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

@@ -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> {