Re: mode_t bitwise operations different under kFreeBSD?

[Petr Salinger <Petr.Salinger@seznam.cz>]

> > It is roughly equal to this:
> >
> > void foo(unsigned short int a)
> > {
> >    a = (( a & (~0x1F)) | 0x10);
> > }
>
> It seems to me that the S_* constants should have the same type as mode_t, so it's not quite the same...

The "~S_IFMT" is not a constant.

See also 6.3.1 in ISO/IEC 9899 - Programming languages - C, namely "integer promotions".

> > This code will warn also under Linux.
>
> Do you mean the fragment above or the original code? Because the original code produces problems only on kFreeBSD, see https://buildd.debian.org/status/package.php?p=python-llfuse

The fragment above, because

Linux:    mode_t is unsigned int
FreeBSD:  mode_t is short unsigned int

Again please see "unsigned short" x "signed int".

Or also try to compile with "-Wconversion -Werror" just
**
unsigned short a = ~0x1F;
**

Petr