# Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
# This file is part of the "cmake-common" project.
# For details, see https://github.com/egor-tensin/cmake-common.
# Distributed under the MIT License.
# Hate speech
# -----------
#
# Is there a person who doesn't hate Boost.Build? I'm not sure, I'm definitely
# _not_ one of these people. Maybe it's the lack of adoption (meaning that
# learning it is useless outside of Boost), maybe it's the incomprehensible
# syntax. Maybe it's the absolutely insane compiler-specific configuration
# files (tools/build/src/tools/*.jam), which are impossible to figure out.
# Maybe it's the fact that the implementation switched from C to C++ while some
# half-baked Python implementation has been there since at least 2015 (see the
# marvelous memo "Status: mostly ported." at the top of tools/build/src/build_system.py).
#
# What I hate the most though is how its various subtle, implicit and invisible
# decision-making heuristics changed thoughout the release history of Boost.
# You have a config and a compiler that will happily build version 1.65.0?
# Great! Want to use the same config and the same compiler to build version
# 1.72.0? Well, too fucking bad, it doesn't work anymore. This I really do
# hate the most.
#
# Three kinds of toolsets
# -----------------------
#
# b2 accepts the toolset= parameter. What about building b2 itself though?
# Well, this is what the bootstrap.{sh,bat} scripts do. They also accept a
# toolset argument, but it is _completely_ different to that of b2. That's
# sort of OK, since e.g. cross-compiling b2 is something we rarely want to do
# (and hence there must typically be a native toolset available).
#
# bootstrap.sh and bootstrap.bat are completely different (of course!), and
# accept different arguments for their toolset parameters.
#
# Config file insanity
# --------------------
#
# Say, we're building Boost on Windows using the GCC from a MinGW-w64
# distribution. We can pass toolset=gcc and all the required flags on the
# command line no problem. What if we want to make a user configuration file
# so that 1) the command line is less polluted, and 2) it can possibly be
# shared? Well, if we put
#
# using gcc : : : <name>value... ;
#
# there, Boost 1.65.0 will happily build everything, while Boost 1.72.0 will
# complain about "duplicate initialization of gcc". This is because when we
# ran `bootstrap.bat gcc` earlier, it wrote `using gcc ;` in project-config.jam.
# And while Boost 1.65.0 detects that toolset=gcc means we're going to use the
# MinGW GCC, and magically turns toolset=gcc to toolset=gcc-mingw, Boost 1.72.0
# does no such thing, and chokes on the "duplicate" GCC declaration.
#
# We also cannot put
#
# using gcc : custom : : <options> ;
#
# without the executable path, since Boost insists that `g++ -dumpversion` must
# equal to "custom" (which makes total sense, lol). So we have to force it,
# and do provide the path.
#
# Windows & Clang
# ---------------
#
# Building Boost using Clang on Windows is a sad story. As of 2020, there're
# three main ways to install the native Clang toolchain on Windows:
#
# * download the installer from llvm.org (`choco install llvm` does this)
# a.k.a. the upstream,
# * install it as part of a MSYS2 installation (`pacman -S mingw-w64-x86_64-clang`),
# * install as part of a Visual Studio installation.
#
# Using the latter method, you can switch a project to use the LLVM toolset
# using Visual Studio, but that's stupid. The former two, on the other hand,
# give us the the required clang/clang++/clang-cl executables, so everything
# seems to be fine.
#
# Except it's not fine. Let's start with the fact that prior to 1.66.0,
# toolset=clang is completely broken on Windows. It's just an alias for
# clang-linux, and it's hardcoded to require the ar & ranlib executables to
# create static libraries. Which is fine on Linux, since, and I'm quoting the
# source, "ar is always available". But it's not fine on Windows, since
# ar/ranlib are not, in fact, available there by default. Sure, you can
# install some kind of MinGW toolchain, and it might even work, but what the
# hell, honestly?
#
# Luckily, both the upstream distribution and the MSYS2 mingw-w64-x86_64-llvm
# package come with the llvm-ar and llvm-ranlib utilities. So we can put
# something like this in the config:
#
# using clang : custom : clang++.exe : <archiver>llvm-ar <ranlib>llvm-ranlib.exe ;
#
# and later call
#
# b2 toolset=clang-custom --user-config=path/to/config.jam ...
#
# But, as I mentioned, prior to 1.66.0, toolset=clang is _hardcoded_ to use ar
# & ranlib, these exact utility names. So either get them as part of some
# MinGW distribution or build Boost using another toolset.
#
# Now, it's all fine, but building stuff on Windows adds another thing into the
# equation: debug runtimes. When you build Boost using MSVC, for example, it
# picks one of the appropriate /MT[d] or /MD[d] flags to build the Boost
# libraries with. Emulating these flags with toolset=clang is complicated and
# inconvenient. Luckily, there's the clang-cl.exe executable, which aims to
# provide command line interface compatible with that of cl.exe.
#
# Boost.Build even supports toolset=clang-win, which should use clang-cl.exe.
# But alas, it's completely broken prior to 1.69.0. It just doesn't work at
# all. So, if you want to build w/ clang-cl.exe, either use Boost 1.69.0 or
# later, or build using another toolset.
#
# Cygwin & Clang
# --------------
#
# Now, a few words about Clang on Cygwin. When building 1.65.0, I encountered
# the following error:
#
# /usr/include/w32api/synchapi.h:127:26: error: conflicting types for 'Sleep'
# WINBASEAPI VOID WINAPI Sleep (DWORD dwMilliseconds);
# ^
# ./boost/smart_ptr/detail/yield_k.hpp:64:29: note: previous declaration is here
# extern "C" void __stdcall Sleep( unsigned long ms );
# ^
#
# GCC doesn't emit an error here because /usr/include is in a pre-configured
# "system" include directories list, and the declaration there take precedence,
# I guess? The root of the problem BTW is that sizeof(unsigned long) is
#
# * 4 for MSVC and MinGW-born GCCs,
# * 8 for Clang (and, strangely, Cygwin GCC; why don't we get runtime
# errors?).
#
# The fix is to add `define=BOOST_USE_WINDOWS_H`. I don't even know what's the
# point of not having it as a default.
import abc
from contextlib import contextmanager
import logging
import os.path
import shutil
import project.mingw
import project.os
from project.toolchain import ToolchainType
from project.utils import temp_file
class BootstrapToolchain(abc.ABC):
@abc.abstractmethod
def get_bootstrap_bat_args(self):
pass
@abc.abstractmethod
def get_bootstrap_sh_args(self):
pass
@staticmethod
def detect(hint):
if hint is ToolchainType.AUTO:
return BootstrapAuto()
if hint is ToolchainType.MSVC:
return BootstrapMSVC()
if hint is ToolchainType.GCC:
return BootstrapGCC()
if hint is ToolchainType.MINGW:
return BootstrapMinGW()
if hint is ToolchainType.CLANG:
return BootstrapClang()
if hint is ToolchainType.CLANG_CL:
return BootstrapClangCL()
raise NotImplementedError(f'unrecognized toolset: {hint}')
class BootstrapAuto(BootstrapToolchain):
# Let Boost.Build do the detection. Most commonly it means GCC on
# Linux-likes and MSVC on Windows.
def get_bootstrap_bat_args(self):
return []
def get_bootstrap_sh_args(self):
return []
class BootstrapMSVC(BootstrapAuto):
# bootstrap.bat picks up MSVC by default.
pass
class BootstrapGCC(BootstrapToolchain):
def get_bootstrap_bat_args(self):
return ['gcc']
def get_bootstrap_sh_args(self):
return ['--with-toolset=gcc']
def _gcc_or_auto():
if shutil.which('gcc') is not None:
return ['gcc']
return []
class BootstrapMinGW(BootstrapToolchain):
def get_bootstrap_bat_args(self):
# On Windows, prefer GCC if it's available.
return _gcc_or_auto()
def get_bootstrap_sh_args(self):
return []
class BootstrapClang(BootstrapToolchain):
def get_bootstrap_bat_args(self):
# As of 1.74.0, bootstrap.bat isn't really aware of Clang, so try GCC,
# then auto-detect.
return _gcc_or_auto()
def get_bootstrap_sh_args(self):
# bootstrap.sh, on the other hand, is very much aware of Clang, and
# it can build b2 using this compiler.
return ['--with-toolset=clang']
class BootstrapClangCL(BootstrapClang):
# There's no point in building b2 using clang-cl; clang though, presumably
# installed alongside clang-cl, should still be used if possible.
pass
class Toolchain(abc.ABC):
def __init__(self, platform):
self.platform = platform
def get_b2_args(self):
return [
# Always pass the address-model explicitly.
f'address-model={self.platform.get_address_model()}'
]
@staticmethod
@contextmanager
def detect(hint, platform):
if hint is ToolchainType.AUTO:
yield Auto(platform)
elif hint is ToolchainType.MSVC:
yield MSVC(platform)
elif hint is ToolchainType.GCC:
with GCC.setup(platform) as toolchain:
yield toolchain
elif hint is ToolchainType.MINGW:
with MinGW.setup(platform) as toolchain:
yield toolchain
elif hint is ToolchainType.CLANG:
with Clang.setup(platform) as toolchain:
yield toolchain
elif hint is ToolchainType.CLANG_CL:
yield ClangCL(platform)
else:
raise NotImplementedError(f'unrecognized toolset: {hint}')
class Auto(Toolchain):
# Let Boost.Build do the detection. Most commonly it means GCC on
# Linux-likes and MSVC on Windows.
pass
class MSVC(Auto):
def get_b2_args(self):
return super().get_b2_args() + [
'toolset=msvc',
]
def _full_exe_name(exe):
if project.os.on_linux():
# There's no PATHEXT on Linux.
return exe
# b2 on Windows/Cygwin doesn't like it when the executable name doesn't
# include the extension.
dir_path = os.path.dirname(exe) or None
path = shutil.which(exe, path=dir_path)
if not path:
raise RuntimeError(f"executable '{exe}' could not be found")
if project.os.on_cygwin():
# On Cygwin, shutil.which('gcc') == '/usr/bin/gcc' and shutil.which('gcc.exe')
# == '/usr/bin/gcc.exe'; we want the latter version. shutil.which('clang++')
# == '/usr/bin/clang++' is fine though, since it _is_ the complete path
# (clang++ is a symlink).
if os.path.exists(path) and os.path.exists(path + '.exe'):
path += '.exe'
if dir_path:
# If it was found in a specific directory, include the directory in the
# result. shutil.which returns the executable name prefixed with the
# path argument.
return path
# If it was found in PATH, just return the basename (which includes the
# extension).
return os.path.basename(path)
class BoostBuildToolset:
CUSTOM = 'custom'
def __init__(self, compiler, path, options):
if not compiler:
raise RuntimeError('compiler type is required (like gcc, clang, etc.)')
self.compiler = compiler
self.version = BoostBuildToolset.CUSTOM
path = path or ''
path = path and _full_exe_name(path)
self.path = path
options = options or []
self.options = options
@property
def toolset_id(self):
if self.version:
return f'{self.compiler}-{self.version}'
return self.compiler
@property
def b2_arg(self):
return f'toolset={self.toolset_id}'
def _format_using_options(self):
return ''.join(f'\n <{name}>{val}' for name, val in self.options)
def format_using(self):
version = self.version and f'{self.version} '
path = self.path and f'{self.path} '
return f'''using {self.compiler} : {version}: {path}:{self._format_using_options()}
;'''
class ConfigFile(Toolchain):
def __init__(self, platform, config_path, toolset):
super().__init__(platform)
self.config_path = config_path
self.toolset = toolset
@staticmethod
@abc.abstractmethod
def get_toolset(platform):
pass
@staticmethod
@abc.abstractmethod
def format_config(toolset):
pass
@classmethod
@contextmanager
def setup(cls, platform):
toolset = cls.get_toolset(platform)
config = cls.format_config(toolset)
logging.info('Using user config:\n%s', config)
tmp = temp_file(config, mode='w', prefix='user_config_', suffix='.jam')
with tmp as path:
yield cls(platform, path, toolset)
def get_b2_args(self):
# All the required options and the toolset definition should be in the
# user configuration file.
return super().get_b2_args() + [
f'--user-config={self.config_path}',
self.toolset.b2_arg,
]
class GCC(ConfigFile):
# Force GCC. We don't care whether it's a native Linux GCC or a
# MinGW-flavoured GCC on Windows.
COMPILER = 'gcc'
@staticmethod
def get_options():
return [
# TODO: this is a petty attempt to get rid of build warnings in
# older Boost versions. Revise and expand this list or remove it?
# warning: 'template<class> class std::auto_ptr' is deprecated
('cxxflags', '-Wno-deprecated-declarations'),
# warning: unnecessary parentheses in declaration of 'assert_arg'
('cxxflags', '-Wno-parentheses'),
]
@staticmethod
def get_toolset(platform):
return BoostBuildToolset(GCC.COMPILER, 'g++', GCC.get_options())
@staticmethod
def format_config(toolset):
return toolset.format_using()
class MinGW(GCC):
# It's important that Boost.Build is actually smart enough to detect the
# GCC prefix (like "x86_64-w64-mingw32" and prepend it to other tools like
# "ar").
@staticmethod
def get_toolset(platform):
path = project.mingw.get_gxx(platform)
return BoostBuildToolset(MinGW.COMPILER, path, MinGW.get_options())
class Clang(ConfigFile):
COMPILER = 'clang'
@staticmethod
def get_toolset(platform):
options = [
('cxxflags', '-DBOOST_USE_WINDOWS_H'),
# TODO: this is a petty attempt to get rid of build warnings in
# older Boost versions. Revise and expand this list or remove it?
# warning: unused typedef 'boost_concept_check464' [-Wunused-local-typedef]
('cxxflags', '-Wno-unused-local-typedef'),
# error: constant expression evaluates to -105 which cannot be narrowed to type 'boost::re_detail::cpp_regex_traits_implementation<char>::char_class_type' (aka 'unsigned int')
('cxxflags', '-Wno-c++11-narrowing'),
] + GCC.get_options()
if project.os.on_windows():
# Prefer LLVM binutils:
if shutil.which('llvm-ar') is not None:
options.append(('archiver', 'llvm-ar'))
if shutil.which('llvm-ranlib') is not None:
options.append(('ranlib', 'llvm-ranlib'))
return BoostBuildToolset(Clang.COMPILER, 'clang++', options)
@staticmethod
def format_config(toolset):
# To make clang.exe/clang++.exe work on Windows, some tweaks are
# required. I borrowed them from CMake's Windows-Clang.cmake [1].
# Adding them globally to Boost.Build options is described in [2].
#
# [1]: https://github.com/Kitware/CMake/blob/v3.18.4/Modules/Platform/Windows-Clang.cmake
# [2]: https://stackoverflow.com/questions/2715106/how-to-create-a-new-variant-in-bjam
return f'''project : requirements
<target-os>windows:<define>_MT
<target-os>windows,<variant>debug:<define>_DEBUG
<target-os>windows,<runtime-link>static,<variant>debug:<cxxflags>"-Xclang -flto-visibility-public-std -Xclang --dependent-lib=libcmtd"
<target-os>windows,<runtime-link>static,<variant>release:<cxxflags>"-Xclang -flto-visibility-public-std -Xclang --dependent-lib=libcmt"
<target-os>windows,<runtime-link>shared,<variant>debug:<cxxflags>"-D_DLL -Xclang --dependent-lib=msvcrtd"
<target-os>windows,<runtime-link>shared,<variant>release:<cxxflags>"-D_DLL -Xclang --dependent-lib=msvcrt"
;
{toolset.format_using()}
'''
class ClangCL(Toolchain):
def get_b2_args(self):
return super().get_b2_args() + [
'toolset=clang-win',
'define=BOOST_USE_WINDOWS_H',
]
