abi
});
+impl_stable_hash_for!(struct ty::ResolvedOpaqueTy<'tcx> {
+ concrete_type,
+ substs
+});
+
impl<'a, 'gcx, T> HashStable<StableHashingContext<'a>> for ty::Binder<T>
where T: HashStable<StableHashingContext<'a>>
{
///
/// winds up desugared to:
///
- /// abstract type Foo<'x, T>: Trait<'x>
+ /// abstract type Foo<'x, X>: Trait<'x>
/// fn foo<'a, 'b, T>() -> Foo<'a, T>
///
/// then `substs` would be `['a, T]`.
}
}
+/// All information necessary to validate and reveal an `impl Trait` or `existential Type`
+#[derive(RustcEncodable, RustcDecodable, Debug)]
+pub struct ResolvedOpaqueTy<'tcx> {
+ /// The revealed type as seen by this function.
+ pub concrete_type: Ty<'tcx>,
+ /// Generic parameters on the opaque type as passed by this function.
+ /// For `existential type Foo<A, B>; fn foo<T, U>() -> Foo<T, U> { .. }` this is `[T, U]`, not
+ /// `[A, B]`
+ pub substs: &'tcx Substs<'tcx>,
+}
+
#[derive(RustcEncodable, RustcDecodable, Debug)]
pub struct TypeckTables<'tcx> {
/// The HirId::owner all ItemLocalIds in this table are relative to.
/// All the existential types that are restricted to concrete types
/// by this function
- pub concrete_existential_types: FxHashMap<DefId, Ty<'tcx>>,
+ pub concrete_existential_types: FxHashMap<DefId, ResolvedOpaqueTy<'tcx>>,
/// Given the closure ID this map provides the list of UpvarIDs used by it.
/// The upvarID contains the HIR node ID and it also contains the full path
pub use self::context::{Lift, TypeckTables, CtxtInterners};
pub use self::context::{
UserTypeAnnotationIndex, UserType, CanonicalUserType,
- CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations,
+ CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, ResolvedOpaqueTy,
};
pub use self::instance::{Instance, InstanceDef};
}
}
+ let new = ty::ResolvedOpaqueTy {
+ concrete_type: definition_ty,
+ substs: self.tcx().lift_to_global(&opaque_defn.substs).unwrap(),
+ };
+
let old = self.tables
.concrete_existential_types
- .insert(def_id, definition_ty);
+ .insert(def_id, new);
if let Some(old) = old {
- if old != definition_ty {
+ if old.concrete_type != definition_ty || old.substs != opaque_defn.substs {
span_bug!(
span,
"visit_opaque_types tried to write \
- different types for the same existential type: {:?}, {:?}, {:?}",
+ different types for the same existential type: {:?}, {:?}, {:?}, {:?}",
def_id,
definition_ty,
+ opaque_defn,
old,
);
}
use middle::weak_lang_items;
use rustc::mir::mono::Linkage;
use rustc::ty::query::Providers;
-use rustc::ty::subst::Substs;
+use rustc::ty::subst::{Subst, Substs};
use rustc::ty::util::Discr;
use rustc::ty::util::IntTypeExt;
+use rustc::ty::subst::UnpackedKind;
use rustc::ty::{self, AdtKind, ToPolyTraitRef, Ty, TyCtxt};
use rustc::ty::{ReprOptions, ToPredicate};
use rustc::util::captures::Captures;
tcx.typeck_tables_of(owner)
.concrete_existential_types
.get(&def_id)
- .cloned()
+ .map(|opaque| opaque.concrete_type)
.unwrap_or_else(|| {
// This can occur if some error in the
// owner fn prevented us from populating
struct ConstraintLocator<'a, 'tcx: 'a> {
tcx: TyCtxt<'a, 'tcx, 'tcx>,
def_id: DefId,
- found: Option<(Span, ty::Ty<'tcx>)>,
+ // First found type span, actual type, mapping from the existential type's generic
+ // parameters to the concrete type's generic parameters
+ //
+ // The mapping is an index for each use site of a generic parameter in the concrete type
+ //
+ // The indices index into the generic parameters on the existential type.
+ found: Option<(Span, ty::Ty<'tcx>, Vec<usize>)>,
}
impl<'a, 'tcx> ConstraintLocator<'a, 'tcx> {
.tcx
.typeck_tables_of(def_id)
.concrete_existential_types
- .get(&self.def_id)
- .cloned();
- if let Some(ty) = ty {
+ .get(&self.def_id);
+ if let Some(ty::ResolvedOpaqueTy { concrete_type, substs }) = ty {
// FIXME(oli-obk): trace the actual span from inference to improve errors
let span = self.tcx.def_span(def_id);
- if let Some((prev_span, prev_ty)) = self.found {
- let mut ty = ty.walk().fuse();
+ // used to quickly look up the position of a generic parameter
+ let mut index_map: FxHashMap<ty::ParamTy, usize> = FxHashMap::default();
+ // skip binder is ok, since we only use this to find generic parameters and their
+ // positions.
+ for subst in substs.iter() {
+ if let UnpackedKind::Type(ty) = subst.unpack() {
+ if let ty::Param(p) = ty.sty {
+ let idx = index_map.len();
+ if index_map.insert(p, idx).is_some() {
+ // there was already an entry for `p`, meaning a generic parameter
+ // was used twice
+ self.tcx.sess.span_err(
+ span,
+ &format!("defining existential type use restricts existential \
+ type by using the generic parameter `{}` twice", p.name),
+ );
+ return;
+ }
+ } else {
+ self.tcx.sess.delay_span_bug(
+ span,
+ &format!(
+ "non-defining exist ty use in defining scope: {:?}, {:?}",
+ concrete_type, substs,
+ ),
+ );
+ }
+ }
+ }
+ // compute the index within the existential type for each generic parameter used in
+ // the concrete type
+ let indices = concrete_type
+ .subst(self.tcx, substs)
+ .walk()
+ .filter_map(|t| match &t.sty {
+ ty::Param(p) => Some(*index_map.get(p).unwrap()),
+ _ => None,
+ }).collect();
+ if let Some((prev_span, prev_ty, ref prev_indices)) = self.found {
+ let mut ty = concrete_type.walk().fuse();
let mut prev_ty = prev_ty.walk().fuse();
let iter_eq = (&mut ty).zip(&mut prev_ty).all(|(t, p)| match (&t.sty, &p.sty) {
// type parameters are equal to any other type parameter for the purpose of
// found different concrete types for the existential type
let mut err = self.tcx.sess.struct_span_err(
span,
- "defining existential type use differs from previous",
+ "concrete type differs from previous defining existential type use",
+ );
+ err.span_note(prev_span, "previous use here");
+ err.emit();
+ } else if indices != *prev_indices {
+ // found "same" concrete types, but the generic parameter order differs
+ let mut err = self.tcx.sess.struct_span_err(
+ span,
+ "concrete type's generic parameters differ from previous defining use",
);
err.span_note(prev_span, "previous use here");
err.emit();
}
} else {
- self.found = Some((span, ty));
+ self.found = Some((span, concrete_type, indices));
}
}
}
}
match locator.found {
- Some((_, ty)) => ty,
+ Some((_, ty, _)) => ty,
None => {
let span = tcx.def_span(def_id);
tcx.sess.span_err(span, "could not find defining uses");
""
}
-fn bar() -> Foo { //~ ERROR defining existential type use differs from previous
+fn bar() -> Foo { //~ ERROR concrete type differs from previous
42i32
}
-error: defining existential type use differs from previous
+error: concrete type differs from previous defining existential type use
--> $DIR/different_defining_uses.rs:12:1
|
-LL | / fn bar() -> Foo { //~ ERROR defining existential type use differs from previous
+LL | / fn bar() -> Foo { //~ ERROR concrete type differs from previous
LL | | 42i32
LL | | }
| |_^
""
}
-fn bar() -> Foo { //~ ERROR defining existential type use differs from previous
+fn bar() -> Foo { //~ ERROR concrete type differs from previous
panic!()
}
-fn boo() -> Foo { //~ ERROR defining existential type use differs from previous
+fn boo() -> Foo { //~ ERROR concrete type differs from previous
loop {}
}
-error: defining existential type use differs from previous
+error: concrete type differs from previous defining existential type use
--> $DIR/different_defining_uses_never_type.rs:12:1
|
-LL | / fn bar() -> Foo { //~ ERROR defining existential type use differs from previous
+LL | / fn bar() -> Foo { //~ ERROR concrete type differs from previous
LL | | panic!()
LL | | }
| |_^
LL | | }
| |_^
-error: defining existential type use differs from previous
+error: concrete type differs from previous defining existential type use
--> $DIR/different_defining_uses_never_type.rs:16:1
|
-LL | / fn boo() -> Foo { //~ ERROR defining existential type use differs from previous
+LL | / fn boo() -> Foo { //~ ERROR concrete type differs from previous
LL | | loop {}
LL | | }
| |_^
std::iter::once(t)
}
-fn my_iter2<T>(t: T) -> MyIter<T> { //~ ERROR defining existential type use differs from previous
+fn my_iter2<T>(t: T) -> MyIter<T> { //~ ERROR concrete type differs from previous
Some(t).into_iter()
}
-error: defining existential type use differs from previous
+error: concrete type differs from previous defining existential type use
--> $DIR/generic_different_defining_uses.rs:11:1
|
-LL | / fn my_iter2<T>(t: T) -> MyIter<T> { //~ ERROR defining existential type use differs from previous
+LL | / fn my_iter2<T>(t: T) -> MyIter<T> { //~ ERROR concrete type differs from previous
LL | | Some(t).into_iter()
LL | | }
| |_^
-// compile-pass
#![feature(existential_type)]
use std::fmt::Debug;
// test that unused generic parameters are ok
existential type Two<T, U>: Debug;
+//~^ could not find defining uses
fn one<T: Debug>(t: T) -> Two<T, T> {
+//~^ ERROR defining existential type use restricts existential type
t
}
--- /dev/null
+error: defining existential type use restricts existential type by using the generic parameter `T` twice
+ --> $DIR/generic_duplicate_param_use.rs:11:1
+ |
+LL | / fn one<T: Debug>(t: T) -> Two<T, T> {
+LL | | //~^ ERROR defining existential type use restricts existential type
+LL | | t
+LL | | }
+ | |_^
+
+error: could not find defining uses
+ --> $DIR/generic_duplicate_param_use.rs:8:1
+ |
+LL | existential type Two<T, U>: Debug;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
-// compile-pass
#![feature(existential_type)]
use std::fmt::Debug;
existential type Two<T, U>: Debug;
fn one<T: Debug>(t: T) -> Two<T, T> {
+//~^ defining existential type use restricts existential type
t
}
--- /dev/null
+error: defining existential type use restricts existential type by using the generic parameter `T` twice
+ --> $DIR/generic_duplicate_param_use2.rs:10:1
+ |
+LL | / fn one<T: Debug>(t: T) -> Two<T, T> {
+LL | | //~^ defining existential type use restricts existential type
+LL | | t
+LL | | }
+ | |_^
+
+error: aborting due to previous error
+
-// compile-pass
#![feature(existential_type)]
use std::fmt::Debug;
existential type Two<T, U>: Debug;
fn one<T: Debug>(t: T) -> Two<T, T> {
+//~^ defining existential type use restricts existential type
t
}
}
fn three<T, U: Debug>(_: T, u: U) -> Two<T, U> {
+//~^ concrete type's generic parameters differ from previous defining use
u
}
--- /dev/null
+error: defining existential type use restricts existential type by using the generic parameter `T` twice
+ --> $DIR/generic_duplicate_param_use3.rs:10:1
+ |
+LL | / fn one<T: Debug>(t: T) -> Two<T, T> {
+LL | | //~^ defining existential type use restricts existential type
+LL | | t
+LL | | }
+ | |_^
+
+error: concrete type's generic parameters differ from previous defining use
+ --> $DIR/generic_duplicate_param_use3.rs:19:1
+ |
+LL | / fn three<T, U: Debug>(_: T, u: U) -> Two<T, U> {
+LL | | //~^ concrete type's generic parameters differ from previous defining use
+LL | | u
+LL | | }
+ | |_^
+ |
+note: previous use here
+ --> $DIR/generic_duplicate_param_use3.rs:15:1
+ |
+LL | / fn two<T: Debug, U>(t: T, _: U) -> Two<T, U> {
+LL | | t
+LL | | }
+ | |_^
+
+error: aborting due to 2 previous errors
+
-// compile-pass
#![feature(existential_type)]
use std::fmt::Debug;
existential type Two<T, U>: Debug;
fn one<T: Debug>(t: T) -> Two<T, T> {
+//~^ ERROR defining existential type use restricts existential type
t
}
--- /dev/null
+error: defining existential type use restricts existential type by using the generic parameter `T` twice
+ --> $DIR/generic_duplicate_param_use4.rs:10:1
+ |
+LL | / fn one<T: Debug>(t: T) -> Two<T, T> {
+LL | | //~^ ERROR defining existential type use restricts existential type
+LL | | t
+LL | | }
+ | |_^
+
+error: aborting due to previous error
+
--- /dev/null
+#![feature(existential_type)]
+
+use std::fmt::Debug;
+
+fn main() {}
+
+// test that unused generic parameters are ok
+existential type Two<T, U>: Debug;
+
+fn two<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+ (t, u)
+}
+
+fn three<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+//~^ concrete type differs from previous
+ (u, t)
+}
--- /dev/null
+error: concrete type differs from previous defining existential type use
+ --> $DIR/generic_duplicate_param_use5.rs:14:1
+ |
+LL | / fn three<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+LL | | //~^ concrete type differs from previous
+LL | | (u, t)
+LL | | }
+ | |_^
+ |
+note: previous use here
+ --> $DIR/generic_duplicate_param_use5.rs:10:1
+ |
+LL | / fn two<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+LL | | (t, u)
+LL | | }
+ | |_^
+
+error: aborting due to previous error
+
--- /dev/null
+#![feature(existential_type)]
+
+use std::fmt::Debug;
+
+fn main() {}
+
+// test that unused generic parameters are ok
+existential type Two<T, U>: Debug;
+
+fn two<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+ (t, t)
+}
+
+fn three<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+//~^ concrete type differs from previous
+ (u, t)
+}
--- /dev/null
+error: concrete type differs from previous defining existential type use
+ --> $DIR/generic_duplicate_param_use6.rs:14:1
+ |
+LL | / fn three<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+LL | | //~^ concrete type differs from previous
+LL | | (u, t)
+LL | | }
+ | |_^
+ |
+note: previous use here
+ --> $DIR/generic_duplicate_param_use6.rs:10:1
+ |
+LL | / fn two<T: Debug, U: Debug>(t: T, u: U) -> Two<T, U> {
+LL | | (t, t)
+LL | | }
+ | |_^
+
+error: aborting due to previous error
+
--- /dev/null
+// compile-pass
+#![feature(existential_type)]
+
+use std::fmt::Debug;
+
+fn main() {}
+
+existential type Two<A, B>: Debug;
+
+fn two<T: Debug + Copy, U>(t: T, u: U) -> Two<T, U> {
+ (t, t)
+}
+
+fn three<T: Debug, U>(t: T, t2: T, u: U) -> Two<T, U> {
+ (t, t2)
+}
projects / rust.git / commitdiff