1
Fork 0
hermetic_cc_toolchain/toolchain/defs.bzl

387 lines
13 KiB
Python

load("@bazel_skylib//lib:shell.bzl", "shell")
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
load(":zig_toolchain.bzl", "zig_cc_toolchain_config")
DEFAULT_TOOL_PATHS = {
"ar": "ar",
"gcc": "c++", # https://github.com/bazelbuild/bazel/issues/4644
"cpp": "/usr/bin/false",
"gcov": "/usr/bin/false",
"nm": "/usr/bin/false",
"objdump": "/usr/bin/false",
"strip": "/usr/bin/false",
}.items()
DEFAULT_INCLUDE_DIRECTORIES = [
"include",
"libcxx/include",
"libcxxabi/include",
]
# -Os, -O2 or -O3 must be set, because some dependencies use C's undefined
# behavior. See https://github.com/ziglang/zig/issues/4830
DEFAULT_COPTS = ["-O3"]
_fcntl_map = """
GLIBC_2.2.5 {
fcntl;
};
"""
_fcntl_h = """
#ifdef __ASSEMBLER__
.symver fcntl64, fcntl@GLIBC_2.2.5
#else
__asm__(".symver fcntl64, fcntl@GLIBC_2.2.5");
#endif
"""
# Zig supports even older glibcs than defined below, but we have tested only
# down to 2.17.
# $ zig targets | jq -r '.glibc[]' | sort -V
_GLIBCS = [
"2.17",
"2.18",
"2.19",
"2.22",
"2.23",
"2.24",
"2.25",
"2.26",
"2.27",
"2.28",
"2.29",
"2.30",
"2.31",
"2.32",
"2.33",
]
def _target_darwin(gocpu, zigcpu):
return struct(
gotarget = "darwin_{}".format(gocpu),
zigtarget = "{}-macos-gnu".format(zigcpu),
includes = [
"libunwind/include",
"libc/include/any-macos-any",
"libc/include/{}-macos-any".format(zigcpu),
"libc/include/{}-macos-gnu".format(zigcpu),
],
linkopts = [],
copts = DEFAULT_COPTS,
bazel_target_cpu = "darwin",
constraint_values = [
"@platforms//os:macos",
"@platforms//cpu:{}".format(zigcpu),
],
tool_paths = {"ld": "ld64.lld"},
)
def _target_linux_gnu(gocpu, zigcpu, glibc_version = ""):
glibc_suffix = "gnu"
if glibc_version != "":
glibc_suffix = "gnu.{}".format(glibc_version)
# https://github.com/ziglang/zig/issues/5882#issuecomment-888250676
# fcntl_hack is only required for glibc 2.27 or less. We assume that
# glibc_version == "" (autodetect) is running a recent glibc version, thus
# adding this hack only when glibc is explicitly 2.27 or lower.
fcntl_hack = False
if glibc_version == "":
# zig doesn't reliably detect the glibc version, so
# often falls back to 2.17; the hack should be included.
# https://github.com/ziglang/zig/issues/6469
fcntl_hack = True
else:
# hack is required for 2.27 or less.
fcntl_hack = glibc_version < "2.28"
return struct(
gotarget = "linux_{}_{}".format(gocpu, glibc_suffix),
zigtarget = "{}-linux-{}".format(zigcpu, glibc_suffix),
includes = [
"libunwind/include",
"libc/include/generic-glibc",
"libc/include/any-linux-any",
"libc/include/{}-linux-gnu".format(zigcpu),
"libc/include/{}-linux-any".format(zigcpu),
],
toplevel_include = ["glibc-hacks"] if fcntl_hack else [],
compiler_extra_includes = ["glibc-hacks/glibchack-fcntl.h"] if fcntl_hack else [],
linker_version_scripts = ["glibc-hacks/fcntl.map"] if fcntl_hack else [],
linkopts = ["-lc++", "-lc++abi"],
copts = DEFAULT_COPTS,
bazel_target_cpu = "k8",
constraint_values = [
"@platforms//os:linux",
"@platforms//cpu:{}".format(zigcpu),
],
tool_paths = {"ld": "ld.lld"},
)
def _target_linux_musl(gocpu, zigcpu):
return struct(
gotarget = "linux_{}_musl".format(gocpu),
zigtarget = "{}-linux-musl".format(zigcpu),
includes = [
"libc/include/generic-musl",
"libc/include/any-linux-any",
"libc/include/{}-linux-musl".format(zigcpu),
"libc/include/{}-linux-any".format(zigcpu),
],
linkopts = ["-s", "-w"],
copts = DEFAULT_COPTS + ["-D_LIBCPP_HAS_MUSL_LIBC", "-D_LIBCPP_HAS_THREAD_API_PTHREAD"],
bazel_target_cpu = "k8",
constraint_values = [
"@platforms//os:linux",
"@platforms//cpu:{}".format(zigcpu),
],
tool_paths = {"ld": "ld.lld"},
)
def register_toolchains(
register = [],
speed_first_safety_later = "auto"):
"""
Download zig toolchain and register some.
@param register registers the given toolchains to the system using
native.register_toolchains(). See README for possible choices.
@param speed_first_safety_later is a workaround for
https://github.com/ziglang/zig/issues/9431
"""
zig_repository(
name = "zig_sdk",
# Pre-release:
version = "0.9.0-dev.727+aad459836",
url_format = "https://ziglang.org/builds/zig-{host_platform}-{version}.tar.xz",
# Release:
# version = "0.8.0",
# url_format = "https://ziglang.org/download/{version}/zig-{host_platform}-{version}.tar.xz",
host_platform_sha256 = {
"linux-x86_64": "1a0f45e77e2323d4afb3405868c0d96a88170a922eb60fc06f233ac8395fbfd5",
"macos-x86_64": "cdc76afd3e361c8e217e4d56f2027ec6482d7f612462c27794149b7ad31b9244",
},
host_platform_include_root = {
"macos-x86_64": "lib/zig/",
"linux-x86_64": "lib/",
},
speed_first_safety_later = speed_first_safety_later,
)
toolchains = ["@zig_sdk//:%s_toolchain" % t for t in register]
native.register_toolchains(*toolchains)
ZIG_TOOL_PATH = "tools/{zig_tool}"
ZIG_TOOL_WRAPPER = """#!/bin/bash
set -e
if [[ -n "$TMPDIR" ]]; then
_cache_prefix=$TMPDIR
else
_cache_prefix="$HOME/.cache"
if [[ "$(uname)" = Darwin ]]; then
_cache_prefix="$HOME/Library/Caches"
fi
fi
export ZIG_LOCAL_CACHE_DIR="$_cache_prefix/bazel-zig-cc"
export ZIG_GLOBAL_CACHE_DIR=$ZIG_LOCAL_CACHE_DIR
# https://github.com/ziglang/zig/issues/9431
_flock=
if [[ -n "{do_flock}" ]]; then
_flock=$(command -v flock || :)
if [[ -z "$_flock" && -x /usr/local/bin/flock ]]; then
_flock=/usr/local/bin/flock
else
>&2 echo "WARNING: flock not found, proceeding unsafely."
>&2 echo "If build fails, retry it."
fi
fi
if [[ -n "$_flock" ]]; then
exec "$_flock" "{zig}" "{zig}" "{zig_tool}" "$@"
else
exec "{zig}" "{zig_tool}" "$@"
fi
"""
_ZIG_TOOLS = [
"c++",
"cc",
"ar",
"ld.lld", # ELF
"ld64.lld", # Mach-O
"lld-link", # COFF
"wasm-ld", # WebAssembly
]
def _zig_repository_impl(repository_ctx):
if repository_ctx.os.name.lower().startswith("mac os"):
host_platform = "macos-x86_64"
else:
host_platform = "linux-x86_64"
zig_include_root = repository_ctx.attr.host_platform_include_root[host_platform]
zig_sha256 = repository_ctx.attr.host_platform_sha256[host_platform]
format_vars = {
"version": repository_ctx.attr.version,
"host_platform": host_platform,
}
zig_url = repository_ctx.attr.url_format.format(**format_vars)
repository_ctx.download_and_extract(
url = zig_url,
stripPrefix = "zig-{host_platform}-{version}/".format(**format_vars),
sha256 = zig_sha256,
)
if repository_ctx.attr.speed_first_safety_later == "auto":
do_flock = repository_ctx.os.name.lower().startswith("mac os")
elif repository_ctx.attr.speed_first_safety_later == "yes":
do_flock = False
else:
do_flock = True
for zig_tool in _ZIG_TOOLS:
repository_ctx.file(
ZIG_TOOL_PATH.format(zig_tool = zig_tool),
ZIG_TOOL_WRAPPER.format(
zig = str(repository_ctx.path("zig")),
zig_tool = zig_tool,
do_flock = "1" if do_flock else "",
),
)
repository_ctx.file(
"glibc-hacks/fcntl.map",
content = _fcntl_map,
)
repository_ctx.file(
"glibc-hacks/glibchack-fcntl.h",
content = _fcntl_h,
)
repository_ctx.template(
"BUILD.bazel",
Label("//toolchain:BUILD.sdk.bazel"),
executable = False,
substitutions = {
"{absolute_path}": shell.quote(str(repository_ctx.path(""))),
"{zig_include_root}": shell.quote(zig_include_root),
},
)
zig_repository = repository_rule(
attrs = {
"version": attr.string(),
"host_platform_sha256": attr.string_dict(),
"url_format": attr.string(),
"host_platform_include_root": attr.string_dict(),
"speed_first_safety_later": attr.string(
values = ["yes", "no", "auto"],
default = "auto",
doc = "Workaround for github.com/ziglang/zig/issues/9431; " +
"dramatically decreases compilation time on multi-core " +
"hosts, but may fail compilation. Then re-run it. So far, " +
"the author has reproduced this only on OSX.",
),
},
implementation = _zig_repository_impl,
)
def _target_structs():
ret = []
for zigcpu, gocpu in (("x86_64", "amd64"), ("aarch64", "arm64")):
ret.append(_target_darwin(gocpu, zigcpu))
ret.append(_target_linux_musl(gocpu, zigcpu))
for glibc in [""] + _GLIBCS:
ret.append(_target_linux_gnu(gocpu, zigcpu, glibc))
return ret
def filegroup(name, **kwargs):
native.filegroup(name = name, **kwargs)
return ":" + name
def zig_build_macro(absolute_path, zig_include_root):
filegroup(name = "empty")
native.exports_files(["zig"], visibility = ["//visibility:public"])
filegroup(name = "lib/std", srcs = native.glob(["lib/std/**"]))
lazy_filegroups = {}
for target_config in _target_structs():
gotarget = target_config.gotarget
zigtarget = target_config.zigtarget
cxx_builtin_include_directories = []
for d in DEFAULT_INCLUDE_DIRECTORIES + target_config.includes:
d = zig_include_root + d
if d not in lazy_filegroups:
lazy_filegroups[d] = filegroup(name = d, srcs = native.glob([d + "/**"]))
cxx_builtin_include_directories.append(absolute_path + "/" + d)
for d in getattr(target_config, "toplevel_include", []):
cxx_builtin_include_directories.append(absolute_path + "/" + d)
absolute_tool_paths = {}
for name, path in target_config.tool_paths.items() + DEFAULT_TOOL_PATHS:
if path[0] == "/":
absolute_tool_paths[name] = path
continue
tool_path = ZIG_TOOL_PATH.format(zig_tool = path)
absolute_tool_paths[name] = "%s/%s" % (absolute_path, tool_path)
linkopts = target_config.linkopts
copts = target_config.copts
for s in getattr(target_config, "linker_version_scripts", []):
linkopts = linkopts + ["-Wl,--version-script,%s/%s" % (absolute_path, s)]
for incl in getattr(target_config, "compiler_extra_includes", []):
copts = copts + ["-include", absolute_path + "/" + incl]
zig_cc_toolchain_config(
name = zigtarget + "_toolchain_cc_config",
target = zigtarget,
tool_paths = absolute_tool_paths,
cxx_builtin_include_directories = cxx_builtin_include_directories,
copts = copts,
linkopts = linkopts,
target_cpu = target_config.bazel_target_cpu,
target_system_name = "unknown",
target_libc = "unknown",
compiler = "clang",
abi_version = "unknown",
abi_libc_version = "unknown",
)
native.cc_toolchain(
name = zigtarget + "_toolchain_cc",
toolchain_identifier = zigtarget + "-toolchain",
toolchain_config = ":%s_toolchain_cc_config" % zigtarget,
all_files = ":zig",
ar_files = ":zig",
compiler_files = ":zig",
linker_files = ":zig",
dwp_files = ":empty",
objcopy_files = ":empty",
strip_files = ":empty",
supports_param_files = 0,
)
# register two kinds of toolchain targets: Go and Zig conventions.
# Go convention: amd64/arm64, linux/darwin
native.toolchain(
name = gotarget + "_toolchain",
exec_compatible_with = None,
target_compatible_with = target_config.constraint_values,
toolchain = ":%s_toolchain_cc" % zigtarget,
toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
)
# Zig convention: x86_64/aarch64, linux/macos
native.toolchain(
name = zigtarget + "_toolchain",
exec_compatible_with = None,
target_compatible_with = target_config.constraint_values,
toolchain = ":%s_toolchain_cc" % zigtarget,
toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
)