Rollup of 5 pull requests - #152967
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Otherwise, it systematically fails on: ``` error: process didn't exit successfully: `[...]/rust/build/bootstrap/debug/rustc [...]/rust/build/bootstrap/debug/rustc -vV` (exit status: 127) --- stderr [...]/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory ``` for us at least. Signed-off-by: Paul Mabileau <paul.mabileau@harfanglab.fr>
There are six small macros used in `define_callbacks` that all expand to one thing if a particular query modifier is present, and to another thing otherwise. One of these macros looks for the `arena_cache` modifier: - `query_if_arena` Two of these macros look for the `return_result_from_ensure_ok` modifier: - `query_ensure_select` - `ensure_ok_result` Three of these macros look for the `separate_provide_extern` modifier: - `local_key_if_separate_extern` - `separate_provide_extern_decl` - `separate_provide_extern_default` (There is also `query_helper_param_ty!`, but it follows a different pattern, and I will deal with it later.) The "one thing"/"another thing" is different for every macro. For most of them you can't see at the macro call site what the expansion will be; you have to look at the macro definition. This is annoying. This commit reduces the six macros into three macros: - `if_arena_cache` - `if_return_result_from_ensure_ok` - `if_separate_provide_extern` They all have the same form: they look for a modifier and then expand to one *given* thing or the other *given* thing. You can see at the call site the two possible expansions, which is much nicer. (Note: `query_if_arena` already had this form.) Ideally there would be a single macro instead of three, but I couldn't work out a way to combine them.
So that all `$( ... $name ... )*` repetitions are spread across multiple lines, even if they all fit on one line. I find this much easier to read because the `$name` repetition is the main feature of these macros.
It doesn't make much sense to put the query doc comments on these structs. (The doc comments *are* put on various query functions, where it makes more sense.)
Within `define_callbacks!`: - Use `Key<'tcx>` where possible instead of `$($K)*`. - Use `Value<'tcx>` where possible instead of `$V`. In the other `define_*!` macros: - Use `$K:ty` where possible instead of `$($K:tt)*`. - Add comments about unused `$K` and `$V` cases. - Add `()` key types to the special nodes in the `define_dep_nodes!` invocation for consistency with normal queries.
Elaborate comments. Co-authored-by: Ralf Jung <post@ralfj.de>
Due to a bug, you can currently use `key` within the `desc` block and it'll just work regardless of what actual key name you specified. A subsequent commit will fix this, so let's correct the affected queries first.
Due to a bug they aren't actually necessary! (A few queries already take advantage of this, probably unintentionally.) And the next commit will remove support for explicit `tcx` bindings in favour of implicit.
As currently written, these have big problems. - `desc` and `cache_on_disk_if` modifiers use different syntaxes to introduce `tcx`. - `desc` is mis-implemented such that the explicit binding isn't even necessary and the key name can be botched, as the previous two commits showed. (It's the `let (#tcx, #key) = (tcx, key);` line that messes things up.) It's simpler and less error-prone to simply not require explicit `tcx` bindings, and instead just make it implicitly available to these code snippets.
GVN: consider constants of primitive types as deterministic *[View all comments](https://triagebot.infra.rust-lang.org/gh-comments/rust-lang/rust/pull/149366)* GVN separates MIR constants into deterministic and non-deterministic constants. Deterministic constants are defined here as: gives the exact same value each time it is evaluated. This was mainly useful because of `ConstValue::Slice` that generated an extra `AllocId` each time it appeared in the MIR. That variant has been removed. This is still useful for valtrees that hold references, which generate a fresh `AllocId` for each evaluation. This PR proposes to consider all constants of primitive type to be deterministic. If a constant of primitive type passes validation, then it does not contain provenance, so we have no risk of having a reference becoming different `AllocId`s. In particular, valtrees only are leaves. r? @ghost for perf
…ry-macros, r=Zalathar Clarify aspects of query macros Various clarity and consistency improvements to query macros. r? @Zalathar
…=oli-obk
`rustc_queries` simplifications
Queries have two ways of specifying code snippets, in `desc` and `cache_on_disk_if` blocks. An example:
```rust
query check_liveness(key: LocalDefId) -> &'tcx rustc_index::bit_set::DenseBitSet<abi::FieldIdx> {
arena_cache
desc { |tcx| "checking liveness of variables in `{}`", tcx.def_path_str(key.to_def_id()) }
cache_on_disk_if(tcx) { tcx.is_typeck_child(key.to_def_id()) }
}
```
If you need to use `tcx` in the snippet, you can use an explicit binding. But there are multiple problems with this.
- The syntax used is different in the two snippets: `|tcx|` within the block vs. `(tcx)` outside the block. (!!)
- Bug 1: In `desc` snippets you can leave out the `|tcx|` and still use `tcx`. Several existing queries do this.
- Bug 2: In `desc` snippets you can always use `key` in the snippet to refer to the key, even if that's not the identifier used in the query head.
- Finally, you can bind `tcx` and not use it, without a warning. Several existing queries do this.
I think explicit `tcx` binding is silly. Many queries need `tcx` and this macro is already super-magical, so just making `tcx` implicitly available seems fine, rather than making the query writer jump through a little syntactic hoop. This makes both the query definitions and the proc macro simpler.
r? @petrochenkov
…=JonathanBrouwer stabilize `cfg_select!` *[View all comments](https://triagebot.infra.rust-lang.org/gh-comments/rust-lang/rust/pull/149783)* tracking issue: rust-lang#115585 closes rust-lang#115585 reference PR: - rust-lang/reference#2103 # Request for Stabilization ## Summary The `cfg_select!` macro picks the expansion corresponding to the first `cfg` condition that evaluates to `true`. It simplifies complex conditional expressions. ```rust cfg_select! { unix => { fn foo() { /* unix specific functionality */ } } target_pointer_width = "32" => { fn foo() { /* non-unix, 32-bit functionality */ } } _ => { fn foo() { /* fallback implementation */ } } } let is_unix_str = cfg_select! { unix => "unix", _ => "not unix", }; println!("{is_unix_str}"); ``` ## Semantics The expansion of a `cfg_select!` call is the right-hand side of the first `cfg` rule that evaluates to true. This can be roughly expressed using this macro: ```rust macro_rules! cfg_select { ({ $($tt:tt)* }) => {{ $crate::cfg_select! { $($tt)* } }}; (_ => { $($output:tt)* }) => { $($output)* }; ( $cfg:meta => $output:tt $($( $rest:tt )+)? ) => { #[cfg($cfg)] $crate::cfg_select! { _ => $output } $( #[cfg(not($cfg))] $crate::cfg_select! { $($rest)+ } )? } } ``` The actual implementation uses a builtin macro so that `cfg_select!` can be used both in item and expression position. ## Documentation reference PR: - rust-lang/reference#2103 ## Tests The `cfg_select!` macro is already used extensively in the rust compiler codebase. It has several dedicated tests: - [`tests/ui/check-cfg/cfg-select.rs`](https://github.com/rust-lang/rust/blob/main/tests/ui/check-cfg/cfg-select.rs)tests that warnings are emitted when an unexpected `cfg` condition is used. - [`tests/ui/macros/cfg_select.rs`](https://github.com/rust-lang/rust/blob/main/tests/ui/macros/cfg_select.rs) tests that `cfg_select!` has the expected expansion, and tests that the expected syntax is accepted. ## History - rust-lang#115416 - rust-lang#117162 - rust-lang#133720 - rust-lang#135625 - rust-lang#137198 - rust-lang#138993 - rust-lang#138996 - rust-lang#143461 - rust-lang#143941 - rust-lang#145233 - rust-lang#148712 - rust-lang#149380 - rust-lang#149925 # Resolved questions # Unresolved questions The style team has decided on how to format `cfg_select!`, but this formatting has not yet been implemented. See rust-lang#144323. r? @traviscross <!-- TRIAGEBOT_START --> <!-- TRIAGEBOT_CONCERN-ISSUE_START --> > [!NOTE] > # Concerns (0 active) > > - ~~[allowing-comma-after-closing-brace](rust-lang#149783 (comment) resolved in [this comment](rust-lang#149783 (comment)) > > *Managed by `@rustbot`—see [help](https://forge.rust-lang.org/triagebot/concern.html) for details.* <!-- TRIAGEBOT_CONCERN-ISSUE_END --> <!-- TRIAGEBOT_END -->
….lib, r=clubby789 Build: Add `stdenv.cc.cc.lib` to Nix dependencies Otherwise, it systematically fails on: ``` error: process didn't exit successfully: `[...]/rust/build/bootstrap/debug/rustc [...]/rust/build/bootstrap/debug/rustc -vV` (exit status: 127) --- stderr [...]/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory ``` for us at least. Closes rust-lang#127620. @rustbot label T-bootstrap A-reproducibility
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…uwer Rollup of 5 pull requests Successful merges: - #149366 (GVN: consider constants of primitive types as deterministic) - #152779 (Clarify aspects of query macros) - #152958 (`rustc_queries` simplifications) - #149783 (stabilize `cfg_select!`) - #152708 (Build: Add `stdenv.cc.cc.lib` to Nix dependencies)
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…uwer Rollup of 5 pull requests Successful merges: - #149366 (GVN: consider constants of primitive types as deterministic) - #152779 (Clarify aspects of query macros) - #152958 (`rustc_queries` simplifications) - #149783 (stabilize `cfg_select!`) - #152708 (Build: Add `stdenv.cc.cc.lib` to Nix dependencies)
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Successful merges:
rustc_queriessimplifications #152958 (rustc_queriessimplifications)cfg_select!#149783 (stabilizecfg_select!)stdenv.cc.cc.libto Nix dependencies #152708 (Build: Addstdenv.cc.cc.libto Nix dependencies)r? @ghost
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