Use ParamEnv::reveal_all in CFI · rust-lang/rust@b0beb64 (original) (raw)

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Original file line number Diff line number Diff line change
@@ -6,7 +6,7 @@
6 6
7 7 use rustc_data_structures::fx::FxHashMap;
8 8 use rustc_middle::bug;
9 -use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeFoldable};
9 +use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
10 10 use rustc_target::abi:🤙:{Conv, FnAbi, PassMode};
11 11 use tracing::instrument;
12 12
@@ -112,11 +112,12 @@ pub fn typeid_for_instance<'tcx>(
112 112 instance: Instance<'tcx>,
113 113 options: TypeIdOptions,
114 114 ) -> String {
115 +assert!(!instance.has_non_region_param(), "{instance:#?} must be fully monomorphic");
115 116 let transform_ty_options = TransformTyOptions::from_bits(options.bits())
116 117 .unwrap_or_else(|
117 118 let instance = transform_instance(tcx, instance, transform_ty_options);
118 119 let fn_abi = tcx
119 -.fn_abi_of_instance(tcx.param_env(instance.def_id()).and((instance, ty::List::empty())))
120 +.fn_abi_of_instance(ty::ParamEnv::reveal_all().and((instance, ty::List::empty())))
120 121 .unwrap_or_else(|error
121 122 bug!("typeid_for_instance: couldn't get fn_abi of instance {instance:?}: {error:?}")
122 123 });
Original file line number Diff line number Diff line change
@@ -0,0 +1,44 @@
1 +//@ needs-sanitizer-cfi
2 +//@ compile-flags: -Ccodegen-units=1 -Clto -Ctarget-feature=-crt-static -Zsanitizer=cfi
3 +//@ no-prefer-dynamic
4 +//@ only-x86_64-unknown-linux-gnu
5 +//@ build-pass
6 +
7 +// See comment below for why this test exists.
8 +
9 +trait Tr<U> {
10 +type Projection;
11 +}
12 +
13 +impl<F, U> Tr<U> for F
14 +where
15 +F: Fn() -> U
16 +{
17 +type Projection = U;
18 +}
19 +
20 +fn test<B: Tr<U>, U>(b: B) -> B::Projection
21 +{
22 +todo!()
23 +}
24 +
25 +fn main() {
26 +fn rpit_fn() -> impl Sized {}
27 +
28 +// When CFI runs, it tries to compute the signature of the call. This
29 +// ends up giving us a signature of:
30 +// `fn test::<rpit_fn, ()>() -> <rpit_fn as Tr<()>>::Projection`,
31 +// where `rpit_fn` is the ZST FnDef for the function. However, we were
32 +// previously using a Reveal::UserFacing param-env. This means that the
33 +// `<rpit_fn as Tr<()>>::Projection` return type is impossible to normalize,
34 +// since it would require proving `rpit_fn: Fn() -> ()`, but we cannot
35 +// prove that the `impl Sized` opaque is `()` with a user-facing param-env.
36 +// This leads to a normalization error, and then an ICE.
37 +//
38 +// Side-note:
39 +// So why is the second generic of `test` "`()`", and not the
40 +// `impl Sized` since we inferred it from the return type of `rpit_fn`
41 +// during typeck? Well, that's because we're using the generics from the
42 +// terminator of the MIR, which has had the RevealAll pass performed on it.
43 +let _ = test(rpit_fn);
44 +}