Made the MC disassembler check before accessing

MCInst operands for ARM.  This allows it to be
more tolerant of malformed MCInsts or incorrect
instruction metadata.

llvm-svn: 129840

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCDisassembler/EDOperand.cpp b/llvm/lib/MC/MCDisassembler/EDOperand.cpp
index 04b21cb3592..492bb08f336 100644
--- a/llvm/lib/MC/MCDisassembler/EDOperand.cpp
+++ b/llvm/lib/MC/MCDisassembler/EDOperand.cpp
@@ -198,15 +198,24 @@ int EDOperand::evaluate(uint64_t &result,
     default:
       return -1;
     case kOperandTypeImmediate:
+      if (!Inst.Inst->getOperand(MCOpIndex).isImm())
+        return -1;
+            
       result = Inst.Inst->getOperand(MCOpIndex).getImm();
       return 0;
     case kOperandTypeRegister:
     {
+      if (!Inst.Inst->getOperand(MCOpIndex).isReg())
+        return -1;
+        
       unsigned reg = Inst.Inst->getOperand(MCOpIndex).getReg();
       return callback(&result, reg, arg);
     }
     case kOperandTypeARMBranchTarget:
     {
+      if (!Inst.Inst->getOperand(MCOpIndex).isImm())
+        return -1;
+        
       int64_t displacement = Inst.Inst->getOperand(MCOpIndex).getImm();
       
       uint64_t pcVal;