1 files changed, 104 insertions, 0 deletions
diff --git a/src/main/java/com/code_intelligence/jazzer/utils/Log.java b/src/main/java/com/code_intelligence/jazzer/utils/Log.java
new file mode 100644
index 00000000..bccd3a32
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+++ b/src/main/java/com/code_intelligence/jazzer/utils/Log.java
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2023 Code Intelligence GmbH
+ *
+ * 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 com.code_intelligence.jazzer.utils;
+
+import java.io.PrintStream;
+
+/**
+ * Provides static functions that should be used for any kind of output (structured or unstructured)
+ * emitted by the fuzzer.
+ *
+ * <p>Output is printed to {@link System#err} and {@link System#out} until {@link
+ * Log#fixOutErr(PrintStream, PrintStream)} is called, which locks in the {@link PrintStream}s to be
+ * used from there on.
+ */
+public class Log {
+  // Don't use directly, always use getOut() and getErr() instead - when these fields haven't been
+  // set yet, we want to resolve them dynamically as System.out and System.err, which may change
+  // over the course of the fuzzer's lifetime.
+  private static PrintStream fixedOut;
+  private static PrintStream fixedErr;
+
+  /**
+   * The {@link PrintStream}s to use for all output from this call on.
+   */
+  public static void fixOutErr(PrintStream out, PrintStream err) {
+    if (out == null) {
+      throw new IllegalArgumentException("out must not be null");
+    }
+    if (err == null) {
+      throw new IllegalArgumentException("err must not be null");
+    }
+    Log.fixedOut = out;
+    Log.fixedErr = err;
+  }
+
+  public static void println(String message) {
+    getErr().println(message);
+  }
+
+  public static void structuredOutput(String output) {
+    getOut().println(output);
+  }
+
+  public static void info(String message) {
+    println("INFO: ", message, null);
+  }
+
+  public static void warn(String message) {
+    warn(message, null);
+  }
+
+  public static void warn(String message, Throwable t) {
+    println("WARN: ", message, t);
+  }
+
+  public static void error(String message) {
+    error(message, null);
+  }
+
+  public static void error(Throwable t) {
+    error(null, t);
+  }
+
+  public static void error(String message, Throwable t) {
+    println("ERROR: ", message, t);
+  }
+
+  public static void finding(Throwable t) {
+    println("\n== Java Exception: ", null, t);
+  }
+
+  private static void println(String prefix, String message, Throwable t) {
+    PrintStream err = getErr();
+    err.print(prefix);
+    if (message != null) {
+      err.println(message + (t != null ? ":" : ""));
+    }
+    if (t != null) {
+      t.printStackTrace(err);
+    }
+  }
+
+  private static PrintStream getOut() {
+    return fixedOut != null ? fixedOut : System.out;
+  }
+
+  private static PrintStream getErr() {
+    return fixedErr != null ? fixedErr : System.err;
+  }
+}