// 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.

package com.code_intelligence.jazzer.runtime;

import com.code_intelligence.jazzer.api.HookType;
import com.code_intelligence.jazzer.api.MethodHook;
import java.lang.invoke.MethodHandle;

@SuppressWarnings("unused")
final public class TraceDivHooks {
  @MethodHook(type = HookType.BEFORE, targetClassName = "java.lang.Integer",
      targetMethod = "divideUnsigned", targetMethodDescriptor = "(II)I")
  @MethodHook(type = HookType.BEFORE, targetClassName = "java.lang.Integer",
      targetMethod = "remainderUnsigned", targetMethodDescriptor = "(II)I")
  public static void
  intUnsignedDivide(MethodHandle method, Object thisObject, Object[] arguments, int hookId) {
    // Since the arguments are to be treated as unsigned integers we need a long to fit the
    // divisor.
    TraceDataFlowNativeCallbacks.traceDivLong(Integer.toUnsignedLong((int) arguments[1]), hookId);
  }

  @MethodHook(type = HookType.BEFORE, targetClassName = "java.lang.Long",
      targetMethod = "divideUnsigned", targetMethodDescriptor = "(JJ)J")
  @MethodHook(type = HookType.BEFORE, targetClassName = "java.lang.Long",
      targetMethod = "remainderUnsigned", targetMethodDescriptor = "(JJ)J")
  public static void
  longUnsignedDivide(MethodHandle method, Object thisObject, Object[] arguments, int hookId) {
    long divisor = (long) arguments[1];
    // Run the callback only if the divisor, which is regarded as an unsigned long, fits in a
    // signed long, i.e., does not have the sign bit set.
    if (divisor > 0) {
      TraceDataFlowNativeCallbacks.traceDivLong(divisor, hookId);
    }
  }
}