gdb/psympriv.h

   1 /* Private partial symbol table definitions.
   2
   3    Copyright (C) 2009-2018 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 /* A partial_symbol records the name, domain, and address class of
  27    symbols whose types we have not parsed yet.  For functions, it also
  28    contains their memory address, so we can find them from a PC value.
  29    Each partial_symbol sits in a partial_symtab, all of which are chained
  30    on a  partial symtab list and which points to the corresponding
  31    normal symtab once the partial_symtab has been referenced.  */
  32
  33 /* This structure is space critical.  See space comments at the top of
  34    symtab.h.  */
  35
  36 struct partial_symbol : public general_symbol_info
  37 {
  38   /* Return the section for this partial symbol, or nullptr if no
  39      section has been set.  */
  40   struct obj_section *obj_section (struct objfile *objfile) const
  41   {
  42     if (section >= 0)
  43       return &objfile->sections[section];
  44     return nullptr;
  45   }
  46
  47   /* Return the unrelocated address of this partial symbol.  */
  48   CORE_ADDR unrelocated_address () const
  49   {
  50     return value.address;
  51   }
  52
  53   /* Return the address of this partial symbol, relocated according to
  54      the offsets provided in OBJFILE.  */
  55   CORE_ADDR address (const struct objfile *objfile) const
  56   {
  57     return value.address;
  58   }
  59
  60   /* Set the address of this partial symbol.  The address must be
  61      unrelocated.  */
  62   void set_address (CORE_ADDR addr)
  63   {
  64     value.address = addr;
  65   }
  66
  67   /* Name space code.  */
  68
  69   ENUM_BITFIELD(domain_enum_tag) domain : SYMBOL_DOMAIN_BITS;
  70
  71   /* Address class (for info_symbols).  Note that we don't allow
  72      synthetic "aclass" values here at present, simply because there's
  73      no need.  */
  74
  75   ENUM_BITFIELD(address_class) aclass : SYMBOL_ACLASS_BITS;
  76 };
  77
  78 /* A convenience enum to give names to some constants used when
  79    searching psymtabs.  This is internal to psymtab and should not be
  80    used elsewhere.  */
  81
  82 enum psymtab_search_status
  83   {
  84     PST_NOT_SEARCHED,
  85     PST_SEARCHED_AND_FOUND,
  86     PST_SEARCHED_AND_NOT_FOUND
  87   };
  88
  89 /* Each source file that has not been fully read in is represented by
  90    a partial_symtab.  This contains the information on where in the
  91    executable the debugging symbols for a specific file are, and a
  92    list of names of global symbols which are located in this file.
  93    They are all chained on partial symtab lists.
  94
  95    Even after the source file has been read into a symtab, the
  96    partial_symtab remains around.  They are allocated on an obstack,
  97    objfile_obstack.  */
  98
  99 struct partial_symtab
 100 {
 101   /* Return the low text address of this partial_symtab.  */
 102   CORE_ADDR text_low () const
 103   {
 104     return m_text_low;
 105   }
 106
 107   /* Return the high text address of this partial_symtab.  */
 108   CORE_ADDR text_high () const
 109   {
 110     return m_text_high;
 111   }
 112
 113   /* Set the low text address of this partial_symtab.  */
 114   void set_text_low (CORE_ADDR addr)
 115   {
 116     m_text_low = addr;
 117   }
 118
 119   /* Set the hight text address of this partial_symtab.  */
 120   void set_text_high (CORE_ADDR addr)
 121   {
 122     m_text_high = addr;
 123   }
 124
 125
 126   /* Chain of all existing partial symtabs.  */
 127
 128   struct partial_symtab *next;
 129
 130   /* Name of the source file which this partial_symtab defines,
 131      or if the psymtab is anonymous then a descriptive name for
 132      debugging purposes, or "".  It must not be NULL.  */
 133
 134   const char *filename;
 135
 136   /* Full path of the source file.  NULL if not known.  */
 137
 138   char *fullname;
 139
 140   /* Directory in which it was compiled, or NULL if we don't know.  */
 141
 142   const char *dirname;
 143
 144   /* Range of text addresses covered by this file; texthigh is the
 145      beginning of the next section.  Do not use if PSYMTABS_ADDRMAP_SUPPORTED
 146      is set.  Do not refer directly to these fields.  Instead, use the
 147      accessors.  */
 148
 149   CORE_ADDR m_text_low;
 150   CORE_ADDR m_text_high;
 151
 152   /* If NULL, this is an ordinary partial symbol table.
 153
 154      If non-NULL, this holds a single includer of this partial symbol
 155      table, and this partial symbol table is a shared one.
 156
 157      A shared psymtab is one that is referenced by multiple other
 158      psymtabs, and which conceptually has its contents directly
 159      included in those.
 160
 161      Shared psymtabs have special semantics.  When a search finds a
 162      symbol in a shared table, we instead return one of the non-shared
 163      tables that include this one.
 164
 165      A shared psymtabs can be referred to by other shared ones.
 166
 167      The psymtabs that refer to a shared psymtab will list the shared
 168      psymtab in their 'dependencies' array.
 169
 170      In DWARF terms, a shared psymtab is a DW_TAG_partial_unit; but
 171      of course using a name based on that would be too confusing, so
 172      "shared" was chosen instead.
 173
 174      Only a single user is needed because, when expanding a shared
 175      psymtab, we only need to expand its "canonical" non-shared user.
 176      The choice of which one should be canonical is left to the
 177      debuginfo reader; it can be arbitrary.  */
 178
 179   struct partial_symtab *user;
 180
 181   /* Array of pointers to all of the partial_symtab's which this one
 182      depends on.  Since this array can only be set to previous or
 183      the current (?) psymtab, this dependency tree is guaranteed not
 184      to have any loops.  "depends on" means that symbols must be read
 185      for the dependencies before being read for this psymtab; this is
 186      for type references in stabs, where if foo.c includes foo.h, declarations
 187      in foo.h may use type numbers defined in foo.c.  For other debugging
 188      formats there may be no need to use dependencies.  */
 189
 190   struct partial_symtab **dependencies;
 191
 192   int number_of_dependencies;
 193
 194   /* Global symbol list.  This list will be sorted after readin to
 195      improve access.  Binary search will be the usual method of
 196      finding a symbol within it.  globals_offset is an integer offset
 197      within global_psymbols[].  */
 198
 199   int globals_offset;
 200   int n_global_syms;
 201
 202   /* Static symbol list.  This list will *not* be sorted after readin;
 203      to find a symbol in it, exhaustive search must be used.  This is
 204      reasonable because searches through this list will eventually
 205      lead to either the read in of a files symbols for real (assumed
 206      to take a *lot* of time; check) or an error (and we don't care
 207      how long errors take).  This is an offset and size within
 208      static_psymbols[].  */
 209
 210   int statics_offset;
 211   int n_static_syms;
 212
 213   /* Non-zero if the symtab corresponding to this psymtab has been
 214      readin.  This is located here so that this structure packs better
 215      on 64-bit systems.  */
 216
 217   unsigned char readin;
 218
 219   /* True iff objfile->psymtabs_addrmap is properly populated for this
 220      partial_symtab.  For discontiguous overlapping psymtabs is the only usable
 221      info in PSYMTABS_ADDRMAP.  */
 222
 223   unsigned char psymtabs_addrmap_supported;
 224
 225   /* True if the name of this partial symtab is not a source file name.  */
 226
 227   unsigned char anonymous;
 228
 229   /* A flag that is temporarily used when searching psymtabs.  */
 230
 231   ENUM_BITFIELD (psymtab_search_status) searched_flag : 2;
 232
 233   /* Pointer to compunit eventually allocated for this source file, 0 if
 234      !readin or if we haven't looked for the symtab after it was readin.  */
 235
 236   struct compunit_symtab *compunit_symtab;
 237
 238   /* Pointer to function which will read in the symtab corresponding to
 239      this psymtab.  */
 240
 241   void (*read_symtab) (struct partial_symtab *, struct objfile *);
 242
 243   /* Information that lets read_symtab() locate the part of the symbol table
 244      that this psymtab corresponds to.  This information is private to the
 245      format-dependent symbol reading routines.  For further detail examine
 246      the various symbol reading modules.  */
 247
 248   void *read_symtab_private;
 249 };
 250
 251 /* Add any kind of symbol to a partial_symbol vector.  */
 252
 253 extern void add_psymbol_to_list (const char *, int,
 254                                  int, domain_enum,
 255                                  enum address_class,
 256                                  std::vector<partial_symbol *> *,
 257                                  CORE_ADDR,
 258                                  enum language, struct objfile *);
 259
 260 extern void init_psymbol_list (struct objfile *, int);
 261
 262 extern struct partial_symtab *start_psymtab_common (struct objfile *,
 263                                                     const char *, CORE_ADDR,
 264                                                     std::vector<partial_symbol *> &,
 265                                                     std::vector<partial_symbol *> &);
 266
 267 extern void end_psymtab_common (struct objfile *, struct partial_symtab *);
 268
 269 extern struct partial_symtab *allocate_psymtab (const char *,
 270                                                 struct objfile *)
 271   ATTRIBUTE_NONNULL (1);
 272
 273 extern void discard_psymtab (struct objfile *, struct partial_symtab *);
 274
 275 /* Used when recording partial symbol tables.  On destruction,
 276    discards any partial symbol tables that have been built.  However,
 277    the tables can be kept by calling the "keep" method.  */
 278 class psymtab_discarder
 279 {
 280  public:
 281
 282   psymtab_discarder (struct objfile *objfile)
 283     : m_objfile (objfile),
 284       m_psymtab (objfile->psymtabs)
 285   {
 286   }
 287
 288   ~psymtab_discarder ()
 289   {
 290     if (m_objfile != NULL)
 291       while (m_objfile->psymtabs != m_psymtab)
 292         discard_psymtab (m_objfile, m_objfile->psymtabs);
 293   }
 294
 295   /* Keep any partial symbol tables that were built.  */
 296   void keep ()
 297   {
 298     m_objfile = NULL;
 299   }
 300
 301  private:
 302
 303   /* The objfile.  If NULL this serves as a sentinel to indicate that
 304      the psymtabs should be kept.  */
 305   struct objfile *m_objfile;
 306   /* How far back to free.  */
 307   struct partial_symtab *m_psymtab;
 308 };
 309
 310 /* Traverse all psymtabs in one objfile.  */
 311
 312 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
 313     for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
 314
 315 #endif /* PSYMPRIV_H */