gdb/type-stack.h

   1 /* Type stack for GDB parser.
   2
   3    Copyright (C) 1986-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef TYPE_STACK_H
  21 #define TYPE_STACK_H
  22
  23 #include "gdbtypes.h"
  24 #include <vector>
  25
  26 struct type;
  27 struct expr_builder;
  28
  29 /* For parsing of complicated types.
  30    An array should be preceded in the list by the size of the array.  */
  31 enum type_pieces
  32   {
  33     tp_end = -1,
  34     tp_pointer,
  35     tp_reference,
  36     tp_rvalue_reference,
  37     tp_array,
  38     tp_function,
  39     tp_function_with_arguments,
  40     tp_const,
  41     tp_volatile,
  42     tp_space_identifier,
  43     tp_type_stack,
  44     tp_kind
  45   };
  46
  47 /* The stack can contain either an enum type_pieces or an int.  */
  48 union type_stack_elt
  49   {
  50     enum type_pieces piece;
  51     int int_val;
  52     struct type_stack *stack_val;
  53     std::vector<struct type *> *typelist_val;
  54   };
  55
  56 /* The type stack is an instance of this structure.  */
  57
  58 struct type_stack
  59 {
  60 public:
  61
  62   type_stack () = default;
  63
  64   DISABLE_COPY_AND_ASSIGN (type_stack);
  65
  66   type_stack *create ()
  67   {
  68     type_stack *result = new type_stack ();
  69     result->m_elements = std::move (m_elements);
  70     return result;
  71   }
  72
  73   /* Insert a new type, TP, at the bottom of the type stack.  If TP is
  74      tp_pointer, tp_reference or tp_rvalue_reference, it is inserted at the
  75      bottom.  If TP is a qualifier, it is inserted at slot 1 (just above a
  76      previous tp_pointer) if there is anything on the stack, or simply pushed
  77      if the stack is empty.  Other values for TP are invalid.  */
  78
  79   void insert (enum type_pieces tp);
  80
  81   void push (enum type_pieces tp)
  82   {
  83     type_stack_elt elt;
  84     elt.piece = tp;
  85     m_elements.push_back (elt);
  86   }
  87
  88   void push (int n)
  89   {
  90     type_stack_elt elt;
  91     elt.int_val = n;
  92     m_elements.push_back (elt);
  93   }
  94
  95   /* Push the type stack STACK as an element on this type stack.  */
  96
  97   void push (struct type_stack *stack)
  98   {
  99     type_stack_elt elt;
 100     elt.stack_val = stack;
 101     m_elements.push_back (elt);
 102     push (tp_type_stack);
 103   }
 104
 105   /* Push a function type with arguments onto the global type stack.
 106      LIST holds the argument types.  If the final item in LIST is NULL,
 107      then the function will be varargs.  */
 108
 109   void push (std::vector<struct type *> *list)
 110   {
 111     type_stack_elt elt;
 112     elt.typelist_val = list;
 113     m_elements.push_back (elt);
 114     push (tp_function_with_arguments);
 115   }
 116
 117   enum type_pieces pop ()
 118   {
 119     if (m_elements.empty ())
 120       return tp_end;
 121     type_stack_elt elt = m_elements.back ();
 122     m_elements.pop_back ();
 123     return elt.piece;
 124   }
 125
 126   int pop_int ()
 127   {
 128     if (m_elements.empty ())
 129       {
 130         /* "Can't happen".  */
 131         return 0;
 132       }
 133     type_stack_elt elt = m_elements.back ();
 134     m_elements.pop_back ();
 135     return elt.int_val;
 136   }
 137
 138   std::vector<struct type *> *pop_typelist ()
 139   {
 140     gdb_assert (!m_elements.empty ());
 141     type_stack_elt elt = m_elements.back ();
 142     m_elements.pop_back ();
 143     return elt.typelist_val;
 144   }
 145
 146   /* Pop a type_stack element.  */
 147
 148   struct type_stack *pop_type_stack ()
 149   {
 150     gdb_assert (!m_elements.empty ());
 151     type_stack_elt elt = m_elements.back ();
 152     m_elements.pop_back ();
 153     return elt.stack_val;
 154   }
 155
 156   /* Insert a tp_space_identifier and the corresponding address space
 157      value into the stack.  STRING is the name of an address space, as
 158      recognized by address_space_name_to_int.  If the stack is empty,
 159      the new elements are simply pushed.  If the stack is not empty,
 160      this function assumes that the first item on the stack is a
 161      tp_pointer, and the new values are inserted above the first
 162      item.  */
 163
 164   void insert (struct expr_builder *pstate, const char *string);
 165
 166   /* Append the elements of the type stack FROM to the type stack
 167      THIS.  Always returns THIS.  */
 168
 169   struct type_stack *append (struct type_stack *from)
 170   {
 171     m_elements.insert (m_elements.end (), from->m_elements.begin (),
 172                        from->m_elements.end ());
 173     return this;
 174   }
 175
 176   /* Pop the type stack and return a type_instance_flags that
 177      corresponds the const/volatile qualifiers on the stack.  This is
 178      called by the C++ parser when parsing methods types, and as such no
 179      other kind of type in the type stack is expected.  */
 180
 181   type_instance_flags follow_type_instance_flags ();
 182
 183   /* Pop the type stack and return the type which corresponds to
 184      FOLLOW_TYPE as modified by all the stuff on the stack.  */
 185   struct type *follow_types (struct type *follow_type);
 186
 187 private:
 188
 189   /* A helper function for insert_type and insert_type_address_space.
 190      This does work of expanding the type stack and inserting the new
 191      element, ELEMENT, into the stack at location SLOT.  */
 192
 193   void insert_into (int slot, union type_stack_elt element)
 194   {
 195     gdb_assert (slot <= m_elements.size ());
 196     m_elements.insert (m_elements.begin () + slot, element);
 197   }
 198
 199
 200   /* Elements on the stack.  */
 201   std::vector<union type_stack_elt> m_elements;
 202 };
 203
 204 #endif /* TYPE_STACK_H */