https://gcc.gnu.org/g:97a7ae203920812de36f3131bd096b499718c6fb
commit r16-2799-g97a7ae203920812de36f3131bd096b499718c6fb
Author: Philip Herron <herron.phi...@googlemail.com>
Date: Mon May 5 21:07:20 2025 +0100
gccrs: Emit error diagnostic for bad impl type usage
Rust only allows impl traits to be used in the return position of
functions.
Fixes Rust-GCC#1485
gcc/rust/ChangeLog:
* hir/rust-ast-lower-implitem.cc (ASTLowerImplItem::visit): allow
impl type
* hir/rust-ast-lower-item.cc (ASTLoweringItem::visit): likewise
* hir/rust-ast-lower-type.cc (ASTLoweringType::ASTLoweringType):
new flag for impl trait
(ASTLoweringType::translate): pass flag
(ASTLoweringType::visit): track impl trait tag
(ASTLoweringType::emit_impl_trait_error): new diagnostic
* hir/rust-ast-lower-type.h: add new field
gcc/testsuite/ChangeLog:
* rust/compile/impl_trait_diag.rs: New test.
* rust/compile/issue-1485.rs: New test.
Signed-off-by: Philip Herron <herron.phi...@googlemail.com>
Diff:
---
gcc/rust/hir/rust-ast-lower-implitem.cc | 3 +-
gcc/rust/hir/rust-ast-lower-item.cc | 3 +-
gcc/rust/hir/rust-ast-lower-type.cc | 57 ++++++++++++++++++++-------
gcc/rust/hir/rust-ast-lower-type.h | 13 +++---
gcc/testsuite/rust/compile/impl_trait_diag.rs | 17 ++++++++
gcc/testsuite/rust/compile/issue-1485.rs | 16 ++++++++
6 files changed, 85 insertions(+), 24 deletions(-)
diff --git a/gcc/rust/hir/rust-ast-lower-implitem.cc
b/gcc/rust/hir/rust-ast-lower-implitem.cc
index d815a71564ec..fc9fe1ace4a9 100644
--- a/gcc/rust/hir/rust-ast-lower-implitem.cc
+++ b/gcc/rust/hir/rust-ast-lower-implitem.cc
@@ -138,7 +138,8 @@ ASTLowerImplItem::visit (AST::Function &function)
std::unique_ptr<HIR::Type> return_type
= function.has_return_type () ? std::unique_ptr<HIR::Type> (
- ASTLoweringType::translate (function.get_return_type ()))
+ ASTLoweringType::translate (function.get_return_type (), false,
+ true /* impl trait is allowed here*/))
: nullptr;
Defaultness defaultness
diff --git a/gcc/rust/hir/rust-ast-lower-item.cc
b/gcc/rust/hir/rust-ast-lower-item.cc
index f4396b58e595..1810d16d515d 100644
--- a/gcc/rust/hir/rust-ast-lower-item.cc
+++ b/gcc/rust/hir/rust-ast-lower-item.cc
@@ -411,7 +411,8 @@ ASTLoweringItem::visit (AST::Function &function)
std::unique_ptr<HIR::Type> return_type
= function.has_return_type () ? std::unique_ptr<HIR::Type> (
- ASTLoweringType::translate (function.get_return_type ()))
+ ASTLoweringType::translate (function.get_return_type (), false,
+ true /* impl trait is allowed here*/))
: nullptr;
std::vector<HIR::FunctionParam> function_params;
diff --git a/gcc/rust/hir/rust-ast-lower-type.cc
b/gcc/rust/hir/rust-ast-lower-type.cc
index a678f189ac28..5aedb9196dc5 100644
--- a/gcc/rust/hir/rust-ast-lower-type.cc
+++ b/gcc/rust/hir/rust-ast-lower-type.cc
@@ -209,10 +209,17 @@ ASTLowerQualifiedPathInType::visit
(AST::QualifiedPathInType &path)
path.get_locus ());
}
+ASTLoweringType::ASTLoweringType (bool default_to_static_lifetime,
+ bool impl_trait_allowed)
+ : ASTLoweringBase (), default_to_static_lifetime
(default_to_static_lifetime),
+ impl_trait_allowed (impl_trait_allowed), translated (nullptr)
+{}
+
HIR::Type *
-ASTLoweringType::translate (AST::Type &type, bool default_to_static_lifetime)
+ASTLoweringType::translate (AST::Type &type, bool default_to_static_lifetime,
+ bool impl_trait_allowed)
{
- ASTLoweringType resolver (default_to_static_lifetime);
+ ASTLoweringType resolver (default_to_static_lifetime, impl_trait_allowed);
type.accept_vis (resolver);
rust_assert (resolver.translated != nullptr);
@@ -260,7 +267,8 @@ ASTLoweringType::visit (AST::BareFunctionType &fntype)
HIR::Type *param_type
= ASTLoweringType::translate (param.get_type (),
- default_to_static_lifetime);
+ default_to_static_lifetime,
+ impl_trait_allowed);
HIR::MaybeNamedParam p (param.get_name (), kind,
std::unique_ptr<HIR::Type> (param_type),
@@ -272,7 +280,8 @@ ASTLoweringType::visit (AST::BareFunctionType &fntype)
if (fntype.has_return_type ())
{
return_type = ASTLoweringType::translate (fntype.get_return_type (),
- default_to_static_lifetime);
+ default_to_static_lifetime,
+ impl_trait_allowed);
}
auto crate_num = mappings.get_current_crate ();
@@ -292,8 +301,8 @@ ASTLoweringType::visit (AST::TupleType &tuple)
std::vector<std::unique_ptr<HIR::Type>> elems;
for (auto &e : tuple.get_elems ())
{
- HIR::Type *t
- = ASTLoweringType::translate (*e, default_to_static_lifetime);
+ HIR::Type *t = ASTLoweringType::translate (*e,
default_to_static_lifetime,
+ impl_trait_allowed);
elems.push_back (std::unique_ptr<HIR::Type> (t));
}
@@ -323,7 +332,8 @@ ASTLoweringType::visit (AST::ArrayType &type)
{
HIR::Type *translated_type
= ASTLoweringType::translate (type.get_elem_type (),
- default_to_static_lifetime);
+ default_to_static_lifetime,
+ impl_trait_allowed);
HIR::Expr *array_size = ASTLoweringExpr::translate (type.get_size_expr ());
auto crate_num = mappings.get_current_crate ();
@@ -343,9 +353,9 @@ ASTLoweringType::visit (AST::ReferenceType &type)
HIR::Lifetime lifetime
= lower_lifetime (type.get_lifetime (), default_to_static_lifetime);
- HIR::Type *base_type
- = ASTLoweringType::translate (type.get_base_type (),
- default_to_static_lifetime);
+ HIR::Type *base_type = ASTLoweringType::translate (type.get_base_type (),
+ default_to_static_lifetime,
+ impl_trait_allowed);
auto crate_num = mappings.get_current_crate ();
Analysis::NodeMapping mapping (crate_num, type.get_node_id (),
@@ -364,7 +374,8 @@ ASTLoweringType::visit (AST::RawPointerType &type)
{
HIR::Type *base_type
= ASTLoweringType::translate (type.get_type_pointed_to (),
- default_to_static_lifetime);
+ default_to_static_lifetime,
+ impl_trait_allowed);
auto crate_num = mappings.get_current_crate ();
Analysis::NodeMapping mapping (crate_num, type.get_node_id (),
@@ -384,9 +395,9 @@ ASTLoweringType::visit (AST::RawPointerType &type)
void
ASTLoweringType::visit (AST::SliceType &type)
{
- HIR::Type *base_type
- = ASTLoweringType::translate (type.get_elem_type (),
- default_to_static_lifetime);
+ HIR::Type *base_type = ASTLoweringType::translate (type.get_elem_type (),
+ default_to_static_lifetime,
+ impl_trait_allowed);
auto crate_num = mappings.get_current_crate ();
Analysis::NodeMapping mapping (crate_num, type.get_node_id (),
@@ -463,7 +474,8 @@ void
ASTLoweringType::visit (AST::ParenthesisedType &type)
{
auto *inner = ASTLoweringType::translate (*type.get_type_in_parens (),
- default_to_static_lifetime);
+ default_to_static_lifetime,
+ impl_trait_allowed);
auto crate_num = mappings.get_current_crate ();
Analysis::NodeMapping mapping (crate_num, type.get_node_id (),
@@ -480,6 +492,9 @@ ASTLoweringType::visit (AST::ParenthesisedType &type)
void
ASTLoweringType::visit (AST::ImplTraitType &type)
{
+ if (!impl_trait_allowed)
+ emit_impl_trait_error (type.get_locus ());
+
std::vector<std::unique_ptr<HIR::TypeParamBound>> bounds;
for (auto &bound : type.get_type_param_bounds ())
{
@@ -499,6 +514,9 @@ ASTLoweringType::visit (AST::ImplTraitType &type)
void
ASTLoweringType::visit (AST::ImplTraitTypeOneBound &type)
{
+ if (!impl_trait_allowed)
+ emit_impl_trait_error (type.get_locus ());
+
std::vector<std::unique_ptr<HIR::TypeParamBound>> bounds;
auto b = ASTLoweringTypeBounds::translate (type.get_trait_bound ());
@@ -513,6 +531,15 @@ ASTLoweringType::visit (AST::ImplTraitTypeOneBound &type)
= new HIR::ImplTraitType (mapping, std::move (bounds), type.get_locus ());
}
+void
+ASTLoweringType::emit_impl_trait_error (location_t locus)
+{
+ rich_location r (line_table, locus);
+ rust_error_at (r, ErrorCode::E0562,
+ "%<impl Trait%> not allowed outside of function and inherent "
+ "method return types");
+}
+
HIR::GenericParam *
ASTLowerGenericParam::translate (AST::GenericParam ¶m)
{
diff --git a/gcc/rust/hir/rust-ast-lower-type.h
b/gcc/rust/hir/rust-ast-lower-type.h
index 4efaeee13149..50f543a357cf 100644
--- a/gcc/rust/hir/rust-ast-lower-type.h
+++ b/gcc/rust/hir/rust-ast-lower-type.h
@@ -66,7 +66,8 @@ class ASTLoweringType : public ASTLoweringBase
public:
static HIR::Type *translate (AST::Type &type,
- bool default_to_static_lifetime = false);
+ bool default_to_static_lifetime = false,
+ bool impl_trait_allowed = false);
void visit (AST::BareFunctionType &fntype) override;
void visit (AST::TupleType &tuple) override;
@@ -81,19 +82,17 @@ public:
void visit (AST::TraitObjectTypeOneBound &type) override;
void visit (AST::TraitObjectType &type) override;
void visit (AST::ParenthesisedType &type) override;
-
void visit (AST::ImplTraitType &type) override;
void visit (AST::ImplTraitTypeOneBound &type) override;
+ void emit_impl_trait_error (location_t locus);
+
private:
- ASTLoweringType (bool default_to_static_lifetime)
- : ASTLoweringBase (),
- default_to_static_lifetime (default_to_static_lifetime),
- translated (nullptr)
- {}
+ ASTLoweringType (bool default_to_static_lifetime, bool impl_trait_allowed);
/** Used when compiling const and static items. */
bool default_to_static_lifetime;
+ bool impl_trait_allowed;
HIR::Type *translated;
};
diff --git a/gcc/testsuite/rust/compile/impl_trait_diag.rs
b/gcc/testsuite/rust/compile/impl_trait_diag.rs
new file mode 100644
index 000000000000..54a0cd220a39
--- /dev/null
+++ b/gcc/testsuite/rust/compile/impl_trait_diag.rs
@@ -0,0 +1,17 @@
+#[lang = "sized"]
+pub trait Sized {}
+
+trait Foo {
+ fn method(&self);
+}
+
+struct Bar;
+impl Foo for Bar {}
+
+fn main() {
+ let x: impl Foo = Bar; // { dg-error ".impl Trait. not allowed outside of
function and inherent method return types .E0562." }
+
+ struct Wrapper {
+ field: impl Foo, // { dg-error ".impl Trait. not allowed outside of
function and inherent method return types .E0562." }
+ }
+}
diff --git a/gcc/testsuite/rust/compile/issue-1485.rs
b/gcc/testsuite/rust/compile/issue-1485.rs
new file mode 100644
index 000000000000..a0cd5a0f1f92
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-1485.rs
@@ -0,0 +1,16 @@
+#[lang = "sized"]
+pub trait Sized {}
+
+#[lang = "fn_once"]
+pub trait FnOnce<Args> {
+ #[lang = "fn_once_output"]
+ type Output;
+
+ extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
+}
+
+struct BinOpInvalid {
+ lhs: i32,
+ rhs: i32,
+ f: impl FnOnce(i32) -> i32, // { dg-error ".impl Trait. not allowed
outside of function and inherent method return types .E0562." }
+}
