src/scan-skel.l

   1 /* Scan Bison Skeletons.                                       -*- C -*-
   2    Copyright (C) 2001, 2002  Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    Bison is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    Bison is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with Bison; see the file COPYING.  If not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19    02111-1307, USA.  */
  20
  21 %option nodefault noyywrap nounput never-interactive
  22 %option prefix="skel_" outfile="lex.yy.c"
  23
  24 %{
  25 #include "system.h"
  26 #include "error.h"
  27 #include "getargs.h"
  28 #include "files.h"
  29 int skel_lex PARAMS ((void));
  30 static int yylineno = 1;
  31 static char *yyoutname = NULL;
  32 %}
  33 %%
  34   /* This is an approximation, but we don't need more. */
  35 ^"#output \""[^\"]+\"\n        {
  36      yytext[yyleng - 2] = '\0';
  37      XFREE (yyoutname);
  38      yyoutname = xstrdup (yytext + strlen ("#output \""));
  39      yyout = xfopen (yyoutname, "w");
  40      yylineno = 1;
  41    }
  42
  43 "@<:@"           fputc ('[', yyout);
  44 "@:>@"           fputc (']', yyout);
  45
  46 "__oline__"      fprintf (yyout, "%d", yylineno+1);
  47 "__ofile__"      fprintf (yyout, "%s", yyoutname);
  48 [^@_\n]+         ECHO;
  49 \n+              yylineno += yyleng; ECHO;
  50 .                ECHO;
  51
  52 <<EOF>>          xfclose (yyout); free (yyoutname); return EOF;
  53 %%
  54
  55 /* From lib/readpipe.c.  */
  56 FILE *readpipe PARAMS ((const char *, ...));
  57
  58 /*----------------------.
  59 | Run our backend, M4.  |
  60 `----------------------*/
  61
  62 void m4_invoke PARAMS ((const char *definitions));
  63
  64 void
  65 m4_invoke (const char *definitions)
  66 {
  67   /* Invoke m4 on the definition of the muscles, and the skeleton. */
  68   const char *bison_pkgdatadir = getenv ("BISON_PKGDATADIR");
  69   const char *m4 = getenv ("M4");
  70   int pkg_data_len;
  71   char *full_skeleton;
  72
  73   if (!m4)
  74     m4 = M4;
  75   if (!bison_pkgdatadir)
  76     bison_pkgdatadir = PKGDATADIR;
  77   pkg_data_len = strlen (bison_pkgdatadir);
  78   full_skeleton = XMALLOC (char, pkg_data_len + strlen (skeleton) + 2);
  79   if (bison_pkgdatadir[pkg_data_len-1] == '/')
  80     sprintf (full_skeleton, "%s%s", bison_pkgdatadir, skeleton);
  81   else
  82     sprintf (full_skeleton, "%s/%s", bison_pkgdatadir, skeleton);
  83   if (trace_flag)
  84     fprintf (stderr,
  85              "running: %s -I %s m4sugar/m4sugar.m4 %s %s\n",
  86              m4, bison_pkgdatadir, definitions, full_skeleton);
  87   skel_in = readpipe (m4,
  88                       "-I", bison_pkgdatadir,
  89                       "m4sugar/m4sugar.m4",
  90                       definitions,
  91                       full_skeleton,
  92                       NULL);
  93   XFREE (full_skeleton);
  94   if (!skel_in)
  95     error (EXIT_FAILURE, errno, "cannot run m4");
  96   skel_lex ();
  97
  98   /* Reclaim Flex's buffers.  */
  99   yy_delete_buffer (YY_CURRENT_BUFFER);
 100 }