Merge branch 'pr-228'

Conflicts:
	README.md
	src/methods.rs
This commit is contained in:
Manish Goregaokar 2015-08-27 11:09:40 +05:30
commit 193e71be61
4 changed files with 140 additions and 5 deletions

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@ -4,7 +4,7 @@
A collection of lints that give helpful tips to newbies and catch oversights.
##Lints
There are 48 lints included in this crate:
There are 49 lints included in this crate:
name | default | meaning
-----------------------------------------------------------------------------------------------------|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
@ -47,6 +47,7 @@ name
[shadow_reuse](https://github.com/Manishearth/rust-clippy/wiki#shadow_reuse) | allow | rebinding a name to an expression that re-uses the original value, e.g. `let x = x + 1`
[shadow_same](https://github.com/Manishearth/rust-clippy/wiki#shadow_same) | allow | rebinding a name to itself, e.g. `let mut x = &mut x`
[shadow_unrelated](https://github.com/Manishearth/rust-clippy/wiki#shadow_unrelated) | warn | The name is re-bound without even using the original value
[should_implement_trait](https://github.com/Manishearth/rust-clippy/wiki#should_implement_trait) | warn | defining a method that should be implementing a std trait
[single_match](https://github.com/Manishearth/rust-clippy/wiki#single_match) | warn | a match statement with a single nontrivial arm (i.e, where the other arm is `_ => {}`) is used; recommends `if let` instead
[str_to_string](https://github.com/Manishearth/rust-clippy/wiki#str_to_string) | warn | using `to_string()` on a str, which should be `to_owned()`
[string_add](https://github.com/Manishearth/rust-clippy/wiki#string_add) | allow | using `x + ..` where x is a `String`; suggests using `push_str()` instead

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@ -100,6 +100,7 @@ pub fn plugin_registrar(reg: &mut Registry) {
matches::SINGLE_MATCH,
methods::OPTION_UNWRAP_USED,
methods::RESULT_UNWRAP_USED,
methods::SHOULD_IMPLEMENT_TRAIT,
methods::STR_TO_STRING,
methods::STRING_TO_STRING,
misc::CMP_NAN,

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@ -4,9 +4,12 @@ use rustc::middle::ty;
use std::iter;
use std::borrow::Cow;
use utils::{snippet, span_lint, match_type, walk_ptrs_ty_depth};
use utils::{snippet, span_lint, match_path, match_type, walk_ptrs_ty_depth};
use utils::{OPTION_PATH, RESULT_PATH, STRING_PATH};
use self::SelfKind::*;
use self::OutType::*;
#[derive(Copy,Clone)]
pub struct MethodsPass;
@ -18,10 +21,13 @@ declare_lint!(pub STR_TO_STRING, Warn,
"using `to_string()` on a str, which should be `to_owned()`");
declare_lint!(pub STRING_TO_STRING, Warn,
"calling `String.to_string()` which is a no-op");
declare_lint!(pub SHOULD_IMPLEMENT_TRAIT, Warn,
"defining a method that should be implementing a std trait");
impl LintPass for MethodsPass {
fn get_lints(&self) -> LintArray {
lint_array!(OPTION_UNWRAP_USED, RESULT_UNWRAP_USED, STR_TO_STRING, STRING_TO_STRING)
lint_array!(OPTION_UNWRAP_USED, RESULT_UNWRAP_USED, STR_TO_STRING, STRING_TO_STRING,
SHOULD_IMPLEMENT_TRAIT)
}
fn check_expr(&mut self, cx: &Context, expr: &Expr) {
@ -57,4 +63,112 @@ impl LintPass for MethodsPass {
}
}
}
fn check_item(&mut self, cx: &Context, item: &Item) {
if let ItemImpl(_, _, _, None, _, ref items) = item.node {
for item in items {
let name = item.ident.name;
for &(method_name, n_args, self_kind, out_type, trait_name) in &TRAIT_METHODS {
if_let_chain! {
[
name == method_name,
let MethodImplItem(ref sig, _) = item.node,
sig.decl.inputs.len() == n_args,
out_type.matches(&sig.decl.output),
self_kind.matches(&sig.explicit_self.node)
], {
span_lint(cx, SHOULD_IMPLEMENT_TRAIT, item.span, &format!(
"defining a method called `{}` on this type; consider implementing \
the `{}` trait or choosing a less ambiguous name", name, trait_name));
}
}
}
}
}
}
}
const TRAIT_METHODS: [(&'static str, usize, SelfKind, OutType, &'static str); 30] = [
("add", 2, ValueSelf, AnyType, "std::ops::Add`"),
("sub", 2, ValueSelf, AnyType, "std::ops::Sub"),
("mul", 2, ValueSelf, AnyType, "std::ops::Mul"),
("div", 2, ValueSelf, AnyType, "std::ops::Div"),
("rem", 2, ValueSelf, AnyType, "std::ops::Rem"),
("shl", 2, ValueSelf, AnyType, "std::ops::Shl"),
("shr", 2, ValueSelf, AnyType, "std::ops::Shr"),
("bitand", 2, ValueSelf, AnyType, "std::ops::BitAnd"),
("bitor", 2, ValueSelf, AnyType, "std::ops::BitOr"),
("bitxor", 2, ValueSelf, AnyType, "std::ops::BitXor"),
("neg", 1, ValueSelf, AnyType, "std::ops::Neg"),
("not", 1, ValueSelf, AnyType, "std::ops::Not"),
("drop", 1, RefMutSelf, UnitType, "std::ops::Drop"),
("index", 2, RefSelf, RefType, "std::ops::Index"),
("index_mut", 2, RefMutSelf, RefType, "std::ops::IndexMut"),
("deref", 1, RefSelf, RefType, "std::ops::Deref"),
("deref_mut", 1, RefMutSelf, RefType, "std::ops::DerefMut"),
("clone", 1, RefSelf, AnyType, "std::clone::Clone"),
("borrow", 1, RefSelf, RefType, "std::borrow::Borrow"),
("borrow_mut", 1, RefMutSelf, RefType, "std::borrow::BorrowMut"),
("as_ref", 1, RefSelf, RefType, "std::convert::AsRef"),
("as_mut", 1, RefMutSelf, RefType, "std::convert::AsMut"),
("eq", 2, RefSelf, BoolType, "std::cmp::PartialEq"),
("cmp", 2, RefSelf, AnyType, "std::cmp::Ord"),
("default", 0, NoSelf, AnyType, "std::default::Default"),
("hash", 2, RefSelf, UnitType, "std::hash::Hash"),
("next", 1, RefMutSelf, AnyType, "std::iter::Iterator"),
("into_iter", 1, ValueSelf, AnyType, "std::iter::IntoIterator"),
("from_iter", 1, NoSelf, AnyType, "std::iter::FromIterator"),
("from_str", 1, NoSelf, AnyType, "std::str::FromStr"),
];
#[derive(Clone, Copy)]
enum SelfKind {
ValueSelf,
RefSelf,
RefMutSelf,
NoSelf
}
impl SelfKind {
fn matches(&self, slf: &ExplicitSelf_) -> bool {
match (self, slf) {
(&ValueSelf, &SelfValue(_)) => true,
(&RefSelf, &SelfRegion(_, Mutability::MutImmutable, _)) => true,
(&RefMutSelf, &SelfRegion(_, Mutability::MutMutable, _)) => true,
(&NoSelf, &SelfStatic) => true,
_ => false
}
}
}
#[derive(Clone, Copy)]
enum OutType {
UnitType,
BoolType,
AnyType,
RefType,
}
impl OutType {
fn matches(&self, ty: &FunctionRetTy) -> bool {
match (self, ty) {
(&UnitType, &DefaultReturn(_)) => true,
(&UnitType, &Return(ref ty)) if ty.node == TyTup(vec![]) => true,
(&BoolType, &Return(ref ty)) if is_bool(ty) => true,
(&AnyType, &Return(ref ty)) if ty.node != TyTup(vec![]) => true,
(&RefType, &Return(ref ty)) => {
if let TyRptr(_, _) = ty.node { true } else { false }
}
_ => false
}
}
}
fn is_bool(ty: &Ty) -> bool {
if let TyPath(None, ref p) = ty.node {
if match_path(p, &["bool"]) {
return true;
}
}
false
}

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@ -1,8 +1,27 @@
#![feature(plugin)]
#![plugin(clippy)]
#[deny(option_unwrap_used, result_unwrap_used)]
#[deny(str_to_string, string_to_string)]
#![allow(unused)]
#![deny(clippy)]
use std::ops::Mul;
struct T;
impl T {
fn add(self, other: T) -> T { self } //~ERROR defining a method called `add`
fn drop(&mut self) { } //~ERROR defining a method called `drop`
fn sub(&self, other: T) -> &T { self } // no error, self is a ref
fn div(self) -> T { self } // no error, different #arguments
fn rem(self, other: T) { } // no error, wrong return type
}
impl Mul<T> for T {
type Output = T;
fn mul(self, other: T) -> T { self } // no error, obviously
}
fn main() {
let opt = Some(0);
let _ = opt.unwrap(); //~ERROR used unwrap() on an Option