38 lines
1.7 KiB
Rust
38 lines
1.7 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_sugg;
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use clippy_utils::source::snippet_with_context;
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use clippy_utils::visitors::is_const_evaluatable;
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use rustc_ast::ast::LitKind;
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use rustc_errors::Applicability;
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use rustc_hir::{Expr, ExprKind};
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use rustc_lint::LateContext;
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use super::STR_SPLIT_AT_NEWLINE;
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pub(super) fn check<'a>(cx: &LateContext<'a>, expr: &'_ Expr<'_>, split_recv: &'a Expr<'_>, split_arg: &'_ Expr<'_>) {
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// We're looking for `A.trim().split(B)`, where the adjusted type of `A` is `&str` (e.g. an
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// expression returning `String`), and `B` is a `Pattern` that hard-codes a newline (either `"\n"`
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// or `"\r\n"`). There are a lot of ways to specify a pattern, and this lint only checks the most
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// basic ones: a `'\n'`, `"\n"`, and `"\r\n"`.
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if let ExprKind::MethodCall(trim_method_name, trim_recv, [], _) = split_recv.kind
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&& trim_method_name.ident.as_str() == "trim"
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&& cx.typeck_results().expr_ty_adjusted(trim_recv).peel_refs().is_str()
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&& !is_const_evaluatable(cx, trim_recv)
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&& let ExprKind::Lit(split_lit) = split_arg.kind
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&& (matches!(split_lit.node, LitKind::Char('\n'))
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|| matches!(split_lit.node, LitKind::Str(sym, _) if (sym.as_str() == "\n" || sym.as_str() == "\r\n")))
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{
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let mut app = Applicability::MaybeIncorrect;
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span_lint_and_sugg(
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cx,
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STR_SPLIT_AT_NEWLINE,
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expr.span,
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"using `str.trim().split()` with hard-coded newlines",
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"use `str.lines()` instead",
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format!(
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"{}.lines()",
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snippet_with_context(cx, trim_recv.span, expr.span.ctxt(), "..", &mut app).0
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),
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app,
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);
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}
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}
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