bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #57886 - davidtwco:issue-57385, r=estebank

Browse source 
Add suggestion for moving type declaration before associated type bindings in generic arguments.

Fixes #57385.

r? @estebank
This commit is contained in:
Mazdak Farrokhzad 2019-01-25 16:59:29 +01:00 • committed by GitHub
commit 7768358e72
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 305 additions and 29 deletions
Download patch file Download diff file Expand all files Collapse all files

122
src/libsyntax/parse/parser.rs
View file

@ -5543,22 +5543,31 @@ impl<'a> Parser<'a> {
fn parse_generic_args(&mut self) -> PResult<'a, (Vec<GenericArg>, Vec<TypeBinding>)> {
let mut args = Vec::new();
let mut bindings = Vec::new();
let mut seen_type = false;
let mut seen_binding = false;
let mut first_type_or_binding_span: Option<Span> = None;
let mut bad_lifetime_pos = vec![];
let mut last_comma_span = None;
let mut suggestions = vec![];
let mut first_type_or_binding_span: Option<Span> = None;
let mut first_binding_span: Option<Span> = None;
let mut bad_lifetime_pos = vec![];
let mut bad_type_pos = vec![];
let mut lifetime_suggestions = vec![];
let mut type_suggestions = vec![];
loop {
if self.check_lifetime() && self.look_ahead(1, |t| !t.is_like_plus()) {
// Parse lifetime argument.
args.push(GenericArg::Lifetime(self.expect_lifetime()));
if seen_type || seen_binding {
let remove_sp = last_comma_span.unwrap_or(self.prev_span).to(self.prev_span);
bad_lifetime_pos.push(self.prev_span);
if let Ok(snippet) = self.sess.source_map().span_to_snippet(self.prev_span) {
suggestions.push((remove_sp, String::new()));
suggestions.push((
lifetime_suggestions.push((remove_sp, String::new()));
lifetime_suggestions.push((
first_type_or_binding_span.unwrap().shrink_to_lo(),
format!("{}, ", snippet)));
}
@ -5576,24 +5585,29 @@ impl<'a> Parser<'a> {
ty,
span,
});
seen_binding = true;
if first_type_or_binding_span.is_none() {
first_type_or_binding_span = Some(span);
}
if first_binding_span.is_none() {
first_binding_span = Some(span);
}
} else if self.check_type() {
// Parse type argument.
let ty_param = self.parse_ty()?;
if seen_binding {
self.struct_span_err(
ty_param.span,
"type parameters must be declared prior to associated type bindings"
)
.span_label(
ty_param.span,
"must be declared prior to associated type bindings",
)
.emit();
let remove_sp = last_comma_span.unwrap_or(self.prev_span).to(self.prev_span);
bad_type_pos.push(self.prev_span);
if let Ok(snippet) = self.sess.source_map().span_to_snippet(self.prev_span) {
type_suggestions.push((remove_sp, String::new()));
type_suggestions.push((
first_binding_span.unwrap().shrink_to_lo(),
format!("{}, ", snippet)));
}
}
if first_type_or_binding_span.is_none() {
first_type_or_binding_span = Some(ty_param.span);
}
@ -5609,28 +5623,94 @@ impl<'a> Parser<'a> {
last_comma_span = Some(self.prev_span);
}
}
if !bad_lifetime_pos.is_empty() {
let mut err = self.struct_span_err(
self.maybe_report_incorrect_generic_argument_order(
bad_lifetime_pos, bad_type_pos, lifetime_suggestions, type_suggestions
);
Ok((args, bindings))
}
/// Maybe report an error about incorrect generic argument order - "lifetime parameters
/// must be declared before type parameters", "type parameters must be declared before
/// associated type bindings" or both.
fn maybe_report_incorrect_generic_argument_order(
&self,
bad_lifetime_pos: Vec<Span>,
bad_type_pos: Vec<Span>,
lifetime_suggestions: Vec<(Span, String)>,
type_suggestions: Vec<(Span, String)>,
) {
let mut err = if !bad_lifetime_pos.is_empty() && !bad_type_pos.is_empty() {
let mut positions = bad_lifetime_pos.clone();
positions.extend_from_slice(&bad_type_pos);
self.struct_span_err(
positions,
"generic arguments must declare lifetimes, types and associated type bindings in \
that order",
)
} else if !bad_lifetime_pos.is_empty() {
self.struct_span_err(
bad_lifetime_pos.clone(),
"lifetime parameters must be declared prior to type parameters"
);
)
} else if !bad_type_pos.is_empty() {
self.struct_span_err(
bad_type_pos.clone(),
"type parameters must be declared prior to associated type bindings"
)
} else {
return;
};
if !bad_lifetime_pos.is_empty() {
for sp in &bad_lifetime_pos {
err.span_label(*sp, "must be declared prior to type parameters");
}
if !suggestions.is_empty() {
}
if !bad_type_pos.is_empty() {
for sp in &bad_type_pos {
err.span_label(*sp, "must be declared prior to associated type bindings");
}
}
if !lifetime_suggestions.is_empty() && !type_suggestions.is_empty() {
let mut suggestions = lifetime_suggestions;
suggestions.extend_from_slice(&type_suggestions);
let plural = bad_lifetime_pos.len() + bad_type_pos.len() > 1;
err.multipart_suggestion_with_applicability(
&format!(
"move the parameter{}",
if plural { "s" } else { "" },
),
suggestions,
Applicability::MachineApplicable,
);
} else if !lifetime_suggestions.is_empty() {
err.multipart_suggestion_with_applicability(
&format!(
"move the lifetime parameter{} prior to the first type parameter",
if bad_lifetime_pos.len() > 1 { "s" } else { "" },
),
suggestions,
lifetime_suggestions,
Applicability::MachineApplicable,
);
} else if !type_suggestions.is_empty() {
err.multipart_suggestion_with_applicability(
&format!(
"move the type parameter{} prior to the first associated type binding",
if bad_type_pos.len() > 1 { "s" } else { "" },
),
type_suggestions,
Applicability::MachineApplicable,
);
}
err.emit();
}
Ok((args, bindings))
}
/// Parses an optional `where` clause and places it in `generics`.
///

4
src/test/ui/parser/issue-32214.stderr
View file

@ -3,6 +3,10 @@ error: type parameters must be declared prior to associated type bindings
|
LL | pub fn test<W, I: Trait<Item=(), W> >() {}
| ^ must be declared prior to associated type bindings
help: move the type parameter prior to the first associated type binding
|
LL | pub fn test<W, I: Trait<W, Item=()> >() {}
| ^^ --
error: aborting due to previous error

85
src/test/ui/suggestions/suggest-move-types.rs Normal file
View file

@ -0,0 +1,85 @@
// ignore-tidy-linelength
#![allow(warnings)]
// This test verifies that the suggestion to move types before associated type bindings
// is correct.
trait One<T> {
type A;
}
trait OneWithLifetime<'a, T> {
type A;
}
trait Three<T, U, V> {
type A;
type B;
type C;
}
trait ThreeWithLifetime<'a, 'b, 'c, T, U, V> {
type A;
type B;
type C;
}
struct A<T, M: One<A=(), T>> { //~ ERROR type parameters must be declared
m: M,
t: T,
}
struct Al<'a, T, M: OneWithLifetime<A=(), T, 'a>> {
//~^ ERROR generic arguments must declare lifetimes, types and associated type bindings in that order
m: M,
t: &'a T,
}
struct B<T, U, V, M: Three<A=(), B=(), C=(), T, U, V>> { //~ ERROR type parameters must be declared
m: M,
t: T,
u: U,
v: V,
}
struct Bl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<A=(), B=(), C=(), T, U, V, 'a, 'b, 'c>> {
//~^ ERROR generic arguments must declare lifetimes, types and associated type bindings in that order
m: M,
t: &'a T,
u: &'b U,
v: &'c V,
}
struct C<T, U, V, M: Three<T, A=(), B=(), C=(), U, V>> { //~ ERROR type parameters must be declared
m: M,
t: T,
u: U,
v: V,
}
struct Cl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), C=(), U, 'b, V, 'c>> {
//~^ ERROR generic arguments must declare lifetimes, types and associated type bindings in that order
m: M,
t: &'a T,
u: &'b U,
v: &'c V,
}
struct D<T, U, V, M: Three<T, A=(), B=(), U, C=(), V>> { //~ ERROR type parameters must be declared
m: M,
t: T,
u: U,
v: V,
}
struct Dl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), U, 'b, C=(), V, 'c>> {
//~^ ERROR generic arguments must declare lifetimes, types and associated type bindings in that order
m: M,
t: &'a T,
u: &'b U,
v: &'c V,
}
fn main() {}

107
src/test/ui/suggestions/suggest-move-types.stderr Normal file
View file

@ -0,0 +1,107 @@
error: type parameters must be declared prior to associated type bindings
--> $DIR/suggest-move-types.rs:28:26
|
LL | struct A<T, M: One<A=(), T>> { //~ ERROR type parameters must be declared
| ^ must be declared prior to associated type bindings
help: move the type parameter prior to the first associated type binding
|
LL | struct A<T, M: One<T, A=()>> { //~ ERROR type parameters must be declared
| ^^ --
error: generic arguments must declare lifetimes, types and associated type bindings in that order
--> $DIR/suggest-move-types.rs:34:46
|
LL | struct Al<'a, T, M: OneWithLifetime<A=(), T, 'a>> {
| ^ ^^ must be declared prior to type parameters
| |
| must be declared prior to associated type bindings
help: move the parameters
|
LL | struct Al<'a, T, M: OneWithLifetime<'a, T, A=()>> {
| ^^^ ^^ --
error: type parameters must be declared prior to associated type bindings
--> $DIR/suggest-move-types.rs:40:46
|
LL | struct B<T, U, V, M: Three<A=(), B=(), C=(), T, U, V>> { //~ ERROR type parameters must be declared
| ^ ^ ^ must be declared prior to associated type bindings
| | |
| | must be declared prior to associated type bindings
| must be declared prior to associated type bindings
help: move the type parameters prior to the first associated type binding
|
LL | struct B<T, U, V, M: Three<T, U, V, A=(), B=(), C=()>> { //~ ERROR type parameters must be declared
| ^^ ^^ ^^ --
error: generic arguments must declare lifetimes, types and associated type bindings in that order
--> $DIR/suggest-move-types.rs:47:80
|
LL | struct Bl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<A=(), B=(), C=(), T, U, V, 'a, 'b, 'c>> {
| ^ ^ ^ ^^ ^^ ^^ must be declared prior to type parameters
| | | | | |
| | | | | must be declared prior to type parameters
| | | | must be declared prior to type parameters
| | | must be declared prior to associated type bindings
| | must be declared prior to associated type bindings
| must be declared prior to associated type bindings
help: move the parameters
|
LL | struct Bl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<'a, 'b, 'c, T, U, V, A=(), B=(), C=()>> {
| ^^^ ^^^ ^^^ ^^ ^^ ^^ --
error: type parameters must be declared prior to associated type bindings
--> $DIR/suggest-move-types.rs:55:49
|
LL | struct C<T, U, V, M: Three<T, A=(), B=(), C=(), U, V>> { //~ ERROR type parameters must be declared
| ^ ^ must be declared prior to associated type bindings
| |
| must be declared prior to associated type bindings
help: move the type parameters prior to the first associated type binding
|
LL | struct C<T, U, V, M: Three<T, U, V, A=(), B=(), C=()>> { //~ ERROR type parameters must be declared
| ^^ ^^ --
error: generic arguments must declare lifetimes, types and associated type bindings in that order
--> $DIR/suggest-move-types.rs:62:56
|
LL | struct Cl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), C=(), U, 'b, V, 'c>> {
| ^^ ^ ^^ ^ ^^ must be declared prior to type parameters
| | | | |
| | | | must be declared prior to associated type bindings
| | | must be declared prior to type parameters
| | must be declared prior to associated type bindings
| must be declared prior to type parameters
help: move the parameters
|
LL | struct Cl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<'a, 'b, 'c, T, U, V, A=(), B=(), C=()>> {
| ^^^ ^^^ ^^^ -- ^^ ^^ --
error: type parameters must be declared prior to associated type bindings
--> $DIR/suggest-move-types.rs:70:43
|
LL | struct D<T, U, V, M: Three<T, A=(), B=(), U, C=(), V>> { //~ ERROR type parameters must be declared
| ^ ^ must be declared prior to associated type bindings
| |
| must be declared prior to associated type bindings
help: move the type parameters prior to the first associated type binding
|
LL | struct D<T, U, V, M: Three<T, U, V, A=(), B=(), C=()>> { //~ ERROR type parameters must be declared
| ^^ ^^ -- --
error: generic arguments must declare lifetimes, types and associated type bindings in that order
--> $DIR/suggest-move-types.rs:77:56
|
LL | struct Dl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<T, 'a, A=(), B=(), U, 'b, C=(), V, 'c>> {
| ^^ ^ ^^ ^ ^^ must be declared prior to type parameters
| | | | |
| | | | must be declared prior to associated type bindings
| | | must be declared prior to type parameters
| | must be declared prior to associated type bindings
| must be declared prior to type parameters
help: move the parameters
|
LL | struct Dl<'a, 'b, 'c, T, U, V, M: ThreeWithLifetime<'a, 'b, 'c, T, U, V, A=(), B=(), C=()>> {
| ^^^ ^^^ ^^^ -- ^^ ^^ -- --
error: aborting due to 8 previous errors