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Re: PING: PATCH: PR target/46770: Use .init_array/.fini_array sections
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Sun, 14 Aug 2011 09:20:20 -0700
- Subject: Re: PING: PATCH: PR target/46770: Use .init_array/.fini_array sections
- References: <AANLkTik8RB9N52grGxMbpj14jwzoLB0oRYdKnmAXyESu@mail.gmail.com> <AANLkTimtcwsV8Af7a60Jz57g-J38oR==+Ew7BqQvMbJm@mail.gmail.com> <BANLkTikBAnrYSRiRtaPXNat77sEgdSEK1Q@mail.gmail.com> <BANLkTi=M3HKXJa7t3ayavtWMgRPQ6t2row@mail.gmail.com> <BANLkTin34R=s+4zPf7oijd_xzd00xjOLCQ@mail.gmail.com> <BANLkTikfADfNqvuzcsru_RjE8jyiWjFvPw@mail.gmail.com> <BANLkTi=vTT_9j33U5FVNVasqkdt_=qCOyQ@mail.gmail.com> <BANLkTinfhzGcg6oBVeV_LXRQSN1gmtU70g@mail.gmail.com> <BANLkTint+SNsmQxOz-4xk0rrhRPc9L8J8g@mail.gmail.com> <CAMe9rOof=V4c89715u-Z=zG8kqADrupMaemnjuYPJA-xPQaKxg@mail.gmail.com> <20110722123042.GB2687@tyan-ft48-01.lab.bos.redhat.com> <CAMe9rOoqrt_a3ez2-oNa=5gfGQkON741hSrJBgs0xLym5c03KA@mail.gmail.com> <CAMe9rOqYSSvV7roUVgMdBf8oax0j=toMcGu=8eApvYEK4mnUug@mail.gmail.com> <CAMe9rOrpFYbJiNpt715qfgJO=__xxiPbjZ_E45DGB9tCefMdrQ@mail.gmail.com> <CAMe9rOo8r-Z=NrsnUky_Vte36fBDUF_tpKni4ph9wAC9a9RYjg@mail.gmail.com> <CAMe9rOryTBagJUGPDn_1zEAhn1+7CwA_Q7w=osPNyLb6NS5rdQ@mail.gmail.com>
PING
On Tue, Aug 9, 2011 at 6:56 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> 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.
>
--
H.J.