IdentifierHidden: improve variable names and docs/overall readability

Author: knewbury01

cpp/common/src/codingstandards/cpp/Scope.qll

@@ -303,14 +303,14 @@ predicate hasBlockScope(Declaration decl) { exists(BlockStmt b | b.getADeclarati
 /**
  * identifiers in nested (named/nonglobal) namespaces are exceptions to hiding due to being able access via fully qualified ids
  */
-predicate excludedViaNestedNamespaces(UserDeclaration v2, UserDeclaration v1) {
+predicate excludedViaNestedNamespaces(UserDeclaration outerDecl, UserDeclaration innerDecl) {
   exists(Namespace inner, Namespace outer |
     outer.getAChildNamespace+() = inner and
     //outer is not global
     not outer instanceof GlobalNamespace and
     not outer.isAnonymous() and
     not inner.isAnonymous() and
-    v2.getNamespace() = inner and
-    v1.getNamespace() = outer
+    innerDecl.getNamespace() = inner and
+    outerDecl.getNamespace() = outer
   )
 }

cpp/common/src/codingstandards/cpp/rules/identifierhidden/IdentifierHidden.qll

@@ -12,35 +12,35 @@ abstract class IdentifierHiddenSharedQuery extends Query { }
 Query getQuery() { result instanceof IdentifierHiddenSharedQuery }
 
 /**
- * There is a lambda that contains a declaration
- * that hides something that is captured
- * and the lambda exists in the function where this lamda is enclosed
+ * Holds if declaration `innerDecl`, declared in a lambda, hides a declaration `outerDecl` captured by the lambda.
  */
-predicate hiddenInLambda(UserDeclaration v2, UserDeclaration v1) {
+predicate hiddenInLambda(UserVariable outerDecl, UserVariable innerDecl) {
   exists(Scope s, Closure le |
-    s.getADeclaration() = v2 and
+    //innerDecl declared inside of the lambda
+    s.getADeclaration() = innerDecl and
     s.getAnAncestor() = le and
-    le.getEnclosingFunction().getBasicBlock().(Scope) = v1.getParentScope() and
-    exists(LambdaCapture cap, Variable v |
-      v.getAnAccess() = cap.getInitializer().(VariableAccess) and
-      v = v1 and
+    le.getEnclosingFunction().getBasicBlock().(Scope) = outerDecl.getParentScope() and
+    exists(LambdaCapture cap |
+      outerDecl.getAnAccess() = cap.getInitializer().(VariableAccess) and
       le.getLambdaExpression().getACapture() = cap
     ) and
-    v2.getName() = v1.getName()
+    innerDecl.getName() = outerDecl.getName()
   )
 }
 
-query predicate problems(UserDeclaration v2, string message, UserDeclaration v1, string varName) {
-  not isExcluded(v1, getQuery()) and
-  not isExcluded(v2, getQuery()) and
+query predicate problems(
+  UserDeclaration innerDecl, string message, UserDeclaration outerDecl, string varName
+) {
+  not isExcluded(outerDecl, getQuery()) and
+  not isExcluded(innerDecl, getQuery()) and
   //ignore template variables for this rule
-  not v1 instanceof TemplateVariable and
-  not v2 instanceof TemplateVariable and
-  //ignore types for this rule
-  not v2 instanceof Type and
-  not v1 instanceof Type and
-  (hidesStrict(v1, v2) or hiddenInLambda(v2, v1)) and
-  not excludedViaNestedNamespaces(v2, v1) and
-  varName = v1.getName() and
+  not outerDecl instanceof TemplateVariable and
+  not innerDecl instanceof TemplateVariable and
+  //ignore types for this rule as the Misra C/C++ 23 version of this rule (rule 6.4.1 and 6.4.2) focuses solely on variables and functions
+  not innerDecl instanceof Type and
+  not outerDecl instanceof Type and
+  (hidesStrict(outerDecl, innerDecl) or hiddenInLambda(outerDecl, innerDecl)) and
+  not excludedViaNestedNamespaces(outerDecl, innerDecl) and
+  varName = outerDecl.getName() and
   message = "Declaration is hiding declaration $@."
 }