-use crate::utils::{is_try, match_qpath, match_trait_method, paths, span_lint};
-use rustc::hir;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::utils::{is_try, match_trait_method, paths, span_lint};
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// **What it does:** Checks for unused written/read amount.
///
- /// **Why is this bad?** `io::Write::write` and `io::Read::read` are not
- /// guaranteed to
+ /// **Why is this bad?** `io::Write::write(_vectored)` and
+ /// `io::Read::read(_vectored)` are not guaranteed to
/// process the entire buffer. They return how many bytes were processed, which
/// might be smaller
/// than a given buffer's length. If you don't need to deal with
"unused written/read amount"
}
-pub struct UnusedIoAmount;
+declare_lint_pass!(UnusedIoAmount => [UNUSED_IO_AMOUNT]);
-impl LintPass for UnusedIoAmount {
- fn get_lints(&self) -> LintArray {
- lint_array!(UNUSED_IO_AMOUNT)
- }
-
- fn name(&self) -> &'static str {
- "UnusedIoAmount"
- }
-}
-
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedIoAmount {
- fn check_stmt(&mut self, cx: &LateContext<'_, '_>, s: &hir::Stmt) {
- let expr = match s.node {
+impl<'tcx> LateLintPass<'tcx> for UnusedIoAmount {
+ fn check_stmt(&mut self, cx: &LateContext<'_>, s: &hir::Stmt<'_>) {
+ let expr = match s.kind {
hir::StmtKind::Semi(ref expr) | hir::StmtKind::Expr(ref expr) => &**expr,
_ => return,
};
- match expr.node {
- hir::ExprKind::Match(ref res, _, _) if is_try(cx, expr).is_some() => {
- if let hir::ExprKind::Call(ref func, ref args) = res.node {
- if let hir::ExprKind::Path(ref path) = func.node {
- if match_qpath(path, &paths::TRY_INTO_RESULT) && args.len() == 1 {
- check_method_call(cx, &args[0], expr);
- }
+ match expr.kind {
+ hir::ExprKind::Match(ref res, _, _) if is_try(expr).is_some() => {
+ if let hir::ExprKind::Call(ref func, ref args) = res.kind {
+ if matches!(
+ func.kind,
+ hir::ExprKind::Path(hir::QPath::LangItem(hir::LangItem::TryIntoResult, _))
+ ) {
+ check_method_call(cx, &args[0], expr);
}
} else {
check_method_call(cx, res, expr);
}
},
- hir::ExprKind::MethodCall(ref path, _, ref args) => match &*path.ident.as_str() {
+ hir::ExprKind::MethodCall(ref path, _, ref args, _) => match &*path.ident.as_str() {
"expect" | "unwrap" | "unwrap_or" | "unwrap_or_else" => {
check_method_call(cx, &args[0], expr);
},
}
}
-fn check_method_call(cx: &LateContext<'_, '_>, call: &hir::Expr, expr: &hir::Expr) {
- if let hir::ExprKind::MethodCall(ref path, _, _) = call.node {
+fn check_method_call(cx: &LateContext<'_>, call: &hir::Expr<'_>, expr: &hir::Expr<'_>) {
+ if let hir::ExprKind::MethodCall(ref path, _, _, _) = call.kind {
let symbol = &*path.ident.as_str();
- if match_trait_method(cx, call, &paths::IO_READ) && symbol == "read" {
- span_lint(
+ let read_trait = match_trait_method(cx, call, &paths::IO_READ);
+ let write_trait = match_trait_method(cx, call, &paths::IO_WRITE);
+
+ match (read_trait, write_trait, symbol) {
+ (true, _, "read") => span_lint(
cx,
UNUSED_IO_AMOUNT,
expr.span,
- "handle read amount returned or use `Read::read_exact` instead",
- );
- } else if match_trait_method(cx, call, &paths::IO_WRITE) && symbol == "write" {
- span_lint(
+ "read amount is not handled. Use `Read::read_exact` instead",
+ ),
+ (true, _, "read_vectored") => span_lint(cx, UNUSED_IO_AMOUNT, expr.span, "read amount is not handled"),
+ (_, true, "write") => span_lint(
cx,
UNUSED_IO_AMOUNT,
expr.span,
- "handle written amount returned or use `Write::write_all` instead",
- );
+ "written amount is not handled. Use `Write::write_all` instead",
+ ),
+ (_, true, "write_vectored") => span_lint(cx, UNUSED_IO_AMOUNT, expr.span, "written amount is not handled"),
+ _ => (),
}
}
}