3 files changed, 23 insertions, 1 deletions

diff --git a/crates/ra_cfg/src/lib.rs b/crates/ra_cfg/src/lib.rs
index 57feabcb2..f9c73ece1 100644
--- a/crates/ra_cfg/src/lib.rs
+++ b/crates/ra_cfg/src/lib.rs
@@ -46,4 +46,14 @@ impl CfgOptions {
     pub fn insert_key_value(&mut self, key: SmolStr, value: SmolStr) {
         self.key_values.insert((key, value));
     }
+
+    pub fn append(&mut self, other: &CfgOptions) {
+        for atom in &other.atoms {
+            self.atoms.insert(atom.clone());
+        }
+
+        for (key, value) in &other.key_values {
+            self.key_values.insert((key.clone(), value.clone()));
+        }
+    }
 }
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 464c3b2e3..5d1f871c4 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -246,6 +246,7 @@ impl ProjectWorkspace {
         let mut crate_graph = CrateGraph::default();
         match self {
             ProjectWorkspace::Json { project } => {
+                let mut target_cfg_map = FxHashMap::<Option<&str>, CfgOptions>::default();
                 let crates: FxHashMap<_, _> = project
                     .crates
                     .iter()
@@ -265,6 +266,14 @@ impl ProjectWorkspace {
                             .proc_macro_dylib_path
                             .clone()
                             .map(|it| proc_macro_client.by_dylib_path(&it));
+
+                        let target = krate.target.as_deref().or(target);
+                        let target_cfgs = target_cfg_map
+                            .entry(target.clone())
+                            .or_insert_with(|| get_rustc_cfg_options(target.as_deref()));
+                        let mut cfg_options = krate.cfg.clone();
+                        cfg_options.append(target_cfgs);
+
                         // FIXME: No crate name in json definition such that we cannot add OUT_DIR to env
                         Some((
                             CrateId(seq_index as u32),
@@ -273,7 +282,7 @@ impl ProjectWorkspace {
                                 krate.edition,
                                 // FIXME json definitions can store the crate name
                                 None,
-                                krate.cfg.clone(),
+                                cfg_options,
                                 env,
                                 proc_macro.unwrap_or_default(),
                             ),
diff --git a/crates/ra_project_model/src/project_json.rs b/crates/ra_project_model/src/project_json.rs
index b0fe09333..b96227949 100644
--- a/crates/ra_project_model/src/project_json.rs
+++ b/crates/ra_project_model/src/project_json.rs
@@ -31,6 +31,7 @@ pub struct Crate {
     pub(crate) edition: Edition,
     pub(crate) deps: Vec<Dependency>,
     pub(crate) cfg: CfgOptions,
+    pub(crate) target: Option<String>,
     pub(crate) out_dir: Option<AbsPathBuf>,
     pub(crate) proc_macro_dylib_path: Option<AbsPathBuf>,
 }
@@ -65,6 +66,7 @@ impl ProjectJson {
                         }
                         cfg
                     },
+                    target: crate_data.target,
                     out_dir: crate_data.out_dir.map(|it| base.join(it)),
                     proc_macro_dylib_path: crate_data.proc_macro_dylib_path.map(|it| base.join(it)),
                 })
@@ -86,6 +88,7 @@ struct CrateData {
     deps: Vec<DepData>,
     #[serde(default)]
     cfg: FxHashSet<String>,
+    target: Option<String>,
     out_dir: Option<PathBuf>,
     proc_macro_dylib_path: Option<PathBuf>,
 }