Deprecate setStandardEnvironmentEnabled flag in favor of subsetting

bundle/src/main/java/dev/cel/bundle/CelBuilder.java

@@ -292,7 +292,15 @@ public interface CelBuilder {
   @CanIgnoreReturnValue
   CelBuilder addFileTypes(FileDescriptorSet fileDescriptorSet);
 
-  /** Enable or disable the standard CEL library functions and variables */
+  /**
+   * Enable or disable the standard CEL library functions and variables.
+   *
+   * @deprecated Use {@link #setStandardDeclarations(CelStandardDeclarations)} and/or {@link
+   *     #setStandardFunctions(CelStandardFunctions)} to configure or subset the standard
+   *     environment. Use {@link CelStandardDeclarations#EMPTY} and {@link
+   *     CelStandardFunctions#EMPTY} to disable all standard declarations and functions.
+   */
+  @Deprecated
   @CanIgnoreReturnValue
   CelBuilder setStandardEnvironmentEnabled(boolean value);
 
@@ -314,8 +322,7 @@ public interface CelBuilder {
 
   /**
    * Override the standard declarations for the type-checker. This can be used to subset the
-   * standard environment to only expose the desired declarations to the type-checker. {@link
-   * #setStandardEnvironmentEnabled(boolean)} must be set to false for this to take effect.
+   * standard environment to only expose the desired declarations to the type-checker.
    */
   @CanIgnoreReturnValue
   CelBuilder setStandardDeclarations(CelStandardDeclarations standardDeclarations);

bundle/src/main/java/dev/cel/bundle/CelImpl.java

@@ -379,6 +379,7 @@ public CelBuilder addFileTypes(FileDescriptorSet fileDescriptorSet) {
     }
 
     @Override
+    @Deprecated
     public CelBuilder setStandardEnvironmentEnabled(boolean value) {
       compilerBuilder.setStandardEnvironmentEnabled(value);
       runtimeBuilder.setStandardEnvironmentEnabled(value);

bundle/src/test/java/dev/cel/bundle/BUILD.bazel

@@ -27,6 +27,7 @@ java_library(
         "//checker",
         "//checker:checker_legacy_environment",
         "//checker:proto_type_mask",
+        "//checker:standard_decl",
         "//common:cel_ast",
         "//common:cel_descriptor_util",
         "//common:cel_source",
@@ -56,6 +57,7 @@ java_library(
         "//runtime:evaluation_exception_builder",
         "//runtime:evaluation_listener",
         "//runtime:function_binding",
+        "//runtime:standard_functions",
         "//runtime:unknown_attributes",
         "//testing:cel_runtime_flavor",
         "//testing/protos:single_file_extension_java_proto",

bundle/src/test/java/dev/cel/bundle/CelImplTest.java

@@ -60,6 +60,7 @@
 import com.google.testing.junit.testparameterinjector.TestParameter;
 import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import dev.cel.checker.CelCheckerLegacyImpl;
+import dev.cel.checker.CelStandardDeclarations;
 import dev.cel.checker.DescriptorTypeProvider;
 import dev.cel.checker.ProtoTypeMask;
 import dev.cel.checker.TypeProvider;
@@ -110,6 +111,7 @@
 import dev.cel.runtime.CelRuntime.Program;
 import dev.cel.runtime.CelRuntimeFactory;
 import dev.cel.runtime.CelRuntimeLegacyImpl;
+import dev.cel.runtime.CelStandardFunctions;
 import dev.cel.runtime.CelUnknownSet;
 import dev.cel.runtime.CelVariableResolver;
 import dev.cel.runtime.UnknownContext;
@@ -2294,4 +2296,27 @@ private static Cel setupEnv(CelBuilder celBuilder) {
                 .build())
         .build();
   }
+
+  @Test
+  public void plannerCelBuilder_setStandardDeclarationsAndFunctions_subsetsEnvironment()
+      throws Exception {
+    Cel cel =
+        CelFactory.plannerCelBuilder()
+            .setStandardDeclarations(
+                CelStandardDeclarations.newBuilder()
+                    .includeFunctions(CelStandardDeclarations.StandardFunction.ADD)
+                    .build())
+            .setStandardFunctions(
+                CelStandardFunctions.newBuilder()
+                    .includeFunctions(CelStandardFunctions.StandardFunction.ADD)
+                    .build())
+            .build();
+
+    CelAbstractSyntaxTree ast = cel.compile("1 + 1").getAst();
+    assertThat(cel.createProgram(ast).eval()).isEqualTo(2L);
+
+    CelValidationException validationException =
+        assertThrows(CelValidationException.class, () -> cel.compile("1 - 1").getAst());
+    assertThat(validationException).hasMessageThat().contains("undeclared reference to '_-_'");
+  }
 }

checker/src/main/java/dev/cel/checker/CelCheckerBuilder.java

@@ -155,14 +155,20 @@ public interface CelCheckerBuilder {
   @CanIgnoreReturnValue
   CelCheckerBuilder addFileTypes(FileDescriptorSet fileDescriptorSet);
 
-  /** Enable or disable the standard CEL library functions and variables */
+  /**
+   * Enable or disable the standard CEL library functions and variables.
+   *
+   * @deprecated Use {@link #setStandardDeclarations(CelStandardDeclarations)} to configure or
+   *     subset the standard environment. Use {@link CelStandardDeclarations#EMPTY} to disable all
+   *     standard declarations.
+   */
+  @Deprecated
   @CanIgnoreReturnValue
   CelCheckerBuilder setStandardEnvironmentEnabled(boolean value);
 
   /**
    * Override the standard declarations for the type-checker. This can be used to subset the
-   * standard environment to only expose the desired declarations to the type-checker. {@link
-   * #setStandardEnvironmentEnabled(boolean)} must be set to false for this to take effect.
+   * standard environment to only expose the desired declarations to the type-checker.
    */
   @CanIgnoreReturnValue
   CelCheckerBuilder setStandardDeclarations(CelStandardDeclarations standardDeclarations);

checker/src/main/java/dev/cel/checker/CelCheckerLegacyImpl.java

@@ -162,10 +162,10 @@ public void accept(EnvVisitor envVisitor) {
 
   private Env getEnv(Errors errors) {
     Env env;
-    if (standardEnvironmentEnabled) {
-      env = Env.standard(errors, typeProvider, celOptions);
-    } else if (overriddenStandardDeclarations != null) {
+    if (overriddenStandardDeclarations != null) {
       env = Env.standard(overriddenStandardDeclarations, errors, typeProvider, celOptions);
+    } else if (standardEnvironmentEnabled) {
+      env = Env.standard(errors, typeProvider, celOptions);
     } else {
       env = Env.unconfigured(errors, typeProvider, celOptions);
     }
@@ -359,6 +359,7 @@ public CelCheckerBuilder addFileTypes(FileDescriptorSet fileDescriptorSet) {
     }
 
     @Override
+    @Deprecated
     public CelCheckerBuilder setStandardEnvironmentEnabled(boolean value) {
       this.standardEnvironmentEnabled = value;
       return this;
@@ -434,12 +435,6 @@ CelTypeProvider celTypeProvider() {
     @Override
     @CheckReturnValue
     public CelCheckerLegacyImpl build() {
-      if (standardEnvironmentEnabled && standardDeclarations != null) {
-        throw new IllegalArgumentException(
-            "setStandardEnvironmentEnabled must be set to false to override standard"
-                + " declarations.");
-      }
-
       // Add libraries, such as extensions
       ImmutableSet<CelCheckerLibrary> checkerLibraries = celCheckerLibraries.build();
       checkerLibraries.forEach(celLibrary -> celLibrary.setCheckerOptions(this));

checker/src/main/java/dev/cel/checker/CelStandardDeclarations.java

@@ -51,6 +51,10 @@ public final class CelStandardDeclarations {
   private static final TypeParamType TYPE_PARAM_B = TypeParamType.create("B");
   private static final MapType MAP_OF_AB = MapType.create(TYPE_PARAM_A, TYPE_PARAM_B);
 
+  /** An empty instance of {@link CelStandardDeclarations} with no functions or identifiers. */
+  public static final CelStandardDeclarations EMPTY =
+      new CelStandardDeclarations(ImmutableSet.of(), ImmutableSet.of());
+
   private final ImmutableSet<CelFunctionDecl> celFunctionDecls;
   private final ImmutableSet<CelIdentDecl> celIdentDecls;
 

checker/src/test/java/dev/cel/checker/CelStandardDeclarationsTest.java

@@ -86,24 +86,63 @@ public void standardDeclaration_moreThanOneIdentifierFilterSet_throws(
   }
 
   @Test
-  public void compiler_standardEnvironmentEnabled_throwsWhenOverridingDeclarations() {
-    IllegalArgumentException e =
-        assertThrows(
-            IllegalArgumentException.class,
-            () ->
-                CelCompilerFactory.standardCelCompilerBuilder()
-                    .setStandardEnvironmentEnabled(true)
-                    .setStandardDeclarations(
-                        CelStandardDeclarations.newBuilder()
-                            .includeFunctions(StandardFunction.ADD, StandardFunction.SUBTRACT)
-                            .build())
-                    .build());
+  public void compiler_setStandardDeclarations_overridesDefaultStandardEnvironment()
+      throws Exception {
+    CelCompiler compiler =
+        CelCompilerFactory.standardCelCompilerBuilder()
+            .setStandardDeclarations(
+                CelStandardDeclarations.newBuilder()
+                    .includeFunctions(StandardFunction.ADD)
+                    .build())
+            .build();
 
-    assertThat(e)
-        .hasMessageThat()
-        .contains(
-            "setStandardEnvironmentEnabled must be set to false to override standard"
-                + " declarations.");
+    assertThat(compiler.compile("1 + 1").hasError()).isFalse();
+    assertThat(compiler.compile("1 - 1").hasError()).isTrue();
+  }
+
+  @Test
+  public void compiler_setStandardDeclarations_withStandardEnvironmentExplicitlyEnabled()
+      throws Exception {
+    CelCompiler compiler =
+        CelCompilerFactory.standardCelCompilerBuilder()
+            .setStandardEnvironmentEnabled(true)
+            .setStandardDeclarations(
+                CelStandardDeclarations.newBuilder()
+                    .includeFunctions(StandardFunction.ADD)
+                    .build())
+            .build();
+
+    assertThat(compiler.compile("1 + 1").hasError()).isFalse();
+    assertThat(compiler.compile("1 - 1").hasError()).isTrue();
+  }
+
+  @Test
+  public void compiler_setStandardDeclarations_withStandardEnvironmentExplicitlyDisabled()
+      throws Exception {
+    CelCompiler compiler =
+        CelCompilerFactory.standardCelCompilerBuilder()
+            .setStandardEnvironmentEnabled(false)
+            .setStandardDeclarations(
+                CelStandardDeclarations.newBuilder()
+                    .includeFunctions(StandardFunction.ADD)
+                    .build())
+            .build();
+
+    assertThat(compiler.compile("1 + 1").hasError()).isFalse();
+    assertThat(compiler.compile("1 - 1").hasError()).isTrue();
+  }
+
+  @Test
+  public void compiler_setStandardDeclarations_emptyDisablesAllStandardDeclarations()
+      throws Exception {
+    CelCompiler compiler =
+        CelCompilerFactory.standardCelCompilerBuilder()
+            .setStandardDeclarations(CelStandardDeclarations.EMPTY)
+            .build();
+
+    assertThat(compiler.compile("1 + 1").hasError()).isTrue();
+    assertThat(compiler.compile("1 - 1").hasError()).isTrue();
+    assertThat(compiler.compile("size([1])").hasError()).isTrue();
   }
 
   @Test

compiler/src/main/java/dev/cel/compiler/CelCompilerBuilder.java

@@ -200,14 +200,20 @@ public interface CelCompilerBuilder {
   @CanIgnoreReturnValue
   CelCompilerBuilder addFileTypes(FileDescriptorSet fileDescriptorSet);
 
-  /** Enable or disable the standard CEL library functions and variables */
+  /**
+   * Enable or disable the standard CEL library functions and variables.
+   *
+   * @deprecated Use {@link #setStandardDeclarations(CelStandardDeclarations)} to configure or
+   *     subset the standard environment. Use {@link CelStandardDeclarations#EMPTY} to disable all
+   *     standard declarations.
+   */
+  @Deprecated
   @CanIgnoreReturnValue
   CelCompilerBuilder setStandardEnvironmentEnabled(boolean value);
 
   /**
    * Override the standard declarations for the type-checker. This can be used to subset the
-   * standard environment to only expose the desired declarations to the type-checker. {@link
-   * #setStandardEnvironmentEnabled(boolean)} must be set to false for this to take effect.
+   * standard environment to only expose the desired declarations to the type-checker.
    */
   @CanIgnoreReturnValue
   CelCompilerBuilder setStandardDeclarations(CelStandardDeclarations standardDeclarations);

compiler/src/main/java/dev/cel/compiler/CelCompilerImpl.java

@@ -283,6 +283,7 @@ public CelCompilerBuilder addFileTypes(FileDescriptorSet fileDescriptorSet) {
     }
 
     @Override
+    @Deprecated
     public CelCompilerBuilder setStandardEnvironmentEnabled(boolean value) {
       checkerBuilder.setStandardEnvironmentEnabled(value);
       return this;

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

@@ -170,7 +170,14 @@ public interface CelRuntimeBuilder {
   /** Returns the configured {@link CelValueProvider}, or null if not set. */
   CelValueProvider valueProvider();
 
-  /** Enable or disable the standard CEL library functions and variables. */
+  /**
+   * Enable or disable the standard CEL library functions and variables.
+   *
+   * @deprecated Use {@link #setStandardFunctions(CelStandardFunctions)} to configure or subset the
+   *     standard environment. Use {@link CelStandardFunctions#EMPTY} to disable all standard
+   *     functions.
+   */
+  @Deprecated
   @CanIgnoreReturnValue
   CelRuntimeBuilder setStandardEnvironmentEnabled(boolean value);
 

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

@@ -393,6 +393,7 @@ public Builder setTypeFactory(Function<String, Message.Builder> typeFactory) {
     }
 
     @Override
+    @Deprecated
     public Builder setStandardEnvironmentEnabled(boolean value) {
       throw new UnsupportedOperationException(
           "Unsupported. Subset the environment using setStandardFunctions instead.");

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

@@ -219,6 +219,7 @@ public CelRuntimeBuilder setTypeFactory(Function<String, Message.Builder> typeFa
     }
 
     @Override
+    @Deprecated
     public CelRuntimeBuilder setStandardEnvironmentEnabled(boolean value) {
       standardEnvironmentEnabled = value;
       return this;

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

@@ -140,6 +140,10 @@ public final class CelStandardFunctions {
           GreaterEqualsOverload.GREATER_EQUALS_UINT64_DOUBLE,
           GreaterEqualsOverload.GREATER_EQUALS_DOUBLE_UINT64);
 
+  /** An empty instance of {@link CelStandardFunctions} with no functions. */
+  public static final CelStandardFunctions EMPTY =
+      new CelStandardFunctions(ImmutableMultimap.of());
+
   private final ImmutableMultimap<String, CelStandardOverload> standardOverloads;
 
   public static final ImmutableSet<CelStandardFunction> ALL_STANDARD_FUNCTIONS =

runtime/src/test/java/dev/cel/runtime/CelStandardFunctionsTest.java

@@ -136,6 +136,11 @@ public void standardFunctions_filterFunctions() {
         .containsExactly(AddOverload.ADD_INT64, SubtractOverload.SUBTRACT_INT64);
   }
 
+  @Test
+  public void standardFunctions_empty() {
+    assertThat(CelStandardFunctions.EMPTY.getOverloads()).isEmpty();
+  }
+
   @Test
   public void standardEnvironment_subsetEnvironment() throws Exception {
     CelCompiler celCompiler = CelCompilerFactory.standardCelCompilerBuilder().build();