diff options
| -rw-r--r-- | clippy_lints/src/slow_vector_initialization.rs | 39 | ||||
| -rw-r--r-- | tests/ui/slow_vector_initialization.rs | 6 | ||||
| -rw-r--r-- | tests/ui/slow_vector_initialization.stderr | 28 |
3 files changed, 49 insertions, 24 deletions
diff --git a/clippy_lints/src/slow_vector_initialization.rs b/clippy_lints/src/slow_vector_initialization.rs index b4ad5dcbe3e..e5b30937d16 100644 --- a/clippy_lints/src/slow_vector_initialization.rs +++ b/clippy_lints/src/slow_vector_initialization.rs @@ -28,6 +28,9 @@ declare_clippy_lint! { /// let mut vec1 = Vec::with_capacity(len); /// vec1.resize(len, 0); /// + /// let mut vec1 = Vec::with_capacity(len); + /// vec1.resize(vec1.capacity(), 0); + /// /// let mut vec2 = Vec::with_capacity(len); /// vec2.extend(repeat(0).take(len)); /// @@ -210,23 +213,20 @@ impl<'a, 'tcx> VectorInitializationVisitor<'a, 'tcx> { /// Checks if the given expression is resizing a vector with 0 fn search_slow_resize_filling(&mut self, expr: &'tcx Expr<'_>) { - if_chain! { - if self.initialization_found; - if let ExprKind::MethodCall(path, [self_arg, len_arg, fill_arg], _) = expr.kind; - if path_to_local_id(self_arg, self.vec_alloc.local_id); - if path.ident.name == sym!(resize); - + if self.initialization_found + && let ExprKind::MethodCall(path, [self_arg, len_arg, fill_arg], _) = expr.kind + && path_to_local_id(self_arg, self.vec_alloc.local_id) + && path.ident.name == sym!(resize) // Check that is filled with 0 - if let ExprKind::Lit(ref lit) = fill_arg.kind; - if let LitKind::Int(0, _) = lit.node; - - // Check that len expression is equals to `with_capacity` expression - if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr); - - then { - self.slow_expression = Some(InitializationType::Resize(expr)); + && let ExprKind::Lit(ref lit) = fill_arg.kind + && let LitKind::Int(0, _) = lit.node { + // Check that len expression is equals to `with_capacity` expression + if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr) { + self.slow_expression = Some(InitializationType::Resize(expr)); + } else if let ExprKind::MethodCall(path, _, _) = len_arg.kind && path.ident.as_str() == "capacity" { + self.slow_expression = Some(InitializationType::Resize(expr)); + } } - } } /// Returns `true` if give expression is `repeat(0).take(...)` @@ -239,12 +239,15 @@ impl<'a, 'tcx> VectorInitializationVisitor<'a, 'tcx> { if let Some(repeat_expr) = take_args.get(0); if self.is_repeat_zero(repeat_expr); - // Check that len expression is equals to `with_capacity` expression if let Some(len_arg) = take_args.get(1); - if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr); then { - return true; + // Check that len expression is equals to `with_capacity` expression + if SpanlessEq::new(self.cx).eq_expr(len_arg, self.vec_alloc.len_expr) { + return true; + } else if let ExprKind::MethodCall(path, _, _) = len_arg.kind && path.ident.as_str() == "capacity" { + return true; + } } } diff --git a/tests/ui/slow_vector_initialization.rs b/tests/ui/slow_vector_initialization.rs index 7e3d357ae50..16be9f6d203 100644 --- a/tests/ui/slow_vector_initialization.rs +++ b/tests/ui/slow_vector_initialization.rs @@ -19,6 +19,9 @@ fn extend_vector() { // Extend with mismatching expression should not be warned let mut vec3 = Vec::with_capacity(24322); vec3.extend(repeat(0).take(2)); + + let mut vec4 = Vec::with_capacity(len); + vec4.extend(repeat(0).take(vec4.capacity())); } fn mixed_extend_resize_vector() { @@ -48,6 +51,9 @@ fn resize_vector() { let mut vec3 = Vec::with_capacity(len - 10); vec3.resize(len - 10, 0); + let mut vec4 = Vec::with_capacity(len); + vec4.resize(vec4.capacity(), 0); + // Reinitialization should be warned vec1 = Vec::with_capacity(10); vec1.resize(10, 0); diff --git a/tests/ui/slow_vector_initialization.stderr b/tests/ui/slow_vector_initialization.stderr index 5d2788ec260..cb3ce3e95a7 100644 --- a/tests/ui/slow_vector_initialization.stderr +++ b/tests/ui/slow_vector_initialization.stderr @@ -17,7 +17,15 @@ LL | vec2.extend(repeat(0).take(len - 10)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: slow zero-filling initialization - --> $DIR/slow_vector_initialization.rs:31:5 + --> $DIR/slow_vector_initialization.rs:24:5 + | +LL | let mut vec4 = Vec::with_capacity(len); + | ----------------------- help: consider replace allocation with: `vec![0; len]` +LL | vec4.extend(repeat(0).take(vec4.capacity())); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: slow zero-filling initialization + --> $DIR/slow_vector_initialization.rs:34:5 | LL | let mut resized_vec = Vec::with_capacity(30); | ---------------------- help: consider replace allocation with: `vec![0; 30]` @@ -25,7 +33,7 @@ LL | resized_vec.resize(30, 0); | ^^^^^^^^^^^^^^^^^^^^^^^^^ error: slow zero-filling initialization - --> $DIR/slow_vector_initialization.rs:34:5 + --> $DIR/slow_vector_initialization.rs:37:5 | LL | let mut extend_vec = Vec::with_capacity(30); | ---------------------- help: consider replace allocation with: `vec![0; 30]` @@ -33,7 +41,7 @@ LL | extend_vec.extend(repeat(0).take(30)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: slow zero-filling initialization - --> $DIR/slow_vector_initialization.rs:41:5 + --> $DIR/slow_vector_initialization.rs:44:5 | LL | let mut vec1 = Vec::with_capacity(len); | ----------------------- help: consider replace allocation with: `vec![0; len]` @@ -41,7 +49,7 @@ LL | vec1.resize(len, 0); | ^^^^^^^^^^^^^^^^^^^ error: slow zero-filling initialization - --> $DIR/slow_vector_initialization.rs:49:5 + --> $DIR/slow_vector_initialization.rs:52:5 | LL | let mut vec3 = Vec::with_capacity(len - 10); | ---------------------------- help: consider replace allocation with: `vec![0; len - 10]` @@ -49,12 +57,20 @@ LL | vec3.resize(len - 10, 0); | ^^^^^^^^^^^^^^^^^^^^^^^^ error: slow zero-filling initialization - --> $DIR/slow_vector_initialization.rs:53:5 + --> $DIR/slow_vector_initialization.rs:55:5 + | +LL | let mut vec4 = Vec::with_capacity(len); + | ----------------------- help: consider replace allocation with: `vec![0; len]` +LL | vec4.resize(vec4.capacity(), 0); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: slow zero-filling initialization + --> $DIR/slow_vector_initialization.rs:59:5 | LL | vec1 = Vec::with_capacity(10); | ---------------------- help: consider replace allocation with: `vec![0; 10]` LL | vec1.resize(10, 0); | ^^^^^^^^^^^^^^^^^^ -error: aborting due to 7 previous errors +error: aborting due to 9 previous errors |