[lldb-dap] Refactor lldb-dap.cpp to not use a global variable.

This removes the global DAP variable and instead allocates a DAP instance in main. This should allow us to refactor lldb-dap to enable a server mode that accepts multiple connections.

Author: ashgti

lldb/tools/lldb-dap/DAP.cpp

@@ -32,8 +32,6 @@ using namespace lldb_dap;
 
 namespace lldb_dap {
 
-DAP g_dap;
-
 DAP::DAP()
     : broadcaster("lldb-dap"), exception_breakpoints(),
       focus_tid(LLDB_INVALID_THREAD_ID), stop_at_entry(false), is_attach(false),
@@ -693,15 +691,15 @@ bool DAP::HandleObject(const llvm::json::Object &object) {
   if (packet_type == "request") {
     const auto command = GetString(object, "command");
     auto handler_pos = request_handlers.find(command);
-    if (handler_pos != request_handlers.end()) {
-      handler_pos->second(object);
-      return true; // Success
-    } else {
+    if (handler_pos == request_handlers.end()) {
       if (log)
         *log << "error: unhandled command \"" << command.data() << "\""
              << std::endl;
       return false; // Fail
     }
+
+    handler_pos->second(*this, object);
+    return true; // Success
   }
 
   if (packet_type == "response") {

lldb/tools/lldb-dap/DAP.h

@@ -63,7 +63,7 @@ enum DAPBroadcasterBits {
   eBroadcastBitStopProgressThread = 1u << 1
 };
 
-typedef void (*RequestCallback)(const llvm::json::Object &command);
+typedef void (*RequestCallback)(DAP &dap, const llvm::json::Object &command);
 typedef void (*ResponseCallback)(llvm::Expected<llvm::json::Value> value);
 
 enum class PacketStatus {
@@ -353,8 +353,6 @@ struct DAP {
   void SendJSON(const std::string &json_str);
 };
 
-extern DAP g_dap;
-
 } // namespace lldb_dap
 
 #endif