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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "tm.h"
  24 #include "cpplib.h"
  25 #include "cpphash.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 *, fileline, cpp_hashnode *);
  55 static void cb_undef (cpp_reader *, fileline, cpp_hashnode *);
  56 static void cb_include (cpp_reader *, fileline, const unsigned char *,
  57                         const char *, int);
  58 static void cb_ident (cpp_reader *, fileline, const cpp_string *);
  59 static void cb_def_pragma (cpp_reader *, fileline);
  60
  61 /* Preprocess and output.  */
  62 void
  63 preprocess_file (cpp_reader *pfile)
  64 {
  65   /* A successful cpp_read_main_file guarantees that we can call
  66      cpp_scan_nooutput or cpp_get_token next.  */
  67   if (flag_no_output)
  68     {
  69       /* Scan -included buffers, then the main file.  */
  70       while (pfile->buffer->prev)
  71         cpp_scan_nooutput (pfile);
  72       cpp_scan_nooutput (pfile);
  73     }
  74   else if (cpp_get_options (pfile)->traditional)
  75     scan_translation_unit_trad (pfile);
  76   else
  77     scan_translation_unit (pfile);
  78
  79   /* -dM command line option.  Should this be elsewhere?  */
  80   if (flag_dump_macros == 'M')
  81     cpp_forall_identifiers (pfile, dump_macro, NULL);
  82
  83   /* Flush any pending output.  */
  84   if (print.printed)
  85     putc ('\n', print.outf);
  86 }
  87
  88 /* Set up the callbacks as appropriate.  */
  89 void
  90 init_pp_output (FILE *out_stream)
  91 {
  92   cpp_callbacks *cb = cpp_get_callbacks (parse_in);
  93
  94   if (!flag_no_output)
  95     {
  96       cb->line_change = cb_line_change;
  97       /* Don't emit #pragma or #ident directives if we are processing
  98          assembly language; the assembler may choke on them.  */
  99       if (cpp_get_options (parse_in)->lang != CLK_ASM)
 100         {
 101           cb->ident      = cb_ident;
 102           cb->def_pragma = cb_def_pragma;
 103         }
 104     }
 105
 106   if (flag_dump_includes)
 107     cb->include  = cb_include;
 108
 109   if (flag_dump_macros == 'N' || flag_dump_macros == 'D')
 110     {
 111       cb->define = cb_define;
 112       cb->undef  = cb_undef;
 113     }
 114
 115   /* Initialize the print structure.  Setting print.src_line to -1 here is
 116      a trick to guarantee that the first token of the file will cause
 117      a linemarker to be output by maybe_print_line.  */
 118   print.src_line = -1;
 119   print.printed = 0;
 120   print.prev = 0;
 121   print.outf = out_stream;
 122   print.first_time = 1;
 123 }
 124
 125 /* Writes out the preprocessed file, handling spacing and paste
 126    avoidance issues.  */
 127 static void
 128 scan_translation_unit (cpp_reader *pfile)
 129 {
 130   bool avoid_paste = false;
 131
 132   print.source = NULL;
 133   for (;;)
 134     {
 135       const cpp_token *token = cpp_get_token (pfile);
 136
 137       if (token->type == CPP_PADDING)
 138         {
 139           avoid_paste = true;
 140           if (print.source == NULL
 141               || (!(print.source->flags & PREV_WHITE)
 142                   && token->val.source == NULL))
 143             print.source = token->val.source;
 144           continue;
 145         }
 146
 147       if (token->type == CPP_EOF)
 148         break;
 149
 150       /* Subtle logic to output a space if and only if necessary.  */
 151       if (avoid_paste)
 152         {
 153           if (print.source == NULL)
 154             print.source = token;
 155           if (print.source->flags & PREV_WHITE
 156               || (print.prev
 157                   && cpp_avoid_paste (pfile, print.prev, token))
 158               || (print.prev == NULL && token->type == CPP_HASH))
 159             putc (' ', print.outf);
 160         }
 161       else if (token->flags & PREV_WHITE)
 162         putc (' ', print.outf);
 163
 164       avoid_paste = false;
 165       print.source = NULL;
 166       print.prev = token;
 167       cpp_output_token (token, print.outf);
 168
 169       if (token->type == CPP_COMMENT)
 170         account_for_newlines (token->val.str.text, token->val.str.len);
 171     }
 172 }
 173
 174 /* Adjust print.src_line for newlines embedded in output.  */
 175 static void
 176 account_for_newlines (const unsigned char *str, size_t len)
 177 {
 178   while (len--)
 179     if (*str++ == '\n')
 180       print.src_line++;
 181 }
 182
 183 /* Writes out a traditionally preprocessed file.  */
 184 static void
 185 scan_translation_unit_trad (cpp_reader *pfile)
 186 {
 187   while (_cpp_read_logical_line_trad (pfile))
 188     {
 189       size_t len = pfile->out.cur - pfile->out.base;
 190       maybe_print_line (pfile->out.first_line);
 191       fwrite (pfile->out.base, 1, len, print.outf);
 192       print.printed = 1;
 193       if (!CPP_OPTION (pfile, discard_comments))
 194         account_for_newlines (pfile->out.base, len);
 195     }
 196 }
 197
 198 /* If the token read on logical line LINE needs to be output on a
 199    different line to the current one, output the required newlines or
 200    a line marker, and return 1.  Otherwise return 0.  */
 201 static void
 202 maybe_print_line (source_location src_loc)
 203 {
 204   const struct line_map *map = linemap_lookup (&line_table, src_loc);
 205   int src_line = SOURCE_LINE (map, src_loc);
 206   /* End the previous line of text.  */
 207   if (print.printed)
 208     {
 209       putc ('\n', print.outf);
 210       print.src_line++;
 211       print.printed = 0;
 212     }
 213
 214   if (src_line >= print.src_line && src_line < print.src_line + 8)
 215     {
 216       while (src_line > print.src_line)
 217         {
 218           putc ('\n', print.outf);
 219           print.src_line++;
 220         }
 221     }
 222   else
 223     print_line (src_loc, "");
 224 }
 225
 226 /* Output a line marker for logical line LINE.  Special flags are "1"
 227    or "2" indicating entering or leaving a file.  */
 228 static void
 229 print_line (source_location src_loc, const char *special_flags)
 230 {
 231   /* End any previous line of text.  */
 232   if (print.printed)
 233     putc ('\n', print.outf);
 234   print.printed = 0;
 235
 236   if (!flag_no_line_commands)
 237     {
 238       const struct line_map *map = linemap_lookup (&line_table, src_loc);
 239
 240       size_t to_file_len = strlen (map->to_file);
 241       unsigned char *to_file_quoted = alloca (to_file_len * 4 + 1);
 242       unsigned char *p;
 243
 244       print.src_line = SOURCE_LINE (map, src_loc);
 245
 246       /* cpp_quote_string does not nul-terminate, so we have to do it
 247          ourselves.  */
 248       p = cpp_quote_string (to_file_quoted,
 249                             (unsigned char *)map->to_file, to_file_len);
 250       *p = '\0';
 251       fprintf (print.outf, "# %u \"%s\"%s", print.src_line,
 252                to_file_quoted, special_flags);
 253
 254       if (map->sysp == 2)
 255         fputs (" 3 4", print.outf);
 256       else if (map->sysp == 1)
 257         fputs (" 3", print.outf);
 258
 259       putc ('\n', print.outf);
 260     }
 261 }
 262
 263 /* Called when a line of output is started.  TOKEN is the first token
 264    of the line, and at end of file will be CPP_EOF.  */
 265 static void
 266 cb_line_change (cpp_reader *pfile, const cpp_token *token,
 267                 int parsing_args)
 268 {
 269   source_location src_loc = token->src_loc;
 270
 271   if (token->type == CPP_EOF || parsing_args)
 272     return;
 273
 274   maybe_print_line (src_loc);
 275   print.prev = 0;
 276   print.source = 0;
 277
 278   /* Supply enough spaces to put this token in its original column,
 279      one space per column greater than 2, since scan_translation_unit
 280      will provide a space if PREV_WHITE.  Don't bother trying to
 281      reconstruct tabs; we can't get it right in general, and nothing
 282      ought to care.  Some things do care; the fault lies with them.  */
 283   if (!CPP_OPTION (pfile, traditional))
 284     {
 285       const struct line_map *map = linemap_lookup (&line_table, src_loc);
 286       int spaces = SOURCE_COLUMN (map, src_loc) - 2;
 287       print.printed = 1;
 288
 289       while (-- spaces >= 0)
 290         putc (' ', print.outf);
 291     }
 292 }
 293
 294 static void
 295 cb_ident (cpp_reader *pfile ATTRIBUTE_UNUSED, fileline line,
 296           const cpp_string *str)
 297 {
 298   maybe_print_line (line);
 299   fprintf (print.outf, "#ident \"%s\"\n", str->text);
 300   print.src_line++;
 301 }
 302
 303 static void
 304 cb_define (cpp_reader *pfile, fileline line, cpp_hashnode *node)
 305 {
 306   maybe_print_line (line);
 307   fputs ("#define ", print.outf);
 308
 309   /* 'D' is whole definition; 'N' is name only.  */
 310   if (flag_dump_macros == 'D')
 311     fputs ((const char *) cpp_macro_definition (pfile, node),
 312            print.outf);
 313   else
 314     fputs ((const char *) NODE_NAME (node), print.outf);
 315
 316   putc ('\n', print.outf);
 317   print.src_line++;
 318 }
 319
 320 static void
 321 cb_undef (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 322           cpp_hashnode *node)
 323 {
 324   maybe_print_line (line);
 325   fprintf (print.outf, "#undef %s\n", NODE_NAME (node));
 326   print.src_line++;
 327 }
 328
 329 static void
 330 cb_include (cpp_reader *pfile ATTRIBUTE_UNUSED, source_location line,
 331             const unsigned char *dir, const char *header, int angle_brackets)
 332 {
 333   maybe_print_line (line);
 334   if (angle_brackets)
 335     fprintf (print.outf, "#%s <%s>\n", dir, header);
 336   else
 337     fprintf (print.outf, "#%s \"%s\"\n", dir, header);
 338   print.src_line++;
 339 }
 340
 341 /* Callback called when -fworking-director and -E to emit working
 342    directory in cpp output file.  */
 343
 344 void
 345 pp_dir_change (cpp_reader *pfile ATTRIBUTE_UNUSED, const char *dir)
 346 {
 347   size_t to_file_len = strlen (dir);
 348   unsigned char *to_file_quoted = alloca (to_file_len * 4 + 1);
 349   unsigned char *p;
 350
 351   /* cpp_quote_string does not nul-terminate, so we have to do it ourselves.  */
 352   p = cpp_quote_string (to_file_quoted, (unsigned char *) dir, to_file_len);
 353   *p = '\0';
 354   fprintf (print.outf, "# 1 \"%s//\"\n", to_file_quoted);
 355 }
 356
 357 /* The file name, line number or system header flags have changed, as
 358    described in MAP.  */
 359
 360 void
 361 pp_file_change (const struct line_map *map)
 362 {
 363   const char *flags = "";
 364
 365   if (flag_no_line_commands || flag_no_output)
 366     return;
 367
 368   if (map != NULL)
 369     {
 370       if (print.first_time)
 371         {
 372           /* Avoid printing foo.i when the main file is foo.c.  */
 373           if (!cpp_get_options (parse_in)->preprocessed)
 374             print_line (map->start_location, flags);
 375           print.first_time = 0;
 376         }
 377       else
 378         {
 379           /* Bring current file to correct line when entering a new file.  */
 380           if (map->reason == LC_ENTER)
 381             {
 382               const struct line_map *from = INCLUDED_FROM (&line_table, map);
 383               maybe_print_line (LAST_SOURCE_LINE_LOCATION (from));
 384             }
 385           if (map->reason == LC_ENTER)
 386             flags = " 1";
 387           else if (map->reason == LC_LEAVE)
 388             flags = " 2";
 389           print_line (map->start_location, flags);
 390         }
 391     }
 392 }
 393
 394 /* Copy a #pragma directive to the preprocessed output.  */
 395 static void
 396 cb_def_pragma (cpp_reader *pfile, fileline line)
 397 {
 398   maybe_print_line (line);
 399   fputs ("#pragma ", print.outf);
 400   cpp_output_line (pfile, print.outf);
 401   print.src_line++;
 402 }
 403
 404 /* Dump out the hash table.  */
 405 static int
 406 dump_macro (cpp_reader *pfile, cpp_hashnode *node, void *v ATTRIBUTE_UNUSED)
 407 {
 408   if (node->type == NT_MACRO && !(node->flags & NODE_BUILTIN))
 409     {
 410       fputs ("#define ", print.outf);
 411       fputs ((const char *) cpp_macro_definition (pfile, node),
 412              print.outf);
 413       putc ('\n', print.outf);
 414       print.src_line++;
 415     }
 416
 417   return 1;
 418 }