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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160309/a4715848/attachment.html>
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 > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160308/3350673a/attachment.html>
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