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Diffstat (limited to 'gcc-4.9/gcc/ada/a-crbtgk.adb')
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diff --git a/gcc-4.9/gcc/ada/a-crbtgk.adb b/gcc-4.9/gcc/ada/a-crbtgk.adb new file mode 100644 index 000000000..ae8dd7c6c --- /dev/null +++ b/gcc-4.9/gcc/ada/a-crbtgk.adb @@ -0,0 +1,828 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- ADA.CONTAINERS.RED_BLACK_TREES.GENERIC_KEYS -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2004-2013, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- This unit was originally developed by Matthew J Heaney. -- +------------------------------------------------------------------------------ + +package body Ada.Containers.Red_Black_Trees.Generic_Keys is + + package Ops renames Tree_Operations; + + ------------- + -- Ceiling -- + ------------- + + -- AKA Lower_Bound + + function Ceiling (Tree : Tree_Type; Key : Key_Type) return Node_Access is + B : Natural renames Tree'Unrestricted_Access.Busy; + L : Natural renames Tree'Unrestricted_Access.Lock; + + Y : Node_Access; + X : Node_Access; + + begin + -- If the container is empty, return a result immediately, so that we do + -- not manipulate the tamper bits unnecessarily. + + if Tree.Root = null then + return null; + end if; + + -- Per AI05-0022, the container implementation is required to detect + -- element tampering by a generic actual subprogram. + + B := B + 1; + L := L + 1; + + X := Tree.Root; + while X /= null loop + if Is_Greater_Key_Node (Key, X) then + X := Ops.Right (X); + else + Y := X; + X := Ops.Left (X); + end if; + end loop; + + B := B - 1; + L := L - 1; + + return Y; + + exception + when others => + B := B - 1; + L := L - 1; + + raise; + end Ceiling; + + ---------- + -- Find -- + ---------- + + function Find (Tree : Tree_Type; Key : Key_Type) return Node_Access is + B : Natural renames Tree'Unrestricted_Access.Busy; + L : Natural renames Tree'Unrestricted_Access.Lock; + + Y : Node_Access; + X : Node_Access; + + Result : Node_Access; + + begin + -- If the container is empty, return a result immediately, so that we do + -- not manipulate the tamper bits unnecessarily. + + if Tree.Root = null then + return null; + end if; + + -- Per AI05-0022, the container implementation is required to detect + -- element tampering by a generic actual subprogram. + + B := B + 1; + L := L + 1; + + X := Tree.Root; + while X /= null loop + if Is_Greater_Key_Node (Key, X) then + X := Ops.Right (X); + else + Y := X; + X := Ops.Left (X); + end if; + end loop; + + if Y = null then + Result := null; + + elsif Is_Less_Key_Node (Key, Y) then + Result := null; + + else + Result := Y; + end if; + + B := B - 1; + L := L - 1; + + return Result; + + exception + when others => + B := B - 1; + L := L - 1; + + raise; + end Find; + + ----------- + -- Floor -- + ----------- + + function Floor (Tree : Tree_Type; Key : Key_Type) return Node_Access is + B : Natural renames Tree'Unrestricted_Access.Busy; + L : Natural renames Tree'Unrestricted_Access.Lock; + + Y : Node_Access; + X : Node_Access; + + begin + -- If the container is empty, return a result immediately, so that we do + -- not manipulate the tamper bits unnecessarily. + + if Tree.Root = null then + return null; + end if; + + -- Per AI05-0022, the container implementation is required to detect + -- element tampering by a generic actual subprogram. + + B := B + 1; + L := L + 1; + + X := Tree.Root; + while X /= null loop + if Is_Less_Key_Node (Key, X) then + X := Ops.Left (X); + else + Y := X; + X := Ops.Right (X); + end if; + end loop; + + B := B - 1; + L := L - 1; + + return Y; + + exception + when others => + B := B - 1; + L := L - 1; + + raise; + end Floor; + + -------------------------------- + -- Generic_Conditional_Insert -- + -------------------------------- + + procedure Generic_Conditional_Insert + (Tree : in out Tree_Type; + Key : Key_Type; + Node : out Node_Access; + Inserted : out Boolean) + is + X : Node_Access; + Y : Node_Access; + + -- Per AI05-0022, the container implementation is required to detect + -- element tampering by a generic actual subprogram. + + B : Natural renames Tree.Busy; + L : Natural renames Tree.Lock; + + Compare : Boolean; + + begin + -- This is a "conditional" insertion, meaning that the insertion request + -- can "fail" in the sense that no new node is created. If the Key is + -- equivalent to an existing node, then we return the existing node and + -- Inserted is set to False. Otherwise, we allocate a new node (via + -- Insert_Post) and Inserted is set to True. + + -- Note that we are testing for equivalence here, not equality. Key must + -- be strictly less than its next neighbor, and strictly greater than + -- its previous neighbor, in order for the conditional insertion to + -- succeed. + + -- Handle insertion into an empty container as a special case, so that + -- we do not manipulate the tamper bits unnecessarily. + + if Tree.Root = null then + Insert_Post (Tree, null, True, Node); + Inserted := True; + return; + end if; + + -- We search the tree to find the nearest neighbor of Key, which is + -- either the smallest node greater than Key (Inserted is True), or the + -- largest node less or equivalent to Key (Inserted is False). + + begin + B := B + 1; + L := L + 1; + + X := Tree.Root; + Y := null; + Inserted := True; + while X /= null loop + Y := X; + Inserted := Is_Less_Key_Node (Key, X); + X := (if Inserted then Ops.Left (X) else Ops.Right (X)); + end loop; + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Inserted then + + -- Key is less than Y. If Y is the first node in the tree, then there + -- are no other nodes that we need to search for, and we insert a new + -- node into the tree. + + if Y = Tree.First then + Insert_Post (Tree, Y, True, Node); + return; + end if; + + -- Y is the next nearest-neighbor of Key. We know that Key is not + -- equivalent to Y (because Key is strictly less than Y), so we move + -- to the previous node, the nearest-neighbor just smaller or + -- equivalent to Key. + + Node := Ops.Previous (Y); + + else + -- Y is the previous nearest-neighbor of Key. We know that Key is not + -- less than Y, which means either that Key is equivalent to Y, or + -- greater than Y. + + Node := Y; + end if; + + -- Key is equivalent to or greater than Node. We must resolve which is + -- the case, to determine whether the conditional insertion succeeds. + + begin + B := B + 1; + L := L + 1; + + Compare := Is_Greater_Key_Node (Key, Node); + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Compare then + + -- Key is strictly greater than Node, which means that Key is not + -- equivalent to Node. In this case, the insertion succeeds, and we + -- insert a new node into the tree. + + Insert_Post (Tree, Y, Inserted, Node); + Inserted := True; + return; + end if; + + -- Key is equivalent to Node. This is a conditional insertion, so we do + -- not insert a new node in this case. We return the existing node and + -- report that no insertion has occurred. + + Inserted := False; + end Generic_Conditional_Insert; + + ------------------------------------------ + -- Generic_Conditional_Insert_With_Hint -- + ------------------------------------------ + + procedure Generic_Conditional_Insert_With_Hint + (Tree : in out Tree_Type; + Position : Node_Access; + Key : Key_Type; + Node : out Node_Access; + Inserted : out Boolean) + is + -- Per AI05-0022, the container implementation is required to detect + -- element tampering by a generic actual subprogram. + + B : Natural renames Tree.Busy; + L : Natural renames Tree.Lock; + + Test : Node_Access; + Compare : Boolean; + + begin + -- The purpose of a hint is to avoid a search from the root of + -- tree. If we have it hint it means we only need to traverse the + -- subtree rooted at the hint to find the nearest neighbor. Note + -- that finding the neighbor means merely walking the tree; this + -- is not a search and the only comparisons that occur are with + -- the hint and its neighbor. + + -- Handle insertion into an empty container as a special case, so that + -- we do not manipulate the tamper bits unnecessarily. + + if Tree.Root = null then + Insert_Post (Tree, null, True, Node); + Inserted := True; + return; + end if; + + -- If Position is null, this is interpreted to mean that Key is large + -- relative to the nodes in the tree. If Key is greater than the last + -- node in the tree, then we're done; otherwise the hint was "wrong" and + -- we must search. + + if Position = null then -- largest + begin + B := B + 1; + L := L + 1; + + Compare := Is_Greater_Key_Node (Key, Tree.Last); + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Compare then + Insert_Post (Tree, Tree.Last, False, Node); + Inserted := True; + else + Conditional_Insert_Sans_Hint (Tree, Key, Node, Inserted); + end if; + + return; + end if; + + pragma Assert (Tree.Length > 0); + + -- A hint can either name the node that immediately follows Key, + -- or immediately precedes Key. We first test whether Key is + -- less than the hint, and if so we compare Key to the node that + -- precedes the hint. If Key is both less than the hint and + -- greater than the hint's preceding neighbor, then we're done; + -- otherwise we must search. + + -- Note also that a hint can either be an anterior node or a leaf + -- node. A new node is always inserted at the bottom of the tree + -- (at least prior to rebalancing), becoming the new left or + -- right child of leaf node (which prior to the insertion must + -- necessarily be null, since this is a leaf). If the hint names + -- an anterior node then its neighbor must be a leaf, and so + -- (here) we insert after the neighbor. If the hint names a leaf + -- then its neighbor must be anterior and so we insert before the + -- hint. + + begin + B := B + 1; + L := L + 1; + + Compare := Is_Less_Key_Node (Key, Position); + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Compare then + Test := Ops.Previous (Position); -- "before" + + if Test = null then -- new first node + Insert_Post (Tree, Tree.First, True, Node); + + Inserted := True; + return; + end if; + + begin + B := B + 1; + L := L + 1; + + Compare := Is_Greater_Key_Node (Key, Test); + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Compare then + if Ops.Right (Test) = null then + Insert_Post (Tree, Test, False, Node); + else + Insert_Post (Tree, Position, True, Node); + end if; + + Inserted := True; + + else + Conditional_Insert_Sans_Hint (Tree, Key, Node, Inserted); + end if; + + return; + end if; + + -- We know that Key isn't less than the hint so we try again, this time + -- to see if it's greater than the hint. If so we compare Key to the + -- node that follows the hint. If Key is both greater than the hint and + -- less than the hint's next neighbor, then we're done; otherwise we + -- must search. + + begin + B := B + 1; + L := L + 1; + + Compare := Is_Greater_Key_Node (Key, Position); + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Compare then + Test := Ops.Next (Position); -- "after" + + if Test = null then -- new last node + Insert_Post (Tree, Tree.Last, False, Node); + + Inserted := True; + return; + end if; + + begin + B := B + 1; + L := L + 1; + + Compare := Is_Less_Key_Node (Key, Test); + + L := L - 1; + B := B - 1; + + exception + when others => + L := L - 1; + B := B - 1; + + raise; + end; + + if Compare then + if Ops.Right (Position) = null then + Insert_Post (Tree, Position, False, Node); + else + Insert_Post (Tree, Test, True, Node); + end if; + + Inserted := True; + + else + Conditional_Insert_Sans_Hint (Tree, Key, Node, Inserted); + end if; + + return; + end if; + + -- We know that Key is neither less than the hint nor greater than the + -- hint, and that's the definition of equivalence. There's nothing else + -- we need to do, since a search would just reach the same conclusion. + + Node := Position; + Inserted := False; + end Generic_Conditional_Insert_With_Hint; + + ------------------------- + -- Generic_Insert_Post -- + ------------------------- + + procedure Generic_Insert_Post + (Tree : in out Tree_Type; + Y : Node_Access; + Before : Boolean; + Z : out Node_Access) + is + begin + if Tree.Length = Count_Type'Last then + raise Constraint_Error with "too many elements"; + end if; + + if Tree.Busy > 0 then + raise Program_Error with + "attempt to tamper with cursors (container is busy)"; + end if; + + Z := New_Node; + pragma Assert (Z /= null); + pragma Assert (Ops.Color (Z) = Red); + + if Y = null then + pragma Assert (Tree.Length = 0); + pragma Assert (Tree.Root = null); + pragma Assert (Tree.First = null); + pragma Assert (Tree.Last = null); + + Tree.Root := Z; + Tree.First := Z; + Tree.Last := Z; + + elsif Before then + pragma Assert (Ops.Left (Y) = null); + + Ops.Set_Left (Y, Z); + + if Y = Tree.First then + Tree.First := Z; + end if; + + else + pragma Assert (Ops.Right (Y) = null); + + Ops.Set_Right (Y, Z); + + if Y = Tree.Last then + Tree.Last := Z; + end if; + end if; + + Ops.Set_Parent (Z, Y); + Ops.Rebalance_For_Insert (Tree, Z); + Tree.Length := Tree.Length + 1; + end Generic_Insert_Post; + + ----------------------- + -- Generic_Iteration -- + ----------------------- + + procedure Generic_Iteration + (Tree : Tree_Type; + Key : Key_Type) + is + procedure Iterate (Node : Node_Access); + + ------------- + -- Iterate -- + ------------- + + procedure Iterate (Node : Node_Access) is + N : Node_Access; + begin + N := Node; + while N /= null loop + if Is_Less_Key_Node (Key, N) then + N := Ops.Left (N); + elsif Is_Greater_Key_Node (Key, N) then + N := Ops.Right (N); + else + Iterate (Ops.Left (N)); + Process (N); + N := Ops.Right (N); + end if; + end loop; + end Iterate; + + -- Start of processing for Generic_Iteration + + begin + Iterate (Tree.Root); + end Generic_Iteration; + + ------------------------------- + -- Generic_Reverse_Iteration -- + ------------------------------- + + procedure Generic_Reverse_Iteration + (Tree : Tree_Type; + Key : Key_Type) + is + procedure Iterate (Node : Node_Access); + + ------------- + -- Iterate -- + ------------- + + procedure Iterate (Node : Node_Access) is + N : Node_Access; + begin + N := Node; + while N /= null loop + if Is_Less_Key_Node (Key, N) then + N := Ops.Left (N); + elsif Is_Greater_Key_Node (Key, N) then + N := Ops.Right (N); + else + Iterate (Ops.Right (N)); + Process (N); + N := Ops.Left (N); + end if; + end loop; + end Iterate; + + -- Start of processing for Generic_Reverse_Iteration + + begin + Iterate (Tree.Root); + end Generic_Reverse_Iteration; + + ---------------------------------- + -- Generic_Unconditional_Insert -- + ---------------------------------- + + procedure Generic_Unconditional_Insert + (Tree : in out Tree_Type; + Key : Key_Type; + Node : out Node_Access) + is + Y : Node_Access; + X : Node_Access; + + Before : Boolean; + + begin + Y := null; + Before := False; + + X := Tree.Root; + while X /= null loop + Y := X; + Before := Is_Less_Key_Node (Key, X); + X := (if Before then Ops.Left (X) else Ops.Right (X)); + end loop; + + Insert_Post (Tree, Y, Before, Node); + end Generic_Unconditional_Insert; + + -------------------------------------------- + -- Generic_Unconditional_Insert_With_Hint -- + -------------------------------------------- + + procedure Generic_Unconditional_Insert_With_Hint + (Tree : in out Tree_Type; + Hint : Node_Access; + Key : Key_Type; + Node : out Node_Access) + is + begin + -- There are fewer constraints for an unconditional insertion + -- than for a conditional insertion, since we allow duplicate + -- keys. So instead of having to check (say) whether Key is + -- (strictly) greater than the hint's previous neighbor, here we + -- allow Key to be equal to or greater than the previous node. + + -- There is the issue of what to do if Key is equivalent to the + -- hint. Does the new node get inserted before or after the hint? + -- We decide that it gets inserted after the hint, reasoning that + -- this is consistent with behavior for non-hint insertion, which + -- inserts a new node after existing nodes with equivalent keys. + + -- First we check whether the hint is null, which is interpreted + -- to mean that Key is large relative to existing nodes. + -- Following our rule above, if Key is equal to or greater than + -- the last node, then we insert the new node immediately after + -- last. (We don't have an operation for testing whether a key is + -- "equal to or greater than" a node, so we must say instead "not + -- less than", which is equivalent.) + + if Hint = null then -- largest + if Tree.Last = null then + Insert_Post (Tree, null, False, Node); + elsif Is_Less_Key_Node (Key, Tree.Last) then + Unconditional_Insert_Sans_Hint (Tree, Key, Node); + else + Insert_Post (Tree, Tree.Last, False, Node); + end if; + + return; + end if; + + pragma Assert (Tree.Length > 0); + + -- We decide here whether to insert the new node prior to the + -- hint. Key could be equivalent to the hint, so in theory we + -- could write the following test as "not greater than" (same as + -- "less than or equal to"). If Key were equivalent to the hint, + -- that would mean that the new node gets inserted before an + -- equivalent node. That wouldn't break any container invariants, + -- but our rule above says that new nodes always get inserted + -- after equivalent nodes. So here we test whether Key is both + -- less than the hint and equal to or greater than the hint's + -- previous neighbor, and if so insert it before the hint. + + if Is_Less_Key_Node (Key, Hint) then + declare + Before : constant Node_Access := Ops.Previous (Hint); + begin + if Before = null then + Insert_Post (Tree, Hint, True, Node); + elsif Is_Less_Key_Node (Key, Before) then + Unconditional_Insert_Sans_Hint (Tree, Key, Node); + elsif Ops.Right (Before) = null then + Insert_Post (Tree, Before, False, Node); + else + Insert_Post (Tree, Hint, True, Node); + end if; + end; + + return; + end if; + + -- We know that Key isn't less than the hint, so it must be equal + -- or greater. So we just test whether Key is less than or equal + -- to (same as "not greater than") the hint's next neighbor, and + -- if so insert it after the hint. + + declare + After : constant Node_Access := Ops.Next (Hint); + begin + if After = null then + Insert_Post (Tree, Hint, False, Node); + elsif Is_Greater_Key_Node (Key, After) then + Unconditional_Insert_Sans_Hint (Tree, Key, Node); + elsif Ops.Right (Hint) = null then + Insert_Post (Tree, Hint, False, Node); + else + Insert_Post (Tree, After, True, Node); + end if; + end; + end Generic_Unconditional_Insert_With_Hint; + + ----------------- + -- Upper_Bound -- + ----------------- + + function Upper_Bound + (Tree : Tree_Type; + Key : Key_Type) return Node_Access + is + Y : Node_Access; + X : Node_Access; + + begin + X := Tree.Root; + while X /= null loop + if Is_Less_Key_Node (Key, X) then + Y := X; + X := Ops.Left (X); + else + X := Ops.Right (X); + end if; + end loop; + + return Y; + end Upper_Bound; + +end Ada.Containers.Red_Black_Trees.Generic_Keys; |