gcc/java/constants.c

   1 /* Handle the constant pool of the Java(TM) Virtual Machine.
   2    Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15 You should have received a copy of the GNU General Public License
  16 along with GNU CC; see the file COPYING.  If not, write to
  17 the Free Software Foundation, 59 Temple Place - Suite 330,
  18 Boston, MA 02111-1307, USA.
  19
  20 Java and all Java-based marks are trademarks or registered trademarks
  21 of Sun Microsystems, Inc. in the United States and other countries.
  22 The Free Software Foundation is independent of Sun Microsystems, Inc.  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "tm.h"
  28 #include "jcf.h"
  29 #include "tree.h"
  30 #include "java-tree.h"
  31 #include "toplev.h"
  32 #include "ggc.h"
  33
  34 static void set_constant_entry PARAMS ((CPool *, int, int, jword));
  35 static int find_class_or_string_constant PARAMS ((CPool *, int, tree));
  36 static int find_name_and_type_constant PARAMS ((CPool *, tree, tree));
  37 static tree get_tag_node PARAMS ((int));
  38 static tree build_constant_data_ref PARAMS ((void));
  39
  40 /* Set the INDEX'th constant in CPOOL to have the given TAG and VALUE. */
  41
  42 static void
  43 set_constant_entry (cpool, index, tag, value)
  44      CPool *cpool;
  45      int index;
  46      int tag;
  47      jword value;
  48 {
  49   if (cpool->data == NULL)
  50     {
  51       cpool->capacity = 100;
  52       cpool->tags = xmalloc (sizeof(uint8) * cpool->capacity);
  53       cpool->data = xmalloc (sizeof(jword) * cpool->capacity);
  54       cpool->count = 1;
  55     }
  56   if (index >= cpool->capacity)
  57     {
  58       cpool->capacity *= 2;
  59       if (index >= cpool->capacity)
  60         cpool->capacity = index + 10;
  61       cpool->tags = xrealloc (cpool->tags, sizeof(uint8) * cpool->capacity);
  62       cpool->data = xrealloc (cpool->data, sizeof(jword) * cpool->capacity);
  63     }
  64   if (index >= cpool->count)
  65     cpool->count = index + 1;
  66   cpool->tags[index] = tag;
  67   cpool->data[index] = value;
  68 }
  69
  70 /* Find (or create) a constant pool entry matching TAG and VALUE. */
  71
  72 int
  73 find_constant1 (cpool, tag, value)
  74      CPool *cpool;
  75      int tag;
  76      jword value;
  77 {
  78   int i;
  79   for (i = cpool->count;  --i > 0; )
  80     {
  81       if (cpool->tags[i] == tag && cpool->data[i] == value)
  82         return i;
  83     }
  84   i = cpool->count == 0 ? 1 : cpool->count;
  85   set_constant_entry (cpool, i, tag, value);
  86   return i;
  87 }
  88
  89 /* Find a double-word constant pool entry matching TAG and WORD1/WORD2. */
  90
  91 int
  92 find_constant2 (cpool, tag, word1, word2)
  93      CPool *cpool;
  94      int tag;
  95      jword word1, word2;
  96 {
  97   int i;
  98   for (i = cpool->count - 1;  --i > 0; )
  99     {
 100       if (cpool->tags[i] == tag
 101           && cpool->data[i] == word1
 102           && cpool->data[i+1] == word2)
 103         return i;
 104     }
 105   i = cpool->count == 0 ? 1 : cpool->count;
 106   set_constant_entry (cpool, i, tag, word1);
 107   set_constant_entry (cpool, i+1, 0, word2);
 108   return i;
 109 }
 110
 111 int
 112 find_utf8_constant (cpool, name)
 113      CPool *cpool;
 114      tree name;
 115 {
 116   if (name == NULL_TREE)
 117     return 0;
 118   return find_constant1 (cpool, CONSTANT_Utf8, (jword) name);
 119 }
 120
 121 static int
 122 find_class_or_string_constant (cpool, tag, name)
 123      CPool *cpool;
 124      int tag;
 125      tree name;
 126 {
 127   int j = find_utf8_constant (cpool, name);
 128   int i;
 129   for (i = cpool->count;  --i > 0; )
 130     {
 131       if (cpool->tags[i] == tag && cpool->data[i] == (jword) j)
 132         return i;
 133     }
 134   i = cpool->count;
 135   set_constant_entry (cpool, i, tag, (jword) j);
 136   return i;
 137 }
 138
 139 int
 140 find_class_constant (cpool, type)
 141      CPool *cpool;
 142      tree type;
 143 {
 144   return find_class_or_string_constant (cpool, CONSTANT_Class,
 145                                         build_internal_class_name (type));
 146 }
 147
 148 /* Allocate a CONSTANT_string entry given a STRING_CST. */
 149
 150 int
 151 find_string_constant (cpool, string)
 152      CPool *cpool;
 153      tree string;
 154 {
 155   string = get_identifier (TREE_STRING_POINTER (string));
 156   return find_class_or_string_constant (cpool, CONSTANT_String, string);
 157
 158 }
 159
 160 /* Find (or create) a CONSTANT_NameAndType matching NAME and TYPE.
 161    Return its index in the constant pool CPOOL. */
 162
 163 static int
 164 find_name_and_type_constant (cpool, name, type)
 165      CPool *cpool;
 166      tree name;
 167      tree type;
 168 {
 169   int name_index = find_utf8_constant (cpool, name);
 170   int type_index = find_utf8_constant (cpool, build_java_signature (type));
 171   return find_constant1 (cpool, CONSTANT_NameAndType,
 172                          (name_index << 16) | type_index);
 173 }
 174
 175 /* Find (or create) a CONSTANT_Fieldref for DECL (a FIELD_DECL or VAR_DECL).
 176    Return its index in the constant pool CPOOL. */
 177
 178 int
 179 find_fieldref_index (cpool, decl)
 180      CPool *cpool;
 181      tree decl;
 182 {
 183   int class_index = find_class_constant (cpool, DECL_CONTEXT (decl));
 184   int name_type_index
 185     = find_name_and_type_constant (cpool, DECL_NAME (decl), TREE_TYPE (decl));
 186   return find_constant1 (cpool, CONSTANT_Fieldref,
 187                          (class_index << 16) | name_type_index);
 188 }
 189
 190 /* Find (or create) a CONSTANT_Methodref for DECL (a FUNCTION_DECL).
 191    Return its index in the constant pool CPOOL. */
 192
 193 int
 194 find_methodref_index (cpool, decl)
 195      CPool *cpool;
 196      tree decl;
 197 {
 198   return find_methodref_with_class_index (cpool, decl, DECL_CONTEXT (decl));
 199 }
 200
 201 int
 202 find_methodref_with_class_index (cpool, decl, mclass)
 203      CPool *cpool;
 204      tree decl;
 205      tree mclass;
 206 {
 207   int class_index = find_class_constant (cpool, mclass);
 208   tree name = DECL_CONSTRUCTOR_P (decl) ? init_identifier_node
 209     : DECL_NAME (decl);
 210   int name_type_index;
 211   name_type_index =
 212       find_name_and_type_constant (cpool, name, TREE_TYPE (decl));
 213   return find_constant1 (cpool,
 214                          CLASS_INTERFACE (TYPE_NAME (mclass))
 215                          ? CONSTANT_InterfaceMethodref
 216                          : CONSTANT_Methodref,
 217                          (class_index << 16) | name_type_index);
 218 }
 219
 220 #define PUT1(X)  (*ptr++ = (X))
 221 #define PUT2(X)  (PUT1((X) >> 8), PUT1(X))
 222 #define PUT4(X)  (PUT2((X) >> 16), PUT2(X))
 223 #define PUTN(P, N)  (memcpy(ptr, (P), (N)), ptr += (N))
 224
 225 /* Give the number of bytes needed in a .class file for the CPOOL
 226    constant pool.  Includes the 2-byte constant_pool_count. */
 227
 228 int
 229 count_constant_pool_bytes (cpool)
 230      CPool *cpool;
 231 {
 232   int size = 2;
 233   int i = 1;
 234   for ( ;  i < cpool->count;  i++)
 235     {
 236       size++;
 237       switch (cpool->tags[i])
 238         {
 239         case CONSTANT_NameAndType:
 240         case CONSTANT_Fieldref:
 241         case CONSTANT_Methodref:
 242         case CONSTANT_InterfaceMethodref:
 243         case CONSTANT_Float:
 244         case CONSTANT_Integer:
 245           size += 4;
 246           break;
 247         case CONSTANT_Class:
 248         case CONSTANT_String:
 249           size += 2;
 250           break;
 251         case CONSTANT_Long:
 252         case CONSTANT_Double:
 253           size += 8;
 254           i++;
 255           break;
 256         case CONSTANT_Utf8:
 257           {
 258             tree t = (tree) cpool->data[i];
 259             int len = IDENTIFIER_LENGTH (t);
 260             size += len + 2;
 261           }
 262           break;
 263         default:
 264           /* Second word of CONSTANT_Long and  CONSTANT_Double. */
 265           size--;
 266         }
 267     }
 268   return size;
 269 }
 270
 271 /* Write the constant pool CPOOL into BUFFER.
 272    The length of BUFFER is LENGTH, which must match the needed length. */
 273
 274 void
 275 write_constant_pool (cpool, buffer, length)
 276      CPool *cpool;
 277      unsigned char *buffer;
 278      int length;
 279 {
 280   unsigned char *ptr = buffer;
 281   int i = 1;
 282   jword *datap = &cpool->data[1];
 283   PUT2 (cpool->count);
 284   for ( ;  i < cpool->count;  i++, datap++)
 285     {
 286       int tag = cpool->tags[i];
 287       PUT1 (tag);
 288       switch (tag)
 289         {
 290         case CONSTANT_NameAndType:
 291         case CONSTANT_Fieldref:
 292         case CONSTANT_Methodref:
 293         case CONSTANT_InterfaceMethodref:
 294         case CONSTANT_Float:
 295         case CONSTANT_Integer:
 296           PUT4 (*datap);
 297           break;
 298         case CONSTANT_Class:
 299         case CONSTANT_String:
 300           PUT2 (*datap);
 301           break;
 302           break;
 303         case CONSTANT_Long:
 304         case CONSTANT_Double:
 305           PUT4(*datap);
 306           i++;
 307           datap++;
 308           PUT4 (*datap);
 309           break;
 310         case CONSTANT_Utf8:
 311           {
 312             tree t = (tree) *datap;
 313             int len = IDENTIFIER_LENGTH (t);
 314             PUT2 (len);
 315             PUTN (IDENTIFIER_POINTER (t), len);
 316           }
 317           break;
 318         }
 319     }
 320
 321   if (ptr != buffer + length)
 322     abort ();
 323 }
 324
 325 CPool *outgoing_cpool;
 326
 327 static GTY(()) tree tag_nodes[13];
 328 static tree
 329 get_tag_node (tag)
 330      int tag;
 331 {
 332   /* A Cache for build_int_2 (CONSTANT_XXX, 0). */
 333
 334   if (tag_nodes[tag] == NULL_TREE)
 335     tag_nodes[tag] = build_int_2 (tag, 0);
 336   return tag_nodes[tag];
 337 }
 338
 339 /* Look for a constant pool entry that matches TAG and NAME.
 340    Creates a new entry if not found.
 341    TAG is one of CONSTANT_Utf8, CONSTANT_String or CONSTANT_Class.
 342    NAME is an IDENTIFIER_NODE naming the Utf8 constant, string, or class.
 343    Returns the index of the entry. */
 344
 345 int
 346 alloc_name_constant (tag, name)
 347      int tag;
 348      tree name;
 349 {
 350   return find_constant1 (outgoing_cpool, tag, (jword) name);
 351 }
 352
 353 /* Build an identifier for the internal name of reference type TYPE. */
 354
 355 tree
 356 build_internal_class_name (type)
 357      tree type;
 358 {
 359   tree name;
 360   if (TYPE_ARRAY_P (type))
 361     name = build_java_signature (type);
 362   else
 363     {
 364       name = TYPE_NAME (type);
 365       if (TREE_CODE (name) != IDENTIFIER_NODE)
 366         name = DECL_NAME (name);
 367       name = identifier_subst (name, "", '.', '/', "");
 368     }
 369   return name;
 370 }
 371
 372 /* Look for a CONSTANT_Class entry for CLAS, creating a new one if needed. */
 373
 374 int
 375 alloc_class_constant (clas)
 376      tree clas;
 377 {
 378   tree class_name = build_internal_class_name (clas);
 379
 380   return alloc_name_constant (CONSTANT_Class,
 381                               (unmangle_classname
 382                                (IDENTIFIER_POINTER(class_name),
 383                                 IDENTIFIER_LENGTH(class_name))));
 384 }
 385
 386 /* Return a reference to the data array of the current constant pool. */
 387
 388 static tree
 389 build_constant_data_ref ()
 390 {
 391   tree cpool_data_ref = NULL_TREE;
 392
 393   if (TYPE_CPOOL_DATA_REF (current_class))
 394     cpool_data_ref = TYPE_CPOOL_DATA_REF (current_class);
 395
 396   if (cpool_data_ref == NULL_TREE)
 397     {
 398       tree decl;
 399       tree decl_name = mangled_classname ("_CD_", current_class);
 400       decl = build_decl (VAR_DECL, decl_name,
 401                          build_array_type (ptr_type_node,
 402                                            one_elt_array_domain_type));
 403       TREE_STATIC (decl) = 1;
 404       make_decl_rtl (decl, NULL);
 405       TYPE_CPOOL_DATA_REF (current_class) = cpool_data_ref
 406         = build1 (ADDR_EXPR, ptr_type_node, decl);
 407     }
 408   return cpool_data_ref;
 409 }
 410
 411 /* Get the pointer value at the INDEX'th element of the constant pool. */
 412
 413 tree
 414 build_ref_from_constant_pool (index)
 415      int index;
 416 {
 417   tree t = build_constant_data_ref ();
 418   index *= int_size_in_bytes (ptr_type_node);
 419   t = fold (build (PLUS_EXPR, ptr_type_node,
 420                               t, build_int_2 (index, 0)));
 421   return build1 (INDIRECT_REF, ptr_type_node, t);
 422 }
 423
 424 /* Build an initializer for the constants field of the current constal pool.
 425    Should only be called at top-level, since it may emit declarations. */
 426
 427 tree
 428 build_constants_constructor ()
 429 {
 430   tree tags_value, data_value;
 431   tree cons;
 432   tree tags_list = NULL_TREE;
 433   tree data_list = NULL_TREE;
 434   int i;
 435   for (i = outgoing_cpool->count;  --i > 0; )
 436     {
 437       tags_list
 438         = tree_cons (NULL_TREE, get_tag_node (outgoing_cpool->tags[i]),
 439                      tags_list);
 440       data_list
 441         = tree_cons (NULL_TREE, build_utf8_ref ((tree)outgoing_cpool->data[i]),
 442                      data_list);
 443     }
 444   if (outgoing_cpool->count > 0)
 445     {
 446       tree index_type;
 447       tree data_decl, tags_decl, tags_type;
 448       tree max_index = build_int_2 (outgoing_cpool->count - 1, 0);
 449       TREE_TYPE (max_index) = sizetype;
 450       index_type = build_index_type (max_index);
 451
 452       /* Add dummy 0'th element of constant pool. */
 453       tags_list = tree_cons (NULL_TREE, get_tag_node (0), tags_list);
 454       data_list = tree_cons (NULL_TREE, null_pointer_node, data_list);
 455
 456       data_decl = TREE_OPERAND (build_constant_data_ref (), 0);
 457       TREE_TYPE (data_decl) = build_array_type (ptr_type_node, index_type),
 458       DECL_INITIAL (data_decl) = build (CONSTRUCTOR, TREE_TYPE (data_decl),
 459                                         NULL_TREE, data_list);
 460       DECL_SIZE (data_decl) = TYPE_SIZE (TREE_TYPE (data_decl));
 461       DECL_SIZE_UNIT (data_decl) = TYPE_SIZE_UNIT (TREE_TYPE (data_decl));
 462       rest_of_decl_compilation (data_decl, (char *) 0, 1, 0);
 463       data_value = build_address_of (data_decl);
 464
 465       tags_type = build_array_type (unsigned_byte_type_node, index_type);
 466       tags_decl = build_decl (VAR_DECL, mangled_classname ("_CT_",
 467                                                            current_class),
 468                               tags_type);
 469       TREE_STATIC (tags_decl) = 1;
 470       DECL_INITIAL (tags_decl) = build (CONSTRUCTOR, tags_type,
 471                                         NULL_TREE, tags_list);
 472       rest_of_decl_compilation (tags_decl, (char*) 0, 1, 0);
 473       tags_value = build_address_of (tags_decl);
 474     }
 475   else
 476     {
 477       data_value = null_pointer_node;
 478       tags_value = null_pointer_node;
 479     }
 480   START_RECORD_CONSTRUCTOR (cons, constants_type_node);
 481   PUSH_FIELD_VALUE (cons, "size", build_int_2 (outgoing_cpool->count, 0));
 482   PUSH_FIELD_VALUE (cons, "tags", tags_value);
 483   PUSH_FIELD_VALUE (cons, "data", data_value);
 484   FINISH_RECORD_CONSTRUCTOR (cons);
 485   return cons;
 486 }
 487
 488 #include "gt-java-constants.h"