https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98708
--- Comment #11 from Mark Wielaard <mark at gcc dot gnu.org> ---
Aha, now I see in libstdc++-v3/src/c++11/Makefile.am:
if ENABLE_DUAL_ABI
# Rewrite the type info for __ios_failure.
rewrite_ios_failure_typeinfo = sed -e
'/^_*_ZTISt13__ios_failure:/,/_ZTVN10__cxxabiv120__si_class_type_infoE/s/_ZTVN10__cxxabiv120__si_class_type_infoE/_ZTVSt19__iosfail_type_info/'
cxx11-ios_failure-lt.s: cxx11-ios_failure.cc
$(LTCXXCOMPILE) -S $< -o tmp-cxx11-ios_failure-lt.s
-test -f tmp-cxx11-ios_failure-lt.o && mv -f tmp-cxx11-ios_failure-lt.o
tmp-cxx11-ios_failure-lt.s
$(rewrite_ios_failure_typeinfo) tmp-$@ > $@
-rm -f tmp-$@
cxx11-ios_failure.s: cxx11-ios_failure.cc
$(CXXCOMPILE) -S $< -o tmp-$@
$(rewrite_ios_failure_typeinfo) tmp-$@ > $@
-rm -f tmp-$@
cxx11-ios_failure.lo: cxx11-ios_failure-lt.s
$(LTCXXCOMPILE) -g0 -c $< -o $@
cxx11-ios_failure.o: cxx11-ios_failure.s
$(CXXCOMPILE) -g0 -c $<
endif
Then my workaround of checking for debug_info_level > DINFO_LEVEL_NONE indeed
wouldn't work. It is explicitly generating debuginfo for the assembly file and
then adding -g0 when turning the assembly file into an object file. So that is
too late.
I don't think adding -gno-as-loc-support to the -S invocation will work because
of the definition of asm_outputs_debug_line_str () which is true if
dwarf_version >= 5 && ! output_asm_line_debug_info () &&
DWARF5_USE_DEBUG_LINE_STR. So then it will still generate the .file 0
directive.
Ideally gas wouldn't error on .file 0, but simply ignore it when not generating
DWARF5.
Maybe the simplest workaround for now would be also adding -g0 to the -S
invocations?
