https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89526
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
CC| |msebor at gcc dot gnu.org
Resolution|--- |WONTFIX
--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
When NDEBUG is not defined GCC will certainly detect errors in assert
expressions. But it's clear from the test case you meant warnings. I'm not
sure I see what warning GCC could issue for assert("nullptr") or what it could
do to even help here. The assert macro is implemented in the C library, so GCC
has little control over what it expands to. Whatever it does expand to, GCC
does the same checking as in other code. So for instance:
$ cat t.c && gcc -O2 -S -Wall -Wextra t.c
#include <assert.h>
void f (unsigned i)
{
assert (i >= 0);
}
In file included from t.c:1:
t.c: In function âfâ:
t.c:5:13: warning: comparison of unsigned expression >= 0 is always true
[-Wtype-limits]
5 | assert (i >= 0);
| ^~
t.c:5:13: warning: comparison of unsigned expression >= 0 is always true
[-Wtype-limits]
5 | assert (i >= 0);
| ^~
Note the warning is duplicated because in Glibc's definition of assert the
expression appears twice. That's on purpose but it has the unfortunate effect
when the warning isn't controlled by -Wpedantic.
/* The first occurrence of EXPR is not evaluated due to the sizeof,
but will trigger any pedantic warnings masked by the __extension__
for the second occurrence. The ternary operator is required to
support function pointers and bit fields in this context, and to
suppress the evaluation of variable length arrays. */
# define assert(expr) \
((void) sizeof ((expr) ? 1 : 0), __extension__ ({ \
if (expr) \
; /* empty */ \
else \
__assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION); \
}))
With that I have to resolve this as won't fix.
