DeadCode: Add MISRA Rule 2-1

Add MISRA Rule 2.1 as an import of the UnreachableCode query.

Author: lcartey

c/common/test/rules/unreachablecode/UnreachableCode.expected

@@ -0,0 +1,2 @@
+| test.c:17:3:17:12 | declaration | This statement in function $@ is unreachable. | test.c:15:5:15:21 | test_after_return | test_after_return |
+| test.c:21:10:22:12 | { ... } | This statement in function $@ is unreachable. | test.c:20:5:20:27 | test_constant_condition | test_constant_condition |

c/common/test/rules/unreachablecode/UnreachableCode.ql

@@ -0,0 +1,2 @@
+// GENERATED FILE - DO NOT MODIFY
+import codingstandards.cpp.rules.unreachablecode.UnreachableCode

c/common/test/rules/unreachablecode/test.c

@@ -0,0 +1,26 @@
+// NOTICE: THE TEST CASES BELOW ARE ALSO INCLUDED IN THE C++ TEST CASE AND CHANGES
+//         SHOULD BE REFLECTED THERE AS WELL.
+
+void test_switch(int p1) {
+  int l1 = 0;
+  switch (p1) {
+    l1 = p1; // NON_COMPLIANT[FALSE_NEGATIVE]
+  case 1:
+    break;
+  default:
+    break;
+  }
+}
+
+int test_after_return() {
+  return 0;
+  int l1 = 0; // NON_COMPLIANT - function has returned by this point
+}
+
+int test_constant_condition() {
+  if (0) { // NON_COMPLIANT
+    return 1;
+  } else { // COMPLIANT
+    return 2;
+  }
+}

c/misra/src/rules/RULE-2-1/UnreachableCode.ql

@@ -0,0 +1,23 @@
+/**
+ * @id c/misra/unreachable-code
+ * @name RULE-2-1: A project shall not contain unreachable code
+ * @description Unreachable code complicates the program and can indicate a possible mistake on the
+ *              part of the programmer.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity warning
+ * @tags external/misra/id/rule-2-1
+ *       readability
+ *       maintainability
+ *       external/misra/obligation/required
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.rules.unreachablecode.UnreachableCode
+
+class UnreachableCodeQuery extends UnreachableCodeSharedQuery {
+  UnreachableCodeQuery() {
+    this = DeadCodePackage::unreachableCodeQuery()
+  }
+}

c/misra/test/rules/RULE-2-1/UnreachableCode.testref

@@ -0,0 +1 @@
+c/common/test/rules/unreachablecode/UnreachableCode.ql

cpp/common/test/rules/unreachablecode/UnreachableCode.expected

@@ -1,5 +1,5 @@
 | test.cpp:14:3:14:12 | declaration | This statement in function $@ is unreachable. | test.cpp:12:5:12:21 | test_after_return | test_after_return |
 | test.cpp:18:10:19:12 | { ... } | This statement in function $@ is unreachable. | test.cpp:17:5:17:27 | test_constant_condition | test_constant_condition |
-| test.cpp:26:10:27:12 | { ... } | This statement in function $@ is unreachable. | test.cpp:25:24:25:24 | f | f |
-| test.cpp:47:12:48:14 | { ... } | This statement in function $@ is unreachable. | test.cpp:46:7:46:8 | h1 | h1 |
-| test.cpp:52:12:53:14 | { ... } | This statement in function $@ is unreachable. | test.cpp:51:7:51:8 | h2 | h2 |
+| test.cpp:29:10:30:12 | { ... } | This statement in function $@ is unreachable. | test.cpp:28:24:28:24 | f | f |
+| test.cpp:50:12:51:14 | { ... } | This statement in function $@ is unreachable. | test.cpp:49:7:49:8 | h1 | h1 |
+| test.cpp:55:12:56:14 | { ... } | This statement in function $@ is unreachable. | test.cpp:54:7:54:8 | h2 | h2 |

cpp/common/test/rules/unreachablecode/test.cpp

@@ -22,6 +22,9 @@ int test_constant_condition() {
   }
 }
 
+// NOTICE: THE TEST CASES ABOVE ARE ALSO INCLUDED IN THE C TEST CASE AND CHANGES
+//         SHOULD BE REFLECTED THERE AS WELL.
+
 template <class T> int f() {
   if (0) { // NON_COMPLIANT - block is unreachable in all instances
     return 3;