Add CelCompilerTool java binary and compile_cel bzl library

PiperOrigin-RevId: 726254974

Author: l46kok

WORKSPACE

@@ -140,6 +140,7 @@ maven_install(
         "com.google.truth.extensions:truth-java8-extension:1.4.4",
         "com.google.truth.extensions:truth-proto-extension:1.4.4",
         "com.google.truth:truth:1.4.4",
+        "info.picocli:picocli:4.7.6",
         "org.antlr:antlr4-runtime:" + ANTLR4_VERSION,
         "org.jspecify:jspecify:1.0.0",
         "org.threeten:threeten-extra:1.8.0",

common/annotations/BUILD.bazel

@@ -7,5 +7,6 @@ package(
 
 java_library(
     name = "annotations",
+    # used_by_android
     exports = ["//common/src/main/java/dev/cel/common/annotations"],
 )

common/internal/BUILD.bazel

@@ -23,6 +23,7 @@ cel_android_library(
 
 java_library(
     name = "converter",
+    # used_by_android
     exports = ["//common/src/main/java/dev/cel/common/internal:converter"],
 )
 
@@ -78,6 +79,7 @@ java_library(
 
 java_library(
     name = "safe_string_formatter",
+    # used_by_android
     exports = ["//common/src/main/java/dev/cel/common/internal:safe_string_formatter"],
 )
 

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

@@ -17,6 +17,7 @@ ANNOTATION_SOURCES = [
 java_library(
     name = "annotations",
     srcs = ANNOTATION_SOURCES,
+    # used_by_android
     tags = [
     ],
 )

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

@@ -100,6 +100,7 @@ java_library(
         "BidiConverter.java",
         "Converter.java",
     ],
+    # used_by_android
     tags = [
     ],
     deps = [
@@ -264,6 +265,7 @@ java_library(
 java_library(
     name = "safe_string_formatter",
     srcs = ["SafeStringFormatter.java"],
+    # used_by_android
     tags = [
     ],
     deps = [

compiler/src/main/java/dev/cel/compiler/tools/BUILD.bazel

@@ -0,0 +1,32 @@
+load("@rules_java//java:defs.bzl", "java_binary")
+
+package(
+    default_applicable_licenses = [
+        "//:license",
+    ],
+    default_visibility = [
+        "//compiler/tools:__pkg__",
+    ],
+)
+
+java_binary(
+    name = "cel_compiler_tool",
+    srcs = ["CelCompilerTool.java"],
+    main_class = "dev.cel.compiler.tools.CelCompilerTool",
+    neverlink = 1,
+    deps = [
+        "//common",
+        "//common:compiler_common",
+        "//common:options",
+        "//common:proto_ast",
+        "//compiler",
+        "//compiler:compiler_builder",
+        "//extensions",
+        "//extensions:optional_library",
+        "//parser:macro",
+        "@cel_spec//proto/cel/expr:checked_java_proto",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_protobuf_protobuf_java",
+        "@maven//:info_picocli_picocli",
+    ],
+)

compiler/src/main/java/dev/cel/compiler/tools/CelCompilerTool.java

@@ -0,0 +1,138 @@
+// 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.compiler.tools;
+
+import dev.cel.expr.CheckedExpr;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.io.Files;
+import com.google.protobuf.DescriptorProtos.FileDescriptorSet;
+import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.ExtensionRegistry;
+import dev.cel.common.CelAbstractSyntaxTree;
+import dev.cel.common.CelDescriptorUtil;
+import dev.cel.common.CelOptions;
+import dev.cel.common.CelProtoAbstractSyntaxTree;
+import dev.cel.common.CelValidationException;
+import dev.cel.compiler.CelCompiler;
+import dev.cel.compiler.CelCompilerBuilder;
+import dev.cel.compiler.CelCompilerFactory;
+import dev.cel.extensions.CelExtensions;
+import dev.cel.extensions.CelOptionalLibrary;
+import dev.cel.parser.CelStandardMacro;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.concurrent.Callable;
+import picocli.CommandLine;
+import picocli.CommandLine.Option;
+
+/**
+ * CelCompilerTool is a binary that takes a CEL expression in string, compiles it into a
+ * dev.cel.expr.CheckedExpr protobuf message, then writes the content to a .binary pb file.
+ */
+final class CelCompilerTool implements Callable<Integer> {
+
+  @Option(
+      names = {"--cel_expression"},
+      description = "CEL expression")
+  private String celExpression = "";
+
+  @Option(
+      names = {"--transitive_descriptor_set"},
+      description = "Path to the transitive set of descriptors")
+  private String transitiveDescriptorSetPath = "";
+
+  @Option(
+      names = {"--output"},
+      description = "Output path for the compiled binarypb")
+  private String output = "";
+
+  private static final CelOptions CEL_OPTIONS = CelOptions.DEFAULT;
+
+  private static FileDescriptorSet load(String descriptorSetPath) {
+    try {
+      byte[] descriptorBytes = Files.toByteArray(new File(descriptorSetPath));
+      return FileDescriptorSet.parseFrom(descriptorBytes, ExtensionRegistry.getEmptyRegistry());
+    } catch (IOException e) {
+      throw new IllegalArgumentException(
+          "Failed to load FileDescriptorSet from path: " + descriptorSetPath, e);
+    }
+  }
+
+  private static CelAbstractSyntaxTree compile(
+      String expression, String transitiveDescriptorSetPath) throws CelValidationException {
+    CelCompilerBuilder compilerBuilder =
+        CelCompilerFactory.standardCelCompilerBuilder()
+            .setOptions(CEL_OPTIONS)
+            .setStandardMacros(CelStandardMacro.STANDARD_MACROS)
+            .addLibraries(
+                CelExtensions.bindings(),
+                CelExtensions.encoders(),
+                CelExtensions.math(CEL_OPTIONS),
+                CelExtensions.lists(),
+                CelExtensions.protos(),
+                CelExtensions.strings(),
+                CelOptionalLibrary.INSTANCE);
+    if (!transitiveDescriptorSetPath.isEmpty()) {
+      ImmutableSet<FileDescriptor> transitiveFileDescriptors =
+          CelDescriptorUtil.getFileDescriptorsFromFileDescriptorSet(
+              load(transitiveDescriptorSetPath));
+      compilerBuilder.addFileTypes(transitiveFileDescriptors);
+    }
+
+    CelCompiler celCompiler = compilerBuilder.build();
+
+    return celCompiler.compile(expression).getAst();
+  }
+
+  private static void writeCheckedExpr(CelAbstractSyntaxTree ast, String filePath)
+      throws IOException {
+    CheckedExpr checkedExpr = CelProtoAbstractSyntaxTree.fromCelAst(ast).toCheckedExpr();
+    Path path = Paths.get(filePath);
+    try (FileOutputStream output = new FileOutputStream(path.toFile())) {
+      checkedExpr.writeTo(output);
+    }
+  }
+
+  @Override
+  public Integer call() {
+    try {
+      CelAbstractSyntaxTree ast = compile(celExpression, transitiveDescriptorSetPath);
+      writeCheckedExpr(ast, output);
+    } catch (Exception e) {
+      String errorMessage =
+          String.format(
+              "Expression [%s] failed to compile. Reason: %s", celExpression, e.getMessage());
+      System.err.print(errorMessage);
+      return -1;
+    }
+
+    return 0;
+  }
+
+  public static void main(String[] args) {
+    CelCompilerTool compilerTool = new CelCompilerTool();
+    CommandLine cmd = new CommandLine(compilerTool);
+    cmd.setTrimQuotes(false);
+    cmd.parseArgs(args);
+
+    int exitCode = cmd.execute(args);
+    System.exit(exitCode);
+  }
+
+  CelCompilerTool() {}
+}

compiler/src/test/java/dev/cel/compiler/tools/BUILD.bazel

@@ -0,0 +1,69 @@
+load("@rules_java//java:defs.bzl", "java_library")
+load("//:testing.bzl", "junit4_test_suites")
+load("//compiler/tools:compile_cel.bzl", "compile_cel")
+
+package(default_applicable_licenses = [
+    "//:license",
+])
+
+compile_cel(
+    name = "compiled_hello_world",
+    expression = "'hello world'",
+)
+
+compile_cel(
+    name = "compiled_comprehension",
+    expression = "[1,2,3].map(x, x + 1)",
+)
+
+compile_cel(
+    name = "compiled_proto_message",
+    expression = "cel.expr.conformance.proto2.TestAllTypes{single_int32: 1}",
+    proto_srcs = ["@cel_spec//proto/cel/expr/conformance/proto2:test_all_types_proto"],
+)
+
+compile_cel(
+    name = "compiled_extensions",
+    expression = "cel.bind(x, 10, math.greatest([1,x])) < int(' 11  '.trim()) && optional.none().orValue(true) && [].flatten() == []",
+    proto_srcs = ["@cel_spec//proto/cel/expr/conformance/proto2:test_all_types_proto"],
+)
+
+filegroup(
+    name = "compiled_exprs",
+    srcs = [
+        ":compiled_comprehension",
+        ":compiled_extensions",
+        ":compiled_hello_world",
+        ":compiled_proto_message",
+    ],
+)
+
+java_library(
+    name = "tests",
+    testonly = True,
+    srcs = glob(["*Test.java"]),
+    resources = [":compiled_exprs"],
+    deps = [
+        "//:java_truth",
+        "//common:cel_ast",
+        "//common:options",
+        "//common:proto_ast",
+        "//extensions",
+        "//extensions:optional_library",
+        "//runtime",
+        "@cel_spec//proto/cel/expr:checked_java_proto",
+        "@cel_spec//proto/cel/expr/conformance/proto2:test_all_types_java_proto",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_protobuf_protobuf_java",
+        "@maven//:junit_junit",
+    ],
+)
+
+junit4_test_suites(
+    name = "test_suites",
+    sizes = [
+        "small",
+    ],
+    src_dir = "src/test/java",
+    deps = [":tests"],
+)

compiler/src/test/java/dev/cel/compiler/tools/CelCompilerToolTest.java

@@ -0,0 +1,88 @@
+// 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.compiler.tools;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import dev.cel.expr.CheckedExpr;
+import com.google.common.io.Resources;
+import com.google.protobuf.ExtensionRegistryLite;
+import dev.cel.common.CelAbstractSyntaxTree;
+import dev.cel.common.CelOptions;
+import dev.cel.common.CelProtoAbstractSyntaxTree;
+import dev.cel.expr.conformance.proto2.TestAllTypes;
+import dev.cel.extensions.CelExtensions;
+import dev.cel.extensions.CelOptionalLibrary;
+import dev.cel.runtime.CelRuntime;
+import dev.cel.runtime.CelRuntimeFactory;
+import java.net.URL;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class CelCompilerToolTest {
+  private static final CelRuntime CEL_RUNTIME =
+      CelRuntimeFactory.standardCelRuntimeBuilder()
+          .addLibraries(
+              CelExtensions.encoders(),
+              CelExtensions.math(CelOptions.DEFAULT),
+              CelExtensions.lists(),
+              CelExtensions.strings(),
+              CelOptionalLibrary.INSTANCE)
+          .addMessageTypes(TestAllTypes.getDescriptor())
+          .build();
+
+  @Test
+  public void compiledCheckedExpr_string() throws Exception {
+    CelAbstractSyntaxTree ast = readCheckedExpr("compiled_hello_world");
+
+    String result = (String) CEL_RUNTIME.createProgram(ast).eval();
+    assertThat(result).isEqualTo("hello world");
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  public void compiledCheckedExpr_comprehension() throws Exception {
+    CelAbstractSyntaxTree ast = readCheckedExpr("compiled_comprehension");
+
+    List<Long> result = (List<Long>) CEL_RUNTIME.createProgram(ast).eval();
+    assertThat(result).containsExactly(2L, 3L, 4L).inOrder();
+  }
+
+  @Test
+  public void compiledCheckedExpr_protoMessage() throws Exception {
+    CelAbstractSyntaxTree ast = readCheckedExpr("compiled_proto_message");
+
+    TestAllTypes result = (TestAllTypes) CEL_RUNTIME.createProgram(ast).eval();
+    assertThat(result).isEqualTo(TestAllTypes.newBuilder().setSingleInt32(1).build());
+  }
+
+  @Test
+  public void compiledCheckedExpr_extensions() throws Exception {
+    CelAbstractSyntaxTree ast = readCheckedExpr("compiled_extensions");
+
+    assertThat(CEL_RUNTIME.createProgram(ast).eval()).isEqualTo(true);
+  }
+
+  private static CelAbstractSyntaxTree readCheckedExpr(String compiledCelTarget) throws Exception {
+    URL url = Resources.getResource(CelCompilerToolTest.class, compiledCelTarget + ".binarypb");
+    byte[] checkedExprBytes = Resources.toByteArray(url);
+    CheckedExpr checkedExpr =
+        CheckedExpr.parseFrom(checkedExprBytes, ExtensionRegistryLite.getEmptyRegistry());
+    return CelProtoAbstractSyntaxTree.fromCheckedExpr(checkedExpr).getAst();
+  }
+}

compiler/tools/BUILD.bazel

@@ -0,0 +1,9 @@
+package(
+    default_applicable_licenses = ["//:license"],
+    default_visibility = ["//visibility:public"],
+)
+
+alias(
+    name = "cel_compiler_tool",
+    actual = "//compiler/src/main/java/dev/cel/compiler/tools:cel_compiler_tool",
+)