From 486aa5675f79c3852225dd16ac474da335684371 Mon Sep 17 00:00:00 2001
From: Michael Bogdanov <mikhael.bogdanov@jetbrains.com>
Date: Fri, 8 Jul 2016 18:06:10 +0300
Subject: [PATCH] Fix for KT-12908: Variable initialization in loop causes
 VerifyError bad local variable type

 #KT-12908 Fixed
---
 .../kotlin/codegen/ExpressionCodegen.java     | 10 ++++++++--
 .../codegen/box/controlStructures/kt12908.kt  | 20 +++++++++++++++++++
 .../box/controlStructures/kt12908_2.kt        | 20 +++++++++++++++++++
 .../codegen/BlackBoxCodegenTestGenerated.java | 12 +++++++++++
 4 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 compiler/testData/codegen/box/controlStructures/kt12908.kt
 create mode 100644 compiler/testData/codegen/box/controlStructures/kt12908_2.kt

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
index b56beabd1cd..c24f937d23f 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/ExpressionCodegen.java
@@ -561,6 +561,7 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
         KtExpression condition = expression.getCondition();
         StackValue conditionValue;
 
+        StackValueWithLeaveTask leaveTask = null;
         if (body instanceof KtBlockExpression) {
             // If body's a block, it can contain variable declarations which may be used in the condition of a do-while loop.
             // We handle this case separately because otherwise such variable will be out of the frame map after the block ends
@@ -570,7 +571,9 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
             statements.addAll(doWhileStatements);
             statements.add(condition);
 
-            conditionValue = generateBlock((KtBlockExpression) body, statements, false, continueLabel, null);
+            //Need to split leave task and condition cause otherwise BranchedValue optimizations wouldn't work
+            leaveTask = generateBlock((KtBlockExpression) body, statements, false, continueLabel, null);
+            conditionValue = leaveTask.getStackValue();
         }
         else {
             if (body != null) {
@@ -581,6 +584,9 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
         }
 
         BranchedValue.Companion.loopJump(conditionValue, beginLoopLabel, false, v);
+        if (leaveTask != null) {
+            leaveTask.getLeaveTasks().invoke(conditionValue);
+        }
         v.mark(breakLabel);
 
         blockStackElements.pop();
@@ -1759,7 +1765,7 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
         throw new IllegalStateException("Can't get outer value in " + this + " for " + d);
     }
 
-    private StackValue generateBlock(
+    private StackValueWithLeaveTask generateBlock(
             @NotNull KtBlockExpression block,
             @NotNull List<KtExpression> statements,
             boolean isStatement,
diff --git a/compiler/testData/codegen/box/controlStructures/kt12908.kt b/compiler/testData/codegen/box/controlStructures/kt12908.kt
new file mode 100644
index 00000000000..e35d92b93dc
--- /dev/null
+++ b/compiler/testData/codegen/box/controlStructures/kt12908.kt
@@ -0,0 +1,20 @@
+var field: Int = 0
+
+fun next(): Int {
+    return ++field
+}
+
+
+fun box(): String {
+    val task: String
+
+    do {
+        if (next() % 2 == 0) {
+            task = "OK"
+            break
+        }
+    }
+    while (true)
+
+    return task
+}
diff --git a/compiler/testData/codegen/box/controlStructures/kt12908_2.kt b/compiler/testData/codegen/box/controlStructures/kt12908_2.kt
new file mode 100644
index 00000000000..f4fd0e0555e
--- /dev/null
+++ b/compiler/testData/codegen/box/controlStructures/kt12908_2.kt
@@ -0,0 +1,20 @@
+var field: Int = 0
+
+fun next(): Int {
+    return ++field
+}
+
+
+fun box(): String {
+    val task: String
+
+    do {
+        if (next() % 2 == 0) {
+            task = "OK"
+            break
+        }
+    }
+    while (!false)
+
+    return task
+}
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
index c842ac1134e..2ab6fc248bc 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java
@@ -3673,6 +3673,18 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kt12908.kt")
+        public void testKt12908() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/controlStructures/kt12908.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("kt12908_2.kt")
+        public void testKt12908_2() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/controlStructures/kt12908_2.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt1441.kt")
         public void testKt1441() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/controlStructures/kt1441.kt");