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     text_low_valid = 1;
 118   }
 119
 120   /* Set the hight text address of this partial_symtab.  */
 121   void set_text_high (CORE_ADDR addr)
 122   {
 123     m_text_high = addr;
 124     text_high_valid = 1;
 125   }
 126
 127
 128   /* Chain of all existing partial symtabs.  */
 129
 130   struct partial_symtab *next;
 131
 132   /* Name of the source file which this partial_symtab defines,
 133      or if the psymtab is anonymous then a descriptive name for
 134      debugging purposes, or "".  It must not be NULL.  */
 135
 136   const char *filename;
 137
 138   /* Full path of the source file.  NULL if not known.  */
 139
 140   char *fullname;
 141
 142   /* Directory in which it was compiled, or NULL if we don't know.  */
 143
 144   const char *dirname;
 145
 146   /* Range of text addresses covered by this file; texthigh is the
 147      beginning of the next section.  Do not use if PSYMTABS_ADDRMAP_SUPPORTED
 148      is set.  Do not refer directly to these fields.  Instead, use the
 149      accessors.  The validity of these fields is determined by the
 150      text_low_valid and text_high_valid fields; these are located later
 151      in this structure for better packing.  */
 152
 153   CORE_ADDR m_text_low;
 154   CORE_ADDR m_text_high;
 155
 156   /* If NULL, this is an ordinary partial symbol table.
 157
 158      If non-NULL, this holds a single includer of this partial symbol
 159      table, and this partial symbol table is a shared one.
 160
 161      A shared psymtab is one that is referenced by multiple other
 162      psymtabs, and which conceptually has its contents directly
 163      included in those.
 164
 165      Shared psymtabs have special semantics.  When a search finds a
 166      symbol in a shared table, we instead return one of the non-shared
 167      tables that include this one.
 168
 169      A shared psymtabs can be referred to by other shared ones.
 170
 171      The psymtabs that refer to a shared psymtab will list the shared
 172      psymtab in their 'dependencies' array.
 173
 174      In DWARF terms, a shared psymtab is a DW_TAG_partial_unit; but
 175      of course using a name based on that would be too confusing, so
 176      "shared" was chosen instead.
 177
 178      Only a single user is needed because, when expanding a shared
 179      psymtab, we only need to expand its "canonical" non-shared user.
 180      The choice of which one should be canonical is left to the
 181      debuginfo reader; it can be arbitrary.  */
 182
 183   struct partial_symtab *user;
 184
 185   /* Array of pointers to all of the partial_symtab's which this one
 186      depends on.  Since this array can only be set to previous or
 187      the current (?) psymtab, this dependency tree is guaranteed not
 188      to have any loops.  "depends on" means that symbols must be read
 189      for the dependencies before being read for this psymtab; this is
 190      for type references in stabs, where if foo.c includes foo.h, declarations
 191      in foo.h may use type numbers defined in foo.c.  For other debugging
 192      formats there may be no need to use dependencies.  */
 193
 194   struct partial_symtab **dependencies;
 195
 196   int number_of_dependencies;
 197
 198   /* Global symbol list.  This list will be sorted after readin to
 199      improve access.  Binary search will be the usual method of
 200      finding a symbol within it.  globals_offset is an integer offset
 201      within global_psymbols[].  */
 202
 203   int globals_offset;
 204   int n_global_syms;
 205
 206   /* Static symbol list.  This list will *not* be sorted after readin;
 207      to find a symbol in it, exhaustive search must be used.  This is
 208      reasonable because searches through this list will eventually
 209      lead to either the read in of a files symbols for real (assumed
 210      to take a *lot* of time; check) or an error (and we don't care
 211      how long errors take).  This is an offset and size within
 212      static_psymbols[].  */
 213
 214   int statics_offset;
 215   int n_static_syms;
 216
 217   /* Non-zero if the symtab corresponding to this psymtab has been
 218      readin.  This is located here so that this structure packs better
 219      on 64-bit systems.  */
 220
 221   unsigned char readin;
 222
 223   /* True iff objfile->psymtabs_addrmap is properly populated for this
 224      partial_symtab.  For discontiguous overlapping psymtabs is the only usable
 225      info in PSYMTABS_ADDRMAP.  */
 226
 227   unsigned char psymtabs_addrmap_supported;
 228
 229   /* True if the name of this partial symtab is not a source file name.  */
 230
 231   unsigned char anonymous;
 232
 233   /* A flag that is temporarily used when searching psymtabs.  */
 234
 235   ENUM_BITFIELD (psymtab_search_status) searched_flag : 2;
 236
 237   /* Validity of the m_text_low and m_text_high fields.  */
 238
 239   unsigned int text_low_valid : 1;
 240   unsigned int text_high_valid : 1;
 241
 242   /* Pointer to compunit eventually allocated for this source file, 0 if
 243      !readin or if we haven't looked for the symtab after it was readin.  */
 244
 245   struct compunit_symtab *compunit_symtab;
 246
 247   /* Pointer to function which will read in the symtab corresponding to
 248      this psymtab.  */
 249
 250   void (*read_symtab) (struct partial_symtab *, struct objfile *);
 251
 252   /* Information that lets read_symtab() locate the part of the symbol table
 253      that this psymtab corresponds to.  This information is private to the
 254      format-dependent symbol reading routines.  For further detail examine
 255      the various symbol reading modules.  */
 256
 257   void *read_symtab_private;
 258 };
 259
 260 /* Add any kind of symbol to a partial_symbol vector.  */
 261
 262 extern void add_psymbol_to_list (const char *, int,
 263                                  int, domain_enum,
 264                                  enum address_class,
 265                                  std::vector<partial_symbol *> *,
 266                                  CORE_ADDR,
 267                                  enum language, struct objfile *);
 268
 269 extern void init_psymbol_list (struct objfile *, int);
 270
 271 extern struct partial_symtab *start_psymtab_common (struct objfile *,
 272                                                     const char *, CORE_ADDR,
 273                                                     std::vector<partial_symbol *> &,
 274                                                     std::vector<partial_symbol *> &);
 275
 276 extern void end_psymtab_common (struct objfile *, struct partial_symtab *);
 277
 278 extern struct partial_symtab *allocate_psymtab (const char *,
 279                                                 struct objfile *)
 280   ATTRIBUTE_NONNULL (1);
 281
 282 extern void discard_psymtab (struct objfile *, struct partial_symtab *);
 283
 284 /* Used when recording partial symbol tables.  On destruction,
 285    discards any partial symbol tables that have been built.  However,
 286    the tables can be kept by calling the "keep" method.  */
 287 class psymtab_discarder
 288 {
 289  public:
 290
 291   psymtab_discarder (struct objfile *objfile)
 292     : m_objfile (objfile),
 293       m_psymtab (objfile->psymtabs)
 294   {
 295   }
 296
 297   ~psymtab_discarder ()
 298   {
 299     if (m_objfile != NULL)
 300       while (m_objfile->psymtabs != m_psymtab)
 301         discard_psymtab (m_objfile, m_objfile->psymtabs);
 302   }
 303
 304   /* Keep any partial symbol tables that were built.  */
 305   void keep ()
 306   {
 307     m_objfile = NULL;
 308   }
 309
 310  private:
 311
 312   /* The objfile.  If NULL this serves as a sentinel to indicate that
 313      the psymtabs should be kept.  */
 314   struct objfile *m_objfile;
 315   /* How far back to free.  */
 316   struct partial_symtab *m_psymtab;
 317 };
 318
 319 /* Traverse all psymtabs in one objfile.  */
 320
 321 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
 322     for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
 323
 324 #endif /* PSYMPRIV_H */