diff options
Diffstat (limited to 'gcc/ada/a-crbtgk.adb')
| -rw-r--r-- | gcc/ada/a-crbtgk.adb | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/gcc/ada/a-crbtgk.adb b/gcc/ada/a-crbtgk.adb index f1762f8..7cc3b25 100644 --- a/gcc/ada/a-crbtgk.adb +++ b/gcc/ada/a-crbtgk.adb @@ -45,6 +45,13 @@ package body Ada.Containers.Red_Black_Trees.Generic_Keys is 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. @@ -87,6 +94,13 @@ package body Ada.Containers.Red_Black_Trees.Generic_Keys is 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. @@ -137,6 +151,13 @@ package body Ada.Containers.Red_Black_Trees.Generic_Keys is 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. @@ -198,6 +219,15 @@ package body Ada.Containers.Red_Black_Trees.Generic_Keys is -- 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). @@ -227,9 +257,9 @@ package body Ada.Containers.Red_Black_Trees.Generic_Keys is if Inserted then - -- Either Tree is empty, or 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. + -- 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); @@ -316,18 +346,26 @@ package body Ada.Containers.Red_Black_Trees.Generic_Keys is -- is not a search and the only comparisons that occur are with -- the hint and its neighbor. - -- If Position is null, this is interpreted to mean that Key is - -- large relative to the nodes in the tree. If the tree is empty, - -- or Key is greater than the last node in the tree, then we're - -- done; otherwise the hint was "wrong" and we must search. + -- 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 := - Tree.Last = null or else Is_Greater_Key_Node (Key, Tree.Last); + Compare := Is_Greater_Key_Node (Key, Tree.Last); L := L - 1; B := B - 1; |