From caad1c20a22500f22e529757c4590330f9deb6dc Mon Sep 17 00:00:00 2001
From: Evgeny Gerashchenko <Evgeny.Gerashchenko@jetbrains.com>
Date: Tue, 27 Nov 2012 18:10:16 +0400
Subject: [PATCH] Substituting type parameters when checking alt signature.

---
 .../AlternativeMethodSignatureData.java         | 17 +++++++++++++----
 .../java/kotlinSignature/SignaturesUtil.java    | 15 +++++++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/AlternativeMethodSignatureData.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/AlternativeMethodSignatureData.java
index e56f8876f81..b7d952015ef 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/AlternativeMethodSignatureData.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/AlternativeMethodSignatureData.java
@@ -29,8 +29,7 @@ import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.java.JavaDescriptorResolver;
 import org.jetbrains.jet.lang.resolve.java.wrapper.PsiMethodWrapper;
 import org.jetbrains.jet.lang.resolve.name.Name;
-import org.jetbrains.jet.lang.types.JetType;
-import org.jetbrains.jet.lang.types.TypeUtils;
+import org.jetbrains.jet.lang.types.*;
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 
 import java.util.ArrayList;
@@ -94,10 +93,16 @@ public class AlternativeMethodSignatureData extends ElementAlternativeSignatureD
             @NotNull JavaDescriptorResolver.ValueParameterDescriptors valueParameterDescriptors,
             @NotNull List<TypeParameterDescriptor> methodTypeParameters
     ) {
+        TypeSubstitutor substitutor = SignaturesUtil.createSubstitutorForFunctionTypeParameters(originalToAltTypeParameters);
+
         for (ValueParameterDescriptor parameter : valueParameterDescriptors.getDescriptors()) {
             int index = parameter.getIndex();
             ValueParameterDescriptor altParameter = altValueParameters.getDescriptors().get(index);
-            if (!TypeUtils.equalTypes(parameter.getType(), altParameter.getType())) {
+
+            JetType substituted = substitutor.substitute(parameter.getType(), Variance.INVARIANT);
+            assert substituted != null;
+
+            if (!TypeUtils.equalTypes(substituted, altParameter.getType())) {
                 throw new AlternativeSignatureMismatchException(
                         "Parameter type changed for method which overrides another: " + altParameter.getType()
                         + ", was: " + parameter.getType());
@@ -108,7 +113,11 @@ public class AlternativeMethodSignatureData extends ElementAlternativeSignatureD
 
         for (TypeParameterDescriptor parameter : methodTypeParameters) {
             int index = parameter.getIndex();
-            if (!TypeUtils.equalTypes(altTypeParameters.get(index).getUpperBoundsAsType(), parameter.getUpperBoundsAsType())) {
+
+            JetType substituted = substitutor.substitute(altTypeParameters.get(index).getUpperBoundsAsType(), Variance.INVARIANT);
+            assert substituted != null;
+
+            if (!TypeUtils.equalTypes(substituted, parameter.getUpperBoundsAsType())) {
                 throw new AlternativeSignatureMismatchException(
                         "Type parameter's upper bound changed for method which overrides another: "
                         + altTypeParameters.get(index).getUpperBoundsAsType() + ", was: " + parameter.getUpperBoundsAsType());
diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/SignaturesUtil.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/SignaturesUtil.java
index 4b9c109bd59..48c20614c28 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/SignaturesUtil.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/SignaturesUtil.java
@@ -20,6 +20,9 @@ import com.google.common.collect.Maps;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
 import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptorImpl;
+import org.jetbrains.jet.lang.types.TypeConstructor;
+import org.jetbrains.jet.lang.types.TypeProjection;
+import org.jetbrains.jet.lang.types.TypeSubstitutor;
 
 import java.util.List;
 import java.util.Map;
@@ -42,6 +45,18 @@ public class SignaturesUtil {
         return result;
     }
 
+    public static TypeSubstitutor createSubstitutorForFunctionTypeParameters(
+            @NotNull Map<TypeParameterDescriptor, TypeParameterDescriptorImpl> originalToAltTypeParameters
+    ) {
+        Map<TypeConstructor, TypeProjection> typeSubstitutionContext = Maps.newHashMap();
+        for (Map.Entry<TypeParameterDescriptor, TypeParameterDescriptorImpl> originalToAltTypeParameter : originalToAltTypeParameters
+                .entrySet()) {
+            typeSubstitutionContext.put(originalToAltTypeParameter.getKey().getTypeConstructor(),
+                                        new TypeProjection(originalToAltTypeParameter.getValue().getDefaultType()));
+        }
+        return TypeSubstitutor.create(typeSubstitutionContext);
+    }
+
     private SignaturesUtil() {
     }
 }