1 files changed, 58 insertions, 0 deletions
diff --git a/driver/coverage_tracker.h b/driver/coverage_tracker.h
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+++ b/driver/coverage_tracker.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2021 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.
+ */
+
+#pragma once
+
+#include <jni.h>
+
+#include <string>
+
+#include "jvm_tooling.h"
+
+namespace jazzer {
+
+// The members of this struct are only accessed by libFuzzer.
+struct __attribute__((packed)) PCTableEntry {
+  [[maybe_unused]] uintptr_t PC, PCFlags;
+};
+
+// CoverageTracker registers an array of 8-bit coverage counters with
+// libFuzzer. The array is backed by a MappedByteBuffer on the Java
+// side, where it is populated with the actual coverage information.
+class CoverageTracker : public ExceptionPrinter {
+ private:
+  static uint8_t *counters_;
+
+  static uint32_t *fake_instructions_;
+  static PCTableEntry *pc_entries_;
+
+  static void JNICALL RegisterNewCoverageCounters(JNIEnv &env, jclass cls);
+
+ public:
+  static void Setup(JNIEnv &env);
+  // Clears the coverage counters array manually. It is cleared automatically
+  // by libFuzzer prior to running the fuzz target, so this function is only
+  // used in tests.
+  static void Clear();
+
+  // Returns the address of the coverage counters array.
+  static uint8_t *GetCoverageCounters();
+
+  static void RecordInitialCoverage(JNIEnv &env);
+  static void ReplayInitialCoverage(JNIEnv &env);
+  static std::string ComputeCoverage(JNIEnv &env);
+};
+}  // namespace jazzer