Create a version that also emit supply-chain providers.

MODULE.bazel

@@ -1,11 +1,12 @@
 module(
     name = "rules_license",
-    version = "1.0.0",  # Keep in sync with version.bzl
+    version = "1.0.0-supply-chain",  # Keep in sync with version.bzl
     compatibility_level = 1,
 )
 
-# NOTE: rules_license must not depend on any other repositories if you are
-# just using basic rules under //rules/... and //licenses/...
+# NOTE: rules_license must normaly not depend on any other repositories.
+# This version allows for forwards compatibility to bazel-contrib/supply-chain
+bazel_dep(name = "package_metadata", version = "0.0.5")
 
 # TODO(aiuto): Create an extension to enable the rules under //tools/...
 # That will require rules_python, which we do not want to force on people who

README.md

@@ -6,6 +6,12 @@ CI: [![Build status](https://badge.buildkite.com/e12f23186aa579f1e20fcb612a22cd7
 |:----------------------------|
 | Active development has moved to https://github.com/bazel-contrib/supply-chain.  Please look there for current status. If you wish to contribute, please consider doing your work there. |
 
+:warning: WARNING
+Version 1.0.0-supply-chain of this package is version 1 with the addition
+of providers that are compatible with `supply-chain`. This provides a
+slow migration path where you can use supply-chain tools to reason about
+your project, while still incorporating projects using rules_license.
+
 
 This repository contains a set of rules and tools for
 - declaring metadata about packages, such as

doc_build/BUILD

@@ -20,26 +20,26 @@ How to:
 """
 
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
+load("@rules_python//python:py_binary.bzl", "py_binary")
 load("@stardoc//stardoc:stardoc.bzl", "stardoc")
-load("@rules_python//python:defs.bzl", "py_library")
-load("//:version.bzl", "version")
 
-package(default_package_metadata = ["//:license", "//:package_info"])
+package(default_package_metadata = [
+    "//:license",
+    "//:package_info",
+])
 
 filegroup(
     name = "standard_package",
     srcs = [
         "BUILD",
-    ] + glob([
-        "*.bzl",
-        "*.py",
-    ]),
+        "merge.py",
+    ],
     visibility = ["//distro:__pkg__"],
 )
 
 exports_files(
     glob([
-        "*.bzl",
+        "**",
     ]),
     visibility = [
         "//distro:__pkg__",
@@ -62,7 +62,7 @@ ORDER = [
     ("gather_metadata_info",           "//rules_gathering:gather_metadata.bzl"),
     ("gather_metadata_info_and_write", "//rules_gathering:gather_metadata.bzl"),
     ("trace",           "//rules_gathering:trace.bzl"),
-    ("current_module_package_info", "//rules:current_module_package_info.bzl"),
+    ("current_module_package_info",    "//rules:current_module_package_info.bzl"),
 ]
 
 genrule(
@@ -94,6 +94,7 @@ bzl_library(
         "//:version.bzl",
         "//rules:standard_package",
         "//rules_gathering:standard_package",
+        "@package_metadata//:srcs",
     ],
     visibility = ["//visibility:public"],
 )

rules/license_impl.bzl

@@ -15,6 +15,14 @@
 
 """
 
+load(
+    "@package_metadata//licenses/providers:license_kind_info.bzl",
+    _newLicenseKindInfo = "LicenseKindInfo",
+)
+load(
+    "@package_metadata//providers:package_attribute_info.bzl",
+    "PackageAttributeInfo",
+)
 load(
     "@rules_license//rules:providers.bzl",
     "LicenseInfo",
@@ -43,4 +51,49 @@ def license_rule_impl(ctx):
         label = ctx.label,
     )
     _debug(0, provider)
-    return [provider]
+
+    # Also return new style
+    new_license_kinds = [k[_newLicenseKindInfo] for k in ctx.attr.license_kinds]
+    if new_license_kinds:
+        # This is a temporary hack. Just pick the first if there are multiple.
+        # Package metadata should change to allow for more than one.
+        kind = new_license_kinds[0]
+    else:
+        # This should not happen, because the override for license_kind should
+        # always synthesize a new LicenseKindInfo
+        kind = _newLicenseKindInfo(identifier = "<?>", name = "<?>")
+
+    attribute = {
+        "kind": {
+            "identifier": kind.identifier,
+            "name": kind.name,
+        },
+        "label": str(ctx.label),
+    }
+    files = []
+
+    if ctx.attr.license_text:
+        attribute["text"] = ctx.file.license_text.path
+        files.append(ctx.attr.license_text[DefaultInfo].files)
+
+    output = ctx.actions.declare_file("{}.package-attribute.json".format(ctx.attr.name))
+    ctx.actions.write(
+        output = output,
+        content = json.encode(attribute),
+    )
+
+    return [
+        DefaultInfo(
+            files = depset(
+                direct = [
+                    output,
+                ],
+            ),
+        ),
+        provider,
+        PackageAttributeInfo(
+            kind = "build.bazel.attribute.license",
+            attributes = output,
+            files = files,
+        ),
+    ]

rules/license_kind.bzl

@@ -13,6 +13,10 @@
 # limitations under the License.
 """Proof of concept. License restriction."""
 
+load(
+    "@package_metadata//licenses/providers:license_kind_info.bzl",
+    _newLicenseKindInfo = "LicenseKindInfo",
+)
 load("@rules_license//rules:providers.bzl", "LicenseKindInfo")
 
 #
@@ -22,17 +26,22 @@ load("@rules_license//rules:providers.bzl", "LicenseKindInfo")
 #
 
 def _license_kind_impl(ctx):
+    identifier = "@%s//%s:%s" % (
+        ctx.label.workspace_name,
+        ctx.label.package,
+        ctx.label.name,
+    )
     provider = LicenseKindInfo(
         name = ctx.attr.name,
-        label = "@%s//%s:%s" % (
-            ctx.label.workspace_name,
-            ctx.label.package,
-            ctx.label.name,
-        ),
+        label = identifier,
         long_name = ctx.attr.long_name,
         conditions = ctx.attr.conditions,
     )
-    return [provider]
+    new_provider = _newLicenseKindInfo(
+        identifier = identifier,
+        name = ctx.attr.long_name,
+    )
+    return [provider, new_provider]
 
 _license_kind = rule(
     implementation = _license_kind_impl,

version.bzl

@@ -13,4 +13,4 @@
 # limitations under the License.
 """The version of rules_license."""
 
-version = "1.0.0"
+version = "1.0.0-supply-chain"