gdb/d-namespace.c

   1 /* Helper routines for D support in GDB.
   2
   3    Copyright (C) 2014-2022 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 #include "defs.h"
  21 #include "symtab.h"
  22 #include "block.h"
  23 #include "language.h"
  24 #include "namespace.h"
  25 #include "d-lang.h"
  26 #include "gdbsupport/gdb_obstack.h"
  27 #include "gdbarch.h"
  28
  29 /* This returns the length of first component of NAME, which should be
  30    the demangled name of a D variable/function/method/etc.
  31    Specifically, it returns the index of the first dot forming the
  32    boundary of the first component: so, given 'A.foo' or 'A.B.foo'
  33    it returns the 1, and given 'foo', it returns 0.  */
  34
  35 /* The character in NAME indexed by the return value is guaranteed to
  36    always be either '.' or '\0'.  */
  37
  38 static unsigned int
  39 d_find_first_component (const char *name)
  40 {
  41   unsigned int index = 0;
  42
  43   for (;; ++index)
  44     {
  45       if (name[index] == '.' || name[index] == '\0')
  46         return index;
  47     }
  48 }
  49
  50 /* If NAME is the fully-qualified name of a D function/variable/method,
  51    this returns the length of its entire prefix: all of the modules and
  52    classes that make up its name.  Given 'A.foo', it returns 1, given
  53    'A.B.foo', it returns 4, given 'foo', it returns 0.  */
  54
  55 static unsigned int
  56 d_entire_prefix_len (const char *name)
  57 {
  58   unsigned int current_len = d_find_first_component (name);
  59   unsigned int previous_len = 0;
  60
  61   while (name[current_len] != '\0')
  62     {
  63       gdb_assert (name[current_len] == '.');
  64       previous_len = current_len;
  65       /* Skip the '.'  */
  66       current_len++;
  67       current_len += d_find_first_component (name + current_len);
  68     }
  69
  70   return previous_len;
  71 }
  72
  73 /* Look up NAME in BLOCK's static block and in global blocks.
  74    If SEARCH is non-zero, search through base classes for a matching
  75    symbol.  Other arguments are as in d_lookup_symbol_nonlocal.  */
  76
  77 static struct block_symbol
  78 d_lookup_symbol (const struct language_defn *langdef,
  79                  const char *name, const struct block *block,
  80                  const domain_enum domain, int search)
  81 {
  82   struct block_symbol sym;
  83
  84   sym = lookup_symbol_in_static_block (name, block, domain);
  85   if (sym.symbol != NULL)
  86     return sym;
  87
  88   /* If we didn't find a definition for a builtin type in the static block,
  89      such as "ucent" which is a specialist type, search for it now.  */
  90   if (langdef != NULL && domain == VAR_DOMAIN)
  91     {
  92       struct gdbarch *gdbarch;
  93
  94       if (block == NULL)
  95         gdbarch = target_gdbarch ();
  96       else
  97         gdbarch = block_gdbarch (block);
  98       sym.symbol
  99         = language_lookup_primitive_type_as_symbol (langdef, gdbarch, name);
 100       sym.block = NULL;
 101       if (sym.symbol != NULL)
 102         return sym;
 103     }
 104
 105   sym = lookup_global_symbol (name, block, domain);
 106
 107   if (sym.symbol != NULL)
 108     return sym;
 109
 110   if (search)
 111     {
 112       std::string classname, nested;
 113       unsigned int prefix_len;
 114       struct block_symbol class_sym;
 115
 116       /* A simple lookup failed.  Check if the symbol was defined in
 117          a base class.  */
 118
 119       /* Find the name of the class and the name of the method,
 120          variable, etc.  */
 121       prefix_len = d_entire_prefix_len (name);
 122
 123       /* If no prefix was found, search "this".  */
 124       if (prefix_len == 0)
 125         {
 126           struct type *type;
 127           struct block_symbol lang_this;
 128
 129           lang_this = lookup_language_this (language_def (language_d), block);
 130           if (lang_this.symbol == NULL)
 131             return {};
 132
 133           type = check_typedef (TYPE_TARGET_TYPE (lang_this.symbol->type ()));
 134           classname = type->name ();
 135           nested = name;
 136         }
 137       else
 138         {
 139           /* The class name is everything up to and including PREFIX_LEN.  */
 140           classname = std::string (name, prefix_len);
 141
 142           /* The rest of the name is everything else past the initial scope
 143              operator.  */
 144           nested = std::string (name + prefix_len + 1);
 145         }
 146
 147       /* Lookup a class named CLASSNAME.  If none is found, there is nothing
 148          more that can be done.  */
 149       class_sym = lookup_global_symbol (classname.c_str (), block, domain);
 150       if (class_sym.symbol == NULL)
 151         return {};
 152
 153       /* Look for a symbol named NESTED in this class.  */
 154       sym = d_lookup_nested_symbol (class_sym.symbol->type (),
 155                                     nested.c_str (), block);
 156     }
 157
 158   return sym;
 159 }
 160
 161 /* Look up NAME in the D module MODULE.  Other arguments are as in
 162    d_lookup_symbol_nonlocal.  If SEARCH is non-zero, search through
 163    base classes for a matching symbol.  */
 164
 165 static struct block_symbol
 166 d_lookup_symbol_in_module (const char *module, const char *name,
 167                            const struct block *block,
 168                            const domain_enum domain, int search)
 169 {
 170   char *concatenated_name = NULL;
 171
 172   if (module[0] != '\0')
 173     {
 174       concatenated_name
 175         = (char *) alloca (strlen (module) + strlen (name) + 2);
 176       strcpy (concatenated_name, module);
 177       strcat (concatenated_name, ".");
 178       strcat (concatenated_name, name);
 179       name = concatenated_name;
 180     }
 181
 182   return d_lookup_symbol (NULL, name, block, domain, search);
 183 }
 184
 185 /* Lookup NAME at module scope.  SCOPE is the module that the current
 186    function is defined within; only consider modules whose length is at
 187    least SCOPE_LEN.  Other arguments are as in d_lookup_symbol_nonlocal.
 188
 189    For example, if we're within a function A.B.f and looking for a
 190    symbol x, this will get called with NAME = "x", SCOPE = "A.B", and
 191    SCOPE_LEN = 0.  It then calls itself with NAME and SCOPE the same,
 192    but with SCOPE_LEN = 1.  And then it calls itself with NAME and
 193    SCOPE the same, but with SCOPE_LEN = 4.  This third call looks for
 194    "A.B.x"; if it doesn't find it, then the second call looks for "A.x",
 195    and if that call fails, then the first call looks for "x".  */
 196
 197 static struct block_symbol
 198 lookup_module_scope (const struct language_defn *langdef,
 199                      const char *name, const struct block *block,
 200                      const domain_enum domain, const char *scope,
 201                      int scope_len)
 202 {
 203   char *module;
 204
 205   if (scope[scope_len] != '\0')
 206     {
 207       /* Recursively search for names in child modules first.  */
 208
 209       struct block_symbol sym;
 210       int new_scope_len = scope_len;
 211
 212       /* If the current scope is followed by ".", skip past that.  */
 213       if (new_scope_len != 0)
 214         {
 215           gdb_assert (scope[new_scope_len] == '.');
 216           new_scope_len++;
 217         }
 218       new_scope_len += d_find_first_component (scope + new_scope_len);
 219       sym = lookup_module_scope (langdef, name, block, domain,
 220                                  scope, new_scope_len);
 221       if (sym.symbol != NULL)
 222         return sym;
 223     }
 224
 225   /* Okay, we didn't find a match in our children, so look for the
 226      name in the current module.
 227
 228      If we there is no scope and we know we have a bare symbol, then short
 229      circuit everything and call d_lookup_symbol directly.
 230      This isn't an optimization, rather it allows us to pass LANGDEF which
 231      is needed for primitive type lookup.  */
 232
 233   if (scope_len == 0 && strchr (name, '.') == NULL)
 234     return d_lookup_symbol (langdef, name, block, domain, 1);
 235
 236   module = (char *) alloca (scope_len + 1);
 237   strncpy (module, scope, scope_len);
 238   module[scope_len] = '\0';
 239   return d_lookup_symbol_in_module (module, name,
 240                                     block, domain, 1);
 241 }
 242
 243 /* Search through the base classes of PARENT_TYPE for a symbol named
 244    NAME in block BLOCK.  */
 245
 246 static struct block_symbol
 247 find_symbol_in_baseclass (struct type *parent_type, const char *name,
 248                           const struct block *block)
 249 {
 250   struct block_symbol sym = {};
 251   int i;
 252
 253   for (i = 0; i < TYPE_N_BASECLASSES (parent_type); ++i)
 254     {
 255       struct type *base_type = TYPE_BASECLASS (parent_type, i);
 256       const char *base_name = TYPE_BASECLASS_NAME (parent_type, i);
 257
 258       if (base_name == NULL)
 259         continue;
 260
 261       /* Search this particular base class.  */
 262       sym = d_lookup_symbol_in_module (base_name, name, block,
 263                                        VAR_DOMAIN, 0);
 264       if (sym.symbol != NULL)
 265         break;
 266
 267       /* Now search all static file-level symbols.  We have to do this for
 268          things like typedefs in the class.  First search in this symtab,
 269          what we want is possibly there.  */
 270       std::string concatenated_name = std::string (base_name) + "." + name;
 271       sym = lookup_symbol_in_static_block (concatenated_name.c_str (), block,
 272                                            VAR_DOMAIN);
 273       if (sym.symbol != NULL)
 274         break;
 275
 276       /* Nope.  We now have to search all static blocks in all objfiles,
 277          even if block != NULL, because there's no guarantees as to which
 278          symtab the symbol we want is in.  */
 279       sym = lookup_static_symbol (concatenated_name.c_str (), VAR_DOMAIN);
 280       if (sym.symbol != NULL)
 281         break;
 282
 283       /* If this class has base classes, search them next.  */
 284       base_type = check_typedef (base_type);
 285       if (TYPE_N_BASECLASSES (base_type) > 0)
 286         {
 287           sym = find_symbol_in_baseclass (base_type, name, block);
 288           if (sym.symbol != NULL)
 289             break;
 290         }
 291     }
 292
 293   return sym;
 294 }
 295
 296 /* Look up a symbol named NESTED_NAME that is nested inside the D
 297    class or module given by PARENT_TYPE, from within the context
 298    given by BLOCK.  Return NULL if there is no such nested type.  */
 299
 300 struct block_symbol
 301 d_lookup_nested_symbol (struct type *parent_type,
 302                         const char *nested_name,
 303                         const struct block *block)
 304 {
 305   /* type_name_no_tag_required provides better error reporting using the
 306      original type.  */
 307   struct type *saved_parent_type = parent_type;
 308
 309   parent_type = check_typedef (parent_type);
 310
 311   switch (parent_type->code ())
 312     {
 313     case TYPE_CODE_STRUCT:
 314     case TYPE_CODE_UNION:
 315     case TYPE_CODE_ENUM:
 316     case TYPE_CODE_MODULE:
 317         {
 318           int size;
 319           const char *parent_name = type_name_or_error (saved_parent_type);
 320           struct block_symbol sym
 321             = d_lookup_symbol_in_module (parent_name, nested_name,
 322                                          block, VAR_DOMAIN, 0);
 323           char *concatenated_name;
 324
 325           if (sym.symbol != NULL)
 326             return sym;
 327
 328           /* Now search all static file-level symbols.  We have to do this
 329              for things like typedefs in the class.  We do not try to
 330              guess any imported module as even the fully specified
 331              module search is already not D compliant and more assumptions
 332              could make it too magic.  */
 333           size = strlen (parent_name) + strlen (nested_name) + 2;
 334           concatenated_name = (char *) alloca (size);
 335
 336           xsnprintf (concatenated_name, size, "%s.%s",
 337                      parent_name, nested_name);
 338
 339           sym = lookup_static_symbol (concatenated_name, VAR_DOMAIN);
 340           if (sym.symbol != NULL)
 341             return sym;
 342
 343           /* If no matching symbols were found, try searching any
 344              base classes.  */
 345           return find_symbol_in_baseclass (parent_type, nested_name, block);
 346         }
 347
 348     case TYPE_CODE_FUNC:
 349     case TYPE_CODE_METHOD:
 350       return {};
 351
 352     default:
 353       gdb_assert_not_reached ("called with non-aggregate type.");
 354     }
 355 }
 356
 357 /* Search for NAME by applying all import statements belonging to
 358    BLOCK which are applicable in SCOPE.  */
 359
 360 static struct block_symbol
 361 d_lookup_symbol_imports (const char *scope, const char *name,
 362                          const struct block *block,
 363                          const domain_enum domain)
 364 {
 365   struct using_direct *current;
 366   struct block_symbol sym;
 367
 368   /* First, try to find the symbol in the given module.  */
 369   sym = d_lookup_symbol_in_module (scope, name, block, domain, 1);
 370
 371   if (sym.symbol != NULL)
 372     return sym;
 373
 374   /* Go through the using directives.  If any of them add new names to
 375      the module we're searching in, see if we can find a match by
 376      applying them.  */
 377
 378   for (current = block_using (block);
 379        current != NULL;
 380        current = current->next)
 381     {
 382       const char **excludep;
 383
 384       /* If the import destination is the current scope then search it.  */
 385       if (!current->searched && strcmp (scope, current->import_dest) == 0)
 386         {
 387           /* Mark this import as searched so that the recursive call
 388              does not search it again.  */
 389           scoped_restore restore_searched
 390             = make_scoped_restore (&current->searched, 1);
 391
 392           /* If there is an import of a single declaration, compare the
 393              imported declaration (after optional renaming by its alias)
 394              with the sought out name.  If there is a match pass
 395              current->import_src as MODULE to direct the search towards
 396              the imported module.  */
 397           if (current->declaration
 398               && strcmp (name, current->alias
 399                          ? current->alias : current->declaration) == 0)
 400             sym = d_lookup_symbol_in_module (current->import_src,
 401                                              current->declaration,
 402                                              block, domain, 1);
 403
 404           /* If a symbol was found or this import statement was an import
 405              declaration, the search of this import is complete.  */
 406           if (sym.symbol != NULL || current->declaration)
 407             {
 408               if (sym.symbol != NULL)
 409                 return sym;
 410
 411               continue;
 412             }
 413
 414           /* Do not follow CURRENT if NAME matches its EXCLUDES.  */
 415           for (excludep = current->excludes; *excludep; excludep++)
 416             if (strcmp (name, *excludep) == 0)
 417               break;
 418           if (*excludep)
 419             continue;
 420
 421           /* If the import statement is creating an alias.  */
 422           if (current->alias != NULL)
 423             {
 424               if (strcmp (name, current->alias) == 0)
 425                 {
 426                   /* If the alias matches the sought name.  Pass
 427                      current->import_src as the NAME to direct the
 428                      search towards the aliased module.  */
 429                   sym = lookup_module_scope (NULL, current->import_src, block,
 430                                              domain, scope, 0);
 431                 }
 432               else
 433                 {
 434                   /* If the alias matches the first component of the
 435                      sought name, pass current->import_src as MODULE
 436                      to direct the search, skipping over the aliased
 437                      component in NAME.  */
 438                   int name_scope = d_find_first_component (name);
 439
 440                   if (name[name_scope] != '\0'
 441                       && strncmp (name, current->alias, name_scope) == 0)
 442                     {
 443                       /* Skip the '.'  */
 444                       name_scope++;
 445                       sym = d_lookup_symbol_in_module (current->import_src,
 446                                                        name + name_scope,
 447                                                        block, domain, 1);
 448                     }
 449                 }
 450             }
 451           else
 452             {
 453               /* If this import statement creates no alias, pass
 454                  current->import_src as MODULE to direct the search
 455                  towards the imported module.  */
 456               sym = d_lookup_symbol_in_module (current->import_src,
 457                                                name, block, domain, 1);
 458             }
 459
 460           if (sym.symbol != NULL)
 461             return sym;
 462         }
 463     }
 464
 465   return {};
 466 }
 467
 468 /* Searches for NAME in the current module, and by applying relevant
 469    import statements belonging to BLOCK and its parents.  SCOPE is the
 470    module scope of the context in which the search is being evaluated.  */
 471
 472 static struct block_symbol
 473 d_lookup_symbol_module (const char *scope, const char *name,
 474                         const struct block *block,
 475                         const domain_enum domain)
 476 {
 477   struct block_symbol sym;
 478
 479   /* First, try to find the symbol in the given module.  */
 480   sym = d_lookup_symbol_in_module (scope, name,
 481                                    block, domain, 1);
 482   if (sym.symbol != NULL)
 483     return sym;
 484
 485   /* Search for name in modules imported to this and parent
 486      blocks.  */
 487   while (block != NULL)
 488     {
 489       sym = d_lookup_symbol_imports (scope, name, block, domain);
 490
 491       if (sym.symbol != NULL)
 492         return sym;
 493
 494       block = block->superblock ();
 495     }
 496
 497   return {};
 498 }
 499
 500 /* The D-specific version of name lookup for static and global names
 501    This makes sure that names get looked for in all modules that are
 502    in scope.  NAME is the natural name of the symbol that we're looking
 503    looking for, BLOCK is the block that we're searching within, DOMAIN
 504    says what kind of symbols we're looking for, and if SYMTAB is non-NULL,
 505    we should store the symtab where we found the symbol in it.  */
 506
 507 struct block_symbol
 508 d_lookup_symbol_nonlocal (const struct language_defn *langdef,
 509                           const char *name,
 510                           const struct block *block,
 511                           const domain_enum domain)
 512 {
 513   struct block_symbol sym;
 514   const char *scope = block_scope (block);
 515
 516   sym = lookup_module_scope (langdef, name, block, domain, scope, 0);
 517   if (sym.symbol != NULL)
 518     return sym;
 519
 520   return d_lookup_symbol_module (scope, name, block, domain);
 521 }
 522