2009/6/29 Jan Engelhardt <jeng...@medozas.de>: > > On Monday 2009-06-29 16:09, Manuel López-Ibáñez wrote: >>2009/6/29 Richard Guenther wrote: >>> On Mon, Jun 29, 2009 at 3:10 PM, Jan Engelhardt wrote: >>>> Hi gcc list, >>>> >>>> >>>> I am forwarding below's bugreport here(*), to implicitly make aware >>>> of a feature that I deem important to have in a future gcc. >>>> >>> >>> -Wconversion should say >>> >>> t.c:4: warning: conversion to ‘unsigned char’ from ‘int’ may alter its value > > I added -Wconversion to the Linux kernel's global cflags (KBUILD_CFLAGS) > just to see what would happen. As I expected, I get swamped with > warnings, like "conversion to int from unsigned int". All legitimate in > themselves, I would have preferred an option (or even no option at all, > given that the "large integer implicitly truncated to unsigned type" > warning is shown without any -W flags) that only flags up truncation > problems with literals.
A lot of false warnings were fixed in GCC 4.4 and 4.5. And if only truncation problems with literals were warned then your original example wouldn't had been. Cheers, Manuel.
