fix: incorrect host alias symlink on some platforms

3rdparty/bazel-lib/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
+
+bzl_library(
+    name = "bzl_lib",
+    srcs = [
+        "repo_utils.bzl",
+    ],
+    visibility = ["//visibility:public"],
+)

3rdparty/bazel-lib/README.md

@@ -0,0 +1 @@
+repo_utils.bzl vendored from https://github.com/aspect-build/bazel-lib/blob/v2.7.3/lib/private/repo_utils.bzl

3rdparty/bazel-lib/repo_utils.bzl

@@ -0,0 +1,118 @@
+"""Utility functions for repository rules"""
+
+def _is_darwin(rctx):
+    """Returns true if the host operating system is Darwin"""
+    return rctx.os.name.lower().startswith("mac os")
+
+def _is_linux(rctx):
+    """Returns true if the host operating system is Linux"""
+    return rctx.os.name.lower().startswith("linux")
+
+def _is_freebsd(rctx):
+    """Returns true if the host operating system is FreeBSD"""
+    return rctx.os.name.lower().startswith("freebsd")
+
+def _is_windows(rctx):
+    """Returns true if the host operating system is Windows"""
+    return rctx.os.name.lower().find("windows") != -1
+
+def _os(rctx):
+    """Returns the name of the host operating system
+
+    Args:
+        rctx: rctx
+
+    Returns:
+        The string "windows", "linux", "freebsd" or "darwin" that describes the host os
+    """
+    if _is_darwin(rctx):
+        return "darwin"
+    if _is_linux(rctx):
+        return "linux"
+    if _is_freebsd(rctx):
+        return "freebsd"
+    if _is_windows(rctx):
+        return "windows"
+    fail("unrecognized os")
+
+def _get_env_var(rctx, name, default):
+    """Find an environment variable in system. Doesn't %-escape the value!
+
+    Args:
+        rctx: rctx
+        name: environment variable name
+        default: default value to return if env var is not set in system
+
+    Returns:
+        The environment variable value or the default if it is not set
+    """
+
+    # On Windows, the HOME environment variable is named differently.
+    # See https://en.wikipedia.org/wiki/Home_directory#Default_home_directory_per_operating_system
+    if name == "HOME" and _is_windows(rctx):
+        name = "USERPROFILE"
+    if name in rctx.os.environ:
+        return rctx.os.environ[name]
+    return default
+
+def _get_home_directory(rctx):
+    return _get_env_var(rctx, "HOME", None)
+
+def _platform(rctx):
+    """Returns a normalized name of the host os and CPU architecture.
+
+    Alias archictures names are normalized:
+
+    x86_64 => amd64
+    aarch64 => arm64
+
+    The result can be used to generate repository names for host toolchain
+    repositories for toolchains that use these normalized names.
+
+    Common os & architecture pairs that are returned are,
+
+    - darwin_amd64
+    - darwin_arm64
+    - linux_amd64
+    - linux_arm64
+    - linux_s390x
+    - linux_ppc64le
+    - windows_amd64
+
+    Args:
+        rctx: rctx
+
+    Returns:
+        The normalized "<os>_<arch>" string of the host os and CPU architecture.
+    """
+    os = _os(rctx)
+
+    # NB: in bazel 5.1.1 rctx.os.arch was added which https://github.com/bazelbuild/bazel/commit/32d1606dac2fea730abe174c41870b7ee70ae041.
+    # Once we drop support for anything older than Bazel 5.1.1 than we can simplify
+    # this function.
+    if os == "windows":
+        proc_arch = (_get_env_var(rctx, "PROCESSOR_ARCHITECTURE", "") or
+                     _get_env_var(rctx, "PROCESSOR_ARCHITEW6432", ""))
+        if proc_arch == "ARM64":
+            arch = "arm64"
+        else:
+            arch = "amd64"
+    else:
+        arch = rctx.execute(["uname", "-m"]).stdout.strip()
+    arch_map = {
+        "aarch64": "arm64",
+        "x86_64": "amd64",
+    }
+    if arch in arch_map.keys():
+        arch = arch_map[arch]
+    return "%s_%s" % (os, arch)
+
+repo_utils = struct(
+    is_darwin = _is_darwin,
+    is_linux = _is_linux,
+    is_windows = _is_windows,
+    get_env_var = _get_env_var,
+    get_home_directory = _get_home_directory,
+    os = _os,
+    platform = _platform,
+)

docs/BUILD.bazel

@@ -9,6 +9,9 @@ bzl_library(
         "@bazel_tools//tools:bzl_srcs",
     ],
     visibility = ["//visibility:public"],
+    deps = [
+        "//3rdparty/bazel-lib:bzl_lib",
+    ],
 )
 
 stardoc(

helm/repositories.bzl

@@ -2,6 +2,7 @@
 
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
+load("//3rdparty/bazel-lib:repo_utils.bzl", "repo_utils")
 load("//helm/private:versions.bzl", "DEFAULT_HELM_URL_TEMPLATES", "DEFAULT_HELM_VERSION", "HELM_VERSIONS")
 
 _HELM_TAR_BUILD_CONTENT = """\
@@ -124,12 +125,9 @@ exports_files(["helm{ext}"])
         ext = ext,
     ))
 
-    platform = "{}_{}".format(repository_ctx.os.name, repository_ctx.os.arch)
-    platform_repo_name = _helm_bin_repo_name(platform)
-
-    repository_ctx.symlink("../{platform_repo_name}/helm{ext}".format(
+    repository_ctx.symlink("../{name}_{platform}/helm{ext}".format(
         name = repository_ctx.attr.name,
-        platform_repo_name = platform_repo_name,
+        platform = repo_utils.platform(repository_ctx),
         ext = ext,
     ), "helm{ext}".format(ext = ext))