Introduce macro sub-namespaces and macro_use prelude

crates/hir-def/src/body/lower.rs

@@ -37,7 +37,7 @@ use crate::{
     item_scope::BuiltinShadowMode,
     lang_item::LangItem,
     lower::LowerCtx,
-    nameres::DefMap,
+    nameres::{DefMap, MacroSubNs},
     path::{GenericArgs, Path},
     type_ref::{Mutability, Rawness, TypeRef},
     AdtId, BlockId, BlockLoc, ModuleDefId, UnresolvedMacro,
@@ -800,7 +800,13 @@ impl ExprCollector<'_> {
         let module = self.expander.module.local_id;
         let res = self.expander.enter_expand(self.db, mcall, |path| {
             self.def_map
-                .resolve_path(self.db, module, &path, crate::item_scope::BuiltinShadowMode::Other)
+                .resolve_path(
+                    self.db,
+                    module,
+                    &path,
+                    crate::item_scope::BuiltinShadowMode::Other,
+                    Some(MacroSubNs::Bang),
+                )
                 .0
                 .take_macros()
         });
@@ -1056,6 +1062,7 @@ impl ExprCollector<'_> {
                         self.expander.module.local_id,
                         &name.clone().into(),
                         BuiltinShadowMode::Other,
+                        None,
                     );
                     match resolved.take_values() {
                         Some(ModuleDefId::ConstId(_)) => (None, Pat::Path(name.into())),

crates/hir-def/src/data.rs

@@ -22,7 +22,7 @@ use crate::{
         attr_resolution::ResolvedAttr,
         diagnostics::DefDiagnostic,
         proc_macro::{parse_macro_name_and_helper_attrs, ProcMacroKind},
-        DefMap,
+        DefMap, MacroSubNs,
     },
     type_ref::{TraitRef, TypeBound, TypeRef},
     visibility::RawVisibility,
@@ -673,6 +673,7 @@ impl<'a> AssocItemCollector<'a> {
                             module,
                             &path,
                             crate::item_scope::BuiltinShadowMode::Other,
+                            Some(MacroSubNs::Bang),
                         )
                         .0
                         .take_macros()

crates/hir-def/src/find_path.rs

@@ -543,6 +543,7 @@ mod tests {
                 module.local_id,
                 &mod_path,
                 crate::item_scope::BuiltinShadowMode::Module,
+                None,
             )
             .0
             .take_types()

crates/hir-def/src/generics.rs

@@ -22,7 +22,7 @@ use crate::{
     dyn_map::{keys, DynMap},
     expander::Expander,
     lower::LowerCtx,
-    nameres::DefMap,
+    nameres::{DefMap, MacroSubNs},
     src::{HasChildSource, HasSource},
     type_ref::{LifetimeRef, TypeBound, TypeRef},
     AdtId, ConstParamId, GenericDefId, HasModule, LifetimeParamId, LocalLifetimeParamId,
@@ -361,6 +361,7 @@ impl GenericParams {
                             module,
                             &path,
                             crate::item_scope::BuiltinShadowMode::Other,
+                            Some(MacroSubNs::Bang),
                         )
                         .0
                         .take_macros()

crates/hir-def/src/macro_expansion_tests/builtin_fn_macro.rs

@@ -13,12 +13,12 @@ macro_rules! column {() => {}}
 
 fn main() { column!(); }
 "#,
-        expect![[r##"
+        expect![[r#"
 #[rustc_builtin_macro]
 macro_rules! column {() => {}}
 
-fn main() { 0; }
-"##]],
+fn main() { 0 as u32; }
+"#]],
     );
 }
 
@@ -31,12 +31,12 @@ macro_rules! line {() => {}}
 
 fn main() { line!() }
 "#,
-        expect![[r##"
+        expect![[r#"
 #[rustc_builtin_macro]
 macro_rules! line {() => {}}
 
-fn main() { 0 }
-"##]],
+fn main() { 0 as u32 }
+"#]],
     );
 }
 

crates/hir-def/src/macro_expansion_tests/mbe.rs

@@ -922,7 +922,7 @@ macro_rules! m {
 
 fn bar() -> &'a Baz<u8> {}
 
-fn bar() -> extern "Rust"fn() -> Ret {}
+fn bar() -> extern "Rust" fn() -> Ret {}
 "#]],
     );
 }
@@ -1333,7 +1333,7 @@ macro_rules! matches {
 }
 fn main() {
     match 0 {
-        0|1if true =>true , _=>false
+        0|1 if true =>true , _=>false
     };
 }
  "#]],

crates/hir-def/src/macro_expansion_tests/mbe/matching.rs

@@ -73,7 +73,7 @@ fn main() {
 macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
 
 fn main() {
-    let a = 2let b = 5drop(b-a)println!("{}", a+b)
+    let a = 2 let b = 5 drop(b-a)println!("{}", a+b)
 }
 "#]],
     )

crates/hir-def/src/macro_expansion_tests/mbe/regression.rs

@@ -297,55 +297,55 @@ macro_rules! impl_fn_for_zst  {
 
 #[derive(Clone)] struct CharEscapeDebugContinue;
 impl Fn<(char, )> for CharEscapeDebugContinue {
-    #[inline] extern "rust-call"fn call(&self , (c, ): (char, )) -> char::EscapeDebug { {
+    #[inline] extern "rust-call" fn call(&self , (c, ): (char, )) -> char::EscapeDebug { {
             c.escape_debug_ext(false )
         }
     }
 }
 impl FnMut<(char, )> for CharEscapeDebugContinue {
-    #[inline] extern "rust-call"fn call_mut(&mut self , (c, ): (char, )) -> char::EscapeDebug {
+    #[inline] extern "rust-call" fn call_mut(&mut self , (c, ): (char, )) -> char::EscapeDebug {
         Fn::call(&*self , (c, ))
     }
 }
 impl FnOnce<(char, )> for CharEscapeDebugContinue {
     type Output = char::EscapeDebug;
-    #[inline] extern "rust-call"fn call_once(self , (c, ): (char, )) -> char::EscapeDebug {
+    #[inline] extern "rust-call" fn call_once(self , (c, ): (char, )) -> char::EscapeDebug {
         Fn::call(&self , (c, ))
     }
 }
 #[derive(Clone)] struct CharEscapeUnicode;
 impl Fn<(char, )> for CharEscapeUnicode {
-    #[inline] extern "rust-call"fn call(&self , (c, ): (char, )) -> char::EscapeUnicode { {
+    #[inline] extern "rust-call" fn call(&self , (c, ): (char, )) -> char::EscapeUnicode { {
             c.escape_unicode()
         }
     }
 }
 impl FnMut<(char, )> for CharEscapeUnicode {
-    #[inline] extern "rust-call"fn call_mut(&mut self , (c, ): (char, )) -> char::EscapeUnicode {
+    #[inline] extern "rust-call" fn call_mut(&mut self , (c, ): (char, )) -> char::EscapeUnicode {
         Fn::call(&*self , (c, ))
     }
 }
 impl FnOnce<(char, )> for CharEscapeUnicode {
     type Output = char::EscapeUnicode;
-    #[inline] extern "rust-call"fn call_once(self , (c, ): (char, )) -> char::EscapeUnicode {
+    #[inline] extern "rust-call" fn call_once(self , (c, ): (char, )) -> char::EscapeUnicode {
         Fn::call(&self , (c, ))
     }
 }
 #[derive(Clone)] struct CharEscapeDefault;
 impl Fn<(char, )> for CharEscapeDefault {
-    #[inline] extern "rust-call"fn call(&self , (c, ): (char, )) -> char::EscapeDefault { {
+    #[inline] extern "rust-call" fn call(&self , (c, ): (char, )) -> char::EscapeDefault { {
             c.escape_default()
         }
     }
 }
 impl FnMut<(char, )> for CharEscapeDefault {
-    #[inline] extern "rust-call"fn call_mut(&mut self , (c, ): (char, )) -> char::EscapeDefault {
+    #[inline] extern "rust-call" fn call_mut(&mut self , (c, ): (char, )) -> char::EscapeDefault {
         Fn::call(&*self , (c, ))
     }
 }
 impl FnOnce<(char, )> for CharEscapeDefault {
     type Output = char::EscapeDefault;
-    #[inline] extern "rust-call"fn call_once(self , (c, ): (char, )) -> char::EscapeDefault {
+    #[inline] extern "rust-call" fn call_once(self , (c, ): (char, )) -> char::EscapeDefault {
         Fn::call(&self , (c, ))
     }
 }
@@ -833,7 +833,7 @@ macro_rules! rgb_color {
 /* parse error: expected SEMICOLON */
 /* parse error: expected expression, item or let statement */
 pub fn new() {
-    let _ = 0as u32<<(8+8);
+    let _ = 0 as u32<<(8+8);
 }
 // MACRO_ITEMS@0..31
 //   FN@0..31

crates/hir-def/src/macro_expansion_tests/mod.rs

@@ -33,8 +33,13 @@ use syntax::{
 use tt::token_id::{Subtree, TokenId};
 
 use crate::{
-    db::DefDatabase, macro_id_to_def_id, nameres::ModuleSource, resolver::HasResolver,
-    src::HasSource, test_db::TestDB, AdtId, AsMacroCall, Lookup, ModuleDefId,
+    db::DefDatabase,
+    macro_id_to_def_id,
+    nameres::{MacroSubNs, ModuleSource},
+    resolver::HasResolver,
+    src::HasSource,
+    test_db::TestDB,
+    AdtId, AsMacroCall, Lookup, ModuleDefId,
 };
 
 #[track_caller]
@@ -127,7 +132,9 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream
         let macro_call = InFile::new(source.file_id, &macro_call);
         let res = macro_call
             .as_call_id_with_errors(&db, krate, |path| {
-                resolver.resolve_path_as_macro(&db, &path).map(|it| macro_id_to_def_id(&db, it))
+                resolver
+                    .resolve_path_as_macro(&db, &path, Some(MacroSubNs::Bang))
+                    .map(|it| macro_id_to_def_id(&db, it))
             })
             .unwrap();
         let macro_call_id = res.value.unwrap();
@@ -280,6 +287,7 @@ fn pretty_print_macro_expansion(expn: SyntaxNode, map: Option<&TokenMap>) -> Str
         let curr_kind = token.kind();
         let space = match (prev_kind, curr_kind) {
             _ if prev_kind.is_trivia() || curr_kind.is_trivia() => "",
+            _ if prev_kind.is_literal() && !curr_kind.is_punct() => " ",
             (T!['{'], T!['}']) => "",
             (T![=], _) | (_, T![=]) => " ",
             (_, T!['{']) => " ",

crates/hir-def/src/nameres.rs

@@ -59,7 +59,7 @@ mod tests;
 
 use std::{cmp::Ord, ops::Deref};
 
-use base_db::{CrateId, Edition, FileId};
+use base_db::{CrateId, Edition, FileId, ProcMacroKind};
 use hir_expand::{name::Name, InFile, MacroCallId, MacroDefId};
 use itertools::Itertools;
 use la_arena::Arena;
@@ -77,7 +77,8 @@ use crate::{
     path::ModPath,
     per_ns::PerNs,
     visibility::Visibility,
-    AstId, BlockId, BlockLoc, FunctionId, LocalModuleId, MacroId, ModuleId, ProcMacroId,
+    AstId, BlockId, BlockLoc, FunctionId, LocalModuleId, Lookup, MacroExpander, MacroId, ModuleId,
+    ProcMacroId,
 };
 
 /// Contains the results of (early) name resolution.
@@ -105,6 +106,9 @@ pub struct DefMap {
     prelude: Option<ModuleId>,
     /// The extern prelude is only populated for non-block DefMaps
     extern_prelude: FxHashMap<Name, ModuleId>,
+    /// `macro_use` prelude that contains macros from `#[macro_use]`'d external crates. Note that
+    /// this contains all kinds of macro, not just `macro_rules!` macro.
+    macro_use_prelude: FxHashMap<Name, MacroId>,
 
     /// Side table for resolving derive helpers.
     exported_derives: FxHashMap<MacroDefId, Box<[Name]>>,
@@ -277,6 +281,7 @@ impl DefMap {
             edition,
             recursion_limit: None,
             extern_prelude: FxHashMap::default(),
+            macro_use_prelude: FxHashMap::default(),
             exported_derives: FxHashMap::default(),
             fn_proc_macro_mapping: FxHashMap::default(),
             proc_macro_loading_error: None,
@@ -376,9 +381,16 @@ impl DefMap {
         original_module: LocalModuleId,
         path: &ModPath,
         shadow: BuiltinShadowMode,
+        expected_macro_subns: Option<MacroSubNs>,
     ) -> (PerNs, Option<usize>) {
-        let res =
-            self.resolve_path_fp_with_macro(db, ResolveMode::Other, original_module, path, shadow);
+        let res = self.resolve_path_fp_with_macro(
+            db,
+            ResolveMode::Other,
+            original_module,
+            path,
+            shadow,
+            expected_macro_subns,
+        );
         (res.resolved_def, res.segment_index)
     }
 
@@ -395,6 +407,7 @@ impl DefMap {
             original_module,
             path,
             shadow,
+            None, // Currently this function isn't used for macro resolution.
         );
         (res.resolved_def, res.segment_index)
     }
@@ -489,6 +502,7 @@ impl DefMap {
             _c: _,
             exported_derives,
             extern_prelude,
+            macro_use_prelude,
             diagnostics,
             modules,
             registered_attrs,
@@ -507,6 +521,7 @@ impl DefMap {
         } = self;
 
         extern_prelude.shrink_to_fit();
+        macro_use_prelude.shrink_to_fit();
         exported_derives.shrink_to_fit();
         diagnostics.shrink_to_fit();
         modules.shrink_to_fit();
@@ -562,3 +577,48 @@ pub enum ModuleSource {
     Module(ast::Module),
     BlockExpr(ast::BlockExpr),
 }
+
+/// See `sub_namespace_match()`.
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub enum MacroSubNs {
+    /// Function-like macros, suffixed with `!`.
+    Bang,
+    /// Macros inside attributes, i.e. attribute macros and derive macros.
+    Attr,
+}
+
+impl MacroSubNs {
+    fn from_id(db: &dyn DefDatabase, macro_id: MacroId) -> Self {
+        let expander = match macro_id {
+            MacroId::Macro2Id(it) => it.lookup(db).expander,
+            MacroId::MacroRulesId(it) => it.lookup(db).expander,
+            MacroId::ProcMacroId(it) => {
+                return match it.lookup(db).kind {
+                    ProcMacroKind::CustomDerive | ProcMacroKind::Attr => Self::Attr,
+                    ProcMacroKind::FuncLike => Self::Bang,
+                };
+            }
+        };
+
+        // Eager macros aren't *guaranteed* to be bang macros, but they *are* all bang macros currently.
+        match expander {
+            MacroExpander::Declarative
+            | MacroExpander::BuiltIn(_)
+            | MacroExpander::BuiltInEager(_) => Self::Bang,
+            MacroExpander::BuiltInAttr(_) | MacroExpander::BuiltInDerive(_) => Self::Attr,
+        }
+    }
+}
+
+/// Quoted from [rustc]:
+/// Macro namespace is separated into two sub-namespaces, one for bang macros and
+/// one for attribute-like macros (attributes, derives).
+/// We ignore resolutions from one sub-namespace when searching names in scope for another.
+///
+/// [rustc]: https://github.com/rust-lang/rust/blob/1.69.0/compiler/rustc_resolve/src/macros.rs#L75
+fn sub_namespace_match(candidate: Option<MacroSubNs>, expected: Option<MacroSubNs>) -> bool {
+    match (candidate, expected) {
+        (Some(candidate), Some(expected)) => candidate == expected,
+        _ => true,
+    }
+}

crates/hir-def/src/nameres/attr_resolution.rs

@@ -14,7 +14,7 @@ use crate::{
     AstIdWithPath, LocalModuleId, UnresolvedMacro,
 };
 
-use super::DefMap;
+use super::{DefMap, MacroSubNs};
 
 pub enum ResolvedAttr {
     /// Attribute resolved to an attribute macro.
@@ -43,9 +43,12 @@ impl DefMap {
             original_module,
             &ast_id.path,
             BuiltinShadowMode::Module,
+            Some(MacroSubNs::Attr),
         );
         let def = match resolved_res.resolved_def.take_macros() {
             Some(def) => {
+                // `MacroSubNs` is just a hint, so the path may still resolve to a custom derive
+                // macro, or even function-like macro when the path is qualified.
                 if def.is_attribute(db) {
                     def
                 } else {