Re: PING: PATCH: PR target/46770: Use .init_array/.fini_array sections

["H.J. Lu" <hjl dot tools at gmail dot com>]

PING.

On Sat, Aug 6, 2011 at 7:40 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> PING.
>
> On Fri, Jul 22, 2011 at 7:06 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Fri, Jul 22, 2011 at 7:00 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> On Fri, Jul 22, 2011 at 6:03 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>> On Fri, Jul 22, 2011 at 5:30 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>>>>> On Fri, Jul 22, 2011 at 04:59:28AM -0700, H.J. Lu wrote:
>>>>>> @@ -2660,6 +2664,7 @@ esac
>>>>>> ?case ${target} in
>>>>>> ?i[34567]86-*-linux* | x86_64-*-linux*)
>>>>>> ? ? ? tmake_file="${tmake_file} i386/t-pmm_malloc i386/t-i386"
>>>>>> + ? ? use_initfini_array=yes
>>>>>> ? ? ? ;;
>>>>>> ?i[34567]86-*-* | x86_64-*-*)
>>>>>> ? ? ? tmake_file="${tmake_file} i386/t-gmm_malloc i386/t-i386"
>>>>>
>>>>> What is i?86/x86_64 specific on it? ?Don't most other glibc targets
>>>>> want to use it too, perhaps with some arch specific tweaks?
>>>>
>>>> I do have a patch for all ELF targets:
>>>>
>>>> http://gcc.gnu.org/ml/gcc-patches/2011-06/msg01416.html
>>>>
>>>> It touches many targets. . ?But I only have one feedback from one
>>>> target maintainer. ?I don't know how long it will take to review it.
>>>>
>>>>
>>>>>> --- /dev/null
>>>>>> +++ b/gcc/config/initfini-array.c
>>>>>
>>>>> This is ugly. ?varasm.c already has lots of ELF specific code, simply
>>>>> put them there as well and only let configury set some macro which will
>>>>> allow targets to choose which of the implementations in the generic code
>>>>> they want to use (or if they want their own which e.g. calls the generic
>>>>> routine and does something additional to it etc.). ?The sections probably
>>>>> can be created only the first time you actually need them.
>>>>
>>>> I will do that.
>>>>
>>>>>> --- a/gcc/crtstuff.c
>>>>>> +++ b/gcc/crtstuff.c
>>>>>> @@ -189,6 +190,9 @@ typedef void (*func_ptr) (void);
>>>>>> ? ? refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
>>>>>> ? ? symbol in crtbegin.o, where they are defined. ?*/
>>>>>>
>>>>>> +/* No need for .ctors/.dtors section if linker can place them in
>>>>>> + ? .init_array/.fini_array section. ?*/
>>>>>> +#ifndef NO_CTORS_DTORS_SECTIONS
>>>>>> ?/* The -1 is a flag to __do_global_[cd]tors indicating that this table
>>>>>> ? ? does not start with a count of elements. ?*/
>>>>>> ?#ifdef CTOR_LIST_BEGIN
>>>>>> @@ -219,6 +223,7 @@ STATIC func_ptr __DTOR_LIST__[1]
>>>>>> ? ?__attribute__((section(".dtors"), aligned(sizeof(func_ptr))))
>>>>>> ? ?= { (func_ptr) (-1) };
>>>>>> ?#endif /* __DTOR_LIST__ alternatives */
>>>>>> +#endif /* NO_CTORS_DTORS_SECTIONS */
>>>>>>
>>>>>> ?#ifdef USE_EH_FRAME_REGISTRY
>>>>>> ?/* Stick a label at the beginning of the frame unwind info so we can register
>>>>>> @@ -489,6 +494,9 @@ __do_global_ctors_1(void)
>>>>>>
>>>>>> ?#elif defined(CRT_END) /* ! CRT_BEGIN */
>>>>>>
>>>>>> +/* No need for .ctors/.dtors section if linker can place them in
>>>>>> + ? .init_array/.fini_array section. ?*/
>>>>>> +#ifndef NO_CTORS_DTORS_SECTIONS
>>>>>> ?/* Put a word containing zero at the end of each of our two lists of function
>>>>>> ? ? addresses. ?Note that the words defined here go into the .ctors and .dtors
>>>>>> ? ? sections of the crtend.o file, and since that file is always linked in
>>>>>> @@ -534,6 +542,7 @@ STATIC func_ptr __DTOR_END__[1]
>>>>>> ? ?__attribute__((used, section(".dtors"), aligned(sizeof(func_ptr))))
>>>>>> ? ?= { (func_ptr) 0 };
>>>>>> ?#endif
>>>>>> +#endif /* NO_CTORS_DTORS_SECTIONS */
>>>>>>
>>>>>> ?#ifdef EH_FRAME_SECTION_NAME
>>>>>> ?/* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
>>>>>
>>>>> I don't see how you can do this. ?It would IMO break any time you link code
>>>>> built by different gcc versions where some code emitted by the older gcc
>>>>> used .ctors or .dtors.
>>>>
>>>> crtstuff.c is used to generate crt*.o, which is the part of GCC. ?You only use
>>>> it with the GCC you are using. ?Since your GCC doesn't put anything in
>>>> .ctors/.dtors section, you don't need them. ?As for .o files generated by
>>>> old GCCs, that is the linker test, use_initfini_array, is for. ?The newer linker
>>>> can put input .ctors/.dtors sections in output .init_array/,fini_array sections.
>>>>
>>>>
>>>
>>> Here is the updated patch. ?Any comments?
>>>
>>> Thanks.
>>>
>>> --
>>> H.J.
>>> ---
>>> 2011-07-22 ?H.J. Lu ?<hongjiu.lu@intel.com>
>>>
>>> ? ? ? ?PR target/46770
>>> ? ? ? ?* config.gcc (use_initfini_array): New variable.
>>> ? ? ? ?Use .init_arary/.fini_array if they are supported.
>>>
>>> ? ? ? ?* crtstuff.c: Don't generate .ctors nor .dtors sections if
>>> ? ? ? ?USE_INITFINI_ARRAY is defined.
>>>
>>> ? ? ? ?* output.h (default_initfini_array_init_sections): New.
>>> ? ? ? ?* varasm.c (elf_init_array_section): Likewise.
>>> ? ? ? ?(elf_fini_array_section): Likewise.
>>> ? ? ? ?(get_elf_initfini_array_priority_section): Likewise.
>>> ? ? ? ?(default_elf_init_array_asm_out_constructor): Likewise.
>>> ? ? ? ?(default_elf_fini_array_asm_out_destructor): Likewise.
>>> ? ? ? ?(default_initfini_array_init_sections): Likewise.
>>>
>>> ? ? ? ?* config/initfini-array.h: New.
>>> ? ? ? ?* config/t-initfini-array: Likewise.
>>>
>>
>> No need for config/t-initfini-array. ?Here is the updated patch.
>>
>>
>> --
>> H.J.
>> ----
>> 2011-07-22 ?H.J. Lu ?<hongjiu.lu@intel.com>
>>
>> ? ? ? ?PR target/46770
>> ? ? ? ?* config.gcc (use_initfini_array): New variable.
>> ? ? ? ?Use .init_arary/.fini_array if they are supported.
>>
>> ? ? ? ?* crtstuff.c: Don't generate .ctors nor .dtors sections if
>> ? ? ? ?USE_INITFINI_ARRAY is defined.
>>
>> ? ? ? ?* output.h (default_initfini_array_init_sections): New.
>> ? ? ? ?* varasm.c (elf_init_array_section): Likewise.
>> ? ? ? ?(elf_fini_array_section): Likewise.
>> ? ? ? ?(get_elf_initfini_array_priority_section): Likewise.
>> ? ? ? ?(default_elf_init_array_asm_out_constructor): Likewise.
>> ? ? ? ?(default_elf_fini_array_asm_out_destructor): Likewise.
>> ? ? ? ?(default_initfini_array_init_sections): Likewise.
>>
>> ? ? ? ?* config/initfini-array.h: New.
>>
>> ? ? ? ?* config/arm/arm.c (arm_asm_init_sections): Call
>> ? ? ? ?default_initfini_array_init_sections.
>> ? ? ? ?* config/avr/avr.c (avr_asm_init_sections): Likewise.
>> ? ? ? ?* config/ia64/ia64.c (ia64_asm_init_sections): Likewise.
>> ? ? ? ?* config/mep/mep.c (mep_asm_init_sections): Likewise.
>> ? ? ? ?* config/microblaze/microblaze.c (microblaze_elf_asm_init_sections):
>> ? ? ? ?Likewise.
>> ? ? ? ?* config/rs6000/rs6000.c (rs6000_elf_asm_init_sections): Likewise.
>> ? ? ? ?* config/stormy16/stormy16.c (xstormy16_asm_init_sections):
>> ? ? ? ?Likewise.
>> ? ? ? ?* config/v850/v850.c (v850_asm_init_sections): Likewise.
>>
>
>
>
> --
> H.J.
>



-- 
H.J.