Add ra_ide_api::expand

This module should handle all tricky bits with mapping macro-expanded
HirFileId to original files the user actually can see in the editor

4 files changed, 69 insertions, 55 deletions

diff --git a/crates/ra_ide_api/src/display/navigation_target.rs b/crates/ra_ide_api/src/display/navigation_target.rs
index 4703cfaf7..291b5ee40 100644
--- a/crates/ra_ide_api/src/display/navigation_target.rs
+++ b/crates/ra_ide_api/src/display/navigation_target.rs
@@ -9,8 +9,9 @@ use ra_syntax::{
     SyntaxNode, TextRange,
 };
 
+use crate::{db::RootDatabase, expand::original_range, FileSymbol};
+
 use super::short_label::ShortLabel;
-use crate::{db::RootDatabase, FileSymbol};
 
 /// `NavigationTarget` represents and element in the editor's UI which you can
 /// click on to navigate to a particular piece of code.
@@ -79,13 +80,12 @@ impl NavigationTarget {
     pub(crate) fn from_module_to_decl(db: &RootDatabase, module: hir::Module) -> NavigationTarget {
         let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
         if let Some(src) = module.declaration_source(db) {
-            let (file_id, text_range) =
-                find_range_from_node(db, src.as_ref().map(|it| it.syntax()));
+            let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
             return NavigationTarget::from_syntax(
-                file_id,
+                frange.file_id,
                 name,
                 None,
-                text_range,
+                frange.range,
                 src.ast.syntax(),
                 src.ast.doc_comment_text(),
                 src.ast.short_label(),
@@ -149,14 +149,14 @@ impl NavigationTarget {
         //FIXME: use `_` instead of empty string
         let name = node.name().map(|it| it.text().clone()).unwrap_or_default();
         let focus_range =
-            node.name().map(|it| find_range_from_node(db, Source::new(file_id, it.syntax())).1);
-        let (file_id, full_range) = find_range_from_node(db, Source::new(file_id, node.syntax()));
+            node.name().map(|it| original_range(db, Source::new(file_id, it.syntax())).range);
+        let frange = original_range(db, Source::new(file_id, node.syntax()));
 
         NavigationTarget::from_syntax(
-            file_id,
+            frange.file_id,
             name,
             focus_range,
-            full_range,
+            frange.range,
             node.syntax(),
             docs,
             description,
@@ -234,26 +234,26 @@ impl ToNav for hir::Module {
         let name = self.name(db).map(|it| it.to_string().into()).unwrap_or_default();
         match &src.ast {
             ModuleSource::SourceFile(node) => {
-                let (file_id, text_range) = find_range_from_node(db, src.with_ast(node.syntax()));
+                let frange = original_range(db, src.with_ast(node.syntax()));
 
                 NavigationTarget::from_syntax(
-                    file_id,
+                    frange.file_id,
                     name,
                     None,
-                    text_range,
+                    frange.range,
                     node.syntax(),
                     None,
                     None,
                 )
             }
             ModuleSource::Module(node) => {
-                let (file_id, text_range) = find_range_from_node(db, src.with_ast(node.syntax()));
+                let frange = original_range(db, src.with_ast(node.syntax()));
 
                 NavigationTarget::from_syntax(
-                    file_id,
+                    frange.file_id,
                     name,
                     None,
-                    text_range,
+                    frange.range,
                     node.syntax(),
                     node.doc_comment_text(),
                     node.short_label(),
@@ -266,13 +266,13 @@ impl ToNav for hir::Module {
 impl ToNav for hir::ImplBlock {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
-        let (file_id, text_range) = find_range_from_node(db, src.as_ref().map(|it| it.syntax()));
+        let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
 
         NavigationTarget::from_syntax(
-            file_id,
+            frange.file_id,
             "impl".into(),
             None,
-            text_range,
+            frange.range,
             src.ast.syntax(),
             None,
             None,
@@ -293,12 +293,12 @@ impl ToNav for hir::StructField {
                 it.short_label(),
             ),
             FieldSource::Pos(it) => {
-                let (file_id, text_range) = find_range_from_node(db, src.with_ast(it.syntax()));
+                let frange = original_range(db, src.with_ast(it.syntax()));
                 NavigationTarget::from_syntax(
-                    file_id,
+                    frange.file_id,
                     "".into(),
                     None,
-                    text_range,
+                    frange.range,
                     it.syntax(),
                     None,
                     None,
@@ -362,18 +362,6 @@ impl ToNav for hir::Local {
     }
 }
 
-fn find_range_from_node(db: &RootDatabase, node: Source<&SyntaxNode>) -> (FileId, TextRange) {
-    let text_range = node.ast.text_range();
-    let (file_id, text_range) = node
-        .file_id
-        .expansion_info(db)
-        .and_then(|expansion_info| expansion_info.find_range(text_range))
-        .unwrap_or((node.file_id, text_range));
-
-    // FIXME: handle recursive macro generated macro
-    (file_id.original_file(db), text_range)
-}
-
 pub(crate) fn docs_from_symbol(db: &RootDatabase, symbol: &FileSymbol) -> Option<String> {
     let parse = db.parse(symbol.file_id);
     let node = symbol.ptr.to_node(parse.tree().syntax());
diff --git a/crates/ra_ide_api/src/expand.rs b/crates/ra_ide_api/src/expand.rs
new file mode 100644
index 000000000..5f1fb9a12
--- /dev/null
+++ b/crates/ra_ide_api/src/expand.rs
@@ -0,0 +1,42 @@
+//! Utilities to work with files, produced by macros.
+use std::iter::successors;
+
+use hir::Source;
+use ra_db::FileId;
+use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxToken};
+
+use crate::{db::RootDatabase, FileRange};
+
+pub(crate) fn original_range(db: &RootDatabase, node: Source<&SyntaxNode>) -> FileRange {
+    let text_range = node.ast.text_range();
+    let (file_id, range) = node
+        .file_id
+        .expansion_info(db)
+        .and_then(|expansion_info| expansion_info.find_range(text_range))
+        .unwrap_or((node.file_id, text_range));
+
+    // FIXME: handle recursive macro generated macro
+    FileRange { file_id: file_id.original_file(db), range }
+}
+
+pub(crate) fn descend_into_macros(
+    db: &RootDatabase,
+    file_id: FileId,
+    token: SyntaxToken,
+) -> Source<SyntaxToken> {
+    let src = Source::new(file_id.into(), token);
+
+    successors(Some(src), |token| {
+        let macro_call = token.ast.ancestors().find_map(ast::MacroCall::cast)?;
+        let tt = macro_call.token_tree()?;
+        if !token.ast.text_range().is_subrange(&tt.syntax().text_range()) {
+            return None;
+        }
+        let source_analyzer =
+            hir::SourceAnalyzer::new(db, token.with_ast(token.ast.parent()).as_ref(), None);
+        let exp = source_analyzer.expand(db, &macro_call)?;
+        exp.map_token_down(db, token.as_ref())
+    })
+    .last()
+    .unwrap()
+}
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index b693a4c31..1a8db0ea0 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -1,16 +1,15 @@
 //! FIXME: write short doc here
 
-use std::iter::successors;
-
 use hir::{db::AstDatabase, Source};
 use ra_syntax::{
     ast::{self, DocCommentsOwner},
-    match_ast, AstNode, SyntaxNode, SyntaxToken,
+    match_ast, AstNode, SyntaxNode,
 };
 
 use crate::{
     db::RootDatabase,
     display::{ShortLabel, ToNav},
+    expand::descend_into_macros,
     references::{classify_name_ref, NameKind::*},
     FilePosition, NavigationTarget, RangeInfo,
 };
@@ -19,7 +18,9 @@ pub(crate) fn goto_definition(
     db: &RootDatabase,
     position: FilePosition,
 ) -> Option<RangeInfo<Vec<NavigationTarget>>> {
-    let token = descend_into_macros(db, position)?;
+    let file = db.parse_or_expand(position.file_id.into())?;
+    let token = file.token_at_offset(position.offset).filter(|it| !it.kind().is_trivia()).next()?;
+    let token = descend_into_macros(db, position.file_id, token);
 
     let res = match_ast! {
         match (token.ast.parent()) {
@@ -39,24 +40,6 @@ pub(crate) fn goto_definition(
     Some(res)
 }
 
-fn descend_into_macros(db: &RootDatabase, position: FilePosition) -> Option<Source<SyntaxToken>> {
-    let file = db.parse_or_expand(position.file_id.into())?;
-    let token = file.token_at_offset(position.offset).filter(|it| !it.kind().is_trivia()).next()?;
-
-    successors(Some(Source::new(position.file_id.into(), token)), |token| {
-        let macro_call = token.ast.ancestors().find_map(ast::MacroCall::cast)?;
-        let tt = macro_call.token_tree()?;
-        if !token.ast.text_range().is_subrange(&tt.syntax().text_range()) {
-            return None;
-        }
-        let source_analyzer =
-            hir::SourceAnalyzer::new(db, token.with_ast(token.ast.parent()).as_ref(), None);
-        let exp = source_analyzer.expand(db, &macro_call)?;
-        exp.map_token_down(db, token.as_ref())
-    })
-    .last()
-}
-
 #[derive(Debug)]
 pub(crate) enum ReferenceResult {
     Exact(NavigationTarget),
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 484fbcc82..110ddcd62 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -41,6 +41,7 @@ mod matching_brace;
 mod display;
 mod inlay_hints;
 mod wasm_shims;
+mod expand;
 
 #[cfg(test)]
 mod marks;