C++: Respond to review comments.

Author: MathiasVP

cpp/ql/src/Likely Bugs/Memory Management/UsingExpiredStackAddress.ql

@@ -3,7 +3,7 @@
  * @description Accessing the stack-allocated memory of a function
  *              after it has returned can lead to memory corruption.
  * @kind problem
- * @problem.severity warning
+ * @problem.severity error
  * @security-severity 9.3
  * @precision high
  * @id cpp/using-expired-stack-address

cpp/ql/test/query-tests/Likely Bugs/Memory Management/UsingExpiredStackAddress/UsingExpiredStackAddress.expected

@@ -1,5 +1,5 @@
 | test.cpp:15:16:15:16 | Load: p | Stack variable $@ escapes $@ and is used after it has expired. | test.cpp:9:7:9:7 | x | x | test.cpp:10:3:10:13 | Store: ... = ... | here |
-| test.cpp:58:16:58:16 | Load: p | Stack variable $@ escapes $@ and is used after it has expired. | test.cpp:51:36:51:36 | x | x | test.cpp:52:3:52:13 | Store: ... = ... | here |
+| test.cpp:58:16:58:16 | Load: p | Stack variable $@ escapes $@ and is used after it has expired. | test.cpp:51:36:51:36 | y | y | test.cpp:52:3:52:13 | Store: ... = ... | here |
 | test.cpp:73:16:73:16 | Load: p | Stack variable $@ escapes $@ and is used after it has expired. | test.cpp:62:7:62:7 | x | x | test.cpp:68:3:68:13 | Store: ... = ... | here |
 | test.cpp:98:15:98:15 | Load: p | Stack variable $@ escapes $@ and is used after it has expired. | test.cpp:92:8:92:8 | s | s | test.cpp:93:3:93:15 | Store: ... = ... | here |
 | test.cpp:111:16:111:16 | Load: p | Stack variable $@ escapes $@ and is used after it has expired. | test.cpp:102:7:102:7 | x | x | test.cpp:106:3:106:14 | Store: ... = ... | here |

cpp/ql/test/query-tests/Likely Bugs/Memory Management/UsingExpiredStackAddress/test.cpp

@@ -48,8 +48,8 @@ int store_argument_value() {
   return *s101.p; // GOOD
 }
 
-void store_address_of_argument(int x) {
-  s101.p = &x;
+void store_address_of_argument(int y) {
+  s101.p = &y;
 }
 
 int store_argument_address() {
@@ -59,8 +59,8 @@ int store_argument_address() {
 }
 
 void address_escapes_through_pointer_arith() {
-  int x = 0;
-  int* p0 = &x;
+  int x[2];
+  int* p0 = x;
   int* p1 = p0 + 1;
   int* p2 = p1 - 1;
   int* p3 = 1 + p2;