Fix default_hash_types to use resolved path

This commit is contained in:
Cameron Steffen 2021-07-02 14:15:11 -05:00
parent 2545459bff
commit d6b0d0bf97
7 changed files with 71 additions and 70 deletions

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@ -2,15 +2,17 @@
//! Clippy.
use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
use rustc_ast::{ImplKind, Item, ItemKind};
use rustc_data_structures::fx::FxHashMap;
use rustc_ast as ast;
use rustc_errors::Applicability;
use rustc_hir::def::Res;
use rustc_hir::{GenericArg, HirId, MutTy, Mutability, Path, PathSegment, QPath, Ty, TyKind};
use rustc_hir::{
GenericArg, HirId, Item, ItemKind, MutTy, Mutability, Node, Path, PathSegment, QPath, Ty,
TyKind,
};
use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::hygiene::{ExpnKind, MacroKind};
use rustc_span::symbol::{kw, sym, Ident, Symbol};
use rustc_span::symbol::{kw, sym, Symbol};
declare_tool_lint! {
pub rustc::DEFAULT_HASH_TYPES,
@ -19,44 +21,36 @@ declare_tool_lint! {
report_in_external_macro: true
}
pub struct DefaultHashTypes {
map: FxHashMap<Symbol, Symbol>,
}
declare_lint_pass!(DefaultHashTypes => [DEFAULT_HASH_TYPES]);
impl DefaultHashTypes {
// we are allowed to use `HashMap` and `HashSet` as identifiers for implementing the lint itself
#[allow(rustc::default_hash_types)]
pub fn new() -> Self {
let mut map = FxHashMap::default();
map.insert(sym::HashMap, sym::FxHashMap);
map.insert(sym::HashSet, sym::FxHashSet);
Self { map }
impl LateLintPass<'_> for DefaultHashTypes {
fn check_path(&mut self, cx: &LateContext<'_>, path: &Path<'_>, hir_id: HirId) {
let def_id = match path.res {
Res::Def(rustc_hir::def::DefKind::Struct, id) => id,
_ => return,
};
if matches!(cx.tcx.hir().get(hir_id), Node::Item(Item { kind: ItemKind::Use(..), .. })) {
// don't lint imports, only actual usages
return;
}
}
impl_lint_pass!(DefaultHashTypes => [DEFAULT_HASH_TYPES]);
impl EarlyLintPass for DefaultHashTypes {
fn check_ident(&mut self, cx: &EarlyContext<'_>, ident: Ident) {
if let Some(replace) = self.map.get(&ident.name) {
cx.struct_span_lint(DEFAULT_HASH_TYPES, ident.span, |lint| {
// FIXME: We can avoid a copy here. Would require us to take String instead of &str.
let msg = format!("Prefer {} over {}, it has better performance", replace, ident);
let replace = if cx.tcx.is_diagnostic_item(sym::hashmap_type, def_id) {
"FxHashMap"
} else if cx.tcx.is_diagnostic_item(sym::hashset_type, def_id) {
"FxHashSet"
} else {
return;
};
cx.struct_span_lint(DEFAULT_HASH_TYPES, path.span, |lint| {
let msg = format!(
"prefer `{}` over `{}`, it has better performance",
replace,
cx.tcx.item_name(def_id)
);
lint.build(&msg)
.span_suggestion(
ident.span,
"use",
replace.to_string(),
Applicability::MaybeIncorrect, // FxHashMap, ... needs another import
)
.note(&format!(
"a `use rustc_data_structures::fx::{}` may be necessary",
replace
))
.note(&format!("a `use rustc_data_structures::fx::{}` may be necessary", replace))
.emit();
});
}
}
}
declare_tool_lint! {
@ -242,8 +236,9 @@ declare_tool_lint! {
declare_lint_pass!(LintPassImpl => [LINT_PASS_IMPL_WITHOUT_MACRO]);
impl EarlyLintPass for LintPassImpl {
fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
if let ItemKind::Impl(box ImplKind { of_trait: Some(lint_pass), .. }) = &item.kind {
fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
if let ast::ItemKind::Impl(box ast::ImplKind { of_trait: Some(lint_pass), .. }) = &item.kind
{
if let Some(last) = lint_pass.path.segments.last() {
if last.ident.name == sym::LintPass {
let expn_data = lint_pass.path.span.ctxt().outer_expn_data();

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@ -472,10 +472,10 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
}
fn register_internals(store: &mut LintStore) {
store.register_lints(&DefaultHashTypes::get_lints());
store.register_early_pass(|| box DefaultHashTypes::new());
store.register_lints(&LintPassImpl::get_lints());
store.register_early_pass(|| box LintPassImpl);
store.register_lints(&DefaultHashTypes::get_lints());
store.register_late_pass(|| box DefaultHashTypes);
store.register_lints(&ExistingDocKeyword::get_lints());
store.register_late_pass(|| box ExistingDocKeyword);
store.register_lints(&TyTyKind::get_lints());

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@ -207,7 +207,7 @@ fn symbols_with_errors(input: TokenStream) -> (TokenStream, Vec<syn::Error>) {
#keyword_stream
}
#[allow(rustc::default_hash_types)]
#[cfg_attr(bootstrap, allow(rustc::default_hash_types))]
#[allow(non_upper_case_globals)]
#[doc(hidden)]
pub mod sym_generated {

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@ -1,22 +1,29 @@
// compile-flags: -Z unstable-options
#![feature(rustc_private)]
#![deny(rustc::default_hash_types)]
extern crate rustc_data_structures;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use std::collections::{HashMap, HashSet};
#[deny(rustc::default_hash_types)]
mod foo {
pub struct HashMap;
}
fn main() {
let _map: HashMap<String, String> = HashMap::default();
//~^ ERROR Prefer FxHashMap over HashMap, it has better performance
//~^^ ERROR Prefer FxHashMap over HashMap, it has better performance
//~^ ERROR prefer `FxHashMap` over `HashMap`, it has better performance
//~^^ ERROR prefer `FxHashMap` over `HashMap`, it has better performance
let _set: HashSet<String> = HashSet::default();
//~^ ERROR Prefer FxHashSet over HashSet, it has better performance
//~^^ ERROR Prefer FxHashSet over HashSet, it has better performance
//~^ ERROR prefer `FxHashSet` over `HashSet`, it has better performance
//~^^ ERROR prefer `FxHashSet` over `HashSet`, it has better performance
// test that the lint doesn't also match the Fx variants themselves
let _fx_map: FxHashMap<String, String> = FxHashMap::default();
let _fx_set: FxHashSet<String> = FxHashSet::default();
// test another struct of the same name
let _ = foo::HashMap;
}

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@ -1,37 +1,37 @@
error: Prefer FxHashMap over HashMap, it has better performance
--> $DIR/default_hash_types.rs:12:15
error: prefer `FxHashMap` over `HashMap`, it has better performance
--> $DIR/default_hash_types.rs:16:41
|
LL | let _map: HashMap<String, String> = HashMap::default();
| ^^^^^^^ help: use: `FxHashMap`
| ^^^^^^^
|
note: the lint level is defined here
--> $DIR/default_hash_types.rs:10:8
--> $DIR/default_hash_types.rs:4:9
|
LL | #[deny(rustc::default_hash_types)]
LL | #![deny(rustc::default_hash_types)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^
= note: a `use rustc_data_structures::fx::FxHashMap` may be necessary
error: Prefer FxHashMap over HashMap, it has better performance
--> $DIR/default_hash_types.rs:12:41
error: prefer `FxHashMap` over `HashMap`, it has better performance
--> $DIR/default_hash_types.rs:16:15
|
LL | let _map: HashMap<String, String> = HashMap::default();
| ^^^^^^^ help: use: `FxHashMap`
| ^^^^^^^^^^^^^^^^^^^^^^^
|
= note: a `use rustc_data_structures::fx::FxHashMap` may be necessary
error: Prefer FxHashSet over HashSet, it has better performance
--> $DIR/default_hash_types.rs:15:15
error: prefer `FxHashSet` over `HashSet`, it has better performance
--> $DIR/default_hash_types.rs:19:33
|
LL | let _set: HashSet<String> = HashSet::default();
| ^^^^^^^ help: use: `FxHashSet`
| ^^^^^^^
|
= note: a `use rustc_data_structures::fx::FxHashSet` may be necessary
error: Prefer FxHashSet over HashSet, it has better performance
--> $DIR/default_hash_types.rs:15:33
error: prefer `FxHashSet` over `HashSet`, it has better performance
--> $DIR/default_hash_types.rs:19:15
|
LL | let _set: HashSet<String> = HashSet::default();
| ^^^^^^^ help: use: `FxHashSet`
| ^^^^^^^^^^^^^^^
|
= note: a `use rustc_data_structures::fx::FxHashSet` may be necessary

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@ -12,6 +12,5 @@
//~| SUGGESTION rustc::default_hash_types
fn main() {
let _ = std::collections::HashMap::<String, String>::new();
//~^ WARN Prefer FxHashMap over HashMap, it has better performance
//~| HELP use
//~^ WARN prefer `FxHashMap` over `HashMap`, it has better performance
}

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@ -12,11 +12,11 @@ warning: unknown lint: `rustc::foo::default_hash_types`
LL | #[allow(rustc::foo::default_hash_types)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: did you mean: `rustc::default_hash_types`
warning: Prefer FxHashMap over HashMap, it has better performance
--> $DIR/issue-83477.rs:14:31
warning: prefer `FxHashMap` over `HashMap`, it has better performance
--> $DIR/issue-83477.rs:14:13
|
LL | let _ = std::collections::HashMap::<String, String>::new();
| ^^^^^^^ help: use: `FxHashMap`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
note: the lint level is defined here
--> $DIR/issue-83477.rs:3:9