gdb/type-stack.h

   1 /* Type stack for GDB parser.
   2
   3    Copyright (C) 1986-2021 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_atomic,
  44     tp_restrict,
  45     tp_type_stack,
  46     tp_kind
  47   };
  48
  49 /* The stack can contain either an enum type_pieces or an int.  */
  50 union type_stack_elt
  51   {
  52     enum type_pieces piece;
  53     int int_val;
  54     struct type_stack *stack_val;
  55     std::vector<struct type *> *typelist_val;
  56   };
  57
  58 /* The type stack is an instance of this structure.  */
  59
  60 struct type_stack
  61 {
  62 public:
  63
  64   type_stack () = default;
  65
  66   DISABLE_COPY_AND_ASSIGN (type_stack);
  67
  68   type_stack *create ()
  69   {
  70     type_stack *result = new type_stack ();
  71     result->m_elements = std::move (m_elements);
  72     return result;
  73   }
  74
  75   /* Insert a new type, TP, at the bottom of the type stack.  If TP is
  76      tp_pointer, tp_reference or tp_rvalue_reference, it is inserted at the
  77      bottom.  If TP is a qualifier, it is inserted at slot 1 (just above a
  78      previous tp_pointer) if there is anything on the stack, or simply pushed
  79      if the stack is empty.  Other values for TP are invalid.  */
  80
  81   void insert (enum type_pieces tp);
  82
  83   void push (enum type_pieces tp)
  84   {
  85     type_stack_elt elt;
  86     elt.piece = tp;
  87     m_elements.push_back (elt);
  88   }
  89
  90   void push (int n)
  91   {
  92     type_stack_elt elt;
  93     elt.int_val = n;
  94     m_elements.push_back (elt);
  95   }
  96
  97   /* Push the type stack STACK as an element on this type stack.  */
  98
  99   void push (struct type_stack *stack)
 100   {
 101     type_stack_elt elt;
 102     elt.stack_val = stack;
 103     m_elements.push_back (elt);
 104     push (tp_type_stack);
 105   }
 106
 107   /* Push a function type with arguments onto the global type stack.
 108      LIST holds the argument types.  If the final item in LIST is NULL,
 109      then the function will be varargs.  */
 110
 111   void push (std::vector<struct type *> *list)
 112   {
 113     type_stack_elt elt;
 114     elt.typelist_val = list;
 115     m_elements.push_back (elt);
 116     push (tp_function_with_arguments);
 117   }
 118
 119   enum type_pieces pop ()
 120   {
 121     if (m_elements.empty ())
 122       return tp_end;
 123     type_stack_elt elt = m_elements.back ();
 124     m_elements.pop_back ();
 125     return elt.piece;
 126   }
 127
 128   int pop_int ()
 129   {
 130     if (m_elements.empty ())
 131       {
 132         /* "Can't happen".  */
 133         return 0;
 134       }
 135     type_stack_elt elt = m_elements.back ();
 136     m_elements.pop_back ();
 137     return elt.int_val;
 138   }
 139
 140   std::vector<struct type *> *pop_typelist ()
 141   {
 142     gdb_assert (!m_elements.empty ());
 143     type_stack_elt elt = m_elements.back ();
 144     m_elements.pop_back ();
 145     return elt.typelist_val;
 146   }
 147
 148   /* Pop a type_stack element.  */
 149
 150   struct type_stack *pop_type_stack ()
 151   {
 152     gdb_assert (!m_elements.empty ());
 153     type_stack_elt elt = m_elements.back ();
 154     m_elements.pop_back ();
 155     return elt.stack_val;
 156   }
 157
 158   /* Insert a tp_space_identifier and the corresponding address space
 159      value into the stack.  STRING is the name of an address space, as
 160      recognized by address_space_name_to_type_instance_flags.  If the
 161      stack is empty, the new elements are simply pushed.  If the stack
 162      is not empty, this function assumes that the first item on the
 163      stack is a tp_pointer, and the new values are inserted above the
 164      first item.  */
 165
 166   void insert (struct expr_builder *pstate, const char *string);
 167
 168   /* Append the elements of the type stack FROM to the type stack
 169      THIS.  Always returns THIS.  */
 170
 171   struct type_stack *append (struct type_stack *from)
 172   {
 173     m_elements.insert (m_elements.end (), from->m_elements.begin (),
 174                        from->m_elements.end ());
 175     return this;
 176   }
 177
 178   /* Pop the type stack and return a type_instance_flags that
 179      corresponds the const/volatile qualifiers on the stack.  This is
 180      called by the C++ parser when parsing methods types, and as such no
 181      other kind of type in the type stack is expected.  */
 182
 183   type_instance_flags follow_type_instance_flags ();
 184
 185   /* Pop the type stack and return the type which corresponds to
 186      FOLLOW_TYPE as modified by all the stuff on the stack.  */
 187   struct type *follow_types (struct type *follow_type);
 188
 189 private:
 190
 191   /* A helper function for insert_type and insert_type_address_space.
 192      This does work of expanding the type stack and inserting the new
 193      element, ELEMENT, into the stack at location SLOT.  */
 194
 195   void insert_into (int slot, union type_stack_elt element)
 196   {
 197     gdb_assert (slot <= m_elements.size ());
 198     m_elements.insert (m_elements.begin () + slot, element);
 199   }
 200
 201
 202   /* Elements on the stack.  */
 203   std::vector<union type_stack_elt> m_elements;
 204 };
 205
 206 #endif /* TYPE_STACK_H */