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 } 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       /* CPP_COMMENT tokens and raw-string literal tokens can
 255          have embedded new-line characters.  Rather than enumerating
 256          all the possible token types just check if token uses
 257          val.str union member.  */
 258       if (cpp_token_val_index (token) == CPP_TOKEN_FLD_STR)
 259         account_for_newlines (token->val.str.text, token->val.str.len);
 260     }
 261 }
 262
 263 static void
 264 print_lines_directives_only (int lines, const void *buf, size_t size)
 265 {
 266   print.src_line += lines;
 267   fwrite (buf, 1, size, print.outf);
 268 }
 269
 270 /* Writes out the preprocessed file, handling spacing and paste
 271    avoidance issues.  */
 272 static void
 273 scan_translation_unit_directives_only (cpp_reader *pfile)
 274 {
 275   struct _cpp_dir_only_callbacks cb;
 276
 277   cb.print_lines = print_lines_directives_only;
 278   cb.maybe_print_line = maybe_print_line;
 279
 280   _cpp_preprocess_dir_only (pfile, &cb);
 281 }
 282
 283 /* Adjust print.src_line for newlines embedded in output.  */
 284 static void
 285 account_for_newlines (const unsigned char *str, size_t len)
 286 {
 287   while (len--)
 288     if (*str++ == '\n')
 289       print.src_line++;
 290 }
 291
 292 /* Writes out a traditionally preprocessed file.  */
 293 static void
 294 scan_translation_unit_trad (cpp_reader *pfile)
 295 {
 296   while (_cpp_read_logical_line_trad (pfile))
 297     {
 298       size_t len = pfile->out.cur - pfile->out.base;
 299       maybe_print_line (pfile->out.first_line);
 300       fwrite (pfile->out.base, 1, len, print.outf);
 301       print.printed = 1;
 302       if (!CPP_OPTION (pfile, discard_comments))
 303         account_for_newlines (pfile->out.base, len);
 304     }
 305 }
 306
 307 /* If the token read on logical line LINE needs to be output on a
 308    different line to the current one, output the required newlines or
 309    a line marker, and return 1.  Otherwise return 0.  */
 310
 311 static void
 312 maybe_print_line_1 (source_location src_loc, FILE *stream)
 313 {
 314   int src_line = LOCATION_LINE (src_loc);
 315   const char *src_file = LOCATION_FILE (src_loc);
 316
 317   /* End the previous line of text.  */
 318   if (print.printed)
 319     {
 320       putc ('\n', stream);
 321       print.src_line++;
 322       print.printed = 0;
 323     }
 324
 325   if (!flag_no_line_commands
 326       && src_line >= print.src_line
 327       && src_line < print.src_line + 8
 328       && strcmp (src_file, print.src_file) == 0)
 329     {
 330       while (src_line > print.src_line)
 331         {
 332           putc ('\n', stream);
 333           print.src_line++;
 334         }
 335     }
 336   else
 337     print_line_1 (src_loc, "", stream);
 338
 339 }
 340
 341 /* If the token read on logical line LINE needs to be output on a
 342    different line to the current one, output the required newlines or
 343    a line marker, and return 1.  Otherwise return 0.  */
 344
 345 static void
 346 maybe_print_line (source_location src_loc)
 347 {
 348   if (cpp_get_options (parse_in)->debug)
 349     linemap_dump_location (line_table, src_loc,
 350                            print.outf);
 351   maybe_print_line_1 (src_loc, print.outf);
 352 }
 353
 354 /* Output a line marker for logical line LINE.  Special flags are "1"
 355    or "2" indicating entering or leaving a file.  */
 356
 357 static void
 358 print_line_1 (source_location src_loc, const char *special_flags, FILE *stream)
 359 {
 360   /* End any previous line of text.  */
 361   if (print.printed)
 362     putc ('\n', stream);
 363   print.printed = 0;
 364
 365   if (!flag_no_line_commands)
 366     {
 367       const char *file_path = LOCATION_FILE (src_loc);
 368       int sysp;
 369       size_t to_file_len = strlen (file_path);
 370       unsigned char *to_file_quoted =
 371          (unsigned char *) alloca (to_file_len * 4 + 1);
 372       unsigned char *p;
 373
 374       print.src_line = LOCATION_LINE (src_loc);
 375       print.src_file = file_path;
 376
 377       /* cpp_quote_string does not nul-terminate, so we have to do it
 378          ourselves.  */
 379       p = cpp_quote_string (to_file_quoted,
 380                             (const unsigned char *) file_path,
 381                             to_file_len);
 382       *p = '\0';
 383       fprintf (stream, "# %u \"%s\"%s",
 384                print.src_line == 0 ? 1 : print.src_line,
 385                to_file_quoted, special_flags);
 386
 387       sysp = in_system_header_at (src_loc);
 388       if (sysp == 2)
 389         fputs (" 3 4", stream);
 390       else if (sysp == 1)
 391         fputs (" 3", stream);
 392
 393       putc ('\n', stream);
 394     }
 395 }
 396
 397 /* Output a line marker for logical line LINE.  Special flags are "1"
 398    or "2" indicating entering or leaving a file.  */
 399
 400 static void
 401 print_line (source_location src_loc, const char *special_flags)
 402 {
 403     if (cpp_get_options (parse_in)->debug)
 404       linemap_dump_location (line_table, src_loc,
 405                              print.outf);
 406     print_line_1 (src_loc, special_flags, print.outf);
 407 }
 408
 409 /* Helper function for cb_line_change and scan_translation_unit.  */
 410 static void
 411 do_line_change (cpp_reader *pfile, const cpp_token *token,
 412                 source_location src_loc, int parsing_args)
 413 {
 414   if (define_queue || undef_queue)
 415     dump_queued_macros (pfile);
 416
 417   if (token->type == CPP_EOF || parsing_args)
 418     return;
 419
 420   maybe_print_line (src_loc);
 421   print.prev = 0;
 422   print.source = 0;
 423
 424   /* Supply enough spaces to put this token in its original column,
 425      one space per column greater than 2, since scan_translation_unit
 426      will provide a space if PREV_WHITE.  Don't bother trying to
 427      reconstruct tabs; we can't get it right in general, and nothing
 428      ought to care.  Some things do care; the fault lies with them.  */
 429   if (!CPP_OPTION (pfile, traditional))
 430     {
 431       int spaces = LOCATION_COLUMN (src_loc) - 2;
 432       print.printed = 1;
 433
 434       while (-- spaces >= 0)
 435         putc (' ', print.outf);
 436     }
 437 }
 438
 439 /* Called when a line of output is started.  TOKEN is the first token
 440    of the line, and at end of file will be CPP_EOF.  */
 441 static void
 442 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 443                 int parsing_args)
 444 {
 445   do_line_change (pfile, token, token->src_loc, parsing_args);
 446 }
 447
 448 static void
 449 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 450           const cpp_string *str)
 451 {
 452   maybe_print_line (line);
 453   fprintf (print.outf, "#ident %s\n", str->text);
 454   print.src_line++;
 455 }
 456
 457 static void
 458 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 459 {
 460   const struct line_map *map;
 461
 462   maybe_print_line (line);
 463   fputs ("#define ", print.outf);
 464
 465   /* 'D' is whole definition; 'N' is name only.  */
 466   if (flag_dump_macros == 'D')
 467     fputs ((const char *) cpp_macro_definition (pfile, node),
 468            print.outf);
 469   else
 470     fputs ((const char *) NODE_NAME (node), print.outf);
 471
 472   putc ('\n', print.outf);
 473   linemap_resolve_location (line_table, line,
 474                             LRK_MACRO_DEFINITION_LOCATION,
 475                             &map);
 476   if (LINEMAP_LINE (map) != 0)
 477     print.src_line++;
 478 }
 479
 480 static void
 481 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 482           cpp_hashnode *node)
 483 {
 484   maybe_print_line (line);
 485   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 486   print.src_line++;
 487 }
 488
 489 static void
 490 cb_used_define (cpp_reader *pfile, source_location line ATTRIBUTE_UNUSED,
 491                 cpp_hashnode *node)
 492 {
 493   macro_queue *q;
 494   if (node->flags & NODE_BUILTIN)
 495     return;
 496   q = XNEW (macro_queue);
 497   q->macro = xstrdup ((const char *) cpp_macro_definition (pfile, node));
 498   q->next = define_queue;
 499   define_queue = q;
 500 }
 501
 502 static void
 503 cb_used_undef (cpp_reader *pfile ATTRIBUTE_UNUSED,
 504                source_location line ATTRIBUTE_UNUSED,
 505                cpp_hashnode *node)
 506 {
 507   macro_queue *q;
 508   q = XNEW (macro_queue);
 509   q->macro = xstrdup ((const char *) NODE_NAME (node));
 510   q->next = undef_queue;
 511   undef_queue = q;
 512 }
 513
 514 static void
 515 dump_queued_macros (cpp_reader *pfile ATTRIBUTE_UNUSED)
 516 {
 517   macro_queue *q;
 518
 519   /* End the previous line of text.  */
 520   if (print.printed)
 521     {
 522       putc ('\n', print.outf);
 523       print.src_line++;
 524       print.printed = 0;
 525     }
 526
 527   for (q = define_queue; q;)
 528     {
 529       macro_queue *oq;
 530       fputs ("#define ", print.outf);
 531       fputs (q->macro, print.outf);
 532       putc ('\n', print.outf);
 533       print.src_line++;
 534       oq = q;
 535       q = q->next;
 536       free (oq->macro);
 537       free (oq);
 538     }
 539   define_queue = NULL;
 540   for (q = undef_queue; q;)
 541     {
 542       macro_queue *oq;
 543       fprintf (print.outf, "#undef %s\n", q->macro);
 544       print.src_line++;
 545       oq = q;
 546       q = q->next;
 547       free (oq->macro);
 548       free (oq);
 549     }
 550   undef_queue = NULL;
 551 }
 552
 553 static void
 554 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 555             const unsigned char *dir, const char *header, int angle_brackets,
 556             const cpp_token **comments)
 557 {
 558   maybe_print_line (line);
 559   if (angle_brackets)
 560     fprintf (print.outf, "#%s <%s>", dir, header);
 561   else
 562     fprintf (print.outf, "#%s \"%s\"", dir, header);
 563
 564   if (comments != NULL)
 565     {
 566       while (*comments != NULL)
 567         {
 568           if ((*comments)->flags & PREV_WHITE)
 569             putc (' ', print.outf);
 570           cpp_output_token (*comments, print.outf);
 571           ++comments;
 572         }
 573     }
 574
 575   putc ('\n', print.outf);
 576   print.src_line++;
 577 }
 578
 579 /* Callback called when -fworking-director and -E to emit working
 580    directory in cpp output file.  */
 581
 582 void
 583 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 584 {
 585   size_t to_file_len = strlen (dir);
 586   unsigned char *to_file_quoted =
 587      (unsigned char *) alloca (to_file_len * 4 + 1);
 588   unsigned char *p;
 589
 590   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 591   p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir, to_file_len);
 592   *p = '\0';
 593   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 594 }
 595
 596 /* The file name, line number or system header flags have changed, as
 597    described in MAP.  */
 598
 599 void
 600 pp_file_change (const struct line_map *map)
 601 {
 602   const char *flags = "";
 603
 604   if (flag_no_line_commands)
 605     return;
 606
 607   if (map != NULL)
 608     {
 609       input_location = map->start_location;
 610       if (print.first_time)
 611         {
 612           /* Avoid printing foo.i when the main file is foo.c.  */
 613           if (!cpp_get_options (parse_in)->preprocessed)
 614             print_line (map->start_location, flags);
 615           print.first_time = 0;
 616         }
 617       else
 618         {
 619           /* Bring current file to correct line when entering a new file.  */
 620           if (map->reason == LC_ENTER)
 621             {
 622               const struct line_map *from = INCLUDED_FROM (line_table, map);
 623               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 624             }
 625           if (map->reason == LC_ENTER)
 626             flags = " 1";
 627           else if (map->reason == LC_LEAVE)
 628             flags = " 2";
 629           print_line (map->start_location, flags);
 630         }
 631     }
 632 }
 633
 634 /* Copy a #pragma directive to the preprocessed output.  */
 635 static void
 636 cb_def_pragma (cpp_reader *pfile, source_location line)
 637 {
 638   maybe_print_line (line);
 639   fputs ("#pragma ", print.outf);
 640   cpp_output_line (pfile, print.outf);
 641   print.src_line++;
 642 }
 643
 644 /* Dump out the hash table.  */
 645 static int
 646 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 647 {
 648   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 649     {
 650       fputs ("#define ", print.outf);
 651       fputs ((const char *) cpp_macro_definition (pfile, node),
 652              print.outf);
 653       putc ('\n', print.outf);
 654       print.src_line++;
 655     }
 656
 657   return 1;
 658 }
 659
 660 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 661    by ORIG_NAME.  Also, print out a #include command so that the PCH
 662    file can be loaded when the preprocessed output is compiled.  */
 663
 664 static void
 665 cb_read_pch (cpp_reader *pfile, const char *name,
 666              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 667 {
 668   c_common_read_pch (pfile, name, fd, orig_name);
 669
 670   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 671   print.src_line++;
 672 }