mirror of https://github.com/bazelbuild/rules_cc
86 lines
2.6 KiB
Python
86 lines
2.6 KiB
Python
# Copyright 2024 The Bazel Authors. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Implementation of the cc_tool_capability rule."""
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load(
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":cc_toolchain_info.bzl",
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"ArgsListInfo",
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"FeatureConstraintInfo",
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"FeatureInfo",
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"ToolCapabilityInfo",
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)
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def _cc_tool_capability_impl(ctx):
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ft = FeatureInfo(
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name = ctx.attr.feature_name or ctx.label.name,
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label = ctx.label,
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enabled = False,
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args = ArgsListInfo(
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label = ctx.label,
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args = (),
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files = depset(),
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by_action = (),
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allowlist_include_directories = depset(),
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),
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implies = depset(),
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requires_any_of = (),
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mutually_exclusive = (),
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# Mark it as external so that it doesn't complain if we say
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# "requires" on a constraint that was never referenced elsewhere
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# in the toolchain.
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external = True,
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overridable = True,
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overrides = None,
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allowlist_include_directories = depset(),
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)
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return [
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ToolCapabilityInfo(label = ctx.label, feature = ft),
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# Only give it a feature constraint info and not a feature info.
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# This way you can't imply it - you can only require it.
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FeatureConstraintInfo(label = ctx.label, all_of = depset([ft])),
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]
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cc_tool_capability = rule(
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implementation = _cc_tool_capability_impl,
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provides = [ToolCapabilityInfo, FeatureConstraintInfo],
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doc = """A capability is an optional feature that a tool supports.
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For example, not all compilers support PIC, so to handle this, we write:
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```
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cc_tool(
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name = "clang",
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src = "@host_tools/bin/clang",
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capabilities = [
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"//cc/toolchains/capabilities:supports_pic",
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],
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)
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cc_args(
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name = "pic",
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requires = [
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"//cc/toolchains/capabilities:supports_pic"
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],
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args = ["-fPIC"],
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)
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```
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This ensures that `-fPIC` is added to the command-line only when we are using a
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tool that supports PIC.
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""",
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attrs = {
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"feature_name": attr.string(doc = "The name of the feature to generate for this capability"),
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},
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)
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