Add iteration limit control to planned comprehensions

PiperOrigin-RevId: 845589739

Author: l46kok

common/exceptions/BUILD.bazel

@@ -40,3 +40,9 @@ java_library(
     # used_by_android
     exports = ["//common/src/main/java/dev/cel/common/exceptions:invalid_argument"],
 )
+
+java_library(
+    name = "iteration_budget_exceeded",
+    # used_by_android
+    exports = ["//common/src/main/java/dev/cel/common/exceptions:iteration_budget_exceeded"],
+)

common/src/main/java/dev/cel/common/exceptions/BUILD.bazel

@@ -85,3 +85,16 @@ java_library(
         "//common/annotations",
     ],
 )
+
+java_library(
+    name = "iteration_budget_exceeded",
+    srcs = ["CelIterationLimitExceededException.java"],
+    # used_by_android
+    tags = [
+    ],
+    deps = [
+        "//common:error_codes",
+        "//common:runtime_exception",
+        "//common/annotations",
+    ],
+)

common/src/main/java/dev/cel/common/exceptions/CelIterationLimitExceededException.java

@@ -0,0 +1,31 @@
+// Copyright 2025 Google LLC
+//
+// 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
+//
+//      https://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.
+
+package dev.cel.common.exceptions;
+
+import dev.cel.common.CelErrorCode;
+import dev.cel.common.CelRuntimeException;
+import dev.cel.common.annotations.Internal;
+import java.util.Locale;
+
+/** Indicates that the iteration budget for a comprehension has been exceeded. */
+@Internal
+public final class CelIterationLimitExceededException extends CelRuntimeException {
+
+  public CelIterationLimitExceededException(int budget) {
+    super(
+        String.format(Locale.US, "Iteration budget exceeded: %d", budget),
+        CelErrorCode.ITERATION_BUDGET_EXCEEDED);
+  }
+}

common/src/main/java/dev/cel/common/values/CelValueConverter.java

@@ -33,7 +33,7 @@
 @SuppressWarnings("unchecked") // Unchecked cast of generics due to type-erasure (ex: MapValue).
 @Internal
 @Immutable
-abstract class CelValueConverter {
+public abstract class CelValueConverter {
 
   /** Adapts a {@link CelValue} to a plain old Java Object. */
   public Object unwrap(CelValue celValue) {

runtime/BUILD.bazel

@@ -255,3 +255,11 @@ java_library(
     visibility = ["//:internal"],
     exports = ["//runtime/src/main/java/dev/cel/runtime:metadata"],
 )
+
+java_library(
+    name = "concatenated_list_view",
+    visibility = ["//:internal"],
+    exports = [
+        "//runtime/src/main/java/dev/cel/runtime:concatenated_list_view",
+    ],
+)

runtime/src/main/java/dev/cel/runtime/AccumulatedUnknowns.java

@@ -2,7 +2,7 @@
 //
 // 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 aj
+// You may obtain a copy of the License at
 //
 //      https://www.apache.org/licenses/LICENSE-2.0
 //

runtime/src/main/java/dev/cel/runtime/BUILD.bazel

@@ -1142,7 +1142,9 @@ java_library(
     name = "concatenated_list_view",
     srcs = ["ConcatenatedListView.java"],
     # used_by_android
-    visibility = ["//visibility:private"],
+    tags = [
+    ],
+    deps = ["//common/annotations"],
 )
 
 java_library(

runtime/src/main/java/dev/cel/runtime/CelEvaluationExceptionBuilder.java

@@ -83,10 +83,16 @@ public static CelEvaluationExceptionBuilder newBuilder(String message, Object...
    */
   @Internal
   public static CelEvaluationExceptionBuilder newBuilder(CelRuntimeException celRuntimeException) {
+    // TODO: Temporary until migration is complete.
     Throwable cause = celRuntimeException.getCause();
-    return new CelEvaluationExceptionBuilder(cause.getMessage())
-        .setCause(cause)
-        .setErrorCode(celRuntimeException.getErrorCode());
+    String message =
+        cause == null
+            ? celRuntimeException.getMessage()
+            : celRuntimeException.getCause().getMessage();
+
+    return new CelEvaluationExceptionBuilder(message)
+        .setErrorCode(celRuntimeException.getErrorCode())
+        .setCause(cause);
   }
 
   private CelEvaluationExceptionBuilder(String message) {

runtime/src/main/java/dev/cel/runtime/ConcatenatedListView.java

@@ -2,7 +2,7 @@
 //
 // 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 aj
+// You may obtain a copy of the License at
 //
 //      https://www.apache.org/licenses/LICENSE-2.0
 //
@@ -14,6 +14,7 @@
 
 package dev.cel.runtime;
 
+import dev.cel.common.annotations.Internal;
 import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -27,16 +28,20 @@
  * comprehensions that dispatch `add_list` to concat N lists together).
  *
  * <p>This does not support any of the standard list operations from {@link java.util.List}.
+ *
+
+ * <p>CEL Library Internals. Do Not Use.
  */
-final class ConcatenatedListView<E> extends AbstractList<E> {
+@Internal
+public final class ConcatenatedListView<E> extends AbstractList<E> {
   private final List<List<? extends E>> sourceLists;
   private int totalSize = 0;
 
   ConcatenatedListView() {
     this.sourceLists = new ArrayList<>();
   }
 
-  ConcatenatedListView(Collection<? extends E> collection) {
+  public ConcatenatedListView(Collection<? extends E> collection) {
     this();
     addAll(collection);
   }

runtime/src/main/java/dev/cel/runtime/planner/Attribute.java

@@ -14,64 +14,13 @@
 
 package dev.cel.runtime.planner;
 
-
-import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.Immutable;
-import dev.cel.common.types.CelTypeProvider;
-import dev.cel.common.types.TypeType;
 import dev.cel.runtime.GlobalResolver;
 
+/** Represents a resolvable symbol or path (such as a variable or a field selection). */
 @Immutable
 interface Attribute {
-  Object resolve(GlobalResolver ctx);
-
-  final class MaybeAttribute implements Attribute {
-    private final ImmutableList<Attribute> attributes;
-
-    @Override
-    public Object resolve(GlobalResolver ctx) {
-      for (Attribute attr : attributes) {
-        Object value = attr.resolve(ctx);
-        if (value != null) {
-          return value;
-        }
-      }
-
-      // TODO: Handle unknowns
-      throw new UnsupportedOperationException("Unknown attributes is not supported yet");
-    }
-
-    MaybeAttribute(ImmutableList<Attribute> attributes) {
-      this.attributes = attributes;
-    }
-  }
-
-  final class NamespacedAttribute implements Attribute {
-    private final ImmutableList<String> namespacedNames;
-    private final CelTypeProvider typeProvider;
-
-    @Override
-    public Object resolve(GlobalResolver ctx) {
-      for (String name : namespacedNames) {
-        Object value = ctx.resolve(name);
-        if (value != null) {
-          // TODO: apply qualifiers
-          return value;
-        }
-
-        TypeType type = typeProvider.findType(name).map(TypeType::create).orElse(null);
-        if (type != null) {
-          return type;
-        }
-      }
-
-      // TODO: Handle unknowns
-      throw new UnsupportedOperationException("Unknown attributes is not supported yet");
-    }
+  Object resolve(GlobalResolver ctx, ExecutionFrame frame);
 
-    NamespacedAttribute(CelTypeProvider typeProvider, ImmutableList<String> namespacedNames) {
-      this.typeProvider = typeProvider;
-      this.namespacedNames = namespacedNames;
-    }
-  }
+  Attribute addQualifier(Qualifier qualifier);
 }