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Tweak parameter mismatch explanation to not say unknown
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@compiler-errors
compiler-errors committed Nov 25, 2024
1 parent 15b663e commit 78fa5a1
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Showing 8 changed files with 87 additions and 38 deletions.
11 changes: 11 additions & 0 deletions compiler/rustc_errors/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1995,6 +1995,17 @@ pub fn display_list_with_comma_and<T: std::fmt::Display>(v: &[T]) -> String {
}
}

pub fn ordinalize(x: usize) -> String {
let suffix = match x % 10 {
_ if (11..=19).contains(&x) => "th",
1 => "st",
2 => "nd",
3 => "rd",
_ => "th",
};
format!("{x}{suffix}")
}

#[derive(Clone, Copy, PartialEq, Hash, Debug)]
pub enum TerminalUrl {
No,
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55 changes: 31 additions & 24 deletions compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@ use rustc_data_structures::fx::FxIndexSet;
use rustc_errors::codes::*;
use rustc_errors::{
Applicability, Diag, ErrorGuaranteed, MultiSpan, StashKey, a_or_an,
display_list_with_comma_and, pluralize,
display_list_with_comma_and, ordinalize, pluralize,
};
use rustc_hir::def::{CtorOf, DefKind, Res};
use rustc_hir::def_id::DefId;
Expand Down Expand Up @@ -2347,9 +2347,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {

let check_for_matched_generics = || {
if matched_inputs.iter().any(|x| x.is_some())
&& params_with_generics.iter().any(|x| x.0.is_some())
&& params_with_generics.iter().any(|x| x.1.is_some())
{
for (idx, (generic, _)) in params_with_generics.iter().enumerate() {
for &(idx, generic, _) in &params_with_generics {
// Param has to have a generic and be matched to be relevant
if matched_inputs[idx.into()].is_none() {
continue;
Expand All @@ -2362,7 +2362,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
for unmatching_idx in idx + 1..params_with_generics.len() {
if matched_inputs[unmatching_idx.into()].is_none()
&& let Some(unmatched_idx_param_generic) =
params_with_generics[unmatching_idx].0
params_with_generics[unmatching_idx].1
&& unmatched_idx_param_generic.name.ident()
== generic.name.ident()
{
Expand All @@ -2377,8 +2377,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {

let check_for_matched_generics = check_for_matched_generics();

for (idx, (generic_param, param)) in
params_with_generics.iter().enumerate().filter(|(idx, _)| {
for &(idx, generic_param, param) in
params_with_generics.iter().filter(|&(idx, _, _)| {
check_for_matched_generics
|| expected_idx.is_none_or(|expected_idx| expected_idx == *idx)
})
Expand All @@ -2390,8 +2390,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {

let other_params_matched: Vec<(usize, &hir::Param<'_>)> = params_with_generics
.iter()
.enumerate()
.filter(|(other_idx, (other_generic_param, _))| {
.filter(|(other_idx, other_generic_param, _)| {
if *other_idx == idx {
return false;
}
Expand All @@ -2410,18 +2409,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
other_generic_param.name.ident() == generic_param.name.ident()
})
.map(|(other_idx, (_, other_param))| (other_idx, *other_param))
.map(|&(other_idx, _, other_param)| (other_idx, other_param))
.collect();

if !other_params_matched.is_empty() {
let other_param_matched_names: Vec<String> = other_params_matched
.iter()
.map(|(_, other_param)| {
.map(|(idx, other_param)| {
if let hir::PatKind::Binding(_, _, ident, _) = other_param.pat.kind
{
format!("`{ident}`")
} else {
"{unknown}".to_string()
format!("the {} parameter", ordinalize(idx + 1))
}
})
.collect();
Expand Down Expand Up @@ -2478,18 +2477,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
{
let param_idents_matching: Vec<String> = params_with_generics
.iter()
.filter(|(generic, _)| {
.filter(|(_, generic, _)| {
if let Some(generic) = generic {
generic.name.ident() == generic_param.name.ident()
} else {
false
}
})
.map(|(_, param)| {
.map(|(idx, _, param)| {
if let hir::PatKind::Binding(_, _, ident, _) = param.pat.kind {
format!("`{ident}`")
} else {
"{unknown}".to_string()
format!("the {} parameter", ordinalize(idx + 1))
}
})
.collect();
Expand All @@ -2498,8 +2497,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
spans.push_span_label(
generic_param.span,
format!(
"{} all reference this parameter {}",
"{} {} reference this parameter `{}`",
display_list_with_comma_and(&param_idents_matching),
if param_idents_matching.len() == 2 { "both" } else { "all" },
generic_param.name.ident().name,
),
);
Expand Down Expand Up @@ -2580,7 +2580,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {

if let Some(params_with_generics) = self.get_hir_params_with_generics(def_id, is_method) {
debug_assert_eq!(params_with_generics.len(), matched_inputs.len());
for (idx, (generic_param, _)) in params_with_generics.iter().enumerate() {
for &(idx, generic_param, _) in &params_with_generics {
if matched_inputs[idx.into()].is_none() {
continue;
}
Expand All @@ -2594,20 +2594,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
};

let mut idxs_matched: Vec<usize> = vec![];
for (other_idx, (_, _)) in params_with_generics.iter().enumerate().filter(
|(other_idx, (other_generic_param, _))| {
if *other_idx == idx {
for &(other_idx, _, _) in
params_with_generics.iter().filter(|&&(other_idx, other_generic_param, _)| {
if other_idx == idx {
return false;
}
let Some(other_generic_param) = other_generic_param else {
return false;
};
if matched_inputs[(*other_idx).into()].is_some() {
if matched_inputs[other_idx.into()].is_some() {
return false;
}
other_generic_param.name.ident() == generic_param.name.ident()
},
) {
})
{
idxs_matched.push(other_idx);
}

Expand Down Expand Up @@ -2642,7 +2642,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
&self,
def_id: DefId,
is_method: bool,
) -> Option<Vec<(Option<&hir::GenericParam<'_>>, &hir::Param<'_>)>> {
) -> Option<Vec<(usize, Option<&hir::GenericParam<'_>>, &hir::Param<'_>)>> {
let fn_node = self.tcx.hir().get_if_local(def_id)?;
let fn_decl = fn_node.fn_decl()?;

Expand Down Expand Up @@ -2685,7 +2685,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}

debug_assert_eq!(params.len(), generic_params.len());
Some(generic_params.into_iter().zip(params).collect())
Some(
generic_params
.into_iter()
.zip(params)
.enumerate()
.map(|(a, (b, c))| (a, b, c))
.collect(),
)
}
}

Expand Down
6 changes: 3 additions & 3 deletions tests/ui/async-await/coroutine-desc.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ LL | fn fun<F: Future<Output = ()>>(f1: F, f2: F) {}
| ^^^ - ----- ----- this parameter needs to match the `async` block type of `f1`
| | |
| | `f2` needs to match the `async` block type of this parameter
| `f1` and `f2` all reference this parameter F
| `f1` and `f2` both reference this parameter `F`

error[E0308]: mismatched types
--> $DIR/coroutine-desc.rs:12:16
Expand All @@ -39,7 +39,7 @@ LL | fn fun<F: Future<Output = ()>>(f1: F, f2: F) {}
| ^^^ - ----- ----- this parameter needs to match the future type of `f1`
| | |
| | `f2` needs to match the future type of this parameter
| `f1` and `f2` all reference this parameter F
| `f1` and `f2` both reference this parameter `F`

error[E0308]: mismatched types
--> $DIR/coroutine-desc.rs:14:26
Expand All @@ -62,7 +62,7 @@ LL | fn fun<F: Future<Output = ()>>(f1: F, f2: F) {}
| ^^^ - ----- ----- this parameter needs to match the `async` closure body type of `f1`
| | |
| | `f2` needs to match the `async` closure body type of this parameter
| `f1` and `f2` all reference this parameter F
| `f1` and `f2` both reference this parameter `F`

error: aborting due to 3 previous errors

Expand Down
2 changes: 1 addition & 1 deletion tests/ui/coercion/coerce-reborrow-multi-arg-fail.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ LL | fn test<T>(_a: T, _b: T) {}
| ^^^^ - ----- ----- this parameter needs to match the `&mut {integer}` type of `_a`
| | |
| | `_b` needs to match the `&mut {integer}` type of this parameter
| `_a` and `_b` all reference this parameter T
| `_a` and `_b` both reference this parameter `T`

error: aborting due to 1 previous error

Expand Down
10 changes: 5 additions & 5 deletions tests/ui/fn/fn-item-type.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@ LL | fn eq<T>(x: T, y: T) {}
| ^^ - ---- ---- this parameter needs to match the fn item type of `x`
| | |
| | `y` needs to match the fn item type of this parameter
| `x` and `y` all reference this parameter T
| `x` and `y` both reference this parameter `T`
= help: consider casting both fn items to fn pointers using `as fn(isize) -> isize`

error[E0308]: mismatched types
Expand All @@ -39,7 +39,7 @@ LL | fn eq<T>(x: T, y: T) {}
| ^^ - ---- ---- this parameter needs to match the fn item type of `x`
| | |
| | `y` needs to match the fn item type of this parameter
| `x` and `y` all reference this parameter T
| `x` and `y` both reference this parameter `T`
= help: consider casting both fn items to fn pointers using `as fn(isize) -> isize`

error[E0308]: mismatched types
Expand All @@ -61,7 +61,7 @@ LL | fn eq<T>(x: T, y: T) {}
| ^^ - ---- ---- this parameter needs to match the fn item type of `x`
| | |
| | `y` needs to match the fn item type of this parameter
| `x` and `y` all reference this parameter T
| `x` and `y` both reference this parameter `T`
= help: consider casting both fn items to fn pointers using `as fn(isize) -> isize`

error[E0308]: mismatched types
Expand All @@ -83,7 +83,7 @@ LL | fn eq<T>(x: T, y: T) {}
| ^^ - ---- ---- this parameter needs to match the fn item type of `x`
| | |
| | `y` needs to match the fn item type of this parameter
| `x` and `y` all reference this parameter T
| `x` and `y` both reference this parameter `T`
= help: consider casting both fn items to fn pointers using `as fn()`

error[E0308]: mismatched types
Expand All @@ -105,7 +105,7 @@ LL | fn eq<T>(x: T, y: T) {}
| ^^ - ---- ---- this parameter needs to match the fn item type of `x`
| | |
| | `y` needs to match the fn item type of this parameter
| `x` and `y` all reference this parameter T
| `x` and `y` both reference this parameter `T`

error: aborting due to 5 previous errors

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8 changes: 8 additions & 0 deletions tests/ui/fn/param-mismatch-no-names.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,8 @@
fn same_type<T>(_: T, _: T) {}

fn f<X, Y>(x: X, y: Y) {
same_type([x], Some(y));
//~^ ERROR mismatched types
}

fn main() {}
23 changes: 23 additions & 0 deletions tests/ui/fn/param-mismatch-no-names.stderr
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,23 @@
error[E0308]: mismatched types
--> $DIR/param-mismatch-no-names.rs:4:20
|
LL | same_type([x], Some(y));
| --------- --- ^^^^^^^ expected `[X; 1]`, found `Option<Y>`
| | |
| | expected all arguments to be this `[X; 1]` type because they need to match the type of this parameter
| arguments to this function are incorrect
|
= note: expected array `[X; 1]`
found enum `Option<Y>`
note: function defined here
--> $DIR/param-mismatch-no-names.rs:1:4
|
LL | fn same_type<T>(_: T, _: T) {}
| ^^^^^^^^^ - ---- ---- this parameter needs to match the `[X; 1]` type of the 1st parameter
| | |
| | the 2nd parameter needs to match the `[X; 1]` type of this parameter
| the 1st parameter and the 2nd parameter both reference this parameter `T`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0308`.
10 changes: 5 additions & 5 deletions tests/ui/mismatched_types/generic-mismatch-reporting-issue-116615.stderr
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ LL | fn foo<T>(a: T, b: T) {}
| ^^^ - ---- ---- this parameter needs to match the integer type of `a`
| | |
| | `b` needs to match the integer type of this parameter
| `a` and `b` all reference this parameter T
| `a` and `b` both reference this parameter `T`

error[E0308]: arguments to this function are incorrect
--> $DIR/generic-mismatch-reporting-issue-116615.rs:8:5
Expand All @@ -38,7 +38,7 @@ LL | fn foo_multi_same<T>(a: T, b: T, c: T, d: T, e: T, f: i32) {}
| | | | this parameter needs to match the `&str` type of `a` and `b`
| | | `c`, `d` and `e` need to match the `&str` type of this parameter
| | `c`, `d` and `e` need to match the `&str` type of this parameter
| `a`, `b`, `c`, `d` and `e` all reference this parameter T
| `a`, `b`, `c`, `d` and `e` all reference this parameter `T`

error[E0308]: arguments to this function are incorrect
--> $DIR/generic-mismatch-reporting-issue-116615.rs:10:5
Expand All @@ -65,8 +65,8 @@ LL | fn foo_multi_generics<S, T>(a: T, b: T, c: T, d: T, e: T, f: S, g: S) {}
| | | | | `d` and `e` need to match the `&str` type of this parameter
| | | | `d` and `e` need to match the `&str` type of this parameter
| | | `d` and `e` need to match the `&str` type of this parameter
| | `a`, `b`, `c`, `d` and `e` all reference this parameter T
| `f` and `g` all reference this parameter S
| | `a`, `b`, `c`, `d` and `e` all reference this parameter `T`
| `f` and `g` both reference this parameter `S`

error[E0308]: arguments to this function are incorrect
--> $DIR/generic-mismatch-reporting-issue-116615.rs:12:5
Expand All @@ -90,7 +90,7 @@ LL | fn foo_multi_same<T>(a: T, b: T, c: T, d: T, e: T, f: i32) {}
| | | | this parameter needs to match the `&str` type of `a`, `d` and `e`
| | | this parameter needs to match the `&str` type of `a`, `d` and `e`
| | `b` and `c` need to match the `&str` type of this parameter
| `a`, `b`, `c`, `d` and `e` all reference this parameter T
| `a`, `b`, `c`, `d` and `e` all reference this parameter `T`

error: aborting due to 4 previous errors

Expand Down

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