Package: clang Version: 2.6-3 Severity: normal Clangs behaviour differs depending on where NULL is defined. If NULL is defined locally, a warning is issued if NULL is assigned to an int variable. If the (same) definition of NULL is included via a header file, no warning is issued.
1. Definition of NULL in clang's stddef.h
==========================================
#ifdef __cplusplus
#define NULL __null
#else
#define NULL ((void*)0)
#endif
2. Code causing a warning
=========================
#define NULL ((void*)0)
int main(void) {
int i = NULL;
return 0;
}
2.1. Output compiling example 2
-------------------------------
a.c:4:12: warning: incompatible pointer to integer conversion initializing
'void *', expected 'int'
int i = NULL;
^~~~
a.c:1:14: note: instantiated from:
#define NULL ((void*)0)
^~~~~~~~~~
1 diagnostic generated.
3. Code without warning
========================
#include <stdlib.h>
int main(void) {
int i = NULL;
return 0;
}
3.1 Output compiling example 3
------------------------------
(Well, there is no output at all)
-- System Information:
Debian Release: lenny/sid
APT prefers unstable
APT policy: (990, 'unstable'), (350, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 2.6.32-5-amd64 (SMP w/2 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages clang depends on:
ii libc6 2.11.1-2 Embedded GNU C Library: Shared lib
ii libffi5 3.0.9-2 Foreign Function Interface library
ii libgcc1 1:4.4.4-4 GCC support library
ii libstdc++6 4.4.4-4 The GNU Standard C++ Library v3
Versions of packages clang recommends:
ii llvm-dev 2.6-9 Low-Level Virtual Machine (LLVM),
clang suggests no packages.
-- no debconf information
--
Julian Andres Klode - Debian Developer, Ubuntu Member
See http://wiki.debian.org/JulianAndresKlode and http://jak-linux.org/.
pgpV0AtCb8oyU.pgp
Description: PGP signature
