[PATCH] -Wno-parentheses-equality for Clang

[Maxim Dounin]

Hello!

On Mon, Jun 20, 2016 at 03:43:12PM +0900, Taro KOBAYASHI wrote:

> > Fixing issue would be better than silencing the warning.
> 
> I aggree with this. And looking into this problem more detail,
> I found that this is more complicated problem than simple coding
> style problem.
> 
> in src/core/nginx.c:941:19
> 
> 941|        if (ngx_path_separator(*p)) {
> 942|            cycle->conf_prefix.len = p - ngx_cycle->conf_file.data + 1;
> 943|            cycle->conf_prefix.data = ngx_cycle->conf_file.data;
> 944|            break;
> 945|        }
> 
> there is a macro ngx_path_separator defined in
> 
> src/os/unix/ngx_files.h
> 201|#define ngx_path_separator(c)    ((c) == '/')
> 
> the warning is raised by the extraneous parentheses expanded by this
> macro. But generally we cannot say the parentheses in the macro is 'extraneous'
> as the situation could be changed by the context where it is used.

If some version of clang generates the warning for the code in 
question, this looks like a bug in clang for me.  Though I don't 
see the warning generated at least by clang 3.4.1, 3.7.1, 3.8.0, 
and 3.9.0 (trunk 271348), as well as with one shipped by Apple 
(clang-703.0.31).

-- 
Maxim Dounin
http://nginx.org/