Generate separate pod for Core ML delegate

PiperOrigin-RevId: 311651255
Change-Id: I7ba8755d447674fa8d20935b0c9815a5406b879f

tensorflow/lite/experimental/delegates/coreml/BUILD

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ==============================================================================
-
 package(default_visibility = [
     "//visibility:public",
 ])
@@ -46,6 +45,11 @@ objc_library(
     name = "coreml_delegate",
     srcs = ["coreml_delegate.mm"],
     hdrs = ["coreml_delegate.h"],
+    module_name = "TensorFlowLiteCCoreML",
+    # By setting CoreML as weak_framework, the TensorFlow Lite can be built for older iOS versions.
+    weak_sdk_frameworks = [
+        "CoreML",
+    ],
     deps = [
         ":coreml_delegate_kernel",
         ":mlmodel_proto_cc",

tensorflow/lite/experimental/ios/BUILD.apple

@@ -24,7 +24,6 @@ genrule(
 
 TFL_FRAMEWORK_HDRS = [
     "//tensorflow/lite/delegates/gpu:metal_delegate.h",
-    ":coreml_delegate.h",
     "//tensorflow/lite/c:c_api.h",
     "//tensorflow/lite/c:common.h",
 ]
@@ -58,16 +57,35 @@ ios_static_framework(
     ],
 )
 
+# This target builds the Core ML delegate as a separate static framework, which
+# does not include the TensorFlow Lite runtime. As this target does not contain
+# TensorFlow Lite runtime, it is intended to be linked along with the
+# TensorFlowLiteC framework above in a composable way.
+#
+# bazel build -c opt --config=ios_fat //tensorflow/lite/experimental/ios:TensorFlowLiteCCoreMl_framework
+ios_static_framework(
+    name = "TensorFlowLiteCCoreML_framework",
+    hdrs = [
+        ":coreml_delegate.h",
+    ],
+    avoid_deps = [
+        ":tensorflow_lite_c",
+    ],
+    bundle_name = "TensorFlowLiteCCoreML",
+    minimum_os_version = TFL_MINIMUM_OS_VERSION,
+    deps = [
+        "//tensorflow/lite/experimental/delegates/coreml:coreml_delegate",
+    ],
+)
+
 cc_library(
     name = "tensorflow_lite_c",
     hdrs = [
         "//tensorflow/lite/c:c_api.h",
         "//tensorflow/lite/c:common.h",
         "//tensorflow/lite/delegates/gpu:metal_delegate.h",
-        "//tensorflow/lite/experimental/delegates/coreml:coreml_delegate.h",
     ],
     linkopts = [
-        "-Wl,-weak_framework,CoreML",
         "-Wl,-weak_framework,Metal",
     ],
     tags = [
@@ -77,7 +95,6 @@ cc_library(
     deps = [
         "//tensorflow/lite/c:c_api",
         "//tensorflow/lite/delegates/gpu:metal_delegate",
-        "//tensorflow/lite/experimental/delegates/coreml:coreml_delegate",
     ],
 )
 

tensorflow/lite/experimental/ios/TensorFlowLiteC.podspec.template

@@ -19,6 +19,16 @@ Pod::Spec.new do |s|
 
   s.module_name = 'TensorFlowLiteC'
   s.library = 'c++'
-  s.vendored_frameworks = 'Frameworks/TensorFlowLiteC.framework'
+
-  s.weak_frameworks = 'CoreML'
+  s.default_subspec = 'Core'
+
+  s.subspec 'Core' do |core|
+    core.vendored_frameworks = 'Frameworks/TensorFlowLiteC.framework'
+  end
+
+  s.subspec 'CoreML' do |coreml|
+    coreml.weak_framework = 'CoreML'
+    coreml.dependency 'TensorFlowLiteC/Core'
+    coreml.vendored_frameworks = 'Frameworks/TensorFlowLiteCCoreML.framework'
+  end
 end

tensorflow/lite/experimental/swift/BUILD.apple

@@ -10,6 +10,19 @@ package(
     licenses = ["notice"],  # Apache 2.0
 )
 
+# TODO(b/153554551): investigate if separate delegate libraries can be made with same module_name
+# If you don't need delegates and want to reduce size of the app, you can exclude Metal/Core ML
+# delegate related dependencies from the rule.
+# For example, if you don't want to use Core ML delegate:
+# 1. add `exclude = ["Sources/CoreMLDelegate.swift"]` to `glob`, so that `srcs` would look like this:
+#    ```
+#    srcs = glob(
+#        ["Sources/*.swift"],
+#        exclude = ["Sources/CoreMLDelegate.swift"],
+#    ),
+# 2. remove "-Wl,-weak_framework,CoreML" from `linkopts`
+# 3. remove "...:coreml_delegate" from `deps`
+
 swift_library(
     name = "TensorFlowLite",
     srcs = glob(["Sources/*.swift"]),
@@ -21,6 +34,7 @@ swift_library(
     tags = TFL_DEFAULT_TAGS,
     visibility = ios_visibility_whitelist(),
     deps = [
+        "//tensorflow/lite/experimental/delegates/coreml:coreml_delegate",
         "//tensorflow/lite/experimental/ios:tensorflow_lite_c",
     ],
 )

tensorflow/lite/experimental/swift/Sources/CoreMLDelegate.swift

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import TensorFlowLiteC
+import TensorFlowLiteCCoreML
 
 /// A delegate that uses the `Core ML` framework for performing TensorFlow Lite graph operations.
 ///

tensorflow/lite/experimental/swift/TensorFlowLiteSwift-nightly.podspec

@@ -20,8 +20,20 @@ Pod::Spec.new do |s|
 
   tfl_dir = 'tensorflow/lite/'
   swift_dir = tfl_dir + 'experimental/swift/'
-  s.source_files = swift_dir + 'Sources/*.swift'
+
-  s.dependency 'TensorFlowLiteC', "~> #{s.version}"
+  s.default_subspec = 'Core'
+
+  s.subspec 'Core' do |core|
+    core.dependency 'TensorFlowLiteC', "#{s.version}"
+    core.source_files = swift_dir + 'Sources/*.swift'
+    core.exclude_files = swift_dir + 'Sources/CoreMLDelegate.swift'
+  end
+
+  s.subspec 'CoreML' do |coreml|
+    coreml.source_files = swift_dir + 'Sources/CoreMLDelegate.swift'
+    coreml.dependency 'TensorFlowLiteC/CoreML', "#{s.version}"
+    coreml.dependency 'TensorFlowLiteSwift/Core', "#{s.version}"
+  end
 
   s.test_spec 'Tests' do |ts|
     ts.source_files = swift_dir + 'Tests/*.swift'

tensorflow/lite/experimental/swift/TensorFlowLiteSwift.podspec.template

@@ -20,8 +20,20 @@ Pod::Spec.new do |s|
 
   tfl_dir = 'tensorflow/lite/'
   swift_dir = tfl_dir + 'experimental/swift/'
-  s.source_files = swift_dir + 'Sources/*.swift'
+
-  s.dependency 'TensorFlowLiteC', '~> 0.0.1-nightly'
+  s.default_subspec = 'Core'
+
+  s.subspec 'Core' do |core|
+    core.dependency 'TensorFlowLiteC', "#{s.version}"
+    core.source_files = swift_dir + 'Sources/*.swift'
+    core.exclude_files = swift_dir + 'Sources/CoreMLDelegate.swift'
+  end
+
+  s.subspec 'CoreML' do |coreml|
+    coreml.source_files = swift_dir + 'Sources/CoreMLDelegate.swift'
+    coreml.dependency 'TensorFlowLiteC/CoreML', "#{s.version}"
+    coreml.dependency 'TensorFlowLiteSwift/Core', "#{s.version}"
+  end
 
   s.test_spec 'Tests' do |ts|
     ts.source_files = swift_dir + 'Tests/*.swift'