KT-2125 Inconsistent error message on UNSAFE_CALL

#KT-2125 fixed

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

@@ -288,7 +288,7 @@ public class CallResolver {
 
                 return results;
             }
-            if (traceForFirstNonemptyCandidateSet == null && !task.getCandidates().isEmpty()) {
+            if (traceForFirstNonemptyCandidateSet == null && !task.getCandidates().isEmpty() && !results.isNothing()) {
                 traceForFirstNonemptyCandidateSet = temporaryTrace;
                 resultsForFirstNonemptyCandidateSet = results;
             }
@@ -380,7 +380,9 @@ public class CallResolver {
             }
             else {
                 assert status != UNKNOWN_STATUS : "No resolution for " + candidateCall.getCandidateDescriptor();
-                failedCandidates.add(candidateCall);
+                if (candidateCall.getStatus() != STRONG_ERROR) {
+                    failedCandidates.add(candidateCall);
+                }
             }
         }
         
@@ -414,8 +416,13 @@ public class CallResolver {
                 argumentMappingStatus = ValueArgumentsToParametersMapper.mapValueArgumentsToParameters(context.call, context.tracing,
                                                                                                         candidateCall, unmappedArguments);
         if (!argumentMappingStatus.isSuccess()) {
-            candidateCall.addStatus(OTHER_ERROR);
+            if (argumentMappingStatus == ValueArgumentsToParametersMapper.Status.STRONG_ERROR) {
-            if (argumentMappingStatus == ValueArgumentsToParametersMapper.Status.ERROR) {
+                candidateCall.addStatus(STRONG_ERROR);
+            }
+            else {
+                candidateCall.addStatus(OTHER_ERROR);
+            }
+            if (argumentMappingStatus != ValueArgumentsToParametersMapper.Status.WEAK_ERROR) {
                 checkTypesWithNoCallee(context.toBasic());
                 return;
             }

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

@@ -25,12 +25,14 @@ public enum ResolutionStatus {
     UNKNOWN_STATUS,
     UNSAFE_CALL_ERROR,
     OTHER_ERROR,
+    STRONG_ERROR,
     SUCCESS(true);
 
     @SuppressWarnings("unchecked")
     public static final EnumSet<ResolutionStatus>[] SEVERITY_LEVELS = new EnumSet[] {
             EnumSet.of(UNSAFE_CALL_ERROR), // weakest
-            EnumSet.of(OTHER_ERROR), // most severe
+            EnumSet.of(OTHER_ERROR),
+            EnumSet.of(STRONG_ERROR), // most severe
     };
 
     private final boolean success;

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

@@ -152,14 +152,7 @@ public class ResolutionTask<D extends CallableDescriptor, F extends D> extends R
 
         @Override
         public void noReceiverAllowed(@NotNull BindingTrace trace) {
-            if (reference instanceof JetSimpleNameExpression) {
+            trace.report(NO_RECEIVER_ADMITTED.on(reference));
-                //todo temporary hack
-                //should be stored that the reference is unresolved (and not trace the candidate descriptor)
-                trace.report(UNRESOLVED_REFERENCE.on(reference));
-            }
-            else {
-                trace.report(NO_RECEIVER_ADMITTED.on(reference));
-            }
         }
 
         @Override

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

@@ -34,6 +34,8 @@ import java.util.Set;
 import static org.jetbrains.jet.lang.diagnostics.Errors.*;
 import static org.jetbrains.jet.lang.resolve.BindingContext.REFERENCE_TARGET;
 import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMapper.Status.*;
+import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMapper.Status.ERROR;
+import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMapper.Status.STRONG_ERROR;
 
 /**
  * @author abreslav
@@ -41,6 +43,7 @@ import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMap
 /*package*/ class ValueArgumentsToParametersMapper {
 
     public enum Status {
+        STRONG_ERROR(false),
         ERROR(false),
         WEAK_ERROR(false),
         OK(true);
@@ -56,16 +59,10 @@ import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMap
         }
 
         public Status compose(Status other) {
-            switch (other) {
+            if (this == STRONG_ERROR || other == STRONG_ERROR) return STRONG_ERROR;
-                case ERROR:
+            if (this == ERROR || other == ERROR) return ERROR;
-                    return ERROR;
+            if (this == WEAK_ERROR || other == WEAK_ERROR) return WEAK_ERROR;
-                case WEAK_ERROR:
+            return this;
-                    if (this != ERROR) {
-                        return WEAK_ERROR;
-                    }
-                default:
-                    return this;
-            }
         }
     }
 
@@ -220,7 +217,12 @@ import static org.jetbrains.jet.lang.resolve.calls.ValueArgumentsToParametersMap
         }
         if (!receiverParameter.exists() && receiverArgument.exists()) {
             tracing.noReceiverAllowed(temporaryTrace);
-            status = ERROR;
+            if (call.getCalleeExpression() instanceof JetSimpleNameExpression) {
+                status = STRONG_ERROR;
+            }
+            else {
+                status = ERROR;
+            }
         }
 
         assert (candidateCall.getThisObject().exists() == candidateCall.getResultingDescriptor().getExpectedThisObject().exists()) : "Shouldn't happen because of TaskPrioritizer: " + candidateCall.getCandidateDescriptor();

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/BasicExpressionTypingVisitor.java

@@ -613,10 +613,10 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
     private JetType getVariableType(@NotNull JetSimpleNameExpression nameExpression, @NotNull ReceiverDescriptor receiver,
             @Nullable ASTNode callOperationNode, @NotNull ExpressionTypingContext context, @NotNull boolean[] result) {
 
-        TemporaryBindingTrace temporaryTrace = TemporaryBindingTrace.create(context.trace);
+        TemporaryBindingTrace traceForVariable = TemporaryBindingTrace.create(context.trace);
-        OverloadResolutionResults<VariableDescriptor> resolutionResult = context.replaceBindingTrace(temporaryTrace).resolveSimpleProperty(receiver, callOperationNode, nameExpression);
+        OverloadResolutionResults<VariableDescriptor> resolutionResult = context.replaceBindingTrace(traceForVariable).resolveSimpleProperty(receiver, callOperationNode, nameExpression);
         if (!resolutionResult.isNothing()) {
-            temporaryTrace.commit();
+            traceForVariable.commit();
             checkSuper(receiver, resolutionResult, context.trace, nameExpression);
             result[0] = true;
             return resolutionResult.isSingleResult() ? resolutionResult.getResultingDescriptor().getReturnType() : null;
@@ -625,8 +625,10 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
         ExpressionTypingContext newContext = receiver.exists()
                                              ? context.replaceScope(receiver.getType().getMemberScope())
                                              : context;
-        JetType jetType = lookupNamespaceOrClassObject(nameExpression, nameExpression.getReferencedNameAsName(), newContext);
+        TemporaryBindingTrace traceForNamespaceOrClassObject = TemporaryBindingTrace.create(context.trace);
+        JetType jetType = lookupNamespaceOrClassObject(nameExpression, nameExpression.getReferencedNameAsName(), newContext.replaceBindingTrace(traceForNamespaceOrClassObject));
         if (jetType != null) {
+            traceForNamespaceOrClassObject.commit();
 
             // Uncommitted changes in temp context
             context.trace.record(RESOLUTION_SCOPE, nameExpression, context.scope);

compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/kt2125.jet

@@ -0,0 +1,12 @@
+//KT-2125 Inconsistent error message on UNSAFE_CALL
+
+package e
+
+fun main() {
+    val <!UNUSED_VARIABLE!>compareTo<!> = 1
+    val s: String? = null
+    s<!UNSAFE_CALL!>.<!>compareTo("")
+
+    val <!UNUSED_VARIABLE!>bar<!> = 2
+    s.<!UNRESOLVED_REFERENCE!>bar<!>()
+}