Currently, we serialize the same crate metadata for proc-macro crates as
we do for normal crates. This is quite wasteful - almost none of this
metadata is ever used, and much of it can't even be deserialized (if it
contains a foreign `CrateNum`).
This PR changes metadata encoding to skip encoding the majority of crate
metadata for proc-macro crates. Most of the `Lazy<[T]>` fields are left
completetly empty, while the non-lazy fields are left as-is.
Additionally, proc-macros now have a def span that does not include
their body. This was done for normal functions in #75465, but was missed
for proc-macros.
As a result of this PR, we should only ever encode local `CrateNum`s
when encoding proc-macro crates. I've added a specialized serialization
impl for `CrateNum` to assert this.
Remove TrustedLen requirement from BuilderMethods::switch
The main use case of TrustedLen is allowing APIs to specialize on it,
but no use of it uses that specialization. Instead, only the .len()
function provided by ExactSizeIterator is used, which is already
required to be accurate.
Thus, the TrustedLen requirement on BuilderMethods::switch is redundant.
Add `#![feature(const_fn_floating_point_arithmetic)]`
cc #76618
This is a template for splitting up `const_fn` into granular feature gates. I think this will make it easier, both for us and for users, to track stabilization of each individual feature. We don't *have* to do this, however. We could also keep stabilizing things out from under `const_fn`.
cc @rust-lang/wg-const-eval
r? @oli-obk
Rollup of 15 pull requests
Successful merges:
- #76932 (Relax promises about condition variable.)
- #76973 (Unstably allow assume intrinsic in const contexts)
- #77005 (BtreeMap: refactoring around edges)
- #77066 (Fix dest prop miscompilation around references)
- #77073 (dead_code: look at trait impls even if they don't contain items)
- #77086 (Include libunwind in the rust-src component.)
- #77097 (Make [].as_[mut_]ptr_range() (unstably) const.)
- #77106 (clarify that `changelog-seen = 1` goes to the beginning of config.toml)
- #77120 (Add `--keep-stage-std` to `x.py` for keeping only standard library artifacts)
- #77126 (Invalidate local LLVM cache less often)
- #77146 (Install std for non-host targets)
- #77155 (remove enum name from ImplSource variants)
- #77176 (Removing erroneous semicolon in transmute documentation)
- #77183 (Allow multiple allow_internal_unstable attributes)
- #77189 (Remove extra space from vec drawing)
Failed merges:
r? `@ghost`
This refactors handling of `Rvalue::{Unary,Binary}Op` in the
const-checker. Now we `span_bug` if there's an unexpected type in a
primitive operation. This also allows unary negation on
`char` values through the const-checker because it makes the code a bit
cleaner. `char` does not actually support these operations, and if it
did, we could evaluate them at compile-time.
Ignore ZST offsets when deciding whether to use Scalar/ScalarPair layout
This is important because Scalar/ScalarPair layout previously would not be used if any ZST had nonzero offset.
For example, before this change, only `((), u128)` would be laid out like `u128`, not `(u128, ())`.
Fixes#63244
perf: move cold path of `process_obligations` into a separate function
cc #76575
This probably won't matter too much in the long run once #69218 is merged so we may not want to merge this.
r? `@ecstatic-morse`
Fix#76803 miscompilation
Fixes#76803
Seems like it was an oversight that the discriminant value being set was not compared to the target value from the SwitchInt, as a comment says this is a requirement for the optimization to be sound.
r? `@wesleywiser` since you are probably familiar with the optimization and made #76837 to workaround the bug
Rollup of 15 pull requests
Successful merges:
- #75438 (Use adaptive SVG favicon for rustdoc like other rust sites)
- #76304 (Make delegation methods of `std::net::IpAddr` unstably const)
- #76724 (Allow a unique name to be assigned to dataflow graphviz output)
- #76978 (Documented From impls in std/sync/mpsc/mod.rs)
- #77044 (Liballoc bench vec use mem take not replace)
- #77050 (Typo fix: "satsify" -> "satisfy")
- #77074 (add array::from_ref)
- #77078 (Don't use an if guard to check equality with a constant)
- #77079 (Use `Self` in docs when possible)
- #77081 (Merge two almost identical match arms)
- #77121 (Updated html_root_url for compiler crates)
- #77136 (Suggest `const_mut_refs`, not `const_fn` for mutable references in `const fn`)
- #77160 (Suggest `const_fn_transmute`, not `const_fn`)
- #77164 (Remove workaround for deref issue that no longer exists.)
- #77165 (Followup to #76673)
Failed merges:
r? `@ghost`
Suggest `const_fn_transmute`, not `const_fn`
More fallout from #76850 in the vein of #77134. The fix is the same. I looked through the structured errors file and didn't see any more of this kind of diagnostics bug.
r? @oli-obk
Suggest `const_mut_refs`, not `const_fn` for mutable references in `const fn`
Resolves#77134.
Prior to #76850, most uses of `&mut` in `const fn` ~~required~~ involved two feature gates, `const_mut_refs` and `const_fn`. The first allowed all mutable borrows of locals. The second allowed only locals, arguments and return values whose types contained `&mut`. I switched the second check to the `const_mut_refs` gate. However, I forgot update the error message with the new suggestion.
Alternatively, we could revert to having two different feature gates for this. OP's code never borrows anything mutably, so it didn't need `const_mut_refs` in the past, only `const_fn`. I'd prefer to keep everything under a single gate, however.
r? @oli-obk
Allow a unique name to be assigned to dataflow graphviz output
Previously, if the same analysis were invoked multiple times in a single compilation session, the graphviz output for later runs would overwrite that of previous runs. Allow callers to add a unique identifier to each run so this can be avoided.
DroplessArena: Allocate objects from the end of memory chunk
Allocating from the end of memory chunk simplifies the alignment code
and reduces the number of checked arithmetic operations.
Add fast path for match checking
This adds a fast path that would reduce the complexity to linear on matches consisting of only variant patterns (i.e. enum matches). (Also see: #7462) Unfortunately, I was too lazy to add a similar fast path for constants (mostly for integer matches), ideally that could be added another day.
TBH, I'm not confident with the performance claims due to the fact that enums tends to be small and FxHashMap could add a lot of overhead.
r? `@Mark-Simulacrum`
needs perf
The main use case of TrustedLen is allowing APIs to specialize on it,
but no use of it uses that specialization. Instead, only the .len()
function provided by ExactSizeIterator is used, which is already
required to be accurate.
Thus, the TrustedLen requirement on BuilderMethods::switch is redundant.
const_evaluatable_checked: extend predicate collection
We now walk the hir instead of using `ty` so that we get better spans here, While I am still not completely sure if that's
what we want in the end, it does seem a lot closer to the final goal than the previous version.
We also look into type aliases (and use a `TypeVisitor` here), about which I am not completely sure, but we will see how well this works.
We also look into fn decls, so the following should work now.
```rust
fn test<T>() -> [u8; std::mem::size_of::<T>()] {
[0; std::mem::size_of::<T>()]
}
```
Additionally, we visit the optional trait and self type of impls.
r? `@oli-obk`
Fix underflow when calculating the number of no-op jumps folded
When removing unwinds to no-op blocks and folding jumps to no-op blocks,
remove the unwind target first. Otherwise we cannot determine if target
has been already folded or not.
Previous implementation incorrectly assumed that all resume targets had
been folded already, occasionally resulting in an underflow:
```
remove_noop_landing_pads: removed 18446744073709551613 jumps and 3 landing pads
```
- Add `PrimTy::name` and `PrimTy::name_str`
- Use those new functions to distinguish between the name in scope and
the canonical name
- Fix diagnostics for primitive types
- Add tests for primitives
