Merge #11157

11157: internal: Remove `SemanticScope::speculative_resolve_as_mac` r=Veykril a=Veykril

Fixes https://github.com/rust-analyzer/rust-analyzer/issues/11132

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

crates/hir/src/semantics.rs

@@ -5,6 +5,7 @@ mod source_to_def;
 use std::{cell::RefCell, fmt};
 
 use base_db::{FileId, FileRange};
+use either::Either;
 use hir_def::{
     body,
     resolver::{self, HasResolver, Resolver, TypeNs},
@@ -18,13 +19,14 @@ use smallvec::{smallvec, SmallVec};
 use syntax::{
     algo::skip_trivia_token,
     ast::{self, HasAttrs, HasGenericParams, HasLoopBody},
-    match_ast, AstNode, Direction, SyntaxNode, SyntaxNodePtr, SyntaxToken, TextSize,
+    match_ast, AstNode, AstToken, Direction, SyntaxElement, SyntaxNode, SyntaxNodePtr, SyntaxToken,
+    TextSize, T,
 };
 
 use crate::{
     db::HirDatabase,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
-    source_analyzer::{resolve_hir_path, resolve_hir_path_as_macro, SourceAnalyzer},
+    source_analyzer::{resolve_hir_path, SourceAnalyzer},
     Access, AssocItem, BuiltinAttr, Callable, ConstParam, Crate, Field, Function, HasSource,
     HirFileId, Impl, InFile, Label, LifetimeParam, Local, MacroDef, Module, ModuleDef, Name, Path,
     ScopeDef, ToolModule, Trait, Type, TypeAlias, TypeParam, VariantDef,
@@ -354,6 +356,14 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.resolve_bind_pat_to_const(pat)
     }
 
+    pub fn resolve_derive_ident(
+        &self,
+        derive: &ast::Attr,
+        ident: &ast::Ident,
+    ) -> Option<PathResolution> {
+        self.imp.resolve_derive_ident(derive, ident)
+    }
+
     // FIXME: use this instead?
     // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
 
@@ -471,12 +481,12 @@ impl<'db> SemanticsImpl<'db> {
     }
 
     fn derive_macro_calls(&self, attr: &ast::Attr) -> Option<Vec<Option<MacroCallId>>> {
-        let item = attr.syntax().parent().and_then(ast::Item::cast)?;
-        let file_id = self.find_file(item.syntax()).file_id;
-        let item = InFile::new(file_id, &item);
+        let adt = attr.syntax().parent().and_then(ast::Adt::cast)?;
+        let file_id = self.find_file(adt.syntax()).file_id;
+        let adt = InFile::new(file_id, &adt);
         let src = InFile::new(file_id, attr.clone());
         self.with_ctx(|ctx| {
-            let res = ctx.attr_to_derive_macro_call(item, src)?;
+            let res = ctx.attr_to_derive_macro_call(adt, src)?;
             Some(res.to_vec())
         })
     }
@@ -894,6 +904,70 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(pat.syntax()).resolve_bind_pat_to_const(self.db, pat)
     }
 
+    fn resolve_derive_ident(
+        &self,
+        derive: &ast::Attr,
+        ident: &ast::Ident,
+    ) -> Option<PathResolution> {
+        debug_assert!(ident.syntax().parent().and_then(ast::TokenTree::cast).is_some());
+        debug_assert!(ident.syntax().ancestors().any(|anc| anc == *derive.syntax()));
+        // derive macros are always at depth 2, tokentree -> meta -> attribute
+        let syntax = ident.syntax();
+
+        let tt = derive.token_tree()?;
+        let file = self.find_file(derive.syntax());
+        let adt = derive.syntax().parent().and_then(ast::Adt::cast)?;
+
+        let res = self.with_ctx(|ctx| {
+            let attr_def = ctx.attr_to_def(file.with_value(derive.clone()))?;
+            let derives = ctx.attr_to_derive_macro_call(
+                file.with_value(&adt),
+                file.with_value(derive.clone()),
+            )?;
+
+            let mut derive_paths = attr_def.parse_path_comma_token_tree()?;
+
+            let derive_idx = tt
+                .syntax()
+                .children_with_tokens()
+                .filter_map(SyntaxElement::into_token)
+                .take_while(|tok| tok != syntax)
+                .filter(|t| t.kind() == T![,])
+                .count();
+            let path_segment_idx = syntax
+                .siblings_with_tokens(Direction::Prev)
+                .filter_map(SyntaxElement::into_token)
+                .take_while(|tok| matches!(tok.kind(), T![:] | T![ident]))
+                .filter(|tok| tok.kind() == T![ident])
+                .count();
+
+            let mut mod_path = derive_paths.nth(derive_idx)?;
+
+            if path_segment_idx < mod_path.len() {
+                // the path for the given ident is a qualifier, resolve to module if possible
+                while path_segment_idx < mod_path.len() {
+                    mod_path.pop_segment();
+                }
+                Some(Either::Left(mod_path))
+            } else {
+                // otherwise fetch the derive
+                Some(Either::Right(derives[derive_idx]))
+            }
+        })?;
+
+        match res {
+            Either::Left(path) => resolve_hir_path(
+                self.db,
+                &self.scope(derive.syntax()).resolver,
+                &Path::from_known_path(path, []),
+            )
+            .filter(|res| matches!(res, PathResolution::Def(ModuleDef::Module(_)))),
+            Either::Right(derive) => derive
+                .map(|call| MacroDef { id: self.db.lookup_intern_macro_call(call).def })
+                .map(PathResolution::Macro),
+        }
+    }
+
     fn record_literal_missing_fields(&self, literal: &ast::RecordExpr) -> Vec<(Field, Type)> {
         self.analyze(literal.syntax())
             .record_literal_missing_fields(self.db, literal)
@@ -1151,6 +1225,7 @@ to_def_impls![
     (crate::Local, ast::SelfParam, self_param_to_def),
     (crate::Label, ast::Label, label_to_def),
     (crate::Adt, ast::Adt, adt_to_def),
+    (crate::Attr, ast::Attr, attr_to_def),
 ];
 
 fn find_root(node: &SyntaxNode) -> SyntaxNode {
@@ -1230,14 +1305,4 @@ impl<'a> SemanticsScope<'a> {
         let path = Path::from_src(path.clone(), &ctx)?;
         resolve_hir_path(self.db, &self.resolver, &path)
     }
-
-    /// Resolve a path as-if it was written at the given scope. This is
-    /// necessary a heuristic, as it doesn't take hygiene into account.
-    // FIXME: This special casing solely exists for attributes for now
-    // ideally we should have a path resolution infra that properly knows about overlapping namespaces
-    pub fn speculative_resolve_as_mac(&self, path: &ast::Path) -> Option<MacroDef> {
-        let ctx = body::LowerCtx::new(self.db.upcast(), self.file_id);
-        let path = Path::from_src(path.clone(), &ctx)?;
-        resolve_hir_path_as_macro(self.db, &self.resolver, &path)
-    }
 }

crates/hir/src/semantics/source_to_def.rs

@@ -210,6 +210,19 @@ impl SourceToDefCtx<'_, '_> {
             ast::Adt::Union(it) => self.union_to_def(InFile::new(file_id, it)).map(AdtId::UnionId),
         }
     }
+    pub(super) fn attr_to_def(
+        &mut self,
+        InFile { file_id, value }: InFile<ast::Attr>,
+    ) -> Option<crate::Attr> {
+        // FIXME: Use dynmap?
+        let adt = value.syntax().parent().and_then(ast::Adt::cast)?;
+        let attr_pos = ast::HasAttrs::attrs(&adt).position(|it| it == value)?;
+        let attrs = {
+            let def = self.adt_to_def(InFile::new(file_id, adt))?;
+            self.db.attrs(def.into())
+        };
+        attrs.get(attr_pos).cloned()
+    }
     pub(super) fn bind_pat_to_def(
         &mut self,
         src: InFile<ast::IdentPat>,
@@ -246,7 +259,7 @@ impl SourceToDefCtx<'_, '_> {
 
     pub(super) fn attr_to_derive_macro_call(
         &mut self,
-        item: InFile<&ast::Item>,
+        item: InFile<&ast::Adt>,
         src: InFile<ast::Attr>,
     ) -> Option<&[Option<MacroCallId>]> {
         let map = self.dyn_map(item)?;

crates/hir_def/src/attr.rs

@@ -720,11 +720,8 @@ impl Attr {
         Self::from_src(db, ast, hygiene, id)
     }
 
-    /// Parses this attribute as a `#[derive]`, returns an iterator that yields all contained paths
-    /// to derive macros.
-    ///
-    /// Returns `None` when the attribute does not have a well-formed `#[derive]` attribute input.
-    pub(crate) fn parse_derive(&self) -> Option<impl Iterator<Item = ModPath> + '_> {
+    /// Parses this attribute as a token tree consisting of comma separated paths.
+    pub fn parse_path_comma_token_tree(&self) -> Option<impl Iterator<Item = ModPath> + '_> {
         let args = match self.input.as_deref() {
             Some(AttrInput::TokenTree(args, _)) => args,
             _ => return None,
@@ -749,7 +746,11 @@ impl Attr {
             })
             .collect::<Vec<_>>();
 
-        return Some(paths.into_iter());
+        Some(paths.into_iter())
+    }
+
+    pub fn path(&self) -> &ModPath {
+        &self.path
     }
 
     pub fn string_value(&self) -> Option<&SmolStr> {

crates/hir_def/src/nameres/collector.rs

@@ -1145,7 +1145,7 @@ impl DefCollector<'_> {
                             }
                         }
 
-                        match attr.parse_derive() {
+                        match attr.parse_path_comma_token_tree() {
                             Some(derive_macros) => {
                                 let mut len = 0;
                                 for (idx, path) in derive_macros.enumerate() {

crates/ide/src/goto_definition.rs

@@ -1381,6 +1381,18 @@ mod foo {
            // ^^^^
 }
 #[derive(foo::Copy$0)]
+struct Foo;
+            "#,
+        );
+        check(
+            r#"
+//- minicore:derive
+mod foo {
+ // ^^^
+    #[rustc_builtin_macro]
+    pub macro Copy {}
+}
+#[derive(foo$0::Copy)]
 struct Foo;
             "#,
         );

crates/ide/src/syntax_highlighting/highlight.rs

@@ -3,7 +3,7 @@
 use hir::{AsAssocItem, HasVisibility, Semantics};
 use ide_db::{
     defs::{Definition, NameClass, NameRefClass},
-    helpers::{try_resolve_derive_input, FamousDefs},
+    helpers::FamousDefs,
     RootDatabase, SymbolKind,
 };
 use rustc_hash::FxHashMap;
@@ -39,16 +39,17 @@ pub(super) fn token(
         INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(),
         BYTE => HlTag::ByteLiteral.into(),
         CHAR => HlTag::CharLiteral.into(),
-        IDENT if parent_matches::<ast::TokenTree>(&token) => {
-            match token.ancestors().nth(2).and_then(ast::Attr::cast) {
-                Some(attr) => {
-                    match try_resolve_derive_input(sema, &attr, &ast::Ident::cast(token).unwrap()) {
-                        Some(res) => highlight_def(sema, krate, Definition::from(res)),
-                        None => HlTag::None.into(),
-                    }
-                }
-                None => HlTag::None.into(),
-            }
+        IDENT => {
+            let tt = ast::TokenTree::cast(token.parent()?)?;
+            let ident = ast::Ident::cast(token)?;
+            // from this point on we are inside a token tree, this only happens for identifiers
+            // that were not mapped down into macro invocations
+            (|| {
+                let attr = tt.parent_meta()?.parent_attr()?;
+                let res = sema.resolve_derive_ident(&attr, &ident)?;
+                Some(highlight_def(sema, krate, Definition::from(res)))
+            })()
+            .unwrap_or_else(|| HlTag::None.into())
         }
         p if p.is_punct() => punctuation(sema, token, p),
         k if k.is_keyword() => keyword(sema, token, k)?,

crates/ide_db/src/defs.rs

@@ -17,7 +17,7 @@ use syntax::{
     match_ast, AstToken, SyntaxKind, SyntaxNode, SyntaxToken,
 };
 
-use crate::{helpers::try_resolve_derive_input, RootDatabase};
+use crate::RootDatabase;
 
 // FIXME: a more precise name would probably be `Symbol`?
 #[derive(Debug, PartialEq, Eq, Copy, Clone, Hash)]
@@ -56,7 +56,8 @@ impl Definition {
                 .and_then(|tt| tt.parent_meta())
                 .and_then(|meta| meta.parent_attr());
             if let Some(attr) = attr {
-                return try_resolve_derive_input(&sema, &attr, &ident)
+                return sema
+                    .resolve_derive_ident(&attr, &ident)
                     .map(Into::into)
                     .into_iter()
                     .collect();

crates/ide_db/src/helpers.rs

@@ -74,26 +74,6 @@ pub fn get_path_at_cursor_in_tt(cursor: &ast::Ident) -> Option<ast::Path> {
         })
 }
 
-/// Parses and resolves the path at the cursor position in the given attribute, if it is a derive.
-/// This special case is required because the derive macro is a compiler builtin that discards the input derives.
-pub fn try_resolve_derive_input(
-    sema: &hir::Semantics<RootDatabase>,
-    attr: &ast::Attr,
-    cursor: &ast::Ident,
-) -> Option<PathResolution> {
-    let path = get_path_in_derive_attr(sema, attr, cursor)?;
-    let scope = sema.scope(attr.syntax());
-    // FIXME: This double resolve shouldn't be necessary
-    // It's only here so we prefer macros over other namespaces
-    match scope.speculative_resolve_as_mac(&path) {
-        Some(mac) if mac.kind() == hir::MacroKind::Derive => Some(PathResolution::Macro(mac)),
-        Some(_) => return None,
-        None => scope
-            .speculative_resolve(&path)
-            .filter(|res| matches!(res, PathResolution::Def(ModuleDef::Module(_)))),
-    }
-}
-
 /// Picks the token with the highest rank returned by the passed in function.
 pub fn pick_best_token(
     tokens: TokenAtOffset<SyntaxToken>,

crates/ide_db/src/helpers/import_assets.rs

@@ -146,6 +146,7 @@ impl ImportAssets {
         if let Some(_) = path.qualifier() {
             return None;
         }
+
         let name = NameToImport::exact_case_sensitive(path.segment()?.name_ref()?.to_string());
         let candidate_node = attr.syntax().clone();
         Some(Self {