add MSRV check for lines_filter_map_ok

book/src/lint_configuration.md

@@ -740,6 +740,7 @@ The minimum rust version that the project supports. Defaults to the `rust-versio
 * [`index_refutable_slice`](https://rust-lang.github.io/rust-clippy/master/index.html#index_refutable_slice)
 * [`iter_kv_map`](https://rust-lang.github.io/rust-clippy/master/index.html#iter_kv_map)
 * [`legacy_numeric_constants`](https://rust-lang.github.io/rust-clippy/master/index.html#legacy_numeric_constants)
+* [`lines_filter_map_ok`](https://rust-lang.github.io/rust-clippy/master/index.html#lines_filter_map_ok)
 * [`manual_bits`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_bits)
 * [`manual_c_str_literals`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_c_str_literals)
 * [`manual_clamp`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_clamp)

clippy_config/src/conf.rs

@@ -609,6 +609,7 @@ define_Conf! {
         index_refutable_slice,
         iter_kv_map,
         legacy_numeric_constants,
+        lines_filter_map_ok,
         manual_bits,
         manual_c_str_literals,
         manual_clamp,

clippy_lints/src/lib.rs

@@ -900,7 +900,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
     store.register_late_pass(move |_| Box::new(manual_main_separator_str::ManualMainSeparatorStr::new(conf)));
     store.register_late_pass(|_| Box::new(unnecessary_struct_initialization::UnnecessaryStruct));
     store.register_late_pass(move |_| Box::new(unnecessary_box_returns::UnnecessaryBoxReturns::new(conf)));
-    store.register_late_pass(|_| Box::new(lines_filter_map_ok::LinesFilterMapOk));
+    store.register_late_pass(move |_| Box::new(lines_filter_map_ok::LinesFilterMapOk::new(conf)));
     store.register_late_pass(|_| Box::new(tests_outside_test_module::TestsOutsideTestModule));
     store.register_late_pass(|_| Box::new(manual_slice_size_calculation::ManualSliceSizeCalculation));
     store.register_early_pass(move || Box::new(excessive_nesting::ExcessiveNesting::new(conf)));

clippy_lints/src/lines_filter_map_ok.rs

@@ -1,12 +1,26 @@
+use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::ty::is_type_diagnostic_item;
 use clippy_utils::{is_diag_item_method, is_trait_method, path_to_local_id};
 use rustc_errors::Applicability;
 use rustc_hir::{Body, Closure, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::declare_lint_pass;
+use rustc_session::impl_lint_pass;
 use rustc_span::sym;
 
+pub struct LinesFilterMapOk {
+    msrv: Msrv,
+}
+
+impl LinesFilterMapOk {
+    pub fn new(conf: &Conf) -> Self {
+        Self {
+            msrv: conf.msrv.clone(),
+        }
+    }
+}
+
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `lines.filter_map(Result::ok)` or `lines.flat_map(Result::ok)`
@@ -55,11 +69,13 @@ declare_clippy_lint! {
     suspicious,
     "filtering `std::io::Lines` with `filter_map()`, `flat_map()`, or `flatten()` might cause an infinite loop"
 }
-declare_lint_pass!(LinesFilterMapOk => [LINES_FILTER_MAP_OK]);
+
+impl_lint_pass!(LinesFilterMapOk => [LINES_FILTER_MAP_OK]);
 
 impl LateLintPass<'_> for LinesFilterMapOk {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
-        if let ExprKind::MethodCall(fm_method, fm_receiver, fm_args, fm_span) = expr.kind
+        if self.msrv.meets(msrvs::MAP_WHILE)
+            && let ExprKind::MethodCall(fm_method, fm_receiver, fm_args, fm_span) = expr.kind
             && is_trait_method(cx, expr, sym::Iterator)
             && let fm_method_str = fm_method.ident.as_str()
             && matches!(fm_method_str, "filter_map" | "flat_map" | "flatten")
@@ -85,6 +101,8 @@ impl LateLintPass<'_> for LinesFilterMapOk {
             );
         }
     }
+
+    extract_msrv_attr!(LateContext);
 }
 
 fn should_lint(cx: &LateContext<'_>, args: &[Expr<'_>], method_str: &str) -> bool {

clippy_utils/src/msrvs.rs

@@ -34,6 +34,7 @@ msrv_aliases! {
     1,62,0 { BOOL_THEN_SOME, DEFAULT_ENUM_ATTRIBUTE, CONST_EXTERN_C_FN }
     1,59,0 { THREAD_LOCAL_CONST_INIT }
     1,58,0 { FORMAT_ARGS_CAPTURE, PATTERN_TRAIT_CHAR_ARRAY, CONST_RAW_PTR_DEREF }
+    1,57,0 { MAP_WHILE }
     1,56,0 { CONST_FN_UNION }
     1,55,0 { SEEK_REWIND }
     1,54,0 { INTO_KEYS }

tests/ui/lines_filter_map_ok.fixed

@@ -31,3 +31,10 @@ fn main() -> io::Result<()> {
     io::stdin().lines().filter_map(|x| x.err()).for_each(|_| ());
     Ok(())
 }
+
+#[clippy::msrv = "1.56"]
+fn msrv_check() {
+    let _lines = BufReader::new(std::fs::File::open("some-path").unwrap())
+        .lines()
+        .filter_map(Result::ok);
+}

tests/ui/lines_filter_map_ok.rs

@@ -31,3 +31,10 @@ fn main() -> io::Result<()> {
     io::stdin().lines().filter_map(|x| x.err()).for_each(|_| ());
     Ok(())
 }
+
+#[clippy::msrv = "1.56"]
+fn msrv_check() {
+    let _lines = BufReader::new(std::fs::File::open("some-path").unwrap())
+        .lines()
+        .filter_map(Result::ok);
+}