Code cleanups for the split-host work

Author: joshtriplett

src/cargo/core/compiler/build_context/target_info.rs

@@ -691,14 +691,11 @@ impl<'cfg> RustcTargetData<'cfg> {
         // `--target` flag is not specified. Since the unit_dependency code
         // needs access to the target config data, create a copy so that it
         // can be found. See `rebuild_unit_graph_shared` for why this is done.
-        let target_applies_to_host = config.target_applies_to_host();
-        if target_applies_to_host.is_err() {
-            return Err(target_applies_to_host.unwrap_err());
-        }
+        let target_applies_to_host = config.target_applies_to_host()?;
         let host_config = if requested_kinds.iter().any(CompileKind::is_host) {
             let ct = CompileTarget::new(&rustc.host)?;
             target_info.insert(ct, host_info.clone());
-            let target_host_config = if target_applies_to_host.unwrap() {
+            let target_host_config = if target_applies_to_host {
                 let target_cfg_clone = config.target_cfg_triple(&rustc.host)?;
                 target_config.insert(ct, target_cfg_clone.clone());
                 target_cfg_clone
@@ -708,7 +705,7 @@ impl<'cfg> RustcTargetData<'cfg> {
             };
             target_host_config
         } else {
-            if target_applies_to_host.unwrap() {
+            if target_applies_to_host {
                 config.target_cfg_triple(&rustc.host)?
             } else {
                 config.host_cfg_triple(&rustc.host)?

src/cargo/util/config/target.rs

@@ -67,15 +67,10 @@ pub(super) fn load_target_cfgs(config: &Config) -> CargoResult<Vec<(String, Targ
 /// Returns true if the `[target]` table should be applied to host targets.
 pub(super) fn get_target_applies_to_host(config: &Config) -> CargoResult<bool> {
     if config.cli_unstable().target_applies_to_host {
-        let target_applies_to_host = config.get::<bool>("target-applies-to-host");
-        if target_applies_to_host.is_ok() {
-            Ok(target_applies_to_host.unwrap())
+        if let Ok(target_applies_to_host) = config.get::<bool>("target-applies-to-host") {
+            Ok(target_applies_to_host)
         } else {
-            if config.cli_unstable().host_config {
-                Ok(false)
-            } else {
-                Ok(true)
-            }
+            Ok(!config.cli_unstable().host_config)
         }
     } else {
         if config.cli_unstable().host_config {
@@ -91,9 +86,10 @@ pub(super) fn get_target_applies_to_host(config: &Config) -> CargoResult<bool> {
 /// Loads a single `[host]` table for the given triple.
 pub(super) fn load_host_triple(config: &Config, triple: &str) -> CargoResult<TargetConfig> {
     if config.cli_unstable().host_config {
-        let host_triple_key = ConfigKey::from_str(&format!("host.{}", triple));
+        let host_triple_prefix = format!("host.{}", triple);
+        let host_triple_key = ConfigKey::from_str(&host_triple_prefix);
         let host_prefix = match config.get_cv(&host_triple_key)? {
-            Some(_) => format!("host.{}", triple),
+            Some(_) => host_triple_prefix,
             None => "host".to_string(),
         };
         load_config_table(config, &host_prefix)