These can be generated when multiple cfi directives are emitted for an
instruction and the insn frag is closed off between directives, as
happens when listings are enabled. No doubt the advance_loc of zero
could be avoided by backtracking over frags in dw2gencfi.c before
calling cfi_add_advance_loc, but that seems like more work than
cleaning up afterwards as this patch does.
Noticed when looking at the testcase in PR25125.
PR 25125
* dw2gencfi.c (output_cfi_insn): Don't output DW_CFA_advance_loc+0.
* ehopt.c (eh_frame_estimate_size_before_relax): Return -1 for
an advance_loc of zero.
(eh_frame_relax_frag): Translate fr_subtype of 7 to size -1.
(eh_frame_convert_frag): Handle fr_subtype of 7. Abort on
unexpected fr_subtype.
This file was never supposed to be widely used. The fact that it has
found its way into many gas files led to bugs, typically when code
expecting a symbolS* to point at a struct symbol is presented with a
struct local_symbol. Also, commit 158184ac9e changed these structs in
2012 but didn't catch all places where symbol bsym was being used to
test for a local_symbol.
* Makefile.am (HFILES): Delete struc-symbol.h.
* doc/internals.texi: Delete struc-symbol.h reference and out
of date local symbol description.
* struc-symbol.h: Delete. Move contents to..
* symbols.c: ..here.
(symbol_on_chain, symbol_symbolS): New functions.
* symbols.h (symbol_on_chain, symbol_symbolS): Declare.
* cgen.c: Don't #include struc-symbol.h.
(gas_cgen_parse_operand): Don't test for local_symbol using
bsym, instead call symbol_symbolS. Use symbol_get_bfdsym.
(weak_operand_overflow_check, make_right_shifted_expr): Use
symbol accessors.
* config/obj-coff.c: Don't #include struc-symbol.h.
(GET_FILENAME_STRING): Delete.
* config/obj-elf.c: Don't #include struc-symbol.h.
(elf_file_symbol): Use symbol accessors.
(elf_adjust_symtab): Call symbol_on_chain.
* config/obj-evax.c: Don't #include struc-symbol.h.
* config/tc-nds32.c: Likewise.
* config/tc-rl78.c: Likewise.
* config/tc-rx.c: Likewise.
* config/tc-alpha.c: Likewise.
(add_to_link_pool, s_alpha_comm): Use symbol accessors.
* config/tc-arc.c: Don't #include struc-symbol.h.
(arc_check_relocs): Use symbol accessors, testing gas symbol
section rather than bfd symbol section.
* config/tc-avr.c: Don't #include struc-symbol.h.
(avr_patch_gccisr_frag): Use symbol accessors.
* config/tc-bfin.c: Don't #include struc-symbol.h.
(bfin_loop_beginend): Use symbol accessors.
* config/tc-csky.c: Don't #include struc-symbol.h.
(v2_work_movih, v2_work_ori): Use symbol accessors. Check for
absolute symbol as well as O_constant.
* config/tc-riscv.c: Don't #include struc-symbol.h.
(riscv_pre_output_hook): Use symbol accessors.
* config/tc-s390.c: Don't #include struc-symbol.h.
(s390_literals): Use symbol accessors.
* config/tc-score.c (s3_build_la_pic, s3_build_lwst_pic): Use
symbol accessors.
(s3_relax_branch_inst16, s3_relax_cmpbranch_inst32): Don't
test symbol bsym.
* config/tc-score7.c: Don't #include struc-symbol.h.
(s7_build_la_pic, s7_build_lwst_pic): Use symbol accessors.
(s7_b32_relax_to_b16): Don't test symbol bsym.
* config/tc-sh.c: Don't #include struc-symbol.h.
(insert_loop_bounds): Use symbol accessors.
(sh_frob_section): Remove bogus symbol canonicalization.
* config/tc-tic54x.c: Don't #include struc-symbol.h.
(tic54x_bss): Use symbol accessors.
* config/tc-tilegx.c: Don't #include struc-symbol.h.
(emit_tilegx_instruction, tilegx_parse_name): Use symbol accessors.
* config/tc-tilepro.c: Don't #include struc-symbol.h.
(emit_tilepro_instruction, tilepro_parse_name): Use accessors.
* config/tc-xtensa.c: Don't #include struc-symbol.h.
(xg_assemble_vliw_tokens): Use symbol accessors.
(xg_order_trampoline_chain): Likewise.
* ehopt.c: Don't #include struc-symbol.h.
(check_eh_frame): Correct local symbol test. Use symbol accessors.
* write.c: Don't #include struc-symbol.h.
(create_note_reloc, maybe_generate_build_notes): Use symbol accessors.
* Makefile.in: Regenerate.
* po/POTFILES.in: Regenerate.
(dwcfi_hash): New static hash variable.
(get_debugseg_name): New.
(alloc_debugseg_item): New.
(make_debug_seg): New.
(dwcfi_hash_insert): New.
(dwcfi_hash_find): New.
(dwcfi_hash_find_or_make): New.
(cfi_insn_data): New member cur_seg.
(cie_entry): Likewise.
(fde_entry): New cseg and handled members.
(alloc_fde_entry): Initialize cseg member.
(alloc_cfi_insn_data): Initialize cur_seg member.
(dot_cfi_sections): Compare for beginning of
section names via strncmp.
(get_cfi_seg): New.
(cfi_finish): Treat link-once sections.
(is_now_linkonce_segment): New local helper.
(output_cie): Ignore cie entries not member of current
segment.
(output_fde): Likewise.
(select_cie_for_fde): Likewise.
(cfi_change_reg_numbers): Add new argument for current segment
and ignore insn elements, if not part of current segment.
* ehopt.c (get_cie_info): Use strncmp for
section name matching.
(heck_eh_frame): Likewise.
* coffcode.h (sec_to_styp_flags): Allow linkonce for
debugging sections.
* scripttempl/pe.sc: Handle .eh_frame($|.)* sections.
* scripttempl/pep.sc: Likewise.
* ld-pe/pe.exp: Add cfi/cfi32 tests.
* ld-pe/cfi.d: New.
* ld-pe/cfi32.d: New.
* ld-pe/cfia.s: New.
* ld-pe/cfib.s: New.
* Makefile.in: Regenerated.
* ehopt.c: Include struc-symbol.h.
(check_eh_frame): For very small O_constant DW_CFA_advance_loc4
create correct DW_CFA_advance_loc. Handle O_subtract only
for code alignment factor 1, otherwise handle O_divide or
O_right_shift of O_subtract and O_constant.
(eh_frame_estimate_size_before_relax): Always divide by ca.
(eh_frame_convert_frag): Likewise.
* dw2gencfi.c (output_cfi_insn): Scale DW_CFA_advance_loc1,
DW_CFA_advance_loc2 and DW_CFA_advance_loc4 outputs.
* config/tc-mn10300.h (md_allow_eh_opt): Define. Only allow call frame optimization if linker relaxation is not enabled.
* gas/elf/elf.exp: Disable ehopt test for mn10300.
also collect whether to expect an FDE augmentation.
(check_eh_frame): Rewrite as a state machine. Track where in
an FDE we are located, skip any augmentation.
(eh_frame_estimate_size_before_relax): Get code alignment from
the fragment subtype.
(eh_frame_relax_frag, eh_frame_convert_frag): Likewise.
* read.c (emit_leb128_expr): Call check_eh_frame.
