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