Created attachment 23756 [details] aranges.c As following testcases show, while PR48176 fixed some .debug_aranges related regressions, with the addition of .text.startup and .text.exit sections we still sometimes don't emit .debug_aranges covering all the code snippets for a particular CU.
Created attachment 23757 [details] aranges2.c Another testcase, this one needs profile feedback (i.e. run compile/link first with the options and -fprofile-generate, run, compile again with -fprofile-use). On this testcase we can see other bugs, e.g. DW_AT_ranges for f1 DW_TAG_subprogram is wrong, it covers twice the same range, once perhaps with a few extra bytes of padding before it, and then not at all the cold part.
Created attachment 23758 [details] gcc46-pr48253.patch Untested fix.
Author: jakub Date: Mon Mar 28 23:55:47 2011 New Revision: 171642 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=171642 Log: PR debug/48253 * dwarf2out.c (struct dw_fde_struct): Remove dw_fde_hot_section_label, dw_fde_hot_section_end_label, dw_fde_unlikely_section_label, dw_fde_unlikely_section_end_label, cold_in_std_section, dw_fde_switched_sections and dw_fde_switched_cold_to_hot fields. Add dw_fde_second_begin, dw_fde_second_end and second_in_std_section fields. (output_fde): Use dw_fde_second_{begin,end} if second is true, otherwise dw_fde_{begin,end}. (output_call_frame_info): Test dw_fde_second_begin != NULL instead of dw_fde_switched_sections. (dwarf2out_begin_prologue): Stop initializing removed dw_fde_struct fields, initialize new fields. Initialize in_std_section unconditionally from the first partition. (dwarf2out_end_epilogue): Don't override dw_fde_end when dw_fde_second_begin is non-NULL. (dwarf2out_switch_text_section): Stop initializing removed dw_fde_struct fields, initialize new fields, initialize also dw_fde_end here. Set dw_fde_switch_cfi even when dwarf2out_do_cfi_asm (). Call var_location_switch_text_section. (struct var_loc_list_def): Add last_before_switch field. (arange_table, arange_table_allocated, arange_table_in_use, ARANGE_TABLE_INCREMENT, add_arange): Removed. (size_of_aranges): Count !in_std_section and !second_in_std_section hunks in fdes, instead of looking at arange_table_in_use. (output_aranges): Add aranges_length argument, don't call size_of_aranges here. Instead of using aranges_table* emit ranges for fdes when !in_std_section resp. !second_in_std_section. (dw_loc_list): Break ranges crossing section switch. (convert_cfa_to_fb_loc_list): Likewise. If switched sections, use dw_fde_second_end instead of dw_fde_end as end of last range. (gen_subprogram_die): Don't call add_arange. Use dw_fde_{begin,end} for first partition and if switched section dw_fde_second_{begin,end} for the second. (var_location_switch_text_section_1, var_location_switch_text_section): New functions. (dwarf2out_begin_function): Initialize cold_text_section even when function_section () isn't text_section. (prune_unused_types): Don't walk arange_table. (dwarf2out_finish): Don't needlessly test flag_reorder_blocks_and_partition when testing cold_text_section_used. If info_section_emitted, call size_of_aranges and if it indicates non-empty .debug_aranges, call output_aranges with the computed size. Stop using removed dw_fde_struct fields, use dw_fde_{begin,end} for first partition and dw_fde_second_{begin,end} for second. Modified: trunk/gcc/ChangeLog trunk/gcc/dwarf2out.c
Fixed on the trunk so far.
Author: jakub Date: Tue Mar 29 22:47:59 2011 New Revision: 171702 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=171702 Log: PR debug/48253 * dwarf2out.c (struct dw_fde_struct): Remove dw_fde_hot_section_label, dw_fde_hot_section_end_label, dw_fde_unlikely_section_label, dw_fde_unlikely_section_end_label, cold_in_std_section, dw_fde_switched_sections and dw_fde_switched_cold_to_hot fields. Add dw_fde_second_begin, dw_fde_second_end and second_in_std_section fields. (output_fde): Use dw_fde_second_{begin,end} if second is true, otherwise dw_fde_{begin,end}. (output_call_frame_info): Test dw_fde_second_begin != NULL instead of dw_fde_switched_sections. (dwarf2out_begin_prologue): Stop initializing removed dw_fde_struct fields, initialize new fields. Initialize in_std_section unconditionally from the first partition. (dwarf2out_end_epilogue): Don't override dw_fde_end when dw_fde_second_begin is non-NULL. (dwarf2out_switch_text_section): Stop initializing removed dw_fde_struct fields, initialize new fields, initialize also dw_fde_end here. Set dw_fde_switch_cfi even when dwarf2out_do_cfi_asm (). Call var_location_switch_text_section. (struct var_loc_list_def): Add last_before_switch field. (arange_table, arange_table_allocated, arange_table_in_use, ARANGE_TABLE_INCREMENT, add_arange): Removed. (size_of_aranges): Count !in_std_section and !second_in_std_section hunks in fdes, instead of looking at arange_table_in_use. (output_aranges): Add aranges_length argument, don't call size_of_aranges here. Instead of using aranges_table* emit ranges for fdes when !in_std_section resp. !second_in_std_section. (dw_loc_list): Break ranges crossing section switch. (convert_cfa_to_fb_loc_list): Likewise. If switched sections, use dw_fde_second_end instead of dw_fde_end as end of last range. (gen_subprogram_die): Don't call add_arange. Use dw_fde_{begin,end} for first partition and if switched section dw_fde_second_{begin,end} for the second. (var_location_switch_text_section_1, var_location_switch_text_section): New functions. (dwarf2out_begin_function): Initialize cold_text_section even when function_section () isn't text_section. (prune_unused_types): Don't walk arange_table. (dwarf2out_finish): Don't needlessly test flag_reorder_blocks_and_partition when testing cold_text_section_used. If info_section_emitted, call size_of_aranges and if it indicates non-empty .debug_aranges, call output_aranges with the computed size. Stop using removed dw_fde_struct fields, use dw_fde_{begin,end} for first partition and dw_fde_second_{begin,end} for second. Modified: branches/gcc-4_6-branch/gcc/ChangeLog branches/gcc-4_6-branch/gcc/dwarf2out.c
Fixed.