Auto merge of #7525 - xFrednet:7172-update-define-conf-macro, r=flip1995

Updated `define_Conf!` to support multi-line doc comments

Updated the `define_Conf!` macro to support multi-line doc comments for readability. This also enables configuration documentation to have multiple paragraphs.

I've also added the `metadata-collector-lint` feature to the CI build and testing tasks. (I would think that we want this, now that we officially switched over)

---

Now a small informal explanation what this PR changes (just for fun):

* *Once upon a time there was a monster. It was handsome, supportive and happy to dig through the best source code it has ever seen. Spanning over hundreds of lines and reading over complete crates, it was purely marvels!*

    *However, there was one region in its territory that wasn't clean and well formatted like the rest. That was the mighty `define_Conf` macro. The monster would have cleaned it up a long time ago but, the previous ruler of this kingdom a powerful Python script was prohibiting it. But now that the old king was slain in the great battle of rust-1.54.0, everything was possible again. Our lovely monster was now able to grab its cleaning equipment and get some nice formatting into the now unprotected area.*

    *Said and done! Let this day go down in history!*

(I'll be the first to admit, that I'm a bit lost today. And I'm also procrastinating on some other discussions where I have some catching up to do... Oh, well, this was fun)

---

changelog: none

r? `@flip1995`

4 files changed, 113 insertions, 42 deletions

diff --git a/.github/workflows/clippy.yml b/.github/workflows/clippy.yml
index d856c55a41a..0339de77f3c 100644
--- a/.github/workflows/clippy.yml
+++ b/.github/workflows/clippy.yml
@@ -49,13 +49,13 @@ jobs:
         echo "LD_LIBRARY_PATH=${SYSROOT}/lib${LD_LIBRARY_PATH+:${LD_LIBRARY_PATH}}" >> $GITHUB_ENV
 
     - name: Build
-      run: cargo build --features deny-warnings,internal-lints
+      run: cargo build --features deny-warnings,internal-lints,metadata-collector-lint
 
     - name: Test
-      run: cargo test --features deny-warnings,internal-lints
+      run: cargo test --features deny-warnings,internal-lints,metadata-collector-lint
 
     - name: Test clippy_lints
-      run: cargo test --features deny-warnings,internal-lints
+      run: cargo test --features deny-warnings,internal-lints,metadata-collector-lint
       working-directory: clippy_lints
 
     - name: Test rustc_tools_util
diff --git a/.github/workflows/clippy_bors.yml b/.github/workflows/clippy_bors.yml
index 146b6fccd0c..1f4d666c7a9 100644
--- a/.github/workflows/clippy_bors.yml
+++ b/.github/workflows/clippy_bors.yml
@@ -112,13 +112,13 @@ jobs:
         echo "$SYSROOT/bin" >> $GITHUB_PATH
 
     - name: Build
-      run: cargo build --features deny-warnings,internal-lints
+      run: cargo build --features deny-warnings,internal-lints,metadata-collector-lint
 
     - name: Test
-      run: cargo test --features deny-warnings,internal-lints
+      run: cargo test --features deny-warnings,internal-lints,metadata-collector-lint
 
     - name: Test clippy_lints
-      run: cargo test --features deny-warnings,internal-lints
+      run: cargo test --features deny-warnings,internal-lints,metadata-collector-lint
       working-directory: clippy_lints
 
     - name: Test rustc_tools_util
diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index 44d3d456342..a28b1d78f7d 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -36,13 +36,13 @@ impl TryConf {
 /// See (rust-clippy#7172)
 macro_rules! define_Conf {
     ($(
-        #[doc = $doc:literal]
+        $(#[doc = $doc:literal])+
         $(#[conf_deprecated($dep:literal)])?
         ($name:ident: $ty:ty = $default:expr),
     )*) => {
         /// Clippy lint configuration
         pub struct Conf {
-            $(#[doc = $doc] pub $name: $ty,)*
+            $($(#[doc = $doc])+ pub $name: $ty,)*
         }
 
         mod defaults {
@@ -119,7 +119,7 @@ macro_rules! define_Conf {
                                 stringify!($name),
                                 stringify!($ty),
                                 format!("{:?}", super::defaults::$name()),
-                                $doc,
+                                concat!($($doc, '\n',)*),
                                 deprecation_reason,
                             )
                         },
@@ -132,18 +132,30 @@ macro_rules! define_Conf {
 
 // N.B., this macro is parsed by util/lintlib.py
 define_Conf! {
-    /// Lint: ENUM_VARIANT_NAMES, LARGE_TYPES_PASSED_BY_VALUE, TRIVIALLY_COPY_PASS_BY_REF, UNNECESSARY_WRAPS, UPPER_CASE_ACRONYMS, WRONG_SELF_CONVENTION. Suppress lints whenever the suggested change would cause breakage for other crates.
+    /// Lint: ENUM_VARIANT_NAMES, LARGE_TYPES_PASSED_BY_VALUE, TRIVIALLY_COPY_PASS_BY_REF, UNNECESSARY_WRAPS, UPPER_CASE_ACRONYMS, WRONG_SELF_CONVENTION.
+    ///
+    /// Suppress lints whenever the suggested change would cause breakage for other crates.
     (avoid_breaking_exported_api: bool = true),
-    /// Lint: MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE. The minimum rust version that the project supports
+    /// Lint: MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE.
+    ///
+    /// The minimum rust version that the project supports
     (msrv: Option<String> = None),
-    /// Lint: BLACKLISTED_NAME. The list of blacklisted names to lint about. NB: `bar` is not here since it has legitimate uses
+    /// Lint: BLACKLISTED_NAME.
+    ///
+    /// The list of blacklisted names to lint about. NB: `bar` is not here since it has legitimate uses
     (blacklisted_names: Vec<String> = ["foo", "baz", "quux"].iter().map(ToString::to_string).collect()),
-    /// Lint: COGNITIVE_COMPLEXITY. The maximum cognitive complexity a function can have
+    /// Lint: COGNITIVE_COMPLEXITY.
+    ///
+    /// The maximum cognitive complexity a function can have
     (cognitive_complexity_threshold: u64 = 25),
-    /// DEPRECATED LINT: CYCLOMATIC_COMPLEXITY. Use the Cognitive Complexity lint instead.
+    /// DEPRECATED LINT: CYCLOMATIC_COMPLEXITY.
+    ///
+    /// Use the Cognitive Complexity lint instead.
     #[conf_deprecated("Please use `cognitive-complexity-threshold` instead")]
     (cyclomatic_complexity_threshold: Option<u64> = None),
-    /// Lint: DOC_MARKDOWN. The list of words this lint should not consider as identifiers needing ticks
+    /// Lint: DOC_MARKDOWN.
+    ///
+    /// The list of words this lint should not consider as identifiers needing ticks
     (doc_valid_idents: Vec<String> = [
         "KiB", "MiB", "GiB", "TiB", "PiB", "EiB",
         "DirectX",
@@ -164,55 +176,109 @@ define_Conf! {
         "MinGW",
         "CamelCase",
     ].iter().map(ToString::to_string).collect()),
-    /// Lint: TOO_MANY_ARGUMENTS. The maximum number of argument a function or method can have
+    /// Lint: TOO_MANY_ARGUMENTS.
+    ///
+    /// The maximum number of argument a function or method can have
     (too_many_arguments_threshold: u64 = 7),
-    /// Lint: TYPE_COMPLEXITY. The maximum complexity a type can have
+    /// Lint: TYPE_COMPLEXITY.
+    ///
+    /// The maximum complexity a type can have
     (type_complexity_threshold: u64 = 250),
-    /// Lint: MANY_SINGLE_CHAR_NAMES. The maximum number of single char bindings a scope may have
+    /// Lint: MANY_SINGLE_CHAR_NAMES.
+    ///
+    /// The maximum number of single char bindings a scope may have
     (single_char_binding_names_threshold: u64 = 4),
-    /// Lint: BOXED_LOCAL, USELESS_VEC. The maximum size of objects (in bytes) that will be linted. Larger objects are ok on the heap
+    /// Lint: BOXED_LOCAL, USELESS_VEC.
+    ///
+    /// The maximum size of objects (in bytes) that will be linted. Larger objects are ok on the heap
     (too_large_for_stack: u64 = 200),
-    /// Lint: ENUM_VARIANT_NAMES. The minimum number of enum variants for the lints about variant names to trigger
+    /// Lint: ENUM_VARIANT_NAMES.
+    ///
+    /// The minimum number of enum variants for the lints about variant names to trigger
     (enum_variant_name_threshold: u64 = 3),
-    /// Lint: LARGE_ENUM_VARIANT. The maximum size of a enum's variant to avoid box suggestion
+    /// Lint: LARGE_ENUM_VARIANT.
+    ///
+    /// The maximum size of a enum's variant to avoid box suggestion
     (enum_variant_size_threshold: u64 = 200),
-    /// Lint: VERBOSE_BIT_MASK. The maximum allowed size of a bit mask before suggesting to use 'trailing_zeros'
+    /// Lint: VERBOSE_BIT_MASK.
+    ///
+    /// The maximum allowed size of a bit mask before suggesting to use 'trailing_zeros'
     (verbose_bit_mask_threshold: u64 = 1),
-    /// Lint: DECIMAL_LITERAL_REPRESENTATION. The lower bound for linting decimal literals
+    /// Lint: DECIMAL_LITERAL_REPRESENTATION.
+    ///
+    /// The lower bound for linting decimal literals
     (literal_representation_threshold: u64 = 16384),
-    /// Lint: TRIVIALLY_COPY_PASS_BY_REF. The maximum size (in bytes) to consider a `Copy` type for passing by value instead of by reference.
+    /// Lint: TRIVIALLY_COPY_PASS_BY_REF.
+    ///
+    /// The maximum size (in bytes) to consider a `Copy` type for passing by value instead of by reference.
     (trivial_copy_size_limit: Option<u64> = None),
-    /// Lint: LARGE_TYPE_PASS_BY_MOVE. The minimum size (in bytes) to consider a type for passing by reference instead of by value.
+    /// Lint: LARGE_TYPE_PASS_BY_MOVE.
+    ///
+    /// The minimum size (in bytes) to consider a type for passing by reference instead of by value.
     (pass_by_value_size_limit: u64 = 256),
-    /// Lint: TOO_MANY_LINES. The maximum number of lines a function or method can have
+    /// Lint: TOO_MANY_LINES.
+    ///
+    /// The maximum number of lines a function or method can have
     (too_many_lines_threshold: u64 = 100),
-    /// Lint: LARGE_STACK_ARRAYS, LARGE_CONST_ARRAYS. The maximum allowed size for arrays on the stack
+    /// Lint: LARGE_STACK_ARRAYS, LARGE_CONST_ARRAYS.
+    ///
+    /// The maximum allowed size for arrays on the stack
     (array_size_threshold: u64 = 512_000),
-    /// Lint: VEC_BOX. The size of the boxed type in bytes, where boxing in a `Vec` is allowed
+    /// Lint: VEC_BOX.
+    ///
+    /// The size of the boxed type in bytes, where boxing in a `Vec` is allowed
     (vec_box_size_threshold: u64 = 4096),
-    /// Lint: TYPE_REPETITION_IN_BOUNDS. The maximum number of bounds a trait can have to be linted
+    /// Lint: TYPE_REPETITION_IN_BOUNDS.
+    ///
+    /// The maximum number of bounds a trait can have to be linted
     (max_trait_bounds: u64 = 3),
-    /// Lint: STRUCT_EXCESSIVE_BOOLS. The maximum number of bool fields a struct can have
+    /// Lint: STRUCT_EXCESSIVE_BOOLS.
+    ///
+    /// The maximum number of bool fields a struct can have
     (max_struct_bools: u64 = 3),
-    /// Lint: FN_PARAMS_EXCESSIVE_BOOLS. The maximum number of bool parameters a function can have
+    /// Lint: FN_PARAMS_EXCESSIVE_BOOLS.
+    ///
+    /// The maximum number of bool parameters a function can have
     (max_fn_params_bools: u64 = 3),
-    /// Lint: WILDCARD_IMPORTS. Whether to allow certain wildcard imports (prelude, super in tests).
+    /// Lint: WILDCARD_IMPORTS.
+    ///
+    /// Whether to allow certain wildcard imports (prelude, super in tests).
     (warn_on_all_wildcard_imports: bool = false),
-    /// Lint: DISALLOWED_METHOD. The list of disallowed methods, written as fully qualified paths.
+    /// Lint: DISALLOWED_METHOD.
+    ///
+    /// The list of disallowed methods, written as fully qualified paths.
     (disallowed_methods: Vec<String> = Vec::new()),
-    /// Lint: DISALLOWED_TYPE. The list of disallowed types, written as fully qualified paths.
+    /// Lint: DISALLOWED_TYPE.
+    ///
+    /// The list of disallowed types, written as fully qualified paths.
     (disallowed_types: Vec<String> = Vec::new()),
-    /// Lint: UNREADABLE_LITERAL. Should the fraction of a decimal be linted to include separators.
+    /// Lint: UNREADABLE_LITERAL.
+    ///
+    /// Should the fraction of a decimal be linted to include separators.
     (unreadable_literal_lint_fractions: bool = true),
-    /// Lint: UPPER_CASE_ACRONYMS. Enables verbose mode. Triggers if there is more than one uppercase char next to each other
+    /// Lint: UPPER_CASE_ACRONYMS.
+    ///
+    /// Enables verbose mode. Triggers if there is more than one uppercase char next to each other
     (upper_case_acronyms_aggressive: bool = false),
-    /// Lint: _CARGO_COMMON_METADATA. For internal testing only, ignores the current `publish` settings in the Cargo manifest.
+    /// Lint: _CARGO_COMMON_METADATA.
+    ///
+    /// For internal testing only, ignores the current `publish` settings in the Cargo manifest.
     (cargo_ignore_publish: bool = false),
-    /// Lint: NONSTANDARD_MACRO_BRACES. Enforce the named macros always use the braces specified. <br> A `MacroMatcher` can be added like so `{ name = "macro_name", brace = "(" }`. If the macro is could be used with a full path two `MacroMatcher`s have to be added one with the full path `crate_name::macro_name` and one with just the macro name.
+    /// Lint: NONSTANDARD_MACRO_BRACES.
+    ///
+    /// Enforce the named macros always use the braces specified.
+    ///
+    /// A `MacroMatcher` can be added like so `{ name = "macro_name", brace = "(" }`. If the macro
+    /// is could be used with a full path two `MacroMatcher`s have to be added one with the full path
+    /// `crate_name::macro_name` and one with just the macro name.
     (standard_macro_braces: Vec<crate::nonstandard_macro_braces::MacroMatcher> = Vec::new()),
-    /// Lint: MISSING_ENFORCED_IMPORT_RENAMES. The list of imports to always rename, a fully qualified path followed by the rename.
+    /// Lint: MISSING_ENFORCED_IMPORT_RENAMES.
+    ///
+    /// The list of imports to always rename, a fully qualified path followed by the rename.
     (enforced_import_renames: Vec<crate::utils::conf::Rename> = Vec::new()),
-    /// Lint: RESTRICTED_SCRIPTS. The list of unicode scripts allowed to be used in the scope.
+    /// Lint: RESTRICTED_SCRIPTS.
+    ///
+    /// The list of unicode scripts allowed to be used in the scope.
     (allowed_scripts: Vec<String> = vec!["Latin".to_string()]),
 }
 
diff --git a/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
index 47336459d7d..a48a5385083 100644
--- a/clippy_lints/src/utils/internal_lints/metadata_collector.rs
+++ b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
@@ -82,7 +82,7 @@ This lint has the following configuration variables:
 /// `default`
 macro_rules! CONFIGURATION_VALUE_TEMPLATE {
     () => {
-        "* {name}: {ty}: {doc} (defaults to `{default}`)\n"
+        "* {name}: `{ty}`: {doc} (defaults to `{default}`)\n"
     };
 }
 
@@ -344,11 +344,16 @@ fn parse_config_field_doc(doc_comment: &str) -> Option<(Vec<String>, String)> {
         if let Some(split_pos) = doc_comment.find('.');
         then {
             let mut doc_comment = doc_comment.to_string();
-            let documentation = doc_comment.split_off(split_pos);
+            let mut documentation = doc_comment.split_off(split_pos);
 
+            // Extract lints
             doc_comment.make_ascii_lowercase();
             let lints: Vec<String> = doc_comment.split_off(DOC_START.len()).split(", ").map(str::to_string).collect();
 
+            // Format documentation correctly
+            // split off leading `.` from lint name list and indent for correct formatting
+            documentation = documentation.trim_start_matches('.').trim().replace("\n ", "\n    ");
+
             Some((lints, documentation))
         } else {
             None