krzema12 · SerVB · Apr 29, 2022 · May 5, 2022
diff --git a/compiler/ir/backend.py/src/org/jetbrains/kotlin/ir/backend/py/JsLoweringPhases.kt b/compiler/ir/backend.py/src/org/jetbrains/kotlin/ir/backend/py/JsLoweringPhases.kt
@@ -617,6 +617,13 @@ private val callsLoweringPhase = makeBodyLoweringPhase(
     description = "Handle intrinsics"
 )
 
+private val doWhileRemoverPhase = makeBodyLoweringPhase(
+    ::DoWhileRemover,
+    name = "DoWhileRemover",
+    description = "Remove do-while that Python doesn't have (replace with while)",
+    prerequisite = setOf(blockDecomposerLoweringPhase, suspendFunctionsLoweringPhase),
+)
+
 private val objectDeclarationLoweringPhase = makeDeclarationTransformerPhase(
     ::ObjectDeclarationLowering,
     name = "ObjectDeclarationLowering",
@@ -728,6 +735,7 @@ private val loweringList = listOf(
     objectUsageLoweringPhase,
     captureStackTraceInThrowablesPhase,
     callsLoweringPhase,
+    doWhileRemoverPhase,
     cleanupLoweringPhase,
     validateIrAfterLowering
 )

diff --git a/compiler/ir/backend.py/src/org/jetbrains/kotlin/ir/backend/py/lower/DoWhileRemover.kt b/compiler/ir/backend.py/src/org/jetbrains/kotlin/ir/backend/py/lower/DoWhileRemover.kt
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.ir.backend.py.lower
+
+import org.jetbrains.kotlin.backend.common.BodyLoweringPass
+import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
+import org.jetbrains.kotlin.ir.backend.py.PyIrBackendContext
+import org.jetbrains.kotlin.ir.backend.py.ir.JsIrArithBuilder
+import org.jetbrains.kotlin.ir.backend.py.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.builders.createTmpVariable
+import org.jetbrains.kotlin.ir.builders.irComposite
+import org.jetbrains.kotlin.ir.builders.irGet
+import org.jetbrains.kotlin.ir.builders.irSet
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
+import org.jetbrains.kotlin.ir.expressions.IrBody
+import org.jetbrains.kotlin.ir.expressions.IrDoWhileLoop
+import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.expressions.impl.IrWhileLoopImpl
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
+import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
+import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
+
+class DoWhileTransformer(private val context: PyIrBackendContext, private val irSymbol: IrSymbol) : IrElementTransformerVoid() {
+
+    private val calculator = JsIrArithBuilder(context)
+    private val constTrue get() = JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, true)
+    private val constFalse get() = JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, false)
+
+    /*
+        Transform:
+
+        do:
+            <body>
+        while (<condition>)
+
+        To:
+
+        firstIterationLoopName = true
+        while firstIterationLoopName or (<condition>):
+            firstIterationLoopName = false
+            <body>
+    */
+    override fun visitDoWhileLoop(loop: IrDoWhileLoop): IrExpression {
+        return context.createIrBuilder(irSymbol).irComposite {
+            val tmp = createTmpVariable(constTrue, nameHint = "firstIteration")
+            val newCondition = calculator.oror(irGet(tmp), loop.condition)
+            val newBody = irComposite {
+                +irSet(tmp, constFalse)
+                loop.body?.unaryPlus()
+            }
+
+            +IrWhileLoopImpl(loop.startOffset, loop.endOffset, loop.type, loop.origin).apply {
+                condition = newCondition
+                body = newBody
+                label = loop.label
+            }
+        }
+    }
+}
+
+class DoWhileRemover(private val context: PyIrBackendContext) : BodyLoweringPass {
+    override fun lower(irBody: IrBody, container: IrDeclaration) {
+        irBody.transformChildrenVoid(DoWhileTransformer(context, container.symbol))
+    }
+}
diff --git a/...g/jetbrains/kotlin/ir/backend/py/transformers/irToPy/IrElementToPyStatementTransformer.kt b/...g/jetbrains/kotlin/ir/backend/py/transformers/irToPy/IrElementToPyStatementTransformer.kt
@@ -215,33 +215,9 @@ class IrElementToPyStatementTransformer : BaseIrElementToPyNodeTransformer<List<
         ).let { scopeContext.extractStatements() + it }
     }
 
-    override fun visitDoWhileLoop(loop: IrDoWhileLoop, context: PyGenerationContext): List<stmt> {
-        // transform
-        //
-        // do { <body> } while (<condition>)
-        //
-        // like:
-        //
-        // while True:
-        //     <body>
-        //     if not <condition>:
-        //         break
-        //
-        // TODO: support continue inside <body>
-        val scopeContext = context.newScope()
-        val body = loop.body?.accept(this, scopeContext).orEmpty()
-        val condition = If(
-            test = UnaryOp(Not, IrElementToPyExpressionTransformer().visitExpression(loop.condition, scopeContext)),
-            body = listOf(Break),
-            orelse = emptyList(),
-        )
-
-        return While(
-            test = Constant(value = constant("True"), kind = null),
-            body = body + condition,
-            orelse = emptyList(),
-        )
-            .let { scopeContext.extractStatements() + it }
+    override fun visitDoWhileLoop(loop: IrDoWhileLoop, context: PyGenerationContext): List<stmt> {  // todo
+        return listOf(Expr(value = Name(id = identifier("visitDoWhileLoop $loop".toValidPythonSymbol()), ctx = Load)))
+//        error("DoWhile should have been eliminated in a lowering before executing ToPyTransformer")
     }
 
     override fun visitDynamicOperatorExpression(expression: IrDynamicOperatorExpression, context: PyGenerationContext): List<stmt> {

diff --git a/python/README.md b/python/README.md
@@ -92,10 +92,12 @@ It will generate various reports and summaries:
 
 ![git-history-plot](box.tests/reports/git-history-plot.svg)
 
-Current status: **2463**/5970 passed
+Current status: **2468**/5970 passed
 
 #### History (newest on top)
 
+* after fully supporting do-while (with continue/break): **2468**/5970 (+5)
+
 * after supporting static fields initialization: **2463**/5970 (+98: +102 passed, +4 failed because no support for unsigned numbers, chars, property delegates, any-to-string conversions)
 
 * after supporting integer multiplication: **2365**/5970 (+23)