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hermetic_cc_toolchain/toolchain/defs.bzl

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Python

load("@bazel_skylib//lib:paths.bzl", "paths")
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
load("@bazel_tools//tools/build_defs/repo:utils.bzl", "read_user_netrc", "use_netrc")
load("@bazel-zig-cc//toolchain/private:defs.bzl", "target_structs", "zig_tool_path")
# Directories that `zig c++` includes behind the scenes.
_DEFAULT_INCLUDE_DIRECTORIES = [
"libcxx/include",
"libcxxabi/include",
"libunwind/include",
]
# Official recommended version. Should use this when we have a usable release.
URL_FORMAT_RELEASE = "https://ziglang.org/download/{version}/zig-{host_platform}-{version}.{_ext}"
# Caution: nightly releases are purged from ziglang.org after ~90 days. A real
# solution would be to allow the downstream project specify their own mirrors.
# This is explained in
# https://sr.ht/~motiejus/bazel-zig-cc/#alternative-download-urls and is
# awaiting my attention or your contribution.
URL_FORMAT_NIGHTLY = "https://ziglang.org/builds/zig-{host_platform}-{version}.{_ext}"
# Official Bazel's mirror with selected Zig SDK versions. Bazel community is
# generous enough to host the artifacts, which we use.
URL_FORMAT_BAZELMIRROR = "https://mirror.bazel.build/" + URL_FORMAT_NIGHTLY.lstrip("https://")
_VERSION = "0.11.0-dev.1796+c9e02d3e6"
_HOST_PLATFORM_SHA256 = {
"linux-aarch64": "5902b34b463635b25c11555650d095eb5030e2a05d8a4570c091313cd1a38b12",
"linux-x86_64": "aa9da2305fad89f648db2fd1fade9f0f9daf01d06f3b07887ad3098402794778",
"macos-aarch64": "51b4e88123d6cbb102f2a6665dd0d61467341f36b07bb0a8d46a37ea367b60d5",
"macos-x86_64": "dd8eeae5249aa21f9e51ff4ff536a3e7bf2c0686ee78bf6032d18e74c8416c56",
"windows-x86_64": "260f34d0d5312d2642097bb33c14ac552cd57c59a15383364df6764d01f0bfc9",
}
_HOST_PLATFORM_EXT = {
"linux-aarch64": "tar.xz",
"linux-x86_64": "tar.xz",
"macos-aarch64": "tar.xz",
"macos-x86_64": "tar.xz",
"windows-x86_64": "zip",
}
_compile_failed = """
Compilation of launcher.zig failed:
command={compile_cmd}
return_code={return_code}
stderr={stderr}
stdout={stdout}
You most likely hit a rare but known race in Zig SDK. Congratulations?
We are working on fixing it with Zig Software Foundation. If you are curious,
feel free to follow along in https://github.com/ziglang/zig/issues/14815
There isn't much to do now but wait. Now apply the following workaround:
$ rm -fr {cache_prefix}
$ <... re-run your command ...>
... and proceed with your life.
"""
def toolchains(
version = _VERSION,
url_formats = [URL_FORMAT_BAZELMIRROR, URL_FORMAT_NIGHTLY],
host_platform_sha256 = _HOST_PLATFORM_SHA256,
host_platform_ext = _HOST_PLATFORM_EXT):
"""
Download zig toolchain and declare bazel toolchains.
The platforms are not registered automatically, that should be done by
the user with register_toolchains() in the WORKSPACE file. See README
for possible choices.
"""
zig_repository(
name = "zig_sdk",
version = version,
url_formats = url_formats,
host_platform_sha256 = host_platform_sha256,
host_platform_ext = host_platform_ext,
)
_ZIG_TOOLS = [
"c++",
"ar",
]
_template_mapfile = """
%s {
%s;
};
"""
_template_linker = """
#ifdef __ASSEMBLER__
.symver {from_function}, {to_function_abi}
#else
__asm__(".symver {from_function}, {to_function_abi}");
#endif
"""
def _glibc_hack(from_function, to_function_abi):
# Cannot use .format(...) here, because starlark thinks
# that the byte 3 (the opening brace on the first line)
# is a nested { ... }, returning an error:
# Error in format: Nested replacement fields are not supported
to_function, to_abi = to_function_abi.split("@")
mapfile = _template_mapfile % (to_abi, to_function)
header = _template_linker.format(
from_function = from_function,
to_function_abi = to_function_abi,
)
return struct(
mapfile = mapfile,
header = header,
)
def _quote(s):
return "'" + s.replace("'", "'\\''") + "'"
def _zig_repository_impl(repository_ctx):
arch = repository_ctx.os.arch
if arch == "amd64":
arch = "x86_64"
os = repository_ctx.os.name.lower()
if os.startswith("mac os"):
os = "macos"
if os.startswith("windows"):
os = "windows"
host_platform = "{}-{}".format(os, arch)
zig_sha256 = repository_ctx.attr.host_platform_sha256[host_platform]
zig_ext = repository_ctx.attr.host_platform_ext[host_platform]
format_vars = {
"_ext": zig_ext,
"version": repository_ctx.attr.version,
"host_platform": host_platform,
}
# Fetch Label dependencies before doing download/extract.
# The Bazel docs are not very clear about this behavior but see:
# https://bazel.build/extending/repo#when_is_the_implementation_function_executed
# and a related rules_go PR:
# https://github.com/bazelbuild/bazel-gazelle/pull/1206
for dest, src in {
"platform/BUILD": "//toolchain/platform:BUILD",
"toolchain/BUILD": "//toolchain/toolchain:BUILD",
"libc/BUILD": "//toolchain/libc:BUILD",
"libc_aware/platform/BUILD": "//toolchain/libc_aware/platform:BUILD",
"libc_aware/toolchain/BUILD": "//toolchain/libc_aware/toolchain:BUILD",
}.items():
repository_ctx.symlink(Label(src), dest)
for dest, src in {
"BUILD": "//toolchain:BUILD.sdk.bazel",
# "private/BUILD": "//toolchain/private:BUILD.sdk.bazel",
}.items():
repository_ctx.template(
dest,
Label(src),
executable = False,
substitutions = {
"{zig_sdk_path}": _quote("external/zig_sdk"),
"{os}": _quote(os),
},
)
urls = [uf.format(**format_vars) for uf in repository_ctx.attr.url_formats]
repository_ctx.download_and_extract(
auth = use_netrc(read_user_netrc(repository_ctx), urls, {}),
url = urls,
stripPrefix = "zig-{host_platform}-{version}/".format(**format_vars),
sha256 = zig_sha256,
)
cache_prefix = repository_ctx.os.environ.get("BAZEL_ZIG_CC_CACHE_PREFIX", "")
if cache_prefix == "":
if os == "windows":
cache_prefix = "C:\\\\Temp\\\\bazel-zig-cc"
else:
cache_prefix = "/tmp/bazel-zig-cc"
repository_ctx.template(
"tools/launcher.zig",
Label("//toolchain:launcher.zig"),
executable = False,
substitutions = {
"{BAZEL_ZIG_CC_CACHE_PREFIX}": cache_prefix,
},
)
compile_env = {
"ZIG_LOCAL_CACHE_DIR": cache_prefix,
"ZIG_GLOBAL_CACHE_DIR": cache_prefix,
}
compile_cmd = [
paths.join("..", "zig"),
"build-exe",
"-OReleaseSafe",
"launcher.zig",
] + (["-static"] if os == "linux" else [])
ret = repository_ctx.execute(
compile_cmd,
working_directory = "tools",
environment = compile_env,
)
if ret.return_code != 0:
full_cmd = [k + "=" + v for k, v in compile_env.items()] + compile_cmd
fail(_compile_failed.format(
compile_cmd = " ".join(full_cmd),
return_code = ret.return_code,
stdout = ret.stdout,
stderr = ret.stderr,
cache_prefix = cache_prefix,
))
exe = ".exe" if os == "windows" else ""
for target_config in target_structs():
for zig_tool in _ZIG_TOOLS + target_config.tool_paths.values():
tool_path = zig_tool_path(os).format(
zig_tool = zig_tool,
zigtarget = target_config.zigtarget,
)
repository_ctx.symlink("tools/launcher{}".format(exe), tool_path)
fcntl_hack = _glibc_hack("fcntl64", "fcntl@GLIBC_2.2.5")
repository_ctx.file("glibc-hacks/fcntl.map", content = fcntl_hack.mapfile)
repository_ctx.file("glibc-hacks/fcntl.h", content = fcntl_hack.header)
res_search_amd64 = _glibc_hack("res_search", "__res_search@GLIBC_2.2.5")
repository_ctx.file("glibc-hacks/res_search-amd64.map", content = res_search_amd64.mapfile)
repository_ctx.file("glibc-hacks/res_search-amd64.h", content = res_search_amd64.header)
res_search_arm64 = _glibc_hack("res_search", "__res_search@GLIBC_2.17")
repository_ctx.file("glibc-hacks/res_search-arm64.map", content = res_search_arm64.mapfile)
repository_ctx.file("glibc-hacks/res_search-arm64.h", content = res_search_arm64.header)
zig_repository = repository_rule(
attrs = {
"version": attr.string(),
"host_platform_sha256": attr.string_dict(),
"url_formats": attr.string_list(allow_empty = False),
"host_platform_ext": attr.string_dict(),
},
environ = ["BAZEL_ZIG_CC_CACHE_PREFIX"],
implementation = _zig_repository_impl,
)
def filegroup(name, **kwargs):
native.filegroup(name = name, **kwargs)
return ":" + name
def declare_files(os):
filegroup(name = "all", srcs = native.glob(["**"]))
filegroup(name = "empty")
if os == "windows":
native.exports_files(["zig.exe"], visibility = ["//visibility:public"])
native.alias(name = "zig", actual = ":zig.exe")
else:
native.exports_files(["zig"], visibility = ["//visibility:public"])
filegroup(name = "lib/std", srcs = native.glob(["lib/std/**"]))
lazy_filegroups = {}
for target_config in target_structs():
all_includes = [native.glob(["lib/{}/**".format(i)]) for i in target_config.includes]
all_includes.append(getattr(target_config, "compiler_extra_includes", []))
cxx_tool_label = ":" + zig_tool_path(os).format(
zig_tool = "c++",
zigtarget = target_config.zigtarget,
)
filegroup(
name = "{}_includes".format(target_config.zigtarget),
srcs = _flatten(all_includes),
)
filegroup(
name = "{}_compiler_files".format(target_config.zigtarget),
srcs = [
":zig",
":{}_includes".format(target_config.zigtarget),
cxx_tool_label,
],
)
filegroup(
name = "{}_linker_files".format(target_config.zigtarget),
srcs = [
":zig",
":{}_includes".format(target_config.zigtarget),
cxx_tool_label,
] + native.glob([
"lib/libc/{}/**".format(target_config.libc),
"lib/libcxx/**",
"lib/libcxxabi/**",
"lib/libunwind/**",
"lib/compiler_rt/**",
"lib/std/**",
"lib/*.zig",
"lib/*.h",
]),
)
filegroup(
name = "{}_ar_files".format(target_config.zigtarget),
srcs = [
":zig",
":" + zig_tool_path(os).format(
zig_tool = "ar",
zigtarget = target_config.zigtarget,
),
],
)
filegroup(
name = "{}_all_files".format(target_config.zigtarget),
srcs = [
":{}_linker_files".format(target_config.zigtarget),
":{}_compiler_files".format(target_config.zigtarget),
":{}_ar_files".format(target_config.zigtarget),
],
)
for d in _DEFAULT_INCLUDE_DIRECTORIES + target_config.includes:
d = "lib/" + d
if d not in lazy_filegroups:
lazy_filegroups[d] = filegroup(name = d, srcs = native.glob([d + "/**"]))
def _flatten(iterable):
result = []
for element in iterable:
result += element
return result