On Thu, Oct 28, 2021 at 1:26 PM Rasmus Villemoes <r...@rasmusvillemoes.dk>
wrote:
>
> Hi
>
> I was wondering why the vx_crtbegin.o file had a .init_array section and
> not a .init_array.00101, when the function is defined with
> __attribute__((constructor (101))) (see libgcc/config/vxcrtstuff.c).
>
> After a lot of digging, including making sure that EH_CTOR_ATTRIBUTE
> actually gets defined as I expect and adding -frecord-gcc-switches to
> the build to see if any of those made ctor priorities ignored, it turns
> out that the problem is the declarations preceding the definitions. This
> can easily be reproduced by
>
> #define ac(prio) __attribute__((constructor(prio)))
>
> unsigned x = 987;
>
> static void f101(void);
> void f102(void);
>
> static void ac(101) f101(void) { x += 101; }
> void ac(102) f102(void) { x *= 102; }
>
> static void ac(103) f103(void) { x -= 103; }
> void ac(104) f104(void) { x /= 104; }
>
> This results in a .init_array section with two pointers, plus the
> expected .init_array.00103 and .init_array.00104 with one each.
>
> This is rather unexpected, especially since the attribute is not
> entirely ignored, just the priority part.
Probably a bug in decl merging, failing to copy DECL_HAS_INIT_PRIORITY_P
and altering the on-the-side init priority mapping
(decl_{init,fini}_priority_insert).
I suggest to file a bugreport or try to fix it yourself
(gcc/c/c-decl.c:merge_decls)
Richard.
>
> Rasmus
