Merge remote-tracking branch 'upstream/master' into rustup

6 files changed, 69 insertions, 8 deletions

diff --git a/src/docs.rs b/src/docs.rs
index 6c89b4dde37..166be0618ff 100644
--- a/src/docs.rs
+++ b/src/docs.rs
@@ -48,6 +48,7 @@ docs! {
     "borrow_interior_mutable_const",
     "borrowed_box",
     "box_collection",
+    "box_default",
     "boxed_local",
     "branches_sharing_code",
     "builtin_type_shadow",
@@ -521,6 +522,7 @@ docs! {
     "unimplemented",
     "uninit_assumed_init",
     "uninit_vec",
+    "uninlined_format_args",
     "unit_arg",
     "unit_cmp",
     "unit_hash",
diff --git a/src/docs/arithmetic_side_effects.txt b/src/docs/arithmetic_side_effects.txt
index 6c7d51a4989..b8c0872522e 100644
--- a/src/docs/arithmetic_side_effects.txt
+++ b/src/docs/arithmetic_side_effects.txt
@@ -5,7 +5,7 @@ Operators like `+`, `-`, `*` or `<<` are usually capable of overflowing accordin
 Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
 or can panic (`/`, `%`).
 
-Known safe built-in types like `Wrapping` or `Saturing`, floats, operations in constant
+Known safe built-in types like `Wrapping` or `Saturating`, floats, operations in constant
 environments, allowed types and non-constant operations that won't overflow are ignored.
 
 ### Why is this bad?
@@ -30,4 +30,4 @@ let _n = Decimal::MAX + Decimal::MAX;
 ```
 
 ### Allowed types
-Custom allowed types can be specified through the "arithmetic-side-effects-allowed" filter.
\ No newline at end of file
+Custom allowed types can be specified through the "arithmetic-side-effects-allowed" filter.
diff --git a/src/docs/box_default.txt b/src/docs/box_default.txt
new file mode 100644
index 00000000000..ffac894d0c5
--- /dev/null
+++ b/src/docs/box_default.txt
@@ -0,0 +1,23 @@
+### What it does
+checks for `Box::new(T::default())`, which is better written as
+`Box::<T>::default()`.
+
+### Why is this bad?
+First, it's more complex, involving two calls instead of one.
+Second, `Box::default()` can be faster
+[in certain cases](https://nnethercote.github.io/perf-book/standard-library-types.html#box).
+
+### Known problems
+The lint may miss some cases (e.g. Box::new(String::from(""))).
+On the other hand, it will trigger on cases where the `default`
+code comes from a macro that does something different based on
+e.g. target operating system.
+
+### Example
+```
+let x: Box<String> = Box::new(Default::default());
+```
+Use instead:
+```
+let x: Box<String> = Box::default();
+```
\ No newline at end of file
diff --git a/src/docs/uninlined_format_args.txt b/src/docs/uninlined_format_args.txt
new file mode 100644
index 00000000000..3d2966c84db
--- /dev/null
+++ b/src/docs/uninlined_format_args.txt
@@ -0,0 +1,36 @@
+### What it does
+Detect when a variable is not inlined in a format string,
+and suggests to inline it.
+
+### Why is this bad?
+Non-inlined code is slightly more difficult to read and understand,
+as it requires arguments to be matched against the format string.
+The inlined syntax, where allowed, is simpler.
+
+### Example
+```
+format!("{}", var);
+format!("{v:?}", v = var);
+format!("{0} {0}", var);
+format!("{0:1$}", var, width);
+format!("{:.*}", prec, var);
+```
+Use instead:
+```
+format!("{var}");
+format!("{var:?}");
+format!("{var} {var}");
+format!("{var:width$}");
+format!("{var:.prec$}");
+```
+
+### Known Problems
+
+There may be a false positive if the format string is expanded from certain proc macros:
+
+```
+println!(indoc!("{}"), var);
+```
+
+If a format string contains a numbered argument that cannot be inlined
+nothing will be suggested, e.g. `println!("{0}={1}", var, 1+2)`.
\ No newline at end of file
diff --git a/src/driver.rs b/src/driver.rs
index 235eae5af1e..b12208ac62a 100644
--- a/src/driver.rs
+++ b/src/driver.rs
@@ -193,8 +193,8 @@ fn report_clippy_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
 
     let xs: Vec<Cow<'static, str>> = vec![
         "the compiler unexpectedly panicked. this is a bug.".into(),
-        format!("we would appreciate a bug report: {}", bug_report_url).into(),
-        format!("Clippy version: {}", version_info).into(),
+        format!("we would appreciate a bug report: {bug_report_url}").into(),
+        format!("Clippy version: {version_info}").into(),
     ];
 
     for note in &xs {
@@ -290,7 +290,7 @@ pub fn main() {
 
         if orig_args.iter().any(|a| a == "--version" || a == "-V") {
             let version_info = rustc_tools_util::get_version_info!();
-            println!("{}", version_info);
+            println!("{version_info}");
             exit(0);
         }
 
diff --git a/src/main.rs b/src/main.rs
index 4a32e0e54a8..fce3cdfc462 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -37,12 +37,12 @@ You can use tool lints to allow or deny lints from your code, eg.:
 "#;
 
 fn show_help() {
-    println!("{}", CARGO_CLIPPY_HELP);
+    println!("{CARGO_CLIPPY_HELP}");
 }
 
 fn show_version() {
     let version_info = rustc_tools_util::get_version_info!();
-    println!("{}", version_info);
+    println!("{version_info}");
 }
 
 pub fn main() {
@@ -133,7 +133,7 @@ impl ClippyCmd {
         let clippy_args: String = self
             .clippy_args
             .iter()
-            .map(|arg| format!("{}__CLIPPY_HACKERY__", arg))
+            .map(|arg| format!("{arg}__CLIPPY_HACKERY__"))
             .collect();
 
         // Currently, `CLIPPY_TERMINAL_WIDTH` is used only to format "unknown field" error messages.