Remove unused virtuals from ABISysV_ppc*

[brucem]

Summary

The StackUsesFrames and FunctionCallsChangeCFA virtual functions
aren't used anywhere and aren't overridden by anything.

They were introduced when the ABISysV_ppc* code was added and weren't
used at the time. The review for the commit that added them can be
found at http://reviews.llvm.org/D5988

The commit comment notes that backtraces don't yet work:

Backtraces don't work. This is due to PowerPC ABI using a
backchain pointer in memory, instead of a dedicated frame
pointer register for the backchain.

So there is a possibility these were added with the intent of using
them in the future.

[jhibbits]

Backtraces do work now, for ppc at least (ppc64 IIRC still has issues dealing with the function descriptors, but traversing the backchain does work). I can test this after I get my system set up from my move, but if you've tested it either natively or on a core then I'll greenlight it.

[brucem]

There's nothing to test here short of "Does it compile?" as these functions aren't actually used anywhere. I'm cleaning out dead virtuals in various patches.

[jhibbits]

In D13506#261638, @brucem wrote:

There's nothing to test here short of "Does it compile?" as these functions aren't actually used anywhere. I'm cleaning out dead virtuals in various patches.

Ah okay. I think when I added this ABI plugin, those came along for the ride when I copied the SysV-x86_64 plugin, I don't remember adding these myself, so they must be just plain old leftovers.

lldb/trunk/source/Plugins/ABI/SysV-ppc/ABISysV_ppc.h

public:
     CreateFunctionEntryUnwindPlan (lldb_private::UnwindPlan &unwind_plan);
     
     virtual bool
     CreateDefaultUnwindPlan (lldb_private::UnwindPlan &unwind_plan);
         
     virtual bool
     RegisterIsVolatile (const lldb_private::RegisterInfo *reg_info);
     
-    virtual bool
-    StackUsesFrames ()
-    {
-        return true;
-    }
-    
     // The SysV ppc ABI requires that stack frames be 16 byte aligned.
     // When there is a trap handler on the stack, e.g. _sigtramp in userland
     // code, we've seen that the stack pointer is often not aligned properly
     // before the handler is invoked.  This means that lldb will stop the unwind
     // early -- before the function which caused the trap.
     //
     // To work around this, we relax that alignment to be just word-size (8-bytes).
     // Whitelisting the trap handlers for user space would be easy (_sigtramp) but
public:
     virtual bool
     CodeAddressIsValid (lldb::addr_t pc)
     {
         // We have a 64 bit address space, so anything is valid as opcodes
         // aren't fixed width...
         return true;
     }
 
-    virtual bool
-    FunctionCallsChangeCFA ()
-    {
-        return true;
-    }
-
     virtual const lldb_private::RegisterInfo *
     GetRegisterInfoArray (uint32_t &count);
     //------------------------------------------------------------------
     // Static Functions
     //------------------------------------------------------------------
     static void
     Initialize();
 

lldb/trunk/source/Plugins/ABI/SysV-ppc64/ABISysV_ppc64.h

public:
     CreateFunctionEntryUnwindPlan (lldb_private::UnwindPlan &unwind_plan);
     
     virtual bool
     CreateDefaultUnwindPlan (lldb_private::UnwindPlan &unwind_plan);
         
     virtual bool
     RegisterIsVolatile (const lldb_private::RegisterInfo *reg_info);
     
-    virtual bool
-    StackUsesFrames ()
-    {
-        return true;
-    }
-    
     // The SysV ppc64 ABI requires that stack frames be 16 byte aligned.
     // When there is a trap handler on the stack, e.g. _sigtramp in userland
     // code, we've seen that the stack pointer is often not aligned properly
     // before the handler is invoked.  This means that lldb will stop the unwind
     // early -- before the function which caused the trap.
     //
     // To work around this, we relax that alignment to be just word-size (8-bytes).
     // Whitelisting the trap handlers for user space would be easy (_sigtramp) but
public:
     virtual bool
     CodeAddressIsValid (lldb::addr_t pc)
     {
         // We have a 64 bit address space, so anything is valid as opcodes
         // aren't fixed width...
         return true;
     }
 
-    virtual bool
-    FunctionCallsChangeCFA ()
-    {
-        return true;
-    }
-
     virtual const lldb_private::RegisterInfo *
     GetRegisterInfoArray (uint32_t &count);
     //------------------------------------------------------------------
     // Static Functions
     //------------------------------------------------------------------
     static void
     Initialize();