Merge pull request #405 from geoffw0/selfcompare

CPP: Fix false positives in PointlessSelfComparison.ql

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

@@ -18,4 +18,12 @@ from ComparisonOperation cmp
 where pointlessSelfComparison(cmp)
   and not nanTest(cmp)
   and not overflowTest(cmp)
+  and not exists(MacroInvocation mi | 
+    // cmp is in mi 
+    mi.getAnExpandedElement() = cmp and 
+  
+    // and cmp was apparently not passed in as a macro parameter 
+    cmp.getLocation().getStartLine() = mi.getLocation().getStartLine() and 
+    cmp.getLocation().getStartColumn() = mi.getLocation().getStartColumn() 
+  ) 
 select cmp, "Self comparison."