// Copyright 2022 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.runtime;

import com.github.fmeum.rules_jni.RulesJni;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodType;
import jdk.incubator.foreign.CLinker;
import jdk.incubator.foreign.FunctionDescriptor;
import jdk.incubator.foreign.MemoryAddress;
import jdk.incubator.foreign.MemoryLayout;
import jdk.incubator.foreign.MemorySegment;
import jdk.incubator.foreign.ResourceScope;
import jdk.incubator.foreign.SymbolLookup;

/**
 * Pure-Java implementation of the fuzzer callbacks backed by Project Panama (requires JDK 16+).
 * To include the implementation in the benchmark on a supported JDK, uncomment the relevant lines
 * in BUILD.bazel.
 */
public class FuzzerCallbacksPanama {
  static {
    RulesJni.loadLibrary("fuzzer_callbacks", FuzzerCallbacks.class);
  }

  private static final MethodHandle traceCmp4 = CLinker.getInstance().downcallHandle(
      SymbolLookup.loaderLookup().lookup("__sanitizer_cov_trace_cmp4").get(),
      MethodType.methodType(void.class, int.class, int.class),
      FunctionDescriptor.ofVoid(CLinker.C_INT, CLinker.C_INT));
  private static final MethodHandle traceSwitch = CLinker.getInstance().downcallHandle(
      SymbolLookup.loaderLookup().lookup("__sanitizer_cov_trace_switch").get(),
      MethodType.methodType(void.class, long.class, MemoryAddress.class),
      FunctionDescriptor.ofVoid(CLinker.C_LONG, CLinker.C_POINTER));

  static void traceCmpInt(int arg1, int arg2, int pc) throws Throwable {
    traceCmp4.invokeExact(arg1, arg2);
  }

  static void traceCmpSwitch(long val, long[] cases, int pc) throws Throwable {
    try (ResourceScope scope = ResourceScope.newConfinedScope()) {
      MemorySegment nativeCopy = MemorySegment.allocateNative(
          MemoryLayout.sequenceLayout(cases.length, CLinker.C_LONG), scope);
      nativeCopy.copyFrom(MemorySegment.ofArray(cases));
      traceSwitch.invokeExact(val, nativeCopy.address());
    }
  }
}