build-system/gradle-core/src/main/java/com/android/build/gradle/internal/dependency/VersionedCodeShrinker.kt

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * 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.
 */

package com.android.build.gradle.internal.dependency

import com.android.build.gradle.internal.LoggerWrapper
import com.android.build.gradle.internal.scope.CodeShrinker
import com.android.builder.dexing.getR8Version
import com.google.common.annotations.VisibleForTesting
import proguard.ProGuard
import java.io.Serializable

data class VersionedCodeShrinker(val shrinker: CodeShrinker, val version: String) : Serializable {
    companion object {
        @JvmStatic
        fun of(codeShrinker: CodeShrinker) = when (codeShrinker) {
            CodeShrinker.PROGUARD -> VersionedCodeShrinker(
                CodeShrinker.PROGUARD,
                parseProguardVersion(getProguardVersionString())
            )
            CodeShrinker.R8 -> VersionedCodeShrinker(CodeShrinker.R8, getR8Version())
        }

        private val versionPattern = """[^\s.]+(?:\.[^\s.]+)+""".toRegex()

        private fun getProguardVersionString(): String {
            try {
                // Get version through reflection to avoid inlining of the compile time constant
                return ProGuard::class.java.getField("VERSION").get(null) as String
            } catch (e: Exception) { // Multiple reflection related exceptions possible here
                LoggerWrapper.getLogger(VersionedCodeShrinker::class.java)
                    .warning("Unable to find ProGuard.VERSION field, assuming empty string.")
                return ""
            }
        }

        @VisibleForTesting
        internal fun parseProguardVersion(version: String): String {
            val matcher = versionPattern.find(version)
            return if (matcher != null) {
                LoggerWrapper.getLogger(VersionedCodeShrinker::class.java)
                    .verbose("Parsed ProGuard version: ${matcher.groupValues[0]}")
                matcher.groupValues[0]
            } else {
                LoggerWrapper.getLogger(VersionedCodeShrinker::class.java)
                    .warning("Cannot parse ProGuard version, assuming 0.0.0")
                "0.0.0"
            }
        }
    }
}