Refactor: Pass ActivationInterface to CEL function implementations

This change modifies the `cel::Function::Invoke` signature to include a nullable `cel::ActivationInterface*`. This allows custom CEL function implementations to access the current activation context.

PiperOrigin-RevId: 823026720

Author: zeitgeist87

eval/compiler/BUILD

@@ -198,6 +198,7 @@ cc_test(
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:status_matchers",
+        "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/types:span",
         "@com_google_cel_spec//proto/cel/expr:checked_cc_proto",

eval/compiler/flat_expr_builder_test.cc

@@ -31,6 +31,7 @@
 #include "absl/container/flat_hash_map.h"
 #include "absl/status/status.h"
 #include "absl/status/status_matchers.h"
+#include "absl/status/statusor.h"
 #include "absl/strings/str_split.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/span.h"
@@ -2394,10 +2395,10 @@ struct ConstantFoldingTestCase {
 };
 
 class UnknownFunctionImpl : public cel::Function {
-  absl::StatusOr<Value> Invoke(absl::Span<const Value> args,
-                               const google::protobuf::DescriptorPool* absl_nonnull,
-                               google::protobuf::MessageFactory* absl_nonnull,
-                               google::protobuf::Arena* absl_nonnull) const override {
+  absl::StatusOr<Value> Invoke(
+      absl::Span<const Value> args, const google::protobuf::DescriptorPool* absl_nonnull,
+      google::protobuf::MessageFactory* absl_nonnull, google::protobuf::Arena* absl_nonnull,
+      const cel::ActivationInterface* absl_nullable) const override {
     return cel::UnknownValue();
   }
 };

eval/eval/function_step.cc

@@ -178,9 +178,9 @@ inline absl::StatusOr<Value> Invoke(
     const cel::FunctionOverloadReference& overload, int64_t expr_id,
     absl::Span<const cel::Value> args, ExecutionFrameBase& frame) {
   CEL_ASSIGN_OR_RETURN(
-      Value result,
-      overload.implementation.Invoke(args, frame.descriptor_pool(),
-                                     frame.message_factory(), frame.arena()));
+      Value result, overload.implementation.Invoke(
+                        args, frame.descriptor_pool(), frame.message_factory(),
+                        frame.arena(), &frame.activation()));
 
   if (frame.unknown_function_results_enabled() &&
       IsUnknownFunctionResultError(result)) {

eval/public/BUILD

@@ -197,6 +197,7 @@ cc_library(
         "//common:value",
         "//eval/internal:interop",
         "//internal:status_macros",
+        "//runtime:activation_interface",
         "//runtime:function",
         "@com_google_absl//absl/base:nullability",
         "@com_google_absl//absl/status",

eval/public/cel_function.cc

@@ -10,6 +10,7 @@
 #include "eval/internal/interop.h"
 #include "eval/public/cel_value.h"
 #include "internal/status_macros.h"
+#include "runtime/activation_interface.h"
 #include "google/protobuf/arena.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/message.h"
@@ -57,7 +58,8 @@ absl::StatusOr<Value> CelFunction::Invoke(
     absl::Span<const cel::Value> arguments,
     const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,
     google::protobuf::MessageFactory* absl_nonnull message_factory,
-    google::protobuf::Arena* absl_nonnull arena) const {
+    google::protobuf::Arena* absl_nonnull arena,
+    const cel::ActivationInterface* absl_nullable activation) const {
   std::vector<CelValue> legacy_args;
   legacy_args.reserve(arguments.size());
 

eval/public/cel_function.h

@@ -69,7 +69,8 @@ class CelFunction : public ::cel::Function {
       absl::Span<const cel::Value> arguments,
       const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,
       google::protobuf::MessageFactory* absl_nonnull message_factory,
-      google::protobuf::Arena* absl_nonnull arena) const override;
+      google::protobuf::Arena* absl_nonnull arena,
+      const cel::ActivationInterface* absl_nullable activation) const override;
 
   // CelFunction descriptor
   const CelFunctionDescriptor& descriptor() const { return descriptor_; }

eval/public/cel_function_registry.cc

@@ -50,7 +50,7 @@ class ProxyToModernCelFunction : public CelFunction {
         auto modern_result,
         implementation_->Invoke(
             modern_args, google::protobuf::DescriptorPool::generated_pool(),
-            google::protobuf::MessageFactory::generated_factory(), arena));
+            google::protobuf::MessageFactory::generated_factory(), arena, nullptr));
 
     *result = cel::interop_internal::ModernValueToLegacyValueOrDie(
         arena, modern_result);

runtime/BUILD

@@ -500,13 +500,11 @@ cc_library(
         ":function",
         ":register_function_helper",
         "//common:function_descriptor",
-        "//common:kind",
         "//common:value",
         "//internal:status_macros",
         "//runtime/internal:function_adapter",
         "@com_google_absl//absl/base:nullability",
         "@com_google_absl//absl/functional:any_invocable",
-        "@com_google_absl//absl/functional:bind_front",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
@@ -526,10 +524,12 @@ cc_test(
         "//common:value",
         "//common:value_testing",
         "//internal:testing",
+        "@com_google_absl//absl/base:nullability",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/time",
+        "@com_google_protobuf//:protobuf",
     ],
 )
 

runtime/activation_test.cc

@@ -66,10 +66,10 @@ class FunctionImpl : public cel::Function {
  public:
   FunctionImpl() = default;
 
-  absl::StatusOr<Value> Invoke(absl::Span<const Value> args,
-                               const google::protobuf::DescriptorPool* absl_nonnull,
-                               google::protobuf::MessageFactory* absl_nonnull,
-                               google::protobuf::Arena* absl_nonnull) const override {
+  absl::StatusOr<Value> Invoke(
+      absl::Span<const Value> args, const google::protobuf::DescriptorPool* absl_nonnull,
+      google::protobuf::MessageFactory* absl_nonnull, google::protobuf::Arena* absl_nonnull,
+      const ActivationInterface* absl_nullable) const override {
     return NullValue();
   }
 };

runtime/function.h

@@ -25,6 +25,8 @@
 
 namespace cel {
 
+class ActivationInterface;
+
 // Interface for extension functions.
 //
 // The host for the CEL environment may provide implementations to define custom
@@ -47,7 +49,8 @@ class Function {
       absl::Span<const Value> args,
       const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,
       google::protobuf::MessageFactory* absl_nonnull message_factory,
-      google::protobuf::Arena* absl_nonnull arena) const = 0;
+      google::protobuf::Arena* absl_nonnull arena,
+      const ActivationInterface* absl_nullable activation) const = 0;
 };
 
 }  // namespace cel