xref: /llvm-project-15.0.7/lldb/bindings/lua/lua-wrapper.swig (revision a52af6d3)

%header %{

template <typename T>
void
PushSBClass(lua_State* L, T* obj);

// This function is called from Lua::CallBreakpointCallback
llvm::Expected<bool>
lldb_private::LLDBSwigLuaBreakpointCallbackFunction
(
   lua_State *L,
   lldb::StackFrameSP stop_frame_sp,
   lldb::BreakpointLocationSP bp_loc_sp,
   StructuredDataImpl *extra_args_impl
)
{
   lldb::SBFrame sb_frame(stop_frame_sp);
   lldb::SBBreakpointLocation sb_bp_loc(bp_loc_sp);
   int nargs = 2;

   llvm::Optional<lldb::SBStructuredData> extra_args;
   if (extra_args_impl)
      extra_args = lldb::SBStructuredData(extra_args_impl);

   // Push the Lua wrappers
   PushSBClass(L, &sb_frame);
   PushSBClass(L, &sb_bp_loc);

   if (extra_args.hasValue()) {
      PushSBClass(L, extra_args.getPointer());
      nargs++;
   }

   // Call into the Lua callback passing 'sb_frame' and 'sb_bp_loc'.
   // Expects a boolean return.
   if (lua_pcall(L, nargs, 1, 0) != LUA_OK) {
      llvm::Error E = llvm::make_error<llvm::StringError>(
            llvm::formatv("{0}\n", lua_tostring(L, -1)),
            llvm::inconvertibleErrorCode());
      // Pop error message from the stack.
      lua_pop(L, 1);
      return std::move(E);
   }

   // Boolean return from the callback
   bool stop = lua_toboolean(L, -1);
   lua_pop(L, 1);

   return stop;
}

// This function is called from Lua::CallWatchpointCallback
llvm::Expected<bool>
lldb_private::LLDBSwigLuaWatchpointCallbackFunction
(
   lua_State *L,
   lldb::StackFrameSP stop_frame_sp,
   lldb::WatchpointSP wp_sp
)
{
   lldb::SBFrame sb_frame(stop_frame_sp);
   lldb::SBWatchpoint sb_wp(wp_sp);
   int nargs = 2;

   // Push the Lua wrappers
   PushSBClass(L, &sb_frame);
   PushSBClass(L, &sb_wp);

   // Call into the Lua callback passing 'sb_frame' and 'sb_wp'.
   // Expects a boolean return.
   if (lua_pcall(L, nargs, 1, 0) != LUA_OK) {
      llvm::Error E = llvm::make_error<llvm::StringError>(
            llvm::formatv("{0}\n", lua_tostring(L, -1)),
            llvm::inconvertibleErrorCode());
      // Pop error message from the stack.
      lua_pop(L, 1);
      return std::move(E);
   }

   // Boolean return from the callback
   bool stop = lua_toboolean(L, -1);
   lua_pop(L, 1);

   return stop;
}

static void
LLDBSwigLuaCallLuaLogOutputCallback(const char *str, void *baton) {
   lua_State *L = (lua_State *)baton;

   lua_pushlightuserdata(L, (void *)&LLDBSwigLuaCallLuaLogOutputCallback);
   lua_gettable(L, LUA_REGISTRYINDEX);

   // FIXME: There's no way to report errors back to the user
   lua_pushstring(L, str);
   lua_pcall(L, 1, 0, 0);
}

static int LLDBSwigLuaCloseFileHandle(lua_State *L) {
   return luaL_error(L, "You cannot close a file handle used by lldb.");
}

%}