Auto merge of rust-lang#72972 - lzutao:clippy, r=Manishearth

Pull changes from rust-lang/rust-clippy

Author: bors

src/tools/clippy/.github/workflows/clippy_bors.yml

@@ -232,7 +232,8 @@ jobs:
       matrix:
         integration:
         - 'rust-lang/cargo'
-        - 'rust-lang/rls'
+        # FIXME: re-enable once fmt_macros is renamed in RLS
+        # - 'rust-lang/rls'
         - 'rust-lang/chalk'
         - 'rust-lang/rustfmt'
         - 'Marwes/combine'

src/tools/clippy/CHANGELOG.md

@@ -6,11 +6,88 @@ document.
 
 ## Unreleased / In Rust Nightly
 
-[891e1a8...master](https://github.com/rust-lang/rust-clippy/compare/891e1a8...master)
+[7ea7cd1...master](https://github.com/rust-lang/rust-clippy/compare/7ea7cd1...master)
+
+## Rust 1.45
+
+Current beta, release 2020-07-16
+
+[891e1a8...7ea7cd1](https://github.com/rust-lang/rust-clippy/compare/891e1a8...7ea7cd1)
+
+### New lints
+
+* [`match_wildcard_for_single_variants`] [#5582](https://github.com/rust-lang/rust-clippy/pull/5582)
+* [`unsafe_derive_deserialize`] [#5493](https://github.com/rust-lang/rust-clippy/pull/5493)
+* [`if_let_mutex`] [#5332](https://github.com/rust-lang/rust-clippy/pull/5332)
+* [`mismatched_target_os`] [#5506](https://github.com/rust-lang/rust-clippy/pull/5506)
+* [`await_holding_lock`] [#5439](https://github.com/rust-lang/rust-clippy/pull/5439)
+* [`match_on_vec_items`] [#5522](https://github.com/rust-lang/rust-clippy/pull/5522)
+* [`manual_async_fn`] [#5576](https://github.com/rust-lang/rust-clippy/pull/5576)
+* [`reversed_empty_ranges`] [#5583](https://github.com/rust-lang/rust-clippy/pull/5583)
+* [`manual_non_exhaustive`] [#5550](https://github.com/rust-lang/rust-clippy/pull/5550)
+
+### Moves and Deprecations
+
+* Downgrade [`match_bool`] to pedantic [#5408](https://github.com/rust-lang/rust-clippy/pull/5408)
+* Downgrade [`match_wild_err_arm`] to pedantic and update help messages. [#5622](https://github.com/rust-lang/rust-clippy/pull/5622)
+* Downgrade [`useless_let_if_seq`] to nursery. [#5599](https://github.com/rust-lang/rust-clippy/pull/5599)
+* Generalize `option_and_then_some` and rename to [`bind_instead_of_map`]. [#5529](https://github.com/rust-lang/rust-clippy/pull/5529)
+* Rename `identity_conversion` to [`useless_conversion`]. [#5568](https://github.com/rust-lang/rust-clippy/pull/5568)
+* Merge `block_in_if_condition_expr` and `block_in_if_condition_stmt` into [`blocks_in_if_conditions`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `option_map_unwrap_or`, `option_map_unwrap_or_else` and `result_map_unwrap_or_else` into [`map_unwrap_or`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `option_unwrap_used` and `result_unwrap_used` into [`unwrap_used`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `option_expect_used` and `result_expect_used` into [`expect_used`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+* Merge `for_loop_over_option` and `for_loop_over_result` into [`for_loops_over_fallibles`].
+[#5563](https://github.com/rust-lang/rust-clippy/pull/5563)
+
+### Enhancements
+
+* Avoid running cargo lints when not enabled to improve performance. [#5505](https://github.com/rust-lang/rust-clippy/pull/5505)
+* Extend [`useless_conversion`] with `TryFrom` and `TryInto`. [#5631](https://github.com/rust-lang/rust-clippy/pull/5631)
+* Lint also in type parameters and where clauses in [`unused_unit`]. [#5592](https://github.com/rust-lang/rust-clippy/pull/5592)
+* Do not suggest deriving `Default` in [`new_without_default`]. [#5616](https://github.com/rust-lang/rust-clippy/pull/5616)
+
+### False Positive Fixes
+
+* [`while_let_on_iterator`] [#5525](https://github.com/rust-lang/rust-clippy/pull/5525)
+* [`empty_line_after_outer_attr`] [#5609](https://github.com/rust-lang/rust-clippy/pull/5609)
+* [`unnecessary_unwrap`] [#5558](https://github.com/rust-lang/rust-clippy/pull/5558)
+* [`comparison_chain`] [#5596](https://github.com/rust-lang/rust-clippy/pull/5596)
+* Don't trigger [`used_underscore_binding`] in await desugaring. [#5535](https://github.com/rust-lang/rust-clippy/pull/5535)
+* Don't trigger [`borrowed_box`] on mutable references. [#5491](https://github.com/rust-lang/rust-clippy/pull/5491)
+* Allow `1 << 0` in [`identity_op`]. [#5602](https://github.com/rust-lang/rust-clippy/pull/5602)
+* Allow `use super::*;` glob imports in [`wildcard_imports`]. [#5564](https://github.com/rust-lang/rust-clippy/pull/5564)
+* Whitelist more words in [`doc_markdown`]. [#5611](https://github.com/rust-lang/rust-clippy/pull/5611)
+* Skip dev and build deps in [`multiple_crate_versions`]. [#5636](https://github.com/rust-lang/rust-clippy/pull/5636)
+* Honor `allow` attribute on arguments in [`ptr_arg`]. [#5647](https://github.com/rust-lang/rust-clippy/pull/5647)
+* Honor lint level attributes for [`redundant_field_names`], [`just_underscores_and_digits`], [`many_single_char_names`]
+and [`similar_names`]. [#5651](https://github.com/rust-lang/rust-clippy/pull/5651)
+* Ignore calls to `len` in [`or_fun_call`]. [#4429](https://github.com/rust-lang/rust-clippy/pull/4429)
+
+### Suggestion Improvements
+
+* Simplify suggestions in [`manual_memcpy`]. [#5536](https://github.com/rust-lang/rust-clippy/pull/5536)
+* Fix suggestion in [`redundant_pattern_matching`] for macros. [#5511](https://github.com/rust-lang/rust-clippy/pull/5511)
+* Avoid suggesting `copied()` for mutable references in [`map_clone`]. [#5530](https://github.com/rust-lang/rust-clippy/pull/5530)
+* Improve help message for [`clone_double_ref`]. [#5547](https://github.com/rust-lang/rust-clippy/pull/5547)
+
+### ICE Fixes
+
+* Fix ICE caused in unwrap module. [#5590](https://github.com/rust-lang/rust-clippy/pull/5590)
+* Fix ICE on rustc test issue-69020-assoc-const-arith-overflow.rs [#5499](https://github.com/rust-lang/rust-clippy/pull/5499)
+
+### Documentation
+
+* Clarify the documentation of [`unnecessary_mut_passed`]. [#5639](https://github.com/rust-lang/rust-clippy/pull/5639)
+* Extend example for [`unneeded_field_pattern`]. [#5541](https://github.com/rust-lang/rust-clippy/pull/5541)
 
 ## Rust 1.44
 
-Current beta, release 2020-06-04
+Current stable, released 2020-06-04
 
 [204bb9b...891e1a8](https://github.com/rust-lang/rust-clippy/compare/204bb9b...891e1a8)
 
@@ -93,7 +170,7 @@ Current beta, release 2020-06-04
 
 ## Rust 1.43
 
-Current stable, released 2020-04-23
+Released 2020-04-23
 
 [4ee1206...204bb9b](https://github.com/rust-lang/rust-clippy/compare/4ee1206...204bb9b)
 
@@ -1401,6 +1478,7 @@ Released 2018-09-13
 [`items_after_statements`]: https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements
 [`iter_cloned_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_cloned_collect
 [`iter_next_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_loop
+[`iter_next_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_slice
 [`iter_nth`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth
 [`iter_nth_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth_zero
 [`iter_skip_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_skip_next
@@ -1601,9 +1679,11 @@ Released 2018-09-13
 [`unnecessary_fold`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
 [`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed
 [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation
+[`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by
 [`unnecessary_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap
 [`unneeded_field_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_field_pattern
 [`unneeded_wildcard_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_wildcard_pattern
+[`unnested_or_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnested_or_patterns
 [`unreachable`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreachable
 [`unreadable_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreadable_literal
 [`unsafe_derive_deserialize`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_derive_deserialize
@@ -1630,6 +1710,7 @@ Released 2018-09-13
 [`useless_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_transmute
 [`useless_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
 [`vec_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_box
+[`vec_resize_to_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_resize_to_zero
 [`verbose_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_bit_mask
 [`verbose_file_reads`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_file_reads
 [`vtable_address_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#vtable_address_comparisons

src/tools/clippy/CONTRIBUTING.md

@@ -12,14 +12,16 @@ anything, feel free to ask questions on issues or visit the `#clippy` on [Discor
 
 All contributors are expected to follow the [Rust Code of Conduct].
 
-* [Getting started](#getting-started)
-  * [Finding something to fix/improve](#finding-something-to-fiximprove)
-* [Writing code](#writing-code)
-* [How Clippy works](#how-clippy-works)
-* [Fixing nightly build failures](#fixing-build-failures-caused-by-rust)
-* [Issue and PR Triage](#issue-and-pr-triage)
-* [Bors and Homu](#bors-and-homu)
-* [Contributions](#contributions)
+- [Contributing to Clippy](#contributing-to-clippy)
+  - [Getting started](#getting-started)
+    - [Finding something to fix/improve](#finding-something-to-fiximprove)
+  - [Writing code](#writing-code)
+  - [Getting code-completion for rustc internals to work](#getting-code-completion-for-rustc-internals-to-work)
+  - [How Clippy works](#how-clippy-works)
+  - [Fixing build failures caused by Rust](#fixing-build-failures-caused-by-rust)
+  - [Issue and PR triage](#issue-and-pr-triage)
+  - [Bors and Homu](#bors-and-homu)
+  - [Contributions](#contributions)
 
 [Discord]: https://discord.gg/rust-lang
 [Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct
@@ -91,6 +93,24 @@ quick read.
 [rfc_stability]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#stability-guarantees
 [rfc_lint_cats]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories
 
+## Getting code-completion for rustc internals to work
+
+Unfortunately, [`rust-analyzer`][ra_homepage] does not (yet?) understand how Clippy uses compiler-internals 
+using `extern crate` and it also needs to be able to read the source files of the rustc-compiler which are not 
+available via a `rustup` component at the time of writing.  
+To work around this, you need to have a copy of the [rustc-repo][rustc_repo] available which can be obtained via  
+`git clone https://github.com/rust-lang/rust/`.  
+Then you can run a `cargo dev` command to automatically make Clippy use the rustc-repo via path-dependencies 
+which rust-analyzer will be able to understand.  
+Run `cargo dev ra-setup --repo-path <repo-path>` where `<repo-path>` is an absolute path to the rustc repo 
+you just cloned.  
+The command will add path-dependencies pointing towards rustc-crates inside the rustc repo to 
+Clippys `Cargo.toml`s and should allow rust-analyzer to understand most of the types that Clippy uses.
+Just make sure to remove the dependencies again before finally making a pull request!
+
+[ra_homepage]: https://rust-analyzer.github.io/
+[rustc_repo]: https://github.com/rust-lang/rust/
+
 ## How Clippy works
 
 [`clippy_lints/src/lib.rs`][lint_crate_entry] imports all the different lint modules and registers in the [`LintStore`].

src/tools/clippy/Cargo.toml

@@ -37,7 +37,7 @@ tempfile = { version = "3.1.0", optional = true }
 lazy_static = "1.0"
 
 [dev-dependencies]
-cargo_metadata = "0.9.0"
+cargo_metadata = "0.9.1"
 compiletest_rs = { version = "0.5.0", features = ["tmp"] }
 tester = "0.7"
 lazy_static = "1.0"

src/tools/clippy/clippy_dev/src/lib.rs

@@ -11,6 +11,7 @@ use walkdir::WalkDir;
 
 pub mod fmt;
 pub mod new_lint;
+pub mod ra_setup;
 pub mod stderr_length_check;
 pub mod update_lints;
 
@@ -400,7 +401,7 @@ fn test_replace_region_no_changes() {
         changed: false,
         new_lines: "123\n456\n789".to_string(),
     };
-    let result = replace_region_in_text(text, r#"^\s*123$"#, r#"^\s*456"#, false, || vec![]);
+    let result = replace_region_in_text(text, r#"^\s*123$"#, r#"^\s*456"#, false, Vec::new);
     assert_eq!(expected, result);
 }
 

src/tools/clippy/clippy_dev/src/main.rs

@@ -1,7 +1,7 @@
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 
 use clap::{App, Arg, SubCommand};
-use clippy_dev::{fmt, new_lint, stderr_length_check, update_lints};
+use clippy_dev::{fmt, new_lint, ra_setup, stderr_length_check, update_lints};
 
 fn main() {
     let matches = App::new("Clippy developer tooling")
@@ -87,6 +87,19 @@ fn main() {
             SubCommand::with_name("limit_stderr_length")
                 .about("Ensures that stderr files do not grow longer than a certain amount of lines."),
         )
+        .subcommand(
+            SubCommand::with_name("ra-setup")
+                .about("Alter dependencies so rust-analyzer can find rustc internals")
+                .arg(
+                    Arg::with_name("rustc-repo-path")
+                        .long("repo-path")
+                        .short("r")
+                        .help("The path to a rustc repo that will be used for setting the dependencies")
+                        .takes_value(true)
+                        .value_name("path")
+                        .required(true),
+                ),
+        )
         .get_matches();
 
     match matches.subcommand() {
@@ -115,6 +128,7 @@ fn main() {
         ("limit_stderr_length", _) => {
             stderr_length_check::check();
         },
+        ("ra-setup", Some(matches)) => ra_setup::run(matches.value_of("rustc-repo-path")),
         _ => {},
     }
 }

src/tools/clippy/clippy_dev/src/new_lint.rs

@@ -147,6 +147,8 @@ fn get_manifest_contents(lint_name: &str, hint: &str) -> String {
 name = "{}"
 version = "0.1.0"
 publish = false
+
+[workspace]
 "#,
         hint, lint_name
     )

src/tools/clippy/clippy_dev/src/ra_setup.rs

@@ -0,0 +1,90 @@
+#![allow(clippy::filter_map)]
+
+use std::fs;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::PathBuf;
+
+// This module takes an absolute path to a rustc repo and alters the dependencies to point towards
+// the respective rustc subcrates instead of using extern crate xyz.
+// This allows rust analyzer to analyze rustc internals and show proper information inside clippy
+// code. See https://github.com/rust-analyzer/rust-analyzer/issues/3517 and https://github.com/rust-lang/rust-clippy/issues/5514 for details
+
+pub fn run(rustc_path: Option<&str>) {
+    // we can unwrap here because the arg is required here
+    let rustc_path = PathBuf::from(rustc_path.unwrap());
+    assert!(rustc_path.is_dir(), "path is not a directory");
+    let rustc_source_basedir = rustc_path.join("src");
+    assert!(
+        rustc_source_basedir.is_dir(),
+        "are you sure the path leads to a rustc repo?"
+    );
+
+    let clippy_root_manifest = fs::read_to_string("Cargo.toml").expect("failed to read ./Cargo.toml");
+    let clippy_root_lib_rs = fs::read_to_string("src/driver.rs").expect("failed to read ./src/driver.rs");
+    inject_deps_into_manifest(
+        &rustc_source_basedir,
+        "Cargo.toml",
+        &clippy_root_manifest,
+        &clippy_root_lib_rs,
+    )
+    .expect("Failed to inject deps into ./Cargo.toml");
+
+    let clippy_lints_manifest =
+        fs::read_to_string("clippy_lints/Cargo.toml").expect("failed to read ./clippy_lints/Cargo.toml");
+    let clippy_lints_lib_rs =
+        fs::read_to_string("clippy_lints/src/lib.rs").expect("failed to read ./clippy_lints/src/lib.rs");
+    inject_deps_into_manifest(
+        &rustc_source_basedir,
+        "clippy_lints/Cargo.toml",
+        &clippy_lints_manifest,
+        &clippy_lints_lib_rs,
+    )
+    .expect("Failed to inject deps into ./clippy_lints/Cargo.toml");
+}
+
+fn inject_deps_into_manifest(
+    rustc_source_dir: &PathBuf,
+    manifest_path: &str,
+    cargo_toml: &str,
+    lib_rs: &str,
+) -> std::io::Result<()> {
+    let extern_crates = lib_rs
+        .lines()
+        // get the deps
+        .filter(|line| line.starts_with("extern crate"))
+        // we have something like "extern crate foo;", we only care about the "foo"
+        //              ↓          ↓
+        // extern crate rustc_middle;
+        .map(|s| &s[13..(s.len() - 1)]);
+
+    let new_deps = extern_crates.map(|dep| {
+        // format the dependencies that are going to be put inside the Cargo.toml
+        format!(
+            "{dep} = {{ path = \"{source_path}/lib{dep}\" }}\n",
+            dep = dep,
+            source_path = rustc_source_dir.display()
+        )
+    });
+
+    // format a new [dependencies]-block with the new deps we need to inject
+    let mut all_deps = String::from("[dependencies]\n");
+    new_deps.for_each(|dep_line| {
+        all_deps.push_str(&dep_line);
+    });
+
+    // replace "[dependencies]" with
+    // [dependencies]
+    // dep1 = { path = ... }
+    // dep2 = { path = ... }
+    // etc
+    let new_manifest = cargo_toml.replacen("[dependencies]\n", &all_deps, 1);
+
+    // println!("{}", new_manifest);
+    let mut file = File::create(manifest_path)?;
+    file.write_all(new_manifest.as_bytes())?;
+
+    println!("Dependency paths injected: {}", manifest_path);
+
+    Ok(())
+}

src/tools/clippy/clippy_lints/Cargo.toml

@@ -17,11 +17,11 @@ keywords = ["clippy", "lint", "plugin"]
 edition = "2018"
 
 [dependencies]
-cargo_metadata = "0.9.0"
+cargo_metadata = "0.9.1"
 if_chain = "1.0.0"
 itertools = "0.9"
 lazy_static = "1.0.2"
-pulldown-cmark = { version = "0.7", default-features = false }
+pulldown-cmark = { version = "0.7.1", default-features = false }
 quine-mc_cluskey = "0.2.2"
 regex-syntax = "0.6"
 serde = { version = "1.0", features = ["derive"] }

src/tools/clippy/clippy_lints/src/assign_ops.rs

@@ -24,7 +24,11 @@ declare_clippy_lint! {
     /// let mut a = 5;
     /// let b = 0;
     /// // ...
+    /// // Bad
     /// a = a + b;
+    ///
+    /// // Good
+    /// a += b;
     /// ```
     pub ASSIGN_OP_PATTERN,
     style,