Add MessageCollector#hasErrors, get rid of MessageSeverityCollector

Also fix duplicated wrapping of a message collector into a message severity
collector (in CLICompiler and in the beginning of doExecute in
K2JVMCompiler/K2JSCompiler)

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/messages/CompilerMessageSeverity.java

@@ -28,4 +28,8 @@ public enum CompilerMessageSeverity {
 
     public static final EnumSet<CompilerMessageSeverity> ERRORS = EnumSet.of(ERROR, EXCEPTION);
     public static final EnumSet<CompilerMessageSeverity> VERBOSE = EnumSet.of(OUTPUT, LOGGING);
+
+    public boolean isError() {
+        return ERRORS.contains(this);
+    }
 }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/messages/FilteringMessageCollector.java

@@ -36,4 +36,9 @@ public class FilteringMessageCollector implements MessageCollector {
             messageCollector.report(severity, message, location);
         }
     }
+
+    @Override
+    public boolean hasErrors() {
+        return messageCollector.hasErrors();
+    }
 }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/messages/GroupingMessageCollector.java

@@ -47,19 +47,23 @@ public class GroupingMessageCollector implements MessageCollector {
         }
     }
 
-    public void flush() {
-        boolean hasError = false;
-
-        Collection<String> keys = sortedKeys();
-        for (String path : keys) {
-            for (Message message : groupedMessages.get(path)) {
-                hasError |= CompilerMessageSeverity.ERRORS.contains(message.severity);
+    @Override
+    public boolean hasErrors() {
+        for (Map.Entry<String, Message> entry : groupedMessages.entries()) {
+            if (entry.getValue().severity.isError()) {
+                return true;
             }
         }
 
-        for (String path : keys) {
+        return false;
+    }
+
+    public void flush() {
+        boolean hasErrors = hasErrors();
+
+        for (String path : sortedKeys()) {
             for (Message message : groupedMessages.get(path)) {
-                if (!hasError || CompilerMessageSeverity.ERRORS.contains(message.severity)) {
+                if (!hasErrors || message.severity.isError()) {
                     delegate.report(message.severity, message.message, message.location);
                 }
             }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/messages/MessageCollector.java

@@ -19,17 +19,19 @@ package org.jetbrains.kotlin.cli.common.messages;
 import org.jetbrains.annotations.NotNull;
 
 public interface MessageCollector {
-
     MessageCollector NONE = new MessageCollector() {
         @Override
-        public void report(
-                @NotNull CompilerMessageSeverity severity, @NotNull String message, @NotNull CompilerMessageLocation location
-        ) {
+        public void report(@NotNull CompilerMessageSeverity severity, @NotNull String message, @NotNull CompilerMessageLocation location) {
             // Do nothing
         }
+
+        @Override
+        public boolean hasErrors() {
+            return false;
+        }
     };
 
     void report(@NotNull CompilerMessageSeverity severity, @NotNull String message, @NotNull CompilerMessageLocation location);
 
+    boolean hasErrors();
 }
-

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/messages/MessageSeverityCollector.java

@@ -1,49 +0,0 @@
-/*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.kotlin.cli.common.messages;
-
-import com.google.common.collect.Sets;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Arrays;
-import java.util.Set;
-
-public class MessageSeverityCollector implements MessageCollector {
-
-    private final MessageCollector delegate;
-
-    private final Set<CompilerMessageSeverity> reportedSeverities = Sets.newHashSet();
-
-    public MessageSeverityCollector(@NotNull MessageCollector delegate) {
-        this.delegate = delegate;
-    }
-
-    @Override
-    public void report(
-            @NotNull CompilerMessageSeverity severity,
-            @NotNull String message,
-            @NotNull CompilerMessageLocation location
-    ) {
-        delegate.report(severity, message, location);
-
-        reportedSeverities.add(severity);
-    }
-
-    public boolean anyReported(@NotNull CompilerMessageSeverity... severities) {
-        return reportedSeverities.containsAll(Arrays.asList(severities));
-    }
-}