Misc LTO cleanups

compiler/rustc_codegen_gcc/src/back/lto.rs

@@ -305,12 +305,9 @@ pub(crate) fn run_thin(
     )
 }
 
-pub(crate) fn prepare_thin(
-    module: ModuleCodegen<GccContext>,
-    _emit_summary: bool,
-) -> (String, ThinBuffer) {
+pub(crate) fn prepare_thin(module: ModuleCodegen<GccContext>) -> (String, ThinBuffer) {
     let name = module.name;
-    //let buffer = ThinBuffer::new(module.module_llvm.context, true, emit_summary);
+    //let buffer = ThinBuffer::new(module.module_llvm.context, true);
     let buffer = ThinBuffer::new(&module.module_llvm.context);
     (name, buffer)
 }

compiler/rustc_codegen_gcc/src/lib.rs

@@ -408,11 +408,8 @@ impl WriteBackendMethods for GccCodegenBackend {
         back::write::codegen(cgcx, module, config)
     }
 
-    fn prepare_thin(
-        module: ModuleCodegen<Self::Module>,
-        emit_summary: bool,
-    ) -> (String, Self::ThinBuffer) {
-        back::lto::prepare_thin(module, emit_summary)
+    fn prepare_thin(module: ModuleCodegen<Self::Module>) -> (String, Self::ThinBuffer) {
+        back::lto::prepare_thin(module)
     }
 
     fn serialize_module(_module: ModuleCodegen<Self::Module>) -> (String, Self::ModuleBuffer) {

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -185,12 +185,9 @@ pub(crate) fn run_thin(
     thin_lto(cgcx, dcx, modules, upstream_modules, cached_modules, &symbols_below_threshold)
 }
 
-pub(crate) fn prepare_thin(
-    module: ModuleCodegen<ModuleLlvm>,
-    emit_summary: bool,
-) -> (String, ThinBuffer) {
+pub(crate) fn prepare_thin(module: ModuleCodegen<ModuleLlvm>) -> (String, ThinBuffer) {
     let name = module.name;
-    let buffer = ThinBuffer::new(module.module_llvm.llmod(), true, emit_summary);
+    let buffer = ThinBuffer::new(module.module_llvm.llmod(), true);
     (name, buffer)
 }
 
@@ -687,9 +684,9 @@ unsafe impl Send for ThinBuffer {}
 unsafe impl Sync for ThinBuffer {}
 
 impl ThinBuffer {
-    pub(crate) fn new(m: &llvm::Module, is_thin: bool, emit_summary: bool) -> ThinBuffer {
+    pub(crate) fn new(m: &llvm::Module, is_thin: bool) -> ThinBuffer {
         unsafe {
-            let buffer = llvm::LLVMRustThinLTOBufferCreate(m, is_thin, emit_summary);
+            let buffer = llvm::LLVMRustThinLTOBufferCreate(m, is_thin);
             ThinBuffer(buffer)
         }
     }

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -837,7 +837,7 @@ pub(crate) fn codegen(
                         "LLVM_module_codegen_make_bitcode",
                         &*module.name,
                     );
-                    ThinBuffer::new(llmod, config.emit_thin_lto, false)
+                    ThinBuffer::new(llmod, config.emit_thin_lto)
                 };
                 let data = thin.data();
                 let _timer = cgcx

compiler/rustc_codegen_llvm/src/lib.rs

@@ -211,11 +211,8 @@ impl WriteBackendMethods for LlvmCodegenBackend {
     ) -> CompiledModule {
         back::write::codegen(cgcx, module, config)
     }
-    fn prepare_thin(
-        module: ModuleCodegen<Self::Module>,
-        emit_summary: bool,
-    ) -> (String, Self::ThinBuffer) {
-        back::lto::prepare_thin(module, emit_summary)
+    fn prepare_thin(module: ModuleCodegen<Self::Module>) -> (String, Self::ThinBuffer) {
+        back::lto::prepare_thin(module)
     }
     fn serialize_module(module: ModuleCodegen<Self::Module>) -> (String, Self::ModuleBuffer) {
         (module.name, back::lto::ModuleBuffer::new(module.module_llvm.llmod()))

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -2602,7 +2602,6 @@ unsafe extern "C" {
     pub(crate) fn LLVMRustThinLTOBufferCreate(
         M: &Module,
         is_thin: bool,
-        emit_summary: bool,
     ) -> &'static mut ThinLTOBuffer;
     pub(crate) fn LLVMRustThinLTOBufferFree(M: &'static mut ThinLTOBuffer);
     pub(crate) fn LLVMRustThinLTOBufferPtr(M: &ThinLTOBuffer) -> *const c_char;

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -862,7 +862,7 @@ fn execute_optimize_work_item<B: ExtraBackendMethods>(
             WorkItemResult::Finished(module)
         }
         ComputedLtoType::Thin => {
-            let (name, thin_buffer) = B::prepare_thin(module, false);
+            let (name, thin_buffer) = B::prepare_thin(module);
             if let Some(path) = bitcode {
                 fs::write(&path, thin_buffer.data()).unwrap_or_else(|e| {
                     panic!("Error writing pre-lto-bitcode file `{}`: {}", path.display(), e);

compiler/rustc_codegen_ssa/src/traits/write.rs

@@ -50,10 +50,7 @@ pub trait WriteBackendMethods: Clone + 'static {
         module: ModuleCodegen<Self::Module>,
         config: &ModuleConfig,
     ) -> CompiledModule;
-    fn prepare_thin(
-        module: ModuleCodegen<Self::Module>,
-        want_summary: bool,
-    ) -> (String, Self::ThinBuffer);
+    fn prepare_thin(module: ModuleCodegen<Self::Module>) -> (String, Self::ThinBuffer);
     fn serialize_module(module: ModuleCodegen<Self::Module>) -> (String, Self::ModuleBuffer);
 }
 

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -1568,12 +1568,11 @@ extern "C" bool LLVMRustPrepareThinLTOImport(const LLVMRustThinLTOData *Data,
   return true;
 }
 
-extern "C" LLVMRustThinLTOBuffer *
-LLVMRustThinLTOBufferCreate(LLVMModuleRef M, bool is_thin, bool emit_summary) {
+extern "C" LLVMRustThinLTOBuffer *LLVMRustThinLTOBufferCreate(LLVMModuleRef M,
+                                                              bool is_thin) {
   auto Ret = std::make_unique<LLVMRustThinLTOBuffer>();
   {
     auto OS = raw_string_ostream(Ret->data);
-    auto ThinLinkOS = raw_string_ostream(Ret->thin_link_data);
     {
       if (is_thin) {
         PassBuilder PB;
@@ -1587,11 +1586,7 @@ LLVMRustThinLTOBufferCreate(LLVMModuleRef M, bool is_thin, bool emit_summary) {
         PB.registerLoopAnalyses(LAM);
         PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
         ModulePassManager MPM;
-        // We only pass ThinLinkOS to be filled in if we want the summary,
-        // because otherwise LLVM does extra work and may double-emit some
-        // errors or warnings.
-        MPM.addPass(
-            ThinLTOBitcodeWriterPass(OS, emit_summary ? &ThinLinkOS : nullptr));
+        MPM.addPass(ThinLTOBitcodeWriterPass(OS, nullptr));
         MPM.run(*unwrap(M), MAM);
       } else {
         WriteBitcodeToFile(*unwrap(M), OS);