gcc/cppmain.c

   1 /* CPP main program, using CPP Library.
   2    Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001
   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 2, 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; if not, write to the Free Software
  18 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19
  20  In other words, you are welcome to use, share and improve this program.
  21  You are forbidden to forbid anyone else to use, share and improve
  22  what you give them.   Help stamp out software-hoarding!  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "cpplib.h"
  27 #include "intl.h"
  28
  29 /* Encapsulates state used to convert the stream of tokens coming from
  30    cpp_get_token back into a text file.  */
  31 struct printer
  32 {
  33   FILE *outf;                   /* Stream to write to.  */
  34   const struct line_map *map;   /* Logical to physical line mappings.  */
  35   const cpp_token *prev;        /* Previous token.  */
  36   unsigned int line;            /* Line currently being written.  */
  37   unsigned char printed;        /* Nonzero if something output at line.  */
  38 };
  39
  40 int main                PARAMS ((int, char **));
  41 static void general_init PARAMS ((const char *));
  42 static void do_preprocessing PARAMS ((int, char **));
  43 static void setup_callbacks PARAMS ((void));
  44
  45 /* General output routines.  */
  46 static void scan_translation_unit PARAMS ((cpp_reader *));
  47 static void check_multiline_token PARAMS ((const cpp_string *));
  48 static int dump_macro PARAMS ((cpp_reader *, cpp_hashnode *, void *));
  49
  50 static void print_line PARAMS ((const struct line_map *, unsigned int,
  51                                 const char *));
  52 static void maybe_print_line PARAMS ((const struct line_map *, unsigned int));
  53
  54 /* Callback routines for the parser.   Most of these are active only
  55    in specific modes.  */
  56 static void cb_line_change PARAMS ((cpp_reader *, const cpp_token *, int));
  57 static void cb_define   PARAMS ((cpp_reader *, unsigned int, cpp_hashnode *));
  58 static void cb_undef    PARAMS ((cpp_reader *, unsigned int, cpp_hashnode *));
  59 static void cb_include  PARAMS ((cpp_reader *, unsigned int,
  60                                  const unsigned char *, const cpp_token *));
  61 static void cb_ident      PARAMS ((cpp_reader *, unsigned int,
  62                                    const cpp_string *));
  63 static void cb_file_change PARAMS ((cpp_reader *, const struct line_map *));
  64 static void cb_def_pragma PARAMS ((cpp_reader *, unsigned int));
  65
  66 const char *progname;           /* Needs to be global.  */
  67 static cpp_reader *pfile;       /* An opaque handle.  */
  68 static cpp_options *options;    /* Options of pfile.  */
  69 static struct printer print;
  70
  71 int
  72 main (argc, argv)
  73      int argc;
  74      char **argv;
  75 {
  76   general_init (argv[0]);
  77
  78   /* Contruct a reader with default language GNU C89.  */
  79   pfile = cpp_create_reader (NULL, CLK_GNUC89);
  80   options = cpp_get_options (pfile);
  81
  82   do_preprocessing (argc, argv);
  83
  84   if (cpp_destroy (pfile))
  85     return FATAL_EXIT_CODE;
  86
  87   return SUCCESS_EXIT_CODE;
  88 }
  89
  90 /* Store the program name, and set the locale.  */
  91 static void
  92 general_init (argv0)
  93      const char *argv0;
  94 {
  95   progname = argv0 + strlen (argv0);
  96
  97   while (progname != argv0 && ! IS_DIR_SEPARATOR (progname[-1]))
  98     --progname;
  99
 100   xmalloc_set_program_name (progname);
 101
 102 /* LC_CTYPE determines the character set used by the terminal so it
 103    has to be set to output messages correctly.  */
 104
 105 #ifdef HAVE_LC_MESSAGES
 106   setlocale (LC_CTYPE, "");
 107   setlocale (LC_MESSAGES, "");
 108 #else
 109   setlocale (LC_ALL, "");
 110 #endif
 111
 112   (void) bindtextdomain (PACKAGE, localedir);
 113   (void) textdomain (PACKAGE);
 114 }
 115
 116 /* Handle switches, preprocess and output.  */
 117 static void
 118 do_preprocessing (argc, argv)
 119      int argc;
 120      char **argv;
 121 {
 122   int argi = 1;  /* Next argument to handle.  */
 123
 124   argi += cpp_handle_options (pfile, argc - argi , argv + argi);
 125   if (CPP_FATAL_ERRORS (pfile))
 126     return;
 127
 128   if (argi < argc)
 129     cpp_fatal (pfile, "Invalid option %s", argv[argi]);
 130   else
 131     cpp_post_options (pfile);
 132
 133   if (CPP_FATAL_ERRORS (pfile))
 134     return;
 135
 136   /* If cpp_handle_options saw --help or --version on the command
 137      line, it will have set pfile->help_only to indicate this.  Exit
 138      successfully.  [The library does not exit itself, because
 139      e.g. cc1 needs to print its own --help message at this point.]  */
 140   if (options->help_only)
 141     return;
 142
 143   /* Initialize the printer structure.  Setting print.line to -1 here
 144      is a trick to guarantee that the first token of the file will
 145      cause a linemarker to be output by maybe_print_line.  */
 146   print.line = (unsigned int) -1;
 147   print.printed = 0;
 148   print.prev = 0;
 149   print.map = 0;
 150
 151   /* Open the output now.  We must do so even if no_output is on,
 152      because there may be other output than from the actual
 153      preprocessing (e.g. from -dM).  */
 154   if (options->out_fname[0] == '\0')
 155     print.outf = stdout;
 156   else
 157     {
 158       print.outf = fopen (options->out_fname, "w");
 159       if (print.outf == NULL)
 160         {
 161           cpp_notice_from_errno (pfile, options->out_fname);
 162           return;
 163         }
 164     }
 165
 166   setup_callbacks ();
 167
 168   if (cpp_start_read (pfile, options->in_fname))
 169     {
 170       /* A successful cpp_start_read guarantees that we can call
 171          cpp_scan_nooutput or cpp_get_token next.  */
 172       if (options->no_output)
 173         cpp_scan_nooutput (pfile);
 174       else
 175         scan_translation_unit (pfile);
 176
 177       /* -dM command line option.  Should this be in cpp_finish?  */
 178       if (options->dump_macros == dump_only)
 179         cpp_forall_identifiers (pfile, dump_macro, NULL);
 180
 181       cpp_finish (pfile);
 182     }
 183
 184   /* Flush any pending output.  */
 185   if (print.printed)
 186     putc ('\n', print.outf);
 187
 188   if (ferror (print.outf) || fclose (print.outf))
 189     cpp_notice_from_errno (pfile, options->out_fname);
 190 }
 191
 192 /* Set up the callbacks as appropriate.  */
 193 static void
 194 setup_callbacks ()
 195 {
 196   cpp_callbacks *cb = cpp_get_callbacks (pfile);
 197
 198   if (! options->no_output)
 199     {
 200       cb->line_change = cb_line_change;
 201       cb->ident      = cb_ident;
 202       cb->def_pragma = cb_def_pragma;
 203       if (! options->no_line_commands)
 204         cb->file_change = cb_file_change;
 205     }
 206
 207   if (options->dump_includes)
 208     cb->include  = cb_include;
 209
 210   if (options->dump_macros == dump_names
 211       || options->dump_macros == dump_definitions)
 212     {
 213       cb->define = cb_define;
 214       cb->undef  = cb_undef;
 215     }
 216 }
 217
 218 /* Writes out the preprocessed file, handling spacing and paste
 219    avoidance issues.  */
 220 static void
 221 scan_translation_unit (pfile)
 222      cpp_reader *pfile;
 223 {
 224   bool avoid_paste = false;
 225   const cpp_token *source = NULL;
 226
 227   for (;;)
 228     {
 229       const cpp_token *token = cpp_get_token (pfile);
 230
 231       if (token->type == CPP_PADDING)
 232         {
 233           avoid_paste = true;
 234           if (source == NULL
 235               || (!(source->flags & PREV_WHITE) && token->val.source == NULL))
 236             source = token->val.source;
 237           continue;
 238         }
 239
 240       if (token->type == CPP_EOF)
 241         break;
 242
 243       /* Subtle logic to output a space if and only if necessary.  */
 244       if (avoid_paste)
 245         {
 246           if (source == NULL)
 247             source = token;
 248           if (source->flags & PREV_WHITE
 249               || (print.prev && cpp_avoid_paste (pfile, print.prev, token))
 250               || (print.prev == NULL && token->type == CPP_HASH))
 251             putc (' ', print.outf);
 252         }
 253       else if (token->flags & PREV_WHITE)
 254         putc (' ', print.outf);
 255
 256       avoid_paste = false;
 257       source = NULL;
 258       print.prev = token;
 259       cpp_output_token (token, print.outf);
 260
 261       if (token->type == CPP_STRING || token->type == CPP_WSTRING
 262           || token->type == CPP_COMMENT)
 263         check_multiline_token (&token->val.str);
 264     }
 265 }
 266
 267 /* Adjust print.line for newlines embedded in tokens.  */
 268 static void
 269 check_multiline_token (str)
 270      const cpp_string *str;
 271 {
 272   unsigned int i;
 273
 274   for (i = 0; i < str->len; i++)
 275     if (str->text[i] == '\n')
 276       print.line++;
 277 }
 278
 279 /* If the token read on logical line LINE needs to be output on a
 280    different line to the current one, output the required newlines or
 281    a line marker, and return 1.  Otherwise return 0.  */
 282
 283 static void
 284 maybe_print_line (map, line)
 285      const struct line_map *map;
 286      unsigned int line;
 287 {
 288   /* End the previous line of text.  */
 289   if (print.printed)
 290     {
 291       putc ('\n', print.outf);
 292       print.line++;
 293       print.printed = 0;
 294     }
 295
 296   if (line >= print.line && line < print.line + 8)
 297     {
 298       while (line > print.line)
 299         {
 300           putc ('\n', print.outf);
 301           print.line++;
 302         }
 303     }
 304   else
 305     print_line (map, line, "");
 306 }
 307
 308 /* Output a line marker for logical line LINE.  Special flags are "1"
 309    or "2" indicating entering or leaving a file.  */
 310 static void
 311 print_line (map, line, special_flags)
 312      const struct line_map *map;
 313      unsigned int line;
 314      const char *special_flags;
 315 {
 316   /* End any previous line of text.  */
 317   if (print.printed)
 318     putc ('\n', print.outf);
 319   print.printed = 0;
 320
 321   print.line = line;
 322   if (! options->no_line_commands)
 323     {
 324       fprintf (print.outf, "# %u \"%s\"%s",
 325                SOURCE_LINE (map, print.line), map->to_file, special_flags);
 326
 327       if (map->sysp == 2)
 328         fputs (" 3 4", print.outf);
 329       else if (map->sysp == 1)
 330         fputs (" 3", print.outf);
 331
 332       putc ('\n', print.outf);
 333     }
 334 }
 335
 336 /* Called when a line of output is started.  TOKEN is the first token
 337    of the line, and may be CPP_EOF.  */
 338
 339 static void
 340 cb_line_change (pfile, token, parsing_args)
 341      cpp_reader *pfile ATTRIBUTE_UNUSED;
 342      const cpp_token *token;
 343      int parsing_args;
 344 {
 345   if (token->type == CPP_EOF || parsing_args)
 346     return;
 347
 348   maybe_print_line (print.map, token->line);
 349   print.printed = 1;
 350   print.prev = 0;
 351
 352   /* Supply enough spaces to put this token in its original column,
 353      one space per column greater than 2, since scan_translation_unit
 354      will provide a space if PREV_WHITE.  Don't bother trying to
 355      reconstruct tabs; we can't get it right in general, and nothing
 356      ought to care.  Some things do care; the fault lies with them.  */
 357   if (token->col > 2)
 358     {
 359       unsigned int spaces = token->col - 2;
 360
 361       while (spaces--)
 362         putc (' ', print.outf);
 363     }
 364 }
 365
 366 static void
 367 cb_ident (pfile, line, str)
 368      cpp_reader *pfile ATTRIBUTE_UNUSED;
 369      unsigned int line;
 370      const cpp_string * str;
 371 {
 372   maybe_print_line (print.map, line);
 373   fprintf (print.outf, "#ident \"%s\"\n", str->text);
 374   print.line++;
 375 }
 376
 377 static void
 378 cb_define (pfile, line, node)
 379      cpp_reader *pfile;
 380      unsigned int line;
 381      cpp_hashnode *node;
 382 {
 383   maybe_print_line (print.map, line);
 384   fputs ("#define ", print.outf);
 385
 386   /* -dD command line option.  */
 387   if (options->dump_macros == dump_definitions)
 388     fputs ((const char *) cpp_macro_definition (pfile, node), print.outf);
 389   else
 390     fputs ((const char *) NODE_NAME (node), print.outf);
 391
 392   putc ('\n', print.outf);
 393   print.line++;
 394 }
 395
 396 static void
 397 cb_undef (pfile, line, node)
 398      cpp_reader *pfile ATTRIBUTE_UNUSED;
 399      unsigned int line;
 400      cpp_hashnode *node;
 401 {
 402   maybe_print_line (print.map, line);
 403   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 404   print.line++;
 405 }
 406
 407 static void
 408 cb_include (pfile, line, dir, header)
 409      cpp_reader *pfile;
 410      unsigned int line;
 411      const unsigned char *dir;
 412      const cpp_token *header;
 413 {
 414   maybe_print_line (print.map, line);
 415   fprintf (print.outf, "#%s %s\n", dir, cpp_token_as_text (pfile, header));
 416   print.line++;
 417 }
 418
 419 /* The file name, line number or system header flags have changed, as
 420    described in MAP.  From this point on, the old print.map might be
 421    pointing to freed memory, and so must not be dereferenced.  */
 422
 423 static void
 424 cb_file_change (pfile, map)
 425      cpp_reader *pfile ATTRIBUTE_UNUSED;
 426      const struct line_map *map;
 427 {
 428   const char *flags = "";
 429
 430   /* First time?  */
 431   if (print.map == NULL)
 432     {
 433       /* Avoid printing foo.i when the main file is foo.c.  */
 434       if (!options->preprocessed)
 435         print_line (map, map->from_line, flags);
 436     }
 437   else
 438     {
 439       /* Bring current file to correct line when entering a new file.  */
 440       if (map->reason == LC_ENTER)
 441         maybe_print_line (map - 1, map->from_line - 1);
 442
 443       if (map->reason == LC_ENTER)
 444         flags = " 1";
 445       else if (map->reason == LC_LEAVE)
 446         flags = " 2";
 447       print_line (map, map->from_line, flags);
 448     }
 449
 450   print.map = map;
 451 }
 452
 453 /* Copy a #pragma directive to the preprocessed output.  */
 454 static void
 455 cb_def_pragma (pfile, line)
 456      cpp_reader *pfile;
 457      unsigned int line;
 458 {
 459   maybe_print_line (print.map, line);
 460   fputs ("#pragma ", print.outf);
 461   cpp_output_line (pfile, print.outf);
 462   print.line++;
 463 }
 464
 465 /* Dump out the hash table.  */
 466 static int
 467 dump_macro (pfile, node, v)
 468      cpp_reader *pfile;
 469      cpp_hashnode *node;
 470      void *v ATTRIBUTE_UNUSED;
 471 {
 472   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 473     {
 474       fputs ("#define ", print.outf);
 475       fputs ((const char *) cpp_macro_definition (pfile, node), print.outf);
 476       putc ('\n', print.outf);
 477       print.line++;
 478     }
 479
 480   return 1;
 481 }