Adjust getExtensionReceiverParameterIndex predicate name and change note

Author: tamasvajk

java/ql/lib/change-notes/2022-12-09-default-extension-methods.md

@@ -1,4 +1,4 @@
 ---
 category: minorAnalysis
 ---
-* The extraction of extension methods have been improved when default parameter values are present. The dispatch and extension receiver parameters are extracted in the correct order. The `ExtensionMethod::getExtensionParameterIndex` predicate has been introduced to facilitate getting the correct extension parameter index.
+* The extraction of Kotlin extension methods has been improved when default parameter values are present. The dispatch and extension receiver parameters are extracted in the correct order. The `ExtensionMethod::getExtensionReceiverParameterIndex` predicate has been introduced to facilitate getting the correct extension parameter index.

java/ql/lib/semmle/code/java/Member.qll

@@ -820,7 +820,7 @@ class ExtensionMethod extends Method {
    * extension methods that are defined as members, the index is 1. Index 0 is the dispatch receiver of the `$default`
    * method.
    */
-  int getExtensionParameterIndex() {
+  int getExtensionReceiverParameterIndex() {
     if
       exists(Method src |
         this = src.getKotlinParameterDefaultsProxy() and

java/ql/lib/semmle/code/java/Variable.qll

@@ -91,7 +91,7 @@ class Parameter extends Element, @param, LocalScopeVariable {
 
   /** Holds if this formal parameter is a parameter representing the dispatch receiver in an extension method. */
   predicate isExtensionParameter() {
-    this.getPosition() = this.getCallable().(ExtensionMethod).getExtensionParameterIndex()
+    this.getPosition() = this.getCallable().(ExtensionMethod).getExtensionReceiverParameterIndex()
   }
 
   /**

java/ql/lib/semmle/code/java/security/PathSanitizer.qll

@@ -299,7 +299,8 @@ private class PathNormalizeSanitizer extends MethodAccess {
  */
 private Expr getVisualQualifier(MethodAccess ma) {
   if ma.getMethod() instanceof ExtensionMethod
-  then result = ma.getArgument(ma.getMethod().(ExtensionMethod).getExtensionParameterIndex())
+  then
+    result = ma.getArgument(ma.getMethod().(ExtensionMethod).getExtensionReceiverParameterIndex())
   else result = ma.getQualifier()
 }
 
@@ -313,7 +314,8 @@ private Argument getVisualArgument(MethodAccess ma, int argPos) {
   if ma.getMethod() instanceof ExtensionMethod
   then
     result =
-      ma.getArgument(argPos + ma.getMethod().(ExtensionMethod).getExtensionParameterIndex() + 1)
+      ma.getArgument(argPos + ma.getMethod().(ExtensionMethod).getExtensionReceiverParameterIndex() +
+          1)
   else result = ma.getArgument(argPos)
 }
 

java/ql/test/kotlin/library-tests/methods/methods.ql

@@ -29,7 +29,7 @@ query predicate extensionsMismatch(Method src, Method def) {
 
 query predicate extensionIndex(ExtensionMethod m, int i, Type t) {
   m.fromSource() and
-  m.getExtensionParameterIndex() = i and
+  m.getExtensionReceiverParameterIndex() = i and
   m.getExtendedType() = t and
   m.getParameter(i).getType() = t
 }