[JS IR BE] Implement labeled loops

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt

@@ -40,11 +40,11 @@ class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsSta
     }
 
     override fun visitBreak(jump: IrBreak, context: JsGenerationContext): JsStatement {
-        return JsBreak(jump.label?.let(::JsNameRef))
+        return JsBreak(context.getNameForLoop(jump.loop)?.makeRef())
     }
 
     override fun visitContinue(jump: IrContinue, context: JsGenerationContext): JsStatement {
-        return JsContinue(jump.label?.let(::JsNameRef))
+        return JsContinue(context.getNameForLoop(jump.loop)?.makeRef())
     }
 
     override fun visitReturn(expression: IrReturn, context: JsGenerationContext): JsStatement {
@@ -79,11 +79,15 @@ class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsSta
 
     override fun visitWhileLoop(loop: IrWhileLoop, context: JsGenerationContext): JsStatement {
         //TODO what if body null?
-        return JsWhile(loop.condition.accept(IrElementToJsExpressionTransformer(), context), loop.body?.accept(this, context))
+        val label = context.getNameForLoop(loop)
+        val loopStatement = JsWhile(loop.condition.accept(IrElementToJsExpressionTransformer(), context), loop.body?.accept(this, context))
+        return label?.let { JsLabel(it, loopStatement) } ?: loopStatement
     }
 
     override fun visitDoWhileLoop(loop: IrDoWhileLoop, context: JsGenerationContext): JsStatement {
         //TODO what if body null?
-        return JsDoWhile(loop.condition.accept(IrElementToJsExpressionTransformer(), context), loop.body?.accept(this, context))
+        val label = context.getNameForLoop(loop)
+        val loopStatement = JsDoWhile(loop.condition.accept(IrElementToJsExpressionTransformer(), context), loop.body?.accept(this, context))
+        return label?.let { JsLabel(it, loopStatement) } ?: loopStatement
     }
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/JsGenerationContext.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.ir.backend.js.utils
 
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.js.backend.ast.*
 
@@ -42,4 +43,5 @@ class JsGenerationContext {
     }
 
     fun getNameForSymbol(symbol: IrSymbol): JsName = staticContext.getNameForSymbol(symbol, this)
+    fun getNameForLoop(loop: IrLoop): JsName? = staticContext.getNameForLoop(loop, this)
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/JsStaticContext.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.ir.backend.js.utils
 
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.transformers.irToJs.JsIntrinsicTransformers
+import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.js.backend.ast.JsClassModel
 import org.jetbrains.kotlin.js.backend.ast.JsGlobalBlock
@@ -25,4 +26,5 @@ class JsStaticContext(
     val classModels = mutableMapOf<JsName, JsClassModel>()
 
     fun getNameForSymbol(irSymbol: IrSymbol, context: JsGenerationContext) = nameGenerator.getNameForSymbol(irSymbol, context)
+    fun getNameForLoop(loop: IrLoop, context: JsGenerationContext) = nameGenerator.getNameForLoop(loop, context)
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/NameGenerator.kt

@@ -5,9 +5,11 @@
 
 package org.jetbrains.kotlin.ir.backend.js.utils
 
+import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.js.backend.ast.JsName
 
 interface NameGenerator {
     fun getNameForSymbol(symbol: IrSymbol, context: JsGenerationContext): JsName
+    fun getNameForLoop(loop: IrLoop, context: JsGenerationContext): JsName?
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/SimpleNameGenerator.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.ir.backend.js.utils
 
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor
+import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.js.backend.ast.JsName
 import org.jetbrains.kotlin.js.naming.isES5IdentifierPart
@@ -18,8 +19,13 @@ import org.jetbrains.kotlin.resolve.scopes.receivers.ImplicitClassReceiver
 class SimpleNameGenerator : NameGenerator {
 
     private val nameCache = mutableMapOf<DeclarationDescriptor, JsName>()
+    private val loopCache = mutableMapOf<IrLoop, JsName>()
 
     override fun getNameForSymbol(symbol: IrSymbol, context: JsGenerationContext): JsName = getNameForDescriptor(symbol.descriptor, context)
+    override fun getNameForLoop(loop: IrLoop, context: JsGenerationContext): JsName? = loop.label?.let {
+        loopCache.getOrPut(loop) { context.currentScope.declareFreshName(sanitizeName(loop.label!!)) }
+    }
+
 
     private fun getNameForDescriptor(descriptor: DeclarationDescriptor, context: JsGenerationContext): JsName =
         nameCache.getOrPut(descriptor) {