Add example writing custom rule that depends and is dependable from rules_cc
RELNOTES: None.
PiperOrigin-RevId: 235869541
diff --git a/examples/my_c_archive/BUILD b/examples/my_c_archive/BUILD
new file mode 100644
index 0000000..a734c66
--- /dev/null
+++ b/examples/my_c_archive/BUILD
@@ -0,0 +1,42 @@
+# Copyright 2019 The Bazel Authors. All rights reserved.
+#
+# 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
+#
+# http://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.
+
+# Example showing how to create a custom Starlark rule that rules_cc can depend on
+licenses(["notice"])
+
+load("//examples/my_c_compile:my_c_compile.bzl", "my_c_compile")
+load("//examples/my_c_archive:my_c_archive.bzl", "my_c_archive")
+load("//cc:rules.bzl", "cc_binary")
+
+cc_binary(
+ name = "main",
+ srcs = ["main.c"],
+ deps = [":archive"],
+)
+
+my_c_archive(
+ name = "archive",
+ object = ":object",
+ deps = [":bar"],
+)
+
+my_c_compile(
+ name = "object",
+ src = "foo.c",
+)
+
+cc_library(
+ name = "bar",
+ srcs = ["bar.c"],
+)
diff --git a/examples/my_c_archive/bar.c b/examples/my_c_archive/bar.c
new file mode 100644
index 0000000..8c9de53
--- /dev/null
+++ b/examples/my_c_archive/bar.c
@@ -0,0 +1 @@
+int bar() { return -42; }
diff --git a/examples/my_c_archive/foo.c b/examples/my_c_archive/foo.c
new file mode 100644
index 0000000..6718fbd
--- /dev/null
+++ b/examples/my_c_archive/foo.c
@@ -0,0 +1,15 @@
+// Copyright 2019 The Bazel Authors. All rights reserved.
+//
+// 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
+//
+// http://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.
+
+int foo() { return 42; }
diff --git a/examples/my_c_archive/main.c b/examples/my_c_archive/main.c
new file mode 100644
index 0000000..33ca256
--- /dev/null
+++ b/examples/my_c_archive/main.c
@@ -0,0 +1,3 @@
+int foo();
+int bar();
+int main() { return foo() + bar(); }
diff --git a/examples/my_c_archive/my_c_archive.bzl b/examples/my_c_archive/my_c_archive.bzl
new file mode 100644
index 0000000..ee792a8
--- /dev/null
+++ b/examples/my_c_archive/my_c_archive.bzl
@@ -0,0 +1,98 @@
+# Copyright 2019 The Bazel Authors. All rights reserved.
+#
+# 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
+#
+# http://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.
+
+"""Example showing how to create a rule that rules_cc can depend on."""
+
+load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
+load("@bazel_tools//tools/build_defs/cc:action_names.bzl", "CPP_LINK_STATIC_LIBRARY_ACTION_NAME")
+load("//examples/my_c_compile:my_c_compile.bzl", "MyCCompileInfo")
+
+def _my_c_archive_impl(ctx):
+ cc_toolchain = find_cpp_toolchain(ctx)
+ object_file = ctx.attr.object[MyCCompileInfo].object
+ output_file = ctx.actions.declare_file(ctx.label.name + ".a")
+
+ feature_configuration = cc_common.configure_features(
+ cc_toolchain = cc_toolchain,
+ requested_features = ctx.features,
+ unsupported_features = ctx.disabled_features,
+ )
+
+ library_to_link = cc_common.create_library_to_link(
+ actions = ctx.actions,
+ feature_configuration = feature_configuration,
+ cc_toolchain = cc_toolchain,
+ static_library = output_file,
+ )
+ compilation_context = cc_common.create_compilation_context()
+ linking_context = cc_common.create_linking_context(libraries_to_link = [library_to_link])
+
+ feature_configuration = cc_common.configure_features(
+ cc_toolchain = cc_toolchain,
+ requested_features = ctx.features,
+ unsupported_features = ctx.disabled_features,
+ )
+ archiver_path = cc_common.get_tool_for_action(
+ feature_configuration = feature_configuration,
+ action_name = CPP_LINK_STATIC_LIBRARY_ACTION_NAME,
+ )
+ archiver_variables = cc_common.create_link_variables(
+ feature_configuration = feature_configuration,
+ cc_toolchain = cc_toolchain,
+ output_file = output_file.path,
+ is_using_linker = False,
+ )
+ command_line = cc_common.get_memory_inefficient_command_line(
+ feature_configuration = feature_configuration,
+ action_name = CPP_LINK_STATIC_LIBRARY_ACTION_NAME,
+ variables = archiver_variables,
+ )
+ args = ctx.actions.args()
+ args.add_all(command_line)
+ args.add(object_file)
+
+ env = cc_common.get_environment_variables(
+ feature_configuration = feature_configuration,
+ action_name = CPP_LINK_STATIC_LIBRARY_ACTION_NAME,
+ variables = archiver_variables,
+ )
+
+ ctx.actions.run(
+ executable = archiver_path,
+ arguments = [args],
+ env = env,
+ inputs = depset(
+ direct = [object_file],
+ transitive = [
+ # TODO: Use CcToolchainInfo getters when available
+ # See https://github.com/bazelbuild/bazel/issues/7427.
+ ctx.attr._cc_toolchain.files,
+ ],
+ ),
+ outputs = [output_file],
+ )
+
+ cc_info = cc_common.merge_cc_infos(cc_infos = [
+ CcInfo(compilation_context = compilation_context, linking_context = linking_context),
+ ] + [dep[CcInfo] for dep in ctx.attr.deps])
+ return [cc_info]
+
+my_c_archive = rule(
+ implementation = _my_c_archive_impl,
+ attrs = {
+ "object": attr.label(mandatory = True, providers = [MyCCompileInfo]),
+ "deps": attr.label_list(providers = [CcInfo]),
+ "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
+ },
+)
diff --git a/examples/my_c_compile/my_c_compile.bzl b/examples/my_c_compile/my_c_compile.bzl
index a9cec34..7987f6b 100644
--- a/examples/my_c_compile/my_c_compile.bzl
+++ b/examples/my_c_compile/my_c_compile.bzl
@@ -12,11 +12,13 @@
# See the License for the specific language governing permissions and
# limitations under the License.
-"""Example about how to create a custom Starlark rule that just compiles C sources."""
+"""Example showing how to create a rule that just compiles C sources."""
load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
load("@bazel_tools//tools/build_defs/cc:action_names.bzl", "C_COMPILE_ACTION_NAME")
+MyCCompileInfo = provider(doc = "", fields = ["object"])
+
DISABLED_FEATURES = [
]
@@ -36,6 +38,7 @@
c_compile_variables = cc_common.create_compile_variables(
feature_configuration = feature_configuration,
cc_toolchain = cc_toolchain,
+ user_compile_flags = ctx.fragments.cpp.copts + ctx.fragments.cpp.conlyopts,
source_file = source_file.path,
output_file = output_file.path,
)
@@ -62,13 +65,16 @@
),
outputs = [output_file],
)
- return [DefaultInfo(files = depset(items = [output_file]))]
+ return [
+ DefaultInfo(files = depset(items = [output_file])),
+ MyCCompileInfo(object = output_file),
+ ]
-# This rule does nothing, just propagates all cc_toolchain files.
my_c_compile = rule(
implementation = _my_c_compile_impl,
attrs = {
"src": attr.label(mandatory = True, allow_single_file = True),
"_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
},
+ fragments = ["cpp"],
)
diff --git a/examples/write_cc_toolchain_cpu/write_cc_toolchain_cpu.bzl b/examples/write_cc_toolchain_cpu/write_cc_toolchain_cpu.bzl
index 2a62168..549c8b2 100644
--- a/examples/write_cc_toolchain_cpu/write_cc_toolchain_cpu.bzl
+++ b/examples/write_cc_toolchain_cpu/write_cc_toolchain_cpu.bzl
@@ -12,7 +12,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
-"""Example about how to get CcToolchainInfo in a custom starlark rule."""
+"""Example showing how to get CcToolchainInfo in a custom rule."""
load("@bazel_tools//tools/cpp:toolchain_utils.bzl", "find_cpp_toolchain")
