gdb/expprint.c

   1 /* Print in infix form a struct expression.
   2
   3    Copyright (C) 1986-2020 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 "block.h"
  30 #include "objfiles.h"
  31 #include "valprint.h"
  32 #include "cli/cli-style.h"
  33
  34 #include <ctype.h>
  35
  36 void
  37 print_expression (struct expression *exp, struct ui_file *stream)
  38 {
  39   int pc = 0;
  40
  41   print_subexp (exp, &pc, stream, PREC_NULL);
  42 }
  43
  44 /* Print the subexpression of EXP that starts in position POS, on STREAM.
  45    PREC is the precedence of the surrounding operator;
  46    if the precedence of the main operator of this subexpression is less,
  47    parentheses are needed here.  */
  48
  49 void
  50 print_subexp (struct expression *exp, int *pos,
  51               struct ui_file *stream, enum precedence prec)
  52 {
  53   exp->language_defn->la_exp_desc->print_subexp (exp, pos, stream, prec);
  54 }
  55
  56 /* Standard implementation of print_subexp for use in language_defn
  57    vectors.  */
  58 void
  59 print_subexp_standard (struct expression *exp, int *pos,
  60                        struct ui_file *stream, enum precedence prec)
  61 {
  62   unsigned tem;
  63   const struct op_print *op_print_tab;
  64   int pc;
  65   unsigned nargs;
  66   const char *op_str;
  67   int assign_modify = 0;
  68   enum exp_opcode opcode;
  69   enum precedence myprec = PREC_NULL;
  70   /* Set to 1 for a right-associative operator.  */
  71   int assoc = 0;
  72   struct value *val;
  73   char *tempstr = NULL;
  74
  75   op_print_tab = exp->language_defn->la_op_print_tab;
  76   pc = (*pos)++;
  77   opcode = exp->elts[pc].opcode;
  78   switch (opcode)
  79     {
  80       /* Common ops */
  81
  82     case OP_TYPE:
  83       (*pos) += 2;
  84       type_print (exp->elts[pc + 1].type, "", stream, 0);
  85       return;
  86
  87     case OP_SCOPE:
  88       myprec = PREC_PREFIX;
  89       assoc = 0;
  90       fputs_filtered (exp->elts[pc + 1].type->name (), stream);
  91       fputs_filtered ("::", stream);
  92       nargs = longest_to_int (exp->elts[pc + 2].longconst);
  93       (*pos) += 4 + BYTES_TO_EXP_ELEM (nargs + 1);
  94       fputs_filtered (&exp->elts[pc + 3].string, stream);
  95       return;
  96
  97     case OP_LONG:
  98       {
  99         struct value_print_options opts;
 100
 101         get_no_prettyformat_print_options (&opts);
 102         (*pos) += 3;
 103         value_print (value_from_longest (exp->elts[pc + 1].type,
 104                                          exp->elts[pc + 2].longconst),
 105                      stream, &opts);
 106       }
 107       return;
 108
 109     case OP_FLOAT:
 110       {
 111         struct value_print_options opts;
 112
 113         get_no_prettyformat_print_options (&opts);
 114         (*pos) += 3;
 115         value_print (value_from_contents (exp->elts[pc + 1].type,
 116                                           exp->elts[pc + 2].floatconst),
 117                      stream, &opts);
 118       }
 119       return;
 120
 121     case OP_VAR_VALUE:
 122       {
 123         const struct block *b;
 124
 125         (*pos) += 3;
 126         b = exp->elts[pc + 1].block;
 127         if (b != NULL
 128             && BLOCK_FUNCTION (b) != NULL
 129             && BLOCK_FUNCTION (b)->print_name () != NULL)
 130           {
 131             fputs_filtered (BLOCK_FUNCTION (b)->print_name (), stream);
 132             fputs_filtered ("::", stream);
 133           }
 134         fputs_filtered (exp->elts[pc + 2].symbol->print_name (), stream);
 135       }
 136       return;
 137
 138     case OP_VAR_MSYM_VALUE:
 139       {
 140         (*pos) += 3;
 141         fputs_filtered (exp->elts[pc + 2].msymbol->print_name (), stream);
 142       }
 143       return;
 144
 145     case OP_FUNC_STATIC_VAR:
 146       {
 147         tem = longest_to_int (exp->elts[pc + 1].longconst);
 148         (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 149         fputs_filtered (&exp->elts[pc + 1].string, stream);
 150       }
 151       return;
 152
 153     case OP_VAR_ENTRY_VALUE:
 154       {
 155         (*pos) += 2;
 156         fprintf_filtered (stream, "%s@entry",
 157                           exp->elts[pc + 1].symbol->print_name ());
 158       }
 159       return;
 160
 161     case OP_LAST:
 162       (*pos) += 2;
 163       fprintf_filtered (stream, "$%d",
 164                         longest_to_int (exp->elts[pc + 1].longconst));
 165       return;
 166
 167     case OP_REGISTER:
 168       {
 169         const char *name = &exp->elts[pc + 2].string;
 170
 171         (*pos) += 3 + BYTES_TO_EXP_ELEM (exp->elts[pc + 1].longconst + 1);
 172         fprintf_filtered (stream, "$%s", name);
 173         return;
 174       }
 175
 176     case OP_BOOL:
 177       (*pos) += 2;
 178       fprintf_filtered (stream, "%s",
 179                         longest_to_int (exp->elts[pc + 1].longconst)
 180                         ? "TRUE" : "FALSE");
 181       return;
 182
 183     case OP_INTERNALVAR:
 184       (*pos) += 2;
 185       fprintf_filtered (stream, "$%s",
 186                         internalvar_name (exp->elts[pc + 1].internalvar));
 187       return;
 188
 189     case OP_FUNCALL:
 190     case OP_F77_UNDETERMINED_ARGLIST:
 191       (*pos) += 2;
 192       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 193       print_subexp (exp, pos, stream, PREC_SUFFIX);
 194       fputs_filtered (" (", stream);
 195       for (tem = 0; tem < nargs; tem++)
 196         {
 197           if (tem != 0)
 198             fputs_filtered (", ", stream);
 199           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 200         }
 201       fputs_filtered (")", stream);
 202       return;
 203
 204     case OP_NAME:
 205       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 206       (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 207       fputs_filtered (&exp->elts[pc + 2].string, stream);
 208       return;
 209
 210     case OP_STRING:
 211       {
 212         struct value_print_options opts;
 213
 214         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 215         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 216         /* LA_PRINT_STRING will print using the current repeat count threshold.
 217            If necessary, we can temporarily set it to zero, or pass it as an
 218            additional parameter to LA_PRINT_STRING.  -fnf */
 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       }
 224       return;
 225
 226     case OP_OBJC_NSSTRING:      /* Objective-C Foundation Class
 227                                    NSString constant.  */
 228       {
 229         struct value_print_options opts;
 230
 231         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 232         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 233         fputs_filtered ("@\"", stream);
 234         get_user_print_options (&opts);
 235         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 236                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 237                          NULL, 0, &opts);
 238         fputs_filtered ("\"", stream);
 239       }
 240       return;
 241
 242     case OP_OBJC_MSGCALL:
 243       {                 /* Objective C message (method) call.  */
 244         (*pos) += 3;
 245         nargs = longest_to_int (exp->elts[pc + 2].longconst);
 246         fprintf_unfiltered (stream, "[");
 247         print_subexp (exp, pos, stream, PREC_SUFFIX);
 248         gdb::unique_xmalloc_ptr<char> selector
 249           = target_read_string (exp->elts[pc + 1].longconst, 1024);
 250         if (selector == nullptr)
 251           error (_("bad selector"));
 252         if (nargs)
 253           {
 254             char *s, *nextS;
 255
 256             s = selector.get ();
 257             for (tem = 0; tem < nargs; tem++)
 258               {
 259                 nextS = strchr (s, ':');
 260                 gdb_assert (nextS);     /* Make sure we found ':'.  */
 261                 *nextS = '\0';
 262                 fprintf_unfiltered (stream, " %s: ", s);
 263                 s = nextS + 1;
 264                 print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 265               }
 266           }
 267         else
 268           {
 269             fprintf_unfiltered (stream, " %s", selector.get ());
 270           }
 271         fprintf_unfiltered (stream, "]");
 272         return;
 273       }
 274
 275     case OP_ARRAY:
 276       (*pos) += 3;
 277       nargs = longest_to_int (exp->elts[pc + 2].longconst);
 278       nargs -= longest_to_int (exp->elts[pc + 1].longconst);
 279       nargs++;
 280       tem = 0;
 281       if (exp->elts[pc + 4].opcode == OP_LONG
 282           && exp->elts[pc + 5].type
 283              == builtin_type (exp->gdbarch)->builtin_char
 284           && exp->language_defn->la_language == language_c)
 285         {
 286           /* Attempt to print C character arrays using string syntax.
 287              Walk through the args, picking up one character from each
 288              of the OP_LONG expression elements.  If any array element
 289              does not match our expection of what we should find for
 290              a simple string, revert back to array printing.  Note that
 291              the last expression element is an explicit null terminator
 292              byte, which doesn't get printed.  */
 293           tempstr = (char *) alloca (nargs);
 294           pc += 4;
 295           while (tem < nargs)
 296             {
 297               if (exp->elts[pc].opcode != OP_LONG
 298                   || exp->elts[pc + 1].type
 299                      != builtin_type (exp->gdbarch)->builtin_char)
 300                 {
 301                   /* Not a simple array of char, use regular array
 302                      printing.  */
 303                   tem = 0;
 304                   break;
 305                 }
 306               else
 307                 {
 308                   tempstr[tem++] =
 309                     longest_to_int (exp->elts[pc + 2].longconst);
 310                   pc += 4;
 311                 }
 312             }
 313         }
 314       if (tem > 0)
 315         {
 316           struct value_print_options opts;
 317
 318           get_user_print_options (&opts);
 319           LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 320                            (gdb_byte *) tempstr, nargs - 1, NULL, 0, &opts);
 321           (*pos) = pc;
 322         }
 323       else
 324         {
 325           fputs_filtered (" {", stream);
 326           for (tem = 0; tem < nargs; tem++)
 327             {
 328               if (tem != 0)
 329                 {
 330                   fputs_filtered (", ", stream);
 331                 }
 332               print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 333             }
 334           fputs_filtered ("}", stream);
 335         }
 336       return;
 337
 338     case TERNOP_COND:
 339       if ((int) prec > (int) PREC_COMMA)
 340         fputs_filtered ("(", stream);
 341       /* Print the subexpressions, forcing parentheses
 342          around any binary operations within them.
 343          This is more parentheses than are strictly necessary,
 344          but it looks clearer.  */
 345       print_subexp (exp, pos, stream, PREC_HYPER);
 346       fputs_filtered (" ? ", stream);
 347       print_subexp (exp, pos, stream, PREC_HYPER);
 348       fputs_filtered (" : ", stream);
 349       print_subexp (exp, pos, stream, PREC_HYPER);
 350       if ((int) prec > (int) PREC_COMMA)
 351         fputs_filtered (")", stream);
 352       return;
 353
 354     case TERNOP_SLICE:
 355       print_subexp (exp, pos, stream, PREC_SUFFIX);
 356       fputs_filtered ("(", stream);
 357       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 358       fputs_filtered (opcode == TERNOP_SLICE ? " : " : " UP ", stream);
 359       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 360       fputs_filtered (")", stream);
 361       return;
 362
 363     case STRUCTOP_STRUCT:
 364       tem = longest_to_int (exp->elts[pc + 1].longconst);
 365       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 366       print_subexp (exp, pos, stream, PREC_SUFFIX);
 367       fputs_filtered (".", stream);
 368       fputs_filtered (&exp->elts[pc + 2].string, stream);
 369       return;
 370
 371       /* Will not occur for Modula-2.  */
 372     case STRUCTOP_PTR:
 373       tem = longest_to_int (exp->elts[pc + 1].longconst);
 374       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 375       print_subexp (exp, pos, stream, PREC_SUFFIX);
 376       fputs_filtered ("->", stream);
 377       fputs_filtered (&exp->elts[pc + 2].string, stream);
 378       return;
 379
 380     case STRUCTOP_MEMBER:
 381       print_subexp (exp, pos, stream, PREC_SUFFIX);
 382       fputs_filtered (".*", stream);
 383       print_subexp (exp, pos, stream, PREC_SUFFIX);
 384       return;
 385
 386     case STRUCTOP_MPTR:
 387       print_subexp (exp, pos, stream, PREC_SUFFIX);
 388       fputs_filtered ("->*", stream);
 389       print_subexp (exp, pos, stream, PREC_SUFFIX);
 390       return;
 391
 392     case BINOP_SUBSCRIPT:
 393       print_subexp (exp, pos, stream, PREC_SUFFIX);
 394       fputs_filtered ("[", stream);
 395       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 396       fputs_filtered ("]", stream);
 397       return;
 398
 399     case UNOP_POSTINCREMENT:
 400       print_subexp (exp, pos, stream, PREC_SUFFIX);
 401       fputs_filtered ("++", stream);
 402       return;
 403
 404     case UNOP_POSTDECREMENT:
 405       print_subexp (exp, pos, stream, PREC_SUFFIX);
 406       fputs_filtered ("--", stream);
 407       return;
 408
 409     case UNOP_CAST:
 410       (*pos) += 2;
 411       if ((int) prec > (int) PREC_PREFIX)
 412         fputs_filtered ("(", stream);
 413       fputs_filtered ("(", stream);
 414       type_print (exp->elts[pc + 1].type, "", stream, 0);
 415       fputs_filtered (") ", stream);
 416       print_subexp (exp, pos, stream, PREC_PREFIX);
 417       if ((int) prec > (int) PREC_PREFIX)
 418         fputs_filtered (")", stream);
 419       return;
 420
 421     case UNOP_CAST_TYPE:
 422       if ((int) prec > (int) PREC_PREFIX)
 423         fputs_filtered ("(", stream);
 424       fputs_filtered ("(", stream);
 425       print_subexp (exp, pos, stream, PREC_PREFIX);
 426       fputs_filtered (") ", stream);
 427       print_subexp (exp, pos, stream, PREC_PREFIX);
 428       if ((int) prec > (int) PREC_PREFIX)
 429         fputs_filtered (")", stream);
 430       return;
 431
 432     case UNOP_DYNAMIC_CAST:
 433     case UNOP_REINTERPRET_CAST:
 434       fputs_filtered (opcode == UNOP_DYNAMIC_CAST ? "dynamic_cast"
 435                       : "reinterpret_cast", stream);
 436       fputs_filtered ("<", stream);
 437       print_subexp (exp, pos, stream, PREC_PREFIX);
 438       fputs_filtered ("> (", stream);
 439       print_subexp (exp, pos, stream, PREC_PREFIX);
 440       fputs_filtered (")", stream);
 441       return;
 442
 443     case UNOP_MEMVAL:
 444       (*pos) += 2;
 445       if ((int) prec > (int) PREC_PREFIX)
 446         fputs_filtered ("(", stream);
 447       if (exp->elts[pc + 1].type->code () == TYPE_CODE_FUNC
 448           && exp->elts[pc + 3].opcode == OP_LONG)
 449         {
 450           struct value_print_options opts;
 451
 452           /* We have a minimal symbol fn, probably.  It's encoded
 453              as a UNOP_MEMVAL (function-type) of an OP_LONG (int, address).
 454              Swallow the OP_LONG (including both its opcodes); ignore
 455              its type; print the value in the type of the MEMVAL.  */
 456           (*pos) += 4;
 457           val = value_at_lazy (exp->elts[pc + 1].type,
 458                                (CORE_ADDR) exp->elts[pc + 5].longconst);
 459           get_no_prettyformat_print_options (&opts);
 460           value_print (val, stream, &opts);
 461         }
 462       else
 463         {
 464           fputs_filtered ("{", stream);
 465           type_print (exp->elts[pc + 1].type, "", stream, 0);
 466           fputs_filtered ("} ", stream);
 467           print_subexp (exp, pos, stream, PREC_PREFIX);
 468         }
 469       if ((int) prec > (int) PREC_PREFIX)
 470         fputs_filtered (")", stream);
 471       return;
 472
 473     case UNOP_MEMVAL_TYPE:
 474       if ((int) prec > (int) PREC_PREFIX)
 475         fputs_filtered ("(", stream);
 476       fputs_filtered ("{", stream);
 477       print_subexp (exp, pos, stream, PREC_PREFIX);
 478       fputs_filtered ("} ", stream);
 479       print_subexp (exp, pos, stream, PREC_PREFIX);
 480       if ((int) prec > (int) PREC_PREFIX)
 481         fputs_filtered (")", stream);
 482       return;
 483
 484     case BINOP_ASSIGN_MODIFY:
 485       opcode = exp->elts[pc + 1].opcode;
 486       (*pos) += 2;
 487       myprec = PREC_ASSIGN;
 488       assoc = 1;
 489       assign_modify = 1;
 490       op_str = "???";
 491       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 492         if (op_print_tab[tem].opcode == opcode)
 493           {
 494             op_str = op_print_tab[tem].string;
 495             break;
 496           }
 497       if (op_print_tab[tem].opcode != opcode)
 498         /* Not found; don't try to keep going because we don't know how
 499            to interpret further elements.  */
 500         error (_("Invalid expression"));
 501       break;
 502
 503       /* C++ ops */
 504
 505     case OP_THIS:
 506       ++(*pos);
 507       if (exp->language_defn->la_name_of_this)
 508         fputs_filtered (exp->language_defn->la_name_of_this, stream);
 509       else
 510         fprintf_styled (stream, metadata_style.style (),
 511                         _("<language %s has no 'this'>"),
 512                         exp->language_defn->la_name);
 513       return;
 514
 515       /* Modula-2 ops */
 516
 517     case MULTI_SUBSCRIPT:
 518       (*pos) += 2;
 519       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 520       print_subexp (exp, pos, stream, PREC_SUFFIX);
 521       fprintf_unfiltered (stream, " [");
 522       for (tem = 0; tem < nargs; tem++)
 523         {
 524           if (tem != 0)
 525             fprintf_unfiltered (stream, ", ");
 526           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 527         }
 528       fprintf_unfiltered (stream, "]");
 529       return;
 530
 531     case BINOP_VAL:
 532       (*pos) += 2;
 533       fprintf_unfiltered (stream, "VAL(");
 534       type_print (exp->elts[pc + 1].type, "", stream, 0);
 535       fprintf_unfiltered (stream, ",");
 536       print_subexp (exp, pos, stream, PREC_PREFIX);
 537       fprintf_unfiltered (stream, ")");
 538       return;
 539
 540     case TYPE_INSTANCE:
 541       {
 542         type_instance_flags flags
 543           = (type_instance_flag_value) longest_to_int (exp->elts[pc + 1].longconst);
 544         LONGEST count = exp->elts[pc + 2].longconst;
 545
 546         /* The FLAGS.  */
 547         (*pos)++;
 548         /* The COUNT.  */
 549         (*pos)++;
 550         fputs_unfiltered ("TypeInstance(", stream);
 551         while (count-- > 0)
 552           {
 553             type_print (exp->elts[(*pos)++].type, "", stream, 0);
 554             if (count > 0)
 555               fputs_unfiltered (",", stream);
 556           }
 557         fputs_unfiltered (",", stream);
 558         /* Ending COUNT and ending TYPE_INSTANCE.  */
 559         (*pos) += 2;
 560         print_subexp (exp, pos, stream, PREC_PREFIX);
 561
 562         if (flags & TYPE_INSTANCE_FLAG_CONST)
 563           fputs_unfiltered (",const", stream);
 564         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
 565           fputs_unfiltered (",volatile", stream);
 566
 567         fputs_unfiltered (")", stream);
 568         return;
 569       }
 570
 571     case OP_RANGE:
 572       {
 573         enum range_type range_type;
 574
 575         range_type = (enum range_type)
 576           longest_to_int (exp->elts[pc + 1].longconst);
 577         *pos += 2;
 578
 579         if (range_type == NONE_BOUND_DEFAULT_EXCLUSIVE
 580             || range_type == LOW_BOUND_DEFAULT_EXCLUSIVE)
 581           fputs_filtered ("EXCLUSIVE_", stream);
 582         fputs_filtered ("RANGE(", stream);
 583         if (range_type == HIGH_BOUND_DEFAULT
 584             || range_type == NONE_BOUND_DEFAULT
 585             || range_type == NONE_BOUND_DEFAULT_EXCLUSIVE)
 586           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 587         fputs_filtered ("..", stream);
 588         if (range_type == LOW_BOUND_DEFAULT
 589             || range_type == NONE_BOUND_DEFAULT)
 590           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 591         fputs_filtered (")", stream);
 592         return;
 593       }
 594
 595       /* Default ops */
 596
 597     default:
 598       op_str = "???";
 599       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 600         if (op_print_tab[tem].opcode == opcode)
 601           {
 602             op_str = op_print_tab[tem].string;
 603             myprec = op_print_tab[tem].precedence;
 604             assoc = op_print_tab[tem].right_assoc;
 605             break;
 606           }
 607       if (op_print_tab[tem].opcode != opcode)
 608         /* Not found; don't try to keep going because we don't know how
 609            to interpret further elements.  For example, this happens
 610            if opcode is OP_TYPE.  */
 611         error (_("Invalid expression"));
 612     }
 613
 614   /* Note that PREC_BUILTIN will always emit parentheses.  */
 615   if ((int) myprec < (int) prec)
 616     fputs_filtered ("(", stream);
 617   if ((int) opcode > (int) BINOP_END)
 618     {
 619       if (assoc)
 620         {
 621           /* Unary postfix operator.  */
 622           print_subexp (exp, pos, stream, PREC_SUFFIX);
 623           fputs_filtered (op_str, stream);
 624         }
 625       else
 626         {
 627           /* Unary prefix operator.  */
 628           fputs_filtered (op_str, stream);
 629           if (myprec == PREC_BUILTIN_FUNCTION)
 630             fputs_filtered ("(", stream);
 631           print_subexp (exp, pos, stream, PREC_PREFIX);
 632           if (myprec == PREC_BUILTIN_FUNCTION)
 633             fputs_filtered (")", stream);
 634         }
 635     }
 636   else
 637     {
 638       /* Binary operator.  */
 639       /* Print left operand.
 640          If operator is right-associative,
 641          increment precedence for this operand.  */
 642       print_subexp (exp, pos, stream,
 643                     (enum precedence) ((int) myprec + assoc));
 644       /* Print the operator itself.  */
 645       if (assign_modify)
 646         fprintf_filtered (stream, " %s= ", op_str);
 647       else if (op_str[0] == ',')
 648         fprintf_filtered (stream, "%s ", op_str);
 649       else
 650         fprintf_filtered (stream, " %s ", op_str);
 651       /* Print right operand.
 652          If operator is left-associative,
 653          increment precedence for this operand.  */
 654       print_subexp (exp, pos, stream,
 655                     (enum precedence) ((int) myprec + !assoc));
 656     }
 657
 658   if ((int) myprec < (int) prec)
 659     fputs_filtered (")", stream);
 660 }
 661
 662 /* Return the operator corresponding to opcode OP as
 663    a string.   NULL indicates that the opcode was not found in the
 664    current language table.  */
 665 const char *
 666 op_string (enum exp_opcode op)
 667 {
 668   int tem;
 669   const struct op_print *op_print_tab;
 670
 671   op_print_tab = current_language->la_op_print_tab;
 672   for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 673     if (op_print_tab[tem].opcode == op)
 674       return op_print_tab[tem].string;
 675   return NULL;
 676 }
 677
 678 /* Support for dumping the raw data from expressions in a human readable
 679    form.  */
 680
 681 static int dump_subexp_body (struct expression *exp, struct ui_file *, int);
 682
 683 /* Name for OPCODE, when it appears in expression EXP.  */
 684
 685 const char *
 686 op_name (struct expression *exp, enum exp_opcode opcode)
 687 {
 688   if (opcode >= OP_UNUSED_LAST)
 689     {
 690       char *cell = get_print_cell ();
 691       xsnprintf (cell, PRINT_CELL_SIZE, "unknown opcode: %u",
 692                  unsigned (opcode));
 693       return cell;
 694     }
 695   return exp->language_defn->la_exp_desc->op_name (opcode);
 696 }
 697
 698 /* Default name for the standard operator OPCODE (i.e., one defined in
 699    the definition of enum exp_opcode).  */
 700
 701 const char *
 702 op_name_standard (enum exp_opcode opcode)
 703 {
 704   switch (opcode)
 705     {
 706     default:
 707       {
 708         static char buf[30];
 709
 710         xsnprintf (buf, sizeof (buf), "<unknown %d>", opcode);
 711         return buf;
 712       }
 713 #define OP(name)        \
 714     case name:          \
 715       return #name ;
 716 #include "std-operator.def"
 717 #undef OP
 718     }
 719 }
 720
 721 /* Print a raw dump of expression EXP to STREAM.
 722    NOTE, if non-NULL, is printed as extra explanatory text.  */
 723
 724 void
 725 dump_raw_expression (struct expression *exp, struct ui_file *stream,
 726                      const char *note)
 727 {
 728   int elt;
 729   char *eltscan;
 730   int eltsize;
 731
 732   fprintf_filtered (stream, "Dump of expression @ ");
 733   gdb_print_host_address (exp, stream);
 734   if (note)
 735     fprintf_filtered (stream, ", %s:", note);
 736   fprintf_filtered (stream, "\n\tLanguage %s, %d elements, %ld bytes each.\n",
 737                     exp->language_defn->la_name, exp->nelts,
 738                     (long) sizeof (union exp_element));
 739   fprintf_filtered (stream, "\t%5s  %20s  %16s  %s\n", "Index", "Opcode",
 740                     "Hex Value", "String Value");
 741   for (elt = 0; elt < exp->nelts; elt++)
 742     {
 743       fprintf_filtered (stream, "\t%5d  ", elt);
 744
 745       const char *opcode_name = op_name (exp, exp->elts[elt].opcode);
 746       fprintf_filtered (stream, "%20s  ", opcode_name);
 747
 748       print_longest (stream, 'd', 0, exp->elts[elt].longconst);
 749       fprintf_filtered (stream, "  ");
 750
 751       for (eltscan = (char *) &exp->elts[elt],
 752            eltsize = sizeof (union exp_element);
 753            eltsize-- > 0;
 754            eltscan++)
 755         {
 756           fprintf_filtered (stream, "%c",
 757                             isprint (*eltscan) ? (*eltscan & 0xFF) : '.');
 758         }
 759       fprintf_filtered (stream, "\n");
 760     }
 761 }
 762
 763 /* Dump the subexpression of prefix expression EXP whose operator is at
 764    position ELT onto STREAM.  Returns the position of the next
 765    subexpression in EXP.  */
 766
 767 int
 768 dump_subexp (struct expression *exp, struct ui_file *stream, int elt)
 769 {
 770   static int indent = 0;
 771   int i;
 772
 773   fprintf_filtered (stream, "\n");
 774   fprintf_filtered (stream, "\t%5d  ", elt);
 775
 776   for (i = 1; i <= indent; i++)
 777     fprintf_filtered (stream, " ");
 778   indent += 2;
 779
 780   fprintf_filtered (stream, "%-20s  ", op_name (exp, exp->elts[elt].opcode));
 781
 782   elt = dump_subexp_body (exp, stream, elt);
 783
 784   indent -= 2;
 785
 786   return elt;
 787 }
 788
 789 /* Dump the operands of prefix expression EXP whose opcode is at
 790    position ELT onto STREAM.  Returns the position of the next
 791    subexpression in EXP.  */
 792
 793 static int
 794 dump_subexp_body (struct expression *exp, struct ui_file *stream, int elt)
 795 {
 796   return exp->language_defn->la_exp_desc->dump_subexp_body (exp, stream, elt);
 797 }
 798
 799 /* Default value for subexp_body in exp_descriptor vector.  */
 800
 801 int
 802 dump_subexp_body_standard (struct expression *exp,
 803                            struct ui_file *stream, int elt)
 804 {
 805   int opcode = exp->elts[elt++].opcode;
 806
 807   switch (opcode)
 808     {
 809     case TERNOP_COND:
 810     case TERNOP_SLICE:
 811       elt = dump_subexp (exp, stream, elt);
 812       /* FALL THROUGH */
 813     case BINOP_ADD:
 814     case BINOP_SUB:
 815     case BINOP_MUL:
 816     case BINOP_DIV:
 817     case BINOP_REM:
 818     case BINOP_MOD:
 819     case BINOP_LSH:
 820     case BINOP_RSH:
 821     case BINOP_LOGICAL_AND:
 822     case BINOP_LOGICAL_OR:
 823     case BINOP_BITWISE_AND:
 824     case BINOP_BITWISE_IOR:
 825     case BINOP_BITWISE_XOR:
 826     case BINOP_EQUAL:
 827     case BINOP_NOTEQUAL:
 828     case BINOP_LESS:
 829     case BINOP_GTR:
 830     case BINOP_LEQ:
 831     case BINOP_GEQ:
 832     case BINOP_REPEAT:
 833     case BINOP_ASSIGN:
 834     case BINOP_COMMA:
 835     case BINOP_SUBSCRIPT:
 836     case BINOP_EXP:
 837     case BINOP_MIN:
 838     case BINOP_MAX:
 839     case BINOP_INTDIV:
 840     case BINOP_ASSIGN_MODIFY:
 841     case BINOP_VAL:
 842     case BINOP_CONCAT:
 843     case BINOP_END:
 844     case STRUCTOP_MEMBER:
 845     case STRUCTOP_MPTR:
 846       elt = dump_subexp (exp, stream, elt);
 847       /* FALL THROUGH */
 848     case UNOP_NEG:
 849     case UNOP_LOGICAL_NOT:
 850     case UNOP_COMPLEMENT:
 851     case UNOP_IND:
 852     case UNOP_ADDR:
 853     case UNOP_PREINCREMENT:
 854     case UNOP_POSTINCREMENT:
 855     case UNOP_PREDECREMENT:
 856     case UNOP_POSTDECREMENT:
 857     case UNOP_SIZEOF:
 858     case UNOP_ALIGNOF:
 859     case UNOP_PLUS:
 860     case UNOP_CAP:
 861     case UNOP_CHR:
 862     case UNOP_ORD:
 863     case UNOP_ABS:
 864     case UNOP_FLOAT:
 865     case UNOP_HIGH:
 866     case UNOP_MAX:
 867     case UNOP_MIN:
 868     case UNOP_ODD:
 869     case UNOP_TRUNC:
 870       elt = dump_subexp (exp, stream, elt);
 871       break;
 872     case OP_LONG:
 873       fprintf_filtered (stream, "Type @");
 874       gdb_print_host_address (exp->elts[elt].type, stream);
 875       fprintf_filtered (stream, " (");
 876       type_print (exp->elts[elt].type, NULL, stream, 0);
 877       fprintf_filtered (stream, "), value %ld (0x%lx)",
 878                         (long) exp->elts[elt + 1].longconst,
 879                         (long) exp->elts[elt + 1].longconst);
 880       elt += 3;
 881       break;
 882     case OP_FLOAT:
 883       fprintf_filtered (stream, "Type @");
 884       gdb_print_host_address (exp->elts[elt].type, stream);
 885       fprintf_filtered (stream, " (");
 886       type_print (exp->elts[elt].type, NULL, stream, 0);
 887       fprintf_filtered (stream, "), value ");
 888       print_floating (exp->elts[elt + 1].floatconst,
 889                       exp->elts[elt].type, stream);
 890       elt += 3;
 891       break;
 892     case OP_VAR_VALUE:
 893       fprintf_filtered (stream, "Block @");
 894       gdb_print_host_address (exp->elts[elt].block, stream);
 895       fprintf_filtered (stream, ", symbol @");
 896       gdb_print_host_address (exp->elts[elt + 1].symbol, stream);
 897       fprintf_filtered (stream, " (%s)",
 898                         exp->elts[elt + 1].symbol->print_name ());
 899       elt += 3;
 900       break;
 901     case OP_VAR_MSYM_VALUE:
 902       fprintf_filtered (stream, "Objfile @");
 903       gdb_print_host_address (exp->elts[elt].objfile, stream);
 904       fprintf_filtered (stream, ", msymbol @");
 905       gdb_print_host_address (exp->elts[elt + 1].msymbol, stream);
 906       fprintf_filtered (stream, " (%s)",
 907                         exp->elts[elt + 1].msymbol->print_name ());
 908       elt += 3;
 909       break;
 910     case OP_VAR_ENTRY_VALUE:
 911       fprintf_filtered (stream, "Entry value of symbol @");
 912       gdb_print_host_address (exp->elts[elt].symbol, stream);
 913       fprintf_filtered (stream, " (%s)",
 914                         exp->elts[elt].symbol->print_name ());
 915       elt += 2;
 916       break;
 917     case OP_LAST:
 918       fprintf_filtered (stream, "History element %ld",
 919                         (long) exp->elts[elt].longconst);
 920       elt += 2;
 921       break;
 922     case OP_REGISTER:
 923       fprintf_filtered (stream, "Register $%s", &exp->elts[elt + 1].string);
 924       elt += 3 + BYTES_TO_EXP_ELEM (exp->elts[elt].longconst + 1);
 925       break;
 926     case OP_INTERNALVAR:
 927       fprintf_filtered (stream, "Internal var @");
 928       gdb_print_host_address (exp->elts[elt].internalvar, stream);
 929       fprintf_filtered (stream, " (%s)",
 930                         internalvar_name (exp->elts[elt].internalvar));
 931       elt += 2;
 932       break;
 933     case OP_FUNCALL:
 934     case OP_F77_UNDETERMINED_ARGLIST:
 935       {
 936         int i, nargs;
 937
 938         nargs = longest_to_int (exp->elts[elt].longconst);
 939
 940         fprintf_filtered (stream, "Number of args: %d", nargs);
 941         elt += 2;
 942
 943         for (i = 1; i <= nargs + 1; i++)
 944           elt = dump_subexp (exp, stream, elt);
 945       }
 946       break;
 947     case OP_ARRAY:
 948       {
 949         int lower, upper;
 950         int i;
 951
 952         lower = longest_to_int (exp->elts[elt].longconst);
 953         upper = longest_to_int (exp->elts[elt + 1].longconst);
 954
 955         fprintf_filtered (stream, "Bounds [%d:%d]", lower, upper);
 956         elt += 3;
 957
 958         for (i = 1; i <= upper - lower + 1; i++)
 959           elt = dump_subexp (exp, stream, elt);
 960       }
 961       break;
 962     case UNOP_DYNAMIC_CAST:
 963     case UNOP_REINTERPRET_CAST:
 964     case UNOP_CAST_TYPE:
 965     case UNOP_MEMVAL_TYPE:
 966       fprintf_filtered (stream, " (");
 967       elt = dump_subexp (exp, stream, elt);
 968       fprintf_filtered (stream, ")");
 969       elt = dump_subexp (exp, stream, elt);
 970       break;
 971     case UNOP_MEMVAL:
 972     case UNOP_CAST:
 973       fprintf_filtered (stream, "Type @");
 974       gdb_print_host_address (exp->elts[elt].type, stream);
 975       fprintf_filtered (stream, " (");
 976       type_print (exp->elts[elt].type, NULL, stream, 0);
 977       fprintf_filtered (stream, ")");
 978       elt = dump_subexp (exp, stream, elt + 2);
 979       break;
 980     case OP_TYPE:
 981       fprintf_filtered (stream, "Type @");
 982       gdb_print_host_address (exp->elts[elt].type, stream);
 983       fprintf_filtered (stream, " (");
 984       type_print (exp->elts[elt].type, NULL, stream, 0);
 985       fprintf_filtered (stream, ")");
 986       elt += 2;
 987       break;
 988     case OP_TYPEOF:
 989     case OP_DECLTYPE:
 990       fprintf_filtered (stream, "Typeof (");
 991       elt = dump_subexp (exp, stream, elt);
 992       fprintf_filtered (stream, ")");
 993       break;
 994     case OP_TYPEID:
 995       fprintf_filtered (stream, "typeid (");
 996       elt = dump_subexp (exp, stream, elt);
 997       fprintf_filtered (stream, ")");
 998       break;
 999     case STRUCTOP_STRUCT:
1000     case STRUCTOP_PTR:
1001       {
1002         char *elem_name;
1003         int len;
1004
1005         len = longest_to_int (exp->elts[elt].longconst);
1006         elem_name = &exp->elts[elt + 1].string;
1007
1008         fprintf_filtered (stream, "Element name: `%.*s'", len, elem_name);
1009         elt = dump_subexp (exp, stream, elt + 3 + BYTES_TO_EXP_ELEM (len + 1));
1010       }
1011       break;
1012     case OP_SCOPE:
1013       {
1014         char *elem_name;
1015         int len;
1016
1017         fprintf_filtered (stream, "Type @");
1018         gdb_print_host_address (exp->elts[elt].type, stream);
1019         fprintf_filtered (stream, " (");
1020         type_print (exp->elts[elt].type, NULL, stream, 0);
1021         fprintf_filtered (stream, ") ");
1022
1023         len = longest_to_int (exp->elts[elt + 1].longconst);
1024         elem_name = &exp->elts[elt + 2].string;
1025
1026         fprintf_filtered (stream, "Field name: `%.*s'", len, elem_name);
1027         elt += 4 + BYTES_TO_EXP_ELEM (len + 1);
1028       }
1029       break;
1030
1031     case OP_FUNC_STATIC_VAR:
1032       {
1033         int len = longest_to_int (exp->elts[elt].longconst);
1034         const char *var_name = &exp->elts[elt + 1].string;
1035         fprintf_filtered (stream, "Field name: `%.*s'", len, var_name);
1036         elt += 3 + BYTES_TO_EXP_ELEM (len + 1);
1037       }
1038       break;
1039
1040     case TYPE_INSTANCE:
1041       {
1042         type_instance_flags flags
1043           = (type_instance_flag_value) longest_to_int (exp->elts[elt++].longconst);
1044         LONGEST len = exp->elts[elt++].longconst;
1045         fprintf_filtered (stream, "%s TypeInstance: ", plongest (len));
1046         while (len-- > 0)
1047           {
1048             fprintf_filtered (stream, "Type @");
1049             gdb_print_host_address (exp->elts[elt].type, stream);
1050             fprintf_filtered (stream, " (");
1051             type_print (exp->elts[elt].type, NULL, stream, 0);
1052             fprintf_filtered (stream, ")");
1053             elt++;
1054             if (len > 0)
1055               fputs_filtered (", ", stream);
1056           }
1057
1058         fprintf_filtered (stream, " Flags: %s (", hex_string (flags));
1059         bool space = false;
1060         auto print_one = [&] (const char *mod)
1061           {
1062             if (space)
1063               fputs_filtered (" ", stream);
1064             space = true;
1065             fprintf_filtered (stream, "%s", mod);
1066           };
1067         if (flags & TYPE_INSTANCE_FLAG_CONST)
1068           print_one ("const");
1069         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
1070           print_one ("volatile");
1071         fprintf_filtered (stream, ")");
1072
1073         /* Ending LEN and ending TYPE_INSTANCE.  */
1074         elt += 2;
1075         elt = dump_subexp (exp, stream, elt);
1076       }
1077       break;
1078     case OP_STRING:
1079       {
1080         LONGEST len = exp->elts[elt].longconst;
1081         LONGEST type = exp->elts[elt + 1].longconst;
1082
1083         fprintf_filtered (stream, "Language-specific string type: %s",
1084                           plongest (type));
1085
1086         /* Skip length.  */
1087         elt += 1;
1088
1089         /* Skip string content. */
1090         elt += BYTES_TO_EXP_ELEM (len);
1091
1092         /* Skip length and ending OP_STRING. */
1093         elt += 2;
1094       }
1095       break;
1096     case OP_RANGE:
1097       {
1098         enum range_type range_type;
1099
1100         range_type = (enum range_type)
1101           longest_to_int (exp->elts[elt].longconst);
1102         elt += 2;
1103
1104         switch (range_type)
1105           {
1106           case BOTH_BOUND_DEFAULT:
1107             fputs_filtered ("Range '..'", stream);
1108             break;
1109           case LOW_BOUND_DEFAULT:
1110             fputs_filtered ("Range '..EXP'", stream);
1111             break;
1112           case LOW_BOUND_DEFAULT_EXCLUSIVE:
1113             fputs_filtered ("ExclusiveRange '..EXP'", stream);
1114             break;
1115           case HIGH_BOUND_DEFAULT:
1116             fputs_filtered ("Range 'EXP..'", stream);
1117             break;
1118           case NONE_BOUND_DEFAULT:
1119             fputs_filtered ("Range 'EXP..EXP'", stream);
1120             break;
1121           case NONE_BOUND_DEFAULT_EXCLUSIVE:
1122             fputs_filtered ("ExclusiveRange 'EXP..EXP'", stream);
1123             break;
1124           default:
1125             fputs_filtered ("Invalid Range!", stream);
1126             break;
1127           }
1128
1129         if (range_type == HIGH_BOUND_DEFAULT
1130             || range_type == NONE_BOUND_DEFAULT)
1131           elt = dump_subexp (exp, stream, elt);
1132         if (range_type == LOW_BOUND_DEFAULT
1133             || range_type == NONE_BOUND_DEFAULT)
1134           elt = dump_subexp (exp, stream, elt);
1135       }
1136       break;
1137
1138     default:
1139     case OP_NULL:
1140     case MULTI_SUBSCRIPT:
1141     case OP_COMPLEX:
1142     case OP_BOOL:
1143     case OP_M2_STRING:
1144     case OP_THIS:
1145     case OP_NAME:
1146       fprintf_filtered (stream, "Unknown format");
1147     }
1148
1149   return elt;
1150 }
1151
1152 void
1153 dump_prefix_expression (struct expression *exp, struct ui_file *stream)
1154 {
1155   int elt;
1156
1157   fprintf_filtered (stream, "Dump of expression @ ");
1158   gdb_print_host_address (exp, stream);
1159   fputs_filtered (", after conversion to prefix form:\nExpression: `", stream);
1160   print_expression (exp, stream);
1161   fprintf_filtered (stream, "'\n\tLanguage %s, %d elements, %ld bytes each.\n",
1162                     exp->language_defn->la_name, exp->nelts,
1163                     (long) sizeof (union exp_element));
1164   fputs_filtered ("\n", stream);
1165
1166   for (elt = 0; elt < exp->nelts;)
1167     elt = dump_subexp (exp, stream, elt);
1168   fputs_filtered ("\n", stream);
1169 }