[C++] Use 'nullptr'. Transforms edition.

llvm-svn: 207196
diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
index d64006f..f29cb2d 100644
--- a/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
+++ b/llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
@@ -157,7 +157,7 @@
       return FindSingleUseIdentifiedObject(
                cast<CallInst>(Arg)->getArgOperand(0));
     if (!IsObjCIdentifiedObject(Arg))
-      return 0;
+      return nullptr;
     return Arg;
   }
 
@@ -166,12 +166,12 @@
   if (IsObjCIdentifiedObject(Arg)) {
     for (const User *U : Arg->users())
       if (!U->use_empty() || StripPointerCastsAndObjCCalls(U) != Arg)
-         return 0;
+         return nullptr;
 
     return Arg;
   }
 
-  return 0;
+  return nullptr;
 }
 
 /// This is a wrapper around getUnderlyingObjCPtr along the lines of
@@ -374,7 +374,7 @@
     bool CFGHazardAfflicted;
 
     RRInfo() :
-      KnownSafe(false), IsTailCallRelease(false), ReleaseMetadata(0),
+      KnownSafe(false), IsTailCallRelease(false), ReleaseMetadata(nullptr),
       CFGHazardAfflicted(false) {}
 
     void clear();
@@ -389,7 +389,7 @@
 void RRInfo::clear() {
   KnownSafe = false;
   IsTailCallRelease = false;
-  ReleaseMetadata = 0;
+  ReleaseMetadata = nullptr;
   Calls.clear();
   ReverseInsertPts.clear();
   CFGHazardAfflicted = false;
@@ -398,7 +398,7 @@
 bool RRInfo::Merge(const RRInfo &Other) {
     // Conservatively merge the ReleaseMetadata information.
     if (ReleaseMetadata != Other.ReleaseMetadata)
-      ReleaseMetadata = 0;
+      ReleaseMetadata = nullptr;
 
     // Conservatively merge the boolean state.
     KnownSafe &= Other.KnownSafe;
@@ -457,7 +457,7 @@
     }
 
     bool IsTrackingImpreciseReleases() const {
-      return RRI.ReleaseMetadata != 0;
+      return RRI.ReleaseMetadata != nullptr;
     }
 
     const MDNode *GetReleaseMetadata() const {
@@ -1719,7 +1719,7 @@
                                      BBState &MyStates) {
   bool NestingDetected = false;
   InstructionClass Class = GetInstructionClass(Inst);
-  const Value *Arg = 0;
+  const Value *Arg = nullptr;
 
   DEBUG(dbgs() << "Class: " << Class << "\n");
 
@@ -1975,7 +1975,7 @@
                                     BBState &MyStates) {
   bool NestingDetected = false;
   InstructionClass Class = GetInstructionClass(Inst);
-  const Value *Arg = 0;
+  const Value *Arg = nullptr;
 
   switch (Class) {
   case IC_RetainBlock:
@@ -2027,7 +2027,7 @@
     switch (OldSeq) {
     case S_Retain:
     case S_CanRelease:
-      if (OldSeq == S_Retain || ReleaseMetadata != 0)
+      if (OldSeq == S_Retain || ReleaseMetadata != nullptr)
         S.ClearReverseInsertPts();
       // FALL THROUGH
     case S_Use:
@@ -2433,7 +2433,7 @@
           } else {
             if (ReleasesToMove.ReleaseMetadata !=
                 NewRetainReleaseRRI.ReleaseMetadata)
-              ReleasesToMove.ReleaseMetadata = 0;
+              ReleasesToMove.ReleaseMetadata = nullptr;
             if (ReleasesToMove.IsTailCallRelease !=
                 NewRetainReleaseRRI.IsTailCallRelease)
               ReleasesToMove.IsTailCallRelease = false;
@@ -2885,7 +2885,7 @@
   FindDependencies(CanChangeRetainCount, Arg,
                    BB, Autorelease, DepInsts, Visited, PA);
   if (DepInsts.size() != 1)
-    return 0;
+    return nullptr;
 
   CallInst *Retain =
     dyn_cast_or_null<CallInst>(*DepInsts.begin());
@@ -2894,7 +2894,7 @@
   if (!Retain ||
       !IsRetain(GetBasicInstructionClass(Retain)) ||
       GetObjCArg(Retain) != Arg) {
-    return 0;
+    return nullptr;
   }
 
   return Retain;
@@ -2912,17 +2912,17 @@
   FindDependencies(NeedsPositiveRetainCount, Arg,
                    BB, Ret, DepInsts, V, PA);
   if (DepInsts.size() != 1)
-    return 0;
+    return nullptr;
 
   CallInst *Autorelease =
     dyn_cast_or_null<CallInst>(*DepInsts.begin());
   if (!Autorelease)
-    return 0;
+    return nullptr;
   InstructionClass AutoreleaseClass = GetBasicInstructionClass(Autorelease);
   if (!IsAutorelease(AutoreleaseClass))
-    return 0;
+    return nullptr;
   if (GetObjCArg(Autorelease) != Arg)
-    return 0;
+    return nullptr;
 
   return Autorelease;
 }