Replace FileSearch::for_each_lib_search_path with search_paths.

Returning an iterator leads to nicer code all around.

Author: nnethercote

src/librustc/session/filesearch.rs

@@ -29,23 +29,19 @@ pub enum FileMatch {
 // A module for searching for libraries
 
 pub struct FileSearch<'a> {
-    pub sysroot: &'a Path,
-    pub triple: &'a str,
-    pub search_paths: &'a [SearchPath],
-    pub tlib_path: &'a SearchPath,
-    pub kind: PathKind,
+    sysroot: &'a Path,
+    triple: &'a str,
+    search_paths: &'a [SearchPath],
+    tlib_path: &'a SearchPath,
+    kind: PathKind,
 }
 
 impl<'a> FileSearch<'a> {
-    pub fn for_each_lib_search_path<F>(&self, mut f: F) where
-        F: FnMut(&SearchPath)
-    {
-        let iter = self.search_paths.iter().filter(|sp| sp.kind.matches(self.kind));
-        for search_path in iter {
-            f(search_path);
-        }
-
-        f(self.tlib_path);
+    pub fn search_paths(&self) -> impl Iterator<Item = &'a SearchPath> {
+        let kind = self.kind;
+        self.search_paths.iter()
+            .filter(move |sp| sp.kind.matches(kind))
+            .chain(std::iter::once(self.tlib_path))
     }
 
     pub fn get_lib_path(&self) -> PathBuf {
@@ -55,7 +51,7 @@ impl<'a> FileSearch<'a> {
     pub fn search<F>(&self, mut pick: F)
         where F: FnMut(&Path, PathKind) -> FileMatch
     {
-        self.for_each_lib_search_path(|search_path| {
+        for search_path in self.search_paths() {
             debug!("searching {}", search_path.dir.display());
             fn is_rlib(p: &Path) -> bool {
                 p.extension() == Some("rlib".as_ref())
@@ -78,7 +74,7 @@ impl<'a> FileSearch<'a> {
                     }
                 }
             }
-        });
+        }
     }
 
     pub fn new(sysroot: &'a Path,
@@ -97,13 +93,11 @@ impl<'a> FileSearch<'a> {
         }
     }
 
-    // Returns a list of directories where target-specific dylibs might be located.
-    pub fn get_dylib_search_paths(&self) -> Vec<PathBuf> {
-        let mut paths = Vec::new();
-        self.for_each_lib_search_path(|search_path| {
-            paths.push(search_path.dir.to_path_buf());
-        });
-        paths
+    // Returns just the directories within the search paths.
+    pub fn search_path_dirs(&self) -> Vec<PathBuf> {
+        self.search_paths()
+            .map(|sp| sp.dir.to_path_buf())
+            .collect()
     }
 
     // Returns a list of directories where target-specific tool binaries are located.

src/librustc_codegen_llvm/back/link.rs

@@ -212,12 +212,7 @@ fn link_binary_output(sess: &Session,
 }
 
 fn archive_search_paths(sess: &Session) -> Vec<PathBuf> {
-    let mut search = Vec::new();
-    sess.target_filesearch(PathKind::Native).for_each_lib_search_path(|search_path| {
-        search.push(search_path.dir.to_path_buf());
-    });
-
-    search
+    sess.target_filesearch(PathKind::Native).search_path_dirs()
 }
 
 fn archive_config<'a>(sess: &'a Session,
@@ -1067,12 +1062,13 @@ fn link_args(cmd: &mut dyn Linker,
 fn add_local_native_libraries(cmd: &mut dyn Linker,
                               sess: &Session,
                               codegen_results: &CodegenResults) {
-    sess.target_filesearch(PathKind::All).for_each_lib_search_path(|search_path| {
+    let filesearch = sess.target_filesearch(PathKind::All);
+    for search_path in filesearch.search_paths() {
         match search_path.kind {
             PathKind::Framework => { cmd.framework_path(&search_path.dir); }
             _ => { cmd.include_path(&fix_windows_verbatim_for_gcc(&search_path.dir)); }
         }
-    });
+    }
 
     let relevant_libs = codegen_results.crate_info.used_libraries.iter().filter(|l| {
         relevant_lib(sess, l)

src/librustc_driver/driver.rs

@@ -975,7 +975,7 @@ where
         let mut old_path = OsString::new();
         if cfg!(windows) {
             old_path = env::var_os("PATH").unwrap_or(old_path);
-            let mut new_path = sess.host_filesearch(PathKind::All).get_dylib_search_paths();
+            let mut new_path = sess.host_filesearch(PathKind::All).search_path_dirs();
             for path in env::split_paths(&old_path) {
                 if !new_path.contains(&path) {
                     new_path.push(path);