Don't use dyn_cast_or_null if we know the pointer is nonnull.

Fix clang static analyzer null dereference warning by using dyn_cast instead.

diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index e5f7968..80acab3 100644 (file)
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -1128,8 +1128,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
                   OriginAlignment);
     } else {
       Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
-      Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
-      if (ConstantShadow) {
+      if (auto *ConstantShadow = dyn_cast<Constant>(ConvertedShadow)) {
         if (ClCheckConstantShadow && !ConstantShadow->isZeroValue())
           paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
                       OriginAlignment);
@@ -1210,8 +1209,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
     Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
     LLVM_DEBUG(dbgs() << "  SHAD1 : " << *ConvertedShadow << "\n");
 
-    Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
-    if (ConstantShadow) {
+    if (auto *ConstantShadow = dyn_cast<Constant>(ConvertedShadow)) {
       if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) {
         insertWarningFn(IRB, Origin);
       }