On Tue, Dec 01, 2020 at 12:38:16PM +0900, Masahiro Yamada wrote: > > We can bump -Wa,-gdwarf-2 to -Wa,-gdwarf-3 since GNU actually emits > > DWARF v3 DW_AT_ranges (see > > https://sourceware.org/bugzilla/show_bug.cgi?id=26850 ) > > This can avoid the `warning: DWARF2 only supports one section per > > compilation unit` warning for Clang. That warning should be "there can be only one section with executable code per translation unit", or similar. > I am not a DWARF spec expert. Neither am I. > Please teach me. > > In my understanding, "DWARF2 only supports one section ..." > is warned only when building .S files with LLVM_IAS=1 .S files are simply run through the C preprocessor first, and then given to the assembler. The only difference there should be wrt debug info is you could have some macros that expand to assembler debug statements. > If this is due to the limitation of DWARF v2, why is it OK to > build .c files with LLVM_IAS? The compiler can of course make sure not to use certain constructs in its generated assembler code, while the assembler will have to swallow whatever the user wrote. Segher
