CIL mistakenly casts the operands of && and || to intType, when in
fact they are only required to have scalar type. This can lead to a
bug if the operands have type larger than int and have values which
truncate to 0 when cast to an int (and if useLogicalOperators is set
to true). I believe removing the cast solves the problem, but I'm not
sure whether enumerations should still be cast to intType.
Patch:
--- cabs2cil.ml 2009-08-13 15:45:33.862143354 -0400
+++ orig_cabs2cil.ml 2009-08-06 16:58:57.878935879 -0400
@@ -4632,7 +4579,9 @@
CEAnd (ce1, ce2)
| CEExp(se1, e1'), CEExp (se2, e2') when
!useLogicalOperators && isEmpty se1 && isEmpty se2 ->
- CEExp (empty, BinOp(LAnd, e1', e2', intType))
+ CEExp (empty, BinOp(LAnd,
+ makeCast e1' intType,
+ makeCast e2' intType, intType))
| _ -> CEAnd (ce1, ce2)
end
@@ -4652,7 +4601,8 @@
| CEExp (se1, e1'), CEExp (se2, e2') when
!useLogicalOperators && isEmpty se1 && isEmpty se2 ->
- CEExp (empty, BinOp(LOr, e1', e2', intType))
+ CEExp (empty, BinOp(LOr, makeCast e1' intType,
+ makeCast e2' intType, intType))
| _ -> CEOr (ce1, ce2)
end
Program which exhibits the bug when run with useLogicalOperators is
set to true:
#include <stdio.h>
int main() {
long long x = 0x100000000LL;
if (x && x) printf("x\n");
return 0;
}
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