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remove support for the #[start] attribute
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RalfJung committed Jan 21, 2025
1 parent b52c07f commit c4a3398
Showing 1 changed file with 8 additions and 13 deletions.
21 changes: 8 additions & 13 deletions src/main_shim.rs
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
use rustc_hir::LangItem;
use rustc_middle::ty::{AssocKind, GenericArg};
use rustc_session::config::{EntryFnType, sigpipe};
use rustc_session::config::EntryFnType;
use rustc_span::{DUMMY_SP, Ident};

use crate::prelude::*;
Expand All @@ -14,10 +14,9 @@ pub(crate) fn maybe_create_entry_wrapper(
is_jit: bool,
is_primary_cgu: bool,
) {
let (main_def_id, (is_main_fn, sigpipe)) = match tcx.entry_fn(()) {
let (main_def_id, sigpipe) = match tcx.entry_fn(()) {
Some((def_id, entry_ty)) => (def_id, match entry_ty {
EntryFnType::Main { sigpipe } => (true, sigpipe),
EntryFnType::Start => (false, sigpipe::DEFAULT),
EntryFnType::Main { sigpipe } => sigpipe,
}),
None => return,
};
Expand All @@ -31,14 +30,13 @@ pub(crate) fn maybe_create_entry_wrapper(
return;
}

create_entry_fn(tcx, module, main_def_id, is_jit, is_main_fn, sigpipe);
create_entry_fn(tcx, module, main_def_id, is_jit, sigpipe);

fn create_entry_fn(
tcx: TyCtxt<'_>,
m: &mut dyn Module,
rust_main_def_id: DefId,
ignore_lang_start_wrapper: bool,
is_main_fn: bool,
sigpipe: u8,
) {
let main_ret_ty = tcx.fn_sig(rust_main_def_id).no_bound_vars().unwrap().output();
Expand Down Expand Up @@ -94,8 +92,8 @@ pub(crate) fn maybe_create_entry_wrapper(

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
let result = if ignore_lang_start_wrapper {
// 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();
Expand Down Expand Up @@ -133,7 +131,8 @@ pub(crate) fn maybe_create_entry_wrapper(
types::I64 => bcx.ins().sextend(types::I64, res),
_ => unimplemented!("16bit systems are not yet supported"),
}
} else if is_main_fn {
} else {
// Regular main fn invoked via start lang item.
let start_def_id = tcx.require_lang_item(LangItem::Start, None);
let start_instance = Instance::expect_resolve(
tcx,
Expand All @@ -150,10 +149,6 @@ pub(crate) fn maybe_create_entry_wrapper(
let call_inst =
bcx.ins().call(func_ref, &[main_val, arg_argc, arg_argv, arg_sigpipe]);
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]);
Expand Down

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