From 804c0476575e891aa47131d67cbb3b6c21682abf Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 27 Mar 2024 10:56:11 +0000
Subject: [PATCH 1/4] Load missing type of impl associated constant from trait
definition
---
compiler/rustc_hir_typeck/src/lib.rs | 18 +++++++++---
tests/ui/consts/missing_assoc_const_type.rs | 28 +++++++++++++++++++
.../ui/consts/missing_assoc_const_type.stderr | 8 ++++++
tests/ui/consts/missing_assoc_const_type2.rs | 21 ++++++++++++++
.../consts/missing_assoc_const_type2.stderr | 8 ++++++
.../typeck_type_placeholder_item.stderr | 23 +++++++--------
6 files changed, 89 insertions(+), 17 deletions(-)
create mode 100644 tests/ui/consts/missing_assoc_const_type.rs
create mode 100644 tests/ui/consts/missing_assoc_const_type.stderr
create mode 100644 tests/ui/consts/missing_assoc_const_type2.rs
create mode 100644 tests/ui/consts/missing_assoc_const_type2.stderr
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 0b67b37df29d8..f201bfddf4bb1 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -192,10 +192,20 @@ fn typeck_with_fallback<'tcx>(
check_fn(&mut fcx, fn_sig, None, decl, def_id, body, tcx.features().unsized_fn_params);
} else {
let expected_type = if let Some(&hir::Ty { kind: hir::TyKind::Infer, span, .. }) = body_ty {
- Some(fcx.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::TypeInference,
- span,
- }))
+ if let Some(item) = tcx.opt_associated_item(def_id.into())
+ && let ty::AssocKind::Const = item.kind
+ && let ty::ImplContainer = item.container
+ && let Some(trait_item) = item.trait_item_def_id
+ {
+ let args =
+ tcx.impl_trait_ref(item.container_id(tcx)).unwrap().instantiate_identity().args;
+ Some(tcx.type_of(trait_item).instantiate(tcx, args))
+ } else {
+ Some(fcx.next_ty_var(TypeVariableOrigin {
+ kind: TypeVariableOriginKind::TypeInference,
+ span,
+ }))
+ }
} else if let Node::AnonConst(_) = node {
match tcx.parent_hir_node(id) {
Node::Ty(&hir::Ty { kind: hir::TyKind::Typeof(ref anon_const), .. })
diff --git a/tests/ui/consts/missing_assoc_const_type.rs b/tests/ui/consts/missing_assoc_const_type.rs
new file mode 100644
index 0000000000000..8d95e3dca633c
--- /dev/null
+++ b/tests/ui/consts/missing_assoc_const_type.rs
@@ -0,0 +1,28 @@
+//! Test that we compute the right type for associated constants
+//! of impls, even if the type is missing. We know it from the trait
+//! declaration after all.
+
+trait Range {
+ const FIRST: u8;
+ const LAST: u8;
+}
+
+struct TwoDigits;
+impl Range for TwoDigits {
+ const FIRST: = 10;
+ //~^ ERROR: missing type for `const` item
+ const LAST: u8 = 99;
+}
+
+const fn digits(x: u8) -> usize {
+ match x {
+ TwoDigits::FIRST..=TwoDigits::LAST => 0,
+ 0..=9 | 100..=255 => panic!(),
+ }
+}
+
+const FOOMP: [(); {
+ digits(42)
+}] = [];
+
+fn main() {}
diff --git a/tests/ui/consts/missing_assoc_const_type.stderr b/tests/ui/consts/missing_assoc_const_type.stderr
new file mode 100644
index 0000000000000..28af1f0f321e6
--- /dev/null
+++ b/tests/ui/consts/missing_assoc_const_type.stderr
@@ -0,0 +1,8 @@
+error: missing type for `const` item
+ --> $DIR/missing_assoc_const_type.rs:12:17
+ |
+LL | const FIRST: = 10;
+ | ^ help: provide a type for the associated constant: `u8`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/consts/missing_assoc_const_type2.rs b/tests/ui/consts/missing_assoc_const_type2.rs
new file mode 100644
index 0000000000000..baf236700a396
--- /dev/null
+++ b/tests/ui/consts/missing_assoc_const_type2.rs
@@ -0,0 +1,21 @@
+//! Test that we compute the right type for associated constants
+//! of impls, even if the type is missing. We know it from the trait
+//! declaration after all.
+
+trait Range {
+ const FIRST: u8;
+ const LAST: u8;
+}
+
+struct TwoDigits;
+impl Range for TwoDigits {
+ const FIRST: = 10;
+ //~^ ERROR: missing type
+ const LAST: u8 = 99;
+}
+
+const FOOMP: [(); {
+ TwoDigits::FIRST as usize
+}] = [(); 10];
+
+fn main() {}
diff --git a/tests/ui/consts/missing_assoc_const_type2.stderr b/tests/ui/consts/missing_assoc_const_type2.stderr
new file mode 100644
index 0000000000000..1255ca2d102b5
--- /dev/null
+++ b/tests/ui/consts/missing_assoc_const_type2.stderr
@@ -0,0 +1,8 @@
+error: missing type for `const` item
+ --> $DIR/missing_assoc_const_type2.rs:12:17
+ |
+LL | const FIRST: = 10;
+ | ^ help: provide a type for the associated constant: `u8`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/typeck/typeck_type_placeholder_item.stderr b/tests/ui/typeck/typeck_type_placeholder_item.stderr
index 8bcad56916aa9..7977504dae1d6 100644
--- a/tests/ui/typeck/typeck_type_placeholder_item.stderr
+++ b/tests/ui/typeck/typeck_type_placeholder_item.stderr
@@ -546,6 +546,15 @@ help: use type parameters instead
LL | fn fn_test10<T>(&self, _x : T) { }
| +++ ~
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated constants
+ --> $DIR/typeck_type_placeholder_item.rs:194:14
+ |
+LL | const D: _ = 42;
+ | ^
+ | |
+ | not allowed in type signatures
+ | help: replace with the correct type: `i32`
+
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/typeck_type_placeholder_item.rs:217:31
|
@@ -574,19 +583,7 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:209:14
|
LL | const D: _ = 42;
- | ^
- | |
- | not allowed in type signatures
- | help: replace with the correct type: `i32`
-
-error[E0121]: the placeholder `_` is not allowed within types on item signatures for associated constants
- --> $DIR/typeck_type_placeholder_item.rs:194:14
- |
-LL | const D: _ = 42;
- | ^
- | |
- | not allowed in type signatures
- | help: replace with the correct type: `i32`
+ | ^ not allowed in type signatures
error[E0046]: not all trait items implemented, missing: `F`
--> $DIR/typeck_type_placeholder_item.rs:200:1
From d0eb9c86f1ec1d2f6c2c5c09abb31d2b3d3e7069 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 27 Mar 2024 11:12:21 +0000
Subject: [PATCH 2/4] move type inference for missing types on constants into
its own method
---
compiler/rustc_hir_typeck/src/lib.rs | 104 +++++++++++++++------------
1 file changed, 58 insertions(+), 46 deletions(-)
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index f201bfddf4bb1..55e86bbec1c48 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -191,52 +191,7 @@ fn typeck_with_fallback<'tcx>(
check_fn(&mut fcx, fn_sig, None, decl, def_id, body, tcx.features().unsized_fn_params);
} else {
- let expected_type = if let Some(&hir::Ty { kind: hir::TyKind::Infer, span, .. }) = body_ty {
- if let Some(item) = tcx.opt_associated_item(def_id.into())
- && let ty::AssocKind::Const = item.kind
- && let ty::ImplContainer = item.container
- && let Some(trait_item) = item.trait_item_def_id
- {
- let args =
- tcx.impl_trait_ref(item.container_id(tcx)).unwrap().instantiate_identity().args;
- Some(tcx.type_of(trait_item).instantiate(tcx, args))
- } else {
- Some(fcx.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::TypeInference,
- span,
- }))
- }
- } else if let Node::AnonConst(_) = node {
- match tcx.parent_hir_node(id) {
- Node::Ty(&hir::Ty { kind: hir::TyKind::Typeof(ref anon_const), .. })
- if anon_const.hir_id == id =>
- {
- Some(fcx.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::TypeInference,
- span,
- }))
- }
- Node::Expr(&hir::Expr { kind: hir::ExprKind::InlineAsm(asm), .. })
- | Node::Item(&hir::Item { kind: hir::ItemKind::GlobalAsm(asm), .. }) => {
- asm.operands.iter().find_map(|(op, _op_sp)| match op {
- hir::InlineAsmOperand::Const { anon_const } if anon_const.hir_id == id => {
- // Inline assembly constants must be integers.
- Some(fcx.next_int_var())
- }
- hir::InlineAsmOperand::SymFn { anon_const } if anon_const.hir_id == id => {
- Some(fcx.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::MiscVariable,
- span,
- }))
- }
- _ => None,
- })
- }
- _ => None,
- }
- } else {
- None
- };
+ let expected_type = infer_type_if_missing(body_ty, &fcx, node);
let expected_type = expected_type.unwrap_or_else(fallback);
let expected_type = fcx.normalize(body.value.span, expected_type);
@@ -306,6 +261,63 @@ fn typeck_with_fallback<'tcx>(
typeck_results
}
+fn infer_type_if_missing<'tcx>(
+ body_ty: Option<&hir::Ty<'tcx>>,
+ fcx: &FnCtxt<'_, 'tcx>,
+ node: Node<'tcx>,
+) -> Option<Ty<'tcx>> {
+ let tcx = fcx.tcx;
+ let def_id = fcx.body_id;
+ let expected_type = if let Some(&hir::Ty { kind: hir::TyKind::Infer, span, .. }) = body_ty {
+ if let Some(item) = tcx.opt_associated_item(def_id.into())
+ && let ty::AssocKind::Const = item.kind
+ && let ty::ImplContainer = item.container
+ && let Some(trait_item) = item.trait_item_def_id
+ {
+ let args =
+ tcx.impl_trait_ref(item.container_id(tcx)).unwrap().instantiate_identity().args;
+ Some(tcx.type_of(trait_item).instantiate(tcx, args))
+ } else {
+ Some(fcx.next_ty_var(TypeVariableOrigin {
+ kind: TypeVariableOriginKind::TypeInference,
+ span,
+ }))
+ }
+ } else if let Node::AnonConst(_) = node {
+ let id = tcx.local_def_id_to_hir_id(def_id);
+ match tcx.parent_hir_node(id) {
+ Node::Ty(&hir::Ty { kind: hir::TyKind::Typeof(ref anon_const), span, .. })
+ if anon_const.hir_id == id =>
+ {
+ Some(fcx.next_ty_var(TypeVariableOrigin {
+ kind: TypeVariableOriginKind::TypeInference,
+ span,
+ }))
+ }
+ Node::Expr(&hir::Expr { kind: hir::ExprKind::InlineAsm(asm), span, .. })
+ | Node::Item(&hir::Item { kind: hir::ItemKind::GlobalAsm(asm), span, .. }) => {
+ asm.operands.iter().find_map(|(op, _op_sp)| match op {
+ hir::InlineAsmOperand::Const { anon_const } if anon_const.hir_id == id => {
+ // Inline assembly constants must be integers.
+ Some(fcx.next_int_var())
+ }
+ hir::InlineAsmOperand::SymFn { anon_const } if anon_const.hir_id == id => {
+ Some(fcx.next_ty_var(TypeVariableOrigin {
+ kind: TypeVariableOriginKind::MiscVariable,
+ span,
+ }))
+ }
+ _ => None,
+ })
+ }
+ _ => None,
+ }
+ } else {
+ None
+ };
+ expected_type
+}
+
/// When `check_fn` is invoked on a coroutine (i.e., a body that
/// includes yield), it returns back some information about the yield
/// points.
From 7786ee3c9240084ddb2b62d3f78cffce61462199 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 27 Mar 2024 11:13:34 +0000
Subject: [PATCH 3/4] Remove a call-site to `primary_body_of` as it is only
interested in the body id
---
compiler/rustc_hir_typeck/src/lib.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 55e86bbec1c48..c135389ec9861 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -106,7 +106,7 @@ fn has_typeck_results(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
}
if let Some(def_id) = def_id.as_local() {
- primary_body_of(tcx.hir_node_by_def_id(def_id)).is_some()
+ tcx.hir_node_by_def_id(def_id).body_id().is_some()
} else {
false
}
From 86e750f0f777d78a108fa224731ef163b35f2309 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 27 Mar 2024 11:16:41 +0000
Subject: [PATCH 4/4] Inline `primary_body_of` into its sole call site
---
compiler/rustc_hir_typeck/src/lib.rs | 28 +++++-----------------------
1 file changed, 5 insertions(+), 23 deletions(-)
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index c135389ec9861..00d3e262cc891 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -83,20 +83,6 @@ macro_rules! type_error_struct {
})
}
-/// If this `DefId` is a "primary tables entry", returns
-/// `Some((body_id, body_ty, fn_sig))`. Otherwise, returns `None`.
-///
-/// If this function returns `Some`, then `typeck_results(def_id)` will
-/// succeed; if it returns `None`, then `typeck_results(def_id)` may or
-/// may not succeed. In some cases where this function returns `None`
-/// (notably closures), `typeck_results(def_id)` would wind up
-/// redirecting to the owning function.
-fn primary_body_of(
- node: Node<'_>,
-) -> Option<(hir::BodyId, Option<&hir::Ty<'_>>, Option<&hir::FnSig<'_>>)> {
- Some((node.body_id()?, node.ty(), node.fn_sig()))
-}
-
fn has_typeck_results(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
// Closures' typeck results come from their outermost function,
// as they are part of the same "inference environment".
@@ -163,7 +149,7 @@ fn typeck_with_fallback<'tcx>(
let span = tcx.hir().span(id);
// Figure out what primary body this item has.
- let (body_id, body_ty, fn_sig) = primary_body_of(node).unwrap_or_else(|| {
+ let body_id = node.body_id().unwrap_or_else(|| {
span_bug!(span, "can't type-check body of {:?}", def_id);
});
let body = tcx.hir().body(body_id);
@@ -176,7 +162,7 @@ fn typeck_with_fallback<'tcx>(
}
let mut fcx = FnCtxt::new(&inh, param_env, def_id);
- if let Some(hir::FnSig { header, decl, .. }) = fn_sig {
+ if let Some(hir::FnSig { header, decl, .. }) = node.fn_sig() {
let fn_sig = if decl.output.get_infer_ret_ty().is_some() {
fcx.lowerer().lower_fn_ty(id, header.unsafety, header.abi, decl, None, None)
} else {
@@ -191,7 +177,7 @@ fn typeck_with_fallback<'tcx>(
check_fn(&mut fcx, fn_sig, None, decl, def_id, body, tcx.features().unsized_fn_params);
} else {
- let expected_type = infer_type_if_missing(body_ty, &fcx, node);
+ let expected_type = infer_type_if_missing(&fcx, node);
let expected_type = expected_type.unwrap_or_else(fallback);
let expected_type = fcx.normalize(body.value.span, expected_type);
@@ -261,14 +247,10 @@ fn typeck_with_fallback<'tcx>(
typeck_results
}
-fn infer_type_if_missing<'tcx>(
- body_ty: Option<&hir::Ty<'tcx>>,
- fcx: &FnCtxt<'_, 'tcx>,
- node: Node<'tcx>,
-) -> Option<Ty<'tcx>> {
+fn infer_type_if_missing<'tcx>(fcx: &FnCtxt<'_, 'tcx>, node: Node<'tcx>) -> Option<Ty<'tcx>> {
let tcx = fcx.tcx;
let def_id = fcx.body_id;
- let expected_type = if let Some(&hir::Ty { kind: hir::TyKind::Infer, span, .. }) = body_ty {
+ let expected_type = if let Some(&hir::Ty { kind: hir::TyKind::Infer, span, .. }) = node.ty() {
if let Some(item) = tcx.opt_associated_item(def_id.into())
&& let ty::AssocKind::Const = item.kind
&& let ty::ImplContainer = item.container