chore(dso): minor refactor

README.md

@@ -5,3 +5,5 @@
 # Sysroot Cleaner
 
 A tool to clean up sysroots for Linux embedded devices to save storage space.
+
+Note: it will only work on files belonging to the same filesystem. This is a design choice.

src/cleaners/dso.rs

@@ -159,44 +159,7 @@ impl DsoCleaner {
     fn process_elf_file(state: &mut State, path: &Path, elf: &Elf) -> Result<()> {
         log::trace!("dso: adding to graph elf file '{}'", path.display());
 
-        let current_dir = std::env::current_dir()?;
+        let search_paths = Self::determine_lib_search_paths(path, elf)?;
-        let origin = std::fs::canonicalize(path)?
-            .parent()
-            .unwrap()
-            .strip_prefix(current_dir)?
-            .to_path_buf()
-            .into_os_string()
-            .into_string()
-            .map_err(|s| anyhow::anyhow!("cannot represent {:?} as a UTF-8 string", s))?;
-
-        let mut search_paths = vec![];
-
-        if elf.rpaths != vec![""] {
-            if elf.runpaths != vec![""] {
-                let mut rpaths = elf
-                    .rpaths
-                    .iter()
-                    .map(|p| p.replace("$ORIGIN", &origin))
-                    .collect::<Vec<_>>();
-                search_paths.append(&mut rpaths);
-            }
-
-            search_paths.append(&mut Self::get_env_library_paths());
-        }
-
-        if elf.runpaths != vec![""] {
-            let mut runpaths = elf
-                .runpaths
-                .iter()
-                .map(|p| p.replace("$ORIGIN", &origin))
-                .collect::<Vec<_>>();
-            search_paths.append(&mut runpaths);
-        }
-
-        // Standard dirs:
-        search_paths.push("/usr/local/lib".into());
-        search_paths.push("/lib".into());
-        search_paths.push("/usr/lib".into());
 
         let src_stat = nix::sys::stat::stat(path)?;
         let src_inode = if elf.is_lib {
@@ -233,6 +196,47 @@ impl DsoCleaner {
         Ok(())
     }
 
+    fn determine_lib_search_paths(path: &Path, elf: &Elf<'_>) -> Result<Vec<String>> {
+        let mut search_paths = vec![];
+
+        let current_dir = std::env::current_dir()?;
+        let origin = std::fs::canonicalize(path)?
+            .parent()
+            .unwrap()
+            .strip_prefix(current_dir)?
+            .to_path_buf()
+            .into_os_string()
+            .into_string()
+            .map_err(|s| anyhow::anyhow!("cannot represent {:?} as a UTF-8 string", s))?;
+
+        if elf.rpaths != vec![""] {
+            if elf.runpaths != vec![""] {
+                let mut rpaths = elf
+                    .rpaths
+                    .iter()
+                    .map(|p| p.replace("$ORIGIN", &origin))
+                    .collect::<Vec<_>>();
+                search_paths.append(&mut rpaths);
+            }
+
+            search_paths.append(&mut Self::get_env_library_paths());
+        }
+
+        if elf.runpaths != vec![""] {
+            let mut runpaths = elf
+                .runpaths
+                .iter()
+                .map(|p| p.replace("$ORIGIN", &origin))
+                .collect::<Vec<_>>();
+            search_paths.append(&mut runpaths);
+        }
+
+        search_paths.push("/usr/local/lib".into());
+        search_paths.push("/lib".into());
+        search_paths.push("/usr/lib".into());
+        Ok(search_paths)
+    }
+
     fn get_env_library_paths() -> Vec<String> {
         let ld_config_path = std::env::var("LD_LIBRARY_PATH");
         ld_config_path