From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Thu, 30 Apr 2015 19:35:41 +0000 (+0000)
Subject: MachineVerifier: Don't crash if MachineOperand has no parent
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=816fd0095d95ab219dd2a794c87b532ce15b0cba;p=oota-llvm.git

MachineVerifier: Don't crash if MachineOperand has no parent

If you somehow added a MachineOperand to an instruction
that did not have the parent set, the verifier would
crash since it attempts to use the operand's parent.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236249 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 991241e0f74..47e8306f3c9 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -329,8 +329,18 @@ bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
       } else if (!CurBundle)
         report("No bundle header", MBBI);
       visitMachineInstrBefore(MBBI);
-      for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
-        visitMachineOperand(&MBBI->getOperand(I), I);
+      for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I) {
+        const MachineInstr &MI = *MBBI;
+        const MachineOperand &Op = MI.getOperand(I);
+        if (Op.getParent() != &MI) {
+          // Make sure to use correct addOperand / RmeoveOperand / ChangeTo
+          // functions when replacing operands of a MachineInstr.
+          report("Instruction has operand with wrong parent set", &MI);
+        }
+
+        visitMachineOperand(&Op, I);
+      }
+
       visitMachineInstrAfter(MBBI);
 
       // Was this the last bundled instruction?