Auto merge of rust-lang#104963 - petrochenkov:noaddids2, r=cjgillot

bors · bors · commit a1d22808af86 · 2022-12-02T04:24:57.000Z
rustc_ast_lowering: Stop lowering imports into multiple items

Lower them into a single item with multiple resolutions instead.
This also allows to remove additional `NodId`s and `DefId`s related to those additional items.
diff --git a/clippy_lints/src/disallowed_types.rs b/clippy_lints/src/disallowed_types.rs
@@ -106,7 +106,9 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedTypes {
 
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
         if let ItemKind::Use(path, UseKind::Single) = &item.kind {
-            self.check_res_emit(cx, &path.res, item.span);
+            for res in &path.res {
+                self.check_res_emit(cx, res, item.span);
+            }
         }
     }
 
diff --git a/clippy_lints/src/from_over_into.rs b/clippy_lints/src/from_over_into.rs
@@ -126,7 +126,7 @@ impl<'a, 'tcx> Visitor<'tcx> for SelfFinder<'a, 'tcx> {
         self.cx.tcx.hir()
     }
 
-    fn visit_path(&mut self, path: &'tcx Path<'tcx>, _id: HirId) {
+    fn visit_path(&mut self, path: &Path<'tcx>, _id: HirId) {
         for segment in path.segments {
             match segment.ident.name {
                 kw::SelfLower => self.lower.push(segment.ident.span),
diff --git a/clippy_lints/src/macro_use.rs b/clippy_lints/src/macro_use.rs
@@ -94,7 +94,10 @@ impl<'tcx> LateLintPass<'tcx> for MacroUseImports {
             let hir_id = item.hir_id();
             let attrs = cx.tcx.hir().attrs(hir_id);
             if let Some(mac_attr) = attrs.iter().find(|attr| attr.has_name(sym::macro_use));
-            if let Res::Def(DefKind::Mod, id) = path.res;
+            if let Some(id) = path.res.iter().find_map(|res| match res {
+                Res::Def(DefKind::Mod, id) => Some(id),
+                _ => None,
+            });
             if !id.is_local();
             then {
                 for kid in cx.tcx.module_children(id).iter() {
diff --git a/clippy_lints/src/methods/option_map_unwrap_or.rs b/clippy_lints/src/methods/option_map_unwrap_or.rs
@@ -97,7 +97,7 @@ struct UnwrapVisitor<'a, 'tcx> {
 impl<'a, 'tcx> Visitor<'tcx> for UnwrapVisitor<'a, 'tcx> {
     type NestedFilter = nested_filter::All;
 
-    fn visit_path(&mut self, path: &'tcx Path<'_>, _id: HirId) {
+    fn visit_path(&mut self, path: &Path<'tcx>, _id: HirId) {
         self.identifiers.insert(ident(path));
         walk_path(self, path);
     }
@@ -116,7 +116,7 @@ struct MapExprVisitor<'a, 'tcx> {
 impl<'a, 'tcx> Visitor<'tcx> for MapExprVisitor<'a, 'tcx> {
     type NestedFilter = nested_filter::All;
 
-    fn visit_path(&mut self, path: &'tcx Path<'_>, _id: HirId) {
+    fn visit_path(&mut self, path: &Path<'tcx>, _id: HirId) {
         if self.identifiers.contains(&ident(path)) {
             self.found_identifier = true;
             return;
diff --git a/clippy_lints/src/missing_enforced_import_rename.rs b/clippy_lints/src/missing_enforced_import_rename.rs
@@ -66,35 +66,38 @@ impl LateLintPass<'_> for ImportRename {
     }
 
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
-        if_chain! {
-            if let ItemKind::Use(path, UseKind::Single) = &item.kind;
-            if let Res::Def(_, id) = path.res;
-            if let Some(name) = self.renames.get(&id);
-            // Remove semicolon since it is not present for nested imports
-            let span_without_semi = cx.sess().source_map().span_until_char(item.span, ';');
-            if let Some(snip) = snippet_opt(cx, span_without_semi);
-            if let Some(import) = match snip.split_once(" as ") {
-                None => Some(snip.as_str()),
-                Some((import, rename)) => {
-                    if rename.trim() == name.as_str() {
-                        None
-                    } else {
-                        Some(import.trim())
+        if let ItemKind::Use(path, UseKind::Single) = &item.kind {
+            for &res in &path.res {
+                if_chain! {
+                    if let Res::Def(_, id) = res;
+                    if let Some(name) = self.renames.get(&id);
+                    // Remove semicolon since it is not present for nested imports
+                    let span_without_semi = cx.sess().source_map().span_until_char(item.span, ';');
+                    if let Some(snip) = snippet_opt(cx, span_without_semi);
+                    if let Some(import) = match snip.split_once(" as ") {
+                        None => Some(snip.as_str()),
+                        Some((import, rename)) => {
+                            if rename.trim() == name.as_str() {
+                                None
+                            } else {
+                                Some(import.trim())
+                            }
+                        },
+                    };
+                    then {
+                        span_lint_and_sugg(
+                            cx,
+                            MISSING_ENFORCED_IMPORT_RENAMES,
+                            span_without_semi,
+                            "this import should be renamed",
+                            "try",
+                            format!(
+                                "{import} as {name}",
+                            ),
+                            Applicability::MachineApplicable,
+                        );
                     }
-                },
-            };
-            then {
-                span_lint_and_sugg(
-                    cx,
-                    MISSING_ENFORCED_IMPORT_RENAMES,
-                    span_without_semi,
-                    "this import should be renamed",
-                    "try",
-                    format!(
-                        "{import} as {name}",
-                    ),
-                    Applicability::MachineApplicable,
-                );
+                }
             }
         }
     }
diff --git a/clippy_lints/src/redundant_pub_crate.rs b/clippy_lints/src/redundant_pub_crate.rs
@@ -84,7 +84,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantPubCrate {
 
 fn is_not_macro_export<'tcx>(item: &'tcx Item<'tcx>) -> bool {
     if let ItemKind::Use(path, _) = item.kind {
-        if let Res::Def(DefKind::Macro(MacroKind::Bang), _) = path.res {
+        if path.res.iter().all(|res| matches!(res, Res::Def(DefKind::Macro(MacroKind::Bang), _))) {
             return false;
         }
     } else if let ItemKind::Macro(..) = item.kind {
diff --git a/clippy_lints/src/single_component_path_imports.rs b/clippy_lints/src/single_component_path_imports.rs
@@ -149,7 +149,7 @@ impl SingleComponentPathImports {
 
                 // keep track of `use some_module;` usages
                 if segments.len() == 1 {
-                    if let UseTreeKind::Simple(None, _, _) = use_tree.kind {
+                    if let UseTreeKind::Simple(None) = use_tree.kind {
                         let name = segments[0].ident.name;
                         if !macros.contains(&name) {
                             single_use_usages.push(SingleUse {
@@ -169,7 +169,7 @@ impl SingleComponentPathImports {
                         for tree in trees {
                             let segments = &tree.0.prefix.segments;
                             if segments.len() == 1 {
-                                if let UseTreeKind::Simple(None, _, _) = tree.0.kind {
+                                if let UseTreeKind::Simple(None) = tree.0.kind {
                                     let name = segments[0].ident.name;
                                     if !macros.contains(&name) {
                                         single_use_usages.push(SingleUse {
diff --git a/clippy_lints/src/unnecessary_self_imports.rs b/clippy_lints/src/unnecessary_self_imports.rs
@@ -57,7 +57,7 @@ impl EarlyLintPass for UnnecessarySelfImports {
                             format!(
                                 "{}{};",
                                 last_segment.ident,
-                                if let UseTreeKind::Simple(Some(alias), ..) = self_tree.kind { format!(" as {alias}") } else { String::new() },
+                                if let UseTreeKind::Simple(Some(alias)) = self_tree.kind { format!(" as {alias}") } else { String::new() },
                             ),
                             Applicability::MaybeIncorrect,
                         );
diff --git a/clippy_lints/src/unsafe_removed_from_name.rs b/clippy_lints/src/unsafe_removed_from_name.rs
@@ -39,7 +39,7 @@ impl EarlyLintPass for UnsafeNameRemoval {
 
 fn check_use_tree(use_tree: &UseTree, cx: &EarlyContext<'_>, span: Span) {
     match use_tree.kind {
-        UseTreeKind::Simple(Some(new_name), ..) => {
+        UseTreeKind::Simple(Some(new_name)) => {
             let old_name = use_tree
                 .prefix
                 .segments
@@ -48,7 +48,7 @@ fn check_use_tree(use_tree: &UseTree, cx: &EarlyContext<'_>, span: Span) {
                 .ident;
             unsafe_to_safe_check(old_name, new_name, cx, span);
         },
-        UseTreeKind::Simple(None, ..) | UseTreeKind::Glob => {},
+        UseTreeKind::Simple(None) | UseTreeKind::Glob => {},
         UseTreeKind::Nested(ref nested_use_tree) => {
             for (use_tree, _) in nested_use_tree {
                 check_use_tree(use_tree, cx, span);
diff --git a/clippy_lints/src/utils/internal_lints/lint_without_lint_pass.rs b/clippy_lints/src/utils/internal_lints/lint_without_lint_pass.rs
@@ -330,7 +330,7 @@ struct LintCollector<'a, 'tcx> {
 impl<'a, 'tcx> Visitor<'tcx> for LintCollector<'a, 'tcx> {
     type NestedFilter = nested_filter::All;
 
-    fn visit_path(&mut self, path: &'tcx Path<'_>, _: HirId) {
+    fn visit_path(&mut self, path: &Path<'_>, _: HirId) {
         if path.segments.len() == 1 {
             self.output.insert(path.segments[0].ident.name);
         }
diff --git a/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/clippy_lints/src/utils/internal_lints/metadata_collector.rs
@@ -1019,7 +1019,7 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for ApplicabilityResolver<'a, 'hir> {
         self.cx.tcx.hir()
     }
 
-    fn visit_path(&mut self, path: &'hir hir::Path<'hir>, _id: hir::HirId) {
+    fn visit_path(&mut self, path: &hir::Path<'hir>, _id: hir::HirId) {
         for (index, enum_value) in paths::APPLICABILITY_VALUES.iter().enumerate() {
             if match_path(path, enum_value) {
                 self.add_new_index(index);
diff --git a/clippy_lints/src/wildcard_imports.rs b/clippy_lints/src/wildcard_imports.rs
@@ -176,7 +176,8 @@ impl LateLintPass<'_> for WildcardImports {
                     format!("{import_source_snippet}::{imports_string}")
                 };
 
-                let (lint, message) = if let Res::Def(DefKind::Enum, _) = use_path.res {
+                // Glob imports always have a single resolution.
+                let (lint, message) = if let Res::Def(DefKind::Enum, _) = use_path.res[0] {
                     (ENUM_GLOB_USE, "usage of wildcard import for enum variants")
                 } else {
                     (WILDCARD_IMPORTS, "usage of wildcard import")
diff --git a/clippy_utils/src/ast_utils.rs b/clippy_utils/src/ast_utils.rs
@@ -566,7 +566,7 @@ pub fn eq_use_tree_kind(l: &UseTreeKind, r: &UseTreeKind) -> bool {
     use UseTreeKind::*;
     match (l, r) {
         (Glob, Glob) => true,
-        (Simple(l, _, _), Simple(r, _, _)) => both(l, r, |l, r| eq_id(*l, *r)),
+        (Simple(l), Simple(r)) => both(l, r, |l, r| eq_id(*l, *r)),
         (Nested(l), Nested(r)) => over(l, r, |(l, _), (r, _)| eq_use_tree(l, r)),
         _ => false,
     }
diff --git a/clippy_utils/src/usage.rs b/clippy_utils/src/usage.rs
@@ -128,7 +128,7 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for BindingUsageFinder<'a, 'tcx> {
         }
     }
 
-    fn visit_path(&mut self, path: &'tcx hir::Path<'tcx>, _: hir::HirId) {
+    fn visit_path(&mut self, path: &hir::Path<'tcx>, _: hir::HirId) {
         if let hir::def::Res::Local(id) = path.res {
             if self.binding_ids.contains(&id) {
                 self.usage_found = true;
diff --git a/tests/ui/macro_use_imports.stderr b/tests/ui/macro_use_imports.stderr
@@ -1,8 +1,8 @@
 error: `macro_use` attributes are no longer needed in the Rust 2018 edition
-  --> $DIR/macro_use_imports.rs:23:5
+  --> $DIR/macro_use_imports.rs:25:5
    |
 LL |     #[macro_use]
-   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::{inner::foofoo, inner::try_err};`
+   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::inner::nested::string_add;`
    |
    = note: `-D clippy::macro-use-imports` implied by `-D warnings`
 
@@ -13,10 +13,10 @@ LL |     #[macro_use]
    |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mini_mac::ClippyMiniMacroTest;`
 
 error: `macro_use` attributes are no longer needed in the Rust 2018 edition
-  --> $DIR/macro_use_imports.rs:25:5
+  --> $DIR/macro_use_imports.rs:23:5
    |
 LL |     #[macro_use]
-   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::inner::nested::string_add;`
+   |     ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use mac::{inner::foofoo, inner::try_err};`
 
 error: `macro_use` attributes are no longer needed in the Rust 2018 edition
   --> $DIR/macro_use_imports.rs:19:5

Original file line number	Diff line number	Diff line change
`@@ -106,7 +106,9 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedTypes {`
`106`	`106`
`107`	`107`	`fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {`
`108`	`108`	`if let ItemKind::Use(path, UseKind::Single) = &item.kind {`
`109`		`- self.check_res_emit(cx, &path.res, item.span);`
	`109`	`+ for res in &path.res {`
	`110`	`+ self.check_res_emit(cx, res, item.span);`
	`111`	`+ }`
`110`	`112`	`}`
`111`	`113`	`}`
`112`	`114`
Original file line number	Diff line number	Diff line change
`@@ -126,7 +126,7 @@ impl<'a, 'tcx> Visitor<'tcx> for SelfFinder<'a, 'tcx> {`
`126`	`126`	`self.cx.tcx.hir()`
`127`	`127`	`}`
`128`	`128`
`129`		`- fn visit_path(&mut self, path: &'tcx Path<'tcx>, _id: HirId) {`
	`129`	`+ fn visit_path(&mut self, path: &Path<'tcx>, _id: HirId) {`
`130`	`130`	`for segment in path.segments {`
`131`	`131`	`match segment.ident.name {`
`132`	`132`	`kw::SelfLower => self.lower.push(segment.ident.span),`
Original file line number	Diff line number	Diff line change
`@@ -84,7 +84,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantPubCrate {`
`84`	`84`
`85`	`85`	`fn is_not_macro_export<'tcx>(item: &'tcx Item<'tcx>) -> bool {`
`86`	`86`	`if let ItemKind::Use(path, _) = item.kind {`
`87`		`- if let Res::Def(DefKind::Macro(MacroKind::Bang), _) = path.res {`
	`87`	`+ if path.res.iter().all(\|res\| matches!(res, Res::Def(DefKind::Macro(MacroKind::Bang), _))) {`
`88`	`88`	`return false;`
`89`	`89`	`}`
`90`	`90`	`} else if let ItemKind::Macro(..) = item.kind {`
Original file line number	Diff line number	Diff line change
`@@ -330,7 +330,7 @@ struct LintCollector<'a, 'tcx> {`
`330`	`330`	`impl<'a, 'tcx> Visitor<'tcx> for LintCollector<'a, 'tcx> {`
`331`	`331`	`type NestedFilter = nested_filter::All;`
`332`	`332`
`333`		`- fn visit_path(&mut self, path: &'tcx Path<'_>, _: HirId) {`
	`333`	`+ fn visit_path(&mut self, path: &Path<'_>, _: HirId) {`
`334`	`334`	`if path.segments.len() == 1 {`
`335`	`335`	`self.output.insert(path.segments[0].ident.name);`
`336`	`336`	`}`