6 files changed, 91 insertions, 183 deletions

diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index d2cc19b0f..c7bad7e2b 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -4,12 +4,10 @@ use ra_syntax::{SyntaxNode, TreeArc, SourceFile};
 use ra_db::{SourceDatabase, salsa, FileId};
 
 use crate::{
-    MacroCallId, HirFileId,
-    SourceFileItems, SourceItemId, Crate, Module, HirInterner,
+    HirFileId, SourceFileItems, SourceItemId, Crate, Module, HirInterner,
     Function, FnSignature, ExprScopes, TypeAlias,
     Struct, Enum, StructField,
     Const, ConstSignature, Static,
-    macros::MacroExpansion,
     nameres::{Namespace, ImportSourceMap, RawItems, CrateDefMap},
     ty::{InferenceResult, Ty, method_resolution::CrateImplBlocks, TypableDef, CallableDef, FnSig},
     adt::{StructData, EnumData},
@@ -23,9 +21,6 @@ pub trait PersistentHirDatabase: SourceDatabase + AsRef<HirInterner> {
     #[salsa::invoke(HirFileId::hir_parse)]
     fn hir_parse(&self, file_id: HirFileId) -> TreeArc<SourceFile>;
 
-    #[salsa::invoke(crate::macros::expand_macro_invocation)]
-    fn expand_macro_invocation(&self, invoc: MacroCallId) -> Option<Arc<MacroExpansion>>;
-
     #[salsa::invoke(crate::adt::StructData::struct_data_query)]
     fn struct_data(&self, s: Struct) -> Arc<StructData>;
 
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index a144e4a1e..9596488d3 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -89,17 +89,31 @@ impl HirFileId {
     ) -> TreeArc<SourceFile> {
         match file_id.0 {
             HirFileIdRepr::File(file_id) => db.parse(file_id),
-            HirFileIdRepr::Macro(m) => {
-                if let Some(exp) = db.expand_macro_invocation(m) {
-                    return exp.file();
-                }
+            HirFileIdRepr::Macro(macro_call_id) => {
                 // returning an empty string looks fishy...
-                SourceFile::parse("")
+                parse_macro(db, macro_call_id).unwrap_or_else(|| SourceFile::parse(""))
             }
         }
     }
 }
 
+fn parse_macro(
+    db: &impl PersistentHirDatabase,
+    macro_call_id: MacroCallId,
+) -> Option<TreeArc<SourceFile>> {
+    let loc = macro_call_id.loc(db);
+    let syntax = db.file_item(loc.source_item_id);
+    let macro_call = ast::MacroCall::cast(&syntax).unwrap();
+    let (macro_arg, _) = macro_call.token_tree().and_then(mbe::ast_to_token_tree)?;
+
+    let def_map = db.crate_def_map(loc.module.krate);
+    let (krate, macro_id) = def_map.resolve_macro(macro_call_id)?;
+    let def_map = db.crate_def_map(krate);
+    let macro_rules = &def_map[macro_id];
+    let tt = macro_rules.expand(&macro_arg).ok()?;
+    Some(mbe::token_tree_to_ast_item_list(&tt))
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 enum HirFileIdRepr {
     File(FileId),
@@ -373,7 +387,6 @@ impl SourceFileItems {
 impl std::ops::Index<SourceFileItemId> for SourceFileItems {
     type Output = SyntaxNodePtr;
     fn index(&self, idx: SourceFileItemId) -> &SyntaxNodePtr {
-        eprintln!("invalid SourceFileItemId({:?}) for file({:?})", idx, self.file_id);
         &self.arena[idx]
     }
 }
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index a188a3cc8..75c977d32 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -24,7 +24,6 @@ mod path;
 pub mod source_binder;
 
 mod ids;
-mod macros;
 mod name;
 mod nameres;
 mod adt;
@@ -53,7 +52,6 @@ pub use self::{
     path::{Path, PathKind},
     name::Name,
     ids::{HirFileId, MacroCallId, MacroCallLoc, HirInterner},
-    macros::{MacroDef, MacroInput, MacroExpansion},
     nameres::{PerNs, Namespace},
     ty::{Ty, Substs, display::HirDisplay},
     impl_block::{ImplBlock, ImplItem},
diff --git a/crates/ra_hir/src/macros.rs b/crates/ra_hir/src/macros.rs
deleted file mode 100644
index 45128c7df..000000000
--- a/crates/ra_hir/src/macros.rs
+++ /dev/null
@@ -1,135 +0,0 @@
-/// Machinery for macro expansion.
-///
-/// One of the more complicated things about macros is managing the source code
-/// that is produced after expansion. See `HirFileId` and `MacroCallId` for how
-/// do we do that.
-///
-/// When the file-management question is resolved, all that is left is a
-/// token-tree-to-token-tree transformation plus hygiene. We don't have either of
-/// those yet, so all macros are string based at the moment!
-use std::sync::Arc;
-
-use ra_syntax::{
-    TextRange, TextUnit, SourceFile, AstNode, SyntaxNode, TreeArc, SyntaxNodePtr,
-    ast,
-};
-
-use crate::{MacroCallId, PersistentHirDatabase};
-
-// Hard-coded defs for now :-(
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum MacroDef {
-    Vec,
-}
-
-impl MacroDef {
-    /// Expands macro call, returning the expansion and offset to be used to
-    /// convert ranges between expansion and original source.
-    pub fn ast_expand(macro_call: &ast::MacroCall) -> Option<(TextUnit, MacroExpansion)> {
-        let (def, input) = MacroDef::from_call(macro_call)?;
-        let exp = def.expand(input)?;
-        let off = macro_call.token_tree()?.syntax().range().start();
-        Some((off, exp))
-    }
-
-    fn from_call(macro_call: &ast::MacroCall) -> Option<(MacroDef, MacroInput)> {
-        let def = {
-            let path = macro_call.path()?;
-            let name_ref = path.segment()?.name_ref()?;
-            if name_ref.text() == "vec" {
-                MacroDef::Vec
-            } else {
-                return None;
-            }
-        };
-
-        let input = {
-            let arg = macro_call.token_tree()?.syntax();
-            MacroInput { text: arg.text().to_string() }
-        };
-        Some((def, input))
-    }
-
-    fn expand(self, input: MacroInput) -> Option<MacroExpansion> {
-        match self {
-            MacroDef::Vec => self.expand_vec(input),
-        }
-    }
-    fn expand_vec(self, input: MacroInput) -> Option<MacroExpansion> {
-        let text = format!(r"fn dummy() {{ {}; }}", input.text);
-        let file = SourceFile::parse(&text);
-        let array_expr = file.syntax().descendants().find_map(ast::ArrayExpr::cast)?;
-        let ptr = SyntaxNodePtr::new(array_expr.syntax());
-        let src_range = TextRange::offset_len(0.into(), TextUnit::of_str(&input.text));
-        let ranges_map = vec![(src_range, array_expr.syntax().range())];
-        let res = MacroExpansion { text, ranges_map, ptr };
-        Some(res)
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct MacroInput {
-    // Should be token trees
-    pub text: String,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct MacroExpansion {
-    /// The result of macro expansion. Should be token tree as well.
-    text: String,
-    /// Correspondence between ranges in the original source code and ranges in
-    /// the macro.
-    ranges_map: Vec<(TextRange, TextRange)>,
-    /// Implementation detail: internally, a macro is expanded to the whole file,
-    /// even if it is an expression. This `ptr` selects the actual expansion from
-    /// the expanded file.
-    ptr: SyntaxNodePtr,
-}
-
-impl MacroExpansion {
-    // FIXME: does not really make sense, macro expansion is not necessary a
-    // whole file. See `MacroExpansion::ptr` as well.
-    pub(crate) fn file(&self) -> TreeArc<SourceFile> {
-        SourceFile::parse(&self.text)
-    }
-
-    pub fn syntax(&self) -> TreeArc<SyntaxNode> {
-        self.ptr.to_node(&self.file()).to_owned()
-    }
-    /// Maps range in the source code to the range in the expanded code.
-    pub fn map_range_forward(&self, src_range: TextRange) -> Option<TextRange> {
-        for (s_range, t_range) in self.ranges_map.iter() {
-            if src_range.is_subrange(&s_range) {
-                let src_at_zero_range = src_range - src_range.start();
-                let src_range_offset = src_range.start() - s_range.start();
-                let src_range = src_at_zero_range + src_range_offset + t_range.start();
-                return Some(src_range);
-            }
-        }
-        None
-    }
-    /// Maps range in the expanded code to the range in the source code.
-    pub fn map_range_back(&self, tgt_range: TextRange) -> Option<TextRange> {
-        for (s_range, t_range) in self.ranges_map.iter() {
-            if tgt_range.is_subrange(&t_range) {
-                let tgt_at_zero_range = tgt_range - tgt_range.start();
-                let tgt_range_offset = tgt_range.start() - t_range.start();
-                let src_range = tgt_at_zero_range + tgt_range_offset + s_range.start();
-                return Some(src_range);
-            }
-        }
-        None
-    }
-}
-
-pub(crate) fn expand_macro_invocation(
-    db: &impl PersistentHirDatabase,
-    invoc: MacroCallId,
-) -> Option<Arc<MacroExpansion>> {
-    let loc = invoc.loc(db);
-    let syntax = db.file_item(loc.source_item_id);
-    let macro_call = ast::MacroCall::cast(&syntax).unwrap();
-
-    let (def, input) = MacroDef::from_call(macro_call)?;
-    def.expand(input).map(Arc::new)
-}
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index eabaa5691..17602ee6b 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -57,7 +57,7 @@ use test_utils::tested_by;
 use crate::{
     ModuleDef, Name, Crate, Module, Problem,
     PersistentHirDatabase, Path, PathKind, HirFileId,
-    ids::{SourceItemId, SourceFileItemId},
+    ids::{SourceItemId, SourceFileItemId, MacroCallId},
 };
 
 pub(crate) use self::raw::{RawItems, ImportId, ImportSourceMap};
@@ -76,7 +76,9 @@ pub struct CrateDefMap {
     extern_prelude: FxHashMap<Name, ModuleDef>,
     root: CrateModuleId,
     modules: Arena<CrateModuleId, ModuleData>,
-    public_macros: FxHashMap<Name, mbe::MacroRules>,
+    macros: Arena<CrateMacroId, mbe::MacroRules>,
+    public_macros: FxHashMap<Name, CrateMacroId>,
+    macro_resolutions: FxHashMap<MacroCallId, (Crate, CrateMacroId)>,
     problems: CrateDefMapProblems,
 }
 
@@ -87,9 +89,21 @@ impl std::ops::Index<CrateModuleId> for CrateDefMap {
     }
 }
 
+impl std::ops::Index<CrateMacroId> for CrateDefMap {
+    type Output = mbe::MacroRules;
+    fn index(&self, id: CrateMacroId) -> &mbe::MacroRules {
+        &self.macros[id]
+    }
+}
+
+/// An ID of a macro, **local** to a specific crate
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) struct CrateMacroId(RawId);
+impl_arena_id!(CrateMacroId);
+
 /// An ID of a module, **local** to a specific crate
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-struct CrateModuleId(RawId);
+pub(crate) struct CrateModuleId(RawId);
 impl_arena_id!(CrateModuleId);
 
 #[derive(Default, Debug, PartialEq, Eq)]
@@ -192,7 +206,9 @@ impl CrateDefMap {
                 prelude: None,
                 root,
                 modules,
+                macros: Arena::default(),
                 public_macros: FxHashMap::default(),
+                macro_resolutions: FxHashMap::default(),
                 problems: CrateDefMapProblems::default(),
             }
         };
@@ -221,6 +237,13 @@ impl CrateDefMap {
         &self.extern_prelude
     }
 
+    pub(crate) fn resolve_macro(
+        &self,
+        macro_call_id: MacroCallId,
+    ) -> Option<(Crate, CrateMacroId)> {
+        self.macro_resolutions.get(&macro_call_id).map(|&it| it)
+    }
+
     pub(crate) fn find_module_by_source(
         &self,
         file_id: HirFileId,
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index f2336c271..9992e054d 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -6,13 +6,13 @@ use ra_db::FileId;
 
 use crate::{
     Function, Module, Struct, Enum, Const, Static, Trait, TypeAlias,
-    PersistentHirDatabase, HirFileId, Name, Path, Problem,
+    PersistentHirDatabase, HirFileId, Name, Path, Problem, Crate,
     KnownName,
     nameres::{Resolution, PerNs, ModuleDef, ReachedFixedPoint, ResolveMode, raw},
     ids::{AstItemDef, LocationCtx, MacroCallLoc, SourceItemId, MacroCallId},
 };
 
-use super::{CrateDefMap, CrateModuleId, ModuleData};
+use super::{CrateDefMap, CrateModuleId, ModuleData, CrateMacroId};
 
 pub(super) fn collect_defs(
     db: &impl PersistentHirDatabase,
@@ -52,7 +52,7 @@ struct DefCollector<DB> {
     glob_imports: FxHashMap<CrateModuleId, Vec<(CrateModuleId, raw::ImportId)>>,
     unresolved_imports: Vec<(CrateModuleId, raw::ImportId, raw::ImportData)>,
     unexpanded_macros: Vec<(CrateModuleId, MacroCallId, Path, tt::Subtree)>,
-    global_macro_scope: FxHashMap<Name, mbe::MacroRules>,
+    global_macro_scope: FxHashMap<Name, CrateMacroId>,
 }
 
 impl<'a, DB> DefCollector<&'a DB>
@@ -95,10 +95,11 @@ where
 
     fn define_macro(&mut self, name: Name, tt: &tt::Subtree, export: bool) {
         if let Ok(rules) = mbe::MacroRules::parse(tt) {
+            let macro_id = self.def_map.macros.alloc(rules);
             if export {
-                self.def_map.public_macros.insert(name.clone(), rules.clone());
+                self.def_map.public_macros.insert(name.clone(), macro_id);
             }
-            self.global_macro_scope.insert(name, rules);
+            self.global_macro_scope.insert(name, macro_id);
         }
     }
 
@@ -295,6 +296,7 @@ where
     fn resolve_macros(&mut self) -> ReachedFixedPoint {
         let mut macros = std::mem::replace(&mut self.unexpanded_macros, Vec::new());
         let mut resolved = Vec::new();
+        let mut res = ReachedFixedPoint::Yes;
         macros.retain(|(module_id, call_id, path, tt)| {
             if path.segments.len() != 2 {
                 return true;
@@ -308,19 +310,16 @@ where
                 Some(it) => it,
                 _ => return true,
             };
+            res = ReachedFixedPoint::No;
             let def_map = self.db.crate_def_map(krate);
-            let rules = def_map.public_macros.get(&path.segments[1].name).cloned();
-            resolved.push((*module_id, *call_id, rules, tt.clone()));
+            if let Some(macro_id) = def_map.public_macros.get(&path.segments[1].name).cloned() {
+                resolved.push((*module_id, *call_id, (krate, macro_id), tt.clone()));
+            }
             false
         });
-        let res = if resolved.is_empty() { ReachedFixedPoint::Yes } else { ReachedFixedPoint::No };
 
-        for (module_id, macro_call_id, rules, arg) in resolved {
-            if let Some(rules) = rules {
-                if let Ok(tt) = rules.expand(&arg) {
-                    self.collect_macro_expansion(module_id, macro_call_id, tt);
-                }
-            }
+        for (module_id, macro_call_id, macro_def_id, arg) in resolved {
+            self.collect_macro_expansion(module_id, macro_call_id, macro_def_id, arg);
         }
         res
     }
@@ -329,20 +328,32 @@ where
         &mut self,
         module_id: CrateModuleId,
         macro_call_id: MacroCallId,
-        expansion: tt::Subtree,
+        macro_def_id: (Crate, CrateMacroId),
+        macro_arg: tt::Subtree,
     ) {
-        // XXX: this **does not** go through a database, because we can't
-        // identify macro_call without adding the whole state of name resolution
-        // as a parameter to the query.
-        //
-        // So, we run the queries "manually" and we must ensure that
-        // `db.hir_parse(macro_call_id)` returns the same source_file.
-        let file_id: HirFileId = macro_call_id.into();
-        let source_file = mbe::token_tree_to_ast_item_list(&expansion);
-
-        let raw_items = raw::RawItems::from_source_file(&source_file, file_id);
-        ModCollector { def_collector: &mut *self, file_id, module_id, raw_items: &raw_items }
-            .collect(raw_items.items())
+        let (macro_krate, macro_id) = macro_def_id;
+        let dm;
+        let rules = if macro_krate == self.def_map.krate {
+            &self.def_map[macro_id]
+        } else {
+            dm = self.db.crate_def_map(macro_krate);
+            &dm[macro_id]
+        };
+        if let Ok(expansion) = rules.expand(&macro_arg) {
+            self.def_map.macro_resolutions.insert(macro_call_id, macro_def_id);
+            // XXX: this **does not** go through a database, because we can't
+            // identify macro_call without adding the whole state of name resolution
+            // as a parameter to the query.
+            //
+            // So, we run the queries "manually" and we must ensure that
+            // `db.hir_parse(macro_call_id)` returns the same source_file.
+            let file_id: HirFileId = macro_call_id.into();
+            let source_file = mbe::token_tree_to_ast_item_list(&expansion);
+
+            let raw_items = raw::RawItems::from_source_file(&source_file, file_id);
+            ModCollector { def_collector: &mut *self, file_id, module_id, raw_items: &raw_items }
+                .collect(raw_items.items())
+        }
     }
 
     fn finish(self) -> CrateDefMap {
@@ -486,12 +497,15 @@ where
 
         // Case 2: try to expand macro_rules from this crate, triggering
         // recursive item collection.
-        if let Some(rules) =
+        if let Some(&macro_id) =
             mac.path.as_ident().and_then(|name| self.def_collector.global_macro_scope.get(name))
         {
-            if let Ok(tt) = rules.expand(&mac.arg) {
-                self.def_collector.collect_macro_expansion(self.module_id, macro_call_id, tt);
-            }
+            self.def_collector.collect_macro_expansion(
+                self.module_id,
+                macro_call_id,
+                (self.def_collector.def_map.krate, macro_id),
+                mac.arg.clone(),
+            );
             return;
         }