Handle asm const similar to inline const
Previously, asm consts are handled similar to anon consts rather than inline consts. Anon consts are not good at dealing with lifetimes, because `type_of` has lifetimes erased already. Inline consts can deal with lifetimes because they live in an outer typeck context. And since `global_asm!` lacks an outer typeck context, we have implemented asm consts with anon consts while they're in fact more similar to inline consts.
This was changed in #137180, and this means that handling asm consts as inline consts are possible. While as `@compiler-errors` pointed out, `const` currently can't be used with any types with lifetime, this is about to change if #128464 is implemented. This PR is a preparatory PR for that feature.
As an unintentional side effect, fix#117877.
cc `@Amanieu`
r? `@compiler-errors`
Clean up TypeckResults::extract_binding_mode
- Remove the `Option` from the result type, as `None` is never returned.
- Document the difference from the `BindingMode` in `PatKind::Binding`.
It mirrors `ExprKind::Binary`, and contains a `BinOpKind`. This makes
`AssocOp` more like `ExprKind`. Note that the variants removed from
`AssocOp` are all named differently to `BinOpToken`, e.g. `Multiply`
instead of `Mul`, so that's an inconsistency removed.
The commit adds `precedence` and `fixity` methods to `BinOpKind`, and
calls them from the corresponding methods in `AssocOp`. This avoids the
need to create an `AssocOp` from a `BinOpKind` in a bunch of places, and
`AssocOp::from_ast_binop` is removed.
`AssocOp::to_ast_binop` is also no longer needed.
Overall things are shorter and nicer.
#[contracts::requires(...)] + #[contracts::ensures(...)]
cc https://github.com/rust-lang/rust/issues/128044
Updated contract support: attribute syntax for preconditions and postconditions, implemented via a series of desugarings that culminates in:
1. a compile-time flag (`-Z contract-checks`) that, similar to `-Z ub-checks`, attempts to ensure that the decision of enabling/disabling contract checks is delayed until the end user program is compiled,
2. invocations of lang-items that handle invoking the precondition, building a checker for the post-condition, and invoking that post-condition checker at the return sites for the function, and
3. intrinsics for the actual evaluation of pre- and post-condition predicates that third-party verification tools can intercept and reinterpret for their own purposes (e.g. creating shims of behavior that abstract away the function body and replace it solely with the pre- and post-conditions).
Known issues:
* My original intent, as described in the MCP (https://github.com/rust-lang/compiler-team/issues/759) was to have a rustc-prefixed attribute namespace (like rustc_contracts::requires). But I could not get things working when I tried to do rewriting via a rustc-prefixed builtin attribute-macro. So for now it is called `contracts::requires`.
* Our attribute macro machinery does not provide direct support for attribute arguments that are parsed like rust expressions. I spent some time trying to add that (e.g. something that would parse the attribute arguments as an AST while treating the remainder of the items as a token-tree), but its too big a lift for me to undertake. So instead I hacked in something approximating that goal, by semi-trivially desugaring the token-tree attribute contents into internal AST constucts. This may be too fragile for the long-term.
* (In particular, it *definitely* breaks when you try to add a contract to a function like this: `fn foo1(x: i32) -> S<{ 23 }> { ... }`, because its token-tree based search for where to inject the internal AST constructs cannot immediately see that the `{ 23 }` is within a generics list. I think we can live for this for the short-term, i.e. land the work, and continue working on it while in parallel adding a new attribute variant that takes a token-tree attribute alongside an AST annotation, which would completely resolve the issue here.)
* the *intent* of `-Z contract-checks` is that it behaves like `-Z ub-checks`, in that we do not prematurely commit to including or excluding the contract evaluation in upstream crates (most notably, `core` and `std`). But the current test suite does not actually *check* that this is the case. Ideally the test suite would be extended with a multi-crate test that explores the matrix of enabling/disabling contracts on both the upstream lib and final ("leaf") bin crates.
Allow using named consts in pattern types
This required a refactoring first: I had to stop using `hir::Pat`in `hir::TyKind::Pat` and instead create a separate `TyPat` that has `ConstArg` for range ends instead of `PatExpr`. Within the type system we should be using `ConstArg` for all constants, as otherwise we'd be maintaining two separate const systems that could diverge. The big advantage of this PR is that we now inherit all the rules from const generics and don't have a separate system. While this makes things harder for users (const generic rules wrt what is allowed in those consts), it also means we don't accidentally allow some things like referring to assoc consts or doing math on generic consts.
includes post-developed commit: do not suggest internal-only keywords as corrections to parse failures.
includes post-developed commit: removed tabs that creeped in into rustfmt tool source code.
includes post-developed commit, placating rustfmt self dogfooding.
includes post-developed commit: add backquotes to prevent markdown checking from trying to treat an attr as a markdown hyperlink/
includes post-developed commit: fix lowering to keep contracts from being erroneously inherited by nested bodies (like closures).
Rebase Conflicts:
- compiler/rustc_parse/src/parser/diagnostics.rs
- compiler/rustc_parse/src/parser/item.rs
- compiler/rustc_span/src/hygiene.rs
Remove contracts keywords from diagnostic messages
Stable Hash: Ignore all HirIds that just identify the node itself
This should provide better incremental caching, but it seems there is more to it.
These IDs also serve no purpose being in the stable hash of the item they refer to, only when referring to *another* item is it important that we hash the `HirId`. So we can at least avoid the cost during stable hashing, even if we don't benefit from it by avoiding some queries' caches from being invalidated
Unsure how to make sure we do this right by construction. Would be nice to do something type based
Suggest Replacing Comma with Semicolon in Incorrect Repeat Expressions
Fixes#80173
This PR detects typos in repeat expressions like `["_", 10]` and `vec![String::new(), 10]` and suggests replacing comma with semicolon.
Also, improves code in other place by adding doc comments and making use of a helper function to check if a type implements `Clone`.
References:
1. For `vec![T; N]`: https://doc.rust-lang.org/std/macro.vec.html
2. For `[T; N]`: https://doc.rust-lang.org/std/primitive.array.html
rustc_intrinsic: support functions without body
We synthesize a HIR body `loop {}` but such bodyless intrinsics.
Most of the diff is due to turning `ItemKind::Fn` into a brace (named-field) enum variant, because it carries a `bool`-typed field now. This is to remember whether the function has a body. MIR building panics to avoid ever translating the fake `loop {}` body, and the intrinsic logic uses the lack of a body to implicitly mark that intrinsic as must-be-overridden.
I first tried actually having no body rather than generating the fake body, but there's a *lot* of code that assumes that all function items have HIR and MIR, so this didn't work very well. Then I noticed that even `rustc_intrinsic_must_be_overridden` intrinsics have MIR generated (they are filled with an `Unreachable` terminator) so I guess I am not the first to discover this. ;)
r? `@oli-obk`
