compiler/rustc_codegen_llvm/src/lib.rs - toolchain/rustc - Git at Google

 //! The Rust compiler.
 //!
 //! # Note
 //!
 //! This API is completely unstable and subject to change.

 #![cfg_attr(not(bootstrap), allow(internal_features))]
 #![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
 #![cfg_attr(not(bootstrap), doc(rust_logo))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(exact_size_is_empty)]
 #![feature(extern_types)]
 #![feature(hash_raw_entry)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
 #![feature(never_type)]
 #![feature(impl_trait_in_assoc_type)]
 #![recursion_limit = "256"]
 #![allow(rustc::potential_query_instability)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

 #[macro_use]
 extern crate rustc_macros;
 #[macro_use]
 extern crate tracing;

 use back::owned_target_machine::OwnedTargetMachine;
 use back::write::{create_informational_target_machine, create_target_machine};

 use errors::ParseTargetMachineConfig;
 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, TargetMachineFactoryConfig, TargetMachineFactoryFn,
 };
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::ModuleCodegen;
 use rustc_codegen_ssa::{CodegenResults, CompiledModule};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::{DiagnosticMessage, ErrorGuaranteed, FatalError, Handler, SubdiagnosticMessage};
 use rustc_fluent_macro::fluent_messages;
 use rustc_metadata::EncodedMetadata;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::util::Providers;
 use rustc_session::config::{OptLevel, OutputFilenames, PrintKind, PrintRequest};
 use rustc_session::Session;
 use rustc_span::symbol::Symbol;

 use std::any::Any;
 use std::ffi::CStr;
 use std::io::Write;
 use std::mem::ManuallyDrop;

 mod back {
     pub mod archive;
     pub mod lto;
     pub mod owned_target_machine;
     mod profiling;
     pub mod write;
 }

 mod abi;
 mod allocator;
 mod asm;
 mod attributes;
 mod base;
 mod builder;
 mod callee;
 mod common;
 mod consts;
 mod context;
 mod coverageinfo;
 mod debuginfo;
 mod declare;
 mod errors;
 mod intrinsic;

 // The following is a workaround that replaces `pub mod llvm;` and that fixes issue 53912.
 #[path = "llvm/mod.rs"]
 mod llvm_;
 pub mod llvm {
     pub use super::llvm_::*;
 }

 mod llvm_util;
 mod mono_item;
 mod type_;
 mod type_of;
 mod va_arg;
 mod value;

 fluent_messages! { "../messages.ftl" }

 #[derive(Clone)]
 pub struct LlvmCodegenBackend(());

 struct TimeTraceProfiler {
     enabled: bool,
 }

 impl TimeTraceProfiler {
     fn new(enabled: bool) -> Self {
         if enabled {
             unsafe { llvm::LLVMTimeTraceProfilerInitialize() }
         }
         TimeTraceProfiler { enabled }
     }
 }

 impl Drop for TimeTraceProfiler {
     fn drop(&mut self) {
         if self.enabled {
             unsafe { llvm::LLVMTimeTraceProfilerFinishThread() }
         }
     }
 }

 impl ExtraBackendMethods for LlvmCodegenBackend {
     fn codegen_allocator<'tcx>(
         &self,
         tcx: TyCtxt<'tcx>,
         module_name: &str,
         kind: AllocatorKind,
         alloc_error_handler_kind: AllocatorKind,
     ) -> ModuleLlvm {
         let mut module_llvm = ModuleLlvm::new_metadata(tcx, module_name);
         unsafe {
             allocator::codegen(tcx, &mut module_llvm, module_name, kind, alloc_error_handler_kind);
         }
         module_llvm
     }
     fn compile_codegen_unit(
         &self,
         tcx: TyCtxt<'_>,
         cgu_name: Symbol,
     ) -> (ModuleCodegen<ModuleLlvm>, u64) {
         base::compile_codegen_unit(tcx, cgu_name)
     }
     fn target_machine_factory(
         &self,
         sess: &Session,
         optlvl: OptLevel,
         target_features: &[String],
     ) -> TargetMachineFactoryFn<Self> {
         back::write::target_machine_factory(sess, optlvl, target_features)
     }

     fn spawn_named_thread<F, T>(
         time_trace: bool,
         name: String,
         f: F,
     ) -> std::io::Result<std::thread::JoinHandle<T>>
     where
         F: FnOnce() -> T,
         F: Send + 'static,
         T: Send + 'static,
     {
         std::thread::Builder::new().name(name).spawn(move || {
             let _profiler = TimeTraceProfiler::new(time_trace);
             f()
         })
     }
 }

 impl WriteBackendMethods for LlvmCodegenBackend {
     type Module = ModuleLlvm;
     type ModuleBuffer = back::lto::ModuleBuffer;
     type TargetMachine = OwnedTargetMachine;
     type TargetMachineError = crate::errors::LlvmError<'static>;
     type ThinData = back::lto::ThinData;
     type ThinBuffer = back::lto::ThinBuffer;
     fn print_pass_timings(&self) {
         unsafe {
             let mut size = 0;
             let cstr = llvm::LLVMRustPrintPassTimings(&mut size as *mut usize);
             if cstr.is_null() {
                 println!("failed to get pass timings");
             } else {
                 let timings = std::slice::from_raw_parts(cstr as *const u8, size);
                 std::io::stdout().write_all(timings).unwrap();
                 libc::free(cstr as *mut _);
             }
         }
     }
     fn print_statistics(&self) {
         unsafe {
             let mut size = 0;
             let cstr = llvm::LLVMRustPrintStatistics(&mut size as *mut usize);
             if cstr.is_null() {
                 println!("failed to get pass stats");
             } else {
                 let stats = std::slice::from_raw_parts(cstr as *const u8, size);
                 std::io::stdout().write_all(stats).unwrap();
                 libc::free(cstr as *mut _);
             }
         }
     }
     fn run_link(
         cgcx: &CodegenContext<Self>,
         diag_handler: &Handler,
         modules: Vec<ModuleCodegen<Self::Module>>,
     ) -> Result<ModuleCodegen<Self::Module>, FatalError> {
         back::write::link(cgcx, diag_handler, modules)
     }
     fn run_fat_lto(
         cgcx: &CodegenContext<Self>,
         modules: Vec<FatLtoInput<Self>>,
         cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>,
     ) -> Result<LtoModuleCodegen<Self>, FatalError> {
         back::lto::run_fat(cgcx, modules, cached_modules)
     }
     fn run_thin_lto(
         cgcx: &CodegenContext<Self>,
         modules: Vec<(String, Self::ThinBuffer)>,
         cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>,
     ) -> Result<(Vec<LtoModuleCodegen<Self>>, Vec<WorkProduct>), FatalError> {
         back::lto::run_thin(cgcx, modules, cached_modules)
     }
     unsafe fn optimize(
         cgcx: &CodegenContext<Self>,
         diag_handler: &Handler,
         module: &ModuleCodegen<Self::Module>,
         config: &ModuleConfig,
     ) -> Result<(), FatalError> {
         back::write::optimize(cgcx, diag_handler, module, config)
     }
     fn optimize_fat(
         cgcx: &CodegenContext<Self>,
         module: &mut ModuleCodegen<Self::Module>,
     ) -> Result<(), FatalError> {
         let diag_handler = cgcx.create_diag_handler();
         back::lto::run_pass_manager(cgcx, &diag_handler, module, false)
     }
     unsafe fn optimize_thin(
         cgcx: &CodegenContext<Self>,
         thin: ThinModule<Self>,
     ) -> Result<ModuleCodegen<Self::Module>, FatalError> {
         back::lto::optimize_thin_module(thin, cgcx)
     }
     unsafe fn codegen(
         cgcx: &CodegenContext<Self>,
         diag_handler: &Handler,
         module: ModuleCodegen<Self::Module>,
         config: &ModuleConfig,
     ) -> Result<CompiledModule, FatalError> {
         back::write::codegen(cgcx, diag_handler, module, config)
     }
     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()))
     }
 }

 unsafe impl Send for LlvmCodegenBackend {} // Llvm is on a per-thread basis
 unsafe impl Sync for LlvmCodegenBackend {}

 impl LlvmCodegenBackend {
     pub fn new() -> Box<dyn CodegenBackend> {
         Box::new(LlvmCodegenBackend(()))
     }
 }

 impl CodegenBackend for LlvmCodegenBackend {
     fn locale_resource(&self) -> &'static str {
         crate::DEFAULT_LOCALE_RESOURCE
     }

     fn init(&self, sess: &Session) {
         llvm_util::init(sess); // Make sure llvm is inited
     }

     fn provide(&self, providers: &mut Providers) {
         providers.global_backend_features =
             |tcx, ()| llvm_util::global_llvm_features(tcx.sess, true)
     }

     fn print(&self, req: &PrintRequest, out: &mut dyn PrintBackendInfo, sess: &Session) {
         match req.kind {
             PrintKind::RelocationModels => {
                 writeln!(out, "Available relocation models:");
                 for name in &[
                     "static",
                     "pic",
                     "pie",
                     "dynamic-no-pic",
                     "ropi",
                     "rwpi",
                     "ropi-rwpi",
                     "default",
                 ] {
                     writeln!(out, "    {name}");
                 }
                 writeln!(out);
             }
             PrintKind::CodeModels => {
                 writeln!(out, "Available code models:");
                 for name in &["tiny", "small", "kernel", "medium", "large"] {
                     writeln!(out, "    {name}");
                 }
                 writeln!(out);
             }
             PrintKind::TlsModels => {
                 writeln!(out, "Available TLS models:");
                 for name in &["global-dynamic", "local-dynamic", "initial-exec", "local-exec"] {
                     writeln!(out, "    {name}");
                 }
                 writeln!(out);
             }
             PrintKind::StackProtectorStrategies => {
                 writeln!(
                     out,
                     r#"Available stack protector strategies:
     all
         Generate stack canaries in all functions.

     strong
         Generate stack canaries in a function if it either:
         - has a local variable of `[T; N]` type, regardless of `T` and `N`
         - takes the address of a local variable.

           (Note that a local variable being borrowed is not equivalent to its
           address being taken: e.g. some borrows may be removed by optimization,
           while by-value argument passing may be implemented with reference to a
           local stack variable in the ABI.)

     basic
         Generate stack canaries in functions with local variables of `[T; N]`
         type, where `T` is byte-sized and `N` >= 8.

     none
         Do not generate stack canaries.
 "#
                 );
             }
             _other => llvm_util::print(req, out, sess),
         }
     }

     fn print_passes(&self) {
         llvm_util::print_passes();
     }

     fn print_version(&self) {
         llvm_util::print_version();
     }

     fn target_features(&self, sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
         target_features(sess, allow_unstable)
     }

     fn codegen_crate<'tcx>(
         &self,
         tcx: TyCtxt<'tcx>,
         metadata: EncodedMetadata,
         need_metadata_module: bool,
     ) -> 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,
         ))
     }

     fn join_codegen(
         &self,
         ongoing_codegen: Box<dyn Any>,
         sess: &Session,
         outputs: &OutputFilenames,
     ) -> Result<(CodegenResults, FxIndexMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
         let (codegen_results, work_products) = ongoing_codegen
             .downcast::<rustc_codegen_ssa::back::write::OngoingCodegen<LlvmCodegenBackend>>()
             .expect("Expected LlvmCodegenBackend's OngoingCodegen, found Box<Any>")
             .join(sess);

         if sess.opts.unstable_opts.llvm_time_trace {
             sess.time("llvm_dump_timing_file", || {
                 let file_name = outputs.with_extension("llvm_timings.json");
                 llvm_util::time_trace_profiler_finish(&file_name);
             });
         }

         Ok((codegen_results, work_products))
     }

     fn link(
         &self,
         sess: &Session,
         codegen_results: CodegenResults,
         outputs: &OutputFilenames,
     ) -> Result<(), ErrorGuaranteed> {
         use crate::back::archive::LlvmArchiveBuilderBuilder;
         use rustc_codegen_ssa::back::link::link_binary;

         // 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)
     }
 }

 pub struct ModuleLlvm {
     llcx: &'static mut llvm::Context,
     llmod_raw: *const llvm::Module,

     // This field is `ManuallyDrop` because it is important that the `TargetMachine`
     // is disposed prior to the `Context` being disposed otherwise UAFs can occur.
     tm: ManuallyDrop<OwnedTargetMachine>,
 }

 unsafe impl Send for ModuleLlvm {}
 unsafe impl Sync for ModuleLlvm {}

 impl ModuleLlvm {
     fn new(tcx: TyCtxt<'_>, mod_name: &str) -> Self {
         unsafe {
             let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
             let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
             ModuleLlvm {
                 llmod_raw,
                 llcx,
                 tm: ManuallyDrop::new(create_target_machine(tcx, mod_name)),
             }
         }
     }

     fn new_metadata(tcx: TyCtxt<'_>, mod_name: &str) -> Self {
         unsafe {
             let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
             let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
             ModuleLlvm {
                 llmod_raw,
                 llcx,
                 tm: ManuallyDrop::new(create_informational_target_machine(tcx.sess)),
             }
         }
     }

     fn parse(
         cgcx: &CodegenContext<LlvmCodegenBackend>,
         name: &CStr,
         buffer: &[u8],
         handler: &Handler,
     ) -> Result<Self, FatalError> {
         unsafe {
             let llcx = llvm::LLVMRustContextCreate(cgcx.fewer_names);
             let llmod_raw = back::lto::parse_module(llcx, name, buffer, handler)?;
             let tm_factory_config = TargetMachineFactoryConfig::new(cgcx, name.to_str().unwrap());
             let tm = match (cgcx.tm_factory)(tm_factory_config) {
                 Ok(m) => m,
                 Err(e) => {
                     return Err(handler.emit_almost_fatal(ParseTargetMachineConfig(e)));
                 }
             };

             Ok(ModuleLlvm { llmod_raw, llcx, tm: ManuallyDrop::new(tm) })
         }
     }

     fn llmod(&self) -> &llvm::Module {
         unsafe { &*self.llmod_raw }
     }
 }

 impl Drop for ModuleLlvm {
     fn drop(&mut self) {
         unsafe {
             ManuallyDrop::drop(&mut self.tm);
             llvm::LLVMContextDispose(&mut *(self.llcx as *mut _));
         }
     }
 }
	//! The Rust compiler.
	//!
	//! # Note
	//!
	//! This API is completely unstable and subject to change.

	#![cfg_attr(not(bootstrap), allow(internal_features))]
	#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
	#![cfg_attr(not(bootstrap), doc(rust_logo))]
	#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
	#![feature(exact_size_is_empty)]
	#![feature(extern_types)]
	#![feature(hash_raw_entry)]
	#![feature(iter_intersperse)]
	#![feature(let_chains)]
	#![feature(min_specialization)]
	#![feature(never_type)]
	#![feature(impl_trait_in_assoc_type)]
	#![recursion_limit = "256"]
	#![allow(rustc::potential_query_instability)]
	#![deny(rustc::untranslatable_diagnostic)]
	#![deny(rustc::diagnostic_outside_of_impl)]

	#[macro_use]
	extern crate rustc_macros;
	#[macro_use]
	extern crate tracing;

	use back::owned_target_machine::OwnedTargetMachine;
	use back::write::{create_informational_target_machine, create_target_machine};

	use errors::ParseTargetMachineConfig;
	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, TargetMachineFactoryConfig, TargetMachineFactoryFn,
	};
	use rustc_codegen_ssa::traits::*;
	use rustc_codegen_ssa::ModuleCodegen;
	use rustc_codegen_ssa::{CodegenResults, CompiledModule};
	use rustc_data_structures::fx::FxIndexMap;
	use rustc_errors::{DiagnosticMessage, ErrorGuaranteed, FatalError, Handler, SubdiagnosticMessage};
	use rustc_fluent_macro::fluent_messages;
	use rustc_metadata::EncodedMetadata;
	use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
	use rustc_middle::ty::TyCtxt;
	use rustc_middle::util::Providers;
	use rustc_session::config::{OptLevel, OutputFilenames, PrintKind, PrintRequest};
	use rustc_session::Session;
	use rustc_span::symbol::Symbol;

	use std::any::Any;
	use std::ffi::CStr;
	use std::io::Write;
	use std::mem::ManuallyDrop;

	mod back {
	pub mod archive;
	pub mod lto;
	pub mod owned_target_machine;
	mod profiling;
	pub mod write;
	}

	mod abi;
	mod allocator;
	mod asm;
	mod attributes;
	mod base;
	mod builder;
	mod callee;
	mod common;
	mod consts;
	mod context;
	mod coverageinfo;
	mod debuginfo;
	mod declare;
	mod errors;
	mod intrinsic;

	// The following is a workaround that replaces `pub mod llvm;` and that fixes issue 53912.
	#[path = "llvm/mod.rs"]
	mod llvm_;
	pub mod llvm {
	pub use super::llvm_::*;
	}

	mod llvm_util;
	mod mono_item;
	mod type_;
	mod type_of;
	mod va_arg;
	mod value;

	fluent_messages! { "../messages.ftl" }

	#[derive(Clone)]
	pub struct LlvmCodegenBackend(());

	struct TimeTraceProfiler {
	enabled: bool,
	}

	impl TimeTraceProfiler {
	fn new(enabled: bool) -> Self {
	if enabled {
	unsafe { llvm::LLVMTimeTraceProfilerInitialize() }
	}
	TimeTraceProfiler { enabled }
	}
	}

	impl Drop for TimeTraceProfiler {
	fn drop(&mut self) {
	if self.enabled {
	unsafe { llvm::LLVMTimeTraceProfilerFinishThread() }
	}
	}
	}

	impl ExtraBackendMethods for LlvmCodegenBackend {
	fn codegen_allocator<'tcx>(
	&self,
	tcx: TyCtxt<'tcx>,
	module_name: &str,
	kind: AllocatorKind,
	alloc_error_handler_kind: AllocatorKind,
	) -> ModuleLlvm {
	let mut module_llvm = ModuleLlvm::new_metadata(tcx, module_name);
	unsafe {
	allocator::codegen(tcx, &mut module_llvm, module_name, kind, alloc_error_handler_kind);
	}
	module_llvm
	}
	fn compile_codegen_unit(
	&self,
	tcx: TyCtxt<'_>,
	cgu_name: Symbol,
	) -> (ModuleCodegen<ModuleLlvm>, u64) {
	base::compile_codegen_unit(tcx, cgu_name)
	}
	fn target_machine_factory(
	&self,
	sess: &Session,
	optlvl: OptLevel,
	target_features: &[String],
	) -> TargetMachineFactoryFn<Self> {
	back::write::target_machine_factory(sess, optlvl, target_features)
	}

	fn spawn_named_thread<F, T>(
	time_trace: bool,
	name: String,
	f: F,
	) -> std::io::Result<std::thread::JoinHandle<T>>
	where
	F: FnOnce() -> T,
	F: Send + 'static,
	T: Send + 'static,
	{
	std::thread::Builder::new().name(name).spawn(move \|\| {
	let _profiler = TimeTraceProfiler::new(time_trace);
	f()
	})
	}
	}

	impl WriteBackendMethods for LlvmCodegenBackend {
	type Module = ModuleLlvm;
	type ModuleBuffer = back::lto::ModuleBuffer;
	type TargetMachine = OwnedTargetMachine;
	type TargetMachineError = crate::errors::LlvmError<'static>;
	type ThinData = back::lto::ThinData;
	type ThinBuffer = back::lto::ThinBuffer;
	fn print_pass_timings(&self) {
	unsafe {
	let mut size = 0;
	let cstr = llvm::LLVMRustPrintPassTimings(&mut size as *mut usize);
	if cstr.is_null() {
	println!("failed to get pass timings");
	} else {
	let timings = std::slice::from_raw_parts(cstr as *const u8, size);
	std::io::stdout().write_all(timings).unwrap();
	libc::free(cstr as *mut _);
	}
	}
	}
	fn print_statistics(&self) {
	unsafe {
	let mut size = 0;
	let cstr = llvm::LLVMRustPrintStatistics(&mut size as *mut usize);
	if cstr.is_null() {
	println!("failed to get pass stats");
	} else {
	let stats = std::slice::from_raw_parts(cstr as *const u8, size);
	std::io::stdout().write_all(stats).unwrap();
	libc::free(cstr as *mut _);
	}
	}
	}
	fn run_link(
	cgcx: &CodegenContext<Self>,
	diag_handler: &Handler,
	modules: Vec<ModuleCodegen<Self::Module>>,
	) -> Result<ModuleCodegen<Self::Module>, FatalError> {
	back::write::link(cgcx, diag_handler, modules)
	}
	fn run_fat_lto(
	cgcx: &CodegenContext<Self>,
	modules: Vec<FatLtoInput<Self>>,
	cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>,
	) -> Result<LtoModuleCodegen<Self>, FatalError> {
	back::lto::run_fat(cgcx, modules, cached_modules)
	}
	fn run_thin_lto(
	cgcx: &CodegenContext<Self>,
	modules: Vec<(String, Self::ThinBuffer)>,
	cached_modules: Vec<(SerializedModule<Self::ModuleBuffer>, WorkProduct)>,
	) -> Result<(Vec<LtoModuleCodegen<Self>>, Vec<WorkProduct>), FatalError> {
	back::lto::run_thin(cgcx, modules, cached_modules)
	}
	unsafe fn optimize(
	cgcx: &CodegenContext<Self>,
	diag_handler: &Handler,
	module: &ModuleCodegen<Self::Module>,
	config: &ModuleConfig,
	) -> Result<(), FatalError> {
	back::write::optimize(cgcx, diag_handler, module, config)
	}
	fn optimize_fat(
	cgcx: &CodegenContext<Self>,
	module: &mut ModuleCodegen<Self::Module>,
	) -> Result<(), FatalError> {
	let diag_handler = cgcx.create_diag_handler();
	back::lto::run_pass_manager(cgcx, &diag_handler, module, false)
	}
	unsafe fn optimize_thin(
	cgcx: &CodegenContext<Self>,
	thin: ThinModule<Self>,
	) -> Result<ModuleCodegen<Self::Module>, FatalError> {
	back::lto::optimize_thin_module(thin, cgcx)
	}
	unsafe fn codegen(
	cgcx: &CodegenContext<Self>,
	diag_handler: &Handler,
	module: ModuleCodegen<Self::Module>,
	config: &ModuleConfig,
	) -> Result<CompiledModule, FatalError> {
	back::write::codegen(cgcx, diag_handler, module, config)
	}
	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()))
	}
	}

	unsafe impl Send for LlvmCodegenBackend {} // Llvm is on a per-thread basis
	unsafe impl Sync for LlvmCodegenBackend {}

	impl LlvmCodegenBackend {
	pub fn new() -> Box<dyn CodegenBackend> {
	Box::new(LlvmCodegenBackend(()))
	}
	}

	impl CodegenBackend for LlvmCodegenBackend {
	fn locale_resource(&self) -> &'static str {
	crate::DEFAULT_LOCALE_RESOURCE
	}

	fn init(&self, sess: &Session) {
	llvm_util::init(sess); // Make sure llvm is inited
	}

	fn provide(&self, providers: &mut Providers) {
	providers.global_backend_features =
	\|tcx, ()\| llvm_util::global_llvm_features(tcx.sess, true)
	}

	fn print(&self, req: &PrintRequest, out: &mut dyn PrintBackendInfo, sess: &Session) {
	match req.kind {
	PrintKind::RelocationModels => {
	writeln!(out, "Available relocation models:");
	for name in &[
	"static",
	"pic",
	"pie",
	"dynamic-no-pic",
	"ropi",
	"rwpi",
	"ropi-rwpi",
	"default",
	] {
	writeln!(out, " {name}");
	}
	writeln!(out);
	}
	PrintKind::CodeModels => {
	writeln!(out, "Available code models:");
	for name in &["tiny", "small", "kernel", "medium", "large"] {
	writeln!(out, " {name}");
	}
	writeln!(out);
	}
	PrintKind::TlsModels => {
	writeln!(out, "Available TLS models:");
	for name in &["global-dynamic", "local-dynamic", "initial-exec", "local-exec"] {
	writeln!(out, " {name}");
	}
	writeln!(out);
	}
	PrintKind::StackProtectorStrategies => {
	writeln!(
	out,
	r#"Available stack protector strategies:
	all
	Generate stack canaries in all functions.

	strong
	Generate stack canaries in a function if it either:
	- has a local variable of `[T; N]` type, regardless of `T` and `N`
	- takes the address of a local variable.

	(Note that a local variable being borrowed is not equivalent to its
	address being taken: e.g. some borrows may be removed by optimization,
	while by-value argument passing may be implemented with reference to a
	local stack variable in the ABI.)

	basic
	Generate stack canaries in functions with local variables of `[T; N]`
	type, where `T` is byte-sized and `N` >= 8.

	none
	Do not generate stack canaries.
	"#
	);
	}
	_other => llvm_util::print(req, out, sess),
	}
	}

	fn print_passes(&self) {
	llvm_util::print_passes();
	}

	fn print_version(&self) {
	llvm_util::print_version();
	}

	fn target_features(&self, sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
	target_features(sess, allow_unstable)
	}

	fn codegen_crate<'tcx>(
	&self,
	tcx: TyCtxt<'tcx>,
	metadata: EncodedMetadata,
	need_metadata_module: bool,
	) -> 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,
	))
	}

	fn join_codegen(
	&self,
	ongoing_codegen: Box<dyn Any>,
	sess: &Session,
	outputs: &OutputFilenames,
	) -> Result<(CodegenResults, FxIndexMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
	let (codegen_results, work_products) = ongoing_codegen
	.downcast::<rustc_codegen_ssa::back::write::OngoingCodegen<LlvmCodegenBackend>>()
	.expect("Expected LlvmCodegenBackend's OngoingCodegen, found Box<Any>")
	.join(sess);

	if sess.opts.unstable_opts.llvm_time_trace {
	sess.time("llvm_dump_timing_file", \|\| {
	let file_name = outputs.with_extension("llvm_timings.json");
	llvm_util::time_trace_profiler_finish(&file_name);
	});
	}

	Ok((codegen_results, work_products))
	}

	fn link(
	&self,
	sess: &Session,
	codegen_results: CodegenResults,
	outputs: &OutputFilenames,
	) -> Result<(), ErrorGuaranteed> {
	use crate::back::archive::LlvmArchiveBuilderBuilder;
	use rustc_codegen_ssa::back::link::link_binary;

	// 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)
	}
	}

	pub struct ModuleLlvm {
	llcx: &'static mut llvm::Context,
	llmod_raw: *const llvm::Module,

	// This field is `ManuallyDrop` because it is important that the `TargetMachine`
	// is disposed prior to the `Context` being disposed otherwise UAFs can occur.
	tm: ManuallyDrop<OwnedTargetMachine>,
	}

	unsafe impl Send for ModuleLlvm {}
	unsafe impl Sync for ModuleLlvm {}

	impl ModuleLlvm {
	fn new(tcx: TyCtxt<'_>, mod_name: &str) -> Self {
	unsafe {
	let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
	let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
	ModuleLlvm {
	llmod_raw,
	llcx,
	tm: ManuallyDrop::new(create_target_machine(tcx, mod_name)),
	}
	}
	}

	fn new_metadata(tcx: TyCtxt<'_>, mod_name: &str) -> Self {
	unsafe {
	let llcx = llvm::LLVMRustContextCreate(tcx.sess.fewer_names());
	let llmod_raw = context::create_module(tcx, llcx, mod_name) as *const _;
	ModuleLlvm {
	llmod_raw,
	llcx,
	tm: ManuallyDrop::new(create_informational_target_machine(tcx.sess)),
	}
	}
	}

	fn parse(
	cgcx: &CodegenContext<LlvmCodegenBackend>,
	name: &CStr,
	buffer: &[u8],
	handler: &Handler,
	) -> Result<Self, FatalError> {
	unsafe {
	let llcx = llvm::LLVMRustContextCreate(cgcx.fewer_names);
	let llmod_raw = back::lto::parse_module(llcx, name, buffer, handler)?;
	let tm_factory_config = TargetMachineFactoryConfig::new(cgcx, name.to_str().unwrap());
	let tm = match (cgcx.tm_factory)(tm_factory_config) {
	Ok(m) => m,
	Err(e) => {
	return Err(handler.emit_almost_fatal(ParseTargetMachineConfig(e)));
	}
	};

	Ok(ModuleLlvm { llmod_raw, llcx, tm: ManuallyDrop::new(tm) })
	}
	}

	fn llmod(&self) -> &llvm::Module {
	unsafe { &*self.llmod_raw }
	}
	}

	impl Drop for ModuleLlvm {
	fn drop(&mut self) {
	unsafe {
	ManuallyDrop::drop(&mut self.tm);
	llvm::LLVMContextDispose(&mut (self.llcx as mut _));
	}
	}
	}