[llvm-branch-commits] [lldb] [lldb] Override UpdateBreakpointSites in ProcessGDBRemote to use MultiBreakpoint (PR #192988)

[Jonas Devlieghere via llvm-branch-commits]

================
@@ -6392,3 +6392,194 @@ void ProcessGDBRemote::DidExec() {
   }
   Process::DidExec();
 }
+
+llvm::Error ProcessGDBRemote::UpdateBreakpointSitesNotBatched(
+    const BreakpointSiteToActionMap &site_to_action) {
+  llvm::Error joined = llvm::Error::success();
+  for (auto &[site, action] : site_to_action) {
+    llvm::Error error = action == Process::BreakpointAction::Enable
+                            ? DoEnableBreakpointSite(*site)
+                            : DoDisableBreakpointSite(*site);
+    joined = llvm::joinErrors(std::move(joined), std::move(error));
+  }
+  return joined;
+}
+
+static llvm::Expected<StringExtractorGDBRemote>
+SendMultiBreakpointPacket(GDBRemoteCommunicationClient &gdb_comm,
+                          llvm::StringRef packet_str,
+                          std::chrono::seconds interrupt_timeout) {
+  StringExtractorGDBRemote response;
+  GDBRemoteCommunication::PacketResult packet_result =
+      gdb_comm.SendPacketAndWaitForResponse(packet_str, response,
+                                            interrupt_timeout);
+  if (packet_result != GDBRemoteCommunication::PacketResult::Success)
+    return llvm::createStringErrorV(
+        "MultiBreakpoint failed to send packet: '{0}'", packet_str);
+
+  if (response.IsUnsupportedResponse())
+    return llvm::createStringErrorV(
+        "MultiBreakpoint unsupported response: '{0}'", response.GetStringRef());
+
+  return response;
+}
+
+/// Parse a MultiBreakpoint response into per-request results.
+/// Returns a vector of results: std::nullopt means OK, a uint8_t value is the
+/// error code from an Exx response.
+static llvm::SmallVector<std::optional<uint8_t>>
+ParseMultiBreakpointResponse(llvm::StringRef response_str) {
+  llvm::SmallVector<std::optional<uint8_t>> results;
+
+  StructuredData::ObjectSP parsed = StructuredData::ParseJSON(response_str);
+  StructuredData::Dictionary *dict =
+      parsed ? parsed->GetAsDictionary() : nullptr;
+  StructuredData::Array *array = nullptr;
+  if (dict)
+    dict->GetValueForKeyAsArray("results", array);
+  if (!array)
+    return results;
+
+  array->ForEach([&results](StructuredData::Object *object) -> bool {
+    llvm::StringRef token;
+    if (auto *string = object->GetAsString())
+      token = string->GetValue();
+    if (token == "OK") {
+      results.push_back(std::nullopt);
+      return true;
+    }
+    if (token.size() != 3 || !token.starts_with("E")) {
+      results.push_back(uint8_t(0xff));
+      return true;
+    }
+    uint8_t error_code = 0;
+    if (token.drop_front(1).getAsInteger(16, error_code))
+      results.push_back(0xff);
+    else
+      results.push_back(error_code);
+    return true;
+  });
+  return results;
+}
+
+/// Determine the GDB stoppoint type for a breakpoint site by checking which
+/// packet types the remote supports (for insertions), or by checking the site
+/// type (for deletions).
+static std::optional<GDBStoppointType>
+GetStoppointType(BreakpointSite &site, bool insert,
+                 GDBRemoteCommunicationClient &gdb_comm) {
+  if (insert) {
+    if (!site.HardwareRequired() &&
+        gdb_comm.SupportsGDBStoppointPacket(eBreakpointSoftware))
+      return eBreakpointSoftware;
+    if (gdb_comm.SupportsGDBStoppointPacket(eBreakpointHardware))
+      return eBreakpointHardware;
+    return std::nullopt;
+  }
+
+  switch (site.GetType()) {
+  case BreakpointSite::eExternal:
+    return eBreakpointSoftware;
+  case BreakpointSite::eHardware:
+    return eBreakpointHardware;
+  case BreakpointSite::eSoftware:
+    return std::nullopt;
----------------
JDevlieghere wrote:

This means that if you have one `eSoftware` site in the batch causes ALL sites to fall back to individual packets. I assume that's uncommon enough that it doesn't undermine the optimization? How hard would it be to filter out the software ones and still batch up the Z packets?

https://github.com/llvm/llvm-project/pull/192988