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 (struct objfile *);
  68
  69   ~minimal_symbol_reader ();
  70
  71   /* Install the minimal symbols that have been collected into the
  72      given objfile.  */
  73
  74   void install ();
  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   struct objfile *m_objfile;
  84 };
  85
  86 /* Record a new minimal symbol.  This is the "full" entry point;
  87    simpler convenience entry points are also provided below.
  88
  89    This returns a new minimal symbol.  It is ok to modify the returned
  90    minimal symbol (though generally not necessary).  It is not ok,
  91    though, to stash the pointer anywhere; as minimal symbols may be
  92    moved after creation.  The memory for the returned minimal symbol
  93    is still owned by the minsyms.c code, and should not be freed.
  94
  95    Arguments are:
  96
  97    NAME - the symbol's name
  98    NAME_LEN - the length of the name
  99    COPY_NAME - if true, the minsym code must make a copy of NAME.  If
 100    false, then NAME must be NUL-terminated, and must have a lifetime
 101    that is at least as long as OBJFILE's lifetime.
 102    ADDRESS - the address of the symbol
 103    MS_TYPE - the type of the symbol
 104    SECTION - the symbol's section
 105    appropriate obj_section for the minimal symbol.  This can be NULL.
 106    OBJFILE - the objfile associated with the minimal symbol.  */
 107
 108 struct minimal_symbol *prim_record_minimal_symbol_full
 109     (const char *name,
 110      int name_len,
 111      int copy_name,
 112      CORE_ADDR address,
 113      enum minimal_symbol_type ms_type,
 114      int section,
 115      struct objfile *objfile);
 116
 117 /* Like prim_record_minimal_symbol_full, but:
 118    - uses strlen to compute NAME_LEN,
 119    - passes COPY_NAME = 1,
 120    - and passes a default SECTION, depending on the type
 121
 122    This variant does not return the new symbol.  */
 123
 124 void prim_record_minimal_symbol (const char *, CORE_ADDR,
 125                                  enum minimal_symbol_type,
 126                                  struct objfile *);
 127
 128 /* Like prim_record_minimal_symbol_full, but:
 129    - uses strlen to compute NAME_LEN,
 130    - passes COPY_NAME = 1.  */
 131
 132 struct minimal_symbol *prim_record_minimal_symbol_and_info
 133     (const char *,
 134      CORE_ADDR,
 135      enum minimal_symbol_type,
 136      int section,
 137      struct objfile *);
 138
 139 /* Create the terminating entry of OBJFILE's minimal symbol table.
 140    If OBJFILE->msymbols is zero, allocate a single entry from
 141    OBJFILE->objfile_obstack; otherwise, just initialize
 142    OBJFILE->msymbols[OBJFILE->minimal_symbol_count].  */
 143
 144 void terminate_minimal_symbol_table (struct objfile *objfile);
 145
 146 \f
 147
 148 /* Compute a hash code for the string argument.  */
 149
 150 unsigned int msymbol_hash (const char *);
 151
 152 /* Like msymbol_hash, but compute a hash code that is compatible with
 153    strcmp_iw.  */
 154
 155 unsigned int msymbol_hash_iw (const char *);
 156
 157 /* Compute the next hash value from previous HASH and the character C.  This
 158    is only a GDB in-memory computed value with no external files compatibility
 159    requirements.  */
 160
 161 #define SYMBOL_HASH_NEXT(hash, c)                       \
 162   ((hash) * 67 + tolower ((unsigned char) (c)) - 113)
 163
 164 \f
 165
 166 /* Look through all the current minimal symbol tables and find the
 167    first minimal symbol that matches NAME.  If OBJF is non-NULL, limit
 168    the search to that objfile.  If SFILE is non-NULL, the only
 169    file-scope symbols considered will be from that source file (global
 170    symbols are still preferred).  Returns a bound minimal symbol that
 171    matches, or an empty bound minimal symbol if no match is found.  */
 172
 173 struct bound_minimal_symbol lookup_minimal_symbol (const char *,
 174                                                    const char *,
 175                                                    struct objfile *);
 176
 177 /* Like lookup_minimal_symbol, but searches all files and
 178    objfiles.  */
 179
 180 struct bound_minimal_symbol lookup_bound_minimal_symbol (const char *);
 181
 182 /* Find the minimal symbol named NAME, and return both the minsym
 183    struct and its objfile.  This only checks the linkage name.  */
 184
 185 struct bound_minimal_symbol lookup_minimal_symbol_and_objfile (const char *);
 186
 187 /* Look through all the current minimal symbol tables and find the
 188    first minimal symbol that matches NAME and has text type.  If OBJF
 189    is non-NULL, limit the search to that objfile.  Returns a bound
 190    minimal symbol that matches, or an "empty" bound minimal symbol
 191    otherwise.
 192
 193    This function only searches the mangled (linkage) names.  */
 194
 195 struct bound_minimal_symbol lookup_minimal_symbol_text (const char *,
 196                                                         struct objfile *);
 197
 198 /* Look through all the current minimal symbol tables and find the
 199    first minimal symbol that matches NAME and is a solib trampoline.
 200    If OBJF is non-NULL, limit the search to that objfile.  Returns a
 201    pointer to the minimal symbol that matches, or NULL if no match is
 202    found.
 203
 204    This function only searches the mangled (linkage) names.  */
 205
 206 struct bound_minimal_symbol lookup_minimal_symbol_solib_trampoline
 207     (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 PC.  If OBJF is non-NULL,
 212    limit the search to that objfile.  Returns a pointer to the minimal
 213    symbol that matches, or NULL if no match is found.  */
 214
 215 struct minimal_symbol *lookup_minimal_symbol_by_pc_name
 216     (CORE_ADDR, const char *, struct objfile *);
 217
 218 /* Search through the minimal symbol table for each objfile and find
 219    the symbol whose address is the largest address that is still less
 220    than or equal to PC, and which matches SECTION.
 221
 222    If SECTION is NULL, this uses the result of find_pc_section
 223    instead.
 224
 225    The result has a non-NULL 'minsym' member if such a symbol is
 226    found, or NULL if PC is not in a suitable range.  */
 227
 228 struct bound_minimal_symbol lookup_minimal_symbol_by_pc_section
 229     (CORE_ADDR,
 230      struct obj_section *);
 231
 232 /* Backward compatibility: search through the minimal symbol table
 233    for a matching PC (no section given).
 234
 235    This is a wrapper that calls lookup_minimal_symbol_by_pc_section
 236    with a NULL section argument.  */
 237
 238 struct bound_minimal_symbol lookup_minimal_symbol_by_pc (CORE_ADDR);
 239
 240 /* Iterate over all the minimal symbols in the objfile OBJF which
 241    match NAME.  Both the ordinary and demangled names of each symbol
 242    are considered.  The caller is responsible for canonicalizing NAME,
 243    should that need to be done.
 244
 245    For each matching symbol, CALLBACK is called with the symbol and
 246    USER_DATA as arguments.  */
 247
 248 void iterate_over_minimal_symbols (struct objfile *objf,
 249                                    const char *name,
 250                                    void (*callback) (struct minimal_symbol *,
 251                                                      void *),
 252                                    void *user_data);
 253
 254 /* Compute the upper bound of MINSYM.  The upper bound is the last
 255    address thought to be part of the symbol.  If the symbol has a
 256    size, it is used.  Otherwise use the lesser of the next minimal
 257    symbol in the same section, or the end of the section, as the end
 258    of the function.  */
 259
 260 CORE_ADDR minimal_symbol_upper_bound (struct bound_minimal_symbol minsym);
 261
 262 #endif /* MINSYMS_H */