Complex lib target for private member fn hooking

This is slightly more complex than the basic target, because the private
member function to be hooked / called makes use of `this`.

That means an actual instance of the class must be constructed and setup
according to the calling convention of the private function before the
call can be made.

cpp/.gitignore

@@ -1,3 +1,5 @@
 /app/app_basic
+/app/app_complex
 /target/libtarget_basic.so
+/target/libtarget_complex.so
 /hooks/call_private_basic

cpp/app/build.sh

@@ -5,3 +5,9 @@ if [[ -f ./app_basic ]]; then
 fi
 
 clang++ -I../target/include/ -L../target/ -ltarget_basic ./src/app_basic.cpp -o app_basic
+
+if [[ -f ./app_complex ]]; then
+  rm ./app_complex
+fi
+
+clang++ -I../target/include/ -L../target/ -ltarget_complex ./src/app_complex.cpp -o app_complex

cpp/app/src/app_complex.cpp

@@ -0,0 +1,16 @@
+#include <iostream>
+#include <cstdlib>
+#include "target_complex.hpp"
+
+int main(int argc, char **argv) {
+  if(argc < 2) {
+    std::cout << "Usage: " << argv[0] << " <integer>" << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  int input = std::atoi(argv[1]);
+  Target t = Target();
+  t.maybe_say(input);
+
+  return EXIT_SUCCESS;
+}

cpp/target/build.sh

@@ -5,3 +5,9 @@ if [[ -f ./libtarget_basic.so ]]; then
 fi
 
 clang++ -shared -I./include/ ./src/target_basic.cpp -o ./libtarget_basic.so
+
+if [[ -f ./libtarget_complex.so ]]; then
+  rm ./libtarget_complex.so
+fi
+
+clang++ -shared -I./include/ ./src/target_complex.cpp -o ./libtarget_complex.so

cpp/target/include/target_complex.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+// Complex target with private member function
+// which *does* reference `this` to access private
+// member initialized by constructor.
+
+class Target {
+public:
+  void maybe_say(int num);
+  Target();
+  ~Target();
+
+private:
+  void say_something();
+  const char *message;
+};

cpp/target/src/target_complex.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <cstdlib>
+#include "target_complex.hpp"
+
+void __attribute__((__noinline__)) Target::say_something() {
+  std::cout << this->message << std::endl;
+}
+
+void Target::maybe_say(int num) {
+  if(num == std::rand()) {
+    this->say_something();
+  }
+}
+
+Target::Target() {
+  this->message = "This is really something!";
+}
+
+Target::~Target() {
+  this->message = NULL;
+}