gdb/expprint.c

   1 /* Print in infix form a struct expression.
   2
   3    Copyright (C) 1986-2017 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
  33 #include <ctype.h>
  34
  35 void
  36 print_expression (struct expression *exp, struct ui_file *stream)
  37 {
  38   int pc = 0;
  39
  40   print_subexp (exp, &pc, stream, PREC_NULL);
  41 }
  42
  43 /* Print the subexpression of EXP that starts in position POS, on STREAM.
  44    PREC is the precedence of the surrounding operator;
  45    if the precedence of the main operator of this subexpression is less,
  46    parentheses are needed here.  */
  47
  48 void
  49 print_subexp (struct expression *exp, int *pos,
  50               struct ui_file *stream, enum precedence prec)
  51 {
  52   exp->language_defn->la_exp_desc->print_subexp (exp, pos, stream, prec);
  53 }
  54
  55 /* Standard implementation of print_subexp for use in language_defn
  56    vectors.  */
  57 void
  58 print_subexp_standard (struct expression *exp, int *pos,
  59                        struct ui_file *stream, enum precedence prec)
  60 {
  61   unsigned tem;
  62   const struct op_print *op_print_tab;
  63   int pc;
  64   unsigned nargs;
  65   const char *op_str;
  66   int assign_modify = 0;
  67   enum exp_opcode opcode;
  68   enum precedence myprec = PREC_NULL;
  69   /* Set to 1 for a right-associative operator.  */
  70   int assoc = 0;
  71   struct value *val;
  72   char *tempstr = NULL;
  73
  74   op_print_tab = exp->language_defn->la_op_print_tab;
  75   pc = (*pos)++;
  76   opcode = exp->elts[pc].opcode;
  77   switch (opcode)
  78     {
  79       /* Common ops */
  80
  81     case OP_TYPE:
  82       (*pos) += 2;
  83       type_print (exp->elts[pc + 1].type, "", stream, 0);
  84       return;
  85
  86     case OP_SCOPE:
  87       myprec = PREC_PREFIX;
  88       assoc = 0;
  89       fputs_filtered (type_name_no_tag (exp->elts[pc + 1].type), stream);
  90       fputs_filtered ("::", stream);
  91       nargs = longest_to_int (exp->elts[pc + 2].longconst);
  92       (*pos) += 4 + BYTES_TO_EXP_ELEM (nargs + 1);
  93       fputs_filtered (&exp->elts[pc + 3].string, stream);
  94       return;
  95
  96     case OP_LONG:
  97       {
  98         struct value_print_options opts;
  99
 100         get_no_prettyformat_print_options (&opts);
 101         (*pos) += 3;
 102         value_print (value_from_longest (exp->elts[pc + 1].type,
 103                                          exp->elts[pc + 2].longconst),
 104                      stream, &opts);
 105       }
 106       return;
 107
 108     case OP_DOUBLE:
 109       {
 110         struct value_print_options opts;
 111
 112         get_no_prettyformat_print_options (&opts);
 113         (*pos) += 3;
 114         value_print (value_from_double (exp->elts[pc + 1].type,
 115                                         exp->elts[pc + 2].doubleconst),
 116                      stream, &opts);
 117       }
 118       return;
 119
 120     case OP_VAR_VALUE:
 121       {
 122         const struct block *b;
 123
 124         (*pos) += 3;
 125         b = exp->elts[pc + 1].block;
 126         if (b != NULL
 127             && BLOCK_FUNCTION (b) != NULL
 128             && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)) != NULL)
 129           {
 130             fputs_filtered (SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)), stream);
 131             fputs_filtered ("::", stream);
 132           }
 133         fputs_filtered (SYMBOL_PRINT_NAME (exp->elts[pc + 2].symbol), stream);
 134       }
 135       return;
 136
 137     case OP_VAR_MSYM_VALUE:
 138       {
 139         (*pos) += 3;
 140         fputs_filtered (MSYMBOL_PRINT_NAME (exp->elts[pc + 2].msymbol), stream);
 141       }
 142       return;
 143
 144     case OP_FUNC_STATIC_VAR:
 145       {
 146         tem = longest_to_int (exp->elts[pc + 1].longconst);
 147         (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 148         fputs_filtered (&exp->elts[pc + 1].string, stream);
 149       }
 150       return;
 151
 152     case OP_VAR_ENTRY_VALUE:
 153       {
 154         (*pos) += 2;
 155         fprintf_filtered (stream, "%s@entry",
 156                           SYMBOL_PRINT_NAME (exp->elts[pc + 1].symbol));
 157       }
 158       return;
 159
 160     case OP_LAST:
 161       (*pos) += 2;
 162       fprintf_filtered (stream, "$%d",
 163                         longest_to_int (exp->elts[pc + 1].longconst));
 164       return;
 165
 166     case OP_REGISTER:
 167       {
 168         const char *name = &exp->elts[pc + 2].string;
 169
 170         (*pos) += 3 + BYTES_TO_EXP_ELEM (exp->elts[pc + 1].longconst + 1);
 171         fprintf_filtered (stream, "$%s", name);
 172         return;
 173       }
 174
 175     case OP_BOOL:
 176       (*pos) += 2;
 177       fprintf_filtered (stream, "%s",
 178                         longest_to_int (exp->elts[pc + 1].longconst)
 179                         ? "TRUE" : "FALSE");
 180       return;
 181
 182     case OP_INTERNALVAR:
 183       (*pos) += 2;
 184       fprintf_filtered (stream, "$%s",
 185                         internalvar_name (exp->elts[pc + 1].internalvar));
 186       return;
 187
 188     case OP_FUNCALL:
 189       (*pos) += 2;
 190       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 191       print_subexp (exp, pos, stream, PREC_SUFFIX);
 192       fputs_filtered (" (", stream);
 193       for (tem = 0; tem < nargs; tem++)
 194         {
 195           if (tem != 0)
 196             fputs_filtered (", ", stream);
 197           print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 198         }
 199       fputs_filtered (")", stream);
 200       return;
 201
 202     case OP_NAME:
 203       nargs = longest_to_int (exp->elts[pc + 1].longconst);
 204       (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 205       fputs_filtered (&exp->elts[pc + 2].string, stream);
 206       return;
 207
 208     case OP_STRING:
 209       {
 210         struct value_print_options opts;
 211
 212         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 213         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 214         /* LA_PRINT_STRING will print using the current repeat count threshold.
 215            If necessary, we can temporarily set it to zero, or pass it as an
 216            additional parameter to LA_PRINT_STRING.  -fnf */
 217         get_user_print_options (&opts);
 218         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 219                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 220                          NULL, 0, &opts);
 221       }
 222       return;
 223
 224     case OP_OBJC_NSSTRING:      /* Objective-C Foundation Class
 225                                    NSString constant.  */
 226       {
 227         struct value_print_options opts;
 228
 229         nargs = longest_to_int (exp->elts[pc + 1].longconst);
 230         (*pos) += 3 + BYTES_TO_EXP_ELEM (nargs + 1);
 231         fputs_filtered ("@\"", stream);
 232         get_user_print_options (&opts);
 233         LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 234                          (gdb_byte *) &exp->elts[pc + 2].string, nargs,
 235                          NULL, 0, &opts);
 236         fputs_filtered ("\"", stream);
 237       }
 238       return;
 239
 240     case OP_OBJC_MSGCALL:
 241       {                 /* Objective C message (method) call.  */
 242         char *selector;
 243
 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         if (0 == target_read_string (exp->elts[pc + 1].longconst,
 249                                      &selector, 1024, NULL))
 250           {
 251             error (_("bad selector"));
 252             return;
 253           }
 254         if (nargs)
 255           {
 256             char *s, *nextS;
 257
 258             s = (char *) alloca (strlen (selector) + 1);
 259             strcpy (s, selector);
 260             for (tem = 0; tem < nargs; tem++)
 261               {
 262                 nextS = strchr (s, ':');
 263                 gdb_assert (nextS);     /* Make sure we found ':'.  */
 264                 *nextS = '\0';
 265                 fprintf_unfiltered (stream, " %s: ", s);
 266                 s = nextS + 1;
 267                 print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 268               }
 269           }
 270         else
 271           {
 272             fprintf_unfiltered (stream, " %s", selector);
 273           }
 274         fprintf_unfiltered (stream, "]");
 275         /* "selector" was malloc'd by target_read_string.  Free it.  */
 276         xfree (selector);
 277         return;
 278       }
 279
 280     case OP_ARRAY:
 281       (*pos) += 3;
 282       nargs = longest_to_int (exp->elts[pc + 2].longconst);
 283       nargs -= longest_to_int (exp->elts[pc + 1].longconst);
 284       nargs++;
 285       tem = 0;
 286       if (exp->elts[pc + 4].opcode == OP_LONG
 287           && exp->elts[pc + 5].type
 288              == builtin_type (exp->gdbarch)->builtin_char
 289           && exp->language_defn->la_language == language_c)
 290         {
 291           /* Attempt to print C character arrays using string syntax.
 292              Walk through the args, picking up one character from each
 293              of the OP_LONG expression elements.  If any array element
 294              does not match our expection of what we should find for
 295              a simple string, revert back to array printing.  Note that
 296              the last expression element is an explicit null terminator
 297              byte, which doesn't get printed.  */
 298           tempstr = (char *) alloca (nargs);
 299           pc += 4;
 300           while (tem < nargs)
 301             {
 302               if (exp->elts[pc].opcode != OP_LONG
 303                   || exp->elts[pc + 1].type
 304                      != builtin_type (exp->gdbarch)->builtin_char)
 305                 {
 306                   /* Not a simple array of char, use regular array
 307                      printing.  */
 308                   tem = 0;
 309                   break;
 310                 }
 311               else
 312                 {
 313                   tempstr[tem++] =
 314                     longest_to_int (exp->elts[pc + 2].longconst);
 315                   pc += 4;
 316                 }
 317             }
 318         }
 319       if (tem > 0)
 320         {
 321           struct value_print_options opts;
 322
 323           get_user_print_options (&opts);
 324           LA_PRINT_STRING (stream, builtin_type (exp->gdbarch)->builtin_char,
 325                            (gdb_byte *) tempstr, nargs - 1, NULL, 0, &opts);
 326           (*pos) = pc;
 327         }
 328       else
 329         {
 330           fputs_filtered (" {", stream);
 331           for (tem = 0; tem < nargs; tem++)
 332             {
 333               if (tem != 0)
 334                 {
 335                   fputs_filtered (", ", stream);
 336                 }
 337               print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 338             }
 339           fputs_filtered ("}", stream);
 340         }
 341       return;
 342
 343     case TERNOP_COND:
 344       if ((int) prec > (int) PREC_COMMA)
 345         fputs_filtered ("(", stream);
 346       /* Print the subexpressions, forcing parentheses
 347          around any binary operations within them.
 348          This is more parentheses than are strictly necessary,
 349          but it looks clearer.  */
 350       print_subexp (exp, pos, stream, PREC_HYPER);
 351       fputs_filtered (" ? ", stream);
 352       print_subexp (exp, pos, stream, PREC_HYPER);
 353       fputs_filtered (" : ", stream);
 354       print_subexp (exp, pos, stream, PREC_HYPER);
 355       if ((int) prec > (int) PREC_COMMA)
 356         fputs_filtered (")", stream);
 357       return;
 358
 359     case TERNOP_SLICE:
 360       print_subexp (exp, pos, stream, PREC_SUFFIX);
 361       fputs_filtered ("(", stream);
 362       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 363       fputs_filtered (opcode == TERNOP_SLICE ? " : " : " UP ", stream);
 364       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 365       fputs_filtered (")", stream);
 366       return;
 367
 368     case STRUCTOP_STRUCT:
 369       tem = longest_to_int (exp->elts[pc + 1].longconst);
 370       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 371       print_subexp (exp, pos, stream, PREC_SUFFIX);
 372       fputs_filtered (".", stream);
 373       fputs_filtered (&exp->elts[pc + 2].string, stream);
 374       return;
 375
 376       /* Will not occur for Modula-2.  */
 377     case STRUCTOP_PTR:
 378       tem = longest_to_int (exp->elts[pc + 1].longconst);
 379       (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1);
 380       print_subexp (exp, pos, stream, PREC_SUFFIX);
 381       fputs_filtered ("->", stream);
 382       fputs_filtered (&exp->elts[pc + 2].string, stream);
 383       return;
 384
 385     case STRUCTOP_MEMBER:
 386       print_subexp (exp, pos, stream, PREC_SUFFIX);
 387       fputs_filtered (".*", stream);
 388       print_subexp (exp, pos, stream, PREC_SUFFIX);
 389       return;
 390
 391     case STRUCTOP_MPTR:
 392       print_subexp (exp, pos, stream, PREC_SUFFIX);
 393       fputs_filtered ("->*", stream);
 394       print_subexp (exp, pos, stream, PREC_SUFFIX);
 395       return;
 396
 397     case BINOP_SUBSCRIPT:
 398       print_subexp (exp, pos, stream, PREC_SUFFIX);
 399       fputs_filtered ("[", stream);
 400       print_subexp (exp, pos, stream, PREC_ABOVE_COMMA);
 401       fputs_filtered ("]", stream);
 402       return;
 403
 404     case UNOP_POSTINCREMENT:
 405       print_subexp (exp, pos, stream, PREC_SUFFIX);
 406       fputs_filtered ("++", stream);
 407       return;
 408
 409     case UNOP_POSTDECREMENT:
 410       print_subexp (exp, pos, stream, PREC_SUFFIX);
 411       fputs_filtered ("--", stream);
 412       return;
 413
 414     case UNOP_CAST:
 415       (*pos) += 2;
 416       if ((int) prec > (int) PREC_PREFIX)
 417         fputs_filtered ("(", stream);
 418       fputs_filtered ("(", stream);
 419       type_print (exp->elts[pc + 1].type, "", stream, 0);
 420       fputs_filtered (") ", stream);
 421       print_subexp (exp, pos, stream, PREC_PREFIX);
 422       if ((int) prec > (int) PREC_PREFIX)
 423         fputs_filtered (")", stream);
 424       return;
 425
 426     case UNOP_CAST_TYPE:
 427       if ((int) prec > (int) PREC_PREFIX)
 428         fputs_filtered ("(", stream);
 429       fputs_filtered ("(", stream);
 430       print_subexp (exp, pos, stream, PREC_PREFIX);
 431       fputs_filtered (") ", stream);
 432       print_subexp (exp, pos, stream, PREC_PREFIX);
 433       if ((int) prec > (int) PREC_PREFIX)
 434         fputs_filtered (")", stream);
 435       return;
 436
 437     case UNOP_DYNAMIC_CAST:
 438     case UNOP_REINTERPRET_CAST:
 439       fputs_filtered (opcode == UNOP_DYNAMIC_CAST ? "dynamic_cast"
 440                       : "reinterpret_cast", stream);
 441       fputs_filtered ("<", stream);
 442       print_subexp (exp, pos, stream, PREC_PREFIX);
 443       fputs_filtered ("> (", stream);
 444       print_subexp (exp, pos, stream, PREC_PREFIX);
 445       fputs_filtered (")", stream);
 446       return;
 447
 448     case UNOP_MEMVAL:
 449       (*pos) += 2;
 450       if ((int) prec > (int) PREC_PREFIX)
 451         fputs_filtered ("(", stream);
 452       if (TYPE_CODE (exp->elts[pc + 1].type) == TYPE_CODE_FUNC
 453           && exp->elts[pc + 3].opcode == OP_LONG)
 454         {
 455           struct value_print_options opts;
 456
 457           /* We have a minimal symbol fn, probably.  It's encoded
 458              as a UNOP_MEMVAL (function-type) of an OP_LONG (int, address).
 459              Swallow the OP_LONG (including both its opcodes); ignore
 460              its type; print the value in the type of the MEMVAL.  */
 461           (*pos) += 4;
 462           val = value_at_lazy (exp->elts[pc + 1].type,
 463                                (CORE_ADDR) exp->elts[pc + 5].longconst);
 464           get_no_prettyformat_print_options (&opts);
 465           value_print (val, stream, &opts);
 466         }
 467       else
 468         {
 469           fputs_filtered ("{", stream);
 470           type_print (exp->elts[pc + 1].type, "", stream, 0);
 471           fputs_filtered ("} ", stream);
 472           print_subexp (exp, pos, stream, PREC_PREFIX);
 473         }
 474       if ((int) prec > (int) PREC_PREFIX)
 475         fputs_filtered (")", stream);
 476       return;
 477
 478     case UNOP_MEMVAL_TYPE:
 479       if ((int) prec > (int) PREC_PREFIX)
 480         fputs_filtered ("(", stream);
 481       fputs_filtered ("{", stream);
 482       print_subexp (exp, pos, stream, PREC_PREFIX);
 483       fputs_filtered ("} ", stream);
 484       print_subexp (exp, pos, stream, PREC_PREFIX);
 485       if ((int) prec > (int) PREC_PREFIX)
 486         fputs_filtered (")", stream);
 487       return;
 488
 489     case BINOP_ASSIGN_MODIFY:
 490       opcode = exp->elts[pc + 1].opcode;
 491       (*pos) += 2;
 492       myprec = PREC_ASSIGN;
 493       assoc = 1;
 494       assign_modify = 1;
 495       op_str = "???";
 496       for (tem = 0; op_print_tab[tem].opcode != OP_NULL; tem++)
 497         if (op_print_tab[tem].opcode == opcode)
 498           {
 499             op_str = op_print_tab[tem].string;
 500             break;
 501           }
 502       if (op_print_tab[tem].opcode != opcode)
 503         /* Not found; don't try to keep going because we don't know how
 504            to interpret further elements.  */
 505         error (_("Invalid expression"));
 506       break;
 507
 508       /* C++ ops */
 509
 510     case OP_THIS:
 511       ++(*pos);
 512       if (exp->language_defn->la_name_of_this)
 513         fputs_filtered (exp->language_defn->la_name_of_this, stream);
 514       else
 515         fprintf_filtered (stream, _("<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         fputs_filtered ("RANGE(", stream);
 584         if (range_type == HIGH_BOUND_DEFAULT
 585             || range_type == NONE_BOUND_DEFAULT)
 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   return exp->language_defn->la_exp_desc->op_name (opcode);
 689 }
 690
 691 /* Default name for the standard operator OPCODE (i.e., one defined in
 692    the definition of enum exp_opcode).  */
 693
 694 const char *
 695 op_name_standard (enum exp_opcode opcode)
 696 {
 697   switch (opcode)
 698     {
 699     default:
 700       {
 701         static char buf[30];
 702
 703         xsnprintf (buf, sizeof (buf), "<unknown %d>", opcode);
 704         return buf;
 705       }
 706 #define OP(name)        \
 707     case name:          \
 708       return #name ;
 709 #include "std-operator.def"
 710 #undef OP
 711     }
 712 }
 713
 714 /* Print a raw dump of expression EXP to STREAM.
 715    NOTE, if non-NULL, is printed as extra explanatory text.  */
 716
 717 void
 718 dump_raw_expression (struct expression *exp, struct ui_file *stream,
 719                      const char *note)
 720 {
 721   int elt;
 722   char *eltscan;
 723   int eltsize;
 724
 725   fprintf_filtered (stream, "Dump of expression @ ");
 726   gdb_print_host_address (exp, stream);
 727   if (note)
 728     fprintf_filtered (stream, ", %s:", note);
 729   fprintf_filtered (stream, "\n\tLanguage %s, %d elements, %ld bytes each.\n",
 730                     exp->language_defn->la_name, exp->nelts,
 731                     (long) sizeof (union exp_element));
 732   fprintf_filtered (stream, "\t%5s  %20s  %16s  %s\n", "Index", "Opcode",
 733                     "Hex Value", "String Value");
 734   for (elt = 0; elt < exp->nelts; elt++)
 735     {
 736       fprintf_filtered (stream, "\t%5d  ", elt);
 737
 738       const char *opcode_name = op_name (exp, exp->elts[elt].opcode);
 739       fprintf_filtered (stream, "%20s  ", opcode_name);
 740
 741       print_longest (stream, 'd', 0, exp->elts[elt].longconst);
 742       fprintf_filtered (stream, "  ");
 743
 744       for (eltscan = (char *) &exp->elts[elt],
 745            eltsize = sizeof (union exp_element);
 746            eltsize-- > 0;
 747            eltscan++)
 748         {
 749           fprintf_filtered (stream, "%c",
 750                             isprint (*eltscan) ? (*eltscan & 0xFF) : '.');
 751         }
 752       fprintf_filtered (stream, "\n");
 753     }
 754 }
 755
 756 /* Dump the subexpression of prefix expression EXP whose operator is at
 757    position ELT onto STREAM.  Returns the position of the next
 758    subexpression in EXP.  */
 759
 760 int
 761 dump_subexp (struct expression *exp, struct ui_file *stream, int elt)
 762 {
 763   static int indent = 0;
 764   int i;
 765
 766   fprintf_filtered (stream, "\n");
 767   fprintf_filtered (stream, "\t%5d  ", elt);
 768
 769   for (i = 1; i <= indent; i++)
 770     fprintf_filtered (stream, " ");
 771   indent += 2;
 772
 773   fprintf_filtered (stream, "%-20s  ", op_name (exp, exp->elts[elt].opcode));
 774
 775   elt = dump_subexp_body (exp, stream, elt);
 776
 777   indent -= 2;
 778
 779   return elt;
 780 }
 781
 782 /* Dump the operands of prefix expression EXP whose opcode is at
 783    position ELT onto STREAM.  Returns the position of the next
 784    subexpression in EXP.  */
 785
 786 static int
 787 dump_subexp_body (struct expression *exp, struct ui_file *stream, int elt)
 788 {
 789   return exp->language_defn->la_exp_desc->dump_subexp_body (exp, stream, elt);
 790 }
 791
 792 /* Default value for subexp_body in exp_descriptor vector.  */
 793
 794 int
 795 dump_subexp_body_standard (struct expression *exp,
 796                            struct ui_file *stream, int elt)
 797 {
 798   int opcode = exp->elts[elt++].opcode;
 799
 800   switch (opcode)
 801     {
 802     case TERNOP_COND:
 803     case TERNOP_SLICE:
 804       elt = dump_subexp (exp, stream, elt);
 805       /* FALL THROUGH */
 806     case BINOP_ADD:
 807     case BINOP_SUB:
 808     case BINOP_MUL:
 809     case BINOP_DIV:
 810     case BINOP_REM:
 811     case BINOP_MOD:
 812     case BINOP_LSH:
 813     case BINOP_RSH:
 814     case BINOP_LOGICAL_AND:
 815     case BINOP_LOGICAL_OR:
 816     case BINOP_BITWISE_AND:
 817     case BINOP_BITWISE_IOR:
 818     case BINOP_BITWISE_XOR:
 819     case BINOP_EQUAL:
 820     case BINOP_NOTEQUAL:
 821     case BINOP_LESS:
 822     case BINOP_GTR:
 823     case BINOP_LEQ:
 824     case BINOP_GEQ:
 825     case BINOP_REPEAT:
 826     case BINOP_ASSIGN:
 827     case BINOP_COMMA:
 828     case BINOP_SUBSCRIPT:
 829     case BINOP_EXP:
 830     case BINOP_MIN:
 831     case BINOP_MAX:
 832     case BINOP_INTDIV:
 833     case BINOP_ASSIGN_MODIFY:
 834     case BINOP_VAL:
 835     case BINOP_CONCAT:
 836     case BINOP_END:
 837     case STRUCTOP_MEMBER:
 838     case STRUCTOP_MPTR:
 839       elt = dump_subexp (exp, stream, elt);
 840       /* FALL THROUGH */
 841     case UNOP_NEG:
 842     case UNOP_LOGICAL_NOT:
 843     case UNOP_COMPLEMENT:
 844     case UNOP_IND:
 845     case UNOP_ADDR:
 846     case UNOP_PREINCREMENT:
 847     case UNOP_POSTINCREMENT:
 848     case UNOP_PREDECREMENT:
 849     case UNOP_POSTDECREMENT:
 850     case UNOP_SIZEOF:
 851     case UNOP_PLUS:
 852     case UNOP_CAP:
 853     case UNOP_CHR:
 854     case UNOP_ORD:
 855     case UNOP_ABS:
 856     case UNOP_FLOAT:
 857     case UNOP_HIGH:
 858     case UNOP_MAX:
 859     case UNOP_MIN:
 860     case UNOP_ODD:
 861     case UNOP_TRUNC:
 862       elt = dump_subexp (exp, stream, elt);
 863       break;
 864     case OP_LONG:
 865       fprintf_filtered (stream, "Type @");
 866       gdb_print_host_address (exp->elts[elt].type, stream);
 867       fprintf_filtered (stream, " (");
 868       type_print (exp->elts[elt].type, NULL, stream, 0);
 869       fprintf_filtered (stream, "), value %ld (0x%lx)",
 870                         (long) exp->elts[elt + 1].longconst,
 871                         (long) exp->elts[elt + 1].longconst);
 872       elt += 3;
 873       break;
 874     case OP_DOUBLE:
 875       fprintf_filtered (stream, "Type @");
 876       gdb_print_host_address (exp->elts[elt].type, stream);
 877       fprintf_filtered (stream, " (");
 878       type_print (exp->elts[elt].type, NULL, stream, 0);
 879       fprintf_filtered (stream, "), value %g",
 880                         (double) exp->elts[elt + 1].doubleconst);
 881       elt += 3;
 882       break;
 883     case OP_VAR_VALUE:
 884       fprintf_filtered (stream, "Block @");
 885       gdb_print_host_address (exp->elts[elt].block, stream);
 886       fprintf_filtered (stream, ", symbol @");
 887       gdb_print_host_address (exp->elts[elt + 1].symbol, stream);
 888       fprintf_filtered (stream, " (%s)",
 889                         SYMBOL_PRINT_NAME (exp->elts[elt + 1].symbol));
 890       elt += 3;
 891       break;
 892     case OP_VAR_MSYM_VALUE:
 893       fprintf_filtered (stream, "Objfile @");
 894       gdb_print_host_address (exp->elts[elt].objfile, stream);
 895       fprintf_filtered (stream, ", msymbol @");
 896       gdb_print_host_address (exp->elts[elt + 1].msymbol, stream);
 897       fprintf_filtered (stream, " (%s)",
 898                         MSYMBOL_PRINT_NAME (exp->elts[elt + 1].msymbol));
 899       elt += 3;
 900       break;
 901     case OP_VAR_ENTRY_VALUE:
 902       fprintf_filtered (stream, "Entry value of symbol @");
 903       gdb_print_host_address (exp->elts[elt].symbol, stream);
 904       fprintf_filtered (stream, " (%s)",
 905                         SYMBOL_PRINT_NAME (exp->elts[elt].symbol));
 906       elt += 2;
 907       break;
 908     case OP_LAST:
 909       fprintf_filtered (stream, "History element %ld",
 910                         (long) exp->elts[elt].longconst);
 911       elt += 2;
 912       break;
 913     case OP_REGISTER:
 914       fprintf_filtered (stream, "Register $%s", &exp->elts[elt + 1].string);
 915       elt += 3 + BYTES_TO_EXP_ELEM (exp->elts[elt].longconst + 1);
 916       break;
 917     case OP_INTERNALVAR:
 918       fprintf_filtered (stream, "Internal var @");
 919       gdb_print_host_address (exp->elts[elt].internalvar, stream);
 920       fprintf_filtered (stream, " (%s)",
 921                         internalvar_name (exp->elts[elt].internalvar));
 922       elt += 2;
 923       break;
 924     case OP_FUNCALL:
 925       {
 926         int i, nargs;
 927
 928         nargs = longest_to_int (exp->elts[elt].longconst);
 929
 930         fprintf_filtered (stream, "Number of args: %d", nargs);
 931         elt += 2;
 932
 933         for (i = 1; i <= nargs + 1; i++)
 934           elt = dump_subexp (exp, stream, elt);
 935       }
 936       break;
 937     case OP_ARRAY:
 938       {
 939         int lower, upper;
 940         int i;
 941
 942         lower = longest_to_int (exp->elts[elt].longconst);
 943         upper = longest_to_int (exp->elts[elt + 1].longconst);
 944
 945         fprintf_filtered (stream, "Bounds [%d:%d]", lower, upper);
 946         elt += 3;
 947
 948         for (i = 1; i <= upper - lower + 1; i++)
 949           elt = dump_subexp (exp, stream, elt);
 950       }
 951       break;
 952     case UNOP_DYNAMIC_CAST:
 953     case UNOP_REINTERPRET_CAST:
 954     case UNOP_CAST_TYPE:
 955     case UNOP_MEMVAL_TYPE:
 956       fprintf_filtered (stream, " (");
 957       elt = dump_subexp (exp, stream, elt);
 958       fprintf_filtered (stream, ")");
 959       elt = dump_subexp (exp, stream, elt);
 960       break;
 961     case UNOP_MEMVAL:
 962     case UNOP_CAST:
 963       fprintf_filtered (stream, "Type @");
 964       gdb_print_host_address (exp->elts[elt].type, stream);
 965       fprintf_filtered (stream, " (");
 966       type_print (exp->elts[elt].type, NULL, stream, 0);
 967       fprintf_filtered (stream, ")");
 968       elt = dump_subexp (exp, stream, elt + 2);
 969       break;
 970     case OP_TYPE:
 971       fprintf_filtered (stream, "Type @");
 972       gdb_print_host_address (exp->elts[elt].type, stream);
 973       fprintf_filtered (stream, " (");
 974       type_print (exp->elts[elt].type, NULL, stream, 0);
 975       fprintf_filtered (stream, ")");
 976       elt += 2;
 977       break;
 978     case OP_TYPEOF:
 979     case OP_DECLTYPE:
 980       fprintf_filtered (stream, "Typeof (");
 981       elt = dump_subexp (exp, stream, elt);
 982       fprintf_filtered (stream, ")");
 983       break;
 984     case OP_TYPEID:
 985       fprintf_filtered (stream, "typeid (");
 986       elt = dump_subexp (exp, stream, elt);
 987       fprintf_filtered (stream, ")");
 988       break;
 989     case STRUCTOP_STRUCT:
 990     case STRUCTOP_PTR:
 991       {
 992         char *elem_name;
 993         int len;
 994
 995         len = longest_to_int (exp->elts[elt].longconst);
 996         elem_name = &exp->elts[elt + 1].string;
 997
 998         fprintf_filtered (stream, "Element name: `%.*s'", len, elem_name);
 999         elt = dump_subexp (exp, stream, elt + 3 + BYTES_TO_EXP_ELEM (len + 1));
1000       }
1001       break;
1002     case OP_SCOPE:
1003       {
1004         char *elem_name;
1005         int len;
1006
1007         fprintf_filtered (stream, "Type @");
1008         gdb_print_host_address (exp->elts[elt].type, stream);
1009         fprintf_filtered (stream, " (");
1010         type_print (exp->elts[elt].type, NULL, stream, 0);
1011         fprintf_filtered (stream, ") ");
1012
1013         len = longest_to_int (exp->elts[elt + 1].longconst);
1014         elem_name = &exp->elts[elt + 2].string;
1015
1016         fprintf_filtered (stream, "Field name: `%.*s'", len, elem_name);
1017         elt += 4 + BYTES_TO_EXP_ELEM (len + 1);
1018       }
1019       break;
1020
1021     case OP_FUNC_STATIC_VAR:
1022       {
1023         int len = longest_to_int (exp->elts[elt].longconst);
1024         const char *var_name = &exp->elts[elt + 1].string;
1025         fprintf_filtered (stream, "Field name: `%.*s'", len, var_name);
1026         elt += 3 + BYTES_TO_EXP_ELEM (len + 1);
1027       }
1028       break;
1029
1030     case TYPE_INSTANCE:
1031       {
1032         type_instance_flags flags
1033           = (type_instance_flag_value) longest_to_int (exp->elts[elt++].longconst);
1034         LONGEST len = exp->elts[elt++].longconst;
1035         fprintf_filtered (stream, "%s TypeInstance: ", plongest (len));
1036         while (len-- > 0)
1037           {
1038             fprintf_filtered (stream, "Type @");
1039             gdb_print_host_address (exp->elts[elt].type, stream);
1040             fprintf_filtered (stream, " (");
1041             type_print (exp->elts[elt].type, NULL, stream, 0);
1042             fprintf_filtered (stream, ")");
1043             elt++;
1044             if (len > 0)
1045               fputs_filtered (", ", stream);
1046           }
1047
1048         fprintf_filtered (stream, " Flags: %s (", hex_string (flags));
1049         bool space = false;
1050         auto print_one = [&] (const char *mod)
1051           {
1052             if (space)
1053               fputs_filtered (" ", stream);
1054             space = true;
1055             fprintf_filtered (stream, "%s", mod);
1056           };
1057         if (flags & TYPE_INSTANCE_FLAG_CONST)
1058           print_one ("const");
1059         if (flags & TYPE_INSTANCE_FLAG_VOLATILE)
1060           print_one ("volatile");
1061         fprintf_filtered (stream, ")");
1062
1063         /* Ending LEN and ending TYPE_INSTANCE.  */
1064         elt += 2;
1065         elt = dump_subexp (exp, stream, elt);
1066       }
1067       break;
1068     case OP_STRING:
1069       {
1070         LONGEST len = exp->elts[elt].longconst;
1071         LONGEST type = exp->elts[elt + 1].longconst;
1072
1073         fprintf_filtered (stream, "Language-specific string type: %s",
1074                           plongest (type));
1075
1076         /* Skip length.  */
1077         elt += 1;
1078
1079         /* Skip string content. */
1080         elt += BYTES_TO_EXP_ELEM (len);
1081
1082         /* Skip length and ending OP_STRING. */
1083         elt += 2;
1084       }
1085       break;
1086     case OP_RANGE:
1087       {
1088         enum range_type range_type;
1089
1090         range_type = (enum range_type)
1091           longest_to_int (exp->elts[elt].longconst);
1092         elt += 2;
1093
1094         switch (range_type)
1095           {
1096           case BOTH_BOUND_DEFAULT:
1097             fputs_filtered ("Range '..'", stream);
1098             break;
1099           case LOW_BOUND_DEFAULT:
1100             fputs_filtered ("Range '..EXP'", stream);
1101             break;
1102           case HIGH_BOUND_DEFAULT:
1103             fputs_filtered ("Range 'EXP..'", stream);
1104             break;
1105           case NONE_BOUND_DEFAULT:
1106             fputs_filtered ("Range 'EXP..EXP'", stream);
1107             break;
1108           default:
1109             fputs_filtered ("Invalid Range!", stream);
1110             break;
1111           }
1112
1113         if (range_type == HIGH_BOUND_DEFAULT
1114             || range_type == NONE_BOUND_DEFAULT)
1115           elt = dump_subexp (exp, stream, elt);
1116         if (range_type == LOW_BOUND_DEFAULT
1117             || range_type == NONE_BOUND_DEFAULT)
1118           elt = dump_subexp (exp, stream, elt);
1119       }
1120       break;
1121
1122     default:
1123     case OP_NULL:
1124     case MULTI_SUBSCRIPT:
1125     case OP_F77_UNDETERMINED_ARGLIST:
1126     case OP_COMPLEX:
1127     case OP_BOOL:
1128     case OP_M2_STRING:
1129     case OP_THIS:
1130     case OP_NAME:
1131       fprintf_filtered (stream, "Unknown format");
1132     }
1133
1134   return elt;
1135 }
1136
1137 void
1138 dump_prefix_expression (struct expression *exp, struct ui_file *stream)
1139 {
1140   int elt;
1141
1142   fprintf_filtered (stream, "Dump of expression @ ");
1143   gdb_print_host_address (exp, stream);
1144   fputs_filtered (", after conversion to prefix form:\nExpression: `", stream);
1145   print_expression (exp, stream);
1146   fprintf_filtered (stream, "'\n\tLanguage %s, %d elements, %ld bytes each.\n",
1147                     exp->language_defn->la_name, exp->nelts,
1148                     (long) sizeof (union exp_element));
1149   fputs_filtered ("\n", stream);
1150
1151   for (elt = 0; elt < exp->nelts;)
1152     elt = dump_subexp (exp, stream, elt);
1153   fputs_filtered ("\n", stream);
1154 }