3 files changed, 213 insertions, 70 deletions

diff --git a/crates/ra_db/src/fixture.rs b/crates/ra_db/src/fixture.rs
index da7af110c..3dc86ca2d 100644
--- a/crates/ra_db/src/fixture.rs
+++ b/crates/ra_db/src/fixture.rs
@@ -5,7 +5,7 @@ use std::sync::Arc;
 
 use ra_cfg::CfgOptions;
 use rustc_hash::FxHashMap;
-use test_utils::{extract_offset, parse_fixture, CURSOR_MARKER};
+use test_utils::{extract_offset, parse_fixture, parse_single_fixture, CURSOR_MARKER};
 
 use crate::{
     input::CrateName, CrateGraph, CrateId, Edition, Env, FileId, FilePosition, RelativePathBuf,
@@ -45,22 +45,45 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
 
 impl<DB: SourceDatabaseExt + Default + 'static> WithFixture for DB {}
 
-fn with_single_file(db: &mut dyn SourceDatabaseExt, text: &str) -> FileId {
+fn with_single_file(db: &mut dyn SourceDatabaseExt, ra_fixture: &str) -> FileId {
     let file_id = FileId(0);
     let rel_path: RelativePathBuf = "/main.rs".into();
 
     let mut source_root = SourceRoot::new_local();
     source_root.insert_file(rel_path.clone(), file_id);
 
-    let mut crate_graph = CrateGraph::default();
-    crate_graph.add_crate_root(
-        file_id,
-        Edition::Edition2018,
-        CfgOptions::default(),
-        Env::default(),
-    );
-
-    db.set_file_text(file_id, Arc::new(text.to_string()));
+    let fixture = parse_single_fixture(ra_fixture);
+
+    let crate_graph = if let Some(entry) = fixture {
+        let meta = match parse_meta(&entry.meta) {
+            ParsedMeta::File(it) => it,
+            _ => panic!("with_single_file only support file meta"),
+        };
+
+        let mut crate_graph = CrateGraph::default();
+        crate_graph.add_crate_root(
+            file_id,
+            meta.edition,
+            meta.krate,
+            meta.cfg,
+            meta.env,
+            Default::default(),
+        );
+        crate_graph
+    } else {
+        let mut crate_graph = CrateGraph::default();
+        crate_graph.add_crate_root(
+            file_id,
+            Edition::Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        crate_graph
+    };
+
+    db.set_file_text(file_id, Arc::new(ra_fixture.to_string()));
     db.set_file_relative_path(file_id, rel_path);
     db.set_file_source_root(file_id, WORKSPACE);
     db.set_source_root(WORKSPACE, Arc::new(source_root));
@@ -98,8 +121,14 @@ fn with_files(db: &mut dyn SourceDatabaseExt, fixture: &str) -> Option<FilePosit
         assert!(meta.path.starts_with(&source_root_prefix));
 
         if let Some(krate) = meta.krate {
-            let crate_id =
-                crate_graph.add_crate_root(file_id, meta.edition, meta.cfg, Env::default());
+            let crate_id = crate_graph.add_crate_root(
+                file_id,
+                meta.edition,
+                Some(krate.clone()),
+                meta.cfg,
+                meta.env,
+                Default::default(),
+            );
             let prev = crates.insert(krate.clone(), crate_id);
             assert!(prev.is_none());
             for dep in meta.deps {
@@ -132,8 +161,10 @@ fn with_files(db: &mut dyn SourceDatabaseExt, fixture: &str) -> Option<FilePosit
         crate_graph.add_crate_root(
             crate_root,
             Edition::Edition2018,
+            None,
             CfgOptions::default(),
             Env::default(),
+            Default::default(),
         );
     } else {
         for (from, to) in crate_deps {
@@ -160,9 +191,10 @@ struct FileMeta {
     deps: Vec<String>,
     cfg: CfgOptions,
     edition: Edition,
+    env: Env,
 }
 
-//- /lib.rs crate:foo deps:bar,baz
+//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo)
 fn parse_meta(meta: &str) -> ParsedMeta {
     let components = meta.split_ascii_whitespace().collect::<Vec<_>>();
 
@@ -179,6 +211,7 @@ fn parse_meta(meta: &str) -> ParsedMeta {
     let mut deps = Vec::new();
     let mut edition = Edition::Edition2018;
     let mut cfg = CfgOptions::default();
+    let mut env = Env::default();
     for component in components[1..].iter() {
         let (key, value) = split1(component, ':').unwrap();
         match key {
@@ -193,11 +226,18 @@ fn parse_meta(meta: &str) -> ParsedMeta {
                     }
                 }
             }
+            "env" => {
+                for key in value.split(',') {
+                    if let Some((k, v)) = split1(key, '=') {
+                        env.set(k.into(), v.into());
+                    }
+                }
+            }
             _ => panic!("bad component: {:?}", component),
         }
     }
 
-    ParsedMeta::File(FileMeta { path, krate, deps, edition, cfg })
+    ParsedMeta::File(FileMeta { path, krate, deps, edition, cfg, env })
 }
 
 fn split1(haystack: &str, delim: char) -> Option<(&str, &str)> {
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index eaff99fd3..06d40db96 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -6,7 +6,7 @@
 //! actual IO. See `vfs` and `project_model` in the `rust-analyzer` crate for how
 //! actual IO is done and lowered to input.
 
-use std::{fmt, str::FromStr};
+use std::{fmt, ops, str::FromStr};
 
 use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
@@ -86,7 +86,7 @@ pub struct CrateId(pub u32);
 pub struct CrateName(SmolStr);
 
 impl CrateName {
-    /// Crates a crate name, checking for dashes in the string provided.
+    /// Creates a crate name, checking for dashes in the string provided.
     /// Dashes are not allowed in the crate names,
     /// hence the input string is returned as `Err` for those cases.
     pub fn new(name: &str) -> Result<CrateName, &str> {
@@ -97,19 +97,24 @@ impl CrateName {
         }
     }
 
-    /// Crates a crate name, unconditionally replacing the dashes with underscores.
+    /// Creates a crate name, unconditionally replacing the dashes with underscores.
     pub fn normalize_dashes(name: &str) -> CrateName {
         Self(SmolStr::new(name.replace('-', "_")))
     }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-struct CrateData {
-    file_id: FileId,
-    edition: Edition,
-    cfg_options: CfgOptions,
-    env: Env,
-    dependencies: Vec<Dependency>,
+pub struct CrateData {
+    pub root_file_id: FileId,
+    pub edition: Edition,
+    /// The name to display to the end user.
+    /// This actual crate name can be different in a particular dependent crate
+    /// or may even be missing for some cases, such as a dummy crate for the code snippet.
+    pub display_name: Option<String>,
+    pub cfg_options: CfgOptions,
+    pub env: Env,
+    pub extern_source: ExternSource,
+    pub dependencies: Vec<Dependency>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -118,11 +123,22 @@ pub enum Edition {
     Edition2015,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct ExternSourceId(pub u32);
+
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct Env {
     entries: FxHashMap<String, String>,
 }
 
+// FIXME: Redesign vfs for solve the following limitation ?
+// Note: Some env variables (e.g. OUT_DIR) are located outside of the
+// crate. We store a map to allow remap it to ExternSourceId
+#[derive(Default, Debug, Clone, PartialEq, Eq)]
+pub struct ExternSource {
+    extern_paths: FxHashMap<String, ExternSourceId>,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Dependency {
     pub crate_id: CrateId,
@@ -134,20 +150,26 @@ impl CrateGraph {
         &mut self,
         file_id: FileId,
         edition: Edition,
+        display_name: Option<String>,
         cfg_options: CfgOptions,
         env: Env,
+        extern_source: ExternSource,
     ) -> CrateId {
-        let data = CrateData::new(file_id, edition, cfg_options, env);
+        let data = CrateData {
+            root_file_id: file_id,
+            edition,
+            display_name,
+            cfg_options,
+            env,
+            extern_source,
+            dependencies: Vec::new(),
+        };
         let crate_id = CrateId(self.arena.len() as u32);
         let prev = self.arena.insert(crate_id, data);
         assert!(prev.is_none());
         crate_id
     }
 
-    pub fn cfg_options(&self, crate_id: CrateId) -> &CfgOptions {
-        &self.arena[&crate_id].cfg_options
-    }
-
     pub fn add_dep(
         &mut self,
         from: CrateId,
@@ -169,24 +191,13 @@ impl CrateGraph {
         self.arena.keys().copied()
     }
 
-    pub fn crate_root(&self, crate_id: CrateId) -> FileId {
-        self.arena[&crate_id].file_id
-    }
-
-    pub fn edition(&self, crate_id: CrateId) -> Edition {
-        self.arena[&crate_id].edition
-    }
-
     // FIXME: this only finds one crate with the given root; we could have multiple
     pub fn crate_id_for_crate_root(&self, file_id: FileId) -> Option<CrateId> {
-        let (&crate_id, _) = self.arena.iter().find(|(_crate_id, data)| data.file_id == file_id)?;
+        let (&crate_id, _) =
+            self.arena.iter().find(|(_crate_id, data)| data.root_file_id == file_id)?;
         Some(crate_id)
     }
 
-    pub fn dependencies(&self, crate_id: CrateId) -> impl Iterator<Item = &Dependency> {
-        self.arena[&crate_id].dependencies.iter()
-    }
-
     /// Extends this crate graph by adding a complete disjoint second crate
     /// graph.
     ///
@@ -209,8 +220,8 @@ impl CrateGraph {
             return false;
         }
 
-        for dep in self.dependencies(from) {
-            let crate_id = dep.crate_id();
+        for dep in &self[from].dependencies {
+            let crate_id = dep.crate_id;
             if crate_id == target {
                 return true;
             }
@@ -223,6 +234,13 @@ impl CrateGraph {
     }
 }
 
+impl ops::Index<CrateId> for CrateGraph {
+    type Output = CrateData;
+    fn index(&self, crate_id: CrateId) -> &CrateData {
+        &self.arena[&crate_id]
+    }
+}
+
 impl CrateId {
     pub fn shift(self, amount: u32) -> CrateId {
         CrateId(self.0 + amount)
@@ -230,10 +248,6 @@ impl CrateId {
 }
 
 impl CrateData {
-    fn new(file_id: FileId, edition: Edition, cfg_options: CfgOptions, env: Env) -> CrateData {
-        CrateData { file_id, edition, dependencies: Vec::new(), cfg_options, env }
-    }
-
     fn add_dep(&mut self, name: SmolStr, crate_id: CrateId) {
         self.dependencies.push(Dependency { name, crate_id })
     }
@@ -261,9 +275,34 @@ impl fmt::Display for Edition {
     }
 }
 
-impl Dependency {
-    pub fn crate_id(&self) -> CrateId {
-        self.crate_id
+impl Env {
+    pub fn set(&mut self, env: &str, value: String) {
+        self.entries.insert(env.to_owned(), value);
+    }
+
+    pub fn get(&self, env: &str) -> Option<String> {
+        self.entries.get(env).cloned()
+    }
+}
+
+impl ExternSource {
+    pub fn extern_path(&self, path: &str) -> Option<(ExternSourceId, RelativePathBuf)> {
+        self.extern_paths.iter().find_map(|(root_path, id)| {
+            if path.starts_with(root_path) {
+                let mut rel_path = &path[root_path.len()..];
+                if rel_path.starts_with("/") {
+                    rel_path = &rel_path[1..];
+                }
+                let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+                Some((id.clone(), rel_path))
+            } else {
+                None
+            }
+        })
+    }
+
+    pub fn set_extern_path(&mut self, root_path: &str, root: ExternSourceId) {
+        self.extern_paths.insert(root_path.to_owned(), root);
     }
 }
 
@@ -290,12 +329,30 @@ mod tests {
     #[test]
     fn it_should_panic_because_of_cycle_dependencies() {
         let mut graph = CrateGraph::default();
-        let crate1 =
-            graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default(), Env::default());
-        let crate2 =
-            graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default(), Env::default());
-        let crate3 =
-            graph.add_crate_root(FileId(3u32), Edition2018, CfgOptions::default(), Env::default());
+        let crate1 = graph.add_crate_root(
+            FileId(1u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let crate2 = graph.add_crate_root(
+            FileId(2u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let crate3 = graph.add_crate_root(
+            FileId(3u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
         assert!(graph.add_dep(crate1, CrateName::new("crate2").unwrap(), crate2).is_ok());
         assert!(graph.add_dep(crate2, CrateName::new("crate3").unwrap(), crate3).is_ok());
         assert!(graph.add_dep(crate3, CrateName::new("crate1").unwrap(), crate1).is_err());
@@ -304,12 +361,30 @@ mod tests {
     #[test]
     fn it_works() {
         let mut graph = CrateGraph::default();
-        let crate1 =
-            graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default(), Env::default());
-        let crate2 =
-            graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default(), Env::default());
-        let crate3 =
-            graph.add_crate_root(FileId(3u32), Edition2018, CfgOptions::default(), Env::default());
+        let crate1 = graph.add_crate_root(
+            FileId(1u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let crate2 = graph.add_crate_root(
+            FileId(2u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let crate3 = graph.add_crate_root(
+            FileId(3u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
         assert!(graph.add_dep(crate1, CrateName::new("crate2").unwrap(), crate2).is_ok());
         assert!(graph.add_dep(crate2, CrateName::new("crate3").unwrap(), crate3).is_ok());
     }
@@ -317,16 +392,28 @@ mod tests {
     #[test]
     fn dashes_are_normalized() {
         let mut graph = CrateGraph::default();
-        let crate1 =
-            graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default(), Env::default());
-        let crate2 =
-            graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default(), Env::default());
+        let crate1 = graph.add_crate_root(
+            FileId(1u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let crate2 = graph.add_crate_root(
+            FileId(2u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
         assert!(graph
             .add_dep(crate1, CrateName::normalize_dashes("crate-name-with-dashes"), crate2)
             .is_ok());
         assert_eq!(
-            graph.dependencies(crate1).collect::<Vec<_>>(),
-            vec![&Dependency { crate_id: crate2, name: "crate_name_with_dashes".into() }]
+            graph[crate1].dependencies,
+            vec![Dependency { crate_id: crate2, name: "crate_name_with_dashes".into() }]
         );
     }
 }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index fb002d717..d500d5e85 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -11,7 +11,8 @@ use ra_syntax::{ast, Parse, SourceFile, TextRange, TextUnit};
 pub use crate::{
     cancellation::Canceled,
     input::{
-        CrateGraph, CrateId, CrateName, Dependency, Edition, Env, FileId, SourceRoot, SourceRootId,
+        CrateGraph, CrateId, CrateName, Dependency, Edition, Env, ExternSource, ExternSourceId,
+        FileId, SourceRoot, SourceRootId,
     },
 };
 pub use relative_path::{RelativePath, RelativePathBuf};
@@ -87,6 +88,12 @@ pub trait FileLoader {
     fn resolve_relative_path(&self, anchor: FileId, relative_path: &RelativePath)
         -> Option<FileId>;
     fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>>;
+
+    fn resolve_extern_path(
+        &self,
+        extern_id: ExternSourceId,
+        relative_path: &RelativePath,
+    ) -> Option<FileId>;
 }
 
 /// Database which stores all significant input facts: source code and project
@@ -164,4 +171,13 @@ impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
         let source_root = self.0.file_source_root(file_id);
         self.0.source_root_crates(source_root)
     }
+
+    fn resolve_extern_path(
+        &self,
+        extern_id: ExternSourceId,
+        relative_path: &RelativePath,
+    ) -> Option<FileId> {
+        let source_root = self.0.source_root(SourceRootId(extern_id.0));
+        source_root.file_by_relative_path(&relative_path)
+    }
 }