| use cranelift_codegen::binemit::{NullStackMapSink, NullTrapSink}; |
| use rustc_hir::LangItem; |
| use rustc_middle::ty::subst::GenericArg; |
| use rustc_middle::ty::AssocKind; |
| use rustc_session::config::EntryFnType; |
| use rustc_span::symbol::Ident; |
| |
| use crate::prelude::*; |
| |
| /// Create the `main` function which will initialize the rust runtime and call |
| /// users main function. |
| pub(crate) fn maybe_create_entry_wrapper( |
| tcx: TyCtxt<'_>, |
| module: &mut impl Module, |
| unwind_context: &mut UnwindContext, |
| is_jit: bool, |
| is_primary_cgu: bool, |
| ) { |
| let (main_def_id, is_main_fn) = match tcx.entry_fn(()) { |
| Some((def_id, entry_ty)) => ( |
| def_id, |
| match entry_ty { |
| EntryFnType::Main => true, |
| EntryFnType::Start => false, |
| }, |
| ), |
| None => return, |
| }; |
| |
| if main_def_id.is_local() { |
| let instance = Instance::mono(tcx, main_def_id).polymorphize(tcx); |
| if !is_jit && module.get_name(&*tcx.symbol_name(instance).name).is_none() { |
| return; |
| } |
| } else if !is_primary_cgu { |
| return; |
| } |
| |
| create_entry_fn(tcx, module, unwind_context, main_def_id, is_jit, is_main_fn); |
| |
| fn create_entry_fn( |
| tcx: TyCtxt<'_>, |
| m: &mut impl Module, |
| unwind_context: &mut UnwindContext, |
| rust_main_def_id: DefId, |
| ignore_lang_start_wrapper: bool, |
| is_main_fn: bool, |
| ) { |
| let main_ret_ty = tcx.fn_sig(rust_main_def_id).output(); |
| // Given that `main()` has no arguments, |
| // then its return type cannot have |
| // late-bound regions, since late-bound |
| // regions must appear in the argument |
| // listing. |
| let main_ret_ty = tcx.erase_regions(main_ret_ty.no_bound_vars().unwrap()); |
| |
| let cmain_sig = Signature { |
| params: vec![ |
| AbiParam::new(m.target_config().pointer_type()), |
| AbiParam::new(m.target_config().pointer_type()), |
| ], |
| returns: vec![AbiParam::new(m.target_config().pointer_type() /*isize*/)], |
| call_conv: CallConv::triple_default(m.isa().triple()), |
| }; |
| |
| let cmain_func_id = m.declare_function("main", Linkage::Export, &cmain_sig).unwrap(); |
| |
| let instance = Instance::mono(tcx, rust_main_def_id).polymorphize(tcx); |
| |
| let main_name = tcx.symbol_name(instance).name; |
| let main_sig = get_function_sig(tcx, m.isa().triple(), instance); |
| let main_func_id = m.declare_function(main_name, Linkage::Import, &main_sig).unwrap(); |
| |
| let mut ctx = Context::new(); |
| ctx.func = Function::with_name_signature(ExternalName::user(0, 0), cmain_sig); |
| { |
| let mut func_ctx = FunctionBuilderContext::new(); |
| let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx); |
| |
| let block = bcx.create_block(); |
| bcx.switch_to_block(block); |
| let arg_argc = bcx.append_block_param(block, m.target_config().pointer_type()); |
| let arg_argv = bcx.append_block_param(block, m.target_config().pointer_type()); |
| |
| let main_func_ref = m.declare_func_in_func(main_func_id, &mut bcx.func); |
| |
| let result = if is_main_fn && ignore_lang_start_wrapper { |
| // regular main fn, but ignoring #[lang = "start"] as we are running in the jit |
| // FIXME set program arguments somehow |
| let call_inst = bcx.ins().call(main_func_ref, &[]); |
| let call_results = bcx.func.dfg.inst_results(call_inst).to_owned(); |
| |
| let termination_trait = tcx.require_lang_item(LangItem::Termination, None); |
| let report = tcx |
| .associated_items(termination_trait) |
| .find_by_name_and_kind( |
| tcx, |
| Ident::from_str("report"), |
| AssocKind::Fn, |
| termination_trait, |
| ) |
| .unwrap(); |
| let report = Instance::resolve( |
| tcx, |
| ParamEnv::reveal_all(), |
| report.def_id, |
| tcx.mk_substs([GenericArg::from(main_ret_ty)].iter()), |
| ) |
| .unwrap() |
| .unwrap(); |
| |
| let report_name = tcx.symbol_name(report).name; |
| let report_sig = get_function_sig(tcx, m.isa().triple(), report); |
| let report_func_id = |
| m.declare_function(report_name, Linkage::Import, &report_sig).unwrap(); |
| let report_func_ref = m.declare_func_in_func(report_func_id, &mut bcx.func); |
| |
| // FIXME do proper abi handling instead of expecting the pass mode to be identical |
| // for returns and arguments. |
| let report_call_inst = bcx.ins().call(report_func_ref, &call_results); |
| let res = bcx.func.dfg.inst_results(report_call_inst)[0]; |
| match m.target_config().pointer_type() { |
| types::I32 => res, |
| types::I64 => bcx.ins().sextend(types::I64, res), |
| _ => unimplemented!("16bit systems are not yet supported"), |
| } |
| } else if is_main_fn { |
| let start_def_id = tcx.require_lang_item(LangItem::Start, None); |
| let start_instance = Instance::resolve( |
| tcx, |
| ParamEnv::reveal_all(), |
| start_def_id, |
| tcx.intern_substs(&[main_ret_ty.into()]), |
| ) |
| .unwrap() |
| .unwrap() |
| .polymorphize(tcx); |
| let start_func_id = import_function(tcx, m, start_instance); |
| |
| let main_val = bcx.ins().func_addr(m.target_config().pointer_type(), main_func_ref); |
| |
| let func_ref = m.declare_func_in_func(start_func_id, &mut bcx.func); |
| let call_inst = bcx.ins().call(func_ref, &[main_val, arg_argc, arg_argv]); |
| bcx.inst_results(call_inst)[0] |
| } else { |
| // using user-defined start fn |
| let call_inst = bcx.ins().call(main_func_ref, &[arg_argc, arg_argv]); |
| bcx.inst_results(call_inst)[0] |
| }; |
| |
| bcx.ins().return_(&[result]); |
| bcx.seal_all_blocks(); |
| bcx.finalize(); |
| } |
| m.define_function(cmain_func_id, &mut ctx, &mut NullTrapSink {}, &mut NullStackMapSink {}) |
| .unwrap(); |
| unwind_context.add_function(cmain_func_id, &ctx, m.isa()); |
| } |
| } |