From d810d426a4c66d3cae8022547c170e38488d95fb Mon Sep 17 00:00:00 2001 From: Kalle Wachsmuth Date: Mon, 17 Jun 2024 18:49:19 +0200 Subject: [PATCH 1/3] unrelated cleanup --- compiler/rustc_lint/src/builtin.rs | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs index 876ef944d650b..3da9ef3ff7c6b 100644 --- a/compiler/rustc_lint/src/builtin.rs +++ b/compiler/rustc_lint/src/builtin.rs @@ -90,19 +90,11 @@ declare_lint! { declare_lint_pass!(WhileTrue => [WHILE_TRUE]); -/// Traverse through any amount of parenthesis and return the first non-parens expression. -fn pierce_parens(mut expr: &ast::Expr) -> &ast::Expr { - while let ast::ExprKind::Paren(sub) = &expr.kind { - expr = sub; - } - expr -} - impl EarlyLintPass for WhileTrue { #[inline] fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { if let ast::ExprKind::While(cond, _, label) = &e.kind - && let ast::ExprKind::Lit(token_lit) = pierce_parens(cond).kind + && let ast::ExprKind::Lit(token_lit) = cond.peel_parens().kind && let token::Lit { kind: token::Bool, symbol: kw::True, .. } = token_lit && !cond.span.from_expansion() { @@ -2651,7 +2643,7 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue { } declare_lint! { - /// The `deref_nullptr` lint detects when an null pointer is dereferenced, + /// The `deref_nullptr` lint detects when a null pointer is dereferenced, /// which causes [undefined behavior]. /// /// ### Example From 9e316f34720a27477c79fdb5e0193554bd4d3fb5 Mon Sep 17 00:00:00 2001 From: Kalle Wachsmuth Date: Tue, 29 Oct 2024 20:49:22 +0100 Subject: [PATCH 2/3] remove `clippy::double_neg` --- src/tools/clippy/.github/driver.sh | 6 +- src/tools/clippy/book/src/usage.md | 9 +- src/tools/clippy/clippy_dev/src/new_lint.rs | 4 +- .../clippy/clippy_lints/src/declared_lints.rs | 1 - .../clippy_lints/src/deprecated_lints.rs | 2 + .../clippy_lints/src/misc_early/double_neg.rs | 18 --- .../clippy/clippy_lints/src/misc_early/mod.rs | 22 --- src/tools/clippy/tests/ui/double_neg.rs | 10 -- src/tools/clippy/tests/ui/double_neg.stderr | 11 -- src/tools/clippy/tests/ui/rename.fixed | 15 ++- src/tools/clippy/tests/ui/rename.rs | 15 ++- src/tools/clippy/tests/ui/rename.stderr | 126 +++++++++--------- 12 files changed, 93 insertions(+), 146 deletions(-) delete mode 100644 src/tools/clippy/clippy_lints/src/misc_early/double_neg.rs delete mode 100644 src/tools/clippy/tests/ui/double_neg.rs delete mode 100644 src/tools/clippy/tests/ui/double_neg.stderr diff --git a/src/tools/clippy/.github/driver.sh b/src/tools/clippy/.github/driver.sh index 09202b1878b23..701be6bd76d34 100755 --- a/src/tools/clippy/.github/driver.sh +++ b/src/tools/clippy/.github/driver.sh @@ -47,9 +47,9 @@ unset CARGO_MANIFEST_DIR # Run a lint and make sure it produces the expected output. It's also expected to exit with code 1 # FIXME: How to match the clippy invocation in compile-test.rs? -./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/double_neg.rs 2>double_neg.stderr && exit 1 -sed -e "/= help: for/d" double_neg.stderr > normalized.stderr -diff -u normalized.stderr tests/ui/double_neg.stderr +./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/box_default.rs 2>box_default.stderr && exit 1 +sed -e "/= help: for/d" box_default.stderr > normalized.stderr +diff -u normalized.stderr tests/ui/box_default.stderr # make sure "clippy-driver --rustc --arg" and "rustc --arg" behave the same SYSROOT=$(rustc --print sysroot) diff --git a/src/tools/clippy/book/src/usage.md b/src/tools/clippy/book/src/usage.md index 7a0be6994fe1b..23edf6c2abaaf 100644 --- a/src/tools/clippy/book/src/usage.md +++ b/src/tools/clippy/book/src/usage.md @@ -33,7 +33,7 @@ You can configure lint levels on the command line by adding `-A/W/D clippy::lint_name` like this: ```bash -cargo clippy -- -Aclippy::style -Wclippy::double_neg -Dclippy::perf +cargo clippy -- -Aclippy::style -Wclippy::box_default -Dclippy::perf ``` For [CI] all warnings can be elevated to errors which will in turn fail @@ -101,11 +101,10 @@ You can configure lint levels in source code the same way you can configure ```rust,ignore #![allow(clippy::style)] -#[warn(clippy::double_neg)] +#[warn(clippy::box_default)] fn main() { - let x = 1; - let y = --x; - // ^^ warning: double negation + let _ = Box::::new(Default::default()); + // ^ warning: `Box::new(_)` of default value } ``` diff --git a/src/tools/clippy/clippy_dev/src/new_lint.rs b/src/tools/clippy/clippy_dev/src/new_lint.rs index 24d1a53266a07..35dd986ff614f 100644 --- a/src/tools/clippy/clippy_dev/src/new_lint.rs +++ b/src/tools/clippy/clippy_dev/src/new_lint.rs @@ -455,7 +455,7 @@ fn setup_mod_file(path: &Path, lint: &LintData<'_>) -> io::Result<&'static str> }); // Find both the last lint declaration (declare_clippy_lint!) and the lint pass impl - while let Some(LintDeclSearchResult { content, .. }) = iter.find(|result| result.token == TokenKind::Ident) { + while let Some(LintDeclSearchResult { content, .. }) = iter.find(|result| result.token_kind == TokenKind::Ident) { let mut iter = iter .by_ref() .filter(|t| !matches!(t.token_kind, TokenKind::Whitespace | TokenKind::LineComment { .. })); @@ -465,7 +465,7 @@ fn setup_mod_file(path: &Path, lint: &LintData<'_>) -> io::Result<&'static str> // matches `!{` match_tokens!(iter, Bang OpenBrace); if let Some(LintDeclSearchResult { range, .. }) = - iter.find(|result| result.token == TokenKind::CloseBrace) + iter.find(|result| result.token_kind == TokenKind::CloseBrace) { last_decl_curly_offset = Some(range.end); } diff --git a/src/tools/clippy/clippy_lints/src/declared_lints.rs b/src/tools/clippy/clippy_lints/src/declared_lints.rs index 3ff10d850f82b..87e546fbf0144 100644 --- a/src/tools/clippy/clippy_lints/src/declared_lints.rs +++ b/src/tools/clippy/clippy_lints/src/declared_lints.rs @@ -507,7 +507,6 @@ pub static LINTS: &[&crate::LintInfo] = &[ crate::misc::USED_UNDERSCORE_BINDING_INFO, crate::misc::USED_UNDERSCORE_ITEMS_INFO, crate::misc_early::BUILTIN_TYPE_SHADOW_INFO, - crate::misc_early::DOUBLE_NEG_INFO, crate::misc_early::DUPLICATE_UNDERSCORE_ARGUMENT_INFO, crate::misc_early::MIXED_CASE_HEX_LITERALS_INFO, crate::misc_early::REDUNDANT_AT_REST_PATTERN_INFO, diff --git a/src/tools/clippy/clippy_lints/src/deprecated_lints.rs b/src/tools/clippy/clippy_lints/src/deprecated_lints.rs index 3ea792d8b835c..5604172d6f309 100644 --- a/src/tools/clippy/clippy_lints/src/deprecated_lints.rs +++ b/src/tools/clippy/clippy_lints/src/deprecated_lints.rs @@ -129,6 +129,8 @@ declare_with_version! { RENAMED(RENAMED_VERSION): &[(&str, &str)] = &[ ("clippy::clone_double_ref", "suspicious_double_ref_op"), #[clippy::version = ""] ("clippy::cmp_nan", "invalid_nan_comparisons"), + #[clippy::version = "1.86.0"] + ("clippy::double_neg", "double_negations"), #[clippy::version = ""] ("clippy::drop_bounds", "drop_bounds"), #[clippy::version = ""] diff --git a/src/tools/clippy/clippy_lints/src/misc_early/double_neg.rs b/src/tools/clippy/clippy_lints/src/misc_early/double_neg.rs deleted file mode 100644 index 06ba968fa4ed3..0000000000000 --- a/src/tools/clippy/clippy_lints/src/misc_early/double_neg.rs +++ /dev/null @@ -1,18 +0,0 @@ -use clippy_utils::diagnostics::span_lint; -use rustc_ast::ast::{Expr, ExprKind, UnOp}; -use rustc_lint::EarlyContext; - -use super::DOUBLE_NEG; - -pub(super) fn check(cx: &EarlyContext<'_>, expr: &Expr) { - if let ExprKind::Unary(UnOp::Neg, ref inner) = expr.kind { - if let ExprKind::Unary(UnOp::Neg, _) = inner.kind { - span_lint( - cx, - DOUBLE_NEG, - expr.span, - "`--x` could be misinterpreted as pre-decrement by C programmers, is usually a no-op", - ); - } - } -} diff --git a/src/tools/clippy/clippy_lints/src/misc_early/mod.rs b/src/tools/clippy/clippy_lints/src/misc_early/mod.rs index 37d7427f9a5d2..637d6ed3ad2c6 100644 --- a/src/tools/clippy/clippy_lints/src/misc_early/mod.rs +++ b/src/tools/clippy/clippy_lints/src/misc_early/mod.rs @@ -1,5 +1,4 @@ mod builtin_type_shadow; -mod double_neg; mod literal_suffix; mod mixed_case_hex_literals; mod redundant_at_rest_pattern; @@ -85,25 +84,6 @@ declare_clippy_lint! { "function arguments having names which only differ by an underscore" } -declare_clippy_lint! { - /// ### What it does - /// Detects expressions of the form `--x`. - /// - /// ### Why is this bad? - /// It can mislead C/C++ programmers to think `x` was - /// decremented. - /// - /// ### Example - /// ```no_run - /// let mut x = 3; - /// --x; - /// ``` - #[clippy::version = "pre 1.29.0"] - pub DOUBLE_NEG, - style, - "`--x`, which is a double negation of `x` and not a pre-decrement as in C/C++" -} - declare_clippy_lint! { /// ### What it does /// Warns on hexadecimal literals with mixed-case letter @@ -352,7 +332,6 @@ declare_clippy_lint! { declare_lint_pass!(MiscEarlyLints => [ UNNEEDED_FIELD_PATTERN, DUPLICATE_UNDERSCORE_ARGUMENT, - DOUBLE_NEG, MIXED_CASE_HEX_LITERALS, UNSEPARATED_LITERAL_SUFFIX, SEPARATED_LITERAL_SUFFIX, @@ -415,7 +394,6 @@ impl EarlyLintPass for MiscEarlyLints { if let ExprKind::Lit(lit) = expr.kind { MiscEarlyLints::check_lit(cx, lit, expr.span); } - double_neg::check(cx, expr); } } diff --git a/src/tools/clippy/tests/ui/double_neg.rs b/src/tools/clippy/tests/ui/double_neg.rs deleted file mode 100644 index 3be8c62887381..0000000000000 --- a/src/tools/clippy/tests/ui/double_neg.rs +++ /dev/null @@ -1,10 +0,0 @@ -#[warn(clippy::double_neg)] -#[allow(clippy::no_effect)] -fn main() { - let x = 1; - -x; - -(-x); - --x; - //~^ ERROR: `--x` could be misinterpreted as pre-decrement by C programmers, is usually - //~| NOTE: `-D clippy::double-neg` implied by `-D warnings` -} diff --git a/src/tools/clippy/tests/ui/double_neg.stderr b/src/tools/clippy/tests/ui/double_neg.stderr deleted file mode 100644 index 9a902d1323ccd..0000000000000 --- a/src/tools/clippy/tests/ui/double_neg.stderr +++ /dev/null @@ -1,11 +0,0 @@ -error: `--x` could be misinterpreted as pre-decrement by C programmers, is usually a no-op - --> tests/ui/double_neg.rs:7:5 - | -LL | --x; - | ^^^ - | - = note: `-D clippy::double-neg` implied by `-D warnings` - = help: to override `-D warnings` add `#[allow(clippy::double_neg)]` - -error: aborting due to 1 previous error - diff --git a/src/tools/clippy/tests/ui/rename.fixed b/src/tools/clippy/tests/ui/rename.fixed index 47d6e119543d1..501811fa491b3 100644 --- a/src/tools/clippy/tests/ui/rename.fixed +++ b/src/tools/clippy/tests/ui/rename.fixed @@ -13,9 +13,8 @@ #![allow(clippy::disallowed_methods)] #![allow(clippy::disallowed_types)] #![allow(clippy::mixed_read_write_in_expression)] -#![allow(clippy::manual_find_map)] #![allow(clippy::manual_filter_map)] -#![allow(unpredictable_function_pointer_comparisons)] +#![allow(clippy::manual_find_map)] #![allow(clippy::useless_conversion)] #![allow(clippy::redundant_pattern_matching)] #![allow(clippy::match_result_ok)] @@ -30,6 +29,7 @@ #![allow(clippy::unwrap_used)] #![allow(clippy::panicking_overflow_checks)] #![allow(clippy::needless_borrow)] +#![allow(clippy::reversed_empty_ranges)] #![allow(clippy::single_char_add_str)] #![allow(clippy::module_name_repetitions)] #![allow(clippy::missing_const_for_thread_local)] @@ -39,9 +39,11 @@ #![allow(invalid_reference_casting)] #![allow(suspicious_double_ref_op)] #![allow(invalid_nan_comparisons)] +#![allow(double_negations)] #![allow(drop_bounds)] #![allow(dropping_copy_types)] #![allow(dropping_references)] +#![allow(unpredictable_function_pointer_comparisons)] #![allow(useless_ptr_null_checks)] #![allow(for_loops_over_fallibles)] #![allow(forgetting_copy_types)] @@ -60,8 +62,6 @@ #![allow(unknown_lints)] #![allow(unused_labels)] #![allow(ambiguous_wide_pointer_comparisons)] -#![allow(unpredictable_function_pointer_comparisons)] -#![allow(clippy::reversed_empty_ranges)] #![warn(clippy::almost_complete_range)] //~ ERROR: lint `clippy::almost_complete_letter_range` #![warn(clippy::disallowed_names)] //~ ERROR: lint `clippy::blacklisted_name` #![warn(clippy::blocks_in_conditions)] //~ ERROR: lint `clippy::block_in_if_condition_expr` @@ -74,9 +74,8 @@ #![warn(clippy::disallowed_methods)] //~ ERROR: lint `clippy::disallowed_method` #![warn(clippy::disallowed_types)] //~ ERROR: lint `clippy::disallowed_type` #![warn(clippy::mixed_read_write_in_expression)] //~ ERROR: lint `clippy::eval_order_dependence` -#![warn(clippy::manual_find_map)] //~ ERROR: lint `clippy::find_map` #![warn(clippy::manual_filter_map)] //~ ERROR: lint `clippy::filter_map` -#![warn(unpredictable_function_pointer_comparisons)] //~ ERROR: lint `clippy::fn_address_comparisons` +#![warn(clippy::manual_find_map)] //~ ERROR: lint `clippy::find_map` #![warn(clippy::useless_conversion)] //~ ERROR: lint `clippy::identity_conversion` #![warn(clippy::redundant_pattern_matching)] //~ ERROR: lint `clippy::if_let_redundant_pattern_matching` #![warn(clippy::match_result_ok)] //~ ERROR: lint `clippy::if_let_some_result` @@ -95,6 +94,7 @@ #![warn(clippy::expect_used)] //~ ERROR: lint `clippy::result_expect_used` #![warn(clippy::map_unwrap_or)] //~ ERROR: lint `clippy::result_map_unwrap_or_else` #![warn(clippy::unwrap_used)] //~ ERROR: lint `clippy::result_unwrap_used` +#![warn(clippy::reversed_empty_ranges)] //~ ERROR: lint `clippy::reverse_range_loop` #![warn(clippy::single_char_add_str)] //~ ERROR: lint `clippy::single_char_push_str` #![warn(clippy::module_name_repetitions)] //~ ERROR: lint `clippy::stutter` #![warn(clippy::missing_const_for_thread_local)] //~ ERROR: lint `clippy::thread_local_initializer_can_be_made_const` @@ -104,9 +104,11 @@ #![warn(invalid_reference_casting)] //~ ERROR: lint `clippy::cast_ref_to_mut` #![warn(suspicious_double_ref_op)] //~ ERROR: lint `clippy::clone_double_ref` #![warn(invalid_nan_comparisons)] //~ ERROR: lint `clippy::cmp_nan` +#![warn(double_negations)] //~ ERROR: lint `clippy::double_neg` #![warn(drop_bounds)] //~ ERROR: lint `clippy::drop_bounds` #![warn(dropping_copy_types)] //~ ERROR: lint `clippy::drop_copy` #![warn(dropping_references)] //~ ERROR: lint `clippy::drop_ref` +#![warn(unpredictable_function_pointer_comparisons)] //~ ERROR: lint `clippy::fn_address_comparisons` #![warn(useless_ptr_null_checks)] //~ ERROR: lint `clippy::fn_null_check` #![warn(for_loops_over_fallibles)] //~ ERROR: lint `clippy::for_loop_over_option` #![warn(for_loops_over_fallibles)] //~ ERROR: lint `clippy::for_loop_over_result` @@ -128,6 +130,5 @@ #![warn(unknown_lints)] //~ ERROR: lint `clippy::unknown_clippy_lints` #![warn(unused_labels)] //~ ERROR: lint `clippy::unused_label` #![warn(ambiguous_wide_pointer_comparisons)] //~ ERROR: lint `clippy::vtable_address_comparisons` -#![warn(clippy::reversed_empty_ranges)] //~ ERROR: lint `clippy::reverse_range_loop` fn main() {} diff --git a/src/tools/clippy/tests/ui/rename.rs b/src/tools/clippy/tests/ui/rename.rs index 12c7db69be2e4..7f4b8062e1b4b 100644 --- a/src/tools/clippy/tests/ui/rename.rs +++ b/src/tools/clippy/tests/ui/rename.rs @@ -13,9 +13,8 @@ #![allow(clippy::disallowed_methods)] #![allow(clippy::disallowed_types)] #![allow(clippy::mixed_read_write_in_expression)] -#![allow(clippy::manual_find_map)] #![allow(clippy::manual_filter_map)] -#![allow(unpredictable_function_pointer_comparisons)] +#![allow(clippy::manual_find_map)] #![allow(clippy::useless_conversion)] #![allow(clippy::redundant_pattern_matching)] #![allow(clippy::match_result_ok)] @@ -30,6 +29,7 @@ #![allow(clippy::unwrap_used)] #![allow(clippy::panicking_overflow_checks)] #![allow(clippy::needless_borrow)] +#![allow(clippy::reversed_empty_ranges)] #![allow(clippy::single_char_add_str)] #![allow(clippy::module_name_repetitions)] #![allow(clippy::missing_const_for_thread_local)] @@ -39,9 +39,11 @@ #![allow(invalid_reference_casting)] #![allow(suspicious_double_ref_op)] #![allow(invalid_nan_comparisons)] +#![allow(double_negations)] #![allow(drop_bounds)] #![allow(dropping_copy_types)] #![allow(dropping_references)] +#![allow(unpredictable_function_pointer_comparisons)] #![allow(useless_ptr_null_checks)] #![allow(for_loops_over_fallibles)] #![allow(forgetting_copy_types)] @@ -60,8 +62,6 @@ #![allow(unknown_lints)] #![allow(unused_labels)] #![allow(ambiguous_wide_pointer_comparisons)] -#![allow(unpredictable_function_pointer_comparisons)] -#![allow(clippy::reversed_empty_ranges)] #![warn(clippy::almost_complete_letter_range)] //~ ERROR: lint `clippy::almost_complete_letter_range` #![warn(clippy::blacklisted_name)] //~ ERROR: lint `clippy::blacklisted_name` #![warn(clippy::block_in_if_condition_expr)] //~ ERROR: lint `clippy::block_in_if_condition_expr` @@ -74,9 +74,8 @@ #![warn(clippy::disallowed_method)] //~ ERROR: lint `clippy::disallowed_method` #![warn(clippy::disallowed_type)] //~ ERROR: lint `clippy::disallowed_type` #![warn(clippy::eval_order_dependence)] //~ ERROR: lint `clippy::eval_order_dependence` -#![warn(clippy::find_map)] //~ ERROR: lint `clippy::find_map` #![warn(clippy::filter_map)] //~ ERROR: lint `clippy::filter_map` -#![warn(clippy::fn_address_comparisons)] //~ ERROR: lint `clippy::fn_address_comparisons` +#![warn(clippy::find_map)] //~ ERROR: lint `clippy::find_map` #![warn(clippy::identity_conversion)] //~ ERROR: lint `clippy::identity_conversion` #![warn(clippy::if_let_redundant_pattern_matching)] //~ ERROR: lint `clippy::if_let_redundant_pattern_matching` #![warn(clippy::if_let_some_result)] //~ ERROR: lint `clippy::if_let_some_result` @@ -95,6 +94,7 @@ #![warn(clippy::result_expect_used)] //~ ERROR: lint `clippy::result_expect_used` #![warn(clippy::result_map_unwrap_or_else)] //~ ERROR: lint `clippy::result_map_unwrap_or_else` #![warn(clippy::result_unwrap_used)] //~ ERROR: lint `clippy::result_unwrap_used` +#![warn(clippy::reverse_range_loop)] //~ ERROR: lint `clippy::reverse_range_loop` #![warn(clippy::single_char_push_str)] //~ ERROR: lint `clippy::single_char_push_str` #![warn(clippy::stutter)] //~ ERROR: lint `clippy::stutter` #![warn(clippy::thread_local_initializer_can_be_made_const)] //~ ERROR: lint `clippy::thread_local_initializer_can_be_made_const` @@ -104,9 +104,11 @@ #![warn(clippy::cast_ref_to_mut)] //~ ERROR: lint `clippy::cast_ref_to_mut` #![warn(clippy::clone_double_ref)] //~ ERROR: lint `clippy::clone_double_ref` #![warn(clippy::cmp_nan)] //~ ERROR: lint `clippy::cmp_nan` +#![warn(clippy::double_neg)] //~ ERROR: lint `clippy::double_neg` #![warn(clippy::drop_bounds)] //~ ERROR: lint `clippy::drop_bounds` #![warn(clippy::drop_copy)] //~ ERROR: lint `clippy::drop_copy` #![warn(clippy::drop_ref)] //~ ERROR: lint `clippy::drop_ref` +#![warn(clippy::fn_address_comparisons)] //~ ERROR: lint `clippy::fn_address_comparisons` #![warn(clippy::fn_null_check)] //~ ERROR: lint `clippy::fn_null_check` #![warn(clippy::for_loop_over_option)] //~ ERROR: lint `clippy::for_loop_over_option` #![warn(clippy::for_loop_over_result)] //~ ERROR: lint `clippy::for_loop_over_result` @@ -128,6 +130,5 @@ #![warn(clippy::unknown_clippy_lints)] //~ ERROR: lint `clippy::unknown_clippy_lints` #![warn(clippy::unused_label)] //~ ERROR: lint `clippy::unused_label` #![warn(clippy::vtable_address_comparisons)] //~ ERROR: lint `clippy::vtable_address_comparisons` -#![warn(clippy::reverse_range_loop)] //~ ERROR: lint `clippy::reverse_range_loop` fn main() {} diff --git a/src/tools/clippy/tests/ui/rename.stderr b/src/tools/clippy/tests/ui/rename.stderr index 1ec45c4f1f7ba..f24eaec3917ad 100644 --- a/src/tools/clippy/tests/ui/rename.stderr +++ b/src/tools/clippy/tests/ui/rename.stderr @@ -73,132 +73,132 @@ error: lint `clippy::eval_order_dependence` has been renamed to `clippy::mixed_r LL | #![warn(clippy::eval_order_dependence)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::mixed_read_write_in_expression` -error: lint `clippy::find_map` has been renamed to `clippy::manual_find_map` - --> tests/ui/rename.rs:77:9 - | -LL | #![warn(clippy::find_map)] - | ^^^^^^^^^^^^^^^^ help: use the new name: `clippy::manual_find_map` - error: lint `clippy::filter_map` has been renamed to `clippy::manual_filter_map` - --> tests/ui/rename.rs:78:9 + --> tests/ui/rename.rs:77:9 | LL | #![warn(clippy::filter_map)] | ^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::manual_filter_map` -error: lint `clippy::fn_address_comparisons` has been renamed to `unpredictable_function_pointer_comparisons` - --> tests/ui/rename.rs:79:9 +error: lint `clippy::find_map` has been renamed to `clippy::manual_find_map` + --> tests/ui/rename.rs:78:9 | -LL | #![warn(clippy::fn_address_comparisons)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unpredictable_function_pointer_comparisons` +LL | #![warn(clippy::find_map)] + | ^^^^^^^^^^^^^^^^ help: use the new name: `clippy::manual_find_map` error: lint `clippy::identity_conversion` has been renamed to `clippy::useless_conversion` - --> tests/ui/rename.rs:80:9 + --> tests/ui/rename.rs:79:9 | LL | #![warn(clippy::identity_conversion)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::useless_conversion` error: lint `clippy::if_let_redundant_pattern_matching` has been renamed to `clippy::redundant_pattern_matching` - --> tests/ui/rename.rs:81:9 + --> tests/ui/rename.rs:80:9 | LL | #![warn(clippy::if_let_redundant_pattern_matching)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::redundant_pattern_matching` error: lint `clippy::if_let_some_result` has been renamed to `clippy::match_result_ok` - --> tests/ui/rename.rs:82:9 + --> tests/ui/rename.rs:81:9 | LL | #![warn(clippy::if_let_some_result)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::match_result_ok` error: lint `clippy::incorrect_clone_impl_on_copy_type` has been renamed to `clippy::non_canonical_clone_impl` - --> tests/ui/rename.rs:83:9 + --> tests/ui/rename.rs:82:9 | LL | #![warn(clippy::incorrect_clone_impl_on_copy_type)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::non_canonical_clone_impl` error: lint `clippy::incorrect_partial_ord_impl_on_ord_type` has been renamed to `clippy::non_canonical_partial_ord_impl` - --> tests/ui/rename.rs:84:9 + --> tests/ui/rename.rs:83:9 | LL | #![warn(clippy::incorrect_partial_ord_impl_on_ord_type)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::non_canonical_partial_ord_impl` error: lint `clippy::integer_arithmetic` has been renamed to `clippy::arithmetic_side_effects` - --> tests/ui/rename.rs:85:9 + --> tests/ui/rename.rs:84:9 | LL | #![warn(clippy::integer_arithmetic)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::arithmetic_side_effects` error: lint `clippy::logic_bug` has been renamed to `clippy::overly_complex_bool_expr` - --> tests/ui/rename.rs:86:9 + --> tests/ui/rename.rs:85:9 | LL | #![warn(clippy::logic_bug)] | ^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::overly_complex_bool_expr` error: lint `clippy::new_without_default_derive` has been renamed to `clippy::new_without_default` - --> tests/ui/rename.rs:87:9 + --> tests/ui/rename.rs:86:9 | LL | #![warn(clippy::new_without_default_derive)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::new_without_default` error: lint `clippy::option_and_then_some` has been renamed to `clippy::bind_instead_of_map` - --> tests/ui/rename.rs:88:9 + --> tests/ui/rename.rs:87:9 | LL | #![warn(clippy::option_and_then_some)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::bind_instead_of_map` error: lint `clippy::option_expect_used` has been renamed to `clippy::expect_used` - --> tests/ui/rename.rs:89:9 + --> tests/ui/rename.rs:88:9 | LL | #![warn(clippy::option_expect_used)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::expect_used` error: lint `clippy::option_map_unwrap_or` has been renamed to `clippy::map_unwrap_or` - --> tests/ui/rename.rs:90:9 + --> tests/ui/rename.rs:89:9 | LL | #![warn(clippy::option_map_unwrap_or)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or` error: lint `clippy::option_map_unwrap_or_else` has been renamed to `clippy::map_unwrap_or` - --> tests/ui/rename.rs:91:9 + --> tests/ui/rename.rs:90:9 | LL | #![warn(clippy::option_map_unwrap_or_else)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or` error: lint `clippy::option_unwrap_used` has been renamed to `clippy::unwrap_used` - --> tests/ui/rename.rs:92:9 + --> tests/ui/rename.rs:91:9 | LL | #![warn(clippy::option_unwrap_used)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::unwrap_used` error: lint `clippy::overflow_check_conditional` has been renamed to `clippy::panicking_overflow_checks` - --> tests/ui/rename.rs:93:9 + --> tests/ui/rename.rs:92:9 | LL | #![warn(clippy::overflow_check_conditional)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::panicking_overflow_checks` error: lint `clippy::ref_in_deref` has been renamed to `clippy::needless_borrow` - --> tests/ui/rename.rs:94:9 + --> tests/ui/rename.rs:93:9 | LL | #![warn(clippy::ref_in_deref)] | ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::needless_borrow` error: lint `clippy::result_expect_used` has been renamed to `clippy::expect_used` - --> tests/ui/rename.rs:95:9 + --> tests/ui/rename.rs:94:9 | LL | #![warn(clippy::result_expect_used)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::expect_used` error: lint `clippy::result_map_unwrap_or_else` has been renamed to `clippy::map_unwrap_or` - --> tests/ui/rename.rs:96:9 + --> tests/ui/rename.rs:95:9 | LL | #![warn(clippy::result_map_unwrap_or_else)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or` error: lint `clippy::result_unwrap_used` has been renamed to `clippy::unwrap_used` - --> tests/ui/rename.rs:97:9 + --> tests/ui/rename.rs:96:9 | LL | #![warn(clippy::result_unwrap_used)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::unwrap_used` +error: lint `clippy::reverse_range_loop` has been renamed to `clippy::reversed_empty_ranges` + --> tests/ui/rename.rs:97:9 + | +LL | #![warn(clippy::reverse_range_loop)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::reversed_empty_ranges` + error: lint `clippy::single_char_push_str` has been renamed to `clippy::single_char_add_str` --> tests/ui/rename.rs:98:9 | @@ -253,155 +253,161 @@ error: lint `clippy::cmp_nan` has been renamed to `invalid_nan_comparisons` LL | #![warn(clippy::cmp_nan)] | ^^^^^^^^^^^^^^^ help: use the new name: `invalid_nan_comparisons` -error: lint `clippy::drop_bounds` has been renamed to `drop_bounds` +error: lint `clippy::double_neg` has been renamed to `double_negations` --> tests/ui/rename.rs:107:9 | +LL | #![warn(clippy::double_neg)] + | ^^^^^^^^^^^^^^^^^^ help: use the new name: `double_negations` + +error: lint `clippy::drop_bounds` has been renamed to `drop_bounds` + --> tests/ui/rename.rs:108:9 + | LL | #![warn(clippy::drop_bounds)] | ^^^^^^^^^^^^^^^^^^^ help: use the new name: `drop_bounds` error: lint `clippy::drop_copy` has been renamed to `dropping_copy_types` - --> tests/ui/rename.rs:108:9 + --> tests/ui/rename.rs:109:9 | LL | #![warn(clippy::drop_copy)] | ^^^^^^^^^^^^^^^^^ help: use the new name: `dropping_copy_types` error: lint `clippy::drop_ref` has been renamed to `dropping_references` - --> tests/ui/rename.rs:109:9 + --> tests/ui/rename.rs:110:9 | LL | #![warn(clippy::drop_ref)] | ^^^^^^^^^^^^^^^^ help: use the new name: `dropping_references` +error: lint `clippy::fn_address_comparisons` has been renamed to `unpredictable_function_pointer_comparisons` + --> tests/ui/rename.rs:111:9 + | +LL | #![warn(clippy::fn_address_comparisons)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unpredictable_function_pointer_comparisons` + error: lint `clippy::fn_null_check` has been renamed to `useless_ptr_null_checks` - --> tests/ui/rename.rs:110:9 + --> tests/ui/rename.rs:112:9 | LL | #![warn(clippy::fn_null_check)] | ^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `useless_ptr_null_checks` error: lint `clippy::for_loop_over_option` has been renamed to `for_loops_over_fallibles` - --> tests/ui/rename.rs:111:9 + --> tests/ui/rename.rs:113:9 | LL | #![warn(clippy::for_loop_over_option)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles` error: lint `clippy::for_loop_over_result` has been renamed to `for_loops_over_fallibles` - --> tests/ui/rename.rs:112:9 + --> tests/ui/rename.rs:114:9 | LL | #![warn(clippy::for_loop_over_result)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles` error: lint `clippy::for_loops_over_fallibles` has been renamed to `for_loops_over_fallibles` - --> tests/ui/rename.rs:113:9 + --> tests/ui/rename.rs:115:9 | LL | #![warn(clippy::for_loops_over_fallibles)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles` error: lint `clippy::forget_copy` has been renamed to `forgetting_copy_types` - --> tests/ui/rename.rs:114:9 + --> tests/ui/rename.rs:116:9 | LL | #![warn(clippy::forget_copy)] | ^^^^^^^^^^^^^^^^^^^ help: use the new name: `forgetting_copy_types` error: lint `clippy::forget_ref` has been renamed to `forgetting_references` - --> tests/ui/rename.rs:115:9 + --> tests/ui/rename.rs:117:9 | LL | #![warn(clippy::forget_ref)] | ^^^^^^^^^^^^^^^^^^ help: use the new name: `forgetting_references` error: lint `clippy::into_iter_on_array` has been renamed to `array_into_iter` - --> tests/ui/rename.rs:116:9 + --> tests/ui/rename.rs:118:9 | LL | #![warn(clippy::into_iter_on_array)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `array_into_iter` error: lint `clippy::invalid_atomic_ordering` has been renamed to `invalid_atomic_ordering` - --> tests/ui/rename.rs:117:9 + --> tests/ui/rename.rs:119:9 | LL | #![warn(clippy::invalid_atomic_ordering)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_atomic_ordering` error: lint `clippy::invalid_ref` has been renamed to `invalid_value` - --> tests/ui/rename.rs:118:9 + --> tests/ui/rename.rs:120:9 | LL | #![warn(clippy::invalid_ref)] | ^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_value` error: lint `clippy::invalid_utf8_in_unchecked` has been renamed to `invalid_from_utf8_unchecked` - --> tests/ui/rename.rs:119:9 + --> tests/ui/rename.rs:121:9 | LL | #![warn(clippy::invalid_utf8_in_unchecked)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_from_utf8_unchecked` error: lint `clippy::let_underscore_drop` has been renamed to `let_underscore_drop` - --> tests/ui/rename.rs:120:9 + --> tests/ui/rename.rs:122:9 | LL | #![warn(clippy::let_underscore_drop)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `let_underscore_drop` error: lint `clippy::maybe_misused_cfg` has been renamed to `unexpected_cfgs` - --> tests/ui/rename.rs:121:9 + --> tests/ui/rename.rs:123:9 | LL | #![warn(clippy::maybe_misused_cfg)] | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unexpected_cfgs` error: lint `clippy::mem_discriminant_non_enum` has been renamed to `enum_intrinsics_non_enums` - --> tests/ui/rename.rs:122:9 + --> tests/ui/rename.rs:124:9 | LL | #![warn(clippy::mem_discriminant_non_enum)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `enum_intrinsics_non_enums` error: lint `clippy::mismatched_target_os` has been renamed to `unexpected_cfgs` - --> tests/ui/rename.rs:123:9 + --> tests/ui/rename.rs:125:9 | LL | #![warn(clippy::mismatched_target_os)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unexpected_cfgs` error: lint `clippy::panic_params` has been renamed to `non_fmt_panics` - --> tests/ui/rename.rs:124:9 + --> tests/ui/rename.rs:126:9 | LL | #![warn(clippy::panic_params)] | ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `non_fmt_panics` error: lint `clippy::positional_named_format_parameters` has been renamed to `named_arguments_used_positionally` - --> tests/ui/rename.rs:125:9 + --> tests/ui/rename.rs:127:9 | LL | #![warn(clippy::positional_named_format_parameters)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `named_arguments_used_positionally` error: lint `clippy::temporary_cstring_as_ptr` has been renamed to `dangling_pointers_from_temporaries` - --> tests/ui/rename.rs:126:9 + --> tests/ui/rename.rs:128:9 | LL | #![warn(clippy::temporary_cstring_as_ptr)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `dangling_pointers_from_temporaries` error: lint `clippy::undropped_manually_drops` has been renamed to `undropped_manually_drops` - --> tests/ui/rename.rs:127:9 + --> tests/ui/rename.rs:129:9 | LL | #![warn(clippy::undropped_manually_drops)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `undropped_manually_drops` error: lint `clippy::unknown_clippy_lints` has been renamed to `unknown_lints` - --> tests/ui/rename.rs:128:9 + --> tests/ui/rename.rs:130:9 | LL | #![warn(clippy::unknown_clippy_lints)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unknown_lints` error: lint `clippy::unused_label` has been renamed to `unused_labels` - --> tests/ui/rename.rs:129:9 + --> tests/ui/rename.rs:131:9 | LL | #![warn(clippy::unused_label)] | ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unused_labels` error: lint `clippy::vtable_address_comparisons` has been renamed to `ambiguous_wide_pointer_comparisons` - --> tests/ui/rename.rs:130:9 + --> tests/ui/rename.rs:132:9 | LL | #![warn(clippy::vtable_address_comparisons)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `ambiguous_wide_pointer_comparisons` -error: lint `clippy::reverse_range_loop` has been renamed to `clippy::reversed_empty_ranges` - --> tests/ui/rename.rs:131:9 - | -LL | #![warn(clippy::reverse_range_loop)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::reversed_empty_ranges` - -error: aborting due to 67 previous errors +error: aborting due to 68 previous errors From c1dcbebd0b4f721cead9d0f7ad63b88d8effed43 Mon Sep 17 00:00:00 2001 From: Kalle Wachsmuth Date: Sun, 1 Sep 2024 19:22:35 +0200 Subject: [PATCH 3/3] implement lint `double_negations` --- compiler/rustc_lint/messages.ftl | 5 ++ compiler/rustc_lint/src/builtin.rs | 75 ++++++++++++++++++---- compiler/rustc_lint/src/lib.rs | 1 + compiler/rustc_lint/src/lints.rs | 18 ++++++ tests/ui/lint/lint-double-negations.rs | 9 +++ tests/ui/lint/lint-double-negations.stderr | 42 ++++++++++++ tests/ui/lint/lint-type-overflow2.rs | 1 + tests/ui/lint/lint-type-overflow2.stderr | 24 +++++-- 8 files changed, 159 insertions(+), 16 deletions(-) create mode 100644 tests/ui/lint/lint-double-negations.rs create mode 100644 tests/ui/lint/lint-double-negations.stderr diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl index 0c1bd08474fc1..55c6a122d35d5 100644 --- a/compiler/rustc_lint/messages.ftl +++ b/compiler/rustc_lint/messages.ftl @@ -76,6 +76,11 @@ lint_builtin_deprecated_attr_link = use of deprecated attribute `{$name}`: {$rea lint_builtin_deref_nullptr = dereferencing a null pointer .label = this code causes undefined behavior when executed +lint_builtin_double_negations = use of a double negation + .note = the prefix `--` could be misinterpreted as a decrement operator which exists in other languages + .note_decrement = use `-= 1` if you meant to decrement the value + .add_parens_suggestion = add parentheses for clarity + lint_builtin_ellipsis_inclusive_range_patterns = `...` range patterns are deprecated .suggestion = use `..=` for an inclusive range diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs index 3da9ef3ff7c6b..c03de687a338b 100644 --- a/compiler/rustc_lint/src/builtin.rs +++ b/compiler/rustc_lint/src/builtin.rs @@ -49,16 +49,16 @@ use rustc_trait_selection::traits::{self}; use crate::errors::BuiltinEllipsisInclusiveRangePatterns; use crate::lints::{ BuiltinAnonymousParams, BuiltinConstNoMangle, BuiltinDeprecatedAttrLink, - BuiltinDeprecatedAttrLinkSuggestion, BuiltinDerefNullptr, - BuiltinEllipsisInclusiveRangePatternsLint, BuiltinExplicitOutlives, - BuiltinExplicitOutlivesSuggestion, BuiltinFeatureIssueNote, BuiltinIncompleteFeatures, - BuiltinIncompleteFeaturesHelp, BuiltinInternalFeatures, BuiltinKeywordIdents, - BuiltinMissingCopyImpl, BuiltinMissingDebugImpl, BuiltinMissingDoc, BuiltinMutablesTransmutes, - BuiltinNoMangleGeneric, BuiltinNonShorthandFieldPatterns, BuiltinSpecialModuleNameUsed, - BuiltinTrivialBounds, BuiltinTypeAliasBounds, BuiltinUngatedAsyncFnTrackCaller, - BuiltinUnpermittedTypeInit, BuiltinUnpermittedTypeInitSub, BuiltinUnreachablePub, - BuiltinUnsafe, BuiltinUnstableFeatures, BuiltinUnusedDocComment, BuiltinUnusedDocCommentSub, - BuiltinWhileTrue, InvalidAsmLabel, + BuiltinDeprecatedAttrLinkSuggestion, BuiltinDerefNullptr, BuiltinDoubleNegations, + BuiltinDoubleNegationsAddParens, BuiltinEllipsisInclusiveRangePatternsLint, + BuiltinExplicitOutlives, BuiltinExplicitOutlivesSuggestion, BuiltinFeatureIssueNote, + BuiltinIncompleteFeatures, BuiltinIncompleteFeaturesHelp, BuiltinInternalFeatures, + BuiltinKeywordIdents, BuiltinMissingCopyImpl, BuiltinMissingDebugImpl, BuiltinMissingDoc, + BuiltinMutablesTransmutes, BuiltinNoMangleGeneric, BuiltinNonShorthandFieldPatterns, + BuiltinSpecialModuleNameUsed, BuiltinTrivialBounds, BuiltinTypeAliasBounds, + BuiltinUngatedAsyncFnTrackCaller, BuiltinUnpermittedTypeInit, BuiltinUnpermittedTypeInitSub, + BuiltinUnreachablePub, BuiltinUnsafe, BuiltinUnstableFeatures, BuiltinUnusedDocComment, + BuiltinUnusedDocCommentSub, BuiltinWhileTrue, InvalidAsmLabel, }; use crate::nonstandard_style::{MethodLateContext, method_context}; use crate::{ @@ -1568,6 +1568,58 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints { } } +declare_lint! { + /// The `double_negations` lint detects expressions of the form `--x`. + /// + /// ### Example + /// + /// ```rust + /// fn main() { + /// let x = 1; + /// let _b = --x; + /// } + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Negating something twice is usually the same as not negating it at all. + /// However, a double negation in Rust can easily be confused with the + /// prefix decrement operator that exists in many languages derived from C. + /// Use `-(-x)` if you really wanted to negate the value twice. + /// + /// To decrement a value, use `x -= 1` instead. + pub DOUBLE_NEGATIONS, + Warn, + "detects expressions of the form `--x`" +} + +declare_lint_pass!( + /// Lint for expressions of the form `--x` that can be confused with C's + /// prefix decrement operator. + DoubleNegations => [DOUBLE_NEGATIONS] +); + +impl EarlyLintPass for DoubleNegations { + #[inline] + fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) { + // only lint on the innermost `--` in a chain of `-` operators, + // even if there are 3 or more negations + if let ExprKind::Unary(UnOp::Neg, ref inner) = expr.kind + && let ExprKind::Unary(UnOp::Neg, ref inner2) = inner.kind + && !matches!(inner2.kind, ExprKind::Unary(UnOp::Neg, _)) + { + cx.emit_span_lint(DOUBLE_NEGATIONS, expr.span, BuiltinDoubleNegations { + add_parens: BuiltinDoubleNegationsAddParens { + start_span: inner.span.shrink_to_lo(), + end_span: inner.span.shrink_to_hi(), + }, + }); + } + } +} + declare_lint_pass!( /// Does nothing as a lint pass, but registers some `Lint`s /// which are used by other parts of the compiler. @@ -1586,7 +1638,8 @@ declare_lint_pass!( UNSTABLE_FEATURES, UNREACHABLE_PUB, TYPE_ALIAS_BOUNDS, - TRIVIAL_BOUNDS + TRIVIAL_BOUNDS, + DOUBLE_NEGATIONS ] ); diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index 1465c2cff7bc1..83a168c3f4462 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -181,6 +181,7 @@ early_lint_methods!( UnusedDocComment: UnusedDocComment, Expr2024: Expr2024, Precedence: Precedence, + DoubleNegations: DoubleNegations, ] ] ); diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 3163bc8a300a1..677fc86a23519 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -331,6 +331,24 @@ pub(crate) struct BuiltinTrivialBounds<'a> { pub predicate: Clause<'a>, } +#[derive(LintDiagnostic)] +#[diag(lint_builtin_double_negations)] +#[note(lint_note)] +#[note(lint_note_decrement)] +pub(crate) struct BuiltinDoubleNegations { + #[subdiagnostic] + pub add_parens: BuiltinDoubleNegationsAddParens, +} + +#[derive(Subdiagnostic)] +#[multipart_suggestion(lint_add_parens_suggestion, applicability = "maybe-incorrect")] +pub(crate) struct BuiltinDoubleNegationsAddParens { + #[suggestion_part(code = "(")] + pub start_span: Span, + #[suggestion_part(code = ")")] + pub end_span: Span, +} + #[derive(LintDiagnostic)] pub(crate) enum BuiltinEllipsisInclusiveRangePatternsLint { #[diag(lint_builtin_ellipsis_inclusive_range_patterns)] diff --git a/tests/ui/lint/lint-double-negations.rs b/tests/ui/lint/lint-double-negations.rs new file mode 100644 index 0000000000000..43e61dd7c1327 --- /dev/null +++ b/tests/ui/lint/lint-double-negations.rs @@ -0,0 +1,9 @@ +//@ check-pass +fn main() { + let x = 1; + -x; + -(-x); + --x; //~ WARN use of a double negation + ---x; //~ WARN use of a double negation + let _y = --(-x); //~ WARN use of a double negation +} diff --git a/tests/ui/lint/lint-double-negations.stderr b/tests/ui/lint/lint-double-negations.stderr new file mode 100644 index 0000000000000..9367f74be546d --- /dev/null +++ b/tests/ui/lint/lint-double-negations.stderr @@ -0,0 +1,42 @@ +warning: use of a double negation + --> $DIR/lint-double-negations.rs:6:5 + | +LL | --x; + | ^^^ + | + = note: the prefix `--` could be misinterpreted as a decrement operator which exists in other languages + = note: use `-= 1` if you meant to decrement the value + = note: `#[warn(double_negations)]` on by default +help: add parentheses for clarity + | +LL | -(-x); + | + + + +warning: use of a double negation + --> $DIR/lint-double-negations.rs:7:6 + | +LL | ---x; + | ^^^ + | + = note: the prefix `--` could be misinterpreted as a decrement operator which exists in other languages + = note: use `-= 1` if you meant to decrement the value +help: add parentheses for clarity + | +LL | --(-x); + | + + + +warning: use of a double negation + --> $DIR/lint-double-negations.rs:8:14 + | +LL | let _y = --(-x); + | ^^^^^^ + | + = note: the prefix `--` could be misinterpreted as a decrement operator which exists in other languages + = note: use `-= 1` if you meant to decrement the value +help: add parentheses for clarity + | +LL | let _y = -(-(-x)); + | + + + +warning: 3 warnings emitted + diff --git a/tests/ui/lint/lint-type-overflow2.rs b/tests/ui/lint/lint-type-overflow2.rs index f007b45b8479d..ac7420326c893 100644 --- a/tests/ui/lint/lint-type-overflow2.rs +++ b/tests/ui/lint/lint-type-overflow2.rs @@ -4,6 +4,7 @@ fn main() { let x2: i8 = --128; //~ ERROR literal out of range for `i8` + //~| WARN use of a double negation let x = -3.40282357e+38_f32; //~ ERROR literal out of range for `f32` let x = 3.40282357e+38_f32; //~ ERROR literal out of range for `f32` diff --git a/tests/ui/lint/lint-type-overflow2.stderr b/tests/ui/lint/lint-type-overflow2.stderr index eb593d062f218..2cfb18e9fe924 100644 --- a/tests/ui/lint/lint-type-overflow2.stderr +++ b/tests/ui/lint/lint-type-overflow2.stderr @@ -1,3 +1,17 @@ +warning: use of a double negation + --> $DIR/lint-type-overflow2.rs:6:18 + | +LL | let x2: i8 = --128; + | ^^^^^ + | + = note: the prefix `--` could be misinterpreted as a decrement operator which exists in other languages + = note: use `-= 1` if you meant to decrement the value + = note: `#[warn(double_negations)]` on by default +help: add parentheses for clarity + | +LL | let x2: i8 = -(-128); + | + + + error: literal out of range for `i8` --> $DIR/lint-type-overflow2.rs:6:20 | @@ -13,7 +27,7 @@ LL | #![deny(overflowing_literals)] | ^^^^^^^^^^^^^^^^^^^^ error: literal out of range for `f32` - --> $DIR/lint-type-overflow2.rs:8:14 + --> $DIR/lint-type-overflow2.rs:9:14 | LL | let x = -3.40282357e+38_f32; | ^^^^^^^^^^^^^^^^^^ @@ -21,7 +35,7 @@ LL | let x = -3.40282357e+38_f32; = note: the literal `3.40282357e+38_f32` does not fit into the type `f32` and will be converted to `f32::INFINITY` error: literal out of range for `f32` - --> $DIR/lint-type-overflow2.rs:9:14 + --> $DIR/lint-type-overflow2.rs:10:14 | LL | let x = 3.40282357e+38_f32; | ^^^^^^^^^^^^^^^^^^ @@ -29,7 +43,7 @@ LL | let x = 3.40282357e+38_f32; = note: the literal `3.40282357e+38_f32` does not fit into the type `f32` and will be converted to `f32::INFINITY` error: literal out of range for `f64` - --> $DIR/lint-type-overflow2.rs:10:14 + --> $DIR/lint-type-overflow2.rs:11:14 | LL | let x = -1.7976931348623159e+308_f64; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -37,12 +51,12 @@ LL | let x = -1.7976931348623159e+308_f64; = note: the literal `1.7976931348623159e+308_f64` does not fit into the type `f64` and will be converted to `f64::INFINITY` error: literal out of range for `f64` - --> $DIR/lint-type-overflow2.rs:11:14 + --> $DIR/lint-type-overflow2.rs:12:14 | LL | let x = 1.7976931348623159e+308_f64; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the literal `1.7976931348623159e+308_f64` does not fit into the type `f64` and will be converted to `f64::INFINITY` -error: aborting due to 5 previous errors +error: aborting due to 5 previous errors; 1 warning emitted