[Lldb-commits] [lldb] [lldb] Implement ProcessGDBRemote support for ReadMemoryRanges (PR #164311)

[David Spickett via lldb-commits]

================
@@ -2762,6 +2763,107 @@ size_t ProcessGDBRemote::DoReadMemory(addr_t addr, void *buf, size_t size,
   return 0;
 }
 
+llvm::SmallVector<llvm::MutableArrayRef<uint8_t>>
+ProcessGDBRemote::ReadMemoryRanges(
+    llvm::ArrayRef<Range<lldb::addr_t, size_t>> ranges,
+    llvm::MutableArrayRef<uint8_t> buffer) {
+  if (!m_gdb_comm.GetMultiMemReadSupported())
+    return Process::ReadMemoryRanges(ranges, buffer);
+
+  llvm::Expected<StringExtractorGDBRemote> response =
+      SendMultiMemReadPacket(ranges);
+  if (!response) {
+    LLDB_LOG_ERROR(GetLog(GDBRLog::Process), response.takeError(),
+                   "MultiMemRead error response: {0}");
+    return Process::ReadMemoryRanges(ranges, buffer);
+  }
+
+  llvm::StringRef response_str = response->GetStringRef();
+  const unsigned expected_num_ranges = ranges.size();
+  llvm::Expected<llvm::SmallVector<llvm::MutableArrayRef<uint8_t>>>
+      parsed_response =
+          ParseMultiMemReadPacket(response_str, buffer, expected_num_ranges);
+  if (!parsed_response) {
+    LLDB_LOG_ERROR(GetLog(GDBRLog::Process), parsed_response.takeError(),
+                   "MultiMemRead error parsing response: {0}");
+    return Process::ReadMemoryRanges(ranges, buffer);
+  }
+  return std::move(*parsed_response);
+}
+
+llvm::Expected<StringExtractorGDBRemote>
+ProcessGDBRemote::SendMultiMemReadPacket(
+    llvm::ArrayRef<Range<lldb::addr_t, size_t>> ranges) {
+  std::string packet_str;
+  llvm::raw_string_ostream stream(packet_str);
+  stream << "MultiMemRead:ranges:";
+
+  auto range_to_stream = [&](auto range) {
+    // the "-" marker omits the '0x' prefix.
+    stream << llvm::formatv("{0:x-},{1:x-}", range.base, range.size);
+  };
+  llvm::interleave(ranges, stream, range_to_stream, ",");
+  stream << ";";
+
+  StringExtractorGDBRemote response;
+  GDBRemoteCommunication::PacketResult packet_result =
+      m_gdb_comm.SendPacketAndWaitForResponse(packet_str.data(), response,
+                                              GetInterruptTimeout());
+  if (packet_result != GDBRemoteCommunication::PacketResult::Success)
+    return llvm::createStringError(
+        llvm::formatv("MultiMemRead failed to send packet: '{0}'", packet_str));
+
+  if (response.IsErrorResponse())
+    return llvm::createStringError(
+        llvm::formatv("MultiMemRead failed: '{0}'", response.GetStringRef()));
+
+  if (!response.IsNormalResponse())
+    return llvm::createStringError(llvm::formatv(
+        "MultiMemRead unexpected response: '{0}'", response.GetStringRef()));
+
+  return response;
+}
+
+llvm::Expected<llvm::SmallVector<llvm::MutableArrayRef<uint8_t>>>
+ProcessGDBRemote::ParseMultiMemReadPacket(llvm::StringRef response_str,
+                                          llvm::MutableArrayRef<uint8_t> buffer,
+                                          unsigned expected_num_ranges) {
+  // The sizes and the data are separated by a `;`.
+  auto [sizes_str, memory_data] = response_str.split(';');
+  if (sizes_str.size() == response_str.size())
+    return llvm::createStringError(llvm::formatv(
+        "MultiMemRead response missing field separator: '{0}'", response_str));
----------------
DavidSpickett wrote:

"separator ';' in:"

https://github.com/llvm/llvm-project/pull/164311