Rule 2.2: Report dead function, if the op is a call

Author: lcartey

c/misra/src/rules/RULE-2-2/DeadCode.ql

@@ -76,6 +76,21 @@ class DeadOperationInstance extends Expr {
 
 class DeadOperation = HoldsForAllInstances<DeadOperationInstance, Expr>::LogicalResultElement;
 
-from DeadOperation deadOperation
-where not isExcluded(deadOperation.getAnElementInstance(), DeadCodePackage::deadCodeQuery())
-select deadOperation, deadOperation.getAnElementInstance().getDescription() + "."
+from
+  DeadOperation deadOperation, DeadOperationInstance instance, string message, Element explainer,
+  string explainerDescription
+where
+  not isExcluded(instance, DeadCodePackage::deadCodeQuery()) and
+  instance = deadOperation.getAnElementInstance() and
+  if instance instanceof FunctionCall
+  then
+    message = instance.getDescription() + " from call to function $@" and
+    explainer = instance.(FunctionCall).getTarget() and
+    explainerDescription = explainer.(Function).getName()
+  else (
+    message = instance.getDescription() and
+    // Ignore the explainer
+    explainer = instance and
+    explainerDescription = ""
+  )
+select deadOperation, message + ".", explainer, explainerDescription

c/misra/test/rules/RULE-2-2/DeadCode.expected

@@ -1,9 +1,9 @@
-| test.c:15:3:15:11 | ... = ... | Assignment to dead1 is unused and has no side effects. |
-| test.c:16:3:16:11 | ... = ... | Assignment to dead2 is unused and has no side effects. |
-| test.c:19:3:19:7 | ... + ... | Result of operation is unused and has no side effects. |
-| test.c:21:3:21:17 | call to no_side_effects | Result of operation is unused and has no side effects. |
-| test.c:23:3:23:30 | (int)... | Cast operation is unused. |
-| test.c:24:3:24:25 | (int)... | Cast operation is unused. |
-| test.c:27:4:27:18 | call to no_side_effects | Result of operation is unused and has no side effects. |
-| test.c:37:3:37:27 | call to no_side_effects | Result of operation is unused and has no side effects. |
-| test.c:38:7:38:31 | call to no_side_effects | Result of operation is unused and has no side effects. |
+| test.c:15:3:15:11 | ... = ... | Assignment to dead1 is unused and has no side effects. | test.c:15:3:15:11 | ... = ... |  |
+| test.c:16:3:16:11 | ... = ... | Assignment to dead2 is unused and has no side effects. | test.c:16:3:16:11 | ... = ... |  |
+| test.c:19:3:19:7 | ... + ... | Result of operation is unused and has no side effects. | test.c:19:3:19:7 | ... + ... |  |
+| test.c:21:3:21:17 | call to no_side_effects | Result of operation is unused and has no side effects from call to function $@. | test.c:2:5:2:19 | no_side_effects | no_side_effects |
+| test.c:23:3:23:30 | (int)... | Cast operation is unused. | test.c:23:3:23:30 | (int)... |  |
+| test.c:24:3:24:25 | (int)... | Cast operation is unused. | test.c:24:3:24:25 | (int)... |  |
+| test.c:27:4:27:18 | call to no_side_effects | Result of operation is unused and has no side effects from call to function $@. | test.c:2:5:2:19 | no_side_effects | no_side_effects |
+| test.c:37:3:37:27 | call to no_side_effects | Result of operation is unused and has no side effects from call to function $@. | test.c:2:5:2:19 | no_side_effects | no_side_effects |
+| test.c:38:7:38:31 | call to no_side_effects | Result of operation is unused and has no side effects from call to function $@. | test.c:2:5:2:19 | no_side_effects | no_side_effects |