diff options
Diffstat (limited to 'clippy_lints/src/utils')
| -rw-r--r-- | clippy_lints/src/utils/eager_or_lazy.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/utils/higher.rs | 54 | ||||
| -rw-r--r-- | clippy_lints/src/utils/mod.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/utils/sugg.rs | 59 | ||||
| -rw-r--r-- | clippy_lints/src/utils/usage.rs | 50 |
5 files changed, 157 insertions, 10 deletions
diff --git a/clippy_lints/src/utils/eager_or_lazy.rs b/clippy_lints/src/utils/eager_or_lazy.rs index 27e9567740d..4ceea13df37 100644 --- a/clippy_lints/src/utils/eager_or_lazy.rs +++ b/clippy_lints/src/utils/eager_or_lazy.rs @@ -82,7 +82,7 @@ fn identify_some_pure_patterns(expr: &Expr<'_>) -> bool { /// Identify some potentially computationally expensive patterns. /// This function is named so to stress that its implementation is non-exhaustive. /// It returns FNs and FPs. -fn identify_some_potentially_expensive_patterns<'a, 'tcx>(cx: &'a LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool { +fn identify_some_potentially_expensive_patterns<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool { // Searches an expression for method calls or function calls that aren't ctors struct FunCallFinder<'a, 'tcx> { cx: &'a LateContext<'tcx>, diff --git a/clippy_lints/src/utils/higher.rs b/clippy_lints/src/utils/higher.rs index 8563b469a30..6d7c5058b4f 100644 --- a/clippy_lints/src/utils/higher.rs +++ b/clippy_lints/src/utils/higher.rs @@ -7,6 +7,7 @@ use crate::utils::{is_expn_of, match_def_path, paths}; use if_chain::if_chain; use rustc_ast::ast; use rustc_hir as hir; +use rustc_hir::{BorrowKind, Expr, ExprKind, StmtKind, UnOp}; use rustc_lint::LateContext; /// Converts a hir binary operator to the corresponding `ast` type. @@ -241,3 +242,56 @@ pub fn vec_macro<'e>(cx: &LateContext<'_>, expr: &'e hir::Expr<'_>) -> Option<Ve None } + +/// Extract args from an assert-like macro. +/// Currently working with: +/// - `assert!`, `assert_eq!` and `assert_ne!` +/// - `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!` +/// For example: +/// `assert!(expr)` will return Some([expr]) +/// `debug_assert_eq!(a, b)` will return Some([a, b]) +pub fn extract_assert_macro_args<'tcx>(e: &'tcx Expr<'tcx>) -> Option<Vec<&'tcx Expr<'tcx>>> { + /// Try to match the AST for a pattern that contains a match, for example when two args are + /// compared + fn ast_matchblock(matchblock_expr: &'tcx Expr<'tcx>) -> Option<Vec<&Expr<'_>>> { + if_chain! { + if let ExprKind::Match(ref headerexpr, _, _) = &matchblock_expr.kind; + if let ExprKind::Tup([lhs, rhs]) = &headerexpr.kind; + if let ExprKind::AddrOf(BorrowKind::Ref, _, lhs) = lhs.kind; + if let ExprKind::AddrOf(BorrowKind::Ref, _, rhs) = rhs.kind; + then { + return Some(vec![lhs, rhs]); + } + } + None + } + + if let ExprKind::Block(ref block, _) = e.kind { + if block.stmts.len() == 1 { + if let StmtKind::Semi(ref matchexpr) = block.stmts[0].kind { + // macros with unique arg: `{debug_}assert!` (e.g., `debug_assert!(some_condition)`) + if_chain! { + if let ExprKind::Match(ref ifclause, _, _) = matchexpr.kind; + if let ExprKind::DropTemps(ref droptmp) = ifclause.kind; + if let ExprKind::Unary(UnOp::UnNot, condition) = droptmp.kind; + then { + return Some(vec![condition]); + } + } + + // debug macros with two args: `debug_assert_{ne, eq}` (e.g., `assert_ne!(a, b)`) + if_chain! { + if let ExprKind::Block(ref matchblock,_) = matchexpr.kind; + if let Some(ref matchblock_expr) = matchblock.expr; + then { + return ast_matchblock(matchblock_expr); + } + } + } + } else if let Some(matchblock_expr) = block.expr { + // macros with two args: `assert_{ne, eq}` (e.g., `assert_ne!(a, b)`) + return ast_matchblock(&matchblock_expr); + } + } + None +} diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 790ac4f7dd8..a9d26d48b12 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -708,7 +708,7 @@ fn reindent_multiline_inner(s: &str, ignore_first: bool, indent: Option<usize>, } /// Gets the parent expression, if any –- this is useful to constrain a lint. -pub fn get_parent_expr<'c>(cx: &'c LateContext<'_>, e: &Expr<'_>) -> Option<&'c Expr<'c>> { +pub fn get_parent_expr<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { let map = &cx.tcx.hir(); let hir_id = e.hir_id; let parent_id = map.get_parent_node(hir_id); diff --git a/clippy_lints/src/utils/sugg.rs b/clippy_lints/src/utils/sugg.rs index a2a1d109c9a..625120b880e 100644 --- a/clippy_lints/src/utils/sugg.rs +++ b/clippy_lints/src/utils/sugg.rs @@ -13,8 +13,10 @@ use rustc_span::{BytePos, Pos}; use std::borrow::Cow; use std::convert::TryInto; use std::fmt::Display; +use std::ops::{Add, Neg, Not, Sub}; /// A helper type to build suggestion correctly handling parenthesis. +#[derive(Clone, PartialEq)] pub enum Sugg<'a> { /// An expression that never needs parenthesis such as `1337` or `[0; 42]`. NonParen(Cow<'a, str>), @@ -25,8 +27,12 @@ pub enum Sugg<'a> { BinOp(AssocOp, Cow<'a, str>), } +/// Literal constant `0`, for convenience. +pub const ZERO: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("0")); /// Literal constant `1`, for convenience. pub const ONE: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("1")); +/// a constant represents an empty string, for convenience. +pub const EMPTY: Sugg<'static> = Sugg::NonParen(Cow::Borrowed("")); impl Display for Sugg<'_> { fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> { @@ -269,21 +275,60 @@ impl<'a> Sugg<'a> { } } -impl<'a, 'b> std::ops::Add<Sugg<'b>> for Sugg<'a> { +// Copied from the rust standart library, and then edited +macro_rules! forward_binop_impls_to_ref { + (impl $imp:ident, $method:ident for $t:ty, type Output = $o:ty) => { + impl $imp<$t> for &$t { + type Output = $o; + + fn $method(self, other: $t) -> $o { + $imp::$method(self, &other) + } + } + + impl $imp<&$t> for $t { + type Output = $o; + + fn $method(self, other: &$t) -> $o { + $imp::$method(&self, other) + } + } + + impl $imp for $t { + type Output = $o; + + fn $method(self, other: $t) -> $o { + $imp::$method(&self, &other) + } + } + }; +} + +impl Add for &Sugg<'_> { type Output = Sugg<'static>; - fn add(self, rhs: Sugg<'b>) -> Sugg<'static> { - make_binop(ast::BinOpKind::Add, &self, &rhs) + fn add(self, rhs: &Sugg<'_>) -> Sugg<'static> { + make_binop(ast::BinOpKind::Add, self, rhs) } } -impl<'a, 'b> std::ops::Sub<Sugg<'b>> for Sugg<'a> { +impl Sub for &Sugg<'_> { + type Output = Sugg<'static>; + fn sub(self, rhs: &Sugg<'_>) -> Sugg<'static> { + make_binop(ast::BinOpKind::Sub, self, rhs) + } +} + +forward_binop_impls_to_ref!(impl Add, add for Sugg<'_>, type Output = Sugg<'static>); +forward_binop_impls_to_ref!(impl Sub, sub for Sugg<'_>, type Output = Sugg<'static>); + +impl Neg for Sugg<'_> { type Output = Sugg<'static>; - fn sub(self, rhs: Sugg<'b>) -> Sugg<'static> { - make_binop(ast::BinOpKind::Sub, &self, &rhs) + fn neg(self) -> Sugg<'static> { + make_unop("-", self) } } -impl<'a> std::ops::Not for Sugg<'a> { +impl Not for Sugg<'_> { type Output = Sugg<'static>; fn not(self) -> Sugg<'static> { make_unop("!", self) diff --git a/clippy_lints/src/utils/usage.rs b/clippy_lints/src/utils/usage.rs index ea1dc3be29b..2fd6046ebcf 100644 --- a/clippy_lints/src/utils/usage.rs +++ b/clippy_lints/src/utils/usage.rs @@ -1,10 +1,11 @@ +use crate::utils; use crate::utils::match_var; use rustc_data_structures::fx::FxHashSet; use rustc_hir as hir; use rustc_hir::def::Res; use rustc_hir::intravisit; use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor}; -use rustc_hir::{Expr, HirId, Path}; +use rustc_hir::{Expr, ExprKind, HirId, Path}; use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::LateContext; use rustc_middle::hir::map::Map; @@ -174,3 +175,50 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for BindingUsageFinder<'a, 'tcx> { intravisit::NestedVisitorMap::OnlyBodies(self.cx.tcx.hir()) } } + +struct ReturnBreakContinueMacroVisitor { + seen_return_break_continue: bool, +} + +impl ReturnBreakContinueMacroVisitor { + fn new() -> ReturnBreakContinueMacroVisitor { + ReturnBreakContinueMacroVisitor { + seen_return_break_continue: false, + } + } +} + +impl<'tcx> Visitor<'tcx> for ReturnBreakContinueMacroVisitor { + type Map = Map<'tcx>; + fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { + NestedVisitorMap::None + } + + fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) { + if self.seen_return_break_continue { + // No need to look farther if we've already seen one of them + return; + } + match &ex.kind { + ExprKind::Ret(..) | ExprKind::Break(..) | ExprKind::Continue(..) => { + self.seen_return_break_continue = true; + }, + // Something special could be done here to handle while or for loop + // desugaring, as this will detect a break if there's a while loop + // or a for loop inside the expression. + _ => { + if utils::in_macro(ex.span) { + self.seen_return_break_continue = true; + } else { + rustc_hir::intravisit::walk_expr(self, ex); + } + }, + } + } +} + +pub fn contains_return_break_continue_macro(expression: &Expr<'_>) -> bool { + let mut recursive_visitor = ReturnBreakContinueMacroVisitor::new(); + recursive_visitor.visit_expr(expression); + recursive_visitor.seen_return_break_continue +} |