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 struct type;
  24
  25 /* Several lookup functions return both a minimal symbol and the
  26    objfile in which it is found.  This structure is used in these
  27    cases.  */
  28
  29 struct bound_minimal_symbol
  30 {
  31   /* The minimal symbol that was found, or NULL if no minimal symbol
  32      was found.  */
  33
  34   struct minimal_symbol *minsym;
  35
  36   /* If MINSYM is not NULL, then this is the objfile in which the
  37      symbol is defined.  */
  38
  39   struct objfile *objfile;
  40 };
  41
  42 /* This header declares most of the API for dealing with minimal
  43    symbols and minimal symbol tables.  A few things are declared
  44    elsewhere; see below.
  45
  46    A minimal symbol is a symbol for which there is no direct debug
  47    information.  For example, for an ELF binary, minimal symbols are
  48    created from the ELF symbol table.
  49
  50    For the definition of the minimal symbol structure, see struct
  51    minimal_symbol in symtab.h.
  52
  53    Minimal symbols are stored in tables attached to an objfile; see
  54    objfiles.h for details.  Code should generally treat these tables
  55    as opaque and use functions provided by minsyms.c to inspect them.
  56 */
  57
  58 struct msym_bunch;
  59
  60 /* An RAII-based object that is used to record minimal symbols while
  61    they are being read.  */
  62 class minimal_symbol_reader
  63 {
  64  public:
  65
  66   /* Prepare to start collecting minimal symbols.  This should be
  67      called by a symbol reader to initialize the minimal symbol
  68      module.  */
  69
  70   explicit minimal_symbol_reader (struct objfile *);
  71
  72   ~minimal_symbol_reader ();
  73
  74   /* Install the minimal symbols that have been collected into the
  75      given objfile.  */
  76
  77   void install ();
  78
  79   /* Record a new minimal symbol.  This is the "full" entry point;
  80      simpler convenience entry points are also provided below.
  81
  82      This returns a new minimal symbol.  It is ok to modify the returned
  83      minimal symbol (though generally not necessary).  It is not ok,
  84      though, to stash the pointer anywhere; as minimal symbols may be
  85      moved after creation.  The memory for the returned minimal symbol
  86      is still owned by the minsyms.c code, and should not be freed.
  87
  88      Arguments are:
  89
  90      NAME - the symbol's name
  91      NAME_LEN - the length of the name
  92      COPY_NAME - if true, the minsym code must make a copy of NAME.  If
  93      false, then NAME must be NUL-terminated, and must have a lifetime
  94      that is at least as long as OBJFILE's lifetime.
  95      ADDRESS - the address of the symbol
  96      MS_TYPE - the type of the symbol
  97      SECTION - the symbol's section
  98   */
  99
 100   struct minimal_symbol *record_full (const char *name,
 101                                       int name_len,
 102                                       bool copy_name,
 103                                       CORE_ADDR address,
 104                                       enum minimal_symbol_type ms_type,
 105                                       int section);
 106
 107   /* Like record_full, but:
 108      - uses strlen to compute NAME_LEN,
 109      - passes COPY_NAME = true,
 110      - and passes a default SECTION, depending on the type
 111
 112      This variant does not return the new symbol.  */
 113
 114   void record (const char *name, CORE_ADDR address,
 115                enum minimal_symbol_type ms_type);
 116
 117   /* Like record_full, but:
 118      - uses strlen to compute NAME_LEN,
 119      - passes COPY_NAME = true.  */
 120
 121   struct minimal_symbol *record_with_info (const char *name,
 122                                            CORE_ADDR address,
 123                                            enum minimal_symbol_type ms_type,
 124                                            int section)
 125   {
 126     return record_full (name, strlen (name), true, address, ms_type, section);
 127   }
 128
 129  private:
 130
 131   /* No need for these.  They are intentionally not defined anywhere.  */
 132   minimal_symbol_reader &operator=
 133     (const minimal_symbol_reader &);
 134   minimal_symbol_reader (const minimal_symbol_reader &);
 135
 136   struct objfile *m_objfile;
 137
 138   /* Bunch currently being filled up.
 139      The next field points to chain of filled bunches.  */
 140
 141   struct msym_bunch *m_msym_bunch;
 142
 143   /* Number of slots filled in current bunch.  */
 144
 145   int m_msym_bunch_index;
 146
 147   /* Total number of minimal symbols recorded so far for the
 148      objfile.  */
 149
 150   int m_msym_count;
 151 };
 152
 153 /* Create the terminating entry of OBJFILE's minimal symbol table.
 154    If OBJFILE->msymbols is zero, allocate a single entry from
 155    OBJFILE->objfile_obstack; otherwise, just initialize
 156    OBJFILE->msymbols[OBJFILE->minimal_symbol_count].  */
 157
 158 void terminate_minimal_symbol_table (struct objfile *objfile);
 159
 160 \f
 161
 162 /* Return whether MSYMBOL is a function/method.  */
 163
 164 bool msymbol_is_text (minimal_symbol *msymbol);
 165
 166 /* Compute a hash code for the string argument.  */
 167
 168 unsigned int msymbol_hash (const char *);
 169
 170 /* Like msymbol_hash, but compute a hash code that is compatible with
 171    strcmp_iw.  */
 172
 173 unsigned int msymbol_hash_iw (const char *);
 174
 175 /* Compute the next hash value from previous HASH and the character C.  This
 176    is only a GDB in-memory computed value with no external files compatibility
 177    requirements.  */
 178
 179 #define SYMBOL_HASH_NEXT(hash, c)                       \
 180   ((hash) * 67 + tolower ((unsigned char) (c)) - 113)
 181
 182 \f
 183
 184 /* Look through all the current minimal symbol tables and find the
 185    first minimal symbol that matches NAME.  If OBJF is non-NULL, limit
 186    the search to that objfile.  If SFILE is non-NULL, the only
 187    file-scope symbols considered will be from that source file (global
 188    symbols are still preferred).  Returns a bound minimal symbol that
 189    matches, or an empty bound minimal symbol if no match is found.  */
 190
 191 struct bound_minimal_symbol lookup_minimal_symbol (const char *,
 192                                                    const char *,
 193                                                    struct objfile *);
 194
 195 /* Like lookup_minimal_symbol, but searches all files and
 196    objfiles.  */
 197
 198 struct bound_minimal_symbol lookup_bound_minimal_symbol (const char *);
 199
 200 /* Find the minimal symbol named NAME, and return both the minsym
 201    struct and its objfile.  This only checks the linkage name.  */
 202
 203 struct bound_minimal_symbol lookup_minimal_symbol_and_objfile (const char *);
 204
 205 /* Look through all the current minimal symbol tables and find the
 206    first minimal symbol that matches NAME and has text type.  If OBJF
 207    is non-NULL, limit the search to that objfile.  Returns a bound
 208    minimal symbol that matches, or an "empty" bound minimal symbol
 209    otherwise.
 210
 211    This function only searches the mangled (linkage) names.  */
 212
 213 struct bound_minimal_symbol lookup_minimal_symbol_text (const char *,
 214                                                         struct objfile *);
 215
 216 /* Look through all the current minimal symbol tables and find the
 217    first minimal symbol that matches NAME and is a solib trampoline.
 218    If OBJF is non-NULL, limit the search to that objfile.  Returns a
 219    pointer to the minimal symbol that matches, or NULL if no match is
 220    found.
 221
 222    This function only searches the mangled (linkage) names.  */
 223
 224 struct bound_minimal_symbol lookup_minimal_symbol_solib_trampoline
 225     (const char *,
 226      struct objfile *);
 227
 228 /* Look through all the current minimal symbol tables and find the
 229    first minimal symbol that matches NAME and PC.  If OBJF is non-NULL,
 230    limit the search to that objfile.  Returns a pointer to the minimal
 231    symbol that matches, or NULL if no match is found.  */
 232
 233 struct minimal_symbol *lookup_minimal_symbol_by_pc_name
 234     (CORE_ADDR, const char *, struct objfile *);
 235
 236 /* Search through the minimal symbol table for each objfile and find
 237    the symbol whose address is the largest address that is still less
 238    than or equal to PC, and which matches SECTION.
 239
 240    If SECTION is NULL, this uses the result of find_pc_section
 241    instead.
 242
 243    The result has a non-NULL 'minsym' member if such a symbol is
 244    found, or NULL if PC is not in a suitable range.  */
 245
 246 struct bound_minimal_symbol lookup_minimal_symbol_by_pc_section
 247     (CORE_ADDR,
 248      struct obj_section *);
 249
 250 /* Backward compatibility: search through the minimal symbol table
 251    for a matching PC (no section given).
 252
 253    This is a wrapper that calls lookup_minimal_symbol_by_pc_section
 254    with a NULL section argument.  */
 255
 256 struct bound_minimal_symbol lookup_minimal_symbol_by_pc (CORE_ADDR);
 257
 258 /* Iterate over all the minimal symbols in the objfile OBJF which
 259    match NAME.  Both the ordinary and demangled names of each symbol
 260    are considered.  The caller is responsible for canonicalizing NAME,
 261    should that need to be done.
 262
 263    For each matching symbol, CALLBACK is called with the symbol and
 264    USER_DATA as arguments.  */
 265
 266 void iterate_over_minimal_symbols (struct objfile *objf,
 267                                    const lookup_name_info &name,
 268                                    void (*callback) (struct minimal_symbol *,
 269                                                      void *),
 270                                    void *user_data);
 271
 272 /* Compute the upper bound of MINSYM.  The upper bound is the last
 273    address thought to be part of the symbol.  If the symbol has a
 274    size, it is used.  Otherwise use the lesser of the next minimal
 275    symbol in the same section, or the end of the section, as the end
 276    of the function.  */
 277
 278 CORE_ADDR minimal_symbol_upper_bound (struct bound_minimal_symbol minsym);
 279
 280 /* Return the type of MSYMBOL, a minimal symbol of OBJFILE.  If
 281    ADDRESS_P is not NULL, set it to the MSYMBOL's resolved
 282    address.  */
 283
 284 type *find_minsym_type_and_address (minimal_symbol *msymbol, objfile *objf,
 285                                     CORE_ADDR *address_p);
 286
 287 #endif /* MINSYMS_H */