Merge pull request #14921 from jketema/kr-style-function-parameters

C++: Expose whether a function was prototyped or not

cpp/downgrades/0a9eb01d3650642e013eb86be45d952289537f91/upgrade.properties

@@ -0,0 +1,3 @@
+description: Expose whether a function was prototyped or not
+compatibility: backwards
+function_prototyped.rel: delete

cpp/ql/lib/change-notes/2023-11-28-prototyped.md

@@ -0,0 +1,4 @@
+---
+category: feature
+---
+* Added an `isPrototyped` predicate to `Function` that holds when the function has a prototype.

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

@@ -112,6 +112,16 @@ class Function extends Declaration, ControlFlowNode, AccessHolder, @function {
    */
   predicate isDeleted() { function_deleted(underlyingElement(this)) }
 
+  /**
+   * Holds if this function has a prototyped interface.
+   *
+   * Functions generally have a prototyped interface, unless they are
+   * K&R-style functions either without any forward function declaration,
+   * or with all the forward declarations omitting the parameters of the
+   * function.
+   */
+  predicate isPrototyped() { function_prototyped(underlyingElement(this)) }
+
   /**
    * Holds if this function is explicitly defaulted with the `= default`
    * specifier.

cpp/ql/lib/semmlecode.cpp.dbscheme

@@ -405,6 +405,8 @@ function_deleted(unique int id: @function ref);
 
 function_defaulted(unique int id: @function ref);
 
+function_prototyped(unique int id: @function ref)
+
 member_function_this_type(
     unique int id: @function ref,
     int this_type: @type ref

cpp/ql/lib/upgrades/8cba93a44180e0d50a80a660950800d822b981fc/upgrade.properties

@@ -0,0 +1,2 @@
+description: Expose whether a function was prototyped or not
+compatibility: partial