gcc/c-ppoutput.c

   1 /* Preprocess only, using cpplib.
   2    Copyright (C) 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
   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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  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 scan_translation_unit_trad (cpp_reader *);
  45 static void account_for_newlines (const unsigned char *, size_t);
  46 static int dump_macro (cpp_reader *, cpp_hashnode *, void *);
  47
  48 static void print_line (source_location, const char *);
  49 static void maybe_print_line (source_location);
  50
  51 /* Callback routines for the parser.   Most of these are active only
  52    in specific modes.  */
  53 static void cb_line_change (cpp_reader *, const cpp_token *, int);
  54 static void cb_define (cpp_reader *, source_location, cpp_hashnode *);
  55 static void cb_undef (cpp_reader *, source_location, cpp_hashnode *);
  56 static void cb_include (cpp_reader *, source_location, const unsigned char *,
  57                         const char *, int, const cpp_token **);
  58 static void cb_ident (cpp_reader *, source_location, const cpp_string *);
  59 static void cb_def_pragma (cpp_reader *, source_location);
  60 static void cb_read_pch (cpp_reader *pfile, const char *name,
  61                          int fd, const char *orig_name);
  62
  63 /* Preprocess and output.  */
  64 void
  65 preprocess_file (cpp_reader *pfile)
  66 {
  67   /* A successful cpp_read_main_file guarantees that we can call
  68      cpp_scan_nooutput or cpp_get_token next.  */
  69   if (flag_no_output)
  70     {
  71       /* Scan -included buffers, then the main file.  */
  72       while (pfile->buffer->prev)
  73         cpp_scan_nooutput (pfile);
  74       cpp_scan_nooutput (pfile);
  75     }
  76   else if (cpp_get_options (pfile)->traditional)
  77     scan_translation_unit_trad (pfile);
  78   else
  79     scan_translation_unit (pfile);
  80
  81   /* -dM command line option.  Should this be elsewhere?  */
  82   if (flag_dump_macros == 'M')
  83     cpp_forall_identifiers (pfile, dump_macro, NULL);
  84
  85   /* Flush any pending output.  */
  86   if (print.printed)
  87     putc ('\n', print.outf);
  88 }
  89
  90 /* Set up the callbacks as appropriate.  */
  91 void
  92 init_pp_output (FILE *out_stream)
  93 {
  94   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
  95
  96   if (!flag_no_output)
  97     {
  98       cb->line_change = cb_line_change;
  99       /* Don't emit #pragma or #ident directives if we are processing
 100          assembly language; the assembler may choke on them.  */
 101       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 102         {
 103           cb->ident      = cb_ident;
 104           cb->def_pragma = cb_def_pragma;
 105         }
 106     }
 107
 108   if (flag_dump_includes)
 109     cb->include  = cb_include;
 110
 111   if (flag_pch_preprocess)
 112     {
 113       cb->valid_pch = c_common_valid_pch;
 114       cb->read_pch = cb_read_pch;
 115     }
 116
 117   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 118     {
 119       cb->define = cb_define;
 120       cb->undef  = cb_undef;
 121     }
 122
 123   /* Initialize the print structure.  Setting print.src_line to -1 here is
 124      a trick to guarantee that the first token of the file will cause
 125      a linemarker to be output by maybe_print_line.  */
 126   print.src_line = -1;
 127   print.printed = 0;
 128   print.prev = 0;
 129   print.outf = out_stream;
 130   print.first_time = 1;
 131 }
 132
 133 /* Writes out the preprocessed file, handling spacing and paste
 134    avoidance issues.  */
 135 static void
 136 scan_translation_unit (cpp_reader *pfile)
 137 {
 138   bool avoid_paste = false;
 139
 140   print.source = NULL;
 141   for (;;)
 142     {
 143       const cpp_token *token = cpp_get_token (pfile);
 144
 145       if (token->type == CPP_PADDING)
 146         {
 147           avoid_paste = true;
 148           if (print.source == NULL
 149               || (!(print.source->flags & PREV_WHITE)
 150                   && token->val.source == NULL))
 151             print.source = token->val.source;
 152           continue;
 153         }
 154
 155       if (token->type == CPP_EOF)
 156         break;
 157
 158       /* Subtle logic to output a space if and only if necessary.  */
 159       if (avoid_paste)
 160         {
 161           if (print.source == NULL)
 162             print.source = token;
 163           if (print.source->flags & PREV_WHITE
 164               || (print.prev
 165                   && cpp_avoid_paste (pfile, print.prev, token))
 166               || (print.prev == NULL && token->type == CPP_HASH))
 167             putc (' ', print.outf);
 168         }
 169       else if (token->flags & PREV_WHITE)
 170         putc (' ', print.outf);
 171
 172       avoid_paste = false;
 173       print.source = NULL;
 174       print.prev = token;
 175       cpp_output_token (token, print.outf);
 176
 177       if (token->type == CPP_COMMENT)
 178         account_for_newlines (token->val.str.text, token->val.str.len);
 179     }
 180 }
 181
 182 /* Adjust print.src_line for newlines embedded in output.  */
 183 static void
 184 account_for_newlines (const unsigned char *str, size_t len)
 185 {
 186   while (len--)
 187     if (*str++ == '\n')
 188       print.src_line++;
 189 }
 190
 191 /* Writes out a traditionally preprocessed file.  */
 192 static void
 193 scan_translation_unit_trad (cpp_reader *pfile)
 194 {
 195   while (_cpp_read_logical_line_trad (pfile))
 196     {
 197       size_t len = pfile->out.cur - pfile->out.base;
 198       maybe_print_line (pfile->out.first_line);
 199       fwrite (pfile->out.base, 1, len, print.outf);
 200       print.printed = 1;
 201       if (!CPP_OPTION (pfile, discard_comments))
 202         account_for_newlines (pfile->out.base, len);
 203     }
 204 }
 205
 206 /* If the token read on logical line LINE needs to be output on a
 207    different line to the current one, output the required newlines or
 208    a line marker, and return 1.  Otherwise return 0.  */
 209 static void
 210 maybe_print_line (source_location src_loc)
 211 {
 212   const struct line_map *map = linemap_lookup (&line_table, src_loc);
 213   int src_line = SOURCE_LINE (map, src_loc);
 214   /* End the previous line of text.  */
 215   if (print.printed)
 216     {
 217       putc ('\n', print.outf);
 218       print.src_line++;
 219       print.printed = 0;
 220     }
 221
 222   if (src_line >= print.src_line && src_line < print.src_line + 8)
 223     {
 224       while (src_line > print.src_line)
 225         {
 226           putc ('\n', print.outf);
 227           print.src_line++;
 228         }
 229     }
 230   else
 231     print_line (src_loc, "");
 232 }
 233
 234 /* Output a line marker for logical line LINE.  Special flags are "1"
 235    or "2" indicating entering or leaving a file.  */
 236 static void
 237 print_line (source_location src_loc, const char *special_flags)
 238 {
 239   /* End any previous line of text.  */
 240   if (print.printed)
 241     putc ('\n', print.outf);
 242   print.printed = 0;
 243
 244   if (!flag_no_line_commands)
 245     {
 246       const struct line_map *map = linemap_lookup (&line_table, src_loc);
 247
 248       size_t to_file_len = strlen (map->to_file);
 249       unsigned char *to_file_quoted =
 250          (unsigned char *) alloca (to_file_len * 4 + 1);
 251       unsigned char *p;
 252
 253       print.src_line = SOURCE_LINE (map, src_loc);
 254
 255       /* cpp_quote_string does not nul-terminate, so we have to do it
 256          ourselves.  */
 257       p = cpp_quote_string (to_file_quoted,
 258                             (unsigned char *) map->to_file, to_file_len);
 259       *p = '\0';
 260       fprintf (print.outf, "# %u \"%s\"%s",
 261                print.src_line == 0 ? 1 : print.src_line,
 262                to_file_quoted, special_flags);
 263
 264       if (map->sysp == 2)
 265         fputs (" 3 4", print.outf);
 266       else if (map->sysp == 1)
 267         fputs (" 3", print.outf);
 268
 269       putc ('\n', print.outf);
 270     }
 271 }
 272
 273 /* Called when a line of output is started.  TOKEN is the first token
 274    of the line, and at end of file will be CPP_EOF.  */
 275 static void
 276 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 277                 int parsing_args)
 278 {
 279   source_location src_loc = token->src_loc;
 280
 281   if (token->type == CPP_EOF || parsing_args)
 282     return;
 283
 284   maybe_print_line (src_loc);
 285   print.prev = 0;
 286   print.source = 0;
 287
 288   /* Supply enough spaces to put this token in its original column,
 289      one space per column greater than 2, since scan_translation_unit
 290      will provide a space if PREV_WHITE.  Don't bother trying to
 291      reconstruct tabs; we can't get it right in general, and nothing
 292      ought to care.  Some things do care; the fault lies with them.  */
 293   if (!CPP_OPTION (pfile, traditional))
 294     {
 295       const struct line_map *map = linemap_lookup (&line_table, src_loc);
 296       int spaces = SOURCE_COLUMN (map, src_loc) - 2;
 297       print.printed = 1;
 298
 299       while (-- spaces >= 0)
 300         putc (' ', print.outf);
 301     }
 302 }
 303
 304 static void
 305 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 306           const cpp_string *str)
 307 {
 308   maybe_print_line (line);
 309   fprintf (print.outf, "#ident %s\n", str->text);
 310   print.src_line++;
 311 }
 312
 313 static void
 314 cb_define (cpp_reader *pfile, source_location line, cpp_hashnode *node)
 315 {
 316   maybe_print_line (line);
 317   fputs ("#define ", print.outf);
 318
 319   /* 'D' is whole definition; 'N' is name only.  */
 320   if (flag_dump_macros == 'D')
 321     fputs ((const char *) cpp_macro_definition (pfile, node),
 322            print.outf);
 323   else
 324     fputs ((const char *) NODE_NAME (node), print.outf);
 325
 326   putc ('\n', print.outf);
 327   if (linemap_lookup (&line_table, line)->to_line != 0)
 328     print.src_line++;
 329 }
 330
 331 static void
 332 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 333           cpp_hashnode *node)
 334 {
 335   maybe_print_line (line);
 336   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 337   print.src_line++;
 338 }
 339
 340 static void
 341 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 342             const unsigned char *dir, const char *header, int angle_brackets,
 343             const cpp_token **comments)
 344 {
 345   maybe_print_line (line);
 346   if (angle_brackets)
 347     fprintf (print.outf, "#%s <%s>", dir, header);
 348   else
 349     fprintf (print.outf, "#%s \"%s\"", dir, header);
 350
 351   if (comments != NULL)
 352     {
 353       while (*comments != NULL)
 354         {
 355           if ((*comments)->flags & PREV_WHITE)
 356             putc (' ', print.outf);
 357           cpp_output_token (*comments, print.outf);
 358           ++comments;
 359         }
 360     }
 361
 362   putc ('\n', print.outf);
 363   print.src_line++;
 364 }
 365
 366 /* Callback called when -fworking-director and -E to emit working
 367    directory in cpp output file.  */
 368
 369 void
 370 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 371 {
 372   size_t to_file_len = strlen (dir);
 373   unsigned char *to_file_quoted =
 374      (unsigned char *) alloca (to_file_len * 4 + 1);
 375   unsigned char *p;
 376
 377   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 378   p = cpp_quote_string (to_file_quoted, (unsigned char *) dir, to_file_len);
 379   *p = '\0';
 380   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 381 }
 382
 383 /* The file name, line number or system header flags have changed, as
 384    described in MAP.  */
 385
 386 void
 387 pp_file_change (const struct line_map *map)
 388 {
 389   const char *flags = "";
 390
 391   if (flag_no_line_commands)
 392     return;
 393
 394   if (map != NULL)
 395     {
 396       if (print.first_time)
 397         {
 398           /* Avoid printing foo.i when the main file is foo.c.  */
 399           if (!cpp_get_options (parse_in)->preprocessed)
 400             print_line (map->start_location, flags);
 401           print.first_time = 0;
 402         }
 403       else
 404         {
 405           /* Bring current file to correct line when entering a new file.  */
 406           if (map->reason == LC_ENTER)
 407             {
 408               const struct line_map *from = INCLUDED_FROM (&line_table, map);
 409               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 410             }
 411           if (map->reason == LC_ENTER)
 412             flags = " 1";
 413           else if (map->reason == LC_LEAVE)
 414             flags = " 2";
 415           print_line (map->start_location, flags);
 416         }
 417     }
 418 }
 419
 420 /* Copy a #pragma directive to the preprocessed output.  */
 421 static void
 422 cb_def_pragma (cpp_reader *pfile, source_location line)
 423 {
 424   maybe_print_line (line);
 425   fputs ("#pragma ", print.outf);
 426   cpp_output_line (pfile, print.outf);
 427   print.src_line++;
 428 }
 429
 430 /* Dump out the hash table.  */
 431 static int
 432 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 433 {
 434   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 435     {
 436       fputs ("#define ", print.outf);
 437       fputs ((const char *) cpp_macro_definition (pfile, node),
 438              print.outf);
 439       putc ('\n', print.outf);
 440       print.src_line++;
 441     }
 442
 443   return 1;
 444 }
 445
 446 /* Load in the PCH file NAME, open on FD.  It was originally searched for
 447    by ORIG_NAME.  Also, print out a #include command so that the PCH
 448    file can be loaded when the preprocessed output is compiled.  */
 449
 450 static void
 451 cb_read_pch (cpp_reader *pfile, const char *name,
 452              int fd, const char *orig_name ATTRIBUTE_UNUSED)
 453 {
 454   c_common_read_pch (pfile, name, fd, orig_name);
 455
 456   fprintf (print.outf, "#pragma GCC pch_preprocess \"%s\"\n", name);
 457   print.src_line++;
 458 }