Make use of some existing diagnostic items

[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 4e0d2c24f751a4b2973d0006b8d8f463d487039a..0bd4c4805b34c3d2f4d285a0963d136a720271c0 100644 (file)
--- a/clippy_lints/src/mem_replace.rs
+++ b/clippy_lints/src/mem_replace.rs
@@ -1,13 +1,15 @@
 use crate::utils::{
-    in_macro, match_def_path, match_qpath, paths, snippet_with_applicability, span_help_and_lint, span_lint_and_sugg,
+    in_macro, match_def_path, match_qpath, paths, snippet, snippet_with_applicability, span_lint_and_help,
+    span_lint_and_sugg, span_lint_and_then,
 };
 use if_chain::if_chain;
-use rustc::declare_lint_pass;
-use rustc::hir::{BorrowKind, Expr, ExprKind, Mutability, QPath};
-use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintPass};
 use rustc_errors::Applicability;
-use rustc_session::declare_tool_lint;
-use syntax::source_map::Span;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::sym;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for `mem::replace()` on an `Option` with
@@ -95,7 +97,7 @@
 declare_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) {
@@ -133,24 +135,24 @@ fn check_replace_option_with_none(cx: &LateContext<'_, '_>, src: &Expr, dest: &E
     }
 }
 
-fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr, expr_span: Span) {
+fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, expr_span: Span) {
     if let ExprKind::Call(ref repl_func, ref repl_args) = src.kind {
         if_chain! {
             if repl_args.is_empty();
             if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
             if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
             then {
-                if match_def_path(cx, repl_def_id, &paths::MEM_UNINITIALIZED) {
-                    span_help_and_lint(
+                if cx.tcx.is_diagnostic_item(sym::mem_uninitialized, repl_def_id) {
+                    span_lint_and_help(
                         cx,
                         MEM_REPLACE_WITH_UNINIT,
                         expr_span,
                         "replacing with `mem::uninitialized()`",
                         "consider using the `take_mut` crate instead",
                     );
-                } else if match_def_path(cx, repl_def_id, &paths::MEM_ZEROED) &&
+                } else if cx.tcx.is_diagnostic_item(sym::mem_zeroed, repl_def_id) &&
                         !cx.tables.expr_ty(src).is_primitive() {
-                    span_help_and_lint(
+                    span_lint_and_help(
                         cx,
                         MEM_REPLACE_WITH_UNINIT,
                         expr_span,
@@ -163,27 +165,31 @@ fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr, expr_span: Sp
     }
 }
 
-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_macro(expr_span) && !in_external_macro(cx.tcx.sess, expr_span);
+            if !in_external_macro(cx.tcx.sess, expr_span);
             if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
             if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
             if match_def_path(cx, repl_def_id, &paths::DEFAULT_TRAIT_METHOD);
             then {
-                let mut applicability = Applicability::MachineApplicable;
-
-                span_lint_and_sugg(
+                span_lint_and_then(
                     cx,
                     MEM_REPLACE_WITH_DEFAULT,
                     expr_span,
                     "replacing a value of type `T` with `T::default()` is better expressed using `std::mem::take`",
-                    "consider using",
-                    format!(
-                        "std::mem::take({})",
-                        snippet_with_applicability(cx, dest.span, "", &mut applicability)
-                    ),
-                    applicability,
+                    |db| {
+                        if !in_macro(expr_span) {
+                            let suggestion = format!("std::mem::take({})", snippet(cx, dest.span, ""));
+
+                            db.span_suggestion(
+                                expr_span,
+                                "consider using",
+                                suggestion,
+                                Applicability::MachineApplicable
+                            );
+                        }
+                    }
                 );
             }
         }