On 11/09/2017 07:34 PM, Alexandre Oliva wrote: > This patch introduces an option to enable the generation of location > views along with location lists. The exact format depends on the > DWARF version: it can be a separate attribute (DW_AT_GNU_locviews) or > (DW_LLE_view_pair) entries in DWARF5+ loclists. > > Line number tables are also affected. If the assembler is found, at > compiler build time, to support .loc views, we use them and > assembler-computed view labels, otherwise we output compiler-generated > line number programs with conservatively-computed view labels. In > either case, we output view information next to line number changes > when verbose assembly output is requested. > > This patch requires an LVU patch that modifies the exported API of > final_scan_insn. It also expects the entire SFN patchset to be > installed first, although SFN is not a requirement for LVU. > > for include/ChangeLog > > * dwarf2.def (DW_AT_GNU_locviews): New. > * dwarf2.h (enum dwarf_location_list_entry_type): Add > DW_LLE_GNU_view_pair. > (DW_LLE_view_pair): Define. > > for gcc/ChangeLog > > * common.opt (gvariable-location-views): New. > * config.in: Rebuilt. > * configure: Rebuilt. > * configure.ac: Test assembler for view support. > * dwarf2asm.c (dw2_asm_output_symname_uleb128): New. > * dwarf2asm.h (dw2_asm_output_symname_uleb128): Declare. > * dwarf2out.c (var_loc_view): New typedef. > (struct dw_loc_list_struct): Add vl_symbol, vbegin, vend. > (dwarf2out_locviews_in_attribute): New. > (dwarf2out_locviews_in_loclist): New. > (dw_val_equal_p): Compare val_view_list of dw_val_class_view_lists. > (enum dw_line_info_opcode): Add LI_adv_address. > (struct dw_line_info_table): Add view. > (RESET_NEXT_VIEW, RESETTING_VIEW_P): New macros. > (DWARF2_ASM_VIEW_DEBUG_INFO): Define default. > (zero_view_p): New variable. > (ZERO_VIEW_P): New macro. > (output_asm_line_debug_info): New. > (struct var_loc_node): Add view. > (add_AT_view_list, AT_loc_list): New. > (add_var_loc_to_decl): Add view param. Test it against last. > (new_loc_list): Add view params. Record them. > (AT_loc_list_ptr): Handle loc and view lists. > (view_list_to_loc_list_val_node): New. > (print_dw_val): Handle dw_val_class_view_list. > (size_of_die): Likewise. > (value_format): Likewise. > (loc_list_has_views): New. > (gen_llsym): Set vl_symbol too. > (maybe_gen_llsym, skip_loc_list_entry): New. > (dwarf2out_maybe_output_loclist_view_pair): New. > (output_loc_list): Output view list or entries too. > (output_view_list_offset): New. > (output_die): Handle dw_val_class_view_list. > (output_dwarf_version): New. > (output_compilation_unit_header): Use it. > (output_skeleton_debug_sections): Likewise. > (output_rnglists, output_line_info): Likewise. > (output_pubnames, output_aranges): Update version comments. > (output_one_line_info_table): Output view numbers in asm comments. > (dw_loc_list): Determine current endview, pass it to new_loc_list. > Call maybe_gen_llsym. > (loc_list_from_tree_1): Adjust. > (add_AT_location_description): Create view list attribute if > needed, check it's absent otherwise. > (convert_cfa_to_fb_loc_list): Adjust. > (maybe_emit_file): Call output_asm_line_debug_info for test. > (dwarf2out_var_location): Reset views as needed. Precompute > add_var_loc_to_decl args. Call get_attr_min_length only if we have the > attribute. Set view. > (new_line_info_table): Reset next view. > (set_cur_line_info_table): Call output_asm_line_debug_info for test. > (dwarf2out_source_line): Likewise. Output view resets and labels to > the assembler, or select appropriate line info opcodes. > (prune_unused_types_walk_attribs): Handle dw_val_class_view_list. > (optimize_string_length): Catch it. Adjust. > (resolve_addr): Copy vl_symbol along with ll_symbol. Handle > dw_val_class_view_list, and remove it if no longer needed. > (hash_loc_list): Hash view numbers. > (loc_list_hasher::equal): Compare them. > (optimize_location_lists): Check whether a view list symbol is > needed, and whether the locview attribute is present, and > whether they match. Remove the locview attribute if no longer > needed. > (index_location_lists): Call skip_loc_list_entry for test. > (dwarf2out_finish): Call output_asm_line_debug_info for test. > Use output_dwarf_version. > * dwarf2out.h (enum dw_val_class): Add dw_val_class_view_list. > (struct dw_val_node): Add val_view_list. > * final.c: Include langhooks.h. > (SEEN_NEXT_VIEW): New. > (set_next_view_needed): New. > (clear_next_view_needed): New. > (maybe_output_next_view): New. > (final_start_function): Rename to... > (final_start_function_1): ... this. Take pointer to FIRST, > add SEEN parameter. Emit param bindings in the initial view. > (final_start_function): Reintroduce SEEN-less interface. > (final): Rename to... > (final_1): ... this. Take SEEN parameter. Output final pending > next view at the end. > (final): Reintroduce seen-less interface. > (final_scan_insn): Output pending next view before switching > sections or ending a block. Mark the next view as needed when > outputting variable locations. Notify debug backend of section > changes, and of location view changes. > (rest_of_handle_final): Adjust. > * opts.c (common_handle_option): Accept -gdwarf version 6. > * toplev.c (process_options): Autodetect value for debug variable > location views option. > * doc/invoke.texi (gvariable-location-views): New. > (gno-variable-location-views): New. > --- > diff --git a/gcc/dwarf2asm.c b/gcc/dwarf2asm.c > index 8e3e86f224c1..f19e6d65020e 100644 > --- a/gcc/dwarf2asm.c > +++ b/gcc/dwarf2asm.c > @@ -768,6 +768,31 @@ dw2_asm_output_data_sleb128 (HOST_WIDE_INT value, > } > > void > +dw2_asm_output_symname_uleb128 (const char *lab1 ATTRIBUTE_UNUSED, > + const char *comment, ...) Needs a function comment. Yes I realize others are missing in that file. But I think it's best to avoid making the problem worse.
The stuff outside dwarf2*.c is OK. We really need Jason or Jakub to comment on the meat of the dwarf2 bits. Jeff
