[lldb] Add QSupported key to report watchpoint types supported (#80376)

debugserver on arm64 devices can manage both Byte Address Select
watchpoints (1-8 bytes) and MASK watchpoints (8 bytes-2 gigabytes). This
adds a SupportedWatchpointTypes key to the QSupported response from
debugserver with a list of these, so lldb can take full advantage of
them when creating larger regions with a single hardware watchpoint.

Also add documentation for this, and two other lldb extensions, to the
lldb-gdb-remote.txt documentation.

Re-enable TestLargeWatchpoint.py on Darwin systems when testing with the
in-tree built debugserver. I can remove the "in-tree built debugserver"
in the future when this new key is handled by an Xcode debugserver.

1 files changed, 1 insertions, 10 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 4e3447e..629b191 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -3156,16 +3156,7 @@ Status ProcessGDBRemote::EnableWatchpoint(WatchpointSP wp_sp, bool notify) {
 
   ArchSpec target_arch = GetTarget().GetArchitecture();
   WatchpointHardwareFeature supported_features =
-      eWatchpointHardwareFeatureUnknown;
-
-  // LWP_TODO: enable MASK watchpoint for arm64 debugserver
-  // when it reports that it supports them.
-  if (target_arch.GetTriple().getOS() == llvm::Triple::MacOSX &&
-      target_arch.GetTriple().getArch() == llvm::Triple::aarch64) {
-#if 0
-       supported_features |= eWatchpointHardwareArmMASK;
-#endif
-  }
+      m_gdb_comm.GetSupportedWatchpointTypes();
 
   std::vector<WatchpointResourceSP> resources =
       WatchpointAlgorithms::AtomizeWatchpointRequest(