> On 26 May 2026, at 22:35, H.J. Lu <[email protected]> wrote:
>
> On Tue, May 26, 2026 at 11:19 PM Iain Sandoe <[email protected]> wrote:
>>
>> HJ,
>>
>> Bootstrap on 32b Darwin (and 64b Darwin with 32b multilib) is still broken
>> after
>> more than three weeks,
>>
>> It is reasonable to have a temporary break if there is a trivial typo or
>> other fix
>> that can be applied in a timely manner.
>>
>> However, in this case, it seems your initial design needed some amendment,
>> and that means a more complex fix is needed - which needs additional review.
>>
>> Today I now faced two concurrent bootstrap breaks on some platform versions
>> - this is just consuming time in a non-constructive manner.
>
> It only shows that maintainers pay no attention to Darwin. In the meantime,
> you can submit a very simple libssp patch to fix Darwin build by changing
> __stack_chk_guard to unsigned long for Darwin.
I find this unbelievable, and cannot think of any other maintainer who would
leave a regulalry-tested platform broken for weeks, and then try pass the blame
to reviewers for not being quick enough review band aid upon band aid.
The responsibility for producing good reviewed patches lies with you - not
with other maintainers for platforms you break with bad patches, and not with
reviewers who might have more pressing things to address.
I would be very disappointed if this is what is considered to be “good
community” behaviour.
Iain
** even with all your patches applied the testcases need work - it is not at all
helpful that you leave it to others to finish off your incomplete work.
>
>> Please revert your changes until you have an agreed design for this facility.
>> thanks
>> Iain
>>
>>> On 16 May 2026, at 00:52, H.J. Lu <[email protected]> wrote:
>>>
>>> On Mon, May 11, 2026 at 4:49 PM Iain Sandoe <[email protected]> wrote:
>>>>
>>>> Hi HJ
>>>>
>>>>> On 8 May 2026, at 11:05, H.J. Lu <[email protected]> wrote:
>>>>>
>>>>> default_stack_protect_guard calls
>>>>>
>>>>> lang_hooks.types.type_for_mode (ptr_mode, 1);
>>>>>
>>>>> to get an integer type for __stack_chk_guard which is declared as a
>>>>> global symbol of type uintptr_t. For 32-bit systems, uintptr_t may
>>>>> be either unsigned int or unsigned long int. On 32-bit Darwin, we get
>>>>
>>>> FWIW, I suspect that, at the very least, Windows does the same.
>>>>
>>>>> $ cat /tmp/x.c
>>>>> __UINTPTR_TYPE__ __stack_chk_guard = 0x1000;
>>>>> $ ./xgcc -B./ -S /tmp/x.c -m32
>>>>> /tmp/x.c:1:18: error: conflicting types for ‘__stack_chk_guard’; have
>>>>> ‘long unsigned int’
>>>>> 1 | __UINTPTR_TYPE__ __stack_chk_guard = 0x1000;
>>>>> | ^~~~~~~~~~~~~~~~~
>>>>> cc1: note: previous declaration of ‘__stack_chk_guard’ with type
>>>>> ‘unsigned int’
>>>>> $
>>>>>
>>>>> since lang_hooks.types.type_for_mode returns unsigned int while Darwin's
>>>>> uintptr_t is unsigned long int.
>>>>>
>>>>> Add LANG_HOOKS_TYPE_FOR_MODE_KIND to specify signed or unsigned integer
>>>>> type for pointer and update default_stack_protect_guard to call
>>>>>
>>>>> lang_hooks.types.type_for_mode_kind
>>>>> (ptr_mode, 1, KIND_IS_INTEGER_FOR_POINTER);
>>>>>
>>>>> to get unsigned integer type for pointer.
>>>>
>>>> OK. So this does fix bootstrap on Darwin platform versions with 32b
>>>> mulitilibs (and
>>>> 32b hosts). However there is still work to do on the testcases
>>>> (ABI-related differences
>>>> at least).
>>>>
>>>> It seems rather excessive to need to add two target hooks for this small
>>>> feature.
>>>>
>>>> We have C++ - could you not add a defaulted parameter to the original hook
>>>> that
>>>> would allow for querying a specific result for the mode type without
>>>> needing to
>>>> churn the code for every other use?
>>>
>>> The default function parameter doesn't work on function pointers:
>>>
>>> [hjl@gnu-tgl-3 tmp]$ cat x.cc
>>> void (*foo) (int = 0);
>>> [hjl@gnu-tgl-3 tmp]$ gcc -S x.cc
>>> x.cc:1:18: error: default arguments are only permitted for function
>>> parameters [-fpermissive]
>>> 1 | void (*foo) (int = 0);
>>> | ^
>>> [hjl@gnu-tgl-3 tmp]$
>>>
>>>> thanks
>>>> Iain
>>>>
>>>>>
>>>>> gcc/
>>>>>
>>>>> PR c/125226
>>>>> * langhooks-def.h (LANG_HOOKS_TYPE_FOR_MODE_KIND): New.
>>>>> (LANG_HOOKS_FOR_TYPES_INITIALIZER): Add
>>>>> LANG_HOOKS_TYPE_FOR_MODE_KIND.
>>>>> * langhooks.h (type_kind): New enum.
>>>>> (lang_hooks_for_types): Add type_for_mode_kind.
>>>>> * targhooks.c (default_stack_protect_guard): Call
>>>>> lang_hooks.types.type_for_mode_kind if not NULL.
>>>>>
>>>>> gcc/c-family/
>>>>>
>>>>> PR c/125226
>>>>> * c-common.cc (c_common_type_for_mode): Renamed to ...
>>>>> (c_common_type_for_mode_kind): This. Add an argument for type
>>>>> kind. Return intptr_type_node/uintptr_type_node when asking
>>>>> for integer type for pointers.
>>>>> (c_common_type_for_mode): New. Call c_common_type_for_mode_kind
>>>>> with KIND_IS_UNKNOWN.
>>>>> * c-common.h: Include "langhooks.h".
>>>>> (c_common_type_for_mode_kind): New prototype.
>>>>> * c-objc-common.h (LANG_HOOKS_TYPE_FOR_MODE_KIND): New.
>>>>>
>>>>> gcc/cp/
>>>>>
>>>>> PR c/125226
>>>>> * cp-objcp-common.h (LANG_HOOKS_TYPE_FOR_MODE_KIND): New.
>>>>
>>>>
>>>>>
>>>>>
>>>>> --
>>>>> H.J.
>>>>> <0001-c-c-Get-unsigned-integer-type-for-pointer.patch>
>>>>
>>>
>>>
>>> --
>>> H.J.
>>
>>
>
>
> --
> H.J.
