Merge commit 'ac0e10aa68325235069a842f47499852b2dee79e' into clippyup

11 files changed, 182 insertions, 20 deletions

diff --git a/src/docs.rs b/src/docs.rs
index 6c89b4dde37..3bf488ab477 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",
@@ -105,6 +106,7 @@ docs! {
     "derive_hash_xor_eq",
     "derive_ord_xor_partial_ord",
     "derive_partial_eq_without_eq",
+    "disallowed_macros",
     "disallowed_methods",
     "disallowed_names",
     "disallowed_script_idents",
@@ -190,6 +192,7 @@ docs! {
     "implicit_clone",
     "implicit_hasher",
     "implicit_return",
+    "implicit_saturating_add",
     "implicit_saturating_sub",
     "imprecise_flops",
     "inconsistent_digit_grouping",
@@ -254,6 +257,7 @@ docs! {
     "manual_assert",
     "manual_async_fn",
     "manual_bits",
+    "manual_clamp",
     "manual_filter_map",
     "manual_find",
     "manual_find_map",
@@ -521,6 +525,7 @@ 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..4ae8bce88ad 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?
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/disallowed_macros.txt b/src/docs/disallowed_macros.txt
new file mode 100644
index 00000000000..96fa15afabf
--- /dev/null
+++ b/src/docs/disallowed_macros.txt
@@ -0,0 +1,36 @@
+### What it does
+Denies the configured macros in clippy.toml
+
+Note: Even though this lint is warn-by-default, it will only trigger if
+macros are defined in the clippy.toml file.
+
+### Why is this bad?
+Some macros are undesirable in certain contexts, and it's beneficial to
+lint for them as needed.
+
+### Example
+An example clippy.toml configuration:
+```
+disallowed-macros = [
+    # Can use a string as the path of the disallowed macro.
+    "std::print",
+    # Can also use an inline table with a `path` key.
+    { path = "std::println" },
+    # When using an inline table, can add a `reason` for why the macro
+    # is disallowed.
+    { path = "serde::Serialize", reason = "no serializing" },
+]
+```
+```
+use serde::Serialize;
+
+// Example code where clippy issues a warning
+println!("warns");
+
+// The diagnostic will contain the message "no serializing"
+#[derive(Serialize)]
+struct Data {
+    name: String,
+    value: usize,
+}
+```
\ No newline at end of file
diff --git a/src/docs/implicit_saturating_add.txt b/src/docs/implicit_saturating_add.txt
new file mode 100644
index 00000000000..5883a5363e2
--- /dev/null
+++ b/src/docs/implicit_saturating_add.txt
@@ -0,0 +1,20 @@
+### What it does
+Checks for implicit saturating addition.
+
+### Why is this bad?
+The built-in function is more readable and may be faster.
+
+### Example
+```
+let mut u:u32 = 7000;
+
+if u != u32::MAX {
+    u += 1;
+}
+```
+Use instead:
+```
+let mut u:u32 = 7000;
+
+u = u.saturating_add(1);
+```
\ No newline at end of file
diff --git a/src/docs/manual_clamp.txt b/src/docs/manual_clamp.txt
new file mode 100644
index 00000000000..8993f6683ad
--- /dev/null
+++ b/src/docs/manual_clamp.txt
@@ -0,0 +1,46 @@
+### What it does
+Identifies good opportunities for a clamp function from std or core, and suggests using it.
+
+### Why is this bad?
+clamp is much shorter, easier to read, and doesn't use any control flow.
+
+### Known issue(s)
+If the clamped variable is NaN this suggestion will cause the code to propagate NaN
+rather than returning either `max` or `min`.
+
+`clamp` functions will panic if `max < min`, `max.is_nan()`, or `min.is_nan()`.
+Some may consider panicking in these situations to be desirable, but it also may
+introduce panicking where there wasn't any before.
+
+### Examples
+```
+if input > max {
+    max
+} else if input < min {
+    min
+} else {
+    input
+}
+```
+
+```
+input.max(min).min(max)
+```
+
+```
+match input {
+    x if x > max => max,
+    x if x < min => min,
+    x => x,
+}
+```
+
+```
+let mut x = input;
+if x < min { x = min; }
+if x > max { x = max; }
+```
+Use instead:
+```
+input.clamp(min, max)
+```
\ No newline at end of file
diff --git a/src/docs/needless_borrowed_reference.txt b/src/docs/needless_borrowed_reference.txt
index 55faa0cf571..152459ba1c9 100644
--- a/src/docs/needless_borrowed_reference.txt
+++ b/src/docs/needless_borrowed_reference.txt
@@ -1,30 +1,22 @@
 ### What it does
-Checks for bindings that destructure a reference and borrow the inner
+Checks for bindings that needlessly destructure a reference and borrow the inner
 value with `&ref`.
 
 ### Why is this bad?
 This pattern has no effect in almost all cases.
 
-### Known problems
-In some cases, `&ref` is needed to avoid a lifetime mismatch error.
-Example:
-```
-fn foo(a: &Option<String>, b: &Option<String>) {
-    match (a, b) {
-        (None, &ref c) | (&ref c, None) => (),
-        (&Some(ref c), _) => (),
-    };
-}
-```
-
 ### Example
 ```
 let mut v = Vec::<String>::new();
 v.iter_mut().filter(|&ref a| a.is_empty());
+
+if let &[ref first, ref second] = v.as_slice() {}
 ```
 
 Use instead:
 ```
 let mut v = Vec::<String>::new();
 v.iter_mut().filter(|a| a.is_empty());
+
+if let [first, second] = v.as_slice() {}
 ```
\ No newline at end of file
diff --git a/src/docs/similar_names.txt b/src/docs/similar_names.txt
index 13aca9c0bb7..f9eff21b679 100644
--- a/src/docs/similar_names.txt
+++ b/src/docs/similar_names.txt
@@ -1,6 +1,10 @@
 ### What it does
 Checks for names that are very similar and thus confusing.
 
+Note: this lint looks for similar names throughout each
+scope. To allow it, you need to allow it on the scope
+level, not on the name that is reported.
+
 ### Why is this bad?
 It's hard to distinguish between names that differ only
 by a single character.
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.