"NULL !=" = NULL

src/gpu/GrRedBlackTree.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrRedBlackTree_DEFINED
 #define GrRedBlackTree_DEFINED
 
@@ skipping 186 matching lines @@
         return fN == i.fN && fTree == i.fTree;
     }
     bool operator !=(const Iter& i) const { return !(*this == i); }
     Iter& operator ++() {
         SkASSERT(*this != fTree->end());
         fN = SuccessorNode(fN);
         return *this;
     }
     Iter& operator --() {
         SkASSERT(*this != fTree->begin());
-        if (NULL != fN) {
+        if (fN) {
             fN = PredecessorNode(fN);
         } else {
             *this = fTree->last();
         }
         return *this;
     }
 
 private:
     friend class GrRedBlackTree;
     explicit Iter(Node* n, GrRedBlackTree* tree) {
@@ skipping 29 matching lines @@
 }
 
 template <typename T, typename C>
 typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::last() {
     return Iter(fLast, this);
 }
 
 template <typename T, typename C>
 typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::find(const T& t) {
     Node* n = fRoot;
-    while (NULL != n) {
+    while (n) {
         if (fComp(t, n->fItem)) {
             n = n->fChildren[kLeft_Child];
         } else {
             if (!fComp(n->fItem, t)) {
                 return Iter(n, this);
             }
             n = n->fChildren[kRight_Child];
         }
     }
     return end();
 }
 
 template <typename T, typename C>
 typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::findFirst(const T& t) {
     Node* n = fRoot;
     Node* leftMost = NULL;
-    while (NULL != n) {
+    while (n) {
         if (fComp(t, n->fItem)) {
             n = n->fChildren[kLeft_Child];
         } else {
             if (!fComp(n->fItem, t)) {
                 // found one. check if another in left subtree.
                 leftMost = n;
                 n = n->fChildren[kLeft_Child];
             } else {
                 n = n->fChildren[kRight_Child];
             }
         }
     }
     return Iter(leftMost, this);
 }
 
 template <typename T, typename C>
 typename GrRedBlackTree<T,C>::Iter GrRedBlackTree<T,C>::findLast(const T& t) {
     Node* n = fRoot;
     Node* rightMost = NULL;
-    while (NULL != n) {
+    while (n) {
         if (fComp(t, n->fItem)) {
             n = n->fChildren[kLeft_Child];
         } else {
             if (!fComp(n->fItem, t)) {
                 // found one. check if another in right subtree.
                 rightMost = n;
             }
             n = n->fChildren[kRight_Child];
         }
     }
     return Iter(rightMost, this);
 }
 
 template <typename T, typename C>
 int GrRedBlackTree<T,C>::countOf(const T& t) const {
     return onCountOf(fRoot, t);
 }
 
 template <typename T, typename C>
 int GrRedBlackTree<T,C>::onCountOf(const Node* n, const T& t) const {
     // this is count*log(n) :(
-    while (NULL != n) {
+    while (n) {
         if (fComp(t, n->fItem)) {
             n = n->fChildren[kLeft_Child];
         } else {
             if (!fComp(n->fItem, t)) {
                 int count = 1;
                 count += onCountOf(n->fChildren[kLeft_Child], t);
                 count += onCountOf(n->fChildren[kRight_Child], t);
                 return count;
             }
             n = n->fChildren[kRight_Child];
@@ skipping 26 matching lines @@
     Node* returnNode = x;
 
     Node* gp = NULL;
     Node* p = NULL;
     Node* n = fRoot;
     Child pc = kLeft_Child; // suppress uninit warning
     Child gpc = kLeft_Child;
 
     bool first = true;
     bool last = true;
-    while (NULL != n) {
+    while (n) {
         gpc = pc;
         pc = fComp(x->fItem, n->fItem) ? kLeft_Child : kRight_Child;
         first = first && kLeft_Child == pc;
         last = last && kRight_Child == pc;
         gp = p;
         p = n;
         n = p->fChildren[pc];
     }
     if (last) {
         fLast = x;
     }
     if (first) {
         fFirst = x;
     }
 
     if (NULL == p) {
         fRoot = x;
         x->fColor = kBlack_Color;
         x->fParent = NULL;
         SkASSERT(1 == fCount);
         return Iter(returnNode, this);
     }
     p->fChildren[pc] = x;
     x->fColor = kRed_Color;
     x->fParent = p;
 
     do {
         // assumptions at loop start.
-        SkASSERT(NULL != x);
+        SkASSERT(x);
         SkASSERT(kRed_Color == x->fColor);
         // can't have a grandparent but no parent.
-        SkASSERT(!(NULL != gp && NULL == p));
+        SkASSERT(!(gp && NULL == p));
         // make sure pc and gpc are correct
         SkASSERT(NULL == p  || p->fChildren[pc] == x);
         SkASSERT(NULL == gp || gp->fChildren[gpc] == p);
 
         // if x's parent is black then we didn't violate any of the
         // red/black properties when we added x as red.
         if (kBlack_Color == p->fColor) {
             return Iter(returnNode, this);
         }
         // gp must be valid because if p was the root then it is black
-        SkASSERT(NULL != gp);
+        SkASSERT(gp);
         // gp must be black since it's child, p, is red.
         SkASSERT(kBlack_Color == gp->fColor);
 
 
         // x and its parent are red, violating red-black property.
         Node* u = gp->fChildren[1-gpc];
         // if x's uncle (p's sibling) is also red then we can flip
         // p and u to black and make gp red. But then we have to recurse
         // up to gp since it's parent may also be red.
-        if (NULL != u && kRed_Color == u->fColor) {
+        if (u && kRed_Color == u->fColor) {
             p->fColor = kBlack_Color;
             u->fColor = kBlack_Color;
             gp->fColor = kRed_Color;
             x = gp;
             p = x->fParent;
             if (NULL == p) {
                 // x (prev gp) is the root, color it black and be done.
                 SkASSERT(fRoot == x);
                 x->fColor = kBlack_Color;
                 validate();
                 return Iter(returnNode, this);
             }
             gp = p->fParent;
             pc = (p->fChildren[kLeft_Child] == x) ? kLeft_Child :
                                                     kRight_Child;
-            if (NULL != gp) {
+            if (gp) {
                 gpc = (gp->fChildren[kLeft_Child] == p) ? kLeft_Child :
                                                           kRight_Child;
             }
             continue;
         } break;
     } while (true);
     // Here p is red but u is black and we still have to resolve the fact
     // that x and p are both red.
     SkASSERT(NULL == gp->fChildren[1-gpc] || kBlack_Color == gp->fChildren[1-gpc]->fColor);
     SkASSERT(kRed_Color == x->fColor);
@@ skipping 43 matching lines @@
     /*            d?              d?
      *           /               /
      *          n               s
      *         / \     --->    / \
      *        s   a?          c?  n
      *       / \                 / \
      *      c?  b?              b?  a?
      */
     Node* d = n->fParent;
     Node* s = n->fChildren[kLeft_Child];
-    SkASSERT(NULL != s);
+    SkASSERT(s);
     Node* b = s->fChildren[kRight_Child];
 
-    if (NULL != d) {
+    if (d) {
         Child c = d->fChildren[kLeft_Child] == n ? kLeft_Child :
                                              kRight_Child;
         d->fChildren[c] = s;
     } else {
         SkASSERT(fRoot == n);
         fRoot = s;
     }
     s->fParent = d;
     s->fChildren[kRight_Child] = n;
     n->fParent = s;
     n->fChildren[kLeft_Child] = b;
-    if (NULL != b) {
+    if (b) {
         b->fParent = n;
     }
 
     GR_DEBUGASSERT(validateChildRelations(d, true));
     GR_DEBUGASSERT(validateChildRelations(s, true));
     GR_DEBUGASSERT(validateChildRelations(n, false));
     GR_DEBUGASSERT(validateChildRelations(n->fChildren[kRight_Child], true));
     GR_DEBUGASSERT(validateChildRelations(b, true));
     GR_DEBUGASSERT(validateChildRelations(s->fChildren[kLeft_Child], true));
 }
 
 template <typename T, typename C>
 void GrRedBlackTree<T,C>::rotateLeft(Node* n) {
 
     Node* d = n->fParent;
     Node* s = n->fChildren[kRight_Child];
-    SkASSERT(NULL != s);
+    SkASSERT(s);
     Node* b = s->fChildren[kLeft_Child];
 
-    if (NULL != d) {
+    if (d) {
         Child c = d->fChildren[kRight_Child] == n ? kRight_Child :
                                                    kLeft_Child;
         d->fChildren[c] = s;
     } else {
         SkASSERT(fRoot == n);
         fRoot = s;
     }
     s->fParent = d;
     s->fChildren[kLeft_Child] = n;
     n->fParent = s;
     n->fChildren[kRight_Child] = b;
-    if (NULL != b) {
+    if (b) {
         b->fParent = n;
     }
 
     GR_DEBUGASSERT(validateChildRelations(d, true));
     GR_DEBUGASSERT(validateChildRelations(s, true));
     GR_DEBUGASSERT(validateChildRelations(n, true));
     GR_DEBUGASSERT(validateChildRelations(n->fChildren[kLeft_Child], true));
     GR_DEBUGASSERT(validateChildRelations(b, true));
     GR_DEBUGASSERT(validateChildRelations(s->fChildren[kRight_Child], true));
 }
 
 template <typename T, typename C>
 typename GrRedBlackTree<T,C>::Node* GrRedBlackTree<T,C>::SuccessorNode(Node* x) {
-    SkASSERT(NULL != x);
-    if (NULL != x->fChildren[kRight_Child]) {
+    SkASSERT(x);
+    if (x->fChildren[kRight_Child]) {
         x = x->fChildren[kRight_Child];
-        while (NULL != x->fChildren[kLeft_Child]) {
+        while (x->fChildren[kLeft_Child]) {
             x = x->fChildren[kLeft_Child];
         }
         return x;
     }
-    while (NULL != x->fParent && x == x->fParent->fChildren[kRight_Child]) {
+    while (x->fParent && x == x->fParent->fChildren[kRight_Child]) {
         x = x->fParent;
     }
     return x->fParent;
 }
 
 template <typename T, typename C>
 typename GrRedBlackTree<T,C>::Node* GrRedBlackTree<T,C>::PredecessorNode(Node* x) {
-    SkASSERT(NULL != x);
-    if (NULL != x->fChildren[kLeft_Child]) {
+    SkASSERT(x);
+    if (x->fChildren[kLeft_Child]) {
         x = x->fChildren[kLeft_Child];
-        while (NULL != x->fChildren[kRight_Child]) {
+        while (x->fChildren[kRight_Child]) {
             x = x->fChildren[kRight_Child];
         }
         return x;
     }
-    while (NULL != x->fParent && x == x->fParent->fChildren[kLeft_Child]) {
+    while (x->fParent && x == x->fParent->fChildren[kLeft_Child]) {
         x = x->fParent;
     }
     return x->fParent;
 }
 
 template <typename T, typename C>
 void GrRedBlackTree<T,C>::deleteAtNode(Node* x) {
-    SkASSERT(NULL != x);
+    SkASSERT(x);
     validate();
     --fCount;
 
-    bool hasLeft =  NULL != x->fChildren[kLeft_Child];
-    bool hasRight = NULL != x->fChildren[kRight_Child];
+    bool hasLeft =  SkToBool(x->fChildren[kLeft_Child]);
+    bool hasRight = SkToBool(x->fChildren[kRight_Child]);
     Child c = hasLeft ? kLeft_Child : kRight_Child;
 
     if (hasLeft && hasRight) {
         // first and last can't have two children.
         SkASSERT(fFirst != x);
         SkASSERT(fLast != x);
         // if x is an interior node then we find it's successor
         // and swap them.
         Node* s = x->fChildren[kRight_Child];
-        while (NULL != s->fChildren[kLeft_Child]) {
+        while (s->fChildren[kLeft_Child]) {
             s = s->fChildren[kLeft_Child];
         }
-        SkASSERT(NULL != s);
+        SkASSERT(s);
         // this might be expensive relative to swapping node ptrs around.
         // depends on T.
         x->fItem = s->fItem;
         x = s;
         c = kRight_Child;
     } else if (NULL == x->fParent) {
         // if x was the root we just replace it with its child and make
         // the new root (if the tree is not empty) black.
         SkASSERT(fRoot == x);
         fRoot = x->fChildren[c];
-        if (NULL != fRoot) {
+        if (fRoot) {
             fRoot->fParent = NULL;
             fRoot->fColor = kBlack_Color;
             if (x == fLast) {
                 SkASSERT(c == kLeft_Child);
                 fLast = fRoot;
             } else if (x == fFirst) {
                 SkASSERT(c == kRight_Child);
                 fFirst = fRoot;
             }
         } else {
@@ skipping 29 matching lines @@
         if (kRed_Color == xcolor) {
             validate();
             return;
         }
         // s is p's other child (x's sibling)
         Node* s = p->fChildren[1-pc];
 
         //s cannot be an implicit black node because the original
         // black-height at x was >= 2 and s's black-height must equal the
         // initial black height of x.
-        SkASSERT(NULL != s);
+        SkASSERT(s);
         SkASSERT(p == s->fParent);
 
         // assigned in loop
         Node* sl;
         Node* sr;
         bool slRed;
         bool srRed;
 
         do {
             // When we start this loop x may already be deleted it is/was
             // p's child on its pc side. x's children are/were black. The
             // first time through the loop they are implict children.
             // On later passes we will be walking up the tree and they will
             // be real nodes.
             // The x side of p has a black-height that is one less than the
             // s side. It must be rebalanced.
-            SkASSERT(NULL != s);
+            SkASSERT(s);
             SkASSERT(p == s->fParent);
             SkASSERT(NULL == x || x->fParent == p);
 
             //sl and sr are s's children, which may be implicit.
             sl = s->fChildren[kLeft_Child];
             sr = s->fChildren[kRight_Child];
 
             // if the s is red we will rotate s and p, swap their colors so
             // that x's new sibling is black
             if (kRed_Color == s->fColor) {
                 // if s is red then it's parent must be black.
                 SkASSERT(kBlack_Color == p->fColor);
                 // s's children must also be black since s is red. They can't
                 // be implicit since s is red and it's black-height is >= 2.
-                SkASSERT(NULL != sl && kBlack_Color == sl->fColor);
-                SkASSERT(NULL != sr && kBlack_Color == sr->fColor);
+                SkASSERT(sl && kBlack_Color == sl->fColor);
+                SkASSERT(sr && kBlack_Color == sr->fColor);
                 p->fColor = kRed_Color;
                 s->fColor = kBlack_Color;
                 if (kLeft_Child == pc) {
                     rotateLeft(p);
                     s = sl;
                 } else {
                     rotateRight(p);
                     s = sr;
                 }
                 sl = s->fChildren[kLeft_Child];
                 sr = s->fChildren[kRight_Child];
             }
             // x and s are now both black.
             SkASSERT(kBlack_Color == s->fColor);
             SkASSERT(NULL == x || kBlack_Color == x->fColor);
             SkASSERT(p == s->fParent);
             SkASSERT(NULL == x || p == x->fParent);
 
             // when x is deleted its subtree will have reduced black-height.
-            slRed = (NULL != sl && kRed_Color == sl->fColor);
-            srRed = (NULL != sr && kRed_Color == sr->fColor);
+            slRed = (sl && kRed_Color == sl->fColor);
+            srRed = (sr && kRed_Color == sr->fColor);
             if (!slRed && !srRed) {
                 // if s can be made red that will balance out x's removal
                 // to make both subtrees of p have the same black-height.
                 if (kBlack_Color == p->fColor) {
                     s->fColor = kRed_Color;
                     // now subtree at p has black-height of one less than
                     // p's parent's other child's subtree. We move x up to
                     // p and go through the loop again. At the top of loop
                     // we assumed x and x's children are black, which holds
                     // by above ifs.
                     // if p is the root there is no other subtree to balance
                     // against.
                     x = p;
                     p = x->fParent;
                     if (NULL == p) {
                         SkASSERT(fRoot == x);
                         validate();
                         return;
                     } else {
                         pc = p->fChildren[kLeft_Child] == x ? kLeft_Child :
                                                               kRight_Child;
 
                     }
                     s = p->fChildren[1-pc];
-                    SkASSERT(NULL != s);
+                    SkASSERT(s);
                     SkASSERT(p == s->fParent);
                     continue;
                 } else if (kRed_Color == p->fColor) {
                     // we can make p black and s red. This balance out p's
                     // two subtrees and keep the same black-height as it was
                     // before the delete.
                     s->fColor = kRed_Color;
                     p->fColor = kBlack_Color;
                     validate();
                     return;
@@ skipping 24 matching lines @@
         // child is red.
         // We rotate p towards x, pulling s up to replace p. We make
         // p be black and s takes p's old color.
         // Whether p was red or black, we've increased its pc subtree
         // rooted at x by 1 (balancing the imbalance at the start) and
         // we've also its subtree rooted at s's black-height by 1. This
         // can be balanced by making s's red child be black.
         s->fColor = p->fColor;
         p->fColor = kBlack_Color;
         if (kLeft_Child == pc) {
-            SkASSERT(NULL != sr && kRed_Color == sr->fColor);
+            SkASSERT(sr && kRed_Color == sr->fColor);
             sr->fColor = kBlack_Color;
             rotateLeft(p);
         } else {
-            SkASSERT(NULL != sl && kRed_Color == sl->fColor);
+            SkASSERT(sl && kRed_Color == sl->fColor);
             sl->fColor = kBlack_Color;
             rotateRight(p);
         }
     }
     else {
         // x has exactly one implicit black child. x cannot be red.
         // Proof by contradiction: Assume X is red. Let c0 be x's implicit
         // child and c1 be its non-implicit child. c1 must be black because
         // red nodes always have two black children. Then the two subtrees
         // of x rooted at c0 and c1 will have different black-heights.
         SkASSERT(kBlack_Color == x->fColor);
         // So we know x is black and has one implicit black child, c0. c1
         // must be red, otherwise the subtree at c1 will have a different
         // black-height than the subtree rooted at c0.
         SkASSERT(kRed_Color == x->fChildren[c]->fColor);
         // replace x with c1, making c1 black, preserves all red-black tree
         // props.
         Node* c1 = x->fChildren[c];
         if (x == fFirst) {
             SkASSERT(c == kRight_Child);
             fFirst = c1;
-            while (NULL != fFirst->fChildren[kLeft_Child]) {
+            while (fFirst->fChildren[kLeft_Child]) {
                 fFirst = fFirst->fChildren[kLeft_Child];
             }
             SkASSERT(fFirst == SuccessorNode(x));
         } else if (x == fLast) {
             SkASSERT(c == kLeft_Child);
             fLast = c1;
-            while (NULL != fLast->fChildren[kRight_Child]) {
+            while (fLast->fChildren[kRight_Child]) {
                 fLast = fLast->fChildren[kRight_Child];
             }
             SkASSERT(fLast == PredecessorNode(x));
         }
         c1->fParent = p;
         p->fChildren[pc] = c1;
         c1->fColor = kBlack_Color;
         delete x;
         validate();
     }
     validate();
 }
 
 template <typename T, typename C>
 void GrRedBlackTree<T,C>::RecursiveDelete(Node* x) {
-    if (NULL != x) {
+    if (x) {
         RecursiveDelete(x->fChildren[kLeft_Child]);
         RecursiveDelete(x->fChildren[kRight_Child]);
         delete x;
     }
 }
 
 #ifdef SK_DEBUG
 template <typename T, typename C>
 void GrRedBlackTree<T,C>::validate() const {
     if (fCount) {
         SkASSERT(NULL == fRoot->fParent);
-        SkASSERT(NULL != fFirst);
-        SkASSERT(NULL != fLast);
+        SkASSERT(fFirst);
+        SkASSERT(fLast);
 
         SkASSERT(kBlack_Color == fRoot->fColor);
         if (1 == fCount) {
             SkASSERT(fFirst == fRoot);
             SkASSERT(fLast == fRoot);
             SkASSERT(0 == fRoot->fChildren[kLeft_Child]);
             SkASSERT(0 == fRoot->fChildren[kRight_Child]);
         }
     } else {
         SkASSERT(NULL == fRoot);
         SkASSERT(NULL == fFirst);
         SkASSERT(NULL == fLast);
     }
 #if DEEP_VALIDATE
     int bh;
     int count = checkNode(fRoot, &bh);
     SkASSERT(count == fCount);
 #endif
 }
 
 template <typename T, typename C>
 int GrRedBlackTree<T,C>::checkNode(Node* n, int* bh) const {
-    if (NULL != n) {
+    if (n) {
         SkASSERT(validateChildRelations(n, false));
         if (kBlack_Color == n->fColor) {
             *bh += 1;
         }
         SkASSERT(!fComp(n->fItem, fFirst->fItem));
         SkASSERT(!fComp(fLast->fItem, n->fItem));
         int leftBh = *bh;
         int rightBh = *bh;
         int cl = checkNode(n->fChildren[kLeft_Child], &leftBh);
         int cr = checkNode(n->fChildren[kRight_Child], &rightBh);
         SkASSERT(leftBh == rightBh);
         *bh = leftBh;
         return 1 + cl + cr;
     }
     return 0;
 }
 
 template <typename T, typename C>
 bool GrRedBlackTree<T,C>::validateChildRelations(const Node* n,
                                                  bool allowRedRed) const {
-    if (NULL != n) {
-        if (NULL != n->fChildren[kLeft_Child] ||
-            NULL != n->fChildren[kRight_Child]) {
+    if (n) {
+        if (n->fChildren[kLeft_Child] ||
+            n->fChildren[kRight_Child]) {
             if (n->fChildren[kLeft_Child] == n->fChildren[kRight_Child]) {
                 return validateChildRelationsFailed();
             }
             if (n->fChildren[kLeft_Child] == n->fParent &&
-                NULL != n->fParent) {
+                n->fParent) {
                 return validateChildRelationsFailed();
             }
             if (n->fChildren[kRight_Child] == n->fParent &&
-                NULL != n->fParent) {
+                n->fParent) {
                 return validateChildRelationsFailed();
             }
-            if (NULL != n->fChildren[kLeft_Child]) {
+            if (n->fChildren[kLeft_Child]) {
                 if (!allowRedRed &&
                     kRed_Color == n->fChildren[kLeft_Child]->fColor &&
                     kRed_Color == n->fColor) {
                     return validateChildRelationsFailed();
                 }
                 if (n->fChildren[kLeft_Child]->fParent != n) {
                     return validateChildRelationsFailed();
                 }
                 if (!(fComp(n->fChildren[kLeft_Child]->fItem, n->fItem) ||
                       (!fComp(n->fChildren[kLeft_Child]->fItem, n->fItem) &&
                        !fComp(n->fItem, n->fChildren[kLeft_Child]->fItem)))) {
                     return validateChildRelationsFailed();
                 }
             }
-            if (NULL != n->fChildren[kRight_Child]) {
+            if (n->fChildren[kRight_Child]) {
                 if (!allowRedRed &&
                     kRed_Color == n->fChildren[kRight_Child]->fColor &&
                     kRed_Color == n->fColor) {
                     return validateChildRelationsFailed();
                 }
                 if (n->fChildren[kRight_Child]->fParent != n) {
                     return validateChildRelationsFailed();
                 }
                 if (!(fComp(n->fItem, n->fChildren[kRight_Child]->fItem) ||
                       (!fComp(n->fChildren[kRight_Child]->fItem, n->fItem) &&
                        !fComp(n->fItem, n->fChildren[kRight_Child]->fItem)))) {
                     return validateChildRelationsFailed();
                 }
             }
         }
     }
     return true;
 }
 #endif
 
 #endif