CPP: Fix false positives in while/for loops.

geoffw0 · geoffw0 · commit 83d4b23ae375 · 2019-07-11T20:00:50.000+01:00
diff --git a/cpp/ql/src/Likely Bugs/ContinueInFalseLoop.ql b/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,
diff --git a/cpp/ql/test/query-tests/Likely Bugs/ContinueInFalseLoop/ContinueInFalseLoop.expected b/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 |
diff --git a/cpp/ql/test/query-tests/Likely Bugs/ContinueInFalseLoop/test.cpp b/cpp/ql/test/query-tests/Likely Bugs/ContinueInFalseLoop/test.cpp
@@ -36,15 +36,15 @@ 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;
 	}
 
 	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;
 	}

Original file line number	Diff line number	Diff line change
`@@ -36,15 +36,15 @@ void test1()`
`36`	`36`	`while (false)`
`37`	`37`	`{`
`38`	`38`	`if (cond())`
`39`		`- continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply] [FALSE POSITIVE]`
	`39`	`+ continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply]`
`40`	`40`	`if (cond())`
`41`	`41`	`break;`
`42`	`42`	`}`
`43`	`43`
`44`	`44`	`for (i = 0; false; i++)`
`45`	`45`	`{`
`46`	`46`	`if (cond())`
`47`		`- continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply] [FALSE POSITIVE]`
	`47`	`+ continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply]`
`48`	`48`	`if (cond())`
`49`	`49`	`break;`
`50`	`50`	`}`