gccrs: Fix ICE on raw reference

This patch adds support for raw references which enforce the pointer
type away from a reference type.

Fixes Rust-GCC#3667

gcc/rust/ChangeLog:

	* backend/rust-compile-base.cc (HIRCompileBase::address_expression): allow optional type
	* backend/rust-compile-base.h: update prototype
	* backend/rust-compile-expr.cc (CompileExpr::visit): update borrow expr
	* backend/rust-compile-extern.h: remove unused debug
	* backend/rust-compile-resolve-path.cc (HIRCompileBase::query_compile): update usage
	* hir/rust-ast-lower-expr.cc (ASTLoweringExpr::visit): lower raw ref
	* hir/tree/rust-hir-expr.cc (BorrowExpr::BorrowExpr): add flag for raw ref
	* hir/tree/rust-hir-expr.h (class BorrowExpr): add new raw ref field
	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit): add handle for raw ref

gcc/testsuite/ChangeLog:

	* rust/compile/issue-3667.rs: New test.

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

5 files changed, 11 insertions, 12 deletions

diff --git a/gcc/rust/backend/rust-compile-base.cc b/gcc/rust/backend/rust-compile-base.cc
index b6bee8f..0647718 100644
--- a/gcc/rust/backend/rust-compile-base.cc
+++ b/gcc/rust/backend/rust-compile-base.cc
@@ -549,7 +549,7 @@ HIRCompileBase::mark_addressable (tree exp, location_t locus)
 }
 
 tree
-HIRCompileBase::address_expression (tree expr, location_t location)
+HIRCompileBase::address_expression (tree expr, location_t location, tree ptrty)
 {
   if (expr == error_mark_node)
     return error_mark_node;
@@ -557,7 +557,10 @@ HIRCompileBase::address_expression (tree expr, location_t location)
   if (!mark_addressable (expr, location))
     return error_mark_node;
 
-  return build_fold_addr_expr_loc (location, expr);
+  if (ptrty == NULL || ptrty == error_mark_node)
+    ptrty = build_pointer_type (TREE_TYPE (expr));
+
+  return build_fold_addr_expr_with_type_loc (location, expr, ptrty);
 }
 
 tree
diff --git a/gcc/rust/backend/rust-compile-base.h b/gcc/rust/backend/rust-compile-base.h
index 64c8106..467bfd0 100644
--- a/gcc/rust/backend/rust-compile-base.h
+++ b/gcc/rust/backend/rust-compile-base.h
@@ -29,7 +29,8 @@ class HIRCompileBase
 public:
   virtual ~HIRCompileBase () {}
 
-  static tree address_expression (tree expr, location_t locus);
+  static tree address_expression (tree expr, location_t locus,
+				  tree ptrty = NULL_TREE);
 
   static tree compile_constant_expr (
     Context *ctx, HirId coercion_id, TyTy::BaseType *resolved_type,
diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc
index e4ab9f0..37856a7 100644
--- a/gcc/rust/backend/rust-compile-expr.cc
+++ b/gcc/rust/backend/rust-compile-expr.cc
@@ -905,7 +905,8 @@ CompileExpr::visit (HIR::BorrowExpr &expr)
 				       &tyty))
     return;
 
-  translated = address_expression (main_expr, expr.get_locus ());
+  tree expected_type = TyTyResolveCompile::compile (ctx, tyty);
+  translated = address_expression (main_expr, expr.get_locus (), expected_type);
 }
 
 void
diff --git a/gcc/rust/backend/rust-compile-extern.h b/gcc/rust/backend/rust-compile-extern.h
index bacd1c0..d6aa589 100644
--- a/gcc/rust/backend/rust-compile-extern.h
+++ b/gcc/rust/backend/rust-compile-extern.h
@@ -34,16 +34,10 @@ class CompileExternItem : public HIRCompileBase,
 public:
   static tree compile (HIR::ExternalItem *item, Context *ctx,
 		       TyTy::BaseType *concrete = nullptr,
-		       bool is_query_mode = false,
 		       location_t ref_locus = UNDEF_LOCATION)
   {
     CompileExternItem compiler (ctx, concrete, ref_locus);
     item->accept_vis (compiler);
-
-    if (is_query_mode && compiler.reference == error_mark_node)
-      rust_internal_error_at (ref_locus, "failed to compile extern item: %s",
-			      item->as_string ().c_str ());
-
     return compiler.reference;
   }
 
diff --git a/gcc/rust/backend/rust-compile-resolve-path.cc b/gcc/rust/backend/rust-compile-resolve-path.cc
index bba0498..81d2dbb 100644
--- a/gcc/rust/backend/rust-compile-resolve-path.cc
+++ b/gcc/rust/backend/rust-compile-resolve-path.cc
@@ -261,10 +261,10 @@ HIRCompileBase::query_compile (HirId ref, TyTy::BaseType *lookup,
       HIR::ExternalItem *resolved_extern_item = hir_extern_item->first;
       if (!lookup->has_substitutions_defined ())
 	return CompileExternItem::compile (resolved_extern_item, ctx, nullptr,
-					   true, expr_locus);
+					   expr_locus);
       else
 	return CompileExternItem::compile (resolved_extern_item, ctx, lookup,
-					   true, expr_locus);
+					   expr_locus);
     }
   else
     {