From c9fef98b8d79ad60551d02eb71223363da188097 Mon Sep 17 00:00:00 2001
From: Svetlana Isakova <svetlana.isakova@jetbrains.com>
Date: Wed, 11 Jul 2012 18:48:38 +0400
Subject: [PATCH] added assert that constraining type doesn't contain type
 variables

---
 .../inference/ConstraintsSystemImpl.java      | 39 ++++++++++++-------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsSystemImpl.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsSystemImpl.java
index 4eec087690c..972f3268f02 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsSystemImpl.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintsSystemImpl.java
@@ -136,21 +136,16 @@ public class ConstraintsSystemImpl implements ConstraintsSystem {
         DeclarationDescriptor subjectTypeDescriptor = subjectType.getConstructor().getDeclarationDescriptor();
 
         if (subjectTypeDescriptor instanceof TypeParameterDescriptor) {
-            if (TypeUtils.dependsOnTypeParameterConstructors(constrainingType, Collections.singleton(DONT_CARE.getConstructor()))) return;
-            if (subjectType.isNullable()) {
-                constrainingType = TypeUtils.makeNotNullable(constrainingType);
-            }
             TypeParameterDescriptor typeParameter = (TypeParameterDescriptor) subjectTypeDescriptor;
-            if (constraintKind == ConstraintKind.SUPER_TYPE) {
-                typeParameterConstraints.get(typeParameter).addLowerBound(constrainingType);
+            TypeConstraintsImpl typeConstraints = typeParameterConstraints.get(typeParameter);
+            if (typeConstraints != null) {
+                addBoundToTypeConstraints(constraintKind, subjectType, constrainingType, typeConstraints);
+                return;
             }
-            else if (constraintKind == ConstraintKind.SUB_TYPE) {
-                typeParameterConstraints.get(typeParameter).addUpperBound(constrainingType);
-            }
-            else {
-                typeParameterConstraints.get(typeParameter).addExactBound(constrainingType);
-            }
-            return;
+        }
+        if (constrainingTypeDescriptor instanceof TypeParameterDescriptor) {
+            // assert that constraining type doesn't contain type variables
+            assert typeParameterConstraints.get(constrainingTypeDescriptor) == null;
         }
 
         if (constrainingTypeDescriptor instanceof ClassDescriptor && subjectTypeDescriptor instanceof ClassDescriptor) {
@@ -190,6 +185,24 @@ public class ConstraintsSystemImpl implements ConstraintsSystem {
         errorConstraintPositions.add(constraintPosition);
     }
 
+    private void addBoundToTypeConstraints(@NotNull ConstraintKind constraintKind, @NotNull JetType subjectType,
+            @NotNull JetType constrainingType, @NotNull TypeConstraintsImpl typeConstraints) {
+
+        if (TypeUtils.dependsOnTypeParameterConstructors(constrainingType, Collections.singleton(DONT_CARE.getConstructor()))) return;
+        if (subjectType.isNullable()) {
+            constrainingType = TypeUtils.makeNotNullable(constrainingType);
+        }
+        if (constraintKind == ConstraintKind.SUPER_TYPE) {
+            typeConstraints.addLowerBound(constrainingType);
+        }
+        else if (constraintKind == ConstraintKind.SUB_TYPE) {
+            typeConstraints.addUpperBound(constrainingType);
+        }
+        else {
+            typeConstraints.addExactBound(constrainingType);
+        }
+    }
+
     @NotNull
     @Override
     public Set<TypeParameterDescriptor> getTypeVariables() {