CPP: Exclude code in macro invocations.

Author: geoffw0

cpp/ql/src/Likely Bugs/Arithmetic/PointlessSelfComparison.ql

@@ -18,4 +18,5 @@ from ComparisonOperation cmp
 where pointlessSelfComparison(cmp)
   and not nanTest(cmp)
   and not overflowTest(cmp)
+  and not cmp.isInMacroExpansion()
 select cmp, "Self comparison."

cpp/ql/test/query-tests/Likely Bugs/Arithmetic/BadAdditionOverflowCheck/PointlessSelfComparison.expected

@@ -3,4 +3,3 @@
 | test.cpp:83:10:83:15 | ... == ... | Self comparison. |
 | test.cpp:90:10:90:15 | ... == ... | Self comparison. |
 | test.cpp:118:7:118:32 | ... != ... | Self comparison. |
-| test.cpp:145:2:145:30 | ... == ... | Self comparison. |

cpp/ql/test/query-tests/Likely Bugs/Arithmetic/BadAdditionOverflowCheck/test.cpp

@@ -142,5 +142,5 @@ void useMarkRange(int offs) {
 	markRange(buffer, 10, 20);
 	markRange(buffer, 30, 30);
 	markRange(buffer, offs, offs + 10);
-	markRange(buffer, offs, offs); // GOOD (comparison is in the macro) [FALSE POSITIVE]
+	markRange(buffer, offs, offs); // GOOD (comparison is in the macro)
 }