valery pykhtin via llvm-dev
2016-Mar-09 06:52 UTC
[llvm-dev] "Do not use Static Constructors" LLVM Coding Standard rule question
Hi,
I'm new here and have a question about the rule in title. Is the following
use case also prohibited?
int findNameId(StringRef Name)
{
static StringMap<int> Map = createSomeIDMap();
return Map.lookup(Name);
};
It seems it isn't influence startup time and doesn't create
initialization
order problems. Clang isn't complaining about it with -Wglobal-constructor
flag.
I'm asking because under some interpretation of rule wording it can be
called static constructor too.
Thanks,
Valery
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Craig Topper via llvm-dev
2016-Mar-09 07:42 UTC
[llvm-dev] "Do not use Static Constructors" LLVM Coding Standard rule question
I believe the rule is only for global variables. At least that's what the first sentence in the section says. "Static constructors and destructors (e.g. global variables whose types have a constructor or destructor) should not be added to the code base, and should be removed wherever possible." On Tue, Mar 8, 2016 at 10:52 PM, valery pykhtin via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Hi, > > I'm new here and have a question about the rule in title. Is the following > use case also prohibited? > > int findNameId(StringRef Name) > { > static StringMap<int> Map = createSomeIDMap(); > return Map.lookup(Name); > }; > > It seems it isn't influence startup time and doesn't create initialization > order problems. Clang isn't complaining about it with -Wglobal-constructor > flag. > > I'm asking because under some interpretation of rule wording it can be > called static constructor too. > > Thanks, > Valery > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > >-- ~Craig -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160308/78d36470/attachment.html>
David Blaikie via llvm-dev
2016-Mar-09 07:49 UTC
[llvm-dev] "Do not use Static Constructors" LLVM Coding Standard rule question
a static local still produces a static dtor, though
One of the ways you can get around this is with a deliberate non-cleanup:
const foo &getFoo() {
static const foo &f = *new foo();
return f;
}
that way no global dtor runs. Obviously only works if you don't need
foo's
dtor to run.
On Tue, Mar 8, 2016 at 11:42 PM, Craig Topper via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> I believe the rule is only for global variables. At least that's what
the
> first sentence in the section says.
>
> "Static constructors and destructors (e.g. global variables whose
types
> have a constructor or destructor) should not be added to the code base, and
> should be removed wherever possible."
>
> On Tue, Mar 8, 2016 at 10:52 PM, valery pykhtin via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Hi,
>>
>> I'm new here and have a question about the rule in title. Is the
>> following use case also prohibited?
>>
>> int findNameId(StringRef Name)
>> {
>> static StringMap<int> Map = createSomeIDMap();
>> return Map.lookup(Name);
>> };
>>
>> It seems it isn't influence startup time and doesn't create
>> initialization order problems. Clang isn't complaining about it
with
>> -Wglobal-constructor flag.
>>
>> I'm asking because under some interpretation of rule wording it can
be
>> called static constructor too.
>>
>> Thanks,
>> Valery
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>
>
> --
> ~Craig
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
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