ChuanqiXu added inline comments.
================ Comment at: clang/lib/Serialization/ASTWriterDecl.cpp:623-626 + VisitDeclaratorDecl(D); + Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName()); + Record.push_back(D->getIdentifierNamespace()); + ---------------- ChuanqiXu wrote: > mizvekov wrote: > > ChuanqiXu wrote: > > > mizvekov wrote: > > > > ChuanqiXu wrote: > > > > > mizvekov wrote: > > > > > > ChuanqiXu wrote: > > > > > > > ChuanqiXu wrote: > > > > > > > > ChuanqiXu wrote: > > > > > > > > > mizvekov wrote: > > > > > > > > > > ChuanqiXu wrote: > > > > > > > > > > > I still don't get the reason for the move. What's the > > > > > > > > > > > benefit? Or why is it necessary? > > > > > > > > > > Yeah, now the type can reference the template decl, so > > > > > > > > > > without moving this, it can happen during import of the > > > > > > > > > > type that we try to read this function template bits > > > > > > > > > > without having imported them yet. > > > > > > > > > Oh, I guess I met the problem before (D129748 ) and I made a > > > > > > > > > workaround for it (https://reviews.llvm.org/D130331). If I > > > > > > > > > understood right, the patch will solve that problem. I'll > > > > > > > > > check it out later. > > > > > > > > > > > > > > > > > > (This kind of code move looks dangerous you know and I'll > > > > > > > > > take a double check) > > > > > > > > After looking into the detailed change for the serialization > > > > > > > > part, I feel it is a not-so-good workaround indeed.. It looks > > > > > > > > like we need a better method to delay reading the type in the > > > > > > > > serializer. And I'm looking at it. @mizvekov would you like to > > > > > > > > rebase the series of patches to the main branch so that I can > > > > > > > > test it actually. > > > > > > > Or would it be simpler to rebase and squash them into a draft > > > > > > > revision? > > > > > > I had given this some thought, and it made sense to me that we > > > > > > should deal with the template bits first, since these are closer to > > > > > > the introducer for these declarations, and so that it would be > > > > > > harder to have a dependence the other way around. > > > > > > > > > > > > But I would like to hear your thoughts on this after you have taken > > > > > > a better look. > > > > > > I am working on a bunch of things right now, I should be able to > > > > > > rebase this on the next few days, but otherwise > > > > > > I last rebased about 4 days ago, so you can also check that out at > > > > > > https://github.com/mizvekov/llvm-project/tree/resugar > > > > > > That link has the whole stack, you probably should check out just > > > > > > the commit for this patch, as you are probably going to encounter > > > > > > issues with the resugarer if you try it on substantial code bases. > > > > > > It will carry other changes with it, but I think those should be > > > > > > safe. > > > > > I won't say it is bad to deal with template bits first. I just feel > > > > > it is a workaround to avoid the circular dependent problem in > > > > > deserialization. Or in another word, here the method works due to you > > > > > put some decls* in the template parameter types. And we avoid the > > > > > circular dependent problem by adjusting the order we deserializes. > > > > > The reasons why I don't feel it is good include: > > > > > (1) Although we touched template function decl and template var decl, > > > > > we don't touched template var decl. I guess it'll be a problem now or > > > > > later. > > > > > (2) The solution here can't solve the similar circular dependent > > > > > problem I sawed in attributes. So the method only workarounds some > > > > > resulting of the same problem. > > > > > > > > > > Or in one shorter explanation, it should be greater to solve the root > > > > > problems. I have an idea and I am going to to do a proof-of-concept > > > > > implementation first since I feel like nobody are happy about an > > > > > unimplementable idea. Generally I don't like to block patches due to > > > > > such reasons since it is completely not your fault but I guess it may > > > > > be better to wait some time. Since if we want to allow workarounds > > > > > first and clear the workarounds, things will be harder. If you want a > > > > > timeline, I guess 2 months may be reasonable choices. I mean if I > > > > > can't make it in 2 months and other reviewers feel this is good (what > > > > > I am seeing), I feel bad to block this. (But if we're more patient, > > > > > it'll be better). How do you think about this? > > > > Well we touch FunctionTemplates and VariableTemplates in this patch, > > > > because they were not doing template first. > > > > For whatever reason, class templates were already doing template first, > > > > so no need to fix that. > > > > > > > > So this patch at least puts that into consistency. > > > > > > > > Also, this patch is a pre-requisite for the template resugaring > > > > specialization project I am working on, and the deadline for the whole > > > > project is about two months from now. > > > > > > > > If I leave merging this patch until the end, it seems impossible that I > > > > will finish in time, as we will leave field testing this to the very > > > > end. > > > > > > > > So while I understand the need for a better approach, it is indeed > > > > putting me in an impossible situation. > > > > Also, this patch is a pre-requisite for the template resugaring > > > > specialization project I am working on, and the deadline for the whole > > > > project is about two months from now. > > > > > > What is the deadline you're referring? According to > > > https://llvm.org/docs/HowToReleaseLLVM.html, the next release branch will > > > be in January. > > > > > > > So while I understand the need for a better approach, it is indeed > > > > putting me in an impossible situation. > > > > > > I see. I understand it is bad to make perfect the enemy of better. I'll > > > try to give a faster response. > > > What is the deadline you're referring? According to > > > https://llvm.org/docs/HowToReleaseLLVM.html, the next release branch will > > > be in January. > > > > This is a GSoC that is fast becoming a GWoC, since it has been extended to > > the maximum possible amount of time already. > > > > > I see. Although GSoC projects are not guaranteed to be landed, I don't want > to block/object this. Update: when I took a look at this again. I found it break a my toy implementation for std modules (https://github.com/ChuanqiXu9/stdmodules). I reduced the failure and submit it directly at here: https://github.com/llvm/llvm-project/commit/1aaba40dcbe8fdc93d825d1f4e22edaa3e9aa5b1 since the more testing should be always good. I guess the reason may be that when we read the function decl, we need to defer reading its type. But I had no time to check. I am going to take vacation in the next 2 weeks so probably I can't respond quickly. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D131858/new/ https://reviews.llvm.org/D131858 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
