[lldb-dap] Refactor lldb-dap.cpp to not use global DAP variable. (llvm#116272)

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.

(cherry picked from commit 3121f75)

Author: ashgti

lldb/tools/lldb-dap/DAP.cpp

@@ -32,19 +32,18 @@ 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),
+DAP::DAP(llvm::StringRef path, ReplMode repl_mode)
+    : debug_adaptor_path(path), broadcaster("lldb-dap"),
+      exception_breakpoints(), focus_tid(LLDB_INVALID_THREAD_ID),
+      stop_at_entry(false), is_attach(false),
       enable_auto_variable_summaries(false),
       enable_synthetic_child_debugging(false),
       display_extended_backtrace(false),
       restarting_process_id(LLDB_INVALID_PROCESS_ID),
       configuration_done_sent(false), waiting_for_run_in_terminal(false),
       progress_event_reporter(
           [&](const ProgressEvent &event) { SendJSON(event.ToJSON()); }),
-      reverse_request_seq(0), repl_mode(ReplMode::Auto) {
+      reverse_request_seq(0), repl_mode(repl_mode) {
   const char *log_file_path = getenv("LLDBDAP_LOG");
 #if defined(_WIN32)
   // Windows opens stdout and stdin in text mode which converts \n to 13,10
@@ -695,15 +694,15 @@ 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 {
@@ -137,7 +137,7 @@ struct SendEventRequestHandler : public lldb::SBCommandPluginInterface {
 };
 
 struct DAP {
-  std::string debug_adaptor_path;
+  llvm::StringRef debug_adaptor_path;
   InputStream input;
   OutputStream output;
   lldb::SBDebugger debugger;
@@ -198,7 +198,7 @@ struct DAP {
   // will contain that expression.
   std::string last_nonempty_var_expression;
 
-  DAP();
+  DAP(llvm::StringRef path, ReplMode repl_mode);
   ~DAP();
   DAP(const DAP &rhs) = delete;
   void operator=(const DAP &rhs) = delete;
@@ -353,8 +353,6 @@ struct DAP {
   void SendJSON(const std::string &json_str);
 };
 
-extern DAP g_dap;
-
 } // namespace lldb_dap
 
 #endif