2 files changed, 148 insertions, 0 deletions

diff --git a/crates/ra_ide_db/src/lib.rs b/crates/ra_ide_db/src/lib.rs
index aa312c140..79f48c9e3 100644
--- a/crates/ra_ide_db/src/lib.rs
+++ b/crates/ra_ide_db/src/lib.rs
@@ -9,6 +9,7 @@ pub mod feature_flags;
 pub mod symbol_index;
 pub mod change;
 pub mod defs;
+pub mod search;
 pub mod imports_locator;
 mod wasm_shims;
 
diff --git a/crates/ra_ide_db/src/search.rs b/crates/ra_ide_db/src/search.rs
new file mode 100644
index 000000000..add63b870
--- /dev/null
+++ b/crates/ra_ide_db/src/search.rs
@@ -0,0 +1,147 @@
+//! Generally, `search_scope` returns files that might contain references for the element.
+//! For `pub(crate)` things it's a crate, for `pub` things it's a crate and dependant crates.
+//! In some cases, the location of the references is known to within a `TextRange`,
+//! e.g. for things like local variables.
+use std::mem;
+
+use hir::{DefWithBody, HasSource, ModuleSource};
+use ra_db::{FileId, SourceDatabaseExt};
+use ra_prof::profile;
+use ra_syntax::{AstNode, TextRange};
+use rustc_hash::FxHashMap;
+
+use crate::{defs::Definition, RootDatabase};
+
+pub struct SearchScope {
+    entries: FxHashMap<FileId, Option<TextRange>>,
+}
+
+impl SearchScope {
+    fn new(entries: FxHashMap<FileId, Option<TextRange>>) -> SearchScope {
+        SearchScope { entries }
+    }
+
+    pub fn empty() -> SearchScope {
+        SearchScope::new(FxHashMap::default())
+    }
+
+    pub fn single_file(file: FileId) -> SearchScope {
+        SearchScope::new(std::iter::once((file, None)).collect())
+    }
+
+    pub fn for_def(def: &Definition, db: &RootDatabase) -> SearchScope {
+        let _p = profile("search_scope");
+        let module = match def.module(db) {
+            Some(it) => it,
+            None => return SearchScope::empty(),
+        };
+        let module_src = module.definition_source(db);
+        let file_id = module_src.file_id.original_file(db);
+
+        if let Definition::Local(var) = def {
+            let range = match var.parent(db) {
+                DefWithBody::Function(f) => f.source(db).value.syntax().text_range(),
+                DefWithBody::Const(c) => c.source(db).value.syntax().text_range(),
+                DefWithBody::Static(s) => s.source(db).value.syntax().text_range(),
+            };
+            let mut res = FxHashMap::default();
+            res.insert(file_id, Some(range));
+            return SearchScope::new(res);
+        }
+
+        let vis = def.visibility(db).as_ref().map(|v| v.syntax().to_string()).unwrap_or_default();
+
+        if vis.as_str() == "pub(super)" {
+            if let Some(parent_module) = module.parent(db) {
+                let mut res = FxHashMap::default();
+                let parent_src = parent_module.definition_source(db);
+                let file_id = parent_src.file_id.original_file(db);
+
+                match parent_src.value {
+                    ModuleSource::Module(m) => {
+                        let range = Some(m.syntax().text_range());
+                        res.insert(file_id, range);
+                    }
+                    ModuleSource::SourceFile(_) => {
+                        res.insert(file_id, None);
+                        res.extend(parent_module.children(db).map(|m| {
+                            let src = m.definition_source(db);
+                            (src.file_id.original_file(db), None)
+                        }));
+                    }
+                }
+                return SearchScope::new(res);
+            }
+        }
+
+        if vis.as_str() != "" {
+            let source_root_id = db.file_source_root(file_id);
+            let source_root = db.source_root(source_root_id);
+            let mut res = source_root.walk().map(|id| (id, None)).collect::<FxHashMap<_, _>>();
+
+            // FIXME: add "pub(in path)"
+
+            if vis.as_str() == "pub(crate)" {
+                return SearchScope::new(res);
+            }
+            if vis.as_str() == "pub" {
+                let krate = module.krate();
+                for rev_dep in krate.reverse_dependencies(db) {
+                    let root_file = rev_dep.root_file(db);
+                    let source_root_id = db.file_source_root(root_file);
+                    let source_root = db.source_root(source_root_id);
+                    res.extend(source_root.walk().map(|id| (id, None)));
+                }
+                return SearchScope::new(res);
+            }
+        }
+
+        let mut res = FxHashMap::default();
+        let range = match module_src.value {
+            ModuleSource::Module(m) => Some(m.syntax().text_range()),
+            ModuleSource::SourceFile(_) => None,
+        };
+        res.insert(file_id, range);
+        SearchScope::new(res)
+    }
+
+    pub fn intersection(&self, other: &SearchScope) -> SearchScope {
+        let (mut small, mut large) = (&self.entries, &other.entries);
+        if small.len() > large.len() {
+            mem::swap(&mut small, &mut large)
+        }
+
+        let res = small
+            .iter()
+            .filter_map(|(file_id, r1)| {
+                let r2 = large.get(file_id)?;
+                let r = intersect_ranges(*r1, *r2)?;
+                Some((*file_id, r))
+            })
+            .collect();
+
+        return SearchScope::new(res);
+
+        fn intersect_ranges(
+            r1: Option<TextRange>,
+            r2: Option<TextRange>,
+        ) -> Option<Option<TextRange>> {
+            match (r1, r2) {
+                (None, r) | (r, None) => Some(r),
+                (Some(r1), Some(r2)) => {
+                    let r = r1.intersection(&r2)?;
+                    Some(Some(r))
+                }
+            }
+        }
+    }
+}
+
+impl IntoIterator for SearchScope {
+    type Item = (FileId, Option<TextRange>);
+    type IntoIter = std::collections::hash_map::IntoIter<FileId, Option<TextRange>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.entries.into_iter()
+    }
+}