Merge branch 'statements1' of github.com:github/codeql-coding-standards into statements1

Author: s-samadi

c/misra/src/rules/RULE-15-3/GotoLabelBlockCondition.ql

@@ -1,6 +1,6 @@
 /**
  * @id c/misra/goto-label-block-condition
- * @name RULE-15-3: The goto statement and any of its label shall be declared or enclosed in the same block.
+ * @name RULE-15-3: The goto statement and any of its label shall be declared or enclosed in the same block. 
  * @description Any label referenced by a goto statement shall be declared in the same block, or in
  *              any block enclosing the goto statement
  * @kind problem

c/misra/src/rules/RULE-16-6/SwitchClauseNumberCondition.ql

@@ -1,18 +1,24 @@
 /**
  * @id c/misra/switch-clause-number-condition
  * @name RULE-16-6: Every switch statement shall have at least two switch-clauses
- * @description 
+ * @description Switch Statements with a single path are redundant and may cause programming errors.
  * @kind problem
  * @precision very-high
- * @problem.severity error
+ * @problem.severity recommendation
  * @tags external/misra/id/rule-16-6
+ *       maintainability
+ *       readability
  *       external/misra/obligation/required
  */
 
 import cpp
 import codingstandards.c.misra
 
-from
+from SwitchStmt switch
 where
-  not isExcluded(x, Statements2Package::switchClauseNumberConditionQuery()) and
-select
+  not isExcluded(switch, Statements2Package::switchClauseNumberConditionQuery()) and
+  count(SwitchCase case |
+      switch.getASwitchCase() = case and
+      case.getNextSwitchCase() != case.getFollowingStmt()
+    ) + 1 < 2
+select switch, "$@ statement has a single path.", switch, "Switch"

c/misra/test/rules/RULE-16-6/SwitchClauseNumberCondition.expected

@@ -1 +1,3 @@
-No expected results have yet been specified
+| test.c:3:3:6:3 | switch (...) ...  | $@ statement has a single path. | test.c:3:3:6:3 | switch (...) ...  | Switch |
+| test.c:8:3:12:3 | switch (...) ...  | $@ statement has a single path. | test.c:8:3:12:3 | switch (...) ...  | Switch |
+| test.c:14:3:19:3 | switch (...) ...  | $@ statement has a single path. | test.c:14:3:19:3 | switch (...) ...  | Switch |

c/misra/test/rules/RULE-16-6/test.c

@@ -0,0 +1,49 @@
+void f1(int p1) {
+  int i = 0;
+  switch (p1) { // NON_COMPLIANT
+  default:
+    break;
+  }
+
+  switch (p1) { // NON_COMPLIANT
+  case 1:
+  default:
+    break;
+  }
+
+  switch (p1) { // NON_COMPLIANT
+  case 1:
+  case 2:
+  default:
+    break;
+  }
+
+  switch (p1) { // COMPLIANT
+  case 1:
+    i++;
+  default:
+    i = 1;
+    break;
+  }
+
+  switch (p1) { // COMPLIANT
+  case 1:
+    i++;
+  case 2:
+    i = 2;
+  default:
+    i = 1;
+    break;
+  }
+
+  switch (p1) { // COMPLIANT
+  case 1:
+    i++;
+  case 2:
+    i = 2;
+  case 3:
+  default:
+    i = 1;
+    break;
+  }
+}

rule_packages/c/Statements2.json

@@ -67,13 +67,16 @@
       },
       "queries": [
         {
-          "description": "",
+          "description": "Switch Statements with a single path are redundant and may cause programming errors.",
           "kind": "problem",
           "name": "Every switch statement shall have at least two switch-clauses",
           "precision": "very-high",
-          "severity": "error",
+          "severity": "recommendation",
           "short_name": "SwitchClauseNumberCondition",
-          "tags": []
+          "tags": [
+            "maintainability",
+            "readability"
+          ]
         }
       ],
       "title": "Every switch statement shall have at least two switch-clauses"
@@ -96,4 +99,4 @@
       "title": "A switch-expression shall not have essentially Boolean type"
     }
   }
-}
+}