46 lines
1.1 KiB
Rust
46 lines
1.1 KiB
Rust
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use rustc::lint::*;
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use syntax::ast::*;
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use syntax::codemap::{BytePos, Span};
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declare_lint!{ pub ZERO_WIDTH_SPACE, Deny, "Zero-width space is confusing" }
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#[derive(Copy, Clone)]
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pub struct Unicode;
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impl LintPass for Unicode {
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fn get_lints(&self) -> LintArray {
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lint_array!(ZERO_WIDTH_SPACE)
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}
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fn check_expr(&mut self, cx: &Context, expr: &Expr) {
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if let ExprLit(ref lit) = expr.node {
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if let LitStr(ref string, _) = lit.node {
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check_str(cx, string, lit.span)
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}
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}
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}
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}
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fn check_str(cx: &Context, string: &str, span: Span) {
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let mut start: Option<usize> = None;
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for (i, c) in string.char_indices() {
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if c == '\u{200B}' {
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if start.is_none() { start = Some(i); }
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} else {
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lint_zero_width(cx, span, start);
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start = None;
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}
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}
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lint_zero_width(cx, span, start);
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}
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fn lint_zero_width(cx: &Context, span: Span, start: Option<usize>) {
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start.map(|index| {
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cx.span_lint(ZERO_WIDTH_SPACE, Span {
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lo: span.lo + BytePos(index as u32),
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hi: span.lo + BytePos(index as u32),
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expn_id: span.expn_id,
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}, "Zero-width space detected. Consider using \\u{200B}")
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});
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}
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