Auto merge of #8947 - Serial-ATA:lint-produces-output, r=xFrednet

Add lint output to lint list

changelog: Add the ability to show the lint output in the lint list

This just adds the logic to produce the output, it hasn't been added to any lints yet. It did help find some mistakes in some docs though 😄.

### Screenshots

<details>
<summary>A single code block</summary>

![single-code-block](https://user-images.githubusercontent.com/69764315/172013766-145b22b1-1d91-4fb8-9cd0-b967a52d6330.png)
</details>

<details>
<summary>A single code block with a "Use instead" section</summary>

![with-usage](https://user-images.githubusercontent.com/69764315/172013792-d2dd6c9c-defa-41e0-8c27-8e8e311adb63.png)
</details>

<details>
<summary>Multiple code blocks</summary>

![multi-code-block](https://user-images.githubusercontent.com/69764315/172013808-5328f59b-e7c5-4914-a396-253822a6d350.png)
</details>

This is the last task in #7172 🎉.
r? `@xFrednet` (?)

Author: bors

Cargo.toml

@@ -59,7 +59,7 @@ rustc_tools_util = { version = "0.2", path = "rustc_tools_util" }
 [features]
 deny-warnings = ["clippy_lints/deny-warnings"]
 integration = ["tempfile"]
-internal = ["clippy_lints/internal"]
+internal = ["clippy_lints/internal", "tempfile"]
 
 [package.metadata.rust-analyzer]
 # This package uses #[feature(rustc_private)]

clippy_lints/Cargo.toml

@@ -10,6 +10,7 @@ edition = "2021"
 
 [dependencies]
 cargo_metadata = "0.14"
+clippy_dev = { path = "../clippy_dev", optional = true }
 clippy_utils = { path = "../clippy_utils" }
 if_chain = "1.0"
 itertools = "0.10.1"
@@ -18,6 +19,7 @@ quine-mc_cluskey = "0.2"
 regex-syntax = "0.6"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = { version = "1.0", optional = true }
+tempfile = { version = "3.3.0", optional = true }
 toml = "0.5"
 unicode-normalization = "0.1"
 unicode-script = { version = "0.5", default-features = false }
@@ -30,7 +32,7 @@ url = { version = "2.2", features = ["serde"] }
 [features]
 deny-warnings = ["clippy_utils/deny-warnings"]
 # build clippy with internal lints enabled, off by default
-internal = ["clippy_utils/internal", "serde_json"]
+internal = ["clippy_utils/internal", "serde_json", "tempfile", "clippy_dev"]
 
 [package.metadata.rust-analyzer]
 # This crate uses #[feature(rustc_private)]

clippy_lints/src/collapsible_if.rs

@@ -32,20 +32,20 @@ declare_clippy_lint! {
     /// makes code look more complex than it really is.
     ///
     /// ### Example
-    /// ```rust,ignore
+    /// ```rust
+    /// # let (x, y) = (true, true);
     /// if x {
     ///     if y {
-    ///         …
+    ///         // …
     ///     }
     /// }
-    ///
     /// ```
     ///
     /// Use instead:
-    ///
-    /// ```rust,ignore
+    /// ```rust
+    /// # let (x, y) = (true, true);
     /// if x && y {
-    ///     …
+    ///     // …
     /// }
     /// ```
     #[clippy::version = "pre 1.29.0"]

clippy_lints/src/doc.rs

@@ -178,7 +178,7 @@ declare_clippy_lint! {
     /// if the `fn main()` is left implicit.
     ///
     /// ### Examples
-    /// ``````rust
+    /// ```rust
     /// /// An example of a doctest with a `main()` function
     /// ///
     /// /// # Examples
@@ -191,7 +191,7 @@ declare_clippy_lint! {
     /// fn needless_main() {
     ///     unimplemented!();
     /// }
-    /// ``````
+    /// ```
     #[clippy::version = "1.40.0"]
     pub NEEDLESS_DOCTEST_MAIN,
     style,

clippy_lints/src/large_include_file.rs

@@ -22,10 +22,11 @@ declare_clippy_lint! {
     /// let included_bytes = include_bytes!("very_large_file.txt");
     /// ```
     ///
-    /// Instead, you can load the file at runtime:
+    /// Use instead:
     /// ```rust,ignore
     /// use std::fs;
     ///
+    /// // You can load the file at runtime
     /// let string = fs::read_to_string("very_large_file.txt")?;
     /// let bytes = fs::read("very_large_file.txt")?;
     /// ```

clippy_lints/src/literal_representation.rs

@@ -51,6 +51,7 @@ declare_clippy_lint! {
     /// - Does not match on `_127` since that is a valid grouping for decimal and octal numbers
     ///
     /// ### Example
+    /// ```ignore
     /// `2_32` => `2_i32`
     /// `250_8 => `250_u8`
     /// ```