gcc/rust/checks/errors/rust-feature-gate.cc

   1 // Copyright (C) 2020-2022 Free Software Foundation, Inc.
   2
   3 // This file is part of GCC.
   4
   5 // GCC is free software; you can redistribute it and/or modify it under
   6 // the terms of the GNU General Public License as published by the Free
   7 // Software Foundation; either version 3, or (at your option) any later
   8 // version.
   9
  10 // GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  11 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13 // for more details.
  14
  15 // You should have received a copy of the GNU General Public License
  16 // along with GCC; see the file COPYING3.  If not see
  17 // <http://www.gnu.org/licenses/>.
  18
  19 #include "rust-feature-gate.h"
  20 #include "rust-feature.h"
  21
  22 namespace Rust {
  23
  24 void
  25 FeatureGate::check (AST::Crate &crate)
  26 {
  27   std::vector<Feature> valid_features;
  28   for (const auto &attr : crate.inner_attrs)
  29     {
  30       if (attr.get_path ().as_string () == "feature")
  31         {
  32           const auto &attr_input = attr.get_attr_input ();
  33           auto type = attr_input.get_attr_input_type ();
  34           if (type == AST::AttrInput::AttrInputType::TOKEN_TREE)
  35             {
  36               const auto &option = static_cast<const AST::DelimTokenTree &> (
  37                 attr.get_attr_input ());
  38               std::unique_ptr<AST::AttrInputMetaItemContainer> meta_item (
  39                 option.parse_to_meta_item ());
  40               for (const auto &item : meta_item->get_items ())
  41                 {
  42                   const auto &name = item->as_string ();
  43                   auto tname = Feature::as_name (name);
  44                   if (!tname.is_none ())
  45                     valid_features.push_back (Feature::create (tname.get ()));
  46                   else
  47                     rust_error_at (item->get_locus (), "unknown feature '%s'",
  48                                    name.c_str ());
  49                 }
  50             }
  51         }
  52     }
  53   valid_features.shrink_to_fit ();
  54
  55   // TODO (mxlol233): add the real feature gate stuff.
  56   auto &items = crate.items;
  57   for (auto it = items.begin (); it != items.end (); it++)
  58     {
  59       auto &item = *it;
  60       item->accept_vis (*this);
  61     }
  62 }
  63 } // namespace Rust