Revert "Remove ExtensionMethodAccess to see extension method flows"

This reverts commit 9df4f2074379ba4668054a2a66eaaaaf5cb9b6c8.

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

@@ -550,13 +550,12 @@ private module ControlFlowGraphImpl {
       or
       index = 0 and result = this.(RValue).getQualifier() and not result instanceof TypeAccess
       or
-      exists(Call e | e = this | // and not e instanceof ExtensionMethodAccess |
+      exists(Call e | e = this and not e instanceof ExtensionMethodAccess |
         index = -1 and result = e.getQualifier() and not result instanceof TypeAccess
         or
         result = e.getArgument(index)
       )
       or
-      /*
       exists(ExtensionMethodAccess e | e = this |
         // the actual qualifier of the expression method access
         index = -1 and result.(Expr).isNthChildOf(this, index) and not result instanceof TypeAccess
@@ -568,7 +567,6 @@ private module ControlFlowGraphImpl {
         result = e.getArgument(index - 1)
       )
       or
-      */
       exists(StringTemplateExpr e | e = this | result = e.getComponent(index))
       or
       index = 0 and result = this.(ClassExpr).getExpr()

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

@@ -1987,7 +1987,6 @@ class MethodAccess extends Expr, Call, @methodaccess {
 /**
  * An invocation of a Kotlin `ExtensionMethod`.
  */
-/*
 class ExtensionMethodAccess extends MethodAccess {
   ExtensionMethodAccess() { this.getMethod() instanceof ExtensionMethod }
 
@@ -1999,7 +1998,6 @@ class ExtensionMethodAccess extends MethodAccess {
 
   override Expr getArgument(int index) { result = super.getArgument(index + 1) and index >= 0 }
 }
-*/
 
 /** A type access is a (possibly qualified) reference to a type. */
 class TypeAccess extends Expr, Annotatable, @typeaccess {

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

@@ -111,18 +111,16 @@ class Parameter extends Element, @param, LocalScopeVariable {
       (
         exists(int idx |
           (
-            idx = i //and not call instanceof ExtensionMethodAccess
-            // or
-            // idx = i - 1 and call instanceof ExtensionMethodAccess
+            idx = i and not call instanceof ExtensionMethodAccess
+            or
+            idx = i - 1 and call instanceof ExtensionMethodAccess
           ) and
           result = call.getArgument(idx)
         )
-        /*
         or
         i = 0 and
         call instanceof ExtensionMethodAccess and
         result = call.getQualifier()
-        */
       ) and
       call.getCallee().getSourceDeclaration().getAParameter() = this
     )

java/ql/test/kotlin/library-tests/dataflow/extensionMethod/test.expected

@@ -1,6 +1,2 @@
 | test.kt:20:29:20:31 | new C(...) | test.kt:23:22:23:28 | self1(...) |
-| test.kt:20:29:20:31 | new C(...) | test.kt:26:22:26:28 | self2(...) |
 | test.kt:20:29:20:31 | new C(...) | test.kt:29:18:29:29 | fn1(...) |
-| test.kt:20:29:20:31 | new C(...) | test.kt:32:18:32:29 | fn2(...) |
-| test.kt:20:29:20:31 | new C(...) | test.kt:35:18:35:31 | call1(...) |
-| test.kt:20:29:20:31 | new C(...) | test.kt:38:22:38:28 | call2(...) |