Rename rbtree.c functions to use "rbt" prefix not "rb" prefix.

The "rb" prefix is used by Ruby, so that our existing code results
in name collisions that break plruby.  We discussed ways to prevent
that by adjusting dynamic linker options, but it seems that at best
we'd move the pain to other cases.  Renaming to avoid the collision
is the only portable fix anyway.  Fortunately, our rbtree code is
not (yet?) widely used --- in core, there's only a single usage
in GIN --- so it seems likely that we can get away with a rename.

I chose to do this basically as s/rb/rbt/g, except for places where
there already was a "t" after "rb".  The patch could have been made
smaller by only touching linker-visible symbols, but it would have
resulted in oddly inconsistent-looking code.  Better to make it look
like "rbt" was the plan all along.

Back-patch to v10.  The rbtree.c code exists back to 9.5, but
rb_iterate() which is the actual immediate source of pain was added
in v10, so it seems like changing the names before that would have
more risk than benefit.

Per report from Pavel Raiskup.

Discussion: https://postgr.es/m/4738198.8KVIIDhgEB@nb.usersys.redhat.com

5 files changed, 267 insertions, 264 deletions

diff --git a/src/backend/access/gin/ginbulk.c b/src/backend/access/gin/ginbulk.c
index 989c2a0c02..f2fbe6fa3f 100644
--- a/src/backend/access/gin/ginbulk.c
+++ b/src/backend/access/gin/ginbulk.c
@@ -27,7 +27,7 @@
 
 /* Combiner function for rbtree.c */
 static void
-ginCombineData(RBNode *existing, const RBNode *newdata, void *arg)
+ginCombineData(RBTNode *existing, const RBTNode *newdata, void *arg)
 {
 	GinEntryAccumulator *eo = (GinEntryAccumulator *) existing;
 	const GinEntryAccumulator *en = (const GinEntryAccumulator *) newdata;
@@ -69,7 +69,7 @@ ginCombineData(RBNode *existing, const RBNode *newdata, void *arg)
 
 /* Comparator function for rbtree.c */
 static int
-cmpEntryAccumulator(const RBNode *a, const RBNode *b, void *arg)
+cmpEntryAccumulator(const RBTNode *a, const RBTNode *b, void *arg)
 {
 	const GinEntryAccumulator *ea = (const GinEntryAccumulator *) a;
 	const GinEntryAccumulator *eb = (const GinEntryAccumulator *) b;
@@ -81,7 +81,7 @@ cmpEntryAccumulator(const RBNode *a, const RBNode *b, void *arg)
 }
 
 /* Allocator function for rbtree.c */
-static RBNode *
+static RBTNode *
 ginAllocEntryAccumulator(void *arg)
 {
 	BuildAccumulator *accum = (BuildAccumulator *) arg;
@@ -89,7 +89,7 @@ ginAllocEntryAccumulator(void *arg)
 
 	/*
 	 * Allocate memory by rather big chunks to decrease overhead.  We have no
-	 * need to reclaim RBNodes individually, so this costs nothing.
+	 * need to reclaim RBTNodes individually, so this costs nothing.
 	 */
 	if (accum->entryallocator == NULL || accum->eas_used >= DEF_NENTRY)
 	{
@@ -98,11 +98,11 @@ ginAllocEntryAccumulator(void *arg)
 		accum->eas_used = 0;
 	}
 
-	/* Allocate new RBNode from current chunk */
+	/* Allocate new RBTNode from current chunk */
 	ea = accum->entryallocator + accum->eas_used;
 	accum->eas_used++;
 
-	return (RBNode *) ea;
+	return (RBTNode *) ea;
 }
 
 void
@@ -112,12 +112,12 @@ ginInitBA(BuildAccumulator *accum)
 	accum->allocatedMemory = 0;
 	accum->entryallocator = NULL;
 	accum->eas_used = 0;
-	accum->tree = rb_create(sizeof(GinEntryAccumulator),
-							cmpEntryAccumulator,
-							ginCombineData,
-							ginAllocEntryAccumulator,
-							NULL,	/* no freefunc needed */
-							(void *) accum);
+	accum->tree = rbt_create(sizeof(GinEntryAccumulator),
+							 cmpEntryAccumulator,
+							 ginCombineData,
+							 ginAllocEntryAccumulator,
+							 NULL,	/* no freefunc needed */
+							 (void *) accum);
 }
 
 /*
@@ -163,8 +163,8 @@ ginInsertBAEntry(BuildAccumulator *accum,
 	/* temporarily set up single-entry itempointer list */
 	eatmp.list = heapptr;
 
-	ea = (GinEntryAccumulator *) rb_insert(accum->tree, (RBNode *) &eatmp,
-										   &isNew);
+	ea = (GinEntryAccumulator *) rbt_insert(accum->tree, (RBTNode *) &eatmp,
+											&isNew);
 
 	if (isNew)
 	{
@@ -256,7 +256,7 @@ qsortCompareItemPointers(const void *a, const void *b)
 void
 ginBeginBAScan(BuildAccumulator *accum)
 {
-	rb_begin_iterate(accum->tree, LeftRightWalk, &accum->tree_walk);
+	rbt_begin_iterate(accum->tree, LeftRightWalk, &accum->tree_walk);
 }
 
 /*
@@ -272,7 +272,7 @@ ginGetBAEntry(BuildAccumulator *accum,
 	GinEntryAccumulator *entry;
 	ItemPointerData *list;
 
-	entry = (GinEntryAccumulator *) rb_iterate(&accum->tree_walk);
+	entry = (GinEntryAccumulator *) rbt_iterate(&accum->tree_walk);
 
 	if (entry == NULL)
 		return NULL;			/* no more entries */
diff --git a/src/backend/lib/rbtree.c b/src/backend/lib/rbtree.c
index a43d5938d5..c35928daad 100644
--- a/src/backend/lib/rbtree.c
+++ b/src/backend/lib/rbtree.c
@@ -30,26 +30,26 @@
 
 
 /*
- * Colors of nodes (values of RBNode.color)
+ * Colors of nodes (values of RBTNode.color)
  */
-#define RBBLACK		(0)
-#define RBRED		(1)
+#define RBTBLACK	(0)
+#define RBTRED		(1)
 
 /*
  * RBTree control structure
  */
 struct RBTree
 {
-	RBNode	   *root;			/* root node, or RBNIL if tree is empty */
+	RBTNode    *root;			/* root node, or RBTNIL if tree is empty */
 
-	/* Remaining fields are constant after rb_create */
+	/* Remaining fields are constant after rbt_create */
 
 	Size		node_size;		/* actual size of tree nodes */
 	/* The caller-supplied manipulation functions */
-	rb_comparator comparator;
-	rb_combiner combiner;
-	rb_allocfunc allocfunc;
-	rb_freefunc freefunc;
+	rbt_comparator comparator;
+	rbt_combiner combiner;
+	rbt_allocfunc allocfunc;
+	rbt_freefunc freefunc;
 	/* Passthrough arg passed to all manipulation functions */
 	void	   *arg;
 };
@@ -58,28 +58,31 @@ struct RBTree
  * all leafs are sentinels, use customized NIL name to prevent
  * collision with system-wide constant NIL which is actually NULL
  */
-#define RBNIL (&sentinel)
+#define RBTNIL (&sentinel)
 
-static RBNode sentinel = {RBBLACK, RBNIL, RBNIL, NULL};
+static RBTNode sentinel =
+{
+	RBTBLACK, RBTNIL, RBTNIL, NULL
+};
 
 
 /*
- * rb_create: create an empty RBTree
+ * rbt_create: create an empty RBTree
  *
  * Arguments are:
- *	node_size: actual size of tree nodes (> sizeof(RBNode))
+ *	node_size: actual size of tree nodes (> sizeof(RBTNode))
  *	The manipulation functions:
- *	comparator: compare two RBNodes for less/equal/greater
+ *	comparator: compare two RBTNodes for less/equal/greater
  *	combiner: merge an existing tree entry with a new one
- *	allocfunc: allocate a new RBNode
- *	freefunc: free an old RBNode
+ *	allocfunc: allocate a new RBTNode
+ *	freefunc: free an old RBTNode
  *	arg: passthrough pointer that will be passed to the manipulation functions
  *
  * Note that the combiner's righthand argument will be a "proposed" tree node,
- * ie the input to rb_insert, in which the RBNode fields themselves aren't
+ * ie the input to rbt_insert, in which the RBTNode fields themselves aren't
  * valid.  Similarly, either input to the comparator may be a "proposed" node.
  * This shouldn't matter since the functions aren't supposed to look at the
- * RBNode fields, only the extra fields of the struct the RBNode is embedded
+ * RBTNode fields, only the extra fields of the struct the RBTNode is embedded
  * in.
  *
  * The freefunc should just be pfree or equivalent; it should NOT attempt
@@ -96,18 +99,18 @@ static RBNode sentinel = {RBBLACK, RBNIL, RBNIL, NULL};
  * the RBTree node if you feel the urge.
  */
 RBTree *
-rb_create(Size node_size,
-		  rb_comparator comparator,
-		  rb_combiner combiner,
-		  rb_allocfunc allocfunc,
-		  rb_freefunc freefunc,
-		  void *arg)
+rbt_create(Size node_size,
+		   rbt_comparator comparator,
+		   rbt_combiner combiner,
+		   rbt_allocfunc allocfunc,
+		   rbt_freefunc freefunc,
+		   void *arg)
 {
 	RBTree	   *tree = (RBTree *) palloc(sizeof(RBTree));
 
-	Assert(node_size > sizeof(RBNode));
+	Assert(node_size > sizeof(RBTNode));
 
-	tree->root = RBNIL;
+	tree->root = RBTNIL;
 	tree->node_size = node_size;
 	tree->comparator = comparator;
 	tree->combiner = combiner;
@@ -119,11 +122,11 @@ rb_create(Size node_size,
 	return tree;
 }
 
-/* Copy the additional data fields from one RBNode to another */
+/* Copy the additional data fields from one RBTNode to another */
 static inline void
-rb_copy_data(RBTree *rb, RBNode *dest, const RBNode *src)
+rbt_copy_data(RBTree *rbt, RBTNode *dest, const RBTNode *src)
 {
-	memcpy(dest + 1, src + 1, rb->node_size - sizeof(RBNode));
+	memcpy(dest + 1, src + 1, rbt->node_size - sizeof(RBTNode));
 }
 
 /**********************************************************************
@@ -131,21 +134,21 @@ rb_copy_data(RBTree *rb, RBNode *dest, const RBNode *src)
  **********************************************************************/
 
 /*
- * rb_find: search for a value in an RBTree
+ * rbt_find: search for a value in an RBTree
  *
- * data represents the value to try to find.  Its RBNode fields need not
+ * data represents the value to try to find.  Its RBTNode fields need not
  * be valid, it's the extra data in the larger struct that is of interest.
  *
  * Returns the matching tree entry, or NULL if no match is found.
  */
-RBNode *
-rb_find(RBTree *rb, const RBNode *data)
+RBTNode *
+rbt_find(RBTree *rbt, const RBTNode *data)
 {
-	RBNode	   *node = rb->root;
+	RBTNode    *node = rbt->root;
 
-	while (node != RBNIL)
+	while (node != RBTNIL)
 	{
-		int			cmp = rb->comparator(data, node, rb->arg);
+		int			cmp = rbt->comparator(data, node, rbt->arg);
 
 		if (cmp == 0)
 			return node;
@@ -159,26 +162,26 @@ rb_find(RBTree *rb, const RBNode *data)
 }
 
 /*
- * rb_leftmost: fetch the leftmost (smallest-valued) tree node.
+ * rbt_leftmost: fetch the leftmost (smallest-valued) tree node.
  * Returns NULL if tree is empty.
  *
  * Note: in the original implementation this included an unlink step, but
- * that's a bit awkward.  Just call rb_delete on the result if that's what
+ * that's a bit awkward.  Just call rbt_delete on the result if that's what
  * you want.
  */
-RBNode *
-rb_leftmost(RBTree *rb)
+RBTNode *
+rbt_leftmost(RBTree *rbt)
 {
-	RBNode	   *node = rb->root;
-	RBNode	   *leftmost = rb->root;
+	RBTNode    *node = rbt->root;
+	RBTNode    *leftmost = rbt->root;
 
-	while (node != RBNIL)
+	while (node != RBTNIL)
 	{
 		leftmost = node;
 		node = node->left;
 	}
 
-	if (leftmost != RBNIL)
+	if (leftmost != RBTNIL)
 		return leftmost;
 
 	return NULL;
@@ -195,17 +198,17 @@ rb_leftmost(RBTree *rb)
  * child of that node.
  */
 static void
-rb_rotate_left(RBTree *rb, RBNode *x)
+rbt_rotate_left(RBTree *rbt, RBTNode *x)
 {
-	RBNode	   *y = x->right;
+	RBTNode    *y = x->right;
 
 	/* establish x->right link */
 	x->right = y->left;
-	if (y->left != RBNIL)
+	if (y->left != RBTNIL)
 		y->left->parent = x;
 
 	/* establish y->parent link */
-	if (y != RBNIL)
+	if (y != RBTNIL)
 		y->parent = x->parent;
 	if (x->parent)
 	{
@@ -216,12 +219,12 @@ rb_rotate_left(RBTree *rb, RBNode *x)
 	}
 	else
 	{
-		rb->root = y;
+		rbt->root = y;
 	}
 
 	/* link x and y */
 	y->left = x;
-	if (x != RBNIL)
+	if (x != RBTNIL)
 		x->parent = y;
 }
 
@@ -232,17 +235,17 @@ rb_rotate_left(RBTree *rb, RBNode *x)
  * child of that node.
  */
 static void
-rb_rotate_right(RBTree *rb, RBNode *x)
+rbt_rotate_right(RBTree *rbt, RBTNode *x)
 {
-	RBNode	   *y = x->left;
+	RBTNode    *y = x->left;
 
 	/* establish x->left link */
 	x->left = y->right;
-	if (y->right != RBNIL)
+	if (y->right != RBTNIL)
 		y->right->parent = x;
 
 	/* establish y->parent link */
-	if (y != RBNIL)
+	if (y != RBTNIL)
 		y->parent = x->parent;
 	if (x->parent)
 	{
@@ -253,12 +256,12 @@ rb_rotate_right(RBTree *rb, RBNode *x)
 	}
 	else
 	{
-		rb->root = y;
+		rbt->root = y;
 	}
 
 	/* link x and y */
 	y->right = x;
-	if (x != RBNIL)
+	if (x != RBTNIL)
 		x->parent = y;
 }
 
@@ -276,13 +279,13 @@ rb_rotate_right(RBTree *rb, RBNode *x)
  * the invariant that every leaf has equal black-height.)
  */
 static void
-rb_insert_fixup(RBTree *rb, RBNode *x)
+rbt_insert_fixup(RBTree *rbt, RBTNode *x)
 {
 	/*
 	 * x is always a red node.  Initially, it is the newly inserted node. Each
 	 * iteration of this loop moves it higher up in the tree.
 	 */
-	while (x != rb->root && x->parent->color == RBRED)
+	while (x != rbt->root && x->parent->color == RBTRED)
 	{
 		/*
 		 * x and x->parent are both red.  Fix depends on whether x->parent is
@@ -302,60 +305,60 @@ rb_insert_fixup(RBTree *rb, RBNode *x)
 		 */
 		if (x->parent == x->parent->parent->left)
 		{
-			RBNode	   *y = x->parent->parent->right;
+			RBTNode    *y = x->parent->parent->right;
 
-			if (y->color == RBRED)
+			if (y->color == RBTRED)
 			{
-				/* uncle is RBRED */
-				x->parent->color = RBBLACK;
-				y->color = RBBLACK;
-				x->parent->parent->color = RBRED;
+				/* uncle is RBTRED */
+				x->parent->color = RBTBLACK;
+				y->color = RBTBLACK;
+				x->parent->parent->color = RBTRED;
 
 				x = x->parent->parent;
 			}
 			else
 			{
-				/* uncle is RBBLACK */
+				/* uncle is RBTBLACK */
 				if (x == x->parent->right)
 				{
 					/* make x a left child */
 					x = x->parent;
-					rb_rotate_left(rb, x);
+					rbt_rotate_left(rbt, x);
 				}
 
 				/* recolor and rotate */
-				x->parent->color = RBBLACK;
-				x->parent->parent->color = RBRED;
+				x->parent->color = RBTBLACK;
+				x->parent->parent->color = RBTRED;
 
-				rb_rotate_right(rb, x->parent->parent);
+				rbt_rotate_right(rbt, x->parent->parent);
 			}
 		}
 		else
 		{
 			/* mirror image of above code */
-			RBNode	   *y = x->parent->parent->left;
+			RBTNode    *y = x->parent->parent->left;
 
-			if (y->color == RBRED)
+			if (y->color == RBTRED)
 			{
-				/* uncle is RBRED */
-				x->parent->color = RBBLACK;
-				y->color = RBBLACK;
-				x->parent->parent->color = RBRED;
+				/* uncle is RBTRED */
+				x->parent->color = RBTBLACK;
+				y->color = RBTBLACK;
+				x->parent->parent->color = RBTRED;
 
 				x = x->parent->parent;
 			}
 			else
 			{
-				/* uncle is RBBLACK */
+				/* uncle is RBTBLACK */
 				if (x == x->parent->left)
 				{
 					x = x->parent;
-					rb_rotate_right(rb, x);
+					rbt_rotate_right(rbt, x);
 				}
-				x->parent->color = RBBLACK;
-				x->parent->parent->color = RBRED;
+				x->parent->color = RBTBLACK;
+				x->parent->parent->color = RBTRED;
 
-				rb_rotate_left(rb, x->parent->parent);
+				rbt_rotate_left(rbt, x->parent->parent);
 			}
 		}
 	}
@@ -364,13 +367,13 @@ rb_insert_fixup(RBTree *rb, RBNode *x)
 	 * The root may already have been black; if not, the black-height of every
 	 * node in the tree increases by one.
 	 */
-	rb->root->color = RBBLACK;
+	rbt->root->color = RBTBLACK;
 }
 
 /*
- * rb_insert: insert a new value into the tree.
+ * rbt_insert: insert a new value into the tree.
  *
- * data represents the value to insert.  Its RBNode fields need not
+ * data represents the value to insert.  Its RBTNode fields need not
  * be valid, it's the extra data in the larger struct that is of interest.
  *
  * If the value represented by "data" is not present in the tree, then
@@ -384,28 +387,28 @@ rb_insert_fixup(RBTree *rb, RBNode *x)
  * "data" is unmodified in either case; it's typically just a local
  * variable in the caller.
  */
-RBNode *
-rb_insert(RBTree *rb, const RBNode *data, bool *isNew)
+RBTNode *
+rbt_insert(RBTree *rbt, const RBTNode *data, bool *isNew)
 {
-	RBNode	   *current,
+	RBTNode    *current,
 			   *parent,
 			   *x;
 	int			cmp;
 
 	/* find where node belongs */
-	current = rb->root;
+	current = rbt->root;
 	parent = NULL;
 	cmp = 0;					/* just to prevent compiler warning */
 
-	while (current != RBNIL)
+	while (current != RBTNIL)
 	{
-		cmp = rb->comparator(data, current, rb->arg);
+		cmp = rbt->comparator(data, current, rbt->arg);
 		if (cmp == 0)
 		{
 			/*
 			 * Found node with given key.  Apply combiner.
 			 */
-			rb->combiner(current, data, rb->arg);
+			rbt->combiner(current, data, rbt->arg);
 			*isNew = false;
 			return current;
 		}
@@ -418,14 +421,14 @@ rb_insert(RBTree *rb, const RBNode *data, bool *isNew)
 	 */
 	*isNew = true;
 
-	x = rb->allocfunc(rb->arg);
+	x = rbt->allocfunc(rbt->arg);
 
-	x->color = RBRED;
+	x->color = RBTRED;
 
-	x->left = RBNIL;
-	x->right = RBNIL;
+	x->left = RBTNIL;
+	x->right = RBTNIL;
 	x->parent = parent;
-	rb_copy_data(rb, x, data);
+	rbt_copy_data(rbt, x, data);
 
 	/* insert node in tree */
 	if (parent)
@@ -437,10 +440,10 @@ rb_insert(RBTree *rb, const RBNode *data, bool *isNew)
 	}
 	else
 	{
-		rb->root = x;
+		rbt->root = x;
 	}
 
-	rb_insert_fixup(rb, x);
+	rbt_insert_fixup(rbt, x);
 
 	return x;
 }
@@ -453,14 +456,14 @@ rb_insert(RBTree *rb, const RBNode *data, bool *isNew)
  * Maintain Red-Black tree balance after deleting a black node.
  */
 static void
-rb_delete_fixup(RBTree *rb, RBNode *x)
+rbt_delete_fixup(RBTree *rbt, RBTNode *x)
 {
 	/*
 	 * x is always a black node.  Initially, it is the former child of the
 	 * deleted node.  Each iteration of this loop moves it higher up in the
 	 * tree.
 	 */
-	while (x != rb->root && x->color == RBBLACK)
+	while (x != rbt->root && x->color == RBTBLACK)
 	{
 		/*
 		 * Left and right cases are symmetric.  Any nodes that are children of
@@ -471,93 +474,93 @@ rb_delete_fixup(RBTree *rb, RBNode *x)
 		 */
 		if (x == x->parent->left)
 		{
-			RBNode	   *w = x->parent->right;
+			RBTNode    *w = x->parent->right;
 
-			if (w->color == RBRED)
+			if (w->color == RBTRED)
 			{
-				w->color = RBBLACK;
-				x->parent->color = RBRED;
+				w->color = RBTBLACK;
+				x->parent->color = RBTRED;
 
-				rb_rotate_left(rb, x->parent);
+				rbt_rotate_left(rbt, x->parent);
 				w = x->parent->right;
 			}
 
-			if (w->left->color == RBBLACK && w->right->color == RBBLACK)
+			if (w->left->color == RBTBLACK && w->right->color == RBTBLACK)
 			{
-				w->color = RBRED;
+				w->color = RBTRED;
 
 				x = x->parent;
 			}
 			else
 			{
-				if (w->right->color == RBBLACK)
+				if (w->right->color == RBTBLACK)
 				{
-					w->left->color = RBBLACK;
-					w->color = RBRED;
+					w->left->color = RBTBLACK;
+					w->color = RBTRED;
 
-					rb_rotate_right(rb, w);
+					rbt_rotate_right(rbt, w);
 					w = x->parent->right;
 				}
 				w->color = x->parent->color;
-				x->parent->color = RBBLACK;
-				w->right->color = RBBLACK;
+				x->parent->color = RBTBLACK;
+				w->right->color = RBTBLACK;
 
-				rb_rotate_left(rb, x->parent);
-				x = rb->root;	/* Arrange for loop to terminate. */
+				rbt_rotate_left(rbt, x->parent);
+				x = rbt->root;	/* Arrange for loop to terminate. */
 			}
 		}
 		else
 		{
-			RBNode	   *w = x->parent->left;
+			RBTNode    *w = x->parent->left;
 
-			if (w->color == RBRED)
+			if (w->color == RBTRED)
 			{
-				w->color = RBBLACK;
-				x->parent->color = RBRED;
+				w->color = RBTBLACK;
+				x->parent->color = RBTRED;
 
-				rb_rotate_right(rb, x->parent);
+				rbt_rotate_right(rbt, x->parent);
 				w = x->parent->left;
 			}
 
-			if (w->right->color == RBBLACK && w->left->color == RBBLACK)
+			if (w->right->color == RBTBLACK && w->left->color == RBTBLACK)
 			{
-				w->color = RBRED;
+				w->color = RBTRED;
 
 				x = x->parent;
 			}
 			else
 			{
-				if (w->left->color == RBBLACK)
+				if (w->left->color == RBTBLACK)
 				{
-					w->right->color = RBBLACK;
-					w->color = RBRED;
+					w->right->color = RBTBLACK;
+					w->color = RBTRED;
 
-					rb_rotate_left(rb, w);
+					rbt_rotate_left(rbt, w);
 					w = x->parent->left;
 				}
 				w->color = x->parent->color;
-				x->parent->color = RBBLACK;
-				w->left->color = RBBLACK;
+				x->parent->color = RBTBLACK;
+				w->left->color = RBTBLACK;
 
-				rb_rotate_right(rb, x->parent);
-				x = rb->root;	/* Arrange for loop to terminate. */
+				rbt_rotate_right(rbt, x->parent);
+				x = rbt->root;	/* Arrange for loop to terminate. */
 			}
 		}
 	}
-	x->color = RBBLACK;
+	x->color = RBTBLACK;
 }
 
 /*
  * Delete node z from tree.
  */
 static void
-rb_delete_node(RBTree *rb, RBNode *z)
+rbt_delete_node(RBTree *rbt, RBTNode *z)
 {
-	RBNode	   *x,
+	RBTNode    *x,
 			   *y;
 
 	/* This is just paranoia: we should only get called on a valid node */
-	if (!z || z == RBNIL)
+	if (!z || z == RBTNIL)
 		return;
 
 	/*
@@ -565,21 +568,21 @@ rb_delete_node(RBTree *rb, RBNode *z)
 	 * be z if z has fewer than two children, or the tree successor of z
 	 * otherwise.
 	 */
-	if (z->left == RBNIL || z->right == RBNIL)
+	if (z->left == RBTNIL || z->right == RBTNIL)
 	{
-		/* y has a RBNIL node as a child */
+		/* y has a RBTNIL node as a child */
 		y = z;
 	}
 	else
 	{
 		/* find tree successor */
 		y = z->right;
-		while (y->left != RBNIL)
+		while (y->left != RBTNIL)
 			y = y->left;
 	}
 
 	/* x is y's only child */
-	if (y->left != RBNIL)
+	if (y->left != RBTNIL)
 		x = y->left;
 	else
 		x = y->right;
@@ -595,7 +598,7 @@ rb_delete_node(RBTree *rb, RBNode *z)
 	}
 	else
 	{
-		rb->root = x;
+		rbt->root = x;
 	}
 
 	/*
@@ -603,55 +606,55 @@ rb_delete_node(RBTree *rb, RBNode *z)
 	 * the data for the removed node to the one we were supposed to remove.
 	 */
 	if (y != z)
-		rb_copy_data(rb, z, y);
+		rbt_copy_data(rbt, z, y);
 
 	/*
 	 * Removing a black node might make some paths from root to leaf contain
 	 * fewer black nodes than others, or it might make two red nodes adjacent.
 	 */
-	if (y->color == RBBLACK)
-		rb_delete_fixup(rb, x);
+	if (y->color == RBTBLACK)
+		rbt_delete_fixup(rbt, x);
 
 	/* Now we can recycle the y node */
-	if (rb->freefunc)
-		rb->freefunc(y, rb->arg);
+	if (rbt->freefunc)
+		rbt->freefunc(y, rbt->arg);
 }
 
 /*
- * rb_delete: remove the given tree entry
+ * rbt_delete: remove the given tree entry
  *
- * "node" must have previously been found via rb_find or rb_leftmost.
+ * "node" must have previously been found via rbt_find or rbt_leftmost.
  * It is caller's responsibility to free any subsidiary data attached
- * to the node before calling rb_delete.  (Do *not* try to push that
+ * to the node before calling rbt_delete.  (Do *not* try to push that
  * responsibility off to the freefunc, as some other physical node
  * may be the one actually freed!)
  */
 void
-rb_delete(RBTree *rb, RBNode *node)
+rbt_delete(RBTree *rbt, RBTNode *node)
 {
-	rb_delete_node(rb, node);
+	rbt_delete_node(rbt, node);
 }
 
 /**********************************************************************
  *						  Traverse									  *
  **********************************************************************/
 
-static RBNode *
-rb_left_right_iterator(RBTreeIterator *iter)
+static RBTNode *
+rbt_left_right_iterator(RBTreeIterator *iter)
 {
 	if (iter->last_visited == NULL)
 	{
-		iter->last_visited = iter->rb->root;
-		while (iter->last_visited->left != RBNIL)
+		iter->last_visited = iter->rbt->root;
+		while (iter->last_visited->left != RBTNIL)
 			iter->last_visited = iter->last_visited->left;
 
 		return iter->last_visited;
 	}
 
-	if (iter->last_visited->right != RBNIL)
+	if (iter->last_visited->right != RBTNIL)
 	{
 		iter->last_visited = iter->last_visited->right;
-		while (iter->last_visited->left != RBNIL)
+		while (iter->last_visited->left != RBTNIL)
 			iter->last_visited = iter->last_visited->left;
 
 		return iter->last_visited;
@@ -659,7 +662,7 @@ rb_left_right_iterator(RBTreeIterator *iter)
 
 	for (;;)
 	{
-		RBNode	   *came_from = iter->last_visited;
+		RBTNode    *came_from = iter->last_visited;
 
 		iter->last_visited = iter->last_visited->parent;
 		if (iter->last_visited == NULL)
@@ -678,22 +681,22 @@ rb_left_right_iterator(RBTreeIterator *iter)
 	return iter->last_visited;
 }
 
-static RBNode *
-rb_right_left_iterator(RBTreeIterator *iter)
+static RBTNode *
+rbt_right_left_iterator(RBTreeIterator *iter)
 {
 	if (iter->last_visited == NULL)
 	{
-		iter->last_visited = iter->rb->root;
-		while (iter->last_visited->right != RBNIL)
+		iter->last_visited = iter->rbt->root;
+		while (iter->last_visited->right != RBTNIL)
 			iter->last_visited = iter->last_visited->right;
 
 		return iter->last_visited;
 	}
 
-	if (iter->last_visited->left != RBNIL)
+	if (iter->last_visited->left != RBTNIL)
 	{
 		iter->last_visited = iter->last_visited->left;
-		while (iter->last_visited->right != RBNIL)
+		while (iter->last_visited->right != RBTNIL)
 			iter->last_visited = iter->last_visited->right;
 
 		return iter->last_visited;
@@ -701,7 +704,7 @@ rb_right_left_iterator(RBTreeIterator *iter)
 
 	for (;;)
 	{
-		RBNode	   *came_from = iter->last_visited;
+		RBTNode    *came_from = iter->last_visited;
 
 		iter->last_visited = iter->last_visited->parent;
 		if (iter->last_visited == NULL)
@@ -721,33 +724,33 @@ rb_right_left_iterator(RBTreeIterator *iter)
 }
 
 /*
- * rb_begin_iterate: prepare to traverse the tree in any of several orders
+ * rbt_begin_iterate: prepare to traverse the tree in any of several orders
  *
- * After calling rb_begin_iterate, call rb_iterate repeatedly until it
+ * After calling rbt_begin_iterate, call rbt_iterate repeatedly until it
  * returns NULL or the traversal stops being of interest.
  *
  * If the tree is changed during traversal, results of further calls to
- * rb_iterate are unspecified.  Multiple concurrent iterators on the same
+ * rbt_iterate are unspecified.  Multiple concurrent iterators on the same
  * tree are allowed.
  *
  * The iterator state is stored in the 'iter' struct.  The caller should
  * treat it as an opaque struct.
  */
 void
-rb_begin_iterate(RBTree *rb, RBOrderControl ctrl, RBTreeIterator *iter)
+rbt_begin_iterate(RBTree *rbt, RBTOrderControl ctrl, RBTreeIterator *iter)
 {
 	/* Common initialization for all traversal orders */
-	iter->rb = rb;
+	iter->rbt = rbt;
 	iter->last_visited = NULL;
-	iter->is_over = (rb->root == RBNIL);
+	iter->is_over = (rbt->root == RBTNIL);
 
 	switch (ctrl)
 	{
 		case LeftRightWalk:		/* visit left, then self, then right */
-			iter->iterate = rb_left_right_iterator;
+			iter->iterate = rbt_left_right_iterator;
 			break;
 		case RightLeftWalk:		/* visit right, then self, then left */
-			iter->iterate = rb_right_left_iterator;
+			iter->iterate = rbt_right_left_iterator;
 			break;
 		default:
 			elog(ERROR, "unrecognized rbtree iteration order: %d", ctrl);
@@ -755,10 +758,10 @@ rb_begin_iterate(RBTree *rb, RBOrderControl ctrl, RBTreeIterator *iter)
 }
 
 /*
- * rb_iterate: return the next node in traversal order, or NULL if no more
+ * rbt_iterate: return the next node in traversal order, or NULL if no more
  */
-RBNode *
-rb_iterate(RBTreeIterator *iter)
+RBTNode *
+rbt_iterate(RBTreeIterator *iter)
 {
 	if (iter->is_over)
 		return NULL;
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index f0baac6586..81bf8734ce 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -391,7 +391,7 @@ extern bool ginvalidate(Oid opclassoid);
 /* ginbulk.c */
 typedef struct GinEntryAccumulator
 {
-	RBNode		rbnode;
+	RBTNode		rbtnode;
 	Datum		key;
 	GinNullCategory category;
 	OffsetNumber attnum;
diff --git a/src/include/lib/rbtree.h b/src/include/lib/rbtree.h
index c46db47a75..51e4ed321c 100644
--- a/src/include/lib/rbtree.h
+++ b/src/include/lib/rbtree.h
@@ -14,29 +14,29 @@
 #define RBTREE_H
 
 /*
- * RBNode is intended to be used as the first field of a larger struct,
+ * RBTNode is intended to be used as the first field of a larger struct,
  * whose additional fields carry whatever payload data the caller needs
  * for a tree entry.  (The total size of that larger struct is passed to
- * rb_create.)	RBNode is declared here to support this usage, but
+ * rbt_create.)	RBTNode is declared here to support this usage, but
  * callers must treat it as an opaque struct.
  */
-typedef struct RBNode
+typedef struct RBTNode
 {
 	char color;					/* node's current color, red or black */
-	struct RBNode *left;		/* left child, or RBNIL if none */
-	struct RBNode *right;		/* right child, or RBNIL if none */
-	struct RBNode *parent;		/* parent, or NULL (not RBNIL!) if none */
-} RBNode;
+	struct RBTNode *left;		/* left child, or RBTNIL if none */
+	struct RBTNode *right;		/* right child, or RBTNIL if none */
+	struct RBTNode *parent;		/* parent, or NULL (not RBTNIL!) if none */
+} RBTNode;
 
 /* Opaque struct representing a whole tree */
 typedef struct RBTree RBTree;
 
 /* Available tree iteration orderings */
-typedef enum RBOrderControl
+typedef enum RBTOrderControl
 {
 	LeftRightWalk,				/* inorder: left child, node, right child */
 	RightLeftWalk				/* reverse inorder: right, node, left */
-} RBOrderControl;
+} RBTOrderControl;
 
 /*
  * RBTreeIterator holds state while traversing a tree.  This is declared
@@ -47,33 +47,33 @@ typedef struct RBTreeIterator RBTreeIterator;
 
 struct RBTreeIterator
 {
-	RBTree	   *rb;
-	RBNode	   *(*iterate) (RBTreeIterator *iter);
-	RBNode	   *last_visited;
+	RBTree	   *rbt;
+	RBTNode    *(*iterate) (RBTreeIterator *iter);
+	RBTNode    *last_visited;
 	bool		is_over;
 };
 
 /* Support functions to be provided by caller */
-typedef int (*rb_comparator) (const RBNode *a, const RBNode *b, void *arg);
-typedef void (*rb_combiner) (RBNode *existing, const RBNode *newdata, void *arg);
-typedef RBNode *(*rb_allocfunc) (void *arg);
-typedef void (*rb_freefunc) (RBNode *x, void *arg);
+typedef int (*rbt_comparator) (const RBTNode *a, const RBTNode *b, void *arg);
+typedef void (*rbt_combiner) (RBTNode *existing, const RBTNode *newdata, void *arg);
+typedef RBTNode *(*rbt_allocfunc) (void *arg);
+typedef void (*rbt_freefunc) (RBTNode *x, void *arg);
 
-extern RBTree *rb_create(Size node_size,
-		  rb_comparator comparator,
-		  rb_combiner combiner,
-		  rb_allocfunc allocfunc,
-		  rb_freefunc freefunc,
-		  void *arg);
+extern RBTree *rbt_create(Size node_size,
+		   rbt_comparator comparator,
+		   rbt_combiner combiner,
+		   rbt_allocfunc allocfunc,
+		   rbt_freefunc freefunc,
+		   void *arg);
 
-extern RBNode *rb_find(RBTree *rb, const RBNode *data);
-extern RBNode *rb_leftmost(RBTree *rb);
+extern RBTNode *rbt_find(RBTree *rbt, const RBTNode *data);
+extern RBTNode *rbt_leftmost(RBTree *rbt);
 
-extern RBNode *rb_insert(RBTree *rb, const RBNode *data, bool *isNew);
-extern void rb_delete(RBTree *rb, RBNode *node);
+extern RBTNode *rbt_insert(RBTree *rbt, const RBTNode *data, bool *isNew);
+extern void rbt_delete(RBTree *rbt, RBTNode *node);
 
-extern void rb_begin_iterate(RBTree *rb, RBOrderControl ctrl,
-				 RBTreeIterator *iter);
-extern RBNode *rb_iterate(RBTreeIterator *iter);
+extern void rbt_begin_iterate(RBTree *rbt, RBTOrderControl ctrl,
+				  RBTreeIterator *iter);
+extern RBTNode *rbt_iterate(RBTreeIterator *iter);
 
 #endif							/* RBTREE_H */
diff --git a/src/test/modules/test_rbtree/test_rbtree.c b/src/test/modules/test_rbtree/test_rbtree.c
index 1274b9995d..e12284cd8c 100644
--- a/src/test/modules/test_rbtree/test_rbtree.c
+++ b/src/test/modules/test_rbtree/test_rbtree.c
@@ -25,7 +25,7 @@ PG_MODULE_MAGIC;
  */
 typedef struct IntRBTreeNode
 {
-	RBNode		rbnode;
+	RBTNode		rbtnode;
 	int			key;
 } IntRBTreeNode;
 
@@ -35,7 +35,7 @@ typedef struct IntRBTreeNode
  * since none of our test keys are negative.
  */
 static int
-irb_cmp(const RBNode *a, const RBNode *b, void *arg)
+irbt_cmp(const RBTNode *a, const RBTNode *b, void *arg)
 {
 	const IntRBTreeNode *ea = (const IntRBTreeNode *) a;
 	const IntRBTreeNode *eb = (const IntRBTreeNode *) b;
@@ -48,7 +48,7 @@ irb_cmp(const RBNode *a, const RBNode *b, void *arg)
  * try to combine unequal keys.
  */
 static void
-irb_combine(RBNode *existing, const RBNode *newdata, void *arg)
+irbt_combine(RBTNode *existing, const RBTNode *newdata, void *arg)
 {
 	const IntRBTreeNode *eexist = (const IntRBTreeNode *) existing;
 	const IntRBTreeNode *enew = (const IntRBTreeNode *) newdata;
@@ -59,15 +59,15 @@ irb_combine(RBNode *existing, const RBNode *newdata, void *arg)
 }
 
 /* Node allocator */
-static RBNode *
-irb_alloc(void *arg)
+static RBTNode *
+irbt_alloc(void *arg)
 {
-	return (RBNode *) palloc(sizeof(IntRBTreeNode));
+	return (RBTNode *) palloc(sizeof(IntRBTreeNode));
 }
 
 /* Node freer */
 static void
-irb_free(RBNode *node, void *arg)
+irbt_free(RBTNode *node, void *arg)
 {
 	pfree(node);
 }
@@ -78,12 +78,12 @@ irb_free(RBNode *node, void *arg)
 static RBTree *
 create_int_rbtree(void)
 {
-	return rb_create(sizeof(IntRBTreeNode),
-					 irb_cmp,
-					 irb_combine,
-					 irb_alloc,
-					 irb_free,
-					 NULL);
+	return rbt_create(sizeof(IntRBTreeNode),
+					  irbt_cmp,
+					  irbt_combine,
+					  irbt_alloc,
+					  irbt_free,
+					  NULL);
 }
 
 /*
@@ -123,7 +123,7 @@ GetPermutation(int size)
  * 0, step, 2*step, 3*step, ..., inserting them in random order
  */
 static void
-rb_populate(RBTree *tree, int size, int step)
+rbt_populate(RBTree *tree, int size, int step)
 {
 	int		   *permutation = GetPermutation(size);
 	IntRBTreeNode node;
@@ -134,9 +134,9 @@ rb_populate(RBTree *tree, int size, int step)
 	for (i = 0; i < size; i++)
 	{
 		node.key = step * permutation[i];
-		rb_insert(tree, (RBNode *) &node, &isNew);
+		rbt_insert(tree, (RBTNode *) &node, &isNew);
 		if (!isNew)
-			elog(ERROR, "unexpected !isNew result from rb_insert");
+			elog(ERROR, "unexpected !isNew result from rbt_insert");
 	}
 
 	/*
@@ -146,9 +146,9 @@ rb_populate(RBTree *tree, int size, int step)
 	if (size > 0)
 	{
 		node.key = step * permutation[0];
-		rb_insert(tree, (RBNode *) &node, &isNew);
+		rbt_insert(tree, (RBTNode *) &node, &isNew);
 		if (isNew)
-			elog(ERROR, "unexpected isNew result from rb_insert");
+			elog(ERROR, "unexpected isNew result from rbt_insert");
 	}
 
 	pfree(permutation);
@@ -169,17 +169,17 @@ testleftright(int size)
 	int			count = 0;
 
 	/* check iteration over empty tree */
-	rb_begin_iterate(tree, LeftRightWalk, &iter);
-	if (rb_iterate(&iter) != NULL)
+	rbt_begin_iterate(tree, LeftRightWalk, &iter);
+	if (rbt_iterate(&iter) != NULL)
 		elog(ERROR, "left-right walk over empty tree produced an element");
 
 	/* fill tree with consecutive natural numbers */
-	rb_populate(tree, size, 1);
+	rbt_populate(tree, size, 1);
 
 	/* iterate over the tree */
-	rb_begin_iterate(tree, LeftRightWalk, &iter);
+	rbt_begin_iterate(tree, LeftRightWalk, &iter);
 
-	while ((node = (IntRBTreeNode *) rb_iterate(&iter)) != NULL)
+	while ((node = (IntRBTreeNode *) rbt_iterate(&iter)) != NULL)
 	{
 		/* check that order is increasing */
 		if (node->key <= lastKey)
@@ -209,17 +209,17 @@ testrightleft(int size)
 	int			count = 0;
 
 	/* check iteration over empty tree */
-	rb_begin_iterate(tree, RightLeftWalk, &iter);
-	if (rb_iterate(&iter) != NULL)
+	rbt_begin_iterate(tree, RightLeftWalk, &iter);
+	if (rbt_iterate(&iter) != NULL)
 		elog(ERROR, "right-left walk over empty tree produced an element");
 
 	/* fill tree with consecutive natural numbers */
-	rb_populate(tree, size, 1);
+	rbt_populate(tree, size, 1);
 
 	/* iterate over the tree */
-	rb_begin_iterate(tree, RightLeftWalk, &iter);
+	rbt_begin_iterate(tree, RightLeftWalk, &iter);
 
-	while ((node = (IntRBTreeNode *) rb_iterate(&iter)) != NULL)
+	while ((node = (IntRBTreeNode *) rbt_iterate(&iter)) != NULL)
 	{
 		/* check that order is decreasing */
 		if (node->key >= lastKey)
@@ -235,7 +235,7 @@ testrightleft(int size)
 }
 
 /*
- * Check the correctness of the rb_find operation by searching for
+ * Check the correctness of the rbt_find operation by searching for
  * both elements we inserted and elements we didn't.
  */
 static void
@@ -245,7 +245,7 @@ testfind(int size)
 	int			i;
 
 	/* Insert even integers from 0 to 2 * (size-1) */
-	rb_populate(tree, size, 2);
+	rbt_populate(tree, size, 2);
 
 	/* Check that all inserted elements can be found */
 	for (i = 0; i < size; i++)
@@ -254,7 +254,7 @@ testfind(int size)
 		IntRBTreeNode *resultNode;
 
 		node.key = 2 * i;
-		resultNode = (IntRBTreeNode *) rb_find(tree, (RBNode *) &node);
+		resultNode = (IntRBTreeNode *) rbt_find(tree, (RBTNode *) &node);
 		if (resultNode == NULL)
 			elog(ERROR, "inserted element was not found");
 		if (node.key != resultNode->key)
@@ -271,14 +271,14 @@ testfind(int size)
 		IntRBTreeNode *resultNode;
 
 		node.key = i;
-		resultNode = (IntRBTreeNode *) rb_find(tree, (RBNode *) &node);
+		resultNode = (IntRBTreeNode *) rbt_find(tree, (RBTNode *) &node);
 		if (resultNode != NULL)
 			elog(ERROR, "not-inserted element was found");
 	}
 }
 
 /*
- * Check the correctness of the rb_leftmost operation.
+ * Check the correctness of the rbt_leftmost operation.
  * This operation should always return the smallest element of the tree.
  */
 static void
@@ -288,20 +288,20 @@ testleftmost(int size)
 	IntRBTreeNode *result;
 
 	/* Check that empty tree has no leftmost element */
-	if (rb_leftmost(tree) != NULL)
+	if (rbt_leftmost(tree) != NULL)
 		elog(ERROR, "leftmost node of empty tree is not NULL");
 
 	/* fill tree with consecutive natural numbers */
-	rb_populate(tree, size, 1);
+	rbt_populate(tree, size, 1);
 
 	/* Check that leftmost element is the smallest one */
-	result = (IntRBTreeNode *) rb_leftmost(tree);
+	result = (IntRBTreeNode *) rbt_leftmost(tree);
 	if (result == NULL || result->key != 0)
-		elog(ERROR, "rb_leftmost gave wrong result");
+		elog(ERROR, "rbt_leftmost gave wrong result");
 }
 
 /*
- * Check the correctness of the rb_delete operation.
+ * Check the correctness of the rbt_delete operation.
  */
 static void
 testdelete(int size, int delsize)
@@ -312,7 +312,7 @@ testdelete(int size, int delsize)
 	int			i;
 
 	/* fill tree with consecutive natural numbers */
-	rb_populate(tree, size, 1);
+	rbt_populate(tree, size, 1);
 
 	/* Choose unique ids to delete */
 	deleteIds = (int *) palloc(delsize * sizeof(int));
@@ -336,11 +336,11 @@ testdelete(int size, int delsize)
 
 		find.key = deleteIds[i];
 		/* Locate the node to be deleted */
-		node = (IntRBTreeNode *) rb_find(tree, (RBNode *) &find);
+		node = (IntRBTreeNode *) rbt_find(tree, (RBTNode *) &find);
 		if (node == NULL || node->key != deleteIds[i])
 			elog(ERROR, "expected element was not found during deleting");
 		/* Delete it */
-		rb_delete(tree, (RBNode *) node);
+		rbt_delete(tree, (RBTNode *) node);
 	}
 
 	/* Check that deleted elements are deleted */
@@ -350,7 +350,7 @@ testdelete(int size, int delsize)
 		IntRBTreeNode *result;
 
 		node.key = i;
-		result = (IntRBTreeNode *) rb_find(tree, (RBNode *) &node);
+		result = (IntRBTreeNode *) rbt_find(tree, (RBTNode *) &node);
 		if (chosen[i])
 		{
 			/* Deleted element should be absent */
@@ -375,15 +375,15 @@ testdelete(int size, int delsize)
 			continue;
 		find.key = i;
 		/* Locate the node to be deleted */
-		node = (IntRBTreeNode *) rb_find(tree, (RBNode *) &find);
+		node = (IntRBTreeNode *) rbt_find(tree, (RBTNode *) &find);
 		if (node == NULL || node->key != i)
 			elog(ERROR, "expected element was not found during deleting");
 		/* Delete it */
-		rb_delete(tree, (RBNode *) node);
+		rbt_delete(tree, (RBTNode *) node);
 	}
 
 	/* Tree should now be empty */
-	if (rb_leftmost(tree) != NULL)
+	if (rbt_leftmost(tree) != NULL)
 		elog(ERROR, "deleting all elements failed");
 
 	pfree(deleteIds);