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->expression_ops ()->print_subexp (exp, pos, stream,
  54                                                        prec);
  55 }
  56
  57 /* See parser-defs.h.  */
  58
  59 void
  60 print_subexp_funcall (struct expression *exp, int *pos,
  61                       struct ui_file *stream)
  62 {
  63   (*pos) += 2;
  64   unsigned nargs = longest_to_int (exp->elts[*pos].longconst);
  65   print_subexp (exp, pos, stream, PREC_SUFFIX);
  66   fputs_filtered (" (", stream);
  67   for (unsigned tem = 0; tem < nargs; tem++)
  68     {
  69       if (tem != 0)
  70         fputs_filtered (", ", stream);
  71       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
  72     }
  73   fputs_filtered (")", stream);
  74 }
  75
  76 /* Standard implementation of print_subexp for use in language_defn
  77    vectors.  */
  78 void
  79 print_subexp_standard (struct expression *exp, int *pos,
  80                        struct ui_file *stream, enum precedence prec)
  81 {
  82   unsigned tem;
  83   const struct op_print *op_print_tab;
  84   int pc;
  85   unsigned nargs;
  86   const char *op_str;
  87   int assign_modify = 0;
  88   enum exp_opcode opcode;
  89   enum precedence myprec = PREC_NULL;
  90   /* Set to 1 for a right-associative operator.  */
  91   int assoc = 0;
  92   struct value *val;
  93   char *tempstr = NULL;
  94
  95   op_print_tab = exp->language_defn->opcode_print_table ();
  96   pc = (*pos)++;
  97   opcode = exp->elts[pc].opcode;
  98   switch (opcode)
  99     {
 100       /* Common ops */
 101
 102     case OP_TYPE:
 103       (*pos) += 2;
 104       type_print (exp->elts[pc + 1].type, "", stream, 0);
 105       return;
 106
 107     case OP_SCOPE:
 108       myprec = PREC_PREFIX;
 109       assoc = 0;
 110       fputs_filtered (exp->elts[pc + 1].type->name (), stream);
 111       fputs_filtered ("::", stream);
 112       nargs = longest_to_int (exp->elts[pc + 2].longconst);
 113       (*pos) += 4 + BYTES_TO_EXP_ELEM (nargs + 1);
 114       fputs_filtered (&exp->elts[pc + 3].string, stream);
 115       return;
 116
 117     case OP_LONG:
 118       {
 119         struct value_print_options opts;
 120
 121         get_no_prettyformat_print_options (&opts);
 122         (*pos) += 3;
 123         value_print (value_from_longest (exp->elts[pc + 1].type,
 124                                          exp->elts[pc + 2].longconst),
 125                      stream, &opts);
 126       }
 127       return;
 128
 129     case OP_FLOAT:
 130       {
 131         struct value_print_options opts;
 132
 133         get_no_prettyformat_print_options (&opts);
 134         (*pos) += 3;
 135         value_print (value_from_contents (exp->elts[pc + 1].type,
 136                                           exp->elts[pc + 2].floatconst),
 137                      stream, &opts);
 138       }
 139       return;
 140
 141     case OP_VAR_VALUE:
 142       {
 143         const struct block *b;
 144
 145         (*pos) += 3;
 146         b = exp->elts[pc + 1].block;
 147         if (b != NULL
 148             && BLOCK_FUNCTION (b) != NULL
 149             && BLOCK_FUNCTION (b)->print_name () != NULL)
 150           {
 151             fputs_filtered (BLOCK_FUNCTION (b)->print_name (), stream);
 152             fputs_filtered ("::", stream);
 153           }
 154         fputs_filtered (exp->elts[pc + 2].symbol->print_name (), stream);
 155       }
 156       return;
 157
 158     case OP_VAR_MSYM_VALUE:
 159       {
 160         (*pos) += 3;
 161         fputs_filtered (exp->elts[pc + 2].msymbol->print_name (), stream);
 162       }
 163       return;
 164
 165     case OP_FUNC_STATIC_VAR:
 166       {
 167         tem = longest_to_int (exp->elts[pc + 1].longconst);
 168         (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 169         fputs_filtered (&exp->elts[pc + 1].string, stream);
 170       }
 171       return;
 172
 173     case OP_VAR_ENTRY_VALUE:
 174       {
 175         (*pos) += 2;
 176         fprintf_filtered (stream, "%s@entry",
 177                           exp->elts[pc + 1].symbol->print_name ());
 178       }
 179       return;
 180
 181     case OP_LAST:
 182       (*pos) += 2;
 183       fprintf_filtered (stream, "$%d",
 184                         longest_to_int (exp->elts[pc + 1].longconst));
 185       return;
 186
 187     case OP_REGISTER:
 188       {
 189         const char *name = &exp->elts[pc + 2].string;
 190
 191         (*pos) += 3 + BYTES_TO_EXP_ELEM (exp->elts[pc + 1].longconst + 1);
 192         fprintf_filtered (stream, "$%s", name);
 193         return;
 194       }
 195
 196     case OP_BOOL:
 197       (*pos) += 2;
 198       fprintf_filtered (stream, "%s",
 199                         longest_to_int (exp->elts[pc + 1].longconst)
 200                         ? "TRUE" : "FALSE");
 201       return;
 202
 203     case OP_INTERNALVAR:
 204       (*pos) += 2;
 205       fprintf_filtered (stream, "$%s",
 206                         internalvar_name (exp->elts[pc + 1].internalvar));
 207       return;
 208
 209     case OP_FUNCALL:
 210       print_subexp_funcall (exp, pos, stream);
 211       return;
 212
 213     case OP_NAME:
 214       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 215       (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 216       fputs_filtered (&exp->elts[pc + 2].string, stream);
 217       return;
 218
 219     case OP_STRING:
 220       {
 221         struct value_print_options opts;
 222
 223         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 224         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 225         /* LA_PRINT_STRING will print using the current repeat count threshold.
 226            If necessary, we can temporarily set it to zero, or pass it as an
 227            additional parameter to LA_PRINT_STRING.  -fnf */
 228         get_user_print_options (&opts);
 229         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 230                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 231                          NULL, 0, &opts);
 232       }
 233       return;
 234
 235     case OP_OBJC_NSSTRING:      /* Objective-C Foundation Class
 236                                    NSString constant.  */
 237       {
 238         struct value_print_options opts;
 239
 240         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 241         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 242         fputs_filtered ("@\"", stream);
 243         get_user_print_options (&opts);
 244         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 245                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 246                          NULL, 0, &opts);
 247         fputs_filtered ("\"", stream);
 248       }
 249       return;
 250
 251     case OP_OBJC_MSGCALL:
 252       {                 /* Objective C message (method) call.  */
 253         (*pos) += 3;
 254         nargs = longest_to_int (exp->elts[pc + 2].longconst);
 255         fprintf_unfiltered (stream, "[");
 256         print_subexp (exp, pos, stream, PREC_SUFFIX);
 257         gdb::unique_xmalloc_ptr<char> selector
 258           = target_read_string (exp->elts[pc + 1].longconst, 1024);
 259         if (selector == nullptr)
 260           error (_("bad selector"));
 261         if (nargs)
 262           {
 263             char *s, *nextS;
 264
 265             s = selector.get ();
 266             for (tem = 0; tem < nargs; tem++)
 267               {
 268                 nextS = strchr (s, ':');
 269                 gdb_assert (nextS);     /* Make sure we found ':'.  */
 270                 *nextS = '\0';
 271                 fprintf_unfiltered (stream, " %s: ", s);
 272                 s = nextS + 1;
 273                 print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 274               }
 275           }
 276         else
 277           {
 278             fprintf_unfiltered (stream, " %s", selector.get ());
 279           }
 280         fprintf_unfiltered (stream, "]");
 281         return;
 282       }
 283
 284     case OP_ARRAY:
 285       (*pos) += 3;
 286       nargs = longest_to_int (exp->elts[pc + 2].longconst);
 287       nargs -= longest_to_int (exp->elts[pc + 1].longconst);
 288       nargs++;
 289       tem = 0;
 290       if (exp->elts[pc + 4].opcode == OP_LONG
 291           && exp->elts[pc + 5].type
 292              == builtin_type (exp->gdbarch)->builtin_char
 293           && exp->language_defn->la_language == language_c)
 294         {
 295           /* Attempt to print C character arrays using string syntax.
 296              Walk through the args, picking up one character from each
 297              of the OP_LONG expression elements.  If any array element
 298              does not match our expection of what we should find for
 299              a simple string, revert back to array printing.  Note that
 300              the last expression element is an explicit null terminator
 301              byte, which doesn't get printed.  */
 302           tempstr = (char *) alloca (nargs);
 303           pc += 4;
 304           while (tem < nargs)
 305             {
 306               if (exp->elts[pc].opcode != OP_LONG
 307                   || exp->elts[pc + 1].type
 308                      != builtin_type (exp->gdbarch)->builtin_char)
 309                 {
 310                   /* Not a simple array of char, use regular array
 311                      printing.  */
 312                   tem = 0;
 313                   break;
 314                 }
 315               else
 316                 {
 317                   tempstr[tem++] =
 318                     longest_to_int (exp->elts[pc + 2].longconst);
 319                   pc += 4;
 320                 }
 321             }
 322         }
 323       if (tem > 0)
 324         {
 325           struct value_print_options opts;
 326
 327           get_user_print_options (&opts);
 328           LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 329                            (gdb_byte *) tempstr, nargs - 1, NULL, 0, &opts);
 330           (*pos) = pc;
 331         }
 332       else
 333         {
 334           fputs_filtered (" {", stream);
 335           for (tem = 0; tem < nargs; tem++)
 336             {
 337               if (tem != 0)
 338                 {
 339                   fputs_filtered (", ", stream);
 340                 }
 341               print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 342             }
 343           fputs_filtered ("}", stream);
 344         }
 345       return;
 346
 347     case TERNOP_COND:
 348       if ((int) prec > (int) PREC_COMMA)
 349         fputs_filtered ("(", stream);
 350       /* Print the subexpressions, forcing parentheses
 351          around any binary operations within them.
 352          This is more parentheses than are strictly necessary,
 353          but it looks clearer.  */
 354       print_subexp (exp, pos, stream, PREC_HYPER);
 355       fputs_filtered (" ? ", stream);
 356       print_subexp (exp, pos, stream, PREC_HYPER);
 357       fputs_filtered (" : ", stream);
 358       print_subexp (exp, pos, stream, PREC_HYPER);
 359       if ((int) prec > (int) PREC_COMMA)
 360         fputs_filtered (")", stream);
 361       return;
 362
 363     case TERNOP_SLICE:
 364       print_subexp (exp, pos, stream, PREC_SUFFIX);
 365       fputs_filtered ("(", stream);
 366       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 367       fputs_filtered (opcode == TERNOP_SLICE ? " : " : " UP ", stream);
 368       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 369       fputs_filtered (")", stream);
 370       return;
 371
 372     case STRUCTOP_STRUCT:
 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       /* Will not occur for Modula-2.  */
 381     case STRUCTOP_PTR:
 382       tem = longest_to_int (exp->elts[pc + 1].longconst);
 383       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 384       print_subexp (exp, pos, stream, PREC_SUFFIX);
 385       fputs_filtered ("->", stream);
 386       fputs_filtered (&exp->elts[pc + 2].string, stream);
 387       return;
 388
 389     case STRUCTOP_MEMBER:
 390       print_subexp (exp, pos, stream, PREC_SUFFIX);
 391       fputs_filtered (".*", stream);
 392       print_subexp (exp, pos, stream, PREC_SUFFIX);
 393       return;
 394
 395     case STRUCTOP_MPTR:
 396       print_subexp (exp, pos, stream, PREC_SUFFIX);
 397       fputs_filtered ("->*", stream);
 398       print_subexp (exp, pos, stream, PREC_SUFFIX);
 399       return;
 400
 401     case BINOP_SUBSCRIPT:
 402       print_subexp (exp, pos, stream, PREC_SUFFIX);
 403       fputs_filtered ("[", stream);
 404       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 405       fputs_filtered ("]", stream);
 406       return;
 407
 408     case UNOP_POSTINCREMENT:
 409       print_subexp (exp, pos, stream, PREC_SUFFIX);
 410       fputs_filtered ("++", stream);
 411       return;
 412
 413     case UNOP_POSTDECREMENT:
 414       print_subexp (exp, pos, stream, PREC_SUFFIX);
 415       fputs_filtered ("--", stream);
 416       return;
 417
 418     case UNOP_CAST:
 419       (*pos) += 2;
 420       if ((int) prec > (int) PREC_PREFIX)
 421         fputs_filtered ("(", stream);
 422       fputs_filtered ("(", stream);
 423       type_print (exp->elts[pc + 1].type, "", stream, 0);
 424       fputs_filtered (") ", stream);
 425       print_subexp (exp, pos, stream, PREC_PREFIX);
 426       if ((int) prec > (int) PREC_PREFIX)
 427         fputs_filtered (")", stream);
 428       return;
 429
 430     case UNOP_CAST_TYPE:
 431       if ((int) prec > (int) PREC_PREFIX)
 432         fputs_filtered ("(", stream);
 433       fputs_filtered ("(", stream);
 434       print_subexp (exp, pos, stream, PREC_PREFIX);
 435       fputs_filtered (") ", stream);
 436       print_subexp (exp, pos, stream, PREC_PREFIX);
 437       if ((int) prec > (int) PREC_PREFIX)
 438         fputs_filtered (")", stream);
 439       return;
 440
 441     case UNOP_DYNAMIC_CAST:
 442     case UNOP_REINTERPRET_CAST:
 443       fputs_filtered (opcode == UNOP_DYNAMIC_CAST ? "dynamic_cast"
 444                       : "reinterpret_cast", stream);
 445       fputs_filtered ("<", stream);
 446       print_subexp (exp, pos, stream, PREC_PREFIX);
 447       fputs_filtered ("> (", stream);
 448       print_subexp (exp, pos, stream, PREC_PREFIX);
 449       fputs_filtered (")", stream);
 450       return;
 451
 452     case UNOP_MEMVAL:
 453       (*pos) += 2;
 454       if ((int) prec > (int) PREC_PREFIX)
 455         fputs_filtered ("(", stream);
 456       if (exp->elts[pc + 1].type->code () == TYPE_CODE_FUNC
 457           && exp->elts[pc + 3].opcode == OP_LONG)
 458         {
 459           struct value_print_options opts;
 460
 461           /* We have a minimal symbol fn, probably.  It's encoded
 462              as a UNOP_MEMVAL (function-type) of an OP_LONG (int, address).
 463              Swallow the OP_LONG (including both its opcodes); ignore
 464              its type; print the value in the type of the MEMVAL.  */
 465           (*pos) += 4;
 466           val = value_at_lazy (exp->elts[pc + 1].type,
 467                                (CORE_ADDR) exp->elts[pc + 5].longconst);
 468           get_no_prettyformat_print_options (&opts);
 469           value_print (val, stream, &opts);
 470         }
 471       else
 472         {
 473           fputs_filtered ("{", stream);
 474           type_print (exp->elts[pc + 1].type, "", stream, 0);
 475           fputs_filtered ("} ", stream);
 476           print_subexp (exp, pos, stream, PREC_PREFIX);
 477         }
 478       if ((int) prec > (int) PREC_PREFIX)
 479         fputs_filtered (")", stream);
 480       return;
 481
 482     case UNOP_MEMVAL_TYPE:
 483       if ((int) prec > (int) PREC_PREFIX)
 484         fputs_filtered ("(", stream);
 485       fputs_filtered ("{", stream);
 486       print_subexp (exp, pos, stream, PREC_PREFIX);
 487       fputs_filtered ("} ", stream);
 488       print_subexp (exp, pos, stream, PREC_PREFIX);
 489       if ((int) prec > (int) PREC_PREFIX)
 490         fputs_filtered (")", stream);
 491       return;
 492
 493     case BINOP_ASSIGN_MODIFY:
 494       opcode = exp->elts[pc + 1].opcode;
 495       (*pos) += 2;
 496       myprec = PREC_ASSIGN;
 497       assoc = 1;
 498       assign_modify = 1;
 499       op_str = "???";
 500       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 501         if (op_print_tab[tem].opcode == opcode)
 502           {
 503             op_str = op_print_tab[tem].string;
 504             break;
 505           }
 506       if (op_print_tab[tem].opcode != opcode)
 507         /* Not found; don't try to keep going because we don't know how
 508            to interpret further elements.  */
 509         error (_("Invalid expression"));
 510       break;
 511
 512       /* C++ ops */
 513
 514     case OP_THIS:
 515       ++(*pos);
 516       if (exp->language_defn->name_of_this () != NULL)
 517         fputs_filtered (exp->language_defn->name_of_this (), stream);
 518       else
 519         fprintf_styled (stream, metadata_style.style (),
 520                         _("<language %s has no 'this'>"),
 521                         exp->language_defn->name ());
 522       return;
 523
 524       /* Modula-2 ops */
 525
 526     case MULTI_SUBSCRIPT:
 527       (*pos) += 2;
 528       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 529       print_subexp (exp, pos, stream, PREC_SUFFIX);
 530       fprintf_unfiltered (stream, " [");
 531       for (tem = 0; tem < nargs; tem++)
 532         {
 533           if (tem != 0)
 534             fprintf_unfiltered (stream, ", ");
 535           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 536         }
 537       fprintf_unfiltered (stream, "]");
 538       return;
 539
 540     case BINOP_VAL:
 541       (*pos) += 2;
 542       fprintf_unfiltered (stream, "VAL(");
 543       type_print (exp->elts[pc + 1].type, "", stream, 0);
 544       fprintf_unfiltered (stream, ",");
 545       print_subexp (exp, pos, stream, PREC_PREFIX);
 546       fprintf_unfiltered (stream, ")");
 547       return;
 548
 549     case TYPE_INSTANCE:
 550       {
 551         type_instance_flags flags
 552           = (type_instance_flag_value) longest_to_int (exp->elts[pc + 1].longconst);
 553         LONGEST count = exp->elts[pc + 2].longconst;
 554
 555         /* The FLAGS.  */
 556         (*pos)++;
 557         /* The COUNT.  */
 558         (*pos)++;
 559         fputs_unfiltered ("TypeInstance(", stream);
 560         while (count-- > 0)
 561           {
 562             type_print (exp->elts[(*pos)++].type, "", stream, 0);
 563             if (count > 0)
 564               fputs_unfiltered (",", stream);
 565           }
 566         fputs_unfiltered (",", stream);
 567         /* Ending COUNT and ending TYPE_INSTANCE.  */
 568         (*pos) += 2;
 569         print_subexp (exp, pos, stream, PREC_PREFIX);
 570
 571         if (flags & TYPE_INSTANCE_FLAG_CONST)
 572           fputs_unfiltered (",const", stream);
 573         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
 574           fputs_unfiltered (",volatile", stream);
 575
 576         fputs_unfiltered (")", stream);
 577         return;
 578       }
 579
 580     case OP_RANGE:
 581       {
 582         enum range_type range_type;
 583
 584         range_type = (enum range_type)
 585           longest_to_int (exp->elts[pc + 1].longconst);
 586         *pos += 2;
 587
 588         if (range_type == NONE_BOUND_DEFAULT_EXCLUSIVE
 589             || range_type == LOW_BOUND_DEFAULT_EXCLUSIVE)
 590           fputs_filtered ("EXCLUSIVE_", stream);
 591         fputs_filtered ("RANGE(", stream);
 592         if (range_type == HIGH_BOUND_DEFAULT
 593             || range_type == NONE_BOUND_DEFAULT
 594             || range_type == NONE_BOUND_DEFAULT_EXCLUSIVE)
 595           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 596         fputs_filtered ("..", stream);
 597         if (range_type == LOW_BOUND_DEFAULT
 598             || range_type == NONE_BOUND_DEFAULT)
 599           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 600         fputs_filtered (")", stream);
 601         return;
 602       }
 603
 604       /* Default ops */
 605
 606     default:
 607       op_str = "???";
 608       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 609         if (op_print_tab[tem].opcode == opcode)
 610           {
 611             op_str = op_print_tab[tem].string;
 612             myprec = op_print_tab[tem].precedence;
 613             assoc = op_print_tab[tem].right_assoc;
 614             break;
 615           }
 616       if (op_print_tab[tem].opcode != opcode)
 617         /* Not found; don't try to keep going because we don't know how
 618            to interpret further elements.  For example, this happens
 619            if opcode is OP_TYPE.  */
 620         error (_("Invalid expression"));
 621     }
 622
 623   /* Note that PREC_BUILTIN will always emit parentheses.  */
 624   if ((int) myprec < (int) prec)
 625     fputs_filtered ("(", stream);
 626   if ((int) opcode > (int) BINOP_END)
 627     {
 628       if (assoc)
 629         {
 630           /* Unary postfix operator.  */
 631           print_subexp (exp, pos, stream, PREC_SUFFIX);
 632           fputs_filtered (op_str, stream);
 633         }
 634       else
 635         {
 636           /* Unary prefix operator.  */
 637           fputs_filtered (op_str, stream);
 638           if (myprec == PREC_BUILTIN_FUNCTION)
 639             fputs_filtered ("(", stream);
 640           print_subexp (exp, pos, stream, PREC_PREFIX);
 641           if (myprec == PREC_BUILTIN_FUNCTION)
 642             fputs_filtered (")", stream);
 643         }
 644     }
 645   else
 646     {
 647       /* Binary operator.  */
 648       /* Print left operand.
 649          If operator is right-associative,
 650          increment precedence for this operand.  */
 651       print_subexp (exp, pos, stream,
 652                     (enum precedence) ((int) myprec + assoc));
 653       /* Print the operator itself.  */
 654       if (assign_modify)
 655         fprintf_filtered (stream, " %s= ", op_str);
 656       else if (op_str[0] == ',')
 657         fprintf_filtered (stream, "%s ", op_str);
 658       else
 659         fprintf_filtered (stream, " %s ", op_str);
 660       /* Print right operand.
 661          If operator is left-associative,
 662          increment precedence for this operand.  */
 663       print_subexp (exp, pos, stream,
 664                     (enum precedence) ((int) myprec + !assoc));
 665     }
 666
 667   if ((int) myprec < (int) prec)
 668     fputs_filtered (")", stream);
 669 }
 670
 671 /* Return the operator corresponding to opcode OP as
 672    a string.   NULL indicates that the opcode was not found in the
 673    current language table.  */
 674 const char *
 675 op_string (enum exp_opcode op)
 676 {
 677   int tem;
 678   const struct op_print *op_print_tab;
 679
 680   op_print_tab = current_language->opcode_print_table ();
 681   for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 682     if (op_print_tab[tem].opcode == op)
 683       return op_print_tab[tem].string;
 684   return NULL;
 685 }
 686
 687 /* Support for dumping the raw data from expressions in a human readable
 688    form.  */
 689
 690 static int dump_subexp_body (struct expression *exp, struct ui_file *, int);
 691
 692 /* Name for OPCODE, when it appears in expression EXP.  */
 693
 694 const char *
 695 op_name (struct expression *exp, enum exp_opcode opcode)
 696 {
 697   if (opcode >= OP_UNUSED_LAST)
 698     {
 699       char *cell = get_print_cell ();
 700       xsnprintf (cell, PRINT_CELL_SIZE, "unknown opcode: %u",
 701                  unsigned (opcode));
 702       return cell;
 703     }
 704   return exp->language_defn->expression_ops ()->op_name (opcode);
 705 }
 706
 707 /* Default name for the standard operator OPCODE (i.e., one defined in
 708    the definition of enum exp_opcode).  */
 709
 710 const char *
 711 op_name_standard (enum exp_opcode opcode)
 712 {
 713   switch (opcode)
 714     {
 715     default:
 716       {
 717         static char buf[30];
 718
 719         xsnprintf (buf, sizeof (buf), "<unknown %d>", opcode);
 720         return buf;
 721       }
 722 #define OP(name)        \
 723     case name:          \
 724       return #name ;
 725 #include "std-operator.def"
 726 #undef OP
 727     }
 728 }
 729
 730 /* Print a raw dump of expression EXP to STREAM.
 731    NOTE, if non-NULL, is printed as extra explanatory text.  */
 732
 733 void
 734 dump_raw_expression (struct expression *exp, struct ui_file *stream,
 735                      const char *note)
 736 {
 737   int elt;
 738   char *eltscan;
 739   int eltsize;
 740
 741   fprintf_filtered (stream, "Dump of expression @ ");
 742   gdb_print_host_address (exp, stream);
 743   if (note)
 744     fprintf_filtered (stream, ", %s:", note);
 745   fprintf_filtered (stream, "\n\tLanguage %s, %d elements, %ld bytes each.\n",
 746                     exp->language_defn->name (), exp->nelts,
 747                     (long) sizeof (union exp_element));
 748   fprintf_filtered (stream, "\t%5s  %20s  %16s  %s\n", "Index", "Opcode",
 749                     "Hex Value", "String Value");
 750   for (elt = 0; elt < exp->nelts; elt++)
 751     {
 752       fprintf_filtered (stream, "\t%5d  ", elt);
 753
 754       const char *opcode_name = op_name (exp, exp->elts[elt].opcode);
 755       fprintf_filtered (stream, "%20s  ", opcode_name);
 756
 757       print_longest (stream, 'd', 0, exp->elts[elt].longconst);
 758       fprintf_filtered (stream, "  ");
 759
 760       for (eltscan = (char *) &exp->elts[elt],
 761            eltsize = sizeof (union exp_element);
 762            eltsize-- > 0;
 763            eltscan++)
 764         {
 765           fprintf_filtered (stream, "%c",
 766                             isprint (*eltscan) ? (*eltscan & 0xFF) : '.');
 767         }
 768       fprintf_filtered (stream, "\n");
 769     }
 770 }
 771
 772 /* Dump the subexpression of prefix expression EXP whose operator is at
 773    position ELT onto STREAM.  Returns the position of the next
 774    subexpression in EXP.  */
 775
 776 int
 777 dump_subexp (struct expression *exp, struct ui_file *stream, int elt)
 778 {
 779   static int indent = 0;
 780   int i;
 781
 782   fprintf_filtered (stream, "\n");
 783   fprintf_filtered (stream, "\t%5d  ", elt);
 784
 785   for (i = 1; i <= indent; i++)
 786     fprintf_filtered (stream, " ");
 787   indent += 2;
 788
 789   fprintf_filtered (stream, "%-20s  ", op_name (exp, exp->elts[elt].opcode));
 790
 791   elt = dump_subexp_body (exp, stream, elt);
 792
 793   indent -= 2;
 794
 795   return elt;
 796 }
 797
 798 /* Dump the operands of prefix expression EXP whose opcode is at
 799    position ELT onto STREAM.  Returns the position of the next
 800    subexpression in EXP.  */
 801
 802 static int
 803 dump_subexp_body (struct expression *exp, struct ui_file *stream, int elt)
 804 {
 805   return exp->language_defn->expression_ops ()->dump_subexp_body (exp, stream,
 806                                                                   elt);
 807 }
 808
 809 /* See parser-defs.h.  */
 810
 811 int
 812 dump_subexp_body_funcall (struct expression *exp,
 813                           struct ui_file *stream, int elt)
 814 {
 815   int nargs = longest_to_int (exp->elts[elt].longconst);
 816   fprintf_filtered (stream, "Number of args: %d", nargs);
 817   elt += 2;
 818
 819   for (int i = 1; i <= nargs + 1; i++)
 820     elt = dump_subexp (exp, stream, elt);
 821
 822   return elt;
 823 }
 824
 825 /* Default value for subexp_body in exp_descriptor vector.  */
 826
 827 int
 828 dump_subexp_body_standard (struct expression *exp,
 829                            struct ui_file *stream, int elt)
 830 {
 831   int opcode = exp->elts[elt++].opcode;
 832
 833   switch (opcode)
 834     {
 835     case TERNOP_COND:
 836     case TERNOP_SLICE:
 837       elt = dump_subexp (exp, stream, elt);
 838       /* FALL THROUGH */
 839     case BINOP_ADD:
 840     case BINOP_SUB:
 841     case BINOP_MUL:
 842     case BINOP_DIV:
 843     case BINOP_REM:
 844     case BINOP_MOD:
 845     case BINOP_LSH:
 846     case BINOP_RSH:
 847     case BINOP_LOGICAL_AND:
 848     case BINOP_LOGICAL_OR:
 849     case BINOP_BITWISE_AND:
 850     case BINOP_BITWISE_IOR:
 851     case BINOP_BITWISE_XOR:
 852     case BINOP_EQUAL:
 853     case BINOP_NOTEQUAL:
 854     case BINOP_LESS:
 855     case BINOP_GTR:
 856     case BINOP_LEQ:
 857     case BINOP_GEQ:
 858     case BINOP_REPEAT:
 859     case BINOP_ASSIGN:
 860     case BINOP_COMMA:
 861     case BINOP_SUBSCRIPT:
 862     case BINOP_EXP:
 863     case BINOP_MIN:
 864     case BINOP_MAX:
 865     case BINOP_INTDIV:
 866     case BINOP_ASSIGN_MODIFY:
 867     case BINOP_VAL:
 868     case BINOP_CONCAT:
 869     case BINOP_END:
 870     case STRUCTOP_MEMBER:
 871     case STRUCTOP_MPTR:
 872       elt = dump_subexp (exp, stream, elt);
 873       /* FALL THROUGH */
 874     case UNOP_NEG:
 875     case UNOP_LOGICAL_NOT:
 876     case UNOP_COMPLEMENT:
 877     case UNOP_IND:
 878     case UNOP_ADDR:
 879     case UNOP_PREINCREMENT:
 880     case UNOP_POSTINCREMENT:
 881     case UNOP_PREDECREMENT:
 882     case UNOP_POSTDECREMENT:
 883     case UNOP_SIZEOF:
 884     case UNOP_ALIGNOF:
 885     case UNOP_PLUS:
 886     case UNOP_CAP:
 887     case UNOP_CHR:
 888     case UNOP_ORD:
 889     case UNOP_ABS:
 890     case UNOP_FLOAT:
 891     case UNOP_HIGH:
 892     case UNOP_MAX:
 893     case UNOP_MIN:
 894     case UNOP_ODD:
 895     case UNOP_TRUNC:
 896       elt = dump_subexp (exp, stream, elt);
 897       break;
 898     case OP_LONG:
 899       fprintf_filtered (stream, "Type @");
 900       gdb_print_host_address (exp->elts[elt].type, stream);
 901       fprintf_filtered (stream, " (");
 902       type_print (exp->elts[elt].type, NULL, stream, 0);
 903       fprintf_filtered (stream, "), value %ld (0x%lx)",
 904                         (long) exp->elts[elt + 1].longconst,
 905                         (long) exp->elts[elt + 1].longconst);
 906       elt += 3;
 907       break;
 908     case OP_FLOAT:
 909       fprintf_filtered (stream, "Type @");
 910       gdb_print_host_address (exp->elts[elt].type, stream);
 911       fprintf_filtered (stream, " (");
 912       type_print (exp->elts[elt].type, NULL, stream, 0);
 913       fprintf_filtered (stream, "), value ");
 914       print_floating (exp->elts[elt + 1].floatconst,
 915                       exp->elts[elt].type, stream);
 916       elt += 3;
 917       break;
 918     case OP_VAR_VALUE:
 919       fprintf_filtered (stream, "Block @");
 920       gdb_print_host_address (exp->elts[elt].block, stream);
 921       fprintf_filtered (stream, ", symbol @");
 922       gdb_print_host_address (exp->elts[elt + 1].symbol, stream);
 923       fprintf_filtered (stream, " (%s)",
 924                         exp->elts[elt + 1].symbol->print_name ());
 925       elt += 3;
 926       break;
 927     case OP_VAR_MSYM_VALUE:
 928       fprintf_filtered (stream, "Objfile @");
 929       gdb_print_host_address (exp->elts[elt].objfile, stream);
 930       fprintf_filtered (stream, ", msymbol @");
 931       gdb_print_host_address (exp->elts[elt + 1].msymbol, stream);
 932       fprintf_filtered (stream, " (%s)",
 933                         exp->elts[elt + 1].msymbol->print_name ());
 934       elt += 3;
 935       break;
 936     case OP_VAR_ENTRY_VALUE:
 937       fprintf_filtered (stream, "Entry value of symbol @");
 938       gdb_print_host_address (exp->elts[elt].symbol, stream);
 939       fprintf_filtered (stream, " (%s)",
 940                         exp->elts[elt].symbol->print_name ());
 941       elt += 2;
 942       break;
 943     case OP_LAST:
 944       fprintf_filtered (stream, "History element %ld",
 945                         (long) exp->elts[elt].longconst);
 946       elt += 2;
 947       break;
 948     case OP_REGISTER:
 949       fprintf_filtered (stream, "Register $%s", &exp->elts[elt + 1].string);
 950       elt += 3 + BYTES_TO_EXP_ELEM (exp->elts[elt].longconst + 1);
 951       break;
 952     case OP_INTERNALVAR:
 953       fprintf_filtered (stream, "Internal var @");
 954       gdb_print_host_address (exp->elts[elt].internalvar, stream);
 955       fprintf_filtered (stream, " (%s)",
 956                         internalvar_name (exp->elts[elt].internalvar));
 957       elt += 2;
 958       break;
 959     case OP_FUNCALL:
 960       elt = dump_subexp_body_funcall (exp, stream, elt);
 961       break;
 962     case OP_ARRAY:
 963       {
 964         int lower, upper;
 965         int i;
 966
 967         lower = longest_to_int (exp->elts[elt].longconst);
 968         upper = longest_to_int (exp->elts[elt + 1].longconst);
 969
 970         fprintf_filtered (stream, "Bounds [%d:%d]", lower, upper);
 971         elt += 3;
 972
 973         for (i = 1; i <= upper - lower + 1; i++)
 974           elt = dump_subexp (exp, stream, elt);
 975       }
 976       break;
 977     case UNOP_DYNAMIC_CAST:
 978     case UNOP_REINTERPRET_CAST:
 979     case UNOP_CAST_TYPE:
 980     case UNOP_MEMVAL_TYPE:
 981       fprintf_filtered (stream, " (");
 982       elt = dump_subexp (exp, stream, elt);
 983       fprintf_filtered (stream, ")");
 984       elt = dump_subexp (exp, stream, elt);
 985       break;
 986     case UNOP_MEMVAL:
 987     case UNOP_CAST:
 988       fprintf_filtered (stream, "Type @");
 989       gdb_print_host_address (exp->elts[elt].type, stream);
 990       fprintf_filtered (stream, " (");
 991       type_print (exp->elts[elt].type, NULL, stream, 0);
 992       fprintf_filtered (stream, ")");
 993       elt = dump_subexp (exp, stream, elt + 2);
 994       break;
 995     case OP_TYPE:
 996       fprintf_filtered (stream, "Type @");
 997       gdb_print_host_address (exp->elts[elt].type, stream);
 998       fprintf_filtered (stream, " (");
 999       type_print (exp->elts[elt].type, NULL, stream, 0);
1000       fprintf_filtered (stream, ")");
1001       elt += 2;
1002       break;
1003     case OP_TYPEOF:
1004     case OP_DECLTYPE:
1005       fprintf_filtered (stream, "Typeof (");
1006       elt = dump_subexp (exp, stream, elt);
1007       fprintf_filtered (stream, ")");
1008       break;
1009     case OP_TYPEID:
1010       fprintf_filtered (stream, "typeid (");
1011       elt = dump_subexp (exp, stream, elt);
1012       fprintf_filtered (stream, ")");
1013       break;
1014     case STRUCTOP_STRUCT:
1015     case STRUCTOP_PTR:
1016       {
1017         char *elem_name;
1018         int len;
1019
1020         len = longest_to_int (exp->elts[elt].longconst);
1021         elem_name = &exp->elts[elt + 1].string;
1022
1023         fprintf_filtered (stream, "Element name: `%.*s'", len, elem_name);
1024         elt = dump_subexp (exp, stream, elt + 3 + BYTES_TO_EXP_ELEM (len + 1));
1025       }
1026       break;
1027     case OP_SCOPE:
1028       {
1029         char *elem_name;
1030         int len;
1031
1032         fprintf_filtered (stream, "Type @");
1033         gdb_print_host_address (exp->elts[elt].type, stream);
1034         fprintf_filtered (stream, " (");
1035         type_print (exp->elts[elt].type, NULL, stream, 0);
1036         fprintf_filtered (stream, ") ");
1037
1038         len = longest_to_int (exp->elts[elt + 1].longconst);
1039         elem_name = &exp->elts[elt + 2].string;
1040
1041         fprintf_filtered (stream, "Field name: `%.*s'", len, elem_name);
1042         elt += 4 + BYTES_TO_EXP_ELEM (len + 1);
1043       }
1044       break;
1045
1046     case OP_FUNC_STATIC_VAR:
1047       {
1048         int len = longest_to_int (exp->elts[elt].longconst);
1049         const char *var_name = &exp->elts[elt + 1].string;
1050         fprintf_filtered (stream, "Field name: `%.*s'", len, var_name);
1051         elt += 3 + BYTES_TO_EXP_ELEM (len + 1);
1052       }
1053       break;
1054
1055     case TYPE_INSTANCE:
1056       {
1057         type_instance_flags flags
1058           = (type_instance_flag_value) longest_to_int (exp->elts[elt++].longconst);
1059         LONGEST len = exp->elts[elt++].longconst;
1060         fprintf_filtered (stream, "%s TypeInstance: ", plongest (len));
1061         while (len-- > 0)
1062           {
1063             fprintf_filtered (stream, "Type @");
1064             gdb_print_host_address (exp->elts[elt].type, stream);
1065             fprintf_filtered (stream, " (");
1066             type_print (exp->elts[elt].type, NULL, stream, 0);
1067             fprintf_filtered (stream, ")");
1068             elt++;
1069             if (len > 0)
1070               fputs_filtered (", ", stream);
1071           }
1072
1073         fprintf_filtered (stream, " Flags: %s (", hex_string (flags));
1074         bool space = false;
1075         auto print_one = [&] (const char *mod)
1076           {
1077             if (space)
1078               fputs_filtered (" ", stream);
1079             space = true;
1080             fprintf_filtered (stream, "%s", mod);
1081           };
1082         if (flags & TYPE_INSTANCE_FLAG_CONST)
1083           print_one ("const");
1084         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
1085           print_one ("volatile");
1086         fprintf_filtered (stream, ")");
1087
1088         /* Ending LEN and ending TYPE_INSTANCE.  */
1089         elt += 2;
1090         elt = dump_subexp (exp, stream, elt);
1091       }
1092       break;
1093     case OP_STRING:
1094       {
1095         LONGEST len = exp->elts[elt].longconst;
1096         LONGEST type = exp->elts[elt + 1].longconst;
1097
1098         fprintf_filtered (stream, "Language-specific string type: %s",
1099                           plongest (type));
1100
1101         /* Skip length.  */
1102         elt += 1;
1103
1104         /* Skip string content. */
1105         elt += BYTES_TO_EXP_ELEM (len);
1106
1107         /* Skip length and ending OP_STRING. */
1108         elt += 2;
1109       }
1110       break;
1111     case OP_RANGE:
1112       {
1113         enum range_type range_type;
1114
1115         range_type = (enum range_type)
1116           longest_to_int (exp->elts[elt].longconst);
1117         elt += 2;
1118
1119         switch (range_type)
1120           {
1121           case BOTH_BOUND_DEFAULT:
1122             fputs_filtered ("Range '..'", stream);
1123             break;
1124           case LOW_BOUND_DEFAULT:
1125             fputs_filtered ("Range '..EXP'", stream);
1126             break;
1127           case LOW_BOUND_DEFAULT_EXCLUSIVE:
1128             fputs_filtered ("ExclusiveRange '..EXP'", stream);
1129             break;
1130           case HIGH_BOUND_DEFAULT:
1131             fputs_filtered ("Range 'EXP..'", stream);
1132             break;
1133           case NONE_BOUND_DEFAULT:
1134             fputs_filtered ("Range 'EXP..EXP'", stream);
1135             break;
1136           case NONE_BOUND_DEFAULT_EXCLUSIVE:
1137             fputs_filtered ("ExclusiveRange 'EXP..EXP'", stream);
1138             break;
1139           default:
1140             fputs_filtered ("Invalid Range!", stream);
1141             break;
1142           }
1143
1144         if (range_type == HIGH_BOUND_DEFAULT
1145             || range_type == NONE_BOUND_DEFAULT)
1146           elt = dump_subexp (exp, stream, elt);
1147         if (range_type == LOW_BOUND_DEFAULT
1148             || range_type == NONE_BOUND_DEFAULT)
1149           elt = dump_subexp (exp, stream, elt);
1150       }
1151       break;
1152
1153     default:
1154     case OP_NULL:
1155     case MULTI_SUBSCRIPT:
1156     case OP_COMPLEX:
1157     case OP_BOOL:
1158     case OP_M2_STRING:
1159     case OP_THIS:
1160     case OP_NAME:
1161       fprintf_filtered (stream, "Unknown format");
1162     }
1163
1164   return elt;
1165 }
1166
1167 void
1168 dump_prefix_expression (struct expression *exp, struct ui_file *stream)
1169 {
1170   int elt;
1171
1172   fprintf_filtered (stream, "Dump of expression @ ");
1173   gdb_print_host_address (exp, stream);
1174   fputs_filtered (", after conversion to prefix form:\nExpression: `", stream);
1175   print_expression (exp, stream);
1176   fprintf_filtered (stream, "'\n\tLanguage %s, %d elements, %ld bytes each.\n",
1177                     exp->language_defn->name (), exp->nelts,
1178                     (long) sizeof (union exp_element));
1179   fputs_filtered ("\n", stream);
1180
1181   for (elt = 0; elt < exp->nelts;)
1182     elt = dump_subexp (exp, stream, elt);
1183   fputs_filtered ("\n", stream);
1184 }