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Fix the issue of typo of comma in arm parsing

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This commit is contained in:
yukang
2025-05-16 12:38:51 +02:00
parent c79bbfab78
commit 5f8954bc41
4 changed files with 110 additions and 18 deletions
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54
compiler/rustc_parse/src/parser/expr.rs
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@@ -3311,26 +3311,44 @@ impl<'a> Parser<'a> {
let sm = this.psess.source_map();
if let Ok(expr_lines) = sm.span_to_lines(expr_span)
&& let Ok(arm_start_lines) = sm.span_to_lines(arm_start_span)
&& arm_start_lines.lines[0].end_col == expr_lines.lines[0].end_col
&& expr_lines.lines.len() == 2
{
// We check whether there's any trailing code in the parse span,
// if there isn't, we very likely have the following:
//
// X | &Y => "y"
// | -- - missing comma
// | |
// | arrow_span
// X | &X => "x"
// | - ^^ self.token.span
// | |
// | parsed until here as `"y" & X`
err.span_suggestion_short(
arm_start_span.shrink_to_hi(),
"missing a comma here to end this `match` arm",
",",
Applicability::MachineApplicable,
);
if arm_start_lines.lines[0].end_col == expr_lines.lines[0].end_col {
// We check whether there's any trailing code in the parse span,
// if there isn't, we very likely have the following:
//
// X | &Y => "y"
// | -- - missing comma
// | |
// | arrow_span
// X | &X => "x"
// | - ^^ self.token.span
// | |
// | parsed until here as `"y" & X`
err.span_suggestion_short(
arm_start_span.shrink_to_hi(),
"missing a comma here to end this `match` arm",
",",
Applicability::MachineApplicable,
);
} else if arm_start_lines.lines[0].end_col + rustc_span::CharPos(1)
== expr_lines.lines[0].end_col
{
// similar to the above, but we may typo a `.` or `/` at the end of the line
let comma_span = arm_start_span
.shrink_to_hi()
.with_hi(arm_start_span.hi() + rustc_span::BytePos(1));
if let Ok(res) = sm.span_to_snippet(comma_span)
&& (res == "." || res == "/")
{
err.span_suggestion_short(
comma_span,
"you might have meant to write a `,` to end this `match` arm",
",",
Applicability::MachineApplicable,
);
}
}
}
} else {
err.span_label(