Bump protobuf to v4 (#588)

CEL conformance tests still have to use protobuf 3, because grpc-java doesn't work with protobuf 4 yet. To allow that, a new artifact `cel-generated-pb3` has been added.

Author: snazy

bom/build.gradle.kts

@@ -26,6 +26,7 @@ dependencies {
     api(project(":cel-core"))
     api(project(":cel-generated-antlr", "shadow"))
     api(project(":cel-generated-pb"))
+    api(project(":cel-generated-pb3"))
     api(project(":cel-conformance"))
     api(project(":cel-jackson"))
     api(project(":cel-tools"))

conformance/build.gradle.kts

@@ -33,12 +33,14 @@ sourceSets.main {
   java.srcDir(layout.buildDirectory.dir("generated/source/proto/main/grpc"))
 }
 
+configurations.all { exclude(group = "org.projectnessie.cel", module = "cel-generated-pb") }
+
 dependencies {
   implementation(project(":cel-core"))
   implementation(testFixtures(project(":cel-core")))
-  implementation(testFixtures(project(":cel-generated-pb")))
+  implementation(testFixtures(project(":cel-generated-pb3")))
 
-  implementation(libs.protobuf.java)
+  implementation(libs.protobuf.java) { version { strictly(libs.versions.protobuf3.get()) } }
 
   implementation(libs.grpc.protobuf)
   implementation(libs.grpc.stub)
@@ -59,7 +61,7 @@ configure<ProtobufExtension> {
   // Configure the protoc executable
   protoc {
     // Download from repositories
-    artifact = "com.google.protobuf:protoc:${libs.versions.protobuf.get()}"
+    artifact = "com.google.protobuf:protoc:${libs.versions.protobuf3.get()}"
   }
   plugins {
     this.create("grpc") { artifact = "io.grpc:protoc-gen-grpc-java:${libs.versions.grpc.get()}" }

generated-pb3/build.gradle.kts

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2021 The Authors of CEL-Java
+ *
+ * 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
+ *
+ * http://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.
+ */
+
+import com.google.protobuf.gradle.ProtobufExtension
+import com.google.protobuf.gradle.ProtobufPlugin
+
+plugins {
+  `java-library`
+  `maven-publish`
+  signing
+  `cel-conventions`
+  `java-test-fixtures`
+}
+
+apply<ProtobufPlugin>()
+
+sourceSets.main {
+  java.srcDir(layout.buildDirectory.dir("generated/source/proto/main/java"))
+  java.destinationDirectory.set(layout.buildDirectory.dir("classes/java/generated"))
+}
+
+sourceSets.test {
+  java.srcDir(layout.buildDirectory.dir("generated/source/proto/test/java"))
+  java.destinationDirectory.set(layout.buildDirectory.dir("classes/java/generatedTest"))
+}
+
+dependencies {
+  api(libs.protobuf.java) { version { strictly(libs.versions.protobuf3.get()) } }
+
+  // Since we need the protobuf stuff in this cel-core module, it's easy to generate the
+  // gRPC code as well. But do not expose the gRPC dependencies "publicly".
+  compileOnly(libs.grpc.protobuf)
+  compileOnly(libs.grpc.stub)
+  compileOnly(libs.tomcat.annotations.api)
+}
+
+// *.proto files taken from https://github.com/googleapis/googleapis/ repo, available as a git
+// submodule
+configure<ProtobufExtension> {
+  // Configure the protoc executable
+  protoc {
+    // Download from repositories
+    artifact = "com.google.protobuf:protoc:${libs.versions.protobuf3.get()}"
+  }
+}

generated-pb3/src

@@ -0,0 +1 @@
+../generated-pb/src

gradle/libs.versions.toml

@@ -14,7 +14,8 @@ jmh = "1.37"
 junit = "5.10.3"
 nessieBuildPlugins = "0.2.24"
 nessieRunPlugin = "0.27.3"
-protobuf = "3.25.4"
+protobuf = "4.27.3"
+protobuf3 = "3.25.4"
 protobufPlugin = "0.9.4"
 shadowPlugin = "8.1.1"
 slf4j = "1.7.36"

settings.gradle.kts

@@ -91,6 +91,8 @@ celProject("generated-antlr")
 
 celProject("generated-pb")
 
+celProject("generated-pb3")
+
 celProject("core")
 
 celProject("jackson")