Added a function to lldb_private::Address:

        addr_t
        Address::GetCallableLoadAddress (Target *target) const;
        
This will resolve the load address in the Address object and optionally
decorate the address up to be able to be called. For all non ARM targets, this
just essentially returns the result of "Address::GetLoadAddress (target)". But
for ARM targets, it checks if the address is Thumb, and if so, it returns
an address with bit zero set to indicate a mode switch to Thumb. This is how
we need function pointers to be for return addresses and when resolving 
function addresses for the JIT. It is also nice to centralize this in one spot
to avoid having multiple copies of this code.

llvm-svn: 131588

1 files changed, 11 insertions, 24 deletions

diff --git a/lldb/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp b/lldb/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp
index a1fc2829455..b8ac50171da 100644
--- a/lldb/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp
+++ b/lldb/source/Plugins/ABI/MacOSX-arm/ABIMacOSX_arm.cpp
@@ -126,24 +126,16 @@ ABIMacOSX_arm::PrepareTrivialCall (Thread &thread,
         }
     }
     
-    // Figure out if our return address is ARM or Thumb. We assume if we don't
-    // know about an address then it is ARM code.
 
     Target *target = &thread.GetProcess().GetTarget();
     Address so_addr;
-    bool ra_is_thumb = false;
-    if (return_addr & 3)
-        ra_is_thumb = true;
-    else if (so_addr.SetLoadAddress (return_addr, target))
-        ra_is_thumb = so_addr.GetAddressClass() == eAddressClassCodeAlternateISA;
-
-    // Set our clear bit zero for the return address if needed. We should never
-    // need to clear bit zero since the return address will either have bit zero
-    // or bit one (a thumb instruction on a two byte boundary) already set, or
-    // it won't and it will need it.
-    if (ra_is_thumb)
-        return_addr |= 1u;
-        
+
+    // Figure out if our return address is ARM or Thumb by using the 
+    // Address::GetCallableLoadAddress(Target*) which will figure out the ARM
+    // thumb-ness and set the correct address bits for us.
+    so_addr.SetLoadAddress (return_addr, target);
+    return_addr = so_addr.GetCallableLoadAddress (target);
+
     // Set "lr" to the return address
     if (!reg_ctx->WriteRegisterFromUnsigned (ra_reg_num, return_addr))
         return false;
@@ -152,15 +144,10 @@ ABIMacOSX_arm::PrepareTrivialCall (Thread &thread,
     if (!reg_ctx->WriteRegisterFromUnsigned (sp_reg_num, sp))
         return false;
     
-    bool pc_is_thumb = false;
-
     // If bit zero or 1 is set, this must be a thumb function, no need to figure
     // this out from the symbols.
-    if (function_addr & 3)
-        pc_is_thumb = true;
-    else if (so_addr.SetLoadAddress (function_addr, target))
-        pc_is_thumb = so_addr.GetAddressClass() == eAddressClassCodeAlternateISA;
-
+    so_addr.SetLoadAddress (function_addr, target);
+    function_addr = so_addr.GetCallableLoadAddress (target);
     
     const RegisterInfo *cpsr_reg_info = reg_ctx->GetRegisterInfoByName("cpsr");
     const uint32_t curr_cpsr = reg_ctx->ReadRegisterAsUnsigned(cpsr_reg_info, 0);
@@ -168,7 +155,7 @@ ABIMacOSX_arm::PrepareTrivialCall (Thread &thread,
     // Make a new CPSR and mask out any Thumb IT (if/then) bits
     uint32_t new_cpsr = curr_cpsr & ~MASK_CPSR_IT_MASK;
     // If bit zero or 1 is set, this must be thumb...
-    if (pc_is_thumb)
+    if (function_addr & 1ull)
         new_cpsr |= MASK_CPSR_T;    // Set T bit in CPSR
     else
         new_cpsr &= ~MASK_CPSR_T;   // Clear T bit in CPSR
@@ -179,7 +166,7 @@ ABIMacOSX_arm::PrepareTrivialCall (Thread &thread,
             return false;
     }
 
-    function_addr &= ~1u;   // clear bit zero since the CPSR will take care of the mode for us
+    function_addr &= ~1ull;   // clear bit zero since the CPSR will take care of the mode for us
     
     // Set "pc" to the address requested
     if (!reg_ctx->WriteRegisterFromUnsigned (pc_reg_num, function_addr))