// Copyright 2015 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.
package com.google.devtools.build.lib.rules.objc;
import static com.google.devtools.build.lib.packages.Attribute.attr;
import static com.google.devtools.build.lib.packages.BuildType.LABEL_LIST;
import com.google.devtools.build.lib.analysis.RuleDefinition;
import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
import com.google.devtools.build.lib.packages.RuleClass;
import com.google.devtools.build.lib.packages.RuleClass.Builder;
import com.google.devtools.build.lib.rules.apple.AppleConfiguration;
import com.google.devtools.build.lib.rules.cpp.CppConfiguration;
/** j2objc_library
rule declaration. */
public class J2ObjcLibraryRule implements RuleDefinition {
private final J2ObjcAspect j2ObjcAspect;
public J2ObjcLibraryRule(J2ObjcAspect j2ObjcAspect) {
this.j2ObjcAspect = j2ObjcAspect;
}
@Override
public RuleClass build(Builder builder, RuleDefinitionEnvironment env) {
return builder
.requiresConfigurationFragments(
J2ObjcConfiguration.class,
ObjcConfiguration.class,
AppleConfiguration.class,
CppConfiguration.class)
/*
A list of j2objc_library
, java_library
and java_import
targets that contain
Java files to be transpiled to Objective-C.
All java_library
and java_import
targets that can be reached
transitively through exports
, deps
and runtime_deps
will be translated and compiled. Currently there is no support for files generated by Java
annotation processing or java_import
targets with no srcjar
specified.
The J2ObjC translation works differently depending on the type of source Java source
files included in the transitive closure. For each .java source files included in
srcs
of java_library
, a corresponding .h and .m source file
will be generated. For each source jar included in srcs
of
java_library
or srcjar
of java_import
, a
corresponding .h and .m source file will be generated with all the code for that jar.
Users can import the J2ObjC-generated header files in their code. The import paths for
these files are the root-relative path of the original Java artifacts. For example,
//some/package/foo.java
has an import path of some/package/foo.h
and //some/package/bar.srcjar
has some/package/bar.h
If proto_library rules are in the transitive closure of this rule, J2ObjC protos will also
be generated, compiled and linked-in at the binary level. For proto
//some/proto/foo.proto
, users can reference the generated code using import
path some/proto/foo.j2objc.pb.h
.
name_fully_linked.a
: A fully linked static library that
contains the full transitive closure of transpiled dependencies.This rule uses J2ObjC to translate Java source files to Objective-C, which then can be used used as dependencies of objc_library and objc_binary rules. Detailed information about J2ObjC itself can be found at the J2ObjC site
Custom J2ObjC transpilation flags can be specified using the build flag
--j2objc_translation_flags
in the command line.
Please note that the translated files included in a j2objc_library target will be compiled using the default compilation configuration, the same configuration as for the sources of an objc_library rule with no compilation options specified in attributes.
Plus, generated code is de-duplicated at target level, not source level. If you have two different Java targets that include the same Java source files, you may see a duplicate symbol error at link time. The correct way to resolve this issue is to move the shared Java source files into a separate common target that can be depended upon.
*/