From 6316375dfcd09132d0f1759571f1da5959a0f1b3 Mon Sep 17 00:00:00 2001
From: Luke Cartey <lcartey@github.com>
Date: Sun, 12 Jan 2025 22:00:41 +0000
Subject: [PATCH] ReturnRefOrPointerToAutoVar: Exclude global or member
 variables

This false positive case was introduced when the rule was shared
during the creation of RULE-6-8-2, where `Variable` was used
instead of `StackVariable`.
---
 change_notes/2025-01-09-return-reference.md         |  2 ++
 ...rnReferenceOrPointerToAutomaticLocalVariable.qll |  2 +-
 .../test.cpp                                        | 13 +++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 change_notes/2025-01-09-return-reference.md

diff --git a/change_notes/2025-01-09-return-reference.md b/change_notes/2025-01-09-return-reference.md
new file mode 100644
index 0000000000..69480916c7
--- /dev/null
+++ b/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.
\ No newline at end of file
diff --git a/cpp/common/src/codingstandards/cpp/rules/returnreferenceorpointertoautomaticlocalvariable/ReturnReferenceOrPointerToAutomaticLocalVariable.qll b/cpp/common/src/codingstandards/cpp/rules/returnreferenceorpointertoautomaticlocalvariable/ReturnReferenceOrPointerToAutomaticLocalVariable.qll
index cd623f711c..b37a9cd02b 100644
--- a/cpp/common/src/codingstandards/cpp/rules/returnreferenceorpointertoautomaticlocalvariable/ReturnReferenceOrPointerToAutomaticLocalVariable.qll
+++ b/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
diff --git a/cpp/common/test/rules/returnreferenceorpointertoautomaticlocalvariable/test.cpp b/cpp/common/test/rules/returnreferenceorpointertoautomaticlocalvariable/test.cpp
index bc4fbf8f1d..d383d7859f 100644
--- a/cpp/common/test/rules/returnreferenceorpointertoautomaticlocalvariable/test.cpp
+++ b/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
 }
\ No newline at end of file