add MSRV to more lints specified in #6097

[rust.git] / clippy_lints / src / mem_replace.rs

diff --git a/clippy_lints/src/mem_replace.rs b/clippy_lints/src/mem_replace.rs
index 703f91f8ac028401a62c8b59e861c56e18795ff7..19087b02077142fb84d86a62c87beffa7ac844d7 100644 (file)
--- a/clippy_lints/src/mem_replace.rs
+++ b/clippy_lints/src/mem_replace.rs
@@ -1,13 +1,14 @@
 use crate::utils::{
-    in_macro, match_def_path, match_qpath, paths, snippet, snippet_with_applicability, span_lint_and_help,
+    in_macro, match_def_path, match_qpath, meets_msrv, paths, snippet, snippet_with_applicability, span_lint_and_help,
     span_lint_and_sugg, span_lint_and_then,
 };
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, QPath};
-use rustc_lint::{LateContext, LateLintPass};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
-use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 use rustc_span::symbol::sym;
 
@@ -94,10 +95,10 @@
     "replacing a value of type `T` with `T::default()` instead of using `std::mem::take`"
 }
 
-declare_lint_pass!(MemReplace =>
+impl_lint_pass!(MemReplace =>
     [MEM_REPLACE_OPTION_WITH_NONE, MEM_REPLACE_WITH_UNINIT, MEM_REPLACE_WITH_DEFAULT]);
 
-fn check_replace_option_with_none(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
+fn check_replace_option_with_none(cx: &LateContext<'_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
     if let ExprKind::Path(ref replacement_qpath) = src.kind {
         // Check that second argument is `Option::None`
         if match_qpath(replacement_qpath, &paths::OPTION_NONE) {
@@ -135,10 +136,10 @@ fn check_replace_option_with_none(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest
     }
 }
 
-fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
+fn check_replace_with_uninit(cx: &LateContext<'_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
     if_chain! {
         // check if replacement is mem::MaybeUninit::uninit().assume_init()
-        if let Some(method_def_id) = cx.tables().type_dependent_def_id(src.hir_id);
+        if let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(src.hir_id);
         if cx.tcx.is_diagnostic_item(sym::assume_init, method_def_id);
         then {
             let mut applicability = Applicability::MachineApplicable;
@@ -179,7 +180,7 @@ fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Ex
                     applicability,
                 );
             } else if cx.tcx.is_diagnostic_item(sym::mem_zeroed, repl_def_id) &&
-                    !cx.tables().expr_ty(src).is_primitive() {
+                    !cx.typeck_results().expr_ty(src).is_primitive() {
                 span_lint_and_help(
                     cx,
                     MEM_REPLACE_WITH_UNINIT,
@@ -193,7 +194,7 @@ fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Ex
     }
 }
 
-fn check_replace_with_default(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
+fn check_replace_with_default(cx: &LateContext<'_>, src: &Expr<'_>, dest: &Expr<'_>, expr_span: Span) {
     if let ExprKind::Call(ref repl_func, _) = src.kind {
         if_chain! {
             if !in_external_macro(cx.tcx.sess, expr_span);
@@ -224,8 +225,21 @@ fn check_replace_with_default(cx: &LateContext<'_, '_>, src: &Expr<'_>, dest: &E
     }
 }
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MemReplace {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+const MEM_REPLACE_WITH_DEFAULT_MSRV: RustcVersion = RustcVersion::new(1, 40, 0);
+
+pub struct MemReplace {
+    msrv: Option<RustcVersion>,
+}
+
+impl MemReplace {
+    #[must_use]
+    pub fn new(msrv: Option<RustcVersion>) -> Self {
+        Self { msrv }
+    }
+}
+
+impl<'tcx> LateLintPass<'tcx> for MemReplace {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         if_chain! {
             // Check that `expr` is a call to `mem::replace()`
             if let ExprKind::Call(ref func, ref func_args) = expr.kind;
@@ -236,8 +250,11 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
             then {
                 check_replace_option_with_none(cx, src, dest, expr.span);
                 check_replace_with_uninit(cx, src, dest, expr.span);
-                check_replace_with_default(cx, src, dest, expr.span);
+                if meets_msrv(self.msrv.as_ref(), &MEM_REPLACE_WITH_DEFAULT_MSRV) {
+                    check_replace_with_default(cx, src, dest, expr.span);
+                }
             }
         }
     }
+    extract_msrv_attr!(LateContext);
 }