Re: gcc 4.3.0, -Wconversion: assignment-by operators for shorter types

["Manuel López-Ibáñez" <lopezibanez at gmail dot com>]

Please, open a bug report: http://gcc.gnu.org/bugzilla/

Thanks,

Manuel.

2008/5/26 Andriy Gapon <avg@icyb.net.ua>:
>
> If I write something like the following:
> uint8_t x;
> uint8_t y;
> x ^= y;
>
> and compile with gcc 4.3.0 with  -Wconversion option, then I get the
> following warning:
> warning: conversion to 'unsigned char' from 'int' may alter its value
> [-Wconversion]
>
> While technically this warning is correct (because x and y are
> implicitly advanced to "int"before actual xor operation), it seems that
> it doesn't make much practical sense.
>
> I think that this applies to all "assignment-by" operators working on
> types shorter than int.
>
> OTOH, proper implementation should be smart enough to warn about the
> following:
> uint8_t x;
> uint16_t y;
> x ^= y;
>
>
> --
> Andriy Gapon
>