[iOS/GN] Convert //ios/third_party/ochamcrest to build a framework.

build/config/ios/rules.gni

Index: build/config/ios/rules.gni
diff --git a/build/config/ios/rules.gni b/build/config/ios/rules.gni
index 604e7abec65b1ea63c80a47a95a254ea4864789b..e1937e12c48bb4e5fc375a88428fc5be8a310984 100644
--- a/build/config/ios/rules.gni
+++ b/build/config/ios/rules.gni
@@ -76,8 +76,8 @@ template("ios_app_bundle") {
           "-s=PRODUCT_NAME=$_output_name",
           "-s=XCODE_BUILD=$xcode_build",
           "-s=XCODE_VERSION=$xcode_version",
-          "-o=" + rebase_path(outputs[0], root_build_dir),
-        ] + rebase_path(sources, root_build_dir)
+          "-o=" + rebase_path(outputs[0], root_out_dir),
+        ] + rebase_path(sources, root_out_dir)
     args = [ "@{{response_file_name}}" ]
   }
 
@@ -110,7 +110,7 @@ template("ios_app_bundle") {
                              "visibility",
                            ])
 
-    output_name = rebase_path("$target_gen_dir/$_output_name", root_build_dir)
+    output_name = rebase_path("$target_gen_dir/$_output_name", root_out_dir)
     if (!defined(libs)) {
       libs = []
     }
@@ -210,7 +210,7 @@ template("bundle_data_xib") {
       "--output",
       rebase_path("$target_gen_dir/$_nib_filename"),
       "--input",
-      rebase_path(invoker.source, root_build_dir),
+      rebase_path(invoker.source, root_out_dir),
     ]
   }
 
@@ -246,10 +246,97 @@ template("bundle_data_xib") {
 #         structure will not be created, and build output will go directly
 #         into the framework subdirectory.
 #
+#     public_headers:
+#         (optional) list of paths to header file that needs to be copied
+#         into the framework bundle Headers subdirectory. If omitted or
+#         empty then the Headers subdirectory is not created.
+#
 # See "gn help shared_library" for more information on arguments supported
 # by shared library target.
 template("ios_framework_bundle") {
+  if (defined(invoker.public_headers) && invoker.public_headers != []) {
+    _target_name = target_name

[Robert Sesek, 2016/04/11 18:32:28]

optional: pull _target_name and _output_name out of the if, and use _target_name
in framework_bundle() below.

[sdefresne, 2016/04/12 13:05:19]

I tried to pull _output_name outside of the "if" but this resulted in errors
about unused variables. The only variable I could move out is "_target_name" and
I'm not sure it is worth it, so not done.

+    _output_name = target_name
+    if (defined(invoker.output_name)) {
+      _output_name = invoker.output_name
+    }
+
+    _public_headers = invoker.public_headers
+    _framework_name = _output_name + ".framework"

[Robert Sesek, 2016/04/11 18:32:28]

I wish we didn't have to duplicate this, but I don't see another way.

[sdefresne, 2016/04/12 13:05:19]

Acknowledge. One option would be to change framework_bundle to accept a
framework_name argument that would override the value used in the template, but
then it would be confusing (i.e. what if I define both output_name and
framework_name).

+    _framework_root = "$root_out_dir/$_framework_name"
+
+    _header_map_filename = "$target_gen_dir/$_output_name.headers.map"
+
+    _compile_headers_map_target = _target_name + "_compile_headers_map"
+    action(_compile_headers_map_target) {

[Robert Sesek, 2016/04/11 18:32:29]

Should each of these sub-targets have visibility set to limit their access?

[sdefresne, 2016/04/12 13:05:19]

Done, except for "_create_module_map_target" as I do not know how to limit
visibility to all targets generated by "framework_bundle" template.

+      script = "$root_out_dir/gyp-mac-tool"
+      outputs = [
+        _header_map_filename,
+      ]
+
+      sources = []
+      foreach(_source_file, invoker.sources) {
+        _source_extension = get_path_info(_source_file, "extension")
+        if (_source_extension == "h") {
+          sources += [ _source_file ]
+        }
+      }
+
+      args = [
+               "compile-ios-framework-header-map",
+               rebase_path(_header_map_filename),
+               rebase_path(_framework_root, root_out_dir),
+             ] + rebase_path(sources, root_out_dir)
+    }
+
+    _create_module_map_target = _target_name + "_module_map"
+    action(_create_module_map_target) {
+      script = "$root_out_dir/gyp-mac-tool"
+      outputs = [
+        "$_framework_root/Modules/module.modulemap",
+      ]
+      args = [
+        "package-ios-framework",
+        rebase_path("$_framework_root", root_out_dir),
+      ]
+    }
+
+    _copy_public_headers_target = _target_name + "_copy_public_headers"
+    copy(_copy_public_headers_target) {
+      sources = _public_headers
+      outputs = [
+        "$_framework_root/Headers/{{source_file_part}}",
+      ]
+    }
+
+    _headers_map_config = _target_name + "_headers_map"
+    config(_headers_map_config) {
+      include_dirs = [ _header_map_filename ]
+    }
+
+    _framework_headers_target = _target_name + "_framework_headers"
+    group(_framework_headers_target) {
+      deps = [
+        ":$_compile_headers_map_target",
+        ":$_copy_public_headers_target",
+        ":$_create_module_map_target",
+      ]
+    }
+  }
+
   framework_bundle(target_name) {
-    forward_variables_from(invoker, "*")
+    forward_variables_from(invoker, "*", [ "configs" ])
+
+    configs = []
+    if (defined(invoker.configs)) {
+      configs += invoker.configs
+    }
+
+    if (defined(_public_headers)) {
+      configs += [ ":$_headers_map_config" ]
+      deps = [
+        ":$_framework_headers_target",
+      ]
+    }
   }
 }