Rust: Define getNumberOfOperands in Operation class

Author: paldepind

rust/ql/lib/codeql/rust/elements/internal/BinaryExprImpl.qll

@@ -28,8 +28,6 @@ module Impl {
 
     override string getOperatorName() { result = Generated::BinaryExpr.super.getOperatorName() }
 
-    override int getNumberOfOperands() { result = 2 }
-
     override Expr getOperand(int n) {
       n = 0 and result = this.getLhs()
       or

rust/ql/lib/codeql/rust/elements/internal/OperationImpl.qll

@@ -99,7 +99,7 @@ module Impl {
      *
      * This is either 1 for prefix operations, or 2 for binary operations.
      */
-    abstract int getNumberOfOperands();
+    final int getNumberOfOperands() { result = count(this.getAnOperand()) }
 
     /** Gets an operand of this operation. */
     Expr getAnOperand() { result = this.getOperand(_) }

rust/ql/lib/codeql/rust/elements/internal/PrefixExprImpl.qll

@@ -26,8 +26,6 @@ module Impl {
 
     override string getOperatorName() { result = Generated::PrefixExpr.super.getOperatorName() }
 
-    override int getNumberOfOperands() { result = 1 }
-
     override Expr getOperand(int n) { n = 0 and result = this.getExpr() }
   }
 }

rust/ql/lib/codeql/rust/elements/internal/RefExprImpl.qll

@@ -29,8 +29,6 @@ module Impl {
 
     override string getOperatorName() { result = "&" }
 
-    override int getNumberOfOperands() { result = 1 }
-
     override Expr getOperand(int n) { n = 0 and result = this.getExpr() }
 
     private string getSpecPart(int index) {