Auto merge of #7502 - flip1995:rollup-y3ho3w0, r=flip1995

Rollup of 3 pull requests

Successful merges:

 - #7279 (Adapting the lint list to Clippy's new metadata format)
 - #7298 (Switch CI to new metadata collection)
 - #7420 (Update lint documentation to use markdown headlines)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

changelog: rollup

4 files changed, 99 insertions, 76 deletions

diff --git a/clippy_lints/src/utils/author.rs b/clippy_lints/src/utils/author.rs
index c1e7fd7fe95..61fd375a989 100644
--- a/clippy_lints/src/utils/author.rs
+++ b/clippy_lints/src/utils/author.rs
@@ -13,9 +13,10 @@ use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
-    /// **What it does:** Generates clippy code that detects the offending pattern
+    /// ### What it does
+    /// Generates clippy code that detects the offending pattern
     ///
-    /// **Example:**
+    /// ### Example
     /// ```rust,ignore
     /// // ./tests/ui/my_lint.rs
     /// fn foo() {
diff --git a/clippy_lints/src/utils/inspector.rs b/clippy_lints/src/utils/inspector.rs
index 4665eeeff7b..f7ddee12dcf 100644
--- a/clippy_lints/src/utils/inspector.rs
+++ b/clippy_lints/src/utils/inspector.rs
@@ -8,10 +8,11 @@ use rustc_session::Session;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
-    /// **What it does:** Dumps every ast/hir node which has the `#[clippy::dump]`
+    /// ### What it does
+    /// Dumps every ast/hir node which has the `#[clippy::dump]`
     /// attribute
     ///
-    /// **Example:**
+    /// ### Example
     /// ```rust,ignore
     /// #[clippy::dump]
     /// extern crate foo;
diff --git a/clippy_lints/src/utils/internal_lints.rs b/clippy_lints/src/utils/internal_lints.rs
index 668807f499f..d660008e7d1 100644
--- a/clippy_lints/src/utils/internal_lints.rs
+++ b/clippy_lints/src/utils/internal_lints.rs
@@ -36,29 +36,33 @@ use std::borrow::{Borrow, Cow};
 pub mod metadata_collector;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for various things we like to keep tidy in clippy.
+    /// ### What it does
+    /// Checks for various things we like to keep tidy in clippy.
     ///
-    /// **Why is this bad?** We like to pretend we're an example of tidy code.
+    /// ### Why is this bad?
+    /// We like to pretend we're an example of tidy code.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:** Wrong ordering of the util::paths constants.
+    /// ### Example
+    /// Wrong ordering of the util::paths constants.
     pub CLIPPY_LINTS_INTERNAL,
     internal,
     "various things that will negatively affect your clippy experience"
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Ensures every lint is associated to a `LintPass`.
+    /// ### What it does
+    /// Ensures every lint is associated to a `LintPass`.
     ///
-    /// **Why is this bad?** The compiler only knows lints via a `LintPass`. Without
+    /// ### Why is this bad?
+    /// The compiler only knows lints via a `LintPass`. Without
     /// putting a lint to a `LintPass::get_lints()`'s return, the compiler will not
     /// know the name of the lint.
     ///
-    /// **Known problems:** Only checks for lints associated using the
+    /// ### Known problems
+    /// Only checks for lints associated using the
     /// `declare_lint_pass!`, `impl_lint_pass!`, and `lint_array!` macros.
     ///
-    /// **Example:**
+    /// ### Example
     /// ```rust,ignore
     /// declare_lint! { pub LINT_1, ... }
     /// declare_lint! { pub LINT_2, ... }
@@ -73,15 +77,15 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for calls to `cx.span_lint*` and suggests to use the `utils::*`
+    /// ### What it does
+    /// Checks for calls to `cx.span_lint*` and suggests to use the `utils::*`
     /// variant of the function.
     ///
-    /// **Why is this bad?** The `utils::*` variants also add a link to the Clippy documentation to the
+    /// ### Why is this bad?
+    /// The `utils::*` variants also add a link to the Clippy documentation to the
     /// warning/error messages.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// cx.span_lint(LINT_NAME, "message");
@@ -97,14 +101,14 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for calls to `cx.outer().expn_data()` and suggests to use
+    /// ### What it does
+    /// Checks for calls to `cx.outer().expn_data()` and suggests to use
     /// the `cx.outer_expn_data()`
     ///
-    /// **Why is this bad?** `cx.outer_expn_data()` is faster and more concise.
-    ///
-    /// **Known problems:** None.
+    /// ### Why is this bad?
+    /// `cx.outer_expn_data()` is faster and more concise.
     ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// expr.span.ctxt().outer().expn_data()
@@ -120,14 +124,14 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Not an actual lint. This lint is only meant for testing our customized internal compiler
+    /// ### What it does
+    /// Not an actual lint. This lint is only meant for testing our customized internal compiler
     /// error message by calling `panic`.
     ///
-    /// **Why is this bad?** ICE in large quantities can damage your teeth
+    /// ### Why is this bad?
+    /// ICE in large quantities can damage your teeth
     ///
-    /// **Known problems:** None
-    ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// 🍦🍦🍦🍦🍦
@@ -138,14 +142,14 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for cases of an auto-generated lint without an updated description,
+    /// ### What it does
+    /// Checks for cases of an auto-generated lint without an updated description,
     /// i.e. `default lint description`.
     ///
-    /// **Why is this bad?** Indicates that the lint is not finished.
-    ///
-    /// **Known problems:** None
+    /// ### Why is this bad?
+    /// Indicates that the lint is not finished.
     ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// declare_lint! { pub COOL_LINT, nursery, "default lint description" }
@@ -161,7 +165,8 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Lints `span_lint_and_then` function calls, where the
+    /// ### What it does
+    /// Lints `span_lint_and_then` function calls, where the
     /// closure argument has only one statement and that statement is a method
     /// call to `span_suggestion`, `span_help`, `span_note` (using the same
     /// span), `help` or `note`.
@@ -170,12 +175,11 @@ declare_clippy_lint! {
     /// wrapper functions `span_lint_and_sugg`, span_lint_and_help`, or
     /// `span_lint_and_note`.
     ///
-    /// **Why is this bad?** Using the wrapper `span_lint_and_*` functions, is more
+    /// ### Why is this bad?
+    /// Using the wrapper `span_lint_and_*` functions, is more
     /// convenient, readable and less error prone.
     ///
-    /// **Known problems:** None
-    ///
-    /// *Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| {
@@ -222,14 +226,14 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for calls to `utils::match_type()` on a type diagnostic item
+    /// ### What it does
+    /// Checks for calls to `utils::match_type()` on a type diagnostic item
     /// and suggests to use `utils::is_type_diagnostic_item()` instead.
     ///
-    /// **Why is this bad?** `utils::is_type_diagnostic_item()` does not require hardcoded paths.
-    ///
-    /// **Known problems:** None.
+    /// ### Why is this bad?
+    /// `utils::is_type_diagnostic_item()` does not require hardcoded paths.
     ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// utils::match_type(cx, ty, &paths::VEC)
@@ -245,30 +249,27 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:**
+    /// ### What it does
     /// Checks the paths module for invalid paths.
     ///
-    /// **Why is this bad?**
+    /// ### Why is this bad?
     /// It indicates a bug in the code.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:** None.
+    /// ### Example
+    /// None.
     pub INVALID_PATHS,
     internal,
     "invalid path"
 }
 
 declare_clippy_lint! {
-    /// **What it does:**
+    /// ### What it does
     /// Checks for interning symbols that have already been pre-interned and defined as constants.
     ///
-    /// **Why is this bad?**
+    /// ### Why is this bad?
     /// It's faster and easier to use the symbol constant.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// let _ = sym!(f32);
@@ -284,13 +285,13 @@ declare_clippy_lint! {
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for unnecessary conversion from Symbol to a string.
-    ///
-    /// **Why is this bad?** It's faster use symbols directly intead of strings.
+    /// ### What it does
+    /// Checks for unnecessary conversion from Symbol to a string.
     ///
-    /// **Known problems:** None.
+    /// ### Why is this bad?
+    /// It's faster use symbols directly intead of strings.
     ///
-    /// **Example:**
+    /// ### Example
     /// Bad:
     /// ```rust,ignore
     /// symbol.as_str() == "clippy";
diff --git a/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
index 3eccc89cdeb..47336459d7d 100644
--- a/clippy_lints/src/utils/internal_lints/metadata_collector.rs
+++ b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
@@ -32,7 +32,7 @@ use clippy_utils::{
 };
 
 /// This is the output file of the lint collector.
-const OUTPUT_FILE: &str = "../util/gh-pages/metadata_collection.json";
+const OUTPUT_FILE: &str = "../util/gh-pages/lints.json";
 /// These lints are excluded from the export.
 const BLACK_LISTED_LINTS: [&str; 3] = ["lint_author", "deep_code_inspection", "internal_metadata_collector"];
 /// These groups will be ignored by the lint group matcher. This is useful for collections like
@@ -68,7 +68,7 @@ const CLIPPY_LINT_GROUP_PREFIX: &str = "clippy::";
 macro_rules! CONFIGURATION_SECTION_TEMPLATE {
     () => {
         r#"
-**Configuration**
+### Configuration
 This lint has the following configuration variables:
 
 {configurations}
@@ -114,20 +114,25 @@ const DEPRECATED_LINT_TYPE: [&str; 3] = ["clippy_lints", "deprecated_lints", "Cl
 
 /// The index of the applicability name of `paths::APPLICABILITY_VALUES`
 const APPLICABILITY_NAME_INDEX: usize = 2;
+/// This applicability will be set for unresolved applicability values.
+const APPLICABILITY_UNRESOLVED_STR: &str = "Unresolved";
 
 declare_clippy_lint! {
-    /// **What it does:** Collects metadata about clippy lints for the website.
+    /// ### What it does
+    /// Collects metadata about clippy lints for the website.
     ///
     /// This lint will be used to report problems of syntax parsing. You should hopefully never
     /// see this but never say never I guess ^^
     ///
-    /// **Why is this bad?** This is not a bad thing but definitely a hacky way to do it. See
+    /// ### Why is this bad?
+    /// This is not a bad thing but definitely a hacky way to do it. See
     /// issue [#4310](https://github.com/rust-lang/rust-clippy/issues/4310) for a discussion
     /// about the implementation.
     ///
-    /// **Known problems:** Hopefully none. It would be pretty uncool to have a problem here :)
+    /// ### Known problems
+    /// Hopefully none. It would be pretty uncool to have a problem here :)
     ///
-    /// **Example output:**
+    /// ### Example output
     /// ```json,ignore
     /// {
     ///     "id": "internal_metadata_collector",
@@ -136,7 +141,7 @@ declare_clippy_lint! {
     ///         "line": 1
     ///     },
     ///     "group": "clippy::internal",
-    ///     "docs": " **What it does:** Collects metadata about clippy lints for the website. [...] "
+    ///     "docs": " ### What it does\nCollects metadata about clippy lints for the website. [...] "
     /// }
     /// ```
     pub INTERNAL_METADATA_COLLECTOR,
@@ -192,7 +197,7 @@ impl Drop for MetadataCollector {
         let mut lints = std::mem::take(&mut self.lints).into_sorted_vec();
         lints
             .iter_mut()
-            .for_each(|x| x.applicability = applicability_info.remove(&x.id));
+            .for_each(|x| x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default()));
 
         // Outputting
         if Path::new(OUTPUT_FILE).exists() {
@@ -208,7 +213,7 @@ struct LintMetadata {
     id: String,
     id_span: SerializableSpan,
     group: String,
-    level: &'static str,
+    level: String,
     docs: String,
     /// This field is only used in the output and will only be
     /// mapped shortly before the actual output.
@@ -221,7 +226,7 @@ impl LintMetadata {
             id,
             id_span,
             group,
-            level,
+            level: level.to_string(),
             docs,
             applicability: None,
         }
@@ -269,14 +274,16 @@ impl Serialize for ApplicabilityInfo {
     where
         S: Serializer,
     {
-        let index = self.applicability.unwrap_or_default();
-
         let mut s = serializer.serialize_struct("ApplicabilityInfo", 2)?;
         s.serialize_field("is_multi_part_suggestion", &self.is_multi_part_suggestion)?;
-        s.serialize_field(
-            "applicability",
-            &paths::APPLICABILITY_VALUES[index][APPLICABILITY_NAME_INDEX],
-        )?;
+        if let Some(index) = self.applicability {
+            s.serialize_field(
+                "applicability",
+                &paths::APPLICABILITY_VALUES[index][APPLICABILITY_NAME_INDEX],
+            )?;
+        } else {
+            s.serialize_field("applicability", APPLICABILITY_UNRESOLVED_STR)?;
+        }
         s.end()
     }
 }
@@ -374,7 +381,8 @@ impl<'hir> LateLintPass<'hir> for MetadataCollector {
     /// Collecting lint declarations like:
     /// ```rust, ignore
     /// declare_clippy_lint! {
-    ///     /// **What it does:** Something IDK.
+    ///     /// ### What it does
+    ///     /// Something IDK.
     ///     pub SOME_LINT,
     ///     internal,
     ///     "Who am I?"
@@ -486,6 +494,13 @@ fn extract_attr_docs_or_lint(cx: &LateContext<'_>, item: &Item<'_>) -> Option<St
 /// ```
 ///
 /// Would result in `Hello world!\n=^.^=\n`
+///
+/// ---
+///
+/// This function may modify the doc comment to ensure that the string can be displayed using a
+/// markdown viewer in Clippy's lint list. The following modifications could be applied:
+/// * Removal of leading space after a new line. (Important to display tables)
+/// * Ensures that code blocks only contain language information
 fn extract_attr_docs(cx: &LateContext<'_>, item: &Item<'_>) -> Option<String> {
     let attrs = cx.tcx.hir().attrs(item.hir_id());
     let mut lines = attrs.iter().filter_map(ast::Attribute::doc_str);
@@ -510,7 +525,12 @@ fn extract_attr_docs(cx: &LateContext<'_>, item: &Item<'_>) -> Option<String> {
                 continue;
             }
         }
-        docs.push_str(line);
+        // This removes the leading space that the macro translation introduces
+        if let Some(stripped_doc) = line.strip_prefix(' ') {
+            docs.push_str(stripped_doc);
+        } else if !line.is_empty() {
+            docs.push_str(line);
+        }
     }
     Some(docs)
 }