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 <vector>
  24
  25 struct type;
  26 struct expr_builder;
  27
  28 /* For parsing of complicated types.
  29    An array should be preceded in the list by the size of the array.  */
  30 enum type_pieces
  31   {
  32     tp_end = -1,
  33     tp_pointer,
  34     tp_reference,
  35     tp_rvalue_reference,
  36     tp_array,
  37     tp_function,
  38     tp_function_with_arguments,
  39     tp_const,
  40     tp_volatile,
  41     tp_space_identifier,
  42     tp_type_stack,
  43     tp_kind
  44   };
  45
  46 /* The stack can contain either an enum type_pieces or an int.  */
  47 union type_stack_elt
  48   {
  49     enum type_pieces piece;
  50     int int_val;
  51     struct type_stack *stack_val;
  52     std::vector<struct type *> *typelist_val;
  53   };
  54
  55 /* The type stack is an instance of this structure.  */
  56
  57 struct type_stack
  58 {
  59 public:
  60
  61   type_stack () = default;
  62
  63   DISABLE_COPY_AND_ASSIGN (type_stack);
  64
  65   type_stack *create ()
  66   {
  67     type_stack *result = new type_stack ();
  68     result->m_elements = std::move (m_elements);
  69     return result;
  70   }
  71
  72   /* Insert a new type, TP, at the bottom of the type stack.  If TP is
  73      tp_pointer, tp_reference or tp_rvalue_reference, it is inserted at the
  74      bottom.  If TP is a qualifier, it is inserted at slot 1 (just above a
  75      previous tp_pointer) if there is anything on the stack, or simply pushed
  76      if the stack is empty.  Other values for TP are invalid.  */
  77
  78   void insert (enum type_pieces tp);
  79
  80   void push (enum type_pieces tp)
  81   {
  82     type_stack_elt elt;
  83     elt.piece = tp;
  84     m_elements.push_back (elt);
  85   }
  86
  87   void push (int n)
  88   {
  89     type_stack_elt elt;
  90     elt.int_val = n;
  91     m_elements.push_back (elt);
  92   }
  93
  94   /* Push the type stack STACK as an element on this type stack.  */
  95
  96   void push (struct type_stack *stack)
  97   {
  98     type_stack_elt elt;
  99     elt.stack_val = stack;
 100     m_elements.push_back (elt);
 101     push (tp_type_stack);
 102   }
 103
 104   /* Push a function type with arguments onto the global type stack.
 105      LIST holds the argument types.  If the final item in LIST is NULL,
 106      then the function will be varargs.  */
 107
 108   void push (std::vector<struct type *> *list)
 109   {
 110     type_stack_elt elt;
 111     elt.typelist_val = list;
 112     m_elements.push_back (elt);
 113     push (tp_function_with_arguments);
 114   }
 115
 116   enum type_pieces pop ()
 117   {
 118     if (m_elements.empty ())
 119       return tp_end;
 120     type_stack_elt elt = m_elements.back ();
 121     m_elements.pop_back ();
 122     return elt.piece;
 123   }
 124
 125   int pop_int ()
 126   {
 127     if (m_elements.empty ())
 128       {
 129         /* "Can't happen".  */
 130         return 0;
 131       }
 132     type_stack_elt elt = m_elements.back ();
 133     m_elements.pop_back ();
 134     return elt.int_val;
 135   }
 136
 137   std::vector<struct type *> *pop_typelist ()
 138   {
 139     gdb_assert (!m_elements.empty ());
 140     type_stack_elt elt = m_elements.back ();
 141     m_elements.pop_back ();
 142     return elt.typelist_val;
 143   }
 144
 145   /* Pop a type_stack element.  */
 146
 147   struct type_stack *pop_type_stack ()
 148   {
 149     gdb_assert (!m_elements.empty ());
 150     type_stack_elt elt = m_elements.back ();
 151     m_elements.pop_back ();
 152     return elt.stack_val;
 153   }
 154
 155   /* Insert a tp_space_identifier and the corresponding address space
 156      value into the stack.  STRING is the name of an address space, as
 157      recognized by address_space_name_to_int.  If the stack is empty,
 158      the new elements are simply pushed.  If the stack is not empty,
 159      this function assumes that the first item on the stack is a
 160      tp_pointer, and the new values are inserted above the first
 161      item.  */
 162
 163   void insert (struct expr_builder *pstate, const char *string);
 164
 165   /* Append the elements of the type stack FROM to the type stack
 166      THIS.  Always returns THIS.  */
 167
 168   struct type_stack *append (struct type_stack *from)
 169   {
 170     m_elements.insert (m_elements.end (), from->m_elements.begin (),
 171                        from->m_elements.end ());
 172     return this;
 173   }
 174
 175   /* Pop the type stack and return a type_instance_flags that
 176      corresponds the const/volatile qualifiers on the stack.  This is
 177      called by the C++ parser when parsing methods types, and as such no
 178      other kind of type in the type stack is expected.  */
 179
 180   type_instance_flags follow_type_instance_flags ();
 181
 182   /* Pop the type stack and return the type which corresponds to
 183      FOLLOW_TYPE as modified by all the stuff on the stack.  */
 184   struct type *follow_types (struct type *follow_type);
 185
 186 private:
 187
 188   /* A helper function for insert_type and insert_type_address_space.
 189      This does work of expanding the type stack and inserting the new
 190      element, ELEMENT, into the stack at location SLOT.  */
 191
 192   void insert_into (int slot, union type_stack_elt element)
 193   {
 194     gdb_assert (slot <= m_elements.size ());
 195     m_elements.insert (m_elements.begin () + slot, element);
 196   }
 197
 198
 199   /* Elements on the stack.  */
 200   std::vector<union type_stack_elt> m_elements;
 201 };
 202
 203 #endif /* TYPE_STACK_H */