Remove enableHiddenAccumulatorVar option

Hidden accumulator variable (@Result) is now unconditionally enabled across all parsers (Antlr and Pratt), matching cel-go and cel-cpp.

PiperOrigin-RevId: 981327426

Author: l46kok

common/src/main/java/dev/cel/common/CelOptions.java

@@ -68,8 +68,6 @@ public enum ProtoUnsetFieldOptions {
 
   public abstract boolean retainUnbalancedLogicalExpressions();
 
-  public abstract boolean enableHiddenAccumulatorVar();
-
   public abstract boolean enableQuotedIdentifierSyntax();
 
   public abstract boolean enablePrattParser();
@@ -144,7 +142,6 @@ public static Builder newBuilder() {
         .populateMacroCalls(false)
         .retainRepeatedUnaryOperators(false)
         .retainUnbalancedLogicalExpressions(false)
-        .enableHiddenAccumulatorVar(true)
         .enableQuotedIdentifierSyntax(true)
         .enablePrattParser(false)
         // Type-Checker options
@@ -262,16 +259,6 @@ public abstract static class Builder {
      */
     public abstract Builder retainUnbalancedLogicalExpressions(boolean value);
 
-    /**
-     * Enable the use of a hidden accumulator variable name.
-     *
-     * <p>This is a temporary option to transition to using an internal identifier for the
-     * accumulator variable used by builtin comprehension macros. When enabled, parses result in a
-     * semantically equivalent AST, but with a different accumulator variable that can't be directly
-     * referenced in the source expression.
-     */
-    public abstract Builder enableHiddenAccumulatorVar(boolean value);
-
     /**
      * Enable quoted identifier syntax.
      *

common/src/test/java/dev/cel/common/ast/CelExprFormatterTest.java

@@ -21,7 +21,6 @@
 import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelContainer;
 import dev.cel.common.CelFunctionDecl;
-import dev.cel.common.CelOptions;
 import dev.cel.common.CelOverloadDecl;
 import dev.cel.common.types.SimpleType;
 import dev.cel.common.types.StructTypeReference;
@@ -274,7 +273,6 @@ public void map() throws Exception {
   public void comprehension() throws Exception {
     CelCompiler celCompiler =
         CelCompilerFactory.standardCelCompilerBuilder()
-            .setOptions(CelOptions.current().enableHiddenAccumulatorVar(true).build())
             .setStandardMacros(CelStandardMacro.STANDARD_MACROS)
             .build();
     CelAbstractSyntaxTree ast = celCompiler.compile("[1, 2, 3].exists(x, x > 0)").getAst();

common/src/test/java/dev/cel/common/ast/CelExprVisitorTest.java

@@ -21,7 +21,6 @@
 import com.google.common.collect.ImmutableList;
 import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelContainer;
-import dev.cel.common.CelOptions;
 import dev.cel.common.Operator;
 import dev.cel.common.ast.CelExpr.CelCall;
 import dev.cel.common.ast.CelExpr.CelComprehension;
@@ -327,7 +326,6 @@ public void visitList() throws Exception {
   public void visitComprehension() throws Exception {
     CelCompiler celCompiler =
         CelCompilerFactory.standardCelCompilerBuilder()
-            .setOptions(CelOptions.current().enableHiddenAccumulatorVar(true).build())
             .setStandardMacros(CelStandardMacro.ALL)
             .build();
     CelAbstractSyntaxTree ast = celCompiler.compile("[1, 1].all(x, x == 1)").getAst();

common/src/test/java/dev/cel/common/navigation/CelNavigableExprVisitorTest.java

@@ -811,7 +811,6 @@ public void emptyMapConstruction_allNodesReturned() throws Exception {
   public void comprehension_preOrder_allNodesReturned() throws Exception {
     CelCompiler compiler =
         CelCompilerFactory.standardCelCompilerBuilder()
-            .setOptions(CelOptions.current().enableHiddenAccumulatorVar(true).build())
             .setStandardMacros(CelStandardMacro.EXISTS)
             .build();
     CelAbstractSyntaxTree ast = compiler.compile("[true].exists(i, i)").getAst();
@@ -873,7 +872,6 @@ public void comprehension_preOrder_allNodesReturned() throws Exception {
   public void comprehension_postOrder_allNodesReturned() throws Exception {
     CelCompiler compiler =
         CelCompilerFactory.standardCelCompilerBuilder()
-            .setOptions(CelOptions.current().enableHiddenAccumulatorVar(true).build())
             .setStandardMacros(CelStandardMacro.EXISTS)
             .build();
     CelAbstractSyntaxTree ast = compiler.compile("[true].exists(i, i)").getAst();
@@ -1011,7 +1009,6 @@ public void comprehension_postOrder_maxIdsSet() throws Exception {
   public void comprehension_allNodes_parentsPopulated() throws Exception {
     CelCompiler compiler =
         CelCompilerFactory.standardCelCompilerBuilder()
-            .setOptions(CelOptions.current().enableHiddenAccumulatorVar(true).build())
             .setStandardMacros(CelStandardMacro.EXISTS)
             .build();
     CelAbstractSyntaxTree ast = compiler.compile("[true].exists(i, i)").getAst();
@@ -1070,7 +1067,6 @@ public void comprehension_allNodes_parentsPopulated() throws Exception {
   public void comprehension_filterComprehension_allNodesReturned() throws Exception {
     CelCompiler compiler =
         CelCompilerFactory.standardCelCompilerBuilder()
-            .setOptions(CelOptions.current().enableHiddenAccumulatorVar(true).build())
             .setStandardMacros(CelStandardMacro.EXISTS)
             .build();
     CelAbstractSyntaxTree ast = compiler.compile("[true].exists(i, i)").getAst();

extensions/src/main/java/dev/cel/extensions/CelComprehensionsExtensions.java

@@ -495,7 +495,8 @@ private static CelExpr validatedIterationVariable(
     CelExpr arg = checkNotNull(argument);
     if (!isSimpleIdentifier(arg)) {
       return reportArgumentError(exprFactory, arg);
-    } else if (arg.exprKind().ident().name().equals("__result__")) {
+    } else if (arg.exprKind().ident().name().equals(exprFactory.getAccumulatorVarName())
+        || arg.exprKind().ident().name().equals("__result__")) {
       return reportAccumulatorOverwriteError(exprFactory, arg);
     } else {
       return arg;

optimizer/src/main/java/dev/cel/optimizer/AstMutator.java

@@ -714,7 +714,7 @@ private CelMutableExpr mangleIdentsInComprehensionExpr(
 
     comprehension.setIterVar(mangledComprehensionName.iterVarName());
 
-    // Most standard macros set accu_var as __result__, but not all (ex: cel.bind).
+    // Most standard macros set accu_var as @result, but not all (ex: cel.bind).
     if (comprehension.accuVar().equals(originalAccuVar)) {
       comprehension.setAccuVar(mangledComprehensionName.resultName());
     }

parser/src/main/java/dev/cel/parser/AntlrParser.java

@@ -129,8 +129,7 @@ final class AntlrParser extends CELBaseVisitor<CelExpr> {
           "var",
           "void",
           "while");
-  private static final String ACCUMULATOR_NAME = "__result__";
-  private static final String HIDDEN_ACCUMULATOR_NAME = "@result";
+  private static final String ACCUMULATOR_NAME = "@result";
 
   static CelValidationResult parse(
       CelSource source, CelOptions options, Collection<CelMacro> macros) {
@@ -151,10 +150,7 @@ static CelValidationResult parse(
     sourceInfo.setDescription(source.getDescription());
     ExprFactory exprFactory =
         new ExprFactory(
-            antlrParser,
-            sourceInfo,
-            options.enableHiddenAccumulatorVar() ? HIDDEN_ACCUMULATOR_NAME : ACCUMULATOR_NAME,
-            options.maxParseExpressionNodeCount());
+            antlrParser, sourceInfo, ACCUMULATOR_NAME, options.maxParseExpressionNodeCount());
     AntlrParser parserImpl = new AntlrParser(options, macros, sourceInfo, exprFactory);
     ErrorListener errorListener = new ErrorListener(exprFactory);
     antlrLexer.removeErrorListeners();

parser/src/main/java/dev/cel/parser/CelStandardMacro.java

@@ -307,7 +307,8 @@ private static CelExpr validatedIterationVariable(
     CelExpr arg = checkNotNull(argument);
     if (!isSimpleIdentifier(arg)) {
       return reportArgumentError(exprFactory, arg);
-    } else if (arg.exprKind().ident().name().equals("__result__")) {
+    } else if (arg.exprKind().ident().name().equals(exprFactory.getAccumulatorVarName())
+        || arg.exprKind().ident().name().equals("__result__")) {
       return reportAccumulatorOverwriteError(exprFactory, arg);
     } else {
       return arg;

parser/src/test/java/dev/cel/parser/CelMacroExprFactoryTest.java

@@ -63,7 +63,7 @@ public CelExpr reportError(CelIssue issue) {
 
     @Override
     public String getAccumulatorVarName() {
-      return "__result__";
+      return "@result";
     }
 
     @Override

parser/src/test/java/dev/cel/parser/CelParserParameterizedTest.java

@@ -50,7 +50,6 @@ public final class CelParserParameterizedTest extends BaselineTestCase {
           .populateMacroCalls(true)
           .enableOptionalSyntax(true)
           .enableQuotedIdentifierSyntax(true)
-          .enableHiddenAccumulatorVar(true)
           .build();
 
   private static final CelOptions OPTIONS_MAX_RECURSION_DEPTH_32 =
@@ -74,9 +73,6 @@ public final class CelParserParameterizedTest extends BaselineTestCase {
   private static final CelOptions OPTIONS_MAX_ERROR_RECOVERY_LIMIT_2 =
       OPTIONS.toBuilder().maxParseErrorRecoveryLimit(2).build();
 
-  private static final CelOptions OPTIONS_OLD_ACCU_VAR =
-      OPTIONS.toBuilder().enableHiddenAccumulatorVar(false).build();
-
   private static final ImmutableMap<String, CelMacro> MACROS =
       ImmutableMap.<String, CelMacro>builder()
           .putAll(
@@ -681,17 +677,6 @@ public void parser_errors() {
     runTest(OPTIONS_MAX_ERROR_RECOVERY_LIMIT_2, "[1 2 3 a b c]");
   }
 
-  @Test
-  public void parser_legacyAccuVar() {
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "x * 2");
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "has(m.f)");
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "m.exists_one(v, f)");
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "m.all(v, f)");
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "m.map(v, f)");
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "m.map(v, p, f)");
-    runAntlrTest(OPTIONS_OLD_ACCU_VAR, "m.filter(v, p)");
-  }
-
   private void runAntlrTest(CelOptions options, String expression) {
     testOutput().println("I: " + sanitizeForBaseline(expression));
     testOutput().println("=====>");