1  /* Support for offering suggestions for handling unrecognized names.
       2     Copyright (C) 2016-2023 Free Software Foundation, Inc.
       3  
       4  This file is part of GCC.
       5  
       6  GCC is free software; you can redistribute it and/or modify it under
       7  the terms of the GNU General Public License as published by the Free
       8  Software Foundation; either version 3, or (at your option) any later
       9  version.
      10  
      11  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      12  WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      14  for more details.
      15  
      16  You should have received a copy of the GNU General Public License
      17  along with GCC; see the file COPYING3.  If not see
      18  <http://www.gnu.org/licenses/>.  */
      19  
      20  #ifndef GCC_NAME_HINT_H
      21  #define GCC_NAME_HINT_H
      22  
      23  /* This header uses std::unique_ptr, but <memory> can't be directly
      24     included due to issues with macros.  Hence it must be included from
      25     system.h by defining INCLUDE_MEMORY in any source file using it.  */
      26  
      27  #ifndef INCLUDE_MEMORY
      28  # error "You must define INCLUDE_MEMORY before including system.h to use name-hint.h"
      29  #endif
      30  
      31  enum lookup_name_fuzzy_kind {
      32    /* Names of types.  */
      33    FUZZY_LOOKUP_TYPENAME,
      34  
      35    /* Names of function decls.  */
      36    FUZZY_LOOKUP_FUNCTION_NAME,
      37  
      38    /* Any name.  */
      39    FUZZY_LOOKUP_NAME
      40  };
      41  
      42  /* A deferred_diagnostic is a wrapper around optional extra diagnostics
      43     that we may want to bundle into a name_hint.
      44  
      45     The diagnostic is emitted by the subclass destructor, which should
      46     check that is_suppressed_p () is not true.  */
      47  
      48  class deferred_diagnostic
      49  {
      50   public:
      51    virtual ~deferred_diagnostic () {}
      52  
      53    location_t get_location () const { return m_loc; }
      54  
      55    /* Call this if the corresponding warning was not emitted,
      56       in which case we should also not emit the deferred_diagnostic.  */
      57    void suppress ()
      58    {
      59      m_suppress = true;
      60    }
      61  
      62    bool is_suppressed_p () const { return m_suppress; }
      63  
      64   protected:
      65    deferred_diagnostic (location_t loc)
      66    : m_loc (loc), m_suppress (false) {}
      67  
      68   private:
      69    location_t m_loc;
      70    bool m_suppress;
      71  };
      72  
      73  /* A name_hint is an optional string suggestion, along with an
      74     optional deferred_diagnostic.
      75     For example:
      76  
      77         error: unknown foo named 'bar'
      78  
      79     if the SUGGESTION is "baz", then one might print:
      80  
      81         error: unknown foo named 'bar'; did you mean 'baz'?
      82  
      83     and the deferred_diagnostic allows for additional (optional)
      84     diagnostics e.g.:
      85  
      86         note: did you check behind the couch?
      87  
      88     The deferred_diagnostic is emitted by its destructor, when the
      89     name_hint goes out of scope.  */
      90  
      91  class name_hint
      92  {
      93  public:
      94    name_hint () : m_suggestion (NULL), m_deferred () {}
      95  
      96    name_hint (const char *suggestion, deferred_diagnostic *deferred)
      97    : m_suggestion (suggestion), m_deferred (deferred)
      98    {
      99    }
     100  
     101    const char *suggestion () const { return m_suggestion; }
     102  
     103    /* Does this name_hint have a suggestion or a deferred diagnostic?  */
     104    operator bool () const { return (m_suggestion != NULL
     105  				   || m_deferred != NULL); }
     106  
     107    /* Take ownership of this name_hint's deferred_diagnostic, for use
     108       in chaining up deferred diagnostics.  */
     109    std::unique_ptr<deferred_diagnostic> take_deferred () { return std::move (m_deferred); }
     110  
     111    /* Call this on a name_hint if the corresponding warning was not emitted,
     112       in which case we should also not emit the deferred_diagnostic.  */
     113  
     114    void suppress ()
     115    {
     116      if (m_deferred)
     117        m_deferred->suppress ();
     118    }
     119  
     120  private:
     121    const char *m_suggestion;
     122    std::unique_ptr<deferred_diagnostic> m_deferred;
     123  };
     124  
     125  extern name_hint lookup_name_fuzzy (tree, enum lookup_name_fuzzy_kind,
     126  				    location_t);
     127  
     128  #endif /* ! GCC_NAME_HINT_H */