Re: [patch,avr]: Part2: Fix various problems with specs and specs file generation.

[Denis Chertykov <chertykov@gmail.com>]

2015-03-09 19:02 GMT+03:00 Georg-Johann Lay <avr@gjlay.de>:
> Am 03/03/2015 um 02:21 PM schrieb Senthil Kumar Selvaraj:
>>
>> On Mon, Mar 02, 2015 at 08:40:17PM +0100, Georg-Johann Lay wrote:
>>>
>>> The new specs file generation introduces several problems.  This patch
>>>
>>> - Fix build warnings
>>>
>>> - Clean up unused code and the old, now dead specs definitions.
>>>
>>> - Removes unused files and adjust build scripts / rules.
>>>
>>> - Issues with avr-libc awareness:
>>>
>>> -- Makes specs-generation aware of avr-libc (include tm.h in build script
>>> and depend on WITH_AVRLIBC).
>>>
>>> -- avr-libc implements functions in libm.a which usually live in libgcc,
>>> hence add -lm to libgcc_spec, cf. PR54461.
>>>
>>> -- The new libdev.a is a feature of avr-libc and not available with,
>>> e.g.,
>>> newlib.  Hence remove it from lib_spec if the compiler is not configured
>>> for
>>> avr-libc (--with-avrlibc=no).
>>>
>>> - Many minor issues with option propagation.
>>>
>>> - -march had been added to multilib generation some time ago, but
>>> driver_self_spec was not aware of that option.
>>>
>>>
>>> Ok for trunk?
>>>
>>>
>>> BTW, anyone knows what -march= is good for?  It allows all kinds of silly
>>> option combinations like "-march=avrtiny -mmcu=atmega8" without any
>>> complaints.
>>
>>
>> IIRC, -march was added because replacing -mmcu=<device> to
>> -mmcu=<arch> in the driver's self specs broke multilib selection - the
>> driver always acted as if no -mmcu was specified. Adding
>
>
> For me both multilib selection and multilib generation are working as
> expected with -mmcu= and without that -march=.
>
> Attached is a 2nd part of improvements for the specs file generation:
>
> - Remove -arch= and use -mmcu= again.
>
> - Wrap specs file selection into a new specs function so that a
> comprehensible error message can be issued if no specs file is found.  It
> also informs about a link to spec file documentation of gcc inline docs.
>
> - Remove genopt.sh and avr-tables.opt.  These files are no more used because
> -mmcu= is a vanilla string option now.  Using Enum option for -mmcu= does
> not allow to specify unknown devices, and target_handle_option cannot
> letgigimize unknown strings of Enum options.
>
> - Resurrect driver-avr.c but with new content: The new specs function.
>
> - New file specs.h with specs known to gcc and which can be overridden by
> avrlibc.h, rtems.h, etc.
>
> - New device-specs files mostly repeat spec definitions, e.g.
>
>     fprintf (f, "*startfile:\n\t%s\n\n", STARTFILE_SPEC);
>     fprintf (f, "*endfile:\n\t%s\n\n", ENDFILE_SPEC);
>
> - Device feature are expressed as subspecs now, e.g. avrlibc_startfile spec.
>
> - Clean up code from "current device" stuff, adjust diagnostics, avr-arch.h,
> etc.
>
> - Use INSTALL_DATA to install spec files, not INSTALL_PROGRAM.
>
>
>
> Ok to install this, too?
>
>
> Johann
>
>         PR target/65296
>         * config.gcc (extra_options) [avr]: Remove.
>         (extra_gcc_objs) [avr]: Use driver-avr.o, avr-devices.o.
>         (tm_file) [avr]: Add avr/specs.h after avr/avr.h.
>         (tm_defines) [avr, rtems]: Add WITH_RTEMS.
>
>         * config/avr/genmultilib.awk: Use -mmcu= instead of -march=.
>         * config/avr/t-multilib: Regenerate.
>         * config/avr/specs.h: New file.
>         * config/avr/driver-avr.c: New file.
>         * config/avr/genopt.sh: Remove file.
>         * config/avr/avr-tables.opt: Remove file.
>         * config/avr/predicates.md (avr_current_arch): Rename to avr_arch.
>         * config/avr/avr-c.c: Same.
>         * avr-arch.h: Same.
>         (avr_current_device): Remove proto.
>         * config/avr/avr.c (avr_current_arch): Rename to avr_arch.
>         (avr_current_device): Remove definition and usage.
>         (avr_set_core_architecture): New static function.
>         (avr_option_override): Use it.
>         * config/avr/avr.h (avr_current_arch): Rename to avr_arch.
>         (AVR_HAVE_8BIT_SP): Don't depend on avr_current_device.
>         (EXTRA_SPEC_FUNCTIONS): Define.
>         (avr_devicespecs_file): New specs function proto.
>         (DRIVER_SELF_SPECS): Use device-specs-file spec function.
>         * config/avr/avr-devices.c (diagnostic.h, avr-arch.h): Include them.
>         (mcu_name): New static array.
>         (comparator, avr_archs_str, avr_mcus_str): New static functions.
>         (avr_inform_devices, avr_inform_core_architectures): New functions.
>         * config/avr/gen-avr-mmcu-specs.c (avr-arch.h, specs.h): Include.
>         (avrlibc.h) [WITH_AVRLIBC]: Include.
>         (../rtems.h, rtems.h) [WITH_RTEMS]: Include.
>         (print_mcu): Rewrite from scratch.
>         * config/avr/avrlibc.h (LIB_SPEC, LIBGCC_SPEC, STARTFILE_SPEC):
>         Forward to avr-specific specs defined in device-specs file.
>         * config/avr/avr.opt (config/avr/avr-arch.h): Remove include.
>         (-mmcu=): Add Var and MissingArgError properties.
>         (-march=): Remove.
>         * config/avr/t-avr (driver-avr.o): New rule.
>         (avr-devices.o): Depend on avr-arch.h.
>         (avr-mcus): No more depend on avr-tables.opt.
>         (avr-tables.opt): Remove rule.
>         (install-device-specs): Use INSTALL_DATA, not INSTALL_PROGRAM.
>

Please, apply.

Denis.