On Thu, 2011-08-18 at 17:59 +0200, Maarten Bosmans wrote: > 2011/8/18 R?mi Denis-Courmont <remi at remlab.net>: > > Le jeudi 18 ao?t 2011 17:53:43 Arun Raghavan, vous avez ?crit : > >> The condition in the if statement may evaluate to false if pa_bool_t is > >> typedef'ed to a signed type (it definitely is if you don't have > >> stdbool.h, not sure if _Bool is a signed type or not). > > > > The ISO C standard requires that _Bool bit fields with non-zero width can > > store _and_ *compare* to 0 and 1. > > > >> This happens > >> because it's a single bit field and thus when the msb (the only bit) is > >> set to 1 it is interpreted as -1. > > > > Right. So pa_bool_t should be typedef'd to 'unsigned' rather than 'int' > > wherever HAVE_STD_BOOL is not defined. > > > > Then again, <stdbool.h> is a non-optional part of the C standard. Defining > > your own boolean type feels very 90's (and indeed error-prone). > > Indeed, and we already use other headers from the C99 spec, like > inttypes.h extensively. > > Moreover, in configure.ac we alread try to use C99 by calling > AC_PROG_CC_C99. If that macro is followed by a check for > ac_cv_prog_cc_c99 and error out if set to 'no'. Then we can just > assume _Bool is always present and use it. Fair enough. If there are no objections, I'll remove the !HAVE_STD_BOOL condition from the headers post 1.0. -- Arun
