gcc/c-family/name-hint.h

   1 /* Support for offering suggestions for handling unrecognized names.
   2    Copyright (C) 2016-2018 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 gnu::unique_ptr, but unique-ptr.h can't be directly
  24    included due to issues with macros.  Hence it must be included from
  25    system.h by defining INCLUDE_UNIQUE_PTR in any source file using it.  */
  26
  27 #ifndef GNU_UNIQUE_PTR_H
  28 # error "You must define INCLUDE_UNIQUE_PTR 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   operator bool () const { return m_suggestion != NULL; }
 103
 104   /* Call this on a name_hint if the corresponding warning was not emitted,
 105      in which case we should also not emit the deferred_diagnostic.  */
 106
 107   void suppress ()
 108   {
 109     if (m_deferred)
 110       m_deferred->suppress ();
 111   }
 112
 113 private:
 114   const char *m_suggestion;
 115   gnu::unique_ptr<deferred_diagnostic> m_deferred;
 116 };
 117
 118 extern name_hint lookup_name_fuzzy (tree, enum lookup_name_fuzzy_kind,
 119                                     location_t);
 120
 121 #endif /* ! GCC_NAME_HINT_H */