Java: Add ConditionalExpr to overflow candidate pattern.

aschackmull · aschackmull · commit 8cd6b5176316 · 2019-11-12T17:27:18.000+01:00
diff --git a/java/ql/src/Likely Bugs/Comparison/UselessComparisonTest.ql b/java/ql/src/Likely Bugs/Comparison/UselessComparisonTest.ql
@@ -132,6 +132,11 @@ Expr overFlowCand() {
   result.(AssignExpr).getRhs() = overFlowCand()
   or
   result.(LocalVariableDeclExpr).getInit() = overFlowCand()
+  or
+  exists(ConditionalExpr c | c = result |
+    c.getTrueExpr() = overFlowCand() and
+    c.getFalseExpr() = overFlowCand()
+  )
 }
 
 predicate positiveOrNegative(Expr e) { positive(e) or negative(e) }
diff --git a/java/ql/test/query-tests/UselessComparisonTest/A.java b/java/ql/test/query-tests/UselessComparisonTest/A.java
@@ -121,6 +121,11 @@ void overflowTests(int x, int y) {
     }
   }
 
+  void overflowTests2(int[] a, boolean b) {
+    int newlen = b ? (a.length + 1) << 1 : (a.length >> 1) + a.length;
+    if (newlen < 0) overflow();
+  }
+
   static final long VAL = 100L;
 
   long overflowAwareIncrease(long x) {

Original file line number	Diff line number	Diff line change
`@@ -121,6 +121,11 @@ void overflowTests(int x, int y) {`
`121`	`121`	`}`
`122`	`122`	`}`
`123`	`123`
	`124`	`+ void overflowTests2(int[] a, boolean b) {`
	`125`	`+ int newlen = b ? (a.length + 1) << 1 : (a.length >> 1) + a.length;`
	`126`	`+ if (newlen < 0) overflow();`
	`127`	`+ }`
	`128`	`+`
`124`	`129`	`static final long VAL = 100L;`
`125`	`130`
`126`	`131`	`long overflowAwareIncrease(long x) {`