| # Copyright 2019 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. |
| |
| # -*- mode: python; -*- |
| # vim:set ft=blazebuild: |
| """Build defs for Emboss. |
| |
| This file exports emboss_library, which creates an Emboss library, and |
| cc_emboss_library, which creates a header file and can be used as a dep in a |
| `cc_library`, `cc_binary`, or `cc_test` rule. |
| |
| There is also a convenience macro, `emboss_cc_library()`, which creates an |
| `emboss_library` and a `cc_emboss_library` based on it. |
| """ |
| |
| load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain") |
| |
| def emboss_cc_library(name, srcs, deps = [], visibility = None, import_dirs = []): |
| """Constructs a C++ library from an .emb file.""" |
| if len(srcs) != 1: |
| fail( |
| "Must specify exactly one Emboss source file for emboss_cc_library.", |
| "srcs", |
| ) |
| |
| emboss_library( |
| name = name + "_ir", |
| srcs = srcs, |
| deps = [dep + "_ir" for dep in deps], |
| import_dirs = import_dirs, |
| ) |
| |
| cc_emboss_library( |
| name = name, |
| deps = [":" + name + "_ir"], |
| visibility = visibility, |
| ) |
| |
| # Full Starlark rules for emboss_library and cc_emboss_library. |
| # |
| # This implementation is loosely based on the proto_library and |
| # cc_proto_library rules that are included with Bazel. |
| |
| EmbossInfo = provider( |
| doc = "Encapsulates information provided by a `emboss_library.`", |
| fields = { |
| "direct_source": "(File) The `.emb` source files from the `srcs`" + |
| " attribute.", |
| "transitive_sources": "(depset[File]) The `.emb` files from `srcs` " + |
| "and all `deps`.", |
| "transitive_roots": "(list[str]) The root paths for all " + |
| "transitive_sources.", |
| "direct_ir": "(list[File]) The `.emb.ir` files generated from the " + |
| "`srcs`.", |
| "transitive_ir": "(depset[File]) The `.emb.ir` files generated from " + |
| "transitive_srcs.", |
| }, |
| ) |
| |
| def _emboss_library_impl(ctx): |
| deps = [dep[EmbossInfo] for dep in ctx.attr.deps] |
| outs = [] |
| if len(ctx.attr.srcs) != 1: |
| fail("`srcs` attribute must contain exactly one label.", attr = "srcs") |
| src = ctx.files.srcs[0] |
| out = ctx.actions.declare_file(src.basename + ".ir", sibling = src) |
| outs.append(out) |
| inputs = depset( |
| direct = [src], |
| transitive = [dep.transitive_sources for dep in deps], |
| ) |
| |
| # If the file is in an external repo, we want to use the path to that repo |
| # as the root (e.g. ./external/my-repo) so that import paths are resolved |
| # relative to the external repo root. |
| fixed_src_root = src.root.path |
| if src.path.startswith("external/"): |
| path_segments = src.path.split("/")[:2] |
| fixed_src_root = "/".join(path_segments) |
| |
| transitive_roots = depset( |
| direct = [fixed_src_root], |
| transitive = [dep.transitive_roots for dep in deps], |
| ) |
| |
| imports = ["--import-dir=" + root for root in transitive_roots.to_list()] |
| imports_arg = ["--import-dir=" + impt for impt in ctx.attr.import_dirs] |
| ctx.actions.run( |
| inputs = inputs.to_list(), |
| outputs = [out], |
| arguments = [src.path, "--output-file=" + out.path] + imports + imports_arg, |
| executable = ctx.executable._emboss_compiler, |
| ) |
| transitive_sources = depset( |
| direct = [src], |
| transitive = [dep.transitive_sources for dep in deps], |
| ) |
| transitive_ir = depset( |
| direct = outs, |
| transitive = [dep.transitive_ir for dep in deps], |
| ) |
| return [ |
| EmbossInfo( |
| direct_source = src, |
| transitive_sources = transitive_sources, |
| transitive_roots = transitive_roots, |
| direct_ir = outs, |
| transitive_ir = transitive_ir, |
| ), |
| DefaultInfo( |
| files = depset(outs), |
| ), |
| ] |
| |
| emboss_library = rule( |
| _emboss_library_impl, |
| attrs = { |
| "srcs": attr.label_list( |
| allow_files = [".emb"], |
| ), |
| "deps": attr.label_list( |
| providers = [EmbossInfo], |
| ), |
| "import_dirs": attr.label_list( |
| allow_files = True, |
| ), |
| "licenses": attr.license() if hasattr(attr, "license") else attr.string_list(), |
| "_emboss_compiler": attr.label( |
| executable = True, |
| cfg = "exec", |
| allow_files = True, |
| default = Label( |
| "@com_google_emboss//compiler/front_end:emboss_front_end", |
| ), |
| ), |
| }, |
| provides = [EmbossInfo], |
| ) |
| |
| EmbossCcHeaderInfo = provider( |
| fields = { |
| "headers": "(list[File]) The `.emb.h` headers from this rule.", |
| "transitive_headers": "(list[File]) The `.emb.h` headers from this " + |
| "rule and all dependencies.", |
| }, |
| doc = "Provide cc emboss headers.", |
| ) |
| |
| def _cc_emboss_aspect_impl(target, ctx): |
| cc_toolchain = find_cpp_toolchain(ctx, mandatory = True) |
| emboss_cc_compiler = ctx.executable._emboss_cc_compiler |
| emboss_info = target[EmbossInfo] |
| feature_configuration = cc_common.configure_features( |
| ctx = ctx, |
| cc_toolchain = cc_toolchain, |
| requested_features = list(ctx.features), |
| unsupported_features = list(ctx.disabled_features), |
| ) |
| src = target[EmbossInfo].direct_source |
| headers = [ ctx.actions.declare_file( src.basename + ".h", sibling = src) ] |
| args = ctx.actions.args() |
| args.add("--input-file") |
| args.add_all(emboss_info.direct_ir) |
| args.add("--output-file") |
| args.add_all(headers) |
| ctx.actions.run( |
| executable = emboss_cc_compiler, |
| arguments = [args], |
| inputs = emboss_info.direct_ir, |
| outputs = headers, |
| ) |
| runtime_cc_info = ctx.attr._emboss_cc_runtime[CcInfo] |
| transitive_headers = depset( |
| direct = headers, |
| transitive = [ |
| dep[EmbossCcHeaderInfo].transitive_headers |
| for dep in ctx.rule.attr.deps |
| ], |
| ) |
| (cc_compilation_context, cc_compilation_outputs) = cc_common.compile( |
| name = ctx.label.name, |
| actions = ctx.actions, |
| feature_configuration = feature_configuration, |
| cc_toolchain = cc_toolchain, |
| public_hdrs = headers, |
| private_hdrs = transitive_headers.to_list(), |
| compilation_contexts = [runtime_cc_info.compilation_context], |
| ) |
| return [ |
| CcInfo(compilation_context = cc_compilation_context), |
| EmbossCcHeaderInfo( |
| headers = depset(headers), |
| transitive_headers = transitive_headers, |
| ), |
| ] |
| |
| _cc_emboss_aspect = aspect( |
| implementation = _cc_emboss_aspect_impl, |
| attr_aspects = ["deps"], |
| fragments = ["cpp"], |
| required_providers = [EmbossInfo], |
| attrs = { |
| "_cc_toolchain": attr.label( |
| default = "@bazel_tools//tools/cpp:current_cc_toolchain", |
| ), |
| "_emboss_cc_compiler": attr.label( |
| executable = True, |
| cfg = "exec", |
| default = "@com_google_emboss//compiler/back_end/cpp:emboss_codegen_cpp", |
| ), |
| "_emboss_cc_runtime": attr.label( |
| default = "@com_google_emboss//runtime/cpp:cpp_utils", |
| ), |
| }, |
| toolchains = ["@bazel_tools//tools/cpp:toolchain_type"], |
| ) |
| |
| def _cc_emboss_library_impl(ctx): |
| if len(ctx.attr.deps) != 1: |
| fail("`deps` attribute must contain exactly one label.", attr = "deps") |
| dep = ctx.attr.deps[0] |
| return [ |
| dep[CcInfo], |
| dep[EmbossInfo], |
| DefaultInfo(files = dep[EmbossCcHeaderInfo].headers), |
| ] |
| |
| cc_emboss_library = rule( |
| implementation = _cc_emboss_library_impl, |
| attrs = { |
| "deps": attr.label_list( |
| aspects = [_cc_emboss_aspect], |
| allow_rules = ["emboss_library"], |
| allow_files = False, |
| ), |
| }, |
| provides = [CcInfo, EmbossInfo], |
| ) |