C++: Add utility predicates.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll

@@ -1714,6 +1714,11 @@ class CallInstruction extends Instruction {
     result = this.getPositionalArgumentOperand(index).getDef()
   }
 
+  /**
+   * Gets a positional argument, if any.
+   */
+  final Instruction getAPositionalArgument() { result = this.getPositionalArgument(_) }
+
   /**
    * Gets the argument operand at the specified index, or `this` if `index` is `-1`.
    */
@@ -1735,6 +1740,11 @@ class CallInstruction extends Instruction {
    */
   final int getNumberOfArguments() { result = count(this.getAnArgumentOperand()) }
 
+  /**
+   * Gets the number of positional arguments of the call.
+   */
+  final int getNumberOfPositionalArguments() { result = count(this.getAPositionalArgument()) }
+
   /**
    * Holds if the result is a side effect for the argument at the specified index, or `this` if
    * `index` is `-1`.

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/Instruction.qll

@@ -1714,6 +1714,11 @@ class CallInstruction extends Instruction {
     result = this.getPositionalArgumentOperand(index).getDef()
   }
 
+  /**
+   * Gets a positional argument, if any.
+   */
+  final Instruction getAPositionalArgument() { result = this.getPositionalArgument(_) }
+
   /**
    * Gets the argument operand at the specified index, or `this` if `index` is `-1`.
    */
@@ -1735,6 +1740,11 @@ class CallInstruction extends Instruction {
    */
   final int getNumberOfArguments() { result = count(this.getAnArgumentOperand()) }
 
+  /**
+   * Gets the number of positional arguments of the call.
+   */
+  final int getNumberOfPositionalArguments() { result = count(this.getAPositionalArgument()) }
+
   /**
    * Holds if the result is a side effect for the argument at the specified index, or `this` if
    * `index` is `-1`.

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll

@@ -1714,6 +1714,11 @@ class CallInstruction extends Instruction {
     result = this.getPositionalArgumentOperand(index).getDef()
   }
 
+  /**
+   * Gets a positional argument, if any.
+   */
+  final Instruction getAPositionalArgument() { result = this.getPositionalArgument(_) }
+
   /**
    * Gets the argument operand at the specified index, or `this` if `index` is `-1`.
    */
@@ -1735,6 +1740,11 @@ class CallInstruction extends Instruction {
    */
   final int getNumberOfArguments() { result = count(this.getAnArgumentOperand()) }
 
+  /**
+   * Gets the number of positional arguments of the call.
+   */
+  final int getNumberOfPositionalArguments() { result = count(this.getAPositionalArgument()) }
+
   /**
    * Holds if the result is a side effect for the argument at the specified index, or `this` if
    * `index` is `-1`.