diff options
Diffstat (limited to 'compiler/rustc_codegen_cranelift/src/driver')
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/driver/aot.rs | 436 | ||||
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/driver/jit.rs | 385 | ||||
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/driver/mod.rs | 53 |
3 files changed, 874 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/driver/aot.rs b/compiler/rustc_codegen_cranelift/src/driver/aot.rs new file mode 100644 index 000000000..3cd1ef563 --- /dev/null +++ b/compiler/rustc_codegen_cranelift/src/driver/aot.rs @@ -0,0 +1,436 @@ +//! The AOT driver uses [`cranelift_object`] to write object files suitable for linking into a +//! standalone executable. + +use std::path::PathBuf; + +use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece}; +use rustc_codegen_ssa::back::metadata::create_compressed_metadata_file; +use rustc_codegen_ssa::{CodegenResults, CompiledModule, CrateInfo, ModuleKind}; +use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; +use rustc_metadata::EncodedMetadata; +use rustc_middle::dep_graph::{WorkProduct, WorkProductId}; +use rustc_middle::mir::mono::{CodegenUnit, MonoItem}; +use rustc_session::cgu_reuse_tracker::CguReuse; +use rustc_session::config::{DebugInfo, OutputType}; +use rustc_session::Session; + +use cranelift_codegen::isa::TargetIsa; +use cranelift_object::{ObjectBuilder, ObjectModule}; + +use crate::{prelude::*, BackendConfig}; + +struct ModuleCodegenResult(CompiledModule, Option<(WorkProductId, WorkProduct)>); + +impl<HCX> HashStable<HCX> for ModuleCodegenResult { + fn hash_stable(&self, _: &mut HCX, _: &mut StableHasher) { + // do nothing + } +} + +fn make_module(sess: &Session, isa: Box<dyn TargetIsa>, name: String) -> ObjectModule { + let mut builder = + ObjectBuilder::new(isa, name + ".o", cranelift_module::default_libcall_names()).unwrap(); + // Unlike cg_llvm, cg_clif defaults to disabling -Zfunction-sections. For cg_llvm binary size + // is important, while cg_clif cares more about compilation times. Enabling -Zfunction-sections + // can easily double the amount of time necessary to perform linking. + builder.per_function_section(sess.opts.unstable_opts.function_sections.unwrap_or(false)); + ObjectModule::new(builder) +} + +fn emit_module( + tcx: TyCtxt<'_>, + backend_config: &BackendConfig, + name: String, + kind: ModuleKind, + module: ObjectModule, + debug: Option<DebugContext<'_>>, + unwind_context: UnwindContext, +) -> ModuleCodegenResult { + let mut product = module.finish(); + + if let Some(mut debug) = debug { + debug.emit(&mut product); + } + + unwind_context.emit(&mut product); + + let tmp_file = tcx.output_filenames(()).temp_path(OutputType::Object, Some(&name)); + let obj = product.object.write().unwrap(); + + tcx.sess.prof.artifact_size("object_file", name.clone(), obj.len().try_into().unwrap()); + + if let Err(err) = std::fs::write(&tmp_file, obj) { + tcx.sess.fatal(&format!("error writing object file: {}", err)); + } + + let work_product = if backend_config.disable_incr_cache { + None + } else { + rustc_incremental::copy_cgu_workproduct_to_incr_comp_cache_dir( + tcx.sess, + &name, + &[("o", &tmp_file)], + ) + }; + + ModuleCodegenResult( + CompiledModule { name, kind, object: Some(tmp_file), dwarf_object: None, bytecode: None }, + work_product, + ) +} + +fn reuse_workproduct_for_cgu( + tcx: TyCtxt<'_>, + cgu: &CodegenUnit<'_>, + work_products: &mut FxHashMap<WorkProductId, WorkProduct>, +) -> CompiledModule { + let work_product = cgu.previous_work_product(tcx); + let obj_out = tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str())); + let source_file = rustc_incremental::in_incr_comp_dir_sess( + &tcx.sess, + &work_product.saved_files.get("o").expect("no saved object file in work product"), + ); + if let Err(err) = rustc_fs_util::link_or_copy(&source_file, &obj_out) { + tcx.sess.err(&format!( + "unable to copy {} to {}: {}", + source_file.display(), + obj_out.display(), + err + )); + } + + work_products.insert(cgu.work_product_id(), work_product); + + CompiledModule { + name: cgu.name().to_string(), + kind: ModuleKind::Regular, + object: Some(obj_out), + dwarf_object: None, + bytecode: None, + } +} + +fn module_codegen( + tcx: TyCtxt<'_>, + (backend_config, cgu_name): (BackendConfig, rustc_span::Symbol), +) -> ModuleCodegenResult { + let cgu = tcx.codegen_unit(cgu_name); + let mono_items = cgu.items_in_deterministic_order(tcx); + + let isa = crate::build_isa(tcx.sess, &backend_config); + let mut module = make_module(tcx.sess, isa, cgu_name.as_str().to_string()); + + let mut cx = crate::CodegenCx::new( + tcx, + backend_config.clone(), + module.isa(), + tcx.sess.opts.debuginfo != DebugInfo::None, + cgu_name, + ); + super::predefine_mono_items(tcx, &mut module, &mono_items); + for (mono_item, _) in mono_items { + match mono_item { + MonoItem::Fn(inst) => { + cx.tcx + .sess + .time("codegen fn", || crate::base::codegen_fn(&mut cx, &mut module, inst)); + } + MonoItem::Static(def_id) => crate::constant::codegen_static(tcx, &mut module, def_id), + MonoItem::GlobalAsm(item_id) => { + let item = cx.tcx.hir().item(item_id); + if let rustc_hir::ItemKind::GlobalAsm(asm) = item.kind { + if !asm.options.contains(InlineAsmOptions::ATT_SYNTAX) { + cx.global_asm.push_str("\n.intel_syntax noprefix\n"); + } else { + cx.global_asm.push_str("\n.att_syntax\n"); + } + for piece in asm.template { + match *piece { + InlineAsmTemplatePiece::String(ref s) => cx.global_asm.push_str(s), + InlineAsmTemplatePiece::Placeholder { .. } => todo!(), + } + } + cx.global_asm.push_str("\n.att_syntax\n\n"); + } else { + bug!("Expected GlobalAsm found {:?}", item); + } + } + } + } + crate::main_shim::maybe_create_entry_wrapper( + tcx, + &mut module, + &mut cx.unwind_context, + false, + cgu.is_primary(), + ); + + let debug_context = cx.debug_context; + let unwind_context = cx.unwind_context; + let codegen_result = tcx.sess.time("write object file", || { + emit_module( + tcx, + &backend_config, + cgu.name().as_str().to_string(), + ModuleKind::Regular, + module, + debug_context, + unwind_context, + ) + }); + + codegen_global_asm(tcx, cgu.name().as_str(), &cx.global_asm); + + codegen_result +} + +pub(crate) fn run_aot( + tcx: TyCtxt<'_>, + backend_config: BackendConfig, + metadata: EncodedMetadata, + need_metadata_module: bool, +) -> Box<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>)> { + let mut work_products = FxHashMap::default(); + + let cgus = if tcx.sess.opts.output_types.should_codegen() { + tcx.collect_and_partition_mono_items(()).1 + } else { + // If only `--emit metadata` is used, we shouldn't perform any codegen. + // Also `tcx.collect_and_partition_mono_items` may panic in that case. + &[] + }; + + if tcx.dep_graph.is_fully_enabled() { + for cgu in &*cgus { + tcx.ensure().codegen_unit(cgu.name()); + } + } + + let modules = super::time(tcx, backend_config.display_cg_time, "codegen mono items", || { + cgus.iter() + .map(|cgu| { + let cgu_reuse = determine_cgu_reuse(tcx, cgu); + tcx.sess.cgu_reuse_tracker.set_actual_reuse(cgu.name().as_str(), cgu_reuse); + + match cgu_reuse { + _ if backend_config.disable_incr_cache => {} + CguReuse::No => {} + CguReuse::PreLto => { + return reuse_workproduct_for_cgu(tcx, &*cgu, &mut work_products); + } + CguReuse::PostLto => unreachable!(), + } + + let dep_node = cgu.codegen_dep_node(tcx); + let (ModuleCodegenResult(module, work_product), _) = tcx.dep_graph.with_task( + dep_node, + tcx, + (backend_config.clone(), cgu.name()), + module_codegen, + Some(rustc_middle::dep_graph::hash_result), + ); + + if let Some((id, product)) = work_product { + work_products.insert(id, product); + } + + module + }) + .collect::<Vec<_>>() + }); + + tcx.sess.abort_if_errors(); + + let isa = crate::build_isa(tcx.sess, &backend_config); + let mut allocator_module = make_module(tcx.sess, isa, "allocator_shim".to_string()); + assert_eq!(pointer_ty(tcx), allocator_module.target_config().pointer_type()); + let mut allocator_unwind_context = UnwindContext::new(allocator_module.isa(), true); + let created_alloc_shim = + crate::allocator::codegen(tcx, &mut allocator_module, &mut allocator_unwind_context); + + let allocator_module = if created_alloc_shim { + let ModuleCodegenResult(module, work_product) = emit_module( + tcx, + &backend_config, + "allocator_shim".to_string(), + ModuleKind::Allocator, + allocator_module, + None, + allocator_unwind_context, + ); + if let Some((id, product)) = work_product { + work_products.insert(id, product); + } + Some(module) + } else { + None + }; + + let metadata_module = if need_metadata_module { + let _timer = tcx.prof.generic_activity("codegen crate metadata"); + let (metadata_cgu_name, tmp_file) = tcx.sess.time("write compressed metadata", || { + use rustc_middle::mir::mono::CodegenUnitNameBuilder; + + let cgu_name_builder = &mut CodegenUnitNameBuilder::new(tcx); + let metadata_cgu_name = cgu_name_builder + .build_cgu_name(LOCAL_CRATE, &["crate"], Some("metadata")) + .as_str() + .to_string(); + + let tmp_file = + tcx.output_filenames(()).temp_path(OutputType::Metadata, Some(&metadata_cgu_name)); + + let symbol_name = rustc_middle::middle::exported_symbols::metadata_symbol_name(tcx); + let obj = create_compressed_metadata_file(tcx.sess, &metadata, &symbol_name); + + if let Err(err) = std::fs::write(&tmp_file, obj) { + tcx.sess.fatal(&format!("error writing metadata object file: {}", err)); + } + + (metadata_cgu_name, tmp_file) + }); + + Some(CompiledModule { + name: metadata_cgu_name, + kind: ModuleKind::Metadata, + object: Some(tmp_file), + dwarf_object: None, + bytecode: None, + }) + } else { + None + }; + + // FIXME handle `-Ctarget-cpu=native` + let target_cpu = match tcx.sess.opts.cg.target_cpu { + Some(ref name) => name, + None => tcx.sess.target.cpu.as_ref(), + } + .to_owned(); + + Box::new(( + CodegenResults { + modules, + allocator_module, + metadata_module, + metadata, + crate_info: CrateInfo::new(tcx, target_cpu), + }, + work_products, + )) +} + +fn codegen_global_asm(tcx: TyCtxt<'_>, cgu_name: &str, global_asm: &str) { + use std::io::Write; + use std::process::{Command, Stdio}; + + if global_asm.is_empty() { + return; + } + + if cfg!(not(feature = "inline_asm")) + || tcx.sess.target.is_like_osx + || tcx.sess.target.is_like_windows + { + if global_asm.contains("__rust_probestack") { + return; + } + + // FIXME fix linker error on macOS + if cfg!(not(feature = "inline_asm")) { + tcx.sess.fatal( + "asm! and global_asm! support is disabled while compiling rustc_codegen_cranelift", + ); + } else { + tcx.sess.fatal("asm! and global_asm! are not yet supported on macOS and Windows"); + } + } + + let assembler = crate::toolchain::get_toolchain_binary(tcx.sess, "as"); + let linker = crate::toolchain::get_toolchain_binary(tcx.sess, "ld"); + + // Remove all LLVM style comments + let global_asm = global_asm + .lines() + .map(|line| if let Some(index) = line.find("//") { &line[0..index] } else { line }) + .collect::<Vec<_>>() + .join("\n"); + + let output_object_file = tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu_name)); + + // Assemble `global_asm` + let global_asm_object_file = add_file_stem_postfix(output_object_file.clone(), ".asm"); + let mut child = Command::new(assembler) + .arg("-o") + .arg(&global_asm_object_file) + .stdin(Stdio::piped()) + .spawn() + .expect("Failed to spawn `as`."); + child.stdin.take().unwrap().write_all(global_asm.as_bytes()).unwrap(); + let status = child.wait().expect("Failed to wait for `as`."); + if !status.success() { + tcx.sess.fatal(&format!("Failed to assemble `{}`", global_asm)); + } + + // Link the global asm and main object file together + let main_object_file = add_file_stem_postfix(output_object_file.clone(), ".main"); + std::fs::rename(&output_object_file, &main_object_file).unwrap(); + let status = Command::new(linker) + .arg("-r") // Create a new object file + .arg("-o") + .arg(output_object_file) + .arg(&main_object_file) + .arg(&global_asm_object_file) + .status() + .unwrap(); + if !status.success() { + tcx.sess.fatal(&format!( + "Failed to link `{}` and `{}` together", + main_object_file.display(), + global_asm_object_file.display(), + )); + } + + std::fs::remove_file(global_asm_object_file).unwrap(); + std::fs::remove_file(main_object_file).unwrap(); +} + +fn add_file_stem_postfix(mut path: PathBuf, postfix: &str) -> PathBuf { + let mut new_filename = path.file_stem().unwrap().to_owned(); + new_filename.push(postfix); + if let Some(extension) = path.extension() { + new_filename.push("."); + new_filename.push(extension); + } + path.set_file_name(new_filename); + path +} + +// Adapted from https://github.com/rust-lang/rust/blob/303d8aff6092709edd4dbd35b1c88e9aa40bf6d8/src/librustc_codegen_ssa/base.rs#L922-L953 +fn determine_cgu_reuse<'tcx>(tcx: TyCtxt<'tcx>, cgu: &CodegenUnit<'tcx>) -> CguReuse { + if !tcx.dep_graph.is_fully_enabled() { + return CguReuse::No; + } + + let work_product_id = &cgu.work_product_id(); + if tcx.dep_graph.previous_work_product(work_product_id).is_none() { + // We don't have anything cached for this CGU. This can happen + // if the CGU did not exist in the previous session. + return CguReuse::No; + } + + // Try to mark the CGU as green. If it we can do so, it means that nothing + // affecting the LLVM module has changed and we can re-use a cached version. + // If we compile with any kind of LTO, this means we can re-use the bitcode + // of the Pre-LTO stage (possibly also the Post-LTO version but we'll only + // know that later). If we are not doing LTO, there is only one optimized + // version of each module, so we re-use that. + let dep_node = cgu.codegen_dep_node(tcx); + assert!( + !tcx.dep_graph.dep_node_exists(&dep_node), + "CompileCodegenUnit dep-node for CGU `{}` already exists before marking.", + cgu.name() + ); + + if tcx.try_mark_green(&dep_node) { CguReuse::PreLto } else { CguReuse::No } +} diff --git a/compiler/rustc_codegen_cranelift/src/driver/jit.rs b/compiler/rustc_codegen_cranelift/src/driver/jit.rs new file mode 100644 index 000000000..a56a91000 --- /dev/null +++ b/compiler/rustc_codegen_cranelift/src/driver/jit.rs @@ -0,0 +1,385 @@ +//! The JIT driver uses [`cranelift_jit`] to JIT execute programs without writing any object +//! files. + +use std::cell::RefCell; +use std::ffi::CString; +use std::os::raw::{c_char, c_int}; +use std::sync::{mpsc, Mutex}; + +use rustc_codegen_ssa::CrateInfo; +use rustc_middle::mir::mono::MonoItem; +use rustc_session::Session; +use rustc_span::Symbol; + +use cranelift_jit::{JITBuilder, JITModule}; + +// FIXME use std::sync::OnceLock once it stabilizes +use once_cell::sync::OnceCell; + +use crate::{prelude::*, BackendConfig}; +use crate::{CodegenCx, CodegenMode}; + +struct JitState { + backend_config: BackendConfig, + jit_module: JITModule, +} + +thread_local! { + static LAZY_JIT_STATE: RefCell<Option<JitState>> = const { RefCell::new(None) }; +} + +/// The Sender owned by the rustc thread +static GLOBAL_MESSAGE_SENDER: OnceCell<Mutex<mpsc::Sender<UnsafeMessage>>> = OnceCell::new(); + +/// A message that is sent from the jitted runtime to the rustc thread. +/// Senders are responsible for upholding `Send` semantics. +enum UnsafeMessage { + /// Request that the specified `Instance` be lazily jitted. + /// + /// Nothing accessible through `instance_ptr` may be moved or mutated by the sender after + /// this message is sent. + JitFn { + instance_ptr: *const Instance<'static>, + trampoline_ptr: *const u8, + tx: mpsc::Sender<*const u8>, + }, +} +unsafe impl Send for UnsafeMessage {} + +impl UnsafeMessage { + /// Send the message. + fn send(self) -> Result<(), mpsc::SendError<UnsafeMessage>> { + thread_local! { + /// The Sender owned by the local thread + static LOCAL_MESSAGE_SENDER: mpsc::Sender<UnsafeMessage> = + GLOBAL_MESSAGE_SENDER + .get().unwrap() + .lock().unwrap() + .clone(); + } + LOCAL_MESSAGE_SENDER.with(|sender| sender.send(self)) + } +} + +fn create_jit_module<'tcx>( + tcx: TyCtxt<'tcx>, + backend_config: &BackendConfig, + hotswap: bool, +) -> (JITModule, CodegenCx<'tcx>) { + let crate_info = CrateInfo::new(tcx, "dummy_target_cpu".to_string()); + let imported_symbols = load_imported_symbols_for_jit(tcx.sess, crate_info); + + let isa = crate::build_isa(tcx.sess, backend_config); + let mut jit_builder = JITBuilder::with_isa(isa, cranelift_module::default_libcall_names()); + jit_builder.hotswap(hotswap); + crate::compiler_builtins::register_functions_for_jit(&mut jit_builder); + jit_builder.symbols(imported_symbols); + jit_builder.symbol("__clif_jit_fn", clif_jit_fn as *const u8); + let mut jit_module = JITModule::new(jit_builder); + + let mut cx = crate::CodegenCx::new( + tcx, + backend_config.clone(), + jit_module.isa(), + false, + Symbol::intern("dummy_cgu_name"), + ); + + crate::allocator::codegen(tcx, &mut jit_module, &mut cx.unwind_context); + crate::main_shim::maybe_create_entry_wrapper( + tcx, + &mut jit_module, + &mut cx.unwind_context, + true, + true, + ); + + (jit_module, cx) +} + +pub(crate) fn run_jit(tcx: TyCtxt<'_>, backend_config: BackendConfig) -> ! { + if !tcx.sess.opts.output_types.should_codegen() { + tcx.sess.fatal("JIT mode doesn't work with `cargo check`"); + } + + if !tcx.sess.crate_types().contains(&rustc_session::config::CrateType::Executable) { + tcx.sess.fatal("can't jit non-executable crate"); + } + + let (mut jit_module, mut cx) = create_jit_module( + tcx, + &backend_config, + matches!(backend_config.codegen_mode, CodegenMode::JitLazy), + ); + + let (_, cgus) = tcx.collect_and_partition_mono_items(()); + let mono_items = cgus + .iter() + .map(|cgu| cgu.items_in_deterministic_order(tcx).into_iter()) + .flatten() + .collect::<FxHashMap<_, (_, _)>>() + .into_iter() + .collect::<Vec<(_, (_, _))>>(); + + super::time(tcx, backend_config.display_cg_time, "codegen mono items", || { + super::predefine_mono_items(tcx, &mut jit_module, &mono_items); + for (mono_item, _) in mono_items { + match mono_item { + MonoItem::Fn(inst) => match backend_config.codegen_mode { + CodegenMode::Aot => unreachable!(), + CodegenMode::Jit => { + cx.tcx.sess.time("codegen fn", || { + crate::base::codegen_fn(&mut cx, &mut jit_module, inst) + }); + } + CodegenMode::JitLazy => codegen_shim(&mut cx, &mut jit_module, inst), + }, + MonoItem::Static(def_id) => { + crate::constant::codegen_static(tcx, &mut jit_module, def_id); + } + MonoItem::GlobalAsm(item_id) => { + let item = tcx.hir().item(item_id); + tcx.sess.span_fatal(item.span, "Global asm is not supported in JIT mode"); + } + } + } + }); + + if !cx.global_asm.is_empty() { + tcx.sess.fatal("Inline asm is not supported in JIT mode"); + } + + tcx.sess.abort_if_errors(); + + jit_module.finalize_definitions(); + unsafe { cx.unwind_context.register_jit(&jit_module) }; + + println!( + "Rustc codegen cranelift will JIT run the executable, because -Cllvm-args=mode=jit was passed" + ); + + let args = std::iter::once(&*tcx.crate_name(LOCAL_CRATE).as_str().to_string()) + .chain(backend_config.jit_args.iter().map(|arg| &**arg)) + .map(|arg| CString::new(arg).unwrap()) + .collect::<Vec<_>>(); + + let start_sig = Signature { + params: vec![ + AbiParam::new(jit_module.target_config().pointer_type()), + AbiParam::new(jit_module.target_config().pointer_type()), + ], + returns: vec![AbiParam::new(jit_module.target_config().pointer_type() /*isize*/)], + call_conv: jit_module.target_config().default_call_conv, + }; + let start_func_id = jit_module.declare_function("main", Linkage::Import, &start_sig).unwrap(); + let finalized_start: *const u8 = jit_module.get_finalized_function(start_func_id); + + LAZY_JIT_STATE.with(|lazy_jit_state| { + let mut lazy_jit_state = lazy_jit_state.borrow_mut(); + assert!(lazy_jit_state.is_none()); + *lazy_jit_state = Some(JitState { backend_config, jit_module }); + }); + + let f: extern "C" fn(c_int, *const *const c_char) -> c_int = + unsafe { ::std::mem::transmute(finalized_start) }; + + let (tx, rx) = mpsc::channel(); + GLOBAL_MESSAGE_SENDER.set(Mutex::new(tx)).unwrap(); + + // Spawn the jitted runtime in a new thread so that this rustc thread can handle messages + // (eg to lazily JIT further functions as required) + std::thread::spawn(move || { + let mut argv = args.iter().map(|arg| arg.as_ptr()).collect::<Vec<_>>(); + + // Push a null pointer as a terminating argument. This is required by POSIX and + // useful as some dynamic linkers use it as a marker to jump over. + argv.push(std::ptr::null()); + + let ret = f(args.len() as c_int, argv.as_ptr()); + std::process::exit(ret); + }); + + // Handle messages + loop { + match rx.recv().unwrap() { + // lazy JIT compilation request - compile requested instance and return pointer to result + UnsafeMessage::JitFn { instance_ptr, trampoline_ptr, tx } => { + tx.send(jit_fn(instance_ptr, trampoline_ptr)) + .expect("jitted runtime hung up before response to lazy JIT request was sent"); + } + } + } +} + +extern "C" fn clif_jit_fn( + instance_ptr: *const Instance<'static>, + trampoline_ptr: *const u8, +) -> *const u8 { + // send the JIT request to the rustc thread, with a channel for the response + let (tx, rx) = mpsc::channel(); + UnsafeMessage::JitFn { instance_ptr, trampoline_ptr, tx } + .send() + .expect("rustc thread hung up before lazy JIT request was sent"); + + // block on JIT compilation result + rx.recv().expect("rustc thread hung up before responding to sent lazy JIT request") +} + +fn jit_fn(instance_ptr: *const Instance<'static>, trampoline_ptr: *const u8) -> *const u8 { + rustc_middle::ty::tls::with(|tcx| { + // lift is used to ensure the correct lifetime for instance. + let instance = tcx.lift(unsafe { *instance_ptr }).unwrap(); + + LAZY_JIT_STATE.with(|lazy_jit_state| { + let mut lazy_jit_state = lazy_jit_state.borrow_mut(); + let lazy_jit_state = lazy_jit_state.as_mut().unwrap(); + let jit_module = &mut lazy_jit_state.jit_module; + let backend_config = lazy_jit_state.backend_config.clone(); + + let name = tcx.symbol_name(instance).name; + let sig = crate::abi::get_function_sig(tcx, jit_module.isa().triple(), instance); + let func_id = jit_module.declare_function(name, Linkage::Export, &sig).unwrap(); + + let current_ptr = jit_module.read_got_entry(func_id); + + // If the function's GOT entry has already been updated to point at something other + // than the shim trampoline, don't re-jit but just return the new pointer instead. + // This does not need synchronization as this code is executed only by a sole rustc + // thread. + if current_ptr != trampoline_ptr { + return current_ptr; + } + + jit_module.prepare_for_function_redefine(func_id).unwrap(); + + let mut cx = crate::CodegenCx::new( + tcx, + backend_config, + jit_module.isa(), + false, + Symbol::intern("dummy_cgu_name"), + ); + tcx.sess.time("codegen fn", || crate::base::codegen_fn(&mut cx, jit_module, instance)); + + assert!(cx.global_asm.is_empty()); + jit_module.finalize_definitions(); + unsafe { cx.unwind_context.register_jit(&jit_module) }; + jit_module.get_finalized_function(func_id) + }) + }) +} + +fn load_imported_symbols_for_jit( + sess: &Session, + crate_info: CrateInfo, +) -> Vec<(String, *const u8)> { + use rustc_middle::middle::dependency_format::Linkage; + + let mut dylib_paths = Vec::new(); + + let data = &crate_info + .dependency_formats + .iter() + .find(|(crate_type, _data)| *crate_type == rustc_session::config::CrateType::Executable) + .unwrap() + .1; + for &cnum in &crate_info.used_crates { + let src = &crate_info.used_crate_source[&cnum]; + match data[cnum.as_usize() - 1] { + Linkage::NotLinked | Linkage::IncludedFromDylib => {} + Linkage::Static => { + let name = crate_info.crate_name[&cnum]; + let mut err = sess.struct_err(&format!("Can't load static lib {}", name)); + err.note("rustc_codegen_cranelift can only load dylibs in JIT mode."); + err.emit(); + } + Linkage::Dynamic => { + dylib_paths.push(src.dylib.as_ref().unwrap().0.clone()); + } + } + } + + let mut imported_symbols = Vec::new(); + for path in dylib_paths { + use object::{Object, ObjectSymbol}; + let lib = libloading::Library::new(&path).unwrap(); + let obj = std::fs::read(path).unwrap(); + let obj = object::File::parse(&*obj).unwrap(); + imported_symbols.extend(obj.dynamic_symbols().filter_map(|symbol| { + let name = symbol.name().unwrap().to_string(); + if name.is_empty() || !symbol.is_global() || symbol.is_undefined() { + return None; + } + if name.starts_with("rust_metadata_") { + // The metadata is part of a section that is not loaded by the dynamic linker in + // case of cg_llvm. + return None; + } + let dlsym_name = if cfg!(target_os = "macos") { + // On macOS `dlsym` expects the name without leading `_`. + assert!(name.starts_with('_'), "{:?}", name); + &name[1..] + } else { + &name + }; + let symbol: libloading::Symbol<'_, *const u8> = + unsafe { lib.get(dlsym_name.as_bytes()) }.unwrap(); + Some((name, *symbol)) + })); + std::mem::forget(lib) + } + + sess.abort_if_errors(); + + imported_symbols +} + +fn codegen_shim<'tcx>(cx: &mut CodegenCx<'tcx>, module: &mut JITModule, inst: Instance<'tcx>) { + let tcx = cx.tcx; + + let pointer_type = module.target_config().pointer_type(); + + let name = tcx.symbol_name(inst).name; + let sig = crate::abi::get_function_sig(tcx, module.isa().triple(), inst); + let func_id = module.declare_function(name, Linkage::Export, &sig).unwrap(); + + let instance_ptr = Box::into_raw(Box::new(inst)); + + let jit_fn = module + .declare_function( + "__clif_jit_fn", + Linkage::Import, + &Signature { + call_conv: module.target_config().default_call_conv, + params: vec![AbiParam::new(pointer_type), AbiParam::new(pointer_type)], + returns: vec![AbiParam::new(pointer_type)], + }, + ) + .unwrap(); + + cx.cached_context.clear(); + let trampoline = &mut cx.cached_context.func; + trampoline.signature = sig.clone(); + + let mut builder_ctx = FunctionBuilderContext::new(); + let mut trampoline_builder = FunctionBuilder::new(trampoline, &mut builder_ctx); + + let trampoline_fn = module.declare_func_in_func(func_id, trampoline_builder.func); + let jit_fn = module.declare_func_in_func(jit_fn, trampoline_builder.func); + let sig_ref = trampoline_builder.func.import_signature(sig); + + let entry_block = trampoline_builder.create_block(); + trampoline_builder.append_block_params_for_function_params(entry_block); + let fn_args = trampoline_builder.func.dfg.block_params(entry_block).to_vec(); + + trampoline_builder.switch_to_block(entry_block); + let instance_ptr = trampoline_builder.ins().iconst(pointer_type, instance_ptr as u64 as i64); + let trampoline_ptr = trampoline_builder.ins().func_addr(pointer_type, trampoline_fn); + let jitted_fn = trampoline_builder.ins().call(jit_fn, &[instance_ptr, trampoline_ptr]); + let jitted_fn = trampoline_builder.func.dfg.inst_results(jitted_fn)[0]; + let call_inst = trampoline_builder.ins().call_indirect(sig_ref, jitted_fn, &fn_args); + let ret_vals = trampoline_builder.func.dfg.inst_results(call_inst).to_vec(); + trampoline_builder.ins().return_(&ret_vals); + + module.define_function(func_id, &mut cx.cached_context).unwrap(); +} diff --git a/compiler/rustc_codegen_cranelift/src/driver/mod.rs b/compiler/rustc_codegen_cranelift/src/driver/mod.rs new file mode 100644 index 000000000..8f5714ecb --- /dev/null +++ b/compiler/rustc_codegen_cranelift/src/driver/mod.rs @@ -0,0 +1,53 @@ +//! Drivers are responsible for calling [`codegen_fn`] or [`codegen_static`] for each mono item and +//! performing any further actions like JIT executing or writing object files. +//! +//! [`codegen_fn`]: crate::base::codegen_fn +//! [`codegen_static`]: crate::constant::codegen_static + +use rustc_middle::mir::mono::{Linkage as RLinkage, MonoItem, Visibility}; + +use crate::prelude::*; + +pub(crate) mod aot; +#[cfg(feature = "jit")] +pub(crate) mod jit; + +fn predefine_mono_items<'tcx>( + tcx: TyCtxt<'tcx>, + module: &mut dyn Module, + mono_items: &[(MonoItem<'tcx>, (RLinkage, Visibility))], +) { + tcx.sess.time("predefine functions", || { + let is_compiler_builtins = tcx.is_compiler_builtins(LOCAL_CRATE); + for &(mono_item, (linkage, visibility)) in mono_items { + match mono_item { + MonoItem::Fn(instance) => { + let name = tcx.symbol_name(instance).name; + let _inst_guard = crate::PrintOnPanic(|| format!("{:?} {}", instance, name)); + let sig = get_function_sig(tcx, module.isa().triple(), instance); + let linkage = crate::linkage::get_clif_linkage( + mono_item, + linkage, + visibility, + is_compiler_builtins, + ); + module.declare_function(name, linkage, &sig).unwrap(); + } + MonoItem::Static(_) | MonoItem::GlobalAsm(_) => {} + } + } + }); +} + +fn time<R>(tcx: TyCtxt<'_>, display: bool, name: &'static str, f: impl FnOnce() -> R) -> R { + if display { + println!("[{:<30}: {}] start", tcx.crate_name(LOCAL_CRATE), name); + let before = std::time::Instant::now(); + let res = tcx.sess.time(name, f); + let after = std::time::Instant::now(); + println!("[{:<30}: {}] end time: {:?}", tcx.crate_name(LOCAL_CRATE), name, after - before); + res + } else { + tcx.sess.time(name, f) + } +} |