based longjmp support also uses. Emscripten EH is by default disabled # so we don't need to do anything here. if not settings.WASM_EXCEPTIONS: default_setting('SUPPORT_LONGJMP', 0) if options.no_entry: settings.EXPECT_MAIN = 0 elif settings.STANDALONE_WASM: if '_main' in settings.EXPORTED_FUNCTIONS: # TODO(sbc): Make this into a warning? logger.debug('including `_main` in EXPORTED_FUNCTIONS is not necessary in standalone mode') else: # In normal non-standalone mode we have special handling of `_main` in EXPORTED_FUNCTIONS. # 1. If the user specifies exports, but doesn't include `_main` we assume they want to build a # reactor. # 2. If the user doesn't export anything we default to exporting `_main` (unless `--no-entry` # is specified (see above). if 'EXPORTED_FUNCTIONS' in user_settings: if '_main' in settings.USER_EXPORTS: settings.EXPORTED_FUNCTIONS.remove('_main') settings.EXPORT_IF_DEFINED.append('main') else: settings.EXPECT_MAIN = 0 else: settings.EXPORT_IF_DEFINED.append('main') if settings.STANDALONE_WASM: # In STANDALONE_WASM mode we either build a command or a reactor. # See https://github.com/WebAssembly/WASI/blob/main/design/application-abi.md # For a command we always want EXIT_RUNTIME=1 # For a reactor we always want EXIT_RUNTIME=0 if 'EXIT_RUNTIME' in user_settings: exit_with_error('explicitly setting EXIT_RUNTIME not compatible with STANDALONE_WASM. EXIT_RUNTIME will always be True for programs (with a main function) and False for reactors (not main function).') settings.EXIT_RUNTIME = settings.EXPECT_MAIN settings.IGNORE_MISSING_MAIN = 0 # the wasm must be runnable without the JS, so there cannot be anything that # requires JS legalization default_setting('LEGALIZE_JS_FFI', 0) if 'MEMORY_GROWTH_LINEAR_STEP' in user_settings: exit_with_error('MEMORY_GROWTH_LINEAR_STEP is not compatible with STANDALONE_WASM') if 'MEMORY_GROWTH_GEOMETRIC_CAP' in user_settings: exit_with_error('MEMORY_GROWTH_GEOMETRIC_CAP is not compatible with STANDALONE_WASM') # Note the exports the user requested building.user_requested_exports.update(settings.EXPORTED_FUNCTIONS) if '_main' in settings.EXPORTED_FUNCTIONS or 'main' in settings.EXPORT_IF_DEFINED: settings.EXPORT_IF_DEFINED.append('__main_argc_argv') elif settings.ASSERTIONS and not settings.STANDALONE_WASM: # In debug builds when `main` is not explicitly requested as an # export we still add it to EXPORT_IF_DEFINED so that we can warn # users who forget to explicitly export `main`. # See other.test_warn_unexported_main. # This is not needed in STANDALONE_WASM mode since we export _start # (unconditionally) rather than main. settings.EXPORT_IF_DEFINED += ['main', '__main_argc_argv'] if settings.ASSERTIONS: # Exceptions are thrown with a stack trace by default when ASSERTIONS is # set and when building with either -fexceptions or -fwasm-exceptions. if 'EXCEPTION_STACK_TRACES' in user_settings and not settings.EXCEPTION_STACK_TRACES: exit_with_error('EXCEPTION_STACK_TRACES cannot be disabled when ASSERTIONS are enabled') if settings.WASM_EXCEPTIONS or not settings.DISABLE_EXCEPTION_CATCHING: settings.EXCEPTION_STACK_TRACES = 1 # -sASSERTIONS implies basic stack overflow checks, and ASSERTIONS=2 # implies full stack overflow checks. However, we don't set this default in # PURE_WASI, or when we are linking without standard libraries because # STACK_OVERFLOW_CHECK depends on emscripten_stack_get_end which is defined # in libcompiler-rt. if not settings.PURE_WASI and not options.nostdlib and not options.nodefaultlibs: default_setting('STACK_OVERFLOW_CHECK', max(settings.ASSERTIONS, settings.STACK_OVERFLOW_CHECK)) # For users that opt out of WARN_ON_UNDEFINED_SYMBOLS we assume they also # want to opt out of ERROR_ON_UNDEFINED_SYMBOLS. if user_settings.get('WARN_ON_UNDEFINED_SYMBOLS') == '0': default_setting('ERROR_ON_UNDEFINED_SYMBOLS', 0) # It is unlikely that developers targeting "native web" APIs with MINIMAL_RUNTIME need # errno support by default. if settings.MINIMAL_RUNTIME: # Require explicit -lfoo.js flags to link with JS libraries. default_setting('AUTO_JS_LIBRARIES', 0) # When using MINIMAL_RUNTIME, symbols should only be exported if requested. default_setting('EXPORT_KEEPALIVE', 0) if settings.EXPORT_ES6 and not settings.MODULARIZE: # EXPORT_ES6 requires output to be a module if 'MODULARIZE' in user_settings: exit_with_error('EXPORT_ES6 requires MODULARIZE to be set') settings.MODULARIZE = 1 if not options.shell_path: # Minimal runtime uses a different default shell file if settings.MINIMAL_RUNTIME: options.shell_path = options.shell_path = utils.path_from_root('src/shell_minimal_runtime.html') else: options.shell_path = DEFAULT_SHELL_HTML if options.oformat == OFormat.HTML and options.shell_path == DEFAULT_SHELL_HTML: settings.EXPORTED_RUNTIME_METHODS.append('requestFullscreen') if settings.STRICT: if not settings.MODULARIZE: default_setting('STRICT_JS', 1) default_setting('DEFAULT_TO_CXX', 0) default_setting('IGNORE_MISSING_MAIN', 0) default_setting('AUTO_NATIVE_LIBRARIES', 0) if settings.MAIN_MODULE != 1: # These two settings cannot be disabled with MAIN_MODULE=1 because all symbols # are needed in this mode. default_setting('AUTO_JS_LIBRARIES', 0) default_setting('ALLOW_UNIMPLEMENTED_SYSCALLS', 0) limit_incoming_module_api() for prop in settings.INCOMING_MODULE_JS_API: if prop not in settings.ALL_INCOMING_MODULE_JS_API: diagnostics.warning('unused-command-line-argument', f'invalid entry in INCOMING_MODULE_JS_API: {prop}') settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('$wasmMemory') if 'noExitRuntime' in settings.INCOMING_MODULE_JS_API: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('$noExitRuntime') # Default to TEXTDECODER=2 (always use TextDecoder to decode UTF-8 strings) # in -Oz builds, since custom decoder for UTF-8 takes up space. # When supporting shell environments, do not do this as TextDecoder is not # widely supported there. # In Audio Worklets TextDecoder API is intentionally not exposed # (https://github.com/WebAudio/web-audio-api/issues/2499) so we also need to # keep the JavaScript-based fallback. if settings.SHRINK_LEVEL >= 2 and not settings.AUDIO_WORKLET and \ not settings.ENVIRONMENT_MAY_BE_SHELL: default_setting('TEXTDECODER', 2) # If set to 1, we will run the autodebugger (the automatic debugging tool, see # tools/autodebugger). Note that this will disable inclusion of libraries. This # is useful because including dlmalloc makes it hard to compare native and js # builds if os.environ.get('EMCC_AUTODEBUG'): settings.AUTODEBUG = 1 # Use settings if settings.JS_MATH and settings.MAIN_MODULE == 1: # MODULE_MODULE=1 adds`--whole-archive` around all the system libraries which # results in duplicate math symbols when JS_MATH is used. exit_with_error('JS_MATH is not compatible with dynamic linking (MAIN_MODULE=1)') if settings.WASM == 2 and settings.SINGLE_FILE: exit_with_error('cannot have both WASM=2 and SINGLE_FILE enabled at the same time') if settings.MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION and options.oformat != OFormat.HTML: exit_with_error('MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION is only compatible with html output') if settings.MINIMAL_RUNTIME_STREAMING_WASM_INSTANTIATION and not settings.MINIMAL_RUNTIME: exit_with_error('MINIMAL_RUNTIME_STREAMING_WASM_INSTANTIATION requires MINIMAL_RUNTIME') if settings.MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION and not settings.MINIMAL_RUNTIME: exit_with_error('MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION requires MINIMAL_RUNTIME') if settings.MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION and options.oformat != OFormat.HTML: exit_with_error('MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION is only compatible with html output') if options.use_closure_compiler: settings.USE_CLOSURE_COMPILER = 1 if 'CLOSURE_WARNINGS' in user_settings: if settings.CLOSURE_WARNINGS not in ['quiet', 'warn', 'error']: exit_with_error('invalid option -sCLOSURE_WARNINGS=%s specified! Allowed values are "quiet", "warn" or "error".' % settings.CLOSURE_WARNINGS) closure_warnings = diagnostics.manager.warnings['closure'] if settings.CLOSURE_WARNINGS == 'error': closure_warnings['error'] = True closure_warnings['enabled'] = True elif settings.CLOSURE_WARNINGS == 'warn': closure_warnings['error'] = False closure_warnings['enabled'] = True elif settings.CLOSURE_WARNINGS == 'quiet': closure_warnings['error'] = False closure_warnings['enabled'] = False if not settings.MINIMAL_RUNTIME: if not settings.BOOTSTRAPPING_STRUCT_INFO: if settings.DYNCALLS: # Include dynCall() function by default in DYNCALLS builds in classic runtime; in MINIMAL_RUNTIME, must add this explicitly. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$dynCall'] if settings.ASSERTIONS: # "checkUnflushedContent()" and "missingLibrarySymbol()" depend on warnOnce settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$warnOnce'] settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$getValue', '$setValue'] settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$ExitStatus'] # Certain configurations require the removeRunDependency/addRunDependency system. if settings.LOAD_SOURCE_MAP or (settings.WASM_ASYNC_COMPILATION and not settings.MODULARIZE): settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$addRunDependency', '$removeRunDependency'] if settings.ABORT_ON_WASM_EXCEPTIONS or settings.SPLIT_MODULE: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$wasmTable'] if settings.MAIN_MODULE: assert not settings.SIDE_MODULE if settings.MAIN_MODULE == 1: settings.INCLUDE_FULL_LIBRARY = 1 # Called from preamble.js once the main module is instantiated. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$loadDylibs'] if not settings.RELOCATABLE: settings.REQUIRED_EXPORTS += ['__stack_pointer'] if settings.MAIN_MODULE == 1 or settings.SIDE_MODULE == 1: settings.LINKABLE = 1 if settings.LINKABLE and settings.USER_EXPORTS: diagnostics.warning('unused-command-line-argument', 'EXPORTED_FUNCTIONS is not valid with LINKABLE set (normally due to SIDE_MODULE=1/MAIN_MODULE=1) since all functions are exported this mode. To export only a subset use SIDE_MODULE=2/MAIN_MODULE=2') if settings.MAIN_MODULE: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += [ '$getDylinkMetadata', '$mergeLibSymbols', ] if settings.PTHREADS: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += [ '$registerTLSInit', ] if settings.MAIN_MODULE or settings.RELOCATABLE: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += [ '$reportUndefinedSymbols', '$relocateExports', '$GOTHandler', ] # shared modules need memory utilities to allocate their memory settings.ALLOW_TABLE_GROWTH = 1 # various settings require sbrk() access if settings.DETERMINISTIC or \ settings.EMSCRIPTEN_TRACING or \ settings.SAFE_HEAP or \ settings.MEMORYPROFILER: settings.REQUIRED_EXPORTS += ['sbrk'] if settings.MEMORYPROFILER: settings.REQUIRED_EXPORTS += ['__heap_base', 'emscripten_stack_get_base', 'emscripten_stack_get_end', 'emscripten_stack_get_current'] settings.ASYNCIFY_ADD = unmangle_symbols_from_cmdline(settings.ASYNCIFY_ADD) settings.ASYNCIFY_REMOVE = unmangle_symbols_from_cmdline(settings.ASYNCIFY_REMOVE) settings.ASYNCIFY_ONLY = unmangle_symbols_from_cmdline(settings.ASYNCIFY_ONLY) if settings.EMULATE_FUNCTION_POINTER_CASTS: # Emulated casts forces a wasm ABI of (i64, i64, ...) in the table, which # means all table functions are illegal for JS to call directly. Use # dyncalls which call into the wasm, which then does an indirect call. settings.DYNCALLS = 1 if options.oformat != OFormat.OBJECT and final_suffix in ('.o', '.bc', '.so', '.dylib') and not settings.SIDE_MODULE: diagnostics.warning('emcc', 'object file output extension (%s) used for non-object output. If you meant to build an object file please use `-c, `-r`, or `-shared`' % final_suffix) if settings.SUPPORT_BIG_ENDIAN: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += [ '$LE_HEAP_STORE_U16', '$LE_HEAP_STORE_I16', '$LE_HEAP_STORE_U32', '$LE_HEAP_STORE_I32', '$LE_HEAP_STORE_U64', '$LE_HEAP_STORE_I64', '$LE_HEAP_STORE_F32', '$LE_HEAP_STORE_F64', '$LE_HEAP_LOAD_U16', '$LE_HEAP_LOAD_I16', '$LE_HEAP_LOAD_U32', '$LE_HEAP_LOAD_I32', '$LE_HEAP_LOAD_U64', '$LE_HEAP_LOAD_I64', '$LE_HEAP_LOAD_F32', '$LE_HEAP_LOAD_F64', '$LE_ATOMICS_NATIVE_BYTE_ORDER', '$LE_ATOMICS_ADD', '$LE_ATOMICS_AND', '$LE_ATOMICS_COMPAREEXCHANGE', '$LE_ATOMICS_EXCHANGE', '$LE_ATOMICS_ISLOCKFREE', '$LE_ATOMICS_LOAD', '$LE_ATOMICS_NOTIFY', '$LE_ATOMICS_OR', '$LE_ATOMICS_STORE', '$LE_ATOMICS_SUB', '$LE_ATOMICS_WAIT', '$LE_ATOMICS_WAITASYNC', '$LE_ATOMICS_XOR', ] if settings.RUNTIME_DEBUG or settings.ASSERTIONS or settings.STACK_OVERFLOW_CHECK or settings.PTHREADS_PROFILING or settings.GL_ASSERTIONS: # Lots of code in debug/assertion blocks uses ptrToString. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$ptrToString'] if settings.STACK_OVERFLOW_CHECK: settings.REQUIRED_EXPORTS += [ 'emscripten_stack_get_end', 'emscripten_stack_get_free', 'emscripten_stack_get_base', 'emscripten_stack_get_current', ] # We call one of these two functions during startup which caches the stack limits # in wasm globals allowing get_base/get_free to be super fast. # See compiler-rt/stack_limits.S. if settings.RELOCATABLE: settings.REQUIRED_EXPORTS += ['emscripten_stack_set_limits'] else: settings.REQUIRED_EXPORTS += ['emscripten_stack_init'] if settings.STACK_OVERFLOW_CHECK >= 2: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$setStackLimits'] check_browser_versions() if settings.MIN_NODE_VERSION >= 150000: default_setting('NODEJS_CATCH_REJECTION', 0) # Do not catch rejections or exits in modularize mode, as these options # are for use when running emscripten modules standalone # see https://github.com/emscripten-core/emscripten/issues/18723#issuecomment-1429236996 if settings.MODULARIZE: default_setting('NODEJS_CATCH_REJECTION', 0) if settings.POLYFILL: # Emscripten requires certain ES6+ constructs by default in library code # - (various ES6 operators available in all browsers listed below) # - https://caniuse.com/mdn-javascript_operators_nullish_coalescing: # FF:72 CHROME:80 SAFARI:13.1 NODE:14 # - https://caniuse.com/mdn-javascript_operators_optional_chaining: # FF:74 CHROME:80 SAFARI:13.1 NODE:14 # - https://caniuse.com/mdn-javascript_operators_logical_or_assignment: # FF:79 CHROME:85 SAFARI:14 NODE:16 # Taking the highest requirements gives is our minimum: # Max Version: FF:79 CHROME:85 SAFARI:14 NODE:16 # TODO: replace this with feature matrix in the future. settings.TRANSPILE = (settings.MIN_FIREFOX_VERSION < 79 or settings.MIN_CHROME_VERSION < 85 or settings.MIN_SAFARI_VERSION < 140000 or settings.MIN_NODE_VERSION < 160000) if settings.STB_IMAGE: settings.EXPORTED_FUNCTIONS += ['_stbi_load', '_stbi_load_from_memory', '_stbi_image_free'] if settings.USE_WEBGL2: settings.MAX_WEBGL_VERSION = 2 # MIN_WEBGL_VERSION=2 implies MAX_WEBGL_VERSION=2 if settings.MIN_WEBGL_VERSION == 2: default_setting('MAX_WEBGL_VERSION', 2) if settings.MIN_WEBGL_VERSION > settings.MAX_WEBGL_VERSION: exit_with_error('MIN_WEBGL_VERSION must be smaller or equal to MAX_WEBGL_VERSION!') if options.use_preload_plugins or len(options.preload_files) or len(options.embed_files): if settings.NODERAWFS: exit_with_error('--preload-file and --embed-file cannot be used with NODERAWFS which disables virtual filesystem') # if we include any files, or intend to use preload plugins, then we definitely need filesystem support settings.FORCE_FILESYSTEM = 1 if options.preload_files: # File preloading uses `Module['preRun']`. settings.INCOMING_MODULE_JS_API.append('preRun') if settings.FORCE_FILESYSTEM and not settings.FILESYSTEM: exit_with_error('`-sFORCE_FILESYSTEM` cannot be used with `-sFILESYSTEM=0`') if settings.WASMFS: settings.FILESYSTEM = 1 settings.SYSCALLS_REQUIRE_FILESYSTEM = 0 add_system_js_lib('libwasmfs.js') if settings.ASSERTIONS: # used in assertion checks for unflushed content settings.REQUIRED_EXPORTS += ['wasmfs_flush'] if settings.FORCE_FILESYSTEM or settings.INCLUDE_FULL_LIBRARY: # Add exports for the JS API. Like the old JS FS, WasmFS by default # includes just what JS parts it actually needs, and FORCE_FILESYSTEM is # required to force all of it to be included if the user wants to use the # JS API directly. (INCLUDE_FULL_LIBRARY also causes this code to be # included, as the entire JS library can refer to things that require # these exports.) settings.REQUIRED_EXPORTS += [ 'emscripten_builtin_memalign', 'wasmfs_create_file', 'wasmfs_unmount', '_wasmfs_mount', '_wasmfs_read_file', '_wasmfs_write_file', '_wasmfs_open', '_wasmfs_close', '_wasmfs_write', '_wasmfs_pwrite', '_wasmfs_rename', '_wasmfs_mkdir', '_wasmfs_unlink', '_wasmfs_chdir', '_wasmfs_mknod', '_wasmfs_rmdir', '_wasmfs_mmap', '_wasmfs_munmap', '_wasmfs_msync', '_wasmfs_read', '_wasmfs_pread', '_wasmfs_symlink', '_wasmfs_truncate', '_wasmfs_ftruncate', '_wasmfs_stat', '_wasmfs_lstat', '_wasmfs_chmod', '_wasmfs_fchmod', '_wasmfs_lchmod', '_wasmfs_utime', '_wasmfs_llseek', '_wasmfs_identify', '_wasmfs_readlink', '_wasmfs_readdir_start', '_wasmfs_readdir_get', '_wasmfs_readdir_finish', '_wasmfs_get_cwd', ] if settings.FULL_ES3: settings.FULL_ES2 = 1 settings.MAX_WEBGL_VERSION = max(2, settings.MAX_WEBGL_VERSION) if settings.MAIN_READS_PARAMS and not settings.STANDALONE_WASM: # callMain depends on _emscripten_stack_alloc settings.REQUIRED_EXPORTS += ['_emscripten_stack_alloc'] if settings.SUPPORT_LONGJMP == 'emscripten' or not settings.DISABLE_EXCEPTION_CATCHING: # make_invoke depends on stackSave and stackRestore settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$stackSave', '$stackRestore'] if settings.SIDE_MODULE and 'GLOBAL_BASE' in user_settings: diagnostics.warning('unused-command-line-argument', 'GLOBAL_BASE is not compatible with SIDE_MODULE') if options.use_preload_plugins: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$Browser'] if not settings.BOOTSTRAPPING_STRUCT_INFO: if settings.DYNAMIC_EXECUTION == 2 and not settings.MINIMAL_RUNTIME: # Used by makeEval in the DYNAMIC_EXECUTION == 2 case settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$stackTrace'] if not settings.STANDALONE_WASM and (settings.EXIT_RUNTIME or settings.ASSERTIONS): # to flush streams on FS exit, we need to be able to call fflush # we only include it if the runtime is exitable, or when ASSERTIONS # (ASSERTIONS will check that streams do not need to be flushed, # helping people see when they should have enabled EXIT_RUNTIME) settings.EXPORT_IF_DEFINED += ['fflush'] if settings.SAFE_HEAP: # SAFE_HEAP check includes calling emscripten_get_sbrk_ptr() from wasm settings.REQUIRED_EXPORTS += ['emscripten_get_sbrk_ptr', 'emscripten_stack_get_base'] if not settings.DECLARE_ASM_MODULE_EXPORTS: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$assignWasmExports'] if settings.ALLOW_MEMORY_GROWTH: # Setting ALLOW_MEMORY_GROWTH turns off ABORTING_MALLOC, as in that mode we default to # the behavior of trying to grow and returning 0 from malloc on failure, like # a standard system would. However, if the user sets the flag it # overrides that. default_setting('ABORTING_MALLOC', 0) if settings.EMBIND: # Workaround for embind+LTO issue: # https://github.com/emscripten-core/emscripten/issues/21653 settings.REQUIRED_EXPORTS.append('__getTypeName') if settings.PTHREADS or settings.WASM_WORKERS: settings.REQUIRED_EXPORTS.append('_embind_initialize_bindings') # Needed to assign the embind exports to the ES exports. if settings.MODULARIZE == 'instance': settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$addOnPostCtor'] if options.emit_tsd: settings.EMIT_TSD = True if settings.PTHREADS: setup_pthreads() add_system_js_lib('libpthread.js') if settings.PROXY_TO_PTHREAD: settings.PTHREAD_POOL_SIZE_STRICT = 0 settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$runtimeKeepalivePush'] else: if settings.PROXY_TO_PTHREAD: exit_with_error('-sPROXY_TO_PTHREAD requires -pthread to work!') add_system_js_lib('libpthread_stub.js') if settings.MEMORY64: # Any "pointers" passed to JS will now be i64's, in both modes. settings.WASM_BIGINT = 1 if settings.MEMORY64 and settings.RELOCATABLE: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('__table_base32') if settings.WASM_WORKERS: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$_wasmWorkerInitializeRuntime'] add_system_js_lib('libwasm_worker.js') # Set min browser versions based on certain settings such as WASM_BIGINT, # PTHREADS, AUDIO_WORKLET # Such setting must be set before this point feature_matrix.apply_min_browser_versions() # TODO(sbc): Find make a generic way to expose the feature matrix to JS # compiler rather then adding them all ad-hoc as internal settings settings.SUPPORTS_PROMISE_ANY = feature_matrix.caniuse(Feature.PROMISE_ANY) default_setting('WASM_BIGINT', feature_matrix.caniuse(Feature.JS_BIGINT_INTEGRATION)) if settings.AUDIO_WORKLET: add_system_js_lib('libwebaudio.js') settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('$getWasmTableEntry') if not settings.MINIMAL_RUNTIME: if 'preRun' in settings.INCOMING_MODULE_JS_API: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('$addOnPreRun') if 'postRun' in settings.INCOMING_MODULE_JS_API: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('$addOnPostRun') if settings.FORCE_FILESYSTEM and not settings.MINIMAL_RUNTIME: # when the filesystem is forced, we export by default methods that filesystem usage # may need, including filesystem usage from standalone file packager output (i.e. # file packages not built together with emcc, but that are loaded at runtime # separately, and they need emcc's output to contain the support they need) settings.EXPORTED_RUNTIME_METHODS += [ 'FS_createPath', 'FS_createDataFile', 'FS_preloadFile', 'FS_unlink', ] if not settings.WASMFS: # The old FS has some functionality that WasmFS lacks. settings.EXPORTED_RUNTIME_METHODS += [ 'FS_createLazyFile', 'FS_createDevice', ] settings.EXPORTED_RUNTIME_METHODS += [ 'addRunDependency', 'removeRunDependency', ] if settings.PTHREADS or settings.WASM_WORKERS or settings.RELOCATABLE: settings.IMPORTED_MEMORY = 1 set_initial_memory() # When not declaring wasm module exports in outer scope one by one, disable minifying # wasm module export names so that the names can be passed directly to the outer scope. # Also, if using libexports.js API, disable minification so that the feature can work. if not settings.DECLARE_ASM_MODULE_EXPORTS or '-lexports.js' in linker_args: settings.MINIFY_WASM_EXPORT_NAMES = 0 # Enable minification of wasm imports and exports when appropriate, if we # are emitting an optimized JS+wasm combo (then the JS knows how to load the minified names). # Things that process the JS after this operation would be done must disable this. # ASYNCIFY=2 does not support this optimization yet as it has a hardcoded # check for 'main' as an export name. TODO if will_metadce() and \ settings.OPT_LEVEL >= 2 and \ settings.DEBUG_LEVEL <= 2 and \ options.oformat not in (OFormat.WASM, OFormat.BARE) and \ settings.ASYNCIFY != 2 and \ not settings.LINKABLE and \ not settings.STANDALONE_WASM and \ not settings.AUTODEBUG and \ not settings.ASSERTIONS and \ not settings.RELOCATABLE and \ not settings.MAIN_MODULE and \ settings.MINIFY_WASM_EXPORT_NAMES: settings.MINIFY_WASM_IMPORTS_AND_EXPORTS = 1 settings.MINIFY_WASM_IMPORTED_MODULES = 1 if settings.MODULARIZE and not (settings.EXPORT_ES6 and not settings.SINGLE_FILE) and \ settings.EXPORT_NAME == 'Module' and options.oformat == OFormat.HTML and \ (options.shell_path == DEFAULT_SHELL_HTML or options.shell_path == utils.path_from_root('src/shell_minimal.html')): exit_with_error(f'Due to collision in variable name "Module", the shell file "{options.shell_path}" is not compatible with build options "-sMODULARIZE -sEXPORT_NAME=Module". Either provide your own shell file, change the name of the export to something else to avoid the name collision. (see https://github.com/emscripten-core/emscripten/issues/7950 for details)') if settings.WASM_BIGINT: settings.LEGALIZE_JS_FFI = 0 if settings.SINGLE_FILE and settings.GENERATE_SOURCE_MAP: diagnostics.warning('emcc', 'SINGLE_FILE disables source map support (which requires a .map file)') settings.GENERATE_SOURCE_MAP = 0 if options.use_closure_compiler == 2 and not settings.WASM2JS: exit_with_error('closure compiler mode 2 assumes the code is asm.js, so not meaningful for wasm') if settings.AUTODEBUG: settings.REQUIRED_EXPORTS += ['_emscripten_tempret_set'] if settings.LEGALIZE_JS_FFI: settings.REQUIRED_EXPORTS += ['__get_temp_ret', '__set_temp_ret'] if settings.SPLIT_MODULE and settings.ASYNCIFY == 2: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['_load_secondary_module'] # wasm side modules have suffix .wasm if settings.SIDE_MODULE and utils.suffix(target) in ('.js', '.mjs'): diagnostics.warning('emcc', 'JavaScript output suffix requested, but wasm side modules are just wasm files; emitting only a .wasm, no .js') if options.sanitize: setup_sanitizers(options) if settings.USE_ASAN or settings.SAFE_HEAP: # ASan and SAFE_HEAP check address 0 themselves settings.CHECK_NULL_WRITES = 0 if 'GLOBAL_BASE' not in user_settings and not settings.SHRINK_LEVEL and not settings.OPT_LEVEL and not settings.USE_ASAN: # When optimizing for size it helps to put static data first before # the stack (since this makes instructions for accessing this data # use a smaller LEB encoding). # However, for debugability is better to have the stack come first # (because stack overflows will trap rather than corrupting data). settings.STACK_FIRST = True if '--stack-first' in linker_args: settings.STACK_FIRST = True if settings.USE_ASAN: exit_with_error('--stack-first is not compatible with asan') if 'GLOBAL_BASE' in user_settings: exit_with_error('--stack-first is not compatible with -sGLOBAL_BASE') set_max_memory() # check if we can address the 2GB mark and higher. if not settings.MEMORY64 and settings.MAXIMUM_MEMORY > 2 * 1024 * 1024 * 1024: settings.CAN_ADDRESS_2GB = 1 if settings.MAX_WEBGL_VERSION >= 2: settings.WEBGL_USE_GARBAGE_FREE_APIS = 1 # Some browsers have issues using the WebGL2 garbage-free APIs when the # memory offsets are over 2^31 or 2^32 # For firefox see: https://bugzil.la/1838218 if settings.MIN_FIREFOX_VERSION != feature_matrix.UNSUPPORTED and settings.MAXIMUM_MEMORY > 2 ** 31: settings.WEBGL_USE_GARBAGE_FREE_APIS = 0 # For chrome see: https://crbug.com/324992397 if settings.MIN_CHROME_VERSION != feature_matrix.UNSUPPORTED and settings.MEMORY64 and settings.MAXIMUM_MEMORY > 2 ** 32: settings.WEBGL_USE_GARBAGE_FREE_APIS = 0 if settings.WEBGL_USE_GARBAGE_FREE_APIS and settings.MIN_WEBGL_VERSION >= 2: settings.INCLUDE_WEBGL1_FALLBACK = 0 if settings.MINIMAL_RUNTIME: if settings.EXIT_RUNTIME: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['proc_exit', '$callRuntimeCallbacks'] else: # MINIMAL_RUNTIME only needs callRuntimeCallbacks in certain cases, but the normal runtime # always does. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$callRuntimeCallbacks'] if settings.EXIT_RUNTIME and not settings.STANDALONE_WASM: # Internal function implemented in musl that calls any functions registered # via `atexit` et al. With STANDALONE_WASM this is all taken care of via # _start and exit handling in musl, but with the normal emscripten ABI we # need to be able to call these explicitly. settings.REQUIRED_EXPORTS += ['__funcs_on_exit'] if settings.BUILD_AS_WORKER: # The worker code in src/build_as_worker.js depends on realloc settings.REQUIRED_EXPORTS += ['realloc'] options.post_js.append(utils.path_from_root('src/build_as_worker.js')) if not settings.DISABLE_EXCEPTION_CATCHING: settings.REQUIRED_EXPORTS += [ # For normal builds the entries in deps_info.py are enough to include # these symbols whenever __cxa_find_matching_catch_* functions are # found. However, under LTO these symbols don't exist prior to linking # so we include then unconditionally when exceptions are enabled. '__cxa_can_catch', # __cxa_begin_catch depends on this but we can't use deps info in this # case because that only works for user-level code, and __cxa_begin_catch # can be used by the standard library. '__cxa_increment_exception_refcount', # Same for __cxa_end_catch '__cxa_decrement_exception_refcount', # Emscripten exception handling can generate invoke calls, and they call # setThrew(). We cannot handle this using deps_info as the invokes are not # emitted because of library function usage, but by codegen itself. 'setThrew', '__cxa_free_exception', ] if settings.ASYNCIFY: if not settings.ASYNCIFY_IGNORE_INDIRECT: # if we are not ignoring indirect calls, then we must treat invoke_* as if # they are indirect calls, since that is what they do - we can't see their # targets statically. settings.ASYNCIFY_IMPORTS += ['invoke_*'] # add the default imports settings.ASYNCIFY_IMPORTS += DEFAULT_ASYNCIFY_IMPORTS # add the default exports (only used for ASYNCIFY == 2) settings.ASYNCIFY_EXPORTS += DEFAULT_ASYNCIFY_EXPORTS # return the full import name, including module. The name may # already have a module prefix; if not, we assume it is "env". def get_full_import_name(name): if '.' in name: return name return 'env.' + name settings.ASYNCIFY_IMPORTS = [get_full_import_name(i) for i in settings.ASYNCIFY_IMPORTS] if settings.ASYNCIFY == 2: diagnostics.warning('experimental', '-sASYNCIFY=2 (JSPI) is still experimental') if settings.WASM2JS: if settings.GENERATE_SOURCE_MAP: exit_with_error('wasm2js does not support source maps yet (debug in wasm for now)') if settings.MEMORY64: exit_with_error('wasm2js does not support MEMORY64') if settings.WASM_BIGINT: exit_with_error('wasm2js does not support WASM_BIGINT') if settings.CAN_ADDRESS_2GB: exit_with_error('wasm2js does not support >2gb address space') if settings.NODE_CODE_CACHING: if settings.WASM_ASYNC_COMPILATION: exit_with_error('NODE_CODE_CACHING requires sync compilation (WASM_ASYNC_COMPILATION=0)') if not settings.ENVIRONMENT_MAY_BE_NODE: exit_with_error('NODE_CODE_CACHING only works in node, but target environments do not include it') if settings.SINGLE_FILE: exit_with_error('NODE_CODE_CACHING saves a file on the side and is not compatible with SINGLE_FILE') if not js_manipulation.isidentifier(settings.EXPORT_NAME): exit_with_error(f'EXPORT_NAME is not a valid JS identifier: `{settings.EXPORT_NAME}`') if settings.EMSCRIPTEN_TRACING: add_system_js_lib('libtrace.js') if settings.ALLOW_MEMORY_GROWTH: settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['emscripten_trace_report_memory_layout'] settings.REQUIRED_EXPORTS += ['emscripten_stack_get_current', 'emscripten_stack_get_base', 'emscripten_stack_get_end'] settings.EMSCRIPTEN_VERSION = utils.EMSCRIPTEN_VERSION if settings.RETAIN_COMPILER_SETTINGS: settings.PUBLIC_SETTINGS = [k for k in settings.attrs.keys() if k not in settings.internal_settings] # Also include EMSCRIPTEN_VERSION from the internal settings since there are # known usage of this with `emscripten_get_compiler_setting`. settings.PUBLIC_SETTINGS.append('EMSCRIPTEN_VERSION') settings.SOURCE_MAP_BASE = options.source_map_base or '' settings.LINK_AS_CXX = (shared.run_via_emxx or settings.DEFAULT_TO_CXX) and not options.nostdlibxx # WASMFS itself is written in C++, and needs C++ standard libraries if settings.WASMFS: settings.LINK_AS_CXX = True # Some settings make no sense when not linking as C++ if not settings.LINK_AS_CXX: cxx_only_settings = [ 'EXCEPTION_DEBUG', 'DISABLE_EXCEPTION_CATCHING', 'EXCEPTION_CATCHING_ALLOWED', 'DISABLE_EXCEPTION_THROWING', ] for setting in cxx_only_settings: if setting in user_settings: diagnostics.warning('linkflags', 'setting `%s` is not meaningful unless linking as C++', setting) if settings.WASM_EXCEPTIONS: settings.REQUIRED_EXPORTS += ['__trap'] if settings.EXCEPTION_STACK_TRACES: # If the user explicitly gave EXCEPTION_STACK_TRACES=1 without enabling EH, # errors out. if settings.DISABLE_EXCEPTION_CATCHING and not settings.WASM_EXCEPTIONS: exit_with_error('EXCEPTION_STACK_TRACES requires either of -fexceptions or -fwasm-exceptions') # EXCEPTION_STACK_TRACES implies EXPORT_EXCEPTION_HANDLING_HELPERS settings.EXPORT_EXCEPTION_HANDLING_HELPERS = True # Make `getExceptionMessage` and other necessary functions available for use. if settings.EXPORT_EXCEPTION_HANDLING_HELPERS: # If the user explicitly gave EXPORT_EXCEPTION_HANDLING_HELPERS=1 without # enabling EH, errors out. if settings.DISABLE_EXCEPTION_CATCHING and not settings.WASM_EXCEPTIONS: exit_with_error('EXPORT_EXCEPTION_HANDLING_HELPERS requires either of -fexceptions or -fwasm-exceptions') # We also export refcount increasing and decreasing functions because if you # catch an exception, be it an Emscripten exception or a Wasm exception, in # JS, you may need to manipulate the refcount manually not to leak memory. # What you need to do is different depending on the kind of EH you use # (https://github.com/emscripten-core/emscripten/issues/17115). settings.EXPORTED_FUNCTIONS += ['getExceptionMessage', 'incrementExceptionRefcount', 'decrementExceptionRefcount'] if settings.WASM_EXCEPTIONS: settings.REQUIRED_EXPORTS += ['__cpp_exception'] if settings.SIDE_MODULE: # For side modules, we ignore all REQUIRED_EXPORTS that might have been added above. # They all come from either libc or compiler-rt. The exception is __wasm_call_ctors # and _emscripten_tls_init which are per-module exports. settings.REQUIRED_EXPORTS.clear() if not settings.STANDALONE_WASM: # in standalone mode, crt1 will call the constructors from inside the wasm settings.REQUIRED_EXPORTS.append('__wasm_call_ctors') if settings.PTHREADS: settings.REQUIRED_EXPORTS.append('_emscripten_tls_init') if settings.NODERAWFS: default_setting('NODE_HOST_ENV', 1) if not settings.ENVIRONMENT_MAY_BE_NODE: # Node-specific settings only make sense if ENVIRONMENT_MAY_BE_NODE if settings.NODERAWFS: diagnostics.warning('unused-command-line-argument', 'NODERAWFS ignored since `node` not in `ENVIRONMENT`') if settings.NODE_CODE_CACHING: diagnostics.warning('unused-command-line-argument', 'NODE_CODE_CACHING ignored since `node` not in `ENVIRONMENT`') if settings.NODEJS_CATCH_EXIT: diagnostics.warning('unused-command-line-argument', 'NODEJS_CATCH_EXIT ignored since `node` not in `ENVIRONMENT`') if settings.NODEJS_CATCH_REJECTION and 'NODEJS_CATCH_REJECTION' in user_settings: diagnostics.warning('unused-command-line-argument', 'NODEJS_CATCH_REJECTION ignored since `node` not in `ENVIRONMENT`') settings.PRE_JS_FILES = options.pre_js settings.POST_JS_FILES = options.post_js settings.MINIFY_WHITESPACE = settings.OPT_LEVEL >= 2 and settings.DEBUG_LEVEL == 0 and not options.no_minify # Closure might be run if we run it ourselves, or if whitespace is not being # minifed. In the latter case we keep both whitespace and comments, and the # purpose of the comments might be closure compiler, so also perform all # adjustments necessary to ensure that works (which amounts to a few more # comments; adding some more of them is not an issue in such a build which # includes all comments and whitespace anyhow). if settings.USE_CLOSURE_COMPILER or not settings.MINIFY_WHITESPACE: settings.MAYBE_CLOSURE_COMPILER = 1 check_settings() return target, wasm_target @ToolchainProfiler.profile_block('calculate system libraries') def phase_calculate_system_libraries(options): extra_files_to_link = [] # Link in ports and system libraries, if necessary if not settings.SIDE_MODULE: # Ports are always linked into the main module, never the side module. extra_files_to_link += ports.get_libs(settings) extra_files_to_link += system_libs.calculate(options) return extra_files_to_link @ToolchainProfiler.profile_block('link') def phase_link(linker_args, wasm_target, js_syms): logger.debug(f'linking: {linker_args}') # Make a final pass over settings.EXPORTED_FUNCTIONS to remove any # duplication between functions added by the driver/libraries and function # specified by the user settings.EXPORTED_FUNCTIONS = dedup_list(settings.EXPORTED_FUNCTIONS) settings.REQUIRED_EXPORTS = dedup_list(settings.REQUIRED_EXPORTS) settings.EXPORT_IF_DEFINED = dedup_list(settings.EXPORT_IF_DEFINED) rtn = None if settings.LINKABLE and not settings.EXPORT_ALL: # In LINKABLE mode we pass `--export-dynamic` along with `--whole-archive`. This results # in over 7000 exports, which cannot be distinguished from the few symbols we explicitly # export via EMSCRIPTEN_KEEPALIVE or EXPORTED_FUNCTIONS. # In order to avoid unnecessary exported symbols on the `Module` object we run the linker # twice in this mode: # 1. Without `--export-dynamic` to get the base exports # 2. With `--export-dynamic` to get the actual linkable Wasm binary # TODO(sbc): Remove this double execution of wasm-ld if we ever find a way to # distinguish EMSCRIPTEN_KEEPALIVE exports from `--export-dynamic` exports. settings.LINKABLE = False building.link_lld(linker_args, wasm_target, external_symbols=js_syms) settings.LINKABLE = True rtn = extract_metadata.extract_metadata(wasm_target) building.link_lld(linker_args, wasm_target, external_symbols=js_syms) return rtn @ToolchainProfiler.profile_block('post link') def phase_post_link(options, in_wasm, wasm_target, target, js_syms, base_metadata=None): global final_js target_basename = unsuffixed_basename(target) if options.oformat != OFormat.WASM: final_js = in_temp(target_basename + '.js') settings.TARGET_BASENAME = unsuffixed_basename(target) if options.oformat in (OFormat.JS, OFormat.MJS): js_target = target else: js_target = get_secondary_target(target, '.js') settings.TARGET_JS_NAME = os.path.basename(js_target) metadata = phase_emscript(in_wasm, wasm_target, js_syms, base_metadata) if settings.EMBIND_AOT: phase_embind_aot(options, wasm_target, js_syms) if options.emit_tsd: phase_emit_tsd(options, wasm_target, js_target, js_syms, metadata) if options.js_transform: phase_source_transforms(options) phase_binaryen(target, options, wasm_target) # If we are not emitting any JS then we are all done now if options.oformat != OFormat.WASM: phase_final_emitting(options, target, js_target, wasm_target) @ToolchainProfiler.profile_block('emscript') def phase_emscript(in_wasm, wasm_target, js_syms, base_metadata): # Emscripten logger.debug('emscript') # No need to support base64 embedding in wasm2js mode since # the module is already in JS format. if settings.SINGLE_FILE and not settings.WASM2JS: settings.SUPPORT_BASE64_EMBEDDING = 1 settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.append('$base64Decode') if shared.SKIP_SUBPROCS: return metadata = emscripten.emscript(in_wasm, wasm_target, final_js, js_syms, base_metadata=base_metadata) save_intermediate('original') return metadata def run_embind_gen(options, wasm_target, js_syms, extra_settings): # Save settings so they can be restored after TS generation. original_settings = settings.backup() settings.attrs.update(extra_settings) settings.EMBIND_GEN_MODE = True if settings.MAIN_MODULE: # Copy libraries to the temp directory so they can be used when running # in node. for f in options.input_files: if building.is_wasm_dylib(f): safe_copy(f, in_temp('')) # Ignore any options or settings that can conflict with running the TS # generation output. # Don't invoke the program's `main` function. settings.INVOKE_RUN = False # Ignore -sMODULARIZE which could otherwise effect how we run the module # to generate the bindings. settings.MODULARIZE = False # Disable ESM integration to avoid enabling the experimental feature in node. settings.WASM_ESM_INTEGRATION = False # Don't include any custom user JS or files. settings.PRE_JS_FILES = [] settings.POST_JS_FILES = [] # Force node since that is where the tool runs. settings.ENVIRONMENT = ['node'] settings.MINIMAL_RUNTIME = 0 # Required function to trigger TS generation. settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$callRuntimeCallbacks', '$addRunDependency', '$removeRunDependency'] settings.EXPORT_ES6 = False # Disable proxying and thread pooling so a worker is not automatically created. settings.PROXY_TO_PTHREAD = False settings.PTHREAD_POOL_SIZE = 0 # Assume wasm support at binding generation time settings.WASM2JS = 0 # Disable minify since the binaryen pass has not been run yet to change the # import names. settings.MINIFY_WASM_IMPORTED_MODULES = False setup_environment_settings() # Use a separate Wasm file so the JS does not need to be modified after emscripten.emscript. settings.SINGLE_FILE = False # Replace embind with the TypeScript generation version. for i, lib in enumerate(settings.JS_LIBRARIES): dirname, basename = os.path.split(lib) if basename == 'libembind.js': settings.JS_LIBRARIES[i] = os.path.join(dirname, 'libembind_gen.js') settings.MIN_NODE_VERSION = 160000 if settings.MEMORY64 else 150000 # The final version of the memory64 proposal is not implemented until node # v24, so we need to lower it away in order to execute the binary at build # time. # TODO Remove lowering when emsdk version of node is >= 24 and just require it. if settings.MEMORY64: settings.MEMORY64 = 2 # Source maps haven't been generated yet and aren't needed to run embind_gen. settings.LOAD_SOURCE_MAP = 0 outfile_js = in_temp('tsgen.js') # The Wasm outfile may be modified by emscripten.emscript, so use a temporary file. outfile_wasm = in_temp('tsgen.wasm') emscripten.emscript(wasm_target, outfile_wasm, outfile_js, js_syms, finalize=False) # Build the flags needed by Node.js to properly run the output file. node_args = [] if settings.MEMORY64: # See comment above about lowering memory64. building.run_wasm_opt(outfile_wasm, outfile_wasm, ['--memory64-lowering', '--table64-lowering']) if settings.WASM_EXCEPTIONS: node_args += shared.node_exception_flags(config.NODE_JS) # Run the generated JS file with the proper flags to generate the TypeScript bindings. output_file = in_temp('embind_generated_output.js') shared.run_js_tool(outfile_js, [output_file], node_args) settings.restore(original_settings) return read_file(output_file) @ToolchainProfiler.profile_block('emit tsd') def phase_emit_tsd(options, wasm_target, js_target, js_syms, metadata): logger.debug('emit tsd') filename = options.emit_tsd embind_tsd = '' if settings.EMBIND: embind_tsd = run_embind_gen(options, wasm_target, js_syms, {'EMBIND_AOT': False}) all_tsd = emscripten.create_tsd(metadata, embind_tsd) out_file = os.path.join(os.path.dirname(js_target), filename) write_file(out_file, all_tsd) @ToolchainProfiler.profile_block('embind aot js') def phase_embind_aot(options, wasm_target, js_syms): out = run_embind_gen(options, wasm_target, js_syms, {}) if DEBUG: write_file(in_temp('embind_aot.json'), out) out = json.loads(out) src = read_file(final_js) src = do_replace(src, '<<< EMBIND_AOT_INVOKERS >>>', out['invokers']) if settings.MODULARIZE == 'instance': # Add ES module exports for the embind exports. decls = '\n'.join([f'export var {name};' for name in out['publicSymbols']]) # Assign the runtime exports from Module to the ES export. assigns = '\n'.join([f'{name} = Module[\'{name}\'];' for name in out['publicSymbols']]) exports = f''' // start embind exports function assignEmbindExports() {{ {assigns} }}; addOnPostCtor(assignEmbindExports); {decls} // end embind exports''' src += exports write_file(final_js, src) if settings.WASM_ESM_INTEGRATION: # With ESM integration the embind exports also need to be exported by the main file. settings.EXPORTED_RUNTIME_METHODS.extend(out['publicSymbols']) # for Popen, we cannot have doublequotes, so provide functionality to # remove them when needed. def remove_quotes(arg): if isinstance(arg, list): return [remove_quotes(a) for a in arg] if arg.startswith('"') and arg.endswith('"'): return arg[1:-1].replace('\\"', '"') elif arg.startswith("'") and arg.endswith("'"): return arg[1:-1].replace("\\'", "'") else: return arg @ToolchainProfiler.profile_block('source transforms') def phase_source_transforms(options): # Apply a source code transformation, if requested global final_js safe_copy(final_js, final_js + '.tr.js') final_js += '.tr.js' posix = not WINDOWS logger.debug('applying transform: %s', options.js_transform) shared.check_call(remove_quotes(shlex.split(options.js_transform, posix=posix) + [os.path.abspath(final_js)])) save_intermediate('transformed') # Unmangle previously mangled `import.meta` and `await import` references in # both main code and libraries. # See also: `preprocess` in parseTools.js. def fix_js_mangling(js_file): # We don't apply these mangliings except in MODULARIZE/EXPORT_ES6 modes. if not settings.MODULARIZE: return src = read_file(js_file) write_file(js_file, src .replace('EMSCRIPTEN$IMPORT$META', 'import.meta') .replace('EMSCRIPTEN$AWAIT$IMPORT', 'await import') .replace('EMSCRIPTEN$AWAIT(', 'await (')) save_intermediate('js-mangling') def node_detection_code(): return "globalThis.process?.versions?.node && globalThis.process?.type != 'renderer'" def create_esm_wrapper(wrapper_file, support_target, wasm_target): js_exports = building.user_requested_exports.union(settings.EXPORTED_RUNTIME_METHODS) js_exports = ', '.join(sorted(js_exports)) wrapper = [] wrapper.append('// The wasm module must be imported here first before the support file') wrapper.append('// in order to avoid issues with circular dependencies.') wrapper.append(f"import * as unused from './{settings.WASM_BINARY_FILE}';") support_url = f'./{os.path.basename(support_target)}' if js_exports: wrapper.append(f"export {{ default, {js_exports} }} from '{support_url}';") else: wrapper.append(f"export {{ default }} from '{support_url}';") if settings.ENVIRONMENT_MAY_BE_NODE: wrapper.append(f''' // When run as the main module under node, create the module directly. This will // execute any startup code along with main (if it exists). import init from '{support_url}'; const isNode = {node_detection_code()}; if (isNode) {{ const url = await import('url'); const isMainModule = url.pathToFileURL(process.argv[1]).href === import.meta.url; if (isMainModule) await init(); }}''') write_file(wrapper_file, '\n'.join(wrapper) + '\n') # FIXME(sbc): This is a huge hack to rename the imports in the # wasm file. Find a better way to do this. wasm_dis = os.path.join(building.get_binaryen_bin(), 'wasm-dis') mod = shared.check_call([wasm_dis, wasm_target], stdout=PIPE).stdout mod = mod.replace('(import "env"', f'(import "{support_url}"') mod = mod.replace('(import "wasi_snapshot_preview1"', f'(import "{support_url}"') wasm_as = os.path.join(building.get_binaryen_bin(), 'wasm-as') cmd = [wasm_as, '--all-features', '-o', wasm_target, '-'] if settings.EMIT_NAME_SECTION: cmd.append('-g') shared.check_call(cmd, input=mod) @ToolchainProfiler.profile_block('final emitting') def phase_final_emitting(options, target, js_target, wasm_target): global final_js if shared.SKIP_SUBPROCS: return if settings.MODULARIZE and settings.MODULARIZE != 'instance': modularize() elif settings.USE_CLOSURE_COMPILER: module_export_name_substitution() # Run a final optimization pass to clean up items that were not possible to # optimize by Closure, or unoptimalities that were left behind by processing # steps that occurred after Closure. if settings.MINIMAL_RUNTIME == 2 and settings.USE_CLOSURE_COMPILER and settings.DEBUG_LEVEL == 0: args = [final_js, '-o', final_js] if not settings.MINIFY_WHITESPACE: args.append('--pretty') shared.run_js_tool(utils.path_from_root('tools/unsafe_optimizations.mjs'), args, cwd=utils.path_from_root('.')) save_intermediate('unsafe-optimizations') # Finally, rerun Closure compile with simple optimizations. It will be able # to further minify the code. (n.b. it would not be safe to run in advanced # mode) final_js = building.closure_compiler(final_js, advanced=False, extra_closure_args=settings.CLOSURE_ARGS) # Run unsafe_optimizations.js once more. This allows the cleanup of newly # unused things that closure compiler leaves behind (e.g `new Float64Array(x)`). shared.run_js_tool(utils.path_from_root('tools/unsafe_optimizations.mjs'), [final_js, '-o', final_js], cwd=utils.path_from_root('.')) save_intermediate('unsafe-optimizations2') fix_js_mangling(final_js) # Apply pre and postjs files if options.extern_pre_js or options.extern_post_js: extern_pre_js = read_js_files(options.extern_pre_js) extern_post_js = read_js_files(options.extern_post_js) logger.debug('applying extern pre/postjses') src = read_file(final_js) final_js += '.epp.js' with open(final_js, 'w', encoding='utf-8') as f: f.write(extern_pre_js) f.write(src) f.write(extern_post_js) save_intermediate('extern-pre-post') js_manipulation.handle_license(final_js) # The JS is now final. Move it to its final location if settings.WASM_ESM_INTEGRATION: support_target = unsuffixed(js_target) + '.support.mjs' move_file(final_js, support_target) create_esm_wrapper(js_target, support_target, wasm_target) if settings.PTHREADS: support_target = unsuffixed(js_target) + '.pthread.mjs' pthread_code = building.read_and_preprocess(utils.path_from_root('src/pthread_esm_startup.mjs'), expand_macros=True) write_file(support_target, pthread_code) fix_js_mangling(support_target) else: move_file(final_js, js_target) target_basename = unsuffixed_basename(target) utils.convert_line_endings_in_file(js_target, options.output_eol) # If we were asked to also generate HTML, do that if options.oformat == OFormat.HTML: generate_html(target, options, js_target, target_basename, wasm_target) if settings.SPLIT_MODULE: do_split_module(wasm_target, options) if options.executable: make_js_executable(js_target) @ToolchainProfiler.profile_block('binaryen') def phase_binaryen(target, options, wasm_target): global final_js logger.debug('using binaryen') # whether we need to emit -g (function name debug info) in the final wasm debug_function_names = settings.DEBUG_LEVEL >= 2 or settings.EMIT_NAME_SECTION # whether we need to emit -g in the intermediate binaryen invocations (but not # necessarily at the very end). this is necessary if we depend on debug info # during compilation, even if we do not emit it at the end. # we track the number of causes for needing intermdiate debug info so # that we can stop emitting it when possible - in particular, that is # important so that we stop emitting it before the end, and it is not in the # final binary (if it shouldn't be) intermediate_debug_info = 0 if debug_function_names: intermediate_debug_info += 1 if options.emit_symbol_map: intermediate_debug_info += 1 if settings.ASYNCIFY == 1: intermediate_debug_info += 1 # run wasm-opt if we have work for it: either passes, or if we are using # source maps (which requires some extra processing to keep the source map # but remove DWARF) passes = get_binaryen_passes(options) if passes: # if asyncify is used, we will use it in the next stage, and so if it is # the only reason we need intermediate debug info, we can stop keeping it if settings.ASYNCIFY == 1: intermediate_debug_info -= 1 # currently binaryen's DWARF support will limit some optimizations; warn on # that. see https://github.com/emscripten-core/emscripten/issues/15269 if settings.GENERATE_DWARF and should_run_binaryen_optimizer(): diagnostics.warning('limited-postlink-optimizations', 'running limited binaryen optimizations because DWARF info requested (or indirectly required)') with ToolchainProfiler.profile_block('wasm_opt'): building.run_wasm_opt(wasm_target, wasm_target, args=passes, debug=intermediate_debug_info) building.save_intermediate(wasm_target, 'byn.wasm') if settings.EVAL_CTORS: with ToolchainProfiler.profile_block('eval_ctors'): building.eval_ctors(final_js, wasm_target, debug_info=intermediate_debug_info) building.save_intermediate(wasm_target, 'ctors.wasm') # after generating the wasm, do some final operations if final_js: # >=2GB heap support requires pointers in JS to be unsigned. rather than # require all pointers to be unsigned by default, which increases code size # a little, keep them signed, and just unsign them here if we need that. if settings.CAN_ADDRESS_2GB: with ToolchainProfiler.profile_block('use_unsigned_pointers_in_js'): final_js = building.use_unsigned_pointers_in_js(final_js) if settings.USE_ASAN: final_js = building.instrument_js_for_asan(final_js) if settings.SAFE_HEAP: final_js = building.instrument_js_for_safe_heap(final_js) # shared memory growth requires some additional JS fixups. # note that we must do this after handling of unsigned pointers. unsigning # adds some >>> 0 things, while growth will replace a HEAP8 with a call to # a method to get the heap, and that call would not be recognized by the # unsigning pass. # we also must do this after the asan or safe_heap instrumentation, as they # wouldn't be able to recognize patterns produced by the growth pass. if settings.SHARED_MEMORY and settings.ALLOW_MEMORY_GROWTH and not settings.GROWABLE_ARRAYBUFFERS: with ToolchainProfiler.profile_block('apply_wasm_memory_growth'): final_js = building.apply_wasm_memory_growth(final_js) if settings.SUPPORT_BIG_ENDIAN: with ToolchainProfiler.profile_block('little_endian_heap'): final_js = building.little_endian_heap(final_js) if settings.OPT_LEVEL >= 2 and settings.DEBUG_LEVEL <= 2: # minify the JS. Do not minify whitespace if Closure is used, so that # Closure can print out readable error messages (Closure will then # minify whitespace afterwards) with ToolchainProfiler.profile_block('minify_wasm'): save_intermediate_with_wasm('preclean', wasm_target) final_js = building.minify_wasm_js(js_file=final_js, wasm_file=wasm_target, expensive_optimizations=will_metadce(), debug_info=intermediate_debug_info) save_intermediate_with_wasm('postclean', wasm_target) if options.use_closure_compiler: with ToolchainProfiler.profile_block('closure_compile'): final_js = building.closure_compiler(final_js, extra_closure_args=settings.CLOSURE_ARGS) save_intermediate('closure') if settings.TRANSPILE: with ToolchainProfiler.profile_block('transpile'): final_js = building.transpile(final_js) save_intermediate('transpile') # Run acorn one more time to minify whitespace after babel runs if settings.MINIFY_WHITESPACE: final_js = building.acorn_optimizer(final_js, ['--minify-whitespace']) symbols_file = None if options.emit_symbol_map: symbols_file = shared.replace_or_append_suffix(target, '.symbols') if settings.WASM2JS: symbols_file_js = None if settings.WASM == 2: # With normal wasm2js mode this file gets included as part of the # preamble, but with WASM=2 its a separate file. wasm2js_polyfill = building.read_and_preprocess(utils.path_from_root('src/wasm2js.js'), expand_macros=True) wasm2js_template = wasm_target + '.js' write_file(wasm2js_template, wasm2js_polyfill) # generate secondary file for JS symbols if options.emit_symbol_map: symbols_file_js = shared.replace_or_append_suffix(wasm2js_template, '.symbols') else: wasm2js_template = final_js if options.emit_symbol_map: symbols_file_js = shared.replace_or_append_suffix(target, '.symbols') wasm2js = building.wasm2js(wasm2js_template, wasm_target, opt_level=settings.OPT_LEVEL, use_closure_compiler=options.use_closure_compiler, debug_info=debug_function_names, symbols_file=symbols_file, symbols_file_js=symbols_file_js) shared.get_temp_files().note(wasm2js) if settings.WASM == 2: safe_copy(wasm2js, wasm2js_template) if settings.WASM != 2: final_js = wasm2js save_intermediate('wasm2js') generating_wasm = settings.WASM == 2 or not settings.WASM2JS # emit the final symbols, either in the binary or in a symbol map. # this will also remove debug info if we only kept it around in the intermediate invocations. # note that if we aren't emitting a binary (like in wasm2js) then we don't # have anything to do here. if options.emit_symbol_map: intermediate_debug_info -= 1 if generating_wasm: building.write_symbol_map(wasm_target, symbols_file) if not intermediate_debug_info: building.strip(wasm_target, wasm_target, sections=['name']) if settings.GENERATE_DWARF and settings.SEPARATE_DWARF and generating_wasm: # if the dwarf filename wasn't provided, use the default target + a suffix wasm_file_with_dwarf = settings.SEPARATE_DWARF if wasm_file_with_dwarf is True: # Historically this file has been called `.wasm.debug.wasm` # TODO(sbc): Should this just be `.debug.wasm` wasm_file_with_dwarf = get_secondary_target(target, '.wasm.debug.wasm') building.emit_debug_on_side(wasm_target, wasm_file_with_dwarf) # we have finished emitting the wasm, and so intermediate debug info will # definitely no longer be used tracking it. if debug_function_names: intermediate_debug_info -= 1 assert intermediate_debug_info == 0 # strip debug info if it was not already stripped by the last command if not debug_function_names and building.binaryen_kept_debug_info and generating_wasm: with ToolchainProfiler.profile_block('strip_name_section'): building.strip(wasm_target, wasm_target, debug=False, sections=["name"]) # replace placeholder strings with correct subresource locations if final_js and settings.SINGLE_FILE and not settings.WASM2JS: js = read_file(final_js) if settings.SINGLE_FILE_BINARY_ENCODE: js = do_replace(js, '"<<< WASM_BINARY_DATA >>>"', binary_encode(wasm_target)) else: js = do_replace(js, '<<< WASM_BINARY_DATA >>>', base64_encode(wasm_target)) delete_file(wasm_target) write_file(final_js, js) def modularize(): global final_js logger.debug(f'Modularizing, creating factory function called `{settings.EXPORT_NAME}`') modularize_src = building.read_and_preprocess(utils.path_from_root('src/modularize.js'), expand_macros=True) if settings.MINIFY_WHITESPACE: with shared.get_temp_files().get_file(suffix='.js') as tmp: write_file(tmp, modularize_src) minified_file = building.acorn_optimizer(tmp, ['--minify-whitespace']) modularize_src = read_file(minified_file) # Replace INNER_JS_CODE in the minified code full_src = do_replace(modularize_src, '"<<< INNER_JS_CODE >>>"', read_file(final_js)) final_js += '.modular.js' write_file(final_js, full_src) shared.get_temp_files().note(final_js) save_intermediate('modularized') # FIXME(https://github.com/emscripten-core/emscripten/issues/24558): Running acorn at this # late phase seems to cause OOM (some kind of inifite loop perhaps) in node. # Instead we minify src/modularize.js in isolation above. #if settings.MINIFY_WHITESPACE: # final_js = building.acorn_optimizer(final_js, ['--minify-whitespace']) def module_export_name_substitution(): assert not settings.MODULARIZE global final_js logger.debug(f'Private module export name substitution with {settings.EXPORT_NAME}') src = read_file(final_js) final_js += '.module_export_name_substitution.js' if settings.MINIMAL_RUNTIME and not settings.ENVIRONMENT_MAY_BE_NODE and not settings.ENVIRONMENT_MAY_BE_SHELL and not settings.AUDIO_WORKLET: # On the web, with MINIMAL_RUNTIME, the Module object is always provided # via the shell html in order to provide the .asm.js/.wasm content. replacement = settings.EXPORT_NAME else: replacement = "typeof %(EXPORT_NAME)s != 'undefined' ? %(EXPORT_NAME)s : {}" % {"EXPORT_NAME": settings.EXPORT_NAME} new_src = re.sub(r'{\s*[\'"]?__EMSCRIPTEN_PRIVATE_MODULE_EXPORT_NAME_SUBSTITUTION__[\'"]?:\s*1\s*}', replacement, src) assert new_src != src, 'Unable to find Closure syntax __EMSCRIPTEN_PRIVATE_MODULE_EXPORT_NAME_SUBSTITUTION__ in source!' write_file(final_js, new_src) shared.get_temp_files().note(final_js) save_intermediate('module_export_name_substitution') def generate_traditional_runtime_html(target, options, js_target, wasm_target): script = ScriptSource() if settings.EXPORT_NAME != 'Module' and options.shell_path == DEFAULT_SHELL_HTML: # the minimal runtime shell HTML is designed to support changing the export # name, but the normal one does not support that currently exit_with_error('customizing EXPORT_NAME requires that the HTML be customized to use that name (see https://github.com/emscripten-core/emscripten/issues/10086)') shell = building.read_and_preprocess(options.shell_path) if '{{{ SCRIPT }}}' not in shell: exit_with_error('HTML shell must contain {{{ SCRIPT }}}, see src/shell.html for an example') if settings.SINGLE_FILE: js_contents = script.inline or '' js_contents += read_file(js_target) script.inline = read_file(js_target) delete_file(js_target) else: script.src = os.path.basename(js_target) if not settings.WASM_ASYNC_COMPILATION: # We need to load the wasm file before anything else, since it # has be synchronously ready. script.un_src() script.inline = ''' fetch(%s).then((result) => result.arrayBuffer()) .then((buf) => { Module.wasmBinary = buf; %s; }); ''' % (get_subresource_location(wasm_target), script.inline) if settings.WASM == 2: # If target browser does not support WebAssembly, we need to load # the .wasm.js file before the main .js file. script.un_src() script.inline = ''' function loadMainJs() { %s } if (!window.WebAssembly || location.search.indexOf('_rwasm=0') > 0) { // Current browser does not support WebAssembly, load the .wasm.js JavaScript fallback // before the main JS runtime. var wasm2js = document.createElement('script'); wasm2js.src = %s; wasm2js.onload = loadMainJs; document.body.appendChild(wasm2js); } else { // Current browser supports Wasm, proceed with loading the main JS runtime. loadMainJs(); } ''' % (script.inline, get_subresource_location_js(wasm_target + '.js')) shell = do_replace(shell, '{{{ SCRIPT }}}', script.replacement()) shell = shell.replace('{{{ SHELL_CSS }}}', utils.read_file(utils.path_from_root('src/shell.css'))) logo_filename = utils.path_from_root('media/powered_by_logo_shell.png') logo_b64 = base64_encode(logo_filename) shell = shell.replace('{{{ SHELL_LOGO }}}', f'') check_output_file(target) write_file(target, shell) def minify_html(filename): if settings.DEBUG_LEVEL >= 2: return opts = [] # -g1 and greater retain whitespace and comments in source if settings.DEBUG_LEVEL == 0: opts += ['--collapse-whitespace', '--remove-comments', '--remove-tag-whitespace', '--sort-attributes', '--sort-class-name'] # -g2 and greater do not minify HTML at all if settings.DEBUG_LEVEL <= 1: opts += ['--decode-entities', '--collapse-boolean-attributes', '--remove-attribute-quotes', '--remove-redundant-attributes', '--remove-script-type-attributes', '--remove-style-link-type-attributes', '--use-short-doctype', '--minify-css', 'true', '--minify-js', 'true'] # html-minifier also has the following options, but they look unsafe for use: # '--collapse-inline-tag-whitespace': removes whitespace between inline tags in visible text, # causing words to be joined together. See # https://github.com/terser/html-minifier-terser/issues/179 # https://github.com/emscripten-core/emscripten/issues/22188 # '--remove-optional-tags': removes e.g. and tags from the page. # (Breaks at least browser.test_sdl2glshader) # '--remove-empty-attributes': removes all attributes with whitespace-only values. # (Breaks at least browser.test_asmfs_hello_file) # '--remove-empty-elements': removes all elements with empty contents. # (Breaks at least browser.test_asm_swapping) logger.debug(f'minifying HTML file {filename}') size_before = os.path.getsize(filename) start_time = time.time() shared.check_call(shared.get_npm_cmd('html-minifier-terser') + [filename, '-o', filename] + opts, env=shared.env_with_node_in_path()) # HTML minifier will turn all null bytes into an escaped two-byte sequence "\0". Turn those back to single byte sequences. def unescape_nulls(filename): with open(filename, encoding="utf-8") as f: data = f.read() out = [] in_escape = False i = 0 while i < len(data): ch = data[i] i += 1 if ch == '\\': if in_escape: out.append('\\\\') in_escape = not in_escape elif in_escape: in_escape = False if ch == '0': out.append('\x00') # Convert '\\0' (5Ch 00h) into '\0' (00h) elif ch == 'x' and data[i] == '0' and data[i + 1] == '0': out.append('\x00') # Oddly html-minifier generates both "\\0" and "\\x00", so handle that too. i += 2 else: out.append('\\') out.append(ch) else: out.append(ch) with open(filename, "wb") as f: f.write(''.join(out).encode("utf-8")) unescape_nulls(filename) elapsed_time = time.time() - start_time size_after = os.path.getsize(filename) delta = size_after - size_before logger.debug(f'HTML minification took {elapsed_time:.2f} seconds, and shrunk size of {filename} from {size_before} to {size_after} bytes, delta={delta} ({delta * 100.0 / size_before:+.2f}%)') def generate_html(target, options, js_target, target_basename, wasm_target): logger.debug('generating HTML') if settings.MINIMAL_RUNTIME: generate_minimal_runtime_html(target, options, js_target, target_basename) else: generate_traditional_runtime_html(target, options, js_target, wasm_target) if settings.MINIFY_HTML and (settings.OPT_LEVEL >= 1 or settings.SHRINK_LEVEL >= 1): minify_html(target) utils.convert_line_endings_in_file(target, options.output_eol) def find_library(lib, lib_dirs): for lib_dir in lib_dirs: path = os.path.join(lib_dir, lib) if os.path.isfile(path): logger.debug('found library "%s" at %s', lib, path) return path return None def map_to_js_libs(library_name): """Given the name of a special Emscripten-implemented system library, returns an pair containing 1. Array of absolute paths to JS library files, inside emscripten/src/ that corresponds to the library name. `None` means there is no mapping and the library will be processed by the linker as a require for normal native library. 2. Optional name of a corresponding native library to link in. """ # Some native libraries are implemented in Emscripten as system side JS libraries library_map = { 'embind': ['libembind.js', 'libemval.js'], 'EGL': ['libegl.js'], 'GL': ['libwebgl.js', 'libhtml5_webgl.js'], 'webgl.js': ['libwebgl.js', 'libhtml5_webgl.js'], 'GLESv2': ['libwebgl.js'], # N.b. there is no GLESv3 to link to (note [f] in https://www.khronos.org/registry/implementers_guide.html) 'GLEW': ['libglew.js'], 'glfw': ['libglfw.js'], 'glfw3': ['libglfw.js'], 'GLU': [], 'glut': ['libglut.js'], 'openal': ['libopenal.js'], 'X11': ['libxlib.js'], 'SDL': ['libsdl.js'], 'uuid': ['libuuid.js'], 'fetch': ['libfetch.js'], 'websocket': ['libwebsocket.js'], # These 4 libraries are separate under glibc but are all rolled into # libc with musl. For compatibility with glibc we just ignore them # completely. 'dl': [], 'm': [], 'rt': [], 'pthread': [], # This is the name of GNU's C++ standard library. We ignore it here # for compatibility with GNU toolchains. 'stdc++': [], 'SDL2_mixer': [], } if library_name in library_map: libs = library_map[library_name] logger.debug('Mapping library `%s` to JS libraries: %s' % (library_name, libs)) return libs return None def process_libraries(options, flags): """Process `-l` and `--js-library` flags.""" new_flags = [] system_libs_map = system_libs.Library.get_usable_variations() for flag in flags: if flag.startswith('--js-library='): js_lib = flag.split('=', 1)[1] settings.JS_LIBRARIES.append(js_lib) continue if not flag.startswith('-l'): new_flags.append(flag) continue lib = flag.removeprefix('-l') logger.debug('looking for library "%s"', lib) js_libs = map_to_js_libs(lib) if js_libs is not None: for l in js_libs: add_system_js_lib(l) # We don't need to resolve system libraries to absolute paths here, we can just # let wasm-ld handle that. However, we do want to map to the correct variant. # For example we map `-lc` to `-lc-mt` if we are building with threading support. if 'lib' + lib in system_libs_map: lib = system_libs_map['lib' + lib].get_link_flag() new_flags.append(lib) continue if js_libs is not None: continue if lib.endswith('.js'): name = 'lib' + lib path = find_library(name, options.lib_dirs) if not path: exit_with_error(f'unable to find library {flag}') settings.JS_LIBRARIES.append(os.path.abspath(path)) continue static_lib = f'lib{lib}.a' if not settings.RELOCATABLE and not settings.MAIN_MODULE and not find_library(static_lib, options.lib_dirs): # Normally we can rely on the native linker to expand `-l` args. # However, emscripten also supports fake `.so` files that are actually # just regular object files. This means we need to support `.so` files even # when statically linking. The native linker (wasm-ld) will otherwise # ignore .so files in this mode. found_dylib = False for ext in DYLIB_EXTENSIONS: name = 'lib' + lib + ext path = find_library(name, options.lib_dirs) if path and not building.is_wasm_dylib(path): found_dylib = True new_flags.append(path) break if found_dylib: continue new_flags.append(flag) return new_flags def apply_library_settings(linker_args): for arg in linker_args: if not arg.startswith('-l'): continue library_name = arg[2:] settings_map = { 'embind': {'EMBIND': 1}, 'glfw': {'USE_GLFW': 2}, 'glfw3': {'USE_GLFW': 3}, 'SDL': {'USE_SDL': 1}, 'SDL2_mixer': {'USE_SDL_MIXER': 2}, } if library_name in settings_map: for key, value in settings_map[library_name].items(): default_setting(key, value) class ScriptSource: def __init__(self): self.src = None # if set, we have a script to load with a src attribute self.inline = None # if set, we have the contents of a script to write inline in a script def un_src(self): """Use this if you want to modify the script and need it to be inline.""" if self.src is None: return quoted_src = quote(self.src) if settings.EXPORT_ES6: self.inline = f''' import("./{quoted_src}").then(exports => exports.default(Module)) ''' else: self.inline = f''' var script = document.createElement('script'); script.src = "{quoted_src}"; document.body.appendChild(script); ''' self.src = None def replacement(self): """Returns the script tag to replace the {{{ SCRIPT }}} tag in the target""" assert (self.src or self.inline) and not (self.src and self.inline) if self.src: src = quote(self.src) filename = f'./{src}' if settings.EXPORT_ES6: return f''' ''' else: return f'' else: return f'' def filter_out_fake_dynamic_libs(options, inputs): """Filter out "fake" dynamic libraries that are really just intermediate object files.""" def is_fake_dylib(input_file): if get_file_suffix(input_file) in DYLIB_EXTENSIONS and os.path.exists(input_file) and not building.is_wasm_dylib(input_file): if not options.ignore_dynamic_linking: diagnostics.warning('emcc', 'ignoring dynamic library %s when generating an object file, this will need to be included explicitly in the final link', os.path.basename(input_file)) return True else: return False return [f for f in inputs if not is_fake_dylib(f)] def filter_out_duplicate_fake_dynamic_libs(inputs): """Filter out duplicate "fake" shared libraries (intermediate object files). See test_core.py:test_redundant_link """ seen = set() def check(input_file): if get_file_suffix(input_file) in DYLIB_EXTENSIONS 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 in library path: `{needed}`. (library path: {lib_dirs}') to_process.append(path) dylibs += extras for dylib in dylibs: exports = webassembly.get_exports(dylib) exports = {e.name for e in exports} # EM_JS function are exports with a special prefix. We need to strip # this prefix to get the actual symbol name. For the main module, this # is handled by extract_metadata.py. exports = [e.removeprefix('__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.invoke_funcs that comes from the # main module to avoid creating new invoke functions at runtime. imports = set(imports) imports = {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 get_secondary_target(target, ext): # Depending on the output format emscripten creates zero or more secondary # output files (e.g. the .wasm file when creating JS output, or the # .js and the .wasm file when creating html output. # Thus function names the secondary output files, while ensuring they # never collide with the primary one. base = unsuffixed(target) if get_file_suffix(target) == ext: base += '_' return base + ext def dedup_list(lst): # Since we require python 3.6, that ordering of dictionaries is guaranteed # to be insertion order so we can use 'dict' here but not 'set'. return list(dict.fromkeys(lst)) def check_output_file(f): if os.path.isdir(f): exit_with_error(f'cannot write output file `{f}`: Is a directory') def move_file(src, dst): logging.debug('move: %s -> %s', src, dst) check_output_file(dst) src = os.path.abspath(src) dst = os.path.abspath(dst) if src == dst: return if dst == os.devnull: return shutil.move(src, dst) def binary_encode(filename): """This function encodes the given binary byte array to a UTF-8 string, by encoding each byte values as UTF-8, except for specific byte values that are escaped as two bytes. This kind of encoding results in a string that will compress well by both gzip and brotli, unlike base64 encoding binary data would do. """ data = utils.read_binary(filename) # Decide whether to enclose the generated binary data in single-quotes '' or # double-quotes "" by looking at which character ends up requiring fewer # escapes of that string character. num_single_quotes = data.count(ord("'")) num_double_quotes = data.count(ord('"')) quote_char = ord("'") if num_single_quotes < num_double_quotes else ord('"') out = bytearray(len(data) * 2 + 2) # Size output buffer conservatively out[0] = quote_char # Emit string start quote i = 1 for d in data: if d == quote_char: buf = [ord('\\'), d] # Escape the string quote character with a backslash since we are writing the binary data inside a string. elif d == ord('\r'): buf = [ord('\\'), ord('r')] # Escape carriage return 0x0D as \r -> 2 bytes elif d == ord('\n'): buf = [ord('\\'), ord('n')] # Escape newline 0x0A as \n -> 2 bytes elif d == ord('\\'): buf = [ord('\\'), ord('\\')] # Escape backslash \ as \\ -> 2 bytes else: buf = chr(d).encode('utf-8') # Otherwise write the original value encoded in UTF-8 (1 or 2 bytes). for b in buf: # Write the bytes to output buffer out[i] = b i += 1 out[i] = quote_char # Emit string end quote i += 1 return out[0:i].decode('utf-8') # Crop output buffer to the actual used size # Returns the subresource location for run-time access def get_subresource_location(path, mimetype='application/octet-stream'): if settings.SINGLE_FILE: if settings.SINGLE_FILE_BINARY_ENCODE: return binary_encode(path) return f'"data:{mimetype};base64,{base64_encode(path)}"' else: return f'"{os.path.basename(path)}"' def get_subresource_location_js(path): return get_subresource_location(path, 'text/javascript') @ToolchainProfiler.profile() def package_files(options, target): rtn = [] logger.debug('setting up files') file_args = ['--from-emcc'] if options.preload_files: file_args.append('--preload') file_args += options.preload_files if options.embed_files: file_args.append('--embed') file_args += options.embed_files if options.exclude_files: file_args.append('--exclude') file_args += options.exclude_files if options.use_preload_cache: file_args.append('--use-preload-cache') if settings.LZ4: file_args.append('--lz4') if options.use_preload_plugins: file_args.append('--use-preload-plugins') if not settings.ENVIRONMENT_MAY_BE_NODE: file_args.append('--no-node') if options.embed_files: if settings.MEMORY64: file_args += ['--wasm64'] object_file = in_temp('embedded_files.o') file_args += ['--obj-output=' + object_file] rtn.append(object_file) cmd = building.get_command_with_possible_response_file( [shared.FILE_PACKAGER, utils.replace_suffix(target, '.data')] + file_args) if options.preload_files: # Preloading files uses --pre-js code that runs before the module is loaded. file_code = shared.check_call(cmd, stdout=PIPE).stdout js_manipulation.add_files_pre_js(settings.PRE_JS_FILES, file_code) else: # Otherwise, we are embedding files, which does not require --pre-js code, # and instead relies on a static constructor to populate the filesystem. shared.check_call(cmd) return rtn @ToolchainProfiler.profile_block('calculate linker inputs') def phase_calculate_linker_inputs(options, linker_args): using_lld = not (options.oformat == OFormat.OBJECT and settings.LTO) linker_args = filter_link_flags(linker_args, using_lld) # If we are linking to an intermediate object then ignore other # "fake" dynamic libraries, since otherwise we will end up with # multiple copies in the final executable. if options.oformat == OFormat.OBJECT or options.ignore_dynamic_linking: linker_args = filter_out_fake_dynamic_libs(options, linker_args) else: linker_args = filter_out_duplicate_fake_dynamic_libs(linker_args) if settings.MAIN_MODULE: process_dynamic_libs(options.dylibs, options.lib_dirs) return linker_args def calc_extra_ldflags(options): extra_args = [] system_libpath = str(cache.get_lib_dir(absolute=True)) system_js_path = utils.path_from_root('src', 'lib') options.lib_dirs.append(system_libpath) options.lib_dirs.append(system_js_path) extra_args.append('-L' + system_libpath) extra_args.append('-L' + system_js_path) if settings.FETCH: extra_args.append('-lfetch') if settings.STB_IMAGE: extra_args.append('-lstb_image') if settings.WASMFS and settings.NODERAWFS: # wasmfs will be included normally in system_libs.py, but we must include # noderawfs in a forced manner so that it is always linked in (the hook it # implements can remain unimplemented, so it won't be linked in # automatically) # TODO: find a better way to do this extra_args.append('--whole-archive') extra_args.append('-lwasmfs_noderawfs') extra_args.append('--no-whole-archive') return extra_args def run_post_link(wasm_input, options, linker_args): settings.limit_settings(None) target, wasm_target = phase_linker_setup(options, linker_args) process_libraries(options, linker_args) phase_post_link(options, wasm_input, wasm_target, target, {}) def run(options, linker_args): # We have now passed the compile phase, allow reading/writing of all settings. settings.limit_settings(None) if settings.RUNTIME_LINKED_LIBS: linker_args += settings.RUNTIME_LINKED_LIBS if not linker_args: exit_with_error('no input files') if options.output_file and options.output_file.startswith('-'): exit_with_error(f'invalid output filename: `{options.output_file}`') target, wasm_target = phase_linker_setup(options, linker_args) linker_args = process_libraries(options, linker_args) # Link object files using wasm-ld or llvm-link (for bitcode linking) linker_args = phase_calculate_linker_inputs(options, linker_args) # Embed and preload files if len(options.preload_files) or len(options.embed_files): linker_args += package_files(options, target) if options.oformat == OFormat.OBJECT: logger.debug(f'link_to_object: {linker_args} -> {target}') building.link_to_object(linker_args, target) logger.debug('stopping after linking to object file') return 0 system_libs = phase_calculate_system_libraries(options) # Only add system libraries that have not already been specified. # This avoids issues where the user explictly includes, for example, `-lGL`. # This is not normally a problem except in the case of -sMAIN_MODULE=1 where # the duplicate library would result in duplicate symbols. for s in system_libs: if s.startswith('-l') and s in linker_args: continue linker_args.append(s) js_syms = {} if (not settings.SIDE_MODULE or settings.ASYNCIFY) and not shared.SKIP_SUBPROCS: js_info = get_js_sym_info() if not settings.SIDE_MODULE: js_syms = js_info['deps'] if settings.LINKABLE: for native_deps in js_syms.values(): settings.REQUIRED_EXPORTS += native_deps else: def add_js_deps(sym): if sym in js_syms: native_deps = js_syms[sym] if native_deps: settings.REQUIRED_EXPORTS += native_deps for sym in settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE: add_js_deps(sym) for sym in js_info['extraLibraryFuncs']: add_js_deps(sym) for sym in settings.EXPORTED_RUNTIME_METHODS: add_js_deps(shared.demangle_c_symbol_name(sym)) for sym in settings.EXPORTED_FUNCTIONS: add_js_deps(shared.demangle_c_symbol_name(sym)) if settings.ASYNCIFY: settings.ASYNCIFY_IMPORTS_EXCEPT_JS_LIBS = settings.ASYNCIFY_IMPORTS[:] settings.ASYNCIFY_IMPORTS += ['*.' + x for x in js_info['asyncFuncs']] base_metadata = phase_link(linker_args, wasm_target, js_syms) # Special handling for when the user passed '-Wl,--version'. In this case the linker # does not create the output file, but just prints its version and exits with 0. if '--version' in linker_args: return 0 # TODO(sbc): In theory we should really run the whole pipeline even if the output is # /dev/null, but that will take some refactoring if target == os.devnull: return 0 # Perform post-link steps (unless we are running bare mode) if options.oformat != OFormat.BARE: phase_post_link(options, wasm_target, wasm_target, target, js_syms, base_metadata) return 0