Auto merge of #77856 - GuillaumeGomez:automatic-links-lint, r=jyn514,ollie27

Add non_autolinks lint

Part of #77501.

r? `@jyn514`

Author: bors

Cargo.lock

@@ -4297,6 +4297,7 @@ dependencies = [
  "itertools 0.9.0",
  "minifier",
  "pulldown-cmark 0.8.0",
+ "regex",
  "rustc-rayon",
  "serde",
  "serde_json",

compiler/rustc_codegen_cranelift/src/discriminant.rs

@@ -1,6 +1,6 @@
 //! Handling of enum discriminants
 //!
-//! Adapted from https://github.com/rust-lang/rust/blob/d760df5aea483aae041c9a241e7acacf48f75035/src/librustc_codegen_ssa/mir/place.rs
+//! Adapted from <https://github.com/rust-lang/rust/blob/d760df5aea483aae041c9a241e7acacf48f75035/src/librustc_codegen_ssa/mir/place.rs>
 
 use rustc_target::abi::{Int, TagEncoding, Variants};
 

compiler/rustc_lint/src/lib.rs

@@ -69,7 +69,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::{
     BARE_TRAIT_OBJECTS, BROKEN_INTRA_DOC_LINKS, ELIDED_LIFETIMES_IN_PATHS,
     EXPLICIT_OUTLIVES_REQUIREMENTS, INVALID_CODEBLOCK_ATTRIBUTES, INVALID_HTML_TAGS,
-    MISSING_DOC_CODE_EXAMPLES, PRIVATE_DOC_TESTS,
+    MISSING_DOC_CODE_EXAMPLES, NON_AUTOLINKS, PRIVATE_DOC_TESTS,
 };
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::Span;
@@ -313,6 +313,7 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
 
     add_lint_group!(
         "rustdoc",
+        NON_AUTOLINKS,
         BROKEN_INTRA_DOC_LINKS,
         PRIVATE_INTRA_DOC_LINKS,
         INVALID_CODEBLOCK_ATTRIBUTES,

compiler/rustc_lint_defs/src/builtin.rs

@@ -1890,6 +1890,17 @@ declare_lint! {
     "detects invalid HTML tags in doc comments"
 }
 
+declare_lint! {
+    /// The `non_autolinks` lint detects when a URL could be written using
+    /// only angle brackets. This is a `rustdoc` only lint, see the
+    /// documentation in the [rustdoc book].
+    ///
+    /// [rustdoc book]: ../../../rustdoc/lints.html#non_autolinks
+    pub NON_AUTOLINKS,
+    Warn,
+    "detects URLs that could be written using only angle brackets"
+}
+
 declare_lint! {
     /// The `where_clauses_object_safety` lint detects for [object safety] of
     /// [where clauses].
@@ -2795,6 +2806,7 @@ declare_lint_pass! {
         MISSING_DOC_CODE_EXAMPLES,
         INVALID_HTML_TAGS,
         PRIVATE_DOC_TESTS,
+        NON_AUTOLINKS,
         WHERE_CLAUSES_OBJECT_SAFETY,
         PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
         MACRO_USE_EXTERN_CRATE,

compiler/rustc_lint_defs/src/lib.rs

@@ -99,13 +99,13 @@ pub struct Lint {
     /// The name is written with underscores, e.g., "unused_imports".
     /// On the command line, underscores become dashes.
     ///
-    /// See https://rustc-dev-guide.rust-lang.org/diagnostics.html#lint-naming
+    /// See <https://rustc-dev-guide.rust-lang.org/diagnostics.html#lint-naming>
     /// for naming guidelines.
     pub name: &'static str,
 
     /// Default level for the lint.
     ///
-    /// See https://rustc-dev-guide.rust-lang.org/diagnostics.html#diagnostic-levels
+    /// See <https://rustc-dev-guide.rust-lang.org/diagnostics.html#diagnostic-levels>
     /// for guidelines on choosing a default level.
     pub default_level: Level,
 
@@ -330,8 +330,8 @@ impl LintBuffer {
 
 /// Declares a static item of type `&'static Lint`.
 ///
-/// See https://rustc-dev-guide.rust-lang.org/diagnostics.html for documentation
-/// and guidelines on writing lints.
+/// See <https://rustc-dev-guide.rust-lang.org/diagnostics.html> for
+/// documentation and guidelines on writing lints.
 ///
 /// The macro call should start with a doc comment explaining the lint
 /// which will be embedded in the rustc user documentation book. It should

compiler/rustc_middle/src/mir/coverage.rs

@@ -17,9 +17,9 @@ rustc_index::newtype_index! {
 impl ExpressionOperandId {
     /// An expression operand for a "zero counter", as described in the following references:
     ///
-    /// * https://github.com/rust-lang/llvm-project/blob/llvmorg-8.0.0/llvm/docs/CoverageMappingFormat.rst#counter
-    /// * https://github.com/rust-lang/llvm-project/blob/llvmorg-8.0.0/llvm/docs/CoverageMappingFormat.rst#tag
-    /// * https://github.com/rust-lang/llvm-project/blob/llvmorg-8.0.0/llvm/docs/CoverageMappingFormat.rst#counter-expressions
+    /// * <https://github.com/rust-lang/llvm-project/blob/llvmorg-8.0.0/llvm/docs/CoverageMappingFormat.rst#counter>
+    /// * <https://github.com/rust-lang/llvm-project/blob/llvmorg-8.0.0/llvm/docs/CoverageMappingFormat.rst#tag>
+    /// * <https://github.com/rust-lang/llvm-project/blob/llvmorg-8.0.0/llvm/docs/CoverageMappingFormat.rst#counter-expressions>
     ///
     /// This operand can be used to count two or more separate code regions with a single counter,
     /// if they run sequentially with no branches, by injecting the `Counter` in a `BasicBlock` for

compiler/rustc_middle/src/mir/mono.rs

@@ -228,7 +228,7 @@ pub struct CodegenUnit<'tcx> {
 
 /// Specifies the linkage type for a `MonoItem`.
 ///
-/// See https://llvm.org/docs/LangRef.html#linkage-types for more details about these variants.
+/// See <https://llvm.org/docs/LangRef.html#linkage-types> for more details about these variants.
 #[derive(Copy, Clone, PartialEq, Debug, TyEncodable, TyDecodable, HashStable)]
 pub enum Linkage {
     External,

compiler/rustc_middle/src/ty/context.rs

@@ -368,7 +368,7 @@ pub struct TypeckResults<'tcx> {
     /// leads to a `vec![&&Option<i32>, &Option<i32>]`. Empty vectors are not stored.
     ///
     /// See:
-    /// https://github.com/rust-lang/rfcs/blob/master/text/2005-match-ergonomics.md#definitions
+    /// <https://github.com/rust-lang/rfcs/blob/master/text/2005-match-ergonomics.md#definitions>
     pat_adjustments: ItemLocalMap<Vec<Ty<'tcx>>>,
 
     /// Borrows

compiler/rustc_mir/src/borrow_check/region_infer/mod.rs

@@ -1364,7 +1364,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// terms that the "longer free region" `'a` outlived the "shorter free region" `'b`.
     ///
     /// More details can be found in this blog post by Niko:
-    /// http://smallcultfollowing.com/babysteps/blog/2019/01/17/polonius-and-region-errors/
+    /// <http://smallcultfollowing.com/babysteps/blog/2019/01/17/polonius-and-region-errors/>
     ///
     /// In the canonical example
     ///

compiler/rustc_mir/src/transform/dest_prop.rs

@@ -8,7 +8,7 @@
 //! inside a single block to shuffle a value around unnecessarily.
 //!
 //! LLVM by itself is not good enough at eliminating these redundant copies (eg. see
-//! https://github.com/rust-lang/rust/issues/32966), so this leaves some performance on the table
+//! <https://github.com/rust-lang/rust/issues/32966>), so this leaves some performance on the table
 //! that we can regain by implementing an optimization for removing these assign statements in rustc
 //! itself. When this optimization runs fast enough, it can also speed up the constant evaluation
 //! and code generation phases of rustc due to the reduced number of statements and locals.

compiler/rustc_mir_build/src/thir/pattern/_match.rs

@@ -8,7 +8,7 @@
 //! (b) each pattern is necessary (usefulness)
 //!
 //! The algorithm implemented here is a modified version of the one described in:
-//! http://moscova.inria.fr/~maranget/papers/warn/index.html
+//! <http://moscova.inria.fr/~maranget/papers/warn/index.html>
 //! However, to save future implementors from reading the original paper, we
 //! summarise the algorithm here to hopefully save time and be a little clearer
 //! (without being so rigorous).
@@ -2040,7 +2040,7 @@ impl<'tcx> MissingConstructors<'tcx> {
     }
 }
 
-/// Algorithm from http://moscova.inria.fr/~maranget/papers/warn/index.html.
+/// Algorithm from <http://moscova.inria.fr/~maranget/papers/warn/index.html>.
 /// The algorithm from the paper has been modified to correctly handle empty
 /// types. The changes are:
 ///   (0) We don't exit early if the pattern matrix has zero rows. We just

compiler/rustc_parse/src/lexer/mod.rs

@@ -511,7 +511,7 @@ impl<'a> StringReader<'a> {
     }
 
     /// Note: It was decided to not add a test case, because it would be to big.
-    /// https://github.com/rust-lang/rust/pull/50296#issuecomment-392135180
+    /// <https://github.com/rust-lang/rust/pull/50296#issuecomment-392135180>
     fn report_too_many_hashes(&self, start: BytePos, found: usize) -> ! {
         self.fatal_span_(
             start,

compiler/rustc_privacy/src/lib.rs

@@ -38,7 +38,7 @@ use std::{cmp, fmt, mem};
 /// Implemented to visit all `DefId`s in a type.
 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
 /// The idea is to visit "all components of a type", as documented in
-/// https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type.
+/// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits

compiler/rustc_target/src/spec/crt_objects.rs

@@ -3,7 +3,7 @@
 //!
 //! Table of CRT objects for popular toolchains.
 //! The `crtx` ones are generally distributed with libc and the `begin/end` ones with gcc.
-//! See https://dev.gentoo.org/~vapier/crt.txt for some more details.
+//! See <https://dev.gentoo.org/~vapier/crt.txt> for some more details.
 //!
 //! | Pre-link CRT objects | glibc                  | musl                   | bionic           | mingw             | wasi |
 //! |----------------------|------------------------|------------------------|------------------|-------------------|------|

compiler/rustc_target/src/spec/mod.rs

@@ -950,7 +950,7 @@ pub struct TargetOptions {
     /// The MergeFunctions pass is generally useful, but some targets may need
     /// to opt out. The default is "aliases".
     ///
-    /// Workaround for: https://github.com/rust-lang/rust/issues/57356
+    /// Workaround for: <https://github.com/rust-lang/rust/issues/57356>
     pub merge_functions: MergeFunctions,
 
     /// Use platform dependent mcount function

compiler/rustc_target/src/spec/wasm32_unknown_unknown.rs

@@ -8,7 +8,7 @@
 //! (e.g. trying to create a TCP stream or something like that).
 //!
 //! This target is more or less managed by the Rust and WebAssembly Working
-//! Group nowadays at https://github.com/rustwasm.
+//! Group nowadays at <https://github.com/rustwasm>.
 
 use super::wasm32_base;
 use super::{LinkerFlavor, LldFlavor, Target};

compiler/rustc_target/src/spec/wasm32_wasi.rs

@@ -7,7 +7,7 @@
 //! intended to empower WebAssembly binaries with native capabilities such as
 //! filesystem access, network access, etc.
 //!
-//! You can see more about the proposal at https://wasi.dev
+//! You can see more about the proposal at <https://wasi.dev>.
 //!
 //! The Rust target definition here is interesting in a few ways. We want to
 //! serve two use cases here with this target:

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -621,7 +621,7 @@ fn object_ty_for_trait<'tcx>(
 ///
 /// In practice, we cannot use `dyn Trait` explicitly in the obligation because it would result
 /// in a new check that `Trait` is object safe, creating a cycle (until object_safe_for_dispatch
-/// is stabilized, see tracking issue https://github.com/rust-lang/rust/issues/43561).
+/// is stabilized, see tracking issue <https://github.com/rust-lang/rust/issues/43561>).
 /// Instead, we fudge a little by introducing a new type parameter `U` such that
 /// `Self: Unsize<U>` and `U: Trait + ?Sized`, and use `U` in place of `dyn Trait`.
 /// Written as a chalk-style query:

library/core/src/future/mod.rs

@@ -32,7 +32,7 @@ pub use poll_fn::{poll_fn, PollFn};
 /// This type is needed because:
 ///
 /// a) Generators cannot implement `for<'a, 'b> Generator<&'a mut Context<'b>>`, so we need to pass
-///    a raw pointer (see https://github.com/rust-lang/rust/issues/68923).
+///    a raw pointer (see <https://github.com/rust-lang/rust/issues/68923>).
 /// b) Raw pointers and `NonNull` aren't `Send` or `Sync`, so that would make every single future
 ///    non-Send/Sync as well, and we don't want that.
 ///

library/core/src/intrinsics.rs

@@ -9,7 +9,7 @@
 //! This includes changes in the stability of the constness.
 //!
 //! In order to make an intrinsic usable at compile-time, one needs to copy the implementation
-//! from https://github.com/rust-lang/miri/blob/master/src/shims/intrinsics.rs to
+//! from <https://github.com/rust-lang/miri/blob/master/src/shims/intrinsics.rs> to
 //! `compiler/rustc_mir/src/interpret/intrinsics.rs` and add a
 //! `#[rustc_const_unstable(feature = "foo", issue = "01234")]` to the intrinsic.
 //!

library/core/src/lib.rs

@@ -287,6 +287,7 @@ pub mod primitive;
     unused_imports,
     unsafe_op_in_unsafe_fn
 )]
+#[cfg_attr(not(bootstrap), allow(non_autolinks))]
 // FIXME: This annotation should be moved into rust-lang/stdarch after clashing_extern_declarations is
 // merged. It currently cannot because bootstrap fails as the lint hasn't been defined yet.
 #[allow(clashing_extern_declarations)]

library/core/src/num/dec2flt/mod.rs

@@ -33,7 +33,7 @@
 //!
 //! Primarily, this module and its children implement the algorithms described in:
 //! "How to Read Floating Point Numbers Accurately" by William D. Clinger,
-//! available online: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.45.4152
+//! available online: <http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.45.4152>
 //!
 //! In addition, there are numerous helper functions that are used in the paper but not available
 //! in Rust (or at least in core). Our version is additionally complicated by the need to handle

library/core/src/slice/sort.rs

@@ -1,7 +1,7 @@
 //! Slice sorting
 //!
 //! This module contains a sorting algorithm based on Orson Peters' pattern-defeating quicksort,
-//! published at: https://github.com/orlp/pdqsort
+//! published at: <https://github.com/orlp/pdqsort>
 //!
 //! Unstable sorting is compatible with libcore because it doesn't allocate memory, unlike our
 //! stable sorting implementation.

library/panic_unwind/src/dwarf/eh.rs

@@ -1,9 +1,9 @@
 //! Parsing of GCC-style Language-Specific Data Area (LSDA)
 //! For details see:
-//!   http://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html
-//!   http://mentorembedded.github.io/cxx-abi/exceptions.pdf
-//!   http://www.airs.com/blog/archives/460
-//!   http://www.airs.com/blog/archives/464
+//!  * <http://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-PDA/LSB-PDA/ehframechpt.html>
+//!  * <http://mentorembedded.github.io/cxx-abi/exceptions.pdf>
+//!  * <http://www.airs.com/blog/archives/460>
+//!  * <http://www.airs.com/blog/archives/464>
 //!
 //! A reference implementation may be found in the GCC source tree
 //! (`<root>/libgcc/unwind-c.c` as of this writing).

library/panic_unwind/src/gcc.rs

@@ -4,9 +4,9 @@
 //! "Exception Handling in LLVM" (llvm.org/docs/ExceptionHandling.html) and
 //! documents linked from it.
 //! These are also good reads:
-//!     https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
-//!     http://monoinfinito.wordpress.com/series/exception-handling-in-c/
-//!     http://www.airs.com/blog/index.php?s=exception+frames
+//!  * <https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html>
+//!  * <http://monoinfinito.wordpress.com/series/exception-handling-in-c/>
+//!  * <http://www.airs.com/blog/index.php?s=exception+frames>
 //!
 //! ## A brief summary
 //!

src/bootstrap/toolstate.rs

@@ -152,7 +152,7 @@ impl Step for ToolStateCheck {
     /// error if there are any.
     ///
     /// This also handles publishing the results to the `history` directory of
-    /// the toolstate repo https://github.com/rust-lang-nursery/rust-toolstate
+    /// the toolstate repo <https://github.com/rust-lang-nursery/rust-toolstate>
     /// if the env var `TOOLSTATE_PUBLISH` is set. Note that there is a
     /// *separate* step of updating the `latest.json` file and creating GitHub
     /// issues and comments in `src/ci/publish_toolstate.sh`, which is only
@@ -162,7 +162,7 @@ impl Step for ToolStateCheck {
     /// The rules for failure are:
     /// * If the PR modifies a tool, the status must be test-pass.
     ///   NOTE: There is intent to change this, see
-    ///   https://github.com/rust-lang/rust/issues/65000.
+    ///   <https://github.com/rust-lang/rust/issues/65000>.
     /// * All "stable" tools must be test-pass on the stable or beta branches.
     /// * During beta promotion week, a PR is not allowed to "regress" a
     ///   stable tool. That is, the status is not allowed to get worse

src/build_helper/lib.rs

@@ -32,7 +32,7 @@ macro_rules! t {
 
 /// Reads an environment variable and adds it to dependencies.
 /// Supposed to be used for all variables except those set for build scripts by cargo
-/// https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts
+/// <https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts>
 pub fn tracked_env_var_os<K: AsRef<OsStr> + Display>(key: K) -> Option<OsString> {
     println!("cargo:rerun-if-env-changed={}", key);
     env::var_os(key)

src/doc/rustdoc/src/lints.md

@@ -285,3 +285,41 @@ warning: unclosed HTML tag `h1`
 
 warning: 2 warnings emitted
 ```
+
+## non_autolinks
+
+This lint is **nightly-only** and **warns by default**. It detects links which
+could use the "automatic" link syntax. For example:
+
+```rust
+/// http://example.org
+/// [http://example.com](http://example.com)
+/// [http://example.net]
+///
+/// [http://example.com]: http://example.com
+pub fn foo() {}
+```
+
+Which will give:
+
+```text
+warning: this URL is not a hyperlink
+ --> foo.rs:1:5
+  |
+1 | /// http://example.org
+  |     ^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<http://example.org>`
+  |
+  = note: `#[warn(non_autolinks)]` on by default
+
+warning: unneeded long form for URL
+ --> foo.rs:2:5
+  |
+2 | /// [http://example.com](http://example.com)
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<http://example.com>`
+
+warning: this URL is not a hyperlink
+ --> foo.rs:3:6
+  |
+3 | /// [http://example.net]
+  |      ^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<http://example.net>`
+```

src/librustdoc/Cargo.toml

@@ -16,6 +16,7 @@ serde_json = "1.0"
 smallvec = "1.0"
 tempfile = "3"
 itertools = "0.9"
+regex = "1"
 
 [dev-dependencies]
 expect-test = "1.0"

src/librustdoc/core.rs

@@ -330,6 +330,7 @@ pub fn run_core(
     let invalid_codeblock_attributes_name = rustc_lint::builtin::INVALID_CODEBLOCK_ATTRIBUTES.name;
     let invalid_html_tags = rustc_lint::builtin::INVALID_HTML_TAGS.name;
     let renamed_and_removed_lints = rustc_lint::builtin::RENAMED_AND_REMOVED_LINTS.name;
+    let non_autolinks = rustc_lint::builtin::NON_AUTOLINKS.name;
     let unknown_lints = rustc_lint::builtin::UNKNOWN_LINTS.name;
 
     // In addition to those specific lints, we also need to allow those given through
@@ -344,6 +345,7 @@ pub fn run_core(
         invalid_html_tags.to_owned(),
         renamed_and_removed_lints.to_owned(),
         unknown_lints.to_owned(),
+        non_autolinks.to_owned(),
     ];
 
     let (lint_opts, lint_caps) = init_lints(lints_to_show, lint_opts, |lint| {
@@ -663,7 +665,7 @@ fn run_global_ctxt(
     (krate, ctxt.renderinfo.into_inner(), ctxt.render_options)
 }
 
-/// Due to https://github.com/rust-lang/rust/pull/73566,
+/// Due to <https://github.com/rust-lang/rust/pull/73566>,
 /// the name resolution pass may find errors that are never emitted.
 /// If typeck is called after this happens, then we'll get an ICE:
 /// 'Res::Error found but not reported'. To avoid this, emit the errors now.