Re: [Qemu-devel] [PATCH 2/5] CODING_STYLE: add C type rules

[malc]

On Tue, 17 Aug 2010, Blue Swirl wrote:

> On Tue, Aug 17, 2010 at 8:09 AM, Jes Sorensen <address@hidden> wrote:
> > On 08/12/10 19:50, Blue Swirl wrote:
> >> +While using "bool" is good for readability, it comes with minor caveats:
> >> + - Don't use "bool" in places where the type size must be constant across
> >> +   all systems, like public interfaces and on-the-wire protocols.
> >> + - Don't compare a bool variable against the literal, "true",
> >> +   since a value with a logical non-false value need not be "1".
> >> +   I.e., don't write "if (seen == true) ...".  Rather, write "if 
> >> (seen)...".
> >
> > I'd strongly discourage the use of bool in any code. It doesn't provide
> > anything guarantees and you are not sure about the size of it. Using int
> > is safer. IMHO bool is one of the worse examples of changes to the C
> > standard :(
> >
> > bool foo = false;
> > foo++;
> > if (foo == true)....
> 
> It's already in use. Could you write a replacement rule which forbids
> any new bool use and welcomes patches to remove any existing cases?
> 
> > The other thing that might be worth mentioning in the int/long section
> > is that long is complicated in broken development environments such as
> > Windows where it is only 32 bit :(

There's absolutely nothing broken about LLP64 it's as valid as any other
ABI. (That's to Jes)

> 
> Only on Win64 (http://technet.microsoft.com/en-us/library/bb496995.aspx)
> but we don't support that.

We "don't support" that only because nobody has merged Filip Navara's
port[1]

> We could add something like traditional "don't mix int and pointer
> sizes" and not require intptr_t in place of longs.
> 

[1] 
http://repo.or.cz/w/qemu/navara.git/commit/e777e89c4be2b80b37043e72fe6158da5ea4bf6c

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