Re: build with clang-3.4 warnings report

[Rich Felker <dalias@aerifal.cx>]

On Sat, Apr 05, 2014 at 03:06:03AM +0200, Abdoulaye Walsimou Gaye wrote:
> OK I was not building with --enable-warnings! Here is another round without bogus warnings you rejected:
> -Wstring-plus-int
> -Wtautological-constant-out-of-range-compare
> 
> Thanks,
> awg
> 
> src/aio/aio_readwrite.c:20:16: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
>   .__si_fields.__sigchld.si_pid = __pthread_self()->pid,
>               ~^~~~~~~~~
> src/aio/aio_readwrite.c:18:20: note: previous initialization is here
>   .__si_fields.__rt.si_sigval = sev->sigev_value,
>                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> src/aio/aio_readwrite.c:8:13: warning: function 'dummy' is not needed and will not be emitted [-Wunneeded-internal-declaration]
> static void dummy(void)
>             ^
> 2 warnings generated.

Like I said before, this looks real, and we need to look into it.

> src/env/__init_security.c:8:13: warning: function 'dummy' is not needed and will not be emitted [-Wunneeded-internal-declaration]
> static void dummy(void *ent)
>             ^
> 1 warning generated.

This is a bug in the compiler; the function dummy has an externally
visible alias, so it will not be omitted (and if it is actually
omitted, that means the compiler is generating broken output).

> src/env/__init_tls.c:46:14: warning: function 'simple' is not needed and will not be emitted [-Wunneeded-internal-declaration]
> static void *simple(void *p)
>              ^
> 1 warning generated.

Thanks! This is a great find, cruft that was left behind in the lazy
thread pointer init removal. Fixing it shaved ~40 bytes off the
minimal static-linked program size, bringing the net change from the
change down to near-zero if I'm not mistaken. :-) Our anti-bloat
extremists will be very happy.

> src/env/__libc_start_main.c:9:13: warning: function 'dummy' is not needed and will not be emitted [-Wunneeded-internal-declaration]
> static void dummy() {}
>             ^
> 1 warning generated.

Another false positive.

> In file included from src/errno/strerror.c:7:
> src/errno/__strerror.h:100:1: warning: implicit conversion from 'int' to 'unsigned char' changes value from 1133 to 109 [-Wconstant-conversion]
> 1133,
> ^~~~
> 1 warning generated.

Again, I'm confused why we're getting this one.

> src/regex/regcomp.c:3123:18: warning: explicitly assigning a variable of type 'reg_errcode_t' (aka 'int') to itself [-Wself-assign]
>     do { errcode = errcode; if ( 1) goto error_exit; } while ( 0);
>          ~~~~~~~ ^ ~~~~~~~

This is gratuitous and comes from a macro expansion.

The rest are more duplicates of the weak alias false positive (unused
static functions).

Rich