7 files changed, 118 insertions, 11 deletions

diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 7f9a6e7ca..2f8f02d82 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -61,7 +61,9 @@ impl Attrs {
                 AdtId::UnionId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
             },
             AttrDefId::TraitId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
-            AttrDefId::MacroDefId(it) => attrs_from_ast(it.ast_id, db),
+            AttrDefId::MacroDefId(it) => {
+                it.ast_id.map_or_else(Default::default, |ast_id| attrs_from_ast(ast_id, db))
+            }
             AttrDefId::ImplId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
             AttrDefId::ConstId(it) => attrs_from_loc(it.lookup(db), db),
             AttrDefId::StaticId(it) => attrs_from_loc(it.lookup(db), db),
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index ef1816836..7b385f3fd 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -6,7 +6,9 @@ pub mod scope;
 use std::{ops::Index, sync::Arc};
 
 use either::Either;
-use hir_expand::{hygiene::Hygiene, AstId, HirFileId, InFile, MacroDefId, MacroFileKind};
+use hir_expand::{
+    hygiene::Hygiene, AstId, HirFileId, InFile, MacroCallKind, MacroDefId, MacroFileKind,
+};
 use ra_arena::{map::ArenaMap, Arena};
 use ra_syntax::{ast, AstNode, AstPtr};
 use rustc_hash::FxHashMap;
@@ -46,7 +48,7 @@ impl Expander {
 
         if let Some(path) = macro_call.path().and_then(|path| self.parse_path(path)) {
             if let Some(def) = self.resolve_path_as_macro(db, &path) {
-                let call_id = def.as_call_id(db, ast_id);
+                let call_id = def.as_call_id(db, MacroCallKind::FnLike(ast_id));
                 let file_id = call_id.as_file(MacroFileKind::Expr);
                 if let Some(node) = db.parse_or_expand(file_id) {
                     if let Some(expr) = ast::Expr::cast(node) {
diff --git a/crates/ra_hir_def/src/docs.rs b/crates/ra_hir_def/src/docs.rs
index 3fc6d6934..61727bd26 100644
--- a/crates/ra_hir_def/src/docs.rs
+++ b/crates/ra_hir_def/src/docs.rs
@@ -60,7 +60,7 @@ impl Documentation {
                 docs_from_ast(&src.value[it.local_id])
             }
             AttrDefId::TraitId(it) => docs_from_ast(&it.source(db).value),
-            AttrDefId::MacroDefId(it) => docs_from_ast(&it.ast_id.to_node(db)),
+            AttrDefId::MacroDefId(it) => docs_from_ast(&it.ast_id?.to_node(db)),
             AttrDefId::ConstId(it) => docs_from_ast(&it.lookup(db).source(db).value),
             AttrDefId::StaticId(it) => docs_from_ast(&it.lookup(db).source(db).value),
             AttrDefId::FunctionId(it) => docs_from_ast(&it.lookup(db).source(db).value),
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 9d948d4f4..08693cb13 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -4,9 +4,10 @@
 //! resolves imports and expands macros.
 
 use hir_expand::{
+    builtin_derive::find_builtin_derive,
     builtin_macro::find_builtin_macro,
     name::{self, AsName, Name},
-    HirFileId, MacroCallId, MacroDefId, MacroDefKind, MacroFileKind,
+    HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind, MacroFileKind,
 };
 use ra_cfg::CfgOptions;
 use ra_db::{CrateId, FileId};
@@ -58,6 +59,7 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
         glob_imports: FxHashMap::default(),
         unresolved_imports: Vec::new(),
         unexpanded_macros: Vec::new(),
+        unexpanded_attribute_macros: Vec::new(),
         mod_dirs: FxHashMap::default(),
         macro_stack_monitor: MacroStackMonitor::default(),
         poison_macros: FxHashSet::default(),
@@ -102,6 +104,7 @@ struct DefCollector<'a, DB> {
     glob_imports: FxHashMap<LocalModuleId, Vec<(LocalModuleId, LocalImportId)>>,
     unresolved_imports: Vec<(LocalModuleId, LocalImportId, raw::ImportData)>,
     unexpanded_macros: Vec<(LocalModuleId, AstId<ast::MacroCall>, Path)>,
+    unexpanded_attribute_macros: Vec<(LocalModuleId, AstId<ast::ModuleItem>, Path)>,
     mod_dirs: FxHashMap<LocalModuleId, ModDir>,
 
     /// Some macro use `$tt:tt which mean we have to handle the macro perfectly
@@ -470,6 +473,8 @@ where
 
     fn resolve_macros(&mut self) -> ReachedFixedPoint {
         let mut macros = std::mem::replace(&mut self.unexpanded_macros, Vec::new());
+        let mut attribute_macros =
+            std::mem::replace(&mut self.unexpanded_attribute_macros, Vec::new());
         let mut resolved = Vec::new();
         let mut res = ReachedFixedPoint::Yes;
         macros.retain(|(module_id, ast_id, path)| {
@@ -482,7 +487,19 @@ where
             );
 
             if let Some(def) = resolved_res.resolved_def.take_macros() {
-                let call_id = def.as_call_id(self.db, *ast_id);
+                let call_id = def.as_call_id(self.db, MacroCallKind::FnLike(*ast_id));
+                resolved.push((*module_id, call_id, def));
+                res = ReachedFixedPoint::No;
+                return false;
+            }
+
+            true
+        });
+        attribute_macros.retain(|(module_id, ast_id, path)| {
+            let resolved_res = self.resolve_attribute_macro(path);
+
+            if let Some(def) = resolved_res {
+                let call_id = def.as_call_id(self.db, MacroCallKind::Attr(*ast_id));
                 resolved.push((*module_id, call_id, def));
                 res = ReachedFixedPoint::No;
                 return false;
@@ -492,6 +509,7 @@ where
         });
 
         self.unexpanded_macros = macros;
+        self.unexpanded_attribute_macros = attribute_macros;
 
         for (module_id, macro_call_id, macro_def_id) in resolved {
             self.collect_macro_expansion(module_id, macro_call_id, macro_def_id);
@@ -500,6 +518,20 @@ where
         res
     }
 
+    fn resolve_attribute_macro(&self, path: &Path) -> Option<MacroDefId> {
+        // FIXME this is currently super hacky, just enough to support the
+        // built-in derives
+        if let Some(name) = path.as_ident() {
+            // FIXME this should actually be handled with the normal name
+            // resolution; the std lib defines built-in stubs for the derives,
+            // but these are new-style `macro`s, which we don't support yet
+            if let Some(def_id) = find_builtin_derive(name) {
+                return Some(def_id);
+            }
+        }
+        None
+    }
+
     fn collect_macro_expansion(
         &mut self,
         module_id: LocalModuleId,
@@ -587,7 +619,9 @@ where
                         .def_collector
                         .unresolved_imports
                         .push((self.module_id, import_id, self.raw_items[import_id].clone())),
-                    raw::RawItemKind::Def(def) => self.define_def(&self.raw_items[def]),
+                    raw::RawItemKind::Def(def) => {
+                        self.define_def(&self.raw_items[def], &item.attrs)
+                    }
                     raw::RawItemKind::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
                     raw::RawItemKind::Impl(imp) => {
                         let module = ModuleId {
@@ -682,10 +716,16 @@ where
         res
     }
 
-    fn define_def(&mut self, def: &raw::DefData) {
+    fn define_def(&mut self, def: &raw::DefData, attrs: &Attrs) {
         let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: self.module_id };
         let ctx = LocationCtx::new(self.def_collector.db, module, self.file_id);
 
+        // FIXME: check attrs to see if this is an attribute macro invocation;
+        // in which case we don't add the invocation, just a single attribute
+        // macro invocation
+
+        self.collect_derives(attrs, def);
+
         let name = def.name.clone();
         let def: PerNs = match def.kind {
             raw::DefKind::Function(ast_id) => {
@@ -736,6 +776,23 @@ where
         self.def_collector.update(self.module_id, None, &[(name, resolution)])
     }
 
+    fn collect_derives(&mut self, attrs: &Attrs, def: &raw::DefData) {
+        for derive_subtree in attrs.by_key("derive").tt_values() {
+            // for #[derive(Copy, Clone)], `derive_subtree` is the `(Copy, Clone)` subtree
+            for tt in &derive_subtree.token_trees {
+                let ident = match &tt {
+                    tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => ident,
+                    tt::TokenTree::Leaf(tt::Leaf::Punct(_)) => continue, // , is ok
+                    _ => continue, // anything else would be an error (which we currently ignore)
+                };
+                let path = Path::from_tt_ident(ident);
+
+                let ast_id = AstId::new(self.file_id, def.kind.ast_id());
+                self.def_collector.unexpanded_attribute_macros.push((self.module_id, ast_id, path));
+            }
+        }
+    }
+
     fn collect_macro(&mut self, mac: &raw::MacroData) {
         let ast_id = AstId::new(self.file_id, mac.ast_id);
 
@@ -759,8 +816,8 @@ where
         if is_macro_rules(&mac.path) {
             if let Some(name) = &mac.name {
                 let macro_id = MacroDefId {
-                    ast_id,
-                    krate: self.def_collector.def_map.krate,
+                    ast_id: Some(ast_id),
+                    krate: Some(self.def_collector.def_map.krate),
                     kind: MacroDefKind::Declarative,
                 };
                 self.def_collector.define_macro(self.module_id, name.clone(), macro_id, mac.export);
@@ -773,7 +830,8 @@ where
         if let Some(macro_def) = mac.path.as_ident().and_then(|name| {
             self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
         }) {
-            let macro_call_id = macro_def.as_call_id(self.def_collector.db, ast_id);
+            let macro_call_id =
+                macro_def.as_call_id(self.def_collector.db, MacroCallKind::FnLike(ast_id));
 
             self.def_collector.collect_macro_expansion(self.module_id, macro_call_id, macro_def);
             return;
@@ -829,6 +887,7 @@ mod tests {
             glob_imports: FxHashMap::default(),
             unresolved_imports: Vec::new(),
             unexpanded_macros: Vec::new(),
+            unexpanded_attribute_macros: Vec::new(),
             mod_dirs: FxHashMap::default(),
             macro_stack_monitor: monitor,
             poison_macros: FxHashSet::default(),
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index de4e706c2..a2821e1c3 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -184,6 +184,21 @@ pub(super) enum DefKind {
     TypeAlias(FileAstId<ast::TypeAliasDef>),
 }
 
+impl DefKind {
+    pub fn ast_id(&self) -> FileAstId<ast::ModuleItem> {
+        match self {
+            DefKind::Function(it) => it.upcast(),
+            DefKind::Struct(it) => it.upcast(),
+            DefKind::Union(it) => it.upcast(),
+            DefKind::Enum(it) => it.upcast(),
+            DefKind::Const(it) => it.upcast(),
+            DefKind::Static(it) => it.upcast(),
+            DefKind::Trait(it) => it.upcast(),
+            DefKind::TypeAlias(it) => it.upcast(),
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub(super) struct Macro(RawId);
 impl_arena_id!(Macro);
diff --git a/crates/ra_hir_def/src/nameres/tests/macros.rs b/crates/ra_hir_def/src/nameres/tests/macros.rs
index 704065633..cfa4ecb1a 100644
--- a/crates/ra_hir_def/src/nameres/tests/macros.rs
+++ b/crates/ra_hir_def/src/nameres/tests/macros.rs
@@ -600,3 +600,27 @@ fn macro_dollar_crate_is_correct_in_indirect_deps() {
         ⋮bar: t v
     "###);
 }
+
+#[test]
+fn expand_derive() {
+    let map = compute_crate_def_map(
+        "
+        //- /main.rs
+        #[derive(Clone)]
+        struct Foo;
+        ",
+    );
+    assert_eq!(map.modules[map.root].impls.len(), 1);
+}
+
+#[test]
+fn expand_multiple_derive() {
+    let map = compute_crate_def_map(
+        "
+        //- /main.rs
+        #[derive(Copy, Clone)]
+        struct Foo;
+        ",
+    );
+    assert_eq!(map.modules[map.root].impls.len(), 2);
+}
diff --git a/crates/ra_hir_def/src/path.rs b/crates/ra_hir_def/src/path.rs
index 3030dcdf6..e547b2f03 100644
--- a/crates/ra_hir_def/src/path.rs
+++ b/crates/ra_hir_def/src/path.rs
@@ -199,6 +199,11 @@ impl Path {
         name_ref.as_name().into()
     }
 
+    /// Converts an `tt::Ident` into a single-identifier `Path`.
+    pub(crate) fn from_tt_ident(ident: &tt::Ident) -> Path {
+        ident.as_name().into()
+    }
+
     /// `true` is this path is a single identifier, like `foo`
     pub fn is_ident(&self) -> bool {
         self.kind == PathKind::Plain && self.segments.len() == 1