gdb/typeprint.h

   1 /* Language independent support for printing types for GDB, the GNU debugger.
   2    Copyright (C) 1986-2024 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef TYPEPRINT_H
  20 #define TYPEPRINT_H
  21
  22 #include "gdbsupport/gdb_obstack.h"
  23 #include "gdbsupport/unordered_set.h"
  24 #include "gdbtypes.h"
  25 #include "hashtab.h"
  26
  27 enum language;
  28 struct ui_file;
  29 struct typedef_hash_table;
  30 struct ext_lang_type_printers;
  31
  32 struct type_print_options
  33 {
  34   /* True means that no special printing flags should apply.  */
  35   unsigned int raw : 1;
  36
  37   /* True means print methods in a class.  */
  38   unsigned int print_methods : 1;
  39
  40   /* True means print typedefs in a class.  */
  41   unsigned int print_typedefs : 1;
  42
  43   /* True means to print offsets, a la 'pahole'.  */
  44   unsigned int print_offsets : 1;
  45
  46   /* True means to print offsets in hex, otherwise use decimal.  */
  47   unsigned int print_in_hex : 1;
  48
  49   /* The number of nested type definitions to print.  -1 == all.  */
  50   int print_nested_type_limit;
  51
  52   /* If not NULL, a local typedef hash table used when printing a
  53      type.  */
  54   typedef_hash_table *local_typedefs;
  55
  56   /* If not NULL, a global typedef hash table used when printing a
  57      type.  */
  58   typedef_hash_table *global_typedefs;
  59
  60   /* The list of type printers associated with the global typedef
  61      table.  This is intentionally opaque.  */
  62   struct ext_lang_type_printers *global_printers;
  63 };
  64
  65 struct print_offset_data
  66 {
  67   /* Indicate if the offset an d size fields should be printed in decimal
  68      (default) or hexadecimal.  */
  69   bool print_in_hex  = false;
  70
  71   /* The offset to be applied to bitpos when PRINT_OFFSETS is true.
  72      This is needed for when we are printing nested structs and want
  73      to make sure that the printed offset for each field carries over
  74      the offset of the outer struct.  */
  75   unsigned int offset_bitpos = 0;
  76
  77   /* END_BITPOS is the one-past-the-end bit position of the previous
  78      field (where we expect the current field to be if there is no
  79      hole).  */
  80   unsigned int end_bitpos = 0;
  81
  82   /* Print information about field at index FIELD_IDX of the struct type
  83      TYPE and update this object.
  84
  85      If the field is static, it simply prints the correct number of
  86      spaces.
  87
  88      The output is strongly based on pahole(1).  */
  89   void update (struct type *type, unsigned int field_idx,
  90                struct ui_file *stream);
  91
  92   /* Call when all fields have been printed.  This will print
  93      information about any padding that may exist.  LEVEL is the
  94      desired indentation level.  */
  95   void finish (struct type *type, int level, struct ui_file *stream);
  96
  97   /* When printing the offsets of a struct and its fields (i.e.,
  98      'ptype /o'; type_print_options::print_offsets), we use this many
  99      characters when printing the offset information at the beginning
 100      of the line.  This is needed in order to generate the correct
 101      amount of whitespaces when no offset info should be printed for a
 102      certain field.  */
 103   static const int indentation;
 104
 105   explicit print_offset_data (const struct type_print_options *flags);
 106
 107 private:
 108
 109   /* Helper function for ptype/o implementation that prints
 110      information about a hole, if necessary.  STREAM is where to
 111      print.  BITPOS is the bitpos of the current field.  FOR_WHAT is a
 112      string describing the purpose of the hole.  */
 113
 114   void maybe_print_hole (struct ui_file *stream, unsigned int bitpos,
 115                          const char *for_what);
 116 };
 117
 118 extern const struct type_print_options type_print_raw_options;
 119
 120 /* A hash table holding decl_field objects.  This is more complicated than an
 121    ordinary hash because it must also track the lifetime of some -- but not all
 122    -- of the contained objects.  */
 123
 124 class typedef_hash_table
 125 {
 126 public:
 127
 128   /* Create a new typedef-lookup hash table.  */
 129   typedef_hash_table () = default;
 130
 131   /* Copy a typedef hash.  */
 132   typedef_hash_table (const typedef_hash_table &other)
 133     : m_table (other.m_table)
 134   {}
 135
 136   typedef_hash_table &operator= (const typedef_hash_table &) = delete;
 137
 138   /* Add typedefs from T to the hash table TABLE.  */
 139   void recursively_update (struct type *);
 140
 141   /* Add template parameters from T to the typedef hash TABLE.  */
 142   void add_template_parameters (struct type *t);
 143
 144   /* Look up the type T in the typedef hash tables contained in FLAGS.
 145      The local table is searched first, then the global table (either
 146      table can be NULL, in which case it is skipped).  If T is in a
 147      table, return its short (class-relative) typedef name.  Otherwise
 148      return NULL.  */
 149   static const char *find_typedef (const struct type_print_options *flags,
 150                                    struct type *t);
 151
 152 private:
 153
 154   static const char *find_global_typedef (const struct type_print_options *flags,
 155                                           struct type *t);
 156
 157   struct decl_field_type_hash
 158   {
 159     using is_transparent = void;
 160
 161     std::size_t operator() (type *t) const noexcept
 162     {
 163       /* Use check_typedef: the hash must agree with equals, and types_equal
 164          strips typedefs.  */
 165       return htab_hash_string (TYPE_SAFE_NAME (check_typedef (t)));
 166     }
 167
 168     std::size_t operator() (const decl_field *f) const noexcept
 169     { return (*this) (f->type); }
 170   };
 171
 172   struct decl_field_type_eq
 173   {
 174     using is_transparent = void;
 175
 176     bool operator () (type *t, const decl_field *f) const noexcept
 177     { return types_equal (t, f->type); }
 178
 179     bool operator() (const decl_field *lhs,
 180                      const decl_field *rhs) const noexcept
 181     { return (*this) (lhs->type, rhs); }
 182   };
 183
 184   /* The actual hash table of `decl_field *` identified by their type field.  */
 185   gdb::unordered_set<decl_field *, decl_field_type_hash, decl_field_type_eq>
 186     m_table;
 187
 188   /* Storage for typedef_field objects that must be synthesized.  */
 189   auto_obstack m_storage;
 190 };
 191
 192
 193 void print_type_scalar (struct type * type, LONGEST, struct ui_file *);
 194
 195 /* Assuming the TYPE is a fixed point type, print its type description
 196    on STREAM.  */
 197
 198 void print_type_fixed_point (struct type *type, struct ui_file *stream);
 199
 200 void c_type_print_args (struct type *, struct ui_file *, int, enum language,
 201                         const struct type_print_options *);
 202
 203 /* Print <unknown return type> to stream STREAM.  */
 204
 205 void type_print_unknown_return_type (struct ui_file *stream);
 206
 207 /* Throw an error indicating that the user tried to use a symbol that
 208    has unknown type.  SYM_PRINT_NAME is the name of the symbol, to be
 209    included in the error message.  */
 210 extern void error_unknown_type (const char *sym_print_name);
 211
 212 extern void val_print_not_allocated (struct ui_file *stream);
 213
 214 extern void val_print_not_associated (struct ui_file *stream);
 215
 216 #endif