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Teach llvm backend how to fall back to default bodies

This commit is contained in:
Oli Scherer 2024-01-31 20:39:59 +00:00
parent 432635a9ea
commit 9a0743747f
11 changed files with 109 additions and 103 deletions

View file

@ -956,19 +956,24 @@ fn visit_instance_use<'tcx>(
if !should_codegen_locally(tcx, &instance) {
return;
}
// The intrinsics assert_inhabited, assert_zero_valid, and assert_mem_uninitialized_valid will
// be lowered in codegen to nothing or a call to panic_nounwind. So if we encounter any
// of those intrinsics, we need to include a mono item for panic_nounwind, else we may try to
// codegen a call to that function without generating code for the function itself.
if let ty::InstanceDef::Intrinsic(def_id) = instance.def {
let name = tcx.item_name(def_id);
if let Some(_requirement) = ValidityRequirement::from_intrinsic(name) {
// The intrinsics assert_inhabited, assert_zero_valid, and assert_mem_uninitialized_valid will
// be lowered in codegen to nothing or a call to panic_nounwind. So if we encounter any
// of those intrinsics, we need to include a mono item for panic_nounwind, else we may try to
// codegen a call to that function without generating code for the function itself.
let def_id = tcx.lang_items().get(LangItem::PanicNounwind).unwrap();
let panic_instance = Instance::mono(tcx, def_id);
if should_codegen_locally(tcx, &panic_instance) {
output.push(create_fn_mono_item(tcx, panic_instance, source));
}
} else if tcx.has_attr(def_id, sym::rustc_intrinsic) {
// Codegen the fallback body of intrinsics with fallback bodies
let instance = ty::Instance::new(def_id, instance.args);
if should_codegen_locally(tcx, &instance) {
output.push(create_fn_mono_item(tcx, instance, source));
}
}
}