Added 'getCorrespondingCall' utility function

compiler/frontend/src/org/jetbrains/jet/lang/resolve/BindingContextUtils.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010-2014 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.jet.lang.resolve.bindingContextUtil
+
+import org.jetbrains.jet.lang.psi.JetExpression
+import org.jetbrains.jet.lang.psi.Call
+import org.jetbrains.jet.lang.psi.JetPsiUtil
+import org.jetbrains.jet.lang.psi.JetCallExpression
+import org.jetbrains.jet.lang.psi.JetQualifiedExpression
+import org.jetbrains.jet.lang.psi.JetBinaryExpression
+import org.jetbrains.jet.lang.psi.JetUnaryExpression
+import org.jetbrains.jet.lang.psi.JetArrayAccessExpression
+import org.jetbrains.jet.lang.resolve.BindingContext
+import org.jetbrains.jet.lang.psi.JetOperationExpression
+import org.jetbrains.jet.lang.resolve.BindingContext.CALL
+import com.intellij.psi.util.PsiTreeUtil
+import org.jetbrains.jet.lang.psi.JetSimpleNameExpression
+
+/**
+ *  For expressions like <code>a(), a[i], a.b.c(), +a, a + b, (a()), a(): Int, @label a()</code>
+ *  returns a corresponding call
+ */
+fun JetExpression.getCorrespondingCall(bindingContext: BindingContext): Call? {
+    val expr = JetPsiUtil.deparenthesize(this)
+    if (expr == null) return null
+
+    if (expr is JetQualifiedExpression) {
+        return expr.getSelectorExpression()?.getCorrespondingCall(bindingContext)
+    }
+    val reference = when (expr) {
+        is JetCallExpression -> expr.getCalleeExpression()
+        is JetOperationExpression -> expr.getOperationReference()
+        else -> expr
+    }
+    return bindingContext[CALL, reference]
+}