Don't search for root nodes unnecessarily

[rust.git] / crates / hir_expand / src / lib.rs

diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index ee9a65b2669286479c56ad47b41249434b73dad0..97436446729250640024d9b0349daceef4033af0 100644 (file)
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -18,15 +18,15 @@
 use base_db::ProcMacroKind;
 use either::Either;
 
-pub use mbe::{ExpandError, ExpandResult};
+pub use mbe::{ExpandError, ExpandResult, Origin};
 
 use std::{hash::Hash, iter, sync::Arc};
 
 use base_db::{impl_intern_key, salsa, CrateId, FileId, FileRange};
 use syntax::{
-    algo::skip_trivia_token,
+    algo::{self, skip_trivia_token},
     ast::{self, AstNode, HasAttrs},
-    Direction, SyntaxNode, SyntaxToken, TextRange,
+    Direction, SyntaxNode, SyntaxToken,
 };
 
 use crate::{
@@ -38,9 +38,6 @@
     proc_macro::ProcMacroExpander,
 };
 
-#[cfg(test)]
-mod test_db;
-
 /// Input to the analyzer is a set of files, where each file is identified by
 /// `FileId` and contains source code. However, another source of source code in
 /// Rust are macros: each macro can be thought of as producing a "temporary
@@ -309,6 +306,13 @@ pub fn ast_id(&self) -> Either<AstId<ast::Macro>, AstId<ast::Fn>> {
     pub fn is_proc_macro(&self) -> bool {
         matches!(self.kind, MacroDefKind::ProcMacro(..))
     }
+
+    pub fn is_attribute(&self) -> bool {
+        matches!(
+            self.kind,
+            MacroDefKind::BuiltInAttr(..) | MacroDefKind::ProcMacro(_, ProcMacroKind::Attr, _)
+        )
+    }
 }
 
 // FIXME: attribute indices do not account for `cfg_attr`, which means that we'll strip the whole
@@ -376,9 +380,11 @@ pub struct ExpansionInfo {
     exp_map: Arc<mbe::TokenMap>,
 }
 
-pub use mbe::Origin;
-
 impl ExpansionInfo {
+    pub fn expanded(&self) -> InFile<SyntaxNode> {
+        self.expanded.clone()
+    }
+
     pub fn call_node(&self) -> Option<InFile<SyntaxNode>> {
         Some(self.arg.with_value(self.arg.value.parent()?))
     }
@@ -596,13 +602,15 @@ pub fn original_file_range(self, db: &dyn db::AstDatabase) -> FileRange {
 
     /// Attempts to map the syntax node back up its macro calls.
     pub fn original_file_range_opt(self, db: &dyn db::AstDatabase) -> Option<FileRange> {
-        match original_range_opt(db, self) {
-            Some(range) => {
-                let original_file = range.file_id.original_file(db);
-                if range.file_id != original_file.into() {
+        match ascend_node_border_tokens(db, self) {
+            Some(InFile { file_id, value: (first, last) }) => {
+                let original_file = file_id.original_file(db);
+                let range = first.text_range().cover(last.text_range());
+                if file_id != original_file.into() {
                     tracing::error!("Failed mapping up more for {:?}", range);
+                    return None;
                 }
-                Some(FileRange { file_id: original_file, range: range.value })
+                Some(FileRange { file_id: original_file, range })
             }
             _ if !self.file_id.is_macro() => Some(FileRange {
                 file_id: self.file_id.original_file(db),
@@ -613,28 +621,29 @@ pub fn original_file_range_opt(self, db: &dyn db::AstDatabase) -> Option<FileRan
     }
 }
 
-fn original_range_opt(
+fn ascend_node_border_tokens(
     db: &dyn db::AstDatabase,
-    node: InFile<&SyntaxNode>,
-) -> Option<InFile<TextRange>> {
-    let expansion = node.file_id.expansion_info(db)?;
+    InFile { file_id, value: node }: InFile<&SyntaxNode>,
+) -> Option<InFile<(SyntaxToken, SyntaxToken)>> {
+    let expansion = file_id.expansion_info(db)?;
 
     // the input node has only one token ?
-    let single = skip_trivia_token(node.value.first_token()?, Direction::Next)?
-        == skip_trivia_token(node.value.last_token()?, Direction::Prev)?;
+    let first = skip_trivia_token(node.first_token()?, Direction::Next)?;
+    let last = skip_trivia_token(node.last_token()?, Direction::Prev)?;
+    let is_single_token = first == last;
 
-    node.value.descendants().find_map(|it| {
+    node.descendants().find_map(|it| {
         let first = skip_trivia_token(it.first_token()?, Direction::Next)?;
-        let first = ascend_call_token(db, &expansion, node.with_value(first))?;
+        let first = ascend_call_token(db, &expansion, InFile::new(file_id, first))?;
 
         let last = skip_trivia_token(it.last_token()?, Direction::Prev)?;
-        let last = ascend_call_token(db, &expansion, node.with_value(last))?;
+        let last = ascend_call_token(db, &expansion, InFile::new(file_id, last))?;
 
-        if (!single && first == last) || (first.file_id != last.file_id) {
+        if (!is_single_token && first == last) || (first.file_id != last.file_id) {
             return None;
         }
 
-        Some(first.with_value(first.value.text_range().cover(last.value.text_range())))
+        Some(InFile::new(first.file_id, (first.value, last.value)))
     })
 }
 
@@ -670,6 +679,23 @@ pub fn descendants<T: AstNode>(self) -> impl Iterator<Item = InFile<T>> {
         self.value.syntax().descendants().filter_map(T::cast).map(move |n| self.with_value(n))
     }
 
+    pub fn original_ast_node(self, db: &dyn db::AstDatabase) -> Option<InFile<N>> {
+        match ascend_node_border_tokens(db, self.syntax()) {
+            Some(InFile { file_id, value: (first, last) }) => {
+                let original_file = file_id.original_file(db);
+                if file_id != original_file.into() {
+                    let range = first.text_range().cover(last.text_range());
+                    tracing::error!("Failed mapping up more for {:?}", range);
+                    return None;
+                }
+                let anc = algo::least_common_ancestor(&first.parent()?, &last.parent()?)?;
+                Some(InFile::new(file_id, anc.ancestors().find_map(N::cast)?))
+            }
+            _ if !self.file_id.is_macro() => Some(self),
+            _ => None,
+        }
+    }
+
     pub fn syntax(&self) -> InFile<&SyntaxNode> {
         self.with_value(self.value.syntax())
     }