augusto2112 added a comment. In D141318#4037687 <https://reviews.llvm.org/D141318#4037687>, @JDevlieghere wrote:
> In D141318#4037640 <https://reviews.llvm.org/D141318#4037640>, @augusto2112 > wrote: > >> In D141318#4037557 <https://reviews.llvm.org/D141318#4037557>, @JDevlieghere >> wrote: >> >>> In D141318#4037541 <https://reviews.llvm.org/D141318#4037541>, @augusto2112 >>> wrote: >>> >>>> I changed the value of the map to a shared pointer, but could change it to >>>> a weak pointer instead, not sure which is more appropriate in this case. >>> >>> I was about to ask the same thing. What currently determines the lifetime >>> of the stored objects? >> >> Currently, a bunch of functions in `DWARFASTParserClang` and >> `SymbolFileDWARF` will create a new `Type` SP, store the underlying pointer >> in the map, and return the SP. The lifetime of the stored objects varies by >> whatever the caller does with the returned SP. Looking at some of the >> callers, I don't see a very clear pattern, most seem to use it and >> immediately discard it (use after free when we look up the same type again >> and the underlying pointer is still in the map), but at least one caller >> (`SymbolFileDWARF::ResolveType`) returns the underlying pointer to //its// >> callers, which would still be UB even if we changed the map to store weak >> pointers. Based on that I'm thinking we should store them as shared pointers >> instead of weak ones. > > Then maybe the solution is to store the type as unique pointers in the map > and hand out raw pointers, relying on the map to keep the object alive? I > feel pretty uncomfortable with handing out shared pointers without clearly > understanding its lifetime cycle. Yeah that seems like a better solution. I'm checking how hard implementing that would be. `TypeSP` is used in a bunch of places in LLDB. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D141318/new/ https://reviews.llvm.org/D141318 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
