diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index e9c19331e4a..98ca71b86be 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -111,8 +111,9 @@ pub enum InstanceKind<'tcx> {
/// Dynamic dispatch to `<dyn Trait as Trait>::fn`.
///
- /// This `InstanceKind` does not have callable MIR. Calls to `Virtual` instances must be
- /// codegen'd as virtual calls through the vtable.
+ /// This `InstanceKind` may have a callable MIR as the default implementation.
+ /// Calls to `Virtual` instances must be codegen'd as virtual calls through the vtable.
+ /// *This means we might not know exactly what is being called.*
///
/// If this is reified to a `fn` pointer, a `ReifyShim` is used (see `ReifyShim` above for more
/// details on that).
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index 0ff82f0c256..4fa8c9fe15d 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -309,15 +309,11 @@ fn fn_abi_of_fn_ptr<'tcx>(
query: ty::PseudoCanonicalInput<'tcx, (ty::PolyFnSig<'tcx>, &'tcx ty::List<Ty<'tcx>>)>,
) -> Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, &'tcx FnAbiError<'tcx>> {
let ty::PseudoCanonicalInput { typing_env, value: (sig, extra_args) } = query;
-
- let cx = LayoutCx::new(tcx, typing_env);
fn_abi_new_uncached(
- &cx,
+ &LayoutCx::new(tcx, typing_env),
tcx.instantiate_bound_regions_with_erased(sig),
extra_args,
None,
- None,
- false,
)
}
@@ -326,19 +322,11 @@ fn fn_abi_of_instance<'tcx>(
query: ty::PseudoCanonicalInput<'tcx, (ty::Instance<'tcx>, &'tcx ty::List<Ty<'tcx>>)>,
) -> Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, &'tcx FnAbiError<'tcx>> {
let ty::PseudoCanonicalInput { typing_env, value: (instance, extra_args) } = query;
-
- let sig = fn_sig_for_fn_abi(tcx, instance, typing_env);
-
- let caller_location =
- instance.def.requires_caller_location(tcx).then(|| tcx.caller_location_ty());
-
fn_abi_new_uncached(
&LayoutCx::new(tcx, typing_env),
- sig,
+ fn_sig_for_fn_abi(tcx, instance, typing_env),
extra_args,
- caller_location,
- Some(instance.def_id()),
- matches!(instance.def, ty::InstanceKind::Virtual(..)),
+ Some(instance),
)
}
@@ -547,19 +535,23 @@ fn fn_abi_sanity_check<'tcx>(
fn_arg_sanity_check(cx, fn_abi, spec_abi, &fn_abi.ret);
}
-// FIXME(eddyb) perhaps group the signature/type-containing (or all of them?)
-// arguments of this method, into a separate `struct`.
-#[tracing::instrument(level = "debug", skip(cx, caller_location, fn_def_id, force_thin_self_ptr))]
+#[tracing::instrument(level = "debug", skip(cx, instance))]
fn fn_abi_new_uncached<'tcx>(
cx: &LayoutCx<'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>],
- caller_location: Option<Ty<'tcx>>,
- fn_def_id: Option<DefId>,
- // FIXME(eddyb) replace this with something typed, like an `enum`.
- force_thin_self_ptr: bool,
+ instance: Option<ty::Instance<'tcx>>,
) -> Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, &'tcx FnAbiError<'tcx>> {
let tcx = cx.tcx();
+ let (caller_location, fn_def_id, is_virtual_call) = if let Some(instance) = instance {
+ (
+ instance.def.requires_caller_location(tcx).then(|| tcx.caller_location_ty()),
+ Some(instance.def_id()),
+ matches!(instance.def, ty::InstanceKind::Virtual(..)),
+ )
+ } else {
+ (None, None, false)
+ };
let sig = tcx.normalize_erasing_regions(cx.typing_env, sig);
let conv = conv_from_spec_abi(cx.tcx(), sig.abi, sig.c_variadic);
@@ -568,16 +560,11 @@ fn fn_abi_new_uncached<'tcx>(
let extra_args = if sig.abi == ExternAbi::RustCall {
assert!(!sig.c_variadic && extra_args.is_empty());
- if let Some(input) = sig.inputs().last() {
- if let ty::Tuple(tupled_arguments) = input.kind() {
- inputs = &sig.inputs()[0..sig.inputs().len() - 1];
- tupled_arguments
- } else {
- bug!(
- "argument to function with \"rust-call\" ABI \
- is not a tuple"
- );
- }
+ if let Some(input) = sig.inputs().last()
+ && let ty::Tuple(tupled_arguments) = input.kind()
+ {
+ inputs = &sig.inputs()[0..sig.inputs().len() - 1];
+ tupled_arguments
} else {
bug!(
"argument to function with \"rust-call\" ABI \
@@ -603,7 +590,7 @@ fn fn_abi_new_uncached<'tcx>(
});
let layout = cx.layout_of(ty).map_err(|err| &*tcx.arena.alloc(FnAbiError::Layout(*err)))?;
- let layout = if force_thin_self_ptr && arg_idx == Some(0) {
+ let layout = if is_virtual_call && arg_idx == Some(0) {
// Don't pass the vtable, it's not an argument of the virtual fn.
// Instead, pass just the data pointer, but give it the type `*const/mut dyn Trait`
// or `&/&mut dyn Trait` because this is special-cased elsewhere in codegen
@@ -648,7 +635,15 @@ fn fn_abi_new_uncached<'tcx>(
conv,
can_unwind: fn_can_unwind(cx.tcx(), fn_def_id, sig.abi),
};
- fn_abi_adjust_for_abi(cx, &mut fn_abi, sig.abi, fn_def_id);
+ fn_abi_adjust_for_abi(
+ cx,
+ &mut fn_abi,
+ sig.abi,
+ // If this is a virtual call, we cannot pass the `fn_def_id`, as it might call other
+ // functions from vtable. Internally, `deduced_param_attrs` attempts to infer attributes by
+ // visit the function body.
+ fn_def_id.filter(|_| !is_virtual_call),
+ );
debug!("fn_abi_new_uncached = {:?}", fn_abi);
fn_abi_sanity_check(cx, &fn_abi, sig.abi);
Ok(tcx.arena.alloc(fn_abi))
diff --git a/tests/codegen/virtual-call-attrs-issue-137646.rs b/tests/codegen/virtual-call-attrs-issue-137646.rs
new file mode 100644
index 00000000000..72a25b75856
--- /dev/null
+++ b/tests/codegen/virtual-call-attrs-issue-137646.rs
@@ -0,0 +1,18 @@
+//! Regression test for https://github.com/rust-lang/rust/issues/137646.
+//! Since we don't know the exact implementation of the virtual call,
+//! it might write to parameters, we can't infer the readonly attribute.
+//@ compile-flags: -C opt-level=3 -C no-prepopulate-passes
+
+#![crate_type = "lib"]
+
+pub trait Trait {
+ fn m(&self, _: (i32, i32, i32)) {}
+}
+
+#[no_mangle]
+pub fn foo(trait_: &dyn Trait) {
+ // CHECK-LABEL: @foo(
+ // CHECK: call void
+ // CHECK-NOT: readonly
+ trait_.m((1, 1, 1));
+}
diff --git a/tests/ui/virtual-call-attrs-issue-137646.rs b/tests/ui/virtual-call-attrs-issue-137646.rs
index 055dc6ea4f2..e80bd5768a4 100644
--- a/tests/ui/virtual-call-attrs-issue-137646.rs
+++ b/tests/ui/virtual-call-attrs-issue-137646.rs
@@ -1,8 +1,7 @@
//! Regression test for https://github.com/rust-lang/rust/issues/137646.
-//! FIXME: The parameter value at all calls to `check` should be `(1, 1, 1)`.
+//! The parameter value at all calls to `check` should be `(1, 1, 1)`.
//@ run-pass
-//@ check-run-results
use std::hint::black_box;
@@ -35,8 +34,7 @@ pub fn run_2(trait_: &dyn Trait) {
#[inline(never)]
fn check(v: T) {
- dbg!(v);
- // assert_eq!(v, (1, 1, 1));
+ assert_eq!(v, (1, 1, 1));
}
fn main() {
diff --git a/tests/ui/virtual-call-attrs-issue-137646.run.stderr b/tests/ui/virtual-call-attrs-issue-137646.run.stderr
deleted file mode 100644
index 445975e1e54..00000000000
--- a/tests/ui/virtual-call-attrs-issue-137646.run.stderr
+++ /dev/null
@@ -1,20 +0,0 @@
-[$DIR/virtual-call-attrs-issue-137646.rs:38:5] v = (
- 498486832,
- 22093,
- 498491440,
-)
-[$DIR/virtual-call-attrs-issue-137646.rs:38:5] v = (
- 0,
- 0,
- 0,
-)
-[$DIR/virtual-call-attrs-issue-137646.rs:38:5] v = (
- 0,
- 0,
- 0,
-)
-[$DIR/virtual-call-attrs-issue-137646.rs:38:5] v = (
- 0,
- 0,
- 0,
-)