3 files changed, 61 insertions, 3 deletions

diff --git a/crates/ra_hir_def/src/builtin_type.rs b/crates/ra_hir_def/src/builtin_type.rs
index 12929caa9..2ec0c83fe 100644
--- a/crates/ra_hir_def/src/builtin_type.rs
+++ b/crates/ra_hir_def/src/builtin_type.rs
@@ -3,6 +3,8 @@
 //! A peculiarity of built-in types is that they are always available and are
 //! not associated with any particular crate.
 
+use std::fmt;
+
 use hir_expand::name::{self, Name};
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
@@ -61,3 +63,33 @@ impl BuiltinType {
         (name::F64, BuiltinType::Float { bitness: FloatBitness::X64 }),
     ];
 }
+
+impl fmt::Display for BuiltinType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let type_name = match self {
+            BuiltinType::Char => "char",
+            BuiltinType::Bool => "bool",
+            BuiltinType::Str => "str",
+            BuiltinType::Int { signedness, bitness } => match (signedness, bitness) {
+                (Signedness::Signed, IntBitness::Xsize) => "isize",
+                (Signedness::Signed, IntBitness::X8) => "i8",
+                (Signedness::Signed, IntBitness::X16) => "i16",
+                (Signedness::Signed, IntBitness::X32) => "i32",
+                (Signedness::Signed, IntBitness::X64) => "i64",
+                (Signedness::Signed, IntBitness::X128) => "i128",
+
+                (Signedness::Unsigned, IntBitness::Xsize) => "usize",
+                (Signedness::Unsigned, IntBitness::X8) => "u8",
+                (Signedness::Unsigned, IntBitness::X16) => "u16",
+                (Signedness::Unsigned, IntBitness::X32) => "u32",
+                (Signedness::Unsigned, IntBitness::X64) => "u64",
+                (Signedness::Unsigned, IntBitness::X128) => "u128",
+            },
+            BuiltinType::Float { bitness } => match bitness {
+                FloatBitness::X32 => "f32",
+                FloatBitness::X64 => "f64",
+            },
+        };
+        f.write_str(type_name)
+    }
+}
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 6db9937a4..37d0f3093 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -1,8 +1,9 @@
 //! FIXME: write short doc here
 
 use hir_expand::{
+    builtin_macro::find_builtin_macro,
     name::{self, AsName, Name},
-    HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroFileKind,
+    HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroDefKind, MacroFileKind,
 };
 use ra_cfg::CfgOptions;
 use ra_db::{CrateId, FileId};
@@ -692,10 +693,30 @@ where
     fn collect_macro(&mut self, mac: &raw::MacroData) {
         let ast_id = AstId::new(self.file_id, mac.ast_id);
 
+        // Case 0: builtin macros
+        if mac.builtin {
+            if let Some(name) = &mac.name {
+                let krate = self.def_collector.def_map.krate;
+                if let Some(macro_id) = find_builtin_macro(name, krate, ast_id) {
+                    self.def_collector.define_macro(
+                        self.module_id,
+                        name.clone(),
+                        macro_id,
+                        mac.export,
+                    );
+                    return;
+                }
+            }
+        }
+
         // Case 1: macro rules, define a macro in crate-global mutable scope
         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 };
+                let macro_id = MacroDefId {
+                    ast_id,
+                    krate: self.def_collector.def_map.krate,
+                    kind: MacroDefKind::Declarative,
+                };
                 self.def_collector.define_macro(self.module_id, name.clone(), macro_id, mac.export);
             }
             return;
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index 369376f30..f52002bc0 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -200,6 +200,7 @@ pub(super) struct MacroData {
     pub(super) path: Path,
     pub(super) name: Option<Name>,
     pub(super) export: bool,
+    pub(super) builtin: bool,
 }
 
 struct RawItemsCollector {
@@ -367,7 +368,11 @@ impl RawItemsCollector {
         // FIXME: cfg_attr
         let export = m.attrs().filter_map(|x| x.simple_name()).any(|name| name == "macro_export");
 
-        let m = self.raw_items.macros.alloc(MacroData { ast_id, path, name, export });
+        // FIXME: cfg_attr
+        let builtin =
+            m.attrs().filter_map(|x| x.simple_name()).any(|name| name == "rustc_builtin_macro");
+
+        let m = self.raw_items.macros.alloc(MacroData { ast_id, path, name, export, builtin });
         self.push_item(current_module, attrs, RawItemKind::Macro(m));
     }