If you can guarantee its always compiled in a separate TU and never inlined, sure, might be a practical way so 'solve' this issue, but if you then do some LTO (or do a unity build or something) the compiler might suddenly break your code.
Another way is to add an inline asm block with "memory" clobber to escape the pointer so the optimizer can't destroy your code.
It's really quite ridiculous that compiler implementers have managed to overzealously nitpick the C standard so that you can't implement a memory allocator in C.
> It's really quite ridiculous that compiler implementers have managed to overzealously nitpick the C standard so that you can't implement a memory allocator in C.
This is good because it's also what gives you valgrind and CHERI. Take one away and you can't have the other.
(Because if you define all undefined behavior, then programs will rely on it and you can't assume it's an error anymore.)
It's really quite ridiculous that compiler implementers have managed to overzealously nitpick the C standard so that you can't implement a memory allocator in C.