solve: all "non-structural" logging to trace
This enables us to start with `RUSTC_LOG=rustc_trait_selection::solve=debug` to figure out *where* something went wrong, to then separately use `trace` to get to the details.
r? ``@compiler-errors``
Fix, document, and test parser and pretty-printer edge cases related to braced macro calls
_Review note: this is a deceptively small PR because it comes with 145 lines of docs and 196 lines of tests, and only 25 lines of compiler code changed. However, I recommend reviewing it 1 commit at a time because much of the effect of the code changes is non-local i.e. affecting code that is not visible in the final state of the PR. I have paid attention that reviewing the PR one commit at a time is as easy as I can make it. All of the code you need to know about is touched in those commits, even if some of those changes disappear by the end of the stack._
This is a follow-up to https://github.com/rust-lang/rust/pull/119105. One case that is not relevant to `-Zunpretty=expanded`, but which came up as I'm porting #119105 and #118726 into `syn`'s printer and `prettyplease`'s printer where it **is** relevant, and is also relevant to rustc's `stringify!`, is statement boundaries in the vicinity of braced macro calls.
Rustc's AST pretty-printer produces invalid syntax for statements that begin with a braced macro call:
```rust
macro_rules! stringify_item {
($i:item) => {
stringify!($i)
};
}
macro_rules! repro {
($e:expr) => {
stringify_item!(fn main() { $e + 1; })
};
}
fn main() {
println!("{}", repro!(m! {}));
}
```
**Before this PR:** output is not valid Rust syntax.
```console
fn main() { m! {} + 1; }
```
```console
error: leading `+` is not supported
--> <anon>:1:19
|
1 | fn main() { m! {} + 1; }
| ^ unexpected `+`
|
help: try removing the `+`
|
1 - fn main() { m! {} + 1; }
1 + fn main() { m! {} 1; }
|
```
**After this PR:** valid syntax.
```console
fn main() { (m! {}) + 1; }
```
Uplift various `*Predicate` types into `rustc_type_ir`
Uplifts `ProjectionPredicate`, `ExistentialTraitRef`, `ExistentialProjection`, `TraitPredicate`, `NormalizesTo`, `CoercePredicate`, and `SubtypePredicate`.
Adds `rustc_type_ir_macros`, which semi-duplicates the derive for `TypeVisitable`, `TypeFoldable`, and `Lift`, but in a way that is interner-agnostic.
Moves `rustc_type_ir::trait_ref` to `rustc_type_ir::predicate`. The specific placement of all these structs doesn't matter b/c of glob imports, tho.
Refactoring after the `PlaceValue` addition
I added [`PlaceValue`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_codegen_ssa/mir/place/struct.PlaceValue.html) in #123775, but kept that one line-by-line simple because it touched so many places.
This goes through to add more helpers & docs, and change some `PlaceRef` to `PlaceValue` where the type didn't need to be included.
No behaviour changes -- the codegen is exactly the same.
It is impossible for expr here to be a braced macro call. Expr comes
from `parse_stmt_without_recovery`, in which macro calls are parsed by
`parse_stmt_mac`. See this part:
let kind = if (style == MacStmtStyle::Braces
&& self.token != token::Dot
&& self.token != token::Question)
|| self.token == token::Semi
|| self.token == token::Eof
{
StmtKind::MacCall(P(MacCallStmt { mac, style, attrs, tokens: None }))
} else {
// Since none of the above applied, this is an expression statement macro.
let e = self.mk_expr(lo.to(hi), ExprKind::MacCall(mac));
let e = self.maybe_recover_from_bad_qpath(e)?;
let e = self.parse_expr_dot_or_call_with(e, lo, attrs)?;
let e = self.parse_expr_assoc_with(
0,
LhsExpr::AlreadyParsed { expr: e, starts_statement: false },
)?;
StmtKind::Expr(e)
};
A braced macro call at the head of a statement is always either extended
into ExprKind::Field / MethodCall / Await / Try / Binary, or else
returned as StmtKind::MacCall. We can never get a StmtKind::Expr
containing ExprKind::MacCall containing brace delimiter.
The change to the test is a little goofy because the compiler was
guessing "correctly" before that `falsy! {}` is the condition as opposed
to the else body. But I believe this change is fundamentally correct.
Braced macro invocations in statement position are most often item-like
(`thread_local! {...}`) as opposed to parenthesized macro invocations
which are condition-like (`cfg!(...)`).
I didn't figure out how to reach this condition with `expr` containing
`ExprKind::MacCall`. All the approaches I tried ended up with the macro
call ending up in the `StmtKind::MacCall` case below instead.
In any case, from visual inspection this is a bugfix. If we do end up
with a `StmtKind::Expr` containing `ExprKind::MacCall` with brace
delimiter, it would not need ";" printed after it.
This commit by itself is supposed to have no effect on behavior. All of
the call sites are updated to preserve their previous behavior.
The behavior changes are in the commits that follow.
For each of these, we need to decide whether they need to be using
`expr_requires_semi_to_be_stmt`, or `expr_requires_comma_to_be_match_arm`,
which are supposed to be 2 different behaviors. Previously they were
conflated into one, causing either too much or too little
parenthesization.
Refactor Apple `target_abi`
This was bundled together with `Arch`, which complicated a few code paths and meant we had to do more string matching than necessary.
CC `@BlackHoleFox` as you've worked on the Apple target spec before
Related: Is there a reason why `Target`/`TargetOptions` use `StaticCow` for so many things, instead of an enum with defined values (and perhaps a catch-all case for custom target json files)? Tagging `@Nilstrieb,` as you might know?
Update ena to 0.14.3
Includes https://github.com/rust-lang/ena/pull/53, which removes a trivial `Self: Sized` bound that prevents `ena` from building on the new solver.
I added `PlaceValue` in 123775, but kept that one line-by-line simple because it touched so many places.
This goes through to add more helpers & docs, and change some `PlaceRef` to `PlaceValue` where the type didn't need to be included.
No behaviour changes.
Rollup of 5 pull requests
Successful merges:
- #124233 (Add `-lmingwex` second time in `mingw_libs`)
- #124318 (ignore generics args in attribute paths)
- #124899 (bootstrap: add comments for the automatic dry run)
- #124904 (reachable computation: extend explanation of what this does, and why)
- #124930 (Make sure we consume a generic arg when checking mistyped turbofish)
r? `@ghost`
`@rustbot` modify labels: rollup
Make sure we consume a generic arg when checking mistyped turbofish
When recovering un-turbofish-ed args in expr position (e.g. `let x = a<T, U>();` in `check_mistyped_turbofish_with_multiple_type_params`, we used `parse_seq_to_before_end` to parse the fake generic args; however, it used `parse_generic_arg` which *optionally* parses a generic arg. If it doesn't end up parsing an arg, it returns `Ok(None)` and consumes no tokens. If we don't find a delimiter after this (`,`), we try parsing *another* element. In this case, we just infinitely loop looking for a subsequent element.
We can fix this by making sure that we either parse a generic arg or error in `parse_seq_to_before_end`'s callback.
Fixes#124897
reachable computation: extend explanation of what this does, and why
Follow-up to https://github.com/rust-lang/rust/pull/122769. I had the time to think about this some more, in particular in the context of https://github.com/rust-lang/rust/issues/119214, so I felt it was worth extending these comments some more.
I also gave up on the context of "externally reachable" as it is not called that way anywhere else in the compiler.
Cc `@tmiasko` `@saethlin`
ignore generics args in attribute paths
Fixes#97006Fixes#123911Fixes#123912
This patch ensures that we no longer have to handle invalid generic arguments in attribute paths.
r? `@petrochenkov`
Add `-lmingwex` second time in `mingw_libs`
Upcoming mingw-w64 releases will contain small math functions refactor which moved implementation around. As a result functions like `lgamma`
now depend on libraries in this order:
`libmingwex.a` -> `libmsvcrt.a` -> `libmingwex.a`.
Fixes#124221
Avoid `alloca`s in codegen for simple `mir::Aggregate` statements
The core idea here is to remove the abstraction penalty of simple newtypes in codegen.
Even something simple like constructing a
```rust
#[repr(transparent)] struct Foo(u32);
```
forces an `alloca` to be generated in nightly right now.
Certainly LLVM can optimize that away, but it would be nice if it didn't have to.
Quick example:
```rust
#[repr(transparent)]
pub struct Transparent32(u32);
#[no_mangle]
pub fn make_transparent(x: u32) -> Transparent32 {
let a = Transparent32(x);
a
}
```
on nightly we produce <https://rust.godbolt.org/z/zcvoM79ae>
```llvm
define noundef i32 `@make_transparent(i32` noundef %x) unnamed_addr #0 {
%a = alloca i32, align 4
store i32 %x, ptr %a, align 4
%0 = load i32, ptr %a, align 4, !noundef !3
ret i32 %0
}
```
but after this PR we produce
```llvm
define noundef i32 `@make_transparent(i32` noundef %x) unnamed_addr #0 {
start:
ret i32 %x
}
```
(even before the optimizer runs).
Rename some `FulfillmentErrorCode`/`ObligationCauseCode` variants to be less redundant
1. Rename some `FulfillmentErrorCode` variants.
2. Always use `ObligationCauseCode::` to prefix a code, rather than using a glob import and naming them through `traits::`.
3. Rename some `ObligationCauseCode` variants -- I wasn't particularly thorough with thinking of a new names for these, so could workshop them if necessary.
4. Misc stuff from renaming.
r? lcnr
