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Fixed control operations issue where OP_ELSE expression wasn't being removed if the previous OP_ELSE was evaluated

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This commit is contained in:
Chris Stewart 2016-02-02 17:14:39 -06:00
parent 178b9f70ed
commit b70580de5a
3 changed files with 107 additions and 40 deletions
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64
src/main/scala/org/scalacoin/script/control/ControlOperationsInterpreter.scala
View File

@ -59,7 +59,24 @@ trait ControlOperationsInterpreter {
*/
def opElse(stack : List[ScriptToken], script : List[ScriptToken]) : (List[ScriptToken], List[ScriptToken]) = {
require(script.headOption.isDefined && script.head == OP_ELSE, "First script opt must be OP_ELSE")
(stack,script.tail)
val tree = parseBinaryTree(script)
println("Parsed tree: " + tree)
val treeWithNextOpElseRemoved = tree match {
case Empty => Empty
case leaf : Leaf[ScriptToken] => leaf
case node : Node[ScriptToken] =>
if (node.r.value == Some(OP_ELSE)) {
val replacementTree = node.r.left.getOrElse(Empty).findFirstDFS[ScriptToken](OP_ENDIF)().getOrElse(Empty)
val replacementNode = replacementTree match {
case Empty => Empty
case leaf : Leaf[ScriptToken] => Node(leaf.v, Empty, node.r.right.getOrElse(Empty))
case node1 : Node[ScriptToken] => Node(node1.v,node1.l,node.r.right.getOrElse(Empty))
}
Node(node.v,node.l,replacementNode)
}
else node
}
(stack,treeWithNextOpElseRemoved.toList.tail)
}
@ -122,8 +139,8 @@ trait ControlOperationsInterpreter {
*/
@tailrec
private def loop(script : List[ScriptToken], tree : BinaryTree[ScriptToken]) : BinaryTree[ScriptToken] = {
logger.debug("Script : " + script)
logger.debug("Tree: " + tree)
/* logger.debug("Script : " + script)
logger.debug("Tree: " + tree)*/
script match {
case OP_IF :: t =>
val (newTail, parsedTree) = parseOpIf(script, Empty)
@ -131,7 +148,6 @@ trait ControlOperationsInterpreter {
loop(newTail, newTree)
case OP_ELSE :: t =>
val (newTail, parsedTree) = parseOpElse(script, Empty)
println("parsed tree: " + parsedTree)
val newTree = insertSubTree(tree,parsedTree)
loop(newTail, newTree)
case OP_ENDIF :: t =>
@ -156,7 +172,7 @@ trait ControlOperationsInterpreter {
*/
private def insertSubTree(tree : BinaryTree[ScriptToken],subTree : BinaryTree[ScriptToken]) : BinaryTree[ScriptToken] = {
//TODO: Optimize this to a tailrec function
logger.debug("Inserting subTree: " + subTree + " into tree: " + tree)
//logger.debug("Inserting subTree: " + subTree + " into tree: " + tree)
tree match {
case Empty => subTree
case leaf : Leaf[ScriptToken] => Node(leaf.v, subTree, Empty)
@ -339,22 +355,28 @@ trait ControlOperationsInterpreter {
* @return
*/
def removeFirstOpElse(tree : BinaryTree[ScriptToken]) : BinaryTree[ScriptToken] = {
//need to traverse the tree to see if there is an OP_ENDIF on the left hand side
val leftBranchContainsOpElse = if (tree.left.isDefined) tree.left.get.contains[ScriptToken](OP_ELSE)() else false
val leftBranchContainsOpIf = if (tree.left.isDefined) tree.left.get.contains[ScriptToken](OP_IF)() else false
logger.debug("Tree contains OP_ENDIF: " + leftBranchContainsOpElse)
if (leftBranchContainsOpElse && !leftBranchContainsOpIf) {
//if the left branch contains an OP_ELSE but no OP_IF
//then we need to delete the OP_ELSE in the left branch
val subTree: Option[BinaryTree[ScriptToken]] = tree.left.get.findFirstDFS[ScriptToken](OP_ELSE)()
logger.debug("Sub tree: " + subTree)
//need to remove the subtree for the OP_ELSE
//need to insert the right branch of the subtree into the original place of the OP_ELSE
if (subTree.isDefined) tree.replace(subTree.get, subTree.get.right.getOrElse(Empty))
else tree
} else if (tree.right.isDefined && tree.right.get.value == Some(OP_ELSE)) {
Node(tree.value.get,tree.left.getOrElse(Empty),tree.right.get.right.getOrElse(Empty))
} else tree
tree match {
case Empty => Empty
case leaf : Leaf[ScriptToken] => leaf
case node : Node[ScriptToken] =>
//need to traverse the tree to see if there is an OP_ENDIF on the left hand side
val leftBranchContainsOpElse = node.l.contains[ScriptToken](OP_ELSE)()
val leftBranchContainsOpIf = node.l.contains[ScriptToken](OP_IF)()
if (leftBranchContainsOpElse && !leftBranchContainsOpIf) {
//if the left branch contains an OP_ELSE but no OP_IF
//then we need to delete the OP_ELSE in the left branch
val subTree: Option[BinaryTree[ScriptToken]] = node.l.findFirstDFS[ScriptToken](OP_ELSE)()
logger.debug("Sub tree: " + subTree)
//need to remove the subtree for the OP_ELSE
//need to insert the right branch of the subtree into the original place of the OP_ELSE
if (subTree.isDefined) tree.replace(subTree.get, subTree.get.right.getOrElse(Empty))
else tree
} else if (node.r.value == Some(OP_ELSE)) {
logger.debug("============================**********************************")
Node(node.v,node.l,node.r.right.getOrElse(Empty))
} else tree
}
}

81
src/test/scala/org/scalacoin/script/control/ControlOperationsInterpreterTest.scala
View File

@ -4,7 +4,7 @@ import org.scalacoin.script.arithmetic.OP_ADD
import org.scalacoin.script.bitwise.OP_EQUAL
import org.scalacoin.script.constant._
import org.scalacoin.script.reserved.{OP_VER, OP_RESERVED}
import org.scalacoin.util.Leaf
import org.scalacoin.util.{Empty, Node, Leaf}
import org.scalatest.{MustMatchers, FlatSpec}
/**
@ -85,10 +85,10 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
removeFirstOpElse(List(OP_IF, OP_1,OP_ELSE, OP_2, OP_ELSE, OP_3, OP_ENDIF)) must be (List(OP_IF, OP_1, OP_ELSE, OP_3, OP_ENDIF))
}
/* it must "remove the first OP_ELSE in a binary tree" in {
it must "remove the first OP_ELSE in a binary tree" in {
val script1 = List(OP_IF,OP_ELSE,OP_ENDIF)
val bTree1 = parseBinaryTree(script1)
removeFirstOpElse(bTree1).toSeq must be (List(OP_IF,OP_ENDIF))
removeFirstOpElse(bTree1).toSeq must be (List(OP_IF))
val script2 = List(OP_IF,OP_ENDIF)
val bTree2 = parseBinaryTree(script2)
@ -97,7 +97,7 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
val script3 = List(OP_IF, OP_1,OP_ELSE, OP_2, OP_ELSE, OP_3, OP_ENDIF)
val bTree3 = parseBinaryTree(script3)
removeFirstOpElse(bTree3).toSeq must be (List(OP_IF, OP_1, OP_ELSE, OP_3, OP_ENDIF))
}*/
}
it must "find a matching OP_ENDIF for an OP_IF" in {
//https://gist.github.com/Christewart/381dc1dbbb07e62501c3
@ -229,6 +229,8 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
}
it must "evaluate an OP_IF correctly" in {
val stack = List(OP_0)
val script = List(OP_IF, OP_RESERVED, OP_ENDIF, OP_1)
@ -237,7 +239,6 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
newScript must be (List(OP_ENDIF,OP_1))
}
it must "evaluate an OP_IF OP_ELSE OP_ENDIF block" in {
val stack = List(OP_0)
val script = List(OP_IF, OP_VER, OP_ELSE, OP_1, OP_ENDIF)
@ -259,8 +260,6 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
checkMatchingOpIfOpEndIf(script3) must be (true)
}
it must "evaluate an OP_IF block correctly if the stack top is true" in {
val stack = List(OP_1)
val script = List(OP_IF, OP_1, OP_ELSE, OP_0, OP_ENDIF)
@ -270,17 +269,6 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
newScript must be (List(OP_1))
}
it must "remove the first OP_ELSE if the stack top is true for an OP_IF" in {
val stack = List(ScriptNumberImpl(1))
val script = List(OP_IF, OP_1, OP_ELSE, OP_RETURN, OP_ELSE, OP_1, OP_ENDIF, OP_ELSE, OP_RETURN, OP_ENDIF,
OP_ADD, OP_2, OP_EQUAL)
val (newStack,newScript) = opIf(stack,script)
newStack.isEmpty must be (true)
newScript must be (List(OP_1,OP_ELSE, OP_1, OP_ENDIF, OP_ELSE, OP_RETURN, OP_ENDIF, OP_ADD, OP_2, OP_EQUAL))
}
it must "evaluate a weird case using multiple OP_ELSEs" in {
val stack = List(ScriptNumberImpl(1))
val script = List(OP_IF, OP_ELSE, OP_0, OP_ELSE, OP_1, OP_ENDIF)
@ -320,12 +308,67 @@ class ControlOperationsInterpreterTest extends FlatSpec with MustMatchers with C
newStack.isEmpty must be (true)
newScript must be (List(OP_ELSE, OP_1,OP_IF,OP_1,OP_ELSE,
OP_RETURN,OP_ELSE,OP_1,OP_ENDIF, OP_ELSE,OP_RETURN,OP_ENDIF,OP_ADD,OP_2,OP_EQUAL))
OP_RETURN,OP_ELSE,OP_1,OP_ENDIF,OP_ELSE, OP_RETURN,OP_ENDIF,OP_ADD,OP_2,OP_EQUAL))
val stack1 = newStack
val script1 = newScript
val (newStack1,newScript1) = opElse(stack1,script1)
newStack1.isEmpty must be (true)
newScript1 must be (List(OP_1,OP_IF,OP_1,OP_ELSE,
OP_RETURN,OP_ELSE,OP_1,OP_ENDIF,OP_ENDIF,OP_ADD,OP_2,OP_EQUAL))
}
it must "remove the first OP_ELSE if the stack top is true for an OP_IF" in {
val stack = List(ScriptNumberImpl(1))
val script = List(OP_IF, OP_1, OP_ELSE, OP_RETURN, OP_ELSE, OP_1, OP_ENDIF, OP_ELSE, OP_RETURN, OP_ENDIF,
OP_ADD, OP_2, OP_EQUAL)
val (newStack,newScript) = opIf(stack,script)
newStack.isEmpty must be (true)
newScript must be (List(OP_1,OP_ELSE, OP_1, OP_ENDIF, OP_ELSE, OP_RETURN, OP_ENDIF, OP_ADD, OP_2, OP_EQUAL))
}
it must "evaluate an OP_ENDIF correctly" in {
val stack = List(ScriptNumberImpl(1), ScriptNumberImpl(1))
val script = List(OP_ENDIF, OP_ELSE, OP_RETURN, OP_ENDIF, OP_ADD, OP_2, OP_EQUAL)
val (newStack,newScript) = opEndIf(stack,script)
newStack must be (stack)
newScript must be (script.tail)
}
it must "parse a partial script correctly" in {
val script = List(OP_IF, OP_1, OP_ELSE, OP_RETURN, OP_ELSE, OP_1, OP_ENDIF, OP_ELSE, OP_RETURN, OP_ENDIF,
OP_ADD, OP_2, OP_EQUAL)
val bTree = parseBinaryTree(script)
bTree.value must be (Some(OP_IF))
bTree.left.get.value must be (Some(OP_1))
bTree.right.get.value must be (Some(OP_ELSE))
bTree.right.get.left.get.value must be (Some(OP_RETURN))
bTree.right.get.right.get.value must be (Some(OP_ELSE))
bTree.right.get.right.get.left.get.value must be (Some(OP_1))
bTree.right.get.right.get.left.get.left.get.value must be (Some(OP_ENDIF))
bTree.right.get.right.get.left.get.left.get.left.get.value must be (Some(OP_ELSE))
}
}

2
src/test/scala/org/scalacoin/script/interpreter/ScriptInterpreterTest.scala
View File

@ -38,6 +38,8 @@ class ScriptInterpreterTest extends FlatSpec with MustMatchers with ScriptInterp
}
it must "evaluate all valid scripts from the bitcoin core script_valid.json" in {
import CoreTestCaseProtocol._