rust/compiler/rustc_const_eval
Stuart Cook 0225f8b09c
Rollup merge of #144706 - zachs18:fix-144661, r=RalfJung
Do not give function allocations alignment in consteval and Miri.

We do not yet have a (clear and T-lang approved) design for how `#[align(N)]` on functions should affect function pointers' addresses on various platforms, so for now do not give function pointers alignment in consteval and Miri.

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Old summary:

Not a full solution to <https://github.com/rust-lang/rust/issues/144661>, but fixes the immediate issue by making function allocations all have alignment 1 in consteval, ignoring `#[rustc_align(N)]`, so the compiler doesn't know if any offset other than 0 is non-null.

A more "principlied" solution would probably be to make function pointers to `#[instruction_set(arm::t32)]` functions be at offset 1 of an align-`max(2, align attribute)` allocation instead of at offset 0 of their allocation during consteval, and on wasm to either disallow `#[align(N)]` where N > 1, or to pad the function table such that the function pointer of a `#[align(N)]` function is a multiple of `N` at runtime.
2025-08-04 11:24:39 +10:00
..
2025-07-31 14:19:27 +02:00