submodules: update clippy from af5940b to 6651c1b

Changes:
````
Rename dummy_hir_id -> parent_hir_id
rustup rust-lang/rust#71116
Change default many single char names threshold
Better precedence case management + more tests
Use only check_expr with parent expr and precedence
Check for Deref trait impl + add fixed version
Report using stmts and expr + tests
Global rework + fix imports
Working basic dereference clip
Add test for zero single char names
Make the single char threshold strict inequality
large_enum_variant: Report sizes of variants
Refactor: Use rustc's `match_def_path`
deps: bump compiletest-rs from 0.4 to 0.5
rustup rust-lang/rust#70643
Explain panic on `E0463` in integration tests
Temporarily disable rustfmt integration test
result_map_unit_fn: Fix incorrect UI tests
Cleanup: Use rustc's is_proc_macro_attr
Cleanup: Use our `sym!` macro more
Fixes rust-lang#5405: redundant clone false positive with arrays
Disallow bit-shifting in `integer_arithmetic` lint
update lints
cargo dev fmt
Make use of Option/Result diagnostic items
Make use of some existing diagnostic items
Say that diagnostic items are preferred over paths
verbose_bit_mask: fix bit mask used in docs
Update documentation for new_ret_no_self
Update doc generation script
Add lint on large const arrays
Make the epsilon note spanless
Split check_fn function
Indicate when arrays are compared in error message
Make epsilon note spanless when comparing arrays
Add float cmp const tests for arrays
Add float cmp tests for arrays
Handle constant arrays with single value
Don't show comparison suggestion for arrays
Allow for const arrays of zeros
Handle evaluating constant index expression
Add handling of float arrays to miri_to_const
Update stderr of float_cmp test
Update field names in is_float
Add tests for float in array comparison
Add lint when comparing floats in an array
````

Fixes #71114

Author: matthiaskrgr

.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'

CHANGELOG.md

@@ -1256,6 +1256,7 @@ Released 2018-09-13
 [`expect_fun_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#expect_fun_call
 [`expl_impl_clone_on_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#expl_impl_clone_on_copy
 [`explicit_counter_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
+[`explicit_deref_methods`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_deref_methods
 [`explicit_into_iter_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_into_iter_loop
 [`explicit_iter_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_iter_loop
 [`explicit_write`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_write
@@ -1319,6 +1320,7 @@ Released 2018-09-13
 [`iter_skip_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_skip_next
 [`iterator_step_by_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#iterator_step_by_zero
 [`just_underscores_and_digits`]: https://rust-lang.github.io/rust-clippy/master/index.html#just_underscores_and_digits
+[`large_const_arrays`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_const_arrays
 [`large_digit_groups`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_digit_groups
 [`large_enum_variant`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_enum_variant
 [`large_stack_arrays`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_stack_arrays

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" }

clippy_lints/src/arithmetic.rs

@@ -6,11 +6,17 @@ use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::source_map::Span;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for plain integer arithmetic.
+    /// **What it does:** Checks for integer arithmetic operations which could overflow or panic.
     ///
-    /// **Why is this bad?** This is only checked against overflow in debug builds.
-    /// In some applications one wants explicitly checked, wrapping or saturating
-    /// arithmetic.
+    /// Specifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable
+    /// of overflowing according to the [Rust
+    /// Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
+    /// or which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is
+    /// attempted.
+    ///
+    /// **Why is this bad?** Integer overflow will trigger a panic in debug builds or will wrap in
+    /// release mode. Division by zero will cause a panic in either mode. In some applications one
+    /// wants explicitly checked, wrapping or saturating arithmetic.
     ///
     /// **Known problems:** None.
     ///
@@ -21,7 +27,7 @@ declare_clippy_lint! {
     /// ```
     pub INTEGER_ARITHMETIC,
     restriction,
-    "any integer arithmetic statement"
+    "any integer arithmetic expression which could overflow or panic"
 }
 
 declare_clippy_lint! {
@@ -71,8 +77,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Arithmetic {
                     | hir::BinOpKind::BitAnd
                     | hir::BinOpKind::BitOr
                     | hir::BinOpKind::BitXor
-                    | hir::BinOpKind::Shl
-                    | hir::BinOpKind::Shr
                     | hir::BinOpKind::Eq
                     | hir::BinOpKind::Lt
                     | hir::BinOpKind::Le

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/booleans.rs

@@ -1,5 +1,5 @@
 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;
@@ -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/cognitive_complexity.rs

@@ -9,7 +9,7 @@ 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.
@@ -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

@@ -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,
         }
@@ -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() {
@@ -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/dereference.rs

@@ -0,0 +1,113 @@
+use crate::utils::{get_parent_expr, implements_trait, snippet, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_ast::util::parser::{ExprPrecedence, PREC_POSTFIX, PREC_PREFIX};
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+    /// **What it does:** Checks for explicit `deref()` or `deref_mut()` method calls.
+    ///
+    /// **Why is this bad?** Derefencing by `&*x` or `&mut *x` is clearer and more concise,
+    /// when not part of a method chain.
+    ///
+    /// **Example:**
+    /// ```rust
+    /// use std::ops::Deref;
+    /// let a: &mut String = &mut String::from("foo");
+    /// let b: &str = a.deref();
+    /// ```
+    /// Could be written as:
+    /// ```rust
+    /// let a: &mut String = &mut String::from("foo");
+    /// let b = &*a;
+    /// ```
+    ///
+    /// This lint excludes
+    /// ```rust,ignore
+    /// let _ = d.unwrap().deref();
+    /// ```
+    pub EXPLICIT_DEREF_METHODS,
+    pedantic,
+    "Explicit use of deref or deref_mut method while not in a method chain."
+}
+
+declare_lint_pass!(Dereferencing => [
+    EXPLICIT_DEREF_METHODS
+]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Dereferencing {
+    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+        if_chain! {
+            if !expr.span.from_expansion();
+            if let ExprKind::MethodCall(ref method_name, _, ref args) = &expr.kind;
+            if args.len() == 1;
+
+            then {
+                if let Some(parent_expr) = get_parent_expr(cx, expr) {
+                    // Check if we have the whole call chain here
+                    if let ExprKind::MethodCall(..) = parent_expr.kind {
+                        return;
+                    }
+                    // Check for Expr that we don't want to be linted
+                    let precedence = parent_expr.precedence();
+                    match precedence {
+                        // Lint a Call is ok though
+                        ExprPrecedence::Call | ExprPrecedence::AddrOf => (),
+                        _ => {
+                            if precedence.order() >= PREC_PREFIX && precedence.order() <= PREC_POSTFIX {
+                                return;
+                            }
+                        }
+                    }
+                }
+                let name = method_name.ident.as_str();
+                lint_deref(cx, &*name, &args[0], args[0].span, expr.span);
+            }
+        }
+    }
+}
+
+fn lint_deref(cx: &LateContext<'_, '_>, method_name: &str, call_expr: &Expr<'_>, var_span: Span, expr_span: Span) {
+    match method_name {
+        "deref" => {
+            if cx
+                .tcx
+                .lang_items()
+                .deref_trait()
+                .map_or(false, |id| implements_trait(cx, cx.tables.expr_ty(&call_expr), id, &[]))
+            {
+                span_lint_and_sugg(
+                    cx,
+                    EXPLICIT_DEREF_METHODS,
+                    expr_span,
+                    "explicit deref method call",
+                    "try this",
+                    format!("&*{}", &snippet(cx, var_span, "..")),
+                    Applicability::MachineApplicable,
+                );
+            }
+        },
+        "deref_mut" => {
+            if cx
+                .tcx
+                .lang_items()
+                .deref_mut_trait()
+                .map_or(false, |id| implements_trait(cx, cx.tables.expr_ty(&call_expr), id, &[]))
+            {
+                span_lint_and_sugg(
+                    cx,
+                    EXPLICIT_DEREF_METHODS,
+                    expr_span,
+                    "explicit deref_mut method call",
+                    "try this",
+                    format!("&mut *{}", &snippet(cx, var_span, "..")),
+                    Applicability::MachineApplicable,
+                );
+            }
+        },
+        _ => (),
+    }
+}

clippy_lints/src/doc.rs

@@ -1,4 +1,4 @@
-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_ast::ast::{AttrKind, Attribute};
@@ -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,
@@ -235,7 +235,7 @@ fn lint_for_missing_headers<'a, 'tcx>(
                 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/fallible_impl_from.rs

@@ -1,10 +1,12 @@
-use crate::utils::paths::{BEGIN_PANIC, BEGIN_PANIC_FMT, FROM_TRAIT, OPTION, RESULT};
-use crate::utils::{is_expn_of, match_def_path, method_chain_args, span_lint_and_then, walk_ptrs_ty};
+use crate::utils::paths::{BEGIN_PANIC, BEGIN_PANIC_FMT, FROM_TRAIT};
+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 as hir;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::map::Map;
-use rustc_middle::ty::{self, Ty};
+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,
-    }
-}