From e79fdbe5e87f1f1ec582e308ba6fa0b234703fbf Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Wed, 26 Apr 2017 21:11:45 +0300
Subject: [PATCH] Gradle: print version loaded from environment's compiler jar

And not from the KotlinCompilerVersion class that is accessible in the
current version of kotlin-gradle-plugin, because the version of the
compiler might be different
---
 .../GradleKotlinCompilerRunner.kt             |  3 +-
 .../jetbrains/kotlin/compilerRunner/utils.kt  | 48 +++++++++++++++++++
 2 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/utils.kt

diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/GradleKotlinCompilerRunner.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/GradleKotlinCompilerRunner.kt
index ffc7eda357c..a2ac5a98b03 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/GradleKotlinCompilerRunner.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/GradleKotlinCompilerRunner.kt
@@ -25,7 +25,6 @@ import org.jetbrains.kotlin.cli.common.arguments.K2JSCompilerArguments
 import org.jetbrains.kotlin.cli.common.arguments.K2JVMCompilerArguments
 import org.jetbrains.kotlin.cli.common.arguments.K2MetadataCompilerArguments
 import org.jetbrains.kotlin.com.intellij.openapi.util.io.FileUtil
-import org.jetbrains.kotlin.config.KotlinCompilerVersion
 import org.jetbrains.kotlin.config.Services
 import org.jetbrains.kotlin.daemon.client.CompileServiceSession
 import org.jetbrains.kotlin.daemon.common.*
@@ -102,7 +101,7 @@ internal class GradleCompilerRunner(private val project: Project) : KotlinCompil
             environment: GradleCompilerEnvironment
     ): ExitCode {
         if (compilerArgs.version) {
-            project.logger.lifecycle("Kotlin version " + KotlinCompilerVersion.VERSION +
+            project.logger.lifecycle("Kotlin version " + loadCompilerVersion(environment.compilerJar) +
                     " (JRE " + System.getProperty("java.runtime.version") + ")")
             compilerArgs.version = false
         }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/utils.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/utils.kt
new file mode 100644
index 00000000000..df30739afcd
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/utils.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * 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 org.jetbrains.kotlin.compilerRunner
+
+import org.jetbrains.kotlin.config.KotlinCompilerVersion
+import org.jetbrains.org.objectweb.asm.ClassReader
+import org.jetbrains.org.objectweb.asm.ClassVisitor
+import org.jetbrains.org.objectweb.asm.FieldVisitor
+import org.jetbrains.org.objectweb.asm.Opcodes
+import java.io.File
+import java.util.zip.ZipFile
+
+internal fun loadCompilerVersion(compilerJar: File): String {
+    var result = "<unknown>"
+
+    try {
+        ZipFile(compilerJar).use { file ->
+            val fileName = KotlinCompilerVersion::class.java.name.replace('.', '/') + ".class"
+            file.getInputStream(file.getEntry(fileName)).use { inputStream ->
+                ClassReader(inputStream).accept(object : ClassVisitor(Opcodes.ASM5) {
+                    override fun visitField(access: Int, name: String, desc: String, signature: String?, value: Any?): FieldVisitor {
+                        if (name == KotlinCompilerVersion::VERSION.name && value is String) {
+                            result = value
+                        }
+                        return super.visitField(access, name, desc, signature, value)
+                    }
+                }, ClassReader.SKIP_CODE or ClassReader.SKIP_FRAMES or ClassReader.SKIP_DEBUG)
+            }
+        }
+    }
+    catch (e: Throwable) {}
+
+    return result
+}