25 lines
910 B
Rust
25 lines
910 B
Rust
use super::UNBUFFERED_BYTES;
|
|
use clippy_utils::diagnostics::span_lint_and_help;
|
|
use clippy_utils::is_trait_method;
|
|
use clippy_utils::ty::implements_trait;
|
|
use rustc_hir as hir;
|
|
use rustc_lint::LateContext;
|
|
use rustc_span::sym;
|
|
|
|
pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>) {
|
|
// Lint if the `.bytes()` call is from the `Read` trait and the implementor is not buffered.
|
|
if is_trait_method(cx, expr, sym::IoRead)
|
|
&& let Some(buf_read) = cx.tcx.get_diagnostic_item(sym::IoBufRead)
|
|
&& let ty = cx.typeck_results().expr_ty_adjusted(recv)
|
|
&& !implements_trait(cx, ty, buf_read, &[])
|
|
{
|
|
span_lint_and_help(
|
|
cx,
|
|
UNBUFFERED_BYTES,
|
|
expr.span,
|
|
"calling .bytes() is very inefficient when data is not in memory",
|
|
None,
|
|
"consider using `BufReader`",
|
|
);
|
|
}
|
|
}
|