https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61760
Bug ID: 61760
Summary: -Wconversion inconsistency between gcc and g++
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: js at alien8 dot de
Given the code:
unsigned char foo(unsigned char x)
{
return x >> 1;
}
If you compile this with 'gcc -Wconversion -c foo.c', there is no warning. If
you compile it with 'g++ -Wconversion -c foo.c' you get:
foo.c:3:11: warning: conversion to ‘unsigned char’ from ‘int’ may alter its
value [-Wconversion]
return x >> 1;
I would argue that the conversion warning is false in both cases, because there
is no information loss involved, even though the intermediate result is cast to
an int.
Is there a reason why g++ produces the warning here or is this a bug?
This happens using 4.8.3 and 4.9.1 20140706 (prerelease) on x86_64.
