C++: Expose constant expressions as attribute arguments

Author: jketema

cpp/ql/lib/semmle/code/cpp/Specifier.qll

@@ -258,7 +258,11 @@ class AttributeArgument extends Element, @attribute_arg {
    * Gets the text for the value of this argument, if its value is
    * a constant or token.
    */
-  string getValueText() { attribute_arg_value(underlyingElement(this), result) }
+  string getValueText() {
+    if underlyingElement(this) instanceof @attribute_arg_constant_expr
+    then result = this.getValueConstant().getValue()
+    else attribute_arg_value(underlyingElement(this), result)
+  }
 
   /**
    * Gets the value of this argument, if its value is integral.
@@ -270,6 +274,13 @@ class AttributeArgument extends Element, @attribute_arg {
    */
   Type getValueType() { attribute_arg_type(underlyingElement(this), unresolveElement(result)) }
 
+  /**
+   * Gets the value of this argument, if its value is a constant.
+   */
+  Expr getValueConstant() {
+    attribute_arg_constant(underlyingElement(this), unresolveElement(result))
+  }
+
   /**
    * Gets the attribute to which this is an argument.
    */
@@ -294,7 +305,10 @@ class AttributeArgument extends Element, @attribute_arg {
         (
           if underlyingElement(this) instanceof @attribute_arg_type
           then tail = this.getValueType().getName()
-          else tail = this.getValueText()
+          else
+            if underlyingElement(this) instanceof @attribute_arg_constant_expr
+            then tail = this.getValueConstant().toString()
+            else tail = this.getValueText()
         ) and
         result = prefix + tail
       )