| // 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 static com.google.devtools.build.lib.packages.Type.STRING_LIST; |
| |
| import com.google.devtools.build.lib.analysis.BaseRuleClasses; |
| import com.google.devtools.build.lib.analysis.RuleDefinition; |
| import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment; |
| import com.google.devtools.build.lib.packages.Attribute.ValidityPredicate; |
| import com.google.devtools.build.lib.packages.Rule; |
| import com.google.devtools.build.lib.packages.RuleClass; |
| import com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClassType; |
| import com.google.devtools.build.lib.packages.RuleClass.ToolchainTransitionMode; |
| import com.google.devtools.build.lib.rules.apple.AppleConfiguration; |
| import com.google.devtools.build.lib.rules.cpp.CppConfiguration; |
| import com.google.devtools.build.lib.rules.cpp.CppRuleClasses; |
| |
| /** |
| * Abstract rule definition for j2objc_library. |
| */ |
| public class J2ObjcLibraryBaseRule implements RuleDefinition { |
| private final J2ObjcAspect j2ObjcAspect; |
| |
| public J2ObjcLibraryBaseRule(J2ObjcAspect j2ObjcAspect) { |
| this.j2ObjcAspect = j2ObjcAspect; |
| } |
| |
| @Override |
| public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) { |
| // TODO(rduan): Add support for package prefixes. |
| return builder |
| .requiresConfigurationFragments( |
| AppleConfiguration.class, |
| CppConfiguration.class, |
| J2ObjcConfiguration.class, |
| ObjcConfiguration.class) |
| /* <!-- #BLAZE_RULE($j2objc_library_base_rule).ATTRIBUTE(deps) --> |
| A list of <code>j2objc_library</code>, <code>java_library</code>, |
| <code>java_import</code> and <code>java_proto_library</code> targets that contain |
| Java files to be transpiled to Objective-C. |
| <p>All <code>java_library</code> and <code>java_import</code> targets that can be reached |
| transitively through <code>exports</code>, <code>deps</code> and <code>runtime_deps</code> |
| will be translated and compiled. Currently there is no support for files generated by Java |
| annotation processing or <code>java_import</code> targets with no <code>srcjar</code> |
| specified. |
| </p> |
| <p>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 |
| <code>srcs</code> of <code>java_library</code>, a corresponding .h and .m source file |
| will be generated. For each source jar included in <code>srcs</code> of |
| <code>java_library</code> or <code>srcjar</code> of <code>java_import</code>, a |
| corresponding .h and .m source file will be generated with all the code for that jar. |
| </p> |
| <p>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, |
| <code>//some/package/foo.java</code> has an import path of <code>some/package/foo.h</code> |
| and <code>//some/package/bar.srcjar</code> has <code>some/package/bar.h</code |
| </p> |
| <p> |
| 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 |
| <code>//some/proto/foo.proto</code>, users can reference the generated code using import |
| path <code>some/proto/foo.j2objc.pb.h</code>. |
| </p> |
| <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/ |
| .add( |
| attr("deps", LABEL_LIST) |
| .aspect(j2ObjcAspect) |
| .direct_compile_time_input() |
| .allowedRuleClasses( |
| "j2objc_library", "java_library", "java_import", "java_proto_library") |
| .allowedFileTypes()) |
| /* <!-- #BLAZE_RULE($j2objc_library_base_rule).ATTRIBUTE(entry_classes) --> |
| The list of Java classes whose translated ObjC counterparts will be referenced directly |
| by user ObjC code. This attibute is required if flag <code>--j2objc_dead_code_removal |
| </code> is on. The Java classes should be specified in their canonical names as defined by |
| <a href="http://docs.oracle.com/javase/specs/jls/se8/html/jls-6.html#jls-6.7">the Java |
| Language Specification.</a> |
| When flag <code>--j2objc_dead_code_removal</code> is specified, the list of entry classes |
| will be collected transitively and used as entry points to perform dead code analysis. |
| Unused classes will then be removed from the final ObjC app bundle. |
| <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/ |
| .add(attr("entry_classes", STRING_LIST)) |
| /* <!-- #BLAZE_RULE($j2objc_library_base_rule).ATTRIBUTE(jre_deps) --> |
| The list of additional JRE emulation libraries required by all Java code translated by this |
| <code>j2objc_library</code> rule. Only core JRE functionality is linked by default. |
| <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/ |
| .add( |
| attr("jre_deps", LABEL_LIST) |
| .direct_compile_time_input() |
| .allowedRuleClasses("objc_library") |
| .allowedFileTypes() |
| .validityPredicate( |
| new ValidityPredicate() { |
| @Override |
| public String checkValid(Rule from, Rule to) { |
| if (!to.getRuleTags().contains("j2objc_jre_lib")) { |
| return "Only J2ObjC JRE libraries are allowed"; |
| } |
| return null; |
| } |
| })) |
| .addRequiredToolchains(CppRuleClasses.ccToolchainTypeAttribute(env)) |
| .useToolchainTransition(ToolchainTransitionMode.ENABLED) |
| .build(); |
| } |
| |
| @Override |
| public Metadata getMetadata() { |
| return RuleDefinition.Metadata.builder() |
| .name("$j2objc_library_base_rule") |
| .type(RuleClassType.ABSTRACT) |
| .ancestors(BaseRuleClasses.NativeBuildRule.class) |
| .build(); |
| } |
| } |
| |
| /*<!-- #BLAZE_RULE (NAME = j2objc_library, TYPE = LIBRARY, FAMILY = Objective-C) --> |
| |
| <p> This rule uses <a href="https://github.com/google/j2objc">J2ObjC</a> 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 <a href="http://j2objc.org">the |
| J2ObjC site</a> |
| </p> |
| <p>Custom J2ObjC transpilation flags can be specified using the build flag |
| <code>--j2objc_translation_flags</code> in the command line. |
| </p> |
| <p>Please note that the translated files included in a j2objc_library target will be |
| compiled using the default compilation configuration, same configuration as for the sources of an |
| objc_library rule with no compilation options specified in attributes. |
| </p> |
| <p>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. |
| </p> |
| |
| |
| <!-- #END_BLAZE_RULE -->*/ |