feat: add @aspect_bazel_lib_host repository and normalize function names in repo_utils (#90)

docs/BUILD.bazel

@@ -88,4 +88,9 @@ stardoc_with_diff_test(
     bzl_library_target = "//lib:yq",
 )
 
+stardoc_with_diff_test(
+    name = "host_repo",
+    bzl_library_target = "//lib:host_repo",
+)
+
 update_docs()

docs/host_repo.md

@@ -0,0 +1,23 @@
+<!-- Generated with Stardoc: http://skydoc.bazel.build -->
+
+Public API
+
+<a id="#host_repo"></a>
+
+## host_repo
+
+<pre>
+host_repo(<a href="#host_repo-name">name</a>, <a href="#host_repo-repo_mapping">repo_mapping</a>)
+</pre>
+
+Exposes information about the host platform
+
+**ATTRIBUTES**
+
+
+| Name  | Description | Type | Mandatory | Default |
+| :------------- | :------------- | :------------- | :------------- | :------------- |
+| <a id="host_repo-name"></a>name |  A unique name for this repository.   | <a href="https://bazel.build/docs/build-ref.html#name">Name</a> | required |  |
+| <a id="host_repo-repo_mapping"></a>repo_mapping |  A dictionary from local repository name to global repository name. This allows controls over workspace dependency resolution for dependencies of this repository.&lt;p&gt;For example, an entry <code>"@foo": "@bar"</code> declares that, for any time this repository depends on <code>@foo</code> (such as a dependency on <code>@foo//some:target</code>, it should actually resolve that dependency within globally-declared <code>@bar</code> (<code>@bar//some:target</code>).   | <a href="https://bazel.build/docs/skylark/lib/dict.html">Dictionary: String -> String</a> | required |  |
+
+

docs/repo_utils.md

@@ -2,147 +2,6 @@
 
 Public API
 
-<a id="#get_env_var"></a>
-
-## get_env_var
-
-<pre>
-get_env_var(<a href="#get_env_var-rctx">rctx</a>, <a href="#get_env_var-name">name</a>, <a href="#get_env_var-default">default</a>)
-</pre>
-
-Find an environment variable in system. Doesn't %-escape the value!
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="get_env_var-rctx"></a>rctx |  repository_ctx   |  none |
-| <a id="get_env_var-name"></a>name |  environment variable name   |  none |
-| <a id="get_env_var-default"></a>default |  default value to return if env var is not set in system   |  none |
-
-**RETURNS**
-
-The environment variable value or the default if it is not set
-
-
-<a id="#is_darwin_os"></a>
-
-## is_darwin_os
-
-<pre>
-is_darwin_os(<a href="#is_darwin_os-rctx">rctx</a>)
-</pre>
-
-Returns true if the host operating system is Darwin
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="is_darwin_os-rctx"></a>rctx |  <p align="center"> - </p>   |  none |
-
-
-<a id="#is_linux_os"></a>
-
-## is_linux_os
-
-<pre>
-is_linux_os(<a href="#is_linux_os-rctx">rctx</a>)
-</pre>
-
-Returns true if the host operating system is Linux
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="is_linux_os-rctx"></a>rctx |  <p align="center"> - </p>   |  none |
-
-
-<a id="#is_windows_os"></a>
-
-## is_windows_os
-
-<pre>
-is_windows_os(<a href="#is_windows_os-rctx">rctx</a>)
-</pre>
-
-Returns true if the host operating system is Windows
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="is_windows_os-rctx"></a>rctx |  <p align="center"> - </p>   |  none |
-
-
-<a id="#os_arch_name"></a>
-
-## os_arch_name
-
-<pre>
-os_arch_name(<a href="#os_arch_name-rctx">rctx</a>)
-</pre>
-
-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
-
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="os_arch_name-rctx"></a>rctx |  repository_ctx   |  none |
-
-**RETURNS**
-
-The normalized "<os_name>_<arch>" string of the host os and CPU architecture.
-
-
-<a id="#os_name"></a>
-
-## os_name
-
-<pre>
-os_name(<a href="#os_name-rctx">rctx</a>)
-</pre>
-
-Returns the name of the host operating system
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="os_name-rctx"></a>rctx |  repository_ctx   |  none |
-
-**RETURNS**
-
-The string "windows", "linux" or "darwin" that describes the host os
-
-
 <a id="#patch"></a>
 
 ## patch
@@ -174,3 +33,144 @@ then they are taken from `ctx.attr`.
 | <a id="patch-patch_directory"></a>patch_directory |  Directory to apply the patches in   |  <code>None</code> |
 
 
+<a id="#repo_utils.is_darwin"></a>
+
+## repo_utils.is_darwin
+
+<pre>
+repo_utils.is_darwin(<a href="#repo_utils.is_darwin-rctx">rctx</a>)
+</pre>
+
+Returns true if the host operating system is Darwin
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="repo_utils.is_darwin-rctx"></a>rctx |  <p align="center"> - </p>   |  none |
+
+
+<a id="#repo_utils.is_linux"></a>
+
+## repo_utils.is_linux
+
+<pre>
+repo_utils.is_linux(<a href="#repo_utils.is_linux-rctx">rctx</a>)
+</pre>
+
+Returns true if the host operating system is Linux
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="repo_utils.is_linux-rctx"></a>rctx |  <p align="center"> - </p>   |  none |
+
+
+<a id="#repo_utils.is_windows"></a>
+
+## repo_utils.is_windows
+
+<pre>
+repo_utils.is_windows(<a href="#repo_utils.is_windows-rctx">rctx</a>)
+</pre>
+
+Returns true if the host operating system is Windows
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="repo_utils.is_windows-rctx"></a>rctx |  <p align="center"> - </p>   |  none |
+
+
+<a id="#repo_utils.get_env_var"></a>
+
+## repo_utils.get_env_var
+
+<pre>
+repo_utils.get_env_var(<a href="#repo_utils.get_env_var-rctx">rctx</a>, <a href="#repo_utils.get_env_var-name">name</a>, <a href="#repo_utils.get_env_var-default">default</a>)
+</pre>
+
+Find an environment variable in system. Doesn't %-escape the value!
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="repo_utils.get_env_var-rctx"></a>rctx |  repository_ctx   |  none |
+| <a id="repo_utils.get_env_var-name"></a>name |  environment variable name   |  none |
+| <a id="repo_utils.get_env_var-default"></a>default |  default value to return if env var is not set in system   |  none |
+
+**RETURNS**
+
+The environment variable value or the default if it is not set
+
+
+<a id="#repo_utils.os"></a>
+
+## repo_utils.os
+
+<pre>
+repo_utils.os(<a href="#repo_utils.os-rctx">rctx</a>)
+</pre>
+
+Returns the name of the host operating system
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="repo_utils.os-rctx"></a>rctx |  repository_ctx   |  none |
+
+**RETURNS**
+
+The string "windows", "linux" or "darwin" that describes the host os
+
+
+<a id="#repo_utils.platform"></a>
+
+## repo_utils.platform
+
+<pre>
+repo_utils.platform(<a href="#repo_utils.platform-rctx">rctx</a>)
+</pre>
+
+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
+
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="repo_utils.platform-rctx"></a>rctx |  repository_ctx   |  none |
+
+**RETURNS**
+
+The normalized "<os>_<arch>" string of the host os and CPU architecture.
+
+

lib/BUILD.bazel

@@ -156,3 +156,12 @@ bzl_library(
     visibility = ["//visibility:public"],
     deps = ["//lib/private:yq"],
 )
+
+bzl_library(
+    name = "host_repo",
+    srcs = ["host_repo.bzl"],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//lib/private:host_repo",
+    ],
+)

lib/host_repo.bzl

@@ -0,0 +1,5 @@
+"Public API"
+
+load("//lib/private:host_repo.bzl", _host_repo = "host_repo")
+
+host_repo = _host_repo

lib/private/BUILD.bazel

@@ -157,3 +157,10 @@ bzl_library(
     srcs = ["yq.bzl"],
     visibility = ["//lib:__subpackages__"],
 )
+
+bzl_library(
+    name = "host_repo",
+    srcs = ["host_repo.bzl"],
+    visibility = ["//lib:__subpackages__"],
+    deps = [":repo_utils"],
+)

lib/private/host_repo.bzl

@@ -0,0 +1,37 @@
+"A repository that exposes information about the host platform"
+
+load(":repo_utils.bzl", "repo_utils")
+
+def _impl(rctx):
+    # Base BUILD file for this repository
+    rctx.file("BUILD.bazel", """# Generated by @aspect_bazel_lib//lib/private:host_repo.bzl
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")    
+bzl_library(
+    name = "defs",
+    srcs = ["defs.bzl"],
+    visibility = ["//visibility:public"],
+)
+""")
+
+    # defs.bzl file for this repository
+    rctx.file("defs.bzl", content = """# Generated by @aspect_bazel_lib//lib/private:host_repo.bzl
+# Information about the host platform
+host = struct(
+    is_darwin = {is_darwin},
+    is_linux = {is_linux},
+    is_windows = {is_windows},
+    os = "{os}",
+    platform = "{platform}",
+)
+""".format(
+        is_darwin = repo_utils.is_darwin(rctx),
+        is_linux = repo_utils.is_linux(rctx),
+        is_windows = repo_utils.is_windows(rctx),
+        os = repo_utils.os(rctx),
+        platform = repo_utils.platform(rctx),
+    ))
+
+host_repo = repository_rule(
+    implementation = _impl,
+    doc = "Exposes information about the host platform",
+)

lib/private/jq_toolchain.bzl

@@ -2,7 +2,7 @@
 
 load(":repo_utils.bzl", "repo_utils")
 
-# Platform names follow the os_arch_name() convention in lib/private/repo_utils.bzl
+# Platform names follow the platform naming convention in @aspect_bazel_lib//:lib/private/repo_utils.bzl
 JQ_PLATFORMS = {
     "darwin_amd64": struct(
         release_platform = "osx-amd64",
@@ -197,13 +197,11 @@ alias(name = "jq", actual = "@{name}_{platform}//:jq")
 exports_files(["index.bzl"])
 """.format(
         name = repository_ctx.name,
-        platform = repo_utils.os_arch_name(repository_ctx),
+        platform = repo_utils.platform(repository_ctx),
     ))
 
     # index.bzl file for this repository
     repository_ctx.file("index.bzl", content = """# Generated by @aspect_bazel_lib//lib/private:jq_toolchain.bzl
-load("@aspect_bazel_lib//lib:repo_utils.bzl", "is_windows_os")
-
 host_platform="{host_platform}"
 
 def bin():
@@ -211,8 +209,8 @@ def bin():
     return Label("@{name}_{host_platform}//:jq{maybe_windows}")
 """.format(
         name = repository_ctx.name,
-        host_platform = repo_utils.os_arch_name(repository_ctx),
+        host_platform = repo_utils.platform(repository_ctx),
-        maybe_windows = ".exe" if repo_utils.is_windows_os(repository_ctx) else "",
+        maybe_windows = ".exe" if repo_utils.is_windows(repository_ctx) else "",
     ))
 
 jq_host_alias_repo = repository_rule(

lib/private/patch.bzl

@@ -140,7 +140,7 @@ def patch(ctx, patches = None, patch_cmds = None, patch_cmds_win = None, patch_t
                 fail("Error applying patch %s:\n%s%s" %
                      (str(patchfile), st.stderr, st.stdout))
 
-    if repo_utils.is_windows_os(ctx) and patch_cmds_win:
+    if repo_utils.is_windows(ctx) and patch_cmds_win:
         for cmd in patch_cmds_win:
             st = ctx.execute([powershell_exe, "/c", cmd], working_directory = patch_directory)
             if st.return_code:

lib/private/repo_utils.bzl

@@ -1,18 +1,18 @@
 """Utility functions for repository rules"""
 
-def _is_darwin_os(rctx):
+def _is_darwin(rctx):
     """Returns true if the host operating system is Darwin"""
     return rctx.os.name.lower().startswith("mac os")
 
-def _is_linux_os(rctx):
+def _is_linux(rctx):
     """Returns true if the host operating system is Linux"""
     return rctx.os.name.lower().startswith("linux")
 
-def _is_windows_os(rctx):
+def _is_windows(rctx):
     """Returns true if the host operating system is Windows"""
     return rctx.os.name.lower().find("windows") != -1
 
-def _os_name(rctx):
+def _os(rctx):
     """Returns the name of the host operating system
 
     Args:
@@ -21,11 +21,11 @@ def _os_name(rctx):
     Returns:
         The string "windows", "linux" or "darwin" that describes the host os
     """
-    if _is_darwin_os(rctx):
+    if _is_darwin(rctx):
         return "darwin"
-    if _is_linux_os(rctx):
+    if _is_linux(rctx):
         return "linux"
-    if _is_windows_os(rctx):
+    if _is_windows(rctx):
         return "windows"
     fail("unrecognized os")
 
@@ -44,7 +44,7 @@ def _get_env_var(rctx, name, default):
         return rctx.os.environ[name]
     return default
 
-def _os_arch_name(rctx):
+def _platform(rctx):
     """Returns a normalized name of the host os and CPU architecture.
 
     Alias archictures names are normalized:
@@ -69,14 +69,14 @@ def _os_arch_name(rctx):
         rctx: repository_ctx
 
     Returns:
-        The normalized "<os_name>_<arch>" string of the host os and CPU architecture.
+        The normalized "<os>_<arch>" string of the host os and CPU architecture.
     """
-    os_name = _os_name(rctx)
+    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_name == "windows":
+    if os == "windows":
         proc_arch = (_get_env_var(rctx, "PROCESSOR_ARCHITECTURE", "", False) or
                      _get_env_var(rctx, "PROCESSOR_ARCHITEW6432", "", False))
         if proc_arch == "ARM64":
@@ -91,13 +91,13 @@ def _os_arch_name(rctx):
     }
     if arch in arch_map.keys():
         arch = arch_map[arch]
-    return "%s_%s" % (os_name, arch)
+    return "%s_%s" % (os, arch)
 
 repo_utils = struct(
-    is_darwin_os = _is_darwin_os,
+    is_darwin = _is_darwin,
-    is_linux_os = _is_linux_os,
+    is_linux = _is_linux,
-    is_windows_os = _is_windows_os,
+    is_windows = _is_windows,
     get_env_var = _get_env_var,
-    os_name = _os_name,
+    os = _os,
-    os_arch_name = _os_arch_name,
+    platform = _platform,
 )

lib/private/yq_toolchain.bzl

@@ -2,7 +2,7 @@
 
 load(":repo_utils.bzl", "repo_utils")
 
-# Platform names follow the os_arch_name() convention in lib/private/repo_utils.bzl
+# Platform names follow the platform naming convention in @aspect_bazel_lib//:lib/private/repo_utils.bzl
 YQ_PLATFORMS = {
     "darwin_amd64": struct(
         compatible_with = [
@@ -231,12 +231,11 @@ alias(name = "yq", actual = "@{name}_{platform}//:yq")
 exports_files(["index.bzl"])
 """.format(
         name = repository_ctx.name,
-        platform = repo_utils.os_arch_name(repository_ctx),
+        platform = repo_utils.platform(repository_ctx),
     ))
 
     # index.bzl file for this repository
     repository_ctx.file("index.bzl", content = """# Generated by @aspect_bazel_lib//lib/private:yq_toolchain.bzl
-
 host_platform="{host_platform}"
 
 def bin():
@@ -244,8 +243,8 @@ def bin():
     return Label("@{name}_{host_platform}//:yq{maybe_windows}")
 """.format(
         name = repository_ctx.name,
-        host_platform = repo_utils.os_arch_name(repository_ctx),
+        host_platform = repo_utils.platform(repository_ctx),
-        maybe_windows = ".exe" if repo_utils.is_windows_os(repository_ctx) else "",
+        maybe_windows = ".exe" if repo_utils.is_windows(repository_ctx) else "",
     ))
 
 yq_host_alias_repo = repository_rule(

lib/repo_utils.bzl

@@ -1,12 +1,7 @@
 "Public API"
 
-load("//lib/private:repo_utils.bzl", "repo_utils")
+load("//lib/private:repo_utils.bzl", _repo_utils = "repo_utils")
 load("//lib/private:patch.bzl", _patch = "patch")
 
-is_darwin_os = repo_utils.is_darwin_os
+repo_utils = _repo_utils
-is_linux_os = repo_utils.is_linux_os
-is_windows_os = repo_utils.is_windows_os
-get_env_var = repo_utils.get_env_var
-os_name = repo_utils.os_name
-os_arch_name = repo_utils.os_arch_name
 patch = _patch