gdb/ui-out.c

   1 /* Output generating routines for GDB.
   2
   3    Copyright (C) 1999-2016 Free Software Foundation, Inc.
   4
   5    Contributed by Cygnus Solutions.
   6    Written by Fernando Nasser for Cygnus.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include "defs.h"
  24 #include "expression.h"         /* For language.h */
  25 #include "language.h"
  26 #include "ui-out.h"
  27
  28 /* table header structures */
  29
  30 struct ui_out_hdr
  31   {
  32     int colno;
  33     int width;
  34     enum ui_align alignment;
  35     char *col_name;
  36     char *colhdr;
  37     struct ui_out_hdr *next;
  38   };
  39
  40 struct ui_out_level
  41   {
  42     /* Count each field; the first element is for non-list fields.  */
  43     int field_count;
  44     /* The type of this level.  */
  45     enum ui_out_type type;
  46   };
  47
  48 /* Define uiout->level vector types and operations.  */
  49 typedef struct ui_out_level *ui_out_level_p;
  50 DEF_VEC_P (ui_out_level_p);
  51
  52 /* Tables are special.  Maintain a separate structure that tracks
  53    their state.  At present an output can only contain a single table
  54    but that restriction might eventually be lifted.  */
  55
  56 struct ui_out_table
  57 {
  58   /* If on, a table is being generated.  */
  59   int flag;
  60
  61   /* If on, the body of a table is being generated.  If off, the table
  62      header is being generated.  */
  63   int body_flag;
  64
  65   /* The level at which each entry of the table is to be found.  A row
  66      (a tuple) is made up of entries.  Consequently ENTRY_LEVEL is one
  67      above that of the table.  */
  68   int entry_level;
  69
  70   /* Number of table columns (as specified in the table_begin call).  */
  71   int columns;
  72
  73   /* String identifying the table (as specified in the table_begin
  74      call).  */
  75   char *id;
  76
  77   /* Points to the first table header (if any).  */
  78   struct ui_out_hdr *header_first;
  79
  80   /* Points to the last table header (if any).  */
  81   struct ui_out_hdr *header_last;
  82
  83   /* Points to header of NEXT column to format.  */
  84   struct ui_out_hdr *header_next;
  85
  86 };
  87
  88
  89 /* The ui_out structure */
  90
  91 struct ui_out
  92   {
  93     int flags;
  94     /* Specific implementation of ui-out.  */
  95     const struct ui_out_impl *impl;
  96     void *data;
  97
  98     /* Current level.  */
  99     int level;
 100
 101     /* Vector to store and track the ui-out levels.  */
 102     VEC (ui_out_level_p) *levels;
 103
 104     /* A table, if any.  At present only a single table is supported.  */
 105     struct ui_out_table table;
 106   };
 107
 108 /* The current (inner most) level.  */
 109 static struct ui_out_level *
 110 current_level (struct ui_out *uiout)
 111 {
 112   return VEC_index (ui_out_level_p, uiout->levels, uiout->level);
 113 }
 114
 115 /* Create a new level, of TYPE.  Return the new level's index.  */
 116 static int
 117 push_level (struct ui_out *uiout,
 118             enum ui_out_type type)
 119 {
 120   struct ui_out_level *current;
 121
 122   uiout->level++;
 123   current = XNEW (struct ui_out_level);
 124   current->field_count = 0;
 125   current->type = type;
 126   VEC_safe_push (ui_out_level_p, uiout->levels, current);
 127   return uiout->level;
 128 }
 129
 130 /* Discard the current level, return the discarded level's index.
 131    TYPE is the type of the level being discarded.  */
 132 static int
 133 pop_level (struct ui_out *uiout,
 134            enum ui_out_type type)
 135 {
 136   struct ui_out_level *current;
 137
 138   /* We had better not underflow the buffer.  */
 139   gdb_assert (uiout->level > 0);
 140   gdb_assert (current_level (uiout)->type == type);
 141   current = VEC_pop (ui_out_level_p, uiout->levels);
 142   xfree (current);
 143   uiout->level--;
 144   return uiout->level + 1;
 145 }
 146
 147 /* These are the interfaces to implementation functions.  */
 148
 149 static void uo_table_begin (struct ui_out *uiout, int nbrofcols,
 150                             int nr_rows, const char *tblid);
 151 static void uo_table_body (struct ui_out *uiout);
 152 static void uo_table_end (struct ui_out *uiout);
 153 static void uo_table_header (struct ui_out *uiout, int width,
 154                              enum ui_align align, const char *col_name,
 155                              const char *colhdr);
 156 static void uo_begin (struct ui_out *uiout,
 157                       enum ui_out_type type,
 158                       int level, const char *id);
 159 static void uo_end (struct ui_out *uiout,
 160                     enum ui_out_type type,
 161                     int level);
 162 static void uo_field_int (struct ui_out *uiout, int fldno, int width,
 163                           enum ui_align align, const char *fldname, int value);
 164 static void uo_field_skip (struct ui_out *uiout, int fldno, int width,
 165                            enum ui_align align, const char *fldname);
 166 static void uo_field_fmt (struct ui_out *uiout, int fldno, int width,
 167                           enum ui_align align, const char *fldname,
 168                           const char *format, va_list args)
 169      ATTRIBUTE_PRINTF (6, 0);
 170 static void uo_spaces (struct ui_out *uiout, int numspaces);
 171 static void uo_text (struct ui_out *uiout, const char *string);
 172 static void uo_message (struct ui_out *uiout, int verbosity,
 173                         const char *format, va_list args)
 174      ATTRIBUTE_PRINTF (3, 0);
 175 static void uo_wrap_hint (struct ui_out *uiout, char *identstring);
 176 static void uo_flush (struct ui_out *uiout);
 177 static int uo_redirect (struct ui_out *uiout, struct ui_file *outstream);
 178 static void uo_data_destroy (struct ui_out *uiout);
 179
 180 /* Prototypes for local functions */
 181
 182 extern void _initialize_ui_out (void);
 183 static void append_header_to_list (struct ui_out *uiout, int width,
 184                                    enum ui_align alignment, const char *col_name,
 185                                    const char *colhdr);
 186 static int get_next_header (struct ui_out *uiout, int *colno, int *width,
 187                             enum ui_align *alignment, char **colhdr);
 188 static void clear_header_list (struct ui_out *uiout);
 189 static void clear_table (struct ui_out *uiout);
 190 static void verify_field (struct ui_out *uiout, int *fldno, int *width,
 191                           enum ui_align *align);
 192
 193 /* exported functions (ui_out API) */
 194
 195 /* Mark beginning of a table.  */
 196
 197 static void
 198 ui_out_table_begin (struct ui_out *uiout, int nbrofcols,
 199                     int nr_rows,
 200                     const char *tblid)
 201 {
 202   if (uiout->table.flag)
 203     internal_error (__FILE__, __LINE__,
 204                     _("tables cannot be nested; table_begin found before \
 205 previous table_end."));
 206
 207   uiout->table.flag = 1;
 208   uiout->table.body_flag = 0;
 209   uiout->table.entry_level = uiout->level + 1;
 210   uiout->table.columns = nbrofcols;
 211   if (tblid != NULL)
 212     uiout->table.id = xstrdup (tblid);
 213   else
 214     uiout->table.id = NULL;
 215   clear_header_list (uiout);
 216
 217   uo_table_begin (uiout, nbrofcols, nr_rows, uiout->table.id);
 218 }
 219
 220 void
 221 ui_out_table_body (struct ui_out *uiout)
 222 {
 223   if (!uiout->table.flag)
 224     internal_error (__FILE__, __LINE__,
 225                     _("table_body outside a table is not valid; it must be \
 226 after a table_begin and before a table_end."));
 227   if (uiout->table.body_flag)
 228     internal_error (__FILE__, __LINE__,
 229                     _("extra table_body call not allowed; there must be \
 230 only one table_body after a table_begin and before a table_end."));
 231   if (uiout->table.header_next->colno != uiout->table.columns)
 232     internal_error (__FILE__, __LINE__,
 233                     _("number of headers differ from number of table \
 234 columns."));
 235
 236   uiout->table.body_flag = 1;
 237   uiout->table.header_next = uiout->table.header_first;
 238
 239   uo_table_body (uiout);
 240 }
 241
 242 static void
 243 ui_out_table_end (struct ui_out *uiout)
 244 {
 245   if (!uiout->table.flag)
 246     internal_error (__FILE__, __LINE__,
 247                     _("misplaced table_end or missing table_begin."));
 248
 249   uiout->table.entry_level = 0;
 250   uiout->table.body_flag = 0;
 251   uiout->table.flag = 0;
 252
 253   uo_table_end (uiout);
 254   clear_table (uiout);
 255 }
 256
 257 void
 258 ui_out_table_header (struct ui_out *uiout, int width, enum ui_align alignment,
 259                      const char *col_name,
 260                      const char *colhdr)
 261 {
 262   if (!uiout->table.flag || uiout->table.body_flag)
 263     internal_error (__FILE__, __LINE__,
 264                     _("table header must be specified after table_begin \
 265 and before table_body."));
 266
 267   append_header_to_list (uiout, width, alignment, col_name, colhdr);
 268
 269   uo_table_header (uiout, width, alignment, col_name, colhdr);
 270 }
 271
 272 static void
 273 do_cleanup_table_end (void *data)
 274 {
 275   struct ui_out *ui_out = (struct ui_out *) data;
 276
 277   ui_out_table_end (ui_out);
 278 }
 279
 280 struct cleanup *
 281 make_cleanup_ui_out_table_begin_end (struct ui_out *ui_out, int nr_cols,
 282                                      int nr_rows, const char *tblid)
 283 {
 284   ui_out_table_begin (ui_out, nr_cols, nr_rows, tblid);
 285   return make_cleanup (do_cleanup_table_end, ui_out);
 286 }
 287
 288 void
 289 ui_out_begin (struct ui_out *uiout,
 290               enum ui_out_type type,
 291               const char *id)
 292 {
 293   int new_level;
 294
 295   if (uiout->table.flag && !uiout->table.body_flag)
 296     internal_error (__FILE__, __LINE__,
 297                     _("table header or table_body expected; lists must be \
 298 specified after table_body."));
 299
 300   /* Be careful to verify the ``field'' before the new tuple/list is
 301      pushed onto the stack.  That way the containing list/table/row is
 302      verified and not the newly created tuple/list.  This verification
 303      is needed (at least) for the case where a table row entry
 304      contains either a tuple/list.  For that case bookkeeping such as
 305      updating the column count or advancing to the next heading still
 306      needs to be performed.  */
 307   {
 308     int fldno;
 309     int width;
 310     enum ui_align align;
 311
 312     verify_field (uiout, &fldno, &width, &align);
 313   }
 314
 315   new_level = push_level (uiout, type);
 316
 317   /* If the push puts us at the same level as a table row entry, we've
 318      got a new table row.  Put the header pointer back to the start.  */
 319   if (uiout->table.body_flag
 320       && uiout->table.entry_level == new_level)
 321     uiout->table.header_next = uiout->table.header_first;
 322
 323   uo_begin (uiout, type, new_level, id);
 324 }
 325
 326 void
 327 ui_out_end (struct ui_out *uiout,
 328             enum ui_out_type type)
 329 {
 330   int old_level = pop_level (uiout, type);
 331
 332   uo_end (uiout, type, old_level);
 333 }
 334
 335 struct ui_out_end_cleanup_data
 336 {
 337   struct ui_out *uiout;
 338   enum ui_out_type type;
 339 };
 340
 341 static void
 342 do_cleanup_end (void *data)
 343 {
 344   struct ui_out_end_cleanup_data *end_cleanup_data
 345     = (struct ui_out_end_cleanup_data *) data;
 346
 347   ui_out_end (end_cleanup_data->uiout, end_cleanup_data->type);
 348   xfree (end_cleanup_data);
 349 }
 350
 351 static struct cleanup *
 352 make_cleanup_ui_out_end (struct ui_out *uiout,
 353                          enum ui_out_type type)
 354 {
 355   struct ui_out_end_cleanup_data *end_cleanup_data;
 356
 357   end_cleanup_data = XNEW (struct ui_out_end_cleanup_data);
 358   end_cleanup_data->uiout = uiout;
 359   end_cleanup_data->type = type;
 360   return make_cleanup (do_cleanup_end, end_cleanup_data);
 361 }
 362
 363 struct cleanup *
 364 make_cleanup_ui_out_tuple_begin_end (struct ui_out *uiout,
 365                                      const char *id)
 366 {
 367   ui_out_begin (uiout, ui_out_type_tuple, id);
 368   return make_cleanup_ui_out_end (uiout, ui_out_type_tuple);
 369 }
 370
 371 struct cleanup *
 372 make_cleanup_ui_out_list_begin_end (struct ui_out *uiout,
 373                                     const char *id)
 374 {
 375   ui_out_begin (uiout, ui_out_type_list, id);
 376   return make_cleanup_ui_out_end (uiout, ui_out_type_list);
 377 }
 378
 379 void
 380 ui_out_field_int (struct ui_out *uiout,
 381                   const char *fldname,
 382                   int value)
 383 {
 384   int fldno;
 385   int width;
 386   enum ui_align align;
 387
 388   verify_field (uiout, &fldno, &width, &align);
 389
 390   uo_field_int (uiout, fldno, width, align, fldname, value);
 391 }
 392
 393 void
 394 ui_out_field_fmt_int (struct ui_out *uiout,
 395                       int input_width,
 396                       enum ui_align input_align,
 397                       const char *fldname,
 398                       int value)
 399 {
 400   int fldno;
 401   int width;
 402   enum ui_align align;
 403
 404   verify_field (uiout, &fldno, &width, &align);
 405
 406   uo_field_int (uiout, fldno, input_width, input_align, fldname, value);
 407 }
 408
 409 /* Documented in ui-out.h.  */
 410
 411 void
 412 ui_out_field_core_addr (struct ui_out *uiout,
 413                         const char *fldname,
 414                         struct gdbarch *gdbarch,
 415                         CORE_ADDR address)
 416 {
 417   ui_out_field_string (uiout, fldname,
 418                        print_core_address (gdbarch, address));
 419 }
 420
 421 void
 422 ui_out_field_stream (struct ui_out *uiout,
 423                      const char *fldname,
 424                      struct ui_file *stream)
 425 {
 426   std::string buffer = ui_file_as_string (stream);
 427
 428   if (!buffer.empty ())
 429     ui_out_field_string (uiout, fldname, buffer.c_str ());
 430   else
 431     ui_out_field_skip (uiout, fldname);
 432   ui_file_rewind (stream);
 433 }
 434
 435 /* Used to omit a field.  */
 436
 437 void
 438 ui_out_field_skip (struct ui_out *uiout,
 439                    const char *fldname)
 440 {
 441   int fldno;
 442   int width;
 443   enum ui_align align;
 444
 445   verify_field (uiout, &fldno, &width, &align);
 446
 447   uo_field_skip (uiout, fldno, width, align, fldname);
 448 }
 449
 450 void
 451 ui_out_field_string (struct ui_out *uiout,
 452                      const char *fldname,
 453                      const char *string)
 454 {
 455   int fldno;
 456   int width;
 457   enum ui_align align;
 458
 459   verify_field (uiout, &fldno, &width, &align);
 460
 461   uo_field_string (uiout, fldno, width, align, fldname, string);
 462 }
 463
 464 /* VARARGS */
 465 void
 466 ui_out_field_fmt (struct ui_out *uiout,
 467                   const char *fldname,
 468                   const char *format, ...)
 469 {
 470   va_list args;
 471   int fldno;
 472   int width;
 473   enum ui_align align;
 474
 475   /* Will not align, but has to call anyway.  */
 476   verify_field (uiout, &fldno, &width, &align);
 477
 478   va_start (args, format);
 479
 480   uo_field_fmt (uiout, fldno, width, align, fldname, format, args);
 481
 482   va_end (args);
 483 }
 484
 485 void
 486 ui_out_spaces (struct ui_out *uiout, int numspaces)
 487 {
 488   uo_spaces (uiout, numspaces);
 489 }
 490
 491 void
 492 ui_out_text (struct ui_out *uiout,
 493              const char *string)
 494 {
 495   uo_text (uiout, string);
 496 }
 497
 498 void
 499 ui_out_message (struct ui_out *uiout, int verbosity,
 500                 const char *format,...)
 501 {
 502   va_list args;
 503
 504   va_start (args, format);
 505   uo_message (uiout, verbosity, format, args);
 506   va_end (args);
 507 }
 508
 509 void
 510 ui_out_wrap_hint (struct ui_out *uiout, char *identstring)
 511 {
 512   uo_wrap_hint (uiout, identstring);
 513 }
 514
 515 void
 516 ui_out_flush (struct ui_out *uiout)
 517 {
 518   uo_flush (uiout);
 519 }
 520
 521 int
 522 ui_out_redirect (struct ui_out *uiout, struct ui_file *outstream)
 523 {
 524   return uo_redirect (uiout, outstream);
 525 }
 526
 527 /* Set the flags specified by the mask given.  */
 528 int
 529 ui_out_set_flags (struct ui_out *uiout, int mask)
 530 {
 531   int oldflags = uiout->flags;
 532
 533   uiout->flags |= mask;
 534   return oldflags;
 535 }
 536
 537 /* Clear the flags specified by the mask given.  */
 538 int
 539 ui_out_clear_flags (struct ui_out *uiout, int mask)
 540 {
 541   int oldflags = uiout->flags;
 542
 543   uiout->flags &= ~mask;
 544   return oldflags;
 545 }
 546
 547 /* Test the flags against the mask given.  */
 548 int
 549 ui_out_test_flags (struct ui_out *uiout, int mask)
 550 {
 551   return (uiout->flags & mask);
 552 }
 553
 554 /* Obtain the current verbosity level (as stablished by the
 555    'set verbositylevel' command.  */
 556
 557 int
 558 ui_out_get_verblvl (struct ui_out *uiout)
 559 {
 560   /* FIXME: not implemented yet.  */
 561   return 0;
 562 }
 563
 564 int
 565 ui_out_is_mi_like_p (struct ui_out *uiout)
 566 {
 567   return uiout->impl->is_mi_like_p;
 568 }
 569
 570 /* Interface to the implementation functions.  */
 571
 572 void
 573 uo_table_begin (struct ui_out *uiout, int nbrofcols,
 574                 int nr_rows,
 575                 const char *tblid)
 576 {
 577   if (!uiout->impl->table_begin)
 578     return;
 579   uiout->impl->table_begin (uiout, nbrofcols, nr_rows, tblid);
 580 }
 581
 582 void
 583 uo_table_body (struct ui_out *uiout)
 584 {
 585   if (!uiout->impl->table_body)
 586     return;
 587   uiout->impl->table_body (uiout);
 588 }
 589
 590 void
 591 uo_table_end (struct ui_out *uiout)
 592 {
 593   if (!uiout->impl->table_end)
 594     return;
 595   uiout->impl->table_end (uiout);
 596 }
 597
 598 void
 599 uo_table_header (struct ui_out *uiout, int width, enum ui_align align,
 600                  const char *col_name,
 601                  const char *colhdr)
 602 {
 603   if (!uiout->impl->table_header)
 604     return;
 605   uiout->impl->table_header (uiout, width, align, col_name, colhdr);
 606 }
 607
 608 /* Clear the table associated with UIOUT.  */
 609
 610 static void
 611 clear_table (struct ui_out *uiout)
 612 {
 613   xfree (uiout->table.id);
 614   uiout->table.id = NULL;
 615   clear_header_list (uiout);
 616 }
 617
 618 void
 619 uo_begin (struct ui_out *uiout,
 620           enum ui_out_type type,
 621           int level,
 622           const char *id)
 623 {
 624   if (uiout->impl->begin == NULL)
 625     return;
 626   uiout->impl->begin (uiout, type, level, id);
 627 }
 628
 629 void
 630 uo_end (struct ui_out *uiout,
 631         enum ui_out_type type,
 632         int level)
 633 {
 634   if (uiout->impl->end == NULL)
 635     return;
 636   uiout->impl->end (uiout, type, level);
 637 }
 638
 639 void
 640 uo_field_int (struct ui_out *uiout, int fldno, int width, enum ui_align align,
 641               const char *fldname,
 642               int value)
 643 {
 644   if (!uiout->impl->field_int)
 645     return;
 646   uiout->impl->field_int (uiout, fldno, width, align, fldname, value);
 647 }
 648
 649 void
 650 uo_field_skip (struct ui_out *uiout, int fldno, int width, enum ui_align align,
 651                const char *fldname)
 652 {
 653   if (!uiout->impl->field_skip)
 654     return;
 655   uiout->impl->field_skip (uiout, fldno, width, align, fldname);
 656 }
 657
 658 void
 659 uo_field_string (struct ui_out *uiout, int fldno, int width,
 660                  enum ui_align align,
 661                  const char *fldname,
 662                  const char *string)
 663 {
 664   if (!uiout->impl->field_string)
 665     return;
 666   uiout->impl->field_string (uiout, fldno, width, align, fldname, string);
 667 }
 668
 669 void
 670 uo_field_fmt (struct ui_out *uiout, int fldno, int width, enum ui_align align,
 671               const char *fldname,
 672               const char *format,
 673               va_list args)
 674 {
 675   if (!uiout->impl->field_fmt)
 676     return;
 677   uiout->impl->field_fmt (uiout, fldno, width, align, fldname, format, args);
 678 }
 679
 680 void
 681 uo_spaces (struct ui_out *uiout, int numspaces)
 682 {
 683   if (!uiout->impl->spaces)
 684     return;
 685   uiout->impl->spaces (uiout, numspaces);
 686 }
 687
 688 void
 689 uo_text (struct ui_out *uiout,
 690          const char *string)
 691 {
 692   if (!uiout->impl->text)
 693     return;
 694   uiout->impl->text (uiout, string);
 695 }
 696
 697 void
 698 uo_message (struct ui_out *uiout, int verbosity,
 699             const char *format,
 700             va_list args)
 701 {
 702   if (!uiout->impl->message)
 703     return;
 704   uiout->impl->message (uiout, verbosity, format, args);
 705 }
 706
 707 void
 708 uo_wrap_hint (struct ui_out *uiout, char *identstring)
 709 {
 710   if (!uiout->impl->wrap_hint)
 711     return;
 712   uiout->impl->wrap_hint (uiout, identstring);
 713 }
 714
 715 void
 716 uo_flush (struct ui_out *uiout)
 717 {
 718   if (!uiout->impl->flush)
 719     return;
 720   uiout->impl->flush (uiout);
 721 }
 722
 723 int
 724 uo_redirect (struct ui_out *uiout, struct ui_file *outstream)
 725 {
 726   if (!uiout->impl->redirect)
 727     return -1;
 728   uiout->impl->redirect (uiout, outstream);
 729   return 0;
 730 }
 731
 732 void
 733 uo_data_destroy (struct ui_out *uiout)
 734 {
 735   if (!uiout->impl->data_destroy)
 736     return;
 737
 738   uiout->impl->data_destroy (uiout);
 739 }
 740
 741 /* local functions */
 742
 743 /* List of column headers manipulation routines.  */
 744
 745 static void
 746 clear_header_list (struct ui_out *uiout)
 747 {
 748   while (uiout->table.header_first != NULL)
 749     {
 750       uiout->table.header_next = uiout->table.header_first;
 751       uiout->table.header_first = uiout->table.header_first->next;
 752       xfree (uiout->table.header_next->colhdr);
 753       xfree (uiout->table.header_next->col_name);
 754       xfree (uiout->table.header_next);
 755     }
 756   gdb_assert (uiout->table.header_first == NULL);
 757   uiout->table.header_last = NULL;
 758   uiout->table.header_next = NULL;
 759 }
 760
 761 static void
 762 append_header_to_list (struct ui_out *uiout,
 763                        int width,
 764                        enum ui_align alignment,
 765                        const char *col_name,
 766                        const char *colhdr)
 767 {
 768   struct ui_out_hdr *temphdr;
 769
 770   temphdr = XNEW (struct ui_out_hdr);
 771   temphdr->width = width;
 772   temphdr->alignment = alignment;
 773   /* We have to copy the column title as the original may be an
 774      automatic.  */
 775   if (colhdr != NULL)
 776     temphdr->colhdr = xstrdup (colhdr);
 777   else
 778     temphdr->colhdr = NULL;
 779
 780   if (col_name != NULL)
 781     temphdr->col_name = xstrdup (col_name);
 782   else if (colhdr != NULL)
 783     temphdr->col_name = xstrdup (colhdr);
 784   else
 785     temphdr->col_name = NULL;
 786
 787   temphdr->next = NULL;
 788   if (uiout->table.header_first == NULL)
 789     {
 790       temphdr->colno = 1;
 791       uiout->table.header_first = temphdr;
 792       uiout->table.header_last = temphdr;
 793     }
 794   else
 795     {
 796       temphdr->colno = uiout->table.header_last->colno + 1;
 797       uiout->table.header_last->next = temphdr;
 798       uiout->table.header_last = temphdr;
 799     }
 800   uiout->table.header_next = uiout->table.header_last;
 801 }
 802
 803 /* Extract the format information for the NEXT header and advance
 804    the header pointer.  Return 0 if there was no next header.  */
 805
 806 static int
 807 get_next_header (struct ui_out *uiout,
 808                  int *colno,
 809                  int *width,
 810                  enum ui_align *alignment,
 811                  char **colhdr)
 812 {
 813   /* There may be no headers at all or we may have used all columns.  */
 814   if (uiout->table.header_next == NULL)
 815     return 0;
 816   *colno = uiout->table.header_next->colno;
 817   *width = uiout->table.header_next->width;
 818   *alignment = uiout->table.header_next->alignment;
 819   *colhdr = uiout->table.header_next->colhdr;
 820   /* Advance the header pointer to the next entry.  */
 821   uiout->table.header_next = uiout->table.header_next->next;
 822   return 1;
 823 }
 824
 825
 826 /* Verify that the field/tuple/list is correctly positioned.  Return
 827    the field number and corresponding alignment (if
 828    available/applicable).  */
 829
 830 static void
 831 verify_field (struct ui_out *uiout, int *fldno, int *width,
 832               enum ui_align *align)
 833 {
 834   struct ui_out_level *current = current_level (uiout);
 835   char *text;
 836
 837   if (uiout->table.flag)
 838     {
 839       if (!uiout->table.body_flag)
 840         internal_error (__FILE__, __LINE__,
 841                         _("table_body missing; table fields must be \
 842 specified after table_body and inside a list."));
 843       /* NOTE: cagney/2001-12-08: There was a check here to ensure
 844          that this code was only executed when uiout->level was
 845          greater than zero.  That no longer applies - this code is run
 846          before each table row tuple is started and at that point the
 847          level is zero.  */
 848     }
 849
 850   current->field_count += 1;
 851
 852   if (uiout->table.body_flag
 853       && uiout->table.entry_level == uiout->level
 854       && get_next_header (uiout, fldno, width, align, &text))
 855     {
 856       if (*fldno != current->field_count)
 857         internal_error (__FILE__, __LINE__,
 858                         _("ui-out internal error in handling headers."));
 859     }
 860   else
 861     {
 862       *width = 0;
 863       *align = ui_noalign;
 864       *fldno = current->field_count;
 865     }
 866 }
 867
 868
 869 /* Access to ui-out members data.  */
 870
 871 void *
 872 ui_out_data (struct ui_out *uiout)
 873 {
 874   return uiout->data;
 875 }
 876
 877 /* Access table field parameters.  */
 878 int
 879 ui_out_query_field (struct ui_out *uiout, int colno,
 880                     int *width, int *alignment, char **col_name)
 881 {
 882   struct ui_out_hdr *hdr;
 883
 884   if (!uiout->table.flag)
 885     return 0;
 886
 887   for (hdr = uiout->table.header_first; hdr; hdr = hdr->next)
 888     if (hdr->colno == colno)
 889       {
 890         *width = hdr->width;
 891         *alignment = hdr->alignment;
 892         *col_name = hdr->col_name;
 893         return 1;
 894       }
 895
 896   return 0;
 897 }
 898
 899 /* Initialize private members at startup.  */
 900
 901 struct ui_out *
 902 ui_out_new (const struct ui_out_impl *impl, void *data,
 903             int flags)
 904 {
 905   struct ui_out *uiout = XNEW (struct ui_out);
 906   struct ui_out_level *current = XNEW (struct ui_out_level);
 907
 908   uiout->data = data;
 909   uiout->impl = impl;
 910   uiout->flags = flags;
 911   uiout->table.flag = 0;
 912   uiout->table.body_flag = 0;
 913   uiout->level = 0;
 914   uiout->levels = NULL;
 915
 916   /* Create uiout->level 0, the default level.  */
 917   current->type = ui_out_type_tuple;
 918   current->field_count = 0;
 919   VEC_safe_push (ui_out_level_p, uiout->levels, current);
 920
 921   uiout->table.id = NULL;
 922   uiout->table.header_first = NULL;
 923   uiout->table.header_last = NULL;
 924   uiout->table.header_next = NULL;
 925   return uiout;
 926 }
 927
 928 /* Free  UIOUT and the memory areas it references.  */
 929
 930 void
 931 ui_out_destroy (struct ui_out *uiout)
 932 {
 933   int i;
 934   struct ui_out_level *current;
 935
 936   /* Make sure that all levels are freed in the case where levels have
 937      been pushed, but not popped before the ui_out object is
 938      destroyed.  */
 939   for (i = 0;
 940        VEC_iterate (ui_out_level_p, uiout->levels, i, current);
 941        ++i)
 942     xfree (current);
 943
 944   VEC_free (ui_out_level_p, uiout->levels);
 945   uo_data_destroy (uiout);
 946   clear_table (uiout);
 947   xfree (uiout);
 948 }
 949
 950 /* Standard gdb initialization hook.  */
 951
 952 void
 953 _initialize_ui_out (void)
 954 {
 955   /* nothing needs to be done */
 956 }