1 files changed, 362 insertions, 0 deletions

diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
new file mode 100644
index 000000000..93ad40005
--- /dev/null
+++ b/crates/ra_hir_def/src/lib.rs
@@ -0,0 +1,362 @@
+//! `hir_def` crate contains everything between macro expansion and type
+//! inference.
+//!
+//! It defines various items (structs, enums, traits) which comprises Rust code,
+//! as well as an algorithm for resolving paths to such entities.
+//!
+//! Note that `hir_def` is a work in progress, so not all of the above is
+//! actually true.
+
+pub mod db;
+pub mod attr;
+pub mod path;
+pub mod type_ref;
+pub mod builtin_type;
+
+// FIXME: this should be private
+pub mod nameres;
+
+use std::hash::{Hash, Hasher};
+
+use hir_expand::{ast_id_map::FileAstId, db::AstDatabase, AstId, HirFileId};
+use ra_arena::{impl_arena_id, RawId};
+use ra_db::{salsa, CrateId, FileId};
+use ra_syntax::{ast, AstNode, SyntaxNode};
+
+use crate::{builtin_type::BuiltinType, db::InternDatabase};
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub struct Source<T> {
+    pub file_id: HirFileId,
+    pub ast: T,
+}
+
+pub enum ModuleSource {
+    SourceFile(ast::SourceFile),
+    Module(ast::Module),
+}
+
+impl ModuleSource {
+    pub fn new(
+        db: &impl db::DefDatabase2,
+        file_id: Option<FileId>,
+        decl_id: Option<AstId<ast::Module>>,
+    ) -> ModuleSource {
+        match (file_id, decl_id) {
+            (Some(file_id), _) => {
+                let source_file = db.parse(file_id).tree();
+                ModuleSource::SourceFile(source_file)
+            }
+            (None, Some(item_id)) => {
+                let module = item_id.to_node(db);
+                assert!(module.item_list().is_some(), "expected inline module");
+                ModuleSource::Module(module)
+            }
+            (None, None) => panic!(),
+        }
+    }
+
+    // FIXME: this methods do not belong here
+    pub fn from_position(
+        db: &impl db::DefDatabase2,
+        position: ra_db::FilePosition,
+    ) -> ModuleSource {
+        let parse = db.parse(position.file_id);
+        match &ra_syntax::algo::find_node_at_offset::<ast::Module>(
+            parse.tree().syntax(),
+            position.offset,
+        ) {
+            Some(m) if !m.has_semi() => ModuleSource::Module(m.clone()),
+            _ => {
+                let source_file = parse.tree();
+                ModuleSource::SourceFile(source_file)
+            }
+        }
+    }
+
+    pub fn from_child_node(
+        db: &impl db::DefDatabase2,
+        file_id: FileId,
+        child: &SyntaxNode,
+    ) -> ModuleSource {
+        if let Some(m) = child.ancestors().filter_map(ast::Module::cast).find(|it| !it.has_semi()) {
+            ModuleSource::Module(m)
+        } else {
+            let source_file = db.parse(file_id).tree();
+            ModuleSource::SourceFile(source_file)
+        }
+    }
+
+    pub fn from_file_id(db: &impl db::DefDatabase2, file_id: FileId) -> ModuleSource {
+        let source_file = db.parse(file_id).tree();
+        ModuleSource::SourceFile(source_file)
+    }
+}
+
+impl<T> Source<T> {
+    pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> Source<U> {
+        Source { file_id: self.file_id, ast: f(self.ast) }
+    }
+    pub fn file_syntax(&self, db: &impl AstDatabase) -> SyntaxNode {
+        db.parse_or_expand(self.file_id).expect("source created from invalid file")
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct ModuleId {
+    pub krate: CrateId,
+    pub module_id: CrateModuleId,
+}
+
+/// An ID of a module, **local** to a specific crate
+// FIXME: rename to `LocalModuleId`.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct CrateModuleId(RawId);
+impl_arena_id!(CrateModuleId);
+
+macro_rules! impl_intern_key {
+    ($name:ident) => {
+        impl salsa::InternKey for $name {
+            fn from_intern_id(v: salsa::InternId) -> Self {
+                $name(v)
+            }
+            fn as_intern_id(&self) -> salsa::InternId {
+                self.0
+            }
+        }
+    };
+}
+
+#[derive(Debug)]
+pub struct ItemLoc<N: AstNode> {
+    pub(crate) module: ModuleId,
+    ast_id: AstId<N>,
+}
+
+impl<N: AstNode> PartialEq for ItemLoc<N> {
+    fn eq(&self, other: &Self) -> bool {
+        self.module == other.module && self.ast_id == other.ast_id
+    }
+}
+impl<N: AstNode> Eq for ItemLoc<N> {}
+impl<N: AstNode> Hash for ItemLoc<N> {
+    fn hash<H: Hasher>(&self, hasher: &mut H) {
+        self.module.hash(hasher);
+        self.ast_id.hash(hasher);
+    }
+}
+
+impl<N: AstNode> Clone for ItemLoc<N> {
+    fn clone(&self) -> ItemLoc<N> {
+        ItemLoc { module: self.module, ast_id: self.ast_id }
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct LocationCtx<DB> {
+    db: DB,
+    module: ModuleId,
+    file_id: HirFileId,
+}
+
+impl<'a, DB> LocationCtx<&'a DB> {
+    pub fn new(db: &'a DB, module: ModuleId, file_id: HirFileId) -> LocationCtx<&'a DB> {
+        LocationCtx { db, module, file_id }
+    }
+}
+
+impl<'a, DB: AstDatabase + InternDatabase> LocationCtx<&'a DB> {
+    pub fn to_def<N, DEF>(self, ast: &N) -> DEF
+    where
+        N: AstNode,
+        DEF: AstItemDef<N>,
+    {
+        DEF::from_ast(self, ast)
+    }
+}
+
+pub trait AstItemDef<N: AstNode>: salsa::InternKey + Clone {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<N>) -> Self;
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<N>;
+
+    fn from_ast(ctx: LocationCtx<&(impl AstDatabase + InternDatabase)>, ast: &N) -> Self {
+        let items = ctx.db.ast_id_map(ctx.file_id);
+        let item_id = items.ast_id(ast);
+        Self::from_ast_id(ctx, item_id)
+    }
+    fn from_ast_id(ctx: LocationCtx<&impl InternDatabase>, ast_id: FileAstId<N>) -> Self {
+        let loc = ItemLoc { module: ctx.module, ast_id: AstId::new(ctx.file_id, ast_id) };
+        Self::intern(ctx.db, loc)
+    }
+    fn source(self, db: &(impl AstDatabase + InternDatabase)) -> Source<N> {
+        let loc = self.lookup_intern(db);
+        let ast = loc.ast_id.to_node(db);
+        Source { file_id: loc.ast_id.file_id(), ast }
+    }
+    fn module(self, db: &impl InternDatabase) -> ModuleId {
+        let loc = self.lookup_intern(db);
+        loc.module
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct FunctionId(salsa::InternId);
+impl_intern_key!(FunctionId);
+
+impl AstItemDef<ast::FnDef> for FunctionId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::FnDef>) -> Self {
+        db.intern_function(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::FnDef> {
+        db.lookup_intern_function(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct StructId(salsa::InternId);
+impl_intern_key!(StructId);
+impl AstItemDef<ast::StructDef> for StructId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::StructDef>) -> Self {
+        db.intern_struct(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::StructDef> {
+        db.lookup_intern_struct(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct UnionId(salsa::InternId);
+impl_intern_key!(UnionId);
+impl AstItemDef<ast::StructDef> for UnionId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::StructDef>) -> Self {
+        db.intern_union(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::StructDef> {
+        db.lookup_intern_union(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct EnumId(salsa::InternId);
+impl_intern_key!(EnumId);
+impl AstItemDef<ast::EnumDef> for EnumId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::EnumDef>) -> Self {
+        db.intern_enum(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::EnumDef> {
+        db.lookup_intern_enum(self)
+    }
+}
+
+// FIXME: rename to `VariantId`, only enums can ave variants
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct EnumVariantId {
+    parent: EnumId,
+    local_id: LocalEnumVariantId,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct LocalEnumVariantId(RawId);
+impl_arena_id!(LocalEnumVariantId);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct ConstId(salsa::InternId);
+impl_intern_key!(ConstId);
+impl AstItemDef<ast::ConstDef> for ConstId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::ConstDef>) -> Self {
+        db.intern_const(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::ConstDef> {
+        db.lookup_intern_const(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct StaticId(salsa::InternId);
+impl_intern_key!(StaticId);
+impl AstItemDef<ast::StaticDef> for StaticId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::StaticDef>) -> Self {
+        db.intern_static(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::StaticDef> {
+        db.lookup_intern_static(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct TraitId(salsa::InternId);
+impl_intern_key!(TraitId);
+impl AstItemDef<ast::TraitDef> for TraitId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::TraitDef>) -> Self {
+        db.intern_trait(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::TraitDef> {
+        db.lookup_intern_trait(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct TypeAliasId(salsa::InternId);
+impl_intern_key!(TypeAliasId);
+impl AstItemDef<ast::TypeAliasDef> for TypeAliasId {
+    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::TypeAliasDef>) -> Self {
+        db.intern_type_alias(loc)
+    }
+    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::TypeAliasDef> {
+        db.lookup_intern_type_alias(self)
+    }
+}
+
+macro_rules! impl_froms {
+    ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
+        $(
+            impl From<$v> for $e {
+                fn from(it: $v) -> $e {
+                    $e::$v(it)
+                }
+            }
+            $($(
+                impl From<$sv> for $e {
+                    fn from(it: $sv) -> $e {
+                        $e::$v($v::$sv(it))
+                    }
+                }
+            )*)?
+        )*
+    }
+}
+
+/// A Data Type
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum AdtId {
+    StructId(StructId),
+    UnionId(UnionId),
+    EnumId(EnumId),
+}
+impl_froms!(AdtId: StructId, UnionId, EnumId);
+
+/// The defs which can be visible in the module.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum ModuleDefId {
+    ModuleId(ModuleId),
+    FunctionId(FunctionId),
+    AdtId(AdtId),
+    // Can't be directly declared, but can be imported.
+    EnumVariantId(EnumVariantId),
+    ConstId(ConstId),
+    StaticId(StaticId),
+    TraitId(TraitId),
+    TypeAliasId(TypeAliasId),
+    BuiltinType(BuiltinType),
+}
+impl_froms!(
+    ModuleDefId: ModuleId,
+    FunctionId,
+    AdtId(StructId, EnumId, UnionId),
+    EnumVariantId,
+    ConstId,
+    StaticId,
+    TraitId,
+    TypeAliasId,
+    BuiltinType
+);