On Thu, May 28, 2026 at 2:45 PM Iain Sandoe <[email protected]> wrote:
>
>
>
> > On 28 May 2026, at 00:15, H.J. Lu <[email protected]> wrote:
> >
> > On Thu, May 28, 2026 at 7:11 AM Iain Sandoe <[email protected]> wrote:
> >>
> >>
> >>
> >>> On 27 May 2026, at 23:41, 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
> >>>
> >>> $ 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.  Update default_stack_protect_guard to
> >>> check UINTPTR_TYPE to get unsigned integer type for uintptr_t instead.
> >>>
> >>> gcc/c-family/
> >>>
> >>> PR c/125226
> >>> * targhooks.cc (default_stack_protect_guard): Check UINTPTR_TYPE
> >>> to get unsigned integer type for uintptr_t.
> >>
> >> maybe making uintptr_type_node available would make the code smaller
> >> overall?
> >
> > That will be a much bigger change.
>
> It’s already computed for c-family (in c_common_nodes_and_builtins and
> saved in c_global_trees) - so it’s already available to c-family.
>
> Assuming that the stack protector could be used by non-c-family languages
> then moving the computation to tree.cc/build_common_tree_nodes 
> <http://tree.cc/build_common_tree_nodes>
> and the node to global_trees (c.f. size_type_node, ptr_type_node et . al)
> seems plausible - maybe I miss something, Jason?
>

rust also defines intptr_type_node and uintptr_type_node:

c-family/c-common.h:    CTI_INTPTR_TYPE,
c-family/c-common.h:    CTI_UINTPTR_TYPE,
c-family/c-common.h:#define intptr_type_node    c_global_trees[CTI_INTPTR_TYPE]
c-family/c-common.h:#define uintptr_type_node
c_global_trees[CTI_UINTPTR_TYPE]
rust/backend/rust-tree.h:  CTI_INTPTR_TYPE,
rust/backend/rust-tree.h:  CTI_UINTPTR_TYPE,
rust/backend/rust-tree.h:#define intptr_type_node
c_global_trees[CTI_INTPTR_TYPE]
rust/backend/rust-tree.h:#define uintptr_type_node
c_global_trees[CTI_UINTPTR_TYPE]

I guess they can be moved to  tree-core.h as TI_INTPTR_TYPE/TI_UINTPTR_TYPE.
This will be a much bigger change with rust testing.


--
H.J.

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