gcc/c-family/c-ppoutput.c

   1 /* Preprocess only, using cpplib.
   2    Copyright (C) 1995-2014 Free Software Foundation, Inc.
   3    Written by Per Bothner, 1994-95.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by the
   7    Free Software Foundation; either version 3, or (at your option) any
   8    later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; see the file COPYING3.  If not see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "config.h"
  20 #include "system.h"
  21 #include "coretypes.h"
  22 #include "cpplib.h"
  23 #include "../libcpp/internal.h"
  24 #include "tree.h"
  25 #include "c-common.h"           /* For flags.  */
  26 #include "c-pragma.h"           /* For parse_in.  */
  27
  28 /* Encapsulates state used to convert a stream of tokens into a text
  29    file.  */
  30 static struct
  31 {
  32   FILE *outf;                   /* Stream to write to.  */
  33   const cpp_token *prev;        /* Previous token.  */
  34   const cpp_token *source;      /* Source token for spacing.  */
  35   int src_line;                 /* Line number currently being written.  */
  36   unsigned char printed;        /* Nonzero if something output at line.  */
  37   bool first_time;              /* pp_file_change hasn't been called yet.  */
  38   const char *src_file;         /* Current source file.  */
  39   bool prev_was_system_token;   /* True if the previous token was a
  40                                    system token.*/
  41 } print;
  42
  43 /* Defined and undefined macros being queued for output with -dU at
  44    the next newline.  */
  45 typedef struct macro_queue
  46 {
  47   struct macro_queue *next;     /* Next macro in the list.  */
  48   char *macro;                  /* The name of the macro if not
  49                                    defined, the full definition if
  50                                    defined.  */
  51 } macro_queue;
  52 static macro_queue *define_queue, *undef_queue;
  53
  54 /* General output routines.  */
  55 static void scan_translation_unit (cpp_reader *);
  56 static void print_lines_directives_only (int, const void *, size_t);
  57 static void scan_translation_unit_directives_only (cpp_reader *);
  58 static void scan_translation_unit_trad (cpp_reader *);
  59 static void account_for_newlines (const unsigned char *, size_t);
  60 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
  61 static void dump_queued_macros (cpp_reader *);
  62
  63 static bool print_line_1 (source_location, const char*, FILE *);
  64 static bool print_line (source_location, const char *);
  65 static bool maybe_print_line_1 (source_location, FILE *);
  66 static bool maybe_print_line (source_location);
  67 static bool do_line_change (cpp_reader *, const cpp_token *,
  68                             source_location, int);
  69
  70 /* Callback routines for the parser.   Most of these are active only
  71    in specific modes.  */
  72 static void cb_line_change (cpp_reader *, const cpp_token *, int);
  73 static void cb_define (cpp_reader *, source_location, cpp_hashnode *);
  74 static void cb_undef (cpp_reader *, source_location, cpp_hashnode *);
  75 static void cb_used_define (cpp_reader *, source_location, cpp_hashnode *);
  76 static void cb_used_undef (cpp_reader *, source_location, cpp_hashnode *);
  77 static void cb_include (cpp_reader *, source_location, const unsigned char *,
  78                         const char *, int, const cpp_token **);
  79 static void cb_ident (cpp_reader *, source_location, const cpp_string *);
  80 static void cb_def_pragma (cpp_reader *, source_location);
  81 static void cb_read_pch (cpp_reader *pfile, const char *name,
  82                          int fd, const char *orig_name);
  83
  84 /* Preprocess and output.  */
  85 void
  86 preprocess_file (cpp_reader *pfile)
  87 {
  88   /* A successful cpp_read_main_file guarantees that we can call
  89      cpp_scan_nooutput or cpp_get_token next.  */
  90   if (flag_no_output && pfile->buffer)
  91     {
  92       /* Scan -included buffers, then the main file.  */
  93       while (pfile->buffer->prev)
  94         cpp_scan_nooutput (pfile);
  95       cpp_scan_nooutput (pfile);
  96     }
  97   else if (cpp_get_options (pfile)->traditional)
  98     scan_translation_unit_trad (pfile);
  99   else if (cpp_get_options (pfile)->directives_only
 100            && !cpp_get_options (pfile)->preprocessed)
 101     scan_translation_unit_directives_only (pfile);
 102   else
 103     scan_translation_unit (pfile);
 104
 105   /* -dM command line option.  Should this be elsewhere?  */
 106   if (flag_dump_macros == 'M')
 107     cpp_forall_identifiers (pfile, dump_macro, NULL);
 108
 109   /* Flush any pending output.  */
 110   if (print.printed)
 111     putc ('\n', print.outf);
 112 }
 113
 114 /* Set up the callbacks as appropriate.  */
 115 void
 116 init_pp_output (FILE *out_stream)
 117 {
 118   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
 119
 120   if (!flag_no_output)
 121     {
 122       cb->line_change = cb_line_change;
 123       /* Don't emit #pragma or #ident directives if we are processing
 124          assembly language; the assembler may choke on them.  */
 125       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 126         {
 127           cb->ident      = cb_ident;
 128           cb->def_pragma = cb_def_pragma;
 129         }
 130     }
 131
 132   if (flag_dump_includes)
 133     cb->include  = cb_include;
 134
 135   if (flag_pch_preprocess)
 136     {
 137       cb->valid_pch = c_common_valid_pch;
 138       cb->read_pch = cb_read_pch;
 139     }
 140
 141   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 142     {
 143       cb->define = cb_define;
 144       cb->undef  = cb_undef;
 145     }
 146
 147   if (flag_dump_macros == 'U')
 148     {
 149       cb->before_define = dump_queued_macros;
 150       cb->used_define = cb_used_define;
 151       cb->used_undef = cb_used_undef;
 152     }
 153
 154   /* Initialize the print structure.  */
 155   print.src_line = 1;
 156   print.printed = 0;
 157   print.prev = 0;
 158   print.outf = out_stream;
 159   print.first_time = 1;
 160   print.src_file = "";
 161   print.prev_was_system_token = false;
 162 }
 163
 164 /* Writes out the preprocessed file, handling spacing and paste
 165    avoidance issues.  */
 166 static void
 167 scan_translation_unit (cpp_reader *pfile)
 168 {
 169   bool avoid_paste = false;
 170   bool do_line_adjustments
 171     = cpp_get_options (parse_in)->lang != CLK_ASM
 172       && !flag_no_line_commands;
 173   bool in_pragma = false;
 174   bool line_marker_emitted = false;
 175
 176   print.source = NULL;
 177   for (;;)
 178     {
 179       source_location loc;
 180       const cpp_token *token = cpp_get_token_with_location (pfile, &loc);
 181
 182       if (token->type == CPP_PADDING)
 183         {
 184           avoid_paste = true;
 185           if (print.source == NULL
 186               || (!(print.source->flags & PREV_WHITE)
 187                   && token->val.source == NULL))
 188             print.source = token->val.source;
 189           continue;
 190         }
 191
 192       if (token->type == CPP_EOF)
 193         break;
 194
 195       /* Subtle logic to output a space if and only if necessary.  */
 196       if (avoid_paste)
 197         {
 198           int src_line = LOCATION_LINE (loc);
 199
 200           if (print.source == NULL)
 201             print.source = token;
 202
 203           if (src_line != print.src_line
 204               && do_line_adjustments
 205               && !in_pragma)
 206             {
 207               line_marker_emitted = do_line_change (pfile, token, loc, false);
 208               putc (' ', print.outf);
 209             }
 210           else if (print.source->flags & PREV_WHITE
 211                    || (print.prev
 212                        && cpp_avoid_paste (pfile, print.prev, token))
 213                    || (print.prev == NULL && token->type == CPP_HASH))
 214             putc (' ', print.outf);
 215         }
 216       else if (token->flags & PREV_WHITE)
 217         {
 218           int src_line = LOCATION_LINE (loc);
 219
 220           if (src_line != print.src_line
 221               && do_line_adjustments
 222               && !in_pragma)
 223             line_marker_emitted = do_line_change (pfile, token, loc, false);
 224           putc (' ', print.outf);
 225         }
 226
 227       avoid_paste = false;
 228       print.source = NULL;
 229       print.prev = token;
 230       if (token->type == CPP_PRAGMA)
 231         {
 232           const char *space;
 233           const char *name;
 234
 235           line_marker_emitted = maybe_print_line (token->src_loc);
 236           fputs ("#pragma ", print.outf);
 237           c_pp_lookup_pragma (token->val.pragma, &space, &name);
 238           if (space)
 239             fprintf (print.outf, "%s %s", space, name);
 240           else
 241             fprintf (print.outf, "%s", name);
 242           print.printed = 1;
 243           in_pragma = true;
 244         }
 245       else if (token->type == CPP_PRAGMA_EOL)
 246         {
 247           maybe_print_line (token->src_loc);
 248           in_pragma = false;
 249         }
 250       else
 251         {
 252           if (cpp_get_options (parse_in)->debug)
 253               linemap_dump_location (line_table, token->src_loc,
 254                                      print.outf);
 255
 256           if (do_line_adjustments
 257               && !in_pragma
 258               && !line_marker_emitted
 259               && print.prev_was_system_token != !!in_system_header_at(loc)
 260               && !is_location_from_builtin_token (loc))
 261             /* The system-ness of this token is different from the one
 262                of the previous token.  Let's emit a line change to
 263                mark the new system-ness before we emit the token.  */
 264             {
 265               do_line_change (pfile, token, loc, false);
 266               print.prev_was_system_token = !!in_system_header_at(loc);
 267             }
 268           cpp_output_token (token, print.outf);
 269           line_marker_emitted = false;
 270         }
 271
 272       /* CPP_COMMENT tokens and raw-string literal tokens can
 273          have embedded new-line characters.  Rather than enumerating
 274          all the possible token types just check if token uses
 275          val.str union member.  */
 276       if (cpp_token_val_index (token) == CPP_TOKEN_FLD_STR)
 277         account_for_newlines (token->val.str.text, token->val.str.len);
 278     }
 279 }
 280
 281 static void
 282 print_lines_directives_only (int lines, const void *buf, size_t size)
 283 {
 284   print.src_line += lines;
 285   fwrite (buf, 1, size, print.outf);
 286 }
 287
 288 /* Writes out the preprocessed file, handling spacing and paste
 289    avoidance issues.  */
 290 static void
 291 scan_translation_unit_directives_only (cpp_reader *pfile)
 292 {
 293   struct _cpp_dir_only_callbacks cb;
 294
 295   cb.print_lines = print_lines_directives_only;
 296   cb.maybe_print_line = (void (*) (source_location)) maybe_print_line;
 297
 298   _cpp_preprocess_dir_only (pfile, &cb);
 299 }
 300
 301 /* Adjust print.src_line for newlines embedded in output.  */
 302 static void
 303 account_for_newlines (const unsigned char *str, size_t len)
 304 {
 305   while (len--)
 306     if (*str++ == '\n')
 307       print.src_line++;
 308 }
 309
 310 /* Writes out a traditionally preprocessed file.  */
 311 static void
 312 scan_translation_unit_trad (cpp_reader *pfile)
 313 {
 314   while (_cpp_read_logical_line_trad (pfile))
 315     {
 316       size_t len = pfile->out.cur - pfile->out.base;
 317       maybe_print_line (pfile->out.first_line);
 318       fwrite (pfile->out.base, 1, len, print.outf);
 319       print.printed = 1;
 320       if (!CPP_OPTION (pfile, discard_comments))
 321         account_for_newlines (pfile->out.base, len);
 322     }
 323 }
 324
 325 /* If the token read on logical line LINE needs to be output on a
 326    different line to the current one, output the required newlines or
 327    a line marker.  If a line marker was emitted, return TRUE otherwise
 328    return FALSE.  */
 329
 330 static bool
 331 maybe_print_line_1 (source_location src_loc, FILE *stream)
 332 {
 333   bool emitted_line_marker = false;
 334   int src_line = LOCATION_LINE (src_loc);
 335   const char *src_file = LOCATION_FILE (src_loc);
 336
 337   /* End the previous line of text.  */
 338   if (print.printed)
 339     {
 340       putc ('\n', stream);
 341       print.src_line++;
 342       print.printed = 0;
 343     }
 344
 345   if (!flag_no_line_commands
 346       && src_line >= print.src_line
 347       && src_line < print.src_line + 8
 348       && strcmp (src_file, print.src_file) == 0)
 349     {
 350       while (src_line > print.src_line)
 351         {
 352           putc ('\n', stream);
 353           print.src_line++;
 354         }
 355     }
 356   else
 357     emitted_line_marker = print_line_1 (src_loc, "", stream);
 358
 359   return emitted_line_marker;
 360 }
 361
 362 /* If the token read on logical line LINE needs to be output on a
 363    different line to the current one, output the required newlines or
 364    a line marker.  If a line marker was emitted, return TRUE otherwise
 365    return FALSE.  */
 366
 367 static bool
 368 maybe_print_line (source_location src_loc)
 369 {
 370   if (cpp_get_options (parse_in)->debug)
 371     linemap_dump_location (line_table, src_loc,
 372                            print.outf);
 373   return maybe_print_line_1 (src_loc, print.outf);
 374 }
 375
 376 /* Output a line marker for logical line LINE.  Special flags are "1"
 377    or "2" indicating entering or leaving a file.  If the line marker
 378    was effectively emitted, return TRUE otherwise return FALSE.  */
 379
 380 static bool
 381 print_line_1 (source_location src_loc, const char *special_flags, FILE *stream)
 382 {
 383   bool emitted_line_marker = false;
 384
 385   /* End any previous line of text.  */
 386   if (print.printed)
 387     putc ('\n', stream);
 388   print.printed = 0;
 389
 390   if (!flag_no_line_commands)
 391     {
 392       const char *file_path = LOCATION_FILE (src_loc);
 393       int sysp;
 394       size_t to_file_len = strlen (file_path);
 395       unsigned char *to_file_quoted =
 396          (unsigned char *) alloca (to_file_len * 4 + 1);
 397       unsigned char *p;
 398
 399       print.src_line = LOCATION_LINE (src_loc);
 400       print.src_file = file_path;
 401
 402       /* cpp_quote_string does not nul-terminate, so we have to do it
 403          ourselves.  */
 404       p = cpp_quote_string (to_file_quoted,
 405                             (const unsigned char *) file_path,
 406                             to_file_len);
 407       *p = '\0';
 408       fprintf (stream, "# %u \"%s\"%s",
 409                print.src_line == 0 ? 1 : print.src_line,
 410                to_file_quoted, special_flags);
 411
 412       sysp = in_system_header_at (src_loc);
 413       if (sysp == 2)
 414         fputs (" 3 4", stream);
 415       else if (sysp == 1)
 416         fputs (" 3", stream);
 417
 418       putc ('\n', stream);
 419       emitted_line_marker = true;
 420     }
 421
 422   return emitted_line_marker;
 423 }
 424
 425 /* Output a line marker for logical line LINE.  Special flags are "1"
 426    or "2" indicating entering or leaving a file.  Return TRUE if a
 427    line marker was effectively emitted, FALSE otherwise.  */
 428
 429 static bool
 430 print_line (source_location src_loc, const char *special_flags)
 431 {
 432     if (cpp_get_options (parse_in)->debug)
 433       linemap_dump_location (line_table, src_loc,
 434                              print.outf);
 435     return print_line_1 (src_loc, special_flags, print.outf);
 436 }
 437
 438 /* Helper function for cb_line_change and scan_translation_unit.
 439    Return TRUE if a line marker is emitted, FALSE otherwise.  */
 440 static bool
 441 do_line_change (cpp_reader *pfile, const cpp_token *token,
 442                 source_location src_loc, int parsing_args)
 443 {
 444   bool emitted_line_marker = false;
 445   if (define_queue || undef_queue)
 446     dump_queued_macros (pfile);
 447
 448   if (token->type == CPP_EOF || parsing_args)
 449     return false;
 450
 451   emitted_line_marker = maybe_print_line (src_loc);
 452   print.prev = 0;
 453   print.source = 0;
 454
 455   /* Supply enough spaces to put this token in its original column,
 456      one space per column greater than 2, since scan_translation_unit
 457      will provide a space if PREV_WHITE.  Don't bother trying to
 458      reconstruct tabs; we can't get it right in general, and nothing
 459      ought to care.  Some things do care; the fault lies with them.  */
 460   if (!CPP_OPTION (pfile, traditional))
 461     {
 462       int spaces = LOCATION_COLUMN (src_loc) - 2;
 463       print.printed = 1;
 464
 465       while (-- spaces >= 0)
 466         putc (' ', print.outf);
 467     }
 468
 469   return emitted_line_marker;
 470 }
 471
 472 /* Called when a line of output is started.  TOKEN is the first token
 473    of the line, and at end of file will be CPP_EOF.  */
 474 static void
 475 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 476                 int parsing_args)
 477 {
 478   do_line_change (pfile, token, token->src_loc, parsing_args);
 479 }
 480
 481 static void
 482 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 483           const cpp_string *str)
 484 {
 485   maybe_print_line (line);
 486   fprintf (print.outf, "#ident %s\n", str->text);
 487   print.src_line++;
 488 }
 489
 490 static void
 491 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 492 {
 493   const struct line_map *map;
 494
 495   maybe_print_line (line);
 496   fputs ("#define ", print.outf);
 497
 498   /* 'D' is whole definition; 'N' is name only.  */
 499   if (flag_dump_macros == 'D')
 500     fputs ((const char *) cpp_macro_definition (pfile, node),
 501            print.outf);
 502   else
 503     fputs ((const char *) NODE_NAME (node), print.outf);
 504
 505   putc ('\n', print.outf);
 506   linemap_resolve_location (line_table, line,
 507                             LRK_MACRO_DEFINITION_LOCATION,
 508                             &map);
 509   if (LINEMAP_LINE (map) != 0)
 510     print.src_line++;
 511 }
 512
 513 static void
 514 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 515           cpp_hashnode *node)
 516 {
 517   maybe_print_line (line);
 518   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 519   print.src_line++;
 520 }
 521
 522 static void
 523 cb_used_define (cpp_reader *pfile, source_location line ATTRIBUTE_UNUSED,
 524                 cpp_hashnode *node)
 525 {
 526   macro_queue *q;
 527   if (node->flags & NODE_BUILTIN)
 528     return;
 529   q = XNEW (macro_queue);
 530   q->macro = xstrdup ((const char *) cpp_macro_definition (pfile, node));
 531   q->next = define_queue;
 532   define_queue = q;
 533 }
 534
 535 static void
 536 cb_used_undef (cpp_reader *pfile ATTRIBUTE_UNUSED,
 537                source_location line ATTRIBUTE_UNUSED,
 538                cpp_hashnode *node)
 539 {
 540   macro_queue *q;
 541   q = XNEW (macro_queue);
 542   q->macro = xstrdup ((const char *) NODE_NAME (node));
 543   q->next = undef_queue;
 544   undef_queue = q;
 545 }
 546
 547 static void
 548 dump_queued_macros (cpp_reader *pfile ATTRIBUTE_UNUSED)
 549 {
 550   macro_queue *q;
 551
 552   /* End the previous line of text.  */
 553   if (print.printed)
 554     {
 555       putc ('\n', print.outf);
 556       print.src_line++;
 557       print.printed = 0;
 558     }
 559
 560   for (q = define_queue; q;)
 561     {
 562       macro_queue *oq;
 563       fputs ("#define ", print.outf);
 564       fputs (q->macro, print.outf);
 565       putc ('\n', print.outf);
 566       print.src_line++;
 567       oq = q;
 568       q = q->next;
 569       free (oq->macro);
 570       free (oq);
 571     }
 572   define_queue = NULL;
 573   for (q = undef_queue; q;)
 574     {
 575       macro_queue *oq;
 576       fprintf (print.outf, "#undef %s\n", q->macro);
 577       print.src_line++;
 578       oq = q;
 579       q = q->next;
 580       free (oq->macro);
 581       free (oq);
 582     }
 583   undef_queue = NULL;
 584 }
 585
 586 static void
 587 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 588             const unsigned char *dir, const char *header, int angle_brackets,
 589             const cpp_token **comments)
 590 {
 591   maybe_print_line (line);
 592   if (angle_brackets)
 593     fprintf (print.outf, "#%s <%s>", dir, header);
 594   else
 595     fprintf (print.outf, "#%s \"%s\"", dir, header);
 596
 597   if (comments != NULL)
 598     {
 599       while (*comments != NULL)
 600         {
 601           if ((*comments)->flags & PREV_WHITE)
 602             putc (' ', print.outf);
 603           cpp_output_token (*comments, print.outf);
 604           ++comments;
 605         }
 606     }
 607
 608   putc ('\n', print.outf);
 609   print.src_line++;
 610 }
 611
 612 /* Callback called when -fworking-director and -E to emit working
 613    directory in cpp output file.  */
 614
 615 void
 616 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 617 {
 618   size_t to_file_len = strlen (dir);
 619   unsigned char *to_file_quoted =
 620      (unsigned char *) alloca (to_file_len * 4 + 1);
 621   unsigned char *p;
 622
 623   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 624   p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir, to_file_len);
 625   *p = '\0';
 626   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 627 }
 628
 629 /* The file name, line number or system header flags have changed, as
 630    described in MAP.  */
 631
 632 void
 633 pp_file_change (const struct line_map *map)
 634 {
 635   const char *flags = "";
 636
 637   if (flag_no_line_commands)
 638     return;
 639
 640   if (map != NULL)
 641     {
 642       input_location = map->start_location;
 643       if (print.first_time)
 644         {
 645           /* Avoid printing foo.i when the main file is foo.c.  */
 646           if (!cpp_get_options (parse_in)->preprocessed)
 647             print_line (map->start_location, flags);
 648           print.first_time = 0;
 649         }
 650       else
 651         {
 652           /* Bring current file to correct line when entering a new file.  */
 653           if (map->reason == LC_ENTER)
 654             {
 655               const struct line_map *from = INCLUDED_FROM (line_table, map);
 656               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 657             }
 658           if (map->reason == LC_ENTER)
 659             flags = " 1";
 660           else if (map->reason == LC_LEAVE)
 661             flags = " 2";
 662           print_line (map->start_location, flags);
 663         }
 664     }
 665 }
 666
 667 /* Copy a #pragma directive to the preprocessed output.  */
 668 static void
 669 cb_def_pragma (cpp_reader *pfile, source_location line)
 670 {
 671   maybe_print_line (line);
 672   fputs ("#pragma ", print.outf);
 673   cpp_output_line (pfile, print.outf);
 674   print.src_line++;
 675 }
 676
 677 /* Dump out the hash table.  */
 678 static int
 679 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 680 {
 681   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 682     {
 683       fputs ("#define ", print.outf);
 684       fputs ((const char *) cpp_macro_definition (pfile, node),
 685              print.outf);
 686       putc ('\n', print.outf);
 687       print.src_line++;
 688     }
 689
 690   return 1;
 691 }
 692
 693 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 694    by ORIG_NAME.  Also, print out a #include command so that the PCH
 695    file can be loaded when the preprocessed output is compiled.  */
 696
 697 static void
 698 cb_read_pch (cpp_reader *pfile, const char *name,
 699              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 700 {
 701   c_common_read_pch (pfile, name, fd, orig_name);
 702
 703   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 704   print.src_line++;
 705 }