GlobalISel: prevent heap use-after-free when looking up VReg.

Translating the constant can create more VRegs, which can invalidate the
reference into the DenseMap. So we have to look up the value again after all
that's happened.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292675 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/GlobalISel/IRTranslator.cpp b/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 1cfe5345c650071b924086861d328399709497e2..ba6db371139e8728ce88d12574bac90a72eb582d 100644 (file)
--- a/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -81,7 +81,9 @@ unsigned IRTranslator::getOrCreateVReg(const Value &Val) {
       }
     }
   }
-  return ValReg;
+
+  // Look Val up again in case the reference has been invalidated since.
+  return ValToVReg[&Val];
 }
 
 int IRTranslator::getOrCreateFrameIndex(const AllocaInst &AI) {