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Share outer paren trimming logic

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This commit is contained in:
Kevin Leimkuhler 2018-10-04 09:36:55 -07:00
parent 8552c61c5a
commit 5217527a5b
1 changed files with 46 additions and 84 deletions
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130
src/librustc_lint/unused.rs
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@ -273,43 +273,8 @@ impl UnusedParens {
let necessary = struct_lit_needs_parens &&
parser::contains_exterior_struct_lit(&inner);
if !necessary {
let span_msg = format!("unnecessary parentheses around {}", msg);
let mut err = cx.struct_span_lint(UNUSED_PARENS,
value.span,
&span_msg);
// Remove exactly one pair of parentheses (rather than naïvely
// stripping all paren characters)
let mut ate_left_paren = false;
let mut ate_right_paren = false;
let parens_removed = pprust::expr_to_string(value)
.trim_matches(|c| {
match c {
'(' => {
if ate_left_paren {
false
} else {
ate_left_paren = true;
true
}
},
')' => {
if ate_right_paren {
false
} else {
ate_right_paren = true;
true
}
},
_ => false,
}
}).to_owned();
err.span_suggestion_short_with_applicability(
value.span,
"remove these parentheses",
parens_removed,
Applicability::MachineApplicable
);
err.emit();
let pattern = pprust::expr_to_string(value);
Self::remove_outer_parens(cx, value.span, &pattern, msg)
}
}
}
@ -320,49 +285,48 @@ impl UnusedParens {
msg: &str,
struct_lit_needs_parens: bool) {
if let ast::PatKind::Paren(_) = value.node {
// Does there need to be a check similar to `parser::contains_exterior_struct_lit`
// here?
if !struct_lit_needs_parens {
let span_msg = format!("unnecessary parentheses around {}", msg);
let mut err = cx.struct_span_lint(UNUSED_PARENS,
value.span,
&span_msg);
// Remove exactly one pair of parentheses (rather than naïvely
// stripping all paren characters)
let mut ate_left_paren = false;
let mut ate_right_paren = false;
let parens_removed = pprust::pat_to_string(value)
.trim_matches(|c| {
match c {
'(' => {
if ate_left_paren {
false
} else {
ate_left_paren = true;
true
}
},
')' => {
if ate_right_paren {
false
} else {
ate_right_paren = true;
true
}
},
_ => false,
}
}).to_owned();
err.span_suggestion_short_with_applicability(
value.span,
"remove these parentheses",
parens_removed,
Applicability::MachineApplicable
);
err.emit();
let pattern = pprust::pat_to_string(value);
Self::remove_outer_parens(cx, value.span, &pattern, msg)
}
}
}
fn remove_outer_parens(cx: &EarlyContext, span: Span, pattern: &str, msg: &str) {
let span_msg = format!("unnecessary parentheses around {}", msg);
let mut err = cx.struct_span_lint(UNUSED_PARENS, span, &span_msg);
let mut ate_left_paren = false;
let mut ate_right_paren = false;
let parens_removed = pattern
.trim_matches(|c| {
match c {
'(' => {
if ate_left_paren {
false
} else {
ate_left_paren = true;
true
}
},
')' => {
if ate_right_paren {
false
} else {
ate_right_paren = true;
true
}
},
_ => false,
}
}).to_owned();
err.span_suggestion_short_with_applicability(
span,
"remove these parentheses",
parens_removed,
Applicability::MachineApplicable
);
err.emit();
}
}
impl LintPass for UnusedParens {
@ -414,16 +378,14 @@ impl EarlyLintPass for UnusedParens {
fn check_pat(&mut self, cx: &EarlyContext, p: &ast::Pat) {
use ast::PatKind::*;
let (value, msg) = match p.node {
Paren(ref pat) => {
match pat.node {
Wild => (p, "wildcard pattern"),
_ => return,
}
}
let (value, msg, struct_lit_needs_parens) = match p.node {
Ident(.., Some(ref pat)) => (pat, "optional subpattern", false),
Ref(ref pat, _) => (pat, "reference pattern", false),
Slice(_, Some(ref pat), _) => (pat, "optional position pattern", false),
Paren(_) => (p, "pattern", false),
_ => return,
};
self.check_unused_parens_pat(cx, &value, msg, false);
self.check_unused_parens_pat(cx, &value, msg, struct_lit_needs_parens);
}
fn check_stmt(&mut self, cx: &EarlyContext, s: &ast::Stmt) {