void added a comment. In D121063#3364815 <https://reviews.llvm.org/D121063#3364815>, @erichkeane wrote:
> In D121063#3364810 <https://reviews.llvm.org/D121063#3364810>, @void wrote: > >> In D121063#3364780 <https://reviews.llvm.org/D121063#3364780>, @void wrote: >> >>> In D121063#3363852 <https://reviews.llvm.org/D121063#3363852>, @erichkeane >>> wrote: >>> >>>> I suspect this works because we never really treated this as a LL, just as >>>> a pair of iterators. Two things: >>>> >>>> 1- Can you produce some situation where this is valuable to do? >>> >>> Yes. In the randstruct feature I'm working on, if this code isn't there it >>> goes into an infinite loop: https://reviews.llvm.org/D120857. It's possible >>> that the way it's constructing and using the list of Decls is somehow >>> wrong, but I wasn't able to identify how. >>> >>>> 2- Can you switch this over so that the NextInContextAndBits initializes >>>> to nullptr/0 so that this line isn't necessary? I can't imagine we ever >>>> re-call this on a decl and have the answer be different. >>> >>> I'll give it a shot. I'm with @urnathan though that it should have already >>> been like that. :-) Probably just an oversight. >> >> After looking at the randstruct code again, it's possible that it's not >> doing the correct thing. (#include "MildShockMeme.h"!) The Decls already >> have a their pointers set, but then we shuffle them and all Hell breaks >> loose when we call that function because the end is pointing back to >> somewhere within the structure beginning. This patch is probably not a bad >> idea in general, but if you want me to I can fix it on my end. > > Ah! Shuffling declarations in a chain is not likely to do 'good things', I'm > surprised that this is the first issue we've seen!. Same :-) > I presume that there needs to be a 'RebuildDeclChain' for the purposes of > 'RandStruct' that first nulls-out the next-in-context-and-bits. Without this patch, then yes. It might actually be a better idea to have it in the DeclContext anyway just in case someone else wants to use it. > Alternatively, perhaps "RandStruct" should be 'randomizing' on the first call > to this BuildDeclChain function. I assume that `BuildDeclChain` is called once (and only once) per Record? Will randomizing when calling `BuildDeclChain` mess up the ABI somehow? Or is it safer to do it here because the ABI is decided afterwards? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D121063/new/ https://reviews.llvm.org/D121063 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
