//! The JIT driver uses [`cranelift_simplejit`] 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 rustc_codegen_ssa::CrateInfo;
+use rustc_middle::mir::mono::MonoItem;
+
+use cranelift_jit::{JITBuilder, JITModule};
use crate::prelude::*;
+use crate::{CodegenCx, CodegenMode};
+
+thread_local! {
+ pub static CURRENT_MODULE: RefCell<Option<JITModule>> = RefCell::new(None);
+}
-pub(super) fn run_jit(tcx: TyCtxt<'_>) -> ! {
- use cranelift_simplejit::{SimpleJITBackend, SimpleJITBuilder};
+pub(super) fn run_jit(tcx: TyCtxt<'_>, codegen_mode: CodegenMode) -> ! {
+ if !tcx.sess.opts.output_types.should_codegen() {
+ tcx.sess.fatal("JIT mode doesn't work with `cargo check`.");
+ }
#[cfg(unix)]
unsafe {
let imported_symbols = load_imported_symbols_for_jit(tcx);
- let mut jit_builder = SimpleJITBuilder::with_isa(
- crate::build_isa(tcx.sess, false),
+ let mut jit_builder = JITBuilder::with_isa(
+ crate::build_isa(tcx.sess),
cranelift_module::default_libcall_names(),
);
+ jit_builder.hotswap(matches!(codegen_mode, CodegenMode::JitLazy));
jit_builder.symbols(imported_symbols);
- let mut jit_module: Module<SimpleJITBackend> = Module::new(jit_builder);
+ let mut jit_module = JITModule::new(jit_builder);
assert_eq!(pointer_ty(tcx), jit_module.target_config().pointer_type());
let sig = Signature {
.declare_function("main", Linkage::Import, &sig)
.unwrap();
- if !tcx.sess.opts.output_types.should_codegen() {
- tcx.sess.fatal("JIT mode doesn't work with `cargo check`.");
- }
-
let (_, cgus) = tcx.collect_and_partition_mono_items(LOCAL_CRATE);
let mono_items = cgus
.iter()
.into_iter()
.collect::<Vec<(_, (_, _))>>();
- let mut cx = crate::CodegenCx::new(tcx, jit_module, false);
+ let mut cx = crate::CodegenCx::new(tcx, jit_module, false, false);
+
+ super::time(tcx, "codegen mono items", || {
+ super::predefine_mono_items(&mut cx, &mono_items);
+ for (mono_item, (linkage, visibility)) in mono_items {
+ let linkage = crate::linkage::get_clif_linkage(mono_item, linkage, visibility);
+ match mono_item {
+ MonoItem::Fn(inst) => match codegen_mode {
+ CodegenMode::Aot => unreachable!(),
+ CodegenMode::Jit => {
+ cx.tcx.sess.time("codegen fn", || {
+ crate::base::codegen_fn(&mut cx, inst, linkage)
+ });
+ }
+ CodegenMode::JitLazy => codegen_shim(&mut cx, inst),
+ },
+ MonoItem::Static(def_id) => {
+ crate::constant::codegen_static(&mut cx.constants_cx, def_id);
+ }
+ MonoItem::GlobalAsm(item_id) => {
+ let item = cx.tcx.hir().item(item_id);
+ tcx.sess.span_fatal(item.span, "Global asm is not supported in JIT mode");
+ }
+ }
+ }
+ });
let (mut jit_module, global_asm, _debug, mut unwind_context) =
- super::time(tcx, "codegen mono items", || {
- super::codegen_mono_items(&mut cx, mono_items);
- tcx.sess.time("finalize CodegenCx", || cx.finalize())
- });
+ tcx.sess.time("finalize CodegenCx", || cx.finalize());
+ jit_module.finalize_definitions();
+
if !global_asm.is_empty() {
- tcx.sess.fatal("Global asm is not supported in JIT mode");
+ tcx.sess.fatal("Inline asm is not supported in JIT mode");
}
- crate::main_shim::maybe_create_entry_wrapper(tcx, &mut jit_module, &mut unwind_context);
+
+ crate::main_shim::maybe_create_entry_wrapper(tcx, &mut jit_module, &mut unwind_context, true);
crate::allocator::codegen(tcx, &mut jit_module, &mut unwind_context);
+ tcx.sess.abort_if_errors();
+
jit_module.finalize_definitions();
- let _unwind_register_guard = unsafe { unwind_context.register_jit(&mut jit_module) };
-
- tcx.sess.abort_if_errors();
+ let _unwind_register_guard = unsafe { unwind_context.register_jit(&jit_module) };
let finalized_main: *const u8 = jit_module.get_finalized_function(main_func_id);
- println!("Rustc codegen cranelift will JIT run the executable, because the CG_CLIF_JIT env var is set");
+ println!("Rustc codegen cranelift will JIT run the executable, because -Cllvm-args=mode=jit was passed");
let f: extern "C" fn(c_int, *const *const c_char) -> c_int =
unsafe { ::std::mem::transmute(finalized_main) };
let args = ::std::env::var("CG_CLIF_JIT_ARGS").unwrap_or_else(|_| String::new());
let args = std::iter::once(&*tcx.crate_name(LOCAL_CRATE).as_str().to_string())
- .chain(args.split(" "))
+ .chain(args.split(' '))
.map(|arg| CString::new(arg).unwrap())
.collect::<Vec<_>>();
let mut argv = args.iter().map(|arg| arg.as_ptr()).collect::<Vec<_>>();
// useful as some dynamic linkers use it as a marker to jump over.
argv.push(std::ptr::null());
+ CURRENT_MODULE
+ .with(|current_module| assert!(current_module.borrow_mut().replace(jit_module).is_none()));
+
let ret = f(args.len() as c_int, argv.as_ptr());
- jit_module.finish();
std::process::exit(ret);
}
+#[no_mangle]
+extern "C" fn __clif_jit_fn(instance_ptr: *const Instance<'static>) -> *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();
+
+ CURRENT_MODULE.with(|jit_module| {
+ let mut jit_module = jit_module.borrow_mut();
+ let jit_module = jit_module.as_mut().unwrap();
+ let mut cx = crate::CodegenCx::new(tcx, jit_module, false, false);
+
+ let name = tcx.symbol_name(instance).name.to_string();
+ let sig = crate::abi::get_function_sig(tcx, cx.module.isa().triple(), instance);
+ let func_id = cx
+ .module
+ .declare_function(&name, Linkage::Export, &sig)
+ .unwrap();
+ cx.module.prepare_for_function_redefine(func_id).unwrap();
+
+ tcx.sess.time("codegen fn", || {
+ crate::base::codegen_fn(&mut cx, instance, Linkage::Export)
+ });
+
+ let (jit_module, global_asm, _debug_context, unwind_context) = cx.finalize();
+ assert!(global_asm.is_empty());
+ jit_module.finalize_definitions();
+ std::mem::forget(unsafe { unwind_context.register_jit(&jit_module) });
+ jit_module.get_finalized_function(func_id)
+ })
+ })
+}
+
fn load_imported_symbols_for_jit(tcx: TyCtxt<'_>) -> Vec<(String, *const u8)> {
use rustc_middle::middle::dependency_format::Linkage;
let mut imported_symbols = Vec::new();
for path in dylib_paths {
- use object::Object;
+ 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(|(_idx, symbol)| {
+ 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;
}
let dlsym_name = if cfg!(target_os = "macos") {
// On macOS `dlsym` expects the name without leading `_`.
- assert!(name.starts_with("_"), "{:?}", name);
+ assert!(name.starts_with('_'), "{:?}", name);
&name[1..]
} else {
&name
imported_symbols
}
+
+pub(super) fn codegen_shim<'tcx>(cx: &mut CodegenCx<'tcx, impl Module>, inst: Instance<'tcx>) {
+ let tcx = cx.tcx;
+
+ let pointer_type = cx.module.target_config().pointer_type();
+
+ let name = tcx.symbol_name(inst).name.to_string();
+ let sig = crate::abi::get_function_sig(tcx, cx.module.isa().triple(), inst);
+ let func_id = cx
+ .module
+ .declare_function(&name, Linkage::Export, &sig)
+ .unwrap();
+
+ let instance_ptr = Box::into_raw(Box::new(inst));
+
+ let jit_fn = cx
+ .module
+ .declare_function(
+ "__clif_jit_fn",
+ Linkage::Import,
+ &Signature {
+ call_conv: cx.module.target_config().default_call_conv,
+ params: vec![AbiParam::new(pointer_type)],
+ returns: vec![AbiParam::new(pointer_type)],
+ },
+ )
+ .unwrap();
+
+ let mut trampoline = Function::with_name_signature(ExternalName::default(), sig.clone());
+ let mut builder_ctx = FunctionBuilderContext::new();
+ let mut trampoline_builder = FunctionBuilder::new(&mut trampoline, &mut builder_ctx);
+
+ let jit_fn = cx
+ .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 jitted_fn = trampoline_builder.ins().call(jit_fn, &[instance_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);
+
+ cx.module
+ .define_function(
+ func_id,
+ &mut Context::for_function(trampoline),
+ &mut cranelift_codegen::binemit::NullTrapSink {},
+ )
+ .unwrap();
+}
projects / rust.git / blobdiff