interpret: make read-pointer-as-bytes a CTFE-only error with extra information
Next step in the reaction to https://github.com/rust-lang/rust/issues/99923. Also teaches Miri to implicitly strip provenance in more situations when transmuting pointers to integers, which fixes https://github.com/rust-lang/miri/issues/2456.
Pointer-to-int transmutation during CTFE now produces a message like this:
```
= help: this code performed an operation that depends on the underlying bytes representing a pointer
= help: the absolute address of a pointer is not known at compile-time, so such operations are not supported
```
r? ``@oli-obk``
no alignment check during interning
This should fix https://github.com/rust-lang/rust/issues/101034
r? `@oli-obk`
Unfortunately we don't have a self-contained testcase for this problem. I am not sure how it can be triggered...
There are several indications that we should not ZST as a ScalarInt:
- We had two ways to have ZST valtrees, either an empty `Branch` or a `Leaf` with a ZST in it.
`ValTree::zst()` used the former, but the latter could possibly arise as well.
- Likewise, the interpreter had `Immediate::Uninit` and `Immediate::Scalar(Scalar::ZST)`.
- LLVM codegen already had to special-case ZST ScalarInt.
So instead add new ZST variants to those types that did not have other variants
which could be used for this purpose.
Operand::Uninit is an *allocated* operand that is fully uninitialized.
This lets us lazily allocate the actual backing store of *all* locals (no matter their ABI).
I also reordered things in pop_stack_frame at the same time.
I should probably have made that a separate commit...
Include Refs in Valtree Creation
This adds references to `const_to_valtree`, which isn't used in the compiler yet, but after the previous changes we made to the thir and mir representations and this change we should be able to finally introduce them in the next PR.
I wasn't able to properly test this code, except indirectly by including a call of `const_to_valtree` in the code that currently creates constants (`turn_into_const_value`).
r? `@lcnr`
cc `@oli-obk` `@RalfJung`
Let CTFE to handle partially uninitialized unions without marking the entire value as uninitialized.
follow up to #94411
To fix https://github.com/rust-lang/rust/issues/69488 and by extension fix https://github.com/rust-lang/rust/issues/94371, we should stop treating types like `MaybeUninit<usize>` as something that the `Scalar` type in the interpreter engine can represent. So we add a new field to `abi::Primitive` that records whether the primitive is nested in a union
cc `@RalfJung`
r? `@ghost`
This allows to compute the `BodyOwnerKind` from `DefKind` only, and
removes a direct dependency of some MIR queries onto HIR.
As a side effect, it also simplifies metadata, since we don't need 4
flavours of `EntryKind::*Static` any more.
Currently some `Allocation`s are interned, some are not, and it's very
hard to tell at a use point which is which.
This commit introduces `ConstAllocation` for the known-interned ones,
which makes the division much clearer. `ConstAllocation::inner()` is
used to get the underlying `Allocation`.
In some places it's natural to use an `Allocation`, in some it's natural
to use a `ConstAllocation`, and in some places there's no clear choice.
I've tried to make things look as nice as possible, while generally
favouring `ConstAllocation`, which is the type that embodies more
information. This does require quite a few calls to `inner()`.
The commit also tweaks how `PartialOrd` works for `Interned`. The
previous code was too clever by half, building on `T: Ord` to make the
code shorter. That caused problems with deriving `PartialOrd` and `Ord`
for `ConstAllocation`, so I changed it to build on `T: PartialOrd`,
which is slightly more verbose but much more standard and avoided the
problems.
rustc_const_eval: adopt let else in more places
Continuation of #89933, #91018, #91481, #93046, #93590, #94011.
I have extended my clippy lint to also recognize tuple passing and match statements. The diff caused by fixing it is way above 1 thousand lines. Thus, I split it up into multiple pull requests to make reviewing easier. This PR handles rustc_const_eval.
