On Wed, Nov 4, 2020 at 10:58 PM Nathan Chancellor <natechancellor@xxxxxxxxx> wrote: > > On Tue, Nov 03, 2020 at 04:53:41PM -0800, Nick Desaulniers wrote: > > Clang's integrated assembler produces the warning for assembly files: > > > > warning: DWARF2 only supports one section per compilation unit > > > > If -Wa,-gdwarf-* is unspecified, then debug info is not emitted. This > > Is this something that should be called out somewhere? If I understand > this correctly, LLVM_IAS=1 + CONFIG_DEBUG_INFO=y won't work? Maybe this > should be handled in Kconfig? Specifically, debug info will not be emitted, for assembler source files. It will still be emitted for C source files (via -gdwarf-*). -Wa,-gdwarf-* only affects assembler file sources. > > > will be re-enabled for new DWARF versions in a follow up patch. > > > > Enables defconfig+CONFIG_DEBUG_INFO to build cleanly with > > LLVM=1 LLVM_IAS=1 for x86_64 and arm64. > > > > Cc: <stable@xxxxxxxxxxxxxxx> > > Link: https://github.com/ClangBuiltLinux/linux/issues/716 > > Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > > Suggested-by: Dmitry Golovin <dima@xxxxxxxxxx> > > If you happen to respin, Dmitry deserves a Reported-by tag too :) Sure. > > > Suggested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> > > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Regardless of the other two comments, this is fine as is as a fix for > stable to unblock Android + CrOS since we have been running something > similar to it in CI: > > Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > > > --- > > Makefile | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/Makefile b/Makefile > > index f353886dbf44..75b1a3dcbf30 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -826,7 +826,9 @@ else > > DEBUG_CFLAGS += -g > > endif > > > > +ifndef LLVM_IAS > > Nit: this should probably match the existing LLVM_IAS check Sure, will send a v3. Going to just send this for now, as it's blocking some downstream work I'm trying to get done in Android. > > ifneq ($(LLVM_IAS),1) > > > KBUILD_AFLAGS += -Wa,-gdwarf-2 > > +endif > > > > ifdef CONFIG_DEBUG_INFO_DWARF4 > > DEBUG_CFLAGS += -gdwarf-4 > > -- > > 2.29.1.341.ge80a0c044ae-goog > > -- Thanks, ~Nick Desaulniers
