Disambiguate upper bounds in the mangling.

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/BinaryInterface.kt

@@ -82,13 +82,27 @@ private val exportForCppRuntimeAnnotation = FqName("konan.internal.ExportForCppR
 
 private val exportForCompilerAnnotation = FqName("konan.internal.ExportForCompiler")
 
-private fun typeToHashString(type: KotlinType): String {
+private fun acyclicTypeMangler(visited: MutableSet<TypeParameterDescriptor>, type: KotlinType): String {
-    if (TypeUtils.isTypeParameter(type)) return "GENERIC"
+    val descriptor = TypeUtils.getTypeParameterDescriptorOrNull(type)
+    if (descriptor != null) {
+        val upperBounds = if (visited.contains(descriptor)) "" else {
+
+            visited.add(descriptor)
+
+            descriptor.upperBounds.map {
+                val bound = acyclicTypeMangler(visited, it)
+                if (bound == "kotlin.Any?") "" else "_$bound"
+            }.joinToString("")
+        }
+        return "GENERIC" + upperBounds
+    }
 
     var hashString = TypeUtils.getClassDescriptor(type)!!.fqNameSafe.asString()
     if (!type.arguments.isEmpty()) {
         hashString += "<${type.arguments.map {
-            typeToHashString(it.type)
+            val variance = it.projectionKind.label
+            val projection = if (variance == "") "" else "${variance}_" 
+            projection + acyclicTypeMangler(visited, it.type)
         }.joinToString(",")}>"
     }
 
@@ -96,9 +110,12 @@ private fun typeToHashString(type: KotlinType): String {
     return hashString
 }
 
+private fun typeToHashString(type: KotlinType) 
+    = acyclicTypeMangler(mutableSetOf<TypeParameterDescriptor>(), type)
+
 private val FunctionDescriptor.signature: String
     get() {
-        val extensionReceiverPart = this.extensionReceiverParameter?.let { "${it.type}." } ?: ""
+        val extensionReceiverPart = this.extensionReceiverParameter?.let { "@${typeToHashString(it.type)}." } ?: ""
 
         val argsPart = this.valueParameters.map {
             typeToHashString(it.type)
@@ -180,4 +197,4 @@ internal val ClassDescriptor.objectInstanceFieldSymbolName: String
         assert (!this.isUnit())
 
         return "kobjref:$fqNameSafe"
-    }
+    }