I'd vote for either importing chromium's base version, or sticking with the pure C++ version
On Tue, May 16, 2017 at 3:12 PM <loorong...@gmail.com> wrote: > On Tuesday, May 16, 2017 at 9:05:41 PM UTC+8, Camillo Bruni wrote: >> >> FYI, the code in src/builtin/builtin-*-gen.cc is no longer shipped and >> is neither performance critical as it is only used to create the code stubs >> for the snapshot. >> > > I am aware of that. I noted that in one comment of the CL, but forgot to > re-mention it again in this thread. src/runtime/runtime-regexp.cc and other > codes also use a bit of std::function + lambda, so this refactoring will > still benefit snapshot build slightly. > > By the way, Official Node.js binary is built with snapshot or nosnaphot > configuration? > > >> >> On Tue, May 16, 2017 at 2:52 PM <looro...@gmail.com> wrote: >> > On Tuesday, May 16, 2017 at 8:34:43 PM UTC+8, Jochen Eisinger wrote: >>>> >>>> Thanks for the summary! >>>> >>>> I'm wondering whether you also plan other refactoring work for V8? >>>> >>> >>> No, I only have plan for this refactoring for now. >>> >>> >>>> >>>> Also, why not just import base::Bind and friends from Chromium? >>>> >>> >>> Chromium's implementation uses many other Chromium-specific features >>> like weak_ptr<>, we might end up introducing more code than V8 actually >>> needs. As far as I can see, CodeAssemblerCallback seems to be the only use >>> case of std::function that might benefit from Chromium's Callable<>. >>> >>> >>>> >>>> On Tue, May 16, 2017 at 2:04 PM <looro...@gmail.com> wrote: >>>> >>>>> Hi V8 devs, >>>>> >>>>> I saw a few functions in src/builtin/builtin-*-gen.cc and >>>>> src/code-stub-assembler.h uses quite a few std::function as a parameter, >>>>> then pass lambda function to these functions to avoid code duplication as >>>>> much as possible. std::function was used because raw function pointer >>>>> can't >>>>> accept lambda function. >>>>> >>>>> However, because std::function is really powerful, it comes with a >>>>> cost in terms of code size and overhead when calling std::function. >>>>> >>>>> I am working on introducing function_view to src/base, a lightweight >>>>> callable reference that can accept normal and lambda function. >>>>> >>>>> function_view is adapted from [1] >>>>> <https://vittorioromeo.info/index/blog/passing_functions_to_functions.html>. >>>>> I have changed it so that it can be compiled with C++11, which is the >>>>> minimum compiler support requirement to build Chromium. >>>>> >>>>> Note: >>>>> >>>>> The callable itself must be alive longer or equal to the life time of >>>>> function_view object. Therefore, function_view is not a universal >>>>> replacement for the general-purpose std::function. >>>>> >>>>> If you need to store lambda function as class property, std::function >>>>> is still needed. Use case like [2] >>>>> <https://cs.chromium.org/chromium/src/v8/src/compiler/code-assembler.h?type=cs&l=601> >>>>> cannot be replaced with function_view. >>>>> >>>>> Chromium do have a very powerful library to store callback at >>>>> https://cs.chromium.org/chromium/src/base/bind_internal.h >>>>> (std::function is banned in Chromium). >>>>> >>>>> Plan: >>>>> >>>>> - Add base::function_view implementation to src/base/functional.h >>>>> - Convert std::function to base::function_view in >>>>> src/builtin/builtin-*-gen.cc and maybe other parts of src/* if >>>>> appropriate. >>>>> Usage of std::function in test/* will be ignored. >>>>> - Add documentation. >>>>> - Add unittest. >>>>> >>>>> src/compiler/s390/instruction-selector-s390.cc also uses a lot of >>>>> std::function + lambda, but because I can't test on this platform myself, >>>>> I >>>>> don't feel safe to change it. It looks like dry run does not have bot for >>>>> s390. >>>>> >>>>> WIP CL: >>>>> >>>>> https://chromium-review.googlesource.com/c/505653/ >>>>> >>>>> [1]: >>>>> https://vittorioromeo.info/index/blog/passing_functions_to_functions.html >>>>> [2]: >>>>> https://cs.chromium.org/chromium/src/v8/src/compiler/code-assembler.h?type=cs&l=601 >>>>> >>>>> Sincerely, >>>>> Rong Jie >>>>> >>>> -- >>> -- >>> v8-dev mailing list >>> >> v8-...@googlegroups.com >> >> >>> http://groups.google.com/group/v8-dev >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "v8-dev" group. >>> >> To unsubscribe from this group and stop receiving emails from it, send an >>> email to v8-dev+un...@googlegroups.com. >> >> >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- >> Camillo Bruni | Software Engineer, V8 | Google Germany GmbH | Erika-Mann >> Str. 33, 80636 München >> <https://maps.google.com/?q=Erika-Mann+Str.+33,+80636+M%C3%BCnchen&entry=gmail&source=g> >> >> Registergericht und -nummer: Hamburg, HRB 86891 | Sitz der Gesellschaft: >> Hamburg | Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle >> > -- > -- > v8-dev mailing list > v8-dev@googlegroups.com > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-dev+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-dev mailing list v8-dev@googlegroups.com http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. 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