https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80685
Bug ID: 80685
Summary: -Wnonnull-compare warns based on builtin declaration
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: coypu at sdf dot org
Target Milestone: ---
Hi, I'm building a libc.
It doesn't use __attribute__((nonnull)) anywhere in stdio.h and other headers,
instead asserts in a convoluted way that the arguments aren't NULL.
Building with gcc -Werror -Wall etc. I get lots of warnings about these NULL
checks:
/usr/src/lib/libc/../../common/lib/libc/string/strncat.c: In function
'strncat':
/usr/src/lib/libc/../../common/lib/libc/string/strncat.c:63:2: error: nonnull
argument 'dst' compared to NULL [-Werror=nonnull-compare]
_DIAGASSERT(dst != NULL);
^
I believe that warning may be bogus, feel free to close if you disagree.
