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", ] # https://github.com/ziglang/zig/blob/0cfa39304b18c6a04689bd789f5dc4d035ec43b0/src/main.zig#L2962-L2966 TARGET_CONFIGS = [ struct( target="x86_64-macos-gnu", includes=[ "libunwind/include", "libc/include/any-macos-any", "libc/include/x86_64-macos-any", "libc/include/x86_64-macos-gnu", ], # linkopts=["-lc++", "-lc++abi"], linkopts=[], copts=[], bazel_target_cpu="darwin", constraint_values=[ "@platforms//os:macos", "@platforms//cpu:x86_64", ], tool_paths={"ld": "ld64.lld"}, ), struct( target="x86_64-linux-gnu.2.19", includes=[ "libunwind/include", "libc/include/generic-glibc", "libc/include/any-linux-any", "libc/include/x86_64-linux-gnu", "libc/include/x86_64-linux-any", ], linkopts=["-lc++", "-lc++abi"], copts=[], bazel_target_cpu="k8", constraint_values=[ "@platforms//os:linux", "@platforms//cpu:x86_64", ], tool_paths={"ld": "ld.lld"}, ), struct( target="x86_64-linux-musl", includes=[ "libc/include/generic-musl", "libc/include/any-linux-any", "libc/include/x86_64-linux-musl", "libc/include/x86_64-linux-any", ], linkopts=[], copts=["-D_LIBCPP_HAS_MUSL_LIBC", "-D_LIBCPP_HAS_THREAD_API_PTHREAD"], bazel_target_cpu="k8", constraint_values=[ "@platforms//os:linux", "@platforms//cpu:x86_64", ":musl", ], tool_paths={"ld": "ld.lld"}, ), ] def toolchain_repositories(): zig_repository( name = "com_github_ziglang_zig", version = "0.8.0", url_format = "https://ziglang.org/download/{version}/zig-{host_platform}-{version}.tar.xz", host_platform_sha256 = { "linux-x86_64": "502625d3da3ae595c5f44a809a87714320b7a40e6dff4a895b5fa7df3391d01e", "macos-x86_64": "279f9360b5cb23103f0395dc4d3d0d30626e699b1b4be55e98fd985b62bc6fbe", }, host_platform_include_root = { "macos-x86_64": "lib/zig/", "linux-x86_64": "lib/", } ) def register_all_toolchains(): for target_config in TARGET_CONFIGS: native.register_toolchains( "@com_github_ziglang_zig//:%s_toolchain" % target_config.target, ) ZIG_TOOL_PATH = "tools/{zig_tool}" ZIG_TOOL_WRAPPER = """#!/bin/bash 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=$ZIG_LOCAL_CACHE_DIR exec "{zig}" "{zig_tool}" "$@" """ ZIG_TOOLS = [ "c++", "cc", "ar", # List of ld tools: https://github.com/ziglang/zig/blob/0cfa39304b18c6a04689bd789f5dc4d035ec43b0/src/main.zig#L2962-L2966 # and also: https://github.com/ziglang/zig/issues/3257 "ld.lld", # ELF "ld64.lld", # Mach-O "lld-link", # COFF "wasm-ld", # WebAssembly ] BUILD = """ load("@zig-cc-bazel//toolchain:defs.bzl", "zig_build_macro") package(default_visibility = ["//visibility:public"]) zig_build_macro(absolute_path={absolute_path}, zig_include_root={zig_include_root}) constraint_setting(name = "libc") constraint_value( name = "musl", constraint_setting = ":libc", ) platform( name = "platform_x86_64-macos-gnu", constraint_values = [ "@platforms//os:macos", "@platforms//cpu:x86_64", ], ) platform( name = "platform_x86_64-linux-gnu", constraint_values = [ "@platforms//os:linux", "@platforms//cpu:x86_64", ], ) platform( name = "platform_x86_64-linux-musl", constraint_values = [ "@platforms//os:linux", "@platforms//cpu:x86_64", ":musl", ], ) """ 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, ) 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), ) absolute_path = json.encode(str(repository_ctx.path(""))) repository_ctx.file( "BUILD", BUILD.format(absolute_path=absolute_path, zig_include_root=json.encode(zig_include_root)), ) zig_repository = repository_rule( attrs = { "url": attr.string(), "version": attr.string(), "host_platform_sha256": attr.string_dict(), "url_format": attr.string(), "host_platform_include_root": attr.string_dict(), }, implementation = _zig_repository_impl, ) def filegroup(name, **kwargs): native.filegroup(name = name, **kwargs) return ":" + name def zig_build_macro(absolute_path, zig_include_root): filegroup(name="empty") filegroup(name="zig_compiler", srcs=["zig"]) filegroup(name="lib/std", srcs=native.glob(["lib/std/**"])) lazy_filegroups = {} for target_config in TARGET_CONFIGS: target = target_config.target native.platform(name = target, constraint_values = target_config.constraint_values) all_srcs = [] ar_srcs = [":zig_compiler"] linker_srcs = [":zig_compiler"] compiler_srcs = [":zig_compiler"] tool_srcs = {"gcc": compiler_srcs, "ld": linker_srcs, "ar": ar_srcs} 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 + "/**"])) compiler_srcs.append(lazy_filegroups[d]) 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) tool_srcs[name].append(tool_path) ar_files = filegroup(name=target + "_ar_files", srcs=ar_srcs) linker_files = filegroup(name=target + "_linker_files", srcs=linker_srcs) compiler_files = filegroup(name=target + "_compiler_files", srcs=compiler_srcs) all_files = filegroup(name=target + "_all_files", srcs=all_srcs + [ar_files, linker_files, compiler_files]) zig_cc_toolchain_config( name = target + "_cc_toolchain_config", target = target, tool_paths = absolute_tool_paths, cxx_builtin_include_directories = cxx_builtin_include_directories, copts = target_config.copts, linkopts = target_config.linkopts, target_system_name = "unknown", target_cpu = target_config.bazel_target_cpu, target_libc = "unknown", compiler = "clang", abi_version = "unknown", abi_libc_version = "unknown", ) native.cc_toolchain( name = target + "_cc_toolchain", toolchain_identifier = target + "-toolchain", toolchain_config = ":%s_cc_toolchain_config" % target, all_files = all_files, ar_files = ar_files, compiler_files = compiler_files, linker_files = linker_files, dwp_files = ":empty", objcopy_files = ":empty", strip_files = ":empty", supports_param_files = 0, ) native.cc_toolchain_suite( name = target + "_cc_toolchain_suite", toolchains = { target_config.bazel_target_cpu: ":%s_cc_toolchain" % target, }, tags = ["manual"] ) native.toolchain( name = target + "_toolchain", exec_compatible_with = None, target_compatible_with = target_config.constraint_values, toolchain = ":%s_cc_toolchain" % target, toolchain_type = "@bazel_tools//tools/cpp:toolchain_type", )