Auto merge of rust-lang#102106 - djkoloski:sync-from-clippy, r=Manish…

…earth

Update clippy

r? `@Manishearth`

src/tools/clippy/CHANGELOG.md

@@ -3800,6 +3800,7 @@ Released 2018-09-13
 [`items_after_statements`]: https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements
 [`iter_cloned_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_cloned_collect
 [`iter_count`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_count
+[`iter_kv_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_kv_map
 [`iter_next_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_loop
 [`iter_next_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_slice
 [`iter_not_returning_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_not_returning_iterator

src/tools/clippy/CONTRIBUTING.md

@@ -110,23 +110,28 @@ Just make sure to remove the dependencies again before finally making a pull req
 [IntelliJ_rust_homepage]: https://intellij-rust.github.io/
 
 ### Rust Analyzer
-As of [#6869][6869], [`rust-analyzer`][ra_homepage] can understand that Clippy uses compiler-internals
-using `extern crate` when `package.metadata.rust-analyzer.rustc_private` is set to `true` in Clippy's `Cargo.toml.`
-You will require a `nightly` toolchain with the `rustc-dev` component installed.
-Make sure that in the `rust-analyzer` configuration, you set
+For [`rust-analyzer`][ra_homepage] to work correctly make sure that in the `rust-analyzer` configuration you set
+
 ```json
 { "rust-analyzer.rustc.source": "discover" }
 ```
-and
-```json
-{ "rust-analyzer.updates.channel": "nightly" }
-```
+
 You should be able to see information on things like `Expr` or `EarlyContext` now if you hover them, also
 a lot more type hints.
-This will work with `rust-analyzer 2021-03-15` shipped in nightly `1.52.0-nightly (107896c32 2021-03-15)` or later.
+
+To have `rust-analyzer` also work in the `clippy_dev` and `lintcheck` crates, add the following configuration
+
+```json
+{
+    "rust-analyzer.linkedProjects": [
+        "./Cargo.toml",
+        "clippy_dev/Cargo.toml",
+        "lintcheck/Cargo.toml",
+    ]
+}
+```
 
 [ra_homepage]: https://rust-analyzer.github.io/
-[6869]: https://github.com/rust-lang/rust-clippy/pull/6869
 
 ## How Clippy works
 

src/tools/clippy/book/src/development/adding_lints.md

@@ -90,6 +90,7 @@ We start by opening the test file created at `tests/ui/foo_functions.rs`.
 Update the file with some examples to get started:
 
 ```rust
+#![allow(unused)]
 #![warn(clippy::foo_functions)]
 
 // Impl methods

src/tools/clippy/book/src/development/common_tools_writing_lints.md

@@ -123,7 +123,8 @@ There are three ways to do this, depending on if the target trait has a
 diagnostic item, lang item or neither.
 
 ```rust
-use clippy_utils::{implements_trait, is_trait_method, match_trait_method, paths};
+use clippy_utils::ty::implements_trait;
+use clippy_utils::is_trait_method;
 use rustc_span::symbol::sym;
 
 impl LateLintPass<'_> for MyStructLint {
@@ -143,13 +144,6 @@ impl LateLintPass<'_> for MyStructLint {
             .map_or(false, |id| implements_trait(cx, ty, id, &[])) {
                 // `expr` implements `Drop` trait
             }
-
-        // 3. Using the type path with the expression
-        // we use `match_trait_method` function from Clippy's utils
-        // (This method should be avoided if possible)
-        if match_trait_method(cx, expr, &paths::INTO) {
-            // `expr` implements `Into` trait
-        }
     }
 }
 ```
@@ -233,8 +227,9 @@ functions to deal with macros:
   crates
 
   ```rust
-  #[macro_use]
-  extern crate a_crate_with_macros;
+  use rustc_middle::lint::in_external_macro;
+
+  use a_crate_with_macros::foo;
 
   // `foo` is defined in `a_crate_with_macros`
   foo!("bar");

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

@@ -188,6 +188,7 @@ pub(crate) fn get_stabilization_version() -> String {
 fn get_test_file_contents(lint_name: &str, header_commands: Option<&str>) -> String {
     let mut contents = format!(
         indoc! {"
+            #![allow(unused)]
             #![warn(clippy::{})]
 
             fn main() {{

src/tools/clippy/clippy_lints/src/almost_complete_letter_range.rs

@@ -4,6 +4,7 @@ use clippy_utils::{meets_msrv, msrvs};
 use rustc_ast::ast::{Expr, ExprKind, LitKind, Pat, PatKind, RangeEnd, RangeLimits};
 use rustc_errors::Applicability;
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_semver::RustcVersion;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::Span;
@@ -79,6 +80,7 @@ fn check_range(cx: &EarlyContext<'_>, span: Span, start: &Expr, end: &Expr, sugg
             (LitKind::Byte(b'a') | LitKind::Char('a'), LitKind::Byte(b'z') | LitKind::Char('z'))
             | (LitKind::Byte(b'A') | LitKind::Char('A'), LitKind::Byte(b'Z') | LitKind::Char('Z'))
         )
+        && !in_external_macro(cx.sess(), span)
     {
         span_lint_and_then(
             cx,

src/tools/clippy/clippy_lints/src/assertions_on_result_states.rs

@@ -1,9 +1,9 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::macros::{find_assert_args, root_macro_call_first_node, PanicExpn};
-use clippy_utils::path_res;
 use clippy_utils::source::snippet_with_context;
-use clippy_utils::ty::{implements_trait, is_copy, is_type_diagnostic_item};
+use clippy_utils::ty::{has_debug_impl, is_copy, is_type_diagnostic_item};
 use clippy_utils::usage::local_used_after_expr;
+use clippy_utils::{is_expr_final_block_expr, path_res};
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::{Expr, ExprKind};
@@ -58,6 +58,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
                     return;
                 }
             }
+            let semicolon = if is_expr_final_block_expr(cx.tcx, e) {";"} else {""};
             let mut app = Applicability::MachineApplicable;
             match method_segment.ident.as_str() {
                 "is_ok" if type_suitable_to_unwrap(cx, substs.type_at(1)) => {
@@ -68,8 +69,9 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
                         "called `assert!` with `Result::is_ok`",
                         "replace with",
                         format!(
-                            "{}.unwrap()",
-                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0
+                            "{}.unwrap(){}",
+                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0,
+                            semicolon
                         ),
                         app,
                     );
@@ -82,8 +84,9 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
                         "called `assert!` with `Result::is_err`",
                         "replace with",
                         format!(
-                            "{}.unwrap_err()",
-                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0
+                            "{}.unwrap_err(){}",
+                            snippet_with_context(cx, recv.span, condition.span.ctxt(), "..", &mut app).0,
+                            semicolon
                         ),
                         app,
                     );
@@ -94,13 +97,6 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnResultStates {
     }
 }
 
-/// This checks whether a given type is known to implement Debug.
-fn has_debug_impl<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
-    cx.tcx
-        .get_diagnostic_item(sym::Debug)
-        .map_or(false, |debug| implements_trait(cx, ty, debug, &[]))
-}
-
 fn type_suitable_to_unwrap<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
     has_debug_impl(cx, ty) && !ty.is_unit() && !ty.is_never()
 }

src/tools/clippy/clippy_lints/src/bool_to_int_with_if.rs

@@ -1,9 +1,9 @@
-use rustc_ast::{ExprPrecedence, LitKind};
+use rustc_ast::LitKind;
 use rustc_hir::{Block, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
-use clippy_utils::{diagnostics::span_lint_and_then, is_else_clause, source::snippet_block_with_applicability};
+use clippy_utils::{diagnostics::span_lint_and_then, is_else_clause, sugg::Sugg};
 use rustc_errors::Applicability;
 
 declare_clippy_lint! {
@@ -55,27 +55,42 @@ fn check_if_else<'tcx>(ctx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx
     if let ExprKind::If(check, then, Some(else_)) = expr.kind
         && let Some(then_lit) = int_literal(then)
         && let Some(else_lit) = int_literal(else_)
-        && check_int_literal_equals_val(then_lit, 1)
-        && check_int_literal_equals_val(else_lit, 0)
     {
+        let inverted = if
+            check_int_literal_equals_val(then_lit, 1)
+            && check_int_literal_equals_val(else_lit, 0) {
+            false
+        } else if
+            check_int_literal_equals_val(then_lit, 0)
+            && check_int_literal_equals_val(else_lit, 1) {
+            true
+        } else {
+            // Expression isn't boolean, exit
+            return;
+        };
         let mut applicability = Applicability::MachineApplicable;
-        let snippet = snippet_block_with_applicability(ctx, check.span, "..", None, &mut applicability);
-        let snippet_with_braces = {
-            let need_parens = should_have_parentheses(check);
-            let (left_paren, right_paren) = if need_parens {("(", ")")} else {("", "")};
-            format!("{left_paren}{snippet}{right_paren}")
+        let snippet = {
+            let mut sugg = Sugg::hir_with_applicability(ctx, check, "..", &mut applicability);
+            if inverted {
+                sugg = !sugg;
+            }
+            sugg
         };
 
         let ty = ctx.typeck_results().expr_ty(then_lit); // then and else must be of same type
 
         let suggestion = {
             let wrap_in_curly = is_else_clause(ctx.tcx, expr);
-            let (left_curly, right_curly) = if wrap_in_curly {("{", "}")} else {("", "")};
-            format!(
-                "{left_curly}{ty}::from({snippet}){right_curly}"
-            )
+            let mut s = Sugg::NonParen(format!("{ty}::from({snippet})").into());
+            if wrap_in_curly {
+                s = s.blockify();
+            }
+            s
         }; // when used in else clause if statement should be wrapped in curly braces
 
+        let into_snippet = snippet.clone().maybe_par();
+        let as_snippet = snippet.as_ty(ty);
+
         span_lint_and_then(ctx,
             BOOL_TO_INT_WITH_IF,
             expr.span,
@@ -87,7 +102,7 @@ fn check_if_else<'tcx>(ctx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx
                 suggestion,
                 applicability,
             );
-            diag.note(format!("`{snippet_with_braces} as {ty}` or `{snippet_with_braces}.into()` can also be valid options"));
+            diag.note(format!("`{as_snippet}` or `{into_snippet}.into()` can also be valid options"));
         });
     };
 }
@@ -119,7 +134,3 @@ fn check_int_literal_equals_val<'tcx>(expr: &'tcx rustc_hir::Expr<'tcx>, expecte
         false
     }
 }
-
-fn should_have_parentheses<'tcx>(check: &'tcx rustc_hir::Expr<'tcx>) -> bool {
-    check.precedence().order() < ExprPrecedence::Cast.order()
-}

src/tools/clippy/clippy_lints/src/booleans.rs

@@ -237,7 +237,7 @@ impl<'a, 'tcx, 'v> SuggestContext<'a, 'tcx, 'v> {
                 }
             },
             &Term(n) => {
-                let snip = snippet_opt(self.cx, self.terminals[n as usize].span)?;
+                let snip = snippet_opt(self.cx, self.terminals[n as usize].span.source_callsite())?;
                 self.output.push_str(&snip);
             },
         }

src/tools/clippy/clippy_lints/src/dereference.rs

@@ -297,13 +297,10 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing {
                         if !is_lint_allowed(cx, EXPLICIT_DEREF_METHODS, expr.hir_id)
                             && position.lint_explicit_deref() =>
                     {
+                        let ty_changed_count = usize::from(!deref_method_same_type(expr_ty, typeck.expr_ty(sub_expr)));
                         self.state = Some((
                             State::DerefMethod {
-                                ty_changed_count: if deref_method_same_type(expr_ty, typeck.expr_ty(sub_expr)) {
-                                    0
-                                } else {
-                                    1
-                                },
+                                ty_changed_count,
                                 is_final_ufcs: matches!(expr.kind, ExprKind::Call(..)),
                                 target_mut,
                             },

src/tools/clippy/clippy_lints/src/derivable_impls.rs

@@ -1,5 +1,6 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::{is_default_equivalent, peel_blocks};
+use rustc_errors::Applicability;
 use rustc_hir::{
     def::{DefKind, Res},
     Body, Expr, ExprKind, GenericArg, Impl, ImplItemKind, Item, ItemKind, Node, PathSegment, QPath, TyKind,
@@ -100,15 +101,28 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls {
                     ExprKind::Struct(_, fields, _) => fields.iter().all(|ef| is_default_equivalent(cx, ef.expr)),
                     _ => false,
                 };
+
                 if should_emit {
-                    let path_string = cx.tcx.def_path_str(adt_def.did());
-                    span_lint_and_help(
+                    let struct_span = cx.tcx.def_span(adt_def.did());
+                    span_lint_and_then(
                         cx,
                         DERIVABLE_IMPLS,
                         item.span,
                         "this `impl` can be derived",
-                        None,
-                        &format!("try annotating `{}` with `#[derive(Default)]`", path_string),
+                        |diag| {
+                            diag.span_suggestion_hidden(
+                                item.span,
+                                "remove the manual implementation...",
+                                String::new(),
+                                Applicability::MachineApplicable
+                            );
+                            diag.span_suggestion(
+                                struct_span.shrink_to_lo(),
+                                "...and instead derive it",
+                                "#[derive(Default)]\n".to_string(),
+                                Applicability::MachineApplicable
+                            );
+                        }
                     );
                 }
             }

src/tools/clippy/clippy_lints/src/format.rs

@@ -71,12 +71,12 @@ impl<'tcx> LateLintPass<'tcx> for UselessFormat {
             let value = arg.param.value;
             if_chain! {
                 if format_args.format_string.parts == [kw::Empty];
+                if arg.format.is_default();
                 if match cx.typeck_results().expr_ty(value).peel_refs().kind() {
                     ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(sym::String, adt.did()),
                     ty::Str => true,
                     _ => false,
                 };
-                if !arg.format.has_string_formatting();
                 then {
                     let is_new_string = match value.kind {
                         ExprKind::Binary(..) => true,

src/tools/clippy/clippy_lints/src/format_args.rs

@@ -77,7 +77,7 @@ impl<'tcx> LateLintPass<'tcx> for FormatArgs {
             if let ExpnKind::Macro(_, name) = outermost_expn_data.kind;
             then {
                 for arg in &format_args.args {
-                    if arg.format.has_string_formatting() {
+                    if !arg.format.is_default() {
                         continue;
                     }
                     if is_aliased(&format_args, arg.param.value.hir_id) {