diff options
| -rw-r--r-- | clippy_lints/src/floating_point_arithmetic.rs | 86 | ||||
| -rw-r--r-- | tests/ui/floating_point_log.rs | 26 | ||||
| -rw-r--r-- | tests/ui/floating_point_log.stderr | 74 |
3 files changed, 4 insertions, 182 deletions
diff --git a/clippy_lints/src/floating_point_arithmetic.rs b/clippy_lints/src/floating_point_arithmetic.rs index dbf8e0a9ac4..17babb46daa 100644 --- a/clippy_lints/src/floating_point_arithmetic.rs +++ b/clippy_lints/src/floating_point_arithmetic.rs @@ -4,12 +4,11 @@ use crate::consts::{ }; use crate::utils::*; use if_chain::if_chain; -use rustc::declare_lint_pass; -use rustc::hir::*; -use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; +use rustc_hir::*; +use rustc_lint::{LateContext, LateLintPass}; use rustc::ty; use rustc_errors::Applicability; -use rustc_session::declare_tool_lint; +use rustc_session::{declare_lint_pass, declare_tool_lint}; use std::f32::consts as f32_consts; use std::f64::consts as f64_consts; use sugg::Sugg; @@ -278,84 +277,6 @@ fn check_expm1(cx: &LateContext<'_, '_>, expr: &Expr) { } } -// Checks whether two expressions evaluate to the same value -fn are_exprs_equivalent(cx: &LateContext<'_, '_>, left: &Expr, right: &Expr) -> bool { - // Checks whether the values are constant and equal - if_chain! { - if let Some((left_value, _)) = constant(cx, cx.tables, left); - if let Some((right_value, _)) = constant(cx, cx.tables, right); - if left_value == right_value; - then { - return true; - } - } - - // Checks whether the expressions resolve to the same variable - if_chain! { - if let ExprKind::Path(ref left_qpath) = left.kind; - if let QPath::Resolved(_, ref left_path) = *left_qpath; - if left_path.segments.len() == 1; - if let def::Res::Local(left_local_id) = qpath_res(cx, left_qpath, left.hir_id); - if let ExprKind::Path(ref right_qpath) = right.kind; - if let QPath::Resolved(_, ref right_path) = *right_qpath; - if right_path.segments.len() == 1; - if let def::Res::Local(right_local_id) = qpath_res(cx, right_qpath, right.hir_id); - if left_local_id == right_local_id; - then { - return true; - } - } - - false -} - -fn check_log_division(cx: &LateContext<'_, '_>, expr: &Expr) { - let log_methods = ["log", "log2", "log10", "ln"]; - - if_chain! { - if let ExprKind::Binary(op, ref lhs, ref rhs) = expr.kind; - if op.node == BinOpKind::Div; - if cx.tables.expr_ty(lhs).is_floating_point(); - if let ExprKind::MethodCall(left_path, _, left_args) = &lhs.kind; - if cx.tables.expr_ty(&left_args[0]).is_floating_point(); - if let ExprKind::MethodCall(right_path, _, right_args) = &rhs.kind; - if cx.tables.expr_ty(&right_args[0]).is_floating_point(); - let left_method = left_path.ident.name.as_str(); - if left_method == right_path.ident.name.as_str(); - if log_methods.iter().any(|&method| left_method == method); - then { - let left_recv = &left_args[0]; - let right_recv = &right_args[0]; - - // Return early when bases are not equal - if left_method == "log" && !are_exprs_equivalent(cx, &left_args[1], &right_args[1]) { - return; - } - - // Reduce the expression further for bases 2, 10 and e - let suggestion = if let Some(method) = get_specialized_log_method(cx, right_recv) { - format!("{}.{}()", Sugg::hir(cx, left_recv, ".."), method) - } else { - format!( - "{}.log({})", - Sugg::hir(cx, left_recv, ".."), - Sugg::hir(cx, right_recv, "..") - ) - }; - - span_lint_and_sugg( - cx, - FLOATING_POINT_IMPROVEMENTS, - expr.span, - "x.log(b) / y.log(b) can be reduced to x.log(y)", - "consider using", - suggestion, - Applicability::MachineApplicable, - ); - } - } -} - impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FloatingPointArithmetic { fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { if let ExprKind::MethodCall(ref path, _, args) = &expr.kind { @@ -371,7 +292,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FloatingPointArithmetic { } } else { check_expm1(cx, expr); - check_log_division(cx, expr); } } } diff --git a/tests/ui/floating_point_log.rs b/tests/ui/floating_point_log.rs index 5775d8715d4..18b7686280e 100644 --- a/tests/ui/floating_point_log.rs +++ b/tests/ui/floating_point_log.rs @@ -54,30 +54,4 @@ fn check_ln1p() { let _ = (1.0 + x - 2.0).ln(); } -fn check_log_division() { - let x = 3f32; - let y = 2f32; - let b = 4f32; - - let _ = x.log2() / y.log2(); - let _ = x.log10() / y.log10(); - let _ = x.ln() / y.ln(); - let _ = x.log(4.0) / y.log(4.0); - let _ = x.log(b) / y.log(b); - let _ = x.log(b) / y.log(x); - let _ = x.log(b) / 2f32.log(b); - - let x = 3f64; - let y = 2f64; - let b = 4f64; - - let _ = x.log2() / y.log2(); - let _ = x.log10() / y.log10(); - let _ = x.ln() / y.ln(); - let _ = x.log(4.0) / y.log(4.0); - let _ = x.log(b) / y.log(b); - let _ = x.log(b) / y.log(x); - let _ = x.log(b) / 2f64.log(b); -} - fn main() {} diff --git a/tests/ui/floating_point_log.stderr b/tests/ui/floating_point_log.stderr index cd3142e041a..c169745ddf9 100644 --- a/tests/ui/floating_point_log.stderr +++ b/tests/ui/floating_point_log.stderr @@ -168,77 +168,5 @@ error: ln(1 + x) can be computed more accurately LL | let _ = (x * 2.0 + 1.0).ln(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x * 2.0).ln_1p()` -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:62:13 - | -LL | let _ = x.log2() / y.log2(); - | ^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:63:13 - | -LL | let _ = x.log10() / y.log10(); - | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:64:13 - | -LL | let _ = x.ln() / y.ln(); - | ^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:65:13 - | -LL | let _ = x.log(4.0) / y.log(4.0); - | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:66:13 - | -LL | let _ = x.log(b) / y.log(b); - | ^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:68:13 - | -LL | let _ = x.log(b) / 2f32.log(b); - | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log2()` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:74:13 - | -LL | let _ = x.log2() / y.log2(); - | ^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:75:13 - | -LL | let _ = x.log10() / y.log10(); - | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:76:13 - | -LL | let _ = x.ln() / y.ln(); - | ^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:77:13 - | -LL | let _ = x.log(4.0) / y.log(4.0); - | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:78:13 - | -LL | let _ = x.log(b) / y.log(b); - | ^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` - -error: x.log(b) / y.log(b) can be reduced to x.log(y) - --> $DIR/floating_point_log.rs:80:13 - | -LL | let _ = x.log(b) / 2f64.log(b); - | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log2()` - -error: aborting due to 40 previous errors +error: aborting due to 28 previous errors |