Decompiler: show java file with a comment when kotlin file has incompatible abi version

Introduce JetDecompilerForWrongAbiVersion

idea/src/META-INF/plugin.xml

@@ -330,6 +330,7 @@
     <stubIndex implementation="org.jetbrains.jet.plugin.stubindex.JetTopLevelShortObjectNameIndex"/>
 
     <psi.classFileDecompiler implementation="org.jetbrains.jet.plugin.libraries.JetClassFileDecompiler"/>
+    <psi.classFileDecompiler implementation="org.jetbrains.jet.plugin.libraries.JetDecompilerForWrongAbiVersion"/>
 
     <fileBasedIndex implementation="org.jetbrains.jet.plugin.versions.KotlinAbiVersionIndex"/>
     <fileBasedIndex implementation="org.jetbrains.jet.plugin.vfilefinder.KotlinClassFileIndex"/>

idea/src/org/jetbrains/jet/plugin/libraries/DecompiledTextFactory.kt

@@ -48,7 +48,6 @@ public fun buildDecompiledText(
         buildDecompiledText(packageFqName, listOf(resolver.resolveClass(classFqName)).filterNotNull())
     }
     else {
-        // TODO: support other header kinds: for trait-impl show the trait, for package fragment - the whole package
         throw UnsupportedOperationException("Unknown header kind: " + kind)
     }
 }

idea/src/org/jetbrains/jet/plugin/libraries/DecompiledUtils.kt

@@ -43,10 +43,21 @@ public fun isKotlinCompiledFile(file: VirtualFile): Boolean {
     if (isAnonymousFunction(file)) {
         return true
     }
+    if (isKotlinCompiledFileWithIncompatibleAbiVersion(file)) {
+        return false
+    }
     val header = KotlinBinaryClassCache.getKotlinBinaryClass(file).getClassHeader()
     return header != null && header.getKind() != KotlinClassHeader.Kind.TRAIT_IMPL
 }
 
+public fun isKotlinCompiledFileWithIncompatibleAbiVersion(file: VirtualFile): Boolean {
+    if (!StdFileTypes.CLASS.getDefaultExtension().equals(file.getExtension())) {
+        return false
+    }
+    val header = KotlinBinaryClassCache.getKotlinBinaryClass(file).getClassHeader()
+    return header?.getKind() == KotlinClassHeader.Kind.INCOMPATIBLE_ABI_VERSION
+}
+
 public fun isKotlinInternalCompiledFile(file: VirtualFile): Boolean {
     if (!isKotlinCompiledFile(file)) {
         return false
@@ -58,5 +69,5 @@ public fun isKotlinInternalCompiledFile(file: VirtualFile): Boolean {
         return true
     }
     val header = KotlinBinaryClassCache.getKotlinBinaryClass(file).getClassHeader()
-    return header != null && header.getKind() == KotlinClassHeader.Kind.PACKAGE_PART
+    return header?.getKind() == KotlinClassHeader.Kind.PACKAGE_PART
 }

idea/src/org/jetbrains/jet/plugin/libraries/JetDecompilerForWrongAbiVersion.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2010-2014 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.jet.plugin.libraries
+
+import com.intellij.psi.compiled.ClassFileDecompilers
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.psi.impl.compiled.ClsFileImpl
+
+public class JetDecompilerForWrongAbiVersion : ClassFileDecompilers.Light() {
+    override fun accepts(file: VirtualFile) = isKotlinCompiledFileWithIncompatibleAbiVersion(file)
+
+    override fun getText(file: VirtualFile) = "$INCOMPATIBLE_ABI_VERSION_COMMENT\n${ClsFileImpl.decompile(file)}"
+}
+
+val INCOMPATIBLE_ABI_VERSION_COMMENT = "  // This Kotlin file has an incompatible ABI version and is displayed as Java class"

idea/tests/org/jetbrains/jet/plugin/libraries/DecompiledTextForWrongAbiVersionTest.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2010-2014 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.jet.plugin.libraries
+
+import org.jetbrains.jet.plugin.JetLightCodeInsightFixtureTestCase
+import com.intellij.testFramework.LightProjectDescriptor
+import org.jetbrains.jet.JetTestCaseBuilder
+import com.intellij.psi.PsiManager
+import junit.framework.Assert
+import com.intellij.psi.PsiCompiledFile
+import org.jetbrains.jet.plugin.JetJdkAndLibraryProjectDescriptor
+import java.io.File
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.psi.PsiJavaFile
+import com.intellij.psi.impl.compiled.ClsFileImpl
+
+public class DecompiledTextForWrongAbiVersionTest : JetLightCodeInsightFixtureTestCase() {
+
+    override fun getProjectDescriptor(): LightProjectDescriptor {
+        return JetJdkAndLibraryProjectDescriptor(File(JetTestCaseBuilder.getTestDataPathBase() + "/cli/jvm/wrongAbiVersionLib"))
+    }
+
+    fun testClassWithWrongAbiVersion() {
+        val root = NavigateToDecompiledLibraryTest.findTestLibraryRoot(myModule!!)
+        checkFileWithWrongAbiVersion(root!!.findChild("ClassWithWrongAbiVersion.class")!!)
+    }
+
+    fun testPackageFacadeWithWrongAbiVersion() {
+        val root = NavigateToDecompiledLibraryTest.findTestLibraryRoot(myModule!!)
+        checkFileWithWrongAbiVersion(root!!.findChild("wrong")!!.findChild("WrongPackage.class")!!)
+    }
+
+    private fun checkFileWithWrongAbiVersion(file: VirtualFile) {
+        val psiFile = PsiManager.getInstance(getProject()!!).findFile(file)
+        Assert.assertTrue(psiFile is ClsFileImpl)
+        val decompiledPsiFile = (psiFile as PsiCompiledFile).getDecompiledPsiFile()
+        Assert.assertTrue(decompiledPsiFile is PsiJavaFile)
+        val decompiledText = decompiledPsiFile!!.getText()!!
+        Assert.assertTrue(decompiledText.contains(INCOMPATIBLE_ABI_VERSION_COMMENT))
+        Assert.assertTrue((decompiledPsiFile as PsiJavaFile).getClasses().size == 1)
+    }
+}