gcc/c-family/c-ppoutput.c

   1 /* Preprocess only, using cpplib.
   2    Copyright (C) 1995-2015 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 "alias.h"
  25 #include "symtab.h"
  26 #include "options.h"
  27 #include "tree.h"
  28 #include "c-common.h"           /* For flags.  */
  29 #include "c-pragma.h"           /* For parse_in.  */
  30
  31 /* Encapsulates state used to convert a stream of tokens into a text
  32    file.  */
  33 static struct
  34 {
  35   FILE *outf;                   /* Stream to write to.  */
  36   const cpp_token *prev;        /* Previous token.  */
  37   const cpp_token *source;      /* Source token for spacing.  */
  38   int src_line;                 /* Line number currently being written.  */
  39   unsigned char printed;        /* Nonzero if something output at line.  */
  40   bool first_time;              /* pp_file_change hasn't been called yet.  */
  41   const char *src_file;         /* Current source file.  */
  42   bool prev_was_system_token;   /* True if the previous token was a
  43                                    system token.*/
  44 } print;
  45
  46 /* Defined and undefined macros being queued for output with -dU at
  47    the next newline.  */
  48 typedef struct macro_queue
  49 {
  50   struct macro_queue *next;     /* Next macro in the list.  */
  51   char *macro;                  /* The name of the macro if not
  52                                    defined, the full definition if
  53                                    defined.  */
  54 } macro_queue;
  55 static macro_queue *define_queue, *undef_queue;
  56
  57 /* General output routines.  */
  58 static void scan_translation_unit (cpp_reader *);
  59 static void print_lines_directives_only (int, const void *, size_t);
  60 static void scan_translation_unit_directives_only (cpp_reader *);
  61 static void scan_translation_unit_trad (cpp_reader *);
  62 static void account_for_newlines (const unsigned char *, size_t);
  63 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
  64 static void dump_queued_macros (cpp_reader *);
  65
  66 static bool print_line_1 (source_location, const char*, FILE *);
  67 static bool print_line (source_location, const char *);
  68 static bool maybe_print_line_1 (source_location, FILE *);
  69 static bool maybe_print_line (source_location);
  70 static bool do_line_change (cpp_reader *, const cpp_token *,
  71                             source_location, int);
  72
  73 /* Callback routines for the parser.   Most of these are active only
  74    in specific modes.  */
  75 static void cb_line_change (cpp_reader *, const cpp_token *, int);
  76 static void cb_define (cpp_reader *, source_location, cpp_hashnode *);
  77 static void cb_undef (cpp_reader *, source_location, cpp_hashnode *);
  78 static void cb_used_define (cpp_reader *, source_location, cpp_hashnode *);
  79 static void cb_used_undef (cpp_reader *, source_location, cpp_hashnode *);
  80 static void cb_include (cpp_reader *, source_location, const unsigned char *,
  81                         const char *, int, const cpp_token **);
  82 static void cb_ident (cpp_reader *, source_location, const cpp_string *);
  83 static void cb_def_pragma (cpp_reader *, source_location);
  84 static void cb_read_pch (cpp_reader *pfile, const char *name,
  85                          int fd, const char *orig_name);
  86
  87 /* Preprocess and output.  */
  88 void
  89 preprocess_file (cpp_reader *pfile)
  90 {
  91   /* A successful cpp_read_main_file guarantees that we can call
  92      cpp_scan_nooutput or cpp_get_token next.  */
  93   if (flag_no_output && pfile->buffer)
  94     {
  95       /* Scan -included buffers, then the main file.  */
  96       while (pfile->buffer->prev)
  97         cpp_scan_nooutput (pfile);
  98       cpp_scan_nooutput (pfile);
  99     }
 100   else if (cpp_get_options (pfile)->traditional)
 101     scan_translation_unit_trad (pfile);
 102   else if (cpp_get_options (pfile)->directives_only
 103            && !cpp_get_options (pfile)->preprocessed)
 104     scan_translation_unit_directives_only (pfile);
 105   else
 106     scan_translation_unit (pfile);
 107
 108   /* -dM command line option.  Should this be elsewhere?  */
 109   if (flag_dump_macros == 'M')
 110     cpp_forall_identifiers (pfile, dump_macro, NULL);
 111
 112   /* Flush any pending output.  */
 113   if (print.printed)
 114     putc ('\n', print.outf);
 115 }
 116
 117 /* Set up the callbacks as appropriate.  */
 118 void
 119 init_pp_output (FILE *out_stream)
 120 {
 121   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
 122
 123   if (!flag_no_output)
 124     {
 125       cb->line_change = cb_line_change;
 126       /* Don't emit #pragma or #ident directives if we are processing
 127          assembly language; the assembler may choke on them.  */
 128       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 129         {
 130           cb->ident      = cb_ident;
 131           cb->def_pragma = cb_def_pragma;
 132         }
 133     }
 134
 135   if (flag_dump_includes)
 136     cb->include  = cb_include;
 137
 138   if (flag_pch_preprocess)
 139     {
 140       cb->valid_pch = c_common_valid_pch;
 141       cb->read_pch = cb_read_pch;
 142     }
 143
 144   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 145     {
 146       cb->define = cb_define;
 147       cb->undef  = cb_undef;
 148     }
 149
 150   if (flag_dump_macros == 'U')
 151     {
 152       cb->before_define = dump_queued_macros;
 153       cb->used_define = cb_used_define;
 154       cb->used_undef = cb_used_undef;
 155     }
 156
 157   cb->has_attribute = c_common_has_attribute;
 158
 159   /* Initialize the print structure.  */
 160   print.src_line = 1;
 161   print.printed = 0;
 162   print.prev = 0;
 163   print.outf = out_stream;
 164   print.first_time = 1;
 165   print.src_file = "";
 166   print.prev_was_system_token = false;
 167 }
 168
 169 /* Writes out the preprocessed file, handling spacing and paste
 170    avoidance issues.  */
 171 static void
 172 scan_translation_unit (cpp_reader *pfile)
 173 {
 174   bool avoid_paste = false;
 175   bool do_line_adjustments
 176     = cpp_get_options (parse_in)->lang != CLK_ASM
 177       && !flag_no_line_commands;
 178   bool in_pragma = false;
 179   bool line_marker_emitted = false;
 180
 181   print.source = NULL;
 182   for (;;)
 183     {
 184       source_location loc;
 185       const cpp_token *token = cpp_get_token_with_location (pfile, &loc);
 186
 187       if (token->type == CPP_PADDING)
 188         {
 189           avoid_paste = true;
 190           if (print.source == NULL
 191               || (!(print.source->flags & PREV_WHITE)
 192                   && token->val.source == NULL))
 193             print.source = token->val.source;
 194           continue;
 195         }
 196
 197       if (token->type == CPP_EOF)
 198         break;
 199
 200       /* Subtle logic to output a space if and only if necessary.  */
 201       if (avoid_paste)
 202         {
 203           int src_line = LOCATION_LINE (loc);
 204
 205           if (print.source == NULL)
 206             print.source = token;
 207
 208           if (src_line != print.src_line
 209               && do_line_adjustments
 210               && !in_pragma)
 211             {
 212               line_marker_emitted = do_line_change (pfile, token, loc, false);
 213               putc (' ', print.outf);
 214             }
 215           else if (print.source->flags & PREV_WHITE
 216                    || (print.prev
 217                        && cpp_avoid_paste (pfile, print.prev, token))
 218                    || (print.prev == NULL && token->type == CPP_HASH))
 219             putc (' ', print.outf);
 220         }
 221       else if (token->flags & PREV_WHITE)
 222         {
 223           int src_line = LOCATION_LINE (loc);
 224
 225           if (src_line != print.src_line
 226               && do_line_adjustments
 227               && !in_pragma)
 228             line_marker_emitted = do_line_change (pfile, token, loc, false);
 229           putc (' ', print.outf);
 230         }
 231
 232       avoid_paste = false;
 233       print.source = NULL;
 234       print.prev = token;
 235       if (token->type == CPP_PRAGMA)
 236         {
 237           const char *space;
 238           const char *name;
 239
 240           line_marker_emitted = maybe_print_line (token->src_loc);
 241           fputs ("#pragma ", print.outf);
 242           c_pp_lookup_pragma (token->val.pragma, &space, &name);
 243           if (space)
 244             fprintf (print.outf, "%s %s", space, name);
 245           else
 246             fprintf (print.outf, "%s", name);
 247           print.printed = 1;
 248           in_pragma = true;
 249         }
 250       else if (token->type == CPP_PRAGMA_EOL)
 251         {
 252           maybe_print_line (token->src_loc);
 253           in_pragma = false;
 254         }
 255       else
 256         {
 257           if (cpp_get_options (parse_in)->debug)
 258               linemap_dump_location (line_table, token->src_loc,
 259                                      print.outf);
 260
 261           if (do_line_adjustments
 262               && !in_pragma
 263               && !line_marker_emitted
 264               && print.prev_was_system_token != !!in_system_header_at(loc)
 265               && !is_location_from_builtin_token (loc))
 266             /* The system-ness of this token is different from the one
 267                of the previous token.  Let's emit a line change to
 268                mark the new system-ness before we emit the token.  */
 269             {
 270               do_line_change (pfile, token, loc, false);
 271               print.prev_was_system_token = !!in_system_header_at(loc);
 272             }
 273           cpp_output_token (token, print.outf);
 274           line_marker_emitted = false;
 275         }
 276
 277       /* CPP_COMMENT tokens and raw-string literal tokens can
 278          have embedded new-line characters.  Rather than enumerating
 279          all the possible token types just check if token uses
 280          val.str union member.  */
 281       if (cpp_token_val_index (token) == CPP_TOKEN_FLD_STR)
 282         account_for_newlines (token->val.str.text, token->val.str.len);
 283     }
 284 }
 285
 286 static void
 287 print_lines_directives_only (int lines, const void *buf, size_t size)
 288 {
 289   print.src_line += lines;
 290   fwrite (buf, 1, size, print.outf);
 291 }
 292
 293 /* Writes out the preprocessed file, handling spacing and paste
 294    avoidance issues.  */
 295 static void
 296 scan_translation_unit_directives_only (cpp_reader *pfile)
 297 {
 298   struct _cpp_dir_only_callbacks cb;
 299
 300   cb.print_lines = print_lines_directives_only;
 301   cb.maybe_print_line = (void (*) (source_location)) maybe_print_line;
 302
 303   _cpp_preprocess_dir_only (pfile, &cb);
 304 }
 305
 306 /* Adjust print.src_line for newlines embedded in output.  */
 307 static void
 308 account_for_newlines (const unsigned char *str, size_t len)
 309 {
 310   while (len--)
 311     if (*str++ == '\n')
 312       print.src_line++;
 313 }
 314
 315 /* Writes out a traditionally preprocessed file.  */
 316 static void
 317 scan_translation_unit_trad (cpp_reader *pfile)
 318 {
 319   while (_cpp_read_logical_line_trad (pfile))
 320     {
 321       size_t len = pfile->out.cur - pfile->out.base;
 322       maybe_print_line (pfile->out.first_line);
 323       fwrite (pfile->out.base, 1, len, print.outf);
 324       print.printed = 1;
 325       if (!CPP_OPTION (pfile, discard_comments))
 326         account_for_newlines (pfile->out.base, len);
 327     }
 328 }
 329
 330 /* If the token read on logical line LINE needs to be output on a
 331    different line to the current one, output the required newlines or
 332    a line marker.  If a line marker was emitted, return TRUE otherwise
 333    return FALSE.  */
 334
 335 static bool
 336 maybe_print_line_1 (source_location src_loc, FILE *stream)
 337 {
 338   bool emitted_line_marker = false;
 339   int src_line = LOCATION_LINE (src_loc);
 340   const char *src_file = LOCATION_FILE (src_loc);
 341
 342   /* End the previous line of text.  */
 343   if (print.printed)
 344     {
 345       putc ('\n', stream);
 346       print.src_line++;
 347       print.printed = 0;
 348     }
 349
 350   if (!flag_no_line_commands
 351       && src_line >= print.src_line
 352       && src_line < print.src_line + 8
 353       && strcmp (src_file, print.src_file) == 0)
 354     {
 355       while (src_line > print.src_line)
 356         {
 357           putc ('\n', stream);
 358           print.src_line++;
 359         }
 360     }
 361   else
 362     emitted_line_marker = print_line_1 (src_loc, "", stream);
 363
 364   return emitted_line_marker;
 365 }
 366
 367 /* If the token read on logical line LINE needs to be output on a
 368    different line to the current one, output the required newlines or
 369    a line marker.  If a line marker was emitted, return TRUE otherwise
 370    return FALSE.  */
 371
 372 static bool
 373 maybe_print_line (source_location src_loc)
 374 {
 375   if (cpp_get_options (parse_in)->debug)
 376     linemap_dump_location (line_table, src_loc,
 377                            print.outf);
 378   return maybe_print_line_1 (src_loc, print.outf);
 379 }
 380
 381 /* Output a line marker for logical line LINE.  Special flags are "1"
 382    or "2" indicating entering or leaving a file.  If the line marker
 383    was effectively emitted, return TRUE otherwise return FALSE.  */
 384
 385 static bool
 386 print_line_1 (source_location src_loc, const char *special_flags, FILE *stream)
 387 {
 388   bool emitted_line_marker = false;
 389
 390   /* End any previous line of text.  */
 391   if (print.printed)
 392     putc ('\n', stream);
 393   print.printed = 0;
 394
 395   if (!flag_no_line_commands)
 396     {
 397       const char *file_path = LOCATION_FILE (src_loc);
 398       int sysp;
 399       size_t to_file_len = strlen (file_path);
 400       unsigned char *to_file_quoted =
 401          (unsigned char *) alloca (to_file_len * 4 + 1);
 402       unsigned char *p;
 403
 404       print.src_line = LOCATION_LINE (src_loc);
 405       print.src_file = file_path;
 406
 407       /* cpp_quote_string does not nul-terminate, so we have to do it
 408          ourselves.  */
 409       p = cpp_quote_string (to_file_quoted,
 410                             (const unsigned char *) file_path,
 411                             to_file_len);
 412       *p = '\0';
 413       fprintf (stream, "# %u \"%s\"%s",
 414                print.src_line == 0 ? 1 : print.src_line,
 415                to_file_quoted, special_flags);
 416
 417       sysp = in_system_header_at (src_loc);
 418       if (sysp == 2)
 419         fputs (" 3 4", stream);
 420       else if (sysp == 1)
 421         fputs (" 3", stream);
 422
 423       putc ('\n', stream);
 424       emitted_line_marker = true;
 425     }
 426
 427   return emitted_line_marker;
 428 }
 429
 430 /* Output a line marker for logical line LINE.  Special flags are "1"
 431    or "2" indicating entering or leaving a file.  Return TRUE if a
 432    line marker was effectively emitted, FALSE otherwise.  */
 433
 434 static bool
 435 print_line (source_location src_loc, const char *special_flags)
 436 {
 437     if (cpp_get_options (parse_in)->debug)
 438       linemap_dump_location (line_table, src_loc,
 439                              print.outf);
 440     return print_line_1 (src_loc, special_flags, print.outf);
 441 }
 442
 443 /* Helper function for cb_line_change and scan_translation_unit.
 444    Return TRUE if a line marker is emitted, FALSE otherwise.  */
 445 static bool
 446 do_line_change (cpp_reader *pfile, const cpp_token *token,
 447                 source_location src_loc, int parsing_args)
 448 {
 449   bool emitted_line_marker = false;
 450   if (define_queue || undef_queue)
 451     dump_queued_macros (pfile);
 452
 453   if (token->type == CPP_EOF || parsing_args)
 454     return false;
 455
 456   emitted_line_marker = maybe_print_line (src_loc);
 457   print.prev = 0;
 458   print.source = 0;
 459
 460   /* Supply enough spaces to put this token in its original column,
 461      one space per column greater than 2, since scan_translation_unit
 462      will provide a space if PREV_WHITE.  Don't bother trying to
 463      reconstruct tabs; we can't get it right in general, and nothing
 464      ought to care.  Some things do care; the fault lies with them.  */
 465   if (!CPP_OPTION (pfile, traditional))
 466     {
 467       int spaces = LOCATION_COLUMN (src_loc) - 2;
 468       print.printed = 1;
 469
 470       while (-- spaces >= 0)
 471         putc (' ', print.outf);
 472     }
 473
 474   return emitted_line_marker;
 475 }
 476
 477 /* Called when a line of output is started.  TOKEN is the first token
 478    of the line, and at end of file will be CPP_EOF.  */
 479 static void
 480 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 481                 int parsing_args)
 482 {
 483   do_line_change (pfile, token, token->src_loc, parsing_args);
 484 }
 485
 486 static void
 487 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 488           const cpp_string *str)
 489 {
 490   maybe_print_line (line);
 491   fprintf (print.outf, "#ident %s\n", str->text);
 492   print.src_line++;
 493 }
 494
 495 static void
 496 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 497 {
 498   const line_map_ordinary *map;
 499
 500   maybe_print_line (line);
 501   fputs ("#define ", print.outf);
 502
 503   /* 'D' is whole definition; 'N' is name only.  */
 504   if (flag_dump_macros == 'D')
 505     fputs ((const char *) cpp_macro_definition (pfile, node),
 506            print.outf);
 507   else
 508     fputs ((const char *) NODE_NAME (node), print.outf);
 509
 510   putc ('\n', print.outf);
 511   linemap_resolve_location (line_table, line,
 512                             LRK_MACRO_DEFINITION_LOCATION,
 513                             &map);
 514   if (LINEMAP_LINE (map) != 0)
 515     print.src_line++;
 516 }
 517
 518 static void
 519 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 520           cpp_hashnode *node)
 521 {
 522   maybe_print_line (line);
 523   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 524   print.src_line++;
 525 }
 526
 527 static void
 528 cb_used_define (cpp_reader *pfile, source_location line ATTRIBUTE_UNUSED,
 529                 cpp_hashnode *node)
 530 {
 531   macro_queue *q;
 532   if (node->flags & NODE_BUILTIN)
 533     return;
 534   q = XNEW (macro_queue);
 535   q->macro = xstrdup ((const char *) cpp_macro_definition (pfile, node));
 536   q->next = define_queue;
 537   define_queue = q;
 538 }
 539
 540 static void
 541 cb_used_undef (cpp_reader *pfile ATTRIBUTE_UNUSED,
 542                source_location line ATTRIBUTE_UNUSED,
 543                cpp_hashnode *node)
 544 {
 545   macro_queue *q;
 546   q = XNEW (macro_queue);
 547   q->macro = xstrdup ((const char *) NODE_NAME (node));
 548   q->next = undef_queue;
 549   undef_queue = q;
 550 }
 551
 552 static void
 553 dump_queued_macros (cpp_reader *pfile ATTRIBUTE_UNUSED)
 554 {
 555   macro_queue *q;
 556
 557   /* End the previous line of text.  */
 558   if (print.printed)
 559     {
 560       putc ('\n', print.outf);
 561       print.src_line++;
 562       print.printed = 0;
 563     }
 564
 565   for (q = define_queue; q;)
 566     {
 567       macro_queue *oq;
 568       fputs ("#define ", print.outf);
 569       fputs (q->macro, print.outf);
 570       putc ('\n', print.outf);
 571       print.src_line++;
 572       oq = q;
 573       q = q->next;
 574       free (oq->macro);
 575       free (oq);
 576     }
 577   define_queue = NULL;
 578   for (q = undef_queue; q;)
 579     {
 580       macro_queue *oq;
 581       fprintf (print.outf, "#undef %s\n", q->macro);
 582       print.src_line++;
 583       oq = q;
 584       q = q->next;
 585       free (oq->macro);
 586       free (oq);
 587     }
 588   undef_queue = NULL;
 589 }
 590
 591 static void
 592 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 593             const unsigned char *dir, const char *header, int angle_brackets,
 594             const cpp_token **comments)
 595 {
 596   maybe_print_line (line);
 597   if (angle_brackets)
 598     fprintf (print.outf, "#%s <%s>", dir, header);
 599   else
 600     fprintf (print.outf, "#%s \"%s\"", dir, header);
 601
 602   if (comments != NULL)
 603     {
 604       while (*comments != NULL)
 605         {
 606           if ((*comments)->flags & PREV_WHITE)
 607             putc (' ', print.outf);
 608           cpp_output_token (*comments, print.outf);
 609           ++comments;
 610         }
 611     }
 612
 613   putc ('\n', print.outf);
 614   print.src_line++;
 615 }
 616
 617 /* Callback called when -fworking-director and -E to emit working
 618    directory in cpp output file.  */
 619
 620 void
 621 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 622 {
 623   size_t to_file_len = strlen (dir);
 624   unsigned char *to_file_quoted =
 625      (unsigned char *) alloca (to_file_len * 4 + 1);
 626   unsigned char *p;
 627
 628   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 629   p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir, to_file_len);
 630   *p = '\0';
 631   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 632 }
 633
 634 /* The file name, line number or system header flags have changed, as
 635    described in MAP.  */
 636
 637 void
 638 pp_file_change (const line_map_ordinary *map)
 639 {
 640   const char *flags = "";
 641
 642   if (flag_no_line_commands)
 643     return;
 644
 645   if (map != NULL)
 646     {
 647       input_location = map->start_location;
 648       if (print.first_time)
 649         {
 650           /* Avoid printing foo.i when the main file is foo.c.  */
 651           if (!cpp_get_options (parse_in)->preprocessed)
 652             print_line (map->start_location, flags);
 653           print.first_time = 0;
 654         }
 655       else
 656         {
 657           /* Bring current file to correct line when entering a new file.  */
 658           if (map->reason == LC_ENTER)
 659             {
 660               const line_map_ordinary *from = INCLUDED_FROM (line_table, map);
 661               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 662             }
 663           if (map->reason == LC_ENTER)
 664             flags = " 1";
 665           else if (map->reason == LC_LEAVE)
 666             flags = " 2";
 667           print_line (map->start_location, flags);
 668         }
 669     }
 670 }
 671
 672 /* Copy a #pragma directive to the preprocessed output.  */
 673 static void
 674 cb_def_pragma (cpp_reader *pfile, source_location line)
 675 {
 676   maybe_print_line (line);
 677   fputs ("#pragma ", print.outf);
 678   cpp_output_line (pfile, print.outf);
 679   print.src_line++;
 680 }
 681
 682 /* Dump out the hash table.  */
 683 static int
 684 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 685 {
 686   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 687     {
 688       fputs ("#define ", print.outf);
 689       fputs ((const char *) cpp_macro_definition (pfile, node),
 690              print.outf);
 691       putc ('\n', print.outf);
 692       print.src_line++;
 693     }
 694
 695   return 1;
 696 }
 697
 698 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 699    by ORIG_NAME.  Also, print out a #include command so that the PCH
 700    file can be loaded when the preprocessed output is compiled.  */
 701
 702 static void
 703 cb_read_pch (cpp_reader *pfile, const char *name,
 704              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 705 {
 706   c_common_read_pch (pfile, name, fd, orig_name);
 707
 708   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 709   print.src_line++;
 710 }