gcc/c-family/c-ppoutput.c

   1 /* Preprocess only, using cpplib.
   2    Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007,
   3    2008, 2009, 2010 Free Software Foundation, Inc.
   4    Written by Per Bothner, 1994-95.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any
   9    later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; see the file COPYING3.  If not see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "cpplib.h"
  24 #include "../libcpp/internal.h"
  25 #include "tree.h"
  26 #include "c-common.h"           /* For flags.  */
  27 #include "c-pragma.h"           /* For parse_in.  */
  28
  29 /* Encapsulates state used to convert a stream of tokens into a text
  30    file.  */
  31 static struct
  32 {
  33   FILE *outf;                   /* Stream to write to.  */
  34   const cpp_token *prev;        /* Previous token.  */
  35   const cpp_token *source;      /* Source token for spacing.  */
  36   int src_line;                 /* Line number currently being written.  */
  37   unsigned char printed;        /* Nonzero if something output at line.  */
  38   bool first_time;              /* pp_file_change hasn't been called yet.  */
  39   const char *src_file;         /* Current source file.  */
  40 } print;
  41
  42 /* Defined and undefined macros being queued for output with -dU at
  43    the next newline.  */
  44 typedef struct macro_queue
  45 {
  46   struct macro_queue *next;     /* Next macro in the list.  */
  47   char *macro;                  /* The name of the macro if not
  48                                    defined, the full definition if
  49                                    defined.  */
  50 } macro_queue;
  51 static macro_queue *define_queue, *undef_queue;
  52
  53 /* General output routines.  */
  54 static void scan_translation_unit (cpp_reader *);
  55 static void print_lines_directives_only (int, const void *, size_t);
  56 static void scan_translation_unit_directives_only (cpp_reader *);
  57 static void scan_translation_unit_trad (cpp_reader *);
  58 static void account_for_newlines (const unsigned char *, size_t);
  59 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
  60 static void dump_queued_macros (cpp_reader *);
  61
  62 static void print_line (source_location, const char *);
  63 static void maybe_print_line (source_location);
  64 static void do_line_change (cpp_reader *, const cpp_token *,
  65                             source_location, int);
  66
  67 /* Callback routines for the parser.   Most of these are active only
  68    in specific modes.  */
  69 static void cb_line_change (cpp_reader *, const cpp_token *, int);
  70 static void cb_define (cpp_reader *, source_location, cpp_hashnode *);
  71 static void cb_undef (cpp_reader *, source_location, cpp_hashnode *);
  72 static void cb_used_define (cpp_reader *, source_location, cpp_hashnode *);
  73 static void cb_used_undef (cpp_reader *, source_location, cpp_hashnode *);
  74 static bool cb_include (cpp_reader *, source_location, const unsigned char *,
  75                         const char *, int, const cpp_token **);
  76 static void cb_ident (cpp_reader *, source_location, const cpp_string *);
  77 static void cb_def_pragma (cpp_reader *, source_location);
  78 static void cb_read_pch (cpp_reader *pfile, const char *name,
  79                          int fd, const char *orig_name);
  80
  81 /* Preprocess and output.  */
  82 void
  83 preprocess_file (cpp_reader *pfile)
  84 {
  85   /* A successful cpp_read_main_file guarantees that we can call
  86      cpp_scan_nooutput or cpp_get_token next.  */
  87   if (flag_no_output)
  88     {
  89       /* Scan -included buffers, then the main file.  */
  90       while (pfile->buffer->prev)
  91         cpp_scan_nooutput (pfile);
  92       cpp_scan_nooutput (pfile);
  93     }
  94   else if (cpp_get_options (pfile)->traditional)
  95     scan_translation_unit_trad (pfile);
  96   else if (cpp_get_options (pfile)->directives_only
  97            && !cpp_get_options (pfile)->preprocessed)
  98     scan_translation_unit_directives_only (pfile);
  99   else
 100     scan_translation_unit (pfile);
 101
 102   /* -dM command line option.  Should this be elsewhere?  */
 103   if (flag_dump_macros == 'M')
 104     cpp_forall_identifiers (pfile, dump_macro, NULL);
 105
 106   /* Flush any pending output.  */
 107   if (print.printed)
 108     putc ('\n', print.outf);
 109 }
 110
 111 /* Set up the callbacks as appropriate.  */
 112 void
 113 init_pp_output (FILE *out_stream)
 114 {
 115   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
 116
 117   if (!flag_no_output)
 118     {
 119       cb->line_change = cb_line_change;
 120       /* Don't emit #pragma or #ident directives if we are processing
 121          assembly language; the assembler may choke on them.  */
 122       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 123         {
 124           cb->ident      = cb_ident;
 125           cb->def_pragma = cb_def_pragma;
 126         }
 127     }
 128
 129   if (flag_dump_includes)
 130     cb->include = cb_include;
 131
 132   if (flag_pch_preprocess)
 133     {
 134       cb->valid_pch = c_common_valid_pch;
 135       cb->read_pch = cb_read_pch;
 136     }
 137
 138   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 139     {
 140       cb->define = cb_define;
 141       cb->undef  = cb_undef;
 142     }
 143
 144   if (flag_dump_macros == 'U')
 145     {
 146       cb->before_define = dump_queued_macros;
 147       cb->used_define = cb_used_define;
 148       cb->used_undef = cb_used_undef;
 149     }
 150
 151   /* Initialize the print structure.  */
 152   print.src_line = 1;
 153   print.printed = 0;
 154   print.prev = 0;
 155   print.outf = out_stream;
 156   print.first_time = 1;
 157   print.src_file = "";
 158 }
 159
 160 /* Writes out the preprocessed file, handling spacing and paste
 161    avoidance issues.  */
 162 static void
 163 scan_translation_unit (cpp_reader *pfile)
 164 {
 165   bool avoid_paste = false;
 166   bool do_line_adjustments
 167     = cpp_get_options (parse_in)->lang != CLK_ASM
 168       && !flag_no_line_commands;
 169   bool in_pragma = false;
 170
 171   print.source = NULL;
 172   for (;;)
 173     {
 174       source_location loc;
 175       const cpp_token *token = cpp_get_token_with_location (pfile, &loc);
 176
 177       if (token->type == CPP_PADDING)
 178         {
 179           avoid_paste = true;
 180           if (print.source == NULL
 181               || (!(print.source->flags & PREV_WHITE)
 182                   && token->val.source == NULL))
 183             print.source = token->val.source;
 184           continue;
 185         }
 186
 187       if (token->type == CPP_EOF)
 188         break;
 189
 190       /* Subtle logic to output a space if and only if necessary.  */
 191       if (avoid_paste)
 192         {
 193           const struct line_map *map
 194             = linemap_lookup (line_table, loc);
 195           int src_line = SOURCE_LINE (map, loc);
 196
 197           if (print.source == NULL)
 198             print.source = token;
 199
 200           if (src_line != print.src_line
 201               && do_line_adjustments
 202               && !in_pragma)
 203             {
 204               do_line_change (pfile, token, loc, false);
 205               putc (' ', print.outf);
 206             }
 207           else if (print.source->flags & PREV_WHITE
 208                    || (print.prev
 209                        && cpp_avoid_paste (pfile, print.prev, token))
 210                    || (print.prev == NULL && token->type == CPP_HASH))
 211             putc (' ', print.outf);
 212         }
 213       else if (token->flags & PREV_WHITE)
 214         {
 215           const struct line_map *map
 216             = linemap_lookup (line_table, loc);
 217           int src_line = SOURCE_LINE (map, loc);
 218
 219           if (src_line != print.src_line
 220               && do_line_adjustments
 221               && !in_pragma)
 222             do_line_change (pfile, token, loc, false);
 223           putc (' ', print.outf);
 224         }
 225
 226       avoid_paste = false;
 227       print.source = NULL;
 228       print.prev = token;
 229       if (token->type == CPP_PRAGMA)
 230         {
 231           const char *space;
 232           const char *name;
 233
 234           maybe_print_line (token->src_loc);
 235           fputs ("#pragma ", print.outf);
 236           c_pp_lookup_pragma (token->val.pragma, &space, &name);
 237           if (space)
 238             fprintf (print.outf, "%s %s", space, name);
 239           else
 240             fprintf (print.outf, "%s", name);
 241           print.printed = 1;
 242           in_pragma = true;
 243         }
 244       else if (token->type == CPP_PRAGMA_EOL)
 245         {
 246           maybe_print_line (token->src_loc);
 247           in_pragma = false;
 248         }
 249       else
 250         cpp_output_token (token, print.outf);
 251
 252       if (token->type == CPP_COMMENT)
 253         account_for_newlines (token->val.str.text, token->val.str.len);
 254     }
 255 }
 256
 257 static void
 258 print_lines_directives_only (int lines, const void *buf, size_t size)
 259 {
 260   print.src_line += lines;
 261   fwrite (buf, 1, size, print.outf);
 262 }
 263
 264 /* Writes out the preprocessed file, handling spacing and paste
 265    avoidance issues.  */
 266 static void
 267 scan_translation_unit_directives_only (cpp_reader *pfile)
 268 {
 269   struct _cpp_dir_only_callbacks cb;
 270
 271   cb.print_lines = print_lines_directives_only;
 272   cb.maybe_print_line = maybe_print_line;
 273
 274   _cpp_preprocess_dir_only (pfile, &cb);
 275 }
 276
 277 /* Adjust print.src_line for newlines embedded in output.  */
 278 static void
 279 account_for_newlines (const unsigned char *str, size_t len)
 280 {
 281   while (len--)
 282     if (*str++ == '\n')
 283       print.src_line++;
 284 }
 285
 286 /* Writes out a traditionally preprocessed file.  */
 287 static void
 288 scan_translation_unit_trad (cpp_reader *pfile)
 289 {
 290   while (_cpp_read_logical_line_trad (pfile))
 291     {
 292       size_t len = pfile->out.cur - pfile->out.base;
 293       maybe_print_line (pfile->out.first_line);
 294       fwrite (pfile->out.base, 1, len, print.outf);
 295       print.printed = 1;
 296       if (!CPP_OPTION (pfile, discard_comments))
 297         account_for_newlines (pfile->out.base, len);
 298     }
 299 }
 300
 301 /* If the token read on logical line LINE needs to be output on a
 302    different line to the current one, output the required newlines or
 303    a line marker, and return 1.  Otherwise return 0.  */
 304 static void
 305 maybe_print_line (source_location src_loc)
 306 {
 307   const struct line_map *map = linemap_lookup (line_table, src_loc);
 308   int src_line = SOURCE_LINE (map, src_loc);
 309   /* End the previous line of text.  */
 310   if (print.printed)
 311     {
 312       putc ('\n', print.outf);
 313       print.src_line++;
 314       print.printed = 0;
 315     }
 316
 317   if (src_line >= print.src_line
 318       && src_line < print.src_line + 8
 319       && strcmp (map->to_file, print.src_file) == 0)
 320     {
 321       while (src_line > print.src_line)
 322         {
 323           putc ('\n', print.outf);
 324           print.src_line++;
 325         }
 326     }
 327   else
 328     print_line (src_loc, "");
 329 }
 330
 331 /* Output a line marker for logical line LINE.  Special flags are "1"
 332    or "2" indicating entering or leaving a file.  */
 333 static void
 334 print_line (source_location src_loc, const char *special_flags)
 335 {
 336   /* End any previous line of text.  */
 337   if (print.printed)
 338     putc ('\n', print.outf);
 339   print.printed = 0;
 340
 341   if (!flag_no_line_commands)
 342     {
 343       const struct line_map *map = linemap_lookup (line_table, src_loc);
 344
 345       size_t to_file_len = strlen (map->to_file);
 346       unsigned char *to_file_quoted =
 347          (unsigned char *) alloca (to_file_len * 4 + 1);
 348       unsigned char *p;
 349
 350       print.src_line = SOURCE_LINE (map, src_loc);
 351       print.src_file = map->to_file;
 352
 353       /* cpp_quote_string does not nul-terminate, so we have to do it
 354          ourselves.  */
 355       p = cpp_quote_string (to_file_quoted,
 356                             (const unsigned char *) map->to_file, to_file_len);
 357       *p = '\0';
 358       fprintf (print.outf, "# %u \"%s\"%s",
 359                print.src_line == 0 ? 1 : print.src_line,
 360                to_file_quoted, special_flags);
 361
 362       if (map->sysp == 2)
 363         fputs (" 3 4", print.outf);
 364       else if (map->sysp == 1)
 365         fputs (" 3", print.outf);
 366
 367       putc ('\n', print.outf);
 368     }
 369 }
 370
 371 /* Helper function for cb_line_change and scan_translation_unit.  */
 372 static void
 373 do_line_change (cpp_reader *pfile, const cpp_token *token,
 374                 source_location src_loc, int parsing_args)
 375 {
 376   if (define_queue || undef_queue)
 377     dump_queued_macros (pfile);
 378
 379   if (token->type == CPP_EOF || parsing_args)
 380     return;
 381
 382   maybe_print_line (src_loc);
 383   print.prev = 0;
 384   print.source = 0;
 385
 386   /* Supply enough spaces to put this token in its original column,
 387      one space per column greater than 2, since scan_translation_unit
 388      will provide a space if PREV_WHITE.  Don't bother trying to
 389      reconstruct tabs; we can't get it right in general, and nothing
 390      ought to care.  Some things do care; the fault lies with them.  */
 391   if (!CPP_OPTION (pfile, traditional))
 392     {
 393       const struct line_map *map = linemap_lookup (line_table, src_loc);
 394       int spaces = SOURCE_COLUMN (map, src_loc) - 2;
 395       print.printed = 1;
 396
 397       while (-- spaces >= 0)
 398         putc (' ', print.outf);
 399     }
 400 }
 401
 402 /* Called when a line of output is started.  TOKEN is the first token
 403    of the line, and at end of file will be CPP_EOF.  */
 404 static void
 405 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 406                 int parsing_args)
 407 {
 408   do_line_change (pfile, token, token->src_loc, parsing_args);
 409 }
 410
 411 static void
 412 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 413           const cpp_string *str)
 414 {
 415   maybe_print_line (line);
 416   fprintf (print.outf, "#ident %s\n", str->text);
 417   print.src_line++;
 418 }
 419
 420 static void
 421 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 422 {
 423   maybe_print_line (line);
 424   fputs ("#define ", print.outf);
 425
 426   /* 'D' is whole definition; 'N' is name only.  */
 427   if (flag_dump_macros == 'D')
 428     fputs ((const char *) cpp_macro_definition (pfile, node),
 429            print.outf);
 430   else
 431     fputs ((const char *) NODE_NAME (node), print.outf);
 432
 433   putc ('\n', print.outf);
 434   if (linemap_lookup (line_table, line)->to_line != 0)
 435     print.src_line++;
 436 }
 437
 438 static void
 439 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 440           cpp_hashnode *node)
 441 {
 442   maybe_print_line (line);
 443   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 444   print.src_line++;
 445 }
 446
 447 static void
 448 cb_used_define (cpp_reader *pfile, source_location line ATTRIBUTE_UNUSED,
 449                 cpp_hashnode *node)
 450 {
 451   macro_queue *q;
 452   if (node->flags & NODE_BUILTIN)
 453     return;
 454   q = XNEW (macro_queue);
 455   q->macro = xstrdup ((const char *) cpp_macro_definition (pfile, node));
 456   q->next = define_queue;
 457   define_queue = q;
 458 }
 459
 460 static void
 461 cb_used_undef (cpp_reader *pfile ATTRIBUTE_UNUSED,
 462                source_location line ATTRIBUTE_UNUSED,
 463                cpp_hashnode *node)
 464 {
 465   macro_queue *q;
 466   q = XNEW (macro_queue);
 467   q->macro = xstrdup ((const char *) NODE_NAME (node));
 468   q->next = undef_queue;
 469   undef_queue = q;
 470 }
 471
 472 static void
 473 dump_queued_macros (cpp_reader *pfile ATTRIBUTE_UNUSED)
 474 {
 475   macro_queue *q;
 476
 477   /* End the previous line of text.  */
 478   if (print.printed)
 479     {
 480       putc ('\n', print.outf);
 481       print.src_line++;
 482       print.printed = 0;
 483     }
 484
 485   for (q = define_queue; q;)
 486     {
 487       macro_queue *oq;
 488       fputs ("#define ", print.outf);
 489       fputs (q->macro, print.outf);
 490       putc ('\n', print.outf);
 491       print.src_line++;
 492       oq = q;
 493       q = q->next;
 494       free (oq->macro);
 495       free (oq);
 496     }
 497   define_queue = NULL;
 498   for (q = undef_queue; q;)
 499     {
 500       macro_queue *oq;
 501       fprintf (print.outf, "#undef %s\n", q->macro);
 502       print.src_line++;
 503       oq = q;
 504       q = q->next;
 505       free (oq->macro);
 506       free (oq);
 507     }
 508   undef_queue = NULL;
 509 }
 510
 511 static bool
 512 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 513             const unsigned char *dir, const char *header, int angle_brackets,
 514             const cpp_token **comments)
 515 {
 516   maybe_print_line (line);
 517   if (angle_brackets)
 518     fprintf (print.outf, "#%s <%s>", dir, header);
 519   else
 520     fprintf (print.outf, "#%s \"%s\"", dir, header);
 521
 522   if (comments != NULL)
 523     {
 524       while (*comments != NULL)
 525         {
 526           if ((*comments)->flags & PREV_WHITE)
 527             putc (' ', print.outf);
 528           cpp_output_token (*comments, print.outf);
 529           ++comments;
 530         }
 531     }
 532
 533   putc ('\n', print.outf);
 534   print.src_line++;
 535   return true;
 536 }
 537
 538 /* Callback called when -fworking-director and -E to emit working
 539    directory in cpp output file.  */
 540
 541 void
 542 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 543 {
 544   size_t to_file_len = strlen (dir);
 545   unsigned char *to_file_quoted =
 546      (unsigned char *) alloca (to_file_len * 4 + 1);
 547   unsigned char *p;
 548
 549   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 550   p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir, to_file_len);
 551   *p = '\0';
 552   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 553 }
 554
 555 /* The file name, line number or system header flags have changed, as
 556    described in MAP.  */
 557
 558 void
 559 pp_file_change (const struct line_map *map)
 560 {
 561   const char *flags = "";
 562
 563   if (flag_no_line_commands)
 564     return;
 565
 566   if (map != NULL)
 567     {
 568       input_location = map->start_location;
 569       if (print.first_time)
 570         {
 571           /* Avoid printing foo.i when the main file is foo.c.  */
 572           if (!cpp_get_options (parse_in)->preprocessed)
 573             print_line (map->start_location, flags);
 574           print.first_time = 0;
 575         }
 576       else
 577         {
 578           /* Bring current file to correct line when entering a new file.  */
 579           if (map->reason == LC_ENTER)
 580             {
 581               const struct line_map *from = INCLUDED_FROM (line_table, map);
 582               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 583             }
 584           if (map->reason == LC_ENTER)
 585             flags = " 1";
 586           else if (map->reason == LC_LEAVE)
 587             flags = " 2";
 588           print_line (map->start_location, flags);
 589         }
 590     }
 591 }
 592
 593 /* Copy a #pragma directive to the preprocessed output.  */
 594 static void
 595 cb_def_pragma (cpp_reader *pfile, source_location line)
 596 {
 597   maybe_print_line (line);
 598   fputs ("#pragma ", print.outf);
 599   cpp_output_line (pfile, print.outf);
 600   print.src_line++;
 601 }
 602
 603 /* Dump out the hash table.  */
 604 static int
 605 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 606 {
 607   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 608     {
 609       fputs ("#define ", print.outf);
 610       fputs ((const char *) cpp_macro_definition (pfile, node),
 611              print.outf);
 612       putc ('\n', print.outf);
 613       print.src_line++;
 614     }
 615
 616   return 1;
 617 }
 618
 619 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 620    by ORIG_NAME.  Also, print out a #include command so that the PCH
 621    file can be loaded when the preprocessed output is compiled.  */
 622
 623 static void
 624 cb_read_pch (cpp_reader *pfile, const char *name,
 625              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 626 {
 627   c_common_read_pch (pfile, name, fd, orig_name);
 628
 629   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 630   print.src_line++;
 631 }