Support 1st group of RISC-V Bitmanip backend target features
These target features use the same names as LLVM and `is_riscv_feature_detected!`, they are:
- zba (address generation instructions)
- zbb (basic bit manipulation)
- zbc (carry-less multiplication)
- zbs (single-bit manipulation)
The extension is frozen and ratified, and I don't think we should expect LLVM to change those feature names in the future.
For reference, the specification for the B extension can be found here: https://github.com/riscv/riscv-bitmanip/releases/download/1.0.0/bitmanip-1.0.0-38-g865e7a7.pdf)
On my current project, I see a 7.6% reduction in binary size with these features on, so I have some incentive to try to silence the "unknown feature" warning from `-Ctarget-feature` =)
Adjust span of fn argument declaration
Span of a fn argument declaration goes from:
```
fn foo(i : i32 , ...)
^^^^^^^^
```
to:
```
fn foo(i : i32 , ...)
^^^^^^^
```
That is, we don't include the extra spacing up to the trailing comma, which I think is more correct.
cc https://github.com/rust-lang/rust/pull/99646#discussion_r944568074
r? ``@estebank``
---
The two tests that had dramatic changes in their rendering I think actually are improved, though they are kinda poor spans both before and after the changes. 🤷 Thoughts?
Replace - with _ in fluent slugs to improve developer workflows
This is a proposal to smoothen the compiler contribution experience in the face of the move to fluent.
## Context
The fluent project has introduced a layer of abstraction to compiler errors. Previously, people would write down error messages directly in the same file the code was located to emit them. Now, there is a slug that connects the code in the compiler to the error message in the ftl file.
You can look at 7ef610c003 to see an example of the changes:
Old:
```Rust
let msg = format!(
"bounds on `{}` are most likely incorrect, consider instead \
using `{}` to detect whether a type can be trivially dropped",
predicate,
cx.tcx.def_path_str(needs_drop)
);
lint.build(&msg).emit();
```
New (Rust side):
```Rust
lint.build(fluent::lint::drop_trait_constraints)
.set_arg("predicate", predicate)
.set_arg("needs_drop", cx.tcx.def_path_str(needs_drop))
.emit();
```
New (Fluent side):
```fluent
lint-drop-trait-constraints =
bounds on `{$predicate}` are most likely incorrect, consider instead using `{$needs_drop}` to detect whether a type can be trivially dropped
```
You will note that in the ftl file, the slug is slightly different from the slug in the Rust file: The ftl slug uses `-` (e.g. `lint-drop-trait-constraints`) while the rust slug uses `::` and `_` (e.g. `lint::drop_trait_constraints`). This choice was probably done due to:
* Rust not accepting `-` in identifiers (as it is an operator)
* fluent not supporting the `:` character in slug names (parse error upon attempts)
* all official fluent documentation using `-` instead of `_`
## The problem
The two different types of slugs, one with `-`, and one with `_`, cause difficulties for contributors. Imagine you don't have perfect knowledge of where stuff is in the compiler (i would say this is most people), and you encounter an error for which you think there is something you could improve that is not just a rewording.
So you want to find out where in the compiler's code that error is being emitted. The best way is via grepping.
1. you grep for the message in the compiler's source code. You discover the ftl file and find out the slug for that error.
2. That slug however contains `-` instead of `_`, so you have to manually translate the `-`'s into `_`s, and furthermore either remove the leading module name, or replace the first `-` with a `::`.
3. you do a second grep to get to the emitting location in the compiler's code.
This translation difficulty in step 2 appears also in the other direction when you want to figure out what some code in the compiler is doing and use error messages to help your understanding. Comments and variable names are way less exposed to users so [are more likely going to lie](cc3c5d2700) than error messages.
I think that at least the `-`→`_` translation which makes up most of step 2 can be removed at low cost.
## The solution
If you look closely, the practice of fluent to use `-` is only a stylistic choice and it is not enforced by fluent implementations, neither the playground nor the one the rust compiler uses, that slugs may not contain `_`. Thus, we can in fact migrate the ftl side to `_`. So now we'll have slugs like `lint_drop_trait_constraints` on the ftl side. You only have to do one replacement now to get to the Rust slug: remove the first `_` and place a `::` in its stead. I would argue that this change is in fact useful as it allows you to control whether you want to look at the rust side of things or the ftl side of things via changing the query string only: with an increased number of translations checked into the repository, grepping for raw slugs will return the slug in many ftl files, so an explicit step to look for the source code is always useful. In the other direction (rust to fluent), you don't need a translation at all any more, as you can just take the final piece of the slug (e.g. `drop_trait_constraints`) and grep for that. The PR also adds enforcement to forbid usage of `_` in slug names. Internal slug names (those leading with a `-`) are exempt from that enforcement.
As another workflow that benefits from this change, people who add new errors don't have to do that `-` conversion either.
| Before/After | Fluent slug | Rust slug (no change) |
|--|--|--|
| Before | `lint-drop-trait-constraints` | `lint::drop_trait_constraints`|
| After | `lint_drop_trait_constraints` | `lint::drop_trait_constraints`|
Note that I've suggested this previously in the translation thread on zulip. I think it's important to think about non-translator contribution impact of fluent. I have certainly plans for more improvements, but this is a good first step.
``@rustbot`` label A-diagnostics
Rollup of 6 pull requests
Successful merges:
- #100211 (Refuse to codegen an upstream static.)
- #100277 (Simplify format_args builtin macro implementation.)
- #100483 (Point to generic or arg if it's the self type of unsatisfied projection predicate)
- #100506 (change `InlineAsmCtxt` to not talk about `FnCtxt`)
- #100534 (Make code slightly more uniform)
- #100566 (Use `create_snapshot_for_diagnostic` instead of `clone` for `Parser`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
debuginfo: Generalize C++-like encoding for enums.
The updated encoding should be able to handle niche layouts where more than one variant has fields (as introduced in https://github.com/rust-lang/rust/pull/94075).
The new encoding is more uniform as there is no structural difference between direct-tag, niche-tag, and no-tag layouts anymore. The only difference between those cases is that the "dataful" variant in a niche-tag enum will have a `(start, end)` pair denoting the tag range instead of a single value.
The new encoding now also supports 128-bit tags, which occur in at least some standard library types. These tags are represented as `u64` pairs so that debuggers (which don't always have support for 128-bit integers) can reliably deal with them. The downside is that this adds quite a bit of complexity to the encoding and especially to the corresponding NatVis.
The new encoding seems to increase the size of (x86_64-pc-windows-msvc) debuginfo by 10-15%. The size of binaries is not affected (release builds were built with `-Cdebuginfo=2`, numbers are in kilobytes):
EXE | before | after | relative
-- | -- | -- | --
cargo (debug) | 40453 | 40450 | +0%
ripgrep (debug) | 10275 | 10273 | +0%
cargo (release) | 16186 | 16185 | +0%
ripgrep (release) | 4727 | 4726 | +0%
PDB | before | after | relative
-- | -- | -- | --
cargo (debug) | 236524 | 261412 | +11%
ripgrep (debug) | 53140 | 59060 | +11%
cargo (release) | 148516 | 169620 | +14%
ripgrep (release) | 10676 | 11804 | +11%
Given that the new encoding is more general, this is to be expected. Only platforms using C++-like debuginfo are affected -- which currently is only `*-pc-windows-msvc`.
*TODO*
- [x] Properly update documentation
- [x] Add regression tests for new optimized enum layouts as introduced by #94075.
r? `@wesleywiser`
change `InlineAsmCtxt` to not talk about `FnCtxt`
wip for https://github.com/rust-lang/compiler-team/issues/529. this currently uses both the `FnCtxt` and is used by `check_mod_item_types`. This should be the only thing blocking that MCP afaict.
I am still unsure whether `rustc_hir_typeck` should depend on `rustc_hir_analysis` to use the `InlineAsmCtxt`. I think that's the best solution for now, so that's what I will go for
r? `@compiler-errors`
Point to generic or arg if it's the self type of unsatisfied projection predicate
We do this for `TraitPredicate`s in `point_at_type_arg_instead_of_call_if_possible` and `point_at_arg_instead_of_call_if_possible`, so also do it for `ProjectionPredicate`.
Improves spans for a lot of unit tests.
Simplify format_args builtin macro implementation.
Instead of a FxHashMap<Symbol, (usize, Span)> for the named arguments, this now includes the name and span in the elements of the Vec<FormatArg> directly. The FxHashMap still exists to look up the index, but no longer contains the span. Looking up the name or span of an argument is now trivial and does not need the map anymore.
Visit attributes in more places.
This adds 3 loosely related changes (I can split PRs if desired):
- Attribute checking on pattern struct fields.
- Attribute checking on struct expression fields.
- Lint level visiting on pattern struct fields, struct expression fields, and generic parameters.
There are still some lints which ignore lint levels in various positions. This is a consequence of how the lints themselves are implemented. For example, lint levels on associated consts don't work with `unused_braces`.
`Parser::parse_bottom_expr` currently constructs an empty `attrs` and
then passes it to a large number of other functions. This makes the code
harder to read than it should be, because it's not clear that many
`attrs` arguments are always empty.
This commit removes `attrs` and the passing, simplifying a lot of
functions. The commit also renames `Parser::mk_expr` (which takes an
`attrs` argument) as `mk_expr_with_attrs`, and introduces a new
`mk_expr` which creates an expression with no attributes, which is the
more common case.
rustc_target: Update some old naming around self contained linking
The "fallback" naming pre-dates introduction of `-Clink-self-contained`.
Noticed when reviewing https://github.com/rust-lang/rust/pull/99500.
This PR doesn't break any json target spec, but supporting per-linker-flavor startup objects needed by https://github.com/rust-lang/rust/pull/99500 will break them, so maybe next time I'll remove the compatibility names.
orphan check: rationalize our handling of constants
cc `@rust-lang/types` `@rust-lang/project-const-generics` on whether you agree with this reasoning.
r? types
These use the same names as LLVM and is_riscv_feature_detected!:
- zba (address generation instructions)
- zbb (basic bit manipulation)
- zbc (carry-less multiplication)
- zbs (single-bit manipulation)
Argument type error improvements
Motivated by this interesting code snippet:
```rust
#[derive(Copy, Clone)]
struct Wrapper<T>(T);
fn foo(_: fn(i32), _: Wrapper<i32>) {}
fn f(_: u32) {}
fn main() {
let w = Wrapper::<isize>(1isize);
foo(f, w);
}
```
Which currently errors like:
```
error[E0308]: arguments to this function are incorrect
--> src/main.rs:10:5
|
10 | foo(f, w);
| ^^^ - - expected `i32`, found `isize`
| |
| expected `i32`, found `u32`
|
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
= note: expected struct `Wrapper<i32>`
found struct `Wrapper<isize>`
note: function defined here
--> src/main.rs:4:4
|
4 | fn foo(_: fn(i32), _: Wrapper<i32>) {}
| ^^^ ---------- ---------------
```
Specifically, that double `expected .. found ..` which is very difficult to correlate to the types in the arguments. Also, the fact that "expected `i32`, found `isize`" and the other argument mismatch label don't even really explain what's going on here.
After this PR:
```
error[E0308]: arguments to this function are incorrect
--> $DIR/two-mismatch-notes.rs:10:5
|
LL | foo(f, w);
| ^^^
|
note: expected fn pointer, found fn item
--> $DIR/two-mismatch-notes.rs:10:9
|
LL | foo(f, w);
| ^
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
note: expected struct `Wrapper`, found a different struct `Wrapper`
--> $DIR/two-mismatch-notes.rs:10:12
|
LL | foo(f, w);
| ^
= note: expected struct `Wrapper<i32>`
found struct `Wrapper<isize>`
note: function defined here
--> $DIR/two-mismatch-notes.rs:4:4
|
LL | fn foo(_: fn(i32), _: Wrapper<i32>) {}
| ^^^ ---------- ---------------
error: aborting due to previous error
For more information about this error, try `rustc --explain E0308`.
```
Yeah, it's a bit verbose, but much clearer IMO.
---
Open to discussions about how this could be further improved. Motivated by `@jyn514's` [tweet](https://mobile.twitter.com/joshuayn514/status/1558042020601634816) here.
wf: correctly `shallow_resolve` consts
`shallow_resolve` on `InferConst` is always a noop. this is mostly irrelevant as inference vars should already be resolved at most - if not all - call sites. Haven't actually looked too deeply into whether this was a problem.
Erase regions better in `promote_candidate`
Use `tcx.erase_regions` instead of manually walking through the substs.... this also makes the code slightly simpler 🙈Fixes#100360Fixes#89851
