gdb/minsyms.h

   1 /* Minimal symbol table definitions for GDB.
   2
   3    Copyright (C) 2011-2016 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 MINSYMS_H
  21 #define MINSYMS_H
  22
  23 /* Several lookup functions return both a minimal symbol and the
  24    objfile in which it is found.  This structure is used in these
  25    cases.  */
  26
  27 struct bound_minimal_symbol
  28 {
  29   /* The minimal symbol that was found, or NULL if no minimal symbol
  30      was found.  */
  31
  32   struct minimal_symbol *minsym;
  33
  34   /* If MINSYM is not NULL, then this is the objfile in which the
  35      symbol is defined.  */
  36
  37   struct objfile *objfile;
  38 };
  39
  40 /* This header declares most of the API for dealing with minimal
  41    symbols and minimal symbol tables.  A few things are declared
  42    elsewhere; see below.
  43
  44    A minimal symbol is a symbol for which there is no direct debug
  45    information.  For example, for an ELF binary, minimal symbols are
  46    created from the ELF symbol table.
  47
  48    For the definition of the minimal symbol structure, see struct
  49    minimal_symbol in symtab.h.
  50
  51    Minimal symbols are stored in tables attached to an objfile; see
  52    objfiles.h for details.  Code should generally treat these tables
  53    as opaque and use functions provided by minsyms.c to inspect them.
  54 */
  55
  56 struct msym_bunch;
  57
  58 /* An RAII-based object that is used to record minimal symbols while
  59    they are being read.  */
  60 class minimal_symbol_reader
  61 {
  62  public:
  63
  64   /* Prepare to start collecting minimal symbols.  This should be
  65      called by a symbol reader to initialize the minimal symbol
  66      module.  */
  67
  68   explicit minimal_symbol_reader (struct objfile *);
  69
  70   ~minimal_symbol_reader ();
  71
  72   /* Install the minimal symbols that have been collected into the
  73      given objfile.  */
  74
  75   void install ();
  76
  77   /* Record a new minimal symbol.  This is the "full" entry point;
  78      simpler convenience entry points are also provided below.
  79
  80      This returns a new minimal symbol.  It is ok to modify the returned
  81      minimal symbol (though generally not necessary).  It is not ok,
  82      though, to stash the pointer anywhere; as minimal symbols may be
  83      moved after creation.  The memory for the returned minimal symbol
  84      is still owned by the minsyms.c code, and should not be freed.
  85
  86      Arguments are:
  87
  88      NAME - the symbol's name
  89      NAME_LEN - the length of the name
  90      COPY_NAME - if true, the minsym code must make a copy of NAME.  If
  91      false, then NAME must be NUL-terminated, and must have a lifetime
  92      that is at least as long as OBJFILE's lifetime.
  93      ADDRESS - the address of the symbol
  94      MS_TYPE - the type of the symbol
  95      SECTION - the symbol's section
  96   */
  97
  98   struct minimal_symbol *record_full (const char *name,
  99                                       int name_len,
 100                                       bool copy_name,
 101                                       CORE_ADDR address,
 102                                       enum minimal_symbol_type ms_type,
 103                                       int section);
 104
 105   /* Like record_full, but:
 106      - uses strlen to compute NAME_LEN,
 107      - passes COPY_NAME = true,
 108      - and passes a default SECTION, depending on the type
 109
 110      This variant does not return the new symbol.  */
 111
 112   void record (const char *name, CORE_ADDR address,
 113                enum minimal_symbol_type ms_type);
 114
 115   /* Like record_full, but:
 116      - uses strlen to compute NAME_LEN,
 117      - passes COPY_NAME = true.  */
 118
 119   struct minimal_symbol *record_with_info (const char *name,
 120                                            CORE_ADDR address,
 121                                            enum minimal_symbol_type ms_type,
 122                                            int section)
 123   {
 124     return record_full (name, strlen (name), true, address, ms_type, section);
 125   }
 126
 127  private:
 128
 129   /* No need for these.  They are intentionally not defined anywhere.  */
 130   minimal_symbol_reader &operator=
 131     (const minimal_symbol_reader &);
 132   minimal_symbol_reader (const minimal_symbol_reader &);
 133
 134   struct objfile *m_objfile;
 135
 136   /* Bunch currently being filled up.
 137      The next field points to chain of filled bunches.  */
 138
 139   struct msym_bunch *m_msym_bunch;
 140
 141   /* Number of slots filled in current bunch.  */
 142
 143   int m_msym_bunch_index;
 144
 145   /* Total number of minimal symbols recorded so far for the
 146      objfile.  */
 147
 148   int m_msym_count;
 149 };
 150
 151 /* Create the terminating entry of OBJFILE's minimal symbol table.
 152    If OBJFILE->msymbols is zero, allocate a single entry from
 153    OBJFILE->objfile_obstack; otherwise, just initialize
 154    OBJFILE->msymbols[OBJFILE->minimal_symbol_count].  */
 155
 156 void terminate_minimal_symbol_table (struct objfile *objfile);
 157
 158 \f
 159
 160 /* Compute a hash code for the string argument.  */
 161
 162 unsigned int msymbol_hash (const char *);
 163
 164 /* Like msymbol_hash, but compute a hash code that is compatible with
 165    strcmp_iw.  */
 166
 167 unsigned int msymbol_hash_iw (const char *);
 168
 169 /* Compute the next hash value from previous HASH and the character C.  This
 170    is only a GDB in-memory computed value with no external files compatibility
 171    requirements.  */
 172
 173 #define SYMBOL_HASH_NEXT(hash, c)                       \
 174   ((hash) * 67 + tolower ((unsigned char) (c)) - 113)
 175
 176 \f
 177
 178 /* Look through all the current minimal symbol tables and find the
 179    first minimal symbol that matches NAME.  If OBJF is non-NULL, limit
 180    the search to that objfile.  If SFILE is non-NULL, the only
 181    file-scope symbols considered will be from that source file (global
 182    symbols are still preferred).  Returns a bound minimal symbol that
 183    matches, or an empty bound minimal symbol if no match is found.  */
 184
 185 struct bound_minimal_symbol lookup_minimal_symbol (const char *,
 186                                                    const char *,
 187                                                    struct objfile *);
 188
 189 /* Like lookup_minimal_symbol, but searches all files and
 190    objfiles.  */
 191
 192 struct bound_minimal_symbol lookup_bound_minimal_symbol (const char *);
 193
 194 /* Find the minimal symbol named NAME, and return both the minsym
 195    struct and its objfile.  This only checks the linkage name.  */
 196
 197 struct bound_minimal_symbol lookup_minimal_symbol_and_objfile (const char *);
 198
 199 /* Look through all the current minimal symbol tables and find the
 200    first minimal symbol that matches NAME and has text type.  If OBJF
 201    is non-NULL, limit the search to that objfile.  Returns a bound
 202    minimal symbol that matches, or an "empty" bound minimal symbol
 203    otherwise.
 204
 205    This function only searches the mangled (linkage) names.  */
 206
 207 struct bound_minimal_symbol lookup_minimal_symbol_text (const char *,
 208                                                         struct objfile *);
 209
 210 /* Look through all the current minimal symbol tables and find the
 211    first minimal symbol that matches NAME and is a solib trampoline.
 212    If OBJF is non-NULL, limit the search to that objfile.  Returns a
 213    pointer to the minimal symbol that matches, or NULL if no match is
 214    found.
 215
 216    This function only searches the mangled (linkage) names.  */
 217
 218 struct bound_minimal_symbol lookup_minimal_symbol_solib_trampoline
 219     (const char *,
 220      struct objfile *);
 221
 222 /* Look through all the current minimal symbol tables and find the
 223    first minimal symbol that matches NAME and PC.  If OBJF is non-NULL,
 224    limit the search to that objfile.  Returns a pointer to the minimal
 225    symbol that matches, or NULL if no match is found.  */
 226
 227 struct minimal_symbol *lookup_minimal_symbol_by_pc_name
 228     (CORE_ADDR, const char *, struct objfile *);
 229
 230 /* Search through the minimal symbol table for each objfile and find
 231    the symbol whose address is the largest address that is still less
 232    than or equal to PC, and which matches SECTION.
 233
 234    If SECTION is NULL, this uses the result of find_pc_section
 235    instead.
 236
 237    The result has a non-NULL 'minsym' member if such a symbol is
 238    found, or NULL if PC is not in a suitable range.  */
 239
 240 struct bound_minimal_symbol lookup_minimal_symbol_by_pc_section
 241     (CORE_ADDR,
 242      struct obj_section *);
 243
 244 /* Backward compatibility: search through the minimal symbol table
 245    for a matching PC (no section given).
 246
 247    This is a wrapper that calls lookup_minimal_symbol_by_pc_section
 248    with a NULL section argument.  */
 249
 250 struct bound_minimal_symbol lookup_minimal_symbol_by_pc (CORE_ADDR);
 251
 252 /* Iterate over all the minimal symbols in the objfile OBJF which
 253    match NAME.  Both the ordinary and demangled names of each symbol
 254    are considered.  The caller is responsible for canonicalizing NAME,
 255    should that need to be done.
 256
 257    For each matching symbol, CALLBACK is called with the symbol and
 258    USER_DATA as arguments.  */
 259
 260 void iterate_over_minimal_symbols (struct objfile *objf,
 261                                    const char *name,
 262                                    void (*callback) (struct minimal_symbol *,
 263                                                      void *),
 264                                    void *user_data);
 265
 266 /* Compute the upper bound of MINSYM.  The upper bound is the last
 267    address thought to be part of the symbol.  If the symbol has a
 268    size, it is used.  Otherwise use the lesser of the next minimal
 269    symbol in the same section, or the end of the section, as the end
 270    of the function.  */
 271
 272 CORE_ADDR minimal_symbol_upper_bound (struct bound_minimal_symbol minsym);
 273
 274 #endif /* MINSYMS_H */