cg_ssa: introduce TargetMachineFactoryFn alias

This commit removes the `TargetMachineFactory` struct and adds a
`TargetMachineFactoryFn` type alias which is used everywhere that the
previous, long type was used.

Signed-off-by: David Wood <david@davidtw.co>

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -728,7 +728,7 @@ pub unsafe fn optimize_thin_module(
     cgcx: &CodegenContext<LlvmCodegenBackend>,
 ) -> Result<ModuleCodegen<ModuleLlvm>, FatalError> {
     let diag_handler = cgcx.create_diag_handler();
-    let tm = (cgcx.tm_factory.0)().map_err(|e| write::llvm_err(&diag_handler, &e))?;
+    let tm = (cgcx.tm_factory)().map_err(|e| write::llvm_err(&diag_handler, &e))?;
 
     // Right now the implementation we've got only works over serialized
     // modules, so we create a fresh new LLVM context and parse the module

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -11,7 +11,9 @@ use crate::llvm_util;
 use crate::type_::Type;
 use crate::LlvmCodegenBackend;
 use crate::ModuleLlvm;
-use rustc_codegen_ssa::back::write::{BitcodeSection, CodegenContext, EmitObj, ModuleConfig};
+use rustc_codegen_ssa::back::write::{
+    BitcodeSection, CodegenContext, EmitObj, ModuleConfig, TargetMachineFactoryFn,
+};
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen};
 use rustc_data_structures::small_c_str::SmallCStr;
@@ -129,7 +131,7 @@ fn to_llvm_code_model(code_model: Option<CodeModel>) -> llvm::CodeModel {
 pub fn target_machine_factory(
     sess: &Session,
     optlvl: config::OptLevel,
-) -> Arc<dyn Fn() -> Result<&'static mut llvm::TargetMachine, String> + Send + Sync> {
+) -> TargetMachineFactoryFn<LlvmCodegenBackend> {
     let reloc_model = to_llvm_relocation_model(sess.relocation_model());
 
     let (opt_level, _) = to_llvm_opt_settings(optlvl);

compiler/rustc_codegen_llvm/src/lib.rs

@@ -19,7 +19,9 @@ use back::write::{create_informational_target_machine, create_target_machine};
 pub use llvm_util::target_features;
 use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule};
-use rustc_codegen_ssa::back::write::{CodegenContext, FatLTOInput, ModuleConfig};
+use rustc_codegen_ssa::back::write::{
+    CodegenContext, FatLTOInput, ModuleConfig, TargetMachineFactoryFn,
+};
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::ModuleCodegen;
 use rustc_codegen_ssa::{CodegenResults, CompiledModule};
@@ -34,7 +36,6 @@ use rustc_span::symbol::Symbol;
 
 use std::any::Any;
 use std::ffi::CStr;
-use std::sync::Arc;
 
 mod back {
     pub mod archive;
@@ -109,7 +110,7 @@ impl ExtraBackendMethods for LlvmCodegenBackend {
         &self,
         sess: &Session,
         optlvl: OptLevel,
-    ) -> Arc<dyn Fn() -> Result<&'static mut llvm::TargetMachine, String> + Send + Sync> {
+    ) -> TargetMachineFactoryFn<Self> {
         back::write::target_machine_factory(sess, optlvl)
     }
     fn target_cpu<'b>(&self, sess: &'b Session) -> &'b str {
@@ -352,7 +353,7 @@ impl ModuleLlvm {
         unsafe {
             let llcx = llvm::LLVMRustContextCreate(cgcx.fewer_names);
             let llmod_raw = back::lto::parse_module(llcx, name, buffer, handler)?;
-            let tm = match (cgcx.tm_factory.0)() {
+            let tm = match (cgcx.tm_factory)() {
                 Ok(m) => m,
                 Err(e) => {
                     handler.struct_err(&e).emit();

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -274,16 +274,8 @@ impl ModuleConfig {
     }
 }
 
-// HACK(eddyb) work around `#[derive]` producing wrong bounds for `Clone`.
-pub struct TargetMachineFactory<B: WriteBackendMethods>(
-    pub Arc<dyn Fn() -> Result<B::TargetMachine, String> + Send + Sync>,
-);
-
-impl<B: WriteBackendMethods> Clone for TargetMachineFactory<B> {
-    fn clone(&self) -> Self {
-        TargetMachineFactory(self.0.clone())
-    }
-}
+pub type TargetMachineFactoryFn<B> =
+    Arc<dyn Fn() -> Result<<B as WriteBackendMethods>::TargetMachine, String> + Send + Sync>;
 
 pub type ExportedSymbols = FxHashMap<CrateNum, Arc<Vec<(String, SymbolExportLevel)>>>;
 
@@ -305,7 +297,7 @@ pub struct CodegenContext<B: WriteBackendMethods> {
     pub regular_module_config: Arc<ModuleConfig>,
     pub metadata_module_config: Arc<ModuleConfig>,
     pub allocator_module_config: Arc<ModuleConfig>,
-    pub tm_factory: TargetMachineFactory<B>,
+    pub tm_factory: TargetMachineFactoryFn<B>,
     pub msvc_imps_needed: bool,
     pub is_pe_coff: bool,
     pub target_pointer_width: u32,
@@ -1020,7 +1012,7 @@ fn start_executing_work<B: ExtraBackendMethods>(
         regular_module_config: regular_config,
         metadata_module_config: metadata_config,
         allocator_module_config: allocator_config,
-        tm_factory: TargetMachineFactory(backend.target_machine_factory(tcx.sess, ol)),
+        tm_factory: backend.target_machine_factory(tcx.sess, ol),
         total_cgus,
         msvc_imps_needed: msvc_imps_needed(tcx),
         is_pe_coff: tcx.sess.target.is_like_windows,

compiler/rustc_codegen_ssa/src/traits/backend.rs

@@ -1,5 +1,6 @@
 use super::write::WriteBackendMethods;
 use super::CodegenObject;
+use crate::back::write::TargetMachineFactoryFn;
 use crate::{CodegenResults, ModuleCodegen};
 
 use rustc_ast::expand::allocator::AllocatorKind;
@@ -21,7 +22,6 @@ use rustc_target::spec::Target;
 pub use rustc_data_structures::sync::MetadataRef;
 
 use std::any::Any;
-use std::sync::Arc;
 
 pub trait BackendTypes {
     type Value: CodegenObject;
@@ -123,7 +123,7 @@ pub trait ExtraBackendMethods: CodegenBackend + WriteBackendMethods + Sized + Se
         &self,
         sess: &Session,
         opt_level: config::OptLevel,
-    ) -> Arc<dyn Fn() -> Result<Self::TargetMachine, String> + Send + Sync>;
+    ) -> TargetMachineFactoryFn<Self>;
     fn target_cpu<'b>(&self, sess: &'b Session) -> &'b str;
     fn tune_cpu<'b>(&self, sess: &'b Session) -> Option<&'b str>;
 }