1 files changed, 48 insertions, 0 deletions
diff --git a/agent/src/main/java/com/code_intelligence/jazzer/instrumentor/HookInstrumentor.kt b/agent/src/main/java/com/code_intelligence/jazzer/instrumentor/HookInstrumentor.kt
new file mode 100644
index 00000000..ac5f1780
--- /dev/null
+++ b/agent/src/main/java/com/code_intelligence/jazzer/instrumentor/HookInstrumentor.kt
@@ -0,0 +1,48 @@
+// 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.instrumentor
+
+import com.code_intelligence.jazzer.third_party.objectweb.asm.ClassReader
+import com.code_intelligence.jazzer.third_party.objectweb.asm.ClassVisitor
+import com.code_intelligence.jazzer.third_party.objectweb.asm.ClassWriter
+import com.code_intelligence.jazzer.third_party.objectweb.asm.MethodVisitor
+
+internal class HookInstrumentor(private val hooks: Iterable<Hook>, private val java6Mode: Boolean) : Instrumentor {
+
+    private lateinit var random: DeterministicRandom
+
+    override fun instrument(bytecode: ByteArray): ByteArray {
+        val reader = ClassReader(bytecode)
+        val writer = ClassWriter(reader, ClassWriter.COMPUTE_MAXS)
+        random = DeterministicRandom("hook", reader.className)
+        val interceptor = object : ClassVisitor(Instrumentor.ASM_API_VERSION, writer) {
+            override fun visitMethod(
+                access: Int,
+                name: String?,
+                descriptor: String?,
+                signature: String?,
+                exceptions: Array<String>?,
+            ): MethodVisitor? {
+                val mv = cv.visitMethod(access, name, descriptor, signature, exceptions) ?: return null
+                return if (shouldInstrument(access))
+                    makeHookMethodVisitor(access, descriptor, mv, hooks, java6Mode, random)
+                else
+                    mv
+            }
+        }
+        reader.accept(interceptor, ClassReader.EXPAND_FRAMES)
+        return writer.toByteArray()
+    }
+}