Re: [webkit-dev] using namespace style guideline
On Nov 15, 2009, at 9:57 PM, Chris Jerdonek wrote: In particular, the following file uses using namespace WTF::Unicode five times, but within the bodies of various template definitions: http://trac.webkit.org/browser/trunk/WebCore/platform/text/BidiResolver.h (see line 304, for example) Is this also not okay? This is fine. If the using namespace is scoped to a particular function, then it’s not the same thing we’re talking about. The following is another example. The using statement for this one appears at the beginning, outside of any definitions, but the file seems to be central: http://trac.webkit.org/browser/trunk/JavaScriptGlue/JSUtils.h It uses using namespace JSC. JavaScriptGlue does not follow the WebKit coding style — there’s no need to look at files inside the JavaScriptGlue directory when considering matters of style. My second question is whether the guideline above should apply, for the same reason, to all using statements within header files -- and not just to using namespace statements. Statements of the form using WTF::... would be exceptions. You've already discussed those here: https://lists.webkit.org/pipermail/webkit-dev/2009-November/010453.html I checked, and there are only about 40 files in all of WebKit that wouldn't currently be following this -- slightly less than half of which are in JSC. Probably. We’d have to discuss specific examples to be sure. -- Darin ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] using namespace style guideline
On Tue, Nov 10, 2009 at 8:30 PM, Darin Adler da...@apple.com wrote: No using namespace statements are permitted in header files. The guidelines are talking about non-header files. We should clarify that. Thanks for your later reply explaining the history behind the using WTF::... statements. It sounds reasonable. I have a couple more questions related to the rule above though. (For everyone else's benefit, this rule now appears on the web site). I found there to be seven files in WebKit that don't follow this rule, and I wanted to double-check whether there should be any exceptions to it. In particular, the following file uses using namespace WTF::Unicode five times, but within the bodies of various template definitions: http://trac.webkit.org/browser/trunk/WebCore/platform/text/BidiResolver.h (see line 304, for example) Is this also not okay? The following is another example. The using statement for this one appears at the beginning, outside of any definitions, but the file seems to be central: http://trac.webkit.org/browser/trunk/JavaScriptGlue/JSUtils.h It uses using namespace JSC. My second question is whether the guideline above should apply, for the same reason, to all using statements within header files -- and not just to using namespace statements. Statements of the form using WTF::... would be exceptions. You've already discussed those here: https://lists.webkit.org/pipermail/webkit-dev/2009-November/010453.html I checked, and there are only about 40 files in all of WebKit that wouldn't currently be following this -- slightly less than half of which are in JSC. --Chris ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] using namespace style guideline
On Nov 11, 2009, at 6:56 PM, Chris Jerdonek wrote: What is the current thinking on all of the using WTF::... statements at the end of many header files in JSC? For example, what was the original reason behind including those, and is there any chance that they will be taken out at a later date (or has that already been ruled out)? I searched a bit and didn't come across any discussion of this. WTF uses namespacing differently than most libraries. We’re using it to disambiguate at link time, but not compile time.Having the symbols in a namespace at link time still has a substantial benefit, so it’s good to put things in a WTF namespace instead of just putting them outside any namespace. Maciej Stachowiak devised this scheme for WTF, and I think on balance it’s probably a good way to do things although I would probably not have chosen it myself, and would have used the more conventional scheme. Maciej and I and a few others at Apple discussed this a bit a few years back, but nobody on any WebKit mailing list ever raised the issue before. Since WTF is for use inside WebKit itself, I think we can stick with this approach unless we run into a substantial, concrete problem with it. I don’t think things would be better if we did this in the conventional way and either had to utter WTF::RefPtr and WTF::Vector in WebCore and JavaScriptCore header files, or every client of RefPtr had to include a certain header file with a using WTF::RefPtr in the WebCore or JavaScriptCore namespace. Similarly if many .cpp files had to have using namespace WTF. For a while I was adding using namespace WTF to .cpp files because I did not understand our WTF namespacing approach. -- Darin ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] using namespace style guideline
On Tue, Nov 10, 2009 at 8:30 PM, Darin Adler da...@apple.com wrote: No using namespace statements are permitted in header files. The guidelines are talking about non-header files. We should clarify that. Thanks for the clarification. I will go ahead and try adding that. This is a good segue into another question I have. What is the current thinking on all of the using WTF::... statements at the end of many header files in JSC? For example, what was the original reason behind including those, and is there any chance that they will be taken out at a later date (or has that already been ruled out)? I searched a bit and didn't come across any discussion of this. --Chris ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
[webkit-dev] using namespace style guideline
Hi, I have a question about the last of the WebKit Coding Style Guidelines:
http://webkit.org/coding/coding-style.html
It's the second of these two:
1. Any using namespace statements for a nested namespace whose
parent namespace is also defined in a file must be declared within
that namespace definition.
2. Any other using namespace statements must be declared before the
first namespace definition in the file.
Unlike most or all of the other rules, this one can affect
compilation. So I was wondering what the rule is for.
For example, say I want to write the following in an existing header
file to avoid having to fully qualify several identifiers in the WTF
namespace:
namespace MyNewNameSpace {
using namespace WTF;
// code
}
Following rule 2 and putting the using statement outside the namespace
can cause compilation errors elsewhere in the project (due to
ambiguous overloads for bringing the WTF namespace into files already
including the above). This actually happened to me while doing some
minor refactoring.
If I want to keep the using namespace statement, it seems like the
style guideline would require me to do an unknown amount of
refactoring outside the file.
Let me know your thoughts.
Thanks,
--Chris
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Re: [webkit-dev] using namespace style guideline
On Nov 10, 2009, at 7:41 PM, Chris Jerdonek wrote: Hi, I have a question about the last of the WebKit Coding Style Guidelines: http://webkit.org/coding/coding-style.html It's the second of these two: 1. Any using namespace statements for a nested namespace whose parent namespace is also defined in a file must be declared within that namespace definition. 2. Any other using namespace statements must be declared before the first namespace definition in the file. No using namespace statements are permitted in header files. The guidelines are talking about non-header files. We should clarify that. -- Darin ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
