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         gdb::unique_xmalloc_ptr<char> selector;
 245
 246         (*pos) += 3;
 247         nargs = longest_to_int (exp->elts[pc + 2].longconst);
 248         fprintf_unfiltered (stream, "[");
 249         print_subexp (exp, pos, stream, PREC_SUFFIX);
 250         if (0 == target_read_string (exp->elts[pc + 1].longconst,
 251                                      &selector, 1024, NULL))
 252           {
 253             error (_("bad selector"));
 254             return;
 255           }
 256         if (nargs)
 257           {
 258             char *s, *nextS;
 259
 260             s = selector.get ();
 261             for (tem = 0; tem < nargs; tem++)
 262               {
 263                 nextS = strchr (s, ':');
 264                 gdb_assert (nextS);     /* Make sure we found ':'.  */
 265                 *nextS = '\0';
 266                 fprintf_unfiltered (stream, " %s: ", s);
 267                 s = nextS + 1;
 268                 print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 269               }
 270           }
 271         else
 272           {
 273             fprintf_unfiltered (stream, " %s", selector.get ());
 274           }
 275         fprintf_unfiltered (stream, "]");
 276         return;
 277       }
 278
 279     case OP_ARRAY:
 280       (*pos) += 3;
 281       nargs = longest_to_int (exp->elts[pc + 2].longconst);
 282       nargs -= longest_to_int (exp->elts[pc + 1].longconst);
 283       nargs++;
 284       tem = 0;
 285       if (exp->elts[pc + 4].opcode == OP_LONG
 286           && exp->elts[pc + 5].type
 287              == builtin_type (exp->gdbarch)->builtin_char
 288           && exp->language_defn->la_language == language_c)
 289         {
 290           /* Attempt to print C character arrays using string syntax.
 291              Walk through the args, picking up one character from each
 292              of the OP_LONG expression elements.  If any array element
 293              does not match our expection of what we should find for
 294              a simple string, revert back to array printing.  Note that
 295              the last expression element is an explicit null terminator
 296              byte, which doesn't get printed.  */
 297           tempstr = (char *) alloca (nargs);
 298           pc += 4;
 299           while (tem < nargs)
 300             {
 301               if (exp->elts[pc].opcode != OP_LONG
 302                   || exp->elts[pc + 1].type
 303                      != builtin_type (exp->gdbarch)->builtin_char)
 304                 {
 305                   /* Not a simple array of char, use regular array
 306                      printing.  */
 307                   tem = 0;
 308                   break;
 309                 }
 310               else
 311                 {
 312                   tempstr[tem++] =
 313                     longest_to_int (exp->elts[pc + 2].longconst);
 314                   pc += 4;
 315                 }
 316             }
 317         }
 318       if (tem > 0)
 319         {
 320           struct value_print_options opts;
 321
 322           get_user_print_options (&opts);
 323           LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 324                            (gdb_byte *) tempstr, nargs - 1, NULL, 0, &opts);
 325           (*pos) = pc;
 326         }
 327       else
 328         {
 329           fputs_filtered (" {", stream);
 330           for (tem = 0; tem < nargs; tem++)
 331             {
 332               if (tem != 0)
 333                 {
 334                   fputs_filtered (", ", stream);
 335                 }
 336               print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 337             }
 338           fputs_filtered ("}", stream);
 339         }
 340       return;
 341
 342     case TERNOP_COND:
 343       if ((int) prec > (int) PREC_COMMA)
 344         fputs_filtered ("(", stream);
 345       /* Print the subexpressions, forcing parentheses
 346          around any binary operations within them.
 347          This is more parentheses than are strictly necessary,
 348          but it looks clearer.  */
 349       print_subexp (exp, pos, stream, PREC_HYPER);
 350       fputs_filtered (" ? ", stream);
 351       print_subexp (exp, pos, stream, PREC_HYPER);
 352       fputs_filtered (" : ", stream);
 353       print_subexp (exp, pos, stream, PREC_HYPER);
 354       if ((int) prec > (int) PREC_COMMA)
 355         fputs_filtered (")", stream);
 356       return;
 357
 358     case TERNOP_SLICE:
 359       print_subexp (exp, pos, stream, PREC_SUFFIX);
 360       fputs_filtered ("(", stream);
 361       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 362       fputs_filtered (opcode == TERNOP_SLICE ? " : " : " UP ", stream);
 363       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 364       fputs_filtered (")", stream);
 365       return;
 366
 367     case STRUCTOP_STRUCT:
 368       tem = longest_to_int (exp->elts[pc + 1].longconst);
 369       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 370       print_subexp (exp, pos, stream, PREC_SUFFIX);
 371       fputs_filtered (".", stream);
 372       fputs_filtered (&exp->elts[pc + 2].string, stream);
 373       return;
 374
 375       /* Will not occur for Modula-2.  */
 376     case STRUCTOP_PTR:
 377       tem = longest_to_int (exp->elts[pc + 1].longconst);
 378       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 379       print_subexp (exp, pos, stream, PREC_SUFFIX);
 380       fputs_filtered ("->", stream);
 381       fputs_filtered (&exp->elts[pc + 2].string, stream);
 382       return;
 383
 384     case STRUCTOP_MEMBER:
 385       print_subexp (exp, pos, stream, PREC_SUFFIX);
 386       fputs_filtered (".*", stream);
 387       print_subexp (exp, pos, stream, PREC_SUFFIX);
 388       return;
 389
 390     case STRUCTOP_MPTR:
 391       print_subexp (exp, pos, stream, PREC_SUFFIX);
 392       fputs_filtered ("->*", stream);
 393       print_subexp (exp, pos, stream, PREC_SUFFIX);
 394       return;
 395
 396     case BINOP_SUBSCRIPT:
 397       print_subexp (exp, pos, stream, PREC_SUFFIX);
 398       fputs_filtered ("[", stream);
 399       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 400       fputs_filtered ("]", stream);
 401       return;
 402
 403     case UNOP_POSTINCREMENT:
 404       print_subexp (exp, pos, stream, PREC_SUFFIX);
 405       fputs_filtered ("++", stream);
 406       return;
 407
 408     case UNOP_POSTDECREMENT:
 409       print_subexp (exp, pos, stream, PREC_SUFFIX);
 410       fputs_filtered ("--", stream);
 411       return;
 412
 413     case UNOP_CAST:
 414       (*pos) += 2;
 415       if ((int) prec > (int) PREC_PREFIX)
 416         fputs_filtered ("(", stream);
 417       fputs_filtered ("(", stream);
 418       type_print (exp->elts[pc + 1].type, "", stream, 0);
 419       fputs_filtered (") ", stream);
 420       print_subexp (exp, pos, stream, PREC_PREFIX);
 421       if ((int) prec > (int) PREC_PREFIX)
 422         fputs_filtered (")", stream);
 423       return;
 424
 425     case UNOP_CAST_TYPE:
 426       if ((int) prec > (int) PREC_PREFIX)
 427         fputs_filtered ("(", 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       if ((int) prec > (int) PREC_PREFIX)
 433         fputs_filtered (")", stream);
 434       return;
 435
 436     case UNOP_DYNAMIC_CAST:
 437     case UNOP_REINTERPRET_CAST:
 438       fputs_filtered (opcode == UNOP_DYNAMIC_CAST ? "dynamic_cast"
 439                       : "reinterpret_cast", stream);
 440       fputs_filtered ("<", stream);
 441       print_subexp (exp, pos, stream, PREC_PREFIX);
 442       fputs_filtered ("> (", stream);
 443       print_subexp (exp, pos, stream, PREC_PREFIX);
 444       fputs_filtered (")", stream);
 445       return;
 446
 447     case UNOP_MEMVAL:
 448       (*pos) += 2;
 449       if ((int) prec > (int) PREC_PREFIX)
 450         fputs_filtered ("(", stream);
 451       if (exp->elts[pc + 1].type->code () == TYPE_CODE_FUNC
 452           && exp->elts[pc + 3].opcode == OP_LONG)
 453         {
 454           struct value_print_options opts;
 455
 456           /* We have a minimal symbol fn, probably.  It's encoded
 457              as a UNOP_MEMVAL (function-type) of an OP_LONG (int, address).
 458              Swallow the OP_LONG (including both its opcodes); ignore
 459              its type; print the value in the type of the MEMVAL.  */
 460           (*pos) += 4;
 461           val = value_at_lazy (exp->elts[pc + 1].type,
 462                                (CORE_ADDR) exp->elts[pc + 5].longconst);
 463           get_no_prettyformat_print_options (&opts);
 464           value_print (val, stream, &opts);
 465         }
 466       else
 467         {
 468           fputs_filtered ("{", stream);
 469           type_print (exp->elts[pc + 1].type, "", stream, 0);
 470           fputs_filtered ("} ", stream);
 471           print_subexp (exp, pos, stream, PREC_PREFIX);
 472         }
 473       if ((int) prec > (int) PREC_PREFIX)
 474         fputs_filtered (")", stream);
 475       return;
 476
 477     case UNOP_MEMVAL_TYPE:
 478       if ((int) prec > (int) PREC_PREFIX)
 479         fputs_filtered ("(", stream);
 480       fputs_filtered ("{", stream);
 481       print_subexp (exp, pos, stream, PREC_PREFIX);
 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_styled (stream, metadata_style.style (),
 515                         _("<language %s has no 'this'>"),
 516                         exp->language_defn->la_name);
 517       return;
 518
 519       /* Modula-2 ops */
 520
 521     case MULTI_SUBSCRIPT:
 522       (*pos) += 2;
 523       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 524       print_subexp (exp, pos, stream, PREC_SUFFIX);
 525       fprintf_unfiltered (stream, " [");
 526       for (tem = 0; tem < nargs; tem++)
 527         {
 528           if (tem != 0)
 529             fprintf_unfiltered (stream, ", ");
 530           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 531         }
 532       fprintf_unfiltered (stream, "]");
 533       return;
 534
 535     case BINOP_VAL:
 536       (*pos) += 2;
 537       fprintf_unfiltered (stream, "VAL(");
 538       type_print (exp->elts[pc + 1].type, "", stream, 0);
 539       fprintf_unfiltered (stream, ",");
 540       print_subexp (exp, pos, stream, PREC_PREFIX);
 541       fprintf_unfiltered (stream, ")");
 542       return;
 543
 544     case TYPE_INSTANCE:
 545       {
 546         type_instance_flags flags
 547           = (type_instance_flag_value) longest_to_int (exp->elts[pc + 1].longconst);
 548         LONGEST count = exp->elts[pc + 2].longconst;
 549
 550         /* The FLAGS.  */
 551         (*pos)++;
 552         /* The COUNT.  */
 553         (*pos)++;
 554         fputs_unfiltered ("TypeInstance(", stream);
 555         while (count-- > 0)
 556           {
 557             type_print (exp->elts[(*pos)++].type, "", stream, 0);
 558             if (count > 0)
 559               fputs_unfiltered (",", stream);
 560           }
 561         fputs_unfiltered (",", stream);
 562         /* Ending COUNT and ending TYPE_INSTANCE.  */
 563         (*pos) += 2;
 564         print_subexp (exp, pos, stream, PREC_PREFIX);
 565
 566         if (flags & TYPE_INSTANCE_FLAG_CONST)
 567           fputs_unfiltered (",const", stream);
 568         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
 569           fputs_unfiltered (",volatile", stream);
 570
 571         fputs_unfiltered (")", stream);
 572         return;
 573       }
 574
 575     case OP_RANGE:
 576       {
 577         enum range_type range_type;
 578
 579         range_type = (enum range_type)
 580           longest_to_int (exp->elts[pc + 1].longconst);
 581         *pos += 2;
 582
 583         if (range_type == NONE_BOUND_DEFAULT_EXCLUSIVE
 584             || range_type == LOW_BOUND_DEFAULT_EXCLUSIVE)
 585           fputs_filtered ("EXCLUSIVE_", stream);
 586         fputs_filtered ("RANGE(", stream);
 587         if (range_type == HIGH_BOUND_DEFAULT
 588             || range_type == NONE_BOUND_DEFAULT
 589             || range_type == NONE_BOUND_DEFAULT_EXCLUSIVE)
 590           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 591         fputs_filtered ("..", stream);
 592         if (range_type == LOW_BOUND_DEFAULT
 593             || range_type == NONE_BOUND_DEFAULT)
 594           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 595         fputs_filtered (")", stream);
 596         return;
 597       }
 598
 599       /* Default ops */
 600
 601     default:
 602       op_str = "???";
 603       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 604         if (op_print_tab[tem].opcode == opcode)
 605           {
 606             op_str = op_print_tab[tem].string;
 607             myprec = op_print_tab[tem].precedence;
 608             assoc = op_print_tab[tem].right_assoc;
 609             break;
 610           }
 611       if (op_print_tab[tem].opcode != opcode)
 612         /* Not found; don't try to keep going because we don't know how
 613            to interpret further elements.  For example, this happens
 614            if opcode is OP_TYPE.  */
 615         error (_("Invalid expression"));
 616     }
 617
 618   /* Note that PREC_BUILTIN will always emit parentheses.  */
 619   if ((int) myprec < (int) prec)
 620     fputs_filtered ("(", stream);
 621   if ((int) opcode > (int) BINOP_END)
 622     {
 623       if (assoc)
 624         {
 625           /* Unary postfix operator.  */
 626           print_subexp (exp, pos, stream, PREC_SUFFIX);
 627           fputs_filtered (op_str, stream);
 628         }
 629       else
 630         {
 631           /* Unary prefix operator.  */
 632           fputs_filtered (op_str, stream);
 633           if (myprec == PREC_BUILTIN_FUNCTION)
 634             fputs_filtered ("(", stream);
 635           print_subexp (exp, pos, stream, PREC_PREFIX);
 636           if (myprec == PREC_BUILTIN_FUNCTION)
 637             fputs_filtered (")", stream);
 638         }
 639     }
 640   else
 641     {
 642       /* Binary operator.  */
 643       /* Print left operand.
 644          If operator is right-associative,
 645          increment precedence for this operand.  */
 646       print_subexp (exp, pos, stream,
 647                     (enum precedence) ((int) myprec + assoc));
 648       /* Print the operator itself.  */
 649       if (assign_modify)
 650         fprintf_filtered (stream, " %s= ", op_str);
 651       else if (op_str[0] == ',')
 652         fprintf_filtered (stream, "%s ", op_str);
 653       else
 654         fprintf_filtered (stream, " %s ", op_str);
 655       /* Print right operand.
 656          If operator is left-associative,
 657          increment precedence for this operand.  */
 658       print_subexp (exp, pos, stream,
 659                     (enum precedence) ((int) myprec + !assoc));
 660     }
 661
 662   if ((int) myprec < (int) prec)
 663     fputs_filtered (")", stream);
 664 }
 665
 666 /* Return the operator corresponding to opcode OP as
 667    a string.   NULL indicates that the opcode was not found in the
 668    current language table.  */
 669 const char *
 670 op_string (enum exp_opcode op)
 671 {
 672   int tem;
 673   const struct op_print *op_print_tab;
 674
 675   op_print_tab = current_language->la_op_print_tab;
 676   for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 677     if (op_print_tab[tem].opcode == op)
 678       return op_print_tab[tem].string;
 679   return NULL;
 680 }
 681
 682 /* Support for dumping the raw data from expressions in a human readable
 683    form.  */
 684
 685 static int dump_subexp_body (struct expression *exp, struct ui_file *, int);
 686
 687 /* Name for OPCODE, when it appears in expression EXP.  */
 688
 689 const char *
 690 op_name (struct expression *exp, enum exp_opcode opcode)
 691 {
 692   if (opcode >= OP_UNUSED_LAST)
 693     {
 694       char *cell = get_print_cell ();
 695       xsnprintf (cell, PRINT_CELL_SIZE, "unknown opcode: %u",
 696                  unsigned (opcode));
 697       return cell;
 698     }
 699   return exp->language_defn->la_exp_desc->op_name (opcode);
 700 }
 701
 702 /* Default name for the standard operator OPCODE (i.e., one defined in
 703    the definition of enum exp_opcode).  */
 704
 705 const char *
 706 op_name_standard (enum exp_opcode opcode)
 707 {
 708   switch (opcode)
 709     {
 710     default:
 711       {
 712         static char buf[30];
 713
 714         xsnprintf (buf, sizeof (buf), "<unknown %d>", opcode);
 715         return buf;
 716       }
 717 #define OP(name)        \
 718     case name:          \
 719       return #name ;
 720 #include "std-operator.def"
 721 #undef OP
 722     }
 723 }
 724
 725 /* Print a raw dump of expression EXP to STREAM.
 726    NOTE, if non-NULL, is printed as extra explanatory text.  */
 727
 728 void
 729 dump_raw_expression (struct expression *exp, struct ui_file *stream,
 730                      const char *note)
 731 {
 732   int elt;
 733   char *eltscan;
 734   int eltsize;
 735
 736   fprintf_filtered (stream, "Dump of expression @ ");
 737   gdb_print_host_address (exp, stream);
 738   if (note)
 739     fprintf_filtered (stream, ", %s:", note);
 740   fprintf_filtered (stream, "\n\tLanguage %s, %d elements, %ld bytes each.\n",
 741                     exp->language_defn->la_name, exp->nelts,
 742                     (long) sizeof (union exp_element));
 743   fprintf_filtered (stream, "\t%5s  %20s  %16s  %s\n", "Index", "Opcode",
 744                     "Hex Value", "String Value");
 745   for (elt = 0; elt < exp->nelts; elt++)
 746     {
 747       fprintf_filtered (stream, "\t%5d  ", elt);
 748
 749       const char *opcode_name = op_name (exp, exp->elts[elt].opcode);
 750       fprintf_filtered (stream, "%20s  ", opcode_name);
 751
 752       print_longest (stream, 'd', 0, exp->elts[elt].longconst);
 753       fprintf_filtered (stream, "  ");
 754
 755       for (eltscan = (char *) &exp->elts[elt],
 756            eltsize = sizeof (union exp_element);
 757            eltsize-- > 0;
 758            eltscan++)
 759         {
 760           fprintf_filtered (stream, "%c",
 761                             isprint (*eltscan) ? (*eltscan & 0xFF) : '.');
 762         }
 763       fprintf_filtered (stream, "\n");
 764     }
 765 }
 766
 767 /* Dump the subexpression of prefix expression EXP whose operator is at
 768    position ELT onto STREAM.  Returns the position of the next
 769    subexpression in EXP.  */
 770
 771 int
 772 dump_subexp (struct expression *exp, struct ui_file *stream, int elt)
 773 {
 774   static int indent = 0;
 775   int i;
 776
 777   fprintf_filtered (stream, "\n");
 778   fprintf_filtered (stream, "\t%5d  ", elt);
 779
 780   for (i = 1; i <= indent; i++)
 781     fprintf_filtered (stream, " ");
 782   indent += 2;
 783
 784   fprintf_filtered (stream, "%-20s  ", op_name (exp, exp->elts[elt].opcode));
 785
 786   elt = dump_subexp_body (exp, stream, elt);
 787
 788   indent -= 2;
 789
 790   return elt;
 791 }
 792
 793 /* Dump the operands of prefix expression EXP whose opcode is at
 794    position ELT onto STREAM.  Returns the position of the next
 795    subexpression in EXP.  */
 796
 797 static int
 798 dump_subexp_body (struct expression *exp, struct ui_file *stream, int elt)
 799 {
 800   return exp->language_defn->la_exp_desc->dump_subexp_body (exp, stream, elt);
 801 }
 802
 803 /* Default value for subexp_body in exp_descriptor vector.  */
 804
 805 int
 806 dump_subexp_body_standard (struct expression *exp,
 807                            struct ui_file *stream, int elt)
 808 {
 809   int opcode = exp->elts[elt++].opcode;
 810
 811   switch (opcode)
 812     {
 813     case TERNOP_COND:
 814     case TERNOP_SLICE:
 815       elt = dump_subexp (exp, stream, elt);
 816       /* FALL THROUGH */
 817     case BINOP_ADD:
 818     case BINOP_SUB:
 819     case BINOP_MUL:
 820     case BINOP_DIV:
 821     case BINOP_REM:
 822     case BINOP_MOD:
 823     case BINOP_LSH:
 824     case BINOP_RSH:
 825     case BINOP_LOGICAL_AND:
 826     case BINOP_LOGICAL_OR:
 827     case BINOP_BITWISE_AND:
 828     case BINOP_BITWISE_IOR:
 829     case BINOP_BITWISE_XOR:
 830     case BINOP_EQUAL:
 831     case BINOP_NOTEQUAL:
 832     case BINOP_LESS:
 833     case BINOP_GTR:
 834     case BINOP_LEQ:
 835     case BINOP_GEQ:
 836     case BINOP_REPEAT:
 837     case BINOP_ASSIGN:
 838     case BINOP_COMMA:
 839     case BINOP_SUBSCRIPT:
 840     case BINOP_EXP:
 841     case BINOP_MIN:
 842     case BINOP_MAX:
 843     case BINOP_INTDIV:
 844     case BINOP_ASSIGN_MODIFY:
 845     case BINOP_VAL:
 846     case BINOP_CONCAT:
 847     case BINOP_END:
 848     case STRUCTOP_MEMBER:
 849     case STRUCTOP_MPTR:
 850       elt = dump_subexp (exp, stream, elt);
 851       /* FALL THROUGH */
 852     case UNOP_NEG:
 853     case UNOP_LOGICAL_NOT:
 854     case UNOP_COMPLEMENT:
 855     case UNOP_IND:
 856     case UNOP_ADDR:
 857     case UNOP_PREINCREMENT:
 858     case UNOP_POSTINCREMENT:
 859     case UNOP_PREDECREMENT:
 860     case UNOP_POSTDECREMENT:
 861     case UNOP_SIZEOF:
 862     case UNOP_ALIGNOF:
 863     case UNOP_PLUS:
 864     case UNOP_CAP:
 865     case UNOP_CHR:
 866     case UNOP_ORD:
 867     case UNOP_ABS:
 868     case UNOP_FLOAT:
 869     case UNOP_HIGH:
 870     case UNOP_MAX:
 871     case UNOP_MIN:
 872     case UNOP_ODD:
 873     case UNOP_TRUNC:
 874       elt = dump_subexp (exp, stream, elt);
 875       break;
 876     case OP_LONG:
 877       fprintf_filtered (stream, "Type @");
 878       gdb_print_host_address (exp->elts[elt].type, stream);
 879       fprintf_filtered (stream, " (");
 880       type_print (exp->elts[elt].type, NULL, stream, 0);
 881       fprintf_filtered (stream, "), value %ld (0x%lx)",
 882                         (long) exp->elts[elt + 1].longconst,
 883                         (long) exp->elts[elt + 1].longconst);
 884       elt += 3;
 885       break;
 886     case OP_FLOAT:
 887       fprintf_filtered (stream, "Type @");
 888       gdb_print_host_address (exp->elts[elt].type, stream);
 889       fprintf_filtered (stream, " (");
 890       type_print (exp->elts[elt].type, NULL, stream, 0);
 891       fprintf_filtered (stream, "), value ");
 892       print_floating (exp->elts[elt + 1].floatconst,
 893                       exp->elts[elt].type, stream);
 894       elt += 3;
 895       break;
 896     case OP_VAR_VALUE:
 897       fprintf_filtered (stream, "Block @");
 898       gdb_print_host_address (exp->elts[elt].block, stream);
 899       fprintf_filtered (stream, ", symbol @");
 900       gdb_print_host_address (exp->elts[elt + 1].symbol, stream);
 901       fprintf_filtered (stream, " (%s)",
 902                         exp->elts[elt + 1].symbol->print_name ());
 903       elt += 3;
 904       break;
 905     case OP_VAR_MSYM_VALUE:
 906       fprintf_filtered (stream, "Objfile @");
 907       gdb_print_host_address (exp->elts[elt].objfile, stream);
 908       fprintf_filtered (stream, ", msymbol @");
 909       gdb_print_host_address (exp->elts[elt + 1].msymbol, stream);
 910       fprintf_filtered (stream, " (%s)",
 911                         exp->elts[elt + 1].msymbol->print_name ());
 912       elt += 3;
 913       break;
 914     case OP_VAR_ENTRY_VALUE:
 915       fprintf_filtered (stream, "Entry value of symbol @");
 916       gdb_print_host_address (exp->elts[elt].symbol, stream);
 917       fprintf_filtered (stream, " (%s)",
 918                         exp->elts[elt].symbol->print_name ());
 919       elt += 2;
 920       break;
 921     case OP_LAST:
 922       fprintf_filtered (stream, "History element %ld",
 923                         (long) exp->elts[elt].longconst);
 924       elt += 2;
 925       break;
 926     case OP_REGISTER:
 927       fprintf_filtered (stream, "Register $%s", &exp->elts[elt + 1].string);
 928       elt += 3 + BYTES_TO_EXP_ELEM (exp->elts[elt].longconst + 1);
 929       break;
 930     case OP_INTERNALVAR:
 931       fprintf_filtered (stream, "Internal var @");
 932       gdb_print_host_address (exp->elts[elt].internalvar, stream);
 933       fprintf_filtered (stream, " (%s)",
 934                         internalvar_name (exp->elts[elt].internalvar));
 935       elt += 2;
 936       break;
 937     case OP_FUNCALL:
 938     case OP_F77_UNDETERMINED_ARGLIST:
 939       {
 940         int i, nargs;
 941
 942         nargs = longest_to_int (exp->elts[elt].longconst);
 943
 944         fprintf_filtered (stream, "Number of args: %d", nargs);
 945         elt += 2;
 946
 947         for (i = 1; i <= nargs + 1; i++)
 948           elt = dump_subexp (exp, stream, elt);
 949       }
 950       break;
 951     case OP_ARRAY:
 952       {
 953         int lower, upper;
 954         int i;
 955
 956         lower = longest_to_int (exp->elts[elt].longconst);
 957         upper = longest_to_int (exp->elts[elt + 1].longconst);
 958
 959         fprintf_filtered (stream, "Bounds [%d:%d]", lower, upper);
 960         elt += 3;
 961
 962         for (i = 1; i <= upper - lower + 1; i++)
 963           elt = dump_subexp (exp, stream, elt);
 964       }
 965       break;
 966     case UNOP_DYNAMIC_CAST:
 967     case UNOP_REINTERPRET_CAST:
 968     case UNOP_CAST_TYPE:
 969     case UNOP_MEMVAL_TYPE:
 970       fprintf_filtered (stream, " (");
 971       elt = dump_subexp (exp, stream, elt);
 972       fprintf_filtered (stream, ")");
 973       elt = dump_subexp (exp, stream, elt);
 974       break;
 975     case UNOP_MEMVAL:
 976     case UNOP_CAST:
 977       fprintf_filtered (stream, "Type @");
 978       gdb_print_host_address (exp->elts[elt].type, stream);
 979       fprintf_filtered (stream, " (");
 980       type_print (exp->elts[elt].type, NULL, stream, 0);
 981       fprintf_filtered (stream, ")");
 982       elt = dump_subexp (exp, stream, elt + 2);
 983       break;
 984     case OP_TYPE:
 985       fprintf_filtered (stream, "Type @");
 986       gdb_print_host_address (exp->elts[elt].type, stream);
 987       fprintf_filtered (stream, " (");
 988       type_print (exp->elts[elt].type, NULL, stream, 0);
 989       fprintf_filtered (stream, ")");
 990       elt += 2;
 991       break;
 992     case OP_TYPEOF:
 993     case OP_DECLTYPE:
 994       fprintf_filtered (stream, "Typeof (");
 995       elt = dump_subexp (exp, stream, elt);
 996       fprintf_filtered (stream, ")");
 997       break;
 998     case OP_TYPEID:
 999       fprintf_filtered (stream, "typeid (");
1000       elt = dump_subexp (exp, stream, elt);
1001       fprintf_filtered (stream, ")");
1002       break;
1003     case STRUCTOP_STRUCT:
1004     case STRUCTOP_PTR:
1005       {
1006         char *elem_name;
1007         int len;
1008
1009         len = longest_to_int (exp->elts[elt].longconst);
1010         elem_name = &exp->elts[elt + 1].string;
1011
1012         fprintf_filtered (stream, "Element name: `%.*s'", len, elem_name);
1013         elt = dump_subexp (exp, stream, elt + 3 + BYTES_TO_EXP_ELEM (len + 1));
1014       }
1015       break;
1016     case OP_SCOPE:
1017       {
1018         char *elem_name;
1019         int len;
1020
1021         fprintf_filtered (stream, "Type @");
1022         gdb_print_host_address (exp->elts[elt].type, stream);
1023         fprintf_filtered (stream, " (");
1024         type_print (exp->elts[elt].type, NULL, stream, 0);
1025         fprintf_filtered (stream, ") ");
1026
1027         len = longest_to_int (exp->elts[elt + 1].longconst);
1028         elem_name = &exp->elts[elt + 2].string;
1029
1030         fprintf_filtered (stream, "Field name: `%.*s'", len, elem_name);
1031         elt += 4 + BYTES_TO_EXP_ELEM (len + 1);
1032       }
1033       break;
1034
1035     case OP_FUNC_STATIC_VAR:
1036       {
1037         int len = longest_to_int (exp->elts[elt].longconst);
1038         const char *var_name = &exp->elts[elt + 1].string;
1039         fprintf_filtered (stream, "Field name: `%.*s'", len, var_name);
1040         elt += 3 + BYTES_TO_EXP_ELEM (len + 1);
1041       }
1042       break;
1043
1044     case TYPE_INSTANCE:
1045       {
1046         type_instance_flags flags
1047           = (type_instance_flag_value) longest_to_int (exp->elts[elt++].longconst);
1048         LONGEST len = exp->elts[elt++].longconst;
1049         fprintf_filtered (stream, "%s TypeInstance: ", plongest (len));
1050         while (len-- > 0)
1051           {
1052             fprintf_filtered (stream, "Type @");
1053             gdb_print_host_address (exp->elts[elt].type, stream);
1054             fprintf_filtered (stream, " (");
1055             type_print (exp->elts[elt].type, NULL, stream, 0);
1056             fprintf_filtered (stream, ")");
1057             elt++;
1058             if (len > 0)
1059               fputs_filtered (", ", stream);
1060           }
1061
1062         fprintf_filtered (stream, " Flags: %s (", hex_string (flags));
1063         bool space = false;
1064         auto print_one = [&] (const char *mod)
1065           {
1066             if (space)
1067               fputs_filtered (" ", stream);
1068             space = true;
1069             fprintf_filtered (stream, "%s", mod);
1070           };
1071         if (flags & TYPE_INSTANCE_FLAG_CONST)
1072           print_one ("const");
1073         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
1074           print_one ("volatile");
1075         fprintf_filtered (stream, ")");
1076
1077         /* Ending LEN and ending TYPE_INSTANCE.  */
1078         elt += 2;
1079         elt = dump_subexp (exp, stream, elt);
1080       }
1081       break;
1082     case OP_STRING:
1083       {
1084         LONGEST len = exp->elts[elt].longconst;
1085         LONGEST type = exp->elts[elt + 1].longconst;
1086
1087         fprintf_filtered (stream, "Language-specific string type: %s",
1088                           plongest (type));
1089
1090         /* Skip length.  */
1091         elt += 1;
1092
1093         /* Skip string content. */
1094         elt += BYTES_TO_EXP_ELEM (len);
1095
1096         /* Skip length and ending OP_STRING. */
1097         elt += 2;
1098       }
1099       break;
1100     case OP_RANGE:
1101       {
1102         enum range_type range_type;
1103
1104         range_type = (enum range_type)
1105           longest_to_int (exp->elts[elt].longconst);
1106         elt += 2;
1107
1108         switch (range_type)
1109           {
1110           case BOTH_BOUND_DEFAULT:
1111             fputs_filtered ("Range '..'", stream);
1112             break;
1113           case LOW_BOUND_DEFAULT:
1114             fputs_filtered ("Range '..EXP'", stream);
1115             break;
1116           case LOW_BOUND_DEFAULT_EXCLUSIVE:
1117             fputs_filtered ("ExclusiveRange '..EXP'", stream);
1118             break;
1119           case HIGH_BOUND_DEFAULT:
1120             fputs_filtered ("Range 'EXP..'", stream);
1121             break;
1122           case NONE_BOUND_DEFAULT:
1123             fputs_filtered ("Range 'EXP..EXP'", stream);
1124             break;
1125           case NONE_BOUND_DEFAULT_EXCLUSIVE:
1126             fputs_filtered ("ExclusiveRange 'EXP..EXP'", stream);
1127             break;
1128           default:
1129             fputs_filtered ("Invalid Range!", stream);
1130             break;
1131           }
1132
1133         if (range_type == HIGH_BOUND_DEFAULT
1134             || range_type == NONE_BOUND_DEFAULT)
1135           elt = dump_subexp (exp, stream, elt);
1136         if (range_type == LOW_BOUND_DEFAULT
1137             || range_type == NONE_BOUND_DEFAULT)
1138           elt = dump_subexp (exp, stream, elt);
1139       }
1140       break;
1141
1142     default:
1143     case OP_NULL:
1144     case MULTI_SUBSCRIPT:
1145     case OP_COMPLEX:
1146     case OP_BOOL:
1147     case OP_M2_STRING:
1148     case OP_THIS:
1149     case OP_NAME:
1150       fprintf_filtered (stream, "Unknown format");
1151     }
1152
1153   return elt;
1154 }
1155
1156 void
1157 dump_prefix_expression (struct expression *exp, struct ui_file *stream)
1158 {
1159   int elt;
1160
1161   fprintf_filtered (stream, "Dump of expression @ ");
1162   gdb_print_host_address (exp, stream);
1163   fputs_filtered (", after conversion to prefix form:\nExpression: `", stream);
1164   print_expression (exp, stream);
1165   fprintf_filtered (stream, "'\n\tLanguage %s, %d elements, %ld bytes each.\n",
1166                     exp->language_defn->la_name, exp->nelts,
1167                     (long) sizeof (union exp_element));
1168   fputs_filtered ("\n", stream);
1169
1170   for (elt = 0; elt < exp->nelts;)
1171     elt = dump_subexp (exp, stream, elt);
1172   fputs_filtered ("\n", stream);
1173 }