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Rollup merge of #133151 - tyrone-wu:trim-fn-ptr-whitespace, r=compiler-errors

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Trim extra whitespace in fn ptr suggestion span

Trim extra whitespace when suggesting removal of invalid qualifiers when parsing function pointer type.

Fixes: #133083

---

I made a comment about the format of the diagnostic error message in https://github.com/rust-lang/rust/issues/133083#issuecomment-2480047875. I think the `.label` may be a little redundant if the diagnostic only highlights the bad qualifier instead of the entire `TyKind::BareFn` span. If it makes sense, I can include it in this PR.
This commit is contained in:
Matthias Krüger 2025-01-28 14:23:20 +01:00 • committed by GitHub
commit c0005f1560
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5 changed files with 96 additions and 52 deletions
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6
compiler/rustc_parse/src/errors.rs
View file

@ -2830,9 +2830,10 @@ pub(crate) struct DynAfterMut {
pub(crate) struct FnPointerCannotBeConst {
#[primary_span]
pub span: Span,
#[suggestion(code = "", applicability = "maybe-incorrect", style = "verbose")]
#[label]
pub qualifier: Span,
#[suggestion(code = "", applicability = "maybe-incorrect", style = "verbose")]
pub suggestion: Span,
}
#[derive(Diagnostic)]
@ -2840,9 +2841,10 @@ pub(crate) struct FnPointerCannotBeConst {
pub(crate) struct FnPointerCannotBeAsync {
#[primary_span]
pub span: Span,
#[suggestion(code = "", applicability = "maybe-incorrect", style = "verbose")]
#[label]
pub qualifier: Span,
#[suggestion(code = "", applicability = "maybe-incorrect", style = "verbose")]
pub suggestion: Span,
}
#[derive(Diagnostic)]

50
compiler/rustc_parse/src/parser/ty.rs
View file

@ -609,16 +609,58 @@ impl<'a> Parser<'a> {
let span_start = self.token.span;
let ast::FnHeader { ext, safety, constness, coroutine_kind } =
self.parse_fn_front_matter(&inherited_vis, Case::Sensitive)?;
let fn_start_lo = self.prev_token.span.lo();
if self.may_recover() && self.token == TokenKind::Lt {
self.recover_fn_ptr_with_generics(lo, &mut params, param_insertion_point)?;
}
let decl = self.parse_fn_decl(|_| false, AllowPlus::No, recover_return_sign)?;
let whole_span = lo.to(self.prev_token.span);
if let ast::Const::Yes(span) = constness {
self.dcx().emit_err(FnPointerCannotBeConst { span: whole_span, qualifier: span });
// Order/parsing of "front matter" follows:
// `<constness> <coroutine_kind> <safety> <extern> fn()`
// ^ ^ ^ ^ ^
// | | | | fn_start_lo
// | | | ext_sp.lo
// | | safety_sp.lo
// | coroutine_sp.lo
// const_sp.lo
if let ast::Const::Yes(const_span) = constness {
let next_token_lo = if let Some(
ast::CoroutineKind::Async { span, .. }
| ast::CoroutineKind::Gen { span, .. }
| ast::CoroutineKind::AsyncGen { span, .. },
) = coroutine_kind
{
span.lo()
} else if let ast::Safety::Unsafe(span) | ast::Safety::Safe(span) = safety {
span.lo()
} else if let ast::Extern::Implicit(span) | ast::Extern::Explicit(_, span) = ext {
span.lo()
} else {
fn_start_lo
};
let sugg_span = const_span.with_hi(next_token_lo);
self.dcx().emit_err(FnPointerCannotBeConst {
span: whole_span,
qualifier: const_span,
suggestion: sugg_span,
});
}
if let Some(ast::CoroutineKind::Async { span, .. }) = coroutine_kind {
self.dcx().emit_err(FnPointerCannotBeAsync { span: whole_span, qualifier: span });
if let Some(ast::CoroutineKind::Async { span: async_span, .. }) = coroutine_kind {
let next_token_lo = if let ast::Safety::Unsafe(span) | ast::Safety::Safe(span) = safety
{
span.lo()
} else if let ast::Extern::Implicit(span) | ast::Extern::Explicit(_, span) = ext {
span.lo()
} else {
fn_start_lo
};
let sugg_span = async_span.with_hi(next_token_lo);
self.dcx().emit_err(FnPointerCannotBeAsync {
span: whole_span,
qualifier: async_span,
suggestion: sugg_span,
});
}
// FIXME(gen_blocks): emit a similar error for `gen fn()`
let decl_span = span_start.to(self.prev_token.span);

28
tests/ui/parser/bad-fn-ptr-qualifier.fixed
View file

@ -2,24 +2,24 @@
//@ edition:2018
// Most of items are taken from ./recover-const-async-fn-ptr.rs but this is able to apply rustfix.
pub type T0 = fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type T1 = extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type T2 = unsafe extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type T3 = fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type T4 = extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type T5 = unsafe extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type T6 = unsafe extern "C" fn();
pub type T0 = fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type T1 = extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type T2 = unsafe extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type T3 = fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type T4 = extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type T5 = unsafe extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type T6 = unsafe extern "C" fn();
//~^ ERROR an `fn` pointer type cannot be `const`
//~| ERROR an `fn` pointer type cannot be `async`
pub type FTT0 = for<'a> fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type FTT1 = for<'a> extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type FTT2 = for<'a> unsafe extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type FTT3 = for<'a> fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type FTT4 = for<'a> extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type FTT5 = for<'a> unsafe extern "C" fn();
pub type FTT0 = for<'a> fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type FTT1 = for<'a> extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type FTT2 = for<'a> unsafe extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `const`
pub type FTT3 = for<'a> fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type FTT4 = for<'a> extern "C" fn(); //~ ERROR an `fn` pointer type cannot be `async`
pub type FTT5 = for<'a> unsafe extern "C" fn();
//~^ ERROR an `fn` pointer type cannot be `async`
pub type FTT6 = for<'a> unsafe extern "C" fn();
pub type FTT6 = for<'a> unsafe extern "C" fn();
//~^ ERROR an `fn` pointer type cannot be `const`
//~| ERROR an `fn` pointer type cannot be `async`

32
tests/ui/parser/bad-fn-ptr-qualifier.stderr
View file

@ -9,7 +9,7 @@ LL | pub type T0 = const fn();
help: remove the `const` qualifier
|
LL - pub type T0 = const fn();
LL + pub type T0 = fn();
LL + pub type T0 = fn();
|
error: an `fn` pointer type cannot be `const`
@ -23,7 +23,7 @@ LL | pub type T1 = const extern "C" fn();
help: remove the `const` qualifier
|
LL - pub type T1 = const extern "C" fn();
LL + pub type T1 = extern "C" fn();
LL + pub type T1 = extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -37,7 +37,7 @@ LL | pub type T2 = const unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - pub type T2 = const unsafe extern "C" fn();
LL + pub type T2 = unsafe extern "C" fn();
LL + pub type T2 = unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -51,7 +51,7 @@ LL | pub type T3 = async fn();
help: remove the `async` qualifier
|
LL - pub type T3 = async fn();
LL + pub type T3 = fn();
LL + pub type T3 = fn();
|
error: an `fn` pointer type cannot be `async`
@ -65,7 +65,7 @@ LL | pub type T4 = async extern "C" fn();
help: remove the `async` qualifier
|
LL - pub type T4 = async extern "C" fn();
LL + pub type T4 = extern "C" fn();
LL + pub type T4 = extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -79,7 +79,7 @@ LL | pub type T5 = async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - pub type T5 = async unsafe extern "C" fn();
LL + pub type T5 = unsafe extern "C" fn();
LL + pub type T5 = unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -93,7 +93,7 @@ LL | pub type T6 = const async unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - pub type T6 = const async unsafe extern "C" fn();
LL + pub type T6 = async unsafe extern "C" fn();
LL + pub type T6 = async unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -107,7 +107,7 @@ LL | pub type T6 = const async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - pub type T6 = const async unsafe extern "C" fn();
LL + pub type T6 = const unsafe extern "C" fn();
LL + pub type T6 = const unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -121,7 +121,7 @@ LL | pub type FTT0 = for<'a> const fn();
help: remove the `const` qualifier
|
LL - pub type FTT0 = for<'a> const fn();
LL + pub type FTT0 = for<'a> fn();
LL + pub type FTT0 = for<'a> fn();
|
error: an `fn` pointer type cannot be `const`
@ -135,7 +135,7 @@ LL | pub type FTT1 = for<'a> const extern "C" fn();
help: remove the `const` qualifier
|
LL - pub type FTT1 = for<'a> const extern "C" fn();
LL + pub type FTT1 = for<'a> extern "C" fn();
LL + pub type FTT1 = for<'a> extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -149,7 +149,7 @@ LL | pub type FTT2 = for<'a> const unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - pub type FTT2 = for<'a> const unsafe extern "C" fn();
LL + pub type FTT2 = for<'a> unsafe extern "C" fn();
LL + pub type FTT2 = for<'a> unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -163,7 +163,7 @@ LL | pub type FTT3 = for<'a> async fn();
help: remove the `async` qualifier
|
LL - pub type FTT3 = for<'a> async fn();
LL + pub type FTT3 = for<'a> fn();
LL + pub type FTT3 = for<'a> fn();
|
error: an `fn` pointer type cannot be `async`
@ -177,7 +177,7 @@ LL | pub type FTT4 = for<'a> async extern "C" fn();
help: remove the `async` qualifier
|
LL - pub type FTT4 = for<'a> async extern "C" fn();
LL + pub type FTT4 = for<'a> extern "C" fn();
LL + pub type FTT4 = for<'a> extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -191,7 +191,7 @@ LL | pub type FTT5 = for<'a> async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - pub type FTT5 = for<'a> async unsafe extern "C" fn();
LL + pub type FTT5 = for<'a> unsafe extern "C" fn();
LL + pub type FTT5 = for<'a> unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -205,7 +205,7 @@ LL | pub type FTT6 = for<'a> const async unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - pub type FTT6 = for<'a> const async unsafe extern "C" fn();
LL + pub type FTT6 = for<'a> async unsafe extern "C" fn();
LL + pub type FTT6 = for<'a> async unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -219,7 +219,7 @@ LL | pub type FTT6 = for<'a> const async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - pub type FTT6 = for<'a> const async unsafe extern "C" fn();
LL + pub type FTT6 = for<'a> const unsafe extern "C" fn();
LL + pub type FTT6 = for<'a> const unsafe extern "C" fn();
|
error: aborting due to 16 previous errors

32
tests/ui/parser/recover/recover-const-async-fn-ptr.stderr
View file

@ -9,7 +9,7 @@ LL | type T0 = const fn();
help: remove the `const` qualifier
|
LL - type T0 = const fn();
LL + type T0 = fn();
LL + type T0 = fn();
|
error: an `fn` pointer type cannot be `const`
@ -23,7 +23,7 @@ LL | type T1 = const extern "C" fn();
help: remove the `const` qualifier
|
LL - type T1 = const extern "C" fn();
LL + type T1 = extern "C" fn();
LL + type T1 = extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -37,7 +37,7 @@ LL | type T2 = const unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - type T2 = const unsafe extern "C" fn();
LL + type T2 = unsafe extern "C" fn();
LL + type T2 = unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -51,7 +51,7 @@ LL | type T3 = async fn();
help: remove the `async` qualifier
|
LL - type T3 = async fn();
LL + type T3 = fn();
LL + type T3 = fn();
|
error: an `fn` pointer type cannot be `async`
@ -65,7 +65,7 @@ LL | type T4 = async extern "C" fn();
help: remove the `async` qualifier
|
LL - type T4 = async extern "C" fn();
LL + type T4 = extern "C" fn();
LL + type T4 = extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -79,7 +79,7 @@ LL | type T5 = async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - type T5 = async unsafe extern "C" fn();
LL + type T5 = unsafe extern "C" fn();
LL + type T5 = unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -93,7 +93,7 @@ LL | type T6 = const async unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - type T6 = const async unsafe extern "C" fn();
LL + type T6 = async unsafe extern "C" fn();
LL + type T6 = async unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -107,7 +107,7 @@ LL | type T6 = const async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - type T6 = const async unsafe extern "C" fn();
LL + type T6 = const unsafe extern "C" fn();
LL + type T6 = const unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -121,7 +121,7 @@ LL | type FT0 = for<'a> const fn();
help: remove the `const` qualifier
|
LL - type FT0 = for<'a> const fn();
LL + type FT0 = for<'a> fn();
LL + type FT0 = for<'a> fn();
|
error: an `fn` pointer type cannot be `const`
@ -135,7 +135,7 @@ LL | type FT1 = for<'a> const extern "C" fn();
help: remove the `const` qualifier
|
LL - type FT1 = for<'a> const extern "C" fn();
LL + type FT1 = for<'a> extern "C" fn();
LL + type FT1 = for<'a> extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -149,7 +149,7 @@ LL | type FT2 = for<'a> const unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - type FT2 = for<'a> const unsafe extern "C" fn();
LL + type FT2 = for<'a> unsafe extern "C" fn();
LL + type FT2 = for<'a> unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -163,7 +163,7 @@ LL | type FT3 = for<'a> async fn();
help: remove the `async` qualifier
|
LL - type FT3 = for<'a> async fn();
LL + type FT3 = for<'a> fn();
LL + type FT3 = for<'a> fn();
|
error: an `fn` pointer type cannot be `async`
@ -177,7 +177,7 @@ LL | type FT4 = for<'a> async extern "C" fn();
help: remove the `async` qualifier
|
LL - type FT4 = for<'a> async extern "C" fn();
LL + type FT4 = for<'a> extern "C" fn();
LL + type FT4 = for<'a> extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -191,7 +191,7 @@ LL | type FT5 = for<'a> async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - type FT5 = for<'a> async unsafe extern "C" fn();
LL + type FT5 = for<'a> unsafe extern "C" fn();
LL + type FT5 = for<'a> unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `const`
@ -205,7 +205,7 @@ LL | type FT6 = for<'a> const async unsafe extern "C" fn();
help: remove the `const` qualifier
|
LL - type FT6 = for<'a> const async unsafe extern "C" fn();
LL + type FT6 = for<'a> async unsafe extern "C" fn();
LL + type FT6 = for<'a> async unsafe extern "C" fn();
|
error: an `fn` pointer type cannot be `async`
@ -219,7 +219,7 @@ LL | type FT6 = for<'a> const async unsafe extern "C" fn();
help: remove the `async` qualifier
|
LL - type FT6 = for<'a> const async unsafe extern "C" fn();
LL + type FT6 = for<'a> const unsafe extern "C" fn();
LL + type FT6 = for<'a> const unsafe extern "C" fn();
|
error[E0308]: mismatched types