On Fri, Sep 30, 2022 at 6:06 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Tue, Aug 23, 2022 at 7:42 AM Dmitrii Bundin > <dmitrii.bundin.a@xxxxxxxxx> wrote: > > > > On Tue, Aug 23, 2022 at 12:36 AM Nick Desaulniers > > <ndesaulniers@xxxxxxxxxx> wrote: > > > > > > or perhaps that simply needs to be `-g -gsplit-dwarf`? In which case, > > > that if/else could just be re-arranged. > > > > How about simply assigning DEBUG_CFLAGS := -g at the very beginning > > without any conditions? This would provide the default with the > > possibility of overriding later and -gsplit-dwarf does not necessarily > > come with -g implicitly. > > This was fixed by commit 32ef9e5054ec0321b9336058c58ec749e9c6b0fe, > which is now in the mainline. > > > > > > > Honestly, I really don't think we need to be wrapping every compiler > > > command line flag under the sun in a kconfig option. > > > > This indeed sounds reasonable to me. So the key point here is to not > > bloat the kconfig with options related to every compiler flag. But I > > think it still might be useful to provide some option that would > > include sort of full debug information compilers may produce. With > > this approach there would be, in fact 3 different levels of debug > > information supported by Kconfig: reduced, default and full. The full > > level would increase everything like -g3, and -fdebug-macro for Clang, > > and probably others. > > > I think that would be much saner than this patch. > > > > CONFIG_DEBUG_INFO_LEVEL is a direct way to specify the debug level. > > CONFIG_DEBUG_MACRO_DEFINITIONS is feature-driven. > > Do not mix two different ways. > > > > > > > CONFIG_DEBUG_INFO_LEVEL is here just because Andrew Morton suggested that. > > > The debug level is compiler-specific. There is no guarantee > that there is a common range. > > > The debug level range of GCC is 0-3. > Clang accepts 3, but -g3 has no effect. > The debug level range of Rustc is 0-2. > > See how badly scripts/Makefile.debug looks in linux-next. > > > > > > How should Rustc behave for CONFIG_DEBUG_INFO_LEVEL=3 ? > > -Cdebuginfo=3 is a compile error. > > RUSTC L rust/core.o > error: debug info level needs to be between 0-2 (instead was `3`) > > > > You cannot directly specify the debug level number given that > we support multiple compilers with different policy for > debug level options. > > > > > > > > > Or add -g1 to CONFIG_DEBUG_INFO_REDUCED. > > > > I ran some tests and there was indeed some decrease in size. That > > combination probably might be useful. > > > > Any thoughts? > > > > Regards > > Dmitrii > > > > > > -- > Best Regards > Masahiro Yamada I proposed to do a ground-work like the following first. https://patchwork.kernel.org/project/linux-kbuild/patch/20220930085351.2648034-1-masahiroy@xxxxxxxxxx/ On top of that, it is easier to add CONFIG_DEBUG_INFO_FULL or whatever. And, -g1 for CONFIG_DEBUG_INFO_REDUCED if you think it is worthwhile. -- Best Regards Masahiro Yamada