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FIR DFA: element-wise join at merging points of try expression

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This commit is contained in:
Jinseong Jeon
2020-10-27 01:14:29 -07:00
committed by Dmitriy Novozhilov
parent bd173ebebc
commit 771c839d74
7 changed files with 108 additions and 16 deletions
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compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
+23 -6
View File
@@ -649,7 +649,8 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
fun enterCatchClause(catch: FirCatch) {
// NB: fork to isolate effects inside the catch clause
// Otherwise, changes in the catch clause could affect the previous node: try main block.
graphBuilder.enterCatchClause(catch).mergeIncomingFlow(updateReceivers = true, shouldForkFlow = true)
// NB: element-wise join due to multiple incoming flows: try main enter and exit
graphBuilder.enterCatchClause(catch).mergeIncomingFlowElementwise(updateReceivers = true, shouldForkFlow = true)
}
fun exitCatchClause(catch: FirCatch) {
@@ -659,7 +660,8 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
fun enterFinallyBlock() {
// NB: fork to isolate effects inside the finally block
// Otherwise, changes in the finally block could affect the previous nodes: try main block and catch clauses.
graphBuilder.enterFinallyBlock().mergeIncomingFlow(shouldForkFlow = true)
// NB: element-wise join due to multiple incoming flows: try expression enter, try main exit, and catch exits
graphBuilder.enterFinallyBlock().mergeIncomingFlowElementwise(shouldForkFlow = true)
}
fun exitFinallyBlock(tryExpression: FirTryExpression) {
@@ -670,7 +672,8 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
val (tryExpressionExitNode, unionNode) = graphBuilder.exitTryExpression(callCompleted)
// NB: fork to prevent effects after the try expression from being flown into the try expression
// Otherwise, changes in any following nodes could affect the previous nodes, including try main block and finally block if any.
tryExpressionExitNode.mergeIncomingFlow(shouldForkFlow = true)
// NB: element-wise join due to multiple incoming flows: try main exit and catch exits (if no finally exists)
tryExpressionExitNode.mergeIncomingFlowElementwise(shouldForkFlow = true)
unionNode?.let { unionFlowFromArguments(it) }
}
@@ -899,8 +902,11 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
}
if (isAssignment) {
if (initializer is FirConstExpression<*> && initializer.kind == FirConstKind.Null) return
flow.addTypeStatement(propertyVariable typeEq initializer.typeRef.coneType)
if (initializer is FirConstExpression<*> && initializer.kind == FirConstKind.Null) {
flow.addTypeStatement(propertyVariable typeEq property.returnTypeRef.coneType.withNullability(ConeNullability.NULLABLE))
} else {
flow.addTypeStatement(propertyVariable typeEq initializer.typeRef.coneType)
}
}
}
@@ -1121,12 +1127,23 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
private fun <T : CFGNode<*>> T.mergeIncomingFlow(
updateReceivers: Boolean = false,
shouldForkFlow: Boolean = false
): T = foldIncomingFlow(logicSystem::joinFlow, updateReceivers, shouldForkFlow)
private fun <T : CFGNode<*>> T.mergeIncomingFlowElementwise(
updateReceivers: Boolean = false,
shouldForkFlow: Boolean = false
): T = foldIncomingFlow(logicSystem::elementwiseJoinFlow, updateReceivers, shouldForkFlow)
private inline fun <T : CFGNode<*>> T.foldIncomingFlow(
mergeOperation: (Collection<FLOW>) -> FLOW,
updateReceivers: Boolean = false,
shouldForkFlow: Boolean = false
): T = this.also { node ->
val previousFlows = if (node.isDead)
node.previousNodes.mapNotNull { runIf(!node.incomingEdges.getValue(it).kind.isBack) { it.flow } }
else
node.previousNodes.mapNotNull { prev -> prev.takeIf { node.incomingEdges.getValue(it).kind.usedInDfa }?.flow }
var flow = logicSystem.joinFlow(previousFlows)
var flow = mergeOperation.invoke(previousFlows)
if (updateReceivers) {
logicSystem.updateAllReceivers(flow)
}
compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/LogicSystem.kt
+6
View File
@@ -28,9 +28,15 @@ abstract class LogicSystem<FLOW : Flow>(protected val context: ConeInferenceCont
abstract fun createEmptyFlow(): FLOW
abstract fun forkFlow(flow: FLOW): FLOW
// Differential computation
abstract fun joinFlow(flows: Collection<FLOW>): FLOW
abstract fun unionFlow(flows: Collection<FLOW>): FLOW
// Comprehensive element-wise computation
abstract fun elementwiseJoinFlow(flows: Collection<FLOW>): FLOW
abstract fun elementwiseUnionFlow(flows: Collection<FLOW>): FLOW
abstract fun addTypeStatement(flow: FLOW, statement: TypeStatement)
abstract fun addImplication(flow: FLOW, implication: Implication)
compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/PersistentLogicSystem.kt
+69
View File
@@ -275,6 +275,75 @@ abstract class PersistentLogicSystem(context: ConeInferenceContext) : LogicSyste
}
}
override fun elementwiseJoinFlow(flows: Collection<PersistentFlow>): PersistentFlow {
return elementwiseFoldFlow(
flows,
mergeOperation = { statements -> this.or(statements).takeIf { it.isNotEmpty } }
)
}
override fun elementwiseUnionFlow(flows: Collection<PersistentFlow>): PersistentFlow {
return elementwiseFoldFlow(
flows,
mergeOperation = this::and
)
}
private inline fun elementwiseFoldFlow(
flows: Collection<PersistentFlow>,
mergeOperation: (Collection<TypeStatement>) -> MutableTypeStatement?,
): PersistentFlow {
if (flows.isEmpty()) return createEmptyFlow()
flows.singleOrNull()?.let { return it }
val aliasedVariablesThatDontChangeAlias = computeAliasesThatDontChange(flows)
val commonFlow = flows.reduce(::lowestCommonFlow)
// >>> comprehensive element-wise fold >>>
val variables = flows.flatMap { it.approvedTypeStatements.keys }.toSet()
for (variable in variables) {
val info = mergeOperation(flows.map { it.getApprovedTypeStatements(variable, commonFlow) }) ?: continue
removeAllAboutVariable(commonFlow, variable)
commonFlow.addApprovedStatements(info)
}
// <<< comprehensive element-wise fold <<<
commonFlow.addVariableAliases(aliasedVariablesThatDontChangeAlias)
updateAllReceivers(commonFlow)
return commonFlow
}
@OptIn(DfaInternals::class)
private fun PersistentFlow.getApprovedTypeStatements(variable: RealVariable, parentFlow: PersistentFlow): MutableTypeStatement {
var flow = this
val result = MutableTypeStatement(variable)
val variableUnderAlias = directAliasMap[variable]
if (variableUnderAlias == null) {
// >>> comprehensive element-wise fold >>>
// get approved type statement even though the starting flow == parent flow
if (flow == parentFlow) {
flow.approvedTypeStatements[variable]?.let {
result += it
}
} else {
while (flow != parentFlow) {
flow.approvedTypeStatements[variable]?.let {
result += it
}
flow = flow.previousFlow!!
}
}
// <<< comprehensive element-wise fold <<<
} else {
result.exactType.addIfNotNull(variableUnderAlias.originalType)
flow.approvedTypeStatements[variableUnderAlias.variable]?.let { result += it }
}
return result
}
override fun addTypeStatement(flow: PersistentFlow, statement: TypeStatement) {
if (statement.isEmpty) return
with(flow) {
compiler/testData/diagnostics/testsWithStdLib/tryCatch/correctSmartcasts.fir.kt
Vendored
+4 -4
View File
@@ -16,7 +16,7 @@ fun test1(s: String?) {
requireNotNull(s)
}
t2.<!INAPPLICABLE_CANDIDATE!>not<!>()
s.length
s.<!INAPPLICABLE_CANDIDATE!>length<!>
}
}
@@ -45,7 +45,7 @@ fun test3() {
s = null
return
}
s.<!INAPPLICABLE_CANDIDATE!>length<!>
s.length
}
fun test4() {
@@ -61,7 +61,7 @@ fun test4() {
catch (e: ExcB) {
}
s.<!INAPPLICABLE_CANDIDATE!>length<!>
s.length
}
fun test5(s: String?) {
@@ -74,7 +74,7 @@ fun test5(s: String?) {
catch (e: ExcB) {
}
s.length
s.<!INAPPLICABLE_CANDIDATE!>length<!>
}
fun test6(s: String?) {
compiler/testData/diagnostics/testsWithStdLib/tryCatch/correctSmartcasts_after.fir.kt
Vendored
+4 -4
View File
@@ -17,7 +17,7 @@ fun test1(s: String?) {
requireNotNull(s)
}
t2.<!INAPPLICABLE_CANDIDATE!>not<!>()
s.length
s.<!INAPPLICABLE_CANDIDATE!>length<!>
}
}
@@ -46,7 +46,7 @@ fun test3() {
s = null
return
}
s.<!INAPPLICABLE_CANDIDATE!>length<!>
s.length
}
fun test4() {
@@ -62,7 +62,7 @@ fun test4() {
catch (e: ExcB) {
}
s.<!INAPPLICABLE_CANDIDATE!>length<!>
s.length
}
fun test5(s: String?) {
@@ -75,7 +75,7 @@ fun test5(s: String?) {
catch (e: ExcB) {
}
s.length
s.<!INAPPLICABLE_CANDIDATE!>length<!>
}
fun test6(s: String?) {
compiler/testData/diagnostics/testsWithStdLib/tryCatch/falsePositiveSmartcasts.fir.kt
Vendored
+1 -1
View File
@@ -101,6 +101,6 @@ fun test6(s1: String?, s2: String?) {
requireNotNull(s2)
}
s.<!INAPPLICABLE_CANDIDATE!>length<!>
s1.length
s1.<!INAPPLICABLE_CANDIDATE!>length<!>
s2.length
}
compiler/testData/diagnostics/testsWithStdLib/tryCatch/falsePositiveSmartcasts_after.fir.kt
Vendored
+1 -1
View File
@@ -103,6 +103,6 @@ fun test6(s1: String?, s2: String?) {
requireNotNull(s2)
}
s.<!INAPPLICABLE_CANDIDATE!>length<!>
s1.length
s1.<!INAPPLICABLE_CANDIDATE!>length<!>
s2.length
}