Merge pull request #842 from github/lcartey/fix-returnref-member-var

ReturnRefOrPointerToAutoVar: Exclude global or member variables

Author: lcartey

change_notes/2025-01-09-return-reference.md

@@ -0,0 +1,2 @@
+ - `M7-5-1`, `RULE-6-8-2` - `FunctionReturnAutomaticVarCondition.ql`, `ReturnReferenceOrPointerToAutomaticLocalVariable.ql`:
+   - Remove false positives for member and global variables reported under this rule.

cpp/common/src/codingstandards/cpp/rules/returnreferenceorpointertoautomaticlocalvariable/ReturnReferenceOrPointerToAutomaticLocalVariable.qll

@@ -13,7 +13,7 @@ abstract class ReturnReferenceOrPointerToAutomaticLocalVariableSharedQuery exten
 Query getQuery() { result instanceof ReturnReferenceOrPointerToAutomaticLocalVariableSharedQuery }
 
 query predicate problems(
-  ReturnStmt rs, string message, Function f, string f_string, Variable auto, string auto_string
+  ReturnStmt rs, string message, Function f, string f_string, StackVariable auto, string auto_string
 ) {
   exists(VariableAccess va, string returnType |
     not isExcluded(rs, getQuery()) and

cpp/common/test/rules/returnreferenceorpointertoautomaticlocalvariable/test.cpp

@@ -32,4 +32,17 @@ void test_templatefunction_return() {
   int j = 2;
   int k = 3;
   t1(j, k);
+}
+
+class C1 {
+private:
+  int x;
+
+public:
+  int test() { return x; } // COMPLIANT - ignore member vars
+};
+
+int x;
+int test_global() {
+  return x; // COMPLIANT - ignore global vars
 }