gcc/c-family/c-ppoutput.c

   1 /* Preprocess only, using cpplib.
   2    Copyright (C) 1995-2013 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 } print;
  40
  41 /* Defined and undefined macros being queued for output with -dU at
  42    the next newline.  */
  43 typedef struct macro_queue
  44 {
  45   struct macro_queue *next;     /* Next macro in the list.  */
  46   char *macro;                  /* The name of the macro if not
  47                                    defined, the full definition if
  48                                    defined.  */
  49 } macro_queue;
  50 static macro_queue *define_queue, *undef_queue;
  51
  52 /* General output routines.  */
  53 static void scan_translation_unit (cpp_reader *);
  54 static void print_lines_directives_only (int, const void *, size_t);
  55 static void scan_translation_unit_directives_only (cpp_reader *);
  56 static void scan_translation_unit_trad (cpp_reader *);
  57 static void account_for_newlines (const unsigned char *, size_t);
  58 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
  59 static void dump_queued_macros (cpp_reader *);
  60
  61 static void print_line_1 (source_location, const char*, FILE *);
  62 static void print_line (source_location, const char *);
  63 static void maybe_print_line_1 (source_location, FILE *);
  64 static void maybe_print_line (source_location);
  65 static void do_line_change (cpp_reader *, const cpp_token *,
  66                             source_location, int);
  67
  68 /* Callback routines for the parser.   Most of these are active only
  69    in specific modes.  */
  70 static void cb_line_change (cpp_reader *, const cpp_token *, int);
  71 static void cb_define (cpp_reader *, source_location, cpp_hashnode *);
  72 static void cb_undef (cpp_reader *, source_location, cpp_hashnode *);
  73 static void cb_used_define (cpp_reader *, source_location, cpp_hashnode *);
  74 static void cb_used_undef (cpp_reader *, source_location, cpp_hashnode *);
  75 static void cb_include (cpp_reader *, source_location, const unsigned char *,
  76                         const char *, int, const cpp_token **);
  77 static void cb_ident (cpp_reader *, source_location, const cpp_string *);
  78 static void cb_def_pragma (cpp_reader *, source_location);
  79 static void cb_read_pch (cpp_reader *pfile, const char *name,
  80                          int fd, const char *orig_name);
  81
  82 /* Preprocess and output.  */
  83 void
  84 preprocess_file (cpp_reader *pfile)
  85 {
  86   /* A successful cpp_read_main_file guarantees that we can call
  87      cpp_scan_nooutput or cpp_get_token next.  */
  88   if (flag_no_output && pfile->buffer)
  89     {
  90       /* Scan -included buffers, then the main file.  */
  91       while (pfile->buffer->prev)
  92         cpp_scan_nooutput (pfile);
  93       cpp_scan_nooutput (pfile);
  94     }
  95   else if (cpp_get_options (pfile)->traditional)
  96     scan_translation_unit_trad (pfile);
  97   else if (cpp_get_options (pfile)->directives_only
  98            && !cpp_get_options (pfile)->preprocessed)
  99     scan_translation_unit_directives_only (pfile);
 100   else
 101     scan_translation_unit (pfile);
 102
 103   /* -dM command line option.  Should this be elsewhere?  */
 104   if (flag_dump_macros == 'M')
 105     cpp_forall_identifiers (pfile, dump_macro, NULL);
 106
 107   /* Flush any pending output.  */
 108   if (print.printed)
 109     putc ('\n', print.outf);
 110 }
 111
 112 /* Set up the callbacks as appropriate.  */
 113 void
 114 init_pp_output (FILE *out_stream)
 115 {
 116   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
 117
 118   if (!flag_no_output)
 119     {
 120       cb->line_change = cb_line_change;
 121       /* Don't emit #pragma or #ident directives if we are processing
 122          assembly language; the assembler may choke on them.  */
 123       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 124         {
 125           cb->ident      = cb_ident;
 126           cb->def_pragma = cb_def_pragma;
 127         }
 128     }
 129
 130   if (flag_dump_includes)
 131     cb->include  = cb_include;
 132
 133   if (flag_pch_preprocess)
 134     {
 135       cb->valid_pch = c_common_valid_pch;
 136       cb->read_pch = cb_read_pch;
 137     }
 138
 139   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 140     {
 141       cb->define = cb_define;
 142       cb->undef  = cb_undef;
 143     }
 144
 145   if (flag_dump_macros == 'U')
 146     {
 147       cb->before_define = dump_queued_macros;
 148       cb->used_define = cb_used_define;
 149       cb->used_undef = cb_used_undef;
 150     }
 151
 152   /* Initialize the print structure.  */
 153   print.src_line = 1;
 154   print.printed = 0;
 155   print.prev = 0;
 156   print.outf = out_stream;
 157   print.first_time = 1;
 158   print.src_file = "";
 159 }
 160
 161 /* Writes out the preprocessed file, handling spacing and paste
 162    avoidance issues.  */
 163 static void
 164 scan_translation_unit (cpp_reader *pfile)
 165 {
 166   bool avoid_paste = false;
 167   bool do_line_adjustments
 168     = cpp_get_options (parse_in)->lang != CLK_ASM
 169       && !flag_no_line_commands;
 170   bool in_pragma = false;
 171
 172   print.source = NULL;
 173   for (;;)
 174     {
 175       source_location loc;
 176       const cpp_token *token = cpp_get_token_with_location (pfile, &loc);
 177
 178       if (token->type == CPP_PADDING)
 179         {
 180           avoid_paste = true;
 181           if (print.source == NULL
 182               || (!(print.source->flags & PREV_WHITE)
 183                   && token->val.source == NULL))
 184             print.source = token->val.source;
 185           continue;
 186         }
 187
 188       if (token->type == CPP_EOF)
 189         break;
 190
 191       /* Subtle logic to output a space if and only if necessary.  */
 192       if (avoid_paste)
 193         {
 194           int src_line = LOCATION_LINE (loc);
 195
 196           if (print.source == NULL)
 197             print.source = token;
 198
 199           if (src_line != print.src_line
 200               && do_line_adjustments
 201               && !in_pragma)
 202             {
 203               do_line_change (pfile, token, loc, false);
 204               putc (' ', print.outf);
 205             }
 206           else if (print.source->flags & PREV_WHITE
 207                    || (print.prev
 208                        && cpp_avoid_paste (pfile, print.prev, token))
 209                    || (print.prev == NULL && token->type == CPP_HASH))
 210             putc (' ', print.outf);
 211         }
 212       else if (token->flags & PREV_WHITE)
 213         {
 214           int src_line = LOCATION_LINE (loc);
 215
 216           if (src_line != print.src_line
 217               && do_line_adjustments
 218               && !in_pragma)
 219             do_line_change (pfile, token, loc, false);
 220           putc (' ', print.outf);
 221         }
 222
 223       avoid_paste = false;
 224       print.source = NULL;
 225       print.prev = token;
 226       if (token->type == CPP_PRAGMA)
 227         {
 228           const char *space;
 229           const char *name;
 230
 231           maybe_print_line (token->src_loc);
 232           fputs ("#pragma ", print.outf);
 233           c_pp_lookup_pragma (token->val.pragma, &space, &name);
 234           if (space)
 235             fprintf (print.outf, "%s %s", space, name);
 236           else
 237             fprintf (print.outf, "%s", name);
 238           print.printed = 1;
 239           in_pragma = true;
 240         }
 241       else if (token->type == CPP_PRAGMA_EOL)
 242         {
 243           maybe_print_line (token->src_loc);
 244           in_pragma = false;
 245         }
 246       else
 247         {
 248           if (cpp_get_options (parse_in)->debug)
 249               linemap_dump_location (line_table, token->src_loc,
 250                                      print.outf);
 251           cpp_output_token (token, print.outf);
 252         }
 253
 254       if (token->type == CPP_COMMENT)
 255         account_for_newlines (token->val.str.text, token->val.str.len);
 256     }
 257 }
 258
 259 static void
 260 print_lines_directives_only (int lines, const void *buf, size_t size)
 261 {
 262   print.src_line += lines;
 263   fwrite (buf, 1, size, print.outf);
 264 }
 265
 266 /* Writes out the preprocessed file, handling spacing and paste
 267    avoidance issues.  */
 268 static void
 269 scan_translation_unit_directives_only (cpp_reader *pfile)
 270 {
 271   struct _cpp_dir_only_callbacks cb;
 272
 273   cb.print_lines = print_lines_directives_only;
 274   cb.maybe_print_line = maybe_print_line;
 275
 276   _cpp_preprocess_dir_only (pfile, &cb);
 277 }
 278
 279 /* Adjust print.src_line for newlines embedded in output.  */
 280 static void
 281 account_for_newlines (const unsigned char *str, size_t len)
 282 {
 283   while (len--)
 284     if (*str++ == '\n')
 285       print.src_line++;
 286 }
 287
 288 /* Writes out a traditionally preprocessed file.  */
 289 static void
 290 scan_translation_unit_trad (cpp_reader *pfile)
 291 {
 292   while (_cpp_read_logical_line_trad (pfile))
 293     {
 294       size_t len = pfile->out.cur - pfile->out.base;
 295       maybe_print_line (pfile->out.first_line);
 296       fwrite (pfile->out.base, 1, len, print.outf);
 297       print.printed = 1;
 298       if (!CPP_OPTION (pfile, discard_comments))
 299         account_for_newlines (pfile->out.base, len);
 300     }
 301 }
 302
 303 /* If the token read on logical line LINE needs to be output on a
 304    different line to the current one, output the required newlines or
 305    a line marker, and return 1.  Otherwise return 0.  */
 306
 307 static void
 308 maybe_print_line_1 (source_location src_loc, FILE *stream)
 309 {
 310   int src_line = LOCATION_LINE (src_loc);
 311   const char *src_file = LOCATION_FILE (src_loc);
 312
 313   /* End the previous line of text.  */
 314   if (print.printed)
 315     {
 316       putc ('\n', stream);
 317       print.src_line++;
 318       print.printed = 0;
 319     }
 320
 321   if (!flag_no_line_commands
 322       && src_line >= print.src_line
 323       && src_line < print.src_line + 8
 324       && strcmp (src_file, print.src_file) == 0)
 325     {
 326       while (src_line > print.src_line)
 327         {
 328           putc ('\n', stream);
 329           print.src_line++;
 330         }
 331     }
 332   else
 333     print_line_1 (src_loc, "", stream);
 334
 335 }
 336
 337 /* If the token read on logical line LINE needs to be output on a
 338    different line to the current one, output the required newlines or
 339    a line marker, and return 1.  Otherwise return 0.  */
 340
 341 static void
 342 maybe_print_line (source_location src_loc)
 343 {
 344   if (cpp_get_options (parse_in)->debug)
 345     linemap_dump_location (line_table, src_loc,
 346                            print.outf);
 347   maybe_print_line_1 (src_loc, print.outf);
 348 }
 349
 350 /* Output a line marker for logical line LINE.  Special flags are "1"
 351    or "2" indicating entering or leaving a file.  */
 352
 353 static void
 354 print_line_1 (source_location src_loc, const char *special_flags, FILE *stream)
 355 {
 356   /* End any previous line of text.  */
 357   if (print.printed)
 358     putc ('\n', stream);
 359   print.printed = 0;
 360
 361   if (!flag_no_line_commands)
 362     {
 363       const char *file_path = LOCATION_FILE (src_loc);
 364       int sysp;
 365       size_t to_file_len = strlen (file_path);
 366       unsigned char *to_file_quoted =
 367          (unsigned char *) alloca (to_file_len * 4 + 1);
 368       unsigned char *p;
 369
 370       print.src_line = LOCATION_LINE (src_loc);
 371       print.src_file = file_path;
 372
 373       /* cpp_quote_string does not nul-terminate, so we have to do it
 374          ourselves.  */
 375       p = cpp_quote_string (to_file_quoted,
 376                             (const unsigned char *) file_path,
 377                             to_file_len);
 378       *p = '\0';
 379       fprintf (stream, "# %u \"%s\"%s",
 380                print.src_line == 0 ? 1 : print.src_line,
 381                to_file_quoted, special_flags);
 382
 383       sysp = in_system_header_at (src_loc);
 384       if (sysp == 2)
 385         fputs (" 3 4", stream);
 386       else if (sysp == 1)
 387         fputs (" 3", stream);
 388
 389       putc ('\n', stream);
 390     }
 391 }
 392
 393 /* Output a line marker for logical line LINE.  Special flags are "1"
 394    or "2" indicating entering or leaving a file.  */
 395
 396 static void
 397 print_line (source_location src_loc, const char *special_flags)
 398 {
 399     if (cpp_get_options (parse_in)->debug)
 400       linemap_dump_location (line_table, src_loc,
 401                              print.outf);
 402     print_line_1 (src_loc, special_flags, print.outf);
 403 }
 404
 405 /* Helper function for cb_line_change and scan_translation_unit.  */
 406 static void
 407 do_line_change (cpp_reader *pfile, const cpp_token *token,
 408                 source_location src_loc, int parsing_args)
 409 {
 410   if (define_queue || undef_queue)
 411     dump_queued_macros (pfile);
 412
 413   if (token->type == CPP_EOF || parsing_args)
 414     return;
 415
 416   maybe_print_line (src_loc);
 417   print.prev = 0;
 418   print.source = 0;
 419
 420   /* Supply enough spaces to put this token in its original column,
 421      one space per column greater than 2, since scan_translation_unit
 422      will provide a space if PREV_WHITE.  Don't bother trying to
 423      reconstruct tabs; we can't get it right in general, and nothing
 424      ought to care.  Some things do care; the fault lies with them.  */
 425   if (!CPP_OPTION (pfile, traditional))
 426     {
 427       int spaces = LOCATION_COLUMN (src_loc) - 2;
 428       print.printed = 1;
 429
 430       while (-- spaces >= 0)
 431         putc (' ', print.outf);
 432     }
 433 }
 434
 435 /* Called when a line of output is started.  TOKEN is the first token
 436    of the line, and at end of file will be CPP_EOF.  */
 437 static void
 438 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 439                 int parsing_args)
 440 {
 441   do_line_change (pfile, token, token->src_loc, parsing_args);
 442 }
 443
 444 static void
 445 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 446           const cpp_string *str)
 447 {
 448   maybe_print_line (line);
 449   fprintf (print.outf, "#ident %s\n", str->text);
 450   print.src_line++;
 451 }
 452
 453 static void
 454 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 455 {
 456   const struct line_map *map;
 457
 458   maybe_print_line (line);
 459   fputs ("#define ", print.outf);
 460
 461   /* 'D' is whole definition; 'N' is name only.  */
 462   if (flag_dump_macros == 'D')
 463     fputs ((const char *) cpp_macro_definition (pfile, node),
 464            print.outf);
 465   else
 466     fputs ((const char *) NODE_NAME (node), print.outf);
 467
 468   putc ('\n', print.outf);
 469   linemap_resolve_location (line_table, line,
 470                             LRK_MACRO_DEFINITION_LOCATION,
 471                             &map);
 472   if (LINEMAP_LINE (map) != 0)
 473     print.src_line++;
 474 }
 475
 476 static void
 477 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 478           cpp_hashnode *node)
 479 {
 480   maybe_print_line (line);
 481   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 482   print.src_line++;
 483 }
 484
 485 static void
 486 cb_used_define (cpp_reader *pfile, source_location line ATTRIBUTE_UNUSED,
 487                 cpp_hashnode *node)
 488 {
 489   macro_queue *q;
 490   if (node->flags & NODE_BUILTIN)
 491     return;
 492   q = XNEW (macro_queue);
 493   q->macro = xstrdup ((const char *) cpp_macro_definition (pfile, node));
 494   q->next = define_queue;
 495   define_queue = q;
 496 }
 497
 498 static void
 499 cb_used_undef (cpp_reader *pfile ATTRIBUTE_UNUSED,
 500                source_location line ATTRIBUTE_UNUSED,
 501                cpp_hashnode *node)
 502 {
 503   macro_queue *q;
 504   q = XNEW (macro_queue);
 505   q->macro = xstrdup ((const char *) NODE_NAME (node));
 506   q->next = undef_queue;
 507   undef_queue = q;
 508 }
 509
 510 static void
 511 dump_queued_macros (cpp_reader *pfile ATTRIBUTE_UNUSED)
 512 {
 513   macro_queue *q;
 514
 515   /* End the previous line of text.  */
 516   if (print.printed)
 517     {
 518       putc ('\n', print.outf);
 519       print.src_line++;
 520       print.printed = 0;
 521     }
 522
 523   for (q = define_queue; q;)
 524     {
 525       macro_queue *oq;
 526       fputs ("#define ", print.outf);
 527       fputs (q->macro, print.outf);
 528       putc ('\n', print.outf);
 529       print.src_line++;
 530       oq = q;
 531       q = q->next;
 532       free (oq->macro);
 533       free (oq);
 534     }
 535   define_queue = NULL;
 536   for (q = undef_queue; q;)
 537     {
 538       macro_queue *oq;
 539       fprintf (print.outf, "#undef %s\n", q->macro);
 540       print.src_line++;
 541       oq = q;
 542       q = q->next;
 543       free (oq->macro);
 544       free (oq);
 545     }
 546   undef_queue = NULL;
 547 }
 548
 549 static void
 550 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 551             const unsigned char *dir, const char *header, int angle_brackets,
 552             const cpp_token **comments)
 553 {
 554   maybe_print_line (line);
 555   if (angle_brackets)
 556     fprintf (print.outf, "#%s <%s>", dir, header);
 557   else
 558     fprintf (print.outf, "#%s \"%s\"", dir, header);
 559
 560   if (comments != NULL)
 561     {
 562       while (*comments != NULL)
 563         {
 564           if ((*comments)->flags & PREV_WHITE)
 565             putc (' ', print.outf);
 566           cpp_output_token (*comments, print.outf);
 567           ++comments;
 568         }
 569     }
 570
 571   putc ('\n', print.outf);
 572   print.src_line++;
 573 }
 574
 575 /* Callback called when -fworking-director and -E to emit working
 576    directory in cpp output file.  */
 577
 578 void
 579 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 580 {
 581   size_t to_file_len = strlen (dir);
 582   unsigned char *to_file_quoted =
 583      (unsigned char *) alloca (to_file_len * 4 + 1);
 584   unsigned char *p;
 585
 586   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 587   p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir, to_file_len);
 588   *p = '\0';
 589   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 590 }
 591
 592 /* The file name, line number or system header flags have changed, as
 593    described in MAP.  */
 594
 595 void
 596 pp_file_change (const struct line_map *map)
 597 {
 598   const char *flags = "";
 599
 600   if (flag_no_line_commands)
 601     return;
 602
 603   if (map != NULL)
 604     {
 605       input_location = map->start_location;
 606       if (print.first_time)
 607         {
 608           /* Avoid printing foo.i when the main file is foo.c.  */
 609           if (!cpp_get_options (parse_in)->preprocessed)
 610             print_line (map->start_location, flags);
 611           print.first_time = 0;
 612         }
 613       else
 614         {
 615           /* Bring current file to correct line when entering a new file.  */
 616           if (map->reason == LC_ENTER)
 617             {
 618               const struct line_map *from = INCLUDED_FROM (line_table, map);
 619               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 620             }
 621           if (map->reason == LC_ENTER)
 622             flags = " 1";
 623           else if (map->reason == LC_LEAVE)
 624             flags = " 2";
 625           print_line (map->start_location, flags);
 626         }
 627     }
 628 }
 629
 630 /* Copy a #pragma directive to the preprocessed output.  */
 631 static void
 632 cb_def_pragma (cpp_reader *pfile, source_location line)
 633 {
 634   maybe_print_line (line);
 635   fputs ("#pragma ", print.outf);
 636   cpp_output_line (pfile, print.outf);
 637   print.src_line++;
 638 }
 639
 640 /* Dump out the hash table.  */
 641 static int
 642 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 643 {
 644   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 645     {
 646       fputs ("#define ", print.outf);
 647       fputs ((const char *) cpp_macro_definition (pfile, node),
 648              print.outf);
 649       putc ('\n', print.outf);
 650       print.src_line++;
 651     }
 652
 653   return 1;
 654 }
 655
 656 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 657    by ORIG_NAME.  Also, print out a #include command so that the PCH
 658    file can be loaded when the preprocessed output is compiled.  */
 659
 660 static void
 661 cb_read_pch (cpp_reader *pfile, const char *name,
 662              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 663 {
 664   c_common_read_pch (pfile, name, fd, orig_name);
 665
 666   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 667   print.src_line++;
 668 }