Cleanup target fetching for cargo metadata

crates/project-model/src/cargo_workspace.rs

@@ -13,8 +13,8 @@ use serde_json::from_value;
 use span::Edition;
 use toolchain::Tool;
 
-use crate::{utf8_stdout, ManifestPath, Sysroot, SysrootQueryMetadata};
 use crate::{CfgOverrides, InvocationStrategy};
+use crate::{ManifestPath, Sysroot, SysrootQueryMetadata};
 
 /// [`CargoWorkspace`] represents the logical structure of, well, a Cargo
 /// workspace. It pretty closely mirrors `cargo metadata` output.
@@ -251,6 +251,18 @@ impl TargetKind {
     }
 }
 
+#[derive(Default, Clone, Debug, PartialEq, Eq)]
+pub struct CargoMetadataConfig {
+    /// List of features to activate.
+    pub features: CargoFeatures,
+    /// rustc targets
+    pub targets: Vec<String>,
+    /// Extra args to pass to the cargo command.
+    pub extra_args: Vec<String>,
+    /// Extra env vars to set when invoking the cargo command
+    pub extra_env: FxHashMap<String, String>,
+}
+
 // Deserialize helper for the cargo metadata
 #[derive(Deserialize, Default)]
 struct PackageMetadata {
@@ -265,7 +277,7 @@ impl CargoWorkspace {
     pub fn fetch_metadata(
         cargo_toml: &ManifestPath,
         current_dir: &AbsPath,
-        config: &CargoConfig,
+        config: &CargoMetadataConfig,
         sysroot: &Sysroot,
         locked: bool,
         progress: &dyn Fn(String),
@@ -276,14 +288,12 @@ impl CargoWorkspace {
     fn fetch_metadata_(
         cargo_toml: &ManifestPath,
         current_dir: &AbsPath,
-        config: &CargoConfig,
+        config: &CargoMetadataConfig,
         sysroot: &Sysroot,
         locked: bool,
         no_deps: bool,
         progress: &dyn Fn(String),
     ) -> anyhow::Result<(cargo_metadata::Metadata, Option<anyhow::Error>)> {
-        let targets = find_list_of_build_targets(config, cargo_toml, sysroot);
-
         let cargo = sysroot.tool(Tool::Cargo);
         let mut meta = MetadataCommand::new();
         meta.cargo_path(cargo.get_program());
@@ -319,12 +329,9 @@ impl CargoWorkspace {
             }
         }
 
-        if !targets.is_empty() {
-            other_options.append(
-                &mut targets
-                    .into_iter()
-                    .flat_map(|target| ["--filter-platform".to_owned(), target])
-                    .collect(),
+        if !config.targets.is_empty() {
+            other_options.extend(
+                config.targets.iter().flat_map(|it| ["--filter-platform".to_owned(), it.clone()]),
             );
         }
         // The manifest is a rust file, so this means its a script manifest
@@ -596,79 +603,3 @@ impl CargoWorkspace {
         self.is_virtual_workspace
     }
 }
-
-fn find_list_of_build_targets(
-    config: &CargoConfig,
-    cargo_toml: &ManifestPath,
-    sysroot: &Sysroot,
-) -> Vec<String> {
-    if let Some(target) = &config.target {
-        return [target.into()].to_vec();
-    }
-
-    let build_targets = cargo_config_build_target(cargo_toml, &config.extra_env, sysroot);
-    if !build_targets.is_empty() {
-        return build_targets;
-    }
-
-    rustc_discover_host_triple(cargo_toml, &config.extra_env, sysroot).into_iter().collect()
-}
-
-fn rustc_discover_host_triple(
-    cargo_toml: &ManifestPath,
-    extra_env: &FxHashMap<String, String>,
-    sysroot: &Sysroot,
-) -> Option<String> {
-    let mut rustc = sysroot.tool(Tool::Rustc);
-    rustc.envs(extra_env);
-    rustc.current_dir(cargo_toml.parent()).arg("-vV");
-    tracing::debug!("Discovering host platform by {:?}", rustc);
-    match utf8_stdout(rustc) {
-        Ok(stdout) => {
-            let field = "host: ";
-            let target = stdout.lines().find_map(|l| l.strip_prefix(field));
-            if let Some(target) = target {
-                Some(target.to_owned())
-            } else {
-                // If we fail to resolve the host platform, it's not the end of the world.
-                tracing::info!("rustc -vV did not report host platform, got:\n{}", stdout);
-                None
-            }
-        }
-        Err(e) => {
-            tracing::warn!("Failed to discover host platform: {}", e);
-            None
-        }
-    }
-}
-
-fn cargo_config_build_target(
-    cargo_toml: &ManifestPath,
-    extra_env: &FxHashMap<String, String>,
-    sysroot: &Sysroot,
-) -> Vec<String> {
-    let mut cargo_config = sysroot.tool(Tool::Cargo);
-    cargo_config.envs(extra_env);
-    cargo_config
-        .current_dir(cargo_toml.parent())
-        .args(["-Z", "unstable-options", "config", "get", "build.target"])
-        .env("RUSTC_BOOTSTRAP", "1");
-    // if successful we receive `build.target = "target-triple"`
-    // or `build.target = ["<target 1>", ..]`
-    tracing::debug!("Discovering cargo config target by {:?}", cargo_config);
-    utf8_stdout(cargo_config).map(parse_output_cargo_config_build_target).unwrap_or_default()
-}
-
-fn parse_output_cargo_config_build_target(stdout: String) -> Vec<String> {
-    let trimmed = stdout.trim_start_matches("build.target = ").trim_matches('"');
-
-    if !trimmed.starts_with('[') {
-        return [trimmed.to_owned()].to_vec();
-    }
-
-    let res = serde_json::from_str(trimmed);
-    if let Err(e) = &res {
-        tracing::warn!("Failed to parse `build.target` as an array of target: {}`", e);
-    }
-    res.unwrap_or_default()
-}