Filtering duplicate diagnostics for package facades and package parts

compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/duplicateJvmSignatureUtil.kt

@@ -23,19 +23,25 @@ import org.jetbrains.jet.lang.psi.JetClassBody
 import org.jetbrains.jet.lang.psi.JetClassOrObject
 import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.jet.lang.psi.JetPropertyAccessor
+import org.jetbrains.jet.lang.diagnostics.Diagnostic
+import org.jetbrains.jet.lang.resolve.java.diagnostics.ErrorsJvm.*
+import org.jetbrains.jet.lang.resolve.java.diagnostics.ConflictingJvmDeclarationsData
+import org.jetbrains.jet.lang.resolve.java.diagnostics.JvmDeclarationOriginKind.*
 
 public fun getJvmSignatureDiagnostics(element: PsiElement): Diagnostics? {
-    var parent = element.getParent()
-    if (parent is JetFile) {
-        if (element is JetClassOrObject) {
-            return getDiagnosticsForNonLocalClass(element)
-        }
-        return getDiagnosticsForPackage(parent as JetFile)
-    }
-    else
-        if (element is JetPropertyAccessor) {
-            parent = parent?.getParent()
+    fun doGetDiagnostics(): Diagnostics? {
+        var parent = element.getParent()
+        if (parent is JetFile) {
+            if (element is JetClassOrObject) {
+                return getDiagnosticsForNonLocalClass(element)
+            }
+            return getDiagnosticsForPackage(parent as JetFile)
         }
+        else
+            if (element is JetPropertyAccessor) {
+                parent = parent?.getParent()
+            }
+
         if (parent is JetClassBody) {
             val parentsParent = parent?.getParent()
 
@@ -43,7 +49,47 @@ public fun getJvmSignatureDiagnostics(element: PsiElement): Diagnostics? {
                 return getDiagnosticsForNonLocalClass(parentsParent)
             }
         }
-    return null
+        return null
+    }
+
+    val result = doGetDiagnostics()
+    if (result == null) return null
+
+    return object : Diagnostics by result {
+
+        override fun forElement(psiElement: PsiElement): Collection<Diagnostic> {
+
+            val (conflicting, other) = result.forElement(element).partition { it.getFactory() == CONFLICTING_JVM_DECLARATIONS }
+
+            val filtered = arrayListOf<Diagnostic>()
+            conflicting.groupBy {
+                CONFLICTING_JVM_DECLARATIONS.cast(it).getA().signature
+            }.forEach {
+                val diagnostics = it.getValue()
+                if (diagnostics.size <= 1) {
+                    filtered.addAll(diagnostics)
+                }
+                else {
+                    filtered.addAll(
+                            diagnostics.filter {
+                                me ->
+                                diagnostics.none {
+                                    other ->
+                                    me != other &&
+                                            CONFLICTING_JVM_DECLARATIONS.cast(other).getA() higherThan CONFLICTING_JVM_DECLARATIONS.cast(me).getA()
+                                }
+                            }
+                    )
+                }
+            }
+
+            return filtered + other
+        }
+    }
+}
+
+private fun ConflictingJvmDeclarationsData.higherThan(other: ConflictingJvmDeclarationsData): Boolean {
+    return this.classOrigin.originKind == PACKAGE_FACADE && other.classOrigin.originKind == PACKAGE_PART
 }
 
 private fun getDiagnosticsForPackage(file: JetFile): Diagnostics? {

idea/testData/checker/duplicateJvmSignature/functionAndProperty/trait.kt

@@ -0,0 +1,8 @@
+trait T {
+    <error descr="[CONFLICTING_JVM_DECLARATIONS] Platform declaration clash: The following declarations have the same JVM signature (foo(Ljava/util/List;)V):
+    fun foo(l: kotlin.List<kotlin.String>): kotlin.Unit
+    fun foo(l: kotlin.List<kotlin.Int>): kotlin.Unit">fun foo(l: List<String>)</error> {}
+    <error descr="[CONFLICTING_JVM_DECLARATIONS] Platform declaration clash: The following declarations have the same JVM signature (foo(Ljava/util/List;)V):
+    fun foo(l: kotlin.List<kotlin.String>): kotlin.Unit
+    fun foo(l: kotlin.List<kotlin.Int>): kotlin.Unit">fun foo(l: List<Int>)</error> {}
+}

idea/tests/org/jetbrains/jet/checkers/JetPsiCheckerTestGenerated.java

@@ -469,6 +469,11 @@ public class JetPsiCheckerTestGenerated extends AbstractJetPsiCheckerTest {
                 doTest("idea/testData/checker/duplicateJvmSignature/functionAndProperty/topLevel.kt");
             }
             
+            @TestMetadata("trait.kt")
+            public void testTrait() throws Exception {
+                doTest("idea/testData/checker/duplicateJvmSignature/functionAndProperty/trait.kt");
+            }
+            
         }
         
         @TestMetadata("idea/testData/checker/duplicateJvmSignature/traitImpl")