Auto merge of #5888 - matthiaskrgr:lints, r=yaahc

make a bunch of lints texts adhere to rustc dev guide

According to the rustc-dev guide: "The text should be matter of fact and avoid capitalization and periods, unless multiple sentences are needed"

changelog: make some lint output adhere to the rustc-dev guide

clippy_lints/src/attrs.rs

@@ -605,7 +605,7 @@ fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::as
                         cx,
                         EMPTY_LINE_AFTER_OUTER_ATTR,
                         begin_of_attr_to_item,
-                        "Found an empty line after an outer attribute. \
+                        "found an empty line after an outer attribute. \
                         Perhaps you forgot to add a `!` to make it an inner attribute?",
                     );
                 }

clippy_lints/src/bytecount.rs

@@ -82,8 +82,8 @@ impl<'tcx> LateLintPass<'tcx> for ByteCount {
                             cx,
                             NAIVE_BYTECOUNT,
                             expr.span,
-                            "You appear to be counting bytes the naive way",
-                            "Consider using the bytecount crate",
+                            "you appear to be counting bytes the naive way",
+                            "consider using the bytecount crate",
                             format!("bytecount::count({}, {})",
                                     snippet_with_applicability(cx, haystack.span, "..", &mut applicability),
                                     snippet_with_applicability(cx, needle.span, "..", &mut applicability)),

clippy_lints/src/checked_conversions.rs

@@ -66,7 +66,7 @@ impl<'tcx> LateLintPass<'tcx> for CheckedConversions {
                     cx,
                     CHECKED_CONVERSIONS,
                     item.span,
-                    "Checked cast can be simplified.",
+                    "checked cast can be simplified",
                     "try",
                     format!("{}::try_from({}).is_ok()", to_type, snippet),
                     applicability,

clippy_lints/src/default_trait_access.rs

@@ -61,7 +61,7 @@ impl<'tcx> LateLintPass<'tcx> for DefaultTraitAccess {
                                 cx,
                                 DEFAULT_TRAIT_ACCESS,
                                 expr.span,
-                                &format!("Calling `{}` is more clear than this expression", replacement),
+                                &format!("calling `{}` is more clear than this expression", replacement),
                                 "try",
                                 replacement,
                                 Applicability::Unspecified, // First resolve the TODO above

clippy_lints/src/double_comparison.rs

@@ -60,7 +60,7 @@ impl<'tcx> DoubleComparisons {
                     cx,
                     DOUBLE_COMPARISONS,
                     span,
-                    "This binary expression can be simplified",
+                    "this binary expression can be simplified",
                     "try",
                     sugg,
                     applicability,

clippy_lints/src/double_parens.rs

@@ -45,41 +45,28 @@ impl EarlyLintPass for DoubleParens {
             return;
         }
 
+        let msg: &str = "consider removing unnecessary double parentheses";
+
         match expr.kind {
             ExprKind::Paren(ref in_paren) => match in_paren.kind {
                 ExprKind::Paren(_) | ExprKind::Tup(_) => {
-                    span_lint(
-                        cx,
-                        DOUBLE_PARENS,
-                        expr.span,
-                        "Consider removing unnecessary double parentheses",
-                    );
+                    span_lint(cx, DOUBLE_PARENS, expr.span, &msg);
                 },
                 _ => {},
             },
             ExprKind::Call(_, ref params) => {
                 if params.len() == 1 {
                     let param = &params[0];
                     if let ExprKind::Paren(_) = param.kind {
-                        span_lint(
-                            cx,
-                            DOUBLE_PARENS,
-                            param.span,
-                            "Consider removing unnecessary double parentheses",
-                        );
+                        span_lint(cx, DOUBLE_PARENS, param.span, &msg);
                     }
                 }
             },
             ExprKind::MethodCall(_, ref params, _) => {
                 if params.len() == 2 {
                     let param = &params[1];
                     if let ExprKind::Paren(_) = param.kind {
-                        span_lint(
-                            cx,
-                            DOUBLE_PARENS,
-                            param.span,
-                            "Consider removing unnecessary double parentheses",
-                        );
+                        span_lint(cx, DOUBLE_PARENS, param.span, &msg);
                     }
                 }
             },

clippy_lints/src/drop_bounds.rs

@@ -33,11 +33,11 @@ declare_clippy_lint! {
     /// ```
     pub DROP_BOUNDS,
     correctness,
-    "Bounds of the form `T: Drop` are useless"
+    "bounds of the form `T: Drop` are useless"
 }
 
-const DROP_BOUNDS_SUMMARY: &str = "Bounds of the form `T: Drop` are useless. \
-                                   Use `std::mem::needs_drop` to detect if a type has drop glue.";
+const DROP_BOUNDS_SUMMARY: &str = "bounds of the form `T: Drop` are useless, \
+                                   use `std::mem::needs_drop` to detect if a type has drop glue";
 
 declare_lint_pass!(DropBounds => [DROP_BOUNDS]);
 

clippy_lints/src/functions.rs

@@ -374,7 +374,7 @@ impl<'tcx> Functions {
         }
 
         if line_count > self.max_lines {
-            span_lint(cx, TOO_MANY_LINES, span, "This function has a large number of lines.")
+            span_lint(cx, TOO_MANY_LINES, span, "this function has a large number of lines")
         }
     }
 

clippy_lints/src/misc_early.rs

@@ -271,7 +271,7 @@ impl EarlyLintPass for MiscEarlyLints {
                         cx,
                         BUILTIN_TYPE_SHADOW,
                         param.ident.span,
-                        &format!("This generic shadows the built-in type `{}`", name),
+                        &format!("this generic shadows the built-in type `{}`", name),
                     );
                 }
             }
@@ -298,9 +298,9 @@ impl EarlyLintPass for MiscEarlyLints {
                     cx,
                     UNNEEDED_FIELD_PATTERN,
                     pat.span,
-                    "All the struct fields are matched to a wildcard pattern, consider using `..`.",
+                    "all the struct fields are matched to a wildcard pattern, consider using `..`",
                     None,
-                    &format!("Try with `{} {{ .. }}` instead", type_name),
+                    &format!("try with `{} {{ .. }}` instead", type_name),
                 );
                 return;
             }
@@ -313,7 +313,7 @@ impl EarlyLintPass for MiscEarlyLints {
                                 cx,
                                 UNNEEDED_FIELD_PATTERN,
                                 field.span,
-                                "You matched a field with a wildcard pattern. Consider using `..` instead",
+                                "you matched a field with a wildcard pattern, consider using `..` instead",
                             );
                         } else {
                             let mut normal = vec![];
@@ -333,10 +333,10 @@ impl EarlyLintPass for MiscEarlyLints {
                                 cx,
                                 UNNEEDED_FIELD_PATTERN,
                                 field.span,
-                                "You matched a field with a wildcard pattern. Consider using `..` \
+                                "you matched a field with a wildcard pattern, consider using `..` \
                                  instead",
                                 None,
-                                &format!("Try with `{} {{ {}, .. }}`", type_name, normal[..].join(", ")),
+                                &format!("try with `{} {{ {}, .. }}`", type_name, normal[..].join(", ")),
                             );
                         }
                     }

clippy_lints/src/needless_bool.rs

@@ -243,7 +243,7 @@ fn check_comparison<'a, 'tcx>(
                         cx,
                         BOOL_COMPARISON,
                         e.span,
-                        "This comparison might be written more concisely",
+                        "this comparison might be written more concisely",
                         "try simplifying it as shown",
                         format!(
                             "{} != {}",

clippy_lints/src/neg_cmp_op_on_partial_ord.rs

@@ -79,10 +79,10 @@ impl<'tcx> LateLintPass<'tcx> for NoNegCompOpForPartialOrd {
                         cx,
                         NEG_CMP_OP_ON_PARTIAL_ORD,
                         expr.span,
-                        "The use of negated comparison operators on partially ordered \
-                        types produces code that is hard to read and refactor. Please \
+                        "the use of negated comparison operators on partially ordered \
+                        types produces code that is hard to read and refactor, please \
                         consider using the `partial_cmp` method instead, to make it \
-                        clear that the two values could be incomparable."
+                        clear that the two values could be incomparable"
                     )
                 }
             }

clippy_lints/src/neg_multiply.rs

@@ -47,7 +47,7 @@ fn check_mul(cx: &LateContext<'_>, span: Span, lit: &Expr<'_>, exp: &Expr<'_>) {
         if let Constant::Int(1) = consts::lit_to_constant(&l.node, cx.typeck_results().expr_ty_opt(lit));
         if cx.typeck_results().expr_ty(exp).is_integral();
         then {
-            span_lint(cx, NEG_MULTIPLY, span, "Negation by multiplying with `-1`");
+            span_lint(cx, NEG_MULTIPLY, span, "negation by multiplying with `-1`");
         }
     }
 }

clippy_lints/src/overflow_check_conditional.rs

@@ -42,13 +42,13 @@ impl<'tcx> LateLintPass<'tcx> for OverflowCheckConditional {
                 if let BinOpKind::Lt = op.node {
                     if let BinOpKind::Add = op2.node {
                         span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
-                            "You are trying to use classic C overflow conditions that will fail in Rust.");
+                            "you are trying to use classic C overflow conditions that will fail in Rust");
                     }
                 }
                 if let BinOpKind::Gt = op.node {
                     if let BinOpKind::Sub = op2.node {
                         span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
-                            "You are trying to use classic C underflow conditions that will fail in Rust.");
+                            "you are trying to use classic C underflow conditions that will fail in Rust");
                     }
                 }
             }
@@ -67,13 +67,13 @@ impl<'tcx> LateLintPass<'tcx> for OverflowCheckConditional {
                 if let BinOpKind::Gt = op.node {
                     if let BinOpKind::Add = op2.node {
                         span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
-                            "You are trying to use classic C overflow conditions that will fail in Rust.");
+                            "you are trying to use classic C overflow conditions that will fail in Rust");
                     }
                 }
                 if let BinOpKind::Lt = op.node {
                     if let BinOpKind::Sub = op2.node {
                         span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
-                            "You are trying to use classic C underflow conditions that will fail in Rust.");
+                            "you are trying to use classic C underflow conditions that will fail in Rust");
                     }
                 }
             }

clippy_lints/src/path_buf_push_overwrite.rs

@@ -60,7 +60,7 @@ impl<'tcx> LateLintPass<'tcx> for PathBufPushOverwrite {
                     cx,
                     PATH_BUF_PUSH_OVERWRITE,
                     lit.span,
-                    "Calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition",
+                    "calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition",
                     "try",
                     format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')),
                     Applicability::MachineApplicable,

clippy_lints/src/ptr.rs

@@ -145,7 +145,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
                     cx,
                     CMP_NULL,
                     expr.span,
-                    "Comparing with null is better expressed by the `.is_null()` method",
+                    "comparing with null is better expressed by the `.is_null()` method",
                 );
             }
         }

clippy_lints/src/ranges.rs

@@ -160,7 +160,7 @@ impl<'tcx> LateLintPass<'tcx> for Ranges {
                          span_lint(cx,
                                    RANGE_ZIP_WITH_LEN,
                                    expr.span,
-                                   &format!("It is more idiomatic to use `{}.iter().enumerate()`",
+                                   &format!("it is more idiomatic to use `{}.iter().enumerate()`",
                                             snippet(cx, iter_args[0].span, "_")));
                     }
                 }

clippy_lints/src/redundant_static_lifetimes.rs

@@ -86,13 +86,13 @@ impl EarlyLintPass for RedundantStaticLifetimes {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
         if !item.span.from_expansion() {
             if let ItemKind::Const(_, ref var_type, _) = item.kind {
-                self.visit_type(var_type, cx, "Constants have by default a `'static` lifetime");
+                self.visit_type(var_type, cx, "constants have by default a `'static` lifetime");
                 // Don't check associated consts because `'static` cannot be elided on those (issue
                 // #2438)
             }
 
             if let ItemKind::Static(ref var_type, _, _) = item.kind {
-                self.visit_type(var_type, cx, "Statics have by default a `'static` lifetime");
+                self.visit_type(var_type, cx, "statics have by default a `'static` lifetime");
             }
         }
     }

clippy_lints/src/reference.rs

@@ -92,7 +92,7 @@ impl EarlyLintPass for RefInDeref {
                     cx,
                     REF_IN_DEREF,
                     object.span,
-                    "Creating a reference that is immediately dereferenced.",
+                    "creating a reference that is immediately dereferenced",
                     "try this",
                     snippet_with_applicability(cx, inner.span, "_", &mut applicability).to_string(),
                     applicability,

clippy_lints/src/suspicious_trait_impl.rs

@@ -98,7 +98,7 @@ impl<'tcx> LateLintPass<'tcx> for SuspiciousImpl {
                     cx,
                     SUSPICIOUS_ARITHMETIC_IMPL,
                     binop.span,
-                    &format!(r#"Suspicious use of binary operator in `{}` impl"#, impl_trait),
+                    &format!("suspicious use of binary operator in `{}` impl", impl_trait),
                 );
             }
 
@@ -135,7 +135,7 @@ impl<'tcx> LateLintPass<'tcx> for SuspiciousImpl {
                     cx,
                     SUSPICIOUS_OP_ASSIGN_IMPL,
                     binop.span,
-                    &format!(r#"Suspicious use of binary operator in `{}` impl"#, impl_trait),
+                    &format!("suspicious use of binary operator in `{}` impl", impl_trait),
                 );
             }
         }

clippy_lints/src/unwrap.rs

@@ -181,8 +181,8 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> {
                             self.cx,
                             UNNECESSARY_UNWRAP,
                             expr.span,
-                            &format!("You checked before that `{}()` cannot fail. \
-                            Instead of checking and unwrapping, it's better to use `if let` or `match`.",
+                            &format!("you checked before that `{}()` cannot fail, \
+                            instead of checking and unwrapping, it's better to use `if let` or `match`",
                             method_name.ident.name),
                             |diag| { diag.span_label(unwrappable.check.span, "the check is happening here"); },
                         );
@@ -191,7 +191,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> {
                             self.cx,
                             PANICKING_UNWRAP,
                             expr.span,
-                            &format!("This call to `{}()` will always panic.",
+                            &format!("this call to `{}()` will always panic",
                             method_name.ident.name),
                             |diag| { diag.span_label(unwrappable.check.span, "because of this check"); },
                         );

clippy_lints/src/utils/attrs.rs

@@ -75,12 +75,12 @@ pub fn get_attr<'a>(
                 })
                 .map_or_else(
                     || {
-                        sess.span_err(attr_segments[1].ident.span, "Usage of unknown attribute");
+                        sess.span_err(attr_segments[1].ident.span, "usage of unknown attribute");
                         false
                     },
                     |deprecation_status| {
                         let mut diag =
-                            sess.struct_span_err(attr_segments[1].ident.span, "Usage of deprecated attribute");
+                            sess.struct_span_err(attr_segments[1].ident.span, "usage of deprecated attribute");
                         match *deprecation_status {
                             DeprecationStatus::Deprecated => {
                                 diag.emit();

src/lintlist/mod.rs

@@ -412,7 +412,7 @@ pub static ref ALL_LINTS: Vec<Lint> = vec![
     Lint {
         name: "drop_bounds",
         group: "correctness",
-        desc: "Bounds of the form `T: Drop` are useless",
+        desc: "bounds of the form `T: Drop` are useless",
         deprecation: None,
         module: "drop_bounds",
     },

tests/ui-toml/functions_maxlines/test.stderr

@@ -1,4 +1,4 @@
-error: This function has a large number of lines.
+error: this function has a large number of lines
   --> $DIR/test.rs:18:1
    |
 LL | / fn too_many_lines() {
@@ -9,7 +9,7 @@ LL | | }
    |
    = note: `-D clippy::too-many-lines` implied by `-D warnings`
 
-error: This function has a large number of lines.
+error: this function has a large number of lines
   --> $DIR/test.rs:38:1
    |
 LL | / fn comment_before_code() {

tests/ui/bool_comparison.stderr

@@ -84,25 +84,25 @@ error: order comparisons between booleans can be simplified
 LL |     if x > y {
    |        ^^^^^ help: try simplifying it as shown: `x & !y`
 
-error: This comparison might be written more concisely
+error: this comparison might be written more concisely
   --> $DIR/bool_comparison.rs:120:8
    |
 LL |     if a == !b {};
    |        ^^^^^^^ help: try simplifying it as shown: `a != b`
 
-error: This comparison might be written more concisely
+error: this comparison might be written more concisely
   --> $DIR/bool_comparison.rs:121:8
    |
 LL |     if !a == b {};
    |        ^^^^^^^ help: try simplifying it as shown: `a != b`
 
-error: This comparison might be written more concisely
+error: this comparison might be written more concisely
   --> $DIR/bool_comparison.rs:125:8
    |
 LL |     if b == !a {};
    |        ^^^^^^^ help: try simplifying it as shown: `b != a`
 
-error: This comparison might be written more concisely
+error: this comparison might be written more concisely
   --> $DIR/bool_comparison.rs:126:8
    |
 LL |     if !b == a {};

tests/ui/builtin-type-shadow.stderr

@@ -1,4 +1,4 @@
-error: This generic shadows the built-in type `u32`
+error: this generic shadows the built-in type `u32`
   --> $DIR/builtin-type-shadow.rs:4:8
    |
 LL | fn foo<u32>(a: u32) -> u32 {