Rollup merge of #108363 - cjgillot:unused-crate, r=WaffleLapkin
Move the unused extern crate check back to the resolver. It doesn't have anything to do in `rustc_hir_typeck`.
This commit is contained in:
Matthias Krüger
GitHub
commit
660f184966
13 changed files with 186 additions and 196 deletions
|
|
@ -29,11 +29,12 @@ use crate::Resolver;
|
|||
|
||||
use rustc_ast as ast;
|
||||
use rustc_ast::visit::{self, Visitor};
|
||||
use rustc_data_structures::fx::FxIndexMap;
|
||||
use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
|
||||
use rustc_data_structures::unord::UnordSet;
|
||||
use rustc_errors::{pluralize, MultiSpan};
|
||||
use rustc_session::lint::builtin::{MACRO_USE_EXTERN_CRATE, UNUSED_IMPORTS};
|
||||
use rustc_session::lint::builtin::{MACRO_USE_EXTERN_CRATE, UNUSED_EXTERN_CRATES, UNUSED_IMPORTS};
|
||||
use rustc_session::lint::BuiltinLintDiagnostics;
|
||||
use rustc_span::symbol::Ident;
|
||||
use rustc_span::{Span, DUMMY_SP};
|
||||
|
||||
struct UnusedImport<'a> {
|
||||
|
|
@ -53,11 +54,28 @@ struct UnusedImportCheckVisitor<'a, 'b, 'tcx> {
|
|||
r: &'a mut Resolver<'b, 'tcx>,
|
||||
/// All the (so far) unused imports, grouped path list
|
||||
unused_imports: FxIndexMap<ast::NodeId, UnusedImport<'a>>,
|
||||
extern_crate_items: Vec<ExternCrateToLint>,
|
||||
base_use_tree: Option<&'a ast::UseTree>,
|
||||
base_id: ast::NodeId,
|
||||
item_span: Span,
|
||||
}
|
||||
|
||||
struct ExternCrateToLint {
|
||||
id: ast::NodeId,
|
||||
/// Span from the item
|
||||
span: Span,
|
||||
/// Span to use to suggest complete removal.
|
||||
span_with_attributes: Span,
|
||||
/// Span of the visibility, if any.
|
||||
vis_span: Span,
|
||||
/// Whether the item has attrs.
|
||||
has_attrs: bool,
|
||||
/// Name used to refer to the crate.
|
||||
ident: Ident,
|
||||
/// Whether the statement renames the crate `extern crate orig_name as new_name;`.
|
||||
renames: bool,
|
||||
}
|
||||
|
||||
impl<'a, 'b, 'tcx> UnusedImportCheckVisitor<'a, 'b, 'tcx> {
|
||||
// We have information about whether `use` (import) items are actually
|
||||
// used now. If an import is not used at all, we signal a lint error.
|
||||
|
|
@ -96,18 +114,27 @@ impl<'a, 'b, 'tcx> UnusedImportCheckVisitor<'a, 'b, 'tcx> {
|
|||
|
||||
impl<'a, 'b, 'tcx> Visitor<'a> for UnusedImportCheckVisitor<'a, 'b, 'tcx> {
|
||||
fn visit_item(&mut self, item: &'a ast::Item) {
|
||||
self.item_span = item.span_with_attributes();
|
||||
|
||||
// Ignore is_public import statements because there's no way to be sure
|
||||
// whether they're used or not. Also ignore imports with a dummy span
|
||||
// because this means that they were generated in some fashion by the
|
||||
// compiler and we don't need to consider them.
|
||||
if let ast::ItemKind::Use(..) = item.kind {
|
||||
if item.vis.kind.is_pub() || item.span.is_dummy() {
|
||||
return;
|
||||
match item.kind {
|
||||
// Ignore is_public import statements because there's no way to be sure
|
||||
// whether they're used or not. Also ignore imports with a dummy span
|
||||
// because this means that they were generated in some fashion by the
|
||||
// compiler and we don't need to consider them.
|
||||
ast::ItemKind::Use(..) if item.vis.kind.is_pub() || item.span.is_dummy() => return,
|
||||
ast::ItemKind::ExternCrate(orig_name) => {
|
||||
self.extern_crate_items.push(ExternCrateToLint {
|
||||
id: item.id,
|
||||
span: item.span,
|
||||
vis_span: item.vis.span,
|
||||
span_with_attributes: item.span_with_attributes(),
|
||||
has_attrs: !item.attrs.is_empty(),
|
||||
ident: item.ident,
|
||||
renames: orig_name.is_some(),
|
||||
});
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
|
||||
self.item_span = item.span_with_attributes();
|
||||
visit::walk_item(self, item);
|
||||
}
|
||||
|
||||
|
|
@ -224,6 +251,9 @@ fn calc_unused_spans(
|
|||
|
||||
impl Resolver<'_, '_> {
|
||||
pub(crate) fn check_unused(&mut self, krate: &ast::Crate) {
|
||||
let tcx = self.tcx;
|
||||
let mut maybe_unused_extern_crates = FxHashMap::default();
|
||||
|
||||
for import in self.potentially_unused_imports.iter() {
|
||||
match import.kind {
|
||||
_ if import.used.get()
|
||||
|
|
@ -246,7 +276,14 @@ impl Resolver<'_, '_> {
|
|||
}
|
||||
ImportKind::ExternCrate { id, .. } => {
|
||||
let def_id = self.local_def_id(id);
|
||||
self.maybe_unused_extern_crates.push((def_id, import.span));
|
||||
if self.extern_crate_map.get(&def_id).map_or(true, |&cnum| {
|
||||
!tcx.is_compiler_builtins(cnum)
|
||||
&& !tcx.is_panic_runtime(cnum)
|
||||
&& !tcx.has_global_allocator(cnum)
|
||||
&& !tcx.has_panic_handler(cnum)
|
||||
}) {
|
||||
maybe_unused_extern_crates.insert(id, import.span);
|
||||
}
|
||||
}
|
||||
ImportKind::MacroUse => {
|
||||
let msg = "unused `#[macro_use]` import";
|
||||
|
|
@ -259,6 +296,7 @@ impl Resolver<'_, '_> {
|
|||
let mut visitor = UnusedImportCheckVisitor {
|
||||
r: self,
|
||||
unused_imports: Default::default(),
|
||||
extern_crate_items: Default::default(),
|
||||
base_use_tree: None,
|
||||
base_id: ast::DUMMY_NODE_ID,
|
||||
item_span: DUMMY_SP,
|
||||
|
|
@ -290,7 +328,7 @@ impl Resolver<'_, '_> {
|
|||
let ms = MultiSpan::from_spans(spans.clone());
|
||||
let mut span_snippets = spans
|
||||
.iter()
|
||||
.filter_map(|s| match visitor.r.tcx.sess.source_map().span_to_snippet(*s) {
|
||||
.filter_map(|s| match tcx.sess.source_map().span_to_snippet(*s) {
|
||||
Ok(s) => Some(format!("`{}`", s)),
|
||||
_ => None,
|
||||
})
|
||||
|
|
@ -317,7 +355,7 @@ impl Resolver<'_, '_> {
|
|||
// If we are in the `--test` mode, suppress a help that adds the `#[cfg(test)]`
|
||||
// attribute; however, if not, suggest adding the attribute. There is no way to
|
||||
// retrieve attributes here because we do not have a `TyCtxt` yet.
|
||||
let test_module_span = if visitor.r.tcx.sess.opts.test {
|
||||
let test_module_span = if tcx.sess.opts.test {
|
||||
None
|
||||
} else {
|
||||
let parent_module = visitor.r.get_nearest_non_block_module(
|
||||
|
|
@ -346,5 +384,74 @@ impl Resolver<'_, '_> {
|
|||
BuiltinLintDiagnostics::UnusedImports(fix_msg.into(), fixes, test_module_span),
|
||||
);
|
||||
}
|
||||
|
||||
for extern_crate in visitor.extern_crate_items {
|
||||
let warn_if_unused = !extern_crate.ident.name.as_str().starts_with('_');
|
||||
|
||||
// If the crate is fully unused, we suggest removing it altogether.
|
||||
// We do this in any edition.
|
||||
if warn_if_unused {
|
||||
if let Some(&span) = maybe_unused_extern_crates.get(&extern_crate.id) {
|
||||
visitor.r.lint_buffer.buffer_lint_with_diagnostic(
|
||||
UNUSED_EXTERN_CRATES,
|
||||
extern_crate.id,
|
||||
span,
|
||||
"unused extern crate",
|
||||
BuiltinLintDiagnostics::UnusedExternCrate {
|
||||
removal_span: extern_crate.span_with_attributes,
|
||||
},
|
||||
);
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
||||
// If we are not in Rust 2018 edition, then we don't make any further
|
||||
// suggestions.
|
||||
if !tcx.sess.rust_2018() {
|
||||
continue;
|
||||
}
|
||||
|
||||
// If the extern crate has any attributes, they may have funky
|
||||
// semantics we can't faithfully represent using `use` (most
|
||||
// notably `#[macro_use]`). Ignore it.
|
||||
if extern_crate.has_attrs {
|
||||
continue;
|
||||
}
|
||||
|
||||
// If the extern crate is renamed, then we cannot suggest replacing it with a use as this
|
||||
// would not insert the new name into the prelude, where other imports in the crate may be
|
||||
// expecting it.
|
||||
if extern_crate.renames {
|
||||
continue;
|
||||
}
|
||||
|
||||
// If the extern crate isn't in the extern prelude,
|
||||
// there is no way it can be written as a `use`.
|
||||
if !visitor
|
||||
.r
|
||||
.extern_prelude
|
||||
.get(&extern_crate.ident)
|
||||
.map_or(false, |entry| !entry.introduced_by_item)
|
||||
{
|
||||
continue;
|
||||
}
|
||||
|
||||
let vis_span = extern_crate
|
||||
.vis_span
|
||||
.find_ancestor_inside(extern_crate.span)
|
||||
.unwrap_or(extern_crate.vis_span);
|
||||
let ident_span = extern_crate
|
||||
.ident
|
||||
.span
|
||||
.find_ancestor_inside(extern_crate.span)
|
||||
.unwrap_or(extern_crate.ident.span);
|
||||
visitor.r.lint_buffer.buffer_lint_with_diagnostic(
|
||||
UNUSED_EXTERN_CRATES,
|
||||
extern_crate.id,
|
||||
extern_crate.span,
|
||||
"`extern crate` is not idiomatic in the new edition",
|
||||
BuiltinLintDiagnostics::ExternCrateNotIdiomatic { vis_span, ident_span },
|
||||
);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -946,7 +946,6 @@ pub struct Resolver<'a, 'tcx> {
|
|||
has_pub_restricted: bool,
|
||||
used_imports: FxHashSet<NodeId>,
|
||||
maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
|
||||
maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
|
||||
|
||||
/// Privacy errors are delayed until the end in order to deduplicate them.
|
||||
privacy_errors: Vec<PrivacyError<'a>>,
|
||||
|
|
@ -1284,7 +1283,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
|
|||
has_pub_restricted: false,
|
||||
used_imports: FxHashSet::default(),
|
||||
maybe_unused_trait_imports: Default::default(),
|
||||
maybe_unused_extern_crates: Vec::new(),
|
||||
|
||||
privacy_errors: Vec::new(),
|
||||
ambiguity_errors: Vec::new(),
|
||||
|
|
@ -1400,7 +1398,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
|
|||
let extern_crate_map = self.extern_crate_map;
|
||||
let reexport_map = self.reexport_map;
|
||||
let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
|
||||
let maybe_unused_extern_crates = self.maybe_unused_extern_crates;
|
||||
let glob_map = self.glob_map;
|
||||
let main_def = self.main_def;
|
||||
let confused_type_with_std_module = self.confused_type_with_std_module;
|
||||
|
|
@ -1414,12 +1411,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
|
|||
reexport_map,
|
||||
glob_map,
|
||||
maybe_unused_trait_imports,
|
||||
maybe_unused_extern_crates,
|
||||
extern_prelude: self
|
||||
.extern_prelude
|
||||
.iter()
|
||||
.map(|(ident, entry)| (ident.name, entry.introduced_by_item))
|
||||
.collect(),
|
||||
main_def,
|
||||
trait_impls: self.trait_impls,
|
||||
proc_macros,
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue