gcc/c-ppoutput.c

   1 /* Preprocess only, using cpplib.
   2    Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007
   3    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 "tm.h"
  24 #include "cpplib.h"
  25 #include "../libcpp/internal.h"
  26 #include "tree.h"
  27 #include "c-common.h"           /* For flags.  */
  28 #include "c-pragma.h"           /* For parse_in.  */
  29
  30 /* Encapsulates state used to convert a stream of tokens into a text
  31    file.  */
  32 static struct
  33 {
  34   FILE *outf;                   /* Stream to write to.  */
  35   const cpp_token *prev;        /* Previous token.  */
  36   const cpp_token *source;      /* Source token for spacing.  */
  37   int src_line;                 /* Line number currently being written.  */
  38   unsigned char printed;        /* Nonzero if something output at line.  */
  39   bool first_time;              /* pp_file_change hasn't been called yet.  */
  40 } print;
  41
  42 /* General output routines.  */
  43 static void scan_translation_unit (cpp_reader *);
  44 static void print_lines_directives_only (int, const void *, size_t);
  45 static void scan_translation_unit_directives_only (cpp_reader *);
  46 static void scan_translation_unit_trad (cpp_reader *);
  47 static void account_for_newlines (const unsigned char *, size_t);
  48 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
  49
  50 static void print_line (source_location, const char *);
  51 static void maybe_print_line (source_location);
  52
  53 /* Callback routines for the parser.   Most of these are active only
  54    in specific modes.  */
  55 static void cb_line_change (cpp_reader *, const cpp_token *, int);
  56 static void cb_define (cpp_reader *, source_location, cpp_hashnode *);
  57 static void cb_undef (cpp_reader *, source_location, cpp_hashnode *);
  58 static void cb_include (cpp_reader *, source_location, const unsigned char *,
  59                         const char *, int, const cpp_token **);
  60 static void cb_ident (cpp_reader *, source_location, const cpp_string *);
  61 static void cb_def_pragma (cpp_reader *, source_location);
  62 static void cb_read_pch (cpp_reader *pfile, const char *name,
  63                          int fd, const char *orig_name);
  64
  65 /* Preprocess and output.  */
  66 void
  67 preprocess_file (cpp_reader *pfile)
  68 {
  69   /* A successful cpp_read_main_file guarantees that we can call
  70      cpp_scan_nooutput or cpp_get_token next.  */
  71   if (flag_no_output)
  72     {
  73       /* Scan -included buffers, then the main file.  */
  74       while (pfile->buffer->prev)
  75         cpp_scan_nooutput (pfile);
  76       cpp_scan_nooutput (pfile);
  77     }
  78   else if (cpp_get_options (pfile)->traditional)
  79     scan_translation_unit_trad (pfile);
  80   else if (cpp_get_options (pfile)->directives_only
  81            && !cpp_get_options (pfile)->preprocessed)
  82     scan_translation_unit_directives_only (pfile);
  83   else
  84     scan_translation_unit (pfile);
  85
  86   /* -dM command line option.  Should this be elsewhere?  */
  87   if (flag_dump_macros == 'M')
  88     cpp_forall_identifiers (pfile, dump_macro, NULL);
  89
  90   /* Flush any pending output.  */
  91   if (print.printed)
  92     putc ('\n', print.outf);
  93 }
  94
  95 /* Set up the callbacks as appropriate.  */
  96 void
  97 init_pp_output (FILE *out_stream)
  98 {
  99   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
 100
 101   if (!flag_no_output)
 102     {
 103       cb->line_change = cb_line_change;
 104       /* Don't emit #pragma or #ident directives if we are processing
 105          assembly language; the assembler may choke on them.  */
 106       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 107         {
 108           cb->ident      = cb_ident;
 109           cb->def_pragma = cb_def_pragma;
 110         }
 111     }
 112
 113   if (flag_dump_includes)
 114     cb->include  = cb_include;
 115
 116   if (flag_pch_preprocess)
 117     {
 118       cb->valid_pch = c_common_valid_pch;
 119       cb->read_pch = cb_read_pch;
 120     }
 121
 122   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 123     {
 124       cb->define = cb_define;
 125       cb->undef  = cb_undef;
 126     }
 127
 128   /* Initialize the print structure.  Setting print.src_line to -1 here is
 129      a trick to guarantee that the first token of the file will cause
 130      a linemarker to be output by maybe_print_line.  */
 131   print.src_line = -1;
 132   print.printed = 0;
 133   print.prev = 0;
 134   print.outf = out_stream;
 135   print.first_time = 1;
 136 }
 137
 138 /* Writes out the preprocessed file, handling spacing and paste
 139    avoidance issues.  */
 140 static void
 141 scan_translation_unit (cpp_reader *pfile)
 142 {
 143   bool avoid_paste = false;
 144
 145   print.source = NULL;
 146   for (;;)
 147     {
 148       const cpp_token *token = cpp_get_token (pfile);
 149
 150       if (token->type == CPP_PADDING)
 151         {
 152           avoid_paste = true;
 153           if (print.source == NULL
 154               || (!(print.source->flags & PREV_WHITE)
 155                   && token->val.source == NULL))
 156             print.source = token->val.source;
 157           continue;
 158         }
 159
 160       if (token->type == CPP_EOF)
 161         break;
 162
 163       /* Subtle logic to output a space if and only if necessary.  */
 164       if (avoid_paste)
 165         {
 166           if (print.source == NULL)
 167             print.source = token;
 168           if (print.source->flags & PREV_WHITE
 169               || (print.prev
 170                   && cpp_avoid_paste (pfile, print.prev, token))
 171               || (print.prev == NULL && token->type == CPP_HASH))
 172             putc (' ', print.outf);
 173         }
 174       else if (token->flags & PREV_WHITE)
 175         putc (' ', print.outf);
 176
 177       avoid_paste = false;
 178       print.source = NULL;
 179       print.prev = token;
 180       cpp_output_token (token, print.outf);
 181
 182       if (token->type == CPP_COMMENT)
 183         account_for_newlines (token->val.str.text, token->val.str.len);
 184     }
 185 }
 186
 187 static void
 188 print_lines_directives_only (int lines, const void *buf, size_t size)
 189 {
 190   print.src_line += lines;
 191   fwrite (buf, 1, size, print.outf);
 192 }
 193
 194 /* Writes out the preprocessed file, handling spacing and paste
 195    avoidance issues.  */
 196 static void
 197 scan_translation_unit_directives_only (cpp_reader *pfile)
 198 {
 199   struct _cpp_dir_only_callbacks cb;
 200
 201   cb.print_lines = print_lines_directives_only;
 202   cb.maybe_print_line = maybe_print_line;
 203
 204   _cpp_preprocess_dir_only (pfile, &cb);
 205 }
 206
 207 /* Adjust print.src_line for newlines embedded in output.  */
 208 static void
 209 account_for_newlines (const unsigned char *str, size_t len)
 210 {
 211   while (len--)
 212     if (*str++ == '\n')
 213       print.src_line++;
 214 }
 215
 216 /* Writes out a traditionally preprocessed file.  */
 217 static void
 218 scan_translation_unit_trad (cpp_reader *pfile)
 219 {
 220   while (_cpp_read_logical_line_trad (pfile))
 221     {
 222       size_t len = pfile->out.cur - pfile->out.base;
 223       maybe_print_line (pfile->out.first_line);
 224       fwrite (pfile->out.base, 1, len, print.outf);
 225       print.printed = 1;
 226       if (!CPP_OPTION (pfile, discard_comments))
 227         account_for_newlines (pfile->out.base, len);
 228     }
 229 }
 230
 231 /* If the token read on logical line LINE needs to be output on a
 232    different line to the current one, output the required newlines or
 233    a line marker, and return 1.  Otherwise return 0.  */
 234 static void
 235 maybe_print_line (source_location src_loc)
 236 {
 237   const struct line_map *map = linemap_lookup (line_table, src_loc);
 238   int src_line = SOURCE_LINE (map, src_loc);
 239   /* End the previous line of text.  */
 240   if (print.printed)
 241     {
 242       putc ('\n', print.outf);
 243       print.src_line++;
 244       print.printed = 0;
 245     }
 246
 247   if (src_line >= print.src_line && src_line < print.src_line + 8)
 248     {
 249       while (src_line > print.src_line)
 250         {
 251           putc ('\n', print.outf);
 252           print.src_line++;
 253         }
 254     }
 255   else
 256     print_line (src_loc, "");
 257 }
 258
 259 /* Output a line marker for logical line LINE.  Special flags are "1"
 260    or "2" indicating entering or leaving a file.  */
 261 static void
 262 print_line (source_location src_loc, const char *special_flags)
 263 {
 264   /* End any previous line of text.  */
 265   if (print.printed)
 266     putc ('\n', print.outf);
 267   print.printed = 0;
 268
 269   if (!flag_no_line_commands)
 270     {
 271       const struct line_map *map = linemap_lookup (line_table, src_loc);
 272
 273       size_t to_file_len = strlen (map->to_file);
 274       unsigned char *to_file_quoted =
 275          (unsigned char *) alloca (to_file_len * 4 + 1);
 276       unsigned char *p;
 277
 278       print.src_line = SOURCE_LINE (map, src_loc);
 279
 280       /* cpp_quote_string does not nul-terminate, so we have to do it
 281          ourselves.  */
 282       p = cpp_quote_string (to_file_quoted,
 283                             (const unsigned char *) map->to_file, to_file_len);
 284       *p = '\0';
 285       fprintf (print.outf, "# %u \"%s\"%s",
 286                print.src_line == 0 ? 1 : print.src_line,
 287                to_file_quoted, special_flags);
 288
 289       if (map->sysp == 2)
 290         fputs (" 3 4", print.outf);
 291       else if (map->sysp == 1)
 292         fputs (" 3", print.outf);
 293
 294       putc ('\n', print.outf);
 295     }
 296 }
 297
 298 /* Called when a line of output is started.  TOKEN is the first token
 299    of the line, and at end of file will be CPP_EOF.  */
 300 static void
 301 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 302                 int parsing_args)
 303 {
 304   source_location src_loc = token->src_loc;
 305
 306   if (token->type == CPP_EOF || parsing_args)
 307     return;
 308
 309   maybe_print_line (src_loc);
 310   print.prev = 0;
 311   print.source = 0;
 312
 313   /* Supply enough spaces to put this token in its original column,
 314      one space per column greater than 2, since scan_translation_unit
 315      will provide a space if PREV_WHITE.  Don't bother trying to
 316      reconstruct tabs; we can't get it right in general, and nothing
 317      ought to care.  Some things do care; the fault lies with them.  */
 318   if (!CPP_OPTION (pfile, traditional))
 319     {
 320       const struct line_map *map = linemap_lookup (line_table, src_loc);
 321       int spaces = SOURCE_COLUMN (map, src_loc) - 2;
 322       print.printed = 1;
 323
 324       while (-- spaces >= 0)
 325         putc (' ', print.outf);
 326     }
 327 }
 328
 329 static void
 330 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 331           const cpp_string *str)
 332 {
 333   maybe_print_line (line);
 334   fprintf (print.outf, "#ident %s\n", str->text);
 335   print.src_line++;
 336 }
 337
 338 static void
 339 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 340 {
 341   maybe_print_line (line);
 342   fputs ("#define ", print.outf);
 343
 344   /* 'D' is whole definition; 'N' is name only.  */
 345   if (flag_dump_macros == 'D')
 346     fputs ((const char *) cpp_macro_definition (pfile, node),
 347            print.outf);
 348   else
 349     fputs ((const char *) NODE_NAME (node), print.outf);
 350
 351   putc ('\n', print.outf);
 352   if (linemap_lookup (line_table, line)->to_line != 0)
 353     print.src_line++;
 354 }
 355
 356 static void
 357 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 358           cpp_hashnode *node)
 359 {
 360   maybe_print_line (line);
 361   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 362   print.src_line++;
 363 }
 364
 365 static void
 366 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 367             const unsigned char *dir, const char *header, int angle_brackets,
 368             const cpp_token **comments)
 369 {
 370   maybe_print_line (line);
 371   if (angle_brackets)
 372     fprintf (print.outf, "#%s <%s>", dir, header);
 373   else
 374     fprintf (print.outf, "#%s \"%s\"", dir, header);
 375
 376   if (comments != NULL)
 377     {
 378       while (*comments != NULL)
 379         {
 380           if ((*comments)->flags & PREV_WHITE)
 381             putc (' ', print.outf);
 382           cpp_output_token (*comments, print.outf);
 383           ++comments;
 384         }
 385     }
 386
 387   putc ('\n', print.outf);
 388   print.src_line++;
 389 }
 390
 391 /* Callback called when -fworking-director and -E to emit working
 392    directory in cpp output file.  */
 393
 394 void
 395 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 396 {
 397   size_t to_file_len = strlen (dir);
 398   unsigned char *to_file_quoted =
 399      (unsigned char *) alloca (to_file_len * 4 + 1);
 400   unsigned char *p;
 401
 402   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 403   p = cpp_quote_string (to_file_quoted, (const unsigned char *) dir, to_file_len);
 404   *p = '\0';
 405   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 406 }
 407
 408 /* The file name, line number or system header flags have changed, as
 409    described in MAP.  */
 410
 411 void
 412 pp_file_change (const struct line_map *map)
 413 {
 414   const char *flags = "";
 415
 416   if (flag_no_line_commands)
 417     return;
 418
 419   if (map != NULL)
 420     {
 421       if (print.first_time)
 422         {
 423           /* Avoid printing foo.i when the main file is foo.c.  */
 424           if (!cpp_get_options (parse_in)->preprocessed)
 425             print_line (map->start_location, flags);
 426           print.first_time = 0;
 427         }
 428       else
 429         {
 430           /* Bring current file to correct line when entering a new file.  */
 431           if (map->reason == LC_ENTER)
 432             {
 433               const struct line_map *from = INCLUDED_FROM (line_table, map);
 434               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 435             }
 436           if (map->reason == LC_ENTER)
 437             flags = " 1";
 438           else if (map->reason == LC_LEAVE)
 439             flags = " 2";
 440           print_line (map->start_location, flags);
 441         }
 442     }
 443 }
 444
 445 /* Copy a #pragma directive to the preprocessed output.  */
 446 static void
 447 cb_def_pragma (cpp_reader *pfile, source_location line)
 448 {
 449   maybe_print_line (line);
 450   fputs ("#pragma ", print.outf);
 451   cpp_output_line (pfile, print.outf);
 452   print.src_line++;
 453 }
 454
 455 /* Dump out the hash table.  */
 456 static int
 457 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 458 {
 459   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 460     {
 461       fputs ("#define ", print.outf);
 462       fputs ((const char *) cpp_macro_definition (pfile, node),
 463              print.outf);
 464       putc ('\n', print.outf);
 465       print.src_line++;
 466     }
 467
 468   return 1;
 469 }
 470
 471 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 472    by ORIG_NAME.  Also, print out a #include command so that the PCH
 473    file can be loaded when the preprocessed output is compiled.  */
 474
 475 static void
 476 cb_read_pch (cpp_reader *pfile, const char *name,
 477              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 478 {
 479   c_common_read_pch (pfile, name, fd, orig_name);
 480
 481   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 482   print.src_line++;
 483 }