C++: Move the 'getArgumentIndex' into the abstract 'Position' class. It is implemented in all subclasses anyway.

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -371,7 +371,7 @@ private class PrimaryArgumentNode extends ArgumentNode, OperandNode {
   PrimaryArgumentNode() { exists(CallInstruction call | op = call.getAnArgumentOperand()) }
 
   override predicate argumentOf(DataFlowCall call, ArgumentPosition pos) {
-    op = call.getArgumentOperand(pos.(DirectPosition).getIndex())
+    op = call.getArgumentOperand(pos.(DirectPosition).getArgumentIndex())
   }
 }
 
@@ -410,8 +410,16 @@ class ParameterPosition = Position;
 class ArgumentPosition = Position;
 
 abstract class Position extends TPosition {
+  /** Gets a textual representation of this position. */
   abstract string toString();
 
+  /**
+   * Gets the argument index of this position. The qualifier of a call has
+   * argument index `-1`.
+   */
+  abstract int getArgumentIndex();
+
+  /** Gets the indirection index of this position. */
   abstract int getIndirectionIndex();
 }
 
@@ -428,7 +436,7 @@ class DirectPosition extends Position, TDirectPosition {
     result = index.toString()
   }
 
-  int getIndex() { result = index }
+  override int getArgumentIndex() { result = index }
 
   final override int getIndirectionIndex() { result = 0 }
 }
@@ -445,7 +453,7 @@ class IndirectionPosition extends Position, TIndirectionPosition {
     else result = repeatStars(indirectionIndex) + argumentIndex.toString()
   }
 
-  int getArgumentIndex() { result = argumentIndex }
+  override int getArgumentIndex() { result = argumentIndex }
 
   final override int getIndirectionIndex() { result = indirectionIndex }
 }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -1445,7 +1445,7 @@ private class ExplicitParameterInstructionNode extends AbstractExplicitParameter
   ExplicitParameterInstructionNode() { exists(instr.getParameter()) }
 
   override predicate isSourceParameterOf(Function f, ParameterPosition pos) {
-    f.getParameter(pos.(DirectPosition).getIndex()) = instr.getParameter()
+    f.getParameter(pos.(DirectPosition).getArgumentIndex()) = instr.getParameter()
   }
 
   override string toStringImpl() { result = instr.getParameter().toString() }
@@ -1460,7 +1460,7 @@ class ThisParameterInstructionNode extends AbstractExplicitParameterNode,
   ThisParameterInstructionNode() { instr.getIRVariable() instanceof IRThisVariable }
 
   override predicate isSourceParameterOf(Function f, ParameterPosition pos) {
-    pos.(DirectPosition).getIndex() = -1 and
+    pos.(DirectPosition).getArgumentIndex() = -1 and
     instr.getEnclosingFunction() = f
   }
 
@@ -1494,7 +1494,7 @@ private class DirectBodyLessParameterNode extends AbstractExplicitParameterNode,
 
   override predicate isSourceParameterOf(Function f, ParameterPosition pos) {
     this.getFunction() = f and
-    f.getParameter(pos.(DirectPosition).getIndex()) = p
+    f.getParameter(pos.(DirectPosition).getArgumentIndex()) = p
   }
 
   override Parameter getParameter() { result = p }

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/TaintTrackingUtil.qll

@@ -229,11 +229,11 @@ private module SpeculativeTaintFlow {
       not exists(DataFlowDispatch::viableCallable(call)) and
       src.(DataFlowPrivate::ArgumentNode).argumentOf(call, argpos)
     |
-      not argpos.(DirectPosition).getIndex() = -1 and
+      not argpos.(DirectPosition).getArgumentIndex() = -1 and
       sink.(PostUpdateNode)
           .getPreUpdateNode()
           .(DataFlowPrivate::ArgumentNode)
-          .argumentOf(call, any(DirectPosition qualpos | qualpos.getIndex() = -1))
+          .argumentOf(call, any(DirectPosition qualpos | qualpos.getArgumentIndex() = -1))
       or
       sink.(DataFlowPrivate::OutNode).getCall() = call
     )