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   /* Chain of all existing partial symtabs.  */
 102
 103   struct partial_symtab *next;
 104
 105   /* Name of the source file which this partial_symtab defines,
 106      or if the psymtab is anonymous then a descriptive name for
 107      debugging purposes, or "".  It must not be NULL.  */
 108
 109   const char *filename;
 110
 111   /* Full path of the source file.  NULL if not known.  */
 112
 113   char *fullname;
 114
 115   /* Directory in which it was compiled, or NULL if we don't know.  */
 116
 117   const char *dirname;
 118
 119   /* Range of text addresses covered by this file; texthigh is the
 120      beginning of the next section.  Do not use if PSYMTABS_ADDRMAP_SUPPORTED
 121      is set.  */
 122
 123   CORE_ADDR textlow;
 124   CORE_ADDR texthigh;
 125
 126   /* If NULL, this is an ordinary partial symbol table.
 127
 128      If non-NULL, this holds a single includer of this partial symbol
 129      table, and this partial symbol table is a shared one.
 130
 131      A shared psymtab is one that is referenced by multiple other
 132      psymtabs, and which conceptually has its contents directly
 133      included in those.
 134
 135      Shared psymtabs have special semantics.  When a search finds a
 136      symbol in a shared table, we instead return one of the non-shared
 137      tables that include this one.
 138
 139      A shared psymtabs can be referred to by other shared ones.
 140
 141      The psymtabs that refer to a shared psymtab will list the shared
 142      psymtab in their 'dependencies' array.
 143
 144      In DWARF terms, a shared psymtab is a DW_TAG_partial_unit; but
 145      of course using a name based on that would be too confusing, so
 146      "shared" was chosen instead.
 147
 148      Only a single user is needed because, when expanding a shared
 149      psymtab, we only need to expand its "canonical" non-shared user.
 150      The choice of which one should be canonical is left to the
 151      debuginfo reader; it can be arbitrary.  */
 152
 153   struct partial_symtab *user;
 154
 155   /* Array of pointers to all of the partial_symtab's which this one
 156      depends on.  Since this array can only be set to previous or
 157      the current (?) psymtab, this dependency tree is guaranteed not
 158      to have any loops.  "depends on" means that symbols must be read
 159      for the dependencies before being read for this psymtab; this is
 160      for type references in stabs, where if foo.c includes foo.h, declarations
 161      in foo.h may use type numbers defined in foo.c.  For other debugging
 162      formats there may be no need to use dependencies.  */
 163
 164   struct partial_symtab **dependencies;
 165
 166   int number_of_dependencies;
 167
 168   /* Global symbol list.  This list will be sorted after readin to
 169      improve access.  Binary search will be the usual method of
 170      finding a symbol within it.  globals_offset is an integer offset
 171      within global_psymbols[].  */
 172
 173   int globals_offset;
 174   int n_global_syms;
 175
 176   /* Static symbol list.  This list will *not* be sorted after readin;
 177      to find a symbol in it, exhaustive search must be used.  This is
 178      reasonable because searches through this list will eventually
 179      lead to either the read in of a files symbols for real (assumed
 180      to take a *lot* of time; check) or an error (and we don't care
 181      how long errors take).  This is an offset and size within
 182      static_psymbols[].  */
 183
 184   int statics_offset;
 185   int n_static_syms;
 186
 187   /* Non-zero if the symtab corresponding to this psymtab has been
 188      readin.  This is located here so that this structure packs better
 189      on 64-bit systems.  */
 190
 191   unsigned char readin;
 192
 193   /* True iff objfile->psymtabs_addrmap is properly populated for this
 194      partial_symtab.  For discontiguous overlapping psymtabs is the only usable
 195      info in PSYMTABS_ADDRMAP.  */
 196
 197   unsigned char psymtabs_addrmap_supported;
 198
 199   /* True if the name of this partial symtab is not a source file name.  */
 200
 201   unsigned char anonymous;
 202
 203   /* A flag that is temporarily used when searching psymtabs.  */
 204
 205   ENUM_BITFIELD (psymtab_search_status) searched_flag : 2;
 206
 207   /* Pointer to compunit eventually allocated for this source file, 0 if
 208      !readin or if we haven't looked for the symtab after it was readin.  */
 209
 210   struct compunit_symtab *compunit_symtab;
 211
 212   /* Pointer to function which will read in the symtab corresponding to
 213      this psymtab.  */
 214
 215   void (*read_symtab) (struct partial_symtab *, struct objfile *);
 216
 217   /* Information that lets read_symtab() locate the part of the symbol table
 218      that this psymtab corresponds to.  This information is private to the
 219      format-dependent symbol reading routines.  For further detail examine
 220      the various symbol reading modules.  */
 221
 222   void *read_symtab_private;
 223 };
 224
 225 /* Add any kind of symbol to a partial_symbol vector.  */
 226
 227 extern void add_psymbol_to_list (const char *, int,
 228                                  int, domain_enum,
 229                                  enum address_class,
 230                                  std::vector<partial_symbol *> *,
 231                                  CORE_ADDR,
 232                                  enum language, struct objfile *);
 233
 234 extern void init_psymbol_list (struct objfile *, int);
 235
 236 extern struct partial_symtab *start_psymtab_common (struct objfile *,
 237                                                     const char *, CORE_ADDR,
 238                                                     std::vector<partial_symbol *> &,
 239                                                     std::vector<partial_symbol *> &);
 240
 241 extern void end_psymtab_common (struct objfile *, struct partial_symtab *);
 242
 243 extern struct partial_symtab *allocate_psymtab (const char *,
 244                                                 struct objfile *)
 245   ATTRIBUTE_NONNULL (1);
 246
 247 extern void discard_psymtab (struct objfile *, struct partial_symtab *);
 248
 249 /* Used when recording partial symbol tables.  On destruction,
 250    discards any partial symbol tables that have been built.  However,
 251    the tables can be kept by calling the "keep" method.  */
 252 class psymtab_discarder
 253 {
 254  public:
 255
 256   psymtab_discarder (struct objfile *objfile)
 257     : m_objfile (objfile),
 258       m_psymtab (objfile->psymtabs)
 259   {
 260   }
 261
 262   ~psymtab_discarder ()
 263   {
 264     if (m_objfile != NULL)
 265       while (m_objfile->psymtabs != m_psymtab)
 266         discard_psymtab (m_objfile, m_objfile->psymtabs);
 267   }
 268
 269   /* Keep any partial symbol tables that were built.  */
 270   void keep ()
 271   {
 272     m_objfile = NULL;
 273   }
 274
 275  private:
 276
 277   /* The objfile.  If NULL this serves as a sentinel to indicate that
 278      the psymtabs should be kept.  */
 279   struct objfile *m_objfile;
 280   /* How far back to free.  */
 281   struct partial_symtab *m_psymtab;
 282 };
 283
 284 /* Traverse all psymtabs in one objfile.  */
 285
 286 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
 287     for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
 288
 289 #endif /* PSYMPRIV_H */