mirror of https://github.com/rust-lang/rust.git
Manish Goregaokar
commit
15240a361b
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@ -4,7 +4,7 @@
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A collection of lints that give helpful tips to newbies and catch oversights.
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##Lints
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There are 45 lints included in this crate:
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There are 48 lints included in this crate:
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name | default | meaning
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-------------------------|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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@ -44,6 +44,9 @@ ptr_arg | allow | fn arguments of the type `&Vec<...>` or `&S
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range_step_by_zero | warn | using Range::step_by(0), which produces an infinite iterator
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redundant_closure | warn | using redundant closures, i.e. `|a| foo(a)` (which can be written as just `foo`)
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result_unwrap_used | allow | using `Result.unwrap()`, which might be better handled
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shadow_reuse | allow | rebinding a name to an expression that re-uses the original value, e.g. `let x = x + 1`
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shadow_same | allow | rebinding a name to itself, e.g. `let mut x = &mut x`
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shadow_unrelated | warn | The name is re-bound without even using the original value
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single_match | warn | a match statement with a single nontrivial arm (i.e, where the other arm is `_ => {}`) is used; recommends `if let` instead
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str_to_string | warn | using `to_string()` on a str, which should be `to_owned()`
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string_add | allow | using `x + ..` where x is a `String`; suggests using `push_str()` instead
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11
src/lib.rs
11
src/lib.rs
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@ -32,6 +32,7 @@ pub mod len_zero;
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pub mod attrs;
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pub mod collapsible_if;
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pub mod unicode;
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pub mod shadow;
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pub mod strings;
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pub mod methods;
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pub mod returns;
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@ -64,6 +65,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
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reg.register_lint_pass(box strings::StringAdd as LintPassObject);
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reg.register_lint_pass(box returns::ReturnPass as LintPassObject);
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reg.register_lint_pass(box methods::MethodsPass as LintPassObject);
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reg.register_lint_pass(box shadow::ShadowPass as LintPassObject);
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reg.register_lint_pass(box types::LetPass as LintPassObject);
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reg.register_lint_pass(box types::UnitCmp as LintPassObject);
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reg.register_lint_pass(box loops::LoopsPass as LintPassObject);
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@ -73,6 +75,12 @@ pub fn plugin_registrar(reg: &mut Registry) {
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reg.register_lint_pass(box types::TypeComplexityPass as LintPassObject);
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reg.register_lint_pass(box matches::MatchPass as LintPassObject);
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reg.register_lint_group("shadow", vec![
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shadow::SHADOW_REUSE,
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shadow::SHADOW_SAME,
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shadow::SHADOW_UNRELATED,
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]);
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reg.register_lint_group("clippy", vec![
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approx_const::APPROX_CONSTANT,
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attrs::INLINE_ALWAYS,
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@ -106,6 +114,9 @@ pub fn plugin_registrar(reg: &mut Registry) {
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ranges::RANGE_STEP_BY_ZERO,
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returns::LET_AND_RETURN,
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returns::NEEDLESS_RETURN,
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shadow::SHADOW_REUSE,
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shadow::SHADOW_SAME,
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shadow::SHADOW_UNRELATED,
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strings::STRING_ADD,
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strings::STRING_ADD_ASSIGN,
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types::BOX_VEC,
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@ -11,7 +11,7 @@ declare_lint!(pub LET_AND_RETURN, Warn,
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"creating a let-binding and then immediately returning it like `let x = expr; x` at \
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the end of a function");
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#[derive(Copy,Clone)]
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#[derive(Copy, Clone)]
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pub struct ReturnPass;
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impl ReturnPass {
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@ -0,0 +1,282 @@
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use std::ops::Deref;
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use syntax::ast::*;
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use syntax::codemap::Span;
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use syntax::visit::FnKind;
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use rustc::lint::{Context, LintArray, LintPass};
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use rustc::middle::def::Def::{DefVariant, DefStruct};
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use utils::{in_external_macro, snippet, span_lint};
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declare_lint!(pub SHADOW_SAME, Allow,
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"rebinding a name to itself, e.g. `let mut x = &mut x`");
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declare_lint!(pub SHADOW_REUSE, Allow,
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"rebinding a name to an expression that re-uses the original value, e.g. \
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`let x = x + 1`");
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declare_lint!(pub SHADOW_UNRELATED, Warn,
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"The name is re-bound without even using the original value");
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#[derive(Copy, Clone)]
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pub struct ShadowPass;
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impl LintPass for ShadowPass {
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fn get_lints(&self) -> LintArray {
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lint_array!(SHADOW_SAME, SHADOW_REUSE, SHADOW_UNRELATED)
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}
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fn check_fn(&mut self, cx: &Context, _: FnKind, decl: &FnDecl,
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block: &Block, _: Span, _: NodeId) {
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if in_external_macro(cx, block.span) { return; }
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check_fn(cx, decl, block);
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}
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}
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fn check_fn(cx: &Context, decl: &FnDecl, block: &Block) {
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let mut bindings = Vec::new();
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for arg in &decl.inputs {
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if let PatIdent(_, ident, _) = arg.pat.node {
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bindings.push(ident.node.name)
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}
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}
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check_block(cx, block, &mut bindings);
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}
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fn check_block(cx: &Context, block: &Block, bindings: &mut Vec<Name>) {
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let len = bindings.len();
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for stmt in &block.stmts {
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match stmt.node {
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StmtDecl(ref decl, _) => check_decl(cx, decl, bindings),
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StmtExpr(ref e, _) | StmtSemi(ref e, _) =>
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check_expr(cx, e, bindings),
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_ => ()
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}
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}
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if let Some(ref o) = block.expr { check_expr(cx, o, bindings); }
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bindings.truncate(len);
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}
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fn check_decl(cx: &Context, decl: &Decl, bindings: &mut Vec<Name>) {
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if in_external_macro(cx, decl.span) { return; }
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if let DeclLocal(ref local) = decl.node {
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let Local{ ref pat, ref ty, ref init, id: _, span } = **local;
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if let &Some(ref t) = ty { check_ty(cx, t, bindings) }
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if let &Some(ref o) = init { check_expr(cx, o, bindings) }
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check_pat(cx, pat, init, span, bindings);
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}
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}
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fn is_binding(cx: &Context, pat: &Pat) -> bool {
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match cx.tcx.def_map.borrow().get(&pat.id).map(|d| d.full_def()) {
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Some(DefVariant(..)) | Some(DefStruct(..)) => false,
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_ => true
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}
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}
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fn check_pat<T>(cx: &Context, pat: &Pat, init: &Option<T>, span: Span,
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bindings: &mut Vec<Name>) where T: Deref<Target=Expr> {
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//TODO: match more stuff / destructuring
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match pat.node {
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PatIdent(_, ref ident, ref inner) => {
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let name = ident.node.name;
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if is_binding(cx, pat) {
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if bindings.contains(&name) {
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lint_shadow(cx, name, span, pat.span, init);
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}
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bindings.push(name);
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}
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if let Some(ref p) = *inner { check_pat(cx, p, init, span, bindings); }
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},
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//PatEnum(Path, Option<Vec<P<Pat>>>),
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//PatQPath(QSelf, Path),
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//PatStruct(Path, Vec<Spanned<FieldPat>>, bool),
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//PatTup(Vec<P<Pat>>),
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PatBox(ref inner) => {
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if let Some(ref initp) = *init {
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match initp.node {
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ExprBox(_, ref inner_init) =>
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check_pat(cx, inner, &Some(&**inner_init), span, bindings),
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//TODO: ExprCall on Box::new
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_ => check_pat(cx, inner, init, span, bindings),
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}
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} else {
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check_pat(cx, inner, init, span, bindings);
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}
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},
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//PatRegion(P<Pat>, Mutability),
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//PatRange(P<Expr>, P<Expr>),
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//PatVec(Vec<P<Pat>>, Option<P<Pat>>, Vec<P<Pat>>),
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_ => (),
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}
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}
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fn lint_shadow<T>(cx: &Context, name: Name, span: Span, lspan: Span, init:
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&Option<T>) where T: Deref<Target=Expr> {
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if let &Some(ref expr) = init {
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if is_self_shadow(name, expr) {
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span_lint(cx, SHADOW_SAME, span, &format!(
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"{} is shadowed by itself in {}",
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snippet(cx, lspan, "_"),
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snippet(cx, expr.span, "..")));
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} else {
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if contains_self(name, expr) {
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span_lint(cx, SHADOW_REUSE, span, &format!(
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"{} is shadowed by {} which reuses the original value",
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snippet(cx, lspan, "_"),
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snippet(cx, expr.span, "..")));
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} else {
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span_lint(cx, SHADOW_UNRELATED, span, &format!(
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"{} is shadowed by {} in this declaration",
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snippet(cx, lspan, "_"),
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snippet(cx, expr.span, "..")));
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}
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}
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} else {
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span_lint(cx, SHADOW_UNRELATED, span, &format!(
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"{} is shadowed in this declaration", snippet(cx, lspan, "_")));
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}
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}
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fn check_expr(cx: &Context, expr: &Expr, bindings: &mut Vec<Name>) {
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if in_external_macro(cx, expr.span) { return; }
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match expr.node {
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ExprUnary(_, ref e) | ExprParen(ref e) | ExprField(ref e, _) |
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ExprTupField(ref e, _) | ExprAddrOf(_, ref e) | ExprBox(None, ref e)
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=> { check_expr(cx, e, bindings) },
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ExprBox(Some(ref place), ref e) => {
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check_expr(cx, place, bindings); check_expr(cx, e, bindings) }
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ExprBlock(ref block) | ExprLoop(ref block, _) =>
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{ check_block(cx, block, bindings) },
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//ExprCall
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//ExprMethodCall
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ExprVec(ref v) | ExprTup(ref v) =>
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for ref e in v { check_expr(cx, e, bindings) },
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ExprIf(ref cond, ref then, ref otherwise) => {
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check_expr(cx, cond, bindings);
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check_block(cx, then, bindings);
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if let &Some(ref o) = otherwise { check_expr(cx, o, bindings); }
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},
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ExprWhile(ref cond, ref block, _) => {
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check_expr(cx, cond, bindings);
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check_block(cx, block, bindings);
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},
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ExprMatch(ref init, ref arms, _) => {
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check_expr(cx, init, bindings);
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for ref arm in arms {
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for ref pat in &arm.pats {
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check_pat(cx, &pat, &Some(&**init), pat.span, bindings);
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//TODO: This is ugly, but needed to get the right type
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}
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if let Some(ref guard) = arm.guard {
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check_expr(cx, guard, bindings);
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}
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check_expr(cx, &arm.body, bindings);
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}
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},
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_ => ()
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}
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}
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fn check_ty(cx: &Context, ty: &Ty, bindings: &mut Vec<Name>) {
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match ty.node {
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TyParen(ref sty) | TyObjectSum(ref sty, _) |
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TyVec(ref sty) => check_ty(cx, sty, bindings),
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TyFixedLengthVec(ref fty, ref expr) => {
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check_ty(cx, fty, bindings);
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check_expr(cx, expr, bindings);
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},
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TyPtr(MutTy{ ty: ref mty, .. }) |
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TyRptr(_, MutTy{ ty: ref mty, .. }) => check_ty(cx, mty, bindings),
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TyTup(ref tup) => { for ref t in tup { check_ty(cx, t, bindings) } },
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TyTypeof(ref expr) => check_expr(cx, expr, bindings),
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_ => (),
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}
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}
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fn is_self_shadow(name: Name, expr: &Expr) -> bool {
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match expr.node {
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ExprBox(_, ref inner) |
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ExprParen(ref inner) |
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ExprAddrOf(_, ref inner) => is_self_shadow(name, inner),
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ExprBlock(ref block) => block.stmts.is_empty() && block.expr.as_ref().
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map_or(false, |ref e| is_self_shadow(name, e)),
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ExprUnary(op, ref inner) => (UnUniq == op || UnDeref == op) &&
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is_self_shadow(name, inner),
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ExprPath(_, ref path) => path_eq_name(name, path),
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_ => false,
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}
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}
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fn path_eq_name(name: Name, path: &Path) -> bool {
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!path.global && path.segments.len() == 1 &&
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path.segments[0].identifier.name == name
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}
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fn contains_self(name: Name, expr: &Expr) -> bool {
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match expr.node {
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ExprUnary(_, ref e) | ExprParen(ref e) | ExprField(ref e, _) |
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ExprTupField(ref e, _) | ExprAddrOf(_, ref e) | ExprBox(_, ref e)
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=> contains_self(name, e),
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ExprBinary(_, ref l, ref r) =>
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contains_self(name, l) || contains_self(name, r),
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ExprBlock(ref block) | ExprLoop(ref block, _) =>
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contains_block_self(name, block),
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ExprCall(ref fun, ref args) => contains_self(name, fun) ||
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args.iter().any(|ref a| contains_self(name, a)),
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ExprMethodCall(_, _, ref args) =>
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args.iter().any(|ref a| contains_self(name, a)),
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ExprVec(ref v) | ExprTup(ref v) =>
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v.iter().any(|ref e| contains_self(name, e)),
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ExprIf(ref cond, ref then, ref otherwise) =>
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contains_self(name, cond) || contains_block_self(name, then) ||
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otherwise.as_ref().map_or(false, |ref e| contains_self(name, e)),
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ExprWhile(ref e, ref block, _) =>
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contains_self(name, e) || contains_block_self(name, block),
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ExprMatch(ref e, ref arms, _) =>
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arms.iter().any(|ref arm| arm.pats.iter().any(|ref pat|
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contains_pat_self(name, pat))) || contains_self(name, e),
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ExprPath(_, ref path) => path_eq_name(name, path),
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_ => false
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}
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}
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fn contains_block_self(name: Name, block: &Block) -> bool {
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for stmt in &block.stmts {
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match stmt.node {
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StmtDecl(ref decl, _) =>
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if let DeclLocal(ref local) = decl.node {
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//TODO: We don't currently handle the case where the name
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//is shadowed wiithin the block; this means code including this
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//degenerate pattern will get the wrong warning.
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if let Some(ref init) = local.init {
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if contains_self(name, init) { return true; }
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}
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},
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StmtExpr(ref e, _) | StmtSemi(ref e, _) =>
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if contains_self(name, e) { return true },
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_ => ()
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}
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}
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if let Some(ref e) = block.expr { contains_self(name, e) } else { false }
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}
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fn contains_pat_self(name: Name, pat: &Pat) -> bool {
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match pat.node {
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PatIdent(_, ref ident, ref inner) => name == ident.node.name ||
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inner.as_ref().map_or(false, |ref p| contains_pat_self(name, p)),
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PatEnum(_, ref opats) => opats.as_ref().map_or(false,
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|pats| pats.iter().any(|p| contains_pat_self(name, p))),
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PatQPath(_, ref path) => path_eq_name(name, path),
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PatStruct(_, ref fieldpats, _) => fieldpats.iter().any(
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|ref fp| contains_pat_self(name, &fp.node.pat)),
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PatTup(ref ps) => ps.iter().any(|ref p| contains_pat_self(name, p)),
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PatBox(ref p) |
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PatRegion(ref p, _) => contains_pat_self(name, p),
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PatRange(ref from, ref until) =>
|
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contains_self(name, from) || contains_self(name, until),
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PatVec(ref pre, ref opt, ref post) =>
|
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pre.iter().any(|ref p| contains_pat_self(name, p)) ||
|
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opt.as_ref().map_or(false, |ref p| contains_pat_self(name, p)) ||
|
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post.iter().any(|ref p| contains_pat_self(name, p)),
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_ => false,
|
||||
}
|
||||
}
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|
|
@ -93,9 +93,9 @@ pub fn snippet_block<'a>(cx: &Context, span: Span, default: &'a str) -> Cow<'a,
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/// Trim indentation from a multiline string
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/// with possibility of ignoring the first line
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||||
pub fn trim_multiline(s: Cow<str>, ignore_first: bool) -> Cow<str> {
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let s = trim_multiline_inner(s, ignore_first, ' ');
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let s = trim_multiline_inner(s, ignore_first, '\t');
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trim_multiline_inner(s, ignore_first, ' ')
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let s_space = trim_multiline_inner(s, ignore_first, ' ');
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let s_tab = trim_multiline_inner(s_space, ignore_first, '\t');
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trim_multiline_inner(s_tab, ignore_first, ' ')
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}
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||||
fn trim_multiline_inner(s: Cow<str>, ignore_first: bool, ch: char) -> Cow<str> {
|
||||
|
|
|
|||
|
|
@ -2,7 +2,7 @@
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|||
#![plugin(clippy)]
|
||||
|
||||
#[deny(approx_constant)]
|
||||
#[allow(unused)]
|
||||
#[allow(unused, shadow_unrelated)]
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||||
fn main() {
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||||
let my_e = 2.7182; //~ERROR approximate value of `f{32, 64}::E` found
|
||||
let almost_e = 2.718; //~ERROR approximate value of `f{32, 64}::E` found
|
||||
|
|
|
|||
|
|
@ -0,0 +1,22 @@
|
|||
#![feature(plugin)]
|
||||
#![plugin(clippy)]
|
||||
|
||||
#![allow(unused_parens, unused_variables)]
|
||||
#![deny(shadow)]
|
||||
|
||||
fn id<T>(x: T) -> T { x }
|
||||
|
||||
fn first(x: (isize, isize)) -> isize { x.0 }
|
||||
|
||||
fn main() {
|
||||
let mut x = 1;
|
||||
let x = &mut x; //~ERROR: x is shadowed by itself in &mut x
|
||||
let x = { x }; //~ERROR: x is shadowed by itself in { x }
|
||||
let x = (&*x); //~ERROR: x is shadowed by itself in (&*x)
|
||||
let x = { *x + 1 }; //~ERROR: x is shadowed by { *x + 1 } which reuses
|
||||
let x = id(x); //~ERROR: x is shadowed by id(x) which reuses
|
||||
let x = (1, x); //~ERROR: x is shadowed by (1, x) which reuses
|
||||
let x = first(x); //~ERROR: x is shadowed by first(x) which reuses
|
||||
let y = 1;
|
||||
let x = y; //~ERROR: x is shadowed by y in this declaration
|
||||
}
|
||||
Loading…
Reference in New Issue