| # Protocol Buffers - Google's data interchange format |
| # Copyright 2024 Google Inc. All rights reserved. |
| # |
| # Use of this source code is governed by a BSD-style |
| # license that can be found in the LICENSE file or at |
| # https://developers.google.com/open-source/licenses/bsd |
| # |
| """Implementation of the proto_lang_toolchain rule.""" |
| |
| load("@proto_bazel_features//:features.bzl", "bazel_features") |
| load("//bazel/common:proto_common.bzl", "proto_common") |
| load("//bazel/common:proto_info.bzl", "ProtoInfo") |
| load("//bazel/common:proto_lang_toolchain_info.bzl", "ProtoLangToolchainInfo") |
| load("//bazel/private:toolchain_helpers.bzl", "toolchains") |
| |
| def _rule_impl(ctx): |
| if ctx.attr.blacklisted_protos and ctx.attr.denylisted_protos: |
| fail("Only one of 'denylisted_protos' and 'blacklisted_protos' can be set (prefer 'denylisted_protos').") |
| denylisted_protos = ctx.attr.denylisted_protos or ctx.attr.blacklisted_protos |
| provided_proto_sources = depset(transitive = [bp[ProtoInfo].transitive_sources for bp in denylisted_protos]).to_list() |
| |
| flag = ctx.attr.command_line |
| if flag.find("$(PLUGIN_OUT)") > -1: |
| fail("in attribute 'command_line': Placeholder '$(PLUGIN_OUT)' is not supported.") |
| flag = flag.replace("$(OUT)", "%s") |
| |
| plugin = None |
| if ctx.attr.plugin != None: |
| plugin = ctx.attr.plugin[DefaultInfo].files_to_run |
| |
| if proto_common.INCOMPATIBLE_ENABLE_PROTO_TOOLCHAIN_RESOLUTION: |
| proto_compiler = ctx.toolchains[toolchains.PROTO_TOOLCHAIN].proto.proto_compiler |
| protoc_opts = ctx.toolchains[toolchains.PROTO_TOOLCHAIN].proto.protoc_opts |
| else: |
| proto_compiler = ctx.attr._proto_compiler.files_to_run |
| protoc_opts = ctx.fragments.proto.experimental_protoc_opts |
| |
| if ctx.attr.protoc_minimal_do_not_use: |
| proto_compiler = ctx.attr.protoc_minimal_do_not_use.files_to_run |
| |
| proto_lang_toolchain_info = ProtoLangToolchainInfo( |
| out_replacement_format_flag = flag, |
| output_files = ctx.attr.output_files, |
| plugin_format_flag = ctx.attr.plugin_format_flag, |
| plugin = plugin, |
| runtime = ctx.attr.runtime, |
| provided_proto_sources = provided_proto_sources, |
| proto_compiler = proto_compiler, |
| protoc_opts = protoc_opts, |
| progress_message = ctx.attr.progress_message, |
| mnemonic = ctx.attr.mnemonic, |
| allowlist_different_package = ctx.attr.allowlist_different_package, |
| toolchain_type = ctx.attr.toolchain_type.label if ctx.attr.toolchain_type else None, |
| ) |
| return [ |
| DefaultInfo(files = depset(), runfiles = ctx.runfiles()), |
| platform_common.ToolchainInfo(proto = proto_lang_toolchain_info), |
| # TODO: remove when --incompatible_enable_proto_toolchains is flipped and removed |
| proto_lang_toolchain_info, |
| ] |
| |
| proto_lang_toolchain = rule( |
| _rule_impl, |
| doc = """ |
| <p>If using Bazel, please load the rule from <a href="https://github.com/bazelbuild/rules_proto"> |
| https://github.com/bazelbuild/rules_proto</a>. |
| |
| <p>Specifies how a LANG_proto_library rule (e.g., <code>java_proto_library</code>) should invoke the |
| proto-compiler. |
| Some LANG_proto_library rules allow specifying which toolchain to use using command-line flags; |
| consult their documentation. |
| |
| <p>Normally you should not write those kind of rules unless you want to |
| tune your Java compiler. |
| |
| <p>There's no compiler. The proto-compiler is taken from the proto_library rule we attach to. It is |
| passed as a command-line flag to Blaze. |
| Several features require a proto-compiler to be invoked on the proto_library rule itself. |
| It's beneficial to enforce the compiler that LANG_proto_library uses is the same as the one |
| <code>proto_library</code> does. |
| |
| <h4>Examples</h4> |
| |
| <p>A simple example would be: |
| <pre><code class="lang-starlark"> |
| proto_lang_toolchain( |
| name = "javalite_toolchain", |
| command_line = "--javalite_out=shared,immutable:$(OUT)", |
| plugin = ":javalite_plugin", |
| runtime = ":protobuf_lite", |
| ) |
| </code></pre> |
| """, |
| attrs = { |
| "progress_message": attr.string(default = "Generating proto_library %{label}", doc = """ |
| This value will be set as the progress message on protoc action."""), |
| "mnemonic": attr.string(default = "GenProto", doc = """ |
| This value will be set as the mnemonic on protoc action."""), |
| "command_line": attr.string(mandatory = True, doc = """ |
| This value will be passed to proto-compiler to generate the code. Only include the parts |
| specific to this code-generator/plugin (e.g., do not include -I parameters) |
| <ul> |
| <li><code>$(OUT)</code> is LANG_proto_library-specific. The rules are expected to define |
| how they interpret this variable. For Java, for example, $(OUT) will be replaced with |
| the src-jar filename to create.</li> |
| </ul>"""), |
| "output_files": attr.string(values = ["single", "multiple", "legacy"], default = "legacy", doc = """ |
| Controls how <code>$(OUT)</code> in <code>command_line</code> is formatted, either by |
| a path to a single file or output directory in case of multiple files. |
| Possible values are: "single", "multiple"."""), |
| "plugin_format_flag": attr.string(doc = """ |
| If provided, this value will be passed to proto-compiler to use the plugin. |
| The value must contain a single %s which is replaced with plugin executable. |
| <code>--plugin=protoc-gen-PLUGIN=<executable>.</code>"""), |
| "plugin": attr.label( |
| executable = True, |
| cfg = "exec", |
| doc = """ |
| If provided, will be made available to the action that calls the proto-compiler, and will be |
| passed to the proto-compiler: |
| <code>--plugin=protoc-gen-PLUGIN=<executable>.</code>""", |
| ), |
| "runtime": attr.label(doc = """ |
| A language-specific library that the generated code is compiled against. |
| The exact behavior is LANG_proto_library-specific. |
| Java, for example, should compile against the runtime."""), |
| "denylisted_protos": attr.label_list( |
| providers = [ProtoInfo], |
| doc = """ |
| No code will be generated for files in the <code>srcs</code> attribute of |
| <code>denylisted_protos</code>. |
| This is used for .proto files that are already linked into proto runtimes, such as |
| <code>any.proto</code>.""", |
| ), |
| # TODO: Remove this once it is safe to do so in OSS. |
| "blacklisted_protos": attr.label_list( |
| providers = [ProtoInfo], |
| doc = """ |
| Deprecated. Alias for <code>denylisted_protos</code>. Will be removed in a future release. |
| """, |
| ), |
| # TODO: add doc |
| "allowlist_different_package": attr.label( |
| cfg = "exec", |
| providers = [bazel_features.globals.PackageSpecificationInfo] if bazel_features.globals.PackageSpecificationInfo else [], |
| ), |
| # TODO: add doc |
| "toolchain_type": attr.label(), |
| # DO NOT USE. For Protobuf incremental changes only: b/305068148. |
| "protoc_minimal_do_not_use": attr.label( |
| cfg = "exec", |
| executable = True, |
| ), |
| } | ({} if proto_common.INCOMPATIBLE_ENABLE_PROTO_TOOLCHAIN_RESOLUTION else { |
| "_proto_compiler": attr.label( |
| cfg = "exec", |
| executable = True, |
| allow_files = True, |
| default = configuration_field("proto", "proto_compiler"), |
| ), |
| }), |
| provides = [ProtoLangToolchainInfo], |
| fragments = ["proto"], |
| toolchains = toolchains.use_toolchain(toolchains.PROTO_TOOLCHAIN), # Used to obtain protoc |
| ) |
