1 files changed, 131 insertions, 0 deletions
diff --git a/src/tools/rust-analyzer/crates/base-db/src/lib.rs b/src/tools/rust-analyzer/crates/base-db/src/lib.rs
new file mode 100644
index 000000000..2d0a95b09
--- /dev/null
+++ b/src/tools/rust-analyzer/crates/base-db/src/lib.rs
@@ -0,0 +1,131 @@
+//! base_db defines basic database traits. The concrete DB is defined by ide.
+
+#![warn(rust_2018_idioms, unused_lifetimes, semicolon_in_expressions_from_macros)]
+
+mod input;
+mod change;
+pub mod fixture;
+
+use std::{panic, sync::Arc};
+
+use rustc_hash::FxHashSet;
+use syntax::{ast, Parse, SourceFile, TextRange, TextSize};
+
+pub use crate::{
+    change::Change,
+    input::{
+        CrateData, CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency,
+        Edition, Env, LangCrateOrigin, ProcMacro, ProcMacroExpander, ProcMacroExpansionError,
+        ProcMacroId, ProcMacroKind, ProcMacroLoadResult, SourceRoot, SourceRootId,
+    },
+};
+pub use salsa::{self, Cancelled};
+pub use vfs::{file_set::FileSet, AnchoredPath, AnchoredPathBuf, FileId, VfsPath};
+
+#[macro_export]
+macro_rules! impl_intern_key {
+    ($name:ident) => {
+        impl $crate::salsa::InternKey for $name {
+            fn from_intern_id(v: $crate::salsa::InternId) -> Self {
+                $name(v)
+            }
+            fn as_intern_id(&self) -> $crate::salsa::InternId {
+                self.0
+            }
+        }
+    };
+}
+
+pub trait Upcast<T: ?Sized> {
+    fn upcast(&self) -> &T;
+}
+
+#[derive(Clone, Copy, Debug)]
+pub struct FilePosition {
+    pub file_id: FileId,
+    pub offset: TextSize,
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
+pub struct FileRange {
+    pub file_id: FileId,
+    pub range: TextRange,
+}
+
+pub const DEFAULT_LRU_CAP: usize = 128;
+
+pub trait FileLoader {
+    /// Text of the file.
+    fn file_text(&self, file_id: FileId) -> Arc<String>;
+    fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId>;
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>>;
+}
+
+/// Database which stores all significant input facts: source code and project
+/// model. Everything else in rust-analyzer is derived from these queries.
+#[salsa::query_group(SourceDatabaseStorage)]
+pub trait SourceDatabase: FileLoader + std::fmt::Debug {
+    // Parses the file into the syntax tree.
+    #[salsa::invoke(parse_query)]
+    fn parse(&self, file_id: FileId) -> Parse<ast::SourceFile>;
+
+    /// The crate graph.
+    #[salsa::input]
+    fn crate_graph(&self) -> Arc<CrateGraph>;
+}
+
+fn parse_query(db: &dyn SourceDatabase, file_id: FileId) -> Parse<ast::SourceFile> {
+    let _p = profile::span("parse_query").detail(|| format!("{:?}", file_id));
+    let text = db.file_text(file_id);
+    SourceFile::parse(&*text)
+}
+
+/// We don't want to give HIR knowledge of source roots, hence we extract these
+/// methods into a separate DB.
+#[salsa::query_group(SourceDatabaseExtStorage)]
+pub trait SourceDatabaseExt: SourceDatabase {
+    #[salsa::input]
+    fn file_text(&self, file_id: FileId) -> Arc<String>;
+    /// Path to a file, relative to the root of its source root.
+    /// Source root of the file.
+    #[salsa::input]
+    fn file_source_root(&self, file_id: FileId) -> SourceRootId;
+    /// Contents of the source root.
+    #[salsa::input]
+    fn source_root(&self, id: SourceRootId) -> Arc<SourceRoot>;
+
+    fn source_root_crates(&self, id: SourceRootId) -> Arc<FxHashSet<CrateId>>;
+}
+
+fn source_root_crates(db: &dyn SourceDatabaseExt, id: SourceRootId) -> Arc<FxHashSet<CrateId>> {
+    let graph = db.crate_graph();
+    let res = graph
+        .iter()
+        .filter(|&krate| {
+            let root_file = graph[krate].root_file_id;
+            db.file_source_root(root_file) == id
+        })
+        .collect();
+    Arc::new(res)
+}
+
+/// Silly workaround for cyclic deps between the traits
+pub struct FileLoaderDelegate<T>(pub T);
+
+impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
+    fn file_text(&self, file_id: FileId) -> Arc<String> {
+        SourceDatabaseExt::file_text(self.0, file_id)
+    }
+    fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId> {
+        // FIXME: this *somehow* should be platform agnostic...
+        let source_root = self.0.file_source_root(path.anchor);
+        let source_root = self.0.source_root(source_root);
+        source_root.file_set.resolve_path(path)
+    }
+
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
+        let _p = profile::span("relevant_crates");
+        let source_root = self.0.file_source_root(file_id);
+        self.0.source_root_crates(source_root)
+    }
+}