Move metadata object generation for dylibs to the linker code

compiler/rustc_codegen_cranelift/src/driver/aot.rs

@@ -11,15 +11,13 @@ use std::thread::JoinHandle;
 use cranelift_object::{ObjectBuilder, ObjectModule};
 use rustc_codegen_ssa::assert_module_sources::CguReuse;
 use rustc_codegen_ssa::back::link::ensure_removed;
-use rustc_codegen_ssa::back::metadata::create_compressed_metadata_file;
 use rustc_codegen_ssa::base::determine_cgu_reuse;
 use rustc_codegen_ssa::{
     CodegenResults, CompiledModule, CrateInfo, ModuleKind, errors as ssa_errors,
 };
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::{IntoDynSyncSend, par_map};
-use rustc_metadata::EncodedMetadata;
 use rustc_metadata::fs::copy_to_stdout;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
@@ -61,8 +59,6 @@ impl<HCX> HashStable<HCX> for OngoingModuleCodegen {
 pub(crate) struct OngoingCodegen {
     modules: Vec<OngoingModuleCodegen>,
     allocator_module: Option<CompiledModule>,
-    metadata_module: Option<CompiledModule>,
-    metadata: EncodedMetadata,
     crate_info: CrateInfo,
     concurrency_limiter: ConcurrencyLimiter,
 }
@@ -134,8 +130,6 @@ impl OngoingCodegen {
         let codegen_results = CodegenResults {
             modules,
             allocator_module: self.allocator_module,
-            metadata_module: self.metadata_module,
-            metadata: self.metadata,
             crate_info: self.crate_info,
         };
 
@@ -646,42 +640,6 @@ fn module_codegen(
     }))
 }
 
-fn emit_metadata_module(tcx: TyCtxt<'_>, metadata: &EncodedMetadata) -> CompiledModule {
-    use rustc_middle::mir::mono::CodegenUnitNameBuilder;
-
-    let _timer = tcx.sess.timer("write compressed metadata");
-
-    let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx);
-    let metadata_cgu_name = cgu_name_builder
-        .build_cgu_name(LOCAL_CRATE, ["crate"], Some("metadata"))
-        .as_str()
-        .to_string();
-
-    let tmp_file = tcx.output_filenames(()).temp_path_for_cgu(
-        OutputType::Metadata,
-        &metadata_cgu_name,
-        tcx.sess.invocation_temp.as_deref(),
-    );
-
-    let symbol_name = rustc_middle::middle::exported_symbols::metadata_symbol_name(tcx);
-    let obj = create_compressed_metadata_file(tcx.sess, metadata, &symbol_name);
-
-    if let Err(err) = std::fs::write(&tmp_file, obj) {
-        tcx.dcx().fatal(format!("error writing metadata object file: {}", err));
-    }
-
-    CompiledModule {
-        name: metadata_cgu_name,
-        kind: ModuleKind::Metadata,
-        object: Some(tmp_file),
-        dwarf_object: None,
-        bytecode: None,
-        assembly: None,
-        llvm_ir: None,
-        links_from_incr_cache: Vec::new(),
-    }
-}
-
 fn emit_allocator_module(tcx: TyCtxt<'_>) -> Option<CompiledModule> {
     let mut allocator_module = make_module(tcx.sess, "allocator_shim".to_string());
     let created_alloc_shim = crate::allocator::codegen(tcx, &mut allocator_module);
@@ -706,11 +664,7 @@ fn emit_allocator_module(tcx: TyCtxt<'_>) -> Option<CompiledModule> {
     }
 }
 
-pub(crate) fn run_aot(
-    tcx: TyCtxt<'_>,
-    metadata: EncodedMetadata,
-    need_metadata_module: bool,
-) -> Box<OngoingCodegen> {
+pub(crate) fn run_aot(tcx: TyCtxt<'_>) -> Box<OngoingCodegen> {
     // FIXME handle `-Ctarget-cpu=native`
     let target_cpu = match tcx.sess.opts.cg.target_cpu {
         Some(ref name) => name,
@@ -726,8 +680,6 @@ pub(crate) fn run_aot(
         return Box::new(OngoingCodegen {
             modules: vec![],
             allocator_module: None,
-            metadata_module: None,
-            metadata,
             crate_info: CrateInfo::new(tcx, target_cpu),
             concurrency_limiter: ConcurrencyLimiter::new(0),
         });
@@ -787,14 +739,9 @@ pub(crate) fn run_aot(
 
     let allocator_module = emit_allocator_module(tcx);
 
-    let metadata_module =
-        if need_metadata_module { Some(emit_metadata_module(tcx, &metadata)) } else { None };
-
     Box::new(OngoingCodegen {
         modules,
         allocator_module,
-        metadata_module,
-        metadata,
         crate_info: CrateInfo::new(tcx, target_cpu),
         concurrency_limiter: concurrency_limiter.0,
     })

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -46,7 +46,6 @@ use cranelift_codegen::isa::TargetIsa;
 use cranelift_codegen::settings::{self, Configurable};
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_codegen_ssa::{CodegenResults, TargetConfig};
-use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_session::Session;
 use rustc_session::config::OutputFilenames;
@@ -238,12 +237,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
         println!("Cranelift version: {}", cranelift_codegen::VERSION);
     }
 
-    fn codegen_crate(
-        &self,
-        tcx: TyCtxt<'_>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any> {
+    fn codegen_crate(&self, tcx: TyCtxt<'_>) -> Box<dyn Any> {
         info!("codegen crate {}", tcx.crate_name(LOCAL_CRATE));
         let config = self.config.clone().unwrap_or_else(|| {
             BackendConfig::from_opts(&tcx.sess.opts.cg.llvm_args)
@@ -256,7 +250,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
             #[cfg(not(feature = "jit"))]
             tcx.dcx().fatal("jit support was disabled when compiling rustc_codegen_cranelift");
         } else {
-            driver::aot::run_aot(tcx, metadata, need_metadata_module)
+            driver::aot::run_aot(tcx)
         }
     }
 

compiler/rustc_codegen_gcc/src/lib.rs

@@ -48,7 +48,6 @@ extern crate rustc_index;
 #[cfg(feature = "master")]
 extern crate rustc_interface;
 extern crate rustc_macros;
-extern crate rustc_metadata;
 extern crate rustc_middle;
 extern crate rustc_session;
 extern crate rustc_span;
@@ -106,7 +105,6 @@ use rustc_codegen_ssa::{CodegenResults, CompiledModule, ModuleCodegen, TargetCon
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync::IntoDynSyncSend;
 use rustc_errors::DiagCtxtHandle;
-use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::util::Providers;
@@ -230,20 +228,9 @@ impl CodegenBackend for GccCodegenBackend {
         providers.global_backend_features = |tcx, ()| gcc_util::global_gcc_features(tcx.sess, true)
     }
 
-    fn codegen_crate(
-        &self,
-        tcx: TyCtxt<'_>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any> {
+    fn codegen_crate(&self, tcx: TyCtxt<'_>) -> Box<dyn Any> {
         let target_cpu = target_cpu(tcx.sess);
-        let res = codegen_crate(
-            self.clone(),
-            tcx,
-            target_cpu.to_string(),
-            metadata,
-            need_metadata_module,
-        );
+        let res = codegen_crate(self.clone(), tcx, target_cpu.to_string());
 
         Box::new(res)
     }

compiler/rustc_codegen_llvm/src/lib.rs

@@ -341,18 +341,11 @@ impl CodegenBackend for LlvmCodegenBackend {
         target_config(sess)
     }
 
-    fn codegen_crate<'tcx>(
-        &self,
-        tcx: TyCtxt<'tcx>,
-        metadata: EncodedMetadata,
-        need_metadata_module: bool,
-    ) -> Box<dyn Any> {
+    fn codegen_crate<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Box<dyn Any> {
         Box::new(rustc_codegen_ssa::base::codegen_crate(
             LlvmCodegenBackend(()),
             tcx,
             crate::llvm_util::target_cpu(tcx.sess).to_string(),
-            metadata,
-            need_metadata_module,
         ))
     }
 
@@ -377,14 +370,20 @@ impl CodegenBackend for LlvmCodegenBackend {
         (codegen_results, work_products)
     }
 
-    fn link(&self, sess: &Session, codegen_results: CodegenResults, outputs: &OutputFilenames) {
+    fn link(
+        &self,
+        sess: &Session,
+        codegen_results: CodegenResults,
+        metadata: EncodedMetadata,
+        outputs: &OutputFilenames,
+    ) {
         use rustc_codegen_ssa::back::link::link_binary;
 
         use crate::back::archive::LlvmArchiveBuilderBuilder;
 
         // Run the linker on any artifacts that resulted from the LLVM run.
         // This should produce either a finished executable or library.
-        link_binary(sess, &LlvmArchiveBuilderBuilder, codegen_results, outputs);
+        link_binary(sess, &LlvmArchiveBuilderBuilder, codegen_results, metadata, outputs);
     }
 }
 

compiler/rustc_codegen_ssa/messages.ftl

@@ -200,8 +200,6 @@ codegen_ssa_linking_failed = linking with `{$linker_path}` failed: {$exit_status
 codegen_ssa_malformed_cgu_name =
     found malformed codegen unit name `{$user_path}`. codegen units names must always start with the name of the crate (`{$crate_name}` in this case).
 
-codegen_ssa_metadata_object_file_write = error writing metadata object file: {$error}
-
 codegen_ssa_missing_cpp_build_tool_component = or a necessary component may be missing from the "C++ build tools" workload
 
 codegen_ssa_missing_features = add the missing features in a `target_feature` attribute

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -14,11 +14,12 @@ use object::read::macho::FatArch;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_data_structures::memmap::Mmap;
 use rustc_fs_util::TempDirBuilder;
+use rustc_metadata::EncodedMetadata;
 use rustc_session::Session;
 use rustc_span::Symbol;
 use tracing::trace;
 
-use super::metadata::search_for_section;
+use super::metadata::{create_compressed_metadata_file, search_for_section};
 use crate::common;
 // Re-exporting for rustc_codegen_llvm::back::archive
 pub use crate::errors::{ArchiveBuildFailure, ExtractBundledLibsError, UnknownArchiveKind};
@@ -58,6 +59,15 @@ impl From<ImportLibraryItem> for COFFShortExport {
 pub trait ArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a>;
 
+    fn create_dylib_metadata_wrapper(
+        &self,
+        sess: &Session,
+        metadata: &EncodedMetadata,
+        symbol_name: &str,
+    ) -> Vec<u8> {
+        create_compressed_metadata_file(sess, metadata, symbol_name)
+    }
+
     /// Creates a DLL Import Library <https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-creation#creating-an-import-library>.
     /// and returns the path on disk to that import library.
     /// This functions doesn't take `self` so that it can be called from