Wrap bundled static libraries into object files

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -4,8 +4,11 @@ use rustc_session::cstore::DllImport;
 use rustc_session::Session;
 use rustc_span::symbol::Symbol;
 
+use super::metadata::search_for_section;
+
 use object::read::archive::ArchiveFile;
 
+use std::error::Error;
 use std::fs::File;
 use std::io;
 use std::path::{Path, PathBuf};
@@ -56,6 +59,9 @@ pub trait ArchiveBuilderBuilder {
             if !bundled_lib_file_names.contains(&Symbol::intern(name)) {
                 continue; // We need to extract only native libraries.
             }
+            let data = search_for_section(rlib, data, ".bundled_lib").map_err(|e| {
+                ExtractBundledLibsError::ExtractSection { rlib, error: Box::<dyn Error>::from(e) }
+            })?;
             std::fs::write(&outdir.join(&name), data)
                 .map_err(|e| ExtractBundledLibsError::WriteFile { rlib, error: Box::new(e) })?;
         }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -8,7 +8,7 @@ use rustc_errors::{ErrorGuaranteed, Handler};
 use rustc_fs_util::fix_windows_verbatim_for_gcc;
 use rustc_hir::def_id::CrateNum;
 use rustc_metadata::find_native_static_library;
-use rustc_metadata::fs::{emit_metadata, METADATA_FILENAME};
+use rustc_metadata::fs::{emit_wrapper_file, METADATA_FILENAME};
 use rustc_middle::middle::dependency_format::Linkage;
 use rustc_middle::middle::exported_symbols::SymbolExportKind;
 use rustc_session::config::{self, CFGuard, CrateType, DebugInfo, LdImpl, Lto, Strip};
@@ -29,7 +29,7 @@ use rustc_target::spec::{RelocModel, RelroLevel, SanitizerSet, SplitDebuginfo, T
 use super::archive::{ArchiveBuilder, ArchiveBuilderBuilder};
 use super::command::Command;
 use super::linker::{self, Linker};
-use super::metadata::{create_rmeta_file, MetadataPosition};
+use super::metadata::{create_wrapper_file, MetadataPosition};
 use super::rpath::{self, RPathConfig};
 use crate::{
     errors, looks_like_rust_object_file, CodegenResults, CompiledModule, CrateInfo, NativeLib,
@@ -44,7 +44,7 @@ use std::borrow::Borrow;
 use std::cell::OnceCell;
 use std::collections::BTreeSet;
 use std::ffi::OsString;
-use std::fs::{File, OpenOptions};
+use std::fs::{read, File, OpenOptions};
 use std::io::{BufWriter, Write};
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
@@ -292,8 +292,8 @@ fn link_rlib<'a>(
     let trailing_metadata = match flavor {
         RlibFlavor::Normal => {
             let (metadata, metadata_position) =
-                create_rmeta_file(sess, codegen_results.metadata.raw_data());
-            let metadata = emit_metadata(sess, &metadata, tmpdir);
+                create_wrapper_file(sess, b".rmeta".to_vec(), codegen_results.metadata.raw_data());
+            let metadata = emit_wrapper_file(sess, &metadata, tmpdir, METADATA_FILENAME);
             match metadata_position {
                 MetadataPosition::First => {
                     // Most of the time metadata in rlib files is wrapped in a "dummy" object
@@ -376,12 +376,18 @@ fn link_rlib<'a>(
             let location =
                 find_native_static_library(name.as_str(), lib.verbatim, &lib_search_paths, sess);
             if sess.opts.unstable_opts.packed_bundled_libs && flavor == RlibFlavor::Normal {
-                packed_bundled_libs.push(find_native_static_library(
-                    lib.filename.unwrap().as_str(),
+                let filename = lib.filename.unwrap();
+                let lib_path = find_native_static_library(
+                    filename.as_str(),
                     Some(true),
                     &lib_search_paths,
                     sess,
-                ));
+                );
+                let src = read(lib_path)
+                    .map_err(|e| sess.emit_fatal(errors::ReadFileError { message: e }))?;
+                let (data, _) = create_wrapper_file(sess, b".bundled_lib".to_vec(), &src);
+                let wrapper_file = emit_wrapper_file(sess, &data, tmpdir, filename.as_str());
+                packed_bundled_libs.push(wrapper_file);
                 continue;
             }
             ab.add_archive(&location, Box::new(|_| false)).unwrap_or_else(|error| {

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -60,7 +60,7 @@ impl MetadataLoader for DefaultMetadataLoader {
                     let data = entry
                         .data(data)
                         .map_err(|e| format!("failed to parse rlib '{}': {}", path.display(), e))?;
-                    return search_for_metadata(path, data, ".rmeta");
+                    return search_for_section(path, data, ".rmeta");
                 }
             }
 
@@ -69,11 +69,11 @@ impl MetadataLoader for DefaultMetadataLoader {
     }
 
     fn get_dylib_metadata(&self, _target: &Target, path: &Path) -> Result<MetadataRef, String> {
-        load_metadata_with(path, |data| search_for_metadata(path, data, ".rustc"))
+        load_metadata_with(path, |data| search_for_section(path, data, ".rustc"))
     }
 }
 
-fn search_for_metadata<'a>(
+pub(super) fn search_for_section<'a>(
     path: &Path,
     bytes: &'a [u8],
     section: &str,
@@ -223,7 +223,11 @@ pub enum MetadataPosition {
 // * ELF - All other targets are similar to Windows in that there's a
 //   `SHF_EXCLUDE` flag we can set on sections in an object file to get
 //   automatically removed from the final output.
-pub fn create_rmeta_file(sess: &Session, metadata: &[u8]) -> (Vec<u8>, MetadataPosition) {
+pub fn create_wrapper_file(
+    sess: &Session,
+    section_name: Vec<u8>,
+    data: &[u8],
+) -> (Vec<u8>, MetadataPosition) {
     let Some(mut file) = create_object_file(sess) else {
         // This is used to handle all "other" targets. This includes targets
         // in two categories:
@@ -241,11 +245,11 @@ pub fn create_rmeta_file(sess: &Session, metadata: &[u8]) -> (Vec<u8>, MetadataP
         // WebAssembly and for targets not supported by the `object` crate
         // yet it means that work will need to be done in the `object` crate
         // to add a case above.
-        return (metadata.to_vec(), MetadataPosition::Last);
+        return (data.to_vec(), MetadataPosition::Last);
     };
     let section = file.add_section(
         file.segment_name(StandardSegment::Debug).to_vec(),
-        b".rmeta".to_vec(),
+        section_name,
         SectionKind::Debug,
     );
     match file.format() {
@@ -259,7 +263,7 @@ pub fn create_rmeta_file(sess: &Session, metadata: &[u8]) -> (Vec<u8>, MetadataP
         }
         _ => {}
     };
-    file.append_section_data(section, metadata, 1);
+    file.append_section_data(section, data, 1);
     (file.write().unwrap(), MetadataPosition::First)
 }
 

compiler/rustc_codegen_ssa/src/errors.rs

@@ -507,6 +507,9 @@ pub enum ExtractBundledLibsError<'a> {
 
     #[diag(codegen_ssa_extract_bundled_libs_write_file)]
     WriteFile { rlib: &'a Path, error: Box<dyn std::error::Error> },
+
+    #[diag(codegen_ssa_extract_bundled_libs_write_file)]
+    ExtractSection { rlib: &'a Path, error: Box<dyn std::error::Error> },
 }
 
 #[derive(Diagnostic)]
@@ -521,3 +524,9 @@ pub enum AppleSdkRootError<'a> {
     #[diag(codegen_ssa_apple_sdk_error_sdk_path)]
     SdkPath { sdk_name: &'a str, error: Error },
 }
+
+#[derive(Diagnostic)]
+#[diag(codegen_ssa_read_file)]
+pub struct ReadFileError {
+    pub message: std::io::Error,
+}

compiler/rustc_error_messages/locales/en-US/codegen_ssa.ftl

@@ -182,3 +182,5 @@ codegen_ssa_extract_bundled_libs_write_file = failed to write file '{$rlib}': {$
 codegen_ssa_unsupported_arch = unsupported arch `{$arch}` for os `{$os}`
 
 codegen_ssa_apple_sdk_error_sdk_path = failed to get {$sdk_name} SDK path: {error}
+
+codegen_ssa_read_file = failed to read file: {message}

compiler/rustc_metadata/src/fs.rs

@@ -22,9 +22,14 @@ pub const METADATA_FILENAME: &str = "lib.rmeta";
 /// building an `.rlib` (stomping over one another), or writing an `.rmeta` into a
 /// directory being searched for `extern crate` (observing an incomplete file).
 /// The returned path is the temporary file containing the complete metadata.
-pub fn emit_metadata(sess: &Session, metadata: &[u8], tmpdir: &MaybeTempDir) -> PathBuf {
-    let out_filename = tmpdir.as_ref().join(METADATA_FILENAME);
-    let result = fs::write(&out_filename, metadata);
+pub fn emit_wrapper_file(
+    sess: &Session,
+    data: &[u8],
+    tmpdir: &MaybeTempDir,
+    name: &str,
+) -> PathBuf {
+    let out_filename = tmpdir.as_ref().join(name);
+    let result = fs::write(&out_filename, data);
 
     if let Err(err) = result {
         sess.emit_fatal(FailedWriteError { filename: out_filename, err });

compiler/rustc_metadata/src/lib.rs

@@ -41,6 +41,6 @@ pub mod errors;
 pub mod fs;
 pub mod locator;
 
-pub use fs::{emit_metadata, METADATA_FILENAME};
+pub use fs::{emit_wrapper_file, METADATA_FILENAME};
 pub use native_libs::find_native_static_library;
 pub use rmeta::{encode_metadata, EncodedMetadata, METADATA_HEADER};