// Copyright (C) 2020-2025 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::DefaultASTVisitor
{
public:
  EarlyNameResolver ();

  void go (AST::Crate &crate);

private:
  using AST::DefaultASTVisitor::visit;

  /**
   * Execute a lambda within a scope. This is equivalent to calling
   * `enter_scope` before your code and `exit_scope` after. This ensures
   * no errors can be committed
   */
  void scoped (NodeId scope_id, std::function<void ()> fn)
  {
    auto old_scope = current_scope;
    current_scope = scope_id;
    resolver.get_macro_scope ().push (scope_id);
    resolver.push_new_macro_rib (resolver.get_macro_scope ().peek ());

    fn ();

    resolver.get_macro_scope ().pop ();
    current_scope = old_scope;
  }

  /**
   * Accumulate all of the nested macros which escape their module through the
   * use of the #[macro_use] attribute.
   *
   * This function recursively accumulates macros in all of the nested modules
   * of an item container (an AST::Crate or an AST::Module) and returns this new
   * list of items. You can then use the `take_items` and `set_items` functions
   * on these containers to replace their list of items.
   */
  std::vector<std::unique_ptr<AST::Item>>
  accumulate_escaped_macros (AST::Module &module);

  /**
   * The "scope" we are currently in.
   *
   * This involves lexical scopes:
   *
   * ```rust
   * // current_scope = crate_id;
   * macro_rules! foo { () => {} )
   *
   * {
   *     // current_scope = current_block_id;
   *     macro_rules! foo { () => { something!(); } }
   * }
   * // current_scope = crate_id;
   * ```
   *
   * as well as any sort of scope-like structure that might impact import name
   * resolution or macro name resolution:
   *
   * ```rust
   * macro_rules! foo {
   *     () => { fn empty() {} }
   * }
   *
   *
   * trait Foo {
   *     fn foo() {
   *         fn inner_foo() {
   *             macro_rules! foo { () => {} )
   *
   *             foo!();
   *         }
   *
   *         foo!();
   *     }
   *
   *     foo!();
   * }
   *
   * foo!();
   * ```
   */
  NodeId current_scope;

  /* The crate's scope */
  NodeId crate_scope;

  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::Crate &crate);
  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::LifetimeParam &lifetime_param);
  virtual void visit (AST::ConstGenericParam &const_param);
  virtual void visit (AST::PathInExpression &path);
  virtual void visit (AST::TypePathSegmentGeneric &segment);
  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::AttrInputMacro &attr_input);
  virtual void visit (AST::MetaItemLitExpr &meta_item);
  virtual void visit (AST::MetaItemPathExpr &meta_item);
  virtual void visit (AST::StructExprStruct &expr);
  virtual void visit (AST::StructExprFieldIdentifier &field);
  virtual void visit (AST::StructExprStructBase &expr);
  virtual void visit (AST::BlockExpr &expr);
  virtual void visit (AST::ContinueExpr &expr);
  virtual void visit (AST::RangeFullExpr &expr);
  virtual void visit (AST::ForLoopExpr &expr);
  virtual void visit (AST::IfLetExpr &expr);
  virtual void visit (AST::MatchExpr &expr);
  virtual void visit (AST::LifetimeWhereClauseItem &item);
  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::EnumItem &item);
  virtual void visit (AST::Union &union_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::ExternalTypeItem &item);
  virtual void visit (AST::ExternBlock &block);
  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::MetaNameValueStr &meta_item);
  virtual void visit (AST::MetaListPaths &meta_item);
  virtual void visit (AST::MetaListNameValueStr &meta_item);
  virtual void visit (AST::RangePatternBoundLiteral &bound);
  virtual void visit (AST::RangePatternBoundPath &bound);
  virtual void visit (AST::RangePatternBoundQualPath &bound);
  virtual void visit (AST::StructPatternFieldIdent &field);
  virtual void visit (AST::StructPattern &pattern);
  virtual void visit (AST::TupleStructPattern &pattern);
  virtual void visit (AST::TupleType &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);
};

} // namespace Resolver
} // namespace Rust

#endif // RUST_EARLY_NAME_RESOLVER_H