Auto merge of rust-lang#98098 - bjorn3:archive_refactor, r=michaelwoerister

Remove the source archive functionality of ArchiveWriter

We now build archives through strictly additive means rather than taking an existing archive and potentially substracting parts. This is simpler and makes it easier to swap out the archive writer in rust-lang#97485.

Author: bors

src/archive.rs

@@ -32,7 +32,7 @@ pub struct ArArchiveBuilder<'a> {
 }
 
 impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
-    fn new(sess: &'a Session, output: &Path, input: Option<&Path>) -> Self {
+    fn new(sess: &'a Session, output: &Path) -> Self {
         let config = ArchiveConfig {
             sess,
             dst: output.to_path_buf(),
@@ -41,48 +41,13 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
             use_gnu_style_archive: sess.target.options.archive_format == "gnu",
         };
 
-        let (src_archives, entries) = if let Some(input) = input {
-            let mut archive = ar::Archive::new(File::open(input).unwrap());
-            let mut entries = Vec::new();
-
-            let mut i = 0;
-            while let Some(entry) = archive.next_entry() {
-                let entry = entry.unwrap();
-                entries.push((
-                    String::from_utf8(entry.header().identifier().to_vec()).unwrap(),
-                    ArchiveEntry::FromArchive {
-                        archive_index: 0,
-                        entry_index: i,
-                    },
-                ));
-                i += 1;
-            }
-
-            (vec![(input.to_owned(), archive)], entries)
-        } else {
-            (vec![], Vec::new())
-        };
-
         ArArchiveBuilder {
             config,
-            src_archives,
-            entries,
+            src_archives: vec![],
+            entries: vec![],
         }
     }
 
-    fn src_files(&mut self) -> Vec<String> {
-        self.entries.iter().map(|(name, _)| name.clone()).collect()
-    }
-
-    fn remove_file(&mut self, name: &str) {
-        let index = self
-            .entries
-            .iter()
-            .position(|(entry_name, _)| entry_name == name)
-            .expect("Tried to remove file not existing in src archive");
-        self.entries.remove(index);
-    }
-
     fn add_file(&mut self, file: &Path) {
         self.entries.push((
             file.file_name().unwrap().to_str().unwrap().to_string(),
@@ -113,7 +78,7 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
         Ok(())
     }
 
-    fn build(mut self) {
+    fn build(mut self) -> bool {
         use std::process::Command;
 
         fn add_file_using_ar(archive: &Path, file: &Path) {
@@ -146,6 +111,8 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
             BuilderKind::Bsd(ar::Builder::new(File::create(&self.config.dst).unwrap()))
         };
 
+        let any_members = !self.entries.is_empty();
+
         // Add all files
         for (entry_name, entry) in self.entries.into_iter() {
             match entry {
@@ -206,6 +173,8 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
         if !status.success() {
             self.config.sess.fatal(&format!("Ranlib exited with code {:?}", status.code()));
         }
+
+        any_members
     }
 
     fn inject_dll_import_lib(&mut self, _lib_name: &str, _dll_imports: &[DllImport], _tmpdir: &MaybeTempDir) {