Extend codegen script to take library name, output dir arguments

Summary:
Extend the codegen script to allow arbitrary library name to be passed along as an argument, as well as the desired output directory for TurboModules and Fabric output.

New arguments:

- `:library_name`
- `:modules_output_dir`
- `:components_output_dir`

These arguments remain optional, and in their absence, the codegen will generate output that should work for the FBReactNativeSpec core native modules use case.

Internally, the script has been updated to use the correct path for the core modules use case as well as third party modules.

Changelog:
[Internal] - Extend the codegen script to take additional parameters

Reviewed By: RSNara

Differential Revision: D29243707

fbshipit-source-id: 1921bd3e5fd62d7cbf4c8b5089acfdd112f4b014

scripts/react_native_pods.rb

@@ -152,33 +152,33 @@ end
 def use_react_native_codegen!(spec, options={})
   return if ENV['DISABLE_CODEGEN'] == '1'
 
-  # The path to react-native
-  prefix = options[:path] ||= "${PODS_TARGET_SRCROOT}/../.."
+  # The prefix to react-native
+  prefix = options[:react_native_path] ||= "../.."
 
   # The path to JavaScript files
   js_srcs = options[:js_srcs_dir] ||= "#{prefix}/Libraries"
 
   # Library name (e.g. FBReactNativeSpec)
-  modules_library_name = spec.name
+  modules_library_name = options[:library_name] ||= spec.name
 
-   # Output dir, relative to podspec that invoked this method
-  modules_output_dir = "React/#{modules_library_name}/#{modules_library_name}"
+  # Output dir, relative to podspec that invoked this method
+  modules_output_dir = options[:modules_output_dir] ||= "#{prefix}/React/#{modules_library_name}/#{modules_library_name}"
 
   generated_dirs = [ modules_output_dir ]
   generated_filenames = [ "#{modules_library_name}.h", "#{modules_library_name}-generated.mm" ]
   generated_files = generated_filenames.map { |filename| "#{modules_output_dir}/#{filename}" }
 
   # Run the codegen as part of the Xcode build pipeline.
-  env_vars = "SRCS_DIR='#{js_srcs}'"
-  env_vars += " MODULES_OUTPUT_DIR='#{prefix}/#{modules_output_dir}'"
+  env_vars = "SRCS_DIR='${PODS_TARGET_SRCROOT}/#{js_srcs}'"
+  env_vars += " MODULES_OUTPUT_DIR='${PODS_TARGET_SRCROOT}/#{modules_output_dir}'"
   env_vars += " MODULES_LIBRARY_NAME='#{modules_library_name}'"
 
   if ENV['USE_FABRIC'] == '1'
     # We use a different library name for components, as well as an additional set of files.
     # Eventually, we want these to be part of the same library as #{modules_library_name} above.
-    components_output_dir = "ReactCommon/react/renderer/components/rncore/"
+    components_output_dir = options[:components_output_dir] ||= "#{prefix}/ReactCommon/react/renderer/components/rncore/"
     generated_dirs.push components_output_dir
-    env_vars += " COMPONENTS_OUTPUT_DIR='#{prefix}/#{components_output_dir}'"
+    env_vars += " COMPONENTS_OUTPUT_DIR='${PODS_TARGET_SRCROOT}/#{components_output_dir}'"
     components_generated_filenames = [
       "ComponentDescriptors.h",
       "EventEmitters.cpp",
@@ -193,15 +193,17 @@ def use_react_native_codegen!(spec, options={})
   end
 
   # Prepare filesystem by creating empty files that will be picked up as references by CocoaPods.
-  spec.prepare_command = "mkdir -p #{generated_dirs.map {|dir| "'../../#{dir}'"}.join(" ")} && touch #{generated_files.map {|file| "'../../#{file}'"}.join(" ")}"
+  spec.prepare_command = "mkdir -p #{generated_dirs.join(" ")} && touch #{generated_files.join(" ")}"
 
   spec.script_phase = {
     :name => 'Generate Specs',
-    :input_files => [js_srcs],
-    :output_files => ["${DERIVED_FILE_DIR}/codegen-#{modules_library_name}.log"].concat(generated_files.map { |filename| "#{prefix}/#{filename}"} ),
+    :input_files => [ "${PODS_TARGET_SRCROOT}/#{js_srcs}" ], # This also needs to be relative to Xcode
+    :output_files => ["${DERIVED_FILE_DIR}/codegen-#{modules_library_name}.log"].concat(generated_files.map { |filename| " ${PODS_TARGET_SRCROOT}/#{filename}"} ),
     # The final generated files will be created when this script is invoked at Xcode build time.
     :script => %{set -o pipefail
-bash -l -c '#{env_vars} $\{PODS_TARGET_SRCROOT\}/../../scripts/generate-specs.sh' 2>&1 | tee "${SCRIPT_OUTPUT_FILE_0}"},
+
+bash -l -c '#{env_vars} $\{PODS_TARGET_SRCROOT\}/#{prefix}/scripts/generate-specs.sh' 2>&1 | tee "${SCRIPT_OUTPUT_FILE_0}"
+    },
     :execution_position => :before_compile,
     :show_env_vars_in_log => true
   }