Draft: Attempt at Mac OS compilation

MODULE.bazel

@@ -37,6 +37,8 @@ register_toolchains(
     # (linux,darwin,windows)x(amd64,arm64)
     "@zig_sdk//toolchain:linux_amd64_gnu.2.28",
     "@zig_sdk//toolchain:linux_arm64_gnu.2.28",
+    "@zig_sdk//toolchain:darwin_amd64_sdk.14.2",
+    "@zig_sdk//toolchain:darwin_arm64_sdk.14.2",
     "@zig_sdk//toolchain:windows_amd64",
     "@zig_sdk//toolchain:windows_arm64",
 
@@ -47,6 +49,10 @@ register_toolchains(
     # arm64 toolchains for libc-aware platforms:
     "@zig_sdk//libc_aware/toolchain:linux_arm64_gnu.2.28",
     "@zig_sdk//libc_aware/toolchain:linux_arm64_musl",
+
+    "@zig_sdk//libc_aware/toolchain:darwin_amd64_sdk.14.2",
+    "@zig_sdk//libc_aware/toolchain:darwin_arm64_sdk.14.2",
+
     # wasm/wasi toolchains
     "@zig_sdk//toolchain:wasip1_wasm",
 )

WORKSPACE

@@ -0,0 +1 @@
+

toolchain/BUILD.macos.bazel

@@ -0,0 +1,10 @@
+# Copyright 2023 Uber Technologies, Inc.
+# Licensed under the Apache License, Version 2.0
+
+load("@hermetic_cc_toolchain//toolchain:defs.bzl", "declare_macos_sdk_files")
+
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+declare_macos_sdk_files()

toolchain/BUILD.sdk.bazel

@@ -10,9 +10,11 @@ package(
 
 declare_files(
     os = {os},
+    macos_sdk_versions = {macos_sdk_versions},
 )
 
 declare_cc_toolchains(
     os = {os},
     zig_sdk_path = {zig_sdk_path},
+    macos_sdk_versions = {macos_sdk_versions},
 )

toolchain/defs.bzl

@@ -56,18 +56,54 @@ are. Thus we need a bit of your collaboration to get to the bottom of it.
 After commenting on the issue, `rm -fr {cache_prefix}` and re-run your command.
 """
 
+_want_format = """
+Unexpected MacOS SDK definition. Expected format:
+
+zig_toolchain(
+    macos_sdks = [
+      struct(
+        version = "14.2",
+        urls = [ "https://<...>", ... ],
+        sha256 = "<...>",
+      ),
+      ...
+    ],
+)
+
+"""
+
 def toolchains(
         version = VERSION,
         url_formats = [],
         host_platform_sha256 = HOST_PLATFORM_SHA256,
-        host_platform_ext = _HOST_PLATFORM_EXT):
+        host_platform_ext = _HOST_PLATFORM_EXT,
+        macos_sdks = []):
     """
         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.
     """
 
+    macos_sdk_versions = []
+    for sdk in macos_sdks:
+        if not(bool(sdk.version) and bool(sdk.urls) and bool(sdk.sha256)):
+            fail(_want_format)
+
+        macos_sdk_versions.append(sdk.version)
+
+        if not (len(sdk.version) == 4 and
+                sdk.version[2] == "." and
+                sdk.version[0:2].isdigit() and
+                sdk.version[3].isdigit()):
+            fail("unexpected macos SDK version {}, want DD.D".format(version))
+
+        macos_sdk_repository(
+            name = "macos_sdk_{}".format(sdk.version),
+            urls = sdk.urls,
+            sha256 = sdk.sha256,
+        )
+
     if not url_formats:
         if "dev" in version:
             original_format = URL_FORMAT_NIGHTLY
@@ -83,6 +119,14 @@ def toolchains(
         url_formats = url_formats,
         host_platform_sha256 = host_platform_sha256,
         host_platform_ext = host_platform_ext,
+        macos_sdk_versions = macos_sdk_versions,
+    )
+
+def macos_sdk(version, urls, sha256):
+    return struct(
+        version = version,
+        urls = urls,
+        sha256 = sha256,
     )
 
 def _quote(s):
@@ -115,25 +159,31 @@ def _zig_repository_impl(repository_ctx):
     # 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)
+    macos_sdk_versions_str = _macos_versions(repository_ctx.attr.macos_sdk_versions)
+    repository_ctx.symlink(Label("//toolchain/platform:BUILD"), "platform/BUILD")
+    repository_ctx.template(
+        "BUILD",
+        Label("//toolchain:BUILD.sdk.bazel"),
+        executable = False,
+        substitutions = {
+            "{zig_sdk_path}": _quote("external/zig_sdk"),
+            "{os}": _quote(os),
+            "{macos_sdk_versions}": macos_sdk_versions_str,
+        },
+    )
 
     for dest, src in {
-        "BUILD": "//toolchain:BUILD.sdk.bazel",
+        "toolchain/BUILD": "//toolchain/toolchain:BUILD",
+        "libc/BUILD": "//toolchain/libc:BUILD.sdk.bazel",
+        "libc_aware/platform/BUILD": "//toolchain/libc_aware/platform:BUILD.sdk.bazel",
+        "libc_aware/toolchain/BUILD": "//toolchain/libc_aware/toolchain:BUILD.sdk.bazel",
     }.items():
         repository_ctx.template(
             dest,
             Label(src),
             executable = False,
             substitutions = {
-                "{zig_sdk_path}": _quote("external/zig_sdk"),
-                "{os}": _quote(os),
+                "{macos_sdk_versions}": macos_sdk_versions_str,
             },
         )
 
@@ -216,8 +266,7 @@ def _zig_repository_impl(repository_ctx):
     exe = ".exe" if os == "windows" else ""
     for t in _BUILTIN_TOOLS:
         repository_ctx.symlink("tools/zig-wrapper{}".format(exe), "tools/{}{}".format(t, exe))
-
-    for target_config in target_structs():
+    for target_config in target_structs(repository_ctx.attr.macos_sdk_versions):
         tool_path = zig_tool_path(os).format(
             zig_tool = "c++",
             zigtarget = target_config.zigtarget,
@@ -230,16 +279,42 @@ zig_repository = repository_rule(
         "host_platform_sha256": attr.string_dict(),
         "url_formats": attr.string_list(allow_empty = False),
         "host_platform_ext": attr.string_dict(),
+        "macos_sdk_versions": attr.string_list(),
     },
     environ = ["HERMETIC_CC_TOOLCHAIN_CACHE_PREFIX"],
     implementation = _zig_repository_impl,
 )
 
+def _macos_sdk_repository_impl(repository_ctx):
+    urls = repository_ctx.attr.urls
+    sha256 = repository_ctx.attr.sha256
+
+    repository_ctx.symlink(Label("//toolchain:BUILD.macos.bazel"), "BUILD.bazel")
+    repository_ctx.download_and_extract(
+        auth = use_netrc(read_user_netrc(repository_ctx), urls, {}),
+        url = urls,
+        sha256 = sha256,
+        stripPrefix = 'xcode-frameworks-122b43323db27b2082a2d44ed2121de21c9ccf75',
+    )
+
+macos_sdk_repository = repository_rule(
+    attrs = {
+        "urls": attr.string_list(allow_empty = False, mandatory = True),
+        "sha256": attr.string(mandatory = True),
+    },
+    implementation = _macos_sdk_repository_impl,
+)
+
 def filegroup(name, **kwargs):
     native.filegroup(name = name, **kwargs)
     return ":" + name
 
-def declare_files(os):
+def declare_macos_sdk_files():
+    filegroup(name = "Frameworks", srcs = native.glob(["Frameworks/**"]))
+    filegroup(name = "usr_include", srcs = native.glob(["include/**"]))
+    filegroup(name = "usr_lib", srcs = native.glob(["lib/**"]))
+
+def declare_files(os, macos_sdk_versions):
     exe = ".exe" if os == "windows" else ""
 
     native.exports_files(["zig{}".format(exe)], visibility = ["//visibility:public"])
@@ -253,14 +328,14 @@ def declare_files(os):
     filegroup(name = "empty")
     lazy_filegroups = {}
 
-    for target_config in target_structs():
-        all_includes = [native.glob(["lib/{}/**".format(i)]) for i in target_config.includes]
-
+    for target_config in target_structs(macos_sdk_versions):
         cxx_tool_label = ":" + zig_tool_path(os).format(
             zig_tool = "c++",
             zigtarget = target_config.zigtarget,
         )
 
+        all_includes = [native.glob(["lib/{}/**".format(i)]) for i in target_config.includes]
+
         filegroup(
             name = "{}_includes".format(target_config.zigtarget),
             srcs = _flatten(all_includes),
@@ -270,9 +345,10 @@ def declare_files(os):
             name = "{}_compiler_files".format(target_config.zigtarget),
             srcs = [
                 ":zig",
+                ":lib/std",
                 ":{}_includes".format(target_config.zigtarget),
                 cxx_tool_label,
-            ],
+            ] + getattr(target_config, "sdk_include_files", [])
         )
 
         filegroup(
@@ -282,7 +358,7 @@ def declare_files(os):
                 ":{}_includes".format(target_config.zigtarget),
                 cxx_tool_label,
             ] + native.glob([
-                "lib/libc/{}/**".format(target_config.libc),
+                "lib/libc/{}/**".format('darwin'), # figure out how to pass in the right value: (target_config.libc),
                 "lib/libcxx/**",
                 "lib/libcxxabi/**",
                 "lib/libunwind/**",
@@ -291,7 +367,7 @@ def declare_files(os):
                 "lib/tsan/**",
                 "lib/*.zig",
                 "lib/*.h",
-            ]),
+            ]) + getattr(target_config, "sdk_lib_files", []),
         )
 
         filegroup(
@@ -308,17 +384,23 @@ def declare_files(os):
             ],
         )
 
-        for d in _DEFAULT_INCLUDE_DIRECTORIES + target_config.includes:
+        for d in _DEFAULT_INCLUDE_DIRECTORIES + getattr(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
 
+
+def _macos_versions(versions):
+    return "[{}]".format(", ".join([_quote(v) for v in versions]))
+
+
 ## Copied from https://github.com/bazelbuild/bazel-skylib/blob/1.4.1/lib/paths.bzl#L59-L98
 def _paths_is_absolute(path):
     return path.startswith("/") or (len(path) > 2 and path[1] == ":")

toolchain/ext.bzl

@@ -1,6 +1,15 @@
-load("@hermetic_cc_toolchain//toolchain:defs.bzl", zig_toolchains = "toolchains")
+load("@hermetic_cc_toolchain//toolchain:defs.bzl", "macos_sdk", zig_toolchains = "toolchains")
 
 def _toolchains_impl(ctx):
-    zig_toolchains()
+    zig_toolchains(
+        macos_sdks = [
+            macos_sdk(
+              version = "14.2",
+              urls = [ "https://github.com/hexops/xcode-frameworks/archive/122b43323db27b2082a2d44ed2121de21c9ccf75.zip" ],
+              sha256 = "e774c140fe476e7a030aefb6f782e58ed79a18d0223bb88fee6a89d6d6cf8d30",
+              # strip_prefix = "xcode-frameworks-122b43323db27b2082a2d44ed2121de21c9ccf75",
+            )
+        ],
+    )
 
 toolchains = module_extension(implementation = _toolchains_impl)

toolchain/libc/BUILD

@@ -1,20 +0,0 @@
-# Copyright 2023 Uber Technologies, Inc.
-# Licensed under the MIT License
-
-load("@hermetic_cc_toolchain//toolchain/libc:defs.bzl", "declare_libcs")
-
-package(
-    default_visibility = ["//visibility:public"],
-)
-
-constraint_setting(
-    name = "variant",
-    default_constraint_value = "unconstrained",
-)
-
-constraint_value(
-    name = "unconstrained",
-    constraint_setting = "variant",
-)
-
-declare_libcs()

toolchain/libc/BUILD.sdk.bazel

@@ -0,0 +1,22 @@
+# Copyright 2023 Uber Technologies, Inc.
+# Licensed under the Apache License, Version 2.0
+
+load("@hermetic_cc_toolchain//toolchain/libc:defs.bzl", "declare_libcs")
+
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+constraint_setting(
+    name = "variant",
+    default_constraint_value = "unconstrained",
+)
+
+constraint_value(
+    name = "unconstrained",
+    constraint_setting = "variant",
+)
+
+declare_libcs(
+    macos_sdk_versions = {macos_sdk_versions}
+)

toolchain/libc/defs.bzl

@@ -3,8 +3,8 @@
 
 load("@hermetic_cc_toolchain//toolchain/private:defs.bzl", "LIBCS")
 
-def declare_libcs():
-    for libc in LIBCS:
+def declare_libcs(macos_sdk_versions):
+    for libc in LIBCS + ["macos." + v for v in macos_sdk_versions]:
         native.constraint_value(
             name = libc,
             constraint_setting = "variant",

toolchain/libc_aware/platform/BUILD

@@ -1,10 +0,0 @@
-# Copyright 2023 Uber Technologies, Inc.
-# Licensed under the MIT License
-
-load("@hermetic_cc_toolchain//toolchain/platform:defs.bzl", "declare_libc_aware_platforms")
-
-package(
-    default_visibility = ["//visibility:public"],
-)
-
-declare_libc_aware_platforms()

toolchain/libc_aware/platform/BUILD.sdk.bazel

@@ -0,0 +1,12 @@
+# Copyright 2023 Uber Technologies, Inc.
+# Licensed under the Apache License, Version 2.0
+
+load("@hermetic_cc_toolchain//toolchain/platform:defs.bzl", "declare_libc_aware_platforms")
+
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+declare_libc_aware_platforms(
+    macos_sdk_versions = {macos_sdk_versions}
+)

toolchain/libc_aware/toolchain/BUILD

@@ -1,10 +0,0 @@
-# Copyright 2023 Uber Technologies, Inc.
-# Licensed under the MIT License
-
-load("@hermetic_cc_toolchain//toolchain/toolchain:defs.bzl", "declare_libc_aware_toolchains")
-
-package(
-    default_visibility = ["//visibility:public"],
-)
-
-declare_libc_aware_toolchains()