[lldb-server] Support 'g' packets

Differential Revision: https://reviews.llvm.org/D62221
Patch by Guilherme Andrade <guiandrade@google.com>.

llvm-svn: 362063

1 files changed, 58 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 045f4b43b40..2778b124334 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -187,6 +187,9 @@ void GDBRemoteCommunicationServerLLGS::RegisterPacketHandlers() {
       StringExtractorGDBRemote::eServerPacketType_jTraceConfigRead,
       &GDBRemoteCommunicationServerLLGS::Handle_jTraceConfigRead);
 
+  RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_g,
+                                &GDBRemoteCommunicationServerLLGS::Handle_g);
+
   RegisterPacketHandler(StringExtractorGDBRemote::eServerPacketType_k,
                         [this](StringExtractorGDBRemote packet, Status &error,
                                bool &interrupt, bool &quit) {
@@ -1892,6 +1895,61 @@ GDBRemoteCommunicationServerLLGS::Handle_qsThreadInfo(
 }
 
 GDBRemoteCommunication::PacketResult
+GDBRemoteCommunicationServerLLGS::Handle_g(StringExtractorGDBRemote &packet) {
+  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_THREAD));
+
+  // Move past packet name.
+  packet.SetFilePos(strlen("g"));
+
+  // Get the thread to use.
+  NativeThreadProtocol *thread = GetThreadFromSuffix(packet);
+  if (!thread) {
+    LLDB_LOG(log, "failed, no thread available");
+    return SendErrorResponse(0x15);
+  }
+
+  // Get the thread's register context.
+  NativeRegisterContext &reg_ctx = thread->GetRegisterContext();
+
+  std::vector<uint8_t> regs_buffer;
+  for (uint32_t reg_num = 0; reg_num < reg_ctx.GetUserRegisterCount();
+       ++reg_num) {
+    const RegisterInfo *reg_info = reg_ctx.GetRegisterInfoAtIndex(reg_num);
+
+    if (reg_info == nullptr) {
+      LLDB_LOG(log, "failed to get register info for register index {0}",
+               reg_num);
+      return SendErrorResponse(0x15);
+    }
+
+    if (reg_info->value_regs != nullptr)
+      continue; // skip registers that are contained in other registers
+
+    RegisterValue reg_value;
+    Status error = reg_ctx.ReadRegister(reg_info, reg_value);
+    if (error.Fail()) {
+      LLDB_LOG(log, "failed to read register at index {0}", reg_num);
+      return SendErrorResponse(0x15);
+    }
+
+    if (reg_info->byte_offset + reg_info->byte_size >= regs_buffer.size())
+      // Resize the buffer to guarantee it can store the register offsetted
+      // data.
+      regs_buffer.resize(reg_info->byte_offset + reg_info->byte_size);
+
+    // Copy the register offsetted data to the buffer.
+    memcpy(regs_buffer.data() + reg_info->byte_offset, reg_value.GetBytes(),
+           reg_info->byte_size);
+  }
+
+  // Write the response.
+  StreamGDBRemote response;
+  response.PutBytesAsRawHex8(regs_buffer.data(), regs_buffer.size());
+
+  return SendPacketNoLock(response.GetString());
+}
+
+GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServerLLGS::Handle_p(StringExtractorGDBRemote &packet) {
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_THREAD));