1 files changed, 146 insertions, 0 deletions

diff --git a/crates/ra_analysis/src/descriptors/module/imp.rs b/crates/ra_analysis/src/descriptors/module/imp.rs
new file mode 100644
index 000000000..22e4bd785
--- /dev/null
+++ b/crates/ra_analysis/src/descriptors/module/imp.rs
@@ -0,0 +1,146 @@
+use std::sync::Arc;
+
+use relative_path::RelativePathBuf;
+use rustc_hash::{FxHashMap, FxHashSet};
+use ra_syntax::{
+    SmolStr,
+    ast::{self, NameOwner},
+};
+
+use crate::{
+    FileId, Cancelable, FileResolverImp,
+    db,
+};
+
+use super::{
+    ModuleData, ModuleTree, ModuleId, LinkId, LinkData, Problem, ModulesDatabase
+};
+
+
+pub(super) fn submodules(db: &impl ModulesDatabase, file_id: FileId) -> Cancelable<Arc<Vec<SmolStr>>> {
+    db::check_canceled(db)?;
+    let file = db.file_syntax(file_id);
+    let root = file.ast();
+    let submodules = modules(root).map(|(name, _)| name).collect();
+    Ok(Arc::new(submodules))
+}
+
+pub(super) fn modules(root: ast::Root<'_>) -> impl Iterator<Item = (SmolStr, ast::Module<'_>)> {
+    root.modules().filter_map(|module| {
+        let name = module.name()?.text();
+        if !module.has_semi() {
+            return None;
+        }
+        Some((name, module))
+    })
+}
+
+pub(super) fn module_tree(db: &impl ModulesDatabase) -> Cancelable<Arc<ModuleTree>> {
+    db::check_canceled(db)?;
+    let res = create_module_tree(db)?;
+    Ok(Arc::new(res))
+}
+
+
+#[derive(Clone, Hash, PartialEq, Eq, Debug)]
+pub struct Submodule {
+    pub name: SmolStr,
+}
+
+
+fn create_module_tree<'a>(
+    db: &impl ModulesDatabase,
+) -> Cancelable<ModuleTree> {
+    let mut tree = ModuleTree {
+        mods: Vec::new(),
+        links: Vec::new(),
+    };
+
+    let mut roots = FxHashMap::default();
+    let mut visited = FxHashSet::default();
+
+    for &file_id in db.file_set().files.iter() {
+        if visited.contains(&file_id) {
+            continue; // TODO: use explicit crate_roots here
+        }
+        assert!(!roots.contains_key(&file_id));
+        let module_id = build_subtree(db, &mut tree, &mut visited, &mut roots, None, file_id)?;
+        roots.insert(file_id, module_id);
+    }
+    Ok(tree)
+}
+
+fn build_subtree(
+    db: &impl ModulesDatabase,
+    tree: &mut ModuleTree,
+    visited: &mut FxHashSet<FileId>,
+    roots: &mut FxHashMap<FileId, ModuleId>,
+    parent: Option<LinkId>,
+    file_id: FileId,
+) -> Cancelable<ModuleId> {
+    visited.insert(file_id);
+    let id = tree.push_mod(ModuleData {
+        file_id,
+        parent,
+        children: Vec::new(),
+    });
+    let file_set = db.file_set();
+    let file_resolver = &file_set.resolver;
+    for name in db.submodules(file_id)?.iter() {
+        let (points_to, problem) = resolve_submodule(file_id, name, file_resolver);
+        let link = tree.push_link(LinkData {
+            name: name.clone(),
+            owner: id,
+            points_to: Vec::new(),
+            problem: None,
+        });
+
+        let points_to = points_to
+            .into_iter()
+            .map(|file_id| match roots.remove(&file_id) {
+                Some(module_id) => {
+                    tree.module_mut(module_id).parent = Some(link);
+                    Ok(module_id)
+                }
+                None => build_subtree(db, tree, visited, roots, Some(link), file_id),
+            })
+            .collect::<Cancelable<Vec<_>>>()?;
+        tree.link_mut(link).points_to = points_to;
+        tree.link_mut(link).problem = problem;
+    }
+    Ok(id)
+}
+
+fn resolve_submodule(
+    file_id: FileId,
+    name: &SmolStr,
+    file_resolver: &FileResolverImp,
+) -> (Vec<FileId>, Option<Problem>) {
+    let mod_name = file_resolver.file_stem(file_id);
+    let is_dir_owner = mod_name == "mod" || mod_name == "lib" || mod_name == "main";
+
+    let file_mod = RelativePathBuf::from(format!("../{}.rs", name));
+    let dir_mod = RelativePathBuf::from(format!("../{}/mod.rs", name));
+    let points_to: Vec<FileId>;
+    let problem: Option<Problem>;
+    if is_dir_owner {
+        points_to = [&file_mod, &dir_mod]
+            .iter()
+            .filter_map(|path| file_resolver.resolve(file_id, path))
+            .collect();
+        problem = if points_to.is_empty() {
+            Some(Problem::UnresolvedModule {
+                candidate: file_mod,
+            })
+        } else {
+            None
+        }
+    } else {
+        points_to = Vec::new();
+        problem = Some(Problem::NotDirOwner {
+            move_to: RelativePathBuf::from(format!("../{}/mod.rs", mod_name)),
+            candidate: file_mod,
+        });
+    }
+    (points_to, problem)
+}