C++: Test showing FP with -fno-strict-overflow

jbj · jbj · commit 463bf964a972 · 2019-11-13T14:07:33.000+01:00
diff --git a/cpp/ql/test/query-tests/Likely Bugs/Memory Management/PointerOverflow/PointerOverflow.expected b/cpp/ql/test/query-tests/Likely Bugs/Memory Management/PointerOverflow/PointerOverflow.expected
@@ -1,2 +1,3 @@
+| no_strict_overflow.c:5:9:5:21 | ... < ... | Range check relying on pointer overflow. |
 | test.cpp:6:12:6:33 | ... < ... | Range check relying on pointer overflow. |
 | test.cpp:33:9:33:21 | ... < ... | Range check relying on pointer overflow. |
diff --git a/cpp/ql/test/query-tests/Likely Bugs/Memory Management/PointerOverflow/no_strict_overflow.c b/cpp/ql/test/query-tests/Likely Bugs/Memory Management/PointerOverflow/no_strict_overflow.c
@@ -0,0 +1,6 @@
+// semmle-extractor-options: -fno-strict-overflow
+
+int not_in_range_nostrict(int *ptr, int *ptr_end, unsigned int a) {
+    return ptr + a < ptr_end || // GOOD (for the purpose of this test)
+        ptr + a < ptr; // GOOD (due to compiler options) [FALSE POSITIVE]
+}

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,3 @@`
	`1`	`+\| no_strict_overflow.c:5:9:5:21 \| ... < ... \| Range check relying on pointer overflow. \|`
`1`	`2`	`\| test.cpp:6:12:6:33 \| ... < ... \| Range check relying on pointer overflow. \|`
`2`	`3`	`\| test.cpp:33:9:33:21 \| ... < ... \| Range check relying on pointer overflow. \|`