On Thu, Dec 3, 2020 at 2:56 PM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > On Tue, Nov 3, 2020 at 4:17 PM Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote: > > > > On Tue, Nov 03, 2020 at 04:05:36PM -0800, Nick Desaulniers wrote: > > > On Tue, Nov 3, 2020 at 4:00 PM Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote: > > > > > > > > On Wed, Oct 21, 2020 at 06:21:06PM -0700, Nick Desaulniers wrote: > > > > > Further -gdwarf-X where X is an unsupported value doesn't > > > > > produce an error in $(CC). > > > > > > > > Do you have more details here? On godbolt.org, gcc does report an error > > > > for unsupported dwarf versions. > > > > > > > > https://godbolt.org/z/G35798 > > > > > > > > gcc does not seem to pass the -gdwarf-* options to the assembler when > > > > compiling C source. For assembler, gcc will pass an appropriate option > > > > depending on the version of binutils it was configured with: if the > > > > assembler doesn't support dwarf-5 it can call it with --gdwarf2 for eg. > > > > > > > > If the user is using a properly configured toolchain it doesn't look > > > > like it should be an issue to just use cc-option? > > > > > > I wrote the base patch back in May, and didn't revisit until recently. > > > I could have sworn the cc-option silently failed for the check > > > cc-option does, which is /dev/null input. I need to recheck that, but > > > it doesn't hurt to simply include it for now, which I've done in a v2 > > > I'm about to send. > > > -- > > > Thanks, > > > ~Nick Desaulniers > > > > This is giving me deja vu about the -gz=zlib option. > > > > Didn't Masahiro fix the cc-option issue with > > 4d0831e8a029 ("kconfig: unify cc-option and as-option") > > > > The existing -Wa,-gdwarf-2 in the Makefile seems bogus, btw. GCC 4.9.0 > > at least appears to pass on --gdwarf2 automatically. > > It looks like we don't need -Wa,-gdwarf-2 when -gdwarf-2 is set. So I > can probably drop > +DEBUG_CFLAGS += $(dwarf-aflag) > from v2. Will retest though. That's needed for non LLVM_IAS=1 builds so that clang informs GAS to assembler using DWARF Version 5; otherwise every translation unit fails to assemble with an error from GAS. -- Thanks, ~Nick Desaulniers
