2 use std::os::raw::{c_char, c_int};
4 use rustc_codegen_ssa::CrateInfo;
8 pub(super) fn run_jit(tcx: TyCtxt<'_>) -> ! {
9 use cranelift_simplejit::{SimpleJITBackend, SimpleJITBuilder};
11 // Rustc opens us without the RTLD_GLOBAL flag, so __cg_clif_global_atomic_mutex will not be
12 // exported. We fix this by opening ourself again as global.
13 // FIXME remove once atomic_shim is gone
14 let cg_dylib = std::ffi::OsString::from(
23 libloading::os::unix::Library::open(Some(cg_dylib), libc::RTLD_NOW | libc::RTLD_GLOBAL)
27 let imported_symbols = load_imported_symbols_for_jit(tcx);
29 let mut jit_builder = SimpleJITBuilder::with_isa(
30 crate::build_isa(tcx.sess, false),
31 cranelift_module::default_libcall_names(),
33 jit_builder.symbols(imported_symbols);
34 let mut jit_module: Module<SimpleJITBackend> = Module::new(jit_builder);
35 assert_eq!(pointer_ty(tcx), jit_module.target_config().pointer_type());
39 AbiParam::new(jit_module.target_config().pointer_type()),
40 AbiParam::new(jit_module.target_config().pointer_type()),
42 returns: vec![AbiParam::new(
43 jit_module.target_config().pointer_type(), /*isize*/
45 call_conv: CallConv::triple_default(&crate::target_triple(tcx.sess)),
47 let main_func_id = jit_module
48 .declare_function("main", Linkage::Import, &sig)
51 if !tcx.sess.opts.output_types.should_codegen() {
52 tcx.sess.fatal("JIT mode doesn't work with `cargo check`.");
55 let (_, cgus) = tcx.collect_and_partition_mono_items(LOCAL_CRATE);
58 .map(|cgu| cgu.items_in_deterministic_order(tcx).into_iter())
60 .collect::<FxHashMap<_, (_, _)>>()
62 .collect::<Vec<(_, (_, _))>>();
64 let mut cx = crate::CodegenCx::new(tcx, jit_module, false);
66 let (mut jit_module, global_asm, _debug, mut unwind_context) =
67 super::time(tcx, "codegen mono items", || {
68 super::codegen_mono_items(&mut cx, mono_items);
69 tcx.sess.time("finalize CodegenCx", || cx.finalize())
71 if !global_asm.is_empty() {
72 tcx.sess.fatal("Global asm is not supported in JIT mode");
74 crate::main_shim::maybe_create_entry_wrapper(tcx, &mut jit_module, &mut unwind_context);
75 crate::allocator::codegen(tcx, &mut jit_module, &mut unwind_context);
77 jit_module.finalize_definitions();
79 let _unwind_register_guard = unsafe { unwind_context.register_jit(&mut jit_module) };
81 tcx.sess.abort_if_errors();
83 let finalized_main: *const u8 = jit_module.get_finalized_function(main_func_id);
85 println!("Rustc codegen cranelift will JIT run the executable, because the CG_CLIF_JIT env var is set");
87 let f: extern "C" fn(c_int, *const *const c_char) -> c_int =
88 unsafe { ::std::mem::transmute(finalized_main) };
90 let args = ::std::env::var("CG_CLIF_JIT_ARGS").unwrap_or_else(|_| String::new());
91 let args = std::iter::once(&*tcx.crate_name(LOCAL_CRATE).as_str().to_string())
92 .chain(args.split(" "))
93 .map(|arg| CString::new(arg).unwrap())
95 let mut argv = args.iter().map(|arg| arg.as_ptr()).collect::<Vec<_>>();
97 // Push a null pointer as a terminating argument. This is required by POSIX and
98 // useful as some dynamic linkers use it as a marker to jump over.
99 argv.push(std::ptr::null());
101 let ret = f(args.len() as c_int, argv.as_ptr());
104 std::process::exit(ret);
107 fn load_imported_symbols_for_jit(tcx: TyCtxt<'_>) -> Vec<(String, *const u8)> {
108 use rustc_middle::middle::dependency_format::Linkage;
110 let mut dylib_paths = Vec::new();
112 let crate_info = CrateInfo::new(tcx);
113 let formats = tcx.dependency_formats(LOCAL_CRATE);
116 .find(|(crate_type, _data)| *crate_type == rustc_session::config::CrateType::Executable)
119 for &(cnum, _) in &crate_info.used_crates_dynamic {
120 let src = &crate_info.used_crate_source[&cnum];
121 match data[cnum.as_usize() - 1] {
122 Linkage::NotLinked | Linkage::IncludedFromDylib => {}
124 let name = tcx.crate_name(cnum);
127 .struct_err(&format!("Can't load static lib {}", name.as_str()));
128 err.note("rustc_codegen_cranelift can only load dylibs in JIT mode.");
131 Linkage::Dynamic => {
132 dylib_paths.push(src.dylib.as_ref().unwrap().0.clone());
137 let mut imported_symbols = Vec::new();
138 for path in dylib_paths {
140 let lib = libloading::Library::new(&path).unwrap();
141 let obj = std::fs::read(path).unwrap();
142 let obj = object::File::parse(&obj).unwrap();
143 imported_symbols.extend(obj.dynamic_symbols().filter_map(|(_idx, symbol)| {
144 let name = symbol.name().unwrap().to_string();
145 if name.is_empty() || !symbol.is_global() || symbol.is_undefined() {
148 let dlsym_name = if cfg!(target_os = "macos") {
149 // On macOS `dlsym` expects the name without leading `_`.
150 assert!(name.starts_with("_"), "{:?}", name);
155 let symbol: libloading::Symbol<'_, *const u8> =
156 unsafe { lib.get(dlsym_name.as_bytes()) }.unwrap();
157 Some((name, *symbol))
159 std::mem::forget(lib)
162 tcx.sess.abort_if_errors();