[gcc/devel/rust/master] gccrs: add diagnostic for E0229 no associated type arguments allowed here

[Thomas Schwinge via Gcc-cvs]

https://gcc.gnu.org/g:c005754701addc8a08fd1ed8381826ccbd92e83e

commit c005754701addc8a08fd1ed8381826ccbd92e83e
Author: Philip Herron <herron.phi...@googlemail.com>
Date:   Wed Feb 12 17:10:31 2025 +0000

    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.phi...@googlemail.com>

Diff:
---
 gcc/rust/typecheck/rust-hir-type-check-base.h  |  3 ++-
 gcc/rust/typecheck/rust-hir-type-check-type.cc |  6 ++++--
 gcc/rust/typecheck/rust-tyty-bounds.cc         | 17 ++++++++++++++++-
 gcc/testsuite/rust/compile/issue-2369.rs       | 21 +++++++++++++++++++++
 4 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/gcc/rust/typecheck/rust-hir-type-check-base.h 
b/gcc/rust/typecheck/rust-hir-type-check-base.h
index 8b071949eb4f..d5005447b6fa 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 15533c8cf7fa..36bb4b0e7181 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 1d25d4a71355..e764ddc32830 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 000000000000..9475aef9d71f
--- /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 }
+}