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camelidGrigorenkoPV
camelid
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GrigorenkoPV
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Suggest adding missing braces in const block pattern
Previously it would only suggest wrapping the code in braces in regular expressions; now it does it in patterns too. This is a squashed rebase of #78173
1 parent 7042c26 commit e4a9b8b

13 files changed

+259
-41
lines changed

‎compiler/rustc_parse/src/parser/expr.rs

+2-2
Original file line numberDiff line numberDiff line change
@@ -1472,8 +1472,8 @@ impl<'a> Parser<'a> {
14721472
err
14731473
},
14741474
)
1475-
} else if this.check_inline_const(0) {
1476-
this.parse_const_block(lo.to(this.token.span), false)
1475+
} else if this.eat_keyword(kw::Const) {
1476+
this.parse_const_block(lo.to(this.prev_token.span), false)
14771477
} else if this.may_recover() && this.is_do_catch_block() {
14781478
this.recover_do_catch()
14791479
} else if this.is_try_block() {

‎compiler/rustc_parse/src/parser/mod.rs

+1-2
Original file line numberDiff line numberDiff line change
@@ -1302,12 +1302,11 @@ impl<'a> Parser<'a> {
13021302
}
13031303
}
13041304

1305-
/// Parses inline const expressions.
1305+
/// Parses inline const expressions. The `const` keyword was already eaten.
13061306
fn parse_const_block(&mut self, span: Span, pat: bool) -> PResult<'a, P<Expr>> {
13071307
if pat {
13081308
self.psess.gated_spans.gate(sym::inline_const_pat, span);
13091309
}
1310-
self.expect_keyword(kw::Const)?;
13111310
let (attrs, blk) = self.parse_inner_attrs_and_block()?;
13121311
let anon_const = AnonConst {
13131312
id: DUMMY_NODE_ID,

‎compiler/rustc_parse/src/parser/pat.rs

+6-4
Original file line numberDiff line numberDiff line change
@@ -730,9 +730,9 @@ impl<'a> Parser<'a> {
730730
self.parse_pat_ident(BindingMode(ByRef::Yes(mutbl), Mutability::Not), syntax_loc)?
731731
} else if self.eat_keyword(kw::Box) {
732732
self.parse_pat_box()?
733-
} else if self.check_inline_const(0) {
734-
// Parse `const pat`
735-
let const_expr = self.parse_const_block(lo.to(self.token.span), true)?;
733+
} else if self.eat_keyword(kw::Const) {
734+
// Parse `const { pat }`
735+
let const_expr = self.parse_const_block(lo.to(self.prev_token.span), true)?;
736736

737737
if let Some(re) = self.parse_range_end() {
738738
self.parse_pat_range_begin_with(const_expr, re)?
@@ -1220,7 +1220,9 @@ impl<'a> Parser<'a> {
12201220
.then_some(self.prev_token.span);
12211221

12221222
let bound = if self.check_inline_const(0) {
1223-
self.parse_const_block(self.token.span, true)
1223+
let _eaten = self.eat_keyword(kw::Const);
1224+
debug_assert!(_eaten);
1225+
self.parse_const_block(self.prev_token.span, true)
12241226
} else if self.check_path() {
12251227
let lo = self.token.span;
12261228
let (qself, path) = if self.eat_lt() {

‎compiler/rustc_parse/src/parser/stmt.rs

+10-4
Original file line numberDiff line numberDiff line change
@@ -495,15 +495,21 @@ impl<'a> Parser<'a> {
495495
//
496496
// the place-inside-a-block suggestion would be more likely wrong than right.
497497
//
498+
// But we don't want to trigger this if we just parsed a pattern,
499+
// so this only triggers if the current token is neither `=>` nor `=`.
500+
//
498501
// FIXME(compiler-errors): this should probably parse an arbitrary expr and not
499502
// just lookahead one token, so we can see if there's a brace after _that_,
500503
// since we want to protect against:
501504
// `if 1 1 + 1 {` being suggested as `if { 1 } 1 + 1 {`
502505
// + +
503506
Ok(Some(_))
504-
if (!self.token.is_keyword(kw::Else)
505-
&& self.look_ahead(1, |t| t == &token::OpenDelim(Delimiter::Brace)))
506-
|| do_not_suggest_help => {}
507+
if do_not_suggest_help
508+
|| (self.token != token::FatArrow
509+
&& self.token != token::Eq
510+
&& self.look_ahead(1, |t| {
511+
t == &token::OpenDelim(token::Delimiter::Brace)
512+
})) => {}
507513
// Do not suggest `if foo println!("") {;}` (as would be seen in test for #46836).
508514
Ok(Some(Stmt { kind: StmtKind::Empty, .. })) => {}
509515
Ok(Some(stmt)) => {
@@ -520,7 +526,7 @@ impl<'a> Parser<'a> {
520526
(stmt_span.shrink_to_lo(), "{ ".to_string()),
521527
(stmt_span.shrink_to_hi(), " }".to_string()),
522528
],
523-
// Speculative; has been misleading in the past (#46836).
529+
// Speculative; has been misleading in the past (see #46836).
524530
Applicability::MaybeIncorrect,
525531
);
526532
}

‎tests/ui/parser/bad-if-statements.stderr

-4
Original file line numberDiff line numberDiff line change
@@ -65,10 +65,6 @@ note: the `if` expression is missing a block after this condition
6565
|
6666
LL | if true x else {}
6767
| ^^^^
68-
help: try placing this code inside a block
69-
|
70-
LL | if true { x } else {}
71-
| + +
7268

7369
error: this `if` expression is missing a block after the condition
7470
--> $DIR/bad-if-statements.rs:34:5

‎tests/ui/parser/block-no-opening-brace.rs

+3-4
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
//@ edition:2018
22

3-
#![feature(try_blocks)]
3+
#![feature(try_blocks, inline_const_pat)]
44

55
fn main() {}
66

@@ -35,15 +35,14 @@ fn in_async() {
3535

3636
// FIXME(#78168)
3737
fn in_const() {
38-
let x = const 2; //~ ERROR expected expression, found keyword `const`
38+
let x = const 2; //~ ERROR expected `{`, found `2`
3939
}
4040

4141
// FIXME(#78168)
4242
fn in_const_in_match() {
4343
let x = 2;
4444
match x {
4545
const 2 => {}
46-
//~^ ERROR expected identifier, found keyword `const`
47-
//~| ERROR expected one of `=>`, `if`, or `|`, found `2`
46+
//~^ ERROR expected `{`, found `2`
4847
}
4948
}

‎tests/ui/parser/block-no-opening-brace.stderr

+15-11
Original file line numberDiff line numberDiff line change
@@ -51,23 +51,27 @@ LL | async
5151
LL | let x = 0;
5252
| ^^^ unexpected token
5353

54-
error: expected expression, found keyword `const`
55-
--> $DIR/block-no-opening-brace.rs:38:13
54+
error: expected `{`, found `2`
55+
--> $DIR/block-no-opening-brace.rs:38:19
5656
|
5757
LL | let x = const 2;
58-
| ^^^^^ expected expression
59-
60-
error: expected identifier, found keyword `const`
61-
--> $DIR/block-no-opening-brace.rs:45:9
58+
| ^ expected `{`
6259
|
63-
LL | const 2 => {}
64-
| ^^^^^ expected identifier, found keyword
60+
help: try placing this code inside a block
61+
|
62+
LL | let x = const { 2 };
63+
| + +
6564

66-
error: expected one of `=>`, `if`, or `|`, found `2`
65+
error: expected `{`, found `2`
6766
--> $DIR/block-no-opening-brace.rs:45:15
6867
|
6968
LL | const 2 => {}
70-
| ^ expected one of `=>`, `if`, or `|`
69+
| ^ expected `{`
70+
|
71+
help: try placing this code inside a block
72+
|
73+
LL | const { 2 } => {}
74+
| + +
7175

72-
error: aborting due to 8 previous errors
76+
error: aborting due to 7 previous errors
7377

‎tests/ui/parser/inline-const-pat-let.rs

+29
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,29 @@
1+
//@ run-pass
2+
3+
#![feature(inline_const_pat)]
4+
5+
fn if_let_1() -> i32 {
6+
let x = 2;
7+
const Y: i32 = 3;
8+
9+
if let const { (Y + 1) / 2 } = x {
10+
x
11+
} else {
12+
0
13+
}
14+
}
15+
16+
fn if_let_2() -> i32 {
17+
let x = 2;
18+
19+
if let const { 1 + 2 } = x {
20+
const { 1 + 2 }
21+
} else {
22+
0
23+
}
24+
}
25+
26+
fn main() {
27+
assert_eq!(if_let_1(), 2);
28+
assert_eq!(if_let_2(), 0);
29+
}

‎tests/ui/parser/inline-const-without-block.fixed

+60
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,60 @@
1+
//@ run-rustfix
2+
3+
// See issue #78168.
4+
5+
#![feature(inline_const_pat)]
6+
7+
// FIXME(#78171): the lint has to be allowed because of a bug
8+
#[allow(dead_code)]
9+
const fn one() -> i32 {
10+
1
11+
}
12+
13+
fn foo() -> i32 {
14+
let x = 2;
15+
16+
match x {
17+
const { 2 } => {}
18+
//~^ ERROR expected `{`, found `2`
19+
//~| HELP try placing this code inside a block
20+
_ => {}
21+
}
22+
23+
match x {
24+
const { 1 + 2 * 3 / 4 } => {}
25+
//~^ ERROR expected `{`, found `1`
26+
//~| HELP try placing this code inside a block
27+
_ => {}
28+
}
29+
30+
match x {
31+
const { one() } => {}
32+
//~^ ERROR expected `{`, found `one`
33+
//~| HELP try placing this code inside a block
34+
_ => {}
35+
}
36+
37+
x
38+
}
39+
40+
fn bar() -> i32 {
41+
let x = const { 2 };
42+
//~^ ERROR expected `{`, found `2`
43+
//~| HELP try placing this code inside a block
44+
45+
x
46+
}
47+
48+
fn baz() -> i32 {
49+
let y = const { 1 + 2 * 3 / 4 };
50+
//~^ ERROR expected `{`, found `1`
51+
//~| HELP try placing this code inside a block
52+
53+
y
54+
}
55+
56+
fn main() {
57+
foo();
58+
bar();
59+
baz();
60+
}

‎tests/ui/parser/inline-const-without-block.rs

+60
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,60 @@
1+
//@ run-rustfix
2+
3+
// See issue #78168.
4+
5+
#![feature(inline_const_pat)]
6+
7+
// FIXME(#78171): the lint has to be allowed because of a bug
8+
#[allow(dead_code)]
9+
const fn one() -> i32 {
10+
1
11+
}
12+
13+
fn foo() -> i32 {
14+
let x = 2;
15+
16+
match x {
17+
const 2 => {}
18+
//~^ ERROR expected `{`, found `2`
19+
//~| HELP try placing this code inside a block
20+
_ => {}
21+
}
22+
23+
match x {
24+
const 1 + 2 * 3 / 4 => {}
25+
//~^ ERROR expected `{`, found `1`
26+
//~| HELP try placing this code inside a block
27+
_ => {}
28+
}
29+
30+
match x {
31+
const one() => {}
32+
//~^ ERROR expected `{`, found `one`
33+
//~| HELP try placing this code inside a block
34+
_ => {}
35+
}
36+
37+
x
38+
}
39+
40+
fn bar() -> i32 {
41+
let x = const 2;
42+
//~^ ERROR expected `{`, found `2`
43+
//~| HELP try placing this code inside a block
44+
45+
x
46+
}
47+
48+
fn baz() -> i32 {
49+
let y = const 1 + 2 * 3 / 4;
50+
//~^ ERROR expected `{`, found `1`
51+
//~| HELP try placing this code inside a block
52+
53+
y
54+
}
55+
56+
fn main() {
57+
foo();
58+
bar();
59+
baz();
60+
}

‎tests/ui/parser/inline-const-without-block.stderr

+57
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,57 @@
1+
error: expected `{`, found `2`
2+
--> $DIR/inline-const-without-block.rs:17:15
3+
|
4+
LL | const 2 => {}
5+
| ^ expected `{`
6+
|
7+
help: try placing this code inside a block
8+
|
9+
LL | const { 2 } => {}
10+
| + +
11+
12+
error: expected `{`, found `1`
13+
--> $DIR/inline-const-without-block.rs:24:15
14+
|
15+
LL | const 1 + 2 * 3 / 4 => {}
16+
| ^ expected `{`
17+
|
18+
help: try placing this code inside a block
19+
|
20+
LL | const { 1 + 2 * 3 / 4 } => {}
21+
| + +
22+
23+
error: expected `{`, found `one`
24+
--> $DIR/inline-const-without-block.rs:31:15
25+
|
26+
LL | const one() => {}
27+
| ^^^ expected `{`
28+
|
29+
help: try placing this code inside a block
30+
|
31+
LL | const { one() } => {}
32+
| + +
33+
34+
error: expected `{`, found `2`
35+
--> $DIR/inline-const-without-block.rs:41:19
36+
|
37+
LL | let x = const 2;
38+
| ^ expected `{`
39+
|
40+
help: try placing this code inside a block
41+
|
42+
LL | let x = const { 2 };
43+
| + +
44+
45+
error: expected `{`, found `1`
46+
--> $DIR/inline-const-without-block.rs:49:19
47+
|
48+
LL | let y = const 1 + 2 * 3 / 4;
49+
| ^ expected `{`
50+
|
51+
help: try placing this code inside a block
52+
|
53+
LL | let y = const { 1 + 2 * 3 / 4 };
54+
| + +
55+
56+
error: aborting due to 5 previous errors
57+

‎tests/ui/parser/keyword-const-as-identifier.rs

+3-3
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
1-
// This file was auto-generated using 'src/etc/generate-keyword-tests.py const'
2-
31
fn main() {
4-
let const = "foo"; //~ error: expected identifier, found keyword `const`
2+
let const = "foo";
3+
//~^ ERROR expected `{`, found `=`
4+
//~| ERROR inline-const in pattern position is experimental [E0658]
55
}

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