| # Copyright 2022 Google LLC |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # https://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| """Rules and macros for collecting LicenseInfo providers.""" |
| |
| load("@rules_license//rules:filtered_rule_kinds.bzl", "aspect_filters") |
| load("@rules_license//rules:providers.bzl", "LicenseInfo") |
| load("@rules_license//rules:user_filtered_rule_kinds.bzl", "user_aspect_filters") |
| load( |
| "@rules_license//rules/private:gathering_providers.bzl", |
| "LicensedTargetInfo", |
| "TransitiveLicensesInfo", |
| ) |
| load("@rules_license//rules_gathering:trace.bzl", "TraceInfo") |
| |
| def should_traverse(ctx, attr): |
| """Checks if the dependent attribute should be traversed. |
| |
| Args: |
| ctx: The aspect evaluation context. |
| attr: The name of the attribute to be checked. |
| |
| Returns: |
| True iff the attribute should be traversed. |
| """ |
| k = ctx.rule.kind |
| |
| for filters in [aspect_filters, user_aspect_filters]: |
| always_ignored = filters.get("*", []) |
| if k in filters: |
| attr_matches = filters[k] |
| if (attr in attr_matches or |
| "*" in attr_matches or |
| ("_*" in attr_matches and attr.startswith("_")) or |
| attr in always_ignored): |
| return False |
| |
| for m in attr_matches: |
| if attr == m: |
| return False |
| |
| return True |
| |
| def _get_transitive_metadata(ctx, trans_licenses, trans_other_metadata, trans_package_info, trans_deps, traces, provider, filter_func): |
| attrs = [a for a in dir(ctx.rule.attr)] |
| for name in attrs: |
| if not filter_func(ctx, name): |
| continue |
| a = getattr(ctx.rule.attr, name) |
| |
| # Make anything singleton into a list for convenience. |
| if type(a) != type([]): |
| a = [a] |
| for dep in a: |
| # Ignore anything that isn't a target |
| if type(dep) != "Target": |
| continue |
| |
| # Targets can also include things like input files that won't have the |
| # aspect, so we additionally check for the aspect rather than assume |
| # it's on all targets. Even some regular targets may be synthetic and |
| # not have the aspect. This provides protection against those outlier |
| # cases. |
| if provider in dep: |
| info = dep[provider] |
| if info.licenses: |
| trans_licenses.append(info.licenses) |
| if info.deps: |
| trans_deps.append(info.deps) |
| if info.traces: |
| for trace in info.traces: |
| traces.append("(" + ", ".join([str(ctx.label), ctx.rule.kind, name]) + ") -> " + trace) |
| |
| # We only need one or the other of these stanzas. |
| # If we use a polymorphic approach to metadata providers, then |
| # this works. |
| if hasattr(info, "other_metadata"): |
| if info.other_metadata: |
| trans_other_metadata.append(info.other_metadata) |
| # But if we want more precise type safety, we would have a |
| # trans_* for each type of metadata. That is not user |
| # extensibile. |
| if hasattr(info, "package_info"): |
| if info.package_info: |
| trans_package_info.append(info.package_info) |
| |
| def gather_metadata_info_common(target, ctx, provider_factory, metadata_providers, filter_func): |
| """Collect license and other metadata info from myself and my deps. |
| |
| Any single target might directly depend on a license, or depend on |
| something that transitively depends on a license, or neither. |
| This aspect bundles all those into a single provider. At each level, we add |
| in new direct license deps found and forward up the transitive information |
| collected so far. |
| |
| This is a common abstraction for crawling the dependency graph. It is |
| parameterized to allow specifying the provider that is populated with |
| results. It is configurable to select only a subset of providers. It |
| is also configurable to specify which dependency edges should not |
| be traced for the purpose of tracing the graph. |
| |
| Args: |
| target: The target of the aspect. |
| ctx: The aspect evaluation context. |
| provider_factory: abstracts the provider returned by this aspect |
| metadata_providers: a list of other providers of interest |
| filter_func: a function that returns true iff the dep edge should be ignored |
| |
| Returns: |
| provider of parameterized type |
| """ |
| |
| # First we gather my direct license attachments |
| licenses = [] |
| other_metadata = [] |
| package_info = [] |
| if ctx.rule.kind == "_license": |
| # Don't try to gather licenses from the license rule itself. We'll just |
| # blunder into the text file of the license and pick up the default |
| # attribute of the package, which we don't want. |
| pass |
| else: |
| if hasattr(ctx.rule.attr, "applicable_licenses"): |
| for dep in ctx.rule.attr.applicable_licenses: |
| if LicenseInfo in dep: |
| lic = dep[LicenseInfo] |
| licenses.append(lic) |
| |
| for m_p in metadata_providers: |
| if m_p in dep: |
| other_metadata.append(dep[m_p]) |
| |
| # A hack until https://github.com/bazelbuild/rules_license/issues/89 is |
| # fully resolved. If exec is in the bin_dir path, then the current |
| # configuration is probably cfg = exec. |
| if "-exec-" in ctx.bin_dir.path: |
| return [provider_factory(deps = depset(), licenses = depset(), traces = [])] |
| |
| # Now gather transitive collection of providers from the targets |
| # this target depends upon. |
| trans_licenses = [] |
| trans_other_metadata = [] |
| trans_package_info = [] |
| trans_deps = [] |
| traces = [] |
| |
| _get_transitive_metadata(ctx, trans_licenses, trans_other_metadata, trans_package_info, trans_deps, traces, provider_factory, filter_func) |
| |
| if not licenses and not trans_licenses: |
| return [provider_factory(deps = depset(), licenses = depset(), traces = [])] |
| |
| # If this is the target, start the sequence of traces. |
| if ctx.attr._trace[TraceInfo].trace and ctx.attr._trace[TraceInfo].trace in str(ctx.label): |
| traces = [ctx.attr._trace[TraceInfo].trace] |
| |
| # Trim the number of traces accumulated since the output can be quite large. |
| # A few representative traces are generally sufficient to identify why a dependency |
| # is incorrectly incorporated. |
| if len(traces) > 10: |
| traces = traces[0:10] |
| |
| if licenses: |
| # At this point we have a target and a list of directly used licenses. |
| # Bundle those together so we can report the exact targets that cause the |
| # dependency on each license. Since a list cannot be stored in a |
| # depset, even inside a provider, the list is concatenated into a |
| # string and will be unconcatenated in the output phase. |
| direct_license_uses = [LicensedTargetInfo( |
| target_under_license = target.label, |
| licenses = ",".join([str(x.label) for x in licenses]), |
| )] |
| else: |
| direct_license_uses = None |
| |
| # This is a bit of a hack for bazel 5.x. We can not pass extra fields to |
| # the provider constructor, so we need to do something special for each. |
| # In Bazel 6.x we can use a provider initializer function that would take |
| # all the args and only use the ones it wants. |
| if provider_factory == TransitiveLicensesInfo: |
| return [provider_factory( |
| target_under_license = target.label, |
| licenses = depset(tuple(licenses), transitive = trans_licenses), |
| deps = depset(direct = direct_license_uses, transitive = trans_deps), |
| traces = traces, |
| )] |
| |
| return [provider_factory( |
| target_under_license = target.label, |
| licenses = depset(tuple(licenses), transitive = trans_licenses), |
| other_metadata = depset(tuple(other_metadata), transitive = trans_other_metadata), |
| deps = depset(direct = direct_license_uses, transitive = trans_deps), |
| traces = traces, |
| )] |
