From: Philip Herron <herron.philip@googlemail.com>
Date: Wed, 12 Feb 2025 17:10:31 +0000 (+0000)
Subject: gccrs: add diagnostic for E0229 no associated type arguments allowed here
X-Git-Tag: basepoints/gcc-16~756
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5b8c95b82ceb961dcd8a14072c8a1ed0025a043;p=thirdparty%2Fgcc.git

gccrs: add diagnostic for E0229 no associated type arguments allowed here

It seems bounds in qualified paths are not allowed to specify associated
type bindings because its going to be associated with the impl block
anyway.

Fixes Rust-GCC#2369

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-base.h: add flag
	* typecheck/rust-hir-type-check-type.cc (TypeCheckType::visit): likewise
	* typecheck/rust-tyty-bounds.cc: new diagnostic

gcc/testsuite/ChangeLog:

	* rust/compile/issue-2369.rs: New test.

Signed-off-by: Philip Herron <herron.philip@googlemail.com>
---

diff --git a/gcc/rust/typecheck/rust-hir-type-check-base.h b/gcc/rust/typecheck/rust-hir-type-check-base.h
index e720b947916..8a1bf6f4cb3 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-base.h
+++ b/gcc/rust/typecheck/rust-hir-type-check-base.h
@@ -40,7 +40,8 @@ protected:
   TyTy::TypeBoundPredicate get_predicate_from_bound (
     HIR::TypePath &path,
     tl::optional<std::reference_wrapper<HIR::Type>> associated_self,
-    BoundPolarity polarity = BoundPolarity::RegularBound);
+    BoundPolarity polarity = BoundPolarity::RegularBound,
+    bool is_qualified_type = false);
 
   bool check_for_unconstrained (
     const std::vector<TyTy::SubstitutionParamMapping> &params_to_constrain,
diff --git a/gcc/rust/typecheck/rust-hir-type-check-type.cc b/gcc/rust/typecheck/rust-hir-type-check-type.cc
index 327cbb010a4..6a09772d023 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-type.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-type.cc
@@ -193,8 +193,10 @@ TypeCheckType::visit (HIR::QualifiedPathInType &path)
     return;
 
   // get the predicate for the bound
-  auto specified_bound = get_predicate_from_bound (qual_path_type.get_trait (),
-						   qual_path_type.get_type ());
+  auto specified_bound
+    = get_predicate_from_bound (qual_path_type.get_trait (),
+				qual_path_type.get_type (),
+				BoundPolarity::RegularBound, true);
   if (specified_bound.is_error ())
     return;
 
diff --git a/gcc/rust/typecheck/rust-tyty-bounds.cc b/gcc/rust/typecheck/rust-tyty-bounds.cc
index 3e42427e2ec..fc35abb6ec4 100644
--- a/gcc/rust/typecheck/rust-tyty-bounds.cc
+++ b/gcc/rust/typecheck/rust-tyty-bounds.cc
@@ -196,7 +196,7 @@ TyTy::TypeBoundPredicate
 TypeCheckBase::get_predicate_from_bound (
   HIR::TypePath &type_path,
   tl::optional<std::reference_wrapper<HIR::Type>> associated_self,
-  BoundPolarity polarity)
+  BoundPolarity polarity, bool is_qualified_type_path)
 {
   TyTy::TypeBoundPredicate lookup = TyTy::TypeBoundPredicate::error ();
   bool already_resolved
@@ -222,6 +222,21 @@ TypeCheckBase::get_predicate_from_bound (
 	if (final_generic_seg.has_generic_args ())
 	  {
 	    args = final_generic_seg.get_generic_args ();
+	    if (args.get_binding_args ().size () > 0
+		&& associated_self.has_value () && is_qualified_type_path)
+	      {
+		auto &binding_args = args.get_binding_args ();
+
+		rich_location r (line_table, args.get_locus ());
+		for (auto it = binding_args.begin (); it != binding_args.end ();
+		     it++)
+		  {
+		    auto &arg = *it;
+		    r.add_fixit_remove (arg.get_locus ());
+		  }
+		rust_error_at (r, ErrorCode::E0229,
+			       "associated type bindings are not allowed here");
+	      }
 	  }
       }
       break;
diff --git a/gcc/testsuite/rust/compile/issue-2369.rs b/gcc/testsuite/rust/compile/issue-2369.rs
new file mode 100644
index 00000000000..9475aef9d71
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-2369.rs
@@ -0,0 +1,21 @@
+#[lang = "sized"]
+trait Sized {}
+
+fn main() {
+    pub trait Foo {
+        type A;
+        fn boo(&self) -> <Self as Foo>::A;
+    }
+
+    struct Bar;
+
+    impl Foo for isize {
+        type A = usize;
+        fn boo(&self) -> usize {
+            42
+        }
+    }
+
+    fn baz<I>(x: &<I as Foo<A = Bar>>::A) {}
+    // { dg-error "associated type bindings are not allowed here .E0229." "" { target *-*-* } .-1 }
+}