gcc/java/typeck.c

   1 /* Handle types for the GNU compiler for the Java(TM) language.
   2    Copyright (C) 1996-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC 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 3, or (at your option)
   9 any later version.
  10
  11 GCC 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
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.
  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 /* Written by Per Bothner <bothner@cygnus.com> */
  25
  26 #include "config.h"
  27 #include "system.h"
  28 #include "coretypes.h"
  29 #include "options.h"
  30 #include "tree.h"
  31 #include "stringpool.h"
  32 #include "diagnostic-core.h"
  33 #include "fold-const.h"
  34 #include "stor-layout.h"
  35 #include "java-tree.h"
  36 #include "convert.h"
  37
  38 static tree convert_ieee_real_to_integer (tree, tree);
  39 static tree parse_signature_type (const unsigned char **,
  40                                   const unsigned char *);
  41 static tree lookup_do (tree, int, tree, tree, tree (*)(tree));
  42 static tree build_null_signature (tree);
  43
  44 tree * type_map;
  45
  46 /* Set the type of the local variable with index SLOT to TYPE. */
  47
  48 void
  49 set_local_type (int slot, tree type)
  50 {
  51   int max_locals = DECL_MAX_LOCALS(current_function_decl);
  52   int nslots = TYPE_IS_WIDE (type) ? 2 : 1;
  53
  54   gcc_assert (slot >= 0 && (slot + nslots - 1 < max_locals));
  55
  56   type_map[slot] = type;
  57   while (--nslots > 0)
  58     type_map[++slot] = void_type_node;
  59 }
  60
  61 /* Convert an IEEE real to an integer type.  The result of such a
  62    conversion when the source operand is a NaN isn't defined by
  63    IEEE754, but by the Java language standard: it must be zero.  Also,
  64    overflows must be clipped to within range.  This conversion
  65    produces something like:
  66
  67       ((expr >= (float)MAX_INT)
  68        ? MAX_INT
  69        : ((expr <= (float)MIN_INT)
  70           ? MIN_INT
  71           : ((expr != expr)
  72              ? 0
  73              : (int)expr))) */
  74
  75 static tree
  76 convert_ieee_real_to_integer (tree type, tree expr)
  77 {
  78   tree result;
  79   expr = save_expr (expr);
  80
  81   result = fold_build3 (COND_EXPR, type,
  82                         fold_build2 (NE_EXPR, boolean_type_node, expr, expr),
  83                          convert (type, integer_zero_node),
  84                          convert_to_integer (type, expr));
  85
  86   result = fold_build3 (COND_EXPR, type,
  87                         fold_build2 (LE_EXPR, boolean_type_node, expr,
  88                                      convert (TREE_TYPE (expr),
  89                                               TYPE_MIN_VALUE (type))),
  90                         TYPE_MIN_VALUE (type),
  91                         result);
  92
  93   result = fold_build3 (COND_EXPR, type,
  94                         fold_build2 (GE_EXPR, boolean_type_node, expr,
  95                                      convert (TREE_TYPE (expr),
  96                                               TYPE_MAX_VALUE (type))),
  97                         TYPE_MAX_VALUE (type),
  98                         result);
  99
 100   return result;
 101 }
 102
 103 /* Create an expression whose value is that of EXPR,
 104    converted to type TYPE.  The TREE_TYPE of the value
 105    is always TYPE.  This function implements all reasonable
 106    conversions; callers should filter out those that are
 107    not permitted by the language being compiled.  */
 108
 109 tree
 110 convert (tree type, tree expr)
 111 {
 112   enum tree_code code = TREE_CODE (type);
 113
 114   if (!expr)
 115    return error_mark_node;
 116
 117   if (type == TREE_TYPE (expr)
 118       || TREE_CODE (expr) == ERROR_MARK)
 119     return expr;
 120   if (TREE_CODE (TREE_TYPE (expr)) == ERROR_MARK)
 121     return error_mark_node;
 122   if (code == VOID_TYPE)
 123     return build1 (CONVERT_EXPR, type, expr);
 124   if (code == BOOLEAN_TYPE)
 125     return fold_convert (type, expr);
 126   if (code == INTEGER_TYPE)
 127     {
 128       if (type == char_type_node || type == promoted_char_type_node)
 129         return fold_convert (type, expr);
 130       if ((really_constant_p (expr) || ! flag_unsafe_math_optimizations)
 131           && TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE)
 132         return convert_ieee_real_to_integer (type, expr);
 133       else
 134         {
 135           /* fold very helpfully sets the overflow status if a type
 136              overflows in a narrowing integer conversion, but Java
 137              doesn't care.  */
 138           tree tmp = fold (convert_to_integer (type, expr));
 139           if (TREE_CODE (tmp) == INTEGER_CST)
 140             TREE_OVERFLOW (tmp) = 0;
 141           return tmp;
 142         }
 143     }
 144   if (code == REAL_TYPE)
 145     return fold (convert_to_real (type, expr));
 146   if (code == POINTER_TYPE)
 147     return fold (convert_to_pointer (type, expr));
 148   error ("conversion to non-scalar type requested");
 149   return error_mark_node;
 150 }
 151
 152
 153 /* Return a data type that has machine mode MODE.
 154    If the mode is an integer,
 155    then UNSIGNEDP selects between signed and unsigned types.  */
 156
 157 tree
 158 java_type_for_mode (machine_mode mode, int unsignedp)
 159 {
 160   if (mode == TYPE_MODE (int_type_node))
 161     return unsignedp ? unsigned_int_type_node : int_type_node;
 162   if (mode == TYPE_MODE (long_type_node))
 163     return unsignedp ? unsigned_long_type_node : long_type_node;
 164   if (mode == TYPE_MODE (short_type_node))
 165     return unsignedp ? unsigned_short_type_node : short_type_node;
 166   if (mode == TYPE_MODE (byte_type_node))
 167     return unsignedp ? unsigned_byte_type_node : byte_type_node;
 168   if (mode == TYPE_MODE (float_type_node))
 169     return float_type_node;
 170   if (mode == TYPE_MODE (double_type_node))
 171     return double_type_node;
 172
 173   return 0;
 174 }
 175
 176 /* Return an integer type with BITS bits of precision,
 177    that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */
 178
 179 tree
 180 java_type_for_size (unsigned bits, int unsignedp)
 181 {
 182   if (bits <= TYPE_PRECISION (byte_type_node))
 183     return unsignedp ? unsigned_byte_type_node : byte_type_node;
 184   if (bits <= TYPE_PRECISION (short_type_node))
 185     return unsignedp ? unsigned_short_type_node : short_type_node;
 186   if (bits <= TYPE_PRECISION (int_type_node))
 187     return unsignedp ? unsigned_int_type_node : int_type_node;
 188   if (bits <= TYPE_PRECISION (long_type_node))
 189     return unsignedp ? unsigned_long_type_node : long_type_node;
 190   return 0;
 191 }
 192
 193 /* Thorough checking of the arrayness of TYPE.  */
 194
 195 int
 196 is_array_type_p (tree type)
 197 {
 198   return TREE_CODE (type) == POINTER_TYPE
 199     && TREE_CODE (TREE_TYPE (type)) == RECORD_TYPE
 200     && TYPE_ARRAY_P (TREE_TYPE (type));
 201 }
 202
 203 /* Return the length of a Java array type.
 204    Return -1 if the length is unknown or non-constant. */
 205
 206 HOST_WIDE_INT
 207 java_array_type_length (tree array_type)
 208 {
 209   tree arfld;
 210   if (TREE_CODE (array_type) == POINTER_TYPE)
 211     array_type = TREE_TYPE (array_type);
 212   arfld = DECL_CHAIN (DECL_CHAIN (TYPE_FIELDS (array_type)));
 213   if (arfld != NULL_TREE)
 214     {
 215       tree index_type = TYPE_DOMAIN (TREE_TYPE (arfld));
 216       if (index_type != NULL_TREE)
 217         {
 218           tree high = TYPE_MAX_VALUE (index_type);
 219           if (TREE_CODE (high) == INTEGER_CST)
 220             return TREE_INT_CST_LOW (high) + 1;
 221         }
 222     }
 223   return -1;
 224 }
 225
 226 /* An array of unknown length will be ultimately given a length of
 227    -2, so that we can still have `length' producing a negative value
 228    even if found. This was part of an optimization aiming at removing
 229    `length' from static arrays. We could restore it, FIXME.  */
 230
 231 tree
 232 build_prim_array_type (tree element_type, HOST_WIDE_INT length)
 233 {
 234   tree index = NULL;
 235
 236   if (length != -1)
 237     {
 238       tree max_index = build_int_cst (sizetype, length - 1);
 239       index = build_index_type (max_index);
 240     }
 241   return build_array_type (element_type, index);
 242 }
 243
 244 /* Return a Java array type with a given ELEMENT_TYPE and LENGTH.
 245    These are hashed (shared) using IDENTIFIER_SIGNATURE_TYPE.
 246    The LENGTH is -1 if the length is unknown. */
 247
 248 tree
 249 build_java_array_type (tree element_type, HOST_WIDE_INT length)
 250 {
 251   tree sig, t, fld, atype, arfld;
 252   char buf[23];
 253   tree elsig = build_java_signature (element_type);
 254   tree el_name = element_type;
 255   buf[0] = '[';
 256   if (length >= 0)
 257     sprintf (buf+1, HOST_WIDE_INT_PRINT_DEC, length);
 258   else
 259     buf[1] = '\0';
 260   sig = ident_subst (IDENTIFIER_POINTER (elsig), IDENTIFIER_LENGTH (elsig),
 261                      buf, 0, 0, "");
 262   t = IDENTIFIER_SIGNATURE_TYPE (sig);
 263   if (t != NULL_TREE)
 264     return TREE_TYPE (t);
 265   t = make_class ();
 266   IDENTIFIER_SIGNATURE_TYPE (sig) = build_pointer_type (t);
 267   TYPE_ARRAY_P (t) = 1;
 268
 269   if (TREE_CODE (el_name) == POINTER_TYPE)
 270     el_name = TREE_TYPE (el_name);
 271   el_name = TYPE_NAME (el_name);
 272   if (TREE_CODE (el_name) == TYPE_DECL)
 273     el_name = DECL_NAME (el_name);
 274   {
 275     char suffix[23];
 276     if (length >= 0)
 277       sprintf (suffix, "[%d]", (int)length);
 278     else
 279       strcpy (suffix, "[]");
 280     TYPE_NAME (t)
 281       = TYPE_STUB_DECL (t)
 282       = build_decl (input_location, TYPE_DECL,
 283                     identifier_subst (el_name, "", '.', '.', suffix),
 284                              t);
 285     TYPE_DECL_SUPPRESS_DEBUG (TYPE_STUB_DECL (t)) = true;
 286   }
 287
 288   set_java_signature (t, sig);
 289   set_super_info (0, t, object_type_node, 0);
 290   if (TREE_CODE (element_type) == RECORD_TYPE)
 291     element_type = promote_type (element_type);
 292   TYPE_ARRAY_ELEMENT (t) = element_type;
 293
 294   /* Add length pseudo-field. */
 295   fld = build_decl (input_location,
 296                     FIELD_DECL, get_identifier ("length"), int_type_node);
 297   TYPE_FIELDS (t) = fld;
 298   DECL_CONTEXT (fld) = t;
 299   FIELD_PUBLIC (fld) = 1;
 300   FIELD_FINAL (fld) = 1;
 301   TREE_READONLY (fld) = 1;
 302
 303   atype = build_prim_array_type (element_type, length);
 304   arfld = build_decl (input_location,
 305                       FIELD_DECL, get_identifier ("data"), atype);
 306   DECL_CONTEXT (arfld) = t;
 307   DECL_CHAIN (fld) = arfld;
 308   DECL_ALIGN (arfld) = TYPE_ALIGN (element_type);
 309
 310   /* We could layout_class, but that loads java.lang.Object prematurely.
 311    * This is called by the parser, and it is a bad idea to do load_class
 312    * in the middle of parsing, because of possible circularity problems. */
 313   push_super_field (t, object_type_node);
 314   layout_type (t);
 315
 316   return t;
 317 }
 318
 319 /* Promote TYPE to the type actually used for fields and parameters. */
 320
 321 tree
 322 promote_type (tree type)
 323 {
 324   switch (TREE_CODE (type))
 325     {
 326     case RECORD_TYPE:
 327       return build_pointer_type (type);
 328     case BOOLEAN_TYPE:
 329       if (type == boolean_type_node)
 330         return promoted_boolean_type_node;
 331       goto handle_int;
 332     case INTEGER_TYPE:
 333       if (type == char_type_node)
 334         return promoted_char_type_node;
 335     handle_int:
 336       if (TYPE_PRECISION (type) < TYPE_PRECISION (int_type_node))
 337         {
 338           if (type == short_type_node)
 339             return promoted_short_type_node;
 340           if (type == byte_type_node)
 341             return promoted_byte_type_node;
 342           return int_type_node;
 343         }
 344       /* ... else fall through ... */
 345     default:
 346       return type;
 347     }
 348 }
 349
 350 /* Parse a signature string, starting at *PTR and ending at LIMIT.
 351    Return the seen TREE_TYPE, updating *PTR. */
 352
 353 static tree
 354 parse_signature_type (const unsigned char **ptr, const unsigned char *limit)
 355 {
 356   tree type;
 357   gcc_assert (*ptr < limit);
 358
 359   switch (**ptr)
 360     {
 361     case 'B':  (*ptr)++;  return byte_type_node;
 362     case 'C':  (*ptr)++;  return char_type_node;
 363     case 'D':  (*ptr)++;  return double_type_node;
 364     case 'F':  (*ptr)++;  return float_type_node;
 365     case 'S':  (*ptr)++;  return short_type_node;
 366     case 'I':  (*ptr)++;  return int_type_node;
 367     case 'J':  (*ptr)++;  return long_type_node;
 368     case 'Z':  (*ptr)++;  return boolean_type_node;
 369     case 'V':  (*ptr)++;  return void_type_node;
 370     case '[':
 371       for ((*ptr)++; (*ptr) < limit && ISDIGIT (**ptr); ) (*ptr)++;
 372       type = parse_signature_type (ptr, limit);
 373       type = build_java_array_type (type, -1);
 374       break;
 375     case 'L':
 376       {
 377         const unsigned char *start = ++(*ptr);
 378         const unsigned char *str = start;
 379         for ( ; ; str++)
 380           {
 381             gcc_assert (str < limit);
 382             if (*str == ';')
 383               break;
 384           }
 385         *ptr = str+1;
 386         type = lookup_class (unmangle_classname ((const char *) start, str - start));
 387         break;
 388       }
 389     default:
 390       gcc_unreachable ();
 391     }
 392   return promote_type (type);
 393 }
 394
 395 /* Parse a Java "mangled" signature string, starting at SIG_STRING,
 396    and SIG_LENGTH bytes long.
 397    Return a gcc type node. */
 398
 399 tree
 400 parse_signature_string (const unsigned char *sig_string, int sig_length)
 401 {
 402   tree result_type;
 403   const unsigned char *str = sig_string;
 404   const unsigned char *limit = str + sig_length;
 405
 406   if (str < limit && str[0] == '(')
 407     {
 408       tree argtype_list = NULL_TREE;
 409       str++;
 410       while (str < limit && str[0] != ')')
 411         {
 412           tree argtype = parse_signature_type (&str, limit);
 413           argtype_list = tree_cons (NULL_TREE, argtype, argtype_list);
 414         }
 415       if (str++, str >= limit)
 416         abort ();
 417       result_type = parse_signature_type (&str, limit);
 418       argtype_list = chainon (nreverse (argtype_list), end_params_node);
 419       result_type = build_function_type (result_type, argtype_list);
 420     }
 421   else
 422     result_type = parse_signature_type (&str, limit);
 423   if (str != limit)
 424     error ("junk at end of signature string");
 425   return result_type;
 426 }
 427
 428 /* Convert a signature to its type.
 429  * Uses IDENTIFIER_SIGNATURE_TYPE as a cache (except for primitive types).
 430  */
 431
 432 tree
 433 get_type_from_signature (tree signature)
 434 {
 435   const unsigned char *sig = (const unsigned char *) IDENTIFIER_POINTER (signature);
 436   int len = IDENTIFIER_LENGTH (signature);
 437   tree type;
 438   /* Primitive types aren't cached. */
 439   if (len <= 1)
 440     return parse_signature_string (sig, len);
 441   type = IDENTIFIER_SIGNATURE_TYPE (signature);
 442   if (type == NULL_TREE)
 443     {
 444       type = parse_signature_string (sig, len);
 445       IDENTIFIER_SIGNATURE_TYPE (signature) = type;
 446     }
 447   return type;
 448 }
 449
 450 /* Ignore signature and always return null.  Used by has_method. */
 451
 452 static tree
 453 build_null_signature (tree type ATTRIBUTE_UNUSED)
 454 {
 455   return NULL_TREE;
 456 }
 457
 458 /* Return the signature string for the arguments of method type TYPE. */
 459
 460 tree
 461 build_java_argument_signature (tree type)
 462 {
 463   extern struct obstack temporary_obstack;
 464   tree sig = TYPE_ARGUMENT_SIGNATURE (type);
 465   if (sig == NULL_TREE)
 466     {
 467       tree args = TYPE_ARG_TYPES (type);
 468       if (TREE_CODE (type) == METHOD_TYPE)
 469         args = TREE_CHAIN (args);  /* Skip "this" argument. */
 470       for (; args != end_params_node; args = TREE_CHAIN (args))
 471         {
 472           tree t = build_java_signature (TREE_VALUE (args));
 473           obstack_grow (&temporary_obstack,
 474                         IDENTIFIER_POINTER (t), IDENTIFIER_LENGTH (t));
 475         }
 476       obstack_1grow (&temporary_obstack, '\0');
 477
 478       sig = get_identifier ((char *) obstack_base (&temporary_obstack));
 479       TYPE_ARGUMENT_SIGNATURE (type) = sig;
 480       obstack_free (&temporary_obstack, obstack_base (&temporary_obstack));
 481     }
 482   return sig;
 483 }
 484
 485 /* Return the signature of the given TYPE. */
 486
 487 tree
 488 build_java_signature (tree type)
 489 {
 490   tree sig, t;
 491   while (TREE_CODE (type) == POINTER_TYPE)
 492     type = TREE_TYPE (type);
 493   MAYBE_CREATE_TYPE_TYPE_LANG_SPECIFIC (type);
 494   sig = TYPE_SIGNATURE (type);
 495   if (sig == NULL_TREE)
 496     {
 497       char sg[2];
 498       switch (TREE_CODE (type))
 499         {
 500         case BOOLEAN_TYPE: sg[0] = 'Z';  goto native;
 501         case VOID_TYPE:    sg[0] = 'V';  goto native;
 502         case INTEGER_TYPE:
 503           if (type == char_type_node || type == promoted_char_type_node)
 504             {
 505               sg[0] = 'C';
 506               goto native;
 507             }
 508           switch (TYPE_PRECISION (type))
 509             {
 510             case  8:       sg[0] = 'B';  goto native;
 511             case 16:       sg[0] = 'S';  goto native;
 512             case 32:       sg[0] = 'I';  goto native;
 513             case 64:       sg[0] = 'J';  goto native;
 514             default:  goto bad_type;
 515             }
 516         case REAL_TYPE:
 517           switch (TYPE_PRECISION (type))
 518             {
 519             case 32:       sg[0] = 'F';  goto native;
 520             case 64:       sg[0] = 'D';  goto native;
 521             default:  goto bad_type;
 522             }
 523         native:
 524           sg[1] = 0;
 525           sig = get_identifier (sg);
 526           break;
 527         case RECORD_TYPE:
 528           if (TYPE_ARRAY_P (type))
 529             {
 530               t = build_java_signature (TYPE_ARRAY_ELEMENT (type));
 531               sig = ident_subst (IDENTIFIER_POINTER (t), IDENTIFIER_LENGTH (t),
 532                                  "[", 0, 0, "");
 533             }
 534           else
 535             {
 536               t = DECL_NAME (TYPE_NAME (type));
 537               sig = ident_subst (IDENTIFIER_POINTER (t), IDENTIFIER_LENGTH (t),
 538                                  "L", '.', '/', ";");
 539             }
 540           break;
 541         case METHOD_TYPE:
 542         case FUNCTION_TYPE:
 543           {
 544             extern struct obstack temporary_obstack;
 545             sig = build_java_argument_signature (type);
 546             obstack_1grow (&temporary_obstack, '(');
 547             obstack_grow (&temporary_obstack,
 548                           IDENTIFIER_POINTER (sig), IDENTIFIER_LENGTH (sig));
 549             obstack_1grow (&temporary_obstack, ')');
 550
 551             t = build_java_signature (TREE_TYPE (type));
 552             obstack_grow0 (&temporary_obstack,
 553                            IDENTIFIER_POINTER (t), IDENTIFIER_LENGTH (t));
 554
 555             sig = get_identifier ((char *) obstack_base (&temporary_obstack));
 556             obstack_free (&temporary_obstack,
 557                           obstack_base (&temporary_obstack));
 558           }
 559           break;
 560         bad_type:
 561         default:
 562           gcc_unreachable ();
 563         }
 564       TYPE_SIGNATURE (type) = sig;
 565     }
 566   return sig;
 567 }
 568
 569 /* Save signature string SIG (an IDENTIFIER_NODE) in TYPE for future use. */
 570
 571 void
 572 set_java_signature (tree type, tree sig)
 573 {
 574   tree old_sig;
 575   while (TREE_CODE (type) == POINTER_TYPE)
 576     type = TREE_TYPE (type);
 577   MAYBE_CREATE_TYPE_TYPE_LANG_SPECIFIC (type);
 578   old_sig = TYPE_SIGNATURE (type);
 579   if (old_sig != NULL_TREE && old_sig != sig)
 580     abort ();
 581   TYPE_SIGNATURE (type) = sig;
 582 #if 0 /* careful about METHOD_TYPE */
 583   if (IDENTIFIER_SIGNATURE_TYPE (sig) == NULL_TREE && TREE_PERMANENT (type))
 584     IDENTIFIER_SIGNATURE_TYPE (sig) = type;
 585 #endif
 586 }
 587
 588 /* Search in SEARCHED_CLASS and its superclasses for a method matching
 589    METHOD_NAME and signature METHOD_SIGNATURE.  This function will
 590    only search for methods declared in the class hierarchy; interfaces
 591    will not be considered.  Returns NULL_TREE if the method is not
 592    found.  */
 593 tree
 594 lookup_argument_method (tree searched_class, tree method_name,
 595                         tree method_signature)
 596 {
 597   return lookup_do (searched_class, 0,
 598                     method_name, method_signature,
 599                     build_java_argument_signature);
 600 }
 601
 602 /* Like lookup_argument_method, but lets the caller set any flags
 603    desired.  */
 604 tree
 605 lookup_argument_method_generic (tree searched_class, tree method_name,
 606                                 tree method_signature, int flags)
 607 {
 608   return lookup_do (searched_class, flags,
 609                     method_name, method_signature,
 610                     build_java_argument_signature);
 611 }
 612
 613
 614 /* Search in class SEARCHED_CLASS (and its superclasses) for a method
 615    matching METHOD_NAME and signature METHOD_SIGNATURE.  Return a
 616    FUNCTION_DECL on success, or NULL_TREE if none found.  (Contrast
 617    lookup_argument_method, which ignores return type.)  If
 618    SEARCHED_CLASS is an interface, search it too. */
 619 tree
 620 lookup_java_method (tree searched_class, tree method_name,
 621                     tree method_signature)
 622 {
 623   return lookup_do (searched_class, SEARCH_INTERFACE, method_name,
 624                     method_signature, build_java_signature);
 625 }
 626
 627 /* Return true iff KLASS (or its ancestors) has a method METHOD_NAME.  */
 628 int
 629 has_method (tree klass, tree method_name)
 630 {
 631   return lookup_do (klass, SEARCH_INTERFACE,
 632                     method_name, NULL_TREE,
 633                     build_null_signature) != NULL_TREE;
 634 }
 635
 636 /* Search in class SEARCHED_CLASS, but not its superclasses, for a
 637    method matching METHOD_NAME and signature SIGNATURE.  A private
 638    helper for lookup_do.  */
 639 static tree
 640 shallow_find_method (tree searched_class, int flags, tree method_name,
 641              tree signature, tree (*signature_builder) (tree))
 642 {
 643   tree method;
 644   for (method = TYPE_METHODS (searched_class);
 645        method != NULL_TREE;  method = DECL_CHAIN (method))
 646     {
 647       tree method_sig = (*signature_builder) (TREE_TYPE (method));
 648       if (DECL_NAME (method) == method_name && method_sig == signature)
 649         {
 650           /* If the caller requires a visible method, then we
 651              skip invisible methods here.  */
 652           if (! (flags & SEARCH_VISIBLE)
 653               || ! METHOD_INVISIBLE (method))
 654             return method;
 655         }
 656     }
 657   return NULL_TREE;
 658 }
 659
 660 /* Search in the superclasses of SEARCHED_CLASS for a method matching
 661    METHOD_NAME and signature SIGNATURE.  A private helper for
 662    lookup_do.  */
 663 static tree
 664 find_method_in_superclasses (tree searched_class, int flags,
 665                              tree method_name, tree signature,
 666                              tree (*signature_builder) (tree))
 667 {
 668   tree klass;
 669   for (klass = CLASSTYPE_SUPER (searched_class); klass != NULL_TREE;
 670        klass = CLASSTYPE_SUPER (klass))
 671     {
 672       tree method;
 673       method = shallow_find_method (klass, flags, method_name,
 674                                     signature, signature_builder);
 675       if (method != NULL_TREE)
 676         return method;
 677     }
 678
 679   return NULL_TREE;
 680 }
 681
 682 /* Search in the interfaces of SEARCHED_CLASS and its superinterfaces
 683    for a method matching METHOD_NAME and signature SIGNATURE.  A
 684    private helper for lookup_do.  */
 685 static tree
 686 find_method_in_interfaces (tree searched_class, int flags, tree method_name,
 687                            tree signature, tree (*signature_builder) (tree))
 688 {
 689   int i;
 690   tree binfo, base_binfo;
 691
 692   for (binfo = TYPE_BINFO (searched_class), i = 1;
 693        BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
 694     {
 695       tree iclass = BINFO_TYPE (base_binfo);
 696       tree method;
 697
 698       /* If the superinterface hasn't been loaded yet, do so now.  */
 699       if (!CLASS_LOADED_P (iclass))
 700         load_class (iclass, 1);
 701
 702       /* First, we look in ICLASS.  If that doesn't work we'll
 703          recursively look through all its superinterfaces.  */
 704       method = shallow_find_method (iclass, flags, method_name,
 705                                     signature, signature_builder);
 706       if (method != NULL_TREE)
 707         return method;
 708
 709       method = find_method_in_interfaces
 710         (iclass, flags, method_name, signature, signature_builder);
 711       if (method != NULL_TREE)
 712         return method;
 713     }
 714
 715   return NULL_TREE;
 716 }
 717
 718
 719 /* Search in class SEARCHED_CLASS (and its superclasses) for a method
 720    matching METHOD_NAME and signature SIGNATURE.  FLAGS control some
 721    parameters of the search.
 722
 723    SEARCH_INTERFACE means also search interfaces and superinterfaces
 724    of SEARCHED_CLASS.
 725
 726    SEARCH_SUPER means skip SEARCHED_CLASS and start with its
 727    superclass.
 728
 729    SEARCH_VISIBLE means skip methods for which METHOD_INVISIBLE is
 730    set.
 731
 732    Return the matched method DECL or NULL_TREE.  SIGNATURE_BUILDER is
 733    used on method candidates to build their (sometimes partial)
 734    signature.  */
 735 static tree
 736 lookup_do (tree searched_class, int flags, tree method_name,
 737            tree signature, tree (*signature_builder) (tree))
 738 {
 739   tree method;
 740   tree orig_class = searched_class;
 741
 742   if (searched_class == NULL_TREE)
 743     return NULL_TREE;
 744
 745   if (flags & SEARCH_SUPER)
 746     {
 747       searched_class = CLASSTYPE_SUPER (searched_class);
 748       if (searched_class == NULL_TREE)
 749         return NULL_TREE;
 750     }
 751
 752   /* First look in our own methods.  */
 753   method = shallow_find_method (searched_class, flags, method_name,
 754                                 signature, signature_builder);
 755   if (method)
 756     return method;
 757
 758   /* Then look in our superclasses.  */
 759   if (! CLASS_INTERFACE (TYPE_NAME (searched_class)))
 760     method = find_method_in_superclasses (searched_class, flags, method_name,
 761                                           signature, signature_builder);
 762   if (method)
 763     return method;
 764
 765   /* If that doesn't work, look in our interfaces.  */
 766   if (flags & SEARCH_INTERFACE)
 767     method = find_method_in_interfaces (orig_class, flags, method_name,
 768                                         signature, signature_builder);
 769
 770   return method;
 771 }
 772
 773 /* Search in class CLAS for a constructor matching METHOD_SIGNATURE.
 774    Return a FUNCTION_DECL on success, or NULL_TREE if none found. */
 775
 776 tree
 777 lookup_java_constructor (tree clas, tree method_signature)
 778 {
 779   tree method = TYPE_METHODS (clas);
 780   for ( ; method != NULL_TREE;  method = DECL_CHAIN (method))
 781     {
 782       tree method_sig = build_java_signature (TREE_TYPE (method));
 783       if (DECL_CONSTRUCTOR_P (method) && method_sig == method_signature)
 784         return method;
 785     }
 786   return NULL_TREE;
 787 }
 788
 789 /* Return a type which is the Binary Numeric Promotion of the pair T1,
 790    T2 and convert EXP1 and/or EXP2. See 5.6.2 Binary Numeric
 791    Promotion. It assumes that both T1 and T2 are eligible to BNP. */
 792
 793 tree
 794 binary_numeric_promotion (tree t1, tree t2, tree *exp1, tree *exp2)
 795 {
 796   if (t1 == double_type_node || t2 == double_type_node)
 797     {
 798       if (t1 != double_type_node)
 799         *exp1 = convert (double_type_node, *exp1);
 800       if (t2 != double_type_node)
 801         *exp2 = convert (double_type_node, *exp2);
 802       return double_type_node;
 803     }
 804   if (t1 == float_type_node || t2 == float_type_node)
 805     {
 806       if (t1 != float_type_node)
 807         *exp1 = convert (float_type_node, *exp1);
 808       if (t2 != float_type_node)
 809         *exp2 = convert (float_type_node, *exp2);
 810       return float_type_node;
 811     }
 812   if (t1 == long_type_node || t2 == long_type_node)
 813     {
 814       if (t1 != long_type_node)
 815         *exp1 = convert (long_type_node, *exp1);
 816       if (t2 != long_type_node)
 817         *exp2 = convert (long_type_node, *exp2);
 818       return long_type_node;
 819     }
 820
 821   if (t1 != int_type_node)
 822     *exp1 = convert (int_type_node, *exp1);
 823   if (t2 != int_type_node)
 824     *exp2 = convert (int_type_node, *exp2);
 825   return int_type_node;
 826 }