CPP: Fix false positives in while/for loops.

cpp/ql/src/Likely Bugs/ContinueInFalseLoop.ql

@@ -10,12 +10,12 @@
 
 import cpp
 
-Loop getAFalseLoop() {
+DoStmt getAFalseLoop() {
   result.getControllingExpr().getValue() = "0"
   and not result.getControllingExpr().isAffectedByMacro()
 }
 
-Loop enclosingLoop(Stmt s) {
+DoStmt enclosingLoop(Stmt s) {
   exists(Stmt parent |
     parent = s.getParent() and
     if parent instanceof Loop then
@@ -24,7 +24,7 @@ Loop enclosingLoop(Stmt s) {
       result = enclosingLoop(parent))
 }
 
-from Loop loop, ContinueStmt continue
+from DoStmt loop, ContinueStmt continue
 where loop = getAFalseLoop()
   and loop = enclosingLoop(continue)
 select continue,

cpp/ql/test/query-tests/Likely Bugs/ContinueInFalseLoop/ContinueInFalseLoop.expected

@@ -1,4 +1,2 @@
 | test.cpp:13:4:13:12 | continue; | This 'continue' never re-runs the loop - the $@ is always false. | test.cpp:16:11:16:15 | 0 | loop condition |
-| test.cpp:39:4:39:12 | continue; | This 'continue' never re-runs the loop - the $@ is always false. | test.cpp:36:9:36:13 | 0 | loop condition |
-| test.cpp:47:4:47:12 | continue; | This 'continue' never re-runs the loop - the $@ is always false. | test.cpp:44:14:44:18 | 0 | loop condition |
 | test.cpp:59:5:59:13 | continue; | This 'continue' never re-runs the loop - the $@ is always false. | test.cpp:62:12:62:16 | 0 | loop condition |

cpp/ql/test/query-tests/Likely Bugs/ContinueInFalseLoop/test.cpp

@@ -36,7 +36,7 @@ void test1()
 	while (false)
 	{
 		if (cond())
-			continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply] [FALSE POSITIVE]
+			continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply]
 		if (cond())
 			break;
 	}
@@ -44,7 +44,7 @@ void test1()
 	for (i = 0; false; i++)
 	{
 		if (cond())
-			continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply] [FALSE POSITIVE]
+			continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply]
 		if (cond())
 			break;
 	}