gdb/cp-namespace.c

   1 /* Helper routines for C++ support in GDB.
   2    Copyright 2003 Free Software Foundation, Inc.
   3
   4    Contributed by David Carlton and by Kealia, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "defs.h"
  24 #include "cp-support.h"
  25 #include "gdb_obstack.h"
  26 #include "symtab.h"
  27 #include "symfile.h"
  28 #include "gdb_assert.h"
  29 #include "block.h"
  30
  31 /* When set, the file that we're processing seems to have debugging
  32    info for C++ namespaces, so cp-namespace.c shouldn't try to guess
  33    namespace info itself.  */
  34
  35 unsigned char processing_has_namespace_info;
  36
  37 /* If processing_has_namespace_info is nonzero, this string should
  38    contain the name of the current namespace.  The string is
  39    temporary; copy it if you need it.  */
  40
  41 const char *processing_current_namespace;
  42
  43 /* List of using directives that are active in the current file.  */
  44
  45 static struct using_direct *using_list;
  46
  47 static struct using_direct *cp_add_using (const char *name,
  48                                           unsigned int inner_len,
  49                                           unsigned int outer_len,
  50                                           struct using_direct *next);
  51
  52 static struct using_direct *cp_copy_usings (struct using_direct *using,
  53                                             struct obstack *obstack);
  54
  55 static struct symbol *lookup_namespace_scope (const char *name,
  56                                               const char *linkage_name,
  57                                               const struct block *block,
  58                                               const domain_enum domain,
  59                                               struct symtab **symtab,
  60                                               const char *scope,
  61                                               int scope_len);
  62
  63 static struct symbol *lookup_symbol_file (const char *name,
  64                                           const char *linkage_name,
  65                                           const struct block *block,
  66                                           const domain_enum domain,
  67                                           struct symtab **symtab,
  68                                           int anonymous_namespace);
  69
  70 /* Set up support for dealing with C++ namespace info in the current
  71    symtab.  */
  72
  73 void cp_initialize_namespace ()
  74 {
  75   processing_has_namespace_info = 0;
  76   using_list = NULL;
  77 }
  78
  79 /* Add all the using directives we've gathered to the current symtab.
  80    STATIC_BLOCK should be the symtab's static block; OBSTACK is used
  81    for allocation.  */
  82
  83 void
  84 cp_finalize_namespace (struct block *static_block,
  85                        struct obstack *obstack)
  86 {
  87   if (using_list != NULL)
  88     {
  89       block_set_using (static_block,
  90                        cp_copy_usings (using_list, obstack),
  91                        obstack);
  92       using_list = NULL;
  93     }
  94 }
  95
  96 /* Check to see if SYMBOL refers to an object contained within an
  97    anonymous namespace; if so, add an appropriate using directive.  */
  98
  99 /* Optimize away strlen ("(anonymous namespace)").  */
 100
 101 #define ANONYMOUS_NAMESPACE_LEN 21
 102
 103 void
 104 cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
 105 {
 106   if (!processing_has_namespace_info
 107       && SYMBOL_CPLUS_DEMANGLED_NAME (symbol) != NULL)
 108     {
 109       const char *name = SYMBOL_CPLUS_DEMANGLED_NAME (symbol);
 110       unsigned int previous_component;
 111       unsigned int next_component;
 112       const char *len;
 113
 114       /* Start with a quick-and-dirty check for mention of "(anonymous
 115          namespace)".  */
 116
 117       if (!cp_is_anonymous (name))
 118         return;
 119
 120       previous_component = 0;
 121       next_component = cp_find_first_component (name + previous_component);
 122
 123       while (name[next_component] == ':')
 124         {
 125           if ((next_component - previous_component) == ANONYMOUS_NAMESPACE_LEN
 126               && strncmp (name + previous_component,
 127                           "(anonymous namespace)",
 128                           ANONYMOUS_NAMESPACE_LEN) == 0)
 129             {
 130               /* We've found a component of the name that's an
 131                  anonymous namespace.  So add symbols in it to the
 132                  namespace given by the previous component if there is
 133                  one, or to the global namespace if there isn't.  */
 134               cp_add_using_directive (name,
 135                                       previous_component == 0
 136                                       ? 0 : previous_component - 2,
 137                                       next_component);
 138             }
 139           /* The "+ 2" is for the "::".  */
 140           previous_component = next_component + 2;
 141           next_component = (previous_component
 142                             + cp_find_first_component (name
 143                                                        + previous_component));
 144         }
 145     }
 146 }
 147
 148 /* Add a using directive to using_list.  NAME is the start of a string
 149    that should contain the namespaces we want to add as initial
 150    substrings, OUTER_LENGTH is the end of the outer namespace, and
 151    INNER_LENGTH is the end of the inner namespace.  If the using
 152    directive in question has already been added, don't add it
 153    twice.  */
 154
 155 void
 156 cp_add_using_directive (const char *name, unsigned int outer_length,
 157                         unsigned int inner_length)
 158 {
 159   struct using_direct *current;
 160   struct using_direct *new;
 161
 162   /* Has it already been added?  */
 163
 164   for (current = using_list; current != NULL; current = current->next)
 165     {
 166       if ((strncmp (current->inner, name, inner_length) == 0)
 167           && (strlen (current->inner) == inner_length)
 168           && (strlen (current->outer) == outer_length))
 169         return;
 170     }
 171
 172   using_list = cp_add_using (name, inner_length, outer_length,
 173                              using_list);
 174 }
 175
 176 /* Record the namespace that the function defined by SYMBOL was
 177    defined in, if necessary.  BLOCK is the associated block; use
 178    OBSTACK for allocation.  */
 179
 180 void
 181 cp_set_block_scope (const struct symbol *symbol,
 182                     struct block *block,
 183                     struct obstack *obstack)
 184 {
 185   /* Make sure that the name was originally mangled: if not, there
 186      certainly isn't any namespace information to worry about!  */
 187
 188   if (SYMBOL_CPLUS_DEMANGLED_NAME (symbol) != NULL)
 189     {
 190       if (processing_has_namespace_info)
 191         {
 192           block_set_scope
 193             (block, obsavestring (processing_current_namespace,
 194                                   strlen (processing_current_namespace),
 195                                   obstack),
 196              obstack);
 197         }
 198       else
 199         {
 200           /* Try to figure out the appropriate namespace from the
 201              demangled name.  */
 202
 203           /* FIXME: carlton/2003-04-15: If the function in question is
 204              a method of a class, the name will actually include the
 205              name of the class as well.  This should be harmless, but
 206              is a little unfortunate.  */
 207
 208           const char *name = SYMBOL_CPLUS_DEMANGLED_NAME (symbol);
 209           unsigned int prefix_len = cp_entire_prefix_len (name);
 210
 211           block_set_scope (block,
 212                            obsavestring (name, prefix_len, obstack),
 213                            obstack);
 214         }
 215     }
 216 }
 217
 218 /* Test whether or not NAMESPACE looks like it mentions an anonymous
 219    namespace; return nonzero if so.  */
 220
 221 int
 222 cp_is_anonymous (const char *namespace)
 223 {
 224   return (strstr (namespace, "(anonymous namespace)")
 225           != NULL);
 226 }
 227
 228 /* Create a new struct using direct whose inner namespace is the
 229    initial substring of NAME of leng INNER_LEN and whose outer
 230    namespace is the initial substring of NAME of length OUTER_LENGTH.
 231    Set its next member in the linked list to NEXT; allocate all memory
 232    using xmalloc.  It copies the strings, so NAME can be a temporary
 233    string.  */
 234
 235 static struct using_direct *
 236 cp_add_using (const char *name,
 237               unsigned int inner_len,
 238               unsigned int outer_len,
 239               struct using_direct *next)
 240 {
 241   struct using_direct *retval;
 242
 243   gdb_assert (outer_len < inner_len);
 244
 245   retval = xmalloc (sizeof (struct using_direct));
 246   retval->inner = savestring (name, inner_len);
 247   retval->outer = savestring (name, outer_len);
 248   retval->next = next;
 249
 250   return retval;
 251 }
 252
 253 /* Make a copy of the using directives in the list pointed to by
 254    USING, using OBSTACK to allocate memory.  Free all memory pointed
 255    to by USING via xfree.  */
 256
 257 static struct using_direct *
 258 cp_copy_usings (struct using_direct *using,
 259                 struct obstack *obstack)
 260 {
 261   if (using == NULL)
 262     {
 263       return NULL;
 264     }
 265   else
 266     {
 267       struct using_direct *retval
 268         = obstack_alloc (obstack, sizeof (struct using_direct));
 269       retval->inner = obsavestring (using->inner, strlen (using->inner),
 270                                     obstack);
 271       retval->outer = obsavestring (using->outer, strlen (using->outer),
 272                                     obstack);
 273       retval->next = cp_copy_usings (using->next, obstack);
 274
 275       xfree (using->inner);
 276       xfree (using->outer);
 277       xfree (using);
 278
 279       return retval;
 280     }
 281 }
 282
 283 /* The C++-specific version of name lookup for static and global
 284    names.  This makes sure that names get looked for in all namespaces
 285    that are in scope.  NAME is the natural name of the symbol that
 286    we're looking for, LINKAGE_NAME (which is optional) is its linkage
 287    name, BLOCK is the block that we're searching within, DOMAIN says
 288    what kind of symbols we're looking for, and if SYMTAB is non-NULL,
 289    we should store the symtab where we found the symbol in it.  */
 290
 291 struct symbol *
 292 cp_lookup_symbol_nonlocal (const char *name,
 293                            const char *linkage_name,
 294                            const struct block *block,
 295                            const domain_enum domain,
 296                            struct symtab **symtab)
 297 {
 298   return lookup_namespace_scope (name, linkage_name, block, domain,
 299                                  symtab, block_scope (block), 0);
 300 }
 301
 302 /* Lookup NAME at namespace scope (or, in C terms, in static and
 303    global variables).  SCOPE is the namespace that the current
 304    function is defined within; only consider namespaces whose length
 305    is at least SCOPE_LEN.  Other arguments are as in
 306    cp_lookup_symbol_nonlocal.
 307
 308    For example, if we're within a function A::B::f and looking for a
 309    symbol f, this will get called with NAME = "f", SCOPE = "A::B", and
 310    SCOPE_LEN = 0.  It then calls itself with NAME and SCOPE the same,
 311    but with SCOPE_LEN = 1.  And then it calls itself with NAME and
 312    SCOPE the same, but with SCOPE_LEN = 4.  This third call looks for
 313    "A::B::x"; if it doesn't find it, then the second call looks for
 314    "A::x", and if that call fails, then the first call looks for
 315    "x".  */
 316
 317 static struct symbol *
 318 lookup_namespace_scope (const char *name,
 319                         const char *linkage_name,
 320                         const struct block *block,
 321                         const domain_enum domain,
 322                         struct symtab **symtab,
 323                         const char *scope,
 324                         int scope_len)
 325 {
 326   char *namespace;
 327
 328   if (scope[scope_len] != '\0')
 329     {
 330       /* Recursively search for names in child namespaces first.  */
 331
 332       struct symbol *sym;
 333       int new_scope_len = scope_len;
 334
 335       /* If the current scope is followed by "::", skip past that.  */
 336       if (new_scope_len != 0)
 337         {
 338           gdb_assert (scope[new_scope_len] == ':');
 339           new_scope_len += 2;
 340         }
 341       new_scope_len += cp_find_first_component (scope + new_scope_len);
 342       sym = lookup_namespace_scope (name, linkage_name, block,
 343                                     domain, symtab,
 344                                     scope, new_scope_len);
 345       if (sym != NULL)
 346         return sym;
 347     }
 348
 349   /* Okay, we didn't find a match in our children, so look for the
 350      name in the current namespace.  */
 351
 352   namespace = alloca (scope_len + 1);
 353   strncpy (namespace, scope, scope_len);
 354   namespace[scope_len] = '\0';
 355   return cp_lookup_symbol_namespace (namespace, name, linkage_name,
 356                                      block, domain, symtab);
 357 }
 358
 359 /* Look up NAME in the C++ namespace NAMESPACE, applying the using
 360    directives that are active in BLOCK.  Other arguments are as in
 361    cp_lookup_symbol_nonlocal.  */
 362
 363 struct symbol *
 364 cp_lookup_symbol_namespace (const char *namespace,
 365                             const char *name,
 366                             const char *linkage_name,
 367                             const struct block *block,
 368                             const domain_enum domain,
 369                             struct symtab **symtab)
 370 {
 371   const struct using_direct *current;
 372   struct symbol *sym;
 373
 374   /* First, go through the using directives.  If any of them add new
 375      names to the namespace we're searching in, see if we can find a
 376      match by applying them.  */
 377
 378   for (current = block_using (block);
 379        current != NULL;
 380        current = current->next)
 381     {
 382       if (strcmp (namespace, current->outer) == 0)
 383         {
 384           sym = cp_lookup_symbol_namespace (current->inner,
 385                                             name,
 386                                             linkage_name,
 387                                             block,
 388                                             domain,
 389                                             symtab);
 390           if (sym != NULL)
 391             return sym;
 392         }
 393     }
 394
 395   /* We didn't find anything by applying any of the using directives
 396      that are still applicable; so let's see if we've got a match
 397      using the current namespace.  */
 398
 399   if (namespace[0] == '\0')
 400     {
 401       return lookup_symbol_file (name, linkage_name, block,
 402                                  domain, symtab, 0);
 403     }
 404   else
 405     {
 406       char *concatenated_name
 407         = alloca (strlen (namespace) + 2 + strlen (name) + 1);
 408       strcpy (concatenated_name, namespace);
 409       strcat (concatenated_name, "::");
 410       strcat (concatenated_name, name);
 411       sym = lookup_symbol_file (concatenated_name, linkage_name,
 412                                 block, domain, symtab,
 413                                 cp_is_anonymous (namespace));
 414       return sym;
 415     }
 416 }
 417
 418 /* Look up NAME in BLOCK's static block and in global blocks.  If
 419    ANONYMOUS_NAMESPACE is nonzero, the symbol in question is located
 420    within an anonymous namespace.  Other arguments are as in
 421    cp_lookup_symbol_nonlocal.  */
 422
 423 static struct symbol *
 424 lookup_symbol_file (const char *name,
 425                     const char *linkage_name,
 426                     const struct block *block,
 427                     const domain_enum domain,
 428                     struct symtab **symtab,
 429                     int anonymous_namespace)
 430 {
 431   struct symbol *sym = NULL;
 432
 433   sym = lookup_symbol_static (name, linkage_name, block, domain, symtab);
 434   if (sym != NULL)
 435     return sym;
 436
 437   if (anonymous_namespace)
 438     {
 439       /* Symbols defined in anonymous namespaces have external linkage
 440          but should be treated as local to a single file nonetheless.
 441          So we only search the current file's global block.  */
 442
 443       const struct block *global_block = block_global_block (block);
 444
 445       if (global_block != NULL)
 446         return lookup_symbol_aux_block (name, linkage_name, global_block,
 447                                         domain, symtab);
 448       else
 449         return NULL;
 450     }
 451   else
 452     {
 453       return lookup_symbol_global (name, linkage_name, domain, symtab);
 454     }
 455 }