IdentifierHiding: Include catchblock parameters

Author: lcartey

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

@@ -42,7 +42,16 @@ private Element getParentScope(Element e) {
   then result = e.getParentScope()
   else (
     // Statements do no have a parent scope, so return the enclosing block.
-    result = e.(Stmt).getEnclosingBlock() or result = e.(Expr).getEnclosingBlock()
+    result = e.(Stmt).getEnclosingBlock()
+    or
+    result = e.(Expr).getEnclosingBlock()
+    or
+    // Catch block parameters don't have an enclosing scope, so attach them to the
+    // the block itself
+    exists(CatchBlock cb |
+      e = cb.getParameter() and
+      result = cb
+    )
   )
 }
 

cpp/common/test/rules/identifierhidden/IdentifierHidden.expected

@@ -8,3 +8,4 @@
 | test.cpp:65:11:65:11 | i | Variable is hiding variable $@. | test.cpp:61:7:61:7 | i | i |
 | test.cpp:67:9:67:9 | i | Variable is hiding variable $@. | test.cpp:61:7:61:7 | i | i |
 | test.cpp:70:12:70:12 | i | Variable is hiding variable $@. | test.cpp:61:7:61:7 | i | i |
+| test.cpp:75:16:75:16 | i | Variable is hiding variable $@. | test.cpp:61:7:61:7 | i | i |

cpp/common/test/rules/identifierhidden/test.cpp

@@ -72,6 +72,6 @@ void test_scope_order() {
 
   try {
 
-  } catch (int i) { // NON_COMPLIANT[FALSE_NEGATIVE]
+  } catch (int i) { // NON_COMPLIANT
   }
 }