A pretty big overhaul of the TryFallbackUnwindPlan method in

RegisterContextLLDB.  I have core files of half a dozen tricky
unwind situations on x86/arm and they're all working pretty much
correctly at this point, but we'll need to keep an eye out for
unwinder regressions for a little while; it's tricky to get these
heuristics completely correct in all unwind situations.

<rdar://problem/18937193> 

llvm-svn: 221866

1 files changed, 27 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h
index cf652da2619..636e9524021 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.h
@@ -217,6 +217,18 @@ private:
             return output_regnum;
         }
 
+        uint32_t
+        GetRegisterNumber () const
+        {
+            return m_regnum;
+        }
+
+        lldb::RegisterKind
+        GetRegisterKind () const
+        {
+            return m_kind;
+        }
+
         const char *
         GetName ()
         {
@@ -328,11 +340,26 @@ private:
     bool
     TryFallbackUnwindPlan ();
 
+    //------------------------------------------------------------------
+    /// Switch to the fallback unwind plan unconditionally without any safety
+    /// checks that it is providing better results than the normal unwind plan.
+    ///
+    /// The only time it is valid to call this method is if the full unwindplan is
+    /// found to be fundamentally incorrect/impossible.
+    ///
+    /// Returns true if it was able to install the fallback unwind plan.
+    //------------------------------------------------------------------
+    bool
+    ForceSwitchToFallbackUnwindPlan ();
+
     // Get the contents of a general purpose (address-size) register for this frame
     // (usually retrieved from the next frame)
     bool
     ReadGPRValue (lldb::RegisterKind register_kind, uint32_t regnum, lldb::addr_t &value);
 
+    bool
+    ReadGPRValue (const RegisterNumber &reg_num, lldb::addr_t &value);
+
     // Get the CFA register for a given frame.
     bool
     ReadCFAValueForRow (lldb::RegisterKind register_kind, const UnwindPlan::RowSP &row, lldb::addr_t &value);