Add extension receiver type to function signature in trap file names

java/kotlin-extractor/src/main/kotlin/KotlinUsesExtractor.kt

@@ -249,7 +249,14 @@ open class KotlinUsesExtractor(
             // Note we erase the parameter types before calling useType even though the signature should be the same
             // in order to prevent an infinite loop through useTypeParameter -> useDeclarationParent -> useFunction
             // -> extractFunctionLaterIfExternalFileMember, which would result for `fun <T> f(t: T) { ... }` for example.
-            val paramTypes = f.valueParameters.map { useType(erase(it.type)) }
+            val ext = f.extensionReceiverParameter
+            val parameters = if (ext != null) {
+                listOf(ext) + f.valueParameters
+            } else {
+                f.valueParameters
+            }
+
+            val paramTypes = parameters.map { useType(erase(it.type)) }
             val signature = paramTypes.joinToString(separator = ",", prefix = "(", postfix = ")") { it.javaResult.signature!! }
             dependencyCollector?.addDependency(f, signature)
             externalClassExtractor.extractLater(f, signature)

java/ql/test/kotlin/library-tests/multiple_extensions/calls.expected

@@ -1,2 +1,4 @@
-| test.kt:2:17:2:31 | startsWith(...) | test.kt:2:13:2:15 | url | test.kt:2:29:2:29 | 1 |
-| test.kt:3:17:3:33 | removePrefix(...) | test.kt:3:13:3:15 | url | test.kt:3:31:3:31 | 2 |
+| PropertyReferenceDelegatesKt | getValue(KProperty0<V>, Object, KProperty<?>) |
+| PropertyReferenceDelegatesKt | getValue(KProperty1<T,V>, T, KProperty<?>) |
+| StringsKt | removePrefix(String, CharSequence) |
+| StringsKt | startsWith(String, String, boolean) |

java/ql/test/kotlin/library-tests/multiple_extensions/calls.ql

@@ -1,6 +1,4 @@
 import java
 
-from MethodAccess ma, Expr qualifier, Argument arg
-where ma.getQualifier() = qualifier and
-      ma.getAnArgument() = arg
-select ma, qualifier, arg
+from MethodAccess ma
+select ma.getMethod().getDeclaringType().getName(), ma.getMethod().getStringSignature()

java/ql/test/kotlin/library-tests/multiple_extensions/test.kt

@@ -1,4 +1,7 @@
 fun test(url: String) {
     val s = url.startsWith("1")
     val r = url.removePrefix("2")
+
+    (null!! as kotlin.reflect.KProperty0<Int>).getValue(null, null!!)
+    (null!! as kotlin.reflect.KProperty1<Int, Int>).getValue(1, null!!)
 }