Auto merge of rust-lang#15251 - Veykril:builtin-expand, r=Veykril

Skip building subtrees for builtin derives

This is a waste of resources, we go from node to subtree just to go from subtree to node in the expander impl. We can skip the subtree building and only build the tokenmap instead.

Author: bors

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

@@ -20,8 +20,8 @@ use ::mbe::TokenMap;
 use base_db::{fixture::WithFixture, ProcMacro, SourceDatabase};
 use expect_test::Expect;
 use hir_expand::{
-    db::{ExpandDatabase, TokenExpander},
-    AstId, InFile, MacroDefId, MacroDefKind, MacroFile,
+    db::{DeclarativeMacroExpander, ExpandDatabase},
+    AstId, InFile, MacroFile,
 };
 use stdx::format_to;
 use syntax::{
@@ -100,32 +100,29 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream
         let call_offset = macro_.syntax().text_range().start().into();
         let file_ast_id = db.ast_id_map(source.file_id).ast_id(&macro_);
         let ast_id = AstId::new(source.file_id, file_ast_id.upcast());
-        let kind = MacroDefKind::Declarative(ast_id);
 
-        let macro_def = db
-            .macro_def(MacroDefId { krate, kind, local_inner: false, allow_internal_unsafe: false })
-            .unwrap();
-        if let TokenExpander::DeclarativeMacro { mac, def_site_token_map } = &*macro_def {
-            let tt = match &macro_ {
-                ast::Macro::MacroRules(mac) => mac.token_tree().unwrap(),
-                ast::Macro::MacroDef(_) => unimplemented!(""),
-            };
+        let DeclarativeMacroExpander { mac, def_site_token_map } =
+            &*db.decl_macro_expander(krate, ast_id);
+        assert_eq!(mac.err(), None);
+        let tt = match &macro_ {
+            ast::Macro::MacroRules(mac) => mac.token_tree().unwrap(),
+            ast::Macro::MacroDef(_) => unimplemented!(""),
+        };
 
-            let tt_start = tt.syntax().text_range().start();
-            tt.syntax().descendants_with_tokens().filter_map(SyntaxElement::into_token).for_each(
-                |token| {
-                    let range = token.text_range().checked_sub(tt_start).unwrap();
-                    if let Some(id) = def_site_token_map.token_by_range(range) {
-                        let offset = (range.end() + tt_start).into();
-                        text_edits.push((offset..offset, format!("#{}", id.0)));
-                    }
-                },
-            );
-            text_edits.push((
-                call_offset..call_offset,
-                format!("// call ids will be shifted by {:?}\n", mac.shift()),
-            ));
-        }
+        let tt_start = tt.syntax().text_range().start();
+        tt.syntax().descendants_with_tokens().filter_map(SyntaxElement::into_token).for_each(
+            |token| {
+                let range = token.text_range().checked_sub(tt_start).unwrap();
+                if let Some(id) = def_site_token_map.token_by_range(range) {
+                    let offset = (range.end() + tt_start).into();
+                    text_edits.push((offset..offset, format!("#{}", id.0)));
+                }
+            },
+        );
+        text_edits.push((
+            call_offset..call_offset,
+            format!("// call ids will be shifted by {:?}\n", mac.shift()),
+        ));
     }
 
     for macro_call in source_file.syntax().descendants().filter_map(ast::MacroCall::cast) {

crates/hir-expand/src/builtin_derive_macro.rs

@@ -12,9 +12,7 @@ use crate::{
     name::{AsName, Name},
     tt::{self, TokenId},
 };
-use syntax::ast::{
-    self, AstNode, FieldList, HasAttrs, HasGenericParams, HasModuleItem, HasName, HasTypeBounds,
-};
+use syntax::ast::{self, AstNode, FieldList, HasAttrs, HasGenericParams, HasName, HasTypeBounds};
 
 use crate::{db::ExpandDatabase, name, quote, ExpandError, ExpandResult, MacroCallId};
 
@@ -30,12 +28,13 @@ macro_rules! register_builtin {
                 &self,
                 db: &dyn ExpandDatabase,
                 id: MacroCallId,
-                tt: &tt::Subtree,
+                tt: &ast::Adt,
+                token_map: &TokenMap,
             ) -> ExpandResult<tt::Subtree> {
                 let expander = match *self {
                     $( BuiltinDeriveExpander::$trait => $expand, )*
                 };
-                expander(db, id, tt)
+                expander(db, id, tt, token_map)
             }
 
             fn find_by_name(name: &name::Name) -> Option<Self> {
@@ -118,13 +117,13 @@ impl VariantShape {
         }
     }
 
-    fn from(value: Option<FieldList>, token_map: &TokenMap) -> Result<Self, ExpandError> {
+    fn from(tm: &TokenMap, value: Option<FieldList>) -> Result<Self, ExpandError> {
         let r = match value {
             None => VariantShape::Unit,
             Some(FieldList::RecordFieldList(it)) => VariantShape::Struct(
                 it.fields()
                     .map(|it| it.name())
-                    .map(|it| name_to_token(token_map, it))
+                    .map(|it| name_to_token(tm, it))
                     .collect::<Result<_, _>>()?,
             ),
             Some(FieldList::TupleFieldList(it)) => VariantShape::Tuple(it.fields().count()),
@@ -190,25 +189,12 @@ struct BasicAdtInfo {
     associated_types: Vec<tt::Subtree>,
 }
 
-fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
-    let (parsed, token_map) = mbe::token_tree_to_syntax_node(tt, mbe::TopEntryPoint::MacroItems);
-    let macro_items = ast::MacroItems::cast(parsed.syntax_node()).ok_or_else(|| {
-        debug!("derive node didn't parse");
-        ExpandError::other("invalid item definition")
-    })?;
-    let item = macro_items.items().next().ok_or_else(|| {
-        debug!("no module item parsed");
-        ExpandError::other("no item found")
-    })?;
-    let adt = ast::Adt::cast(item.syntax().clone()).ok_or_else(|| {
-        debug!("expected adt, found: {:?}", item);
-        ExpandError::other("expected struct, enum or union")
-    })?;
+fn parse_adt(tm: &TokenMap, adt: &ast::Adt) -> Result<BasicAdtInfo, ExpandError> {
     let (name, generic_param_list, shape) = match &adt {
         ast::Adt::Struct(it) => (
             it.name(),
             it.generic_param_list(),
-            AdtShape::Struct(VariantShape::from(it.field_list(), &token_map)?),
+            AdtShape::Struct(VariantShape::from(tm, it.field_list())?),
         ),
         ast::Adt::Enum(it) => {
             let default_variant = it
@@ -227,8 +213,8 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
                         .flat_map(|it| it.variants())
                         .map(|it| {
                             Ok((
-                                name_to_token(&token_map, it.name())?,
-                                VariantShape::from(it.field_list(), &token_map)?,
+                                name_to_token(tm, it.name())?,
+                                VariantShape::from(tm, it.field_list())?,
                             ))
                         })
                         .collect::<Result<_, ExpandError>>()?,
@@ -298,7 +284,7 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
         })
         .map(|it| mbe::syntax_node_to_token_tree(it.syntax()).0)
         .collect();
-    let name_token = name_to_token(&token_map, name)?;
+    let name_token = name_to_token(&tm, name)?;
     Ok(BasicAdtInfo { name: name_token, shape, param_types, associated_types })
 }
 
@@ -345,11 +331,12 @@ fn name_to_token(token_map: &TokenMap, name: Option<ast::Name>) -> Result<tt::Id
 /// where B1, ..., BN are the bounds given by `bounds_paths`. Z is a phantom type, and
 /// therefore does not get bound by the derived trait.
 fn expand_simple_derive(
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
     trait_path: tt::Subtree,
     make_trait_body: impl FnOnce(&BasicAdtInfo) -> tt::Subtree,
 ) -> ExpandResult<tt::Subtree> {
-    let info = match parse_adt(tt) {
+    let info = match parse_adt(tm, tt) {
         Ok(info) => info,
         Err(e) => return ExpandResult::new(tt::Subtree::empty(), e),
     };
@@ -405,19 +392,21 @@ fn find_builtin_crate(db: &dyn ExpandDatabase, id: MacroCallId) -> tt::TokenTree
 fn copy_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::marker::Copy }, |_| quote! {})
+    expand_simple_derive(tt, tm, quote! { #krate::marker::Copy }, |_| quote! {})
 }
 
 fn clone_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::clone::Clone }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::clone::Clone }, |adt| {
         if matches!(adt.shape, AdtShape::Union) {
             let star = tt::Punct {
                 char: '*',
@@ -479,10 +468,11 @@ fn and_and() -> ::tt::Subtree<TokenId> {
 fn default_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = &find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::default::Default }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::default::Default }, |adt| {
         let body = match &adt.shape {
             AdtShape::Struct(fields) => {
                 let name = &adt.name;
@@ -518,10 +508,11 @@ fn default_expand(
 fn debug_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = &find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::fmt::Debug }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::fmt::Debug }, |adt| {
         let for_variant = |name: String, v: &VariantShape| match v {
             VariantShape::Struct(fields) => {
                 let for_fields = fields.iter().map(|it| {
@@ -598,10 +589,11 @@ fn debug_expand(
 fn hash_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = &find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::hash::Hash }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::hash::Hash }, |adt| {
         if matches!(adt.shape, AdtShape::Union) {
             // FIXME: Return expand error here
             return quote! {};
@@ -646,19 +638,21 @@ fn hash_expand(
 fn eq_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::cmp::Eq }, |_| quote! {})
+    expand_simple_derive(tt, tm, quote! { #krate::cmp::Eq }, |_| quote! {})
 }
 
 fn partial_eq_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::cmp::PartialEq }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::cmp::PartialEq }, |adt| {
         if matches!(adt.shape, AdtShape::Union) {
             // FIXME: Return expand error here
             return quote! {};
@@ -722,10 +716,11 @@ fn self_and_other_patterns(
 fn ord_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = &find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::cmp::Ord }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::cmp::Ord }, |adt| {
         fn compare(
             krate: &tt::TokenTree,
             left: tt::Subtree,
@@ -786,10 +781,11 @@ fn ord_expand(
 fn partial_ord_expand(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-    tt: &tt::Subtree,
+    tt: &ast::Adt,
+    tm: &TokenMap,
 ) -> ExpandResult<tt::Subtree> {
     let krate = &find_builtin_crate(db, id);
-    expand_simple_derive(tt, quote! { #krate::cmp::PartialOrd }, |adt| {
+    expand_simple_derive(tt, tm, quote! { #krate::cmp::PartialOrd }, |adt| {
         fn compare(
             krate: &tt::TokenTree,
             left: tt::Subtree,