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Add (..) syntax for RTN

This commit is contained in:
Michael Goulet 2023-03-16 22:00:08 +00:00
parent 104aacb49f
commit 8b592db27a
44 changed files with 355 additions and 201 deletions

View file

@ -353,7 +353,13 @@ pub enum BadReturnTypeNotation {
#[diag(ast_lowering_bad_return_type_notation_inputs)]
Inputs {
#[primary_span]
#[suggestion(code = "()", applicability = "maybe-incorrect")]
#[suggestion(code = "(..)", applicability = "maybe-incorrect")]
span: Span,
},
#[diag(ast_lowering_bad_return_type_notation_needs_dots)]
NeedsDots {
#[primary_span]
#[suggestion(code = "(..)", applicability = "maybe-incorrect")]
span: Span,
},
#[diag(ast_lowering_bad_return_type_notation_output)]

View file

@ -66,7 +66,7 @@ use rustc_middle::{
span_bug,
ty::{ResolverAstLowering, TyCtxt},
};
use rustc_session::parse::feature_err;
use rustc_session::parse::{add_feature_diagnostics, feature_err};
use rustc_span::hygiene::MacroKind;
use rustc_span::source_map::DesugaringKind;
use rustc_span::symbol::{kw, sym, Ident, Symbol};
@ -987,33 +987,56 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
GenericArgs::AngleBracketed(data) => {
self.lower_angle_bracketed_parameter_data(data, ParamMode::Explicit, itctx).0
}
GenericArgs::Parenthesized(data) if self.tcx.features().return_type_notation => {
if !data.inputs.is_empty() {
self.tcx.sess.emit_err(errors::BadReturnTypeNotation::Inputs {
span: data.inputs_span,
});
} else if let FnRetTy::Ty(ty) = &data.output {
self.tcx.sess.emit_err(errors::BadReturnTypeNotation::Output {
span: data.inputs_span.shrink_to_hi().to(ty.span),
});
}
GenericArgsCtor {
args: Default::default(),
bindings: &[],
parenthesized: true,
span: data.span,
}
}
&GenericArgs::ReturnTypeNotation(span) => GenericArgsCtor {
args: Default::default(),
bindings: &[],
parenthesized: hir::GenericArgsParentheses::ReturnTypeNotation,
span,
},
GenericArgs::Parenthesized(data) => {
self.emit_bad_parenthesized_trait_in_assoc_ty(data);
// FIXME(return_type_notation): we could issue a feature error
// if the parens are empty and there's no return type.
self.lower_angle_bracketed_parameter_data(
&data.as_angle_bracketed_args(),
ParamMode::Explicit,
itctx,
)
.0
if let Some(start_char) = constraint.ident.as_str().chars().next()
&& start_char.is_ascii_lowercase()
{
let mut err = if !data.inputs.is_empty() {
self.tcx.sess.create_err(errors::BadReturnTypeNotation::Inputs {
span: data.inputs_span,
})
} else if let FnRetTy::Ty(ty) = &data.output {
self.tcx.sess.create_err(errors::BadReturnTypeNotation::Output {
span: data.inputs_span.shrink_to_hi().to(ty.span),
})
} else {
self.tcx.sess.create_err(errors::BadReturnTypeNotation::NeedsDots {
span: data.inputs_span,
})
};
if !self.tcx.features().return_type_notation
&& self.tcx.sess.is_nightly_build()
{
add_feature_diagnostics(
&mut err,
&self.tcx.sess.parse_sess,
sym::return_type_notation,
);
}
err.emit();
GenericArgsCtor {
args: Default::default(),
bindings: &[],
parenthesized: hir::GenericArgsParentheses::ReturnTypeNotation,
span: data.span,
}
} else {
self.emit_bad_parenthesized_trait_in_assoc_ty(data);
// FIXME(return_type_notation): we could issue a feature error
// if the parens are empty and there's no return type.
self.lower_angle_bracketed_parameter_data(
&data.as_angle_bracketed_args(),
ParamMode::Explicit,
itctx,
)
.0
}
}
};
gen_args_ctor.into_generic_args(self)
@ -2094,7 +2117,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
let future_args = self.arena.alloc(hir::GenericArgs {
args: &[],
bindings: arena_vec![self; self.output_ty_binding(span, output_ty)],
parenthesized: false,
parenthesized: hir::GenericArgsParentheses::No,
span_ext: DUMMY_SP,
});
@ -2614,13 +2637,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
struct GenericArgsCtor<'hir> {
args: SmallVec<[hir::GenericArg<'hir>; 4]>,
bindings: &'hir [hir::TypeBinding<'hir>],
parenthesized: bool,
parenthesized: hir::GenericArgsParentheses,
span: Span,
}
impl<'hir> GenericArgsCtor<'hir> {
fn is_empty(&self) -> bool {
self.args.is_empty() && self.bindings.is_empty() && !self.parenthesized
self.args.is_empty()
&& self.bindings.is_empty()
&& self.parenthesized == hir::GenericArgsParentheses::No
}
fn into_generic_args(self, this: &LoweringContext<'_, 'hir>) -> &'hir hir::GenericArgs<'hir> {

View file

@ -13,6 +13,7 @@ use rustc_span::symbol::{kw, sym, Ident};
use rustc_span::{BytePos, Span, DUMMY_SP};
use smallvec::{smallvec, SmallVec};
use thin_vec::ThinVec;
impl<'a, 'hir> LoweringContext<'a, 'hir> {
#[instrument(level = "trace", skip(self))]
@ -218,13 +219,25 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
)
}
},
&GenericArgs::ReturnTypeNotation(span) => {
self.tcx.sess.emit_err(GenericTypeWithParentheses { span, sub: None });
(
self.lower_angle_bracketed_parameter_data(
&AngleBracketedArgs { span, args: ThinVec::default() },
param_mode,
itctx,
)
.0,
false,
)
}
}
} else {
(
GenericArgsCtor {
args: Default::default(),
bindings: &[],
parenthesized: false,
parenthesized: hir::GenericArgsParentheses::No,
span: path_span.shrink_to_hi(),
},
param_mode == ParamMode::Optional,
@ -233,7 +246,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
let has_lifetimes =
generic_args.args.iter().any(|arg| matches!(arg, GenericArg::Lifetime(_)));
if !generic_args.parenthesized && !has_lifetimes {
// FIXME(return_type_notation): Is this correct? I think so.
if generic_args.parenthesized != hir::GenericArgsParentheses::ParenSugar && !has_lifetimes {
self.maybe_insert_elided_lifetimes_in_path(
path_span,
segment.id,
@ -328,7 +343,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
AngleBracketedArg::Constraint(c) => Some(self.lower_assoc_ty_constraint(c, itctx)),
AngleBracketedArg::Arg(_) => None,
}));
let ctor = GenericArgsCtor { args, bindings, parenthesized: false, span: data.span };
let ctor = GenericArgsCtor {
args,
bindings,
parenthesized: hir::GenericArgsParentheses::No,
span: data.span,
};
(ctor, !has_non_lt_args && param_mode == ParamMode::Optional)
}
@ -376,7 +396,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
GenericArgsCtor {
args,
bindings: arena_vec![self; binding],
parenthesized: true,
parenthesized: hir::GenericArgsParentheses::ParenSugar,
span: data.inputs_span,
},
false,
@ -396,7 +416,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
let gen_args = self.arena.alloc(hir::GenericArgs {
args,
bindings,
parenthesized: false,
parenthesized: hir::GenericArgsParentheses::No,
span_ext: DUMMY_SP,
});
hir::TypeBinding {