On 2018-10-15 22:02:00 -0700, Andres Freund wrote: > Hi, > > On 2018-10-15 21:50:51 -0700, Andres Freund wrote: > > .data 0000000000000028 spi_printtupDR > > .data 0000000000000028 printsimpleDR > > .data 0000000000000028 donothingDR > > .data 0000000000000028 debugtupDR > > > > These we could actually make constant, but CreateDestReceiver() as an > > API makes that inconvenient. They also are pretty darn small... There's > > a security benefit in making them constant and casting the constness > > away - I think that might not be insane. > > I.e. do something like the attached.
This just reminded me that a couple times I wanted a cast that casts away const, but otherwise makes sure the type stays the same. I don't think there's a way to do that in C, but we can write one that verifies the cast doesn't do something bad if gcc is used: #if defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P) #define unconstify(cst, var) StaticAssertExpr(__builtin_types_compatible_p(__typeof(var), const cst), "wrong cast"), (cst) (var) #else #define unconstify(cst, var) ((cst) (var)) #endif Does anybody besides me see value in adding a cleaned up version of that? Greetings, Andres Freund
