| Message ID | 20150904110156.GA2813@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 09/04/2015 05:01 AM, Marek Polacek wrote: > While looking into something else I spotted this UB. I rewrote this > to use another UB, but I'd say left-shifting into the sign bit isn't > such an anathema as it was. > > It's -Wshift-negative-value that warns on this. The reason why we haven't > seen the warning before is due to a bug I'm fixing in the other patch. > > Bootstrapped/regtested on x86_64-linux, ok for trunk? > > 2015-09-03 Marek Polacek <polacek@redhat.com> > > * system.h (INTTYPE_MINIMUM): Rewrite to avoid shift warning. > > * system.h (INTTYPE_MINIMUM): Rewrite to avoid shift warning. OK. jeff
diff --git gcc/gcc/system.h gcc/gcc/system.h index 9ca5b5f..78ad609 100644 --- gcc/gcc/system.h +++ gcc/gcc/system.h @@ -307,7 +307,7 @@ extern int errno; /* The outer cast is needed to work around a bug in Cray C 5.0.3.0. It is necessary at least when t == time_t. */ #define INTTYPE_MINIMUM(t) ((t) (INTTYPE_SIGNED (t) \ - ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)) + ? (t) 1 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)) #define INTTYPE_MAXIMUM(t) ((t) (~ (t) 0 - INTTYPE_MINIMUM (t))) /* Use that infrastructure to provide a few constants. */ diff --git gcc/libcpp/system.h gcc/libcpp/system.h index b18d658..a2e8c26 100644 --- gcc/libcpp/system.h +++ gcc/libcpp/system.h @@ -230,7 +230,7 @@ extern int errno; /* The outer cast is needed to work around a bug in Cray C 5.0.3.0. It is necessary at least when t == time_t. */ #define INTTYPE_MINIMUM(t) ((t) (INTTYPE_SIGNED (t) \ - ? ~ (t) 0 << (sizeof(t) * CHAR_BIT - 1) : (t) 0)) + ? (t) 1 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)) #define INTTYPE_MAXIMUM(t) ((t) (~ (t) 0 - INTTYPE_MINIMUM (t))) /* Use that infrastructure to provide a few constants. */