Merge pull request github#452 from github/a2-7-3-undocumented-function-scope

`A2-7-3`: Exclude declarations in function scopes

Author: knewbury01

change_notes/2023-11-24-a2-7-3-remove-function-scope.md

@@ -0,0 +1,3 @@
+ * `A2-7-3` - `UndocumentedUserDefinedType.ql`:
+   - Excluding declarations in function scope. The rationale is that these declarations are not exposed outside the scope of the function.
+   

cpp/autosar/src/rules/A2-7-3/UndocumentedUserDefinedType.ql

@@ -17,6 +17,14 @@
 import cpp
 import codingstandards.cpp.autosar
 
+private predicate isInFunctionScope(Declaration d) {
+  // Type declared in function
+  exists(d.(UserType).getEnclosingFunction())
+  or
+  // Member declared in type which is in function scope
+  isInFunctionScope(d.getDeclaringType())
+}
+
 /**
  * A declaration which is required to be preceded by documentation by AUTOSAR A2-7-3.
  */
@@ -42,10 +50,8 @@ class DocumentableDeclaration extends Declaration {
     declarationType = "member variable" and
     // Exclude memeber variables in instantiated templates, which cannot reasonably be documented.
     not this.(MemberVariable).isFromTemplateInstantiation(_) and
-    // Exclude anonymous lambda functions.
-    // TODO: replace with the following when support is added.
-    // not this.(MemberVariable).isCompilerGenerated()
-    not exists(LambdaExpression lc | lc.getACapture().getField() = this)
+    // Exclude compiler generated variables, such as those for anonymous lambda functions
+    not this.(MemberVariable).isCompilerGenerated()
   }
 
   /** Gets a `DeclarationEntry` for this declaration that should be documented. */
@@ -96,6 +102,7 @@ from DocumentableDeclaration d, DeclarationEntry de
 where
   not isExcluded(de, CommentsPackage::undocumentedUserDefinedTypeQuery()) and
   not isExcluded(d, CommentsPackage::undocumentedUserDefinedTypeQuery()) and
+  not isInFunctionScope(d) and
   d.getAnUndocumentedDeclarationEntry() = de
 select de,
   "Declaration entry for " + d.getDeclarationType() + " " + d.getName() +

cpp/autosar/test/rules/A2-7-3/test.cpp

@@ -160,4 +160,19 @@ template <typename T> class A2_7_3 final {
   const std::string kBar{"bar"}; // NON_COMPLIANT
 };
 /// @brief This is the instantiateA2_7_3 documentation
-void instantiateA2_7_3() { A2_7_3<int> instance; }
+void instantiateA2_7_3() { A2_7_3<int> instance; }
+
+/// Test documentation
+void testFunctionScope() {
+  using my_float = float;
+  class ClassF { // COMPLIANT - in function scope
+  public:
+    int m_x;      // COMPLIANT - in function scope
+    void fTest(); // COMPLIANT - in function scope
+    class ClassFNested {
+    public:
+      int m_nested_x;     // COMPLIANT - in function scope
+      void fNestedTest(); // COMPLIANT - in function scope
+    };
+  };
+}

rule_packages/cpp/Comments.json

@@ -70,7 +70,10 @@
           "tags": [
             "maintainability",
             "readability"
-          ]
+          ],
+          "implementation_scope": {
+            "description": "Function scope declarations are excluded from this rule as they are restricted in scope to only a single function."
+          }
         }
       ],
       "title": "All declarations of 'user-defined' types, static and non-static data members, functions and methods shall be preceded by documentation."