Fix undefined behavior: don't perform array indexing through a potentially null
pointer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161919 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 172402e..f745b41 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -681,10 +681,10 @@
MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const MCInstrDesc &MCID = MI->getDesc();
- const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
// The first MCID.NumDefs operands must be explicit register defines
if (MONum < MCID.getNumDefs()) {
+ const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
if (!MO->isReg())
report("Explicit definition must be a register", MO, MONum);
else if (!MO->isDef() && !MCOI.isOptionalDef())
@@ -692,6 +692,7 @@
else if (MO->isImplicit())
report("Explicit definition marked as implicit", MO, MONum);
} else if (MONum < MCID.getNumOperands()) {
+ const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
// Don't check if it's the last operand in a variadic instruction. See,
// e.g., LDM_RET in the arm back end.
if (MO->isReg() &&