Fix a pair of use after free. Should bring the bots back.

[oota-llvm.git] / lib / CodeGen / ShadowStackGC.cpp

diff --git a/lib/CodeGen/ShadowStackGC.cpp b/lib/CodeGen/ShadowStackGC.cpp
index 55c6cfc1e6f486ff4137a3d78626a573da0368d3..f7c64dac61246ed0d58957d8493c25a6bfc4d9bd 100644 (file)
--- a/lib/CodeGen/ShadowStackGC.cpp
+++ b/lib/CodeGen/ShadowStackGC.cpp
@@ -25,7 +25,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "shadowstackgc"
 #include "llvm/CodeGen/GCs.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/CodeGen/GCStrategy.h"
@@ -36,6 +35,8 @@
 
 using namespace llvm;
 
+#define DEBUG_TYPE "shadowstackgc"
+
 namespace {
 
   class ShadowStackGC : public GCStrategy {
@@ -55,8 +56,8 @@ namespace {
   public:
     ShadowStackGC();
 
-    bool initializeCustomLowering(Module &M);
-    bool performCustomLowering(Function &F);
+    bool initializeCustomLowering(Module &M) override;
+    bool performCustomLowering(Function &F) override;
 
   private:
     bool IsNullValue(Value *V);
@@ -101,7 +102,7 @@ namespace {
     IRBuilder<> *Next() {
       switch (State) {
       default:
-        return 0;
+        return nullptr;
 
       case 0:
         StateBB = F.begin();
@@ -137,7 +138,7 @@ namespace {
                 Calls.push_back(CI);
 
         if (Calls.empty())
-          return 0;
+          return nullptr;
 
         // Create a cleanup block.
         LLVMContext &C = F.getContext();
@@ -194,7 +195,7 @@ namespace {
 
 void llvm::linkShadowStackGC() { }
 
-ShadowStackGC::ShadowStackGC() : Head(0), StackEntryTy(0) {
+ShadowStackGC::ShadowStackGC() : Head(nullptr), StackEntryTy(nullptr) {
   InitRoots = true;
   CustomRoots = true;
 }
@@ -390,8 +391,8 @@ bool ShadowStackGC::performCustomLowering(Function &F) {
   BasicBlock::iterator IP = F.getEntryBlock().begin();
   IRBuilder<> AtEntry(IP->getParent(), IP);
 
-  Instruction *StackEntry   = AtEntry.CreateAlloca(ConcreteStackEntryTy, 0,
-                                                   "gc_frame");
+  Instruction *StackEntry = AtEntry.CreateAlloca(ConcreteStackEntryTy, nullptr,
+                                                 "gc_frame");
 
   while (isa<AllocaInst>(IP)) ++IP;
   AtEntry.SetInsertPoint(IP->getParent(), IP);