On Tue, 2016-11-29 at 18:23 +0100, Bernd Schmidt wrote: > On 11/29/2016 06:20 PM, David Malcolm wrote: > > > > if that distinction makes sense. Clearly we already have a > > diagnostics > > subsystem on the host; what this patch is adding is the separate, > > rtl-s > > pecific diagnostic subsystem to cc1 on the host. > > So that still seems odd to me. Why not use the normal diagnostics > subsystem, and add whatever you need from it to errors.c for use from > the generator programs? What exactly makes it "rtl-specific"?
The main issue is that the normal diagnostics subsystem tracks locations using location_t (aka libcpp's source_location), rather than read-md.h's struct file_location, so we'd need to start using libcpp from the generator programs, porting the location tracking to using libcpp (e.g. creating linemaps for the files). There would also be various Makefile.in tweaking to build various files twice; hopefully that wouldn't lead to any unexpected issues. Quoting from: https://gcc.gnu.org/ml/gcc-patches/2016-10/msg00648.html > There seem to be two ways to do this: > > (A) build the "light" diagnostics system (errors.c) for the host as > well as build machine, and link it with the RTL reader there, so there > are two parallel diagnostics subsystems. > > (B) build the "real" diagnostics system (diagnostics*) for the > *build* machine as well as the host, and use it from the gen* tools, > eliminating the "light" system, and porting the gen* tools to use > libcpp for location tracking. > > Approach (A) seems to be simpler, which is what this part of the patch > does. > > I've experimented with approach (B). I think it's doable, but it's > much more invasive (perhaps needing a libdiagnostics.a and a > build/libdiagnostics.a in gcc/Makefile.in), so I hope this can be > followup work. > > I can split the relevant parts out into a separate patch, but I was > wondering if either of you had a strong opinion on (A) vs (B) before I > do so? This patch implements approach (A). Would you prefer that I went with approach (B), or is approach (A) acceptable? Thanks Dave
