Auto merge of #5000 - JohnTitor:backticks, r=flip1995

Normalize lint messages

On rustc diagnostics, we prefer to use backticks over `'`,  `"`, or something else. I think we should follow their manner here.
In first commit, normalizes lint messages with backticks.
In second commit, updates all stderrs.
In third commit, updates descriptions on lintlist.

changelog: none

clippy_lints/src/assign_ops.rs

@@ -209,7 +209,7 @@ fn lint_misrefactored_assign_op(
                 db.span_suggestion(
                     expr.span,
                     &format!(
-                        "Did you mean {} = {} {} {} or {}? Consider replacing it with",
+                        "Did you mean `{} = {} {} {}` or `{}`? Consider replacing it with",
                         snip_a,
                         snip_a,
                         op.node.as_str(),

clippy_lints/src/attrs.rs

@@ -187,7 +187,7 @@ declare_clippy_lint! {
     /// ```
     pub DEPRECATED_CFG_ATTR,
     complexity,
-    "usage of `cfg_attr(rustfmt)` instead of `tool_attributes`"
+    "usage of `cfg_attr(rustfmt)` instead of tool attributes"
 }
 
 declare_lint_pass!(Attributes => [
@@ -449,7 +449,7 @@ fn check_attrs(cx: &LateContext<'_, '_>, span: Span, name: Name, attrs: &[Attrib
                         EMPTY_LINE_AFTER_OUTER_ATTR,
                         begin_of_attr_to_item,
                         "Found an empty line after an outer attribute. \
-                         Perhaps you forgot to add a '!' to make it an inner attribute?",
+                         Perhaps you forgot to add a `!` to make it an inner attribute?",
                     );
                 }
             }
@@ -520,7 +520,7 @@ impl EarlyLintPass for DeprecatedCfgAttribute {
                     cx,
                     DEPRECATED_CFG_ATTR,
                     attr.span,
-                    "`cfg_attr` is deprecated for rustfmt and got replaced by tool_attributes",
+                    "`cfg_attr` is deprecated for rustfmt and got replaced by tool attributes",
                     "use",
                     "#[rustfmt::skip]".to_string(),
                     Applicability::MachineApplicable,

clippy_lints/src/block_in_if_condition.rs

@@ -68,8 +68,8 @@ impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
 }
 
 const BRACED_EXPR_MESSAGE: &str = "omit braces around single expression condition";
-const COMPLEX_BLOCK_MESSAGE: &str = "in an 'if' condition, avoid complex blocks or closures with blocks; \
-                                     instead, move the block or closure higher and bind it with a 'let'";
+const COMPLEX_BLOCK_MESSAGE: &str = "in an `if` condition, avoid complex blocks or closures with blocks; \
+                                     instead, move the block or closure higher and bind it with a `let`";
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BlockInIfCondition {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {

clippy_lints/src/collapsible_if.rs

@@ -138,7 +138,7 @@ fn check_collapsible_no_if_let(cx: &EarlyContext<'_>, expr: &ast::Expr, check: &
             if expr.span.ctxt() != inner.span.ctxt() {
                 return;
             }
-            span_lint_and_then(cx, COLLAPSIBLE_IF, expr.span, "this if statement can be collapsed", |db| {
+            span_lint_and_then(cx, COLLAPSIBLE_IF, expr.span, "this `if` statement can be collapsed", |db| {
                 let lhs = Sugg::ast(cx, check, "..");
                 let rhs = Sugg::ast(cx, check_inner, "..");
                 db.span_suggestion(

clippy_lints/src/copies.rs

@@ -38,7 +38,7 @@ declare_clippy_lint! {
     /// ```
     pub IFS_SAME_COND,
     correctness,
-    "consecutive `ifs` with the same condition"
+    "consecutive `if`s with the same condition"
 }
 
 declare_clippy_lint! {
@@ -85,7 +85,7 @@ declare_clippy_lint! {
     /// ```
     pub SAME_FUNCTIONS_IN_IF_CONDITION,
     pedantic,
-    "consecutive `ifs` with the same function call"
+    "consecutive `if`s with the same function call"
 }
 
 declare_clippy_lint! {
@@ -106,7 +106,7 @@ declare_clippy_lint! {
     /// ```
     pub IF_SAME_THEN_ELSE,
     correctness,
-    "if with the same *then* and *else* blocks"
+    "`if` with the same `then` and `else` blocks"
 }
 
 declare_clippy_lint! {
@@ -206,7 +206,7 @@ fn lint_same_cond(cx: &LateContext<'_, '_>, conds: &[&Expr<'_>]) {
             cx,
             IFS_SAME_COND,
             j.span,
-            "this `if` has the same condition as a previous if",
+            "this `if` has the same condition as a previous `if`",
             i.span,
             "same as this",
         );
@@ -234,7 +234,7 @@ fn lint_same_fns_in_if_cond(cx: &LateContext<'_, '_>, conds: &[&Expr<'_>]) {
             cx,
             SAME_FUNCTIONS_IN_IF_CONDITION,
             j.span,
-            "this `if` has the same function call as a previous if",
+            "this `if` has the same function call as a previous `if`",
             i.span,
             "same as this",
         );
@@ -300,7 +300,7 @@ fn lint_match_arms<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &Expr<'_>) {
                         db.span_note(
                             i.body.span,
                             &format!(
-                                "`{}` has the same arm body as the `_` wildcard, consider removing it`",
+                                "`{}` has the same arm body as the `_` wildcard, consider removing it",
                                 lhs
                             ),
                         );

clippy_lints/src/default_trait_access.rs

@@ -26,7 +26,7 @@ declare_clippy_lint! {
     /// ```
     pub DEFAULT_TRAIT_ACCESS,
     pedantic,
-    "checks for literal calls to Default::default()"
+    "checks for literal calls to `Default::default()`"
 }
 
 declare_lint_pass!(DefaultTraitAccess => [DEFAULT_TRAIT_ACCESS]);
@@ -62,7 +62,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DefaultTraitAccess {
                                 cx,
                                 DEFAULT_TRAIT_ACCESS,
                                 expr.span,
-                                &format!("Calling {} is more clear than this expression", replacement),
+                                &format!("Calling `{}` is more clear than this expression", replacement),
                                 "try",
                                 replacement,
                                 Applicability::Unspecified, // First resolve the TODO above

clippy_lints/src/drop_forget_ref.rs

@@ -102,9 +102,9 @@ const DROP_REF_SUMMARY: &str = "calls to `std::mem::drop` with a reference inste
                                 Dropping a reference does nothing.";
 const FORGET_REF_SUMMARY: &str = "calls to `std::mem::forget` with a reference instead of an owned value. \
                                   Forgetting a reference does nothing.";
-const DROP_COPY_SUMMARY: &str = "calls to `std::mem::drop` with a value that implements Copy. \
+const DROP_COPY_SUMMARY: &str = "calls to `std::mem::drop` with a value that implements `Copy`. \
                                  Dropping a copy leaves the original intact.";
-const FORGET_COPY_SUMMARY: &str = "calls to `std::mem::forget` with a value that implements Copy. \
+const FORGET_COPY_SUMMARY: &str = "calls to `std::mem::forget` with a value that implements `Copy`. \
                                    Forgetting a copy leaves the original intact.";
 
 declare_lint_pass!(DropForgetRef => [DROP_REF, FORGET_REF, DROP_COPY, FORGET_COPY]);
@@ -137,7 +137,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DropForgetRef {
                                        expr.span,
                                        &msg,
                                        arg.span,
-                                       &format!("argument has type {}", arg_ty));
+                                       &format!("argument has type `{}`", arg_ty));
                 } else if is_copy(cx, arg_ty) {
                     if match_def_path(cx, def_id, &paths::DROP) {
                         lint = DROP_COPY;

clippy_lints/src/else_if_without_else.rs

@@ -43,7 +43,7 @@ declare_clippy_lint! {
     /// ```
     pub ELSE_IF_WITHOUT_ELSE,
     restriction,
-    "if expression with an `else if`, but without a final `else` branch"
+    "`if` expression with an `else if`, but without a final `else` branch"
 }
 
 declare_lint_pass!(ElseIfWithoutElse => [ELSE_IF_WITHOUT_ELSE]);
@@ -60,7 +60,7 @@ impl EarlyLintPass for ElseIfWithoutElse {
                     cx,
                     ELSE_IF_WITHOUT_ELSE,
                     els.span,
-                    "if expression with an `else if`, but without a final `else`",
+                    "`if` expression with an `else if`, but without a final `else`",
                     "add an `else` block here",
                 );
             }

clippy_lints/src/format.rs

@@ -46,9 +46,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessFormat {
 
         // Operate on the only argument of `alloc::fmt::format`.
         if let Some(sugg) = on_new_v1(cx, expr) {
-            span_useless_format(cx, span, "consider using .to_string()", sugg);
+            span_useless_format(cx, span, "consider using `.to_string()`", sugg);
         } else if let Some(sugg) = on_new_v1_fmt(cx, expr) {
-            span_useless_format(cx, span, "consider using .to_string()", sugg);
+            span_useless_format(cx, span, "consider using `.to_string()`", sugg);
         }
     }
 }

clippy_lints/src/if_not_else.rs

@@ -61,7 +61,7 @@ impl EarlyLintPass for IfNotElse {
                             IF_NOT_ELSE,
                             item.span,
                             "Unnecessary boolean `not` operation",
-                            "remove the `!` and swap the blocks of the if/else",
+                            "remove the `!` and swap the blocks of the `if`/`else`",
                         );
                     },
                     ExprKind::Binary(ref kind, _, _) if kind.node == BinOpKind::Ne => {
@@ -70,7 +70,7 @@ impl EarlyLintPass for IfNotElse {
                             IF_NOT_ELSE,
                             item.span,
                             "Unnecessary `!=` operation",
-                            "change to `==` and swap the blocks of the if/else",
+                            "change to `==` and swap the blocks of the `if`/`else`",
                         );
                     },
                     _ => (),

clippy_lints/src/implicit_return.rs

@@ -51,7 +51,7 @@ fn lint(cx: &LateContext<'_, '_>, outer_span: Span, inner_span: Span, msg: &str)
     let outer_span = outer_span.source_callsite();
     let inner_span = inner_span.source_callsite();
 
-    span_lint_and_then(cx, IMPLICIT_RETURN, outer_span, "missing return statement", |db| {
+    span_lint_and_then(cx, IMPLICIT_RETURN, outer_span, "missing `return` statement", |db| {
         if let Some(snippet) = snippet_opt(cx, inner_span) {
             db.span_suggestion(
                 outer_span,
@@ -102,7 +102,7 @@ fn expr_match(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
                     expr_match(cx, &arm.body);
                 }
             } else {
-                expr_match(cx, &arms.first().expect("if let doesn't have a single arm").body);
+                expr_match(cx, &arms.first().expect("`if let` doesn't have a single arm").body);
             }
         },
         // skip if it already has a return statement

clippy_lints/src/infallible_destructuring_match.rs

@@ -38,7 +38,7 @@ declare_clippy_lint! {
     /// ```
     pub INFALLIBLE_DESTRUCTURING_MATCH,
     style,
-    "a match statement with a single infallible arm instead of a `let`"
+    "a `match` statement with a single infallible arm instead of a `let`"
 }
 
 declare_lint_pass!(InfallibleDestructingMatch => [INFALLIBLE_DESTRUCTURING_MATCH]);
@@ -61,7 +61,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InfallibleDestructingMatch {
                     cx,
                     INFALLIBLE_DESTRUCTURING_MATCH,
                     local.span,
-                    "you seem to be trying to use match to destructure a single infallible pattern. \
+                    "you seem to be trying to use `match` to destructure a single infallible pattern. \
                      Consider using `let`",
                     "try this",
                     format!(

clippy_lints/src/inherent_to_string.rs

@@ -88,7 +88,7 @@ declare_clippy_lint! {
     /// ```
     pub INHERENT_TO_STRING_SHADOW_DISPLAY,
     correctness,
-    "type implements inherent method `to_string()`, which gets shadowed by the implementation of the `Display` trait "
+    "type implements inherent method `to_string()`, which gets shadowed by the implementation of the `Display` trait"
 }
 
 declare_lint_pass!(InherentToString => [INHERENT_TO_STRING, INHERENT_TO_STRING_SHADOW_DISPLAY]);

clippy_lints/src/int_plus_one.rs

@@ -32,7 +32,7 @@ declare_clippy_lint! {
     /// ```
     pub INT_PLUS_ONE,
     complexity,
-    "instead of using x >= y + 1, use x > y"
+    "instead of using `x >= y + 1`, use `x > y`"
 }
 
 declare_lint_pass!(IntPlusOne => [INT_PLUS_ONE]);

clippy_lints/src/large_stack_arrays.rs

@@ -59,7 +59,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeStackArrays {
                         self.maximum_allowed_size
                     ),
                     &format!(
-                        "consider allocating on the heap with vec!{}.into_boxed_slice()",
+                        "consider allocating on the heap with `vec!{}.into_boxed_slice()`",
                         snippet(cx, expr.span, "[...]")
                     ),
                 );

clippy_lints/src/let_underscore.rs

@@ -27,7 +27,7 @@ declare_clippy_lint! {
     /// ```
     pub LET_UNDERSCORE_MUST_USE,
     restriction,
-    "non-binding let on a #[must_use] expression"
+    "non-binding let on a `#[must_use]` expression"
 }
 
 declare_lint_pass!(LetUnderscore => [LET_UNDERSCORE_MUST_USE]);
@@ -44,15 +44,15 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetUnderscore {
                         cx,
                         LET_UNDERSCORE_MUST_USE,
                         stmt.span,
-                        "non-binding let on an expression with #[must_use] type",
+                        "non-binding let on an expression with `#[must_use]` type",
                         "consider explicitly using expression value"
                     )
                 } else if is_must_use_func_call(cx, init) {
                     span_help_and_lint(
                         cx,
                         LET_UNDERSCORE_MUST_USE,
                         stmt.span,
-                        "non-binding let on a result of a #[must_use] function",
+                        "non-binding let on a result of a `#[must_use]` function",
                         "consider explicitly using function result"
                     )
                 }

clippy_lints/src/loops.rs

@@ -1353,7 +1353,7 @@ fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, e
                         EXPLICIT_INTO_ITER_LOOP,
                         arg.span,
                         "it is more concise to loop over containers instead of using explicit \
-                         iteration methods`",
+                         iteration methods",
                         "to write this more concisely, try",
                         object.to_string(),
                         applicability,

clippy_lints/src/map_clone.rs

@@ -112,7 +112,7 @@ fn lint_needless_cloning(cx: &LateContext<'_, '_>, root: Span, receiver: Span) {
         MAP_CLONE,
         root.trim_start(receiver).unwrap(),
         "You are needlessly cloning iterator elements",
-        "Remove the map call",
+        "Remove the `map` call",
         String::new(),
         Applicability::MachineApplicable,
     )

clippy_lints/src/map_unit_fn.rs

@@ -48,7 +48,7 @@ declare_clippy_lint! {
     /// ```
     pub OPTION_MAP_UNIT_FN,
     complexity,
-    "using `option.map(f)`, where f is a function or closure that returns ()"
+    "using `option.map(f)`, where `f` is a function or closure that returns `()`"
 }
 
 declare_clippy_lint! {
@@ -89,7 +89,7 @@ declare_clippy_lint! {
     /// ```
     pub RESULT_MAP_UNIT_FN,
     complexity,
-    "using `result.map(f)`, where f is a function or closure that returns ()"
+    "using `result.map(f)`, where `f` is a function or closure that returns `()`"
 }
 
 declare_lint_pass!(MapUnit => [OPTION_MAP_UNIT_FN, RESULT_MAP_UNIT_FN]);
@@ -199,7 +199,7 @@ fn let_binding_name(cx: &LateContext<'_, '_>, var_arg: &hir::Expr<'_>) -> String
 #[must_use]
 fn suggestion_msg(function_type: &str, map_type: &str) -> String {
     format!(
-        "called `map(f)` on an {0} value where `f` is a unit {1}",
+        "called `map(f)` on an `{0}` value where `f` is a unit {1}",
         map_type, function_type
     )
 }