Re: -Wconversion bug in g++-4.3?

Re: -Wconversion bug in g++-4.3?

[Andrew Haley]

Manuel López-Ibáñez writes:
 > For this testcase:
 > 
 > void g(const unsigned char b)
 > {
 >  unsigned short c = b & 0xff;
 > }
 > 
 > we get:
 > 
 > wconversion-3.c:3: warning: conversion to 'unsigned char' from 'int'
 > may alter its value
 > wconversion-3.c:3: warning: conversion to 'short unsigned int' from
 > 'int' may alter its value
 > 
 > Really weird... It is the same in both C and C++.

Please read http://gcc.gnu.org/wiki/NewWconversion.  Please come back
if you have any further questions.

Andrew.

-- 
Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, UK
Registered in England and Wales No. 3798903

Re: -Wconversion bug in g++-4.3?

[Manuel López-Ibáñez]

On 23/11/2007, Andrew Haley <aph@redhat.com> wrote:
>
> Please read http://gcc.gnu.org/wiki/NewWconversion.  Please come back
> if you have any further questions.
>

Funny.  I wrote that page (my name is on the top) and I implemented
that feature.  This is a bug that we are discussing:
http://gcc.gnu.org/PR34198.  I guess you missed this:
http://gcc.gnu.org/ml/gcc/2007-11/msg00577.html

Cheers,

Manuel.

Re: -Wconversion bug in g++-4.3?

[Andrew Haley]

Manuel López-Ibáñez writes:
 > On 23/11/2007, Andrew Haley <aph@redhat.com> wrote:
 > >
 > > Please read http://gcc.gnu.org/wiki/NewWconversion.  Please come back
 > > if you have any further questions.
 > >
 > 
 > Funny.  I wrote that page (my name is on the top) and I implemented
 > that feature.  This is a bug that we are discussing:
 > http://gcc.gnu.org/PR34198.  I guess you missed this:
 > http://gcc.gnu.org/ml/gcc/2007-11/msg00577.html

LOL!  Oops, sorry.  :-)

Andrew.

-- 
Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, UK
Registered in England and Wales No. 3798903

-Wconversion bug in g++-4.3?

[Tom Browder]

(Excuse the previous msg--lost control of the key board.)

Consider the following code:

f.cc ==>
void f(const unsigned char b)
{
  unsigned char c = static_cast<unsigned char>(b & 0xff);
}
<== f.cc

Compile with g++ 4.1.2:

  $ g++-4.3-20071109 -c f.c -Wconversion
  $

Note no warnings.

Compile with g++ 4.3-20071109:

  $ g++-4.3-20071109 -c f.c -Wconversion
  f.cc: In function 'void f(unsigned char)':
  f.cc:3: warning: conversion to 'unsigned char' from 'int' may alter its value

Is this a legitimate warning or a bug?  If so, is there anything to be
done to eliminate the warning while retaining "-Wconversion"?

Thanks.

-Tom

Tom Browder
Niceville, Florida
USA

-Wconversion bug in g++-4.3?

[Tom Browder]

Consider the following code:

void f(const unsigned char b)
{

}

-- 
Tom Browder
Niceville, Florida
USA