Merge pull request #1515 from geoffw0/continuefalseloop

CPP: Improvements to ContinueInFalseLoop.ql

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

@@ -0,0 +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: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/ContinueInFalseLoop.qlref

@@ -0,0 +1 @@
+Likely Bugs/ContinueInFalseLoop.ql

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

@@ -0,0 +1,94 @@
+
+bool cond();
+
+void test1(int x)
+{
+	int i;
+
+	// --- do loops ---
+
+	do
+	{
+		if (cond())
+			continue; // BAD
+		if (cond())
+			break;
+	} while (false);
+
+	do
+	{
+		if (cond())
+			continue;
+		if (cond())
+			break;
+	} while (true);
+
+	do
+	{
+		if (cond())
+			continue;
+		if (cond())
+			break;
+	} while (cond());
+
+	// --- while, for loops ---
+
+	while (false)
+	{
+		if (cond())
+			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]
+		if (cond())
+			break;
+	}
+
+	// --- nested loops ---
+
+	do
+	{
+		do
+		{
+			if (cond())
+				continue; // BAD
+			if (cond())
+				break;
+		} while (false);
+	} while (true);
+
+	do
+	{
+		do
+		{
+			if (cond())
+				continue; // GOOD
+			if (cond())
+				break;
+		} while (true);
+	} while (false);
+
+	do
+	{
+		switch (x)
+		{
+		case 1:
+			// do [1]
+
+			break; // break out of the switch
+
+		default:
+			// do [2]
+
+			continue; // GOOD; break out of the loop entirely, skipping [3]
+		};
+
+		// do [3]
+
+	} while (0);
+}