early-name-resolver: Add simple macro name resolution

This name resolver performs the same macro name resolution as what was
previously done by the AttrVisitor visitor and macro expander.

It also resolves macro expressions in builtin-macros properly, as well
as expanded AST nodes when necessary.

2 files changed, 1297 insertions, 0 deletions

diff --git a/gcc/rust/resolve/rust-early-name-resolver.cc b/gcc/rust/resolve/rust-early-name-resolver.cc
new file mode 100644
index 0000000..6b1f1e9
--- /dev/null
+++ b/gcc/rust/resolve/rust-early-name-resolver.cc
@@ -0,0 +1,1087 @@
+// Copyright (C) 2020-2022 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include "rust-early-name-resolver.h"
+#include "rust-ast-full.h"
+#include "rust-name-resolver.h"
+
+namespace Rust {
+namespace Resolver {
+
+EarlyNameResolver::EarlyNameResolver ()
+  : resolver (*Resolver::get ()), mappings (*Analysis::Mappings::get ())
+{}
+
+void
+EarlyNameResolver::go (AST::Crate &crate)
+{
+  // FIXME: Is that valid? Why is the regular name resolution doing
+  // mappings->get_next_node_id()?
+  resolver.get_macro_scope ().push (crate.get_node_id ());
+
+  for (auto &item : crate.items)
+    item->accept_vis (*this);
+
+  // FIXME: Should we pop the macro scope?
+}
+
+void
+EarlyNameResolver::resolve_generic_args (AST::GenericArgs &generic_args)
+{
+  for (auto &arg : generic_args.get_generic_args ())
+    arg.accept_vis (*this);
+
+  for (auto &arg : generic_args.get_binding_args ())
+    arg.get_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::resolve_qualified_path_type (AST::QualifiedPathType &path)
+{
+  path.get_type ()->accept_vis (*this);
+
+  if (path.has_as_clause ())
+    path.get_as_type_path ().accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::Token &tok)
+{}
+
+void
+EarlyNameResolver::visit (AST::DelimTokenTree &delim_tok_tree)
+{}
+
+void
+EarlyNameResolver::visit (AST::AttrInputMetaItemContainer &input)
+{}
+
+void
+EarlyNameResolver::visit (AST::IdentifierExpr &ident_expr)
+{}
+
+void
+EarlyNameResolver::visit (AST::Lifetime &lifetime)
+{}
+
+void
+EarlyNameResolver::visit (AST::LifetimeParam &lifetime_param)
+{}
+
+void
+EarlyNameResolver::visit (AST::ConstGenericParam &const_param)
+{}
+
+// FIXME: ARTHUR: Do we need to perform macro resolution for paths as well?
+// std::arch::asm!()?
+void
+EarlyNameResolver::visit (AST::PathInExpression &path)
+{
+  for (auto &segment : path.get_segments ())
+    if (segment.has_generic_args ())
+      resolve_generic_args (segment.get_generic_args ());
+}
+
+void
+EarlyNameResolver::visit (AST::TypePathSegment &segment)
+{}
+
+void
+EarlyNameResolver::visit (AST::TypePathSegmentGeneric &segment)
+{
+  if (segment.has_generic_args ())
+    resolve_generic_args (segment.get_generic_args ());
+}
+
+void
+EarlyNameResolver::visit (AST::TypePathSegmentFunction &segment)
+{
+  for (auto &type : segment.get_type_path_function ().get_params ())
+    type->accept_vis (*this);
+
+  segment.get_type_path_function ().get_return_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TypePath &path)
+{
+  for (auto &seg : path.get_segments ())
+    seg->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::QualifiedPathInExpression &path)
+{
+  resolve_qualified_path_type (path.get_qualified_path_type ());
+
+  for (auto &segment : path.get_segments ())
+    if (segment.has_generic_args ())
+      resolve_generic_args (segment.get_generic_args ());
+}
+
+void
+EarlyNameResolver::visit (AST::QualifiedPathInType &path)
+{
+  resolve_qualified_path_type (path.get_qualified_path_type ());
+
+  for (auto &segment : path.get_segments ())
+    segment->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::LiteralExpr &expr)
+{}
+
+void
+EarlyNameResolver::visit (AST::AttrInputLiteral &attr_input)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaItemLitExpr &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaItemPathLit &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::BorrowExpr &expr)
+{
+  expr.get_borrowed_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::DereferenceExpr &expr)
+{
+  expr.get_dereferenced_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ErrorPropagationExpr &expr)
+{
+  expr.get_propagating_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::NegationExpr &expr)
+{
+  expr.get_negated_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ArithmeticOrLogicalExpr &expr)
+{
+  expr.get_left_expr ()->accept_vis (*this);
+  expr.get_right_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ComparisonExpr &expr)
+{
+  expr.get_left_expr ()->accept_vis (*this);
+  expr.get_right_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::LazyBooleanExpr &expr)
+{
+  expr.get_left_expr ()->accept_vis (*this);
+  expr.get_right_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TypeCastExpr &expr)
+{
+  expr.get_casted_expr ()->accept_vis (*this);
+  expr.get_type_to_cast_to ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::AssignmentExpr &expr)
+{
+  expr.get_left_expr ()->accept_vis (*this);
+  expr.get_right_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::CompoundAssignmentExpr &expr)
+{
+  expr.get_left_expr ()->accept_vis (*this);
+  expr.get_right_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::GroupedExpr &expr)
+{
+  expr.get_expr_in_parens ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ArrayElemsValues &elems)
+{
+  for (auto &expr : elems.get_values ())
+    expr->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ArrayElemsCopied &elems)
+{
+  elems.get_elem_to_copy ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ArrayExpr &expr)
+{
+  expr.get_array_elems ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ArrayIndexExpr &expr)
+{
+  expr.get_array_expr ()->accept_vis (*this);
+  expr.get_index_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TupleExpr &expr)
+{
+  for (auto &elem : expr.get_tuple_elems ())
+    elem->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TupleIndexExpr &expr)
+{
+  expr.get_tuple_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructExprStruct &expr)
+{}
+
+void
+EarlyNameResolver::visit (AST::StructExprFieldIdentifier &field)
+{}
+
+void
+EarlyNameResolver::visit (AST::StructExprFieldIdentifierValue &field)
+{
+  field.get_value ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructExprFieldIndexValue &field)
+{
+  field.get_value ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructExprStructFields &expr)
+{
+  for (auto &field : expr.get_fields ())
+    field->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructExprStructBase &expr)
+{}
+
+void
+EarlyNameResolver::visit (AST::CallExpr &expr)
+{
+  expr.get_function_expr ()->accept_vis (*this);
+  for (auto &param : expr.get_params ())
+    param->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::MethodCallExpr &expr)
+{
+  expr.get_receiver_expr ()->accept_vis (*this);
+  for (auto &param : expr.get_params ())
+    param->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::FieldAccessExpr &expr)
+{
+  expr.get_receiver_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ClosureExprInner &expr)
+{
+  expr.get_definition_expr ()->accept_vis (*this);
+
+  for (auto &param : expr.get_params ())
+    param.get_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::BlockExpr &expr)
+{
+  for (auto &stmt : expr.get_statements ())
+    stmt->accept_vis (*this);
+
+  if (expr.has_tail_expr ())
+    expr.get_tail_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ClosureExprInnerTyped &expr)
+{
+  expr.get_definition_block ()->accept_vis (*this);
+
+  for (auto &param : expr.get_params ())
+    param.get_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ContinueExpr &expr)
+{}
+
+void
+EarlyNameResolver::visit (AST::BreakExpr &expr)
+{
+  if (expr.has_break_expr ())
+    expr.get_break_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::RangeFromToExpr &expr)
+{
+  expr.get_from_expr ()->accept_vis (*this);
+  expr.get_to_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::RangeFromExpr &expr)
+{
+  expr.get_from_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::RangeToExpr &expr)
+{
+  expr.get_to_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::RangeFullExpr &expr)
+{}
+
+void
+EarlyNameResolver::visit (AST::RangeFromToInclExpr &expr)
+{
+  expr.get_from_expr ()->accept_vis (*this);
+  expr.get_to_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::RangeToInclExpr &expr)
+{
+  expr.get_to_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ReturnExpr &expr)
+{
+  if (expr.has_returned_expr ())
+    expr.get_returned_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::UnsafeBlockExpr &expr)
+{
+  expr.get_block_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::LoopExpr &expr)
+{
+  expr.get_loop_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::WhileLoopExpr &expr)
+{
+  expr.get_predicate_expr ()->accept_vis (*this);
+  expr.get_loop_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::WhileLetLoopExpr &expr)
+{
+  expr.get_scrutinee_expr ()->accept_vis (*this);
+  expr.get_loop_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ForLoopExpr &expr)
+{
+  expr.get_iterator_expr ()->accept_vis (*this);
+  expr.get_loop_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfExpr &expr)
+{
+  expr.get_condition_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfExprConseqElse &expr)
+{
+  expr.get_condition_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+  expr.get_else_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfExprConseqIf &expr)
+{
+  expr.get_condition_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+  expr.get_conseq_if_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfExprConseqIfLet &expr)
+{
+  expr.get_condition_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+  expr.get_conseq_if_let_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfLetExpr &expr)
+{
+  expr.get_value_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfLetExprConseqElse &expr)
+{
+  expr.get_value_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+  expr.get_else_block ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfLetExprConseqIf &expr)
+{
+  expr.get_value_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+  expr.get_conseq_if_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::IfLetExprConseqIfLet &expr)
+{
+  expr.get_value_expr ()->accept_vis (*this);
+  expr.get_if_block ()->accept_vis (*this);
+  expr.get_conseq_if_let_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::MatchExpr &expr)
+{
+  expr.get_scrutinee_expr ()->accept_vis (*this);
+  for (auto &match_arm : expr.get_match_cases ())
+    {
+      if (match_arm.get_arm ().has_match_arm_guard ())
+	match_arm.get_arm ().get_guard_expr ()->accept_vis (*this);
+
+      for (auto &pattern : match_arm.get_arm ().get_patterns ())
+	pattern->accept_vis (*this);
+
+      match_arm.get_expr ()->accept_vis (*this);
+    }
+}
+
+void
+EarlyNameResolver::visit (AST::AwaitExpr &expr)
+{
+  expr.get_awaited_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::AsyncBlockExpr &expr)
+{
+  expr.get_block_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TypeParam &param)
+{
+  for (auto &bound : param.get_type_param_bounds ())
+    bound->accept_vis (*this);
+
+  if (param.has_type ())
+    param.get_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::LifetimeWhereClauseItem &item)
+{}
+
+void
+EarlyNameResolver::visit (AST::TypeBoundWhereClauseItem &item)
+{
+  for (auto &bound : item.get_type_param_bounds ())
+    bound->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::Method &method)
+{
+  if (method.has_generics ())
+    for (auto &generic : method.get_generic_params ())
+      generic->accept_vis (*this);
+
+  if (method.get_self_param ().has_type ())
+    method.get_self_param ().get_type ()->accept_vis (*this);
+
+  for (auto &param : method.get_function_params ())
+    param.get_type ()->accept_vis (*this);
+
+  if (method.has_return_type ())
+    method.get_return_type ()->accept_vis (*this);
+
+  method.get_definition ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::Module &module)
+{
+  for (auto &item : module.get_items ())
+    item->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ExternCrate &crate)
+{}
+
+void
+EarlyNameResolver::visit (AST::UseTreeGlob &use_tree)
+{}
+
+void
+EarlyNameResolver::visit (AST::UseTreeList &use_tree)
+{}
+
+void
+EarlyNameResolver::visit (AST::UseTreeRebind &use_tree)
+{}
+
+void
+EarlyNameResolver::visit (AST::UseDeclaration &use_decl)
+{}
+
+void
+EarlyNameResolver::visit (AST::Function &function)
+{
+  if (function.has_generics ())
+    for (auto &generic : function.get_generic_params ())
+      generic->accept_vis (*this);
+
+  for (auto &param : function.get_function_params ())
+    param.get_type ()->accept_vis (*this);
+
+  if (function.has_return_type ())
+    function.get_return_type ()->accept_vis (*this);
+
+  function.get_definition ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TypeAlias &type_alias)
+{
+  type_alias.get_type_aliased ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructStruct &struct_item)
+{
+  for (auto &field : struct_item.get_fields ())
+    field.get_field_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TupleStruct &tuple_struct)
+{
+  for (auto &field : tuple_struct.get_fields ())
+    field.get_field_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::EnumItem &item)
+{}
+
+void
+EarlyNameResolver::visit (AST::EnumItemTuple &item)
+{}
+
+void
+EarlyNameResolver::visit (AST::EnumItemStruct &item)
+{}
+
+void
+EarlyNameResolver::visit (AST::EnumItemDiscriminant &item)
+{}
+
+void
+EarlyNameResolver::visit (AST::Enum &enum_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::Union &union_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::ConstantItem &const_item)
+{
+  const_item.get_type ()->accept_vis (*this);
+  const_item.get_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StaticItem &static_item)
+{
+  static_item.get_type ()->accept_vis (*this);
+  static_item.get_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TraitItemFunc &item)
+{
+  auto &decl = item.get_trait_function_decl ();
+
+  if (decl.has_return_type ())
+    decl.get_return_type ()->accept_vis (*this);
+
+  for (auto &generic : decl.get_generic_params ())
+    generic->accept_vis (*this);
+
+  for (auto &param : decl.get_function_params ())
+    param.get_type ()->accept_vis (*this);
+
+  if (item.has_definition ())
+    item.get_definition ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TraitItemMethod &item)
+{
+  // FIXME: Can we factor this with the above function?
+  auto &decl = item.get_trait_method_decl ();
+
+  if (decl.has_return_type ())
+    decl.get_return_type ()->accept_vis (*this);
+
+  for (auto &generic : decl.get_generic_params ())
+    generic->accept_vis (*this);
+
+  for (auto &param : decl.get_function_params ())
+    param.get_type ()->accept_vis (*this);
+
+  if (item.has_definition ())
+    item.get_definition ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TraitItemConst &item)
+{
+  item.get_type ()->accept_vis (*this);
+
+  if (item.has_expr ())
+    item.get_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TraitItemType &item)
+{}
+
+void
+EarlyNameResolver::visit (AST::Trait &trait)
+{
+  for (auto &item : trait.get_trait_items ())
+    item->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::InherentImpl &impl)
+{
+  impl.get_type ()->accept_vis (*this);
+
+  for (auto &generic : impl.get_generic_params ())
+    generic->accept_vis (*this);
+
+  for (auto &item : impl.get_impl_items ())
+    item->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TraitImpl &impl)
+{
+  impl.get_type ()->accept_vis (*this);
+
+  for (auto &generic : impl.get_generic_params ())
+    generic->accept_vis (*this);
+
+  for (auto &item : impl.get_impl_items ())
+    item->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ExternalStaticItem &item)
+{
+  item.get_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ExternalFunctionItem &item)
+{
+  for (auto &generic : item.get_generic_params ())
+    generic->accept_vis (*this);
+
+  for (auto &param : item.get_function_params ())
+    param.get_type ()->accept_vis (*this);
+
+  if (item.has_return_type ())
+    item.get_return_type ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ExternBlock &block)
+{
+  for (auto &item : block.get_extern_items ())
+    item->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::MacroMatchFragment &match)
+{}
+
+void
+EarlyNameResolver::visit (AST::MacroMatchRepetition &match)
+{}
+
+void
+EarlyNameResolver::visit (AST::MacroMatcher &matcher)
+{}
+
+void
+EarlyNameResolver::visit (AST::MacroRulesDefinition &rules_def)
+{
+  auto path = CanonicalPath::new_seg (rules_def.get_node_id (),
+				      rules_def.get_rule_name ());
+  resolver.get_macro_scope ().insert (path, rules_def.get_node_id (),
+				      rules_def.get_locus ());
+  mappings.insert_macro_def (&rules_def);
+  rust_debug_loc (rules_def.get_locus (), "inserting macro def: [%s]",
+		  path.get ().c_str ());
+}
+
+void
+EarlyNameResolver::visit (AST::MacroInvocation &invoc)
+{
+  auto &invoc_data = invoc.get_invoc_data ();
+  auto has_semicolon = invoc.has_semicolon ();
+
+  // ??
+  // switch on type of macro:
+  //  - '!' syntax macro (inner switch)
+  //      - procedural macro - "A token-based function-like macro"
+  //      - 'macro_rules' (by example/pattern-match) macro? or not? "an
+  // AST-based function-like macro"
+  //      - else is unreachable
+  //  - attribute syntax macro (inner switch)
+  //  - procedural macro attribute syntax - "A token-based attribute
+  // macro"
+  //      - legacy macro attribute syntax? - "an AST-based attribute macro"
+  //      - non-macro attribute: mark known
+  //      - else is unreachable
+  //  - derive macro (inner switch)
+  //      - derive or legacy derive - "token-based" vs "AST-based"
+  //      - else is unreachable
+  //  - derive container macro - unreachable
+
+  // lookup the rules for this macro
+  NodeId resolved_node = UNKNOWN_NODEID;
+  NodeId source_node = UNKNOWN_NODEID;
+  if (has_semicolon)
+    source_node = invoc.get_macro_node_id ();
+  else
+    source_node = invoc.get_pattern_node_id ();
+  auto seg
+    = CanonicalPath::new_seg (source_node, invoc_data.get_path ().as_string ());
+
+  bool found = resolver.get_macro_scope ().lookup (seg, &resolved_node);
+  if (!found)
+    {
+      rust_error_at (invoc.get_locus (), "unknown macro: [%s]",
+		     seg.get ().c_str ());
+      return;
+    }
+
+  // lookup the rules
+  AST::MacroRulesDefinition *rules_def = nullptr;
+  bool ok = mappings.lookup_macro_def (resolved_node, &rules_def);
+  rust_assert (ok);
+
+  mappings.insert_macro_invocation (invoc, rules_def);
+}
+
+// FIXME: ARTHUR: Do we need to resolve these as well here?
+
+void
+EarlyNameResolver::visit (AST::MetaItemPath &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaItemSeq &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaWord &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaNameValueStr &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaListPaths &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::MetaListNameValueStr &meta_item)
+{}
+
+void
+EarlyNameResolver::visit (AST::LiteralPattern &pattern)
+{}
+
+void
+EarlyNameResolver::visit (AST::IdentifierPattern &pattern)
+{
+  if (pattern.has_pattern_to_bind ())
+    pattern.get_pattern_to_bind ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::WildcardPattern &pattern)
+{}
+
+void
+EarlyNameResolver::visit (AST::RangePatternBoundLiteral &bound)
+{}
+
+void
+EarlyNameResolver::visit (AST::RangePatternBoundPath &bound)
+{}
+
+void
+EarlyNameResolver::visit (AST::RangePatternBoundQualPath &bound)
+{}
+
+void
+EarlyNameResolver::visit (AST::RangePattern &pattern)
+{
+  pattern.get_lower_bound ()->accept_vis (*this);
+  pattern.get_upper_bound ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ReferencePattern &pattern)
+{
+  pattern.get_referenced_pattern ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructPatternFieldTuplePat &field)
+{
+  field.get_index_pattern ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructPatternFieldIdentPat &field)
+{
+  field.get_ident_pattern ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::StructPatternFieldIdent &field)
+{}
+
+void
+EarlyNameResolver::visit (AST::StructPattern &pattern)
+{}
+
+void
+EarlyNameResolver::visit (AST::TupleStructItemsNoRange &tuple_items)
+{
+  for (auto &pattern : tuple_items.get_patterns ())
+    pattern->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TupleStructItemsRange &tuple_items)
+{
+  for (auto &pattern : tuple_items.get_lower_patterns ())
+    pattern->accept_vis (*this);
+  for (auto &pattern : tuple_items.get_upper_patterns ())
+    pattern->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TupleStructPattern &pattern)
+{
+  pattern.get_items ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TuplePatternItemsMultiple &tuple_items)
+{
+  for (auto &pattern : tuple_items.get_patterns ())
+    pattern->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TuplePatternItemsRanged &tuple_items)
+{
+  for (auto &pattern : tuple_items.get_lower_patterns ())
+    pattern->accept_vis (*this);
+  for (auto &pattern : tuple_items.get_upper_patterns ())
+    pattern->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TuplePattern &pattern)
+{
+  pattern.get_items ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::GroupedPattern &pattern)
+{
+  pattern.get_pattern_in_parens ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::SlicePattern &pattern)
+{
+  for (auto &item : pattern.get_items ())
+    item->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::EmptyStmt &stmt)
+{}
+
+void
+EarlyNameResolver::visit (AST::LetStmt &stmt)
+{
+  if (stmt.has_type ())
+    stmt.get_type ()->accept_vis (*this);
+
+  if (stmt.has_init_expr ())
+    stmt.get_init_expr ()->accept_vis (*this);
+
+  stmt.get_pattern ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ExprStmtWithoutBlock &stmt)
+{
+  stmt.get_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::ExprStmtWithBlock &stmt)
+{
+  stmt.get_expr ()->accept_vis (*this);
+}
+
+void
+EarlyNameResolver::visit (AST::TraitBound &bound)
+{}
+
+void
+EarlyNameResolver::visit (AST::ImplTraitType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::TraitObjectType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::ParenthesisedType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::ImplTraitTypeOneBound &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::TraitObjectTypeOneBound &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::TupleType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::NeverType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::RawPointerType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::ReferenceType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::ArrayType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::SliceType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::InferredType &type)
+{}
+
+void
+EarlyNameResolver::visit (AST::BareFunctionType &type)
+{
+  for (auto &param : type.get_function_params ())
+    param.get_type ()->accept_vis (*this);
+
+  if (type.has_return_type ())
+    type.get_return_type ()->accept_vis (*this);
+}
+
+} // namespace Resolver
+} // namespace Rust
diff --git a/gcc/rust/resolve/rust-early-name-resolver.h b/gcc/rust/resolve/rust-early-name-resolver.h
new file mode 100644
index 0000000..c53ab9f
--- /dev/null
+++ b/gcc/rust/resolve/rust-early-name-resolver.h
@@ -0,0 +1,210 @@
+// Copyright (C) 2020-2022 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef RUST_EARLY_NAME_RESOLVER_H
+#define RUST_EARLY_NAME_RESOLVER_H
+
+#include "rust-name-resolver.h"
+#include "rust-system.h"
+#include "rust-ast.h"
+#include "rust-ast-visitor.h"
+
+namespace Rust {
+namespace Resolver {
+
+class EarlyNameResolver : public AST::ASTVisitor
+{
+public:
+  EarlyNameResolver ();
+
+  void go (AST::Crate &crate);
+
+private:
+  Resolver &resolver;
+  Analysis::Mappings &mappings;
+
+  /**
+   * Early name-resolve generic args, which can be macro invocations
+   */
+  void resolve_generic_args (AST::GenericArgs &generic_args);
+
+  /**
+   * Early name-resolve a qualified path type, which can contain macro
+   * invocations
+   */
+  void resolve_qualified_path_type (AST::QualifiedPathType &path);
+
+  virtual void visit (AST::Token &tok);
+  virtual void visit (AST::DelimTokenTree &delim_tok_tree);
+  virtual void visit (AST::AttrInputMetaItemContainer &input);
+  virtual void visit (AST::IdentifierExpr &ident_expr);
+  virtual void visit (AST::Lifetime &lifetime);
+  virtual void visit (AST::LifetimeParam &lifetime_param);
+  virtual void visit (AST::ConstGenericParam &const_param);
+  virtual void visit (AST::PathInExpression &path);
+  virtual void visit (AST::TypePathSegment &segment);
+  virtual void visit (AST::TypePathSegmentGeneric &segment);
+  virtual void visit (AST::TypePathSegmentFunction &segment);
+  virtual void visit (AST::TypePath &path);
+  virtual void visit (AST::QualifiedPathInExpression &path);
+  virtual void visit (AST::QualifiedPathInType &path);
+  virtual void visit (AST::LiteralExpr &expr);
+  virtual void visit (AST::AttrInputLiteral &attr_input);
+  virtual void visit (AST::MetaItemLitExpr &meta_item);
+  virtual void visit (AST::MetaItemPathLit &meta_item);
+  virtual void visit (AST::BorrowExpr &expr);
+  virtual void visit (AST::DereferenceExpr &expr);
+  virtual void visit (AST::ErrorPropagationExpr &expr);
+  virtual void visit (AST::NegationExpr &expr);
+  virtual void visit (AST::ArithmeticOrLogicalExpr &expr);
+  virtual void visit (AST::ComparisonExpr &expr);
+  virtual void visit (AST::LazyBooleanExpr &expr);
+  virtual void visit (AST::TypeCastExpr &expr);
+  virtual void visit (AST::AssignmentExpr &expr);
+  virtual void visit (AST::CompoundAssignmentExpr &expr);
+  virtual void visit (AST::GroupedExpr &expr);
+  virtual void visit (AST::ArrayElemsValues &elems);
+  virtual void visit (AST::ArrayElemsCopied &elems);
+  virtual void visit (AST::ArrayExpr &expr);
+  virtual void visit (AST::ArrayIndexExpr &expr);
+  virtual void visit (AST::TupleExpr &expr);
+  virtual void visit (AST::TupleIndexExpr &expr);
+  virtual void visit (AST::StructExprStruct &expr);
+  virtual void visit (AST::StructExprFieldIdentifier &field);
+  virtual void visit (AST::StructExprFieldIdentifierValue &field);
+  virtual void visit (AST::StructExprFieldIndexValue &field);
+  virtual void visit (AST::StructExprStructFields &expr);
+  virtual void visit (AST::StructExprStructBase &expr);
+  virtual void visit (AST::CallExpr &expr);
+  virtual void visit (AST::MethodCallExpr &expr);
+  virtual void visit (AST::FieldAccessExpr &expr);
+  virtual void visit (AST::ClosureExprInner &expr);
+  virtual void visit (AST::BlockExpr &expr);
+  virtual void visit (AST::ClosureExprInnerTyped &expr);
+  virtual void visit (AST::ContinueExpr &expr);
+  virtual void visit (AST::BreakExpr &expr);
+  virtual void visit (AST::RangeFromToExpr &expr);
+  virtual void visit (AST::RangeFromExpr &expr);
+  virtual void visit (AST::RangeToExpr &expr);
+  virtual void visit (AST::RangeFullExpr &expr);
+  virtual void visit (AST::RangeFromToInclExpr &expr);
+  virtual void visit (AST::RangeToInclExpr &expr);
+  virtual void visit (AST::ReturnExpr &expr);
+  virtual void visit (AST::UnsafeBlockExpr &expr);
+  virtual void visit (AST::LoopExpr &expr);
+  virtual void visit (AST::WhileLoopExpr &expr);
+  virtual void visit (AST::WhileLetLoopExpr &expr);
+  virtual void visit (AST::ForLoopExpr &expr);
+  virtual void visit (AST::IfExpr &expr);
+  virtual void visit (AST::IfExprConseqElse &expr);
+  virtual void visit (AST::IfExprConseqIf &expr);
+  virtual void visit (AST::IfExprConseqIfLet &expr);
+  virtual void visit (AST::IfLetExpr &expr);
+  virtual void visit (AST::IfLetExprConseqElse &expr);
+  virtual void visit (AST::IfLetExprConseqIf &expr);
+  virtual void visit (AST::IfLetExprConseqIfLet &expr);
+  virtual void visit (AST::MatchExpr &expr);
+  virtual void visit (AST::AwaitExpr &expr);
+  virtual void visit (AST::AsyncBlockExpr &expr);
+  virtual void visit (AST::TypeParam &param);
+  virtual void visit (AST::LifetimeWhereClauseItem &item);
+  virtual void visit (AST::TypeBoundWhereClauseItem &item);
+  virtual void visit (AST::Method &method);
+  virtual void visit (AST::Module &module);
+  virtual void visit (AST::ExternCrate &crate);
+  virtual void visit (AST::UseTreeGlob &use_tree);
+  virtual void visit (AST::UseTreeList &use_tree);
+  virtual void visit (AST::UseTreeRebind &use_tree);
+  virtual void visit (AST::UseDeclaration &use_decl);
+  virtual void visit (AST::Function &function);
+  virtual void visit (AST::TypeAlias &type_alias);
+  virtual void visit (AST::StructStruct &struct_item);
+  virtual void visit (AST::TupleStruct &tuple_struct);
+  virtual void visit (AST::EnumItem &item);
+  virtual void visit (AST::EnumItemTuple &item);
+  virtual void visit (AST::EnumItemStruct &item);
+  virtual void visit (AST::EnumItemDiscriminant &item);
+  virtual void visit (AST::Enum &enum_item);
+  virtual void visit (AST::Union &union_item);
+  virtual void visit (AST::ConstantItem &const_item);
+  virtual void visit (AST::StaticItem &static_item);
+  virtual void visit (AST::TraitItemFunc &item);
+  virtual void visit (AST::TraitItemMethod &item);
+  virtual void visit (AST::TraitItemConst &item);
+  virtual void visit (AST::TraitItemType &item);
+  virtual void visit (AST::Trait &trait);
+  virtual void visit (AST::InherentImpl &impl);
+  virtual void visit (AST::TraitImpl &impl);
+  virtual void visit (AST::ExternalStaticItem &item);
+  virtual void visit (AST::ExternalFunctionItem &item);
+  virtual void visit (AST::ExternBlock &block);
+  virtual void visit (AST::MacroMatchFragment &match);
+  virtual void visit (AST::MacroMatchRepetition &match);
+  virtual void visit (AST::MacroMatcher &matcher);
+  virtual void visit (AST::MacroRulesDefinition &rules_def);
+  virtual void visit (AST::MacroInvocation &macro_invoc);
+  virtual void visit (AST::MetaItemPath &meta_item);
+  virtual void visit (AST::MetaItemSeq &meta_item);
+  virtual void visit (AST::MetaWord &meta_item);
+  virtual void visit (AST::MetaNameValueStr &meta_item);
+  virtual void visit (AST::MetaListPaths &meta_item);
+  virtual void visit (AST::MetaListNameValueStr &meta_item);
+  virtual void visit (AST::LiteralPattern &pattern);
+  virtual void visit (AST::IdentifierPattern &pattern);
+  virtual void visit (AST::WildcardPattern &pattern);
+  virtual void visit (AST::RangePatternBoundLiteral &bound);
+  virtual void visit (AST::RangePatternBoundPath &bound);
+  virtual void visit (AST::RangePatternBoundQualPath &bound);
+  virtual void visit (AST::RangePattern &pattern);
+  virtual void visit (AST::ReferencePattern &pattern);
+  virtual void visit (AST::StructPatternFieldTuplePat &field);
+  virtual void visit (AST::StructPatternFieldIdentPat &field);
+  virtual void visit (AST::StructPatternFieldIdent &field);
+  virtual void visit (AST::StructPattern &pattern);
+  virtual void visit (AST::TupleStructItemsNoRange &tuple_items);
+  virtual void visit (AST::TupleStructItemsRange &tuple_items);
+  virtual void visit (AST::TupleStructPattern &pattern);
+  virtual void visit (AST::TuplePatternItemsMultiple &tuple_items);
+  virtual void visit (AST::TuplePatternItemsRanged &tuple_items);
+  virtual void visit (AST::TuplePattern &pattern);
+  virtual void visit (AST::GroupedPattern &pattern);
+  virtual void visit (AST::SlicePattern &pattern);
+  virtual void visit (AST::EmptyStmt &stmt);
+  virtual void visit (AST::LetStmt &stmt);
+  virtual void visit (AST::ExprStmtWithoutBlock &stmt);
+  virtual void visit (AST::ExprStmtWithBlock &stmt);
+  virtual void visit (AST::TraitBound &bound);
+  virtual void visit (AST::ImplTraitType &type);
+  virtual void visit (AST::TraitObjectType &type);
+  virtual void visit (AST::ParenthesisedType &type);
+  virtual void visit (AST::ImplTraitTypeOneBound &type);
+  virtual void visit (AST::TraitObjectTypeOneBound &type);
+  virtual void visit (AST::TupleType &type);
+  virtual void visit (AST::NeverType &type);
+  virtual void visit (AST::RawPointerType &type);
+  virtual void visit (AST::ReferenceType &type);
+  virtual void visit (AST::ArrayType &type);
+  virtual void visit (AST::SliceType &type);
+  virtual void visit (AST::InferredType &type);
+  virtual void visit (AST::BareFunctionType &type);
+};
+
+} // namespace Resolver
+} // namespace Rust
+
+#endif // RUST_EARLY_NAME_RESOLVER_H