From 3f4b4990679a9a322fb7df64e76e93c13b175831 Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <robert@ocallahan.org>
Date: Sat, 25 Jan 2025 22:37:34 +1300
Subject: [PATCH] Handle various LLDB protocol extensions only if we know we're
 talking to LLDB.

Then if GDB implements any of these extensions in an incompatible way, we won't
be broken.
---
 src/GdbServerConnection.cc | 39 ++++++++++++++++++++++++++------------
 src/GdbServerConnection.h  |  1 +
 2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/GdbServerConnection.cc b/src/GdbServerConnection.cc
index abd72389675..8668cad9ebb 100644
--- a/src/GdbServerConnection.cc
+++ b/src/GdbServerConnection.cc
@@ -831,7 +831,8 @@ bool GdbServerConnection::query(char* payload) {
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "MemoryRegionInfo") && args) {
+  if (!strcmp(name, "MemoryRegionInfo") && args &&
+      debugger_type == DebuggerType::LLDB) {
     req = GdbRequest(DREQ_MEM_INFO);
     req.target = query_thread;
     req.mem().addr = strtoul(args, &args, 16);
@@ -849,7 +850,7 @@ bool GdbServerConnection::query(char* payload) {
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "HostInfo")) {
+  if (!strcmp(name, "HostInfo") && debugger_type == DebuggerType::LLDB) {
     // lldb-server sends a reply like
     // triple:7838365f36342d2d6c696e75782d676e75;ptrsize:8;distribution_id:6665646f7261;
     // watchpoint_exceptions_received:after;endian:little;os_version:6.6.13;
@@ -860,12 +861,12 @@ bool GdbServerConnection::query(char* payload) {
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "VAttachOrWaitSupported")) {
+  if (!strcmp(name, "VAttachOrWaitSupported") && debugger_type == DebuggerType::LLDB) {
     // We don't handle vAttach and variants.
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "ProcessInfo")) {
+  if (!strcmp(name, "ProcessInfo") && debugger_type == DebuggerType::LLDB) {
     // lldb-server sends a reply like
     // pid:3663df;parent-pid:3663de;real-uid:3e8;real-gid:3e8;effective-uid:3e8;effective-gid:3e8;
     // triple:7838365f36342d2d6c696e75782d676e75;ostype:linux;endian:little;ptrsize:8
@@ -874,12 +875,12 @@ bool GdbServerConnection::query(char* payload) {
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "StructuredDataPlugins")) {
+  if (!strcmp(name, "StructuredDataPlugins") && debugger_type == DebuggerType::LLDB) {
     // This isn't documented and lldb-server doesn't support it
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "ShlibInfoAddr")) {
+  if (!strcmp(name, "ShlibInfoAddr") && debugger_type == DebuggerType::LLDB) {
     // This isn't documented and lldb-server doesn't seem to support it
     write_packet("");
     return false;
@@ -890,7 +891,10 @@ bool GdbServerConnection::query(char* payload) {
 }
 
 // LLDB QThreadSuffixSupported extension
-static void parse_thread_suffix_threadid(char* payload, GdbThreadId* out) {
+void GdbServerConnection::parse_thread_suffix_threadid(char* payload, GdbThreadId* out) {
+  if (debugger_type != DebuggerType::LLDB) {
+    return;
+  }
   char* semicolon = strrchr(payload, ';');
   if (!semicolon) {
     return;
@@ -947,27 +951,32 @@ bool GdbServerConnection::set_var(char* payload) {
     write_packet("OK");
     return false;
   }
-  if (!strcmp(name, "ListThreadsInStopReply")) {
+  if (!strcmp(name, "ListThreadsInStopReply") &&
+      debugger_type == DebuggerType::LLDB) {
     write_packet("OK");
     list_threads_in_stop_reply_ = true;
     return false;
   }
 
-  if (!strcmp(name, "ThreadSuffixSupported")) {
+  if (!strcmp(name, "ThreadSuffixSupported") &&
+      debugger_type == DebuggerType::LLDB) {
     write_packet("OK");
     return false;
   }
-  if (!strcmp(name, "EnableErrorStrings")) {
+  if (!strcmp(name, "EnableErrorStrings") &&
+      debugger_type == DebuggerType::LLDB) {
     // We don't support human-readable error strings.
     write_packet("");
     return false;
   }
-  if (!strcmp(name, "SaveRegisterState")) {
+  if (!strcmp(name, "SaveRegisterState") &&
+      debugger_type == DebuggerType::LLDB) {
     req = GdbRequest(DREQ_SAVE_REGISTER_STATE);
     req.target = target;
     return true;
   }
-  if (!strcmp(name, "RestoreRegisterState")) {
+  if (!strcmp(name, "RestoreRegisterState") &&
+      debugger_type == DebuggerType::LLDB) {
     req = GdbRequest(DREQ_RESTORE_REGISTER_STATE);
     req.target = target;
     char* end;
@@ -985,6 +994,9 @@ bool GdbServerConnection::process_underscore(char* payload) {
 
   switch (payload[0]) {
     case 'M': {
+      if (debugger_type != DebuggerType::LLDB) {
+        break;
+      }
       char* end = nullptr;
       req = GdbRequest(DREQ_MEM_ALLOC);
       req.mem_alloc().size = strtol(args, &end, 16);
@@ -1006,6 +1018,9 @@ bool GdbServerConnection::process_underscore(char* payload) {
       return true;
     }
     case 'm': {
+      if (debugger_type != DebuggerType::LLDB) {
+        break;
+      }
       char* end = nullptr;
       req = GdbRequest(DREQ_MEM_FREE);
       req.mem_free().address = strtol(args, &end, 16);
diff --git a/src/GdbServerConnection.h b/src/GdbServerConnection.h
index 72e0d8c9b29..6496f33798a 100644
--- a/src/GdbServerConnection.h
+++ b/src/GdbServerConnection.h
@@ -797,6 +797,7 @@ class GdbServerConnection {
   void write_hex_bytes_packet(const uint8_t* bytes, size_t len);
   void write_xfer_response(const void* data, size_t size, uint64_t offset,
                            uint64_t len);
+  void parse_thread_suffix_threadid(char* payload, GdbThreadId* out);
   /**
    * Consume bytes in the input buffer until start-of-packet ('$') or
    * the interrupt character is seen.  Does not block.  Return true if