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
