Not that I admit to using printf debugging, but if I were to,
hypothetically of course, I would find this patch helpful.
On Mon, Jul 9, 2012 at 2:43 PM, Alexis Menard
<alexis.men...@openbossa.org>wrote:
> Hi,
>
> For those who "secretly" use printf debugging :). I know the
> recommended way is to use a debugger and it's not the point of this
> discussion.
>
> The other day I was working on the Mac port (with no real possibility
> to have a debug build) and I missed a lot a great feature we have in
> Qt : qDebug(). I find the usage of printf cumbersome (so is LOG and
> dataLog).
> QDebug prettify and ease printf based debug workflow. Even in WebKit
> using QDebug is pretty handy as very important core types of WebKit
> have a Qt representation (e.g. WTF::String can be converted to a
> QString). So you can do something like : String string("HELLO");
> qDebug()<<string and it just output "HELLO" for you. Much more
> efficient (to write ofc) than : fprintf(stderr, "%s\n",
> string.utf8().data());
> Still today a lot of WebKit core type have no counterpart in Qt (and
> will never have) so qDebug pretty much fail (worst case it shows a
> pointer address if possible).
>
> I'm also aware of NSLog but it unfortunately only work in objective c
> files.
>
> Then I thought about adding a dedicated debugging helper for WebKit in
> general, not Qt related so it could benefit everyone not just a given
> port.
>
> So I propose wtf() and its stream operator.
>
> Usage :
>
> wtf()<<"Hello"<<"World"<<3<<4.53322323; will output : Hello World 3 4.53322
>
> IntRect rect(10, 20, 50, 100);
> wtf()<<"Rect"<<rect; will output : Rect IntRect(10,20 50x100)
>
> Vector<String> v;
> v.append("3");
> v.append("4");
> v.append("5");
> wtf()<<v; will output : Vector ("3", "4", "5");
>
> These are basic examples but we can really extend it to virtually
> anything, like higher level classes.
>
> Here is the bug with a patch attached :
>
> https://bugs.webkit.org/show_bug.cgi?id=90823
>
> wtf() is not meant to stay in a given function/patch. It is for
> developers only who wants to debug, we don't want to add overhead in
> release build and we do have the LOG macro doing a job similar.
>
> An other alternative could be to extend dataLog to support this
> streaming operator case. I'm open to this alternative too.
>
> It's a work in progress but I want to get feedback before I continue
> further (adding some stream operator overload for example) and also I
> need to make sure it builds on all ports.
>
> Do you think it is useful? Do you think it will ease/make you faster
> when debugging when you use printf? Do you want that in WebKit?
>
> I'm open to suggestion and maybe later improvements (such as showing
> the line numbers, fct names...). If people think that is useless then
> forget about it.
>
> Thanks.
>
> --
> Alexis Menard (darktears)
> Software Engineer
> openBossa @ INdT - Instituto Nokia de Tecnologia
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>
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