diff --git a/compiler/rustc_codegen_gcc/src/back/lto.rs b/compiler/rustc_codegen_gcc/src/back/lto.rs
index a08e3dc0df87..347a15a392af 100644
--- a/compiler/rustc_codegen_gcc/src/back/lto.rs
+++ b/compiler/rustc_codegen_gcc/src/back/lto.rs
@@ -26,7 +26,7 @@
 use rustc_codegen_ssa::back::lto::SerializedModule;
 use rustc_codegen_ssa::back::write::{CodegenContext, FatLtoInput, SharedEmitter};
 use rustc_codegen_ssa::traits::*;
-use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, looks_like_rust_object_file};
+use rustc_codegen_ssa::{CompiledModule, ModuleCodegen, ModuleKind, looks_like_rust_object_file};
 use rustc_data_structures::memmap::Mmap;
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_errors::{DiagCtxt, DiagCtxtHandle};
@@ -34,7 +34,7 @@
 use rustc_session::config::Lto;
 use tempfile::{TempDir, tempdir};
 
-use crate::back::write::save_temp_bitcode;
+use crate::back::write::{codegen, save_temp_bitcode};
 use crate::errors::LtoBitcodeFromRlib;
 use crate::{GccCodegenBackend, GccContext, LtoMode, to_gcc_opt_level};
 
@@ -112,7 +112,7 @@ pub(crate) fn run_fat(
     shared_emitter: &SharedEmitter,
     each_linked_rlib_for_lto: &[PathBuf],
     modules: Vec<FatLtoInput<GccCodegenBackend>>,
-) -> ModuleCodegen<GccContext> {
+) -> CompiledModule {
     let dcx = DiagCtxt::new(Box::new(shared_emitter.clone()));
     let dcx = dcx.handle();
     let lto_data = prepare_lto(cgcx, each_linked_rlib_for_lto, dcx);
@@ -132,12 +132,12 @@ pub(crate) fn run_fat(
 fn fat_lto(
     cgcx: &CodegenContext,
     prof: &SelfProfilerRef,
-    _dcx: DiagCtxtHandle<'_>,
+    dcx: DiagCtxtHandle<'_>,
     modules: Vec<FatLtoInput<GccCodegenBackend>>,
     mut serialized_modules: Vec<(SerializedModule<ModuleBuffer>, CString)>,
     tmp_path: TempDir,
     //symbols_below_threshold: &[String],
-) -> ModuleCodegen<GccContext> {
+) -> CompiledModule {
     let _timer = prof.generic_activity("GCC_fat_lto_build_monolithic_module");
     info!("going for a fat lto");
 
@@ -260,7 +260,7 @@ fn fat_lto(
     // of now.
     module.module_llvm.temp_dir = Some(tmp_path);
 
-    module
+    codegen(cgcx, prof, dcx, module, &cgcx.module_config)
 }
 
 pub struct ModuleBuffer(PathBuf);
diff --git a/compiler/rustc_codegen_gcc/src/back/write.rs b/compiler/rustc_codegen_gcc/src/back/write.rs
index ddf13558027b..24ea2b66ba7d 100644
--- a/compiler/rustc_codegen_gcc/src/back/write.rs
+++ b/compiler/rustc_codegen_gcc/src/back/write.rs
@@ -2,12 +2,10 @@
 
 use gccjit::{Context, OutputKind};
 use rustc_codegen_ssa::back::link::ensure_removed;
-use rustc_codegen_ssa::back::write::{
-    BitcodeSection, CodegenContext, EmitObj, ModuleConfig, SharedEmitter,
-};
+use rustc_codegen_ssa::back::write::{BitcodeSection, CodegenContext, EmitObj, ModuleConfig};
 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen};
 use rustc_data_structures::profiling::SelfProfilerRef;
-use rustc_errors::DiagCtxt;
+use rustc_errors::DiagCtxtHandle;
 use rustc_fs_util::link_or_copy;
 use rustc_log::tracing::debug;
 use rustc_session::config::OutputType;
@@ -20,13 +18,10 @@
 pub(crate) fn codegen(
     cgcx: &CodegenContext,
     prof: &SelfProfilerRef,
-    shared_emitter: &SharedEmitter,
+    dcx: DiagCtxtHandle<'_>,
     module: ModuleCodegen<GccContext>,
     config: &ModuleConfig,
 ) -> CompiledModule {
-    let dcx = DiagCtxt::new(Box::new(shared_emitter.clone()));
-    let dcx = dcx.handle();
-
     let _timer = prof.generic_activity_with_arg("GCC_module_codegen", &*module.name);
     {
         let context = &module.module_llvm.context;
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index 3409c0e02340..ed809eb33a53 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -92,7 +92,7 @@
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::sync::IntoDynSyncSend;
-use rustc_errors::DiagCtxtHandle;
+use rustc_errors::{DiagCtxt, DiagCtxtHandle};
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::util::Providers;
@@ -429,7 +429,7 @@ impl WriteBackendMethods for GccCodegenBackend {
     type ModuleBuffer = ModuleBuffer;
     type ThinData = ();
 
-    fn run_and_optimize_fat_lto(
+    fn optimize_and_codegen_fat_lto(
         cgcx: &CodegenContext,
         prof: &SelfProfilerRef,
         shared_emitter: &SharedEmitter,
@@ -438,7 +438,7 @@ fn run_and_optimize_fat_lto(
         _exported_symbols_for_lto: &[String],
         each_linked_rlib_for_lto: &[PathBuf],
         modules: Vec<FatLtoInput<Self>>,
-    ) -> ModuleCodegen<Self::Module> {
+    ) -> CompiledModule {
         back::lto::run_fat(cgcx, prof, shared_emitter, each_linked_rlib_for_lto, modules)
     }
 
@@ -465,13 +465,13 @@ fn optimize(
         module.module_llvm.context.set_optimization_level(to_gcc_opt_level(config.opt_level));
     }
 
-    fn optimize_thin(
+    fn optimize_and_codegen_thin(
         _cgcx: &CodegenContext,
         _prof: &SelfProfilerRef,
         _shared_emitter: &SharedEmitter,
         _tm_factory: TargetMachineFactoryFn<Self>,
         _thin: ThinModule<Self>,
-    ) -> ModuleCodegen<Self::Module> {
+    ) -> CompiledModule {
         unreachable!()
     }
 
@@ -482,7 +482,9 @@ fn codegen(
         module: ModuleCodegen<Self::Module>,
         config: &ModuleConfig,
     ) -> CompiledModule {
-        back::write::codegen(cgcx, prof, shared_emitter, module, config)
+        let dcx = DiagCtxt::new(Box::new(shared_emitter.clone()));
+        let dcx = dcx.handle();
+        back::write::codegen(cgcx, prof, dcx, module, config)
     }
 
     fn serialize_module(_module: Self::Module, _is_thin: bool) -> Self::ModuleBuffer {
diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs
index c235437aee75..f6cd229cb106 100644
--- a/compiler/rustc_codegen_llvm/src/back/lto.rs
+++ b/compiler/rustc_codegen_llvm/src/back/lto.rs
@@ -12,7 +12,7 @@
     CodegenContext, FatLtoInput, SharedEmitter, TargetMachineFactoryFn,
 };
 use rustc_codegen_ssa::traits::*;
-use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, looks_like_rust_object_file};
+use rustc_codegen_ssa::{CompiledModule, ModuleCodegen, ModuleKind, looks_like_rust_object_file};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::memmap::Mmap;
 use rustc_data_structures::profiling::SelfProfilerRef;
@@ -24,7 +24,8 @@
 use tracing::{debug, info};
 
 use crate::back::write::{
-    self, CodegenDiagnosticsStage, DiagnosticHandlers, bitcode_section_name, save_temp_bitcode,
+    self, CodegenDiagnosticsStage, DiagnosticHandlers, bitcode_section_name, codegen,
+    save_temp_bitcode,
 };
 use crate::errors::{LlvmError, LtoBitcodeFromRlib};
 use crate::llvm::{self, build_string};
@@ -709,13 +710,13 @@ fn data(&self) -> &[u8] {
     }
 }
 
-pub(crate) fn optimize_thin_module(
+pub(crate) fn optimize_and_codegen_thin_module(
     cgcx: &CodegenContext,
     prof: &SelfProfilerRef,
     shared_emitter: &SharedEmitter,
     tm_factory: TargetMachineFactoryFn<LlvmCodegenBackend>,
     thin_module: ThinModule<LlvmCodegenBackend>,
-) -> ModuleCodegen<ModuleLlvm> {
+) -> CompiledModule {
     let dcx = DiagCtxt::new(Box::new(shared_emitter.clone()));
     let dcx = dcx.handle();
 
@@ -794,7 +795,7 @@ pub(crate) fn optimize_thin_module(
             save_temp_bitcode(cgcx, &module, "thin-lto-after-pm");
         }
     }
-    module
+    codegen(cgcx, prof, shared_emitter, module, &cgcx.module_config)
 }
 
 /// Maps LLVM module identifiers to their corresponding LLVM LTO cache keys
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 46b26832d207..cda1e470fce4 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -135,7 +135,7 @@ impl WriteBackendMethods for LlvmCodegenBackend {
     type ModuleBuffer = back::lto::ModuleBuffer;
     type TargetMachine = OwnedTargetMachine;
     type ThinData = back::lto::ThinData;
-    fn run_and_optimize_fat_lto(
+    fn optimize_and_codegen_fat_lto(
         cgcx: &CodegenContext,
         prof: &SelfProfilerRef,
         shared_emitter: &SharedEmitter,
@@ -143,7 +143,7 @@ fn run_and_optimize_fat_lto(
         exported_symbols_for_lto: &[String],
         each_linked_rlib_for_lto: &[PathBuf],
         modules: Vec<FatLtoInput<Self>>,
-    ) -> ModuleCodegen<Self::Module> {
+    ) -> CompiledModule {
         let mut module = back::lto::run_fat(
             cgcx,
             prof,
@@ -158,7 +158,7 @@ fn run_and_optimize_fat_lto(
         let dcx = dcx.handle();
         back::lto::run_pass_manager(cgcx, prof, dcx, &mut module, false);
 
-        module
+        back::write::codegen(cgcx, prof, shared_emitter, module, &cgcx.module_config)
     }
     fn run_thin_lto(
         cgcx: &CodegenContext,
@@ -188,14 +188,14 @@ fn optimize(
     ) {
         back::write::optimize(cgcx, prof, shared_emitter, module, config)
     }
-    fn optimize_thin(
+    fn optimize_and_codegen_thin(
         cgcx: &CodegenContext,
         prof: &SelfProfilerRef,
         shared_emitter: &SharedEmitter,
         tm_factory: TargetMachineFactoryFn<LlvmCodegenBackend>,
         thin: ThinModule<Self>,
-    ) -> ModuleCodegen<Self::Module> {
-        back::lto::optimize_thin_module(cgcx, prof, shared_emitter, tm_factory, thin)
+    ) -> CompiledModule {
+        back::lto::optimize_and_codegen_thin_module(cgcx, prof, shared_emitter, tm_factory, thin)
     }
     fn codegen(
         cgcx: &CodegenContext,
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 55951fde62f6..31a77952ea38 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -988,7 +988,7 @@ fn do_fat_lto<B: ExtraBackendMethods>(
         needs_fat_lto.push(FatLtoInput::Serialized { name: wp.cgu_name, buffer: module })
     }
 
-    let module = B::run_and_optimize_fat_lto(
+    B::optimize_and_codegen_fat_lto(
         cgcx,
         prof,
         &shared_emitter,
@@ -996,8 +996,7 @@ fn do_fat_lto<B: ExtraBackendMethods>(
         exported_symbols_for_lto,
         each_linked_rlib_for_lto,
         needs_fat_lto,
-    );
-    B::codegen(cgcx, prof, &shared_emitter, module, &cgcx.module_config)
+    )
 }
 
 fn do_thin_lto<B: ExtraBackendMethods>(
@@ -1162,8 +1161,7 @@ fn execute_thin_lto_work_item<B: ExtraBackendMethods>(
 ) -> CompiledModule {
     let _timer = prof.generic_activity_with_arg("codegen_module_perform_lto", module.name());
 
-    let module = B::optimize_thin(cgcx, prof, &shared_emitter, tm_factory, module);
-    B::codegen(cgcx, prof, &shared_emitter, module, &cgcx.module_config)
+    B::optimize_and_codegen_thin(cgcx, prof, &shared_emitter, tm_factory, module)
 }
 
 /// Messages sent to the coordinator.
diff --git a/compiler/rustc_codegen_ssa/src/traits/write.rs b/compiler/rustc_codegen_ssa/src/traits/write.rs
index 89bb1e6e88d5..d218b0f31722 100644
--- a/compiler/rustc_codegen_ssa/src/traits/write.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/write.rs
@@ -18,7 +18,7 @@ pub trait WriteBackendMethods: Clone + 'static {
 
     /// Performs fat LTO by merging all modules into a single one, running autodiff
     /// if necessary and running any further optimizations
-    fn run_and_optimize_fat_lto(
+    fn optimize_and_codegen_fat_lto(
         cgcx: &CodegenContext,
         prof: &SelfProfilerRef,
         shared_emitter: &SharedEmitter,
@@ -26,7 +26,7 @@ fn run_and_optimize_fat_lto(
         exported_symbols_for_lto: &[String],
         each_linked_rlib_for_lto: &[PathBuf],
         modules: Vec<FatLtoInput<Self>>,
-    ) -> ModuleCodegen<Self::Module>;
+    ) -> CompiledModule;
     /// Performs thin LTO by performing necessary global analysis and returning two
     /// lists, one of the modules that need optimization and another for modules that
     /// can simply be copied over from the incr. comp. cache.
@@ -46,13 +46,13 @@ fn optimize(
         module: &mut ModuleCodegen<Self::Module>,
         config: &ModuleConfig,
     );
-    fn optimize_thin(
+    fn optimize_and_codegen_thin(
         cgcx: &CodegenContext,
         prof: &SelfProfilerRef,
         shared_emitter: &SharedEmitter,
         tm_factory: TargetMachineFactoryFn<Self>,
         thin: ThinModule<Self>,
-    ) -> ModuleCodegen<Self::Module>;
+    ) -> CompiledModule;
     fn codegen(
         cgcx: &CodegenContext,
         prof: &SelfProfilerRef,