gdb/expprint.c

   1 /* Print in infix form a struct expression.
   2
   3    Copyright (C) 1986-2013 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 "gdbtypes.h"
  23 #include "expression.h"
  24 #include "value.h"
  25 #include "language.h"
  26 #include "parser-defs.h"
  27 #include "user-regs.h"          /* For user_reg_map_regnum_to_name.  */
  28 #include "target.h"
  29 #include "gdb_string.h"
  30 #include "block.h"
  31 #include "objfiles.h"
  32 #include "gdb_assert.h"
  33 #include "valprint.h"
  34
  35 #include <ctype.h>
  36
  37 void
  38 print_expression (struct expression *exp, struct ui_file *stream)
  39 {
  40   int pc = 0;
  41
  42   print_subexp (exp, &pc, stream, PREC_NULL);
  43 }
  44
  45 /* Print the subexpression of EXP that starts in position POS, on STREAM.
  46    PREC is the precedence of the surrounding operator;
  47    if the precedence of the main operator of this subexpression is less,
  48    parentheses are needed here.  */
  49
  50 void
  51 print_subexp (struct expression *exp, int *pos,
  52               struct ui_file *stream, enum precedence prec)
  53 {
  54   exp->language_defn->la_exp_desc->print_subexp (exp, pos, stream, prec);
  55 }
  56
  57 /* Standard implementation of print_subexp for use in language_defn
  58    vectors.  */
  59 void
  60 print_subexp_standard (struct expression *exp, int *pos,
  61                        struct ui_file *stream, enum precedence prec)
  62 {
  63   unsigned tem;
  64   const struct op_print *op_print_tab;
  65   int pc;
  66   unsigned nargs;
  67   char *op_str;
  68   int assign_modify = 0;
  69   enum exp_opcode opcode;
  70   enum precedence myprec = PREC_NULL;
  71   /* Set to 1 for a right-associative operator.  */
  72   int assoc = 0;
  73   struct value *val;
  74   char *tempstr = NULL;
  75
  76   op_print_tab = exp->language_defn->la_op_print_tab;
  77   pc = (*pos)++;
  78   opcode = exp->elts[pc].opcode;
  79   switch (opcode)
  80     {
  81       /* Common ops */
  82
  83     case OP_TYPE:
  84       (*pos) += 2;
  85       type_print (exp->elts[pc + 1].type, "", stream, 0);
  86       return;
  87
  88     case OP_SCOPE:
  89       myprec = PREC_PREFIX;
  90       assoc = 0;
  91       fputs_filtered (type_name_no_tag (exp->elts[pc + 1].type), stream);
  92       fputs_filtered ("::", stream);
  93       nargs = longest_to_int (exp->elts[pc + 2].longconst);
  94       (*pos) += 4 + BYTES_TO_EXP_ELEM (nargs + 1);
  95       fputs_filtered (&exp->elts[pc + 3].string, stream);
  96       return;
  97
  98     case OP_LONG:
  99       {
 100         struct value_print_options opts;
 101
 102         get_raw_print_options (&opts);
 103         (*pos) += 3;
 104         value_print (value_from_longest (exp->elts[pc + 1].type,
 105                                          exp->elts[pc + 2].longconst),
 106                      stream, &opts);
 107       }
 108       return;
 109
 110     case OP_DOUBLE:
 111       {
 112         struct value_print_options opts;
 113
 114         get_raw_print_options (&opts);
 115         (*pos) += 3;
 116         value_print (value_from_double (exp->elts[pc + 1].type,
 117                                         exp->elts[pc + 2].doubleconst),
 118                      stream, &opts);
 119       }
 120       return;
 121
 122     case OP_VAR_VALUE:
 123       {
 124         const struct block *b;
 125
 126         (*pos) += 3;
 127         b = exp->elts[pc + 1].block;
 128         if (b != NULL
 129             && BLOCK_FUNCTION (b) != NULL
 130             && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)) != NULL)
 131           {
 132             fputs_filtered (SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)), stream);
 133             fputs_filtered ("::", stream);
 134           }
 135         fputs_filtered (SYMBOL_PRINT_NAME (exp->elts[pc + 2].symbol), stream);
 136       }
 137       return;
 138
 139     case OP_VAR_ENTRY_VALUE:
 140       {
 141         (*pos) += 2;
 142         fprintf_filtered (stream, "%s@entry",
 143                           SYMBOL_PRINT_NAME (exp->elts[pc + 1].symbol));
 144       }
 145       return;
 146
 147     case OP_LAST:
 148       (*pos) += 2;
 149       fprintf_filtered (stream, "$%d",
 150                         longest_to_int (exp->elts[pc + 1].longconst));
 151       return;
 152
 153     case OP_REGISTER:
 154       {
 155         const char *name = &exp->elts[pc + 2].string;
 156
 157         (*pos) += 3 + BYTES_TO_EXP_ELEM (exp->elts[pc + 1].longconst + 1);
 158         fprintf_filtered (stream, "$%s", name);
 159         return;
 160       }
 161
 162     case OP_BOOL:
 163       (*pos) += 2;
 164       fprintf_filtered (stream, "%s",
 165                         longest_to_int (exp->elts[pc + 1].longconst)
 166                         ? "TRUE" : "FALSE");
 167       return;
 168
 169     case OP_INTERNALVAR:
 170       (*pos) += 2;
 171       fprintf_filtered (stream, "$%s",
 172                         internalvar_name (exp->elts[pc + 1].internalvar));
 173       return;
 174
 175     case OP_FUNCALL:
 176       (*pos) += 2;
 177       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 178       print_subexp (exp, pos, stream, PREC_SUFFIX);
 179       fputs_filtered (" (", stream);
 180       for (tem = 0; tem < nargs; tem++)
 181         {
 182           if (tem != 0)
 183             fputs_filtered (", ", stream);
 184           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 185         }
 186       fputs_filtered (")", stream);
 187       return;
 188
 189     case OP_NAME:
 190       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 191       (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 192       fputs_filtered (&exp->elts[pc + 2].string, stream);
 193       return;
 194
 195     case OP_STRING:
 196       {
 197         struct value_print_options opts;
 198
 199         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 200         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 201         /* LA_PRINT_STRING will print using the current repeat count threshold.
 202            If necessary, we can temporarily set it to zero, or pass it as an
 203            additional parameter to LA_PRINT_STRING.  -fnf */
 204         get_user_print_options (&opts);
 205         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 206                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 207                          NULL, 0, &opts);
 208       }
 209       return;
 210
 211     case OP_OBJC_NSSTRING:      /* Objective-C Foundation Class
 212                                    NSString constant.  */
 213       {
 214         struct value_print_options opts;
 215
 216         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 217         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 218         fputs_filtered ("@\"", stream);
 219         get_user_print_options (&opts);
 220         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 221                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 222                          NULL, 0, &opts);
 223         fputs_filtered ("\"", stream);
 224       }
 225       return;
 226
 227     case OP_OBJC_MSGCALL:
 228       {                 /* Objective C message (method) call.  */
 229         char *selector;
 230
 231         (*pos) += 3;
 232         nargs = longest_to_int (exp->elts[pc + 2].longconst);
 233         fprintf_unfiltered (stream, "[");
 234         print_subexp (exp, pos, stream, PREC_SUFFIX);
 235         if (0 == target_read_string (exp->elts[pc + 1].longconst,
 236                                      &selector, 1024, NULL))
 237           {
 238             error (_("bad selector"));
 239             return;
 240           }
 241         if (nargs)
 242           {
 243             char *s, *nextS;
 244
 245             s = alloca (strlen (selector) + 1);
 246             strcpy (s, selector);
 247             for (tem = 0; tem < nargs; tem++)
 248               {
 249                 nextS = strchr (s, ':');
 250                 gdb_assert (nextS);     /* Make sure we found ':'.  */
 251                 *nextS = '\0';
 252                 fprintf_unfiltered (stream, " %s: ", s);
 253                 s = nextS + 1;
 254                 print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 255               }
 256           }
 257         else
 258           {
 259             fprintf_unfiltered (stream, " %s", selector);
 260           }
 261         fprintf_unfiltered (stream, "]");
 262         /* "selector" was malloc'd by target_read_string.  Free it.  */
 263         xfree (selector);
 264         return;
 265       }
 266
 267     case OP_ARRAY:
 268       (*pos) += 3;
 269       nargs = longest_to_int (exp->elts[pc + 2].longconst);
 270       nargs -= longest_to_int (exp->elts[pc + 1].longconst);
 271       nargs++;
 272       tem = 0;
 273       if (exp->elts[pc + 4].opcode == OP_LONG
 274           && exp->elts[pc + 5].type
 275              == builtin_type (exp->gdbarch)->builtin_char
 276           && exp->language_defn->la_language == language_c)
 277         {
 278           /* Attempt to print C character arrays using string syntax.
 279              Walk through the args, picking up one character from each
 280              of the OP_LONG expression elements.  If any array element
 281              does not match our expection of what we should find for
 282              a simple string, revert back to array printing.  Note that
 283              the last expression element is an explicit null terminator
 284              byte, which doesn't get printed.  */
 285           tempstr = alloca (nargs);
 286           pc += 4;
 287           while (tem < nargs)
 288             {
 289               if (exp->elts[pc].opcode != OP_LONG
 290                   || exp->elts[pc + 1].type
 291                      != builtin_type (exp->gdbarch)->builtin_char)
 292                 {
 293                   /* Not a simple array of char, use regular array
 294                      printing.  */
 295                   tem = 0;
 296                   break;
 297                 }
 298               else
 299                 {
 300                   tempstr[tem++] =
 301                     longest_to_int (exp->elts[pc + 2].longconst);
 302                   pc += 4;
 303                 }
 304             }
 305         }
 306       if (tem > 0)
 307         {
 308           struct value_print_options opts;
 309
 310           get_user_print_options (&opts);
 311           LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 312                            (gdb_byte *) tempstr, nargs - 1, NULL, 0, &opts);
 313           (*pos) = pc;
 314         }
 315       else
 316         {
 317           fputs_filtered (" {", stream);
 318           for (tem = 0; tem < nargs; tem++)
 319             {
 320               if (tem != 0)
 321                 {
 322                   fputs_filtered (", ", stream);
 323                 }
 324               print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 325             }
 326           fputs_filtered ("}", stream);
 327         }
 328       return;
 329
 330     case TERNOP_COND:
 331       if ((int) prec > (int) PREC_COMMA)
 332         fputs_filtered ("(", stream);
 333       /* Print the subexpressions, forcing parentheses
 334          around any binary operations within them.
 335          This is more parentheses than are strictly necessary,
 336          but it looks clearer.  */
 337       print_subexp (exp, pos, stream, PREC_HYPER);
 338       fputs_filtered (" ? ", stream);
 339       print_subexp (exp, pos, stream, PREC_HYPER);
 340       fputs_filtered (" : ", stream);
 341       print_subexp (exp, pos, stream, PREC_HYPER);
 342       if ((int) prec > (int) PREC_COMMA)
 343         fputs_filtered (")", stream);
 344       return;
 345
 346     case TERNOP_SLICE:
 347       print_subexp (exp, pos, stream, PREC_SUFFIX);
 348       fputs_filtered ("(", stream);
 349       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 350       fputs_filtered (opcode == TERNOP_SLICE ? " : " : " UP ", stream);
 351       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 352       fputs_filtered (")", stream);
 353       return;
 354
 355     case STRUCTOP_STRUCT:
 356       tem = longest_to_int (exp->elts[pc + 1].longconst);
 357       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 358       print_subexp (exp, pos, stream, PREC_SUFFIX);
 359       fputs_filtered (".", stream);
 360       fputs_filtered (&exp->elts[pc + 2].string, stream);
 361       return;
 362
 363       /* Will not occur for Modula-2.  */
 364     case STRUCTOP_PTR:
 365       tem = longest_to_int (exp->elts[pc + 1].longconst);
 366       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 367       print_subexp (exp, pos, stream, PREC_SUFFIX);
 368       fputs_filtered ("->", stream);
 369       fputs_filtered (&exp->elts[pc + 2].string, stream);
 370       return;
 371
 372     case STRUCTOP_MEMBER:
 373       print_subexp (exp, pos, stream, PREC_SUFFIX);
 374       fputs_filtered (".*", stream);
 375       print_subexp (exp, pos, stream, PREC_SUFFIX);
 376       return;
 377
 378     case STRUCTOP_MPTR:
 379       print_subexp (exp, pos, stream, PREC_SUFFIX);
 380       fputs_filtered ("->*", stream);
 381       print_subexp (exp, pos, stream, PREC_SUFFIX);
 382       return;
 383
 384     case BINOP_SUBSCRIPT:
 385       print_subexp (exp, pos, stream, PREC_SUFFIX);
 386       fputs_filtered ("[", stream);
 387       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 388       fputs_filtered ("]", stream);
 389       return;
 390
 391     case UNOP_POSTINCREMENT:
 392       print_subexp (exp, pos, stream, PREC_SUFFIX);
 393       fputs_filtered ("++", stream);
 394       return;
 395
 396     case UNOP_POSTDECREMENT:
 397       print_subexp (exp, pos, stream, PREC_SUFFIX);
 398       fputs_filtered ("--", stream);
 399       return;
 400
 401     case UNOP_CAST:
 402       (*pos) += 2;
 403       if ((int) prec > (int) PREC_PREFIX)
 404         fputs_filtered ("(", stream);
 405       fputs_filtered ("(", stream);
 406       type_print (exp->elts[pc + 1].type, "", stream, 0);
 407       fputs_filtered (") ", stream);
 408       print_subexp (exp, pos, stream, PREC_PREFIX);
 409       if ((int) prec > (int) PREC_PREFIX)
 410         fputs_filtered (")", stream);
 411       return;
 412
 413     case UNOP_CAST_TYPE:
 414       if ((int) prec > (int) PREC_PREFIX)
 415         fputs_filtered ("(", stream);
 416       fputs_filtered ("(", stream);
 417       print_subexp (exp, pos, stream, PREC_PREFIX);
 418       fputs_filtered (") ", stream);
 419       print_subexp (exp, pos, stream, PREC_PREFIX);
 420       if ((int) prec > (int) PREC_PREFIX)
 421         fputs_filtered (")", stream);
 422       return;
 423
 424     case UNOP_DYNAMIC_CAST:
 425     case UNOP_REINTERPRET_CAST:
 426       fputs_filtered (opcode == UNOP_DYNAMIC_CAST ? "dynamic_cast"
 427                       : "reinterpret_cast", stream);
 428       fputs_filtered ("<", stream);
 429       print_subexp (exp, pos, stream, PREC_PREFIX);
 430       fputs_filtered ("> (", stream);
 431       print_subexp (exp, pos, stream, PREC_PREFIX);
 432       fputs_filtered (")", stream);
 433       return;
 434
 435     case UNOP_MEMVAL:
 436       (*pos) += 2;
 437       if ((int) prec > (int) PREC_PREFIX)
 438         fputs_filtered ("(", stream);
 439       if (TYPE_CODE (exp->elts[pc + 1].type) == TYPE_CODE_FUNC
 440           && exp->elts[pc + 3].opcode == OP_LONG)
 441         {
 442           struct value_print_options opts;
 443
 444           /* We have a minimal symbol fn, probably.  It's encoded
 445              as a UNOP_MEMVAL (function-type) of an OP_LONG (int, address).
 446              Swallow the OP_LONG (including both its opcodes); ignore
 447              its type; print the value in the type of the MEMVAL.  */
 448           (*pos) += 4;
 449           val = value_at_lazy (exp->elts[pc + 1].type,
 450                                (CORE_ADDR) exp->elts[pc + 5].longconst);
 451           get_raw_print_options (&opts);
 452           value_print (val, stream, &opts);
 453         }
 454       else
 455         {
 456           fputs_filtered ("{", stream);
 457           type_print (exp->elts[pc + 1].type, "", stream, 0);
 458           fputs_filtered ("} ", stream);
 459           print_subexp (exp, pos, stream, PREC_PREFIX);
 460         }
 461       if ((int) prec > (int) PREC_PREFIX)
 462         fputs_filtered (")", stream);
 463       return;
 464
 465     case UNOP_MEMVAL_TYPE:
 466       if ((int) prec > (int) PREC_PREFIX)
 467         fputs_filtered ("(", stream);
 468       fputs_filtered ("{", stream);
 469       print_subexp (exp, pos, stream, PREC_PREFIX);
 470       fputs_filtered ("} ", stream);
 471       print_subexp (exp, pos, stream, PREC_PREFIX);
 472       if ((int) prec > (int) PREC_PREFIX)
 473         fputs_filtered (")", stream);
 474       return;
 475
 476     case UNOP_MEMVAL_TLS:
 477       (*pos) += 3;
 478       if ((int) prec > (int) PREC_PREFIX)
 479         fputs_filtered ("(", stream);
 480       fputs_filtered ("{", stream);
 481       type_print (exp->elts[pc + 2].type, "", stream, 0);
 482       fputs_filtered ("} ", stream);
 483       print_subexp (exp, pos, stream, PREC_PREFIX);
 484       if ((int) prec > (int) PREC_PREFIX)
 485         fputs_filtered (")", stream);
 486       return;
 487
 488     case BINOP_ASSIGN_MODIFY:
 489       opcode = exp->elts[pc + 1].opcode;
 490       (*pos) += 2;
 491       myprec = PREC_ASSIGN;
 492       assoc = 1;
 493       assign_modify = 1;
 494       op_str = "???";
 495       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 496         if (op_print_tab[tem].opcode == opcode)
 497           {
 498             op_str = op_print_tab[tem].string;
 499             break;
 500           }
 501       if (op_print_tab[tem].opcode != opcode)
 502         /* Not found; don't try to keep going because we don't know how
 503            to interpret further elements.  */
 504         error (_("Invalid expression"));
 505       break;
 506
 507       /* C++ ops */
 508
 509     case OP_THIS:
 510       ++(*pos);
 511       if (exp->language_defn->la_name_of_this)
 512         fputs_filtered (exp->language_defn->la_name_of_this, stream);
 513       else
 514         fprintf_filtered (stream, _("<language %s has no 'this'>"),
 515                           exp->language_defn->la_name);
 516       return;
 517
 518       /* Modula-2 ops */
 519
 520     case MULTI_SUBSCRIPT:
 521       (*pos) += 2;
 522       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 523       print_subexp (exp, pos, stream, PREC_SUFFIX);
 524       fprintf_unfiltered (stream, " [");
 525       for (tem = 0; tem < nargs; tem++)
 526         {
 527           if (tem != 0)
 528             fprintf_unfiltered (stream, ", ");
 529           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 530         }
 531       fprintf_unfiltered (stream, "]");
 532       return;
 533
 534     case BINOP_VAL:
 535       (*pos) += 2;
 536       fprintf_unfiltered (stream, "VAL(");
 537       type_print (exp->elts[pc + 1].type, "", stream, 0);
 538       fprintf_unfiltered (stream, ",");
 539       print_subexp (exp, pos, stream, PREC_PREFIX);
 540       fprintf_unfiltered (stream, ")");
 541       return;
 542
 543     case TYPE_INSTANCE:
 544       {
 545         LONGEST count = exp->elts[pc + 1].longconst;
 546
 547         /* The COUNT.  */
 548         (*pos)++;
 549         fputs_unfiltered ("TypesInstance(", stream);
 550         while (count-- > 0)
 551           {
 552             type_print (exp->elts[(*pos)++].type, "", stream, 0);
 553             if (count > 0)
 554               fputs_unfiltered (",", stream);
 555           }
 556         fputs_unfiltered (",", stream);
 557         /* Ending COUNT and ending TYPE_INSTANCE.  */
 558         (*pos) += 2;
 559         print_subexp (exp, pos, stream, PREC_PREFIX);
 560         fputs_unfiltered (")", stream);
 561         return;
 562       }
 563
 564       /* Default ops */
 565
 566     default:
 567       op_str = "???";
 568       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 569         if (op_print_tab[tem].opcode == opcode)
 570           {
 571             op_str = op_print_tab[tem].string;
 572             myprec = op_print_tab[tem].precedence;
 573             assoc = op_print_tab[tem].right_assoc;
 574             break;
 575           }
 576       if (op_print_tab[tem].opcode != opcode)
 577         /* Not found; don't try to keep going because we don't know how
 578            to interpret further elements.  For example, this happens
 579            if opcode is OP_TYPE.  */
 580         error (_("Invalid expression"));
 581     }
 582
 583   /* Note that PREC_BUILTIN will always emit parentheses.  */
 584   if ((int) myprec < (int) prec)
 585     fputs_filtered ("(", stream);
 586   if ((int) opcode > (int) BINOP_END)
 587     {
 588       if (assoc)
 589         {
 590           /* Unary postfix operator.  */
 591           print_subexp (exp, pos, stream, PREC_SUFFIX);
 592           fputs_filtered (op_str, stream);
 593         }
 594       else
 595         {
 596           /* Unary prefix operator.  */
 597           fputs_filtered (op_str, stream);
 598           if (myprec == PREC_BUILTIN_FUNCTION)
 599             fputs_filtered ("(", stream);
 600           print_subexp (exp, pos, stream, PREC_PREFIX);
 601           if (myprec == PREC_BUILTIN_FUNCTION)
 602             fputs_filtered (")", stream);
 603         }
 604     }
 605   else
 606     {
 607       /* Binary operator.  */
 608       /* Print left operand.
 609          If operator is right-associative,
 610          increment precedence for this operand.  */
 611       print_subexp (exp, pos, stream,
 612                     (enum precedence) ((int) myprec + assoc));
 613       /* Print the operator itself.  */
 614       if (assign_modify)
 615         fprintf_filtered (stream, " %s= ", op_str);
 616       else if (op_str[0] == ',')
 617         fprintf_filtered (stream, "%s ", op_str);
 618       else
 619         fprintf_filtered (stream, " %s ", op_str);
 620       /* Print right operand.
 621          If operator is left-associative,
 622          increment precedence for this operand.  */
 623       print_subexp (exp, pos, stream,
 624                     (enum precedence) ((int) myprec + !assoc));
 625     }
 626
 627   if ((int) myprec < (int) prec)
 628     fputs_filtered (")", stream);
 629 }
 630
 631 /* Return the operator corresponding to opcode OP as
 632    a string.   NULL indicates that the opcode was not found in the
 633    current language table.  */
 634 char *
 635 op_string (enum exp_opcode op)
 636 {
 637   int tem;
 638   const struct op_print *op_print_tab;
 639
 640   op_print_tab = current_language->la_op_print_tab;
 641   for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 642     if (op_print_tab[tem].opcode == op)
 643       return op_print_tab[tem].string;
 644   return NULL;
 645 }
 646
 647 /* Support for dumping the raw data from expressions in a human readable
 648    form.  */
 649
 650 static int dump_subexp_body (struct expression *exp, struct ui_file *, int);
 651
 652 /* Name for OPCODE, when it appears in expression EXP.  */
 653
 654 char *
 655 op_name (struct expression *exp, enum exp_opcode opcode)
 656 {
 657   return exp->language_defn->la_exp_desc->op_name (opcode);
 658 }
 659
 660 /* Default name for the standard operator OPCODE (i.e., one defined in
 661    the definition of enum exp_opcode).  */
 662
 663 char *
 664 op_name_standard (enum exp_opcode opcode)
 665 {
 666   switch (opcode)
 667     {
 668     default:
 669       {
 670         static char buf[30];
 671
 672         xsnprintf (buf, sizeof (buf), "<unknown %d>", opcode);
 673         return buf;
 674       }
 675 #define OP(name)        \
 676     case name:          \
 677       return #name ;
 678 #include "std-operator.def"
 679 #undef OP
 680     }
 681 }
 682
 683 /* Print a raw dump of expression EXP to STREAM.
 684    NOTE, if non-NULL, is printed as extra explanatory text.  */
 685
 686 void
 687 dump_raw_expression (struct expression *exp, struct ui_file *stream,
 688                      char *note)
 689 {
 690   int elt;
 691   char *opcode_name;
 692   char *eltscan;
 693   int eltsize;
 694
 695   fprintf_filtered (stream, "Dump of expression @ ");
 696   gdb_print_host_address (exp, stream);
 697   if (note)
 698     fprintf_filtered (stream, ", %s:", note);
 699   fprintf_filtered (stream, "\n\tLanguage %s, %d elements, %ld bytes each.\n",
 700                     exp->language_defn->la_name, exp->nelts,
 701                     (long) sizeof (union exp_element));
 702   fprintf_filtered (stream, "\t%5s  %20s  %16s  %s\n", "Index", "Opcode",
 703                     "Hex Value", "String Value");
 704   for (elt = 0; elt < exp->nelts; elt++)
 705     {
 706       fprintf_filtered (stream, "\t%5d  ", elt);
 707       opcode_name = op_name (exp, exp->elts[elt].opcode);
 708
 709       fprintf_filtered (stream, "%20s  ", opcode_name);
 710       print_longest (stream, 'd', 0, exp->elts[elt].longconst);
 711       fprintf_filtered (stream, "  ");
 712
 713       for (eltscan = (char *) &exp->elts[elt],
 714            eltsize = sizeof (union exp_element);
 715            eltsize-- > 0;
 716            eltscan++)
 717         {
 718           fprintf_filtered (stream, "%c",
 719                             isprint (*eltscan) ? (*eltscan & 0xFF) : '.');
 720         }
 721       fprintf_filtered (stream, "\n");
 722     }
 723 }
 724
 725 /* Dump the subexpression of prefix expression EXP whose operator is at
 726    position ELT onto STREAM.  Returns the position of the next
 727    subexpression in EXP.  */
 728
 729 int
 730 dump_subexp (struct expression *exp, struct ui_file *stream, int elt)
 731 {
 732   static int indent = 0;
 733   int i;
 734
 735   fprintf_filtered (stream, "\n");
 736   fprintf_filtered (stream, "\t%5d  ", elt);
 737
 738   for (i = 1; i <= indent; i++)
 739     fprintf_filtered (stream, " ");
 740   indent += 2;
 741
 742   fprintf_filtered (stream, "%-20s  ", op_name (exp, exp->elts[elt].opcode));
 743
 744   elt = dump_subexp_body (exp, stream, elt);
 745
 746   indent -= 2;
 747
 748   return elt;
 749 }
 750
 751 /* Dump the operands of prefix expression EXP whose opcode is at
 752    position ELT onto STREAM.  Returns the position of the next
 753    subexpression in EXP.  */
 754
 755 static int
 756 dump_subexp_body (struct expression *exp, struct ui_file *stream, int elt)
 757 {
 758   return exp->language_defn->la_exp_desc->dump_subexp_body (exp, stream, elt);
 759 }
 760
 761 /* Default value for subexp_body in exp_descriptor vector.  */
 762
 763 int
 764 dump_subexp_body_standard (struct expression *exp,
 765                            struct ui_file *stream, int elt)
 766 {
 767   int opcode = exp->elts[elt++].opcode;
 768
 769   switch (opcode)
 770     {
 771     case TERNOP_COND:
 772     case TERNOP_SLICE:
 773       elt = dump_subexp (exp, stream, elt);
 774       /* FALL THROUGH */
 775     case BINOP_ADD:
 776     case BINOP_SUB:
 777     case BINOP_MUL:
 778     case BINOP_DIV:
 779     case BINOP_REM:
 780     case BINOP_MOD:
 781     case BINOP_LSH:
 782     case BINOP_RSH:
 783     case BINOP_LOGICAL_AND:
 784     case BINOP_LOGICAL_OR:
 785     case BINOP_BITWISE_AND:
 786     case BINOP_BITWISE_IOR:
 787     case BINOP_BITWISE_XOR:
 788     case BINOP_EQUAL:
 789     case BINOP_NOTEQUAL:
 790     case BINOP_LESS:
 791     case BINOP_GTR:
 792     case BINOP_LEQ:
 793     case BINOP_GEQ:
 794     case BINOP_REPEAT:
 795     case BINOP_ASSIGN:
 796     case BINOP_COMMA:
 797     case BINOP_SUBSCRIPT:
 798     case BINOP_EXP:
 799     case BINOP_MIN:
 800     case BINOP_MAX:
 801     case BINOP_INTDIV:
 802     case BINOP_ASSIGN_MODIFY:
 803     case BINOP_VAL:
 804     case BINOP_CONCAT:
 805     case BINOP_IN:
 806     case BINOP_RANGE:
 807     case BINOP_END:
 808     case STRUCTOP_MEMBER:
 809     case STRUCTOP_MPTR:
 810       elt = dump_subexp (exp, stream, elt);
 811       /* FALL THROUGH */
 812     case UNOP_NEG:
 813     case UNOP_LOGICAL_NOT:
 814     case UNOP_COMPLEMENT:
 815     case UNOP_IND:
 816     case UNOP_ADDR:
 817     case UNOP_PREINCREMENT:
 818     case UNOP_POSTINCREMENT:
 819     case UNOP_PREDECREMENT:
 820     case UNOP_POSTDECREMENT:
 821     case UNOP_SIZEOF:
 822     case UNOP_PLUS:
 823     case UNOP_CAP:
 824     case UNOP_CHR:
 825     case UNOP_ORD:
 826     case UNOP_ABS:
 827     case UNOP_FLOAT:
 828     case UNOP_HIGH:
 829     case UNOP_MAX:
 830     case UNOP_MIN:
 831     case UNOP_ODD:
 832     case UNOP_TRUNC:
 833       elt = dump_subexp (exp, stream, elt);
 834       break;
 835     case OP_LONG:
 836       fprintf_filtered (stream, "Type @");
 837       gdb_print_host_address (exp->elts[elt].type, stream);
 838       fprintf_filtered (stream, " (");
 839       type_print (exp->elts[elt].type, NULL, stream, 0);
 840       fprintf_filtered (stream, "), value %ld (0x%lx)",
 841                         (long) exp->elts[elt + 1].longconst,
 842                         (long) exp->elts[elt + 1].longconst);
 843       elt += 3;
 844       break;
 845     case OP_DOUBLE:
 846       fprintf_filtered (stream, "Type @");
 847       gdb_print_host_address (exp->elts[elt].type, stream);
 848       fprintf_filtered (stream, " (");
 849       type_print (exp->elts[elt].type, NULL, stream, 0);
 850       fprintf_filtered (stream, "), value %g",
 851                         (double) exp->elts[elt + 1].doubleconst);
 852       elt += 3;
 853       break;
 854     case OP_VAR_VALUE:
 855       fprintf_filtered (stream, "Block @");
 856       gdb_print_host_address (exp->elts[elt].block, stream);
 857       fprintf_filtered (stream, ", symbol @");
 858       gdb_print_host_address (exp->elts[elt + 1].symbol, stream);
 859       fprintf_filtered (stream, " (%s)",
 860                         SYMBOL_PRINT_NAME (exp->elts[elt + 1].symbol));
 861       elt += 3;
 862       break;
 863     case OP_VAR_ENTRY_VALUE:
 864       fprintf_filtered (stream, "Entry value of symbol @");
 865       gdb_print_host_address (exp->elts[elt].symbol, stream);
 866       fprintf_filtered (stream, " (%s)",
 867                         SYMBOL_PRINT_NAME (exp->elts[elt].symbol));
 868       elt += 2;
 869       break;
 870     case OP_LAST:
 871       fprintf_filtered (stream, "History element %ld",
 872                         (long) exp->elts[elt].longconst);
 873       elt += 2;
 874       break;
 875     case OP_REGISTER:
 876       fprintf_filtered (stream, "Register $%s", &exp->elts[elt + 1].string);
 877       elt += 3 + BYTES_TO_EXP_ELEM (exp->elts[elt].longconst + 1);
 878       break;
 879     case OP_INTERNALVAR:
 880       fprintf_filtered (stream, "Internal var @");
 881       gdb_print_host_address (exp->elts[elt].internalvar, stream);
 882       fprintf_filtered (stream, " (%s)",
 883                         internalvar_name (exp->elts[elt].internalvar));
 884       elt += 2;
 885       break;
 886     case OP_FUNCALL:
 887       {
 888         int i, nargs;
 889
 890         nargs = longest_to_int (exp->elts[elt].longconst);
 891
 892         fprintf_filtered (stream, "Number of args: %d", nargs);
 893         elt += 2;
 894
 895         for (i = 1; i <= nargs + 1; i++)
 896           elt = dump_subexp (exp, stream, elt);
 897       }
 898       break;
 899     case OP_ARRAY:
 900       {
 901         int lower, upper;
 902         int i;
 903
 904         lower = longest_to_int (exp->elts[elt].longconst);
 905         upper = longest_to_int (exp->elts[elt + 1].longconst);
 906
 907         fprintf_filtered (stream, "Bounds [%d:%d]", lower, upper);
 908         elt += 3;
 909
 910         for (i = 1; i <= upper - lower + 1; i++)
 911           elt = dump_subexp (exp, stream, elt);
 912       }
 913       break;
 914     case UNOP_DYNAMIC_CAST:
 915     case UNOP_REINTERPRET_CAST:
 916     case UNOP_CAST_TYPE:
 917     case UNOP_MEMVAL_TYPE:
 918       fprintf_filtered (stream, " (");
 919       elt = dump_subexp (exp, stream, elt);
 920       fprintf_filtered (stream, ")");
 921       elt = dump_subexp (exp, stream, elt);
 922       break;
 923     case UNOP_MEMVAL:
 924     case UNOP_CAST:
 925       fprintf_filtered (stream, "Type @");
 926       gdb_print_host_address (exp->elts[elt].type, stream);
 927       fprintf_filtered (stream, " (");
 928       type_print (exp->elts[elt].type, NULL, stream, 0);
 929       fprintf_filtered (stream, ")");
 930       elt = dump_subexp (exp, stream, elt + 2);
 931       break;
 932     case UNOP_MEMVAL_TLS:
 933       fprintf_filtered (stream, "TLS type @");
 934       gdb_print_host_address (exp->elts[elt + 1].type, stream);
 935       fprintf_filtered (stream, " (__thread /* \"%s\" */ ",
 936                         (exp->elts[elt].objfile == NULL ? "(null)"
 937                          : exp->elts[elt].objfile->name));
 938       type_print (exp->elts[elt + 1].type, NULL, stream, 0);
 939       fprintf_filtered (stream, ")");
 940       elt = dump_subexp (exp, stream, elt + 3);
 941       break;
 942     case OP_TYPE:
 943       fprintf_filtered (stream, "Type @");
 944       gdb_print_host_address (exp->elts[elt].type, stream);
 945       fprintf_filtered (stream, " (");
 946       type_print (exp->elts[elt].type, NULL, stream, 0);
 947       fprintf_filtered (stream, ")");
 948       elt += 2;
 949       break;
 950     case OP_TYPEOF:
 951     case OP_DECLTYPE:
 952       fprintf_filtered (stream, "Typeof (");
 953       elt = dump_subexp (exp, stream, elt);
 954       fprintf_filtered (stream, ")");
 955       break;
 956     case OP_TYPEID:
 957       fprintf_filtered (stream, "typeid (");
 958       elt = dump_subexp (exp, stream, elt);
 959       fprintf_filtered (stream, ")");
 960       break;
 961     case STRUCTOP_STRUCT:
 962     case STRUCTOP_PTR:
 963       {
 964         char *elem_name;
 965         int len;
 966
 967         len = longest_to_int (exp->elts[elt].longconst);
 968         elem_name = &exp->elts[elt + 1].string;
 969
 970         fprintf_filtered (stream, "Element name: `%.*s'", len, elem_name);
 971         elt = dump_subexp (exp, stream, elt + 3 + BYTES_TO_EXP_ELEM (len + 1));
 972       }
 973       break;
 974     case OP_SCOPE:
 975       {
 976         char *elem_name;
 977         int len;
 978
 979         fprintf_filtered (stream, "Type @");
 980         gdb_print_host_address (exp->elts[elt].type, stream);
 981         fprintf_filtered (stream, " (");
 982         type_print (exp->elts[elt].type, NULL, stream, 0);
 983         fprintf_filtered (stream, ") ");
 984
 985         len = longest_to_int (exp->elts[elt + 1].longconst);
 986         elem_name = &exp->elts[elt + 2].string;
 987
 988         fprintf_filtered (stream, "Field name: `%.*s'", len, elem_name);
 989         elt += 4 + BYTES_TO_EXP_ELEM (len + 1);
 990       }
 991       break;
 992     case TYPE_INSTANCE:
 993       {
 994         LONGEST len;
 995
 996         len = exp->elts[elt++].longconst;
 997         fprintf_filtered (stream, "%s TypeInstance: ", plongest (len));
 998         while (len-- > 0)
 999           {
1000             fprintf_filtered (stream, "Type @");
1001             gdb_print_host_address (exp->elts[elt].type, stream);
1002             fprintf_filtered (stream, " (");
1003             type_print (exp->elts[elt].type, NULL, stream, 0);
1004             fprintf_filtered (stream, ")");
1005             elt++;
1006             if (len > 0)
1007               fputs_filtered (", ", stream);
1008           }
1009         /* Ending LEN and ending TYPE_INSTANCE.  */
1010         elt += 2;
1011         elt = dump_subexp (exp, stream, elt);
1012       }
1013       break;
1014     default:
1015     case OP_NULL:
1016     case MULTI_SUBSCRIPT:
1017     case OP_F77_UNDETERMINED_ARGLIST:
1018     case OP_COMPLEX:
1019     case OP_STRING:
1020     case OP_BOOL:
1021     case OP_M2_STRING:
1022     case OP_THIS:
1023     case OP_NAME:
1024       fprintf_filtered (stream, "Unknown format");
1025     }
1026
1027   return elt;
1028 }
1029
1030 void
1031 dump_prefix_expression (struct expression *exp, struct ui_file *stream)
1032 {
1033   int elt;
1034
1035   fprintf_filtered (stream, "Dump of expression @ ");
1036   gdb_print_host_address (exp, stream);
1037   fputs_filtered (", after conversion to prefix form:\nExpression: `", stream);
1038   print_expression (exp, stream);
1039   fprintf_filtered (stream, "'\n\tLanguage %s, %d elements, %ld bytes each.\n",
1040                     exp->language_defn->la_name, exp->nelts,
1041                     (long) sizeof (union exp_element));
1042   fputs_filtered ("\n", stream);
1043
1044   for (elt = 0; elt < exp->nelts;)
1045     elt = dump_subexp (exp, stream, elt);
1046   fputs_filtered ("\n", stream);
1047 }