gcc/cpptrad.c

   1 /* CPP Library - traditional lexical analysis and macro expansion.
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3    Contributed by Neil Booth, May 2002
   4
   5 This program is free software; you can redistribute it and/or modify it
   6 under the terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option) any
   8 later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 #include "config.h"
  20 #include "system.h"
  21 #include "cpplib.h"
  22 #include "cpphash.h"
  23
  24 /* The replacement text of a function-like macro is stored as a
  25    contiguous sequence of aligned blocks, each representing the text
  26    between subsequent parameters.
  27
  28    Each block comprises the text between its surrounding parameters,
  29    the length of that text, and the one-based index of the following
  30    parameter.  The final block in the replacement text is easily
  31    recognizable as it has an argument index of zero.  */
  32
  33 struct block
  34 {
  35   unsigned int text_len;
  36   unsigned short arg_index;
  37   uchar text[1];
  38 };
  39
  40 #define BLOCK_HEADER_LEN offsetof (struct block, text)
  41 #define BLOCK_LEN(TEXT_LEN) CPP_ALIGN (BLOCK_HEADER_LEN + (TEXT_LEN))
  42
  43 /* Structure holding information about a function-like macro
  44    invocation.  */
  45 struct fun_macro
  46 {
  47   /* Memory buffer holding the trad_arg array.  */
  48   _cpp_buff *buff;
  49
  50   /* An array of size the number of macro parameters + 1, containing
  51      the offsets of the start of each macro argument in the output
  52      buffer.  The argument continues until the character before the
  53      start of the next one.  */
  54   size_t *args;
  55
  56   /* The hashnode of the macro.  */
  57   cpp_hashnode *node;
  58
  59   /* The offset of the macro name in the output buffer.  */
  60   size_t offset;
  61
  62   /* The line the macro name appeared on.  */
  63   unsigned int line;
  64
  65   /* Zero-based index of argument being currently lexed.  */
  66   unsigned int argc;
  67 };
  68
  69 /* Lexing state.  It is mostly used to prevent macro expansion.  */
  70 enum ls {ls_none = 0,           /* Normal state.  */
  71          ls_fun_open,           /* When looking for '('.  */
  72          ls_fun_close,          /* When looking for ')'.  */
  73          ls_defined,            /* After defined.  */
  74          ls_defined_close,      /* Looking for ')' of defined().  */
  75          ls_hash,               /* After # in preprocessor conditional.  */
  76          ls_predicate,          /* After the predicate, maybe paren?  */
  77          ls_answer};            /* In answer to predicate.  */
  78
  79 /* Lexing TODO: Maybe handle space in escaped newlines.  Stop cpplex.c
  80    from recognizing comments and directives during its lexing pass.  */
  81
  82 static const uchar *handle_newline PARAMS ((cpp_reader *, const uchar *));
  83 static const uchar *skip_escaped_newlines PARAMS ((cpp_reader *,
  84                                                    const uchar *));
  85 static const uchar *skip_whitespace PARAMS ((cpp_reader *, const uchar *,
  86                                              int));
  87 static cpp_hashnode *lex_identifier PARAMS ((cpp_reader *, const uchar *));
  88 static const uchar *copy_comment PARAMS ((cpp_reader *, const uchar *, int));
  89 static void scan_out_logical_line PARAMS ((cpp_reader *pfile, cpp_macro *));
  90 static void check_output_buffer PARAMS ((cpp_reader *, size_t));
  91 static void push_replacement_text PARAMS ((cpp_reader *, cpp_hashnode *));
  92 static bool scan_parameters PARAMS ((cpp_reader *, cpp_macro *));
  93 static bool recursive_macro PARAMS ((cpp_reader *, cpp_hashnode *));
  94 static void save_replacement_text PARAMS ((cpp_reader *, cpp_macro *,
  95                                            unsigned int));
  96 static void maybe_start_funlike PARAMS ((cpp_reader *, cpp_hashnode *,
  97                                          const uchar *, struct fun_macro *));
  98 static void save_argument PARAMS ((struct fun_macro *, size_t));
  99 static void replace_args_and_push PARAMS ((cpp_reader *, struct fun_macro *));
 100 static size_t canonicalize_text PARAMS ((uchar *, const uchar *, size_t,
 101                                          uchar *));
 102
 103 /* Ensures we have N bytes' space in the output buffer, and
 104    reallocates it if not.  */
 105 static void
 106 check_output_buffer (pfile, n)
 107      cpp_reader *pfile;
 108      size_t n;
 109 {
 110   /* We might need two bytes to terminate an unterminated comment, and
 111      one more to terminate the line with a NUL.  */
 112   n += 2 + 1;
 113
 114   if (n > (size_t) (pfile->out.limit - pfile->out.cur))
 115     {
 116       size_t size = pfile->out.cur - pfile->out.base;
 117       size_t new_size = (size + n) * 3 / 2;
 118
 119       pfile->out.base
 120         = (uchar *) xrealloc (pfile->out.base, new_size);
 121       pfile->out.limit = pfile->out.base + new_size;
 122       pfile->out.cur = pfile->out.base + size;
 123     }
 124 }
 125
 126 /* To be called whenever a newline character is encountered in the
 127    input file, at CUR.  Handles DOS, Mac and Unix ends of line, and
 128    increments pfile->line.
 129
 130    Returns a pointer the character after the newline sequence.  */
 131 static const uchar *
 132 handle_newline (pfile, cur)
 133      cpp_reader *pfile;
 134      const uchar *cur;
 135 {
 136   pfile->line++;
 137   if (cur[0] + cur[1] == '\r' + '\n')
 138     cur++;
 139   return cur + 1;
 140 }
 141
 142 /* CUR points to any character in the current context, not necessarily
 143    a backslash.  Advances CUR until all escaped newlines are skipped,
 144    and returns the new position without updating the context.
 145
 146    Warns if a file buffer ends in an escaped newline.  */
 147 static const uchar *
 148 skip_escaped_newlines (pfile, cur)
 149      cpp_reader *pfile;
 150      const uchar *cur;
 151 {
 152   const uchar *orig_cur = cur;
 153
 154   while (*cur == '\\' && is_vspace (cur[1]))
 155     cur = handle_newline (pfile, cur + 1);
 156
 157   if (cur != orig_cur && cur == RLIMIT (pfile->context) && pfile->buffer->inc)
 158     cpp_error (pfile, DL_PEDWARN, "backslash-newline at end of file");
 159
 160   return cur;
 161 }
 162
 163 /* CUR points to the asterisk introducing a comment in the current
 164    context.  IN_DEFINE is true if we are in the replacement text of a
 165    macro.
 166
 167    The asterisk and following comment is copied to the buffer pointed
 168    to by pfile->out.cur, which must be of sufficient size.
 169    Unterminated comments are diagnosed, and correctly terminated in
 170    the output.  pfile->out.cur is updated depending upon IN_DEFINE,
 171    -C, -CC and pfile->state.in_directive.
 172
 173    Returns a pointer to the first character after the comment in the
 174    input buffer.  */
 175 static const uchar *
 176 copy_comment (pfile, cur, in_define)
 177      cpp_reader *pfile;
 178      const uchar *cur;
 179      int in_define;
 180 {
 181   unsigned int from_line = pfile->line;
 182   const uchar *limit = RLIMIT (pfile->context);
 183   uchar *out = pfile->out.cur;
 184
 185   do
 186     {
 187       unsigned int c = *cur++;
 188       *out++ = c;
 189
 190       if (c == '/')
 191         {
 192           /* An immediate slash does not terminate the comment.  */
 193           if (out[-2] == '*' && out - 2 > pfile->out.cur)
 194             goto done;
 195
 196           if (*cur == '*' && cur[1] != '/'
 197               && CPP_OPTION (pfile, warn_comments))
 198             cpp_error_with_line (pfile, DL_WARNING, pfile->line, 0,
 199                                  "\"/*\" within comment");
 200         }
 201       else if (is_vspace (c))
 202         {
 203           cur = handle_newline (pfile, cur - 1);
 204           /* Canonicalize newline sequences and skip escaped ones.  */
 205           if (out[-2] == '\\')
 206             out -= 2;
 207           else
 208             out[-1] = '\n';
 209         }
 210     }
 211   while (cur < limit);
 212
 213   cpp_error_with_line (pfile, DL_ERROR, from_line, 0, "unterminated comment");
 214   *out++ = '*';
 215   *out++ = '/';
 216
 217  done:
 218   /* Comments in directives become spaces so that tokens are properly
 219      separated when the ISO preprocessor re-lexes the line.  The
 220      exception is #define.  */
 221   if (pfile->state.in_directive)
 222     {
 223       if (in_define)
 224         {
 225           if (CPP_OPTION (pfile, discard_comments_in_macro_exp))
 226             pfile->out.cur--;
 227           else
 228             pfile->out.cur = out;
 229         }
 230       else
 231         pfile->out.cur[-1] = ' ';
 232     }
 233   else if (CPP_OPTION (pfile, discard_comments))
 234     pfile->out.cur--;
 235   else
 236     pfile->out.cur = out;
 237
 238   return cur;
 239 }
 240
 241 /* CUR points to any character in the input buffer.  Skips over all
 242    contiguous horizontal white space and NULs, including comments if
 243    SKIP_COMMENTS, until reaching the first non-horizontal-whitespace
 244    character or the end of the current context.  Escaped newlines are
 245    removed.
 246
 247    The whitespace is copied verbatim to the output buffer, except that
 248    comments are handled as described in copy_comment().
 249    pfile->out.cur is updated.
 250
 251    Returns a pointer to the first character after the whitespace in
 252    the input buffer.  */
 253 static const uchar *
 254 skip_whitespace (pfile, cur, skip_comments)
 255      cpp_reader *pfile;
 256      const uchar *cur;
 257      int skip_comments;
 258 {
 259   uchar *out = pfile->out.cur;
 260
 261   for (;;)
 262     {
 263       unsigned int c = *cur++;
 264       *out++ = c;
 265
 266       if (is_nvspace (c) && c)
 267         continue;
 268
 269       if (!c && cur - 1 != RLIMIT (pfile->context))
 270         continue;
 271
 272       if (c == '/' && skip_comments)
 273         {
 274           const uchar *tmp = skip_escaped_newlines (pfile, cur);
 275           if (*tmp == '*')
 276             {
 277               pfile->out.cur = out;
 278               cur = copy_comment (pfile, tmp, false /* in_define */);
 279               out = pfile->out.cur;
 280               continue;
 281             }
 282         }
 283
 284       out--;
 285       if (c == '\\' && is_vspace (*cur))
 286         {
 287           cur = skip_escaped_newlines (pfile, cur - 1);
 288           continue;
 289         }
 290
 291       break;
 292     }
 293
 294   pfile->out.cur = out;
 295   return cur - 1;
 296 }
 297
 298 /* Lexes and outputs an identifier starting at CUR, which is assumed
 299    to point to a valid first character of an identifier.  Returns
 300    the hashnode, and updates out.cur.  */
 301 static cpp_hashnode *
 302 lex_identifier (pfile, cur)
 303      cpp_reader *pfile;
 304      const uchar *cur;
 305 {
 306   size_t len;
 307   uchar *out = pfile->out.cur;
 308   cpp_hashnode *result;
 309
 310   do
 311     {
 312       do
 313         *out++ = *cur++;
 314       while (is_numchar (*cur));
 315       cur = skip_escaped_newlines (pfile, cur);
 316     }
 317   while (is_numchar (*cur));
 318
 319   CUR (pfile->context) = cur;
 320   len = out - pfile->out.cur;
 321   result = (cpp_hashnode *) ht_lookup (pfile->hash_table, pfile->out.cur,
 322                                        len, HT_ALLOC);
 323   pfile->out.cur = out;
 324   return result;
 325 }
 326
 327 /* Overlays the true file buffer temporarily with text of length LEN
 328    starting at START.  The true buffer is restored upon calling
 329    restore_buff().  */
 330 void
 331 _cpp_overlay_buffer (pfile, start, len)
 332      cpp_reader *pfile;
 333      const uchar *start;
 334      size_t len;
 335 {
 336   cpp_buffer *buffer = pfile->buffer;
 337
 338   pfile->overlaid_buffer = buffer;
 339   buffer->saved_cur = buffer->cur;
 340   buffer->saved_rlimit = buffer->rlimit;
 341
 342   buffer->cur = start;
 343   buffer->rlimit = start + len;
 344
 345   pfile->saved_line = pfile->line;
 346 }
 347
 348 /* Restores a buffer overlaid by _cpp_overlay_buffer().  */
 349 void
 350 _cpp_remove_overlay (pfile)
 351      cpp_reader *pfile;
 352 {
 353   cpp_buffer *buffer = pfile->overlaid_buffer;
 354
 355   buffer->cur = buffer->saved_cur;
 356   buffer->rlimit = buffer->saved_rlimit;
 357
 358   pfile->line = pfile->saved_line;
 359 }
 360
 361 /* Reads a logical line into the output buffer.  Returns TRUE if there
 362    is more text left in the buffer.  */
 363 bool
 364 _cpp_read_logical_line_trad (pfile)
 365      cpp_reader *pfile;
 366 {
 367   do
 368     {
 369       if (pfile->buffer->cur == pfile->buffer->rlimit)
 370         {
 371           bool stop = true;
 372
 373           /* Don't pop the last buffer.  */
 374           if (pfile->buffer->prev)
 375             {
 376               stop = pfile->buffer->return_at_eof;
 377               _cpp_pop_buffer (pfile);
 378             }
 379
 380           if (stop)
 381             return false;
 382         }
 383
 384       scan_out_logical_line (pfile, NULL);
 385     }
 386   while (pfile->state.skipping);
 387
 388   return true;
 389 }
 390
 391 /* Set up state for finding the opening '(' of a function-like
 392    macro.  */
 393 static void
 394 maybe_start_funlike (pfile, node, start, macro)
 395      cpp_reader *pfile;
 396      cpp_hashnode *node;
 397      const uchar *start;
 398      struct fun_macro *macro;
 399 {
 400   unsigned int n = node->value.macro->paramc + 1;
 401
 402   if (macro->buff)
 403     _cpp_release_buff (pfile, macro->buff);
 404   macro->buff = _cpp_get_buff (pfile, n * sizeof (size_t));
 405   macro->args = (size_t *) BUFF_FRONT (macro->buff);
 406   macro->node = node;
 407   macro->offset = start - pfile->out.base;
 408   macro->argc = 0;
 409 }
 410
 411 /* Save the OFFSET of the start of the next argument to MACRO.  */
 412 static void
 413 save_argument (macro, offset)
 414      struct fun_macro *macro;
 415      size_t offset;
 416 {
 417   macro->argc++;
 418   if (macro->argc <= macro->node->value.macro->paramc)
 419     macro->args[macro->argc] = offset;
 420 }
 421
 422 /* Copies the next logical line in the current buffer (starting at
 423    buffer->cur) to the output buffer.  The output is guaranteed to
 424    terminate with a NUL character.  buffer->cur is updated.
 425
 426    If MACRO is non-NULL, then we are scanning the replacement list of
 427    MACRO, and we call save_replacement_text() every time we meet an
 428    argument.  */
 429 static void
 430 scan_out_logical_line (pfile, macro)
 431      cpp_reader *pfile;
 432      cpp_macro *macro;
 433 {
 434   cpp_context *context;
 435   const uchar *cur;
 436   uchar *out;
 437   struct fun_macro fmacro;
 438   unsigned int c, paren_depth = 0, quote;
 439   enum ls lex_state = ls_none;
 440   bool header_ok;
 441
 442   fmacro.buff = NULL;
 443
 444  start_logical_line:
 445   quote = 0;
 446   header_ok = pfile->state.angled_headers;
 447   CUR (pfile->context) = pfile->buffer->cur;
 448   RLIMIT (pfile->context) = pfile->buffer->rlimit;
 449   pfile->out.cur = pfile->out.base;
 450   pfile->out.first_line = pfile->line;
 451  new_context:
 452   context = pfile->context;
 453   cur = CUR (context);
 454   check_output_buffer (pfile, RLIMIT (context) - cur);
 455   out = pfile->out.cur;
 456
 457   for (;;)
 458     {
 459       c = *cur++;
 460       *out++ = c;
 461
 462       /* Whitespace should "continue" out of the switch,
 463          non-whitespace should "break" out of it.  */
 464       switch (c)
 465         {
 466         case ' ':
 467         case '\t':
 468         case '\f':
 469         case '\v':
 470           continue;
 471
 472         case '\0':
 473           if (cur - 1 != RLIMIT (context))
 474             continue;
 475
 476           /* If this is a macro's expansion, pop it.  */
 477           if (context->prev)
 478             {
 479               pfile->out.cur = out - 1;
 480               _cpp_pop_context (pfile);
 481               goto new_context;
 482             }
 483
 484           /* Premature end of file.  Fake a new line.  */
 485           cur--;
 486           if (!pfile->buffer->from_stage3)
 487             cpp_error (pfile, DL_PEDWARN, "no newline at end of file");
 488           pfile->line++;
 489           goto done;
 490
 491         case '\r': case '\n':
 492           cur = handle_newline (pfile, cur - 1);
 493           if ((lex_state == ls_fun_open || lex_state == ls_fun_close)
 494               && !pfile->state.in_directive)
 495             {
 496               /* Newlines in arguments become a space, but we don't
 497                  clear any in-progress quote.  */
 498               if (lex_state == ls_fun_close)
 499                 out[-1] = ' ';
 500               continue;
 501             }
 502           goto done;
 503
 504         case '<':
 505           if (header_ok)
 506             quote = '>';
 507           break;
 508         case '>':
 509           if (c == quote)
 510             quote = 0;
 511           break;
 512
 513         case '"':
 514         case '\'':
 515           if (c == quote)
 516             quote = 0;
 517           else if (!quote)
 518             quote = c;
 519           break;
 520
 521         case '\\':
 522           if (is_vspace (*cur))
 523             {
 524               out--;
 525               cur = skip_escaped_newlines (pfile, cur - 1);
 526               continue;
 527             }
 528           else
 529             {
 530               /* Skip escaped quotes here, it's easier than above, but
 531                  take care to first skip escaped newlines.  */
 532               cur = skip_escaped_newlines (pfile, cur);
 533               if (*cur == '\\' || *cur == '"' || *cur == '\'')
 534                 *out++ = *cur++;
 535             }
 536           break;
 537
 538         case '/':
 539           /* Traditional CPP does not recognize comments within
 540              literals.  */
 541           if (!quote)
 542             {
 543               cur = skip_escaped_newlines (pfile, cur);
 544               if (*cur == '*')
 545                 {
 546                   pfile->out.cur = out;
 547                   cur = copy_comment (pfile, cur, macro != 0);
 548                   out = pfile->out.cur;
 549                   continue;
 550                 }
 551             }
 552           break;
 553
 554         case '_':
 555         case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
 556         case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
 557         case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
 558         case 's': case 't': case 'u': case 'v': case 'w': case 'x':
 559         case 'y': case 'z':
 560         case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
 561         case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
 562         case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
 563         case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
 564         case 'Y': case 'Z':
 565           if (!pfile->state.skipping && (quote == 0 || macro))
 566             {
 567               cpp_hashnode *node;
 568               uchar *out_start = out - 1;
 569
 570               pfile->out.cur = out_start;
 571               node = lex_identifier (pfile, cur - 1);
 572               out = pfile->out.cur;
 573               cur = CUR (context);
 574
 575               if (node->type == NT_MACRO
 576                   /* Should we expand for ls_answer?  */
 577                   && (lex_state == ls_none || lex_state == ls_fun_open)
 578                   && !pfile->state.prevent_expansion)
 579                 {
 580                   /* Macros invalidate MI optimization.  */
 581                   pfile->mi_valid = false;
 582                   if (! (node->flags & NODE_BUILTIN)
 583                       && node->value.macro->fun_like)
 584                     {
 585                       maybe_start_funlike (pfile, node, out_start, &fmacro);
 586                       lex_state = ls_fun_open;
 587                       fmacro.line = pfile->line;
 588                       continue;
 589                     }
 590                   else if (!recursive_macro (pfile, node))
 591                     {
 592                       /* Remove the object-like macro's name from the
 593                          output, and push its replacement text.  */
 594                       pfile->out.cur = out_start;
 595                       push_replacement_text (pfile, node);
 596                       lex_state = ls_none;
 597                       goto new_context;
 598                     }
 599                 }
 600               else if (macro && node->arg_index)
 601                 {
 602                   /* Found a parameter in the replacement text of a
 603                      #define.  Remove its name from the output.  */
 604                   pfile->out.cur = out_start;
 605                   save_replacement_text (pfile, macro, node->arg_index);
 606                   out = pfile->out.base;
 607                 }
 608               else if (lex_state == ls_hash)
 609                 {
 610                   lex_state = ls_predicate;
 611                   continue;
 612                 }
 613               else if (pfile->state.in_expression
 614                        && node == pfile->spec_nodes.n_defined)
 615                 {
 616                   lex_state = ls_defined;
 617                   continue;
 618                 }
 619             }
 620           break;
 621
 622         case '(':
 623           if (quote == 0)
 624             {
 625               paren_depth++;
 626               if (lex_state == ls_fun_open)
 627                 {
 628                   if (recursive_macro (pfile, fmacro.node))
 629                     lex_state = ls_none;
 630                   else
 631                     {
 632                       lex_state = ls_fun_close;
 633                       paren_depth = 1;
 634                       out = pfile->out.base + fmacro.offset;
 635                       fmacro.args[0] = fmacro.offset;
 636                     }
 637                 }
 638               else if (lex_state == ls_predicate)
 639                 lex_state = ls_answer;
 640               else if (lex_state == ls_defined)
 641                 lex_state = ls_defined_close;
 642             }
 643           break;
 644
 645         case ',':
 646           if (quote == 0 && lex_state == ls_fun_close && paren_depth == 1)
 647             save_argument (&fmacro, out - pfile->out.base);
 648           break;
 649
 650         case ')':
 651           if (quote == 0)
 652             {
 653               paren_depth--;
 654               if (lex_state == ls_fun_close && paren_depth == 0)
 655                 {
 656                   cpp_macro *m = fmacro.node->value.macro;
 657
 658                   m->used = 1;
 659                   lex_state = ls_none;
 660                   save_argument (&fmacro, out - pfile->out.base);
 661
 662                   /* A single zero-length argument is no argument.  */
 663                   if (fmacro.argc == 1
 664                       && m->paramc == 0
 665                       && out == pfile->out.base + fmacro.offset + 1)
 666                     fmacro.argc = 0;
 667
 668                   if (_cpp_arguments_ok (pfile, m, fmacro.node, fmacro.argc))
 669                     {
 670                       /* Remove the macro's invocation from the
 671                          output, and push its replacement text.  */
 672                       pfile->out.cur = (pfile->out.base
 673                                              + fmacro.offset);
 674                       CUR (context) = cur;
 675                       replace_args_and_push (pfile, &fmacro);
 676                       goto new_context;
 677                     }
 678                 }
 679               else if (lex_state == ls_answer || lex_state == ls_defined_close)
 680                 lex_state = ls_none;
 681             }
 682           break;
 683
 684         case '#':
 685           if (out - 1 == pfile->out.base && !pfile->state.in_directive)
 686             {
 687               /* A directive.  With the way _cpp_handle_directive
 688                  currently works, we only want to call it if either we
 689                  know the directive is OK, or we want it to fail and
 690                  be removed from the output.  If we want it to be
 691                  passed through (the assembler case) then we must not
 692                  call _cpp_handle_directive.  */
 693               pfile->out.cur = out;
 694               cur = skip_whitespace (pfile, cur, true /* skip_comments */);
 695               out = pfile->out.cur;
 696
 697               if (is_vspace (*cur))
 698                 {
 699                   /* Null directive.  Ignore it and don't invalidate
 700                      the MI optimization.  */
 701                   out = pfile->out.base;
 702                   continue;
 703                 }
 704               else
 705                 {
 706                   bool do_it = false;
 707
 708                   if (is_numstart (*cur))
 709                     do_it = true;
 710                   else if (is_idstart (*cur))
 711                     /* Check whether we know this directive, but don't
 712                        advance.  */
 713                     do_it = lex_identifier (pfile, cur)->directive_index != 0;
 714
 715                   if (do_it || CPP_OPTION (pfile, lang) != CLK_ASM)
 716                     {
 717                       /* This is a kludge.  We want to have the ISO
 718                          preprocessor lex the next token.  */
 719                       pfile->buffer->cur = cur;
 720                       _cpp_handle_directive (pfile, false /* indented */);
 721                       /* #include changes pfile->buffer so we need to
 722                          update the limits of the current context.  */
 723                       goto start_logical_line;
 724                     }
 725                 }
 726             }
 727
 728           if (pfile->state.in_expression)
 729             {
 730               lex_state = ls_hash;
 731               continue;
 732             }
 733           break;
 734
 735         default:
 736           break;
 737         }
 738
 739       /* Non-whitespace disables MI optimization and stops treating
 740          '<' as a quote in #include.  */
 741       header_ok = false;
 742       if (!pfile->state.in_directive)
 743         pfile->mi_valid = false;
 744
 745       if (lex_state == ls_none)
 746         continue;
 747
 748       /* Some of these transitions of state are syntax errors.  The
 749          ISO preprocessor will issue errors later.  */
 750       if (lex_state == ls_fun_open)
 751         /* Missing '('.  */
 752         lex_state = ls_none;
 753       else if (lex_state == ls_hash
 754                || lex_state == ls_predicate
 755                || lex_state == ls_defined)
 756         lex_state = ls_none;
 757
 758       /* ls_answer and ls_defined_close keep going until ')'.  */
 759     }
 760
 761  done:
 762   out[-1] = '\0';
 763   pfile->buffer->cur = cur;
 764   pfile->out.cur = out - 1;
 765   if (fmacro.buff)
 766     _cpp_release_buff (pfile, fmacro.buff);
 767
 768   if (lex_state == ls_fun_close)
 769     cpp_error_with_line (pfile, DL_ERROR, fmacro.line, 0,
 770                          "unterminated argument list invoking macro \"%s\"",
 771                          NODE_NAME (fmacro.node));
 772 }
 773
 774 /* Push a context holding the replacement text of the macro NODE on
 775    the context stack.  NODE is either object-like, or a function-like
 776    macro with no arguments.  */
 777 static void
 778 push_replacement_text (pfile, node)
 779      cpp_reader *pfile;
 780      cpp_hashnode *node;
 781 {
 782   size_t len;
 783   const uchar *text;
 784
 785   if (node->flags & NODE_BUILTIN)
 786     {
 787       text = _cpp_builtin_macro_text (pfile, node);
 788       len = ustrlen (text);
 789     }
 790   else
 791     {
 792       cpp_macro *macro = node->value.macro;
 793       macro->used = 1;
 794       text = macro->exp.text;
 795       len = macro->count;
 796     }
 797
 798   _cpp_push_text_context (pfile, node, text, len);
 799 }
 800
 801 /* Returns TRUE if traditional macro recursion is detected.  */
 802 static bool
 803 recursive_macro (pfile, node)
 804      cpp_reader *pfile;
 805      cpp_hashnode *node;
 806 {
 807   bool recursing = !!(node->flags & NODE_DISABLED);
 808
 809   /* Object-like macros that are already expanding are necessarily
 810      recursive.
 811
 812      However, it is possible to have traditional function-like macros
 813      that are not infinitely recursive but recurse to any given depth.
 814      Further, it is easy to construct examples that get ever longer
 815      until the point they stop recursing.  So there is no easy way to
 816      detect true recursion; instead we assume any expansion more than
 817      20 deep since the first invocation of this macro must be
 818      recursing.  */
 819   if (recursing && node->value.macro->fun_like)
 820     {
 821       size_t depth = 0;
 822       cpp_context *context = pfile->context;
 823
 824       do
 825         {
 826           depth++;
 827           if (context->macro == node && depth > 20)
 828             break;
 829           context = context->prev;
 830         }
 831       while (context);
 832       recursing = context != NULL;
 833     }
 834
 835   if (recursing)
 836     cpp_error (pfile, DL_ERROR,
 837                "detected recursion whilst expanding macro \"%s\"",
 838                NODE_NAME (node));
 839
 840   return recursing;
 841 }
 842
 843 /* Return the length of the replacement text of a function-like or
 844    object-like non-builtin macro.  */
 845 size_t
 846 _cpp_replacement_text_len (macro)
 847      const cpp_macro *macro;
 848 {
 849   size_t len;
 850
 851   if (macro->fun_like)
 852     {
 853       const uchar *exp;
 854
 855       len = 0;
 856       for (exp = macro->exp.text;;)
 857         {
 858           struct block *b = (struct block *) exp;
 859
 860           len += b->text_len;
 861           if (b->arg_index == 0)
 862             break;
 863           len += NODE_LEN (macro->params[b->arg_index - 1]);
 864           exp += BLOCK_LEN (b->text_len);
 865         }
 866     }
 867   else
 868     len = macro->count;
 869
 870   return len;
 871 }
 872
 873 /* Copy the replacement text of MACRO to DEST, which must be of
 874    sufficient size.  It is not NUL-terminated.  The next character is
 875    returned.  */
 876 uchar *
 877 _cpp_copy_replacement_text (macro, dest)
 878      const cpp_macro *macro;
 879      uchar *dest;
 880 {
 881   if (macro->fun_like)
 882     {
 883       const uchar *exp;
 884
 885       for (exp = macro->exp.text;;)
 886         {
 887           struct block *b = (struct block *) exp;
 888           cpp_hashnode *param;
 889
 890           memcpy (dest, b->text, b->text_len);
 891           dest += b->text_len;
 892           if (b->arg_index == 0)
 893             break;
 894           param = macro->params[b->arg_index - 1];
 895           memcpy (dest, NODE_NAME (param), NODE_LEN (param));
 896           dest += NODE_LEN (param);
 897           exp += BLOCK_LEN (b->text_len);
 898         }
 899     }
 900   else
 901     {
 902       memcpy (dest, macro->exp.text, macro->count);
 903       dest += macro->count;
 904     }
 905
 906   return dest;
 907 }
 908
 909 /* Push a context holding the replacement text of the macro NODE on
 910    the context stack.  NODE is either object-like, or a function-like
 911    macro with no arguments.  */
 912 static void
 913 replace_args_and_push (pfile, fmacro)
 914      cpp_reader *pfile;
 915      struct fun_macro *fmacro;
 916 {
 917   cpp_macro *macro = fmacro->node->value.macro;
 918
 919   if (macro->paramc == 0)
 920     push_replacement_text (pfile, fmacro->node);
 921   else
 922     {
 923       const uchar *exp;
 924       uchar *p;
 925       _cpp_buff *buff;
 926       size_t len = 0;
 927
 928       /* Calculate the length of the argument-replaced text.  */
 929       for (exp = macro->exp.text;;)
 930         {
 931           struct block *b = (struct block *) exp;
 932
 933           len += b->text_len;
 934           if (b->arg_index == 0)
 935             break;
 936           len += (fmacro->args[b->arg_index]
 937                   - fmacro->args[b->arg_index - 1] - 1);
 938           exp += BLOCK_LEN (b->text_len);
 939         }
 940
 941       /* Allocate room for the expansion plus NUL.  */
 942       buff = _cpp_get_buff (pfile, len + 1);
 943
 944       /* Copy the expansion and replace arguments.  */
 945       p = BUFF_FRONT (buff);
 946       for (exp = macro->exp.text;;)
 947         {
 948           struct block *b = (struct block *) exp;
 949           size_t arglen;
 950
 951           memcpy (p, b->text, b->text_len);
 952           p += b->text_len;
 953           if (b->arg_index == 0)
 954             break;
 955           arglen = (fmacro->args[b->arg_index]
 956                     - fmacro->args[b->arg_index - 1] - 1);
 957           memcpy (p, pfile->out.base + fmacro->args[b->arg_index - 1],
 958                   arglen);
 959           p += arglen;
 960           exp += BLOCK_LEN (b->text_len);
 961         }
 962
 963       /* NUL-terminate.  */
 964       *p = '\0';
 965       _cpp_push_text_context (pfile, fmacro->node, BUFF_FRONT (buff), len);
 966
 967       /* So we free buffer allocation when macro is left.  */
 968       pfile->context->buff = buff;
 969     }
 970 }
 971
 972 /* Read and record the parameters, if any, of a function-like macro
 973    definition.  Destroys pfile->out.cur.
 974
 975    Returns true on success, false on failure (syntax error or a
 976    duplicate parameter).  On success, CUR (pfile->context) is just
 977    past the closing parenthesis.  */
 978 static bool
 979 scan_parameters (pfile, macro)
 980      cpp_reader *pfile;
 981      cpp_macro *macro;
 982 {
 983   const uchar *cur = CUR (pfile->context) + 1;
 984   bool ok;
 985
 986   for (;;)
 987     {
 988       cur = skip_whitespace (pfile, cur, true /* skip_comments */);
 989
 990       if (is_idstart (*cur))
 991         {
 992           ok = false;
 993           if (_cpp_save_parameter (pfile, macro, lex_identifier (pfile, cur)))
 994             break;
 995           cur = skip_whitespace (pfile, CUR (pfile->context),
 996                                  true /* skip_comments */);
 997           if (*cur == ',')
 998             {
 999               cur++;
1000               continue;
1001             }
1002           ok = (*cur == ')');
1003           break;
1004         }
1005
1006       ok = (*cur == ')' && macro->paramc == 0);
1007       break;
1008     }
1009
1010   CUR (pfile->context) = cur + (*cur == ')');
1011
1012   return ok;
1013 }
1014
1015 /* Save the text from pfile->out.base to pfile->out.cur as
1016    the replacement text for the current macro, followed by argument
1017    ARG_INDEX, with zero indicating the end of the replacement
1018    text.  */
1019 static void
1020 save_replacement_text (pfile, macro, arg_index)
1021      cpp_reader *pfile;
1022      cpp_macro *macro;
1023      unsigned int arg_index;
1024 {
1025   size_t len = pfile->out.cur - pfile->out.base;
1026   uchar *exp;
1027
1028   if (macro->paramc == 0)
1029     {
1030       /* Object-like and function-like macros without parameters
1031          simply store their NUL-terminated replacement text.  */
1032       exp = _cpp_unaligned_alloc (pfile, len + 1);
1033       memcpy (exp, pfile->out.base, len);
1034       exp[len] = '\0';
1035       macro->exp.text = exp;
1036       macro->count = len;
1037     }
1038   else
1039     {
1040       /* Store the text's length (unsigned int), the argument index
1041          (unsigned short, base 1) and then the text.  */
1042       size_t blen = BLOCK_LEN (len);
1043       struct block *block;
1044
1045       if (macro->count + blen > BUFF_ROOM (pfile->a_buff))
1046         _cpp_extend_buff (pfile, &pfile->a_buff, macro->count + blen);
1047
1048       exp = BUFF_FRONT (pfile->a_buff);
1049       block = (struct block *) (exp + macro->count);
1050       macro->exp.text = exp;
1051
1052       /* Write out the block information.  */
1053       block->text_len = len;
1054       block->arg_index = arg_index;
1055       memcpy (block->text, pfile->out.base, len);
1056
1057       /* Lex the rest into the start of the output buffer.  */
1058       pfile->out.cur = pfile->out.base;
1059
1060       macro->count += blen;
1061
1062       /* If we've finished, commit the memory.  */
1063       if (arg_index == 0)
1064         BUFF_FRONT (pfile->a_buff) += macro->count;
1065     }
1066 }
1067
1068 /* Analyze and save the replacement text of a macro.  Returns true on
1069    success.  */
1070 bool
1071 _cpp_create_trad_definition (pfile, macro)
1072      cpp_reader *pfile;
1073      cpp_macro *macro;
1074 {
1075   const uchar *cur;
1076   uchar *limit;
1077   cpp_context *context = pfile->context;
1078
1079   /* The context has not been set up for command line defines, and CUR
1080      has not been updated for the macro name for in-file defines.  */
1081   pfile->out.cur = pfile->out.base;
1082   CUR (context) = pfile->buffer->cur;
1083   RLIMIT (context) = pfile->buffer->rlimit;
1084   check_output_buffer (pfile, RLIMIT (context) - CUR (context));
1085
1086   /* Is this a function-like macro?  */
1087   if (* CUR (context) == '(')
1088     {
1089       /* Setting macro to NULL indicates an error occurred, and
1090          prevents unnecessary work in scan_out_logical_line.  */
1091       if (!scan_parameters (pfile, macro))
1092         macro = NULL;
1093       else
1094         {
1095           /* Success.  Commit the parameter array.  */
1096           macro->params = (cpp_hashnode **) BUFF_FRONT (pfile->a_buff);
1097           BUFF_FRONT (pfile->a_buff) = (uchar *) &macro->params[macro->paramc];
1098           macro->fun_like = 1;
1099         }
1100     }
1101
1102   /* Skip leading whitespace in the replacement text.  */
1103   pfile->buffer->cur
1104     = skip_whitespace (pfile, CUR (context),
1105                        CPP_OPTION (pfile, discard_comments_in_macro_exp));
1106
1107   pfile->state.prevent_expansion++;
1108   scan_out_logical_line (pfile, macro);
1109   pfile->state.prevent_expansion--;
1110
1111   if (!macro)
1112     return false;
1113
1114   /* Skip trailing white space.  */
1115   cur = pfile->out.base;
1116   limit = pfile->out.cur;
1117   while (limit > cur && is_space (limit[-1]))
1118     limit--;
1119   pfile->out.cur = limit;
1120   save_replacement_text (pfile, macro, 0);
1121
1122   return true;
1123 }
1124
1125 /* Copy SRC of length LEN to DEST, but convert all contiguous
1126    whitespace to a single space, provided it is not in quotes.  The
1127    quote currently in effect is pointed to by PQUOTE, and is updated
1128    by the function.  Returns the number of bytes copied.  */
1129 static size_t
1130 canonicalize_text (dest, src, len, pquote)
1131      uchar *dest;
1132      const uchar *src;
1133      size_t len;
1134      uchar *pquote;
1135 {
1136   uchar *orig_dest = dest;
1137   uchar quote = *pquote;
1138
1139   while (len)
1140     {
1141       if (is_space (*src) && !quote)
1142         {
1143           do
1144             src++, len--;
1145           while (len && is_space (*src));
1146           *dest++ = ' ';
1147         }
1148       else
1149         {
1150           if (*src == '\'' || *src == '"')
1151             {
1152               if (!quote)
1153                 quote = *src;
1154               else if (quote == *src)
1155                 quote = 0;
1156             }
1157           *dest++ = *src++, len--;
1158         }
1159     }
1160
1161   *pquote = quote;
1162   return dest - orig_dest;
1163 }
1164
1165 /* Returns true if MACRO1 and MACRO2 have expansions different other
1166    than in the form of their whitespace.  */
1167 bool
1168 _cpp_expansions_different_trad (macro1, macro2)
1169      const cpp_macro *macro1, *macro2;
1170 {
1171   uchar *p1 = xmalloc (macro1->count + macro2->count);
1172   uchar *p2 = p1 + macro1->count;
1173   uchar quote1 = 0, quote2 = 0;
1174   bool mismatch;
1175   size_t len1, len2;
1176
1177   if (macro1->paramc > 0)
1178     {
1179       const uchar *exp1 = macro1->exp.text, *exp2 = macro2->exp.text;
1180
1181       mismatch = true;
1182       for (;;)
1183         {
1184           struct block *b1 = (struct block *) exp1;
1185           struct block *b2 = (struct block *) exp2;
1186
1187           if (b1->arg_index != b2->arg_index)
1188             break;
1189
1190           len1 = canonicalize_text (p1, b1->text, b1->text_len, &quote1);
1191           len2 = canonicalize_text (p2, b2->text, b2->text_len, &quote2);
1192           if (len1 != len2 || memcmp (p1, p2, len1))
1193             break;
1194           if (b1->arg_index == 0)
1195             {
1196               mismatch = false;
1197               break;
1198             }
1199           exp1 += BLOCK_LEN (b1->text_len);
1200           exp2 += BLOCK_LEN (b2->text_len);
1201         }
1202     }
1203   else
1204     {
1205       len1 = canonicalize_text (p1, macro1->exp.text, macro1->count, &quote1);
1206       len2 = canonicalize_text (p2, macro2->exp.text, macro2->count, &quote2);
1207       mismatch = (len1 != len2 || memcmp (p1, p2, len1));
1208     }
1209
1210   free (p1);
1211   return mismatch;
1212 }