ReaScript IDE reload prompt bypass https://i.imgur.com/kY34oAN.gif

reaper_ideautoreload.cpp

// c++ -fPIC -O2 -std=c++14 -DSWELL_PROVIDED_BY_APP -IWDL -IWDL/WDL -dynamiclib reaper_idenoreload.cpp WDL/WDL/swell/swell-modstub.mm -lc++ -framework AppKit -o reaper_ideautoreload.dylib
//
// cl /nologo /O2 reaper_idenoreload.cpp User32.lib /link /OPT:REF /PDBALTPATH:%_PDB% /DLL /OUT:reaper_ideautoreload.dll

#ifndef _WIN32
#  include <sys/mman.h>
#  include <WDL/wdltypes.h>
#endif

#include <cstdint>

#define REAPERAPI_IMPLEMENT
#include "reaper_plugin_functions.h"

constexpr int RELOAD_TIMER { 3 };

static WNDPROC g_ideProc;
static unsigned int g_mode;

template<typename T>
bool patch(const uintptr_t addr, const T newCode, T *backup = nullptr)
{
  uint8_t *firstByte { reinterpret_cast<uint8_t *>(addr) };

  if(backup)
    memcpy(backup, firstByte, sizeof(T));

#ifdef _WIN32
  DWORD oldProtect;
  if(!VirtualProtect(firstByte, sizeof(T), PAGE_READWRITE, &oldProtect))
    return false;
#else
  const auto pageSize { sysconf(_SC_PAGE_SIZE) };
  void *pageStart { reinterpret_cast<void *>(addr - (addr % pageSize)) };
  if(mprotect(pageStart, pageSize, PROT_READ | PROT_WRITE))
    return false;
#endif

  memcpy(firstByte, &newCode, sizeof(T));

#ifdef _WIN32
  VirtualProtect(firstByte, sizeof(T), oldProtect, &oldProtect);
#else
  mprotect(pageStart, pageSize, PROT_READ | PROT_EXEC);
#endif

  return true;
}

#ifdef _WIN32
#  pragma pack(push, 1)
#  define packed
#else
#  define packed __attribute__((packed))
#endif
struct packed Jump {
#if defined(__x86_64__) || defined(_WIN64)
  // uint8_t int3 = 0xcc;
  uint8_t mov = 0x48, reg = 0xb8; uint64_t dest; // mov rax, dest
  uint8_t jmp = 0xff, modr_m = 0xe0;             // jmp rax
#else
#  error Unimplemented architecture
#endif
};
#ifdef _WIN32
#  pragma pack(pop)
#endif

class Redirect {
public:
  Redirect(const uintptr_t funcAddr, const uintptr_t redirect)
    : m_funcAddr { funcAddr }
  {
    Jump jump;
    jump.dest = redirect;
    patch(m_funcAddr, jump, &m_code);
  }

  ~Redirect()
  {
    patch(m_funcAddr, m_code);
  }

private:
  uintptr_t m_funcAddr;
  Jump m_code;
};

static bool updateMode()
{
  // FIXME: UTF-8 support on Windows
  g_mode = GetPrivateProfileInt("reascriptedit", "autoreload", 1, get_ini_file());
  return g_mode < 2;
}

static int WINAPI fakePrompt(HWND, const char *, const char *, const unsigned int)
{
  return g_mode == 0 ? IDNO : IDYES;
}

static LRESULT CALLBACK bypassReloadProc(HWND hwnd, UINT msg,
  WPARAM wParam, LPARAM lParam)
{
  if(msg != WM_TIMER || wParam != RELOAD_TIMER || !updateMode())
    return g_ideProc(hwnd, msg, wParam, lParam);

#ifdef _WIN32
  Redirect mba { reinterpret_cast<uintptr_t>(&MessageBoxA),
                 reinterpret_cast<uintptr_t>(&fakePrompt) },
           mbw { reinterpret_cast<uintptr_t>(&MessageBoxW),
                 reinterpret_cast<uintptr_t>(&fakePrompt) };
#else // function pointer under SWELL
  Redirect mb { reinterpret_cast<uintptr_t>(MessageBox),
                reinterpret_cast<uintptr_t>(&fakePrompt) };
#endif

  return g_ideProc(hwnd, msg, wParam, lParam);
}

static void installBypassProc(HWND hwnd)
{
  LONG_PTR newProc { reinterpret_cast<LONG_PTR>(&bypassReloadProc) },
           oldProc { SetWindowLongPtr(hwnd, GWLP_WNDPROC, newProc) };
  if(oldProc != newProc)
    g_ideProc = reinterpret_cast<WNDPROC>(oldProc);
}

static BOOL CALLBACK findIde(HWND hwnd, LPARAM)
{
  char title[1024];
  GetWindowText(hwnd, title, sizeof(title));

  // FIXME: localize title string
  if(strstr(title, "ReaScript Development Environment"))
    installBypassProc(hwnd);

  return TRUE;
}

static void pollIdeWindows()
{
#ifdef _WIN32
  EnumThreadWindows(GetCurrentThreadId(), &findIde, 0);
#else
  EnumWindows(&findIde, 0);
#endif
}

extern "C" REAPER_PLUGIN_DLL_EXPORT int REAPER_PLUGIN_ENTRYPOINT(
  REAPER_PLUGIN_HINSTANCE instance, reaper_plugin_info_t *rec)
{
  if(!rec || rec->caller_version != REAPER_PLUGIN_VERSION)
    return 0;
 
  get_ini_file    = reinterpret_cast<decltype(get_ini_file   )>(rec->GetFunc("get_ini_file"));
  plugin_register = reinterpret_cast<decltype(plugin_register)>(rec->GetFunc("plugin_register"));
  plugin_register("timer", reinterpret_cast<void *>(&pollIdeWindows));

  return 1;
}