the unadjusted ABI needs to pass aggregates by-value

This commit is contained in:
Ralf Jung 2023-11-21 10:15:59 +01:00
parent 9a66e4471f
commit a06f3556aa
2 changed files with 30 additions and 6 deletions

View File

@ -382,6 +382,7 @@ impl HomogeneousAggregate {
}
impl<'a, Ty> TyAndLayout<'a, Ty> {
/// Returns `true` if this is an aggregate type (including a ScalarPair!)
fn is_aggregate(&self) -> bool {
match self.abi {
Abi::Uninhabited | Abi::Scalar(_) | Abi::Vector { .. } => false,

View File

@ -327,10 +327,15 @@ fn adjust_for_rust_scalar<'tcx>(
}
/// Ensure that the ABI makes basic sense.
fn fn_abi_sanity_check<'tcx>(cx: &LayoutCx<'tcx, TyCtxt<'tcx>>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) {
fn fn_abi_sanity_check<'tcx>(
cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
spec_abi: SpecAbi,
) {
fn fn_arg_sanity_check<'tcx>(
cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
spec_abi: SpecAbi,
arg: &ArgAbi<'tcx, Ty<'tcx>>,
) {
match &arg.mode {
@ -360,8 +365,8 @@ fn fn_abi_sanity_check<'tcx>(cx: &LayoutCx<'tcx, TyCtxt<'tcx>>, fn_abi: &FnAbi<'
// (See issue: https://github.com/rust-lang/rust/issues/117271)
assert!(
matches!(&*cx.tcx.sess.target.arch, "wasm32" | "wasm64")
|| fn_abi.conv == Conv::PtxKernel,
"`PassMode::Direct` for aggregates only allowed on wasm and `extern \"ptx-kernel\"` fns\nProblematic type: {:#?}",
|| matches!(spec_abi, SpecAbi::PtxKernel | SpecAbi::Unadjusted),
r#"`PassMode::Direct` for aggregates only allowed for "unadjusted" and "ptx-kernel" functions and on wasm\nProblematic type: {:#?}"#,
arg.layout,
);
}
@ -391,9 +396,9 @@ fn fn_abi_sanity_check<'tcx>(cx: &LayoutCx<'tcx, TyCtxt<'tcx>>, fn_abi: &FnAbi<'
}
for arg in fn_abi.args.iter() {
fn_arg_sanity_check(cx, fn_abi, arg);
fn_arg_sanity_check(cx, fn_abi, spec_abi, arg);
}
fn_arg_sanity_check(cx, fn_abi, &fn_abi.ret);
fn_arg_sanity_check(cx, fn_abi, spec_abi, &fn_abi.ret);
}
// FIXME(eddyb) perhaps group the signature/type-containing (or all of them?)
@ -522,7 +527,7 @@ fn fn_abi_new_uncached<'tcx>(
};
fn_abi_adjust_for_abi(cx, &mut fn_abi, sig.abi, fn_def_id)?;
debug!("fn_abi_new_uncached = {:?}", fn_abi);
fn_abi_sanity_check(cx, &fn_abi);
fn_abi_sanity_check(cx, &fn_abi, sig.abi);
Ok(cx.tcx.arena.alloc(fn_abi))
}
@ -534,6 +539,24 @@ fn fn_abi_adjust_for_abi<'tcx>(
fn_def_id: Option<DefId>,
) -> Result<(), &'tcx FnAbiError<'tcx>> {
if abi == SpecAbi::Unadjusted {
// The "unadjusted" ABI passes aggregates in "direct" mode. That's fragile but needed for
// some LLVM intrinsics.
fn unadjust<'tcx>(arg: &mut ArgAbi<'tcx, Ty<'tcx>>) {
// This still uses `PassMode::Pair` for ScalarPair types. That's unlikely to be intended,
// but who knows what breaks if we change this now.
if matches!(arg.layout.abi, Abi::Aggregate { .. }) {
assert!(
arg.layout.abi.is_sized(),
"'unadjusted' ABI does not support unsized arguments"
);
}
arg.make_direct_deprecated();
}
unadjust(&mut fn_abi.ret);
for arg in fn_abi.args.iter_mut() {
unadjust(arg);
}
return Ok(());
}