Rollup merge of #104012 - chenyukang:yukang/fix-103882-deli-indentation, r=petrochenkov

Improve unexpected close and mismatch delimiter hint in TokenTreesReader

Fixes #103882
Fixes #68987
Fixes #69259

The inner indentation mismatching will be covered by outer block, the new added function `report_error_prone_delim_block` will find out the error prone candidates for reporting.
This commit is contained in:
Matthias Krüger 2023-01-28 11:11:05 +01:00 committed by GitHub
commit e3048c7838
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24 changed files with 408 additions and 106 deletions

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@ -0,0 +1,119 @@
use super::UnmatchedBrace;
use rustc_ast::token::Delimiter;
use rustc_errors::Diagnostic;
use rustc_span::source_map::SourceMap;
use rustc_span::Span;
#[derive(Default)]
pub struct TokenTreeDiagInfo {
/// Stack of open delimiters and their spans. Used for error message.
pub open_braces: Vec<(Delimiter, Span)>,
pub unmatched_braces: Vec<UnmatchedBrace>,
/// Used only for error recovery when arriving to EOF with mismatched braces.
pub last_unclosed_found_span: Option<Span>,
/// Collect empty block spans that might have been auto-inserted by editors.
pub empty_block_spans: Vec<Span>,
/// Collect the spans of braces (Open, Close). Used only
/// for detecting if blocks are empty and only braces.
pub matching_block_spans: Vec<(Span, Span)>,
}
pub fn same_identation_level(sm: &SourceMap, open_sp: Span, close_sp: Span) -> bool {
match (sm.span_to_margin(open_sp), sm.span_to_margin(close_sp)) {
(Some(open_padding), Some(close_padding)) => open_padding == close_padding,
_ => false,
}
}
// When we get a `)` or `]` for `{`, we should emit help message here
// it's more friendly compared to report `unmatched error` in later phase
pub fn report_missing_open_delim(
err: &mut Diagnostic,
unmatched_braces: &[UnmatchedBrace],
) -> bool {
let mut reported_missing_open = false;
for unmatch_brace in unmatched_braces.iter() {
if let Some(delim) = unmatch_brace.found_delim
&& matches!(delim, Delimiter::Parenthesis | Delimiter::Bracket)
{
let missed_open = match delim {
Delimiter::Parenthesis => "(",
Delimiter::Bracket => "[",
_ => unreachable!(),
};
err.span_label(
unmatch_brace.found_span.shrink_to_lo(),
format!("missing open `{}` for this delimiter", missed_open),
);
reported_missing_open = true;
}
}
reported_missing_open
}
pub fn report_suspicious_mismatch_block(
err: &mut Diagnostic,
diag_info: &TokenTreeDiagInfo,
sm: &SourceMap,
delim: Delimiter,
) {
if report_missing_open_delim(err, &diag_info.unmatched_braces) {
return;
}
let mut matched_spans: Vec<(Span, bool)> = diag_info
.matching_block_spans
.iter()
.map(|&(open, close)| (open.with_hi(close.lo()), same_identation_level(sm, open, close)))
.collect();
// sort by `lo`, so the large block spans in the front
matched_spans.sort_by(|a, b| a.0.lo().cmp(&b.0.lo()));
// We use larger block whose identation is well to cover those inner mismatched blocks
// O(N^2) here, but we are on error reporting path, so it is fine
for i in 0..matched_spans.len() {
let (block_span, same_ident) = matched_spans[i];
if same_ident {
for j in i + 1..matched_spans.len() {
let (inner_block, inner_same_ident) = matched_spans[j];
if block_span.contains(inner_block) && !inner_same_ident {
matched_spans[j] = (inner_block, true);
}
}
}
}
// Find the inner-most span candidate for final report
let candidate_span =
matched_spans.into_iter().rev().find(|&(_, same_ident)| !same_ident).map(|(span, _)| span);
if let Some(block_span) = candidate_span {
err.span_label(block_span.shrink_to_lo(), "this delimiter might not be properly closed...");
err.span_label(
block_span.shrink_to_hi(),
"...as it matches this but it has different indentation",
);
// If there is a empty block in the mismatched span, note it
if delim == Delimiter::Brace {
for span in diag_info.empty_block_spans.iter() {
if block_span.contains(*span) {
err.span_label(*span, "block is empty, you might have not meant to close it");
break;
}
}
}
} else {
// If there is no suspicious span, give the last properly closed block may help
if let Some(parent) = diag_info.matching_block_spans.last()
&& diag_info.open_braces.last().is_none()
&& diag_info.empty_block_spans.iter().all(|&sp| sp != parent.0.to(parent.1)) {
err.span_label(parent.0, "this opening brace...");
err.span_label(parent.1, "...matches this closing brace");
}
}
}

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@ -17,6 +17,7 @@
use rustc_span::symbol::{sym, Symbol};
use rustc_span::{edition::Edition, BytePos, Pos, Span};
mod diagnostics;
mod tokentrees;
mod unescape_error_reporting;
mod unicode_chars;

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@ -1,29 +1,18 @@
use super::diagnostics::report_suspicious_mismatch_block;
use super::diagnostics::same_identation_level;
use super::diagnostics::TokenTreeDiagInfo;
use super::{StringReader, UnmatchedBrace};
use rustc_ast::token::{self, Delimiter, Token};
use rustc_ast::tokenstream::{DelimSpan, Spacing, TokenStream, TokenTree};
use rustc_ast_pretty::pprust::token_to_string;
use rustc_data_structures::fx::FxHashMap;
use rustc_errors::{PErr, PResult};
use rustc_span::Span;
pub(super) struct TokenTreesReader<'a> {
string_reader: StringReader<'a>,
/// The "next" token, which has been obtained from the `StringReader` but
/// not yet handled by the `TokenTreesReader`.
token: Token,
/// Stack of open delimiters and their spans. Used for error message.
open_braces: Vec<(Delimiter, Span)>,
unmatched_braces: Vec<UnmatchedBrace>,
/// The type and spans for all braces
///
/// Used only for error recovery when arriving to EOF with mismatched braces.
matching_delim_spans: Vec<(Delimiter, Span, Span)>,
last_unclosed_found_span: Option<Span>,
/// Collect empty block spans that might have been auto-inserted by editors.
last_delim_empty_block_spans: FxHashMap<Delimiter, Span>,
/// Collect the spans of braces (Open, Close). Used only
/// for detecting if blocks are empty and only braces.
matching_block_spans: Vec<(Span, Span)>,
diag_info: TokenTreeDiagInfo,
}
impl<'a> TokenTreesReader<'a> {
@ -33,15 +22,10 @@ pub(super) fn parse_all_token_trees(
let mut tt_reader = TokenTreesReader {
string_reader,
token: Token::dummy(),
open_braces: Vec::new(),
unmatched_braces: Vec::new(),
matching_delim_spans: Vec::new(),
last_unclosed_found_span: None,
last_delim_empty_block_spans: FxHashMap::default(),
matching_block_spans: Vec::new(),
diag_info: TokenTreeDiagInfo::default(),
};
let res = tt_reader.parse_token_trees(/* is_delimited */ false);
(res, tt_reader.unmatched_braces)
(res, tt_reader.diag_info.unmatched_braces)
}
// Parse a stream of tokens into a list of `TokenTree`s.
@ -92,9 +76,9 @@ fn parse_token_trees(&mut self, is_delimited: bool) -> PResult<'a, TokenStream>
fn eof_err(&mut self) -> PErr<'a> {
let msg = "this file contains an unclosed delimiter";
let mut err = self.string_reader.sess.span_diagnostic.struct_span_err(self.token.span, msg);
for &(_, sp) in &self.open_braces {
for &(_, sp) in &self.diag_info.open_braces {
err.span_label(sp, "unclosed delimiter");
self.unmatched_braces.push(UnmatchedBrace {
self.diag_info.unmatched_braces.push(UnmatchedBrace {
expected_delim: Delimiter::Brace,
found_delim: None,
found_span: self.token.span,
@ -103,23 +87,13 @@ fn eof_err(&mut self) -> PErr<'a> {
});
}
if let Some((delim, _)) = self.open_braces.last() {
if let Some((_, open_sp, close_sp)) =
self.matching_delim_spans.iter().find(|(d, open_sp, close_sp)| {
let sm = self.string_reader.sess.source_map();
if let Some(close_padding) = sm.span_to_margin(*close_sp) {
if let Some(open_padding) = sm.span_to_margin(*open_sp) {
return delim == d && close_padding != open_padding;
}
}
false
})
// these are in reverse order as they get inserted on close, but
{
// we want the last open/first close
err.span_label(*open_sp, "this delimiter might not be properly closed...");
err.span_label(*close_sp, "...as it matches this but it has different indentation");
}
if let Some((delim, _)) = self.diag_info.open_braces.last() {
report_suspicious_mismatch_block(
&mut err,
&self.diag_info,
&self.string_reader.sess.source_map(),
*delim,
)
}
err
}
@ -128,7 +102,7 @@ fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> TokenTree {
// The span for beginning of the delimited section
let pre_span = self.token.span;
self.open_braces.push((open_delim, self.token.span));
self.diag_info.open_braces.push((open_delim, self.token.span));
// Parse the token trees within the delimiters.
// We stop at any delimiter so we can try to recover if the user
@ -137,35 +111,29 @@ fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> TokenTree {
// Expand to cover the entire delimited token tree
let delim_span = DelimSpan::from_pair(pre_span, self.token.span);
let sm = self.string_reader.sess.source_map();
match self.token.kind {
// Correct delimiter.
token::CloseDelim(close_delim) if close_delim == open_delim => {
let (open_brace, open_brace_span) = self.open_braces.pop().unwrap();
let (open_brace, open_brace_span) = self.diag_info.open_braces.pop().unwrap();
let close_brace_span = self.token.span;
if tts.is_empty() {
if tts.is_empty() && close_delim == Delimiter::Brace {
let empty_block_span = open_brace_span.to(close_brace_span);
let sm = self.string_reader.sess.source_map();
if !sm.is_multiline(empty_block_span) {
// Only track if the block is in the form of `{}`, otherwise it is
// likely that it was written on purpose.
self.last_delim_empty_block_spans.insert(open_delim, empty_block_span);
self.diag_info.empty_block_spans.push(empty_block_span);
}
}
//only add braces
// only add braces
if let (Delimiter::Brace, Delimiter::Brace) = (open_brace, open_delim) {
self.matching_block_spans.push((open_brace_span, close_brace_span));
// Add all the matching spans, we will sort by span later
self.diag_info.matching_block_spans.push((open_brace_span, close_brace_span));
}
if self.open_braces.is_empty() {
// Clear up these spans to avoid suggesting them as we've found
// properly matched delimiters so far for an entire block.
self.matching_delim_spans.clear();
} else {
self.matching_delim_spans.push((open_brace, open_brace_span, close_brace_span));
}
// Move past the closing delimiter.
self.token = self.string_reader.next_token().0;
}
@ -174,28 +142,25 @@ fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> TokenTree {
let mut unclosed_delimiter = None;
let mut candidate = None;
if self.last_unclosed_found_span != Some(self.token.span) {
if self.diag_info.last_unclosed_found_span != Some(self.token.span) {
// do not complain about the same unclosed delimiter multiple times
self.last_unclosed_found_span = Some(self.token.span);
self.diag_info.last_unclosed_found_span = Some(self.token.span);
// This is a conservative error: only report the last unclosed
// delimiter. The previous unclosed delimiters could actually be
// closed! The parser just hasn't gotten to them yet.
if let Some(&(_, sp)) = self.open_braces.last() {
if let Some(&(_, sp)) = self.diag_info.open_braces.last() {
unclosed_delimiter = Some(sp);
};
let sm = self.string_reader.sess.source_map();
if let Some(current_padding) = sm.span_to_margin(self.token.span) {
for (brace, brace_span) in &self.open_braces {
if let Some(padding) = sm.span_to_margin(*brace_span) {
// high likelihood of these two corresponding
if current_padding == padding && brace == &close_delim {
candidate = Some(*brace_span);
}
}
for (brace, brace_span) in &self.diag_info.open_braces {
if same_identation_level(&sm, self.token.span, *brace_span)
&& brace == &close_delim
{
// high likelihood of these two corresponding
candidate = Some(*brace_span);
}
}
let (tok, _) = self.open_braces.pop().unwrap();
self.unmatched_braces.push(UnmatchedBrace {
let (tok, _) = self.diag_info.open_braces.pop().unwrap();
self.diag_info.unmatched_braces.push(UnmatchedBrace {
expected_delim: tok,
found_delim: Some(close_delim),
found_span: self.token.span,
@ -203,7 +168,7 @@ fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> TokenTree {
candidate_span: candidate,
});
} else {
self.open_braces.pop();
self.diag_info.open_braces.pop();
}
// If the incorrect delimiter matches an earlier opening
@ -213,7 +178,7 @@ fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> TokenTree {
// fn foo() {
// bar(baz(
// } // Incorrect delimiter but matches the earlier `{`
if !self.open_braces.iter().any(|&(b, _)| b == close_delim) {
if !self.diag_info.open_braces.iter().any(|&(b, _)| b == close_delim) {
self.token = self.string_reader.next_token().0;
}
}
@ -236,22 +201,12 @@ fn close_delim_err(&mut self, delim: Delimiter) -> PErr<'a> {
let mut err =
self.string_reader.sess.span_diagnostic.struct_span_err(self.token.span, &msg);
// Braces are added at the end, so the last element is the biggest block
if let Some(parent) = self.matching_block_spans.last() {
if let Some(span) = self.last_delim_empty_block_spans.remove(&delim) {
// Check if the (empty block) is in the last properly closed block
if (parent.0.to(parent.1)).contains(span) {
err.span_label(span, "block is empty, you might have not meant to close it");
} else {
err.span_label(parent.0, "this opening brace...");
err.span_label(parent.1, "...matches this closing brace");
}
} else {
err.span_label(parent.0, "this opening brace...");
err.span_label(parent.1, "...matches this closing brace");
}
}
report_suspicious_mismatch_block(
&mut err,
&self.diag_info,
&self.string_reader.sess.source_map(),
delim,
);
err.span_label(self.token.span, "unexpected closing delimiter");
err
}

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@ -0,0 +1,24 @@
#![feature(let_chains)]
trait Demo {}
impl dyn Demo {
pub fn report(&self) -> u32 {
let sum = |a: u32,
b: u32,
c: u32| {
a + b + c
};
sum(1, 2, 3)
}
fn check(&self, val: Option<u32>, num: Option<u32>) {
if let Some(b) = val
&& let Some(c) = num {
&& b == c {
//~^ ERROR expected struct
//~| ERROR mismatched types
}
}
}
fn main() { } //~ ERROR this file contains an unclosed delimiter

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@ -0,0 +1,37 @@
error: this file contains an unclosed delimiter
--> $DIR/deli-ident-issue-1.rs:24:66
|
LL | impl dyn Demo {
| - unclosed delimiter
...
LL | && let Some(c) = num {
| - this delimiter might not be properly closed...
...
LL | }
| - ...as it matches this but it has different indentation
...
LL | fn main() { }
| ^
error[E0574]: expected struct, variant or union type, found local variable `c`
--> $DIR/deli-ident-issue-1.rs:17:17
|
LL | && b == c {
| ^ not a struct, variant or union type
error[E0308]: mismatched types
--> $DIR/deli-ident-issue-1.rs:17:9
|
LL | fn check(&self, val: Option<u32>, num: Option<u32>) {
| - expected `()` because of default return type
...
LL | / && b == c {
LL | |
LL | |
LL | | }
| |_________^ expected `()`, found `bool`
error: aborting due to 3 previous errors
Some errors have detailed explanations: E0308, E0574.
For more information about an error, try `rustc --explain E0308`.

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@ -0,0 +1,7 @@
fn main() {
if 1 < 2 {
let _a = vec!]; //~ ERROR mismatched closing delimiter
}
} //~ ERROR unexpected closing delimiter
fn main() {}

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@ -0,0 +1,19 @@
error: unexpected closing delimiter: `}`
--> $DIR/deli-ident-issue-2.rs:5:1
|
LL | let _a = vec!];
| - missing open `[` for this delimiter
LL | }
LL | }
| ^ unexpected closing delimiter
error: mismatched closing delimiter: `]`
--> $DIR/deli-ident-issue-2.rs:2:14
|
LL | if 1 < 2 {
| ^ unclosed delimiter
LL | let _a = vec!];
| ^ mismatched closing delimiter
error: aborting due to 2 previous errors

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@ -0,0 +1,12 @@
// This file has unexpected closing delimiter,
fn func(o: Option<u32>) {
match o {
Some(_x) => {} // Extra '}'
let _ = if true {};
}
None => {}
}
} //~ ERROR unexpected closing delimiter
fn main() {}

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@ -0,0 +1,16 @@
error: unexpected closing delimiter: `}`
--> $DIR/issue-68987-unmatch-issue-1.rs:10:1
|
LL | match o {
| - this delimiter might not be properly closed...
LL | Some(_x) => {} // Extra '}'
| -- block is empty, you might have not meant to close it
LL | let _ = if true {};
LL | }
| - ...as it matches this but it has different indentation
...
LL | }
| ^ unexpected closing delimiter
error: aborting due to previous error

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@ -0,0 +1,14 @@
// FIXME: this case need more work to fix
// currently the TokenTree matching ')' with '{', which is not user friendly for diagnostics
async fn obstest() -> Result<> {
let obs_connect = || -> Result<(), MyError) { //~ ERROR mismatched closing delimiter
async {
}
}
if let Ok(version, scene_list) = obs_connect() {
} else {
}
} //~ ERROR unexpected closing delimiter

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@ -0,0 +1,19 @@
error: unexpected closing delimiter: `}`
--> $DIR/issue-68987-unmatch-issue-2.rs:14:1
|
LL | let obs_connect = || -> Result<(), MyError) {
| - missing open `(` for this delimiter
...
LL | }
| ^ unexpected closing delimiter
error: mismatched closing delimiter: `)`
--> $DIR/issue-68987-unmatch-issue-2.rs:3:32
|
LL | async fn obstest() -> Result<> {
| ^ unclosed delimiter
LL | let obs_connect = || -> Result<(), MyError) {
| ^ mismatched closing delimiter
error: aborting due to 2 previous errors

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@ -0,0 +1,8 @@
// the `{` is closed with `)`, there is a missing `(`
fn f(i: u32, j: u32) {
let res = String::new();
let mut cnt = i;
while cnt < j {
write!&mut res, " "); //~ ERROR mismatched closing delimiter
}
} //~ ERROR unexpected closing delimiter

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@ -0,0 +1,19 @@
error: unexpected closing delimiter: `}`
--> $DIR/issue-68987-unmatch-issue-3.rs:8:1
|
LL | write!&mut res, " ");
| - missing open `(` for this delimiter
LL | }
LL | }
| ^ unexpected closing delimiter
error: mismatched closing delimiter: `)`
--> $DIR/issue-68987-unmatch-issue-3.rs:5:19
|
LL | while cnt < j {
| ^ unclosed delimiter
LL | write!&mut res, " ");
| ^ mismatched closing delimiter
error: aborting due to 2 previous errors

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@ -0,0 +1,12 @@
// This file has unexpected closing delimiter,
fn func(o: Option<u32>) {
match o {
Some(_x) => // Missing '{'
let _ = if true {};
}
None => {}
}
} //~ ERROR unexpected closing delimiter
fn main() {}

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@ -0,0 +1,16 @@
error: unexpected closing delimiter: `}`
--> $DIR/issue-68987-unmatch-issue.rs:10:1
|
LL | match o {
| - this delimiter might not be properly closed...
LL | Some(_x) => // Missing '{'
LL | let _ = if true {};
| -- block is empty, you might have not meant to close it
LL | }
| - ...as it matches this but it has different indentation
...
LL | }
| ^ unexpected closing delimiter
error: aborting due to previous error

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@ -2,8 +2,9 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-81827.rs:11:27
|
LL | fn r()->i{0|{#[cfg(r(0{]0
| - - ^
| | |
| - - - ^
| | | |
| | | missing open `[` for this delimiter
| | unclosed delimiter
| unclosed delimiter
@ -11,8 +12,9 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-81827.rs:11:27
|
LL | fn r()->i{0|{#[cfg(r(0{]0
| - - ^
| | |
| - - - ^
| | | |
| | | missing open `[` for this delimiter
| | unclosed delimiter
| unclosed delimiter

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@ -2,8 +2,10 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-62973.rs:8:2
|
LL | fn p() { match s { v, E { [) {) }
| - - unclosed delimiter
| |
| - - - - missing open `(` for this delimiter
| | | |
| | | missing open `(` for this delimiter
| | unclosed delimiter
| unclosed delimiter
LL |
LL |
@ -13,8 +15,10 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-62973.rs:8:2
|
LL | fn p() { match s { v, E { [) {) }
| - - unclosed delimiter
| |
| - - - - missing open `(` for this delimiter
| | | |
| | | missing open `(` for this delimiter
| | unclosed delimiter
| unclosed delimiter
LL |
LL |

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@ -2,8 +2,9 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-63116.rs:3:18
|
LL | impl W <s(f;Y(;]
| - ^
| |
| - - ^
| | |
| | missing open `[` for this delimiter
| unclosed delimiter
error: expected one of `!`, `(`, `)`, `+`, `,`, `::`, or `<`, found `;`

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@ -0,0 +1,3 @@
fn main() {}
fn f) {} //~ ERROR unexpected closing delimiter

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@ -0,0 +1,8 @@
error: unexpected closing delimiter: `)`
--> $DIR/issue-69259.rs:3:5
|
LL | fn f) {}
| ^ unexpected closing delimiter
error: aborting due to previous error

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@ -2,10 +2,10 @@ error: unexpected closing delimiter: `}`
--> $DIR/issue-70583-block-is-empty-1.rs:20:1
|
LL | fn struct_generic(x: Vec<i32>) {
| - this opening brace...
| - this delimiter might not be properly closed...
...
LL | }
| - ...matches this closing brace
| - ...as it matches this but it has different indentation
LL | }
| ^ unexpected closing delimiter

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@ -1,8 +1,12 @@
error: unexpected closing delimiter: `}`
--> $DIR/issue-70583-block-is-empty-2.rs:14:1
|
LL | match self {
| - this delimiter might not be properly closed...
LL | ErrorHandled::Reported => {}}
| -- block is empty, you might have not meant to close it
| --- ...as it matches this but it has different indentation
| |
| block is empty, you might have not meant to close it
...
LL | }
| ^ unexpected closing delimiter

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@ -2,10 +2,10 @@ error: unexpected closing delimiter: `}`
--> $DIR/macro-mismatched-delim-paren-brace.rs:5:1
|
LL | fn main() {
| - this opening brace...
| - this delimiter might not be properly closed...
...
LL | }
| - ...matches this closing brace
| - ...as it matches this but it has different indentation
LL | }
| ^ unexpected closing delimiter

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@ -2,8 +2,9 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-91334.rs:10:23
|
LL | fn f(){||yield(((){),
| - - ^
| | |
| - - - ^
| | | |
| | | missing open `(` for this delimiter
| | unclosed delimiter
| unclosed delimiter
@ -11,8 +12,9 @@ error: this file contains an unclosed delimiter
--> $DIR/issue-91334.rs:10:23
|
LL | fn f(){||yield(((){),
| - - ^
| | |
| - - - ^
| | | |
| | | missing open `(` for this delimiter
| | unclosed delimiter
| unclosed delimiter