<rdar://problem/11782789> Changes to the watchpoint implementation on ARM so that we single-step before stopping at the WP. This is necessary because on ARM the WP triggers before the opcode is actually executed, so we would be unable to continue since we would keep hitting the WP. We work around this by disabling the WP, single stepping and then putting the WP back in place.

llvm-svn: 160199

1 files changed, 36 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 83d2843309a9..4fac83d334cc 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -49,6 +49,7 @@ GDBRemoteCommunicationClient::GDBRemoteCommunicationClient(bool is_platform) :
     m_supports_alloc_dealloc_memory (eLazyBoolCalculate),
     m_supports_memory_region_info  (eLazyBoolCalculate),
     m_supports_watchpoint_support_info  (eLazyBoolCalculate),
+    m_watchpoints_trigger_after_instruction(eLazyBoolCalculate),
     m_supports_qProcessInfoPID (true),
     m_supports_qfProcessInfo (true),
     m_supports_qUserName (true),
@@ -1019,6 +1020,17 @@ GDBRemoteCommunicationClient::GetHostInfo (bool force)
                         if (m_os_version_major != UINT32_MAX)
                             ++num_keys_decoded;
                     }
+                    else if (name.compare("watchpoint_exceptions_received") == 0)
+                    {
+                        ++num_keys_decoded;
+                        if (strcmp(value.c_str(),"before") == 0)
+                            m_watchpoints_trigger_after_instruction = eLazyBoolNo;
+                        else if (strcmp(value.c_str(),"after") == 0)
+                            m_watchpoints_trigger_after_instruction = eLazyBoolYes;
+                        else
+                            --num_keys_decoded;
+                    }
+
                 }
                 
                 if (num_keys_decoded > 0)
@@ -1352,6 +1364,30 @@ GDBRemoteCommunicationClient::GetWatchpointSupportInfo (uint32_t &num)
 
 }
 
+lldb_private::Error
+GDBRemoteCommunicationClient::GetWatchpointSupportInfo (uint32_t &num, bool& after)
+{
+    Error error(GetWatchpointSupportInfo(num));
+    if (error.Success())
+        error = GetWatchpointsTriggerAfterInstruction(after);
+    return error;
+}
+
+lldb_private::Error
+GDBRemoteCommunicationClient::GetWatchpointsTriggerAfterInstruction (bool &after)
+{
+    Error error;
+    
+    // we assume watchpoints will happen after running the relevant opcode
+    // and we only want to override this behavior if we have explicitly
+    // received a qHostInfo telling us otherwise
+    if (m_qHostInfo_is_valid != eLazyBoolYes)
+        after = true;
+    else
+        after = (m_watchpoints_trigger_after_instruction != eLazyBoolNo);
+    return error;
+}
+
 int
 GDBRemoteCommunicationClient::SetSTDIN (char const *path)
 {