[Bug preprocessor/39559] New: constants too large for intmax_t need pedwarns

[jsm28 at gcc dot gnu dot org]

unsigned long long l = 9223372036854775808LL;

should get an error with -std=c99 -pedantic-errors, but instead gets a warning:

t.c:1:24: warning: integer constant is so large that it is unsigned

C99 does not allow decimal constants without "U" suffix to get an
unsigned type.  I think the preprocessor should pedwarn in this case
(for C99, not C90), to catch the use of such constants in
#if conditions as well.

The preprocessor already pedwarns for a value large enough to be outside
the range of uintmax_t (which is used to set the preprocessor's
internal precision), so I believe this case of a constant inside the range
of uintmax_t but outside that of intmax_t, in decimal without "U" suffix,
is the only current case of this bug.

See <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38934#c15> for some
historical discussion (but it doesn't appear types wider than intmax_t
can ever appear this way after all).


-- 
           Summary: constants too large for intmax_t need pedwarns
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: preprocessor
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jsm28 at gcc dot gnu dot org
OtherBugsDependingO 16989
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39559