Merge remote-tracking branch 'upstream/master' into clippy-fix

.gitattributes

@@ -1,5 +1,3 @@
-[attr]rust text eol=lf whitespace=tab-in-indent,trailing-space,tabwidth=4
-
 * text=auto eol=lf
-*.rs rust
+*.rs text eol=lf whitespace=tab-in-indent,trailing-space,tabwidth=4
 *.fixed linguist-language=Rust

.github/deploy.sh

@@ -17,6 +17,11 @@ if [[ -n $TAG_NAME ]]; then
   ln -s "$TAG_NAME" out/stable
 fi
 
+if [[ $BETA = "true" ]]; then
+  echo "Update documentation for the beta release"
+  cp -r out/master out/beta
+fi
+
 # Generate version index that is shown as root index page
 cp util/gh-pages/versions.html out/index.html
 
@@ -35,12 +40,15 @@ fi
 
 if [[ -n $TAG_NAME ]]; then
   # Add the new dir
-  git add $TAG_NAME
+  git add "$TAG_NAME"
   # Update the symlink
   git add stable
   # Update versions file
   git add versions.json
   git commit -m "Add documentation for ${TAG_NAME} release: ${SHA}"
+elif [[ $BETA = "true" ]]; then
+  git add beta
+  git commit -m "Automatic deploy to GitHub Pages (beta): ${SHA}"
 else
   git add .
   git commit -m "Automatic deploy to GitHub Pages: ${SHA}"

.github/workflows/clippy_bors.yml

@@ -234,7 +234,8 @@ jobs:
         - 'rust-lang/cargo'
         - 'rust-lang/rls'
         - 'rust-lang/chalk'
-        - 'rust-lang/rustfmt'
+        # FIXME: Disabled until https://github.com/rust-lang/rust/issues/71077 is fixed
+        # - 'rust-lang/rustfmt'
         - 'Marwes/combine'
         - 'Geal/nom'
         - 'rust-lang/stdarch'

.github/workflows/clippy_dev.yml

@@ -38,8 +38,8 @@ jobs:
       run: cargo build --features deny-warnings
       working-directory: clippy_dev
 
-    - name: Test limit-stderr-length
+    - name: Test limit_stderr_length
-      run: cargo dev --limit-stderr-length
+      run: cargo dev limit_stderr_length
 
     - name: Test update_lints
       run: cargo dev update_lints --check

.github/workflows/deploy.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - master
+      - beta
     tags:
       - rust-1.**
 
@@ -34,6 +35,9 @@ jobs:
       run: |
         TAG=$(basename ${{ github.ref }})
         echo "::set-env name=TAG_NAME::$TAG"
+    - name: Set beta to true
+      if: github.ref == 'refs/heads/beta'
+      run: echo "::set-env name=BETA::true"
     - name: Deploy
       run: |
         eval "$(ssh-agent -s)"

CHANGELOG.md

@@ -1271,6 +1271,7 @@ Released 2018-09-13
 [`float_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#float_arithmetic
 [`float_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#float_cmp
 [`float_cmp_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#float_cmp_const
+[`fn_address_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_address_comparisons
 [`fn_params_excessive_bools`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_params_excessive_bools
 [`fn_to_numeric_cast`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_to_numeric_cast
 [`fn_to_numeric_cast_with_truncation`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_to_numeric_cast_with_truncation
@@ -1432,6 +1433,7 @@ Released 2018-09-13
 [`range_plus_one`]: https://rust-lang.github.io/rust-clippy/master/index.html#range_plus_one
 [`range_step_by_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#range_step_by_zero
 [`range_zip_with_len`]: https://rust-lang.github.io/rust-clippy/master/index.html#range_zip_with_len
+[`redundant_allocation`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_allocation
 [`redundant_clone`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_clone
 [`redundant_closure`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
 [`redundant_closure_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_call
@@ -1446,6 +1448,7 @@ Released 2018-09-13
 [`replace_consts`]: https://rust-lang.github.io/rust-clippy/master/index.html#replace_consts
 [`rest_pat_in_fully_bound_structs`]: https://rust-lang.github.io/rust-clippy/master/index.html#rest_pat_in_fully_bound_structs
 [`result_expect_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_expect_used
+[`result_map_or_into_option`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_map_or_into_option
 [`result_map_unit_fn`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_map_unit_fn
 [`result_map_unwrap_or_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_map_unwrap_or_else
 [`result_unwrap_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#result_unwrap_used
@@ -1540,6 +1543,7 @@ Released 2018-09-13
 [`vec_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_box
 [`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
 [`while_immutable_condition`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_immutable_condition
 [`while_let_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_let_loop
 [`while_let_on_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_let_on_iterator

CONTRIBUTING.md

@@ -36,7 +36,8 @@ High level approach:
 
 ### Finding something to fix/improve
 
-All issues on Clippy are mentored, if you want help with a bug just ask @Manishearth, @llogiq, @mcarton or @oli-obk.
+All issues on Clippy are mentored, if you want help with a bug just ask
+@Manishearth, @flip1995, @phansch or @yaahc.
 
 Some issues are easier than others. The [`good first issue`] label can be used to find the easy issues.
 If you want to work on an issue, please leave a comment so that we can assign it to you!
@@ -70,7 +71,7 @@ an AST expression). `match_def_path()` in Clippy's `utils` module can also be us
 [`T-AST`]: https://github.com/rust-lang/rust-clippy/labels/T-AST
 [`T-middle`]: https://github.com/rust-lang/rust-clippy/labels/T-middle
 [`E-medium`]: https://github.com/rust-lang/rust-clippy/labels/E-medium
-[`ty`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc/ty
+[`ty`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty
 [nodes in the AST docs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ast/
 [deep-nesting]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/mem_forget.rs#L29-L43
 [if_chain]: https://docs.rs/if_chain/*/if_chain
@@ -78,8 +79,7 @@ an AST expression). `match_def_path()` in Clippy's `utils` module can also be us
 
 ## Writing code
 
-Have a look at the [docs for writing lints][adding_lints] for more details. [Llogiq's blog post on lints]
+Have a look at the [docs for writing lints][adding_lints] for more details.
-is also a nice primer to lint-writing, though it does get into advanced stuff and may be a bit outdated.
 
 If you want to add a new lint or change existing ones apart from bugfixing, it's
 also a good idea to give the [stability guarantees][rfc_stability] and
@@ -87,7 +87,6 @@ also a good idea to give the [stability guarantees][rfc_stability] and
 quick read.
 
 [adding_lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
-[Llogiq's blog post on lints]: https://llogiq.github.io/2015/06/04/workflows.html
 [clippy_rfc]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md
 [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
@@ -223,7 +222,7 @@ You can find the Clippy bors queue [here][homu_queue].
 If you have @bors permissions, you can find an overview of the available
 commands [here][homu_instructions].
 
-[triage]: https://forge.rust-lang.org/triage-procedure.html
+[triage]: https://forge.rust-lang.org/release/triage-procedure.html
 [l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash%20%3Aboom%3A
 [l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug%20%3Abeetle%3A
 [homu]: https://github.com/rust-lang/homu

Cargo.toml

@@ -42,7 +42,7 @@ lazy_static = "1.0"
 
 [dev-dependencies]
 cargo_metadata = "0.9.0"
-compiletest_rs = { version = "0.4.0", features = ["tmp"] }
+compiletest_rs = { version = "0.5.0", features = ["tmp"] }
 tester = "0.7"
 lazy_static = "1.0"
 clippy-mini-macro-test = { version = "0.2", path = "mini-macro" }

README.md

@@ -5,7 +5,7 @@
 
 A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
 
-[There are 362 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
+[There are over 350 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
 
 We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:
 
@@ -90,14 +90,6 @@ Note that this is still experimental and only supported on the nightly channel:
 cargo fix -Z unstable-options --clippy
 ```
 
-#### Running only a single lint
-
-If you care only about the warnings of a single lint and want to ignore everything else, you
-can first deny all the clippy lints and then explicitly enable the lint(s) you care about:
-````
-cargo clippy -- -Aclippy::all -Wclippy::useless_format
-````
-
 ### Running Clippy from the command line without installing it
 
 To have cargo compile your crate with Clippy without Clippy installation
@@ -183,6 +175,8 @@ If you do not want to include your lint levels in your code, you can globally en
 flags to Clippy during the run: `cargo clippy -- -A clippy::lint_name` will run Clippy with `lint_name` disabled and
 `cargo clippy -- -W clippy::lint_name` will run it with that enabled. This also works with lint groups. For example you
 can run Clippy with warnings for all lints enabled: `cargo clippy -- -W clippy::pedantic`
+If you care only about a single lint, you can allow all others and then explicitly reenable
+the lint(s) you are interested in: `cargo clippy -- -Aclippy::all -Wclippy::useless_format -Wclippy::...`
 
 ## Contributing
 

clippy_dev/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 [dependencies]
 bytecount = "0.6"
 clap = "2.33"
-itertools = "0.8"
+itertools = "0.9"
 regex = "1"
 lazy_static = "1.0"
 shell-escape = "0.1"

clippy_dev/src/fmt.rs

@@ -1,4 +1,4 @@
-use clippy_dev::clippy_project_root;
+use crate::clippy_project_root;
 use shell_escape::escape;
 use std::ffi::OsStr;
 use std::io;

clippy_dev/src/lib.rs

@@ -9,6 +9,11 @@ use std::fs;
 use std::path::{Path, PathBuf};
 use walkdir::WalkDir;
 
+pub mod fmt;
+pub mod new_lint;
+pub mod stderr_length_check;
+pub mod update_lints;
+
 lazy_static! {
     static ref DEC_CLIPPY_LINT_RE: Regex = Regex::new(
         r#"(?x)
@@ -57,13 +62,25 @@ impl Lint {
     }
 
     /// Returns all non-deprecated lints and non-internal lints
-    pub fn usable_lints(lints: impl Iterator<Item = Self>) -> impl Iterator<Item = Self> {
+    #[must_use]
-        lints.filter(|l| l.deprecation.is_none() && !l.is_internal())
+    pub fn usable_lints(lints: &[Self]) -> Vec<Self> {
+        lints
+            .iter()
+            .filter(|l| l.deprecation.is_none() && !l.group.starts_with("internal"))
+            .cloned()
+            .collect()
     }
 
     /// Returns all internal lints (not `internal_warn` lints)
-    pub fn internal_lints(lints: impl Iterator<Item = Self>) -> impl Iterator<Item = Self> {
+    #[must_use]
-        lints.filter(|l| l.group == "internal")
+    pub fn internal_lints(lints: &[Self]) -> Vec<Self> {
+        lints.iter().filter(|l| l.group == "internal").cloned().collect()
+    }
+
+    /// Returns all deprecated lints
+    #[must_use]
+    pub fn deprecated_lints(lints: &[Self]) -> Vec<Self> {
+        lints.iter().filter(|l| l.deprecation.is_some()).cloned().collect()
     }
 
     /// Returns the lints in a `HashMap`, grouped by the different lint groups
@@ -71,96 +88,63 @@ impl Lint {
     pub fn by_lint_group(lints: impl Iterator<Item = Self>) -> HashMap<String, Vec<Self>> {
         lints.map(|lint| (lint.group.to_string(), lint)).into_group_map()
     }
-
-    #[must_use]
-    pub fn is_internal(&self) -> bool {
-        self.group.starts_with("internal")
-    }
 }
 
 /// Generates the Vec items for `register_lint_group` calls in `clippy_lints/src/lib.rs`.
 #[must_use]
-pub fn gen_lint_group_list(lints: Vec<Lint>) -> Vec<String> {
+pub fn gen_lint_group_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .into_iter()
+        .map(|l| format!("        LintId::of(&{}::{}),", l.module, l.name.to_uppercase()))
-        .filter_map(|l| {
-            if l.deprecation.is_some() {
-                None
-            } else {
-                Some(format!("        LintId::of(&{}::{}),", l.module, l.name.to_uppercase()))
-            }
-        })
         .sorted()
         .collect::<Vec<String>>()
 }
 
 /// Generates the `pub mod module_name` list in `clippy_lints/src/lib.rs`.
 #[must_use]
-pub fn gen_modules_list(lints: Vec<Lint>) -> Vec<String> {
+pub fn gen_modules_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .into_iter()
+        .map(|l| &l.module)
-        .filter_map(|l| {
-            if l.is_internal() || l.deprecation.is_some() {
-                None
-            } else {
-                Some(l.module)
-            }
-        })
         .unique()
-        .map(|module| format!("pub mod {};", module))
+        .map(|module| format!("mod {};", module))
         .sorted()
         .collect::<Vec<String>>()
 }
 
 /// Generates the list of lint links at the bottom of the README
 #[must_use]
-pub fn gen_changelog_lint_list(lints: Vec<Lint>) -> Vec<String> {
+pub fn gen_changelog_lint_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
-    let mut lint_list_sorted: Vec<Lint> = lints;
+    lints
-    lint_list_sorted.sort_by_key(|l| l.name.clone());
+        .sorted_by_key(|l| &l.name)
-    lint_list_sorted
+        .map(|l| format!("[`{}`]: {}#{}", l.name, DOCS_LINK, l.name))
-        .iter()
-        .filter_map(|l| {
-            if l.is_internal() {
-                None
-            } else {
-                Some(format!("[`{}`]: {}#{}", l.name, DOCS_LINK, l.name))
-            }
-        })
         .collect()
 }
 
 /// Generates the `register_removed` code in `./clippy_lints/src/lib.rs`.
 #[must_use]
-pub fn gen_deprecated(lints: &[Lint]) -> Vec<String> {
+pub fn gen_deprecated<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .iter()
+        .flat_map(|l| {
-        .filter_map(|l| {
+            l.deprecation
-            l.clone().deprecation.map(|depr_text| {
+                .clone()
-                vec![
+                .map(|depr_text| {
-                    "    store.register_removed(".to_string(),
+                    vec![
-                    format!("        \"clippy::{}\",", l.name),
+                        "    store.register_removed(".to_string(),
-                    format!("        \"{}\",", depr_text),
+                        format!("        \"clippy::{}\",", l.name),
-                    "    );".to_string(),
+                        format!("        \"{}\",", depr_text),
-                ]
+                        "    );".to_string(),
-            })
+                    ]
+                })
+                .expect("only deprecated lints should be passed")
         })
-        .flatten()
         .collect::<Vec<String>>()
 }
 
 #[must_use]
-pub fn gen_register_lint_list(lints: &[Lint]) -> Vec<String> {
+pub fn gen_register_lint_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     let pre = "    store.register_lints(&[".to_string();
     let post = "    ]);".to_string();
     let mut inner = lints
-        .iter()
+        .map(|l| format!("        &{}::{},", l.module, l.name.to_uppercase()))
-        .filter_map(|l| {
-            if !l.is_internal() && l.deprecation.is_none() {
-                Some(format!("        &{}::{},", l.module, l.name.to_uppercase()))
-            } else {
-                None
-            }
-        })
         .sorted()
         .collect::<Vec<String>>();
     inner.insert(0, pre);
@@ -434,7 +418,7 @@ fn test_usable_lints() {
         None,
         "module_name",
     )];
-    assert_eq!(expected, Lint::usable_lints(lints.into_iter()).collect::<Vec<Lint>>());
+    assert_eq!(expected, Lint::usable_lints(&lints));
 }
 
 #[test]
@@ -464,13 +448,12 @@ fn test_gen_changelog_lint_list() {
     let lints = vec![
         Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
         Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
-        Lint::new("incorrect_internal", "internal_style", "abc", None, "module_name"),
     ];
     let expected = vec![
         format!("[`should_assert_eq`]: {}#should_assert_eq", DOCS_LINK.to_string()),
         format!("[`should_assert_eq2`]: {}#should_assert_eq2", DOCS_LINK.to_string()),
     ];
-    assert_eq!(expected, gen_changelog_lint_list(lints));
+    assert_eq!(expected, gen_changelog_lint_list(lints.iter()));
 }
 
 #[test]
@@ -490,7 +473,6 @@ fn test_gen_deprecated() {
             Some("will be removed"),
             "module_name",
         ),
-        Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
     ];
     let expected: Vec<String> = vec![
         "    store.register_removed(",
@@ -505,22 +487,24 @@ fn test_gen_deprecated() {
     .into_iter()
     .map(String::from)
     .collect();
-    assert_eq!(expected, gen_deprecated(&lints));
+    assert_eq!(expected, gen_deprecated(lints.iter()));
+}
+
+#[test]
+#[should_panic]
+fn test_gen_deprecated_fail() {
+    let lints = vec![Lint::new("should_assert_eq2", "group2", "abc", None, "module_name")];
+    let _ = gen_deprecated(lints.iter());
 }
 
 #[test]
 fn test_gen_modules_list() {
     let lints = vec![
         Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
-        Lint::new("should_assert_eq2", "group2", "abc", Some("abc"), "deprecated"),
         Lint::new("incorrect_stuff", "group3", "abc", None, "another_module"),
-        Lint::new("incorrect_internal", "internal_style", "abc", None, "module_name"),
     ];
-    let expected = vec![
+    let expected = vec!["mod another_module;".to_string(), "mod module_name;".to_string()];
-        "pub mod another_module;".to_string(),
+    assert_eq!(expected, gen_modules_list(lints.iter()));
-        "pub mod module_name;".to_string(),
-    ];
-    assert_eq!(expected, gen_modules_list(lints));
 }
 
 #[test]
@@ -528,7 +512,6 @@ fn test_gen_lint_group_list() {
     let lints = vec![
         Lint::new("abc", "group1", "abc", None, "module_name"),
         Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
-        Lint::new("should_assert_eq2", "group2", "abc", Some("abc"), "deprecated"),
         Lint::new("internal", "internal_style", "abc", None, "module_name"),
     ];
     let expected = vec![
@@ -536,5 +519,5 @@ fn test_gen_lint_group_list() {
         "        LintId::of(&module_name::INTERNAL),".to_string(),
         "        LintId::of(&module_name::SHOULD_ASSERT_EQ),".to_string(),
     ];
-    assert_eq!(expected, gen_lint_group_list(lints));
+    assert_eq!(expected, gen_lint_group_list(lints.iter()));
 }

clippy_dev/src/main.rs

@@ -1,21 +1,7 @@
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 
 use clap::{App, Arg, SubCommand};
-use clippy_dev::{
+use clippy_dev::{fmt, new_lint, stderr_length_check, update_lints};
-    gather_all, gen_changelog_lint_list, gen_deprecated, gen_lint_group_list, gen_modules_list, gen_register_lint_list,
-    replace_region_in_file, Lint, DOCS_LINK,
-};
-use std::path::Path;
-
-mod fmt;
-mod new_lint;
-mod stderr_length_check;
-
-#[derive(Clone, Copy, PartialEq)]
-enum UpdateMode {
-    Check,
-    Change,
-}
 
 fn main() {
     let matches = App::new("Clippy developer tooling")
@@ -97,28 +83,23 @@ fn main() {
                         .takes_value(true),
                 ),
         )
-        .arg(
+        .subcommand(
-            Arg::with_name("limit-stderr-length")
+            SubCommand::with_name("limit_stderr_length")
-                .long("limit-stderr-length")
+                .about("Ensures that stderr files do not grow longer than a certain amount of lines."),
-                .help("Ensures that stderr files do not grow longer than a certain amount of lines."),
         )
         .get_matches();
 
-    if matches.is_present("limit-stderr-length") {
-        stderr_length_check::check();
-    }
-
     match matches.subcommand() {
         ("fmt", Some(matches)) => {
             fmt::run(matches.is_present("check"), matches.is_present("verbose"));
         },
         ("update_lints", Some(matches)) => {
             if matches.is_present("print-only") {
-                print_lints();
+                update_lints::print_lints();
             } else if matches.is_present("check") {
-                update_lints(UpdateMode::Check);
+                update_lints::run(update_lints::UpdateMode::Check);
             } else {
-                update_lints(UpdateMode::Change);
+                update_lints::run(update_lints::UpdateMode::Change);
             }
         },
         ("new_lint", Some(matches)) => {
@@ -127,168 +108,13 @@ fn main() {
                 matches.value_of("name"),
                 matches.value_of("category"),
             ) {
-                Ok(_) => update_lints(UpdateMode::Change),
+                Ok(_) => update_lints::run(update_lints::UpdateMode::Change),
                 Err(e) => eprintln!("Unable to create lint: {}", e),
             }
         },
+        ("limit_stderr_length", _) => {
+            stderr_length_check::check();
+        },
         _ => {},
     }
 }
-
-fn print_lints() {
-    let lint_list = gather_all();
-    let usable_lints: Vec<Lint> = Lint::usable_lints(lint_list).collect();
-    let usable_lint_count = usable_lints.len();
-    let grouped_by_lint_group = Lint::by_lint_group(usable_lints.into_iter());
-
-    for (lint_group, mut lints) in grouped_by_lint_group {
-        if lint_group == "Deprecated" {
-            continue;
-        }
-        println!("\n## {}", lint_group);
-
-        lints.sort_by_key(|l| l.name.clone());
-
-        for lint in lints {
-            println!(
-                "* [{}]({}#{}) ({})",
-                lint.name,
-                clippy_dev::DOCS_LINK,
-                lint.name,
-                lint.desc
-            );
-        }
-    }
-
-    println!("there are {} lints", usable_lint_count);
-}
-
-#[allow(clippy::too_many_lines)]
-fn update_lints(update_mode: UpdateMode) {
-    let lint_list: Vec<Lint> = gather_all().collect();
-
-    let internal_lints = Lint::internal_lints(lint_list.clone().into_iter());
-
-    let usable_lints: Vec<Lint> = Lint::usable_lints(lint_list.clone().into_iter()).collect();
-    let usable_lint_count = usable_lints.len();
-
-    let mut sorted_usable_lints = usable_lints.clone();
-    sorted_usable_lints.sort_by_key(|lint| lint.name.clone());
-
-    let mut file_change = replace_region_in_file(
-        Path::new("src/lintlist/mod.rs"),
-        "begin lint list",
-        "end lint list",
-        false,
-        update_mode == UpdateMode::Change,
-        || {
-            format!(
-                "pub const ALL_LINTS: [Lint; {}] = {:#?};",
-                sorted_usable_lints.len(),
-                sorted_usable_lints
-            )
-            .lines()
-            .map(ToString::to_string)
-            .collect::<Vec<_>>()
-        },
-    )
-    .changed;
-
-    file_change |= replace_region_in_file(
-        Path::new("README.md"),
-        &format!(r#"\[There are \d+ lints included in this crate!\]\({}\)"#, DOCS_LINK),
-        "",
-        true,
-        update_mode == UpdateMode::Change,
-        || {
-            vec![format!(
-                "[There are {} lints included in this crate!]({})",
-                usable_lint_count, DOCS_LINK
-            )]
-        },
-    )
-    .changed;
-
-    file_change |= replace_region_in_file(
-        Path::new("CHANGELOG.md"),
-        "<!-- begin autogenerated links to lint list -->",
-        "<!-- end autogenerated links to lint list -->",
-        false,
-        update_mode == UpdateMode::Change,
-        || gen_changelog_lint_list(lint_list.clone()),
-    )
-    .changed;
-
-    file_change |= replace_region_in_file(
-        Path::new("clippy_lints/src/lib.rs"),
-        "begin deprecated lints",
-        "end deprecated lints",
-        false,
-        update_mode == UpdateMode::Change,
-        || gen_deprecated(&lint_list),
-    )
-    .changed;
-
-    file_change |= replace_region_in_file(
-        Path::new("clippy_lints/src/lib.rs"),
-        "begin register lints",
-        "end register lints",
-        false,
-        update_mode == UpdateMode::Change,
-        || gen_register_lint_list(&lint_list),
-    )
-    .changed;
-
-    file_change |= replace_region_in_file(
-        Path::new("clippy_lints/src/lib.rs"),
-        "begin lints modules",
-        "end lints modules",
-        false,
-        update_mode == UpdateMode::Change,
-        || gen_modules_list(lint_list.clone()),
-    )
-    .changed;
-
-    // Generate lists of lints in the clippy::all lint group
-    file_change |= replace_region_in_file(
-        Path::new("clippy_lints/src/lib.rs"),
-        r#"store.register_group\(true, "clippy::all""#,
-        r#"\]\);"#,
-        false,
-        update_mode == UpdateMode::Change,
-        || {
-            // clippy::all should only include the following lint groups:
-            let all_group_lints = usable_lints
-                .clone()
-                .into_iter()
-                .filter(|l| {
-                    l.group == "correctness" || l.group == "style" || l.group == "complexity" || l.group == "perf"
-                })
-                .collect();
-
-            gen_lint_group_list(all_group_lints)
-        },
-    )
-    .changed;
-
-    // Generate the list of lints for all other lint groups
-    for (lint_group, lints) in Lint::by_lint_group(usable_lints.into_iter().chain(internal_lints)) {
-        file_change |= replace_region_in_file(
-            Path::new("clippy_lints/src/lib.rs"),
-            &format!("store.register_group\\(true, \"clippy::{}\"", lint_group),
-            r#"\]\);"#,
-            false,
-            update_mode == UpdateMode::Change,
-            || gen_lint_group_list(lints.clone()),
-        )
-        .changed;
-    }
-
-    if update_mode == UpdateMode::Check && file_change {
-        println!(
-            "Not all lints defined properly. \
-             Please run `cargo dev update_lints` to make sure all lints are defined properly."
-        );
-        std::process::exit(1);
-    }
-}

clippy_dev/src/new_lint.rs

@@ -1,10 +1,15 @@
-use clippy_dev::clippy_project_root;
+use crate::clippy_project_root;
 use std::fs::{File, OpenOptions};
 use std::io;
 use std::io::prelude::*;
 use std::io::ErrorKind;
 use std::path::Path;
 
+/// Creates files required to implement and test a new lint and runs `update_lints`.
+///
+/// # Errors
+///
+/// This function errors, if the files couldn't be created
 pub fn create(pass: Option<&str>, lint_name: Option<&str>, category: Option<&str>) -> Result<(), io::Error> {
     let pass = pass.expect("`pass` argument is validated by clap");
     let lint_name = lint_name.expect("`name` argument is validated by clap");

clippy_dev/src/stderr_length_check.rs

@@ -1,11 +1,9 @@
+use crate::clippy_project_root;
 use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path, PathBuf};
-
 use walkdir::WalkDir;
 
-use clippy_dev::clippy_project_root;
-
 // The maximum length allowed for stderr files.
 //
 // We limit this because small files are easier to deal with than bigger files.

clippy_dev/src/update_lints.rs

@@ -0,0 +1,162 @@
+use crate::{
+    gather_all, gen_changelog_lint_list, gen_deprecated, gen_lint_group_list, gen_modules_list, gen_register_lint_list,
+    replace_region_in_file, Lint, DOCS_LINK,
+};
+use std::path::Path;
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum UpdateMode {
+    Check,
+    Change,
+}
+
+#[allow(clippy::too_many_lines)]
+pub fn run(update_mode: UpdateMode) {
+    let lint_list: Vec<Lint> = gather_all().collect();
+
+    let internal_lints = Lint::internal_lints(&lint_list);
+    let deprecated_lints = Lint::deprecated_lints(&lint_list);
+    let usable_lints = Lint::usable_lints(&lint_list);
+    let mut sorted_usable_lints = usable_lints.clone();
+    sorted_usable_lints.sort_by_key(|lint| lint.name.clone());
+
+    let usable_lint_count = round_to_fifty(usable_lints.len());
+
+    let mut file_change = replace_region_in_file(
+        Path::new("src/lintlist/mod.rs"),
+        "begin lint list",
+        "end lint list",
+        false,
+        update_mode == UpdateMode::Change,
+        || {
+            format!("pub static ref ALL_LINTS: Vec<Lint> = vec!{:#?};", sorted_usable_lints)
+                .lines()
+                .map(ToString::to_string)
+                .collect::<Vec<_>>()
+        },
+    )
+    .changed;
+
+    file_change |= replace_region_in_file(
+        Path::new("README.md"),
+        &format!(
+            r#"\[There are over \d+ lints included in this crate!\]\({}\)"#,
+            DOCS_LINK
+        ),
+        "",
+        true,
+        update_mode == UpdateMode::Change,
+        || {
+            vec![format!(
+                "[There are over {} lints included in this crate!]({})",
+                usable_lint_count, DOCS_LINK
+            )]
+        },
+    )
+    .changed;
+
+    file_change |= replace_region_in_file(
+        Path::new("CHANGELOG.md"),
+        "<!-- begin autogenerated links to lint list -->",
+        "<!-- end autogenerated links to lint list -->",
+        false,
+        update_mode == UpdateMode::Change,
+        || gen_changelog_lint_list(usable_lints.iter().chain(deprecated_lints.iter())),
+    )
+    .changed;
+
+    file_change |= replace_region_in_file(
+        Path::new("clippy_lints/src/lib.rs"),
+        "begin deprecated lints",
+        "end deprecated lints",
+        false,
+        update_mode == UpdateMode::Change,
+        || gen_deprecated(deprecated_lints.iter()),
+    )
+    .changed;
+
+    file_change |= replace_region_in_file(
+        Path::new("clippy_lints/src/lib.rs"),
+        "begin register lints",
+        "end register lints",
+        false,
+        update_mode == UpdateMode::Change,
+        || gen_register_lint_list(usable_lints.iter().chain(internal_lints.iter())),
+    )
+    .changed;
+
+    file_change |= replace_region_in_file(
+        Path::new("clippy_lints/src/lib.rs"),
+        "begin lints modules",
+        "end lints modules",
+        false,
+        update_mode == UpdateMode::Change,
+        || gen_modules_list(usable_lints.iter()),
+    )
+    .changed;
+
+    // Generate lists of lints in the clippy::all lint group
+    file_change |= replace_region_in_file(
+        Path::new("clippy_lints/src/lib.rs"),
+        r#"store.register_group\(true, "clippy::all""#,
+        r#"\]\);"#,
+        false,
+        update_mode == UpdateMode::Change,
+        || {
+            // clippy::all should only include the following lint groups:
+            let all_group_lints = usable_lints.iter().filter(|l| {
+                l.group == "correctness" || l.group == "style" || l.group == "complexity" || l.group == "perf"
+            });
+
+            gen_lint_group_list(all_group_lints)
+        },
+    )
+    .changed;
+
+    // Generate the list of lints for all other lint groups
+    for (lint_group, lints) in Lint::by_lint_group(usable_lints.into_iter().chain(internal_lints)) {
+        file_change |= replace_region_in_file(
+            Path::new("clippy_lints/src/lib.rs"),
+            &format!("store.register_group\\(true, \"clippy::{}\"", lint_group),
+            r#"\]\);"#,
+            false,
+            update_mode == UpdateMode::Change,
+            || gen_lint_group_list(lints.iter()),
+        )
+        .changed;
+    }
+
+    if update_mode == UpdateMode::Check && file_change {
+        println!(
+            "Not all lints defined properly. \
+             Please run `cargo dev update_lints` to make sure all lints are defined properly."
+        );
+        std::process::exit(1);
+    }
+}
+
+pub fn print_lints() {
+    let lint_list: Vec<Lint> = gather_all().collect();
+    let usable_lints = Lint::usable_lints(&lint_list);
+    let usable_lint_count = usable_lints.len();
+    let grouped_by_lint_group = Lint::by_lint_group(usable_lints.into_iter());
+
+    for (lint_group, mut lints) in grouped_by_lint_group {
+        if lint_group == "Deprecated" {
+            continue;
+        }
+        println!("\n## {}", lint_group);
+
+        lints.sort_by_key(|l| l.name.clone());
+
+        for lint in lints {
+            println!("* [{}]({}#{}) ({})", lint.name, DOCS_LINK, lint.name, lint.desc);
+        }
+    }
+
+    println!("there are {} lints", usable_lint_count);
+}
+
+fn round_to_fifty(count: usize) -> usize {
+    count / 50 * 50
+}

clippy_lints/src/as_conversions.rs

@@ -1,6 +1,6 @@
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::{Expr, ExprKind};
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::span_lint_and_help;

clippy_lints/src/assign_ops.rs

@@ -3,11 +3,11 @@ use crate::utils::{
 };
 use crate::utils::{higher, sugg};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
@@ -77,7 +77,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
             },
             hir::ExprKind::Assign(assignee, e, _) => {
                 if let hir::ExprKind::Binary(op, l, r) = &e.kind {
-                    #[allow(clippy::cognitive_complexity)]
                     let lint = |assignee: &hir::Expr<'_>, rhs: &hir::Expr<'_>| {
                         let ty = cx.tables.expr_ty(assignee);
                         let rty = cx.tables.expr_ty(rhs);

clippy_lints/src/atomic_ordering.rs

@@ -1,9 +1,9 @@
 use crate::utils::{match_def_path, span_lint_and_help};
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/attrs.rs

@@ -6,8 +6,6 @@ use crate::utils::{
     span_lint_and_then, without_block_comments,
 };
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
-use rustc::ty;
 use rustc_ast::ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
 use rustc_ast::util::lev_distance::find_best_match_for_name;
 use rustc_errors::Applicability;
@@ -15,6 +13,8 @@ use rustc_hir::{
     Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind,
 };
 use rustc_lint::{CheckLintNameResult, EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 use rustc_span::symbol::Symbol;

clippy_lints/src/bit_mask.rs

@@ -87,7 +87,7 @@ declare_clippy_lint! {
     /// **Example:**
     /// ```rust
     /// # let x = 1;
-    /// if x & 0x1111 == 0 { }
+    /// if x & 0b1111 == 0 { }
     /// ```
     pub VERBOSE_BIT_MASK,
     style,

clippy_lints/src/block_in_if_condition.rs

@@ -1,10 +1,10 @@
 use crate::utils::{differing_macro_contexts, higher, snippet_block_with_applicability, span_lint, span_lint_and_sugg};
-use rustc::hir::map::Map;
-use rustc::lint::in_external_macro;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_hir::{BlockCheckMode, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/booleans.rs

@@ -1,14 +1,14 @@
 use crate::utils::{
-    get_trait_def_id, implements_trait, in_macro, match_type, paths, snippet_opt, span_lint_and_sugg,
+    get_trait_def_id, implements_trait, in_macro, is_type_diagnostic_item, paths, snippet_opt, span_lint_and_sugg,
     span_lint_and_then, SpanlessEq,
 };
 use if_chain::if_chain;
-use rustc::hir::map::Map;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_expr, FnKind, NestedVisitorMap, Visitor};
 use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 
@@ -249,7 +249,9 @@ fn simplify_not(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option<String> {
         },
         ExprKind::MethodCall(path, _, args) if args.len() == 1 => {
             let type_of_receiver = cx.tables.expr_ty(&args[0]);
-            if !match_type(cx, type_of_receiver, &paths::OPTION) && !match_type(cx, type_of_receiver, &paths::RESULT) {
+            if !is_type_diagnostic_item(cx, type_of_receiver, sym!(option_type))
+                && !is_type_diagnostic_item(cx, type_of_receiver, sym!(result_type))
+            {
                 return None;
             }
             METHODS_WITH_NEGATION

clippy_lints/src/bytecount.rs

@@ -3,11 +3,11 @@ use crate::utils::{
     span_lint_and_sugg, walk_ptrs_ty,
 };
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_ast::ast::{Name, UintTy};
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/checked_conversions.rs

@@ -1,11 +1,11 @@
 //! lint on manually implemented checked conversions that could be transformed into `try_from`
 
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, QPath, TyKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::{snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
@@ -21,7 +21,7 @@ declare_clippy_lint! {
     /// ```rust
     /// # let foo: u32 = 5;
     /// # let _ =
-    /// foo <= i32::max_value() as u32
+    /// foo <= i32::MAX as u32
     /// # ;
     /// ```
     ///
@@ -179,7 +179,7 @@ impl ConversionType {
     }
 }
 
-/// Check for `expr <= (to_type::max_value() as from_type)`
+/// Check for `expr <= (to_type::MAX as from_type)`
 fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
     if_chain! {
          if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind;
@@ -194,7 +194,7 @@ fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
     }
 }
 
-/// Check for `expr >= 0|(to_type::min_value() as from_type)`
+/// Check for `expr >= 0|(to_type::MIN as from_type)`
 fn check_lower_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
     fn check_function<'a>(candidate: &'a Expr<'a>, check: &'a Expr<'a>) -> Option<Conversion<'a>> {
         (check_lower_bound_zero(candidate, check)).or_else(|| (check_lower_bound_min(candidate, check)))
@@ -222,7 +222,7 @@ fn check_lower_bound_zero<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> O
     }
 }
 
-/// Check for `expr >= (to_type::min_value() as from_type)`
+/// Check for `expr >= (to_type::MIN as from_type)`
 fn check_lower_bound_min<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option<Conversion<'a>> {
     if let Some((from, to)) = get_types_from_cast(check, MIN_VALUE, SINTS) {
         Conversion::try_new(candidate, from, to)

clippy_lints/src/cognitive_complexity.rs

@@ -1,15 +1,15 @@
 //! calculate cognitive complexity and warn about overly complex functions
 
-use rustc::hir::map::Map;
 use rustc_ast::ast::Attribute;
 use rustc_hir::intravisit::{walk_expr, FnKind, NestedVisitorMap, Visitor};
 use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 use rustc_span::BytePos;
 
-use crate::utils::{match_type, paths, snippet_opt, span_lint_and_help, LimitStack};
+use crate::utils::{is_type_diagnostic_item, snippet_opt, span_lint_and_help, LimitStack};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for methods with high cognitive complexity.
@@ -22,7 +22,7 @@ declare_clippy_lint! {
     ///
     /// **Example:** No. You'll see it when you get the warning.
     pub COGNITIVE_COMPLEXITY,
-    complexity,
+    nursery,
     "functions that should be split up into multiple functions"
 }
 
@@ -61,7 +61,7 @@ impl CognitiveComplexity {
         helper.visit_expr(expr);
         let CCHelper { cc, returns } = helper;
         let ret_ty = cx.tables.node_type(expr.hir_id);
-        let ret_adjust = if match_type(cx, ret_ty, &paths::RESULT) {
+        let ret_adjust = if is_type_diagnostic_item(cx, ret_ty, sym!(result_type)) {
             returns
         } else {
             #[allow(clippy::integer_division)]

clippy_lints/src/consts.rs

@@ -2,14 +2,14 @@
 
 use crate::utils::{clip, higher, sext, unsext};
 use if_chain::if_chain;
-use rustc::ty::subst::{Subst, SubstsRef};
-use rustc::ty::{self, Ty, TyCtxt};
-use rustc::{bug, span_bug};
 use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, QPath, UnOp};
 use rustc_lint::LateContext;
+use rustc_middle::ty::subst::{Subst, SubstsRef};
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::Symbol;
 use std::cmp::Ordering::{self, Equal};
 use std::convert::TryInto;
@@ -268,6 +268,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
                     }
                 }
             },
+            ExprKind::Index(ref arr, ref index) => self.index(arr, index),
             // TODO: add other expressions.
             _ => None,
         }
@@ -333,7 +334,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
                     .tcx
                     .const_eval_resolve(self.param_env, def_id, substs, None, None)
                     .ok()
-                    .map(|val| rustc::ty::Const::from_value(self.lcx.tcx, val, ty))?;
+                    .map(|val| rustc_middle::ty::Const::from_value(self.lcx.tcx, val, ty))?;
                 let result = miri_to_const(&result);
                 if result.is_some() {
                     self.needed_resolution = true;
@@ -345,6 +346,31 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
         }
     }
 
+    fn index(&mut self, lhs: &'_ Expr<'_>, index: &'_ Expr<'_>) -> Option<Constant> {
+        let lhs = self.expr(lhs);
+        let index = self.expr(index);
+
+        match (lhs, index) {
+            (Some(Constant::Vec(vec)), Some(Constant::Int(index))) => match vec[index as usize] {
+                Constant::F32(x) => Some(Constant::F32(x)),
+                Constant::F64(x) => Some(Constant::F64(x)),
+                _ => None,
+            },
+            (Some(Constant::Vec(vec)), _) => {
+                if !vec.is_empty() && vec.iter().all(|x| *x == vec[0]) {
+                    match vec[0] {
+                        Constant::F32(x) => Some(Constant::F32(x)),
+                        Constant::F64(x) => Some(Constant::F64(x)),
+                        _ => None,
+                    }
+                } else {
+                    None
+                }
+            },
+            _ => None,
+        }
+    }
+
     /// A block can only yield a constant if it only has one constant expression.
     fn block(&mut self, block: &Block<'_>) -> Option<Constant> {
         if block.stmts.is_empty() {
@@ -460,7 +486,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
 }
 
 pub fn miri_to_const(result: &ty::Const<'_>) -> Option<Constant> {
-    use rustc::mir::interpret::{ConstValue, Scalar};
+    use rustc_middle::mir::interpret::{ConstValue, Scalar};
     match result.val {
         ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data: d, .. })) => match result.ty.kind {
             ty::Bool => Some(Constant::Bool(d == 1)),
@@ -492,6 +518,41 @@ pub fn miri_to_const(result: &ty::Const<'_>) -> Option<Constant> {
             },
             _ => None,
         },
+        ty::ConstKind::Value(ConstValue::ByRef { alloc, offset: _ }) => match result.ty.kind {
+            ty::Array(sub_type, len) => match sub_type.kind {
+                ty::Float(FloatTy::F32) => match miri_to_const(len) {
+                    Some(Constant::Int(len)) => alloc
+                        .inspect_with_undef_and_ptr_outside_interpreter(0..(4 * len as usize))
+                        .to_owned()
+                        .chunks(4)
+                        .map(|chunk| {
+                            Some(Constant::F32(f32::from_le_bytes(
+                                chunk.try_into().expect("this shouldn't happen"),
+                            )))
+                        })
+                        .collect::<Option<Vec<Constant>>>()
+                        .map(Constant::Vec),
+                    _ => None,
+                },
+                ty::Float(FloatTy::F64) => match miri_to_const(len) {
+                    Some(Constant::Int(len)) => alloc
+                        .inspect_with_undef_and_ptr_outside_interpreter(0..(8 * len as usize))
+                        .to_owned()
+                        .chunks(8)
+                        .map(|chunk| {
+                            Some(Constant::F64(f64::from_le_bytes(
+                                chunk.try_into().expect("this shouldn't happen"),
+                            )))
+                        })
+                        .collect::<Option<Vec<Constant>>>()
+                        .map(Constant::Vec),
+                    _ => None,
+                },
+                // FIXME: implement other array type conversions.
+                _ => None,
+            },
+            _ => None,
+        },
         // FIXME: implement other conversions.
         _ => None,
     }

clippy_lints/src/copies.rs

@@ -1,9 +1,9 @@
 use crate::utils::{get_parent_expr, higher, if_sequence, same_tys, snippet, span_lint_and_note, span_lint_and_then};
 use crate::utils::{SpanlessEq, SpanlessHash};
-use rustc::ty::Ty;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::{Arm, Block, Expr, ExprKind, MatchSource, Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::Ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::Symbol;
 use std::collections::hash_map::Entry;

clippy_lints/src/default_trait_access.rs

@@ -1,8 +1,8 @@
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::{any_parent_is_automatically_derived, match_def_path, paths, span_lint_and_sugg};

clippy_lints/src/deprecated_lints.rs

@@ -147,3 +147,11 @@ declare_deprecated_lint! {
     pub UNUSED_LABEL,
     "this lint has been uplifted to rustc and is now called `unused_labels`"
 }
+
+declare_deprecated_lint! {
+    /// **What it does:** Nothing. This lint has been deprecated.
+    ///
+    /// **Deprecation reason:** Associated-constants are now preferred.
+    pub REPLACE_CONSTS,
+    "associated-constants `MIN`/`MAX` of integers are prefer to `{min,max}_value()` and module constants"
+}

clippy_lints/src/derive.rs

@@ -1,9 +1,9 @@
 use crate::utils::paths;
 use crate::utils::{is_automatically_derived, is_copy, match_path, span_lint_and_then};
 use if_chain::if_chain;
-use rustc::ty::{self, Ty};
 use rustc_hir::{Item, ItemKind, TraitRef};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 
@@ -94,7 +94,8 @@ fn check_hash_peq<'a, 'tcx>(
     if_chain! {
         if match_path(&trait_ref.path, &paths::HASH);
         if let Some(peq_trait_def_id) = cx.tcx.lang_items().eq_trait();
-        if !&trait_ref.trait_def_id().is_local();
+        if let Some(def_id) = &trait_ref.trait_def_id();
+        if !def_id.is_local();
         then {
             // Look for the PartialEq implementations for `ty`
             cx.tcx.for_each_relevant_impl(peq_trait_def_id, ty, |impl_id| {

clippy_lints/src/doc.rs

@@ -1,12 +1,12 @@
-use crate::utils::{implements_trait, is_entrypoint_fn, match_type, paths, return_ty, span_lint};
+use crate::utils::{implements_trait, is_entrypoint_fn, is_type_diagnostic_item, return_ty, span_lint};
 use if_chain::if_chain;
 use itertools::Itertools;
-use rustc::lint::in_external_macro;
-use rustc::ty;
 use rustc_ast::ast::{AttrKind, Attribute};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::{BytePos, MultiSpan, Span};
 use rustc_span::Pos;
@@ -217,7 +217,7 @@ fn lint_for_missing_headers<'a, 'tcx>(
         );
     }
     if !headers.errors {
-        if match_type(cx, return_ty(cx, hir_id), &paths::RESULT) {
+        if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym!(result_type)) {
             span_lint(
                 cx,
                 MISSING_ERRORS_DOC,
@@ -229,13 +229,13 @@ fn lint_for_missing_headers<'a, 'tcx>(
                 if let Some(body_id) = body_id;
                 if let Some(future) = cx.tcx.lang_items().future_trait();
                 let def_id = cx.tcx.hir().body_owner_def_id(body_id);
-                let mir = cx.tcx.optimized_mir(def_id);
+                let mir = cx.tcx.optimized_mir(def_id.to_def_id());
                 let ret_ty = mir.return_ty();
                 if implements_trait(cx, ret_ty, future, &[]);
                 if let ty::Opaque(_, subs) = ret_ty.kind;
                 if let Some(gen) = subs.types().next();
                 if let ty::Generator(_, subs, _) = gen.kind;
-                if match_type(cx, subs.as_generator().return_ty(), &paths::RESULT);
+                if is_type_diagnostic_item(cx, subs.as_generator().return_ty(), sym!(result_type));
                 then {
                     span_lint(
                         cx,

clippy_lints/src/drop_forget_ref.rs

@@ -1,8 +1,8 @@
 use crate::utils::{is_copy, match_def_path, paths, qpath_res, span_lint_and_note};
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/else_if_without_else.rs

@@ -1,8 +1,8 @@
 //! Lint on if expressions with an else if, but without a final else branch.
 
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::{Expr, ExprKind};
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::span_lint_and_help;

clippy_lints/src/entry.rs

@@ -2,11 +2,11 @@ use crate::utils::SpanlessEq;
 use crate::utils::{get_item_name, higher, match_type, paths, snippet, snippet_opt};
 use crate::utils::{snippet_with_applicability, span_lint_and_then, walk_ptrs_ty};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_hir::{BorrowKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 

clippy_lints/src/enum_clike.rs

@@ -3,11 +3,11 @@
 
 use crate::consts::{miri_to_const, Constant};
 use crate::utils::span_lint;
-use rustc::ty;
-use rustc::ty::util::IntTypeExt;
 use rustc_ast::ast::{IntTy, UintTy};
 use rustc_hir::{Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_middle::ty::util::IntTypeExt;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use std::convert::TryFrom;
 
@@ -46,12 +46,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnportableVariant {
             for var in def.variants {
                 if let Some(anon_const) = &var.disr_expr {
                     let def_id = cx.tcx.hir().body_owner_def_id(anon_const.body);
-                    let mut ty = cx.tcx.type_of(def_id);
+                    let mut ty = cx.tcx.type_of(def_id.to_def_id());
                     let constant = cx
                         .tcx
-                        .const_eval_poly(def_id)
+                        .const_eval_poly(def_id.to_def_id())
                         .ok()
-                        .map(|val| rustc::ty::Const::from_value(cx.tcx, val, ty));
+                        .map(|val| rustc_middle::ty::Const::from_value(cx.tcx, val, ty));
                     if let Some(Constant::Int(val)) = constant.and_then(miri_to_const) {
                         if let ty::Adt(adt, _) = ty.kind {
                             if adt.is_enum() {

clippy_lints/src/escape.rs

@@ -1,11 +1,11 @@
-use rustc::ty::layout::LayoutOf;
-use rustc::ty::{self, Ty};
 use rustc_hir::intravisit;
 use rustc_hir::{self, Body, FnDecl, HirId, HirIdSet, ItemKind, Node};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
+use rustc_target::abi::LayoutOf;
 use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, Place, PlaceBase};
 
 use crate::utils::span_lint;
@@ -92,7 +92,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxedLocal {
 }
 
 // TODO: Replace with Map::is_argument(..) when it's fixed
-fn is_argument(map: rustc::hir::map::Map<'_>, id: HirId) -> bool {
+fn is_argument(map: rustc_middle::hir::map::Map<'_>, id: HirId) -> bool {
     match map.find(id) {
         Some(Node::Binding(_)) => (),
         _ => return false,

clippy_lints/src/eta_reduction.rs

@@ -1,9 +1,9 @@
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
-use rustc::ty::{self, Ty};
 use rustc_errors::Applicability;
 use rustc_hir::{def_id, Expr, ExprKind, Param, PatKind, QPath};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::{

clippy_lints/src/eval_order_dependence.rs

@@ -1,10 +1,10 @@
 use crate::utils::{get_parent_expr, span_lint, span_lint_and_note};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
-use rustc::ty;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_hir::{def, BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, QPath, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/fallible_impl_from.rs

@@ -1,10 +1,12 @@
-use crate::utils::paths::{BEGIN_PANIC, BEGIN_PANIC_FMT, FROM_TRAIT, OPTION, RESULT};
+use crate::utils::paths::{BEGIN_PANIC, BEGIN_PANIC_FMT, FROM_TRAIT};
-use crate::utils::{is_expn_of, match_def_path, method_chain_args, span_lint_and_then, walk_ptrs_ty};
+use crate::utils::{
+    is_expn_of, is_type_diagnostic_item, match_def_path, method_chain_args, span_lint_and_then, walk_ptrs_ty,
+};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
-use rustc::ty::{self, Ty};
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::Span;
 
@@ -76,7 +78,9 @@ fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_it
             // check for `unwrap`
             if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
                 let reciever_ty = walk_ptrs_ty(self.tables.expr_ty(&arglists[0][0]));
-                if match_type(self.lcx, reciever_ty, &OPTION) || match_type(self.lcx, reciever_ty, &RESULT) {
+                if is_type_diagnostic_item(self.lcx, reciever_ty, sym!(option_type))
+                    || is_type_diagnostic_item(self.lcx, reciever_ty, sym!(result_type))
+                {
                     self.result.push(expr.span);
                 }
             }
@@ -124,10 +128,3 @@ fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_it
         }
     }
 }
-
-fn match_type(cx: &LateContext<'_, '_>, ty: Ty<'_>, path: &[&str]) -> bool {
-    match ty.kind {
-        ty::Adt(adt, _) => match_def_path(cx, adt.did, path),
-        _ => false,
-    }
-}

clippy_lints/src/float_literal.rs

@@ -1,12 +1,12 @@
 use crate::utils::{numeric_literal, span_lint_and_sugg};
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use std::{f32, f64, fmt};
+use std::fmt;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for float literals with a precision greater

clippy_lints/src/floating_point_arithmetic.rs

@@ -4,10 +4,10 @@ use crate::consts::{
 };
 use crate::utils::{higher, numeric_literal, span_lint_and_sugg, sugg, SpanlessEq};
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Spanned;
 

clippy_lints/src/format.rs

@@ -91,7 +91,7 @@ fn on_argumentv1_new<'a, 'tcx>(
         if pats.len() == 1;
         then {
             let ty = walk_ptrs_ty(cx.tables.pat_ty(&pats[0]));
-            if ty.kind != rustc::ty::Str && !match_type(cx, ty, &paths::STRING) {
+            if ty.kind != rustc_middle::ty::Str && !match_type(cx, ty, &paths::STRING) {
                 return None;
             }
             if let ExprKind::Lit(ref lit) = format_args.kind {

clippy_lints/src/formatting.rs

@@ -1,8 +1,8 @@
 use crate::utils::{differing_macro_contexts, snippet_opt, span_lint_and_help, span_lint_and_note};
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp};
 use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 

clippy_lints/src/functions.rs

@@ -3,9 +3,6 @@ use crate::utils::{
     must_use_attr, qpath_res, return_ty, snippet, snippet_opt, span_lint, span_lint_and_help, span_lint_and_then,
     trait_ref_of_method, type_is_unsafe_function,
 };
-use rustc::hir::map::Map;
-use rustc::lint::in_external_macro;
-use rustc::ty::{self, Ty};
 use rustc_ast::ast::Attribute;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
@@ -13,6 +10,9 @@ use rustc_hir as hir;
 use rustc_hir::intravisit;
 use rustc_hir::{def::Res, def_id::DefId};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 use rustc_target::spec::abi::Abi;

clippy_lints/src/get_last_with_len.rs

@@ -8,7 +8,6 @@ use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::Symbol;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for using `x.get(x.len() - 1)` instead of
@@ -51,12 +50,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for GetLastWithLen {
             if let ExprKind::MethodCall(ref path, _, ref args) = expr.kind;
 
             // Method name is "get"
-            if path.ident.name == Symbol::intern("get");
+            if path.ident.name == sym!(get);
 
             // Argument 0 (the struct we're calling the method on) is a vector
             if let Some(struct_calling_on) = args.get(0);
             let struct_ty = cx.tables.expr_ty(struct_calling_on);
-            if is_type_diagnostic_item(cx, struct_ty, Symbol::intern("vec_type"));
+            if is_type_diagnostic_item(cx, struct_ty, sym!(vec_type));
 
             // Argument to "get" is a subtraction
             if let Some(get_index_arg) = args.get(1);
@@ -71,7 +70,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for GetLastWithLen {
 
             // LHS of subtraction is "x.len()"
             if let ExprKind::MethodCall(arg_lhs_path, _, lhs_args) = &lhs.kind;
-            if arg_lhs_path.ident.name == Symbol::intern("len");
+            if arg_lhs_path.ident.name == sym!(len);
             if let Some(arg_lhs_struct) = lhs_args.get(0);
 
             // The two vectors referenced (x in x.get(...) and in x.len())

clippy_lints/src/identity_op.rs

@@ -1,6 +1,6 @@
-use rustc::ty;
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 

clippy_lints/src/if_let_some_result.rs

@@ -1,7 +1,7 @@
-use crate::utils::{match_type, method_chain_args, paths, snippet_with_applicability, span_lint_and_sugg};
+use crate::utils::{is_type_diagnostic_item, method_chain_args, snippet_with_applicability, span_lint_and_sugg};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{print, Expr, ExprKind, MatchSource, PatKind, QPath};
+use rustc_hir::{Expr, ExprKind, MatchSource, PatKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
@@ -45,8 +45,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for OkIfLet {
             if let ExprKind::MethodCall(_, ok_span, ref result_types) = op.kind; //check is expr.ok() has type Result<T,E>.ok()
             if let PatKind::TupleStruct(QPath::Resolved(_, ref x), ref y, _)  = body[0].pat.kind; //get operation
             if method_chain_args(op, &["ok"]).is_some(); //test to see if using ok() methoduse std::marker::Sized;
-            let is_result_type = match_type(cx, cx.tables.expr_ty(&result_types[0]), &paths::RESULT);
+            if is_type_diagnostic_item(cx, cx.tables.expr_ty(&result_types[0]), sym!(result_type));
-            if print::to_string(print::NO_ANN, |s| s.print_path(x, false)) == "Some" && is_result_type;
+            if rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_path(x, false)) == "Some";
 
             then {
                 let mut applicability = Applicability::MachineApplicable;

clippy_lints/src/if_not_else.rs

@@ -1,9 +1,9 @@
 //! lint on if branches that could be swapped so no `!` operation is necessary
 //! on the condition
 
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::{BinOpKind, Expr, ExprKind, UnOp};
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::span_lint_and_help;

clippy_lints/src/implicit_return.rs

@@ -135,11 +135,11 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImplicitReturn {
         let def_id = cx.tcx.hir().body_owner_def_id(body.id());
 
         // Building MIR for `fn`s with unsatisfiable preds results in ICE.
-        if fn_has_unsatisfiable_preds(cx, def_id) {
+        if fn_has_unsatisfiable_preds(cx, def_id.to_def_id()) {
             return;
         }
 
-        let mir = cx.tcx.optimized_mir(def_id);
+        let mir = cx.tcx.optimized_mir(def_id.to_def_id());
 
         // checking return type through MIR, HIR is not able to determine inferred closure return types
         // make sure it's not a macro

clippy_lints/src/indexing_slicing.rs

@@ -2,10 +2,10 @@
 
 use crate::consts::{constant, Constant};
 use crate::utils::{higher, span_lint, span_lint_and_help};
-use rustc::ty;
 use rustc_ast::ast::RangeLimits;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/large_enum_variant.rs

@@ -1,21 +1,24 @@
 //! lint when there is a large size difference between variants on an enum
 
 use crate::utils::{snippet_opt, span_lint_and_then};
-use rustc::ty::layout::LayoutOf;
 use rustc_errors::Applicability;
 use rustc_hir::{Item, ItemKind, VariantData};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_target::abi::LayoutOf;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for large size differences between variants on
     /// `enum`s.
     ///
     /// **Why is this bad?** Enum size is bounded by the largest variant. Having a
-    /// large variant
+    /// large variant can penalize the memory layout of that enum.
-    /// can penalize the memory layout of that enum.
     ///
-    /// **Known problems:** None.
+    /// **Known problems:** This lint obviously cannot take the distribution of
+    /// variants in your running program into account. It is possible that the
+    /// smaller variants make up less than 1% of all instances, in which case
+    /// the overhead is negligible and the boxing is counter-productive. Always
+    /// measure the change this lint suggests.
     ///
     /// **Example:**
     /// ```rust
@@ -52,8 +55,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeEnumVariant {
             let ty = cx.tcx.type_of(did);
             let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
 
-            let mut smallest_variant: Option<(_, _)> = None;
             let mut largest_variant: Option<(_, _)> = None;
+            let mut second_variant: Option<(_, _)> = None;
 
             for (i, variant) in adt.variants.iter().enumerate() {
                 let size: u64 = variant
@@ -69,12 +72,14 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeEnumVariant {
 
                 let grouped = (size, (i, variant));
 
-                update_if(&mut smallest_variant, grouped, |a, b| b.0 <= a.0);
+                if grouped.0 >= largest_variant.map_or(0, |x| x.0) {
-                update_if(&mut largest_variant, grouped, |a, b| b.0 >= a.0);
+                    second_variant = largest_variant;
+                    largest_variant = Some(grouped);
+                }
             }
 
-            if let (Some(smallest), Some(largest)) = (smallest_variant, largest_variant) {
+            if let (Some(largest), Some(second)) = (largest_variant, second_variant) {
-                let difference = largest.0 - smallest.0;
+                let difference = largest.0 - second.0;
 
                 if difference > self.maximum_size_difference_allowed {
                     let (i, variant) = largest.1;
@@ -114,16 +119,3 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeEnumVariant {
         }
     }
 }
-
-fn update_if<T, F>(old: &mut Option<T>, new: T, f: F)
-where
-    F: Fn(&T, &T) -> bool,
-{
-    if let Some(ref mut val) = *old {
-        if f(val, &new) {
-            *val = new;
-        }
-    } else {
-        *old = Some(new);
-    }
-}

clippy_lints/src/large_stack_arrays.rs

@@ -1,7 +1,7 @@
-use rustc::mir::interpret::ConstValue;
-use rustc::ty::{self, ConstKind};
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir::interpret::ConstValue;
+use rustc_middle::ty::{self, ConstKind};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 
 use if_chain::if_chain;

clippy_lints/src/len_zero.rs

@@ -1,11 +1,11 @@
 use crate::utils::{get_item_name, snippet_with_applicability, span_lint, span_lint_and_sugg, walk_ptrs_ty};
-use rustc::ty;
 use rustc_ast::ast::{LitKind, Name};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{AssocItemKind, BinOpKind, Expr, ExprKind, ImplItemRef, Item, ItemKind, TraitItemRef};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::{Span, Spanned};
 
@@ -121,7 +121,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LenZero {
 fn check_trait_items(cx: &LateContext<'_, '_>, visited_trait: &Item<'_>, trait_items: &[TraitItemRef]) {
     fn is_named_self(cx: &LateContext<'_, '_>, item: &TraitItemRef, name: &str) -> bool {
         item.ident.name.as_str() == name
-            && if let AssocItemKind::Method { has_self } = item.kind {
+            && if let AssocItemKind::Fn { has_self } = item.kind {
                 has_self && {
                     let did = cx.tcx.hir().local_def_id(item.id.hir_id);
                     cx.tcx.fn_sig(did).inputs().skip_binder().len() == 1
@@ -149,8 +149,8 @@ fn check_trait_items(cx: &LateContext<'_, '_>, visited_trait: &Item<'_>, trait_i
             .iter()
             .flat_map(|&i| cx.tcx.associated_items(i).in_definition_order())
             .any(|i| {
-                i.kind == ty::AssocKind::Method
+                i.kind == ty::AssocKind::Fn
-                    && i.method_has_self_argument
+                    && i.fn_has_self_parameter
                     && i.ident.name == sym!(is_empty)
                     && cx.tcx.fn_sig(i.def_id).inputs().skip_binder().len() == 1
             });
@@ -172,7 +172,7 @@ fn check_trait_items(cx: &LateContext<'_, '_>, visited_trait: &Item<'_>, trait_i
 fn check_impl_items(cx: &LateContext<'_, '_>, item: &Item<'_>, impl_items: &[ImplItemRef<'_>]) {
     fn is_named_self(cx: &LateContext<'_, '_>, item: &ImplItemRef<'_>, name: &str) -> bool {
         item.ident.name.as_str() == name
-            && if let AssocItemKind::Method { has_self } = item.kind {
+            && if let AssocItemKind::Fn { has_self } = item.kind {
                 has_self && {
                     let did = cx.tcx.hir().local_def_id(item.id.hir_id);
                     cx.tcx.fn_sig(did).inputs().skip_binder().len() == 1
@@ -261,7 +261,7 @@ fn check_len(
 fn has_is_empty(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
     /// Gets an `AssocItem` and return true if it matches `is_empty(self)`.
     fn is_is_empty(cx: &LateContext<'_, '_>, item: &ty::AssocItem) -> bool {
-        if let ty::AssocKind::Method = item.kind {
+        if let ty::AssocKind::Fn = item.kind {
             if item.ident.name.as_str() == "is_empty" {
                 let sig = cx.tcx.fn_sig(item.def_id);
                 let ty = sig.skip_binder();

clippy_lints/src/let_if_seq.rs

@@ -1,12 +1,12 @@
 use crate::utils::{higher, qpath_res, snippet, span_lint_and_then};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::intravisit;
 use rustc_hir::BindingAnnotation;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/let_underscore.rs

@@ -1,7 +1,8 @@
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
+use rustc_hir::{Local, PatKind};
-use rustc_hir::{PatKind, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::subst::GenericArgKind;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::{is_must_use_func_call, is_must_use_ty, match_type, paths, span_lint_and_help};
@@ -66,22 +67,28 @@ const SYNC_GUARD_PATHS: [&[&str]; 3] = [
 ];
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetUnderscore {
-    fn check_stmt(&mut self, cx: &LateContext<'_, '_>, stmt: &Stmt<'_>) {
+    fn check_local(&mut self, cx: &LateContext<'_, '_>, local: &Local<'_>) {
-        if in_external_macro(cx.tcx.sess, stmt.span) {
+        if in_external_macro(cx.tcx.sess, local.span) {
             return;
         }
 
         if_chain! {
-            if let StmtKind::Local(ref local) = stmt.kind;
             if let PatKind::Wild = local.pat.kind;
             if let Some(ref init) = local.init;
             then {
-                let check_ty = |ty| SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, ty, path));
+                let init_ty = cx.tables.expr_ty(init);
-                if cx.tables.expr_ty(init).walk().any(check_ty) {
+                let contains_sync_guard = init_ty.walk().any(|inner| match inner.unpack() {
+                    GenericArgKind::Type(inner_ty) => {
+                        SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, inner_ty, path))
+                    },
+
+                    GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
+                });
+                if contains_sync_guard {
                     span_lint_and_help(
                         cx,
                         LET_UNDERSCORE_LOCK,
-                        stmt.span,
+                        local.span,
                         "non-binding let on a synchronization lock",
                         "consider using an underscore-prefixed named \
                             binding or dropping explicitly with `std::mem::drop`"
@@ -90,7 +97,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetUnderscore {
                     span_lint_and_help(
                         cx,
                         LET_UNDERSCORE_MUST_USE,
-                        stmt.span,
+                        local.span,
                         "non-binding let on an expression with `#[must_use]` type",
                         "consider explicitly using expression value"
                     )
@@ -98,7 +105,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetUnderscore {
                     span_lint_and_help(
                         cx,
                         LET_UNDERSCORE_MUST_USE,
-                        stmt.span,
+                        local.span,
                         "non-binding let on a result of a `#[must_use]` function",
                         "consider explicitly using function result"
                     )

clippy_lints/src/lib.rs

@@ -18,8 +18,6 @@
 #[allow(unused_extern_crates)]
 extern crate fmt_macros;
 #[allow(unused_extern_crates)]
-extern crate rustc;
-#[allow(unused_extern_crates)]
 extern crate rustc_ast;
 #[allow(unused_extern_crates)]
 extern crate rustc_ast_pretty;
@@ -34,6 +32,8 @@ extern crate rustc_errors;
 #[allow(unused_extern_crates)]
 extern crate rustc_hir;
 #[allow(unused_extern_crates)]
+extern crate rustc_hir_pretty;
+#[allow(unused_extern_crates)]
 extern crate rustc_index;
 #[allow(unused_extern_crates)]
 extern crate rustc_infer;
@@ -42,6 +42,8 @@ extern crate rustc_lexer;
 #[allow(unused_extern_crates)]
 extern crate rustc_lint;
 #[allow(unused_extern_crates)]
+extern crate rustc_middle;
+#[allow(unused_extern_crates)]
 extern crate rustc_mir;
 #[allow(unused_extern_crates)]
 extern crate rustc_parse;
@@ -80,7 +82,7 @@ use rustc_session::Session;
 /// ```
 /// # #![feature(rustc_private)]
 /// # #[allow(unused_extern_crates)]
-/// # extern crate rustc;
+/// # extern crate rustc_middle;
 /// # #[allow(unused_extern_crates)]
 /// # extern crate rustc_session;
 /// # #[macro_use]
@@ -168,157 +170,157 @@ mod consts;
 mod utils;
 
 // begin lints modules, do not remove this comment, it’s used in `update_lints`
-pub mod approx_const;
+mod approx_const;
-pub mod arithmetic;
+mod arithmetic;
-pub mod as_conversions;
+mod as_conversions;
-pub mod assertions_on_constants;
+mod assertions_on_constants;
-pub mod assign_ops;
+mod assign_ops;
-pub mod atomic_ordering;
+mod atomic_ordering;
-pub mod attrs;
+mod attrs;
-pub mod bit_mask;
+mod bit_mask;
-pub mod blacklisted_name;
+mod blacklisted_name;
-pub mod block_in_if_condition;
+mod block_in_if_condition;
-pub mod booleans;
+mod booleans;
-pub mod bytecount;
+mod bytecount;
-pub mod cargo_common_metadata;
+mod cargo_common_metadata;
-pub mod checked_conversions;
+mod checked_conversions;
-pub mod cognitive_complexity;
+mod cognitive_complexity;
-pub mod collapsible_if;
+mod collapsible_if;
-pub mod comparison_chain;
+mod comparison_chain;
-pub mod copies;
+mod copies;
-pub mod copy_iterator;
+mod copy_iterator;
-pub mod dbg_macro;
+mod dbg_macro;
-pub mod default_trait_access;
+mod default_trait_access;
-pub mod derive;
+mod derive;
-pub mod doc;
+mod doc;
-pub mod double_comparison;
+mod double_comparison;
-pub mod double_parens;
+mod double_parens;
-pub mod drop_bounds;
+mod drop_bounds;
-pub mod drop_forget_ref;
+mod drop_forget_ref;
-pub mod duration_subsec;
+mod duration_subsec;
-pub mod else_if_without_else;
+mod else_if_without_else;
-pub mod empty_enum;
+mod empty_enum;
-pub mod entry;
+mod entry;
-pub mod enum_clike;
+mod enum_clike;
-pub mod enum_variants;
+mod enum_variants;
-pub mod eq_op;
+mod eq_op;
-pub mod erasing_op;
+mod erasing_op;
-pub mod escape;
+mod escape;
-pub mod eta_reduction;
+mod eta_reduction;
-pub mod eval_order_dependence;
+mod eval_order_dependence;
-pub mod excessive_bools;
+mod excessive_bools;
-pub mod exit;
+mod exit;
-pub mod explicit_write;
+mod explicit_write;
-pub mod fallible_impl_from;
+mod fallible_impl_from;
-pub mod float_literal;
+mod float_literal;
-pub mod floating_point_arithmetic;
+mod floating_point_arithmetic;
-pub mod format;
+mod format;
-pub mod formatting;
+mod formatting;
-pub mod functions;
+mod functions;
-pub mod get_last_with_len;
+mod get_last_with_len;
-pub mod identity_conversion;
+mod identity_conversion;
-pub mod identity_op;
+mod identity_op;
-pub mod if_let_some_result;
+mod if_let_some_result;
-pub mod if_not_else;
+mod if_not_else;
-pub mod implicit_return;
+mod implicit_return;
-pub mod indexing_slicing;
+mod indexing_slicing;
-pub mod infinite_iter;
+mod infinite_iter;
-pub mod inherent_impl;
+mod inherent_impl;
-pub mod inherent_to_string;
+mod inherent_to_string;
-pub mod inline_fn_without_body;
+mod inline_fn_without_body;
-pub mod int_plus_one;
+mod int_plus_one;
-pub mod integer_division;
+mod integer_division;
-pub mod items_after_statements;
+mod items_after_statements;
-pub mod large_enum_variant;
+mod large_enum_variant;
-pub mod large_stack_arrays;
+mod large_stack_arrays;
-pub mod len_zero;
+mod len_zero;
-pub mod let_if_seq;
+mod let_if_seq;
-pub mod let_underscore;
+mod let_underscore;
-pub mod lifetimes;
+mod lifetimes;
-pub mod literal_representation;
+mod literal_representation;
-pub mod loops;
+mod loops;
-pub mod macro_use;
+mod macro_use;
-pub mod main_recursion;
+mod main_recursion;
-pub mod map_clone;
+mod map_clone;
-pub mod map_unit_fn;
+mod map_unit_fn;
-pub mod matches;
+mod matches;
-pub mod mem_discriminant;
+mod mem_discriminant;
-pub mod mem_forget;
+mod mem_forget;
-pub mod mem_replace;
+mod mem_replace;
-pub mod methods;
+mod methods;
-pub mod minmax;
+mod minmax;
-pub mod misc;
+mod misc;
-pub mod misc_early;
+mod misc_early;
-pub mod missing_const_for_fn;
+mod missing_const_for_fn;
-pub mod missing_doc;
+mod missing_doc;
-pub mod missing_inline;
+mod missing_inline;
-pub mod modulo_arithmetic;
+mod modulo_arithmetic;
-pub mod multiple_crate_versions;
+mod multiple_crate_versions;
-pub mod mut_key;
+mod mut_key;
-pub mod mut_mut;
+mod mut_mut;
-pub mod mut_reference;
+mod mut_reference;
-pub mod mutable_debug_assertion;
+mod mutable_debug_assertion;
-pub mod mutex_atomic;
+mod mutex_atomic;
-pub mod needless_bool;
+mod needless_bool;
-pub mod needless_borrow;
+mod needless_borrow;
-pub mod needless_borrowed_ref;
+mod needless_borrowed_ref;
-pub mod needless_continue;
+mod needless_continue;
-pub mod needless_pass_by_value;
+mod needless_pass_by_value;
-pub mod needless_update;
+mod needless_update;
-pub mod neg_cmp_op_on_partial_ord;
+mod neg_cmp_op_on_partial_ord;
-pub mod neg_multiply;
+mod neg_multiply;
-pub mod new_without_default;
+mod new_without_default;
-pub mod no_effect;
+mod no_effect;
-pub mod non_copy_const;
+mod non_copy_const;
-pub mod non_expressive_names;
+mod non_expressive_names;
-pub mod open_options;
+mod open_options;
-pub mod option_env_unwrap;
+mod option_env_unwrap;
-pub mod overflow_check_conditional;
+mod overflow_check_conditional;
-pub mod panic_unimplemented;
+mod panic_unimplemented;
-pub mod partialeq_ne_impl;
+mod partialeq_ne_impl;
-pub mod path_buf_push_overwrite;
+mod path_buf_push_overwrite;
-pub mod precedence;
+mod precedence;
-pub mod ptr;
+mod ptr;
-pub mod ptr_offset_with_cast;
+mod ptr_offset_with_cast;
-pub mod question_mark;
+mod question_mark;
-pub mod ranges;
+mod ranges;
-pub mod redundant_clone;
+mod redundant_clone;
-pub mod redundant_field_names;
+mod redundant_field_names;
-pub mod redundant_pattern_matching;
+mod redundant_pattern_matching;
-pub mod redundant_pub_crate;
+mod redundant_pub_crate;
-pub mod redundant_static_lifetimes;
+mod redundant_static_lifetimes;
-pub mod reference;
+mod reference;
-pub mod regex;
+mod regex;
-pub mod replace_consts;
+mod returns;
-pub mod returns;
+mod serde_api;
-pub mod serde_api;
+mod shadow;
-pub mod shadow;
+mod single_component_path_imports;
-pub mod single_component_path_imports;
+mod slow_vector_initialization;
-pub mod slow_vector_initialization;
+mod strings;
-pub mod strings;
+mod suspicious_trait_impl;
-pub mod suspicious_trait_impl;
+mod swap;
-pub mod swap;
+mod tabs_in_doc_comments;
-pub mod tabs_in_doc_comments;
+mod temporary_assignment;
-pub mod temporary_assignment;
+mod to_digit_is_some;
-pub mod to_digit_is_some;
+mod trait_bounds;
-pub mod trait_bounds;
+mod transmute;
-pub mod transmute;
+mod transmuting_null;
-pub mod transmuting_null;
+mod trivially_copy_pass_by_ref;
-pub mod trivially_copy_pass_by_ref;
+mod try_err;
-pub mod try_err;
+mod types;
-pub mod types;
+mod unicode;
-pub mod unicode;
+mod unnamed_address;
-pub mod unsafe_removed_from_name;
+mod unsafe_removed_from_name;
-pub mod unused_io_amount;
+mod unused_io_amount;
-pub mod unused_self;
+mod unused_self;
-pub mod unwrap;
+mod unwrap;
-pub mod use_self;
+mod use_self;
-pub mod vec;
+mod vec;
-pub mod verbose_file_reads;
+mod verbose_file_reads;
-pub mod wildcard_dependencies;
+mod wildcard_dependencies;
-pub mod wildcard_imports;
+mod wildcard_imports;
-pub mod write;
+mod write;
-pub mod zero_div_zero;
+mod zero_div_zero;
 // end lints modules, do not remove this comment, it’s used in `update_lints`
 
 pub use crate::utils::conf::Conf;
@@ -468,6 +470,10 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         "clippy::unused_label",
         "this lint has been uplifted to rustc and is now called `unused_labels`",
     );
+    store.register_removed(
+        "clippy::replace_consts",
+        "associated-constants `MIN`/`MAX` of integers are prefer to `{min,max}_value()` and module constants",
+    );
     // end deprecated lints, do not remove this comment, it’s used in `update_lints`
 
     // begin register lints, do not remove this comment, it’s used in `update_lints`
@@ -660,6 +666,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &methods::OPTION_UNWRAP_USED,
         &methods::OR_FUN_CALL,
         &methods::RESULT_EXPECT_USED,
+        &methods::RESULT_MAP_OR_INTO_OPTION,
         &methods::RESULT_MAP_UNWRAP_OR_ELSE,
         &methods::RESULT_UNWRAP_USED,
         &methods::SEARCH_IS_SOME,
@@ -753,7 +760,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &regex::INVALID_REGEX,
         &regex::REGEX_MACRO,
         &regex::TRIVIAL_REGEX,
-        &replace_consts::REPLACE_CONSTS,
         &returns::LET_AND_RETURN,
         &returns::NEEDLESS_RETURN,
         &returns::UNUSED_UNIT,
@@ -806,6 +812,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &types::LET_UNIT_VALUE,
         &types::LINKEDLIST,
         &types::OPTION_OPTION,
+        &types::REDUNDANT_ALLOCATION,
         &types::TYPE_COMPLEXITY,
         &types::UNIT_ARG,
         &types::UNIT_CMP,
@@ -814,12 +821,20 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &unicode::NON_ASCII_LITERAL,
         &unicode::UNICODE_NOT_NFC,
         &unicode::ZERO_WIDTH_SPACE,
+        &unnamed_address::FN_ADDRESS_COMPARISONS,
+        &unnamed_address::VTABLE_ADDRESS_COMPARISONS,
         &unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME,
         &unused_io_amount::UNUSED_IO_AMOUNT,
         &unused_self::UNUSED_SELF,
         &unwrap::PANICKING_UNWRAP,
         &unwrap::UNNECESSARY_UNWRAP,
         &use_self::USE_SELF,
+        &utils::internal_lints::CLIPPY_LINTS_INTERNAL,
+        &utils::internal_lints::COMPILER_LINT_FUNCTIONS,
+        &utils::internal_lints::DEFAULT_LINT,
+        &utils::internal_lints::LINT_WITHOUT_LINT_PASS,
+        &utils::internal_lints::OUTER_EXPN_EXPN_DATA,
+        &utils::internal_lints::PRODUCE_ICE,
         &vec::USELESS_VEC,
         &verbose_file_reads::VERBOSE_FILE_READS,
         &wildcard_dependencies::WILDCARD_DEPENDENCIES,
@@ -951,7 +966,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|| box identity_conversion::IdentityConversion::default());
     store.register_late_pass(|| box types::ImplicitHasher);
     store.register_late_pass(|| box fallible_impl_from::FallibleImplFrom);
-    store.register_late_pass(|| box replace_consts::ReplaceConsts);
     store.register_late_pass(|| box types::UnitArg);
     store.register_late_pass(|| box double_comparison::DoubleComparisons);
     store.register_late_pass(|| box question_mark::QuestionMark);
@@ -1024,6 +1038,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_early_pass(|| box macro_use::MacroUseImports);
     store.register_late_pass(|| box verbose_file_reads::VerboseFileReads);
     store.register_late_pass(|| box redundant_pub_crate::RedundantPubCrate::default());
+    store.register_late_pass(|| box unnamed_address::UnnamedAddress);
 
     store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
         LintId::of(&arithmetic::FLOAT_ARITHMETIC),
@@ -1062,6 +1077,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&shadow::SHADOW_REUSE),
         LintId::of(&shadow::SHADOW_SAME),
         LintId::of(&strings::STRING_ADD),
+        LintId::of(&verbose_file_reads::VERBOSE_FILE_READS),
         LintId::of(&write::PRINT_STDOUT),
         LintId::of(&write::USE_DEBUG),
     ]);
@@ -1089,6 +1105,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&items_after_statements::ITEMS_AFTER_STATEMENTS),
         LintId::of(&large_stack_arrays::LARGE_STACK_ARRAYS),
         LintId::of(&literal_representation::LARGE_DIGIT_GROUPS),
+        LintId::of(&literal_representation::UNREADABLE_LITERAL),
         LintId::of(&loops::EXPLICIT_INTO_ITER_LOOP),
         LintId::of(&loops::EXPLICIT_ITER_LOOP),
         LintId::of(&macro_use::MACRO_USE_IMPORTS),
@@ -1096,6 +1113,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::FILTER_MAP),
         LintId::of(&methods::FILTER_MAP_NEXT),
         LintId::of(&methods::FIND_MAP),
+        LintId::of(&methods::INEFFICIENT_TO_STRING),
         LintId::of(&methods::MAP_FLATTEN),
         LintId::of(&methods::OPTION_MAP_UNWRAP_OR),
         LintId::of(&methods::OPTION_MAP_UNWRAP_OR_ELSE),
@@ -1107,17 +1125,20 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&needless_pass_by_value::NEEDLESS_PASS_BY_VALUE),
         LintId::of(&non_expressive_names::SIMILAR_NAMES),
         LintId::of(&ranges::RANGE_PLUS_ONE),
-        LintId::of(&replace_consts::REPLACE_CONSTS),
         LintId::of(&shadow::SHADOW_UNRELATED),
         LintId::of(&strings::STRING_ADD_ASSIGN),
         LintId::of(&trait_bounds::TYPE_REPETITION_IN_BOUNDS),
+        LintId::of(&trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF),
         LintId::of(&types::CAST_LOSSLESS),
         LintId::of(&types::CAST_POSSIBLE_TRUNCATION),
         LintId::of(&types::CAST_POSSIBLE_WRAP),
         LintId::of(&types::CAST_PRECISION_LOSS),
         LintId::of(&types::CAST_SIGN_LOSS),
+        LintId::of(&types::IMPLICIT_HASHER),
         LintId::of(&types::INVALID_UPCAST_COMPARISONS),
+        LintId::of(&types::LET_UNIT_VALUE),
         LintId::of(&types::LINKEDLIST),
+        LintId::of(&types::OPTION_OPTION),
         LintId::of(&unicode::NON_ASCII_LITERAL),
         LintId::of(&unicode::UNICODE_NOT_NFC),
         LintId::of(&unused_self::UNUSED_SELF),
@@ -1153,7 +1174,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&booleans::LOGIC_BUG),
         LintId::of(&booleans::NONMINIMAL_BOOL),
         LintId::of(&bytecount::NAIVE_BYTECOUNT),
-        LintId::of(&cognitive_complexity::COGNITIVE_COMPLEXITY),
         LintId::of(&collapsible_if::COLLAPSIBLE_IF),
         LintId::of(&comparison_chain::COMPARISON_CHAIN),
         LintId::of(&copies::IFS_SAME_COND),
@@ -1210,7 +1230,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&lifetimes::NEEDLESS_LIFETIMES),
         LintId::of(&literal_representation::INCONSISTENT_DIGIT_GROUPING),
         LintId::of(&literal_representation::MISTYPED_LITERAL_SUFFIXES),
-        LintId::of(&literal_representation::UNREADABLE_LITERAL),
         LintId::of(&loops::EMPTY_LOOP),
         LintId::of(&loops::EXPLICIT_COUNTER_LOOP),
         LintId::of(&loops::FOR_KV_MAP),
@@ -1250,7 +1269,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::EXPECT_FUN_CALL),
         LintId::of(&methods::FILTER_NEXT),
         LintId::of(&methods::FLAT_MAP_IDENTITY),
-        LintId::of(&methods::INEFFICIENT_TO_STRING),
         LintId::of(&methods::INTO_ITER_ON_REF),
         LintId::of(&methods::ITERATOR_STEP_BY_ZERO),
         LintId::of(&methods::ITER_CLONED_COLLECT),
@@ -1264,6 +1282,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::OPTION_AS_REF_DEREF),
         LintId::of(&methods::OPTION_MAP_OR_NONE),
         LintId::of(&methods::OR_FUN_CALL),
+        LintId::of(&methods::RESULT_MAP_OR_INTO_OPTION),
         LintId::of(&methods::SEARCH_IS_SOME),
         LintId::of(&methods::SHOULD_IMPLEMENT_TRAIT),
         LintId::of(&methods::SINGLE_CHAR_PATTERN),
@@ -1356,7 +1375,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&transmute::UNSOUND_COLLECTION_TRANSMUTE),
         LintId::of(&transmute::WRONG_TRANSMUTE),
         LintId::of(&transmuting_null::TRANSMUTING_NULL),
-        LintId::of(&trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF),
         LintId::of(&try_err::TRY_ERR),
         LintId::of(&types::ABSURD_EXTREME_COMPARISONS),
         LintId::of(&types::BORROWED_BOX),
@@ -1366,21 +1384,20 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&types::CHAR_LIT_AS_U8),
         LintId::of(&types::FN_TO_NUMERIC_CAST),
         LintId::of(&types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION),
-        LintId::of(&types::IMPLICIT_HASHER),
+        LintId::of(&types::REDUNDANT_ALLOCATION),
-        LintId::of(&types::LET_UNIT_VALUE),
-        LintId::of(&types::OPTION_OPTION),
         LintId::of(&types::TYPE_COMPLEXITY),
         LintId::of(&types::UNIT_ARG),
         LintId::of(&types::UNIT_CMP),
         LintId::of(&types::UNNECESSARY_CAST),
         LintId::of(&types::VEC_BOX),
         LintId::of(&unicode::ZERO_WIDTH_SPACE),
+        LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
+        LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
         LintId::of(&unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
         LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT),
         LintId::of(&unwrap::PANICKING_UNWRAP),
         LintId::of(&unwrap::UNNECESSARY_UNWRAP),
         LintId::of(&vec::USELESS_VEC),
-        LintId::of(&verbose_file_reads::VERBOSE_FILE_READS),
         LintId::of(&write::PRINTLN_EMPTY_STRING),
         LintId::of(&write::PRINT_LITERAL),
         LintId::of(&write::PRINT_WITH_NEWLINE),
@@ -1418,7 +1435,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&len_zero::LEN_ZERO),
         LintId::of(&let_if_seq::USELESS_LET_IF_SEQ),
         LintId::of(&literal_representation::INCONSISTENT_DIGIT_GROUPING),
-        LintId::of(&literal_representation::UNREADABLE_LITERAL),
         LintId::of(&loops::EMPTY_LOOP),
         LintId::of(&loops::FOR_KV_MAP),
         LintId::of(&loops::NEEDLESS_RANGE_LOOP),
@@ -1443,6 +1459,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::NEW_RET_NO_SELF),
         LintId::of(&methods::OK_EXPECT),
         LintId::of(&methods::OPTION_MAP_OR_NONE),
+        LintId::of(&methods::RESULT_MAP_OR_INTO_OPTION),
         LintId::of(&methods::SHOULD_IMPLEMENT_TRAIT),
         LintId::of(&methods::STRING_EXTEND_CHARS),
         LintId::of(&methods::UNNECESSARY_FOLD),
@@ -1478,8 +1495,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&try_err::TRY_ERR),
         LintId::of(&types::FN_TO_NUMERIC_CAST),
         LintId::of(&types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION),
-        LintId::of(&types::IMPLICIT_HASHER),
-        LintId::of(&types::LET_UNIT_VALUE),
         LintId::of(&unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
         LintId::of(&write::PRINTLN_EMPTY_STRING),
         LintId::of(&write::PRINT_LITERAL),
@@ -1493,7 +1508,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&assign_ops::MISREFACTORED_ASSIGN_OP),
         LintId::of(&attrs::DEPRECATED_CFG_ATTR),
         LintId::of(&booleans::NONMINIMAL_BOOL),
-        LintId::of(&cognitive_complexity::COGNITIVE_COMPLEXITY),
         LintId::of(&double_comparison::DOUBLE_COMPARISONS),
         LintId::of(&double_parens::DOUBLE_PARENS),
         LintId::of(&duration_subsec::DURATION_SUBSEC),
@@ -1557,13 +1571,11 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&transmute::TRANSMUTE_PTR_TO_REF),
         LintId::of(&types::BORROWED_BOX),
         LintId::of(&types::CHAR_LIT_AS_U8),
-        LintId::of(&types::OPTION_OPTION),
         LintId::of(&types::TYPE_COMPLEXITY),
         LintId::of(&types::UNIT_ARG),
         LintId::of(&types::UNNECESSARY_CAST),
         LintId::of(&types::VEC_BOX),
         LintId::of(&unwrap::UNNECESSARY_UNWRAP),
-        LintId::of(&verbose_file_reads::VERBOSE_FILE_READS),
         LintId::of(&zero_div_zero::ZERO_DIVIDED_BY_ZERO),
     ]);
 
@@ -1630,6 +1642,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&types::CAST_REF_TO_MUT),
         LintId::of(&types::UNIT_CMP),
         LintId::of(&unicode::ZERO_WIDTH_SPACE),
+        LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
+        LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
         LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT),
         LintId::of(&unwrap::PANICKING_UNWRAP),
     ]);
@@ -1642,7 +1656,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&loops::MANUAL_MEMCPY),
         LintId::of(&loops::NEEDLESS_COLLECT),
         LintId::of(&methods::EXPECT_FUN_CALL),
-        LintId::of(&methods::INEFFICIENT_TO_STRING),
         LintId::of(&methods::ITER_NTH),
         LintId::of(&methods::OR_FUN_CALL),
         LintId::of(&methods::SINGLE_CHAR_PATTERN),
@@ -1650,8 +1663,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&mutex_atomic::MUTEX_ATOMIC),
         LintId::of(&redundant_clone::REDUNDANT_CLONE),
         LintId::of(&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION),
-        LintId::of(&trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF),
         LintId::of(&types::BOX_VEC),
+        LintId::of(&types::REDUNDANT_ALLOCATION),
         LintId::of(&vec::USELESS_VEC),
     ]);
 
@@ -1663,6 +1676,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
 
     store.register_group(true, "clippy::nursery", Some("clippy_nursery"), vec![
         LintId::of(&attrs::EMPTY_LINE_AFTER_OUTER_ATTR),
+        LintId::of(&cognitive_complexity::COGNITIVE_COMPLEXITY),
         LintId::of(&fallible_impl_from::FALLIBLE_IMPL_FROM),
         LintId::of(&floating_point_arithmetic::IMPRECISE_FLOPS),
         LintId::of(&floating_point_arithmetic::SUBOPTIMAL_FLOPS),

clippy_lints/src/lifetimes.rs

@@ -1,5 +1,3 @@
-use rustc::hir::map::Map;
-use rustc::lint::in_external_macro;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::{
@@ -11,13 +9,14 @@ use rustc_hir::{
     ItemKind, Lifetime, LifetimeName, ParamName, QPath, TraitBoundModifier, TraitFn, TraitItem, TraitItemKind, Ty,
     TyKind, WhereClause, WherePredicate,
 };
-use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 use rustc_span::symbol::kw;
 
 use crate::reexport::Name;
-use crate::utils::{last_path_segment, span_lint, trait_ref_of_method};
+use crate::utils::{in_macro, last_path_segment, span_lint, trait_ref_of_method};
 
 declare_clippy_lint! {
     /// **What it does:** Checks for lifetime annotations which can be removed by
@@ -125,7 +124,7 @@ fn check_fn_inner<'a, 'tcx>(
     span: Span,
     report_extra_lifetimes: bool,
 ) {
-    if in_external_macro(cx.sess(), span) || has_where_lifetimes(cx, &generics.where_clause) {
+    if in_macro(span) || has_where_lifetimes(cx, &generics.where_clause) {
         return;
     }
 

clippy_lints/src/literal_representation.rs

@@ -7,10 +7,10 @@ use crate::utils::{
     snippet_opt, span_lint_and_sugg,
 };
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
 use rustc_errors::Applicability;
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
 
 declare_clippy_lint! {
@@ -27,7 +27,7 @@ declare_clippy_lint! {
     /// let x: u64 = 61864918973511;
     /// ```
     pub UNREADABLE_LITERAL,
-    style,
+    pedantic,
     "long integer literal without underscores"
 }
 
@@ -186,6 +186,9 @@ impl EarlyLintPass for LiteralDigitGrouping {
     }
 }
 
+// Length of each UUID hyphenated group in hex digits.
+const UUID_GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
+
 impl LiteralDigitGrouping {
     fn check_lit(cx: &EarlyContext<'_>, lit: &Lit) {
         if_chain! {
@@ -196,6 +199,10 @@ impl LiteralDigitGrouping {
                     return;
                 }
 
+                if Self::is_literal_uuid_formatted(&mut num_lit) {
+                    return;
+                }
+
                 let result = (|| {
 
                     let integral_group_size = Self::get_group_size(num_lit.integer.split('_'))?;
@@ -266,6 +273,28 @@ impl LiteralDigitGrouping {
         }
     }
 
+    /// Checks whether the numeric literal matches the formatting of a UUID.
+    ///
+    /// Returns `true` if the radix is hexadecimal, and the groups match the
+    /// UUID format of 8-4-4-4-12.
+    fn is_literal_uuid_formatted(num_lit: &mut NumericLiteral<'_>) -> bool {
+        if num_lit.radix != Radix::Hexadecimal {
+            return false;
+        }
+
+        // UUIDs should not have a fraction
+        if num_lit.fraction.is_some() {
+            return false;
+        }
+
+        let group_sizes: Vec<usize> = num_lit.integer.split('_').map(str::len).collect();
+        if UUID_GROUP_LENS.len() == group_sizes.len() {
+            UUID_GROUP_LENS.iter().zip(&group_sizes).all(|(&a, &b)| a == b)
+        } else {
+            false
+        }
+    }
+
     /// Given the sizes of the digit groups of both integral and fractional
     /// parts, and the length
     /// of both parts, determine if the digits have been grouped consistently.

clippy_lints/src/loops.rs

@@ -11,10 +11,6 @@ use crate::utils::{
 use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sext, sugg};
 use if_chain::if_chain;
 use itertools::Itertools;
-use rustc::hir::map::Map;
-use rustc::lint::in_external_macro;
-use rustc::middle::region;
-use rustc::ty::{self, Ty};
 use rustc_ast::ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::Applicability;
@@ -26,9 +22,13 @@ use rustc_hir::{
 };
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::middle::region;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
-use rustc_span::{BytePos, Symbol};
+use rustc_span::BytePos;
 use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, Place, PlaceBase};
 use std::iter::{once, Iterator};
 use std::mem;
@@ -654,7 +654,7 @@ fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult
 
 fn never_loop_block(block: &Block<'_>, main_loop_id: HirId) -> NeverLoopResult {
     let stmts = block.stmts.iter().map(stmt_to_expr);
-    let expr = once(block.expr.as_ref().map(|p| &**p));
+    let expr = once(block.expr.as_deref());
     let mut iter = stmts.chain(expr).filter_map(|e| e);
     never_loop_expr_seq(&mut iter, main_loop_id)
 }
@@ -662,7 +662,7 @@ fn never_loop_block(block: &Block<'_>, main_loop_id: HirId) -> NeverLoopResult {
 fn stmt_to_expr<'tcx>(stmt: &Stmt<'tcx>) -> Option<&'tcx Expr<'tcx>> {
     match stmt.kind {
         StmtKind::Semi(ref e, ..) | StmtKind::Expr(ref e, ..) => Some(e),
-        StmtKind::Local(ref local) => local.init.as_ref().map(|p| &**p),
+        StmtKind::Local(ref local) => local.init.as_deref(),
         _ => None,
     }
 }
@@ -720,7 +720,7 @@ fn never_loop_expr(expr: &Expr<'_>, main_loop_id: HirId) -> NeverLoopResult {
         ExprKind::Struct(_, _, None)
         | ExprKind::Yield(_, _)
         | ExprKind::Closure(_, _, _, _, _)
-        | ExprKind::InlineAsm(_)
+        | ExprKind::LlvmInlineAsm(_)
         | ExprKind::Path(_)
         | ExprKind::Lit(_)
         | ExprKind::Err => NeverLoopResult::Otherwise,
@@ -804,7 +804,7 @@ fn is_slice_like<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'_>) -> bool {
         _ => false,
     };
 
-    is_slice || is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type")) || match_type(cx, ty, &paths::VEC_DEQUE)
+    is_slice || is_type_diagnostic_item(cx, ty, sym!(vec_type)) || match_type(cx, ty, &paths::VEC_DEQUE)
 }
 
 fn get_fixed_offset_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> Option<FixedOffsetVar> {
@@ -922,7 +922,7 @@ fn get_indexed_assignments<'a, 'tcx>(
             .chain(expr.as_ref().into_iter().map(|e| Some(get_assignment(cx, &*e, var))))
             .filter_map(|op| op)
             .collect::<Option<Vec<_>>>()
-            .unwrap_or_else(|| vec![])
+            .unwrap_or_default()
     } else {
         get_assignment(cx, body, var).into_iter().collect()
     }
@@ -1392,7 +1392,7 @@ fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, e
 /// Checks for `for` loops over `Option`s and `Result`s.
 fn check_arg_type(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>) {
     let ty = cx.tables.expr_ty(arg);
-    if match_type(cx, ty, &paths::OPTION) {
+    if is_type_diagnostic_item(cx, ty, sym!(option_type)) {
         span_lint_and_help(
             cx,
             FOR_LOOP_OVER_OPTION,
@@ -1408,7 +1408,7 @@ fn check_arg_type(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>) {
                 snippet(cx, arg.span, "_")
             ),
         );
-    } else if match_type(cx, ty, &paths::RESULT) {
+    } else if is_type_diagnostic_item(cx, ty, sym!(result_type)) {
         span_lint_and_help(
             cx,
             FOR_LOOP_OVER_RESULT,
@@ -1955,7 +1955,7 @@ fn is_ref_iterable_type(cx: &LateContext<'_, '_>, e: &Expr<'_>) -> bool {
     // will allow further borrows afterwards
     let ty = cx.tables.expr_ty(e);
     is_iterable_array(ty, cx) ||
-    is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type")) ||
+    is_type_diagnostic_item(cx, ty, sym!(vec_type)) ||
     match_type(cx, ty, &paths::LINKED_LIST) ||
     match_type(cx, ty, &paths::HASHMAP) ||
     match_type(cx, ty, &paths::HASHSET) ||
@@ -2465,7 +2465,7 @@ fn check_needless_collect<'a, 'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'a, '
         if let Some(GenericArg::Type(ref ty)) = generic_args.args.get(0);
         then {
             let ty = cx.tables.node_type(ty.hir_id);
-            if is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type")) ||
+            if is_type_diagnostic_item(cx, ty, sym!(vec_type)) ||
                 match_type(cx, ty, &paths::VEC_DEQUE) ||
                 match_type(cx, ty, &paths::BTREEMAP) ||
                 match_type(cx, ty, &paths::HASHMAP) {

clippy_lints/src/map_clone.rs

@@ -1,13 +1,13 @@
 use crate::utils::paths;
 use crate::utils::{
-    is_copy, match_trait_method, match_type, remove_blocks, snippet_with_applicability, span_lint_and_sugg,
+    is_copy, is_type_diagnostic_item, match_trait_method, remove_blocks, snippet_with_applicability, span_lint_and_sugg,
 };
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_ast::ast::Ident;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 
@@ -52,7 +52,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
             if args.len() == 2;
             if method.ident.as_str() == "map";
             let ty = cx.tables.expr_ty(&args[0]);
-            if match_type(cx, ty, &paths::OPTION) || match_trait_method(cx, e, &paths::ITERATOR);
+            if is_type_diagnostic_item(cx, ty, sym!(option_type)) || match_trait_method(cx, e, &paths::ITERATOR);
             if let hir::ExprKind::Closure(_, _, body_id, _, _) = args[1].kind;
             let closure_body = cx.tcx.hir().body(body_id);
             let closure_expr = remove_blocks(&closure_body.value);

clippy_lints/src/map_unit_fn.rs

@@ -1,10 +1,9 @@
-use crate::utils::paths;
+use crate::utils::{is_type_diagnostic_item, iter_input_pats, method_chain_args, snippet, span_lint_and_then};
-use crate::utils::{iter_input_pats, match_type, method_chain_args, snippet, span_lint_and_then};
 use if_chain::if_chain;
-use rustc::ty::{self, Ty};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 
@@ -206,9 +205,9 @@ fn suggestion_msg(function_type: &str, map_type: &str) -> String {
 fn lint_map_unit_fn(cx: &LateContext<'_, '_>, stmt: &hir::Stmt<'_>, expr: &hir::Expr<'_>, map_args: &[hir::Expr<'_>]) {
     let var_arg = &map_args[0];
 
-    let (map_type, variant, lint) = if match_type(cx, cx.tables.expr_ty(var_arg), &paths::OPTION) {
+    let (map_type, variant, lint) = if is_type_diagnostic_item(cx, cx.tables.expr_ty(var_arg), sym!(option_type)) {
         ("Option", "Some", OPTION_MAP_UNIT_FN)
-    } else if match_type(cx, cx.tables.expr_ty(var_arg), &paths::RESULT) {
+    } else if is_type_diagnostic_item(cx, cx.tables.expr_ty(var_arg), sym!(result_type)) {
         ("Result", "Ok", RESULT_MAP_UNIT_FN)
     } else {
         return;

clippy_lints/src/matches.rs

@@ -3,22 +3,22 @@ use crate::utils::paths;
 use crate::utils::sugg::Sugg;
 use crate::utils::usage::is_unused;
 use crate::utils::{
-    expr_block, get_arg_name, get_parent_expr, in_macro, indent_of, is_allowed, is_expn_of, is_refutable, is_wild,
+    expr_block, get_arg_name, get_parent_expr, in_macro, indent_of, is_allowed, is_expn_of, is_refutable,
-    match_qpath, match_type, match_var, multispan_sugg, remove_blocks, snippet, snippet_block,
+    is_type_diagnostic_item, is_wild, match_qpath, match_type, match_var, multispan_sugg, remove_blocks, snippet,
-    snippet_with_applicability, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then,
+    snippet_block, snippet_with_applicability, span_lint_and_help, span_lint_and_note, span_lint_and_sugg,
-    walk_ptrs_ty,
+    span_lint_and_then, walk_ptrs_ty,
 };
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
-use rustc::ty::{self, Ty};
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::def::CtorKind;
 use rustc_hir::{
-    print, Arm, BindingAnnotation, Block, BorrowKind, Expr, ExprKind, Local, MatchSource, Mutability, Node, Pat,
+    Arm, BindingAnnotation, Block, BorrowKind, Expr, ExprKind, Local, MatchSource, Mutability, Node, Pat, PatKind,
-    PatKind, QPath, RangeEnd,
+    QPath, RangeEnd,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 use std::cmp::Ordering;
@@ -447,6 +447,11 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Matches {
 #[rustfmt::skip]
 fn check_single_match(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
     if arms.len() == 2 && arms[0].guard.is_none() && arms[1].guard.is_none() {
+        if in_macro(expr.span) {
+            // Don't lint match expressions present in
+            // macro_rules! block
+            return;
+        }
         if let PatKind::Or(..) = arms[0].pat.kind {
             // don't lint for or patterns for now, this makes
             // the lint noisy in unnecessary situations
@@ -536,10 +541,12 @@ fn check_single_match_opt_like(
             if !inner.iter().all(is_wild) {
                 return;
             }
-            print::to_string(print::NO_ANN, |s| s.print_qpath(path, false))
+            rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false))
         },
         PatKind::Binding(BindingAnnotation::Unannotated, .., ident, None) => ident.to_string(),
-        PatKind::Path(ref path) => print::to_string(print::NO_ANN, |s| s.print_qpath(path, false)),
+        PatKind::Path(ref path) => {
+            rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false))
+        },
         _ => return,
     };
 
@@ -635,10 +642,10 @@ fn check_overlapping_arms<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ex: &'tcx Expr<'
 
 fn check_wild_err_arm(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>]) {
     let ex_ty = walk_ptrs_ty(cx.tables.expr_ty(ex));
-    if match_type(cx, ex_ty, &paths::RESULT) {
+    if is_type_diagnostic_item(cx, ex_ty, sym!(result_type)) {
         for arm in arms {
             if let PatKind::TupleStruct(ref path, ref inner, _) = arm.pat.kind {
-                let path_str = print::to_string(print::NO_ANN, |s| s.print_qpath(path, false));
+                let path_str = rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false));
                 if path_str == "Err" {
                     let mut matching_wild = inner.iter().any(is_wild);
                     let mut ident_bind_name = String::from("_");
@@ -1190,3 +1197,40 @@ where
 
     None
 }
+
+#[test]
+fn test_overlapping() {
+    use rustc_span::source_map::DUMMY_SP;
+
+    let sp = |s, e| SpannedRange {
+        span: DUMMY_SP,
+        node: (s, e),
+    };
+
+    assert_eq!(None, overlapping::<u8>(&[]));
+    assert_eq!(None, overlapping(&[sp(1, Bound::Included(4))]));
+    assert_eq!(
+        None,
+        overlapping(&[sp(1, Bound::Included(4)), sp(5, Bound::Included(6))])
+    );
+    assert_eq!(
+        None,
+        overlapping(&[
+            sp(1, Bound::Included(4)),
+            sp(5, Bound::Included(6)),
+            sp(10, Bound::Included(11))
+        ],)
+    );
+    assert_eq!(
+        Some((&sp(1, Bound::Included(4)), &sp(3, Bound::Included(6)))),
+        overlapping(&[sp(1, Bound::Included(4)), sp(3, Bound::Included(6))])
+    );
+    assert_eq!(
+        Some((&sp(5, Bound::Included(6)), &sp(6, Bound::Included(11)))),
+        overlapping(&[
+            sp(1, Bound::Included(4)),
+            sp(5, Bound::Included(6)),
+            sp(6, Bound::Included(11))
+        ],)
+    );
+}

clippy_lints/src/mem_replace.rs

@@ -3,12 +3,13 @@ use crate::utils::{
     span_lint_and_sugg, span_lint_and_then,
 };
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_errors::Applicability;
 use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, QPath};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
+use rustc_span::symbol::sym;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for `mem::replace()` on an `Option` with
@@ -141,7 +142,7 @@ fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, expr_span
             if let ExprKind::Path(ref repl_func_qpath) = repl_func.kind;
             if let Some(repl_def_id) = cx.tables.qpath_res(repl_func_qpath, repl_func.hir_id).opt_def_id();
             then {
-                if match_def_path(cx, repl_def_id, &paths::MEM_UNINITIALIZED) {
+                if cx.tcx.is_diagnostic_item(sym::mem_uninitialized, repl_def_id) {
                     span_lint_and_help(
                         cx,
                         MEM_REPLACE_WITH_UNINIT,
@@ -149,7 +150,7 @@ fn check_replace_with_uninit(cx: &LateContext<'_, '_>, src: &Expr<'_>, expr_span
                         "replacing with `mem::uninitialized()`",
                         "consider using the `take_mut` crate instead",
                     );
-                } else if match_def_path(cx, repl_def_id, &paths::MEM_ZEROED) &&
+                } else if cx.tcx.is_diagnostic_item(sym::mem_zeroed, repl_def_id) &&
                         !cx.tables.expr_ty(src).is_primitive() {
                     span_lint_and_help(
                         cx,

clippy_lints/src/methods/inefficient_to_string.rs

@@ -1,10 +1,10 @@
 use super::INEFFICIENT_TO_STRING;
 use crate::utils::{match_def_path, paths, snippet_with_applicability, span_lint_and_then, walk_ptrs_ty_depth};
 use if_chain::if_chain;
-use rustc::ty::{self, Ty};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
+use rustc_middle::ty::{self, Ty};
 
 /// Checks for the `INEFFICIENT_TO_STRING` lint
 pub fn lint<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>, arg_ty: Ty<'tcx>) {

clippy_lints/src/methods/mod.rs

@@ -8,17 +8,18 @@ use std::fmt;
 use std::iter;
 
 use if_chain::if_chain;
-use rustc::hir::map::Map;
-use rustc::lint::in_external_macro;
-use rustc::ty::{self, Predicate, Ty};
 use rustc_ast::ast;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_lint::{LateContext, LateLintPass, Lint, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::subst::GenericArgKind;
+use rustc_middle::ty::{self, Predicate, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
-use rustc_span::symbol::{sym, Symbol, SymbolStr};
+use rustc_span::symbol::{sym, SymbolStr};
 
 use crate::consts::{constant, Constant};
 use crate::utils::usage::mutated_variables;
@@ -330,6 +331,32 @@ declare_clippy_lint! {
     "using `Option.map_or(None, f)`, which is more succinctly expressed as `and_then(f)`"
 }
 
+declare_clippy_lint! {
+    /// **What it does:** Checks for usage of `_.map_or(None, Some)`.
+    ///
+    /// **Why is this bad?** Readability, this can be written more concisely as
+    /// `_.ok()`.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    ///
+    /// Bad:
+    /// ```rust
+    /// # let r: Result<u32, &str> = Ok(1);
+    /// assert_eq!(Some(1), r.map_or(None, Some));
+    /// ```
+    ///
+    /// Good:
+    /// ```rust
+    /// # let r: Result<u32, &str> = Ok(1);
+    /// assert_eq!(Some(1), r.ok());
+    /// ```
+    pub RESULT_MAP_OR_INTO_OPTION,
+    style,
+    "using `Result.map_or(None, Some)`, which is more succinctly expressed as `ok()`"
+}
+
 declare_clippy_lint! {
     /// **What it does:** Checks for usage of `_.and_then(|x| Some(y))`.
     ///
@@ -698,12 +725,12 @@ declare_clippy_lint! {
     /// ["foo", "bar"].iter().map(|&s| s.to_string());
     /// ```
     pub INEFFICIENT_TO_STRING,
-    perf,
+    pedantic,
     "using `to_string` on `&&T` where `T: ToString`"
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for `new` not returning `Self`.
+    /// **What it does:** Checks for `new` not returning a type that contains `Self`.
     ///
     /// **Why is this bad?** As a convention, `new` methods are used to make a new
     /// instance of a type.
@@ -720,9 +747,31 @@ declare_clippy_lint! {
     ///     }
     /// }
     /// ```
+    ///
+    /// ```rust
+    /// # struct Foo;
+    /// # struct FooError;
+    /// impl Foo {
+    ///     // Good. Return type contains `Self`
+    ///     fn new() -> Result<Foo, FooError> {
+    ///         # Ok(Foo)
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// ```rust
+    /// # struct Foo;
+    /// struct Bar(Foo);
+    /// impl Foo {
+    ///     // Bad. The type name must contain `Self`.
+    ///     fn new() -> Bar {
+    ///         # Bar(Foo)
+    ///     }
+    /// }
+    /// ```
     pub NEW_RET_NO_SELF,
     style,
-    "not returning `Self` in a `new` method"
+    "not returning type containing `Self` in a `new` method"
 }
 
 declare_clippy_lint! {
@@ -1137,8 +1186,8 @@ declare_clippy_lint! {
     /// ```rust
     /// # let y: u32 = 0;
     /// # let x: u32 = 100;
-    /// let add = x.checked_add(y).unwrap_or(u32::max_value());
+    /// let add = x.checked_add(y).unwrap_or(u32::MAX);
-    /// let sub = x.checked_sub(y).unwrap_or(u32::min_value());
+    /// let sub = x.checked_sub(y).unwrap_or(u32::MIN);
     /// ```
     ///
     /// can be written using dedicated methods for saturating addition/subtraction as:
@@ -1248,6 +1297,7 @@ declare_lint_pass!(Methods => [
     OPTION_MAP_UNWRAP_OR,
     OPTION_MAP_UNWRAP_OR_ELSE,
     RESULT_MAP_UNWRAP_OR_ELSE,
+    RESULT_MAP_OR_INTO_OPTION,
     OPTION_MAP_OR_NONE,
     OPTION_AND_THEN_SOME,
     OR_FUN_CALL,
@@ -1289,7 +1339,7 @@ declare_lint_pass!(Methods => [
 ]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
-    #[allow(clippy::cognitive_complexity, clippy::too_many_lines)]
+    #[allow(clippy::too_many_lines)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
         if in_macro(expr.span) {
             return;
@@ -1407,7 +1457,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
         let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id);
         let item = cx.tcx.hir().expect_item(parent);
         let def_id = cx.tcx.hir().local_def_id(item.hir_id);
-        let ty = cx.tcx.type_of(def_id);
+        let self_ty = cx.tcx.type_of(def_id);
         if_chain! {
             if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind;
             if let Some(first_arg) = iter_input_pats(&sig.decl, cx.tcx.hir().body(id)).next();
@@ -1425,11 +1475,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
             then {
                 if cx.access_levels.is_exported(impl_item.hir_id) {
                 // check missing trait implementations
-                    for &(method_name, n_args, self_kind, out_type, trait_name) in &TRAIT_METHODS {
+                    for &(method_name, n_args, fn_header, self_kind, out_type, trait_name) in &TRAIT_METHODS {
                         if name == method_name &&
-                        sig.decl.inputs.len() == n_args &&
+                            sig.decl.inputs.len() == n_args &&
-                        out_type.matches(cx, &sig.decl.output) &&
+                            out_type.matches(cx, &sig.decl.output) &&
-                        self_kind.matches(cx, ty, first_arg_ty) {
+                            self_kind.matches(cx, self_ty, first_arg_ty) &&
+                            fn_header_equals(*fn_header, sig.header) {
                             span_lint(cx, SHOULD_IMPLEMENT_TRAIT, impl_item.span, &format!(
                                 "defining a method called `{}` on this type; consider implementing \
                                 the `{}` trait or choosing a less ambiguous name", name, trait_name));
@@ -1441,7 +1492,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
                     .iter()
                     .find(|(ref conv, _)| conv.check(&name))
                 {
-                    if !self_kinds.iter().any(|k| k.matches(cx, ty, first_arg_ty)) {
+                    if !self_kinds.iter().any(|k| k.matches(cx, self_ty, first_arg_ty)) {
                         let lint = if item.vis.node.is_pub() {
                             WRONG_PUB_SELF_CONVENTION
                         } else {
@@ -1471,8 +1522,16 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
         if let hir::ImplItemKind::Fn(_, _) = impl_item.kind {
             let ret_ty = return_ty(cx, impl_item.hir_id);
 
+            let contains_self_ty = |ty: Ty<'tcx>| {
+                ty.walk().any(|inner| match inner.unpack() {
+                    GenericArgKind::Type(inner_ty) => same_tys(cx, self_ty, inner_ty),
+
+                    GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
+                })
+            };
+
             // walk the return type and check for Self (this does not check associated types)
-            if ret_ty.walk().any(|inner_type| same_tys(cx, ty, inner_type)) {
+            if contains_self_ty(ret_ty) {
                 return;
             }
 
@@ -1486,10 +1545,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
                             let associated_type = binder.skip_binder();
 
                             // walk the associated type and check for Self
-                            for inner_type in associated_type.walk() {
+                            if contains_self_ty(associated_type) {
-                                if same_tys(cx, ty, inner_type) {
+                                return;
-                                    return;
-                                }
                             }
                         },
                         (_, _) => {},
@@ -1497,7 +1554,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
                 }
             }
 
-            if name == "new" && !same_tys(cx, ret_ty, ty) {
+            if name == "new" && !same_tys(cx, ret_ty, self_ty) {
                 span_lint(
                     cx,
                     NEW_RET_NO_SELF,
@@ -1801,9 +1858,9 @@ fn lint_expect_fun_call(
     }
 
     let receiver_type = cx.tables.expr_ty_adjusted(&args[0]);
-    let closure_args = if match_type(cx, receiver_type, &paths::OPTION) {
+    let closure_args = if is_type_diagnostic_item(cx, receiver_type, sym!(option_type)) {
         "||"
-    } else if match_type(cx, receiver_type, &paths::RESULT) {
+    } else if is_type_diagnostic_item(cx, receiver_type, sym!(result_type)) {
         "|_|"
     } else {
         return;
@@ -1912,9 +1969,10 @@ fn lint_clone_on_copy(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, arg: &hir:
             match &cx.tcx.hir().get(parent) {
                 hir::Node::Expr(parent) => match parent.kind {
                     // &*x is a nop, &x.clone() is not
-                    hir::ExprKind::AddrOf(..) |
+                    hir::ExprKind::AddrOf(..) => return,
                     // (*x).func() is useless, x.clone().func() can work in case func borrows mutably
-                    hir::ExprKind::MethodCall(..) => return,
+                    hir::ExprKind::MethodCall(_, _, parent_args) if expr.hir_id == parent_args[0].hir_id => return,
+
                     _ => {},
                 },
                 hir::Node::Stmt(stmt) => {
@@ -1962,9 +2020,9 @@ fn lint_clone_on_ref_ptr(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, arg: &h
     let obj_ty = walk_ptrs_ty(cx.tables.expr_ty(arg));
 
     if let ty::Adt(_, subst) = obj_ty.kind {
-        let caller_type = if match_type(cx, obj_ty, &paths::RC) {
+        let caller_type = if is_type_diagnostic_item(cx, obj_ty, sym::Rc) {
             "Rc"
-        } else if match_type(cx, obj_ty, &paths::ARC) {
+        } else if is_type_diagnostic_item(cx, obj_ty, sym::Arc) {
             "Arc"
         } else if match_type(cx, obj_ty, &paths::WEAK_RC) || match_type(cx, obj_ty, &paths::WEAK_ARC) {
             "Weak"
@@ -2031,7 +2089,7 @@ fn lint_cstring_as_ptr(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, source: &
     if_chain! {
         let source_type = cx.tables.expr_ty(source);
         if let ty::Adt(def, substs) = source_type.kind;
-        if match_def_path(cx, def.did, &paths::RESULT);
+        if cx.tcx.is_diagnostic_item(sym!(result_type), def.did);
         if match_type(cx, substs.type_at(0), &paths::CSTRING);
         then {
             span_lint_and_then(
@@ -2053,7 +2111,7 @@ fn lint_iter_cloned_collect<'a, 'tcx>(
     iter_args: &'tcx [hir::Expr<'_>],
 ) {
     if_chain! {
-        if is_type_diagnostic_item(cx, cx.tables.expr_ty(expr), Symbol::intern("vec_type"));
+        if is_type_diagnostic_item(cx, cx.tables.expr_ty(expr), sym!(vec_type));
         if let Some(slice) = derefs_to_slice(cx, &iter_args[0], cx.tables.expr_ty(&iter_args[0]));
         if let Some(to_replace) = expr.span.trim_start(slice.span.source_callsite());
 
@@ -2182,7 +2240,7 @@ fn lint_iter_nth<'a, 'tcx>(
     let mut_str = if is_mut { "_mut" } else { "" };
     let caller_type = if derefs_to_slice(cx, &iter_args[0], cx.tables.expr_ty(&iter_args[0])).is_some() {
         "slice"
-    } else if is_type_diagnostic_item(cx, cx.tables.expr_ty(&iter_args[0]), Symbol::intern("vec_type")) {
+    } else if is_type_diagnostic_item(cx, cx.tables.expr_ty(&iter_args[0]), sym!(vec_type)) {
         "Vec"
     } else if match_type(cx, cx.tables.expr_ty(&iter_args[0]), &paths::VEC_DEQUE) {
         "VecDeque"
@@ -2239,7 +2297,7 @@ fn lint_get_unwrap<'a, 'tcx>(
     let caller_type = if derefs_to_slice(cx, &get_args[0], expr_ty).is_some() {
         needs_ref = get_args_str.parse::<usize>().is_ok();
         "slice"
-    } else if is_type_diagnostic_item(cx, expr_ty, Symbol::intern("vec_type")) {
+    } else if is_type_diagnostic_item(cx, expr_ty, sym!(vec_type)) {
         needs_ref = get_args_str.parse::<usize>().is_ok();
         "Vec"
     } else if match_type(cx, expr_ty, &paths::VEC_DEQUE) {
@@ -2320,7 +2378,7 @@ fn derefs_to_slice<'a, 'tcx>(
         match ty.kind {
             ty::Slice(_) => true,
             ty::Adt(def, _) if def.is_box() => may_slice(cx, ty.boxed_ty()),
-            ty::Adt(..) => is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type")),
+            ty::Adt(..) => is_type_diagnostic_item(cx, ty, sym!(vec_type)),
             ty::Array(_, size) => {
                 if let Some(size) = size.try_eval_usize(cx.tcx, cx.param_env) {
                     size < 32
@@ -2359,9 +2417,9 @@ fn derefs_to_slice<'a, 'tcx>(
 fn lint_unwrap(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, unwrap_args: &[hir::Expr<'_>]) {
     let obj_ty = walk_ptrs_ty(cx.tables.expr_ty(&unwrap_args[0]));
 
-    let mess = if match_type(cx, obj_ty, &paths::OPTION) {
+    let mess = if is_type_diagnostic_item(cx, obj_ty, sym!(option_type)) {
         Some((OPTION_UNWRAP_USED, "an Option", "None"))
-    } else if match_type(cx, obj_ty, &paths::RESULT) {
+    } else if is_type_diagnostic_item(cx, obj_ty, sym!(result_type)) {
         Some((RESULT_UNWRAP_USED, "a Result", "Err"))
     } else {
         None
@@ -2386,9 +2444,9 @@ fn lint_unwrap(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, unwrap_args: &[hi
 fn lint_expect(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, expect_args: &[hir::Expr<'_>]) {
     let obj_ty = walk_ptrs_ty(cx.tables.expr_ty(&expect_args[0]));
 
-    let mess = if match_type(cx, obj_ty, &paths::OPTION) {
+    let mess = if is_type_diagnostic_item(cx, obj_ty, sym!(option_type)) {
         Some((OPTION_EXPECT_USED, "an Option", "None"))
-    } else if match_type(cx, obj_ty, &paths::RESULT) {
+    } else if is_type_diagnostic_item(cx, obj_ty, sym!(result_type)) {
         Some((RESULT_EXPECT_USED, "a Result", "Err"))
     } else {
         None
@@ -2409,7 +2467,7 @@ fn lint_expect(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, expect_args: &[hi
 fn lint_ok_expect(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, ok_args: &[hir::Expr<'_>]) {
     if_chain! {
         // lint if the caller of `ok()` is a `Result`
-        if match_type(cx, cx.tables.expr_ty(&ok_args[0]), &paths::RESULT);
+        if is_type_diagnostic_item(cx, cx.tables.expr_ty(&ok_args[0]), sym!(result_type));
         let result_type = cx.tables.expr_ty(&ok_args[0]);
         if let Some(error_type) = get_error_type(cx, result_type);
         if has_debug_impl(error_type, cx);
@@ -2455,8 +2513,8 @@ fn lint_map_unwrap_or_else<'a, 'tcx>(
     unwrap_args: &'tcx [hir::Expr<'_>],
 ) {
     // lint if the caller of `map()` is an `Option`
-    let is_option = match_type(cx, cx.tables.expr_ty(&map_args[0]), &paths::OPTION);
+    let is_option = is_type_diagnostic_item(cx, cx.tables.expr_ty(&map_args[0]), sym!(option_type));
-    let is_result = match_type(cx, cx.tables.expr_ty(&map_args[0]), &paths::RESULT);
+    let is_result = is_type_diagnostic_item(cx, cx.tables.expr_ty(&map_args[0]), sym!(result_type));
 
     if is_option || is_result {
         // Don't make a suggestion that may fail to compile due to mutably borrowing
@@ -2517,38 +2575,78 @@ fn lint_map_unwrap_or_else<'a, 'tcx>(
     }
 }
 
-/// lint use of `_.map_or(None, _)` for `Option`s
+/// lint use of `_.map_or(None, _)` for `Option`s and `Result`s
 fn lint_map_or_none<'a, 'tcx>(
     cx: &LateContext<'a, 'tcx>,
     expr: &'tcx hir::Expr<'_>,
     map_or_args: &'tcx [hir::Expr<'_>],
 ) {
-    if match_type(cx, cx.tables.expr_ty(&map_or_args[0]), &paths::OPTION) {
+    let is_option = is_type_diagnostic_item(cx, cx.tables.expr_ty(&map_or_args[0]), sym!(option_type));
-        // check if the first non-self argument to map_or() is None
+    let is_result = is_type_diagnostic_item(cx, cx.tables.expr_ty(&map_or_args[0]), sym!(result_type));
-        let map_or_arg_is_none = if let hir::ExprKind::Path(ref qpath) = map_or_args[1].kind {
+
+    // There are two variants of this `map_or` lint:
+    // (1) using `map_or` as an adapter from `Result<T,E>` to `Option<T>`
+    // (2) using `map_or` as a combinator instead of `and_then`
+    //
+    // (For this lint) we don't care if any other type calls `map_or`
+    if !is_option && !is_result {
+        return;
+    }
+
+    let (lint_name, msg, instead, hint) = {
+        let default_arg_is_none = if let hir::ExprKind::Path(ref qpath) = map_or_args[1].kind {
             match_qpath(qpath, &paths::OPTION_NONE)
+        } else {
+            return;
+        };
+
+        if !default_arg_is_none {
+            // nothing to lint!
+            return;
+        }
+
+        let f_arg_is_some = if let hir::ExprKind::Path(ref qpath) = map_or_args[2].kind {
+            match_qpath(qpath, &paths::OPTION_SOME)
         } else {
             false
         };
 
-        if map_or_arg_is_none {
+        if is_option {
-            // lint message
+            let self_snippet = snippet(cx, map_or_args[0].span, "..");
+            let func_snippet = snippet(cx, map_or_args[2].span, "..");
             let msg = "called `map_or(None, f)` on an `Option` value. This can be done more directly by calling \
                        `and_then(f)` instead";
-            let map_or_self_snippet = snippet(cx, map_or_args[0].span, "..");
+            (
-            let map_or_func_snippet = snippet(cx, map_or_args[2].span, "..");
-            let hint = format!("{0}.and_then({1})", map_or_self_snippet, map_or_func_snippet);
-            span_lint_and_sugg(
-                cx,
                 OPTION_MAP_OR_NONE,
-                expr.span,
                 msg,
                 "try using `and_then` instead",
-                hint,
+                format!("{0}.and_then({1})", self_snippet, func_snippet),
-                Applicability::MachineApplicable,
+            )
-            );
+        } else if f_arg_is_some {
+            let msg = "called `map_or(None, Some)` on a `Result` value. This can be done more directly by calling \
+                       `ok()` instead";
+            let self_snippet = snippet(cx, map_or_args[0].span, "..");
+            (
+                RESULT_MAP_OR_INTO_OPTION,
+                msg,
+                "try using `ok` instead",
+                format!("{0}.ok()", self_snippet),
+            )
+        } else {
+            // nothing to lint!
+            return;
         }
-    }
+    };
+
+    span_lint_and_sugg(
+        cx,
+        lint_name,
+        expr.span,
+        msg,
+        instead,
+        hint,
+        Applicability::MachineApplicable,
+    );
 }
 
 /// Lint use of `_.and_then(|x| Some(y))` for `Option`s
@@ -3133,10 +3231,7 @@ fn is_maybe_uninit_ty_valid(cx: &LateContext<'_, '_>, ty: Ty<'_>) -> bool {
     match ty.kind {
         ty::Array(ref component, _) => is_maybe_uninit_ty_valid(cx, component),
         ty::Tuple(ref types) => types.types().all(|ty| is_maybe_uninit_ty_valid(cx, ty)),
-        ty::Adt(ref adt, _) => {
+        ty::Adt(ref adt, _) => match_def_path(cx, adt.did, &paths::MEM_MAYBEUNINIT),
-            // needs to be a MaybeUninit
-            match_def_path(cx, adt.did, &paths::MEM_MAYBEUNINIT)
-        },
         _ => false,
     }
 }
@@ -3159,6 +3254,8 @@ fn lint_option_as_ref_deref<'a, 'tcx>(
     map_args: &[hir::Expr<'_>],
     is_mut: bool,
 ) {
+    let same_mutability = |m| (is_mut && m == &hir::Mutability::Mut) || (!is_mut && m == &hir::Mutability::Not);
+
     let option_ty = cx.tables.expr_ty(&as_ref_args[0]);
     if !match_type(cx, option_ty, &paths::OPTION) {
         return;
@@ -3181,39 +3278,56 @@ fn lint_option_as_ref_deref<'a, 'tcx>(
         hir::ExprKind::Closure(_, _, body_id, _, _) => {
             let closure_body = cx.tcx.hir().body(body_id);
             let closure_expr = remove_blocks(&closure_body.value);
-            if_chain! {
+
-                if let hir::ExprKind::MethodCall(_, _, args) = &closure_expr.kind;
+            match &closure_expr.kind {
-                if args.len() == 1;
+                hir::ExprKind::MethodCall(_, _, args) => {
-                if let hir::ExprKind::Path(qpath) = &args[0].kind;
+                    if_chain! {
-                if let hir::def::Res::Local(local_id) = cx.tables.qpath_res(qpath, args[0].hir_id);
+                        if args.len() == 1;
-                if closure_body.params[0].pat.hir_id == local_id;
+                        if let hir::ExprKind::Path(qpath) = &args[0].kind;
-                let adj = cx.tables.expr_adjustments(&args[0]).iter().map(|x| &x.kind).collect::<Box<[_]>>();
+                        if let hir::def::Res::Local(local_id) = cx.tables.qpath_res(qpath, args[0].hir_id);
-                if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj;
+                        if closure_body.params[0].pat.hir_id == local_id;
-                then {
+                        let adj = cx.tables.expr_adjustments(&args[0]).iter().map(|x| &x.kind).collect::<Box<[_]>>();
-                    let method_did = cx.tables.type_dependent_def_id(closure_expr.hir_id).unwrap();
+                        if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj;
-                    deref_aliases.iter().any(|path| match_def_path(cx, method_did, path))
+                        then {
-                } else {
+                            let method_did = cx.tables.type_dependent_def_id(closure_expr.hir_id).unwrap();
-                    false
+                            deref_aliases.iter().any(|path| match_def_path(cx, method_did, path))
-                }
+                        } else {
+                            false
+                        }
+                    }
+                },
+                hir::ExprKind::AddrOf(hir::BorrowKind::Ref, m, ref inner) if same_mutability(m) => {
+                    if_chain! {
+                        if let hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner1) = inner.kind;
+                        if let hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner2) = inner1.kind;
+                        if let hir::ExprKind::Path(ref qpath) = inner2.kind;
+                        if let hir::def::Res::Local(local_id) = cx.tables.qpath_res(qpath, inner2.hir_id);
+                        then {
+                            closure_body.params[0].pat.hir_id == local_id
+                        } else {
+                            false
+                        }
+                    }
+                },
+                _ => false,
             }
         },
-
         _ => false,
     };
 
     if is_deref {
         let current_method = if is_mut {
-            ".as_mut().map(DerefMut::deref_mut)"
+            format!(".as_mut().map({})", snippet(cx, map_args[1].span, ".."))
         } else {
-            ".as_ref().map(Deref::deref)"
+            format!(".as_ref().map({})", snippet(cx, map_args[1].span, ".."))
         };
         let method_hint = if is_mut { "as_deref_mut" } else { "as_deref" };
         let hint = format!("{}.{}()", snippet(cx, as_ref_args[0].span, ".."), method_hint);
         let suggestion = format!("try using {} instead", method_hint);
 
         let msg = format!(
-            "called `{0}` (or with one of deref aliases) on an Option value. \
+            "called `{0}` on an Option value. This can be done more directly \
-             This can be done more directly by calling `{1}` instead",
+            by calling `{1}` instead",
             current_method, hint
         );
         span_lint_and_sugg(
@@ -3231,7 +3345,7 @@ fn lint_option_as_ref_deref<'a, 'tcx>(
 /// Given a `Result<T, E>` type, return its error type (`E`).
 fn get_error_type<'a>(cx: &LateContext<'_, '_>, ty: Ty<'a>) -> Option<Ty<'a>> {
     match ty.kind {
-        ty::Adt(_, substs) if match_type(cx, ty, &paths::RESULT) => substs.types().nth(1),
+        ty::Adt(_, substs) if is_type_diagnostic_item(cx, ty, sym!(result_type)) => substs.types().nth(1),
         _ => None,
     }
 }
@@ -3259,38 +3373,45 @@ const CONVENTIONS: [(Convention, &[SelfKind]); 7] = [
     (Convention::StartsWith("to_"), &[SelfKind::Ref]),
 ];
 
+const FN_HEADER: hir::FnHeader = hir::FnHeader {
+    unsafety: hir::Unsafety::Normal,
+    constness: hir::Constness::NotConst,
+    asyncness: hir::IsAsync::NotAsync,
+    abi: rustc_target::spec::abi::Abi::Rust,
+};
+
 #[rustfmt::skip]
-const TRAIT_METHODS: [(&str, usize, SelfKind, OutType, &str); 30] = [
+const TRAIT_METHODS: [(&str, usize, &hir::FnHeader, SelfKind, OutType, &str); 30] = [
-    ("add", 2, SelfKind::Value, OutType::Any, "std::ops::Add"),
+    ("add", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Add"),
-    ("as_mut", 1, SelfKind::RefMut, OutType::Ref, "std::convert::AsMut"),
+    ("as_mut", 1, &FN_HEADER, SelfKind::RefMut, OutType::Ref, "std::convert::AsMut"),
-    ("as_ref", 1, SelfKind::Ref, OutType::Ref, "std::convert::AsRef"),
+    ("as_ref", 1, &FN_HEADER, SelfKind::Ref, OutType::Ref, "std::convert::AsRef"),
-    ("bitand", 2, SelfKind::Value, OutType::Any, "std::ops::BitAnd"),
+    ("bitand", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::BitAnd"),
-    ("bitor", 2, SelfKind::Value, OutType::Any, "std::ops::BitOr"),
+    ("bitor", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::BitOr"),
-    ("bitxor", 2, SelfKind::Value, OutType::Any, "std::ops::BitXor"),
+    ("bitxor", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::BitXor"),
-    ("borrow", 1, SelfKind::Ref, OutType::Ref, "std::borrow::Borrow"),
+    ("borrow", 1, &FN_HEADER, SelfKind::Ref, OutType::Ref, "std::borrow::Borrow"),
-    ("borrow_mut", 1, SelfKind::RefMut, OutType::Ref, "std::borrow::BorrowMut"),
+    ("borrow_mut", 1, &FN_HEADER, SelfKind::RefMut, OutType::Ref, "std::borrow::BorrowMut"),
-    ("clone", 1, SelfKind::Ref, OutType::Any, "std::clone::Clone"),
+    ("clone", 1, &FN_HEADER, SelfKind::Ref, OutType::Any, "std::clone::Clone"),
-    ("cmp", 2, SelfKind::Ref, OutType::Any, "std::cmp::Ord"),
+    ("cmp", 2, &FN_HEADER, SelfKind::Ref, OutType::Any, "std::cmp::Ord"),
-    ("default", 0, SelfKind::No, OutType::Any, "std::default::Default"),
+    ("default", 0, &FN_HEADER, SelfKind::No, OutType::Any, "std::default::Default"),
-    ("deref", 1, SelfKind::Ref, OutType::Ref, "std::ops::Deref"),
+    ("deref", 1, &FN_HEADER, SelfKind::Ref, OutType::Ref, "std::ops::Deref"),
-    ("deref_mut", 1, SelfKind::RefMut, OutType::Ref, "std::ops::DerefMut"),
+    ("deref_mut", 1, &FN_HEADER, SelfKind::RefMut, OutType::Ref, "std::ops::DerefMut"),
-    ("div", 2, SelfKind::Value, OutType::Any, "std::ops::Div"),
+    ("div", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Div"),
-    ("drop", 1, SelfKind::RefMut, OutType::Unit, "std::ops::Drop"),
+    ("drop", 1, &FN_HEADER, SelfKind::RefMut, OutType::Unit, "std::ops::Drop"),
-    ("eq", 2, SelfKind::Ref, OutType::Bool, "std::cmp::PartialEq"),
+    ("eq", 2, &FN_HEADER, SelfKind::Ref, OutType::Bool, "std::cmp::PartialEq"),
-    ("from_iter", 1, SelfKind::No, OutType::Any, "std::iter::FromIterator"),
+    ("from_iter", 1, &FN_HEADER, SelfKind::No, OutType::Any, "std::iter::FromIterator"),
-    ("from_str", 1, SelfKind::No, OutType::Any, "std::str::FromStr"),
+    ("from_str", 1, &FN_HEADER, SelfKind::No, OutType::Any, "std::str::FromStr"),
-    ("hash", 2, SelfKind::Ref, OutType::Unit, "std::hash::Hash"),
+    ("hash", 2, &FN_HEADER, SelfKind::Ref, OutType::Unit, "std::hash::Hash"),
-    ("index", 2, SelfKind::Ref, OutType::Ref, "std::ops::Index"),
+    ("index", 2, &FN_HEADER, SelfKind::Ref, OutType::Ref, "std::ops::Index"),
-    ("index_mut", 2, SelfKind::RefMut, OutType::Ref, "std::ops::IndexMut"),
+    ("index_mut", 2, &FN_HEADER, SelfKind::RefMut, OutType::Ref, "std::ops::IndexMut"),
-    ("into_iter", 1, SelfKind::Value, OutType::Any, "std::iter::IntoIterator"),
+    ("into_iter", 1, &FN_HEADER, SelfKind::Value, OutType::Any, "std::iter::IntoIterator"),
-    ("mul", 2, SelfKind::Value, OutType::Any, "std::ops::Mul"),
+    ("mul", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Mul"),
-    ("neg", 1, SelfKind::Value, OutType::Any, "std::ops::Neg"),
+    ("neg", 1, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Neg"),
-    ("next", 1, SelfKind::RefMut, OutType::Any, "std::iter::Iterator"),
+    ("next", 1, &FN_HEADER, SelfKind::RefMut, OutType::Any, "std::iter::Iterator"),
-    ("not", 1, SelfKind::Value, OutType::Any, "std::ops::Not"),
+    ("not", 1, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Not"),
-    ("rem", 2, SelfKind::Value, OutType::Any, "std::ops::Rem"),
+    ("rem", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Rem"),
-    ("shl", 2, SelfKind::Value, OutType::Any, "std::ops::Shl"),
+    ("shl", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Shl"),
-    ("shr", 2, SelfKind::Value, OutType::Any, "std::ops::Shr"),
+    ("shr", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Shr"),
-    ("sub", 2, SelfKind::Value, OutType::Any, "std::ops::Sub"),
+    ("sub", 2, &FN_HEADER, SelfKind::Value, OutType::Any, "std::ops::Sub"),
 ];
 
 #[rustfmt::skip]
@@ -3324,12 +3445,12 @@ enum SelfKind {
 
 impl SelfKind {
     fn matches<'a>(self, cx: &LateContext<'_, 'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
-        fn matches_value(parent_ty: Ty<'_>, ty: Ty<'_>) -> bool {
+        fn matches_value<'a>(cx: &LateContext<'_, 'a>, parent_ty: Ty<'_>, ty: Ty<'_>) -> bool {
             if ty == parent_ty {
                 true
             } else if ty.is_box() {
                 ty.boxed_ty() == parent_ty
-            } else if ty.is_rc() || ty.is_arc() {
+            } else if is_type_diagnostic_item(cx, ty, sym::Rc) || is_type_diagnostic_item(cx, ty, sym::Arc) {
                 if let ty::Adt(_, substs) = ty.kind {
                     substs.types().next().map_or(false, |t| t == parent_ty)
                 } else {
@@ -3363,7 +3484,7 @@ impl SelfKind {
         }
 
         match self {
-            Self::Value => matches_value(parent_ty, ty),
+            Self::Value => matches_value(cx, parent_ty, ty),
             Self::Ref => matches_ref(cx, hir::Mutability::Not, parent_ty, ty) || ty == parent_ty && is_copy(cx, ty),
             Self::RefMut => matches_ref(cx, hir::Mutability::Mut, parent_ty, ty),
             Self::No => ty != parent_ty,
@@ -3503,3 +3624,9 @@ fn lint_filetype_is_file(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, args: &
     let help_msg = format!("use `{}FileType::is_dir()` instead", help_unary);
     span_lint_and_help(cx, FILETYPE_IS_FILE, span, &lint_msg, &help_msg);
 }
+
+fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool {
+    expected.constness == actual.constness
+        && expected.unsafety == actual.unsafety
+        && expected.asyncness == actual.asyncness
+}

clippy_lints/src/methods/option_map_unwrap_or.rs

@@ -1,11 +1,11 @@
-use crate::utils::{differing_macro_contexts, paths, snippet_with_applicability, span_lint_and_then};
+use crate::utils::{differing_macro_contexts, snippet_with_applicability, span_lint_and_then};
-use crate::utils::{is_copy, match_type};
+use crate::utils::{is_copy, is_type_diagnostic_item};
-use rustc::hir::map::Map;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_path, NestedVisitorMap, Visitor};
 use rustc_hir::{self, HirId, Path};
 use rustc_lint::LateContext;
+use rustc_middle::hir::map::Map;
 use rustc_span::source_map::Span;
 use rustc_span::symbol::Symbol;
 
@@ -20,7 +20,7 @@ pub(super) fn lint<'a, 'tcx>(
     map_span: Span,
 ) {
     // lint if the caller of `map()` is an `Option`
-    if match_type(cx, cx.tables.expr_ty(&map_args[0]), &paths::OPTION) {
+    if is_type_diagnostic_item(cx, cx.tables.expr_ty(&map_args[0]), sym!(option_type)) {
         if !is_copy(cx, cx.tables.expr_ty(&unwrap_args[1])) {
             // Do not lint if the `map` argument uses identifiers in the `map`
             // argument that are also used in the `unwrap_or` argument

clippy_lints/src/methods/unnecessary_filter_map.rs

@@ -1,11 +1,11 @@
 use crate::utils::paths;
 use crate::utils::usage::mutated_variables;
 use crate::utils::{match_qpath, match_trait_method, span_lint};
-use rustc::hir::map::Map;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_lint::LateContext;
+use rustc_middle::hir::map::Map;
 
 use if_chain::if_chain;
 

clippy_lints/src/misc.rs

@@ -1,5 +1,4 @@
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
@@ -8,6 +7,7 @@ use rustc_hir::{
     TyKind, UnOp,
 };
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::{ExpnKind, Span};
 
@@ -57,10 +57,9 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
-    /// # use core::f32::NAN;
     /// # let x = 1.0;
     ///
-    /// if x == NAN { }
+    /// if x == f32::NAN { }
     /// ```
     pub CMP_NAN,
     correctness,
@@ -370,26 +369,28 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MiscLints {
                             return;
                         }
                     }
-                    let (lint, msg) = if is_named_constant(cx, left) || is_named_constant(cx, right) {
+                    let is_comparing_arrays = is_array(cx, left) || is_array(cx, right);
-                        (FLOAT_CMP_CONST, "strict comparison of `f32` or `f64` constant")
+                    let (lint, msg) = get_lint_and_message(
-                    } else {
+                        is_named_constant(cx, left) || is_named_constant(cx, right),
-                        (FLOAT_CMP, "strict comparison of `f32` or `f64`")
+                        is_comparing_arrays,
-                    };
+                    );
                     span_lint_and_then(cx, lint, expr.span, msg, |db| {
                         let lhs = Sugg::hir(cx, left, "..");
                         let rhs = Sugg::hir(cx, right, "..");
 
-                        db.span_suggestion(
+                        if !is_comparing_arrays {
-                            expr.span,
+                            db.span_suggestion(
-                            "consider comparing them within some error",
+                                expr.span,
-                            format!(
+                                "consider comparing them within some error",
-                                "({}).abs() {} error",
+                                format!(
-                                lhs - rhs,
+                                    "({}).abs() {} error",
-                                if op == BinOpKind::Eq { '<' } else { '>' }
+                                    lhs - rhs,
-                            ),
+                                    if op == BinOpKind::Eq { '<' } else { '>' }
-                            Applicability::HasPlaceholders, // snippet
+                                ),
-                        );
+                                Applicability::HasPlaceholders, // snippet
-                        db.span_note(expr.span, "`std::f32::EPSILON` and `std::f64::EPSILON` are available.");
+                            );
+                        }
+                        db.note("`f32::EPSILON` and `f64::EPSILON` are available for the `error`");
                     });
                 } else if op == BinOpKind::Rem && is_integer_const(cx, right, 1) {
                     span_lint(cx, MODULO_ONE, expr.span, "any number modulo 1 will be 0");
@@ -441,6 +442,31 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MiscLints {
     }
 }
 
+fn get_lint_and_message(
+    is_comparing_constants: bool,
+    is_comparing_arrays: bool,
+) -> (&'static rustc_lint::Lint, &'static str) {
+    if is_comparing_constants {
+        (
+            FLOAT_CMP_CONST,
+            if is_comparing_arrays {
+                "strict comparison of `f32` or `f64` constant arrays"
+            } else {
+                "strict comparison of `f32` or `f64` constant"
+            },
+        )
+    } else {
+        (
+            FLOAT_CMP,
+            if is_comparing_arrays {
+                "strict comparison of `f32` or `f64` arrays"
+            } else {
+                "strict comparison of `f32` or `f64`"
+            },
+        )
+    }
+}
+
 fn check_nan(cx: &LateContext<'_, '_>, expr: &Expr<'_>, cmp_expr: &Expr<'_>) {
     if_chain! {
         if !in_constant(cx, cmp_expr.hir_id);
@@ -457,7 +483,7 @@ fn check_nan(cx: &LateContext<'_, '_>, expr: &Expr<'_>, cmp_expr: &Expr<'_>) {
                     cx,
                     CMP_NAN,
                     cmp_expr.span,
-                    "doomed comparison with `NAN`, use `std::{f32,f64}::is_nan()` instead",
+                    "doomed comparison with `NAN`, use `{f32,f64}::is_nan()` instead",
                 );
             }
         }
@@ -476,6 +502,11 @@ fn is_allowed<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> boo
     match constant(cx, cx.tables, expr) {
         Some((Constant::F32(f), _)) => f == 0.0 || f.is_infinite(),
         Some((Constant::F64(f), _)) => f == 0.0 || f.is_infinite(),
+        Some((Constant::Vec(vec), _)) => vec.iter().all(|f| match f {
+            Constant::F32(f) => *f == 0.0 || (*f).is_infinite(),
+            Constant::F64(f) => *f == 0.0 || (*f).is_infinite(),
+            _ => false,
+        }),
         _ => false,
     }
 }
@@ -500,7 +531,17 @@ fn is_signum(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
 }
 
 fn is_float(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
-    matches!(walk_ptrs_ty(cx.tables.expr_ty(expr)).kind, ty::Float(_))
+    let value = &walk_ptrs_ty(cx.tables.expr_ty(expr)).kind;
+
+    if let ty::Array(arr_ty, _) = value {
+        return matches!(arr_ty.kind, ty::Float(_));
+    };
+
+    matches!(value, ty::Float(_))
+}
+
+fn is_array(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
+    matches!(&walk_ptrs_ty(cx.tables.expr_ty(expr)).kind, ty::Array(_, _))
 }
 
 fn check_to_owned(cx: &LateContext<'_, '_>, expr: &Expr<'_>, other: &Expr<'_>) {

clippy_lints/src/misc_early.rs

@@ -3,7 +3,6 @@ use crate::utils::{
     span_lint_and_then,
 };
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::{
     BindingMode, Block, Expr, ExprKind, GenericParamKind, Generics, Lit, LitFloatType, LitIntType, LitKind, Mutability,
     NodeId, Pat, PatKind, StmtKind, UnOp,
@@ -12,6 +11,7 @@ use rustc_ast::visit::{walk_expr, FnKind, Visitor};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::Applicability;
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 

clippy_lints/src/missing_const_for_fn.rs

@@ -1,9 +1,9 @@
 use crate::utils::{fn_has_unsatisfiable_preds, has_drop, is_entrypoint_fn, span_lint, trait_ref_of_method};
-use rustc::lint::in_external_macro;
 use rustc_hir as hir;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{Body, Constness, FnDecl, GenericParamKind, HirId};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
 use rustc_mir::transform::qualify_min_const_fn::is_min_const_fn;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::Span;

clippy_lints/src/missing_doc.rs

@@ -7,11 +7,11 @@
 
 use crate::utils::span_lint;
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_ast::ast::{self, MetaItem, MetaItemKind};
 use rustc_ast::attr;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::ty;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 

clippy_lints/src/missing_inline.rs

@@ -81,7 +81,7 @@ declare_lint_pass!(MissingInline => [MISSING_INLINE_IN_PUBLIC_ITEMS]);
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingInline {
     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, it: &'tcx hir::Item<'_>) {
-        if rustc::lint::in_external_macro(cx.sess(), it.span) || is_executable(cx) {
+        if rustc_middle::lint::in_external_macro(cx.sess(), it.span) || is_executable(cx) {
             return;
         }
 
@@ -130,8 +130,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingInline {
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx hir::ImplItem<'_>) {
-        use rustc::ty::{ImplContainer, TraitContainer};
+        use rustc_middle::ty::{ImplContainer, TraitContainer};
-        if rustc::lint::in_external_macro(cx.sess(), impl_item.span) || is_executable(cx) {
+        if rustc_middle::lint::in_external_macro(cx.sess(), impl_item.span) || is_executable(cx) {
             return;
         }
 

clippy_lints/src/modulo_arithmetic.rs

@@ -1,9 +1,9 @@
 use crate::consts::{constant, Constant};
 use crate::utils::{sext, span_lint_and_then};
 use if_chain::if_chain;
-use rustc::ty::{self};
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use std::fmt::Display;
 

clippy_lints/src/mut_key.rs

@@ -1,7 +1,7 @@
 use crate::utils::{match_def_path, paths, span_lint, trait_ref_of_method, walk_ptrs_ty};
-use rustc::ty::{Adt, Array, RawPtr, Ref, Slice, Tuple, Ty, TypeAndMut};
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{Adt, Array, RawPtr, Ref, Slice, Tuple, Ty, TypeAndMut};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 

clippy_lints/src/mut_mut.rs

@@ -1,10 +1,10 @@
 use crate::utils::{higher, span_lint};
-use rustc::hir::map::Map;
-use rustc::lint::in_external_macro;
-use rustc::ty;
 use rustc_hir as hir;
 use rustc_hir::intravisit;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/mut_reference.rs

@@ -1,8 +1,8 @@
 use crate::utils::span_lint;
-use rustc::ty::subst::Subst;
+use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability};
-use rustc::ty::{self, Ty};
-use rustc_hir::{print, BorrowKind, Expr, ExprKind, Mutability};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::subst::Subst;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
@@ -34,7 +34,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnnecessaryMutPassed {
                         cx,
                         arguments,
                         cx.tables.expr_ty(fn_expr),
-                        &print::to_string(print::NO_ANN, |s| s.print_qpath(path, false)),
+                        &rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_qpath(path, false)),
                     );
                 }
             },

clippy_lints/src/mutable_debug_assertion.rs

@@ -1,10 +1,10 @@
 use crate::utils::{is_direct_expn_of, span_lint};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
-use rustc::ty;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_hir::{BorrowKind, Expr, ExprKind, MatchSource, Mutability, StmtKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::Span;
 
@@ -53,7 +53,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DebugAssertWithMutCall {
 }
 
 //HACK(hellow554): remove this when #4694 is implemented
-#[allow(clippy::cognitive_complexity)]
 fn extract_call<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) -> Option<Span> {
     if_chain! {
         if let ExprKind::Block(ref block, _) = e.kind;

clippy_lints/src/mutex_atomic.rs

@@ -3,10 +3,10 @@
 //! This lint is **warn** by default
 
 use crate::utils::{match_type, paths, span_lint};
-use rustc::ty::{self, Ty};
 use rustc_ast::ast;
 use rustc_hir::Expr;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/needless_bool.rs

@@ -3,13 +3,15 @@
 //! This lint is **warn** by default
 
 use crate::utils::sugg::Sugg;
-use crate::utils::{higher, parent_node_is_if_expr, span_lint, span_lint_and_sugg};
+use crate::utils::{higher, parent_node_is_if_expr, snippet_with_applicability, span_lint, span_lint_and_sugg};
+use if_chain::if_chain;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, Block, Expr, ExprKind, StmtKind};
+use rustc_hir::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Spanned;
+use rustc_span::Span;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for expressions of the form `if c { true } else {
@@ -188,6 +190,34 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoolComparison {
     }
 }
 
+struct ExpressionInfoWithSpan {
+    one_side_is_unary_not: bool,
+    left_span: Span,
+    right_span: Span,
+}
+
+fn is_unary_not(e: &Expr<'_>) -> (bool, Span) {
+    if_chain! {
+        if let ExprKind::Unary(unop, operand) = e.kind;
+        if let UnOp::UnNot = unop;
+        then {
+            return (true, operand.span);
+        }
+    };
+    (false, e.span)
+}
+
+fn one_side_is_unary_not<'tcx>(left_side: &'tcx Expr<'_>, right_side: &'tcx Expr<'_>) -> ExpressionInfoWithSpan {
+    let left = is_unary_not(left_side);
+    let right = is_unary_not(right_side);
+
+    ExpressionInfoWithSpan {
+        one_side_is_unary_not: left.0 != right.0,
+        left_span: left.1,
+        right_span: right.1,
+    }
+}
+
 fn check_comparison<'a, 'tcx>(
     cx: &LateContext<'a, 'tcx>,
     e: &'tcx Expr<'_>,
@@ -199,10 +229,30 @@ fn check_comparison<'a, 'tcx>(
 ) {
     use self::Expression::{Bool, Other};
 
-    if let ExprKind::Binary(_, ref left_side, ref right_side) = e.kind {
+    if let ExprKind::Binary(op, ref left_side, ref right_side) = e.kind {
         let (l_ty, r_ty) = (cx.tables.expr_ty(left_side), cx.tables.expr_ty(right_side));
         if l_ty.is_bool() && r_ty.is_bool() {
             let mut applicability = Applicability::MachineApplicable;
+
+            if let BinOpKind::Eq = op.node {
+                let expression_info = one_side_is_unary_not(&left_side, &right_side);
+                if expression_info.one_side_is_unary_not {
+                    span_lint_and_sugg(
+                        cx,
+                        BOOL_COMPARISON,
+                        e.span,
+                        "This comparison might be written more concisely",
+                        "try simplifying it as shown",
+                        format!(
+                            "{} != {}",
+                            snippet_with_applicability(cx, expression_info.left_span, "..", &mut applicability),
+                            snippet_with_applicability(cx, expression_info.right_span, "..", &mut applicability)
+                        ),
+                        applicability,
+                    )
+                }
+            }
+
             match (fetch_bool_expr(left_side), fetch_bool_expr(right_side)) {
                 (Bool(true), Other) => left_true.map_or((), |(h, m)| {
                     suggest_bool_comparison(cx, e, right_side, applicability, m, h)

clippy_lints/src/needless_borrow.rs

@@ -4,11 +4,11 @@
 
 use crate::utils::{snippet_opt, span_lint_and_then};
 use if_chain::if_chain;
-use rustc::ty;
-use rustc::ty::adjustment::{Adjust, Adjustment};
 use rustc_errors::Applicability;
 use rustc_hir::{BindingAnnotation, BorrowKind, Expr, ExprKind, HirId, Item, Mutability, Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_middle::ty::adjustment::{Adjust, Adjustment};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 
 declare_clippy_lint! {

clippy_lints/src/needless_pass_by_value.rs

@@ -4,7 +4,6 @@ use crate::utils::{
     snippet, snippet_opt, span_lint_and_then,
 };
 use if_chain::if_chain;
-use rustc::ty::{self, TypeFoldable};
 use rustc_ast::ast::Attribute;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{Applicability, DiagnosticBuilder};
@@ -12,8 +11,9 @@ use rustc_hir::intravisit::FnKind;
 use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, ItemKind, Node, PatKind, QPath, TyKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, TypeFoldable};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::{Span, Symbol};
+use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
 use rustc_trait_selection::traits::misc::can_type_implement_copy;
@@ -113,8 +113,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NeedlessPassByValue {
 
         let preds = traits::elaborate_predicates(cx.tcx, cx.param_env.caller_bounds.to_vec())
             .filter(|p| !p.is_global())
-            .filter_map(|pred| {
+            .filter_map(|obligation| {
-                if let ty::Predicate::Trait(poly_trait_ref, _) = pred {
+                if let ty::Predicate::Trait(poly_trait_ref, _) = obligation.predicate {
                     if poly_trait_ref.def_id() == sized_trait || poly_trait_ref.skip_binder().has_escaping_bound_vars()
                     {
                         return None;
@@ -214,7 +214,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NeedlessPassByValue {
 
                         let deref_span = spans_need_deref.get(&canonical_id);
                         if_chain! {
-                            if is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type"));
+                            if is_type_diagnostic_item(cx, ty, sym!(vec_type));
                             if let Some(clone_spans) =
                                 get_spans(cx, Some(body.id()), idx, &[("clone", ".to_owned()")]);
                             if let TyKind::Path(QPath::Resolved(_, ref path)) = input.kind;

clippy_lints/src/needless_update.rs

@@ -1,7 +1,7 @@
 use crate::utils::span_lint;
-use rustc::ty;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/neg_cmp_op_on_partial_ord.rs

@@ -1,7 +1,7 @@
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 use crate::utils::{self, paths, span_lint};
@@ -25,13 +25,13 @@ declare_clippy_lint! {
     ///
     /// // Bad
     /// let a = 1.0;
-    /// let b = std::f64::NAN;
+    /// let b = f64::NAN;
     ///
     /// let _not_less_or_equal = !(a <= b);
     ///
     /// // Good
     /// let a = 1.0;
-    /// let b = std::f64::NAN;
+    /// let b = f64::NAN;
     ///
     /// let _not_less_or_equal = match a.partial_cmp(&b) {
     ///     None | Some(Ordering::Greater) => true,

clippy_lints/src/new_without_default.rs

@@ -2,13 +2,13 @@ use crate::utils::paths;
 use crate::utils::sugg::DiagnosticBuilderExt;
 use crate::utils::{get_trait_def_id, implements_trait, return_ty, same_tys, span_lint_hir_and_then};
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
-use rustc::ty::{self, Ty};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::HirIdSet;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 
@@ -100,7 +100,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NewWithoutDefault {
         } = item.kind
         {
             for assoc_item in items {
-                if let hir::AssocItemKind::Method { has_self: false } = assoc_item.kind {
+                if let hir::AssocItemKind::Fn { has_self: false } = assoc_item.kind {
                     let impl_item = cx.tcx.hir().impl_item(assoc_item.id);
                     if in_external_macro(cx.sess(), impl_item.span) {
                         return;

clippy_lints/src/non_copy_const.rs

@@ -4,11 +4,11 @@
 
 use std::ptr;
 
-use rustc::ty::adjustment::Adjust;
-use rustc::ty::{Ty, TypeFlags};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, Node, TraitItem, TraitItemKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass, Lint};
+use rustc_middle::ty::adjustment::Adjust;
+use rustc_middle::ty::{Ty, TypeFlags};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{InnerSpan, Span, DUMMY_SP};
 use rustc_typeck::hir_ty_to_ty;

clippy_lints/src/ptr.rs

@@ -6,16 +6,16 @@ use crate::utils::{
     walk_ptrs_hir_ty,
 };
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_errors::Applicability;
 use rustc_hir::{
     BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, HirId, ImplItem, ImplItemKind, Item, ItemKind,
     Lifetime, MutTy, Mutability, Node, PathSegment, QPath, TraitFn, TraitItem, TraitItemKind, Ty, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
-use rustc_span::{MultiSpan, Symbol};
+use rustc_span::MultiSpan;
 use std::borrow::Cow;
 
 declare_clippy_lint! {
@@ -153,7 +153,7 @@ fn check_fn(cx: &LateContext<'_, '_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_
 
     for (idx, (arg, ty)) in decl.inputs.iter().zip(fn_ty.inputs()).enumerate() {
         if let ty::Ref(_, ty, Mutability::Not) = ty.kind {
-            if is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type")) {
+            if is_type_diagnostic_item(cx, ty, sym!(vec_type)) {
                 let mut ty_snippet = None;
                 if_chain! {
                     if let TyKind::Path(QPath::Resolved(_, ref path)) = walk_ptrs_hir_ty(arg).kind;

clippy_lints/src/question_mark.rs

@@ -5,10 +5,10 @@ use rustc_hir::{def, BindingAnnotation, Block, Expr, ExprKind, MatchSource, PatK
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
-use crate::utils::paths::{OPTION, OPTION_NONE};
 use crate::utils::sugg::Sugg;
 use crate::utils::{
-    higher, match_def_path, match_qpath, match_type, snippet_with_applicability, span_lint_and_sugg, SpanlessEq,
+    higher, is_type_diagnostic_item, match_def_path, match_qpath, paths, snippet_with_applicability,
+    span_lint_and_sugg, SpanlessEq,
 };
 
 declare_clippy_lint! {
@@ -141,7 +141,7 @@ impl QuestionMark {
     fn is_option(cx: &LateContext<'_, '_>, expression: &Expr<'_>) -> bool {
         let expr_ty = cx.tables.expr_ty(expression);
 
-        match_type(cx, expr_ty, &OPTION)
+        is_type_diagnostic_item(cx, expr_ty, sym!(option_type))
     }
 
     fn expression_returns_none(cx: &LateContext<'_, '_>, expression: &Expr<'_>) -> bool {
@@ -158,7 +158,7 @@ impl QuestionMark {
                 if let Res::Def(DefKind::Ctor(def::CtorOf::Variant, def::CtorKind::Const), def_id) =
                     cx.tables.qpath_res(qp, expression.hir_id)
                 {
-                    return match_def_path(cx, def_id, &OPTION_NONE);
+                    return match_def_path(cx, def_id, &paths::OPTION_NONE);
                 }
 
                 false

clippy_lints/src/redundant_clone.rs

@@ -3,19 +3,19 @@ use crate::utils::{
     span_lint_hir_and_then, walk_ptrs_ty_depth,
 };
 use if_chain::if_chain;
-use rustc::mir::{
-    self, traversal,
-    visit::{MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor as _},
-};
-use rustc::ty::{self, fold::TypeVisitor, Ty};
 use rustc_data_structures::{fx::FxHashMap, transitive_relation::TransitiveRelation};
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{def_id, Body, FnDecl, HirId};
 use rustc_index::bit_set::{BitSet, HybridBitSet};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_mir::dataflow::generic::{Analysis, AnalysisDomain, GenKill, GenKillAnalysis, ResultsCursor};
+use rustc_middle::mir::{
+    self, traversal,
+    visit::{MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor as _},
+};
+use rustc_middle::ty::{self, fold::TypeVisitor, Ty};
 use rustc_mir::dataflow::BottomValue;
+use rustc_mir::dataflow::{Analysis, AnalysisDomain, GenKill, GenKillAnalysis, ResultsCursor};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::{BytePos, Span};
 use std::convert::TryFrom;
@@ -80,20 +80,20 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for RedundantClone {
         let def_id = cx.tcx.hir().body_owner_def_id(body.id());
 
         // Building MIR for `fn`s with unsatisfiable preds results in ICE.
-        if fn_has_unsatisfiable_preds(cx, def_id) {
+        if fn_has_unsatisfiable_preds(cx, def_id.to_def_id()) {
             return;
         }
 
-        let mir = cx.tcx.optimized_mir(def_id);
+        let mir = cx.tcx.optimized_mir(def_id.to_def_id());
         let mir_read_only = mir.unwrap_read_only();
 
         let maybe_storage_live_result = MaybeStorageLive
-            .into_engine(cx.tcx, mir, def_id)
+            .into_engine(cx.tcx, mir, def_id.to_def_id())
             .iterate_to_fixpoint()
             .into_results_cursor(mir);
         let mut possible_borrower = {
             let mut vis = PossibleBorrowerVisitor::new(cx, mir);
-            vis.visit_body(mir_read_only);
+            vis.visit_body(&mir_read_only);
             vis.into_map(cx, maybe_storage_live_result)
         };
 
@@ -335,12 +335,15 @@ fn base_local_and_movability<'tcx>(
     mir: &mir::Body<'tcx>,
     place: mir::Place<'tcx>,
 ) -> Option<(mir::Local, CannotMoveOut)> {
-    use rustc::mir::PlaceRef;
+    use rustc_middle::mir::PlaceRef;
 
     // Dereference. You cannot move things out from a borrowed value.
     let mut deref = false;
     // Accessing a field of an ADT that has `Drop`. Moving the field out will cause E0509.
     let mut field = false;
+    // If projection is a slice index then clone can be removed only if the
+    // underlying type implements Copy
+    let mut slice = false;
 
     let PlaceRef { local, mut projection } = place.as_ref();
     while let [base @ .., elem] = projection {
@@ -348,9 +351,11 @@ fn base_local_and_movability<'tcx>(
         deref |= matches!(elem, mir::ProjectionElem::Deref);
         field |= matches!(elem, mir::ProjectionElem::Field(..))
             && has_drop(cx, mir::Place::ty_from(local, projection, &mir.local_decls, cx.tcx).ty);
+        slice |= matches!(elem, mir::ProjectionElem::Index(..))
+            && !is_copy(cx, mir::Place::ty_from(local, projection, &mir.local_decls, cx.tcx).ty);
     }
 
-    Some((local, deref || field))
+    Some((local, deref || field || slice))
 }
 
 struct LocalUseVisitor {
@@ -437,7 +442,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeStorageLive {
         _block: mir::BasicBlock,
         _func: &mir::Operand<'tcx>,
         _args: &[mir::Operand<'tcx>],
-        _return_place: &mir::Place<'tcx>,
+        _return_place: mir::Place<'tcx>,
     ) {
         // Nothing to do when a call returns successfully
     }
@@ -556,7 +561,7 @@ impl TypeVisitor<'_> for ContainsRegion {
 }
 
 fn rvalue_locals(rvalue: &mir::Rvalue<'_>, mut visit: impl FnMut(mir::Local)) {
-    use rustc::mir::Rvalue::{Aggregate, BinaryOp, Cast, CheckedBinaryOp, Repeat, UnaryOp, Use};
+    use rustc_middle::mir::Rvalue::{Aggregate, BinaryOp, Cast, CheckedBinaryOp, Repeat, UnaryOp, Use};
 
     let mut visit_op = |op: &mir::Operand<'_>| match op {
         mir::Operand::Copy(p) | mir::Operand::Move(p) => visit(p.local),

clippy_lints/src/replace_consts.rs

@@ -1,103 +0,0 @@
-use crate::utils::{match_def_path, span_lint_and_sugg};
-use if_chain::if_chain;
-use rustc_errors::Applicability;
-use rustc_hir::def::{DefKind, Res};
-use rustc_hir::{Expr, ExprKind, Node};
-use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
-
-declare_clippy_lint! {
-    /// **What it does:** Checks for usage of standard library
-    /// `const`s that could be replaced by `const fn`s.
-    ///
-    /// **Why is this bad?** `const fn`s exist
-    ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
-    /// ```rust
-    /// let x = std::u32::MIN;
-    /// let y = std::u32::MAX;
-    /// ```
-    ///
-    /// Could be written:
-    ///
-    /// ```rust
-    /// let x = u32::min_value();
-    /// let y = u32::max_value();
-    /// ```
-    pub REPLACE_CONSTS,
-    pedantic,
-    "Lint usages of standard library `const`s that could be replaced by `const fn`s"
-}
-
-declare_lint_pass!(ReplaceConsts => [REPLACE_CONSTS]);
-
-fn in_pattern(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
-    let map = &cx.tcx.hir();
-    let parent_id = map.get_parent_node(expr.hir_id);
-
-    if let Some(node) = map.find(parent_id) {
-        if let Node::Pat(_) = node {
-            return true;
-        }
-    }
-
-    false
-}
-
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ReplaceConsts {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
-        if_chain! {
-            if let ExprKind::Path(ref qp) = expr.kind;
-            if let Res::Def(DefKind::Const, def_id) = cx.tables.qpath_res(qp, expr.hir_id);
-            // Do not lint within patterns as function calls are disallowed in them
-            if !in_pattern(cx, expr);
-            then {
-                for &(ref const_path, repl_snip) in &REPLACEMENTS {
-                    if match_def_path(cx, def_id, const_path) {
-                        span_lint_and_sugg(
-                            cx,
-                            REPLACE_CONSTS,
-                            expr.span,
-                            &format!("using `{}`", const_path.last().expect("empty path")),
-                            "try this",
-                            repl_snip.to_string(),
-                            Applicability::MachineApplicable,
-                        );
-                        return;
-                    }
-                }
-            }
-        }
-    }
-}
-
-const REPLACEMENTS: [([&str; 3], &str); 24] = [
-    // Min
-    (["core", "isize", "MIN"], "isize::min_value()"),
-    (["core", "i8", "MIN"], "i8::min_value()"),
-    (["core", "i16", "MIN"], "i16::min_value()"),
-    (["core", "i32", "MIN"], "i32::min_value()"),
-    (["core", "i64", "MIN"], "i64::min_value()"),
-    (["core", "i128", "MIN"], "i128::min_value()"),
-    (["core", "usize", "MIN"], "usize::min_value()"),
-    (["core", "u8", "MIN"], "u8::min_value()"),
-    (["core", "u16", "MIN"], "u16::min_value()"),
-    (["core", "u32", "MIN"], "u32::min_value()"),
-    (["core", "u64", "MIN"], "u64::min_value()"),
-    (["core", "u128", "MIN"], "u128::min_value()"),
-    // Max
-    (["core", "isize", "MAX"], "isize::max_value()"),
-    (["core", "i8", "MAX"], "i8::max_value()"),
-    (["core", "i16", "MAX"], "i16::max_value()"),
-    (["core", "i32", "MAX"], "i32::max_value()"),
-    (["core", "i64", "MAX"], "i64::max_value()"),
-    (["core", "i128", "MAX"], "i128::max_value()"),
-    (["core", "usize", "MAX"], "usize::max_value()"),
-    (["core", "u8", "MAX"], "u8::max_value()"),
-    (["core", "u16", "MAX"], "u16::max_value()"),
-    (["core", "u32", "MAX"], "u32::max_value()"),
-    (["core", "u64", "MAX"], "u64::max_value()"),
-    (["core", "u128", "MAX"], "u128::max_value()"),
-];

clippy_lints/src/returns.rs

@@ -1,9 +1,9 @@
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_ast::ast;
 use rustc_ast::visit::FnKind;
 use rustc_errors::Applicability;
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 use rustc_span::BytePos;

clippy_lints/src/shadow.rs

@@ -1,13 +1,13 @@
 use crate::reexport::Name;
 use crate::utils::{contains_name, higher, iter_input_pats, snippet, span_lint_and_then};
-use rustc::lint::in_external_macro;
-use rustc::ty;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
     Block, Body, Expr, ExprKind, FnDecl, Guard, HirId, Local, MutTy, Pat, PatKind, Path, QPath, StmtKind, Ty, TyKind,
     UnOp,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
 

clippy_lints/src/slow_vector_initialization.rs

@@ -1,12 +1,12 @@
 use crate::utils::sugg::Sugg;
 use crate::utils::{get_enclosing_block, match_qpath, span_lint_and_then, SpanlessEq};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_block, walk_expr, walk_stmt, NestedVisitorMap, Visitor};
 use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, HirId, PatKind, QPath, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass, Lint};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::Symbol;
 

clippy_lints/src/strings.rs

@@ -1,7 +1,7 @@
-use rustc::lint::in_external_macro;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Spanned;
 

clippy_lints/src/suspicious_trait_impl.rs

@@ -1,9 +1,9 @@
 use crate::utils::{get_trait_def_id, span_lint, trait_ref_of_method};
 use if_chain::if_chain;
-use rustc::hir::map::Map;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
@@ -54,7 +54,7 @@ declare_lint_pass!(SuspiciousImpl => [SUSPICIOUS_ARITHMETIC_IMPL, SUSPICIOUS_OP_
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
-        if let hir::ExprKind::Binary(binop, _, _) = expr.kind {
+        if let hir::ExprKind::Binary(binop, _, _) | hir::ExprKind::AssignOp(binop, ..) = expr.kind {
             match binop.node {
                 hir::BinOpKind::Eq
                 | hir::BinOpKind::Lt
@@ -65,14 +65,15 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl {
                 _ => {},
             }
             // Check if the binary expression is part of another bi/unary expression
-            // as a child node
+            // or operator assignment as a child node
             let mut parent_expr = cx.tcx.hir().get_parent_node(expr.hir_id);
             while parent_expr != hir::CRATE_HIR_ID {
                 if let hir::Node::Expr(e) = cx.tcx.hir().get(parent_expr) {
                     match e.kind {
                         hir::ExprKind::Binary(..)
                         | hir::ExprKind::Unary(hir::UnOp::UnNot, _)
-                        | hir::ExprKind::Unary(hir::UnOp::UnNeg, _) => return,
+                        | hir::ExprKind::Unary(hir::UnOp::UnNeg, _)
+                        | hir::ExprKind::AssignOp(..) => return,
                         _ => {},
                     }
                 }
@@ -191,7 +192,8 @@ impl<'a, 'tcx> Visitor<'tcx> for BinaryExprVisitor {
         match expr.kind {
             hir::ExprKind::Binary(..)
             | hir::ExprKind::Unary(hir::UnOp::UnNot, _)
-            | hir::ExprKind::Unary(hir::UnOp::UnNeg, _) => self.in_binary_expr = true,
+            | hir::ExprKind::Unary(hir::UnOp::UnNeg, _)
+            | hir::ExprKind::AssignOp(..) => self.in_binary_expr = true,
             _ => {},
         }
 

clippy_lints/src/swap.rs

@@ -4,12 +4,11 @@ use crate::utils::{
     span_lint_and_then, walk_ptrs_ty, SpanlessEq,
 };
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_errors::Applicability;
 use rustc_hir::{Block, Expr, ExprKind, PatKind, QPath, StmtKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::Symbol;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for manual swapping.
@@ -199,7 +198,7 @@ fn check_for_slice<'a>(cx: &LateContext<'_, '_>, lhs1: &'a Expr<'_>, lhs2: &'a E
 
                 if matches!(ty.kind, ty::Slice(_))
                     || matches!(ty.kind, ty::Array(_, _))
-                    || is_type_diagnostic_item(cx, ty, Symbol::intern("vec_type"))
+                    || is_type_diagnostic_item(cx, ty, sym!(vec_type))
                     || match_type(cx, ty, &paths::VEC_DEQUE)
                 {
                     return Slice::Swappable(lhs1, idx1, idx2);

clippy_lints/src/to_digit_is_some.rs

@@ -1,9 +1,9 @@
 use crate::utils::{match_def_path, snippet_with_applicability, span_lint_and_sugg};
 use if_chain::if_chain;
-use rustc::ty;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {

clippy_lints/src/trait_bounds.rs

@@ -1,5 +1,6 @@
-use crate::utils::{in_macro, snippet, span_lint_and_help, SpanlessHash};
+use crate::utils::{in_macro, snippet, snippet_with_applicability, span_lint_and_help, SpanlessHash};
 use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::Applicability;
 use rustc_hir::{GenericBound, Generics, WherePredicate};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
@@ -41,6 +42,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TraitBounds {
             hasher.finish()
         };
         let mut map = FxHashMap::default();
+        let mut applicability = Applicability::MaybeIncorrect;
         for bound in gen.where_clause.predicates {
             if let WherePredicate::BoundPredicate(ref p) = bound {
                 let h = hash(&p.bounded_ty);
@@ -52,13 +54,19 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TraitBounds {
                     for b in v.iter() {
                         if let GenericBound::Trait(ref poly_trait_ref, _) = b {
                             let path = &poly_trait_ref.trait_ref.path;
-                            hint_string.push_str(&format!(" {} +", path));
+                            hint_string.push_str(&format!(
+                                " {} +",
+                                snippet_with_applicability(cx, path.span, "..", &mut applicability)
+                            ));
                         }
                     }
                     for b in p.bounds.iter() {
                         if let GenericBound::Trait(ref poly_trait_ref, _) = b {
                             let path = &poly_trait_ref.trait_ref.path;
-                            hint_string.push_str(&format!(" {} +", path));
+                            hint_string.push_str(&format!(
+                                " {} +",
+                                snippet_with_applicability(cx, path.span, "..", &mut applicability)
+                            ));
                         }
                     }
                     hint_string.truncate(hint_string.len() - 2);

clippy_lints/src/transmute.rs

@@ -2,11 +2,11 @@ use crate::utils::{
     is_normalizable, last_path_segment, match_def_path, paths, snippet, span_lint, span_lint_and_then, sugg,
 };
 use if_chain::if_chain;
-use rustc::ty::{self, Ty};
 use rustc_ast::ast;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, GenericArg, Mutability, QPath, TyKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use std::borrow::Cow;
 

clippy_lints/src/transmuting_null.rs

@@ -1,10 +1,10 @@
 use crate::consts::{constant_context, Constant};
 use crate::utils::{match_qpath, paths, span_lint};
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_ast::ast::LitKind;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {