gdb/psympriv.h

   1 /* Private partial symbol table definitions.
   2
   3    Copyright (C) 2009-2017 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 PSYMPRIV_H
  21 #define PSYMPRIV_H
  22
  23 #include "psymtab.h"
  24 #include "objfiles.h"
  25
  26 struct psymbol_allocation_list;
  27
  28 /* A partial_symbol records the name, domain, and address class of
  29    symbols whose types we have not parsed yet.  For functions, it also
  30    contains their memory address, so we can find them from a PC value.
  31    Each partial_symbol sits in a partial_symtab, all of which are chained
  32    on a  partial symtab list and which points to the corresponding
  33    normal symtab once the partial_symtab has been referenced.  */
  34
  35 /* This structure is space critical.  See space comments at the top of
  36    symtab.h.  */
  37
  38 struct partial_symbol
  39 {
  40   /* The general symbol info required for all types of symbols.  */
  41
  42   struct general_symbol_info ginfo;
  43
  44   /* Name space code.  */
  45
  46   ENUM_BITFIELD(domain_enum_tag) domain : SYMBOL_DOMAIN_BITS;
  47
  48   /* Address class (for info_symbols).  Note that we don't allow
  49      synthetic "aclass" values here at present, simply because there's
  50      no need.  */
  51
  52   ENUM_BITFIELD(address_class) aclass : SYMBOL_ACLASS_BITS;
  53 };
  54
  55 #define PSYMBOL_DOMAIN(psymbol) (psymbol)->domain
  56 #define PSYMBOL_CLASS(psymbol)          (psymbol)->aclass
  57
  58 /* A convenience enum to give names to some constants used when
  59    searching psymtabs.  This is internal to psymtab and should not be
  60    used elsewhere.  */
  61
  62 enum psymtab_search_status
  63   {
  64     PST_NOT_SEARCHED,
  65     PST_SEARCHED_AND_FOUND,
  66     PST_SEARCHED_AND_NOT_FOUND
  67   };
  68
  69 /* Each source file that has not been fully read in is represented by
  70    a partial_symtab.  This contains the information on where in the
  71    executable the debugging symbols for a specific file are, and a
  72    list of names of global symbols which are located in this file.
  73    They are all chained on partial symtab lists.
  74
  75    Even after the source file has been read into a symtab, the
  76    partial_symtab remains around.  They are allocated on an obstack,
  77    objfile_obstack.  */
  78
  79 struct partial_symtab
  80 {
  81   /* Chain of all existing partial symtabs.  */
  82
  83   struct partial_symtab *next;
  84
  85   /* Name of the source file which this partial_symtab defines,
  86      or if the psymtab is anonymous then a descriptive name for
  87      debugging purposes, or "".  It must not be NULL.  */
  88
  89   const char *filename;
  90
  91   /* Full path of the source file.  NULL if not known.  */
  92
  93   char *fullname;
  94
  95   /* Directory in which it was compiled, or NULL if we don't know.  */
  96
  97   const char *dirname;
  98
  99   /* Range of text addresses covered by this file; texthigh is the
 100      beginning of the next section.  Do not use if PSYMTABS_ADDRMAP_SUPPORTED
 101      is set.  */
 102
 103   CORE_ADDR textlow;
 104   CORE_ADDR texthigh;
 105
 106   /* If NULL, this is an ordinary partial symbol table.
 107
 108      If non-NULL, this holds a single includer of this partial symbol
 109      table, and this partial symbol table is a shared one.
 110
 111      A shared psymtab is one that is referenced by multiple other
 112      psymtabs, and which conceptually has its contents directly
 113      included in those.
 114
 115      Shared psymtabs have special semantics.  When a search finds a
 116      symbol in a shared table, we instead return one of the non-shared
 117      tables that include this one.
 118
 119      A shared psymtabs can be referred to by other shared ones.
 120
 121      The psymtabs that refer to a shared psymtab will list the shared
 122      psymtab in their 'dependencies' array.
 123
 124      In DWARF terms, a shared psymtab is a DW_TAG_partial_unit; but
 125      of course using a name based on that would be too confusing, so
 126      "shared" was chosen instead.
 127
 128      Only a single user is needed because, when expanding a shared
 129      psymtab, we only need to expand its "canonical" non-shared user.
 130      The choice of which one should be canonical is left to the
 131      debuginfo reader; it can be arbitrary.  */
 132
 133   struct partial_symtab *user;
 134
 135   /* Array of pointers to all of the partial_symtab's which this one
 136      depends on.  Since this array can only be set to previous or
 137      the current (?) psymtab, this dependency tree is guaranteed not
 138      to have any loops.  "depends on" means that symbols must be read
 139      for the dependencies before being read for this psymtab; this is
 140      for type references in stabs, where if foo.c includes foo.h, declarations
 141      in foo.h may use type numbers defined in foo.c.  For other debugging
 142      formats there may be no need to use dependencies.  */
 143
 144   struct partial_symtab **dependencies;
 145
 146   int number_of_dependencies;
 147
 148   /* Global symbol list.  This list will be sorted after readin to
 149      improve access.  Binary search will be the usual method of
 150      finding a symbol within it.  globals_offset is an integer offset
 151      within global_psymbols[].  */
 152
 153   int globals_offset;
 154   int n_global_syms;
 155
 156   /* Static symbol list.  This list will *not* be sorted after readin;
 157      to find a symbol in it, exhaustive search must be used.  This is
 158      reasonable because searches through this list will eventually
 159      lead to either the read in of a files symbols for real (assumed
 160      to take a *lot* of time; check) or an error (and we don't care
 161      how long errors take).  This is an offset and size within
 162      static_psymbols[].  */
 163
 164   int statics_offset;
 165   int n_static_syms;
 166
 167   /* Non-zero if the symtab corresponding to this psymtab has been
 168      readin.  This is located here so that this structure packs better
 169      on 64-bit systems.  */
 170
 171   unsigned char readin;
 172
 173   /* True iff objfile->psymtabs_addrmap is properly populated for this
 174      partial_symtab.  For discontiguous overlapping psymtabs is the only usable
 175      info in PSYMTABS_ADDRMAP.  */
 176
 177   unsigned char psymtabs_addrmap_supported;
 178
 179   /* True if the name of this partial symtab is not a source file name.  */
 180
 181   unsigned char anonymous;
 182
 183   /* A flag that is temporarily used when searching psymtabs.  */
 184
 185   ENUM_BITFIELD (psymtab_search_status) searched_flag : 2;
 186
 187   /* Pointer to compunit eventually allocated for this source file, 0 if
 188      !readin or if we haven't looked for the symtab after it was readin.  */
 189
 190   struct compunit_symtab *compunit_symtab;
 191
 192   /* Pointer to function which will read in the symtab corresponding to
 193      this psymtab.  */
 194
 195   void (*read_symtab) (struct partial_symtab *, struct objfile *);
 196
 197   /* Information that lets read_symtab() locate the part of the symbol table
 198      that this psymtab corresponds to.  This information is private to the
 199      format-dependent symbol reading routines.  For further detail examine
 200      the various symbol reading modules.  */
 201
 202   void *read_symtab_private;
 203 };
 204
 205 /* Add any kind of symbol to a psymbol_allocation_list.  */
 206
 207 extern void add_psymbol_to_list (const char *, int,
 208                                  int, domain_enum,
 209                                  enum address_class,
 210                                  struct psymbol_allocation_list *,
 211                                  CORE_ADDR,
 212                                  enum language, struct objfile *);
 213
 214 extern void init_psymbol_list (struct objfile *, int);
 215
 216 extern struct partial_symtab *start_psymtab_common (struct objfile *,
 217                                                     const char *, CORE_ADDR,
 218                                                     struct partial_symbol **,
 219                                                     struct partial_symbol **);
 220
 221 extern void end_psymtab_common (struct objfile *, struct partial_symtab *);
 222
 223 extern struct partial_symtab *allocate_psymtab (const char *,
 224                                                 struct objfile *)
 225   ATTRIBUTE_NONNULL (1);
 226
 227 extern void discard_psymtab (struct objfile *, struct partial_symtab *);
 228
 229 /* Used when recording partial symbol tables.  On destruction,
 230    discards any partial symbol tables that have been built.  However,
 231    the tables can be kept by calling the "keep" method.  */
 232 class psymtab_discarder
 233 {
 234  public:
 235
 236   psymtab_discarder (struct objfile *objfile)
 237     : m_objfile (objfile),
 238       m_psymtab (objfile->psymtabs)
 239   {
 240   }
 241
 242   ~psymtab_discarder ()
 243   {
 244     if (m_objfile != NULL)
 245       while (m_objfile->psymtabs != m_psymtab)
 246         discard_psymtab (m_objfile, m_objfile->psymtabs);
 247   }
 248
 249   /* Keep any partial symbol tables that were built.  */
 250   void keep ()
 251   {
 252     m_objfile = NULL;
 253   }
 254
 255  private:
 256
 257   /* The objfile.  If NULL this serves as a sentinel to indicate that
 258      the psymtabs should be kept.  */
 259   struct objfile *m_objfile;
 260   /* How far back to free.  */
 261   struct partial_symtab *m_psymtab;
 262 };
 263
 264 /* Traverse all psymtabs in one objfile.  */
 265
 266 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
 267     for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
 268
 269 #endif /* PSYMPRIV_H */