Change CelExtension definition to return cel::CompilerLibrary.

This change updates the CelExtension interface in cel-python to return a cel::CompilerLibrary instead of implementing a ConfigureCompiler method. This
 simplifies the integration of C++ extensions, allowing the temporary adapter classes used to bridge the old interface to be removed.

PiperOrigin-RevId: 896169754

Author: dmitriplotnikov

README.md

@@ -234,36 +234,34 @@ expr = cel_env.compile("my_func(1)")
 
 To define a custom extension in C++, define a class extending
 `cel_python::CelExtension`. There are two methods you will need to implement:
-`ConfigureCompiler` and `ConfigureRuntime`. The implementations of these methods
-use the same API as extensions written for the C++ CEL runtime. In fact,
+`GetCompilerLibrary` and `ConfigureRuntime`. The implementations of these
+methods use the same API as extensions written for the C++ CEL runtime. In fact,
 extensions written for the C++ runtime can be used unchanged with
 cel-expr-python - you would just need to write a trivial wrapper class invoking
 the registration functions defined by the C++ extension.
 
-```cpp
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const proto2::DescriptorPool& descriptor_pool);
-```
 This method adds extension function definitions to the provided
 `CompilerBuilder`, for example:
 
 ```cpp
-absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const proto2::DescriptorPool& descriptor_pool) {
-    CEL_PYTHON_ASSIGN_OR_RETURN(
-        auto func_translate,
-        cel::MakeFunctionDecl("translate",
-            cel::MakeMemberOverloadDecl("translate_inst",
-                                /*return_type=*/cel::StringType(),
-                                /*target=*/cel::StringType(),
-                                /*from_lang=*/cel::StringType(),
-                                /*to_lang=*/cel::StringType())));
-    CEL_PYTHON_RETURN_IF_ERROR(
-        compiler_builder.GetCheckerBuilder().AddFunction(func_translate));
-    return absl::OkStatus();
-}
+  cel::CompilerLibrary GetCompilerLibrary() {
+    return cel::CompilerLibrary(
+        "translate-ext",
+        [](cel::TypeCheckerBuilder& checker_builder) -> absl::Status {
+          CEL_PYTHON_ASSIGN_OR_RETURN(
+              auto func_translate,
+              cel::MakeFunctionDecl(
+                  "translate",
+                  cel::MakeMemberOverloadDecl("translate_inst",
+                                              /*return_type=*/cel::StringType(),
+                                              /*target=*/cel::StringType(),
+                                              /*from_lang=*/cel::StringType(),
+                                              /*to_lang=*/cel::StringType())));
+          CEL_PYTHON_RETURN_IF_ERROR(
+              checker_builder.AddFunction(func_translate));
+          return absl::OkStatus();
+        });
+  }
 ```
 
 The other method registers the actual implementation

cel_expr_python/cel_extension.h

@@ -24,7 +24,6 @@
 #include "compiler/compiler.h"
 #include "runtime/runtime_builder.h"
 #include "runtime/runtime_options.h"
-#include "google/protobuf/descriptor.h"
 
 #if defined(__cpp_exceptions) || defined(__EXCEPTIONS)
 // This include causes many issues if included in C++ environments that don't
@@ -42,10 +41,8 @@ class CelExtension {
   explicit CelExtension(std::string name) : name_(std::move(name)) {};
   virtual ~CelExtension() = default;
 
-  virtual absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) {
-    return absl::OkStatus();
+  virtual cel::CompilerLibrary GetCompilerLibrary() {
+    return cel::CompilerLibrary(name_, nullptr, nullptr);
   }
 
   virtual absl::Status ConfigureRuntime(cel::RuntimeBuilder& runtime_builder,
@@ -76,11 +73,11 @@ class CelExtension {
 //
 //   CEL_EXTENSION_MODULE(sample_cel_ext, SampleCelExtension);
 //
-#define CEL_EXTENSION_MODULE(module_name, class_name)                        \
-  PYBIND11_MODULE(module_name, m) {                                          \
-    pybind11::module_::import(CEL_MODULE_NAME);                           \
+#define CEL_EXTENSION_MODULE(module_name, class_name)                      \
+  PYBIND11_MODULE(module_name, m) {                                        \
+    pybind11::module_::import(CEL_MODULE_NAME);                            \
     pybind11::class_<class_name, cel_python::CelExtension>(m, #class_name) \
-        .def(pybind11::init<>());                                            \
+        .def(pybind11::init<>());                                          \
   }
 
 }  // namespace cel_python

cel_expr_python/ext/BUILD

@@ -13,10 +13,8 @@ pybind_extension(
     visibility = ["//visibility:public"],
     deps = [
         "//cel_expr_python:cel_extension",
-        "@com_google_absl//absl/status",
         "@com_google_cel_cpp//compiler",
         "@com_google_cel_cpp//extensions:bindings_ext",
-        "@com_google_protobuf//:protobuf",
     ],
 )
 
@@ -32,12 +30,10 @@ pybind_extension(
     deps = [
         "//cel_expr_python:cel_extension",
         "@com_google_absl//absl/status",
-        "@com_google_cel_cpp//checker:type_checker_builder",
         "@com_google_cel_cpp//compiler",
         "@com_google_cel_cpp//extensions:encoders",
         "@com_google_cel_cpp//runtime:runtime_builder",
         "@com_google_cel_cpp//runtime:runtime_options",
-        "@com_google_protobuf//:protobuf",
     ],
 )
 
@@ -52,25 +48,12 @@ pybind_extension(
     visibility = ["//visibility:public"],
     deps = [
         "//cel_expr_python:cel_extension",
-        "//cel_expr_python:status_macros",
-        "@com_google_absl//absl/base:nullability",
         "@com_google_absl//absl/status",
-        "@com_google_absl//absl/status:statusor",
-        "@com_google_absl//absl/types:span",
-        "@com_google_cel_cpp//checker:type_checker_builder",
-        "@com_google_cel_cpp//common:decl",
-        "@com_google_cel_cpp//common:function_descriptor",
-        "@com_google_cel_cpp//common:kind",
-        "@com_google_cel_cpp//common:type",
-        "@com_google_cel_cpp//common:value",
         "@com_google_cel_cpp//compiler",
         "@com_google_cel_cpp//extensions:math_ext",
         "@com_google_cel_cpp//extensions:math_ext_decls",
-        "@com_google_cel_cpp//runtime:function",
         "@com_google_cel_cpp//runtime:runtime_builder",
         "@com_google_cel_cpp//runtime:runtime_options",
-        "@com_google_cel_spec//proto/cel/expr:checked_cc_proto",
-        "@com_google_protobuf//:protobuf",
     ],
 )
 
@@ -91,7 +74,6 @@ pybind_extension(
         "@com_google_cel_cpp//runtime:optional_types",
         "@com_google_cel_cpp//runtime:runtime_builder",
         "@com_google_cel_cpp//runtime:runtime_options",
-        "@com_google_protobuf//:protobuf",
     ],
 )
 
@@ -106,10 +88,8 @@ pybind_extension(
     visibility = ["//visibility:public"],
     deps = [
         "//cel_expr_python:cel_extension",
-        "@com_google_absl//absl/status",
         "@com_google_cel_cpp//compiler",
         "@com_google_cel_cpp//extensions:proto_ext",
-        "@com_google_protobuf//:protobuf",
     ],
 )
 
@@ -129,6 +109,5 @@ pybind_extension(
         "@com_google_cel_cpp//extensions:strings",
         "@com_google_cel_cpp//runtime:runtime_builder",
         "@com_google_cel_cpp//runtime:runtime_options",
-        "@com_google_protobuf//:protobuf",
     ],
 )

cel_expr_python/ext/ext_bindings.cc

@@ -12,23 +12,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "absl/status/status.h"
 #include "compiler/compiler.h"
 #include "extensions/bindings_ext.h"
 #include "cel_expr_python/cel_extension.h"
-#include "google/protobuf/descriptor.h"
 
 namespace cel_python {
 
 class ExtBindings : public CelExtension {
  public:
   explicit ExtBindings() : CelExtension("cel.lib.ext.cel.bindings") {}
 
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) override {
-    return compiler_builder.AddLibrary(
-        cel::extensions::BindingsCompilerLibrary());
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::extensions::BindingsCompilerLibrary();
   }
 };
 

cel_expr_python/ext/ext_encoders.cc

@@ -13,25 +13,20 @@
 // limitations under the License.
 
 #include "absl/status/status.h"
-#include "checker/type_checker_builder.h"
 #include "compiler/compiler.h"
 #include "extensions/encoders.h"
 #include "runtime/runtime_builder.h"
 #include "runtime/runtime_options.h"
 #include "cel_expr_python/cel_extension.h"
-#include "google/protobuf/descriptor.h"
 
 namespace cel_python {
 
 class ExtEncoders : public CelExtension {
  public:
   explicit ExtEncoders() : CelExtension("cel.lib.ext.encoders") {}
 
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) override {
-    return compiler_builder.GetCheckerBuilder().AddLibrary(
-        cel::extensions::EncodersCheckerLibrary());
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::extensions::EncodersCompilerLibrary();
   }
 
   absl::Status ConfigureRuntime(cel::RuntimeBuilder& runtime_builder,

cel_expr_python/ext/ext_math.cc

@@ -19,26 +19,21 @@
 #include "runtime/runtime_builder.h"
 #include "runtime/runtime_options.h"
 #include "cel_expr_python/cel_extension.h"
-#include "cel_expr_python/status_macros.h"
-#include "google/protobuf/descriptor.h"
 
 namespace cel_python {
 
 class ExtMath : public CelExtension {
  public:
   explicit ExtMath() : CelExtension("cel.lib.ext.math") {}
 
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) override {
-    return compiler_builder.AddLibrary(cel::extensions::MathCompilerLibrary());
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::extensions::MathCompilerLibrary();
   }
 
   absl::Status ConfigureRuntime(cel::RuntimeBuilder& runtime_builder,
                                 const cel::RuntimeOptions& opts) override {
-    CEL_PYTHON_RETURN_IF_ERROR(cel::extensions::RegisterMathExtensionFunctions(
-        runtime_builder.function_registry(), opts));
-    return absl::OkStatus();
+    return cel::extensions::RegisterMathExtensionFunctions(
+        runtime_builder.function_registry(), opts);
   }
 };
 

cel_expr_python/ext/ext_optional.cc

@@ -19,18 +19,15 @@
 #include "runtime/runtime_builder.h"
 #include "runtime/runtime_options.h"
 #include "cel_expr_python/cel_extension.h"
-#include "google/protobuf/descriptor.h"
 
 namespace cel_python {
 
 class ExtOptional : public CelExtension {
  public:
   explicit ExtOptional() : CelExtension("optional") {}
 
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) override {
-    return compiler_builder.AddLibrary(cel::OptionalCompilerLibrary());
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::OptionalCompilerLibrary();
   }
 
   absl::Status ConfigureRuntime(cel::RuntimeBuilder& runtime_builder,

cel_expr_python/ext/ext_proto.cc

@@ -12,23 +12,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "absl/status/status.h"
 #include "compiler/compiler.h"
 #include "extensions/proto_ext.h"
 #include "cel_expr_python/cel_extension.h"
-#include "google/protobuf/descriptor.h"
 
 namespace cel_python {
 
 class ExtProto : public CelExtension {
  public:
   explicit ExtProto() : CelExtension("cel.lib.ext.proto") {}
 
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) override {
-    return compiler_builder.AddLibrary(
-        cel::extensions::ProtoExtCompilerLibrary());
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::extensions::ProtoExtCompilerLibrary();
   }
 };
 

cel_expr_python/ext/ext_string.cc

@@ -18,19 +18,15 @@
 #include "runtime/runtime_builder.h"
 #include "runtime/runtime_options.h"
 #include "cel_expr_python/cel_extension.h"
-#include "google/protobuf/descriptor.h"
 
 namespace cel_python {
 
 class ExtString : public CelExtension {
  public:
   explicit ExtString() : CelExtension("cel.lib.ext.string") {}
 
-  absl::Status ConfigureCompiler(
-      cel::CompilerBuilder& compiler_builder,
-      const google::protobuf::DescriptorPool& descriptor_pool) override {
-    return compiler_builder.AddLibrary(
-        cel::extensions::StringsCompilerLibrary());
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::extensions::StringsCompilerLibrary();
   }
 
   absl::Status ConfigureRuntime(cel::RuntimeBuilder& runtime_builder,