gdb/minsyms.h

   1 /* Minimal symbol table definitions for GDB.
   2
   3    Copyright (C) 2011-2017 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 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 /* Return whether MSYMBOL is a function/method.  */
 161
 162 bool msymbol_is_text (minimal_symbol *msymbol);
 163
 164 /* Compute a hash code for the string argument.  */
 165
 166 unsigned int msymbol_hash (const char *);
 167
 168 /* Like msymbol_hash, but compute a hash code that is compatible with
 169    strcmp_iw.  */
 170
 171 unsigned int msymbol_hash_iw (const char *);
 172
 173 /* Compute the next hash value from previous HASH and the character C.  This
 174    is only a GDB in-memory computed value with no external files compatibility
 175    requirements.  */
 176
 177 #define SYMBOL_HASH_NEXT(hash, c)                       \
 178   ((hash) * 67 + tolower ((unsigned char) (c)) - 113)
 179
 180 \f
 181
 182 /* Look through all the current minimal symbol tables and find the
 183    first minimal symbol that matches NAME.  If OBJF is non-NULL, limit
 184    the search to that objfile.  If SFILE is non-NULL, the only
 185    file-scope symbols considered will be from that source file (global
 186    symbols are still preferred).  Returns a bound minimal symbol that
 187    matches, or an empty bound minimal symbol if no match is found.  */
 188
 189 struct bound_minimal_symbol lookup_minimal_symbol (const char *,
 190                                                    const char *,
 191                                                    struct objfile *);
 192
 193 /* Like lookup_minimal_symbol, but searches all files and
 194    objfiles.  */
 195
 196 struct bound_minimal_symbol lookup_bound_minimal_symbol (const char *);
 197
 198 /* Find the minimal symbol named NAME, and return both the minsym
 199    struct and its objfile.  This only checks the linkage name.  */
 200
 201 struct bound_minimal_symbol lookup_minimal_symbol_and_objfile (const char *);
 202
 203 /* Look through all the current minimal symbol tables and find the
 204    first minimal symbol that matches NAME and has text type.  If OBJF
 205    is non-NULL, limit the search to that objfile.  Returns a bound
 206    minimal symbol that matches, or an "empty" bound minimal symbol
 207    otherwise.
 208
 209    This function only searches the mangled (linkage) names.  */
 210
 211 struct bound_minimal_symbol lookup_minimal_symbol_text (const char *,
 212                                                         struct objfile *);
 213
 214 /* Look through all the current minimal symbol tables and find the
 215    first minimal symbol that matches NAME and is a solib trampoline.
 216    If OBJF is non-NULL, limit the search to that objfile.  Returns a
 217    pointer to the minimal symbol that matches, or NULL if no match is
 218    found.
 219
 220    This function only searches the mangled (linkage) names.  */
 221
 222 struct bound_minimal_symbol lookup_minimal_symbol_solib_trampoline
 223     (const char *,
 224      struct objfile *);
 225
 226 /* Look through all the current minimal symbol tables and find the
 227    first minimal symbol that matches NAME and PC.  If OBJF is non-NULL,
 228    limit the search to that objfile.  Returns a pointer to the minimal
 229    symbol that matches, or NULL if no match is found.  */
 230
 231 struct minimal_symbol *lookup_minimal_symbol_by_pc_name
 232     (CORE_ADDR, const char *, struct objfile *);
 233
 234 /* Search through the minimal symbol table for each objfile and find
 235    the symbol whose address is the largest address that is still less
 236    than or equal to PC, and which matches SECTION.
 237
 238    If SECTION is NULL, this uses the result of find_pc_section
 239    instead.
 240
 241    The result has a non-NULL 'minsym' member if such a symbol is
 242    found, or NULL if PC is not in a suitable range.  */
 243
 244 struct bound_minimal_symbol lookup_minimal_symbol_by_pc_section
 245     (CORE_ADDR,
 246      struct obj_section *);
 247
 248 /* Backward compatibility: search through the minimal symbol table
 249    for a matching PC (no section given).
 250
 251    This is a wrapper that calls lookup_minimal_symbol_by_pc_section
 252    with a NULL section argument.  */
 253
 254 struct bound_minimal_symbol lookup_minimal_symbol_by_pc (CORE_ADDR);
 255
 256 /* Iterate over all the minimal symbols in the objfile OBJF which
 257    match NAME.  Both the ordinary and demangled names of each symbol
 258    are considered.  The caller is responsible for canonicalizing NAME,
 259    should that need to be done.
 260
 261    For each matching symbol, CALLBACK is called with the symbol and
 262    USER_DATA as arguments.  */
 263
 264 void iterate_over_minimal_symbols (struct objfile *objf,
 265                                    const char *name,
 266                                    void (*callback) (struct minimal_symbol *,
 267                                                      void *),
 268                                    void *user_data);
 269
 270 /* Compute the upper bound of MINSYM.  The upper bound is the last
 271    address thought to be part of the symbol.  If the symbol has a
 272    size, it is used.  Otherwise use the lesser of the next minimal
 273    symbol in the same section, or the end of the section, as the end
 274    of the function.  */
 275
 276 CORE_ADDR minimal_symbol_upper_bound (struct bound_minimal_symbol minsym);
 277
 278 #endif /* MINSYMS_H */