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KT-53255. Fix StackOverflow during IR verification from K2

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In FIR we desugar when with multiple conditions leading to same block
as tree of OR expressions

Given
```
when(some) {
  "a", "b", "c" -> {}
  else -> {}
}
```

actually desugared into
```
when(val <subj> = some) {
  <subj> == "a" || <subj> == "b" || <subj> == "c" -> {}
  else -> {}
}
```

There is a multiple ways of how we can organize such expressions in FIR
Previously it was just nesting-chain of OR expressions

While the most efficient way in terms of required stack depth is
a balanced tree

KT-53255
This commit is contained in:
Simon Ogorodnik
2022-10-19 04:29:10 +02:00
committed by Space Team
parent ac8cae16ba
commit 2cf8f75a90
6 changed files with 67 additions and 61 deletions
Download Patch File Download Diff File Expand all files Collapse all files
compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/WhenEntry.kt
+3 -14
View File
@@ -6,7 +6,7 @@
package org.jetbrains.kotlin.fir.lightTree.fir
import com.intellij.lang.LighterASTNode
import org.jetbrains.kotlin.fir.builder.generateLazyLogicalOperation
import org.jetbrains.kotlin.fir.builder.buildBalancedOrExpressionTree
import org.jetbrains.kotlin.fir.diagnostics.DiagnosticKind
import org.jetbrains.kotlin.fir.diagnostics.ConeSimpleDiagnostic
import org.jetbrains.kotlin.fir.expressions.FirBlock
@@ -20,19 +20,8 @@ data class WhenEntry(
val isElse: Boolean = false
) {
fun toFirWhenCondition(): FirExpression {
var firCondition: FirExpression? = null
for (condition in conditions) {
val firConditionElement = condition.toFirWhenCondition()
firCondition = when (firCondition) {
null -> firConditionElement
else -> firCondition.generateLazyLogicalOperation(firConditionElement, false, null)
}
}
return firCondition!!
}
private fun FirExpression.toFirWhenCondition(): FirExpression {
return this
require(conditions.isNotEmpty())
return buildBalancedOrExpressionTree(conditions)
}
fun toFirWhenConditionWithoutSubject(): FirExpression {
compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/PsiConversionUtils.kt
+7 -10
View File
@@ -72,17 +72,14 @@ internal fun Array<KtWhenCondition>.toFirWhenCondition(
convert: KtExpression?.(String) -> FirExpression,
toFirOrErrorTypeRef: KtTypeReference?.() -> FirTypeRef,
): FirExpression {
var firCondition: FirExpression? = null
for (condition in this) {
val firConditionElement = condition.toFirWhenCondition(subject, convert, toFirOrErrorTypeRef)
firCondition = when (firCondition) {
null -> firConditionElement
else -> firCondition.generateLazyLogicalOperation(
firConditionElement, false, condition.toKtPsiSourceElement(KtFakeSourceElementKind.WhenCondition),
)
}
val conditions = this.map { condition ->
condition.toFirWhenCondition(subject, convert, toFirOrErrorTypeRef)
}
return firCondition!!
require(conditions.isNotEmpty())
// We build balanced tree of OR expressions to ensure we won't run out of stack
// while processing huge conditions
return buildBalancedOrExpressionTree(conditions)
}
internal fun generateTemporaryVariable(
compiler/fir/raw-fir/raw-fir.common/src/org/jetbrains/kotlin/fir/builder/ConversionUtils.kt
+22 -1
View File
@@ -36,7 +36,6 @@ import org.jetbrains.kotlin.fir.symbols.constructStarProjectedType
import org.jetbrains.kotlin.fir.symbols.impl.*
import org.jetbrains.kotlin.fir.types.ConeClassLikeType
import org.jetbrains.kotlin.fir.types.ConeStarProjection
import org.jetbrains.kotlin.fir.types.FirTypeRef
import org.jetbrains.kotlin.fir.types.builder.buildImplicitTypeRef
import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
import org.jetbrains.kotlin.fir.types.impl.*
@@ -588,3 +587,25 @@ data class CalleeAndReceiver(
val receiverExpression: FirExpression? = null,
val isImplicitInvoke: Boolean = false
)
/**
* Creates balanced tree of OR expressions for given set of conditions
* We do so, to avoid too deep OR-expression structures, that can cause running out of stack while processing
* [conditions] should contain at least one element, otherwise it will cause StackOverflow
*/
fun buildBalancedOrExpressionTree(conditions: List<FirExpression>, lower: Int = 0, upper: Int = conditions.lastIndex): FirExpression {
val size = upper - lower + 1
val middle = size / 2 + lower
if (lower == upper) {
return conditions[middle]
}
val leftNode = buildBalancedOrExpressionTree(conditions, lower, middle - 1)
val rightNode = buildBalancedOrExpressionTree(conditions, middle, upper)
return leftNode.generateLazyLogicalOperation(
rightNode,
isAnd = false,
(leftNode.source ?: rightNode.source)?.fakeElement(KtFakeSourceElementKind.WhenCondition)
)
}
compiler/testData/codegen/box/when/longCondition.kt
Vendored
-1
View File
@@ -1,5 +1,4 @@
// TARGET_BACKEND: JVM_IR
// IGNORE_BACKEND_FIR: JVM_IR
fun box(): String {
return when ("foo") {
compiler/testData/ir/irText/expressions/when.fir.ir.txt
Vendored
+24 -24
View File
@@ -102,50 +102,50 @@ FILE fqName:<root> fileName:/when.kt
BRANCH
if: WHEN type=kotlin.Boolean origin=OROR
BRANCH
if: WHEN type=kotlin.Boolean origin=OROR
BRANCH
if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=1
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=2
if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=1
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=3
arg1: CONST Int type=kotlin.Int value=2
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=4
then: WHEN type=kotlin.Boolean origin=OROR
BRANCH
if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=3
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=4
then: CONST String type=kotlin.String value="1234"
BRANCH
if: WHEN type=kotlin.Boolean origin=OROR
BRANCH
if: WHEN type=kotlin.Boolean origin=OROR
if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=5
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: WHEN type=kotlin.Boolean origin=OROR
BRANCH
if: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=5
arg1: CONST Int type=kotlin.Int value=6
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=6
then: CONST Boolean type=kotlin.Boolean value=true
BRANCH
if: CONST Boolean type=kotlin.Boolean value=true
then: CALL 'public final fun EQEQ (arg0: kotlin.Any?, arg1: kotlin.Any?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EQEQ
arg0: GET_VAR 'val tmp_1: kotlin.Int [val] declared in <root>.testComma' type=kotlin.Int origin=null
arg1: CONST Int type=kotlin.Int value=7
arg1: CONST Int type=kotlin.Int value=7
then: CONST String type=kotlin.String value="567"
BRANCH
if: WHEN type=kotlin.Boolean origin=OROR
compiler/testData/ir/irText/expressions/when.fir.kt.txt
Vendored
+11 -11
View File
@@ -38,20 +38,20 @@ fun testComma(x: Int): String {
when {
when {
when {
when {
EQEQ(arg0 = tmp1_subject, arg1 = 1) -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 2)
} -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 3)
EQEQ(arg0 = tmp1_subject, arg1 = 1) -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 2)
} -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 4)
else -> when {
EQEQ(arg0 = tmp1_subject, arg1 = 3) -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 4)
}
} -> "1234"
when {
when {
EQEQ(arg0 = tmp1_subject, arg1 = 5) -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 6)
} -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 7)
EQEQ(arg0 = tmp1_subject, arg1 = 5) -> true
else -> when {
EQEQ(arg0 = tmp1_subject, arg1 = 6) -> true
else -> EQEQ(arg0 = tmp1_subject, arg1 = 7)
}
} -> "567"
when {
EQEQ(arg0 = tmp1_subject, arg1 = 8) -> true