Add HIR lowering for GenericBindingArgs

We need to lower the bindings for defaults in the GenericArgs structure.
We can also take advantage of RichLocations further improving the
diagnostic errors here.

7 files changed, 51 insertions, 5 deletions

diff --git a/gcc/rust/ast/rust-path.h b/gcc/rust/ast/rust-path.h
index c8542d9..86da203 100644
--- a/gcc/rust/ast/rust-path.h
+++ b/gcc/rust/ast/rust-path.h
@@ -124,6 +124,10 @@ public:
     rust_assert (type != nullptr);
     return type;
   }
+
+  Location get_locus () const { return locus; }
+
+  Identifier get_identifier () const { return identifier; }
 };
 
 // Generic arguments allowed in each path expression segment - inline?
diff --git a/gcc/rust/hir/rust-ast-lower-base.h b/gcc/rust/hir/rust-ast-lower-base.h
index b127ec4..16143d2 100644
--- a/gcc/rust/hir/rust-ast-lower-base.h
+++ b/gcc/rust/hir/rust-ast-lower-base.h
@@ -291,6 +291,8 @@ protected:
   HIR::PathExprSegment lower_path_expr_seg (AST::PathExprSegment &s);
 
   HIR::GenericArgs lower_generic_args (AST::GenericArgs &args);
+
+  HIR::GenericArgsBinding lower_binding (AST::GenericArgsBinding &binding);
 };
 
 } // namespace HIR
diff --git a/gcc/rust/hir/rust-ast-lower.cc b/gcc/rust/hir/rust-ast-lower.cc
index 7ba5d32..f1129ab 100644
--- a/gcc/rust/hir/rust-ast-lower.cc
+++ b/gcc/rust/hir/rust-ast-lower.cc
@@ -314,10 +314,25 @@ ASTLoweringBase::lower_path_expr_seg (AST::PathExprSegment &s)
 			  : HIR::GenericArgs::create_empty ());
 }
 
+HIR::GenericArgsBinding
+ASTLoweringBase::lower_binding (AST::GenericArgsBinding &binding)
+{
+  HIR::Type *lowered_type
+    = ASTLoweringType::translate (binding.get_type ().get ());
+  return HIR::GenericArgsBinding (binding.get_identifier (),
+				  std::unique_ptr<HIR::Type> (lowered_type),
+				  binding.get_locus ());
+}
+
 HIR::GenericArgs
 ASTLoweringBase::lower_generic_args (AST::GenericArgs &args)
 {
-  std::vector<HIR::GenericArgsBinding> binding_args; // TODO
+  std::vector<HIR::GenericArgsBinding> binding_args;
+  for (auto &binding : args.get_binding_args ())
+    {
+      HIR::GenericArgsBinding b = lower_binding (binding);
+      binding_args.push_back (std::move (b));
+    }
 
   std::vector<HIR::Lifetime> lifetime_args;
   for (auto &lifetime : args.get_lifetime_args ())
diff --git a/gcc/rust/hir/tree/rust-hir-path.h b/gcc/rust/hir/tree/rust-hir-path.h
index 262a04a..c163487 100644
--- a/gcc/rust/hir/tree/rust-hir-path.h
+++ b/gcc/rust/hir/tree/rust-hir-path.h
@@ -107,6 +107,12 @@ public:
   GenericArgsBinding &operator= (GenericArgsBinding &&other) = default;
 
   std::string as_string () const;
+
+  Identifier get_identifier () const { return identifier; }
+
+  std::unique_ptr<Type> &get_type () { return type; }
+
+  Location get_locus () const { return locus; }
 };
 
 // Generic arguments allowed in each path expression segment - inline?
diff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc
index c8f5f19..be56dc7 100644
--- a/gcc/rust/typecheck/rust-tyty.cc
+++ b/gcc/rust/typecheck/rust-tyty.cc
@@ -213,15 +213,21 @@ SubstitutionRef::get_mappings_from_generic_args (HIR::GenericArgs &args)
 {
   if (args.get_binding_args ().size () > 0)
     {
-      rust_error_at (args.get_locus (),
-		     "associated type bindings are not allowed here");
+      RichLocation r (args.get_locus ());
+      for (auto &binding : args.get_binding_args ())
+	r.add_range (binding.get_locus ());
+
+      rust_error_at (r, "associated type bindings are not allowed here");
       return SubstitutionArgumentMappings::error ();
     }
 
   if (args.get_type_args ().size () > substitutions.size ())
     {
+      RichLocation r (args.get_locus ());
+      r.add_range (substitutions.front ().get_param_locus ());
+
       rust_error_at (
-	args.get_locus (),
+	r,
 	"generic item takes at most %lu type arguments but %lu were supplied",
 	substitutions.size (), args.get_type_args ().size ());
       return SubstitutionArgumentMappings::error ();
@@ -229,8 +235,11 @@ SubstitutionRef::get_mappings_from_generic_args (HIR::GenericArgs &args)
 
   if (args.get_type_args ().size () < substitutions.size ())
     {
+      RichLocation r (args.get_locus ());
+      r.add_range (substitutions.front ().get_param_locus ());
+
       rust_error_at (
-	args.get_locus (),
+	r,
 	"generic item takes at least %lu type arguments but %lu were supplied",
 	substitutions.size (), args.get_type_args ().size ());
       return SubstitutionArgumentMappings::error ();
diff --git a/gcc/rust/typecheck/rust-tyty.h b/gcc/rust/typecheck/rust-tyty.h
index bcc694b..91c3f06 100644
--- a/gcc/rust/typecheck/rust-tyty.h
+++ b/gcc/rust/typecheck/rust-tyty.h
@@ -444,6 +444,8 @@ public:
     return p->resolve ()->get_kind () == TypeKind::PARAM;
   }
 
+  Location get_param_locus () const { return generic->get_locus_slow (); }
+
 private:
   std::unique_ptr<HIR::GenericParam> &generic;
   ParamType *param;
diff --git a/gcc/testsuite/rust.test/xfail_compile/type-bindings1.rs b/gcc/testsuite/rust.test/xfail_compile/type-bindings1.rs
new file mode 100644
index 0000000..5e00f87
--- /dev/null
+++ b/gcc/testsuite/rust.test/xfail_compile/type-bindings1.rs
@@ -0,0 +1,8 @@
+// { dg-excess-errors "Noisy error and debug" }
+struct Foo<A, B>(A, B);
+
+fn main() {
+    let a;
+    a = Foo::<A = i32, B = f32>(123f32);
+    // { dg-error "associated type bindings are not allowed here" "" { target { *-*-* } } .-1 }
+}