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system_libs.py
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2360 lines (1939 loc) · 76.1 KB
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# Copyright 2014 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.
from .toolchain_profiler import ToolchainProfiler
import itertools
import logging
import os
import shutil
import textwrap
from enum import IntEnum, auto
from glob import iglob
from typing import List, Optional
from . import shared, building, utils
from . import diagnostics
from . import cache
from .settings import settings
from .utils import read_file
logger = logging.getLogger('system_libs')
# Files that are part of libsockets.a and so should be excluded from libc.a
LIBC_SOCKETS = ['socket.c', 'socketpair.c', 'shutdown.c', 'bind.c', 'connect.c',
'listen.c', 'accept.c', 'getsockname.c', 'getpeername.c', 'send.c',
'recv.c', 'sendto.c', 'recvfrom.c', 'sendmsg.c', 'recvmsg.c',
'getsockopt.c', 'setsockopt.c', 'freeaddrinfo.c',
'in6addr_any.c', 'in6addr_loopback.c', 'accept4.c']
# Experimental: Setting EMCC_USE_NINJA will cause system libraries to get built with ninja rather
# than simple subprocesses. The primary benefit here is that we get accurate dependency tracking.
# This means we can avoid completely rebuilding a library and just rebuild based on what changed.
#
# Setting EMCC_USE_NINJA=2 means that ninja will automatically be run for each library needed at
# link time.
USE_NINJA = int(os.environ.get('EMCC_USE_NINJA', '0'))
def files_in_path(path, filenames):
srcdir = utils.path_from_root(path)
return [os.path.join(srcdir, f) for f in filenames]
def glob_in_path(path, glob_pattern, excludes=()):
srcdir = utils.path_from_root(path)
files = iglob(os.path.join(srcdir, glob_pattern), recursive=True)
return sorted(f for f in files if os.path.basename(f) not in excludes)
def get_base_cflags(force_object_files=False, preprocess=True):
# Always build system libraries with debug information. Non-debug builds
# will ignore this at link time because we link with `-strip-debug`.
flags = ['-g', '-sSTRICT', '-Werror']
if settings.LTO and not force_object_files:
flags += ['-flto=' + settings.LTO]
if settings.RELOCATABLE:
flags += ['-sRELOCATABLE']
if preprocess:
flags += ['-DEMSCRIPTEN_DYNAMIC_LINKING']
if settings.MEMORY64:
flags += ['-Wno-experimental', '-sMEMORY64=' + str(settings.MEMORY64)]
return flags
def clean_env():
# building system libraries and ports should be hermetic in that it is not
# affected by things like EMCC_CFLAGS which the user may have set.
# At least one port also uses autoconf (harfbuzz) so we also need to clear
# CFLAGS/LDFLAGS which we don't want to effect the inner call to configure.
safe_env = os.environ.copy()
for opt in ['CFLAGS', 'CXXFLAGS', 'LDFLAGS',
'EMCC_CFLAGS',
'EMCC_AUTODEBUG',
'EMCC_FORCE_STDLIBS',
'EMCC_ONLY_FORCED_STDLIBS',
'EMMAKEN_JUST_CONFIGURE']:
if opt in safe_env:
del safe_env[opt]
return safe_env
def run_build_commands(commands):
# Before running a set of build commands make sure the common sysroot
# headers are installed. This prevents each sub-process from attempting
# to setup the sysroot itself.
ensure_sysroot()
shared.run_multiple_processes(commands, env=clean_env())
logger.info('compiled %d inputs' % len(commands))
def objectfile_sort_key(filename):
"""Sort object files that we pass to llvm-ar."""
# In general, we simply use alphabetical order, but we special case certain
# object files such they come first. For example, `vmlock.o` contains the
# definition of `__vm_wait`, but `mmap.o` also contains a dummy/weak definition
# for use by `mmap.o` when `vmlock.o` is not otherwise included.
#
# When another object looks for `__vm_wait` we prefer that it always find the
# real definition first and not refer to the dummy one (which is really
# intended to be local to `mmap.o` but due to the fact the weak aliases can't
# have internal linkage).
#
# The reason we care is that once an object file is pulled into certain aspects
# of it cannot be undone/removed by the linker. For example, static
# constructors or stub library dependencies.
#
# In the case of `mmap.o`, once it get included by the linker, it pulls in the
# the reverse dependencies of the mmap syscall (memalign). If we don't do this
# sorting we see a slight regression in test_metadce_minimal_pthreads due to
# memalign being included.
basename = os.path.basename(filename)
if basename in {'vmlock.o'}:
return 'AAA_' + basename
else:
return basename
def create_lib(libname, inputs):
"""Create a library from a set of input objects."""
suffix = shared.suffix(libname)
inputs = sorted(inputs, key=objectfile_sort_key)
if suffix in ('.bc', '.o'):
if len(inputs) == 1:
if inputs[0] != libname:
shutil.copyfile(inputs[0], libname)
else:
building.link_to_object(inputs, libname)
else:
assert suffix == '.a'
building.emar('cr', libname, inputs)
def get_top_level_ninja_file():
return os.path.join(cache.get_path('build'), 'build.ninja')
def run_ninja(build_dir):
diagnostics.warning('experimental', 'ninja support is experimental')
cmd = ['ninja', '-C', build_dir, f'-j{shared.get_num_cores()}']
if shared.PRINT_STAGES:
cmd.append('-v')
shared.check_call(cmd, env=clean_env())
def ensure_target_in_ninja_file(ninja_file, target):
if os.path.isfile(ninja_file) and target in read_file(ninja_file):
return
with open(ninja_file, 'a') as f:
f.write(target + '\n')
def create_ninja_file(input_files, filename, libname, cflags, asflags=None, customize_build_flags=None):
if asflags is None:
asflags = []
# TODO(sbc) There is an llvm bug that causes a crash when `-g` is used with
# assembly files that define wasm globals.
asflags = [arg for arg in asflags if arg != '-g']
cflags_asm = [arg for arg in cflags if arg != '-g']
def join(flags):
return ' '.join(flags)
out = f'''\
# Automatically generated by tools/system_libs.py. DO NOT EDIT
ninja_required_version = 1.5
ASFLAGS = {join(asflags)}
CFLAGS = {join(cflags)}
CFLAGS_ASM = {join(cflags_asm)}
EMCC = {shared.EMCC}
EMXX = {shared.EMXX}
EMAR = {shared.EMAR}
rule cc
depfile = $out.d
command = $EMCC -MD -MF $out.d $CFLAGS -c $in -o $out
description = CC $out
rule cxx
depfile = $out.d
command = $EMXX -MD -MF $out.d $CFLAGS -c $in -o $out
description = CXX $out
rule asm
command = $EMCC $ASFLAGS -c $in -o $out
description = ASM $out
rule asm_cpp
depfile = $out.d
command = $EMCC -MD -MF $out.d $CFLAGS_ASM -c $in -o $out
description = ASM $out
rule direct_cc
depfile = $with_depfile
command = $EMCC -MD -MF $with_depfile $CFLAGS -c $in -o $out
description = CC $out
rule archive
command = $EMAR cr $out $in
description = AR $out
'''
suffix = shared.suffix(libname)
build_dir = os.path.dirname(filename)
case_insensitive = is_case_insensitive(os.path.dirname(filename))
if suffix == '.o':
assert len(input_files) == 1
depfile = shared.unsuffixed_basename(input_files[0]) + '.d'
out += f'build {libname}: direct_cc {input_files[0]}\n'
out += f' with_depfile = {depfile}\n'
else:
objects = []
for src in input_files:
# Resolve duplicates by appending unique.
# This is needed on case insensitve filesystem to handle,
# for example, _exit.o and _Exit.o.
o = os.path.join(build_dir, shared.unsuffixed_basename(src) + '.o')
object_uuid = 0
if case_insensitive:
o = o.lower()
# Find a unique basename
while o in objects:
object_uuid += 1
o = f'{o}__{object_uuid}.o'
objects.append(o)
ext = shared.suffix(src)
if ext == '.s':
out += f'build {o}: asm {src}\n'
flags = asflags
elif ext == '.S':
out += f'build {o}: asm_cpp {src}\n'
flags = cflags_asm
elif ext == '.c':
out += f'build {o}: cc {src}\n'
flags = cflags
else:
out += f'build {o}: cxx {src}\n'
flags = cflags
if customize_build_flags:
custom_flags = customize_build_flags(flags, src)
if custom_flags != flags:
out += f' CFLAGS = {join(custom_flags)}'
out += '\n'
objects = sorted(objects, key=objectfile_sort_key)
objects = ' '.join(objects)
out += f'build {libname}: archive {objects}\n'
utils.write_file(filename, out)
ensure_target_in_ninja_file(get_top_level_ninja_file(), f'subninja {filename}')
def is_case_insensitive(path):
"""Returns True if the filesystem at `path` is case insensitive."""
utils.write_file(os.path.join(path, 'test_file'), '')
case_insensitive = os.path.exists(os.path.join(path, 'TEST_FILE'))
os.remove(os.path.join(path, 'test_file'))
return case_insensitive
class Library:
"""
`Library` is the base class of all system libraries.
There are two types of libraries: abstract and concrete.
* An abstract library, e.g. MTLibrary, is a subclass of `Library` that
implements certain behaviour common to multiple libraries. The features
of multiple abstract libraries can be used through multiple inheritance.
* A concrete library, e.g. libc, is a subclass of `Library` that describes
how to build a particular library, and its properties, such as name and
dependencies.
This library system is meant to handle having many versions of the same library,
which we call *variations*. For example, some libraries (those that inherit
from MTLibrary), have both single-threaded and multi-threaded versions.
An instance of a `Library` subclass represents a specific variation of the
library. Instance methods perform operations relating to this variation.
For example, `get_cflags()` would return the emcc flags needed to build this
variation, and `build()` would generate the library file for this variation.
The constructor takes keyword arguments that defines the variation.
Class methods perform tasks relating to all variations. For example,
`variations()` returns a list of all variations that exists for this library,
and `get_default_variation()` returns the variation suitable for the current
environment.
Other class methods act upon a group of libraries. For example,
`Library.get_all_variations()` returns a mapping of all variations of
existing libraries.
To add a new type of variation, you must add an parameter to `__init__` that
selects the variant. Then, override one of `vary_on` or `variations`, as well
as `get_default_variation`.
If the parameter is boolean, overriding `vary_on` to add the parameter name
to the returned list is sufficient:
@classmethod
def vary_on(cls):
return super().vary_on() + ['my_parameter']
Otherwise, you must override `variations`:
@classmethod
def variations(cls):
return [{'my_parameter': value, **other} for value, other in
itertools.product([1, 2, 3], super().variations())]
Overriding either `vary_on` or `variations` allows `embuilder.py` to know all
possible variations so it can build all of them.
You then need to modify `get_default_variation` to detect the correct value
for your new parameter based on the settings:
@classmethod
def get_default_variation(cls, **kwargs):
return super().get_default_variation(my_parameter=settings.MY_PARAMETER, **kwargs)
This allows the correct variation of the library to be selected when building
code with Emscripten.
"""
# The simple name of the library. When linking, this is the name to use to
# automatically get the correct version of the library.
# This should only be overridden in a concrete library class, e.g. libc,
# and left as None in an abstract library class, e.g. MTLibrary.
name: Optional[str] = None
# Set to true to prevent EMCC_FORCE_STDLIBS from linking this library.
never_force = False
# A list of flags to pass to emcc.
# The flags for the parent class is automatically inherited.
# TODO: Investigate whether perf gains from loop unrolling would be worth the
# extra code size. The -fno-unroll-loops flags was added here when loop
# unrolling landed upstream in LLVM to avoid changing behavior but was not
# specifically evaluated.
cflags = ['-O2', '-Wall', '-fno-unroll-loops']
# A list of directories to put in the include path when building.
# This is a list of tuples of path components.
# For example, to put system/lib/a and system/lib/b under the emscripten
# directory into the include path, you would write:
# includes = [('system', 'lib', 'a'), ('system', 'lib', 'b')]
# The include path of the parent class is automatically inherited.
includes: List[str] = []
# By default, `get_files` look for source files for this library under `src_dir`.
# It will either use the files listed in `src_files`, or use the glob pattern in
# `src_glob`. You may not specify both `src_files` and `src_glob`.
# When using `src_glob`, you can specify a list of files in `src_glob_exclude`
# to be excluded from the library.
# Alternatively, you can override `get_files` to use your own logic.
src_dir: Optional[str] = None
src_files: Optional[List[str]] = []
src_glob: Optional[str] = None
src_glob_exclude: Optional[List[str]] = None
# Whether to always generate WASM object files, even when LTO is set
force_object_files = False
def __init__(self):
"""
Creates a variation of this library.
A variation is a specific combination of settings a library can have.
For example, libc++-mt-noexcept is a variation of libc++.
There might be only one variation of a library.
The constructor keyword arguments will define what variation to use.
Use the `variations` classmethod to get the list of all possible constructor
arguments for this library.
Use the `get_default_variation` classmethod to construct the variation
suitable for the current invocation of emscripten.
"""
if not self.name:
raise NotImplementedError('Cannot instantiate an abstract library')
def can_use(self):
"""
Whether this library can be used in the current environment.
For example, libmalloc would override this and return False
if the user requested no malloc.
"""
return True
def can_build(self):
"""
Whether this library can be built in the current environment.
Override this if, for example, the library can only be built on WASM backend.
"""
return True
def erase(self):
cache.erase_file(self.get_path())
def get_path(self, absolute=False):
return cache.get_lib_name(self.get_filename(), absolute=absolute)
def build(self, deterministic_paths=False):
"""
Gets the cached path of this library.
This will trigger a build if this library is not in the cache.
"""
self.deterministic_paths = deterministic_paths
return cache.get(self.get_path(), self.do_build, force=USE_NINJA == 2, quiet=USE_NINJA)
def generate(self):
self.deterministic_paths = False
return cache.get(self.get_path(), self.do_generate, force=USE_NINJA == 2, quiet=USE_NINJA,
deferred=True)
def get_link_flag(self):
"""
Gets the link flags needed to use the library.
This will trigger a build if this library is not in the cache.
"""
fullpath = self.build()
# For non-libraries (e.g. crt1.o) we pass the entire path to the linker
if self.get_ext() != '.a':
return fullpath
# For libraries (.a) files, we pass the abbreviated `-l` form.
base = shared.unsuffixed_basename(fullpath)
return '-l' + utils.removeprefix(base, 'lib')
def get_files(self):
"""
Gets a list of source files for this library.
Typically, you will use `src_dir`, `src_files`, `src_glob` and `src_glob_exclude`.
If those are insufficient to describe the files needed, you can override this method.
"""
if self.src_dir:
if self.src_files and self.src_glob:
raise Exception('Cannot use src_files and src_glob together')
if self.src_files:
return files_in_path(self.src_dir, self.src_files)
elif self.src_glob:
return glob_in_path(self.src_dir, self.src_glob, self.src_glob_exclude or ())
raise NotImplementedError()
def generate_ninja(self, build_dir, libname):
ensure_sysroot()
utils.safe_ensure_dirs(build_dir)
cflags = self.get_cflags()
if self.deterministic_paths:
source_dir = utils.path_from_root()
cflags += [f'-ffile-prefix-map={source_dir}=/emsdk/emscripten',
'-fdebug-compilation-dir=/emsdk/emscripten']
asflags = get_base_cflags(preprocess=False)
input_files = self.get_files()
ninja_file = os.path.join(build_dir, 'build.ninja')
create_ninja_file(input_files, ninja_file, libname, cflags, asflags=asflags, customize_build_flags=self.customize_build_cmd)
def build_objects(self, build_dir):
"""
Returns a list of compiled object files for this library.
By default, this builds all the source files returned by `self.get_files()`,
with the `cflags` returned by `self.get_cflags()`.
"""
commands = []
objects = []
cflags = self.get_cflags()
if self.deterministic_paths:
source_dir = utils.path_from_root()
cflags += [f'-ffile-prefix-map={source_dir}=/emsdk/emscripten',
'-fdebug-compilation-dir=/emsdk/emscripten']
case_insensitive = is_case_insensitive(build_dir)
for src in self.get_files():
object_basename = shared.unsuffixed_basename(src)
# Resolve duplicates by appending unique.
# This is needed on case insensitve filesystem to handle,
# for example, _exit.o and _Exit.o.
if case_insensitive:
object_basename = object_basename.lower()
o = os.path.join(build_dir, object_basename + '.o')
object_uuid = 0
# Find a unique basename
while o in objects:
object_uuid += 1
o = os.path.join(build_dir, f'{object_basename}__{object_uuid}.o')
ext = shared.suffix(src)
if ext in ('.s', '.S', '.c'):
cmd = [shared.EMCC]
else:
cmd = [shared.EMXX]
if ext == '.s':
# .s files are processed directly by the assembler. In this case we can't pass
# pre-processor flags such as `-I` and `-D` but we still want core flags such as
# `-sMEMORY64`.
cmd += get_base_cflags(preprocess=False)
else:
cmd += cflags
if ext in ('.s', '.S'):
# TODO(sbc) There is an llvm bug that causes a crash when `-g` is used with
# assembly files that define wasm globals.
cmd = [arg for arg in cmd if arg != '-g']
cmd = self.customize_build_cmd(cmd, src)
commands.append(cmd + ['-c', src, '-o', o])
objects.append(o)
run_build_commands(commands)
return objects
def customize_build_cmd(self, cmd, _filename):
"""Allows libraries to customize the build command used on per-file basis.
For example, libc uses this to replace -Oz with -O2 for some subset of files."""
return cmd
def do_build(self, out_filename, generate_only=False):
"""Builds the library and returns the path to the file."""
assert out_filename == self.get_path(absolute=True)
build_dir = os.path.join(cache.get_path('build'), self.get_base_name())
if USE_NINJA:
self.generate_ninja(build_dir, out_filename)
if not generate_only:
run_ninja(build_dir)
else:
# Use a seperate build directory to the ninja flavor so that building without
# EMCC_USE_NINJA doesn't clobber the ninja build tree
build_dir += '-tmp'
utils.safe_ensure_dirs(build_dir)
create_lib(out_filename, self.build_objects(build_dir))
if not shared.DEBUG:
utils.delete_dir(build_dir)
def do_generate(self, out_filename):
self.do_build(out_filename, generate_only=True)
@classmethod
def _inherit_list(cls, attr):
# Some properties, like cflags and includes, makes more sense to inherit
# via concatenation than replacement.
result = []
for item in cls.__mro__[::-1]:
# Using __dict__ to avoid inheritance
result += item.__dict__.get(attr, [])
return result
def get_cflags(self):
"""
Returns the list of flags to pass to emcc when building this variation
of the library.
Override and add any flags as needed to handle new variations.
"""
cflags = self._inherit_list('cflags')
cflags += get_base_cflags(force_object_files=self.force_object_files)
if self.includes:
cflags += ['-I' + utils.path_from_root(i) for i in self._inherit_list('includes')]
return cflags
def get_base_name_prefix(self):
"""
Returns the base name of the library without any suffixes.
"""
return self.name
def get_base_name(self):
"""
Returns the base name of the library file.
This will include suffixes such as -mt, but will not include a file extension.
"""
return self.get_base_name_prefix()
def get_ext(self):
"""
Return the appropriate file extension for this library.
"""
return '.a'
def get_filename(self):
"""
Return the full name of the library file, including the file extension.
"""
return self.get_base_name() + self.get_ext()
@classmethod
def vary_on(cls):
"""
Returns a list of strings that are the names of boolean constructor
arguments that defines the variations of this library.
This is used by the default implementation of `cls.variations()` to generate
every possible combination of boolean values to pass to these arguments.
"""
return []
@classmethod
def variations(cls):
"""
Returns a list of keyword arguments to pass to the constructor to create
every possible variation of this library.
By default, this is every possible combination of boolean values to pass
to the list of arguments returned by `vary_on`, but you can override
the behaviour.
"""
vary_on = cls.vary_on()
return [dict(zip(vary_on, toggles)) for toggles in
itertools.product([False, True], repeat=len(vary_on))]
@classmethod
def get_default_variation(cls, **kwargs):
"""
Construct the variation suitable for the current invocation of emscripten.
Subclasses should pass the keyword arguments they introduce to the
superclass version, and propagate **kwargs. The base class collects
all the keyword arguments and creates the instance.
"""
return cls(**kwargs)
@classmethod
def get_inheritance_tree(cls):
"""Returns all the classes in the inheritance tree of the current class."""
yield cls
for subclass in cls.__subclasses__():
for cls in subclass.get_inheritance_tree():
yield cls
@classmethod
def get_all_variations(cls):
"""
Gets all the variations of libraries in the inheritance tree of the current
library.
Calling Library.get_all_variations() returns the variations of ALL libraries
that can be built as a dictionary of variation names to Library objects.
"""
result = {}
for library in cls.get_inheritance_tree():
if library.name:
for flags in library.variations():
variation = library(**flags)
if variation.can_build():
result[variation.get_base_name()] = variation
return result
@classmethod
def get_usable_variations(cls):
"""
Gets all libraries suitable for the current invocation of emscripten.
This returns a dictionary of simple names to Library objects.
"""
if not hasattr(cls, 'useable_variations'):
cls.useable_variations = {}
for subclass in cls.get_inheritance_tree():
if subclass.name:
library = subclass.get_default_variation()
if library.can_build() and library.can_use():
cls.useable_variations[subclass.name] = library
return cls.useable_variations
class MTLibrary(Library):
def __init__(self, **kwargs):
self.is_mt = kwargs.pop('is_mt')
self.is_ww = kwargs.pop('is_ww') and not self.is_mt
super().__init__(**kwargs)
def get_cflags(self):
cflags = super().get_cflags()
if self.is_mt:
cflags += ['-pthread', '-sWASM_WORKERS']
if self.is_ww:
cflags += ['-sWASM_WORKERS']
return cflags
def get_base_name(self):
name = super().get_base_name()
if self.is_mt:
name += '-mt'
if self.is_ww:
name += '-ww'
return name
@classmethod
def vary_on(cls):
return super().vary_on() + ['is_mt', 'is_ww']
@classmethod
def get_default_variation(cls, **kwargs):
return super().get_default_variation(is_mt=settings.PTHREADS, is_ww=settings.WASM_WORKERS and not settings.PTHREADS, **kwargs)
@classmethod
def variations(cls):
combos = super(MTLibrary, cls).variations()
# To save on # of variations, pthreads and Wasm workers when used together, just use pthreads variation.
return [combo for combo in combos if not combo['is_mt'] or not combo['is_ww']]
class DebugLibrary(Library):
def __init__(self, **kwargs):
self.is_debug = kwargs.pop('is_debug')
super().__init__(**kwargs)
def get_cflags(self):
cflags = super().get_cflags()
if not self.is_debug:
cflags += ['-DNDEBUG']
return cflags
def get_base_name(self):
name = super().get_base_name()
if self.is_debug:
name += '-debug'
return name
@classmethod
def vary_on(cls):
return super().vary_on() + ['is_debug']
@classmethod
def get_default_variation(cls, **kwargs):
return super().get_default_variation(is_debug=settings.ASSERTIONS, **kwargs)
class Exceptions(IntEnum):
"""
This represents exception handling mode of Emscripten. Currently there are
three modes of exception handling:
- None: Does not handle exceptions. This includes -fno-exceptions, which
prevents both throwing and catching, and -fignore-exceptions, which only
allows throwing, but library-wise they use the same version.
- Emscripten: Emscripten provides exception handling capability using JS
emulation. This causes code size increase and performance degradation.
- Wasm: Wasm native exception handling support uses Wasm EH instructions and
is meant to be fast. You need to use a VM that has the EH support to use
this. This is not fully working yet and still experimental.
"""
NONE = auto()
EMSCRIPTEN = auto()
WASM = auto()
class NoExceptLibrary(Library):
def __init__(self, **kwargs):
self.eh_mode = kwargs.pop('eh_mode')
super().__init__(**kwargs)
def get_cflags(self):
cflags = super().get_cflags()
if self.eh_mode == Exceptions.NONE:
cflags += ['-fno-exceptions']
elif self.eh_mode == Exceptions.EMSCRIPTEN:
cflags += ['-sDISABLE_EXCEPTION_CATCHING=0']
elif self.eh_mode == Exceptions.WASM:
cflags += ['-fwasm-exceptions']
return cflags
def get_base_name(self):
name = super().get_base_name()
# TODO Currently emscripten-based exception is the default mode, thus no
# suffixes. Change the default to wasm exception later.
if self.eh_mode == Exceptions.NONE:
name += '-noexcept'
elif self.eh_mode == Exceptions.WASM:
name += '-except'
return name
@classmethod
def variations(cls, **kwargs): # noqa
combos = super().variations()
return ([dict(eh_mode=Exceptions.NONE, **combo) for combo in combos] +
[dict(eh_mode=Exceptions.EMSCRIPTEN, **combo) for combo in combos] +
[dict(eh_mode=Exceptions.WASM, **combo) for combo in combos])
@classmethod
def get_default_variation(cls, **kwargs):
if settings.WASM_EXCEPTIONS:
eh_mode = Exceptions.WASM
elif settings.DISABLE_EXCEPTION_CATCHING == 1:
eh_mode = Exceptions.NONE
else:
eh_mode = Exceptions.EMSCRIPTEN
return super().get_default_variation(eh_mode=eh_mode, **kwargs)
class SjLjLibrary(Library):
def __init__(self, **kwargs):
# Whether we use Wasm EH instructions for SjLj support
self.is_wasm = kwargs.pop('is_wasm')
super().__init__(**kwargs)
def get_cflags(self):
cflags = super().get_cflags()
if self.is_wasm:
# DISABLE_EXCEPTION_THROWING=0 is the default, which is for Emscripten
# EH/SjLj, so we should reverse it.
cflags += ['-sSUPPORT_LONGJMP=wasm',
'-sDISABLE_EXCEPTION_THROWING',
'-D__USING_WASM_SJLJ__']
return cflags
def get_base_name(self):
name = super().get_base_name()
# TODO Currently emscripten-based SjLj is the default mode, thus no
# suffixes. Change the default to wasm exception later.
if self.is_wasm:
name += '-wasm-sjlj'
return name
@classmethod
def vary_on(cls):
return super().vary_on() + ['is_wasm']
@classmethod
def get_default_variation(cls, **kwargs):
is_wasm = settings.SUPPORT_LONGJMP == 'wasm'
return super().get_default_variation(is_wasm=is_wasm, **kwargs)
class MuslInternalLibrary(Library):
includes = [
'system/lib/libc/musl/src/internal',
'system/lib/libc/musl/src/include',
'system/lib/libc',
'system/lib/pthread',
]
cflags = [
'-std=c99',
'-D_XOPEN_SOURCE=700',
'-Wno-unused-result', # system call results are often ignored in musl, and in wasi that warns
]
class AsanInstrumentedLibrary(Library):
def __init__(self, **kwargs):
self.is_asan = kwargs.pop('is_asan', False)
super().__init__(**kwargs)
def get_cflags(self):
cflags = super().get_cflags()
if self.is_asan:
cflags += ['-fsanitize=address']
return cflags
def get_base_name(self):
name = super().get_base_name()
if self.is_asan:
name += '-asan'
return name
@classmethod
def vary_on(cls):
return super().vary_on() + ['is_asan']
@classmethod
def get_default_variation(cls, **kwargs):
return super().get_default_variation(is_asan=settings.USE_ASAN, **kwargs)
# Subclass of SjLjLibrary because emscripten_setjmp.c uses SjLj support
class libcompiler_rt(MTLibrary, SjLjLibrary):
name = 'libcompiler_rt'
# compiler_rt files can't currently be part of LTO although we are hoping to remove this
# restriction soon: https://reviews.llvm.org/D71738
force_object_files = True
cflags = ['-fno-builtin']
src_dir = 'system/lib/compiler-rt/lib/builtins'
includes = ['system/lib/libc']
# gcc_personality_v0.c depends on libunwind, which don't include by default.
src_files = glob_in_path(src_dir, '*.c', excludes=['gcc_personality_v0.c', 'truncdfbf2.c', 'truncsfbf2.c'])
src_files += files_in_path(
path='system/lib/compiler-rt',
filenames=[
'stack_ops.S',
'stack_limits.S',
'emscripten_setjmp.c',
'emscripten_exception_builtins.c',
'emscripten_tempret.s',
'__trap.c',
])
class libnoexit(Library):
name = 'libnoexit'
# __cxa_atexit calls can be generated during LTO the implemenation cannot
# itself be LTO. See `get_libcall_files` below for more details.
force_object_files = True
src_dir = 'system/lib/libc'
src_files = ['atexit_dummy.c']
class libc(MuslInternalLibrary,
DebugLibrary,
AsanInstrumentedLibrary,
MTLibrary):
name = 'libc'
# Without -fno-builtin, LLVM can optimize away or convert calls to library
# functions to something else based on assumptions that they behave exactly
# like the standard library. This can cause unexpected bugs when we use our
# custom standard library. The same for other libc/libm builds.
# We use -fno-inline-functions because it can produce slightly smaller
# (and slower) code in some cases. TODO(sbc): remove this and let llvm weight
# the cost/benefit of inlining.
cflags = ['-Os', '-fno-inline-functions', '-fno-builtin']
# Disable certain warnings for code patterns that are contained in upstream musl
cflags += ['-Wno-ignored-attributes',
# tre.h defines NDEBUG internally itself
'-Wno-macro-redefined',
'-Wno-shift-op-parentheses',
'-Wno-string-plus-int',
'-Wno-missing-braces',
'-Wno-logical-op-parentheses',
'-Wno-bitwise-op-parentheses',
'-Wno-unused-but-set-variable',
'-Wno-unused-variable',
'-Wno-unused-label',
'-Wno-pointer-sign']
def __init__(self, **kwargs):
self.non_lto_files = self.get_libcall_files()
super().__init__(**kwargs)
def get_libcall_files(self):
# Combining static linking with LTO is tricky under LLVM. The codegen that
# happens during LTO can generate references to new symbols that didn't exist
# in the linker inputs themselves.
# These symbols are called libcalls in LLVM and are the result of intrinsics
# and builtins at the LLVM level. These libcalls cannot themselves be part
# of LTO because once the linker is running the LTO phase new bitcode objects
# cannot be added to link. Another way of putting it: by the time LTO happens
# the decision about which bitcode symbols to compile has already been made.
# See: https://bugs.llvm.org/show_bug.cgi?id=44353.
# To solve this we force certain parts of libc to never be compiled as LTO/bitcode.
# Note that this also includes things that may be depended on by those
# functions - fmin uses signbit, for example, so signbit must be here (so if
# fmin is added by codegen, it will have all it needs).
math_files = [
'fmin.c', 'fminf.c', 'fminl.c',
'fmax.c', 'fmaxf.c', 'fmaxl.c',
'fmod.c', 'fmodf.c', 'fmodl.c',
'logf.c', 'logf_data.c',
'log2f.c', 'log2f_data.c',
'log10.c', 'log10f.c',
'exp.c', 'exp_data.c',
'exp2.c',
'exp2f.c', 'exp2f_data.c',
'exp10.c', 'exp10f.c',
'ldexp.c', 'ldexpf.c', 'ldexpl.c',
'scalbn.c', '__fpclassifyl.c',
'__signbitl.c', '__signbitf.c', '__signbit.c',
'__math_divzero.c', '__math_divzerof.c',
'__math_oflow.c', '__math_oflowf.c',
'__math_uflow.c', '__math_uflowf.c',
'__math_invalid.c', '__math_invalidf.c', '__math_invalidl.c',
'pow.c', 'pow_data.c', 'log.c', 'log_data.c', 'log2.c', 'log2_data.c',
'scalbnf.c',
]
math_files = files_in_path(path='system/lib/libc/musl/src/math', filenames=math_files)
exit_files = files_in_path(
path='system/lib/libc/musl/src/exit',
filenames=['atexit.c'])
other_files = files_in_path(
path='system/lib/libc',
filenames=['emscripten_memcpy.c', 'emscripten_memset.c',
'emscripten_scan_stack.c',
'emscripten_get_heap_size.c', # needed by malloc
'sbrk.c', # needed by malloc
'emscripten_memmove.c'])
# Calls to iprintf can be generated during codegen. Ideally we wouldn't
# compile these with -O2 like we do the rest of compiler-rt since its
# probably not performance sensitive. However we don't currently have
# a way to set per-file compiler flags. And hopefully we should be able
# move all this stuff back into libc once we it LTO compatible.
iprintf_files = files_in_path(
path='system/lib/libc/musl/src/stdio',
filenames=['__towrite.c', '__overflow.c', 'fwrite.c', 'fputs.c',
'getc.c',
'fputc.c',
'fgets.c',