6 files changed, 25 insertions, 7 deletions

diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 362ee30fe..59f46a2a0 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -56,6 +56,9 @@ pub struct CargoConfig {
 
     /// Runs cargo check on launch to figure out the correct values of OUT_DIR
     pub load_out_dirs_from_check: bool,
+
+    /// rustc target
+    pub target: Option<String>,
 }
 
 impl Default for CargoConfig {
@@ -65,6 +68,7 @@ impl Default for CargoConfig {
             all_features: true,
             features: Vec::new(),
             load_out_dirs_from_check: false,
+            target: None,
         }
     }
 }
@@ -160,6 +164,9 @@ impl CargoWorkspace {
         if let Some(parent) = cargo_toml.parent() {
             meta.current_dir(parent);
         }
+        if let Some(target) = cargo_features.target.as_ref() {
+            meta.other_options(&[String::from("--filter-platform"), target.clone()]);
+        }
         let meta = meta.exec().with_context(|| {
             format!("Failed to run `cargo metadata --manifest-path {}`", cargo_toml.display())
         })?;
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 731cbd291..c2b33c1dc 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -543,7 +543,7 @@ impl ProjectWorkspace {
     }
 }
 
-pub fn get_rustc_cfg_options() -> CfgOptions {
+pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
     let mut cfg_options = CfgOptions::default();
 
     // Some nightly-only cfgs, which are required for stdlib
@@ -558,10 +558,12 @@ pub fn get_rustc_cfg_options() -> CfgOptions {
 
     match (|| -> Result<String> {
         // `cfg(test)` and `cfg(debug_assertion)` are handled outside, so we suppress them here.
-        let output = Command::new("rustc")
-            .args(&["--print", "cfg", "-O"])
-            .output()
-            .context("Failed to get output from rustc --print cfg -O")?;
+        let mut cmd = Command::new("rustc");
+        cmd.args(&["--print", "cfg", "-O"]);
+        if let Some(target) = target {
+            cmd.args(&["--target", target.as_str()]);
+        }
+        let output = cmd.output().context("Failed to get output from rustc --print cfg -O")?;
         if !output.status.success() {
             bail!(
                 "rustc --print cfg -O exited with exit code ({})",
diff --git a/crates/rust-analyzer/src/cli/load_cargo.rs b/crates/rust-analyzer/src/cli/load_cargo.rs
index d0a71120a..023ced6cf 100644
--- a/crates/rust-analyzer/src/cli/load_cargo.rs
+++ b/crates/rust-analyzer/src/cli/load_cargo.rs
@@ -149,7 +149,7 @@ pub(crate) fn load(
 
     // FIXME: cfg options?
     let default_cfg_options = {
-        let mut opts = get_rustc_cfg_options();
+        let mut opts = get_rustc_cfg_options(None);
         opts.insert_atom("test".into());
         opts.insert_atom("debug_assertion".into());
         opts
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 15b7c6912..8d85c60cf 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -131,6 +131,7 @@ impl Config {
         set(value, "/cargo/allFeatures", &mut self.cargo.all_features);
         set(value, "/cargo/features", &mut self.cargo.features);
         set(value, "/cargo/loadOutDirsFromCheck", &mut self.cargo.load_out_dirs_from_check);
+        set(value, "/cargo/target", &mut self.cargo.target);
 
         match get(value, "/procMacro/enable") {
             Some(true) => {
diff --git a/crates/rust-analyzer/src/world.rs b/crates/rust-analyzer/src/world.rs
index 34941931b..16020648d 100644
--- a/crates/rust-analyzer/src/world.rs
+++ b/crates/rust-analyzer/src/world.rs
@@ -131,7 +131,7 @@ impl WorldState {
 
         // FIXME: Read default cfgs from config
         let default_cfg_options = {
-            let mut opts = get_rustc_cfg_options();
+            let mut opts = get_rustc_cfg_options(config.cargo.target.as_ref());
             opts.insert_atom("test".into());
             opts.insert_atom("debug_assertion".into());
             opts
diff --git a/editors/code/package.json b/editors/code/package.json
index 442b9de98..a05a69752 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -233,6 +233,14 @@
                     "default": false,
                     "markdownDescription": "Run `cargo check` on startup to get the correct value for package OUT_DIRs"
                 },
+                "rust-analyzer.cargo.target": {
+                    "type": [
+                        "null",
+                        "string"
+                    ],
+                    "default": null,
+                    "description": "Specify the compilation target"
+                },
                 "rust-analyzer.rustfmt.extraArgs": {
                     "type": "array",
                     "items": {