Show warning alert when the installed Kotlin plugin version is incompatible with the IDE platform version

idea/src/org/jetbrains/kotlin/idea/KotlinPluginCompatibilityVerifier.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea
+
+import com.intellij.openapi.application.ApplicationInfo
+import com.intellij.openapi.ui.Messages
+import com.intellij.util.PlatformUtils
+
+object KotlinPluginCompatibilityVerifier {
+    @JvmStatic
+    fun checkCompatibility() {
+        val kotlinVersion = KotlinPluginVersion.parse(KotlinPluginUtil.getPluginVersion()) ?: return
+        val platformVersion = PlatformVersion.getCurrent() ?: return
+
+        if (kotlinVersion.platformVersion.platform != platformVersion.platform) {
+            Messages.showWarningDialog(
+                "Installed Kotlin plugin version ($kotlinVersion) is not compatible with $platformVersion.\n" +
+                        "Some functionality may be broken.\n\n" +
+                        "Please reinstall the Kotlin plugin.",
+                "Compatibility issue"
+            )
+        }
+    }
+}
+
+internal data class KotlinPluginVersion(
+    val kotlinVersion: String, // 1.2.3
+    val status: String, // release, eap, rc
+    val buildNumber: String, // 53
+    val platformVersion: PlatformVersion,
+    val patchNumber: String // usually '1'
+) {
+    companion object {
+        private val KOTLIN_VERSION_REGEX = "^([\\d\\.]+)\\-([A-Za-z]+)\\-(\\d+)\\-([A-Za-z0-9\\.]+)\\-(\\d+)$".toRegex()
+
+        fun parse(version: String): KotlinPluginVersion? {
+            val matchResult = KOTLIN_VERSION_REGEX.matchEntire(version) ?: return null
+            val (kotlinVersion, status, buildNumber, platformString, patchNumber) = matchResult.destructured
+            val platformVersion = PlatformVersion.parse(platformString) ?: return null
+            return KotlinPluginVersion(kotlinVersion, status, buildNumber, platformVersion, patchNumber)
+        }
+    }
+
+    override fun toString() = "$kotlinVersion for $platformVersion"
+}
+
+internal data class PlatformVersion(val platform: Platform, val version: String /* 3.1 or 2017.3 */) {
+    companion object {
+        fun parse(platformString: String): PlatformVersion? {
+            for (platform in Platform.values()) {
+                if (platformString.startsWith(platform.qualifier)) {
+                    return PlatformVersion(platform, platformString.drop(platform.qualifier.length))
+                }
+            }
+
+            return null
+        }
+
+        fun getCurrent(): PlatformVersion? {
+            val prefix = PlatformUtils.getPlatformPrefix() ?: return null
+            val platform = when (prefix) {
+                PlatformUtils.IDEA_CE_PREFIX, PlatformUtils.IDEA_PREFIX -> Platform.IDEA
+                "AndroidStudio" -> Platform.ANDROID_STUDIO // from 'com.android.tools.idea.IdeInfo'
+                else -> return null
+            }
+
+            val version = ApplicationInfo.getInstance().run { majorVersion + "." + minorVersion.substringBefore(".") }
+            return PlatformVersion(platform, version)
+        }
+    }
+
+    enum class Platform(val qualifier: String, val presentableText: String) {
+        IDEA("IJ", "IDEA"), ANDROID_STUDIO("Studio", "Android Studio")
+    }
+
+    override fun toString() = platform.presentableText + " " + version
+}

idea/src/org/jetbrains/kotlin/idea/PluginStartupComponent.java

@@ -74,6 +74,8 @@ public class PluginStartupComponent implements ApplicationComponent {
 
         ServiceManager.getService(IndexPatternSearch.class).registerExecutor(new KotlinTodoSearcher());
 
+        KotlinPluginCompatibilityVerifier.checkCompatibility();
+
         //todo[Sedunov]: wait for fix in platform to avoid misunderstood from Java newbies (also ConfigureKotlinInTempDirTest)
         //KotlinSdkType.Companion.setUpIfNeeded();
     }

idea/tests/org/jetbrains/kotlin/test/CompatibilityVerifierVersionComparisonTest.kt

@@ -0,0 +1,23 @@
+package org.jetbrains.kotlin.test
+
+import com.intellij.testFramework.LightPlatformTestCase
+import org.jetbrains.kotlin.idea.KotlinPluginVersion
+import org.jetbrains.kotlin.idea.PlatformVersion
+
+class CompatibilityVerifierVersionComparisonTest : LightPlatformTestCase() {
+    fun testKotlinVersionParsing() {
+        val version = KotlinPluginVersion.parse("1.2.40-dev-193-Studio3.0-1")
+                ?: throw AssertionError("Version should not be null")
+
+        assertEquals("1.2.40", version.kotlinVersion)
+        assertEquals("dev", version.status)
+        assertEquals("193", version.buildNumber)
+        assertEquals(PlatformVersion.Platform.ANDROID_STUDIO, version.platformVersion.platform)
+        assertEquals("3.0", version.platformVersion.version)
+        assertEquals("1", version.patchNumber)
+    }
+
+    fun testPlatformVersionParsing() {
+        PlatformVersion.getCurrent() ?: throw AssertionError("Version should not be null")
+    }
+}