[Patch, AVR]: AVR backend cleanup: use elfos.h

Denis Chertykov chertykov@gmail.com
Mon Jun 27 18:03:00 GMT 2011


2011/6/27 Georg-Johann Lay <avr@gjlay.de>:
> Denis Chertykov wrote:
>> 2011/6/27 Georg-Johann Lay <avr@gjlay.de>:
>>> This patch removes ELF dependencies from avr.h and redundancies from
>>> avr.h and avr.c
>>>
>>> The AVR BE defines many things that are readily available in elfos.h.
>>> ELF is the only target supported by avr-gcc.
>>>
>>> The patch includes elfos.h in config.gcc for all avr* targets together
>>> with a new file avr/elf.h.
>>>
>>> ELF for avr deviates in some points from elfos.h. The needed overrides
>>> are defined in avr/elf.h.  avr/elf.h is included after elfos.h because
>>> that is the only way to achieve the needed overrides/undefs.
>>>
>>> The patch removes some hundreds lines from the AVR BE which are
>>> redundant, and the new avr/elf.h makes it much clearer what the actual
>>> deviations to default ELF implementation are.
>>>
>>> Some overrides like that there is no .ident emitted by avr presumably
>>> have just historical reasons; anyway the patch tries to be neutral
>>> compared to the present implementation.
>>>
>>> Same applies for other defines like READONLY_DATA_SECTION_ASM_OP:
>>> .rodata is mapped to .data by avr ldscripts anyway, so there is
>>> actually no need to set readonly_data_section = data_section and
>>> merging of STRING_CST could save some space.
>>>
>>> For zeroes memory the patch will emit
>>>   .zero N
>>> instead of
>>>   .skip N,0
>>>
>>> Tested without regressions and asm-output diffed for real-world avr-code.
>>>
>>> Johann
>>>        * config.gcc (tm_file): Add elfos.h and avr/elf.h for
>>>        avr-*-* and avr-*-rtems* targets.
>>>
>>>        * config/avr/elf.h: New file.
>>>        (ASM_OUTPUT_BEFORE_CASE_LABEL): Define.
>>>        (TARGET_ASM_SELECT_SECTION): Define.
>>>        (INIT_SECTION_ASM_OP): Undefine.
>>>        (FINI_SECTION_ASM_OP): Undefine.
>>>        (IDENT_ASM_OP): Undefine.
>>>        (ASM_OUTPUT_IDENT): Undefine.
>>>        (READONLY_DATA_SECTION_ASM_OP): Undefine.
>>>        (PCC_BITFIELD_TYPE_MATTERS): Undefine.
>>>        (TARGET_HAVE_SWITCHABLE_BSS_SECTIONS): Undefine.
>>>        * config/avr/avr.h:
>>>        (PREFERRED_DEBUGGING_TYPE): Move to elf.h.
>>>        (TARGET_ASM_NAMED_SECTION): Move to elf.h.
>>>        (MAX_OFILE_ALIGNMENT): Move to elf.h.
>>>        (STRING_LIMIT): Move to elf.h.
>>>        (ASM_DECLARE_FUNCTION_NAME): Move to elf.h.
>>>        (ASM_DECLARE_OBJECT_NAME): Remove.
>>>        (ESCAPES): Remove.
>>>        (ASM_OUTPUT_SKIP): Remove.
>>>        (DWARF2_DEBUGGING_INFO): Remove.
>>>        (OBJECT_FORMAT_ELF): Remove.
>>>        (USER_LABEL_PREFIX): Remove.
>>>        (ASM_OUTPUT_EXTERNAL): Remove.
>>>        (ASM_OUTPUT_ASCII): Remove.
>>>        (TYPE_ASM_OP): Remove.
>>>        (SIZE_ASM_OP): Remove.
>>>        (WEAK_ASM_OP): Remove.
>>>        (STRING_ASM_OP): Remove.
>>>        (SET_ASM_OP): Remove.
>>>        (ASM_WEAKEN_LABEL): Remove.
>>>        (TYPE_OPERAND_FMT): Remove.
>>>        (ASM_DECLARE_FUNCTION_SIZE): Remove.
>>>        (ASM_FINISH_DECLARE_OBJECT): Remove.
>>>        (NO_DOLLAR_IN_LABEL): Remove.
>>>        (ASM_GENERATE_INTERNAL_LABEL): Remove.
>>>        (ASM_OUTPUT_CASE_LABEL): Remove.
>>>        * config/avr/avr.c (avr_asm_output_aligned_decl_common): Use
>>>        ASM_OUTPUT_ALIGNED_LOCAL, ASM_OUTPUT_ALIGNED_COMMON.
>>>        (gas_output_ascii): Remove.
>>>        (gas_output_limited_string): Remove.
>>>        (TARGET_ASM_FILE_START_FILE_DIRECTIVE): Remove.
>>>        * config/avr/avr-protos.h
>>>        (gas_output_ascii): Remove prototye.
>>>        (gas_output_limited_string): Remove prototype.
>>>
>>
>> Approved.
>>
>> Denis.
>
> http://gcc.gnu.org/ml/gcc-patches/2011-06/msg02011.html
>
> Is that also for the config.gcc part?
> Or does it need review from global reviewer?
>
> Is there a specific reason not to emit .ident?
> If not, I would remove the #undefs of IDENT_ASM_OP and
> ASM_OUTPUT_IDENT from avr/elf.h.

Sorry, I forgot.

Denis.



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