REPL overload resolution ambiguity

Fix overload resolution ambiguity in REPL. Note, resolution for
functions declared in script is very different from regular programs:
in scripts function declared later wins. See
functionOverloadResolutionAnyBeatsString for example.

#KT-2272 Fixed

compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java

@@ -43,6 +43,7 @@ import org.jetbrains.jet.lang.resolve.AnalyzerScriptParameter;
 import org.jetbrains.jet.lang.resolve.AnalyzingUtils;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.BindingTraceContext;
+import org.jetbrains.jet.lang.resolve.ScriptHeaderResolver;
 import org.jetbrains.jet.lang.resolve.TopDownAnalysisParameters;
 import org.jetbrains.jet.lang.resolve.TraceBasedRedeclarationHandler;
 import org.jetbrains.jet.lang.resolve.java.CompilerDependencies;
@@ -150,6 +151,8 @@ public class ReplInterpreter {
 
         injector.getTopDownAnalyzer().prepareForTheNextReplLine();
 
+        psiFile.getScript().putUserData(ScriptHeaderResolver.PRIORITY_KEY, lineNumber);
+
         ScriptDescriptor scriptDescriptor = doAnalyze(psiFile);
 
         Progress backendProgress = new Progress() {

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/ScriptDescriptor.java

@@ -34,14 +34,17 @@ import java.util.List;
 public class ScriptDescriptor extends DeclarationDescriptorImpl {
     private static final Name NAME = Name.special("<script>");
 
+    private final int priority;
+
     private JetType returnType;
     private List<ValueParameterDescriptor> valueParameters;
 
     private final ScriptCodeDescriptor scriptCodeDescriptor = new ScriptCodeDescriptor(this);
     private final ReceiverDescriptor implicitReceiver = new ScriptReceiver(this);
 
-    public ScriptDescriptor(@Nullable DeclarationDescriptor containingDeclaration) {
+    public ScriptDescriptor(@Nullable DeclarationDescriptor containingDeclaration, int priority) {
         super(containingDeclaration, Collections.<AnnotationDescriptor>emptyList(), NAME);
+        this.priority = priority;
     }
 
     public void initialize(@NotNull JetType returnType) {
@@ -49,6 +52,10 @@ public class ScriptDescriptor extends DeclarationDescriptorImpl {
         scriptCodeDescriptor.initialize(implicitReceiver, valueParameters, returnType);
     }
 
+    public int getPriority() {
+        return priority;
+    }
+
     @NotNull
     public JetType getReturnType() {
         return returnType;

compiler/frontend/src/org/jetbrains/jet/lang/resolve/ScriptHeaderResolver.java

@@ -17,6 +17,7 @@
 package org.jetbrains.jet.lang.resolve;
 
 import com.google.common.collect.Lists;
+import com.intellij.openapi.util.Key;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
@@ -50,6 +51,8 @@ import static org.jetbrains.jet.lang.types.TypeUtils.NO_EXPECTED_TYPE;
  */
 public class ScriptHeaderResolver {
 
+    public static final Key<Integer> PRIORITY_KEY = Key.create(JetScript.class.getName() + ".priority");
+
     @NotNull
     private NamespaceFactory namespaceFactory;
     @NotNull
@@ -118,7 +121,13 @@ public class ScriptHeaderResolver {
 
     public void processScriptHierarchy(@NotNull JetScript script, @NotNull JetScope outerScope) {
         NamespaceDescriptorImpl ns = namespaceFactory.createNamespaceDescriptorPathIfNeeded(FqName.ROOT);
-        ScriptDescriptor scriptDescriptor = new ScriptDescriptor(ns);
+
+        Integer priority = script.getUserData(PRIORITY_KEY);
+        if (priority == null) {
+            priority = 0;
+        }
+
+        ScriptDescriptor scriptDescriptor = new ScriptDescriptor(ns, priority);
         //WriteThroughScope scriptScope = new WriteThroughScope(
         //        outerScope, ns.getMemberScope(), new TraceBasedRedeclarationHandler(trace));
         WritableScopeImpl scriptScope = new WritableScopeImpl(outerScope, scriptDescriptor, RedeclarationHandler.DO_NOTHING, "script");

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/OverloadingConflictResolver.java

@@ -21,6 +21,7 @@ import gnu.trove.TObjectHashingStrategy;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
+import org.jetbrains.jet.lang.descriptors.ScriptDescriptor;
 import org.jetbrains.jet.lang.descriptors.ValueParameterDescriptor;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
 import org.jetbrains.jet.lang.resolve.OverridingUtil;
@@ -80,6 +81,15 @@ public class OverloadingConflictResolver {
      * Int < Short < Byte
      */
     private <Descriptor extends CallableDescriptor> boolean moreSpecific(Descriptor f, Descriptor g, boolean discriminateGenericDescriptors) {
+        if (f.getContainingDeclaration() instanceof ScriptDescriptor && g.getContainingDeclaration() instanceof ScriptDescriptor) {
+            ScriptDescriptor fs = (ScriptDescriptor) f.getContainingDeclaration();
+            ScriptDescriptor gs = (ScriptDescriptor) g.getContainingDeclaration();
+
+            if (fs.getPriority() != gs.getPriority()) {
+                return fs.getPriority() > gs.getPriority();
+            }
+        }
+
         if (discriminateGenericDescriptors && !isGeneric(f) && isGeneric(g)) return true;
         if (OverridingUtil.overrides(f, g)) return true;
         if (OverridingUtil.overrides(g, f)) return false;

compiler/testData/repl/functionOverloadResolution.repl

@@ -0,0 +1,6 @@
+>>> fun foo() = 10
+null
+>>> fun foo() = 11
+null
+>>> foo()
+11

compiler/testData/repl/functionOverloadResolutionAnyBeatsString.repl

@@ -0,0 +1,6 @@
+>>> fun foo(s: String) = "string"
+null
+>>> fun foo(a: Any) = "any"
+null
+>>> foo("a")
+any

compiler/tests/org/jetbrains/jet/repl/ReplInterpreterTest.java

@@ -92,6 +92,16 @@ public class ReplInterpreterTest {
         testFile("twoClosures.repl");
     }
 
+    @Test
+    public void functionOverloadResolutionAnyBeatsString() {
+        testFile("functionOverloadResolutionAnyBeatsString.repl");
+    }
+
+    @Test
+    public void functionOverloadResolution() {
+        testFile("functionOverloadResolution.repl");
+    }
+
     @Test
     public void empty() {
         testFile("empty.repl");