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Add support to intrinsics fallback body

Before this fix, the call to `body()` would crash, since `has_body()`
would return true, but we would try to retrieve the body of an intrinsic
which is not allowed.

Instead, the `Instance::body()` function will now convert an Intrinsic
into an Item before retrieving its body.
This commit is contained in:
Celina G. Val 2024-04-05 15:10:17 -07:00
parent ea40fa210b
commit 1512d06be9
3 changed files with 149 additions and 34 deletions

View file

@ -6,7 +6,7 @@
use crate::rustc_smir::{Stable, Tables};
use rustc_middle::mir;
use rustc_middle::mir::visit::MutVisitor;
use rustc_middle::ty::{self, GenericArgsRef, Ty, TyCtxt};
use rustc_middle::ty::{self, TyCtxt};
/// Builds a monomorphic body for a given instance.
pub struct BodyBuilder<'tcx> {
@ -16,46 +16,41 @@ pub struct BodyBuilder<'tcx> {
impl<'tcx> BodyBuilder<'tcx> {
pub fn new(tcx: TyCtxt<'tcx>, instance: ty::Instance<'tcx>) -> Self {
let instance = match instance.def {
// To get the fallback body of an intrinsic, we need to convert it to an item.
ty::InstanceDef::Intrinsic(def_id) => ty::Instance::new(def_id, instance.args),
_ => instance,
};
BodyBuilder { tcx, instance }
}
/// Build a stable monomorphic body for a given instance based on the MIR body.
///
/// Note that we skip instantiation for static and constants. Trying to do so can cause ICE.
///
/// We do monomorphize non-generic functions to eval unevaluated constants.
/// All constants are also evaluated.
pub fn build(mut self, tables: &mut Tables<'tcx>) -> stable_mir::mir::Body {
let mut body = self.tcx.instance_mir(self.instance.def).clone();
if self.tcx.def_kind(self.instance.def_id()).is_fn_like() || !self.instance.args.is_empty()
let body = tables.tcx.instance_mir(self.instance.def).clone();
let mono_body = if self.tcx.def_kind(self.instance.def_id()).is_fn_like()
|| !self.instance.args.is_empty()
{
self.visit_body(&mut body);
}
body.stable(tables)
}
fn monomorphize<T>(&self, value: T) -> T
where
T: ty::TypeFoldable<TyCtxt<'tcx>>,
{
self.instance.instantiate_mir_and_normalize_erasing_regions(
self.tcx,
ty::ParamEnv::reveal_all(),
ty::EarlyBinder::bind(value),
)
// This call will currently will ICE in some shims which are already monomorphic.
let mut mono_body = self.instance.instantiate_mir_and_normalize_erasing_regions(
tables.tcx,
ty::ParamEnv::reveal_all(),
ty::EarlyBinder::bind(body),
);
self.visit_body(&mut mono_body);
mono_body
} else {
// Already monomorphic.
body
};
mono_body.stable(tables)
}
}
impl<'tcx> MutVisitor<'tcx> for BodyBuilder<'tcx> {
fn visit_ty_const(&mut self, ct: &mut ty::Const<'tcx>, _location: mir::Location) {
*ct = self.monomorphize(*ct);
}
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _: mir::visit::TyContext) {
*ty = self.monomorphize(*ty);
}
fn visit_constant(&mut self, constant: &mut mir::ConstOperand<'tcx>, location: mir::Location) {
let const_ = self.monomorphize(constant.const_);
let const_ = constant.const_;
let val = match const_.eval(self.tcx, ty::ParamEnv::reveal_all(), constant.span) {
Ok(v) => v,
Err(mir::interpret::ErrorHandled::Reported(..)) => return,
@ -68,10 +63,6 @@ impl<'tcx> MutVisitor<'tcx> for BodyBuilder<'tcx> {
self.super_constant(constant, location);
}
fn visit_args(&mut self, args: &mut GenericArgsRef<'tcx>, _: mir::Location) {
*args = self.monomorphize(*args);
}
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx
}