By tracking import use types to check whether it is scope uses or the other situations like module-relative uses, we can do more accurate redundant import checking.

fixes #117448

For example unnecessary imports in std::prelude that can be eliminated:

```rust
use std::option::Option::Some;//~ WARNING the item `Some` is imported redundantly
use std::option::Option::None; //~ WARNING the item `None` is imported redundantly
```
This commit is contained in:
surechen
2023-11-10 10:11:24 +08:00
parent d3df8ff851
commit a61126cef6
52 changed files with 283 additions and 167 deletions

View File

@@ -7,23 +7,22 @@
//! `build_reduced_graph.rs`, `macros.rs` and `imports.rs`.
use crate::errors::ImportsCannotReferTo;
use crate::BindingKey;
use crate::{path_names_to_string, rustdoc, BindingError, Finalize, LexicalScopeBinding};
use crate::{BindingKey, Used};
use crate::{Module, ModuleOrUniformRoot, NameBinding, ParentScope, PathResult};
use crate::{ResolutionError, Resolver, Segment, UseError};
use rustc_ast::ptr::P;
use rustc_ast::visit::{self, AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor};
use rustc_ast::visit::{AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor};
use rustc_ast::*;
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
use rustc_errors::{
codes::*, struct_span_code_err, Applicability, DiagnosticArgValue, ErrCode, IntoDiagnosticArg,
StashKey,
codes::*, struct_span_code_err, Applicability, DiagnosticArgValue, IntoDiagnosticArg, StashKey,
};
use rustc_hir::def::Namespace::{self, *};
use rustc_hir::def::{self, CtorKind, DefKind, LifetimeRes, NonMacroAttrKind, PartialRes, PerNS};
use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
use rustc_hir::{BindingAnnotation, PrimTy, TraitCandidate};
use rustc_hir::{PrimTy, TraitCandidate};
use rustc_metadata::creader::CStore;
use rustc_middle::middle::resolve_bound_vars::Set1;
use rustc_middle::{bug, span_bug};
@@ -3623,7 +3622,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
// whether they can be shadowed by fresh bindings or not, so force an error.
// issues/33118#issuecomment-233962221 (see below) still applies here,
// but we have to ignore it for backward compatibility.
self.r.record_use(ident, binding, false);
self.r.record_use(ident, binding, Used::Other);
return None;
}
LexicalScopeBinding::Item(binding) => (binding.res(), Some(binding)),
@@ -3638,7 +3637,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
) if is_syntactic_ambiguity => {
// Disambiguate in favor of a unit struct/variant or constant pattern.
if let Some(binding) = binding {
self.r.record_use(ident, binding, false);
self.r.record_use(ident, binding, Used::Other);
}
Some(res)
}