Merge pull request #628 from AlexandrosAlexiou/refactor/dependecies/decompiler

refactor: use JetBrains release repository for FernFlower decompiler

Author: fwcd

gradle/libs.versions.toml

@@ -4,6 +4,7 @@ lsp4jVersion = "0.21.2"
 exposedVersion = "0.37.3"
 jmhVersion = "1.37"
 guavaVersion = "33.4.0-jre"
+fernFlowerVersion = "243.22562.218"
 
 [libraries]
 org-jetbrains-kotlin-stdlib = { module = "org.jetbrains.kotlin:kotlin-stdlib", version.ref = "kotlinVersion" }
@@ -28,7 +29,7 @@ org-jetbrains-exposed-core = { module = "org.jetbrains.exposed:exposed-core", ve
 org-jetbrains-exposed-dao = { module = "org.jetbrains.exposed:exposed-dao", version.ref = "exposedVersion" }
 org-jetbrains-exposed-jdbc = { module = "org.jetbrains.exposed:exposed-jdbc", version.ref = "exposedVersion" }
 
-org-jetbrains-fernflower = { module = "org.jetbrains:fernflower", version = "1.0" }
+com-jetbrains-intellij-java-decompiler = { module = "com.jetbrains.intellij.java:java-decompiler-engine", version.ref = "fernFlowerVersion" }
 
 com-github-fwcd-ktfmt = { module = "com.github.fwcd.ktfmt:ktfmt", version = "b5d31d1" }
 

platform/build.gradle.kts

@@ -15,7 +15,7 @@ dependencies {
         api(libs.org.jetbrains.kotlin.sam.with.receiver.compiler.plugin)
         api(libs.org.jetbrains.kotlin.reflect)
         api(libs.org.jetbrains.kotlin.jvm)
-        api(libs.org.jetbrains.fernflower)
+        api(libs.com.jetbrains.intellij.java.decompiler)
         api(libs.org.jetbrains.exposed.core)
         api(libs.org.jetbrains.exposed.dao)
         api(libs.org.jetbrains.exposed.jdbc)

server/build.gradle.kts

@@ -19,16 +19,13 @@ application {
     mainClass.set(serverMainClassName)
     description = "Code completions, diagnostics and more for Kotlin"
     applicationDefaultJvmArgs = listOf("-DkotlinLanguageServer.version=$version")
-    applicationDistribution.into("bin") {
-        filePermissions { unix("755".toInt(radix = 8)) }
-    }
+    applicationDistribution.into("bin") { filePermissions { unix("755".toInt(radix = 8)) } }
 }
 
 repositories {
     maven(url = "https://repo.gradle.org/gradle/libs-releases")
-    maven { url = uri("$projectDir/lib") }
-    maven(uri("$projectDir/lib"))
     maven("https://jitpack.io")
+    maven(url = "https://www.jetbrains.com/intellij-repository/releases")
     mavenCentral()
 }
 
@@ -48,7 +45,7 @@ dependencies {
     implementation(kotlin("scripting-jvm-host-unshaded"))
     implementation(kotlin("sam-with-receiver-compiler-plugin"))
     implementation(kotlin("reflect"))
-    implementation(libs.org.jetbrains.fernflower)
+    implementation(libs.com.jetbrains.intellij.java.decompiler)
     implementation(libs.org.jetbrains.exposed.core)
     implementation(libs.org.jetbrains.exposed.dao)
     implementation(libs.org.jetbrains.exposed.jdbc)
@@ -79,9 +76,9 @@ tasks.register<Exec>("fixFilePermissions") {
 
     onlyIf { !System.getProperty("os.name").lowercase().contains("windows") }
     commandLine(
-            "chmod",
-            "+x",
-            "${tasks.installDist.get().destinationDir}/bin/kotlin-language-server"
+        "chmod",
+        "+x",
+        "${tasks.installDist.get().destinationDir}/bin/kotlin-language-server",
     )
 }
 

server/lib/fernflower-license.txt

@@ -21,7 +21,7 @@ class ClassContentProvider(
     private val cp: CompilerClassPath,
     private val tempDir: TemporaryDirectory,
     private val sourceArchiveProvider: SourceArchiveProvider,
-    private val decompiler: Decompiler = FernflowerDecompiler()
+    private val decompiler: Decompiler = FernFlowerDecompiler()
 ) {
     /** Maps recently used (source-)KLS-URIs to their source contents (e.g. decompiled code) and the file extension. */
     private val cachedContents = object : LinkedHashMap<String, Pair<String, String>>() {

server/lib/gradle-kotlin-dsl-tooling-models-0.11.0-license.txt

@@ -0,0 +1,48 @@
+package org.javacs.kt.externalsources
+
+import java.nio.file.Files
+import java.nio.file.Path
+import org.javacs.kt.LOG
+import org.javacs.kt.util.KotlinLSException
+import org.javacs.kt.util.replaceExtensionWith
+import org.javacs.kt.util.withCustomStdout
+import org.jetbrains.java.decompiler.main.decompiler.ConsoleDecompiler
+
+class FernFlowerDecompiler : Decompiler {
+    private val outputDir: Path by lazy {
+        Files.createTempDirectory("fernflowerOut").also {
+            Runtime.getRuntime().addShutdownHook(Thread { it.toFile().deleteRecursively() })
+        }
+    }
+
+    private val decompilerOptions =
+        arrayOf(
+            "-iec=1", // Include entire classpath for better context
+            "-jpr=1", // Include parameter names in method signatures
+        )
+
+    override fun decompileClass(compiledClass: Path): Path {
+        return decompile(compiledClass, ".java")
+    }
+
+    override fun decompileJar(compiledJar: Path): Path {
+        return decompile(compiledJar, ".jar")
+    }
+
+    private fun decompile(input: Path, extension: String): Path {
+        LOG.info("Decompiling ${input.fileName} using FernFlower...")
+
+        val args = decompilerOptions + arrayOf(input.toString(), outputDir.toString())
+
+        withCustomStdout(LOG.outStream) { ConsoleDecompiler.main(args) }
+
+        val outName = input.fileName.replaceExtensionWith(extension)
+        val outPath = outputDir.resolve(outName)
+        if (!Files.exists(outPath)) {
+            throw KotlinLSException(
+                "Could not decompile ${input.fileName}: FernFlower did not generate sources at $outName"
+            )
+        }
+        return outPath
+    }
+}