FIR CFA: rewrite handling of try-catch-finally
The result is the same, but it should now be much clearer what the shortcomings of the current implementation are.
This commit is contained in:
pyos
+172
-242
@@ -75,12 +75,10 @@ class ControlFlowGraphBuilder {
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private val binaryLogicExpressionExitNodes: Stack<AbstractBinaryExitNode<FirBinaryLogicExpression>> = stackOf()
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private val tryExitNodes: NodeStorage<FirTryExpression, TryExpressionExitNode> = NodeStorage()
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private val tryMainExitNodes: NodeStorage<FirTryExpression, TryMainBlockExitNode> = NodeStorage()
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private val catchNodeStorages: Stack<NodeStorage<FirCatch, CatchClauseEnterNode>> = stackOf()
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private val catchNodeStorage: NodeStorage<FirCatch, CatchClauseEnterNode> get() = catchNodeStorages.top()
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private val catchExitNodeStorages: Stack<NodeStorage<FirCatch, CatchClauseExitNode>> = stackOf()
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private val catchNodes: Stack<List<CatchClauseEnterNode>> = stackOf()
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private val catchBlocksInProgress: Stack<CatchClauseEnterNode> = stackOf()
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private val finallyEnterNodes: Stack<FinallyBlockEnterNode> = stackOf()
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private val finallyExitNodes: NodeStorage<FirTryExpression, FinallyBlockExitNode> = NodeStorage()
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private val finallyBlocksInProgress: Stack<FinallyBlockEnterNode> = stackOf()
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private val initBlockExitNodes: Stack<InitBlockExitNode> = stackOf()
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@@ -684,12 +682,7 @@ class ControlFlowGraphBuilder {
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fun exitJump(jump: FirJump<*>): JumpNode {
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val node = createJumpNode(jump)
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val nextNode = when (jump) {
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is FirReturnExpression -> exitTargetsForReturn[jump.target.labeledElement.symbol]
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is FirContinueExpression -> loopConditionEnterNodes[jump.target.labeledElement.condition]
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is FirBreakExpression -> loopExitNodes[jump.target.labeledElement]
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else -> throw IllegalArgumentException("Unknown jump type: ${jump.render()}")
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}
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addNonTerminatingNode(node)
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if (jump is FirReturnExpression && jump.target.labeledElement is FirAnonymousFunction) {
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// TODO: these should be DFA-only edges; they should be pointed into the postponed function exit node?
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@@ -698,33 +691,41 @@ class ControlFlowGraphBuilder {
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postponedLambdaExits.pop()
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}
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val labelForFinallyBlock = when (jump) {
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is FirReturnExpression -> ReturnPath(jump.target.labeledElement.symbol)
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is FirLoopJump -> LoopPath(jump)
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else -> NormalPath
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val nextNode = when (jump) {
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is FirReturnExpression -> exitTargetsForReturn[jump.target.labeledElement.symbol]
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is FirContinueExpression -> loopConditionEnterNodes[jump.target.labeledElement.condition]
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is FirBreakExpression -> loopExitNodes[jump.target.labeledElement]
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else -> throw IllegalArgumentException("Unknown jump type: ${jump.render()}")
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} ?: return node
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val nextFinally = finallyEnterNodes.topOrNull()?.takeIf { it.level > nextNode.level }
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if (nextFinally != null) {
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addEdge(node, nextFinally, propagateDeadness = false, label = nextNode.returnPathLabel)
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nonDirectJumps.put(nextNode, node)
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} else if (nextNode.returnPathIsBackwards) {
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addBackEdge(node, nextNode)
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} else {
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addEdge(node, nextNode, propagateDeadness = false)
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}
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// while (...) continue // <- jump back
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// do continue while (...) // <- jump forward (block exit node not created yet)
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// do ... while (continue) // <- jump back (to itself), believe it or not
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val isBack = nextNode is LoopConditionEnterNode &&
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(nextNode.loop !is FirDoWhileLoop || nextNode.previousNodes.any { it is LoopBlockExitNode })
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popAndAddEdge(node)
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if (nextNode != null) {
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if (isBack) {
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addBackEdge(node, nextNode) // TODO: shouldn't this go through finally too?
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} else {
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val hadFinally = addEdgeThroughFinally(node, nextNode, labelForFinallyBlock = labelForFinallyBlock)
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if (hadFinally && jump is FirReturnExpression) {
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//actually we can store all returns like this, but not sure if it makes anything better
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nonDirectJumps.put(nextNode, node)
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}
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}
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}
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addWithStub(node)
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return node
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}
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private val CFGNode<*>.returnPathLabel: EdgeLabel
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get() = when (this) {
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is FunctionExitNode -> ReturnPath(fir.symbol)
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is LoopConditionEnterNode -> LoopContinuePath(loop)
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is LoopExitNode -> LoopBreakPath(fir)
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else -> throw IllegalStateException("not a labeled jump target: $this")
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}
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// while (x) { continue }
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// ^------------/ back
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// do { continue } while (x)
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// \---------^ forward
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// do { x } while (continue)
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// ^-------/ back
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private val CFGNode<*>.returnPathIsBackwards: Boolean
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get() = this is LoopConditionEnterNode && (loop !is FirDoWhileLoop || previousNodes.any { it is LoopBlockExitNode })
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// ----------------------------------- When -----------------------------------
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fun enterWhenExpression(whenExpression: FirWhenExpression): WhenEnterNode {
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@@ -923,146 +924,161 @@ class ControlFlowGraphBuilder {
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// ----------------------------------- Try-catch-finally -----------------------------------
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fun enterTryExpression(tryExpression: FirTryExpression): Pair<TryExpressionEnterNode, TryMainBlockEnterNode> {
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catchNodeStorages.push(NodeStorage())
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catchExitNodeStorages.push(NodeStorage())
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val enterTryExpressionNode = createTryExpressionEnterNode(tryExpression)
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val exitTryExpressionNode = createTryExpressionExitNode(tryExpression)
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addNewSimpleNode(enterTryExpressionNode)
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val tryExitNode = createTryExpressionExitNode(tryExpression)
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tryExitNodes.push(tryExitNode)
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levelCounter++
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val enterTryNodeBlock = createTryMainBlockEnterNode(tryExpression)
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addNewSimpleNode(enterTryNodeBlock)
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val exitTryNodeBlock = createTryMainBlockExitNode(tryExpression)
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tryMainExitNodes.push(exitTryNodeBlock)
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for (catch in tryExpression.catches) {
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val catchNode = createCatchClauseEnterNode(catch)
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catchNodeStorage.push(catchNode)
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// a flow where an exception of interest is thrown and caught before executing any of try-main block.
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addEdge(enterTryExpressionNode, catchNode)
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}
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tryExitNodes.push(exitTryExpressionNode)
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levelCounter++
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val enterTryMainBlockNode = createTryMainBlockEnterNode(tryExpression)
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addNewSimpleNode(enterTryMainBlockNode)
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catchNodes.push(tryExpression.catches.map { createCatchClauseEnterNode(it) })
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if (tryExpression.finallyBlock != null) {
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val finallyEnterNode = createFinallyBlockEnterNode(tryExpression)
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// a flow where an uncaught exception is thrown before executing any of try-main block.
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addEdge(enterTryExpressionNode, finallyEnterNode, propagateDeadness = false, label = UncaughtExceptionPath)
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finallyEnterNodes.push(finallyEnterNode)
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finallyExitNodes.push(createFinallyBlockExitNode(tryExpression))
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finallyEnterNodes.push(createFinallyBlockEnterNode(tryExpression))
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}
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for (catchEnterNode in catchNodes.top()) {
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addEdge(enterTryExpressionNode, catchEnterNode)
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}
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if (tryExpression.finallyBlock != null) {
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addEdge(enterTryExpressionNode, finallyEnterNodes.top(), label = UncaughtExceptionPath)
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}
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notCompletedFunctionCalls.push(mutableListOf())
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splitDataFlowForPostponedLambdas()
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return enterTryExpressionNode to enterTryNodeBlock
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levelCounter++
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return enterTryExpressionNode to enterTryMainBlockNode
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}
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fun exitTryMainBlock(): TryMainBlockExitNode {
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levelCounter--
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val node = tryMainExitNodes.top()
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val exitTryExpressionNode = tryExitNodes.top()
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val node = createTryMainBlockExitNode(exitTryExpressionNode.fir)
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popAndAddEdge(node)
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node.updateDeadStatus()
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val finallyEnterNode = finallyEnterNodes.topOrNull()
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// NB: Check the level to avoid adding an edge to the finally block at an upper level.
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if (finallyEnterNode != null && finallyEnterNode.level == levelCounter + 1) {
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// TODO: in case of return/continue/break in try main block, we need a unique label.
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addEdge(node, finallyEnterNode)
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//in case try exit is dead, but there is other edges to finally (eg return)
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// actually finallyEnterNode can't be dead, except for the case when the whole try is dead
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finallyEnterNode.updateDeadStatus()
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} else {
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addEdge(node, tryExitNodes.top(), propagateDeadness = false)
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// try { a } catch (e) { b } [finally { c }]
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// \-----------------^
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val nextNode = if (node.fir.finallyBlock != null) finallyEnterNodes.top() else exitTryExpressionNode
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addEdge(node, nextNode, propagateDeadness = false)
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for (catchEnterNode in catchNodes.pop().asReversed()) {
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catchBlocksInProgress.push(catchEnterNode)
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// At least merge the data flow from enter + exit...but this doesn't really help,
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// see the comment for `addExceptionEdgesFrom`.
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addEdge(node, catchEnterNode, propagateDeadness = false)
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}
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return node
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}
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fun enterCatchClause(catch: FirCatch): CatchClauseEnterNode {
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return catchNodeStorage[catch]!!.also {
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val tryMainExitNode = tryMainExitNodes.top()
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// a flow where an exception of interest is thrown and caught after executing all of try-main block.
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addEdge(tryMainExitNode, it)
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//tryMainExitNode might be dead (eg main block contains return), but it doesn't mean catch block is also dead
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it.updateDeadStatus()
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val finallyEnterNode = finallyEnterNodes.topOrNull()
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// a flow where an uncaught exception is thrown before executing any of catch clause.
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// NB: Check the level to avoid adding an edge to the finally block at an upper level.
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if (finallyEnterNode != null && finallyEnterNode.level == levelCounter + 1) {
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addEdge(it, finallyEnterNode, propagateDeadness = false, label = UncaughtExceptionPath)
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} else {
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addEdge(it, exitTargetsForTry.top(), label = UncaughtExceptionPath)
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}
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lastNodes.push(it)
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levelCounter++
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val catchEnterNode = catchBlocksInProgress.pop()
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assert(catchEnterNode.fir == catch)
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if (tryExitNodes.top().fir.finallyBlock != null) {
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// TODO: not sure this does anything?
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addEdge(catchEnterNode, finallyEnterNodes.top(), propagateDeadness = false, label = UncaughtExceptionPath)
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} else {
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// TODO: this DEFINITELY does nothing, and is in fact incorrect if there are outer try-finally.
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addEdge(catchEnterNode, exitTargetsForTry.top(), propagateDeadness = false, label = UncaughtExceptionPath)
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}
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lastNodes.push(catchEnterNode)
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levelCounter++
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return catchEnterNode
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}
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fun exitCatchClause(catch: FirCatch): CatchClauseExitNode {
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levelCounter--
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return createCatchClauseExitNode(catch).also {
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popAndAddEdge(it)
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val finallyEnterNode = finallyEnterNodes.topOrNull()
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// NB: Check the level to avoid adding an edge to the finally block at an upper level.
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if (finallyEnterNode != null && finallyEnterNode.level == levelCounter + 1) {
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// TODO: in case of return/continue/break in catch clause, we need a unique label.
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addEdge(it, finallyEnterNode, propagateDeadness = false)
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} else {
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addEdge(it, tryExitNodes.top(), propagateDeadness = false)
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}
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catchExitNodeStorages.top().push(it)
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}
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val exitTryExpressionNode = tryExitNodes.top()
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val catchExitNode = createCatchClauseExitNode(catch)
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popAndAddEdge(catchExitNode)
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// try { a } catch (e1) { b } catch (e2) { c } [finally { d }]
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// \------------------^
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val nextNode = if (exitTryExpressionNode.fir.finallyBlock != null) finallyEnterNodes.top() else exitTryExpressionNode
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addEdge(catchExitNode, nextNode, propagateDeadness = false)
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return catchExitNode
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}
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fun enterFinallyBlock(): FinallyBlockEnterNode {
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val enterNode = finallyEnterNodes.pop()
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lastNodes.push(enterNode)
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return enterNode
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return finallyEnterNodes.pop().also {
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lastNodes.push(it)
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finallyBlocksInProgress.push(it)
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}
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}
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fun exitFinallyBlock(): FinallyBlockExitNode {
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return finallyExitNodes.pop().also { finallyExit ->
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popAndAddEdge(finallyExit)
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val tryExitNode = tryExitNodes.top()
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// a flow where either there wasn't any exception or caught if any.
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addEdge(finallyExit, tryExitNode)
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if (finallyExit.isDead) {
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//refresh forward links, which were created before finalizing try expression (eg created by `break`)
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propagateDeadnessForward(finallyExit)
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val enterNode = finallyBlocksInProgress.pop()
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val tryExitNode = tryExitNodes.top()
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val exitNode = createFinallyBlockExitNode(enterNode.fir)
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popAndAddEdge(exitNode)
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val allNormalInputsAreDead = enterNode.previousNodes.all {
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val edge = enterNode.incomingEdges.getValue(it)
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edge.kind.isDead || edge.label != NormalPath
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}
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addEdge(exitNode, tryExitNode, isDead = allNormalInputsAreDead)
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val nextExitLevel = addUncaughtExceptionEdgeFrom(exitNode)
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// /-----------v
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// f@ { try { return@f } finally { b }; c }
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// \-----^
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exitNode.addReturnEdges(exitTargetsForReturn, nextExitLevel)
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// /-----------v
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// f@ while (x) { try { continue@f } finally { b }; c }
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// ^------------------------------------/
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exitNode.addReturnEdges(loopConditionEnterNodes, nextExitLevel)
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// /-----------v
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// f@ while (x) { try { break@f } finally { b }; c }
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// \-----^
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exitNode.addReturnEdges(loopExitNodes, nextExitLevel)
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return exitNode
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}
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private fun <T : CFGNode<*>> CFGNode<*>.addReturnEdges(nodes: Stack<T>, minLevel: Int) {
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for (node in nodes.all()) {
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when {
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node.level <= minLevel -> break
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node !in nonDirectJumps -> continue
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node.returnPathIsBackwards -> addBackEdge(this, node, label = node.returnPathLabel)
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else -> addEdge(this, node, propagateDeadness = false, label = node.returnPathLabel)
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}
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// a flow that exits to the exit target while there was an uncaught exception.
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//todo this edge might exist already if try has jump outside, so we effectively lose labeled edge here
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addEdgeIfNotExist(finallyExit, exitTargetsForTry.top(), propagateDeadness = false, label = UncaughtExceptionPath)
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// TODO: differentiate flows that return/(re)throw in try main block and/or catch clauses
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// To do so, we need mappings from such distinct label to original exit target (fun exit or loop)
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// Also, CFG should support multiple edges towards the same destination node
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}
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}
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fun exitTryExpression(callCompleted: Boolean): TryExpressionExitNode {
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levelCounter--
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catchNodeStorages.pop()
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val catchExitNodes = catchExitNodeStorages.pop()
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val tryMainExitNode = tryMainExitNodes.pop()
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notCompletedFunctionCalls.pop().forEach(::completeFunctionCall)
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val node = tryExitNodes.pop()
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mergeDataFlowFromPostponedLambdas(node, callCompleted)
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node.updateDeadStatus()
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lastNodes.push(node)
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val allCatchesAreDead = tryMainExitNode.fir.catches.all { catch -> catchExitNodes[catch]!!.isDead }
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val tryMainBlockIsDead = tryMainExitNode.previousNodes.all { prev ->
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prev.isDead || tryMainExitNode.incomingEdges.getValue(prev).label != NormalPath
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}
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if (tryMainBlockIsDead && allCatchesAreDead) {
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//if try expression doesn't have any regular non-dead exits, we add stub to make everything after dead
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val stub = createStubNode()
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popAndAddEdge(stub)
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lastNodes.push(stub)
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}
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return node
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}
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private fun addUncaughtExceptionEdgeFrom(node: CFGNode<*>): Int {
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val nextExit = exitTargetsForTry.top()
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val nextFinally = finallyEnterNodes.topOrNull()
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// TODO: this edge is probably redundant if chose `nextExit`
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val nextNode = if (nextFinally != null && nextFinally.level > nextExit.level) nextFinally else nextExit
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addEdge(node, nextNode, propagateDeadness = false, label = UncaughtExceptionPath)
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return nextNode.level
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}
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// TODO: these edges are true for literally any node in the graph. Their existence for *some* nodes
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// might lead to a false sense of security, but things are broken. This should be some sort of implicit knowledge
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// instead of requiring a ton of edges?
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// x = ""
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// try {
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// x = null
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// f() // throws
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// x = ""
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// } catch (e: Throwable) { x.length } // oops
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// Just look at `enterTryExpression` - the edges it adds are literally `addExceptionEdgesFrom(tryExpressionEnterNode)`.
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private fun addExceptionEdgesFrom(node: CFGNode<*>) {
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val nextCatch = catchNodes.topOrNull()
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if (nextCatch != null) {
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for (catchEnterNode in nextCatch) {
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addEdge(node, catchEnterNode, propagateDeadness = false)
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}
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}
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addUncaughtExceptionEdgeFrom(node)
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}
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//this is a workaround to make function call dead when call is completed _after_ building its node in the graph
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//this happens when completing the last call in try/catch blocks
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//todo this doesn't make fully 'right' Nothing node (doesn't support going to catch and pass through finally)
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@@ -1076,10 +1092,9 @@ class ControlFlowGraphBuilder {
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CFGNode.addEdge(node, stub, EdgeKind.DeadForward, propagateDeadness = false)
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for ((to, edge) in edges) {
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val kind = if (edge.kind.isBack) EdgeKind.DeadBackward else EdgeKind.DeadForward
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// TODO: `propagateDeadness` should be redundant if `propagateDeadnessForward` was correct, but it's not.
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CFGNode.addEdge(stub, to, kind, propagateDeadness = true, label = edge.label)
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propagateDeadnessForward(to)
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}
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stub.followingNodes.forEach { propagateDeadnessForward(it, deep = true) }
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}
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// ----------------------------------- Resolvable call -----------------------------------
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@@ -1088,7 +1103,7 @@ class ControlFlowGraphBuilder {
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val returnsNothing = qualifiedAccessExpression.resultType.isNothing
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val node = createQualifiedAccessNode(qualifiedAccessExpression)
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if (returnsNothing) {
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addNodeThatReturnsNothing(node)
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addNonSuccessfullyTerminatingNode(node)
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} else {
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addNewSimpleNode(node)
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}
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@@ -1099,7 +1114,7 @@ class ControlFlowGraphBuilder {
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val returnsNothing = smartCastExpression.resultType.isNothing
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val node = createSmartCastExitNode(smartCastExpression)
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if (returnsNothing) {
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addNodeThatReturnsNothing(node)
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addNonSuccessfullyTerminatingNode(node)
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} else {
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addNewSimpleNode(node)
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}
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@@ -1135,7 +1150,7 @@ class ControlFlowGraphBuilder {
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val node = createFunctionCallNode(functionCall)
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unifyDataFlowFromPostponedLambdas(node, callCompleted)
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if (returnsNothing) {
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addNodeThatReturnsNothing(node)
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addNonSuccessfullyTerminatingNode(node)
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} else {
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addNewSimpleNode(node)
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}
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@@ -1174,7 +1189,7 @@ class ControlFlowGraphBuilder {
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}
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fun exitThrowExceptionNode(throwExpression: FirThrowExpression): ThrowExceptionNode {
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return createThrowExceptionNode(throwExpression).also { addNodeThatReturnsNothing(it) }
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return createThrowExceptionNode(throwExpression).also { addNonSuccessfullyTerminatingNode(it) }
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}
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fun exitCheckNotNullCall(checkNotNullCall: FirCheckNotNullCall, callCompleted: Boolean): CheckNotNullCallNode {
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@@ -1182,7 +1197,7 @@ class ControlFlowGraphBuilder {
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val node = createCheckNotNullCallNode(checkNotNullCall)
|
||||
unifyDataFlowFromPostponedLambdas(node, callCompleted)
|
||||
if (checkNotNullCall.resultType.isNothing) {
|
||||
addNodeThatReturnsNothing(node)
|
||||
addNonSuccessfullyTerminatingNode(node)
|
||||
} else {
|
||||
addNewSimpleNode(node)
|
||||
}
|
||||
@@ -1395,111 +1410,22 @@ class ControlFlowGraphBuilder {
|
||||
addNewSimpleNode(newNode)
|
||||
}
|
||||
|
||||
private fun addWithStub(node: CFGNode<*>) {
|
||||
private fun addNonTerminatingNode(node: CFGNode<*>) {
|
||||
popAndAddEdge(node)
|
||||
val stub = createStubNode()
|
||||
addEdge(node, stub)
|
||||
lastNodes.push(stub)
|
||||
}
|
||||
|
||||
private fun addNodeThatReturnsNothing(node: CFGNode<*>, preferredKind: EdgeKind = EdgeKind.Forward) {
|
||||
// If an expression, which returns Nothing, ...(1)
|
||||
val targetNode = when {
|
||||
tryExitNodes.isEmpty -> {
|
||||
// (1)... isn't inside a try expression, that is an uncaught exception path.
|
||||
exitTargetsForTry.top()
|
||||
}
|
||||
// (1)... inside a try expression...(2)
|
||||
finallyEnterNodes.topOrNull()?.level == levelCounter -> {
|
||||
// (2)... with finally
|
||||
// Either in try-main or catch. Route to `finally`
|
||||
// TODO: that doesn't seem right?
|
||||
// fun bar(): Nothing = throw RuntimeException()
|
||||
// fun main() {
|
||||
// val x: Int
|
||||
// try {
|
||||
// try {
|
||||
// x = 1
|
||||
// println(x)
|
||||
// bar() // addNodeThatReturnsNothing
|
||||
// } finally {} // to this finally?
|
||||
// } finally { // but what about this one?
|
||||
// x = 2
|
||||
// println(x)
|
||||
// }
|
||||
// }
|
||||
// -> compiles and prints 1 then 2
|
||||
// Guessing that there should already be an UncaughtExceptionPath edge from finally 1 to finally 2
|
||||
// regardless of `bar()`, but there isn't.
|
||||
finallyEnterNodes.top()
|
||||
}
|
||||
// (2)... without finally or within finally ...(3)
|
||||
tryExitNodes.top().fir.finallyBlock == null -> {
|
||||
// (3)... without finally ...(4)
|
||||
// Either in try-main or catch.
|
||||
val tryMainExitNode = tryMainExitNodes.top()
|
||||
if (tryMainExitNode.followingNodes.isNotEmpty()) {
|
||||
// (4)... in catch, i.e., re-throw.
|
||||
exitTargetsForTry.top()
|
||||
} else {
|
||||
// (4)... in try-main. Route to exit of try main block.
|
||||
// We already have edges from the exit of try main block to each catch clause.
|
||||
// This edge makes the remaining part of try main block, e.g., following `when` branches, marked as dead.
|
||||
tryMainExitNode
|
||||
}
|
||||
}
|
||||
// (3)... within finally.
|
||||
else -> exitTargetsForTry.top()
|
||||
}
|
||||
popAndAddEdge(node, preferredKind)
|
||||
if (targetNode is TryMainBlockExitNode) {
|
||||
val catches = targetNode.fir.catches
|
||||
if (catches.isEmpty()) {
|
||||
addEdgeThroughFinally(node, exitTargetsForTry.top(), label = UncaughtExceptionPath)
|
||||
} else {
|
||||
for (catch in catches) {
|
||||
addEdge(node, catchNodeStorage[catch]!!, propagateDeadness = false, label = UncaughtExceptionPath)
|
||||
}
|
||||
}
|
||||
} else {
|
||||
addEdgeThroughFinally(node, targetNode, label = UncaughtExceptionPath)
|
||||
}
|
||||
addWithStub(node)
|
||||
}
|
||||
|
||||
private fun addEdgeThroughFinally(
|
||||
node: CFGNode<*>,
|
||||
targetNode: CFGNode<*>,
|
||||
label: EdgeLabel = NormalPath,
|
||||
labelForFinallyBlock: EdgeLabel = label
|
||||
): Boolean {
|
||||
var next = node
|
||||
for (finallyEnter in finallyEnterNodes.all()) {
|
||||
if (finallyEnter.level <= targetNode.level) {
|
||||
break
|
||||
}
|
||||
addEdgeIfNotExist(next, finallyEnter, propagateDeadness = false, label = labelForFinallyBlock)
|
||||
next = finallyExitNodes[finallyEnter.fir]!!
|
||||
}
|
||||
addEdgeIfNotExist(next, targetNode, propagateDeadness = false, label = if (next == node) label else labelForFinallyBlock)
|
||||
return next != node
|
||||
private fun addNonSuccessfullyTerminatingNode(node: CFGNode<*>) {
|
||||
addNonTerminatingNode(node)
|
||||
addExceptionEdgesFrom(node)
|
||||
}
|
||||
|
||||
private fun popAndAddEdge(to: CFGNode<*>, preferredKind: EdgeKind = EdgeKind.Forward) {
|
||||
addEdge(lastNodes.pop(), to, preferredKind = preferredKind)
|
||||
}
|
||||
|
||||
private fun addEdgeIfNotExist(
|
||||
from: CFGNode<*>,
|
||||
to: CFGNode<*>,
|
||||
propagateDeadness: Boolean = true,
|
||||
preferredKind: EdgeKind = EdgeKind.Forward,
|
||||
label: EdgeLabel = NormalPath
|
||||
) {
|
||||
if (!from.followingNodes.contains(to)) {
|
||||
addEdge(from, to, propagateDeadness, preferredKind = preferredKind, label = label)
|
||||
}
|
||||
}
|
||||
|
||||
private fun addEdge(
|
||||
from: CFGNode<*>,
|
||||
to: CFGNode<*>,
|
||||
@@ -1514,22 +1440,26 @@ class ControlFlowGraphBuilder {
|
||||
CFGNode.addEdge(from, to, kind, propagateDeadness, label)
|
||||
}
|
||||
|
||||
private fun addBackEdge(from: CFGNode<*>, to: CFGNode<*>, isDead: Boolean = false) {
|
||||
private fun addBackEdge(from: CFGNode<*>, to: CFGNode<*>, isDead: Boolean = false, label: EdgeLabel = LoopBackPath) {
|
||||
val kind = if (isDead || from.isDead || to.isDead) EdgeKind.DeadBackward else EdgeKind.CfgBackward
|
||||
CFGNode.addEdge(from, to, kind, propagateDeadness = false, label = LoopBackPath)
|
||||
CFGNode.addEdge(from, to, kind, propagateDeadness = false, label = label)
|
||||
}
|
||||
|
||||
private fun propagateDeadnessForward(node: CFGNode<*>, deep: Boolean = false) {
|
||||
private fun propagateDeadnessForward(node: CFGNode<*>) {
|
||||
if (!node.isDead) return
|
||||
node.followingNodes
|
||||
.filter { node.outgoingEdges.getValue(it).kind == EdgeKind.Forward }
|
||||
.forEach { target ->
|
||||
CFGNode.addJustKindEdge(node, target, EdgeKind.DeadForward, false)
|
||||
target.updateDeadStatus()
|
||||
if (deep) {
|
||||
propagateDeadnessForward(target, true)
|
||||
for (next in node.followingNodes) {
|
||||
val kind = node.outgoingEdges.getValue(next).kind
|
||||
if (kind.isDead) continue
|
||||
if (kind.isBack) {
|
||||
CFGNode.addJustKindEdge(node, next, EdgeKind.DeadBackward, propagateDeadness = false)
|
||||
} else {
|
||||
CFGNode.addJustKindEdge(node, next, EdgeKind.DeadForward, propagateDeadness = false)
|
||||
if (kind.usedInCfa) {
|
||||
next.updateDeadStatus()
|
||||
propagateDeadnessForward(next)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// ----------------------------------- Utils -----------------------------------
|
||||
|
||||
Reference in New Issue
Block a user