Move metadata object generation for dylibs to the linker code

This deduplicates some code between codegen backends and may in the
future allow adding extra metadata that is only known at link time.

1 files changed, 7 insertions, 43 deletions

diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index bfad5137140..356f5418d34 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -15,11 +15,10 @@ use rustc_data_structures::unord::UnordMap;
 use rustc_hir::ItemId;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::lang_items::LangItem;
-use rustc_metadata::EncodedMetadata;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::middle::debugger_visualizer::{DebuggerVisualizerFile, DebuggerVisualizerType};
-use rustc_middle::middle::exported_symbols::SymbolExportKind;
-use rustc_middle::middle::{exported_symbols, lang_items};
+use rustc_middle::middle::exported_symbols::{self, SymbolExportKind};
+use rustc_middle::middle::lang_items;
 use rustc_middle::mir::BinOp;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem, MonoItemPartitions};
@@ -28,7 +27,7 @@ use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_session::Session;
-use rustc_session::config::{self, CrateType, EntryFnType, OutputType};
+use rustc_session::config::{self, CrateType, EntryFnType};
 use rustc_span::{DUMMY_SP, Symbol, sym};
 use rustc_symbol_mangling::mangle_internal_symbol;
 use rustc_trait_selection::infer::{BoundRegionConversionTime, TyCtxtInferExt};
@@ -37,7 +36,6 @@ use tracing::{debug, info};
 
 use crate::assert_module_sources::CguReuse;
 use crate::back::link::are_upstream_rust_objects_already_included;
-use crate::back::metadata::create_compressed_metadata_file;
 use crate::back::write::{
     ComputedLtoType, OngoingCodegen, compute_per_cgu_lto_type, start_async_codegen,
     submit_codegened_module_to_llvm, submit_post_lto_module_to_llvm, submit_pre_lto_module_to_llvm,
@@ -48,8 +46,7 @@ use crate::mir::operand::OperandValue;
 use crate::mir::place::PlaceRef;
 use crate::traits::*;
 use crate::{
-    CachedModuleCodegen, CodegenLintLevels, CompiledModule, CrateInfo, ModuleCodegen, ModuleKind,
-    errors, meth, mir,
+    CachedModuleCodegen, CodegenLintLevels, CrateInfo, ModuleCodegen, ModuleKind, errors, meth, mir,
 };
 
 pub(crate) fn bin_op_to_icmp_predicate(op: BinOp, signed: bool) -> IntPredicate {
@@ -669,11 +666,10 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
     backend: B,
     tcx: TyCtxt<'_>,
     target_cpu: String,
-    metadata: Option<&EncodedMetadata>,
 ) -> OngoingCodegen<B> {
     // Skip crate items and just output metadata in -Z no-codegen mode.
     if tcx.sess.opts.unstable_opts.no_codegen || !tcx.sess.opts.output_types.should_codegen() {
-        let ongoing_codegen = start_async_codegen(backend, tcx, target_cpu, None);
+        let ongoing_codegen = start_async_codegen(backend, tcx, target_cpu);
 
         ongoing_codegen.codegen_finished(tcx);
 
@@ -706,40 +702,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
         }
     }
 
-    let metadata_module = if let Some(metadata) = metadata {
-        // Emit compressed metadata object.
-        let metadata_cgu_name =
-            cgu_name_builder.build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata")).to_string();
-        tcx.sess.time("write_compressed_metadata", || {
-            let file_name = tcx.output_filenames(()).temp_path_for_cgu(
-                OutputType::Metadata,
-                &metadata_cgu_name,
-                tcx.sess.invocation_temp.as_deref(),
-            );
-            let data = create_compressed_metadata_file(
-                tcx.sess,
-                metadata,
-                &exported_symbols::metadata_symbol_name(tcx),
-            );
-            if let Err(error) = std::fs::write(&file_name, data) {
-                tcx.dcx().emit_fatal(errors::MetadataObjectFileWrite { error });
-            }
-            Some(CompiledModule {
-                name: metadata_cgu_name,
-                kind: ModuleKind::Metadata,
-                object: Some(file_name),
-                dwarf_object: None,
-                bytecode: None,
-                assembly: None,
-                llvm_ir: None,
-                links_from_incr_cache: Vec::new(),
-            })
-        })
-    } else {
-        None
-    };
-
-    let ongoing_codegen = start_async_codegen(backend.clone(), tcx, target_cpu, metadata_module);
+    let ongoing_codegen = start_async_codegen(backend.clone(), tcx, target_cpu);
 
     // Codegen an allocator shim, if necessary.
     if let Some(kind) = allocator_kind_for_codegen(tcx) {
@@ -1010,6 +973,7 @@ impl CrateInfo {
             windows_subsystem,
             natvis_debugger_visualizers: Default::default(),
             lint_levels: CodegenLintLevels::from_tcx(tcx),
+            metadata_symbol: exported_symbols::metadata_symbol_name(tcx),
         };
 
         info.native_libraries.reserve(n_crates);