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