C++: Add test demonstrating the false positive

MathiasVP · MathiasVP · commit cfb839a8f947 · 2020-01-02T15:48:01.000+01:00
diff --git a/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.c b/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.c
@@ -92,3 +92,13 @@ void use_printf(float f, double d)
 size_t three_chars(unsigned char a, unsigned char b, unsigned char c) {
     return a * b * c; // at most 16581375
 }
+
+void g(unsigned char a, unsigned char b, unsigned char b2, int c) {
+    unsigned long d, e, f, g, h;
+    d = (a + 1) * (b + 1); // GOOD [FALSE POSITIVE]
+    e = (c + 1) * (b + 1); // BAD
+    h = (a + 1) * (b + 1) * (b2 + 1); // GOOD [FALSE POSITIVE]
+
+    f = (a + (a + 1)) * (b + 1); // GOOD [FALSE POSITIVE]
+    g = (c + (a + 1)) * (b + 1); // BAD
+}
diff --git a/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.expected b/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.expected
@@ -7,3 +7,8 @@
 | IntMultToLong.c:61:23:61:33 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'long long'. |
 | IntMultToLong.c:63:23:63:40 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'long long'. |
 | IntMultToLong.c:75:9:75:13 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'size_t'. |
+| IntMultToLong.c:98:9:98:25 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'unsigned long'. |
+| IntMultToLong.c:99:9:99:25 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'unsigned long'. |
+| IntMultToLong.c:100:9:100:36 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'unsigned long'. |
+| IntMultToLong.c:102:9:102:31 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'unsigned long'. |
+| IntMultToLong.c:103:9:103:31 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'unsigned long'. |
