Add android_library template

build/config/android/internal_rules.gni

+import("config.gni")
 
 # Creates a zip archive of the inputs.
 # If base_dir is provided, the archive paths will be relative to it.
 template("_zip") {
   assert(defined(invoker.inputs))
   assert(defined(invoker.output))
 
   rebase_inputs = rebase_path(invoker.inputs)
   rebase_output = rebase_path(invoker.output)
   action(target_name) {
     script = "//build/android/gn/zip.py"
     source_prereqs = invoker.inputs
     outputs = [invoker.output]
     args = [
       "--inputs=$rebase_inputs",
       "--output=$rebase_output",
     ]
     if (defined(invoker.base_dir)) {
       args += [
         "--base-dir", rebase_path(invoker.base_dir)
       ]
     }
   }
 }
 
+# Compiles and jars a set of java_files.
+#
+# Also, creates the .jar.TOC file for the final .jar output.
+#
+# Variables
+#   java_files: List of .java files to compile.
+#   java_deps: List of java dependencies. These should all have a .jar output
+#     at get_target_gen_path(dep, ".jar").
+#   chromium_code: If 1, enable extra warnings.
+#   srcjar_deps: List of srcjar dependencies. The .java files contained in the
+#     dependencies srcjar outputs will be compiled and added to the output jar.
+#   jar_path: Use this to explicitly set the output jar path. Defaults to
+#     get_target_gen_path(":$target_name", ".jar")
+template("_java_library") {
+  assert(defined(invoker.java_files))
+  java_files = invoker.java_files
+
+  if (defined(invoker.java_deps)) {
+    java_deps = invoker.java_deps + []
+  } else {
+    java_deps = []
+  }
+
+  if (defined(invoker.chromium_code)) {
+    chromium_code = invoker.chromium_code + 0

[Nico, 2014/05/05 22:17:51]

Why "+ 0"? Looks asm.js-y :-D

[cjhopman, 2014/06/25 01:20:04]

This was sort of just type-checking. It would provide callers early notice if
the types of arguments weren't as expected (some arguments may only be directly
written as args to a script and you wouldn't get the error until build time and
it might be really unhelpful at that point).

I don't know if it is pattern that I really liked or not. It is probably most
beneficial to people who don't know this stuff well, though, so maybe I'm not a
good test case. That being said, I think I've removed a lot of the explicit
type-checking like that.

+  } else {
+    chromium_code = 0
+  }
+
+  if (defined(invoker.srcjar_deps)) {
+    srcjar_deps = invoker.srcjar_deps + []

[Nico, 2014/05/05 22:17:51]

Same question (/me is a gn noob)

+  } else {
+    srcjar_deps = []
+  }
+  java_srcjars = get_target_gen_path(srcjar_deps, ".srcjar")
+
+  if (defined(invoker.jar_path)) {
+    jar_path = invoker.jar_path
+  } else {
+    jar_path = get_target_gen_path(":${target_name}", ".jar")
+  }
+  jar_toc_path = jar_path + ".TOC"
+
+  dependency_jars = get_target_gen_path(java_deps, ".jar")
+  dependency_jar_tocs = get_target_gen_path(java_deps, ".jar.TOC")
+
+  rebase_java_files = rebase_path(java_files)
+  rebase_jar_path = rebase_path(jar_path)
+
+  android_jar = "${android_sdk}/android.jar"
+  action("${target_name}__javac") {
+    script = "//build/android/gn/javac.py"
+    depfile = "$target_gen_dir/$target_name.d"
+    outputs = [jar_path, jar_path + ".md5.stamp"]
+    source_prereqs = java_files + dependency_jar_tocs + [android_jar] + java_srcjars

[Nico, 2014/05/05 22:17:51]

"""In an action the "sources" and "source_prereqs" are treated the same: they're
both input dependencies on script execution with no special handling. If you
want to pass the sources to your script, you must do so explicitly by including
them in the "args".

It is recommended you put inputs to your script in the "sources" variable, and
stuff like other Python files required to run your script in the
"source_prereqs" variable.""

(from the gn help)

[cjhopman, 2014/06/25 01:20:03]

Done (I think). I'd rather there weren't two names for the same thing, though.

+
+    rebase_dependency_jars = rebase_path(dependency_jars + [android_jar])
+    rebase_java_srcjars = rebase_path(java_srcjars)
+    args = [
+      "--depfile", rebase_path(depfile, root_build_dir),
+      "--classpath-jars=$rebase_dependency_jars",
+      "--java-files=$rebase_java_files",
+      "--jar-path=$rebase_jar_path",
+      "--java-srcjars=$rebase_java_srcjars",
+      "--chromium-code=$chromium_code",
+    ]
+  }
+
+  # TODO(cjhopman): proguard
+
+  rebase_jar_toc_path = rebase_path(jar_toc_path)
+  action("${target_name}__jar_toc") {
+    script = "//build/android/gyp/jar_toc.py"
+    outputs = [jar_toc_path, jar_toc_path + ".md5.stamp"]
+    depfile = "$target_gen_dir/$target_name.d"
+    source_prereqs = [jar_path]
+    args = [
+      "--depfile", rebase_path(depfile, root_build_dir),
+      "--jar-path=${rebase_jar_path}",
+      "--toc-path=${rebase_jar_toc_path}",
+    ]
+  }
+
+  group(target_name) {
+    deps = [
+      ":${target_name}__javac",

[Nico, 2014/05/05 22:17:51]

Do you need this? __jar_toc already depends on it, right? Or is gn smart about
this and ignores unnecessary group() deps if the group-internal deps graph
includes that dep implicitly already?

[cjhopman, 2014/06/25 01:20:04]

I don't think gn is smart about this, but I would like it to be obvious that
this is correct (I shouldn't have to inspect the inputs/outputs of the actions
here to see that it is correct).

+      ":${target_name}__jar_toc",
+    ] + java_deps + srcjar_deps
+  }
+}
+
+# This adds Android-specific parts to the java_library template.
+#
+# Runs Android lint against the compiled java files.
+# Dexes the output jar for inclusion in an APK.
+template("_android_java_library") {
+  if (defined(invoker.library_deps)) {
+    library_deps = invoker.library_deps + []
+  } else {
+    library_deps = []
+  }
+
+
+  assert(defined(invoker.java_files))
+
+  _java_library("${target_name}__java_library") {
+    if (defined(invoker.jar_path)) {
+      jar_path = invoker.jar_path
+    }
+    java_deps = library_deps
+    java_files = invoker.java_files
+
+    if (defined(invoker.srcjar_deps)) {
+      srcjar_deps = invoker.srcjar_deps
+    }
+  }
+
+  # TODO(cjhopman): lint
+  # TODO(cjhopman): dex
+
+  group(target_name) {
+    deps = [
+      ":${target_name}__java_library"
+    ]
+  }
+}