# Copyright 2023 The MediaPipe 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. """Custom rules for building iOS OpenCV xcframework from sources.""" load( "@//third_party:opencv_ios_xcframework_files.bzl", "OPENCV_XCFRAMEWORK_INFO_PLIST_PATH", "OPENCV_XCFRAMEWORK_IOS_DEVICE_FILE_PATHS", "OPENCV_XCFRAMEWORK_IOS_SIMULATOR_FILE_PATHS", ) _OPENCV_XCFRAMEWORK_DIR_NAME = "opencv2.xcframework" _OPENCV_FRAMEWORK_DIR_NAME = "opencv2.framework" _OPENCV_SIMULATOR_PLATFORM_DIR_NAME = "ios-arm64_x86_64-simulator" _OPENCV_DEVICE_PLATFORM_DIR_NAME = "ios-arm64" def _select_headers_impl(ctx): # Should match with `/`. Othewise `ios-arm64` matches with `ios-arm64_x86-64` _files = [f for f in ctx.files.srcs if (f.basename.endswith(".h") or f.basename.endswith(".hpp")) and f.dirname.find(ctx.attr.platform + "/") != -1] return [DefaultInfo(files = depset(_files))] # This rule selects only the headers from an apple static xcframework filtered by # an input platform string. select_headers = rule( implementation = _select_headers_impl, attrs = { "srcs": attr.label_list(mandatory = True, allow_files = True), "platform": attr.string(mandatory = True), }, ) # This function declares and returns symlinks to the directories within each platform # in `opencv2.xcframework` expected to be present. # The symlinks are created according to the structure stipulated by apple xcframeworks # do that they can be correctly consumed by `apple_static_xcframework_import` rule. def _opencv2_directory_symlinks(ctx, platforms): basenames = ["Resources", "Headers", "Modules", "Versions/Current"] symlinks = [] for platform in platforms: symlinks = symlinks + [ ctx.actions.declare_symlink( _OPENCV_XCFRAMEWORK_DIR_NAME + "/{}/{}/{}".format(platform, _OPENCV_FRAMEWORK_DIR_NAME, name), ) for name in basenames ] return symlinks # This function declares and returns all the files for each platform expected # to be present in `opencv2.xcframework` after the unzipping action is run. def _opencv2_file_list(ctx, platform_filepath_lists): binary_name = "opencv2" output_files = [] binaries_to_symlink = [] for (platform, filepaths) in platform_filepath_lists: for path in filepaths: file = ctx.actions.declare_file(path) output_files.append(file) if path.endswith(binary_name): symlink_output = ctx.actions.declare_file( _OPENCV_XCFRAMEWORK_DIR_NAME + "/{}/{}/{}".format( platform, _OPENCV_FRAMEWORK_DIR_NAME, binary_name, ), ) binaries_to_symlink.append((symlink_output, file)) return output_files, binaries_to_symlink def _unzip_opencv_xcframework_impl(ctx): # Array to iterate over the various platforms to declare output files and # symlinks. platform_filepath_lists = [ (_OPENCV_SIMULATOR_PLATFORM_DIR_NAME, OPENCV_XCFRAMEWORK_IOS_SIMULATOR_FILE_PATHS), (_OPENCV_DEVICE_PLATFORM_DIR_NAME, OPENCV_XCFRAMEWORK_IOS_DEVICE_FILE_PATHS), ] # Gets an exhaustive list of output files which are present in the xcframework. # Also gets array of `(binary simlink, binary)` pairs which are to be symlinked # using `ctx.actions.symlink()`. output_files, binaries_to_symlink = _opencv2_file_list(ctx, platform_filepath_lists) output_files.append(ctx.actions.declare_file(OPENCV_XCFRAMEWORK_INFO_PLIST_PATH)) # xcframeworks have a directory structure in which the `opencv2.framework` folders for each # platform contain directories which are symlinked to the respective folders of the version # in use. Simply unzipping the zip of the framework will not make Bazel treat these # as symlinks. They have to be explicity declared as symlinks using `ctx.actions.declare_symlink()`. directory_symlinks = _opencv2_directory_symlinks( ctx, [_OPENCV_SIMULATOR_PLATFORM_DIR_NAME, _OPENCV_DEVICE_PLATFORM_DIR_NAME], ) output_files = output_files + directory_symlinks args = ctx.actions.args() # Add the path of the zip file to be unzipped as an argument to be passed to # `run_shell` action. args.add(ctx.file.zip_file.path) # Add the path to the directory in which the framework is to be unzipped to. args.add(ctx.file.zip_file.dirname) ctx.actions.run_shell( inputs = [ctx.file.zip_file], outputs = output_files, arguments = [args], progress_message = "Unzipping %s" % ctx.file.zip_file.short_path, command = "unzip -qq $1 -d $2", ) # The symlinks of the opencv2 binaries for each platform in the xcframework # have to be symlinked using the `ctx.actions.symlink` unlike the directory # symlinks which can be expected to be valid when unzipping is completed. # Otherwise, when tests are run, the linker complaints that the binary is # not found. binary_symlink_files = [] for (symlink_output, binary_file) in binaries_to_symlink: ctx.actions.symlink(output = symlink_output, target_file = binary_file) binary_symlink_files.append(symlink_output) # Return all the declared output files and symlinks as the output of this # rule. return [DefaultInfo(files = depset(output_files + binary_symlink_files))] # This rule unzips an `opencv2.xcframework.zip` created by a genrule that # invokes a python script in the opencv 4.5.1 github archive. # It returns all the contents of opencv2.xcframework as a list of files in the # output. This rule works by explicitly declaring files at hardcoded # paths in the opencv2 xcframework bundle which are expected to be present when # the zip file is unzipped. This is a prerequisite since the outputs of this rule # will be consumed by apple_static_xcframework_import which can only take a list # of files as inputs. unzip_opencv_xcframework = rule( implementation = _unzip_opencv_xcframework_impl, attrs = { "zip_file": attr.label(mandatory = True, allow_single_file = True), }, )