gradle/generation/antlr.gradle

import java.nio.file.Files

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

configure(project(":lucene:expressions")) {
  configurations {
    antlr
  }

  dependencies {
    antlr "org.antlr:antlr4"
  }

  task generateAntlrInternal() {
    description "Regenerate Javascript.g4"
    group "generation"

    dependsOn configurations.antlr

    def generatedPatterns = [
        "**/JavascriptBaseVisitor.java",
        "**/JavascriptLexer.java",
        "**/JavascriptParser.java",
        "**/JavascriptVisitor.java",
    ]

    def sourceDir = "src/java/org/apache/lucene/expressions/js"
    def inputFiles = file("$sourceDir/Javascript.g4")
    def tempOutput = file("$buildDir/antlr")
    def outputFiles = fileTree(dir: sourceDir, includes: generatedPatterns)

    inputs.files inputFiles
    outputs.files outputFiles

    doFirst {
      project.delete tempOutput

      project.javaexec {
        main = "org.antlr.v4.Tool"
        classpath = configurations.antlr

        ignoreExitValue false
        args = [
            "-no-listener",
            "-visitor",
            "-package", "org.apache.lucene.expressions.js",
            "-o", tempOutput,
            inputFiles
        ]
      }

      def generatedFiles = fileTree(dir: tempOutput, includes: generatedPatterns)
      generatedFiles.each { file ->
        modifyFile(file, { text ->
          text = text.replaceAll("public ((interface|class) Javascript\\w+)", "\$1")
          text = text.replaceAll("// Generated from .*", "// ANTLR GENERATED CODE: DO NOT EDIT")
          return text
        })
      }

      project.copy {
        from tempOutput
        into sourceDir
        include generatedPatterns
      }
    }
  }

  def generateAntlr = wrapWithPersistentChecksums(
      generateAntlrInternal, [ andThenTasks: ["spotlessJava", "spotlessJavaApply"] ])

  regenerate.dependsOn generateAntlr
}