Refactor: extract compile_objects_sequential (#1507)

* Refactor: extract compile_objects_sequential

* Fix fmt in lib.rs

Author: NobodyXu

src/lib.rs

@@ -1683,12 +1683,7 @@ impl Build {
         check_disabled()?;
 
         if objs.len() <= 1 {
-            for obj in objs {
-                let mut cmd = self.create_compile_object_cmd(obj)?;
-                run(&mut cmd, &self.cargo_output)?;
-            }
-
-            return Ok(());
+            return self.compile_objects_sequential(objs);
         }
 
         // Limit our parallelism globally with a jobserver.
@@ -1816,10 +1811,7 @@ impl Build {
         }
     }
 
-    #[cfg(not(feature = "parallel"))]
-    fn compile_objects(&self, objs: &[Object]) -> Result<(), Error> {
-        check_disabled()?;
-
+    fn compile_objects_sequential(&self, objs: &[Object]) -> Result<(), Error> {
         for obj in objs {
             let mut cmd = self.create_compile_object_cmd(obj)?;
             run(&mut cmd, &self.cargo_output)?;
@@ -1828,6 +1820,13 @@ impl Build {
         Ok(())
     }
 
+    #[cfg(not(feature = "parallel"))]
+    fn compile_objects(&self, objs: &[Object]) -> Result<(), Error> {
+        check_disabled()?;
+
+        self.compile_objects_sequential(objs)
+    }
+
     fn create_compile_object_cmd(&self, obj: &Object) -> Result<Command, Error> {
         let asm_ext = AsmFileExt::from_path(&obj.src);
         let is_asm = asm_ext.is_some();