dblaikie added a comment. In https://reviews.llvm.org/D52296#1282603, @probinson wrote:
> In https://reviews.llvm.org/D52296#1282589, @dblaikie wrote: > > > In https://reviews.llvm.org/D52296#1282587, @probinson wrote: > > > > > Any distributed build has to make this work, so the paths in the line > > > table are usable. Not clear what you're thinking might be the problem > > > with the split-in-.o case. > > > > > > Fair point - same sort of problem, but might need distinct handling (ie: > > might not work "for free" with existing tools, but need more support), etc, > > depending on how it's solved? > > > > Mostly just wondering whether Clang would need extra flags to support this > > - to get a sense of the total/overall solution/surface area of the feature, > > etc. > > > Shouldn't. We have licensees using distributed builds all day every day, but > we haven't introduced anything into the compiler itself to make that work. > On Windows, I know SN-DBS will intercept system calls to patch up filespecs. > On Linux I'd expect the remote servers to set up chroot environments so the > path names will Just Work, although I admit I've never actually looked. > Never had to; it Just Works. Neat! > In this patch, where the .o normally points to the .dwo it would instead just > point to itself, right? Right - that's an absolute path, like the line table (between dir+name, if you don't override the base dir to something else, etc). So, yeah, if the solutions for that are implemented at a sufficiently low level as you've described above, sounds like there's a good chance it'd Just Work for this part too. > The linker doesn't need to fix anything up, it just ignores the .dwo > sections. *nod* Not suggesting the linker could/would be able to fix anything up here - but that the compiler might need extra command line features to help ensure the values were written in a way that was useful. For example, I believe the Chromium build system may use -fdebug-compilation-dir and -fdebug-prefix-map to make cached distributed builds work (where it'd be impossible to bake in any particular path - because two users may be building Chromium from different locations, but they should be able to share build artefacts for maximal caching). But if that's not the usual problem/solution (or there are sufficiently many users/use cases that don't have that problem) - that's cool & it's nice if this just works for those users - and if, for whatever reason, that a Chromium-like situation comes up & wants non-split-split-DWARF & needs to address the problem, we can cross that bridge at that time (either by using the existing properties (like -fdebug-compilation-dir and -fdebug-prefix-map) if they provide enough information, or by adding other flags to that family to allow the user to do so) https://reviews.llvm.org/D52296 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
