Re: uninitialized member warnings ?
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Re: uninitialized member warnings ?
On Wed, 2012-09-26 at 15:29 +0200, Lubos Lunak wrote:
> I don't think it can go anywhere practical:
:-) while it's certainly possibly to find cases where it is hard to
detect and warn about these problems, I imagine that catching many of
the banal cases and warning about those would be reasonably do-able -
while punting on the false positives.
> class A
> {
> bool foo;
> void init();
> public:
> A() { init(); }
> };
>
> How should the compiler know?
In this case; it should be clever ;-) we could defer the checking until
we compiled the init function: but of course, this soon gets pretty
intense cost-wise, and (absent LTO-scale visibility of all the code)
can't be perfect.
Warnings for constructors that don't call member functions, don't
initialise POD types, and/or don't pass references to them elsewhere
would surely be a useful if not complete win.
ATB,
Michael.
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Re: uninitialized member warnings ?
On 09/26/2012 03:16 PM, Michael Meeks wrote: There is no way for the compiler to decide this in general (unlike Java, C++ does not have restricting rules to allow the compiler to do so). no way ? Note that I wrote "in general." Stephan ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
Re: uninitialized member warnings ?
On Wednesday 26 of September 2012, Michael Meeks wrote:
> On Tue, 2012-09-25 at 14:26 +0200, Stephan Bergmann wrote:
> > > Neato :-) the deeper question - as to why no warnings are popping out
> > > of the compiler for this when (surely) it's a trivial thing to check /
> > > warn for - is more concerning.
> >
> > Such a warning option has never been there AFAIK.
>
> Oh - must be me mis-remembering it, or remembering valgrind output that
> catches that, silly me.
>
> > There is no way for the compiler to decide this in general (unlike Java,
> > C++ does not have restricting rules to allow the compiler to do so).
>
> no way ? surely there is - add a warning for un-initialized POD members
> on the exit of the constructor. It seems that fools seldom differ, and
> there is such a patch here:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=2972
>
> Doesn't seem to be going anywhere in the last month, but - you can but
> hope :-)
I don't think it can go anywhere practical:
class A
{
bool foo;
void init();
public:
A() { init(); }
};
How should the compiler know?
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Re: uninitialized member warnings ?
On Tue, 2012-09-25 at 14:26 +0200, Stephan Bergmann wrote: > > Neato :-) the deeper question - as to why no warnings are popping out > > of the compiler for this when (surely) it's a trivial thing to check / > > warn for - is more concerning. > > Such a warning option has never been there AFAIK. Oh - must be me mis-remembering it, or remembering valgrind output that catches that, silly me. > There is no way for the compiler to decide this in general (unlike Java, > C++ does not have restricting rules to allow the compiler to do so). no way ? surely there is - add a warning for un-initialized POD members on the exit of the constructor. It seems that fools seldom differ, and there is such a patch here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=2972 Doesn't seem to be going anywhere in the last month, but - you can but hope :-) ATB, Michael. -- michael.me...@suse.com <><, Pseudo Engineer, itinerant idiot ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
Re: uninitialized member warnings ?
On 09/25/2012 11:26 AM, Michael Meeks wrote: On Mon, 2012-09-24 at 20:17 +0100, Caolán McNamara wrote: On Mon, 2012-09-24 at 11:55 -0400, Kohei Yoshida wrote: On Thu, Sep 20, 2012 at 7:02 AM, Michael Meeks wrote: I've noticed a number of these straying in. Did we disable a warning on un-initialized members for some reason ? I could swear the compiler used to complain helpfully about this. Yeah, this was a recent cockup of mine when I did away with CUPSWrapper and merged it into CUPSManager so master only Neato :-) the deeper question - as to why no warnings are popping out of the compiler for this when (surely) it's a trivial thing to check / warn for - is more concerning. Any gbuild experts have a view there ? :-) There is no way for the compiler to decide this in general (unlike Java, C++ does not have restricting rules to allow the compiler to do so). Such a warning option has never been there AFAIK. Stephan ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
uninitialized member warnings ?
On Mon, 2012-09-24 at 20:17 +0100, Caolán McNamara wrote: > On Mon, 2012-09-24 at 11:55 -0400, Kohei Yoshida wrote: > > On Thu, Sep 20, 2012 at 7:02 AM, Michael Meeks > > wrote: > > > I've noticed a number of these straying in. Did we disable a > > > warning on > > > un-initialized members for some reason ? I could swear the compiler used > > > to complain helpfully about this. > > Yeah, this was a recent cockup of mine when I did away with CUPSWrapper > and merged it into CUPSManager so master only Neato :-) the deeper question - as to why no warnings are popping out of the compiler for this when (surely) it's a trivial thing to check / warn for - is more concerning. Any gbuild experts have a view there ? :-) Thanks, Michael. -- michael.me...@suse.com <><, Pseudo Engineer, itinerant idiot ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
