"""A rule for building projects using the [Ninja](https://ninja-build.org/) build tool""" load( "//foreign_cc/private:detect_root.bzl", "detect_root", ) load( "//foreign_cc/private:framework.bzl", "CC_EXTERNAL_RULE_ATTRIBUTES", "CC_EXTERNAL_RULE_FRAGMENTS", "cc_external_rule_impl", "create_attrs", "expand_locations_and_make_variables", ) load("//toolchains/native_tools:tool_access.bzl", "get_ninja_data") def _ninja_impl(ctx): """The implementation of the `ninja` rule Args: ctx (ctx): The rule's context object Returns: list: A list of providers. See `cc_external_rule_impl` """ ninja_data = get_ninja_data(ctx) tools_data = [ninja_data] attrs = create_attrs( ctx.attr, configure_name = "Ninja", create_configure_script = _create_ninja_script, tools_data = tools_data, ninja_path = ninja_data.path, ) return cc_external_rule_impl(ctx, attrs) def _create_ninja_script(configureParameters): """Creates the bash commands for invoking commands to build ninja projects Args: configureParameters (struct): See `ConfigureParameters` Returns: str: A string representing a section of a bash script """ ctx = configureParameters.ctx attrs = configureParameters.attrs script = [] root = detect_root(ctx.attr.lib_source) script.append("##symlink_contents_to_dir## $$EXT_BUILD_ROOT$$/{} $$BUILD_TMPDIR$$ False".format(root)) data = ctx.attr.data + ctx.attr.build_data # Generate a list of arguments for ninja args = " ".join([ ctx.expand_location(arg, data) for arg in ctx.attr.args ]) # Set the directory location for the build commands directory = "$$EXT_BUILD_ROOT$$/{}".format(root) if ctx.attr.directory: directory = ctx.expand_location(ctx.attr.directory, data) prefix = "{} ".format(expand_locations_and_make_variables(ctx, attrs.tool_prefix, "tool_prefix", data)) if attrs.tool_prefix else "" # Generate commands for all the targets, ensuring there's # always at least 1 call to the default target. for target in ctx.attr.targets or [""]: # Note that even though directory is always passed, the # following arguments can take precedence. script.append("{prefix}{ninja} -C {dir} {args} {target}".format( prefix = prefix, ninja = attrs.ninja_path, dir = directory, args = args, target = target, )) return script def _attrs(): """Modifies the common set of attributes used by rules_foreign_cc and sets Ninja specific attrs Returns: dict: Attributes of the `ninja` rule """ attrs = dict(CC_EXTERNAL_RULE_ATTRIBUTES) attrs.update({ "args": attr.string_list( doc = "A list of arguments to pass to the call to `ninja`", ), "directory": attr.string( doc = ( "A directory to pass as the `-C` argument. The rule will always use the root " + "directory of the `lib_sources` attribute if this attribute is not set" ), ), }) return attrs ninja = rule( doc = ( "Rule for building external libraries with [Ninja](https://ninja-build.org/)." ), attrs = _attrs(), fragments = CC_EXTERNAL_RULE_FRAGMENTS, output_to_genfiles = True, implementation = _ninja_impl, toolchains = [ "@rules_foreign_cc//toolchains:ninja_toolchain", "@rules_foreign_cc//foreign_cc/private/framework:shell_toolchain", "@bazel_tools//tools/cpp:toolchain_type", ], # TODO: Remove once https://github.com/bazelbuild/bazel/issues/11584 is closed and the min supported # version is updated to a release of Bazel containing the new default for this setting. incompatible_use_toolchain_transition = True, )