Refactor duplicated code.

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

diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp
index 349b733418e9bd915838de82c9a6c83359403e51..accfe7be18d9847a8caa071d7120a40798bdbf50 100644 (file)
--- a/lib/CodeGen/StackProtector.cpp
+++ b/lib/CodeGen/StackProtector.cpp
@@ -14,7 +14,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "stack-protector"
 #include "llvm/CodeGen/StackProtector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
@@ -37,6 +36,8 @@
 #include <cstdlib>
 using namespace llvm;
 
+#define DEBUG_TYPE "stack-protector"
+
 STATISTIC(NumFunProtected, "Number of functions protected");
 STATISTIC(NumAddrTaken, "Number of local variables that have their address"
                         " taken.");
@@ -83,18 +84,18 @@ bool StackProtector::runOnFunction(Function &Fn) {
   M = F->getParent();
   DominatorTreeWrapperPass *DTWP =
       getAnalysisIfAvailable<DominatorTreeWrapperPass>();
-  DT = DTWP ? &DTWP->getDomTree() : 0;
+  DT = DTWP ? &DTWP->getDomTree() : nullptr;
   TLI = TM->getTargetLowering();
 
-  if (!RequiresStackProtector())
-    return false;
-
   Attribute Attr = Fn.getAttributes().getAttribute(
       AttributeSet::FunctionIndex, "stack-protector-buffer-size");
   if (Attr.isStringAttribute() &&
       Attr.getValueAsString().getAsInteger(10, SSPBufferSize))
       return false; // Invalid integer string
 
+  if (!RequiresStackProtector())
+    return false;
+
   ++NumFunProtected;
   return InsertStackProtectors();
 }
@@ -150,9 +151,7 @@ bool StackProtector::ContainsProtectableArray(Type *Ty, bool &IsLarge,
 }
 
 bool StackProtector::HasAddressTaken(const Instruction *AI) {
-  for (Value::const_use_iterator UI = AI->use_begin(), UE = AI->use_end();
-       UI != UE; ++UI) {
-    const User *U = *UI;
+  for (const User *U : AI->users()) {
     if (const StoreInst *SI = dyn_cast<StoreInst>(U)) {
       if (AI == SI->getValueOperand())
         return true;
@@ -284,8 +283,7 @@ static CallInst *FindPotentialTailCall(BasicBlock *BB, ReturnInst *RI,
   const unsigned MaxSearch = 4;
   bool NoInterposingChain = true;
 
-  for (BasicBlock::reverse_iterator I = llvm::next(BB->rbegin()),
-                                    E = BB->rend();
+  for (BasicBlock::reverse_iterator I = std::next(BB->rbegin()), E = BB->rend();
        I != E && SearchCounter < MaxSearch; ++I) {
     Instruction *Inst = &*I;
 
@@ -322,7 +320,7 @@ static CallInst *FindPotentialTailCall(BasicBlock *BB, ReturnInst *RI,
     SearchCounter++;
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// Insert code into the entry block that stores the __stack_chk_guard
@@ -357,7 +355,7 @@ static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI,
   }
 
   IRBuilder<> B(&F->getEntryBlock().front());
-  AI = B.CreateAlloca(PtrTy, 0, "StackGuardSlot");
+  AI = B.CreateAlloca(PtrTy, nullptr, "StackGuardSlot");
   LoadInst *LI = B.CreateLoad(StackGuardVar, "StackGuard");
   B.CreateCall2(Intrinsic::getDeclaration(M, Intrinsic::stackprotector), LI,
                 AI);
@@ -375,8 +373,8 @@ bool StackProtector::InsertStackProtectors() {
   bool HasPrologue = false;
   bool SupportsSelectionDAGSP =
       EnableSelectionDAGSP && !TM->Options.EnableFastISel;
-  AllocaInst *AI = 0;       // Place on stack that stores the stack guard.
-  Value *StackGuardVar = 0; // The stack guard variable.
+  AllocaInst *AI = nullptr;       // Place on stack that stores the stack guard.
+  Value *StackGuardVar = nullptr; // The stack guard variable.
 
   for (Function::iterator I = F->begin(), E = F->end(); I != E;) {
     BasicBlock *BB = I++;
@@ -393,14 +391,14 @@ bool StackProtector::InsertStackProtectors() {
     if (SupportsSelectionDAGSP) {
       // Since we have a potential tail call, insert the special stack check
       // intrinsic.
-      Instruction *InsertionPt = 0;
+      Instruction *InsertionPt = nullptr;
       if (CallInst *CI = FindPotentialTailCall(BB, RI, TLI)) {
         InsertionPt = CI;
       } else {
         InsertionPt = RI;
         // At this point we know that BB has a return statement so it *DOES*
         // have a terminator.
-        assert(InsertionPt != 0 && "BB must have a terminator instruction at "
+        assert(InsertionPt != nullptr && "BB must have a terminator instruction at "
                                    "this point.");
       }