dblaikie added a comment. In D80391#2497018 <https://reviews.llvm.org/D80391#2497018>, @inglorion wrote:
> For Chrome on Chrome OS, this is https://crbug.com/1158215 > > Here, we saw our links fail with "output file too large". Investigation > revealed that debug info was being included in the binary, instead of in .dwo > files as expected. That turned out to be caused by this change. > > It seems that there are cases where -gsplit-dwarf is passed, but it does not > take effect because there isn't also a -g (or -g<level>) option: > > clang -c -fthinlto-index=foo.o.thinlto.bc -gsplit-dwarf foo.o -o foo.bin.o > > Shows no .dwo file and debug info in foo.bin.o, whereas > > clang -c -fthinlto-index=foo.o.thinlto.bc -gsplit-dwarf -g foo.o -o > foo.bin.o > > shows a .dwo file which is referenced from foo.bin.o > > The only thing that is different here is that the latter command has "-g" > whereas the former doesn't. > > In other words, the new implementation still doesn't make -g and > -gsplit-dwarf fully orthogonal; instead of -gsplit-dwarf always turning on > debug fission, it *only* turns it on when there is also a -g or -g<level> > option - at least in distributed ThinLTO code generation. > > It seems that orthogonality was the motivation for this change, and that > -gsplit-dwarf without -g is supposed to work in the linker (per MaskRay's > comment about -g being ignored by the linker). > > Can we make it so that -gsplit-dwarf turns on debug fission and we then use > that even if no -g options were passed? Ah, sorry - I assumed you were using implicit thinlto rather than explicit thinlto. Yes, I think you've demonstrated a bug here - hopefully @Maskray can look into/fix this so that only -gN is required when the IR is generated and only -gsplit-dwarf is required when real object files are generated - without needing both files even when only one of those operations (IR generation or object generation) is being performed. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D80391/new/ https://reviews.llvm.org/D80391 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
