Wesley Wiser
parent
ed77fcc8a6
commit
974dfe8e31
@ -28,8 +28,8 @@
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//! Use the former for unit-like structs and the latter for structs with
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//! a `pub fn new()`.
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use metadata::{csearch, decoder};
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use middle::{cfg, def, infer, pat_util, stability, traits};
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use metadata::decoder;
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use middle::{cfg, def, infer, stability, traits};
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use middle::def_id::DefId;
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use middle::subst::Substs;
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use middle::ty::{self, Ty};
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@ -37,21 +37,19 @@ use middle::ty::adjustment;
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use middle::const_eval::{eval_const_expr_partial, ConstVal};
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use middle::const_eval::EvalHint::ExprTypeChecked;
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use rustc::front::map as hir_map;
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use util::nodemap::{FnvHashMap, FnvHashSet, NodeSet};
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use lint::{Level, LateContext, EarlyContext, LintContext, LintArray, Lint};
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use lint::{LintPass, EarlyLintPass, LateLintPass};
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use util::nodemap::{FnvHashSet, NodeSet};
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use lint::{Level, LateContext, LintContext, LintArray, Lint};
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use lint::{LintPass, LateLintPass};
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use std::collections::HashSet;
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use std::collections::hash_map::Entry::{Occupied, Vacant};
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use std::{cmp, slice};
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use std::cmp;
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use std::{i8, i16, i32, i64, u8, u16, u32, u64, f32, f64};
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use syntax::{abi, ast};
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use syntax::attr::{self, AttrMetaMethods};
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use syntax::codemap::{self, Span};
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use syntax::feature_gate::{KNOWN_ATTRIBUTES, AttributeType, emit_feature_err, GateIssue};
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use syntax::feature_gate::{emit_feature_err, GateIssue};
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use syntax::ast::{TyIs, TyUs, TyI8, TyU8, TyI16, TyU16, TyI32, TyU32, TyI64, TyU64};
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use syntax::ptr::P;
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use rustc_front::hir;
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use rustc_front::visit::{self, FnKind, Visitor};
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@ -883,302 +881,6 @@ impl LateLintPass for RawPointerDerive {
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}
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}
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declare_lint! {
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UNUSED_ATTRIBUTES,
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Warn,
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"detects attributes that were not used by the compiler"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedAttributes;
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impl LintPass for UnusedAttributes {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_ATTRIBUTES)
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}
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}
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impl LateLintPass for UnusedAttributes {
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fn check_attribute(&mut self, cx: &LateContext, attr: &ast::Attribute) {
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// Note that check_name() marks the attribute as used if it matches.
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for &(ref name, ty, _) in KNOWN_ATTRIBUTES {
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match ty {
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AttributeType::Whitelisted if attr.check_name(name) => {
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break;
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},
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_ => ()
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}
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}
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let plugin_attributes = cx.sess().plugin_attributes.borrow_mut();
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for &(ref name, ty) in plugin_attributes.iter() {
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if ty == AttributeType::Whitelisted && attr.check_name(&*name) {
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break;
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}
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}
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if !attr::is_used(attr) {
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cx.span_lint(UNUSED_ATTRIBUTES, attr.span, "unused attribute");
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// Is it a builtin attribute that must be used at the crate level?
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let known_crate = KNOWN_ATTRIBUTES.iter().find(|&&(name, ty, _)| {
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attr.name() == name &&
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ty == AttributeType::CrateLevel
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}).is_some();
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// Has a plugin registered this attribute as one which must be used at
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// the crate level?
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let plugin_crate = plugin_attributes.iter()
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.find(|&&(ref x, t)| {
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&*attr.name() == &*x &&
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AttributeType::CrateLevel == t
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}).is_some();
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if known_crate || plugin_crate {
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let msg = match attr.node.style {
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ast::AttrOuter => "crate-level attribute should be an inner \
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attribute: add an exclamation mark: #![foo]",
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ast::AttrInner => "crate-level attribute should be in the \
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root module",
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};
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cx.span_lint(UNUSED_ATTRIBUTES, attr.span, msg);
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}
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}
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}
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}
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declare_lint! {
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pub PATH_STATEMENTS,
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Warn,
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"path statements with no effect"
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}
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#[derive(Copy, Clone)]
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pub struct PathStatements;
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impl LintPass for PathStatements {
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fn get_lints(&self) -> LintArray {
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lint_array!(PATH_STATEMENTS)
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}
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}
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impl LateLintPass for PathStatements {
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fn check_stmt(&mut self, cx: &LateContext, s: &hir::Stmt) {
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match s.node {
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hir::StmtSemi(ref expr, _) => {
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match expr.node {
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hir::ExprPath(..) => cx.span_lint(PATH_STATEMENTS, s.span,
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"path statement with no effect"),
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_ => ()
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}
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}
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_ => ()
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}
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}
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}
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declare_lint! {
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pub UNUSED_MUST_USE,
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Warn,
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"unused result of a type flagged as #[must_use]"
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}
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declare_lint! {
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pub UNUSED_RESULTS,
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Allow,
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"unused result of an expression in a statement"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedResults;
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impl LintPass for UnusedResults {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_MUST_USE, UNUSED_RESULTS)
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}
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}
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impl LateLintPass for UnusedResults {
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fn check_stmt(&mut self, cx: &LateContext, s: &hir::Stmt) {
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let expr = match s.node {
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hir::StmtSemi(ref expr, _) => &**expr,
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_ => return
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};
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if let hir::ExprRet(..) = expr.node {
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return;
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}
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let t = cx.tcx.expr_ty(&expr);
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let warned = match t.sty {
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ty::TyTuple(ref tys) if tys.is_empty() => return,
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ty::TyBool => return,
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ty::TyStruct(def, _) |
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ty::TyEnum(def, _) => {
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if def.did.is_local() {
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if let hir_map::NodeItem(it) = cx.tcx.map.get(def.did.node) {
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check_must_use(cx, &it.attrs, s.span)
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} else {
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false
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}
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} else {
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let attrs = csearch::get_item_attrs(&cx.sess().cstore, def.did);
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check_must_use(cx, &attrs[..], s.span)
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}
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}
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_ => false,
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};
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if !warned {
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cx.span_lint(UNUSED_RESULTS, s.span, "unused result");
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}
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fn check_must_use(cx: &LateContext, attrs: &[ast::Attribute], sp: Span) -> bool {
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for attr in attrs {
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if attr.check_name("must_use") {
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let mut msg = "unused result which must be used".to_string();
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// check for #[must_use="..."]
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match attr.value_str() {
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None => {}
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Some(s) => {
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msg.push_str(": ");
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msg.push_str(&s);
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}
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}
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cx.span_lint(UNUSED_MUST_USE, sp, &msg);
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return true;
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}
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}
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false
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}
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}
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}
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declare_lint! {
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UNUSED_PARENS,
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Warn,
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"`if`, `match`, `while` and `return` do not need parentheses"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedParens;
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impl UnusedParens {
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fn check_unused_parens_core(&self, cx: &EarlyContext, value: &ast::Expr, msg: &str,
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struct_lit_needs_parens: bool) {
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if let ast::ExprParen(ref inner) = value.node {
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let necessary = struct_lit_needs_parens && contains_exterior_struct_lit(&**inner);
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if !necessary {
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cx.span_lint(UNUSED_PARENS, value.span,
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&format!("unnecessary parentheses around {}", msg))
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}
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}
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/// Expressions that syntactically contain an "exterior" struct
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/// literal i.e. not surrounded by any parens or other
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/// delimiters, e.g. `X { y: 1 }`, `X { y: 1 }.method()`, `foo
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/// == X { y: 1 }` and `X { y: 1 } == foo` all do, but `(X {
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/// y: 1 }) == foo` does not.
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fn contains_exterior_struct_lit(value: &ast::Expr) -> bool {
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match value.node {
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ast::ExprStruct(..) => true,
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ast::ExprAssign(ref lhs, ref rhs) |
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ast::ExprAssignOp(_, ref lhs, ref rhs) |
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ast::ExprBinary(_, ref lhs, ref rhs) => {
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// X { y: 1 } + X { y: 2 }
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contains_exterior_struct_lit(&**lhs) ||
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contains_exterior_struct_lit(&**rhs)
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}
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ast::ExprUnary(_, ref x) |
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ast::ExprCast(ref x, _) |
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ast::ExprField(ref x, _) |
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ast::ExprTupField(ref x, _) |
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ast::ExprIndex(ref x, _) => {
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// &X { y: 1 }, X { y: 1 }.y
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contains_exterior_struct_lit(&**x)
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}
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ast::ExprMethodCall(_, _, ref exprs) => {
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// X { y: 1 }.bar(...)
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contains_exterior_struct_lit(&*exprs[0])
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}
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_ => false
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}
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}
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}
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}
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impl LintPass for UnusedParens {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_PARENS)
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}
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}
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impl EarlyLintPass for UnusedParens {
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fn check_expr(&mut self, cx: &EarlyContext, e: &ast::Expr) {
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let (value, msg, struct_lit_needs_parens) = match e.node {
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ast::ExprIf(ref cond, _, _) => (cond, "`if` condition", true),
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ast::ExprWhile(ref cond, _, _) => (cond, "`while` condition", true),
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ast::ExprMatch(ref head, _, source) => match source {
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ast::MatchSource::Normal => (head, "`match` head expression", true),
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ast::MatchSource::IfLetDesugar { .. } => (head, "`if let` head expression", true),
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ast::MatchSource::WhileLetDesugar => (head, "`while let` head expression", true),
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ast::MatchSource::ForLoopDesugar => (head, "`for` head expression", true),
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},
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ast::ExprRet(Some(ref value)) => (value, "`return` value", false),
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ast::ExprAssign(_, ref value) => (value, "assigned value", false),
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ast::ExprAssignOp(_, _, ref value) => (value, "assigned value", false),
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_ => return
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};
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self.check_unused_parens_core(cx, &**value, msg, struct_lit_needs_parens);
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}
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fn check_stmt(&mut self, cx: &EarlyContext, s: &ast::Stmt) {
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let (value, msg) = match s.node {
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ast::StmtDecl(ref decl, _) => match decl.node {
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ast::DeclLocal(ref local) => match local.init {
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Some(ref value) => (value, "assigned value"),
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None => return
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},
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_ => return
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},
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_ => return
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};
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self.check_unused_parens_core(cx, &**value, msg, false);
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}
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}
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declare_lint! {
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UNUSED_IMPORT_BRACES,
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Allow,
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"unnecessary braces around an imported item"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedImportBraces;
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impl LintPass for UnusedImportBraces {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_IMPORT_BRACES)
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}
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}
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impl LateLintPass for UnusedImportBraces {
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fn check_item(&mut self, cx: &LateContext, item: &hir::Item) {
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if let hir::ItemUse(ref view_path) = item.node {
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if let hir::ViewPathList(_, ref items) = view_path.node {
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if items.len() == 1 {
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if let hir::PathListIdent {ref name, ..} = items[0].node {
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let m = format!("braces around {} is unnecessary",
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name);
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cx.span_lint(UNUSED_IMPORT_BRACES, item.span,
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&m[..]);
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}
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}
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}
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}
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}
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}
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declare_lint! {
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NON_SHORTHAND_FIELD_PATTERNS,
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Warn,
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@ -1220,33 +922,6 @@ impl LateLintPass for NonShorthandFieldPatterns {
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}
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}
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declare_lint! {
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pub UNUSED_UNSAFE,
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Warn,
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"unnecessary use of an `unsafe` block"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedUnsafe;
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impl LintPass for UnusedUnsafe {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_UNSAFE)
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}
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}
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impl LateLintPass for UnusedUnsafe {
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fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) {
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if let hir::ExprBlock(ref blk) = e.node {
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// Don't warn about generated blocks, that'll just pollute the output.
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if blk.rules == hir::UnsafeBlock(hir::UserProvided) &&
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!cx.tcx.used_unsafe.borrow().contains(&blk.id) {
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cx.span_lint(UNUSED_UNSAFE, blk.span, "unnecessary `unsafe` block");
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}
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}
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}
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}
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declare_lint! {
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UNSAFE_CODE,
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Allow,
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@ -1310,119 +985,6 @@ impl LateLintPass for UnsafeCode {
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}
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}
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declare_lint! {
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pub UNUSED_MUT,
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Warn,
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"detect mut variables which don't need to be mutable"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedMut;
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impl UnusedMut {
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fn check_unused_mut_pat(&self, cx: &LateContext, pats: &[P<hir::Pat>]) {
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// collect all mutable pattern and group their NodeIDs by their Identifier to
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// avoid false warnings in match arms with multiple patterns
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let mut mutables = FnvHashMap();
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for p in pats {
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pat_util::pat_bindings(&cx.tcx.def_map, p, |mode, id, _, path1| {
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let ident = path1.node;
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if let hir::BindByValue(hir::MutMutable) = mode {
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if !ident.name.as_str().starts_with("_") {
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match mutables.entry(ident.name.usize()) {
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Vacant(entry) => { entry.insert(vec![id]); },
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Occupied(mut entry) => { entry.get_mut().push(id); },
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}
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}
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}
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});
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}
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let used_mutables = cx.tcx.used_mut_nodes.borrow();
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for (_, v) in &mutables {
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if !v.iter().any(|e| used_mutables.contains(e)) {
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cx.span_lint(UNUSED_MUT, cx.tcx.map.span(v[0]),
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"variable does not need to be mutable");
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}
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}
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}
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}
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impl LintPass for UnusedMut {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_MUT)
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}
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}
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impl LateLintPass for UnusedMut {
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fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) {
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if let hir::ExprMatch(_, ref arms, _) = e.node {
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for a in arms {
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self.check_unused_mut_pat(cx, &a.pats)
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}
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}
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}
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fn check_stmt(&mut self, cx: &LateContext, s: &hir::Stmt) {
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if let hir::StmtDecl(ref d, _) = s.node {
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if let hir::DeclLocal(ref l) = d.node {
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self.check_unused_mut_pat(cx, slice::ref_slice(&l.pat));
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}
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}
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}
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fn check_fn(&mut self, cx: &LateContext,
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_: FnKind, decl: &hir::FnDecl,
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_: &hir::Block, _: Span, _: ast::NodeId) {
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for a in &decl.inputs {
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self.check_unused_mut_pat(cx, slice::ref_slice(&a.pat));
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}
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}
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}
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declare_lint! {
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UNUSED_ALLOCATION,
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Warn,
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"detects unnecessary allocations that can be eliminated"
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}
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#[derive(Copy, Clone)]
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pub struct UnusedAllocation;
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impl LintPass for UnusedAllocation {
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fn get_lints(&self) -> LintArray {
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lint_array!(UNUSED_ALLOCATION)
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}
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}
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impl LateLintPass for UnusedAllocation {
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fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) {
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match e.node {
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hir::ExprUnary(hir::UnUniq, _) => (),
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_ => return
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}
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|
||||
if let Some(adjustment) = cx.tcx.tables.borrow().adjustments.get(&e.id) {
|
||||
if let adjustment::AdjustDerefRef(adjustment::AutoDerefRef {
|
||||
ref autoref, ..
|
||||
}) = *adjustment {
|
||||
match autoref {
|
||||
&Some(adjustment::AutoPtr(_, hir::MutImmutable)) => {
|
||||
cx.span_lint(UNUSED_ALLOCATION, e.span,
|
||||
"unnecessary allocation, use & instead");
|
||||
}
|
||||
&Some(adjustment::AutoPtr(_, hir::MutMutable)) => {
|
||||
cx.span_lint(UNUSED_ALLOCATION, e.span,
|
||||
"unnecessary allocation, use &mut instead");
|
||||
}
|
||||
_ => ()
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
MISSING_DOCS,
|
||||
Allow,
|
||||
|
||||
@ -60,9 +60,11 @@ use lint::LintId;
|
||||
|
||||
mod bad_style;
|
||||
mod builtin;
|
||||
mod unused;
|
||||
|
||||
use bad_style::*;
|
||||
use builtin::*;
|
||||
use unused::*;
|
||||
|
||||
/// Tell the `LintStore` about all the built-in lints (the ones
|
||||
/// defined in this crate and the ones defined in
|
||||
|
||||
468
src/librustc_lint/unused.rs
Normal file
468
src/librustc_lint/unused.rs
Normal file
@ -0,0 +1,468 @@
|
||||
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution and at
|
||||
// http://rust-lang.org/COPYRIGHT.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
use metadata::csearch;
|
||||
use middle::pat_util;
|
||||
use middle::ty;
|
||||
use middle::ty::adjustment;
|
||||
use rustc::front::map as hir_map;
|
||||
use util::nodemap::FnvHashMap;
|
||||
use lint::{LateContext, EarlyContext, LintContext, LintArray};
|
||||
use lint::{LintPass, EarlyLintPass, LateLintPass};
|
||||
|
||||
use std::collections::hash_map::Entry::{Occupied, Vacant};
|
||||
use std::slice;
|
||||
|
||||
use syntax::ast;
|
||||
use syntax::attr::{self, AttrMetaMethods};
|
||||
use syntax::codemap::Span;
|
||||
use syntax::feature_gate::{KNOWN_ATTRIBUTES, AttributeType};
|
||||
use syntax::ptr::P;
|
||||
|
||||
use rustc_front::hir;
|
||||
|
||||
use rustc_front::visit::FnKind;
|
||||
|
||||
declare_lint! {
|
||||
pub UNUSED_MUT,
|
||||
Warn,
|
||||
"detect mut variables which don't need to be mutable"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedMut;
|
||||
|
||||
impl UnusedMut {
|
||||
fn check_unused_mut_pat(&self, cx: &LateContext, pats: &[P<hir::Pat>]) {
|
||||
// collect all mutable pattern and group their NodeIDs by their Identifier to
|
||||
// avoid false warnings in match arms with multiple patterns
|
||||
|
||||
let mut mutables = FnvHashMap();
|
||||
for p in pats {
|
||||
pat_util::pat_bindings(&cx.tcx.def_map, p, |mode, id, _, path1| {
|
||||
let ident = path1.node;
|
||||
if let hir::BindByValue(hir::MutMutable) = mode {
|
||||
if !ident.name.as_str().starts_with("_") {
|
||||
match mutables.entry(ident.name.usize()) {
|
||||
Vacant(entry) => { entry.insert(vec![id]); },
|
||||
Occupied(mut entry) => { entry.get_mut().push(id); },
|
||||
}
|
||||
}
|
||||
}
|
||||
});
|
||||
}
|
||||
|
||||
let used_mutables = cx.tcx.used_mut_nodes.borrow();
|
||||
for (_, v) in &mutables {
|
||||
if !v.iter().any(|e| used_mutables.contains(e)) {
|
||||
cx.span_lint(UNUSED_MUT, cx.tcx.map.span(v[0]),
|
||||
"variable does not need to be mutable");
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl LintPass for UnusedMut {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_MUT)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for UnusedMut {
|
||||
fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) {
|
||||
if let hir::ExprMatch(_, ref arms, _) = e.node {
|
||||
for a in arms {
|
||||
self.check_unused_mut_pat(cx, &a.pats)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn check_stmt(&mut self, cx: &LateContext, s: &hir::Stmt) {
|
||||
if let hir::StmtDecl(ref d, _) = s.node {
|
||||
if let hir::DeclLocal(ref l) = d.node {
|
||||
self.check_unused_mut_pat(cx, slice::ref_slice(&l.pat));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn check_fn(&mut self, cx: &LateContext,
|
||||
_: FnKind, decl: &hir::FnDecl,
|
||||
_: &hir::Block, _: Span, _: ast::NodeId) {
|
||||
for a in &decl.inputs {
|
||||
self.check_unused_mut_pat(cx, slice::ref_slice(&a.pat));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
pub UNUSED_MUST_USE,
|
||||
Warn,
|
||||
"unused result of a type flagged as #[must_use]"
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
pub UNUSED_RESULTS,
|
||||
Allow,
|
||||
"unused result of an expression in a statement"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedResults;
|
||||
|
||||
impl LintPass for UnusedResults {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_MUST_USE, UNUSED_RESULTS)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for UnusedResults {
|
||||
fn check_stmt(&mut self, cx: &LateContext, s: &hir::Stmt) {
|
||||
let expr = match s.node {
|
||||
hir::StmtSemi(ref expr, _) => &**expr,
|
||||
_ => return
|
||||
};
|
||||
|
||||
if let hir::ExprRet(..) = expr.node {
|
||||
return;
|
||||
}
|
||||
|
||||
let t = cx.tcx.expr_ty(&expr);
|
||||
let warned = match t.sty {
|
||||
ty::TyTuple(ref tys) if tys.is_empty() => return,
|
||||
ty::TyBool => return,
|
||||
ty::TyStruct(def, _) |
|
||||
ty::TyEnum(def, _) => {
|
||||
if def.did.is_local() {
|
||||
if let hir_map::NodeItem(it) = cx.tcx.map.get(def.did.node) {
|
||||
check_must_use(cx, &it.attrs, s.span)
|
||||
} else {
|
||||
false
|
||||
}
|
||||
} else {
|
||||
let attrs = csearch::get_item_attrs(&cx.sess().cstore, def.did);
|
||||
check_must_use(cx, &attrs[..], s.span)
|
||||
}
|
||||
}
|
||||
_ => false,
|
||||
};
|
||||
if !warned {
|
||||
cx.span_lint(UNUSED_RESULTS, s.span, "unused result");
|
||||
}
|
||||
|
||||
fn check_must_use(cx: &LateContext, attrs: &[ast::Attribute], sp: Span) -> bool {
|
||||
for attr in attrs {
|
||||
if attr.check_name("must_use") {
|
||||
let mut msg = "unused result which must be used".to_string();
|
||||
// check for #[must_use="..."]
|
||||
match attr.value_str() {
|
||||
None => {}
|
||||
Some(s) => {
|
||||
msg.push_str(": ");
|
||||
msg.push_str(&s);
|
||||
}
|
||||
}
|
||||
cx.span_lint(UNUSED_MUST_USE, sp, &msg);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
false
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
pub UNUSED_UNSAFE,
|
||||
Warn,
|
||||
"unnecessary use of an `unsafe` block"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedUnsafe;
|
||||
|
||||
impl LintPass for UnusedUnsafe {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_UNSAFE)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for UnusedUnsafe {
|
||||
fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) {
|
||||
if let hir::ExprBlock(ref blk) = e.node {
|
||||
// Don't warn about generated blocks, that'll just pollute the output.
|
||||
if blk.rules == hir::UnsafeBlock(hir::UserProvided) &&
|
||||
!cx.tcx.used_unsafe.borrow().contains(&blk.id) {
|
||||
cx.span_lint(UNUSED_UNSAFE, blk.span, "unnecessary `unsafe` block");
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
pub PATH_STATEMENTS,
|
||||
Warn,
|
||||
"path statements with no effect"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct PathStatements;
|
||||
|
||||
impl LintPass for PathStatements {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(PATH_STATEMENTS)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for PathStatements {
|
||||
fn check_stmt(&mut self, cx: &LateContext, s: &hir::Stmt) {
|
||||
match s.node {
|
||||
hir::StmtSemi(ref expr, _) => {
|
||||
match expr.node {
|
||||
hir::ExprPath(..) => cx.span_lint(PATH_STATEMENTS, s.span,
|
||||
"path statement with no effect"),
|
||||
_ => ()
|
||||
}
|
||||
}
|
||||
_ => ()
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
UNUSED_ATTRIBUTES,
|
||||
Warn,
|
||||
"detects attributes that were not used by the compiler"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedAttributes;
|
||||
|
||||
impl LintPass for UnusedAttributes {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_ATTRIBUTES)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for UnusedAttributes {
|
||||
fn check_attribute(&mut self, cx: &LateContext, attr: &ast::Attribute) {
|
||||
// Note that check_name() marks the attribute as used if it matches.
|
||||
for &(ref name, ty, _) in KNOWN_ATTRIBUTES {
|
||||
match ty {
|
||||
AttributeType::Whitelisted if attr.check_name(name) => {
|
||||
break;
|
||||
},
|
||||
_ => ()
|
||||
}
|
||||
}
|
||||
|
||||
let plugin_attributes = cx.sess().plugin_attributes.borrow_mut();
|
||||
for &(ref name, ty) in plugin_attributes.iter() {
|
||||
if ty == AttributeType::Whitelisted && attr.check_name(&*name) {
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if !attr::is_used(attr) {
|
||||
cx.span_lint(UNUSED_ATTRIBUTES, attr.span, "unused attribute");
|
||||
// Is it a builtin attribute that must be used at the crate level?
|
||||
let known_crate = KNOWN_ATTRIBUTES.iter().find(|&&(name, ty, _)| {
|
||||
attr.name() == name &&
|
||||
ty == AttributeType::CrateLevel
|
||||
}).is_some();
|
||||
|
||||
// Has a plugin registered this attribute as one which must be used at
|
||||
// the crate level?
|
||||
let plugin_crate = plugin_attributes.iter()
|
||||
.find(|&&(ref x, t)| {
|
||||
&*attr.name() == &*x &&
|
||||
AttributeType::CrateLevel == t
|
||||
}).is_some();
|
||||
if known_crate || plugin_crate {
|
||||
let msg = match attr.node.style {
|
||||
ast::AttrOuter => "crate-level attribute should be an inner \
|
||||
attribute: add an exclamation mark: #![foo]",
|
||||
ast::AttrInner => "crate-level attribute should be in the \
|
||||
root module",
|
||||
};
|
||||
cx.span_lint(UNUSED_ATTRIBUTES, attr.span, msg);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
UNUSED_PARENS,
|
||||
Warn,
|
||||
"`if`, `match`, `while` and `return` do not need parentheses"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedParens;
|
||||
|
||||
impl UnusedParens {
|
||||
fn check_unused_parens_core(&self, cx: &EarlyContext, value: &ast::Expr, msg: &str,
|
||||
struct_lit_needs_parens: bool) {
|
||||
if let ast::ExprParen(ref inner) = value.node {
|
||||
let necessary = struct_lit_needs_parens && contains_exterior_struct_lit(&**inner);
|
||||
if !necessary {
|
||||
cx.span_lint(UNUSED_PARENS, value.span,
|
||||
&format!("unnecessary parentheses around {}", msg))
|
||||
}
|
||||
}
|
||||
|
||||
/// Expressions that syntactically contain an "exterior" struct
|
||||
/// literal i.e. not surrounded by any parens or other
|
||||
/// delimiters, e.g. `X { y: 1 }`, `X { y: 1 }.method()`, `foo
|
||||
/// == X { y: 1 }` and `X { y: 1 } == foo` all do, but `(X {
|
||||
/// y: 1 }) == foo` does not.
|
||||
fn contains_exterior_struct_lit(value: &ast::Expr) -> bool {
|
||||
match value.node {
|
||||
ast::ExprStruct(..) => true,
|
||||
|
||||
ast::ExprAssign(ref lhs, ref rhs) |
|
||||
ast::ExprAssignOp(_, ref lhs, ref rhs) |
|
||||
ast::ExprBinary(_, ref lhs, ref rhs) => {
|
||||
// X { y: 1 } + X { y: 2 }
|
||||
contains_exterior_struct_lit(&**lhs) ||
|
||||
contains_exterior_struct_lit(&**rhs)
|
||||
}
|
||||
ast::ExprUnary(_, ref x) |
|
||||
ast::ExprCast(ref x, _) |
|
||||
ast::ExprField(ref x, _) |
|
||||
ast::ExprTupField(ref x, _) |
|
||||
ast::ExprIndex(ref x, _) => {
|
||||
// &X { y: 1 }, X { y: 1 }.y
|
||||
contains_exterior_struct_lit(&**x)
|
||||
}
|
||||
|
||||
ast::ExprMethodCall(_, _, ref exprs) => {
|
||||
// X { y: 1 }.bar(...)
|
||||
contains_exterior_struct_lit(&*exprs[0])
|
||||
}
|
||||
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl LintPass for UnusedParens {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_PARENS)
|
||||
}
|
||||
}
|
||||
|
||||
impl EarlyLintPass for UnusedParens {
|
||||
fn check_expr(&mut self, cx: &EarlyContext, e: &ast::Expr) {
|
||||
let (value, msg, struct_lit_needs_parens) = match e.node {
|
||||
ast::ExprIf(ref cond, _, _) => (cond, "`if` condition", true),
|
||||
ast::ExprWhile(ref cond, _, _) => (cond, "`while` condition", true),
|
||||
ast::ExprMatch(ref head, _, source) => match source {
|
||||
ast::MatchSource::Normal => (head, "`match` head expression", true),
|
||||
ast::MatchSource::IfLetDesugar { .. } => (head, "`if let` head expression", true),
|
||||
ast::MatchSource::WhileLetDesugar => (head, "`while let` head expression", true),
|
||||
ast::MatchSource::ForLoopDesugar => (head, "`for` head expression", true),
|
||||
},
|
||||
ast::ExprRet(Some(ref value)) => (value, "`return` value", false),
|
||||
ast::ExprAssign(_, ref value) => (value, "assigned value", false),
|
||||
ast::ExprAssignOp(_, _, ref value) => (value, "assigned value", false),
|
||||
_ => return
|
||||
};
|
||||
self.check_unused_parens_core(cx, &**value, msg, struct_lit_needs_parens);
|
||||
}
|
||||
|
||||
fn check_stmt(&mut self, cx: &EarlyContext, s: &ast::Stmt) {
|
||||
let (value, msg) = match s.node {
|
||||
ast::StmtDecl(ref decl, _) => match decl.node {
|
||||
ast::DeclLocal(ref local) => match local.init {
|
||||
Some(ref value) => (value, "assigned value"),
|
||||
None => return
|
||||
},
|
||||
_ => return
|
||||
},
|
||||
_ => return
|
||||
};
|
||||
self.check_unused_parens_core(cx, &**value, msg, false);
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
UNUSED_IMPORT_BRACES,
|
||||
Allow,
|
||||
"unnecessary braces around an imported item"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedImportBraces;
|
||||
|
||||
impl LintPass for UnusedImportBraces {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_IMPORT_BRACES)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for UnusedImportBraces {
|
||||
fn check_item(&mut self, cx: &LateContext, item: &hir::Item) {
|
||||
if let hir::ItemUse(ref view_path) = item.node {
|
||||
if let hir::ViewPathList(_, ref items) = view_path.node {
|
||||
if items.len() == 1 {
|
||||
if let hir::PathListIdent {ref name, ..} = items[0].node {
|
||||
let m = format!("braces around {} is unnecessary",
|
||||
name);
|
||||
cx.span_lint(UNUSED_IMPORT_BRACES, item.span,
|
||||
&m[..]);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
declare_lint! {
|
||||
UNUSED_ALLOCATION,
|
||||
Warn,
|
||||
"detects unnecessary allocations that can be eliminated"
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct UnusedAllocation;
|
||||
|
||||
impl LintPass for UnusedAllocation {
|
||||
fn get_lints(&self) -> LintArray {
|
||||
lint_array!(UNUSED_ALLOCATION)
|
||||
}
|
||||
}
|
||||
|
||||
impl LateLintPass for UnusedAllocation {
|
||||
fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) {
|
||||
match e.node {
|
||||
hir::ExprUnary(hir::UnUniq, _) => (),
|
||||
_ => return
|
||||
}
|
||||
|
||||
if let Some(adjustment) = cx.tcx.tables.borrow().adjustments.get(&e.id) {
|
||||
if let adjustment::AdjustDerefRef(adjustment::AutoDerefRef {
|
||||
ref autoref, ..
|
||||
}) = *adjustment {
|
||||
match autoref {
|
||||
&Some(adjustment::AutoPtr(_, hir::MutImmutable)) => {
|
||||
cx.span_lint(UNUSED_ALLOCATION, e.span,
|
||||
"unnecessary allocation, use & instead");
|
||||
}
|
||||
&Some(adjustment::AutoPtr(_, hir::MutMutable)) => {
|
||||
cx.span_lint(UNUSED_ALLOCATION, e.span,
|
||||
"unnecessary allocation, use &mut instead");
|
||||
}
|
||||
_ => ()
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user