Rewrite GenSources including full support for CFR. (#511)

* Rewrite CFR decompiler interface. Support javadoc

* CFR line numbers and fixes.

* Cleanup and fix

* Use WorkerExecutor to fork, massively cleans up the fernflower code, but does remove the fancy multithreaded logging.

* Use IPC to get logging back from the decompilers.

* Cleanup UnpickJarTask, fix leak in IPCServer

* Used published CFR build

* Handle older windows versions that do not support AF_UNIX.

* Fixes and basic unit test

* Improve memory handling of genSources

* Stop decompile worker JVM

1 files changed, 88 insertions, 0 deletions

diff --git a/src/main/java/net/fabricmc/loom/util/ipc/IPCServer.java b/src/main/java/net/fabricmc/loom/util/ipc/IPCServer.java
new file mode 100644
index 00000000..7c8158a8
--- /dev/null
+++ b/src/main/java/net/fabricmc/loom/util/ipc/IPCServer.java
@@ -0,0 +1,88 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2021 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.util.ipc;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.StandardProtocolFamily;
+import java.net.UnixDomainSocketAddress;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.util.Scanner;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Consumer;
+
+public class IPCServer implements AutoCloseable {
+	private final ExecutorService loggerReceiverService = Executors.newSingleThreadExecutor();
+	private final Path path;
+	private final Consumer<String> consumer;
+
+	private final CountDownLatch startupLock = new CountDownLatch(1);
+
+	public IPCServer(Path path, Consumer<String> consumer) {
+		this.path = path;
+		this.consumer = consumer;
+
+		loggerReceiverService.submit(this::run);
+
+		try {
+			startupLock.await(10, TimeUnit.SECONDS);
+		} catch (InterruptedException e) {
+			throw new RuntimeException("Timed out waiting for IPC server thread to start", e);
+		}
+	}
+
+	public void run() {
+		UnixDomainSocketAddress address = UnixDomainSocketAddress.of(path);
+
+		try (ServerSocketChannel serverChannel = ServerSocketChannel.open(StandardProtocolFamily.UNIX)) {
+			serverChannel.bind(address);
+
+			startupLock.countDown();
+
+			try (SocketChannel clientChannel = serverChannel.accept();
+					Scanner scanner = new Scanner(clientChannel, StandardCharsets.UTF_8)) {
+				while (!Thread.currentThread().isInterrupted()) {
+					if (scanner.hasNextLine()) {
+						this.consumer.accept(scanner.nextLine());
+					}
+				}
+			}
+		} catch (IOException e) {
+			throw new UncheckedIOException("Failed to listen for IPC messages", e);
+		}
+	}
+
+	@Override
+	public void close() throws InterruptedException {
+		loggerReceiverService.shutdownNow();
+		loggerReceiverService.awaitTermination(10, TimeUnit.SECONDS);
+	}
+}