lalr1.cc: check (and fix) %initial-action exception safety

[bison.git] / src / files.c

diff --git a/src/files.c b/src/files.c
index 5e01b9f80bfb64565c522258de48da7a19e7447f..f698c7e9c6aeea80182affd0a68541c47e987876 100644 (file)
--- a/src/files.c
+++ b/src/files.c
@@ -1,133 +1,103 @@
-/* Open and close files for bison,
-   Copyright 1984, 1986, 1989, 1992, 2000, 2001 Free Software Foundation, Inc.
+/* Open and close files for Bison.
+
+   Copyright (C) 1984, 1986, 1989, 1992, 2000-2012 Free Software
+   Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 

-   Bison is free software; you can redistribute it and/or modify it
-   under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.

 
 

-   Bison is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.

 
    You should have received a copy of the GNU General Public License
 
    You should have received a copy of the GNU General Public License

-   along with Bison; see the file COPYING.  If not, write to the Free
-   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
-   02111-1307, USA.  */
-
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 

+#include <config.h>

 #include "system.h"
 #include "system.h"

-#include "getargs.h"
+
+#include <error.h>
+#include <dirname.h>
+#include <get-errno.h>
+#include <quote.h>
+#include <quotearg.h>
+#include <stdio-safer.h>
+#include <xstrndup.h>
+
+#include "complain.h"

 #include "files.h"
 #include "files.h"

+#include "getargs.h"

 #include "gram.h"
 #include "gram.h"

-#include "error.h"
-#include "complain.h"

 
 

-FILE *finput = NULL;
+/* Initializing some values below (such SPEC_NAME_PREFIX to `yy') is
+   tempting, but don't do that: for the time being our handling of the
+   %directive vs --option leaves precedence to the options by deciding
+   that if a %directive sets a variable which is really set (i.e., not
+   NULL), then the %directive is ignored.  As a result, %name-prefix,
+   for instance, will not be honored.  */

 
 

-struct obstack action_obstack;
-struct obstack attrs_obstack;
-struct obstack guard_obstack;
-struct obstack output_obstack;
+char const *spec_outfile = NULL;       /* for -o. */
+char const *spec_file_prefix = NULL;   /* for -b. */
+char const *spec_name_prefix = NULL;   /* for -p. */
+char *spec_verbose_file = NULL;  /* for --verbose. */
+char *spec_graph_file = NULL;    /* for -g. */
+char *spec_xml_file = NULL;      /* for -x. */
+char *spec_defines_file = NULL;  /* for --defines. */
+char *parser_file_name;

 
 

-char *spec_outfile = NULL;     /* for -o. */
-char *spec_file_prefix = NULL; /* for -b. */
-const char *spec_name_prefix = "yy";   /* for -p. */
-char *spec_verbose_file = NULL;   /* for --verbose. */
-char *spec_graph_file = NULL;   /* for -g. */
-char *spec_defines_file = NULL; /* for --defines. */
-char *parser_file_name = NULL;
+/* All computed output file names.  */
+static char **file_names = NULL;
+static int file_names_count = 0;

 
 

-char *infile = NULL;
-char *attrsfile = NULL;
+uniqstr grammar_file = NULL;
+uniqstr current_file = NULL;

 
 

-static char *base_name = NULL;
-static char *short_base_name = NULL;
+/* If --output=dir/foo.c was specified,
+   DIR_PREFIX is `dir/' and ALL_BUT_EXT and ALL_BUT_TAB_EXT are `dir/foo'.

 
 

-/* C source file extension (the parser source).  */
-const char *src_extension = NULL;
-/* Header file extension (if option ``-d'' is specified).  */
-const char *header_extension = NULL;
-\f
+   If --output=dir/foo.tab.c was specified, DIR_PREFIX is `dir/',
+   ALL_BUT_EXT is `dir/foo.tab', and ALL_BUT_TAB_EXT is `dir/foo'.

 
 

-/*--------------------------.
-| Is SUFFIX ending STRING?  |
-`--------------------------*/
+   If --output was not specified but --file-prefix=dir/foo was specified,
+   ALL_BUT_EXT = `foo.tab' and ALL_BUT_TAB_EXT = `foo'.

 
 

-static int
-strsuffix (const char *string, const char *suffix)
-{
-  size_t string_len = strlen (string);
-  size_t suffix_len = strlen (suffix);
-  if (suffix_len <= string_len)
-    return !strcmp (string + string_len - suffix_len, suffix);
-  else
-    return 0;
-}
+   If neither --output nor --file was specified but the input grammar
+   is name dir/foo.y, ALL_BUT_EXT and ALL_BUT_TAB_EXT are `foo'.

 
 

+   If neither --output nor --file was specified, DIR_PREFIX is the
+   empty string (meaning the current directory); otherwise it is
+   `dir/'.  */

 
 

+char *all_but_ext;
+static char *all_but_tab_ext;
+char *dir_prefix;
+
+/* C source file extension (the parser source).  */
+static char *src_extension = NULL;
+/* Header file extension (if option ``-d'' is specified).  */
+static char *header_extension = NULL;
+\f

 /*-----------------------------------------------------------------.
 | Return a newly allocated string composed of the concatenation of |
 /*-----------------------------------------------------------------.
 | Return a newly allocated string composed of the concatenation of |

-| STRING1, and STRING2.                                            |
+| STR1, and STR2.                                                  |

 `-----------------------------------------------------------------*/
 
 static char *
 `-----------------------------------------------------------------*/
 
 static char *

-stringappend (const char *string1, const char *string2)
+concat2 (char const *str1, char const *str2)

 {
 {

-  size_t len = strlen (string1) + strlen (string2);
-  char *res = XMALLOC (char, len + 1);
+  size_t len = strlen (str1) + strlen (str2);
+  char *res = xmalloc (len + 1);

   char *cp;
   char *cp;

-  cp = stpcpy (res, string1);
-  cp = stpcpy (cp, string2);
+  cp = stpcpy (res, str1);
+  cp = stpcpy (cp, str2);

   return res;
 }
 
   return res;
 }
 

-
-/*-----------------------------------------------------------------.
-| Computes the macro name used to avoid double inclusion in the    |
-| header of the parser and store it in header_macro_name.  Be sure |
-| to produce valid CPP names (don't start with digit, remain       |
-| alphanumerical + underscore).                                    |
-`-----------------------------------------------------------------*/
-
-char *
-compute_header_macro (void)
-{
-  const char *prefix = "BISON_";
-  char *macro_name, *cp;
-
-  if (spec_defines_file)
-    {
-      macro_name = XMALLOC (char,
-                           strlen (prefix) +
-                           strlen (spec_defines_file) + 1);
-      cp = stpcpy (macro_name, prefix);
-      cp = stpcpy (cp, spec_defines_file);
-    }
-  else
-    {
-      macro_name = XMALLOC (char,
-                           strlen (prefix) +
-                           strlen (base_name) +
-                           strlen (header_extension) + 1);
-      cp = stpcpy (macro_name, prefix);
-      cp = stpcpy (cp, base_name);
-      cp = stpcpy (cp, header_extension);
-    }
-
-  for (cp = macro_name; *cp; ++cp)
-    if (islower (*cp))
-      *cp = toupper (*cp);
-    else if (!isalnum (*cp))
-      *cp = '_';
-
-  return macro_name;
-}
-
-

 /*-----------------------------------------------------------------.
 | Try to open file NAME with mode MODE, and print an error message |
 | if fails.                                                        |
 /*-----------------------------------------------------------------.
 | Try to open file NAME with mode MODE, and print an error message |
 | if fails.                                                        |


@@ -138,9 +108,10 @@ xfopen (const char *name, const char *mode)
 {
   FILE *ptr;
 
 {
   FILE *ptr;
 

-  ptr = fopen (name, mode);
+  ptr = fopen_safer (name, mode);

   if (!ptr)
   if (!ptr)

-    error (2, errno, _("cannot open file `%s'"), name);
+    error (EXIT_FAILURE, get_errno (),
+           _("%s: cannot open"), quotearg_colon (name));

 
   return ptr;
 }
 
   return ptr;
 }


@@ -149,278 +120,277 @@ xfopen (const char *name, const char *mode)
 | Try to close file PTR, and print an error message if fails.  |
 `-------------------------------------------------------------*/
 
 | Try to close file PTR, and print an error message if fails.  |
 `-------------------------------------------------------------*/
 

-int
+void

 xfclose (FILE *ptr)
 {
 xfclose (FILE *ptr)
 {

-  int result;
-

   if (ptr == NULL)
   if (ptr == NULL)

-    return 0;
+    return;

 
 

-  result = fclose (ptr);
-  if (result == EOF)
-    error (2, errno, _("cannot close file"));
+  if (ferror (ptr))
+    error (EXIT_FAILURE, 0, _("input/output error"));

 
 

-  return result;
+  if (fclose (ptr) != 0)
+    error (EXIT_FAILURE, get_errno (), _("cannot close file"));

 }
 }

-
+\f

 
 /*------------------------------------------------------------------.
 
 /*------------------------------------------------------------------.

-| Return the path to the skeleton which locaction might be given in |
-| ENVVAR, otherwise return SKELETON_NAME.                           |
+| Compute ALL_BUT_EXT, ALL_BUT_TAB_EXT and output files extensions. |

 `------------------------------------------------------------------*/
 
 `------------------------------------------------------------------*/
 

-const char *
-skeleton_find (const char *envvar, const char *skeleton_name)
+/* Compute extensions from the grammar file extension.  */
+static void
+compute_exts_from_gf (const char *ext)

 {
 {

-  const char *res = getenv (envvar);
-
-#if defined (MSDOS) || defined (_WIN32)
-  if (!res)
+  if (strcmp (ext, ".y") == 0)

     {
     {

-      /* Skeleton file name without path */
-      const char *skel_name = strrchr (skeleton_name, '/');
-      if (!skel_name)
-        skel_name = strrchr (skeleton_name, '\\');
-      if (!skel_name)
-        skel_name = skeleton_name;
-      else
-        ++skel_name;
-
-      /* File doesn't exist in current directory; try in INIT directory.  */
-      const char *cp = getenv ("INIT");
-      if (cp)
-       {
-         res = XMALLOC (char, strlen (cp) + strlen (skel_name) + 2);
-         sprintf (res, "%s%c%s", cp, '\\', skel_name);
-       }
-      else if (access (skel_name, 4) == 0) /* Look in current dir. */
-        res = skel_name;
-      else
-       {
-         /* Look in program locations dir. */
-         extern char *program_name;
-         cp = strrchr(program_name, '\\');
-         if (!cp)
-           return skeleton_name;
-         else
-           ++cp;
-         res = XMALLOC (char, cp - program_name + strlen (skel_name) + 1);
-         strncpy (res, program_name, cp - program_name);
-         strcpy (res + (cp - program_name), skel_name);
-       }
+      src_extension = xstrdup (language->src_extension);
+      header_extension = xstrdup (language->header_extension);
+    }
+  else
+    {
+      src_extension = xstrdup (ext);
+      header_extension = xstrdup (ext);
+      tr (src_extension, 'y', 'c');
+      tr (src_extension, 'Y', 'C');
+      tr (header_extension, 'y', 'h');
+      tr (header_extension, 'Y', 'H');

     }
     }

-#endif /* defined (MSDOS) || defined (_WIN32) */
-  if (!res)
-    res = skeleton_name;
-
-  return res;

 }
 }

-\f
-
-/*----------------------------------------------------------------.
-| Compute BASE_NAME, SHORT_BASE_NAME and output files extensions. |
-`----------------------------------------------------------------*/

 
 

-/* Replace all characters FROM by TO in the string IN.
-   and returns a new allocated string.  */
-static char *
-tr (const char *in, char from, char to)
+/* Compute extensions from the given c source file extension.  */
+static void
+compute_exts_from_src (const char *ext)

 {
 {

-  char *temp;
-  char *out;
-
-  out = XMALLOC (char, strlen (in) + 1);
-
-  for (temp = out; *in; in++, out++)
-    if (*in == from)
-      *out = to;
-    else
-      *out = *in;
-  *out = 0;
-  return (temp);
+  /* We use this function when the user specifies `-o' or `--output',
+     so the extenions must be computed unconditionally from the file name
+     given by this option.  */
+  src_extension = xstrdup (ext);
+  header_extension = xstrdup (ext);
+  tr (header_extension, 'c', 'h');
+  tr (header_extension, 'C', 'H');

 }
 
 }
 

-/* Gets the extension index in FILENAME. Returns 0 if fails to
-   find an extension.  */
-static int
-get_extension_index (const char *filename)
-{
-  int len;

 
 

-  len = strlen (filename);
+/* Decompose FILE_NAME in four parts: *BASE, *TAB, and *EXT, the fourth
+   part, (the directory) is ranging from FILE_NAME to the char before
+   *BASE, so we don't need an additional parameter.

 
 

-  if (filename[len-- - 1] == '.')
-    return (0);
+   *EXT points to the last period in the basename, or NULL if none.

 
 

-  while ((len > 0) && (filename[len - 1] != '.'))
-    if (filename[len - 1] == '/')
-      return (0);
-    else
-      len--;
+   If there is no *EXT, *TAB is NULL.  Otherwise, *TAB points to
+   `.tab' or `_tab' if present right before *EXT, or is NULL. *TAB
+   cannot be equal to *BASE.

 
 

-  return (len - 1);
-}
+   None are allocated, they are simply pointers to parts of FILE_NAME.
+   Examples:

 
 

-/* Computes extensions from the grammar file extension. */
-static void
-compute_exts_from_gf (const char *ext)
-{
-  src_extension = tr (ext, 'y', 'c');
-  src_extension = tr (src_extension, 'Y', 'C');
-  header_extension = tr (ext, 'y', 'h');
-  header_extension = tr (header_extension, 'Y', 'H');
-}
+   '/tmp/foo.tab.c' -> *BASE = 'foo.tab.c', *TAB = '.tab.c', *EXT =
+   '.c'
+
+   'foo.c' -> *BASE = 'foo.c', *TAB = NULL, *EXT = '.c'
+
+   'tab.c' -> *BASE = 'tab.c', *TAB = NULL, *EXT = '.c'
+
+   '.tab.c' -> *BASE = '.tab.c', *TAB = NULL, *EXT = '.c'
+
+   'foo.tab' -> *BASE = 'foo.tab', *TAB = NULL, *EXT = '.tab'
+
+   'foo_tab' -> *BASE = 'foo_tab', *TAB = NULL, *EXT = NULL
+
+   'foo' -> *BASE = 'foo', *TAB = NULL, *EXT = NULL.  */

 
 

-/* Computes extensions from the given c source file extension. */

 static void
 static void

-compute_exts_from_src (const char *ext)
+file_name_split (const char *file_name,
+                const char **base, const char **tab, const char **ext)

 {
 {

-  /* We use this function when the user specifies `-o' or `--output',
-     so the extenions must be computed unconditionally from the file name
-     given by this option.  */
-  src_extension = xstrdup (ext);
-  header_extension = tr (ext, 'c', 'h');
-  header_extension = tr (header_extension, 'C', 'H');
+  *base = last_component (file_name);
+
+  /* Look for the extension, i.e., look for the last dot. */
+  *ext = mbsrchr (*base, '.');
+  *tab = NULL;
+
+  /* If there is an extension, check if there is a `.tab' part right
+     before.  */
+  if (*ext)
+    {
+      size_t baselen = *ext - *base;
+      size_t dottablen = 4;
+      if (dottablen < baselen
+         && (strncmp (*ext - dottablen, ".tab", dottablen) == 0
+             || strncmp (*ext - dottablen, "_tab", dottablen) == 0))
+       *tab = *ext - dottablen;
+    }

 }
 
 }
 

-/* FIXME: Should use xstrndup. */

 
 static void
 
 static void

-compute_base_names (void)
+compute_file_name_parts (void)

 {
 {

-  size_t base_length;
-  size_t short_base_length;
-  size_t ext_index;
-
-  /* If --output=foo.c was specified (SPEC_OUTFILE == foo.c),
-     BASE_NAME and SHORT_BASE_NAME are `foo'.
+  const char *base, *tab, *ext;

 
 

-     If --output=foo.tab.c was specified, BASE_NAME is `foo.tab' and
-     SHORT_BASE_NAME is `foo'.
+  /* Compute ALL_BUT_EXT and ALL_BUT_TAB_EXT from SPEC_OUTFILE
+     or GRAMMAR_FILE.

 
      The precise -o name will be used for FTABLE.  For other output
      files, remove the ".c" or ".tab.c" suffix.  */
   if (spec_outfile)
     {
 
      The precise -o name will be used for FTABLE.  For other output
      files, remove the ".c" or ".tab.c" suffix.  */
   if (spec_outfile)
     {

-#ifdef MSDOS
-      strlwr (spec_outfile);
-#endif /* MSDOS */
-      /* BASE_LENGTH includes ".tab" but not ".c".  */
-      base_length = strlen (spec_outfile);
-
-      ext_index = get_extension_index (spec_outfile);
-      /* If the initial segment of extension contains 'c' or a 'C', I assume
-         that it is a C or C++ source file.  */
-      if (ext_index)
-       ext_index =
-         (strspn (spec_outfile + ext_index + 1, "cC")) ? ext_index : 0;
-      if (ext_index)
+      file_name_split (spec_outfile, &base, &tab, &ext);
+      dir_prefix = xstrndup (spec_outfile, base - spec_outfile);
+
+      /* ALL_BUT_EXT goes up the EXT, excluding it. */
+      all_but_ext =
+       xstrndup (spec_outfile,
+                 (strlen (spec_outfile) - (ext ? strlen (ext) : 0)));
+
+      /* ALL_BUT_TAB_EXT goes up to TAB, excluding it.  */
+      all_but_tab_ext =
+       xstrndup (spec_outfile,
+                 (strlen (spec_outfile)
+                  - (tab ? strlen (tab) : (ext ? strlen (ext) : 0))));
+
+      if (ext)
+       compute_exts_from_src (ext);
+    }
+  else
+    {
+      file_name_split (grammar_file, &base, &tab, &ext);
+
+      if (spec_file_prefix)

        {
        {

-         base_length -= strlen (spec_outfile + ext_index);
-         compute_exts_from_src (spec_outfile + ext_index);
+         /* If --file-prefix=foo was specified, ALL_BUT_TAB_EXT = `foo'.  */
+         dir_prefix =
+            xstrndup (spec_file_prefix,
+                      last_component (spec_file_prefix) - spec_file_prefix);
+         all_but_tab_ext = xstrdup (spec_file_prefix);
+       }
+      else if (yacc_flag)
+       {
+         /* If --yacc, then the output is `y.tab.c'.  */
+         dir_prefix = xstrdup ("");
+         all_but_tab_ext = xstrdup ("y");
+       }
+      else
+       {
+         /* Otherwise, ALL_BUT_TAB_EXT is computed from the input
+            grammar: `foo/bar.yy' => `bar'.  */
+         dir_prefix = xstrdup ("");
+         all_but_tab_ext =
+           xstrndup (base, (strlen (base) - (ext ? strlen (ext) : 0)));

        }
 
        }
 

-      base_name = strndup (spec_outfile, base_length);
-      /* SHORT_BASE_LENGTH includes neither ".tab" nor ".c".  */
-      short_base_length = base_length;
-      if (strsuffix (base_name, ".tab") || strsuffix (base_name, "_tab"))
-       short_base_length -= 4;
-      short_base_name = strndup (spec_outfile, short_base_length);
+      if (language->add_tab)
+        all_but_ext = concat2 (all_but_tab_ext, TAB_EXT);
+      else
+        all_but_ext = xstrdup (all_but_tab_ext);

 
 

-      return;
+      /* Compute the extensions from the grammar file name.  */
+      if (ext && !yacc_flag)
+       compute_exts_from_gf (ext);

     }
     }

+}

 
 

-  /* If --file-prefix=foo was specified, BASE_NAME and SHORT_BASE_NAME
-     are `foo'.

 
 

-     Construct names from it.  */
-  if (spec_file_prefix)
-    {
-#ifdef MSDOS
-      strlwr (spec_file_prefix);
-#endif /* MSDOS */
-      short_base_name = xstrdup (spec_file_prefix);
-      base_name = XMALLOC (char,
-                          strlen (short_base_name) + strlen (EXT_TAB) + 1);
-      stpcpy (stpcpy (base_name, short_base_name), EXT_TAB);
-
-      /* Computes the extensions from the garmmar file name.  */
-      ext_index = get_extension_index (infile);
-      /* If the initial segment of extension contains a 'y' or a 'Y', I assume
-         that it is a yacc or bison grammar file.  */
-      if (ext_index)
-       ext_index = (strspn (infile + ext_index + 1, "yY")) ? ext_index : 0;
-      if (ext_index)
-       compute_exts_from_gf (infile + ext_index);
-
-      return;
-    }
+/* Compute the output file names.  Warn if we detect conflicting
+   outputs to the same file.  */

 
 

-  /* If neither -o nor --file-prefix were specified, and the input
-     file is foo.y, BASE_NAME is `foo.tab', and SHORT_BASE_NAME is
-     `foo'.
+void
+compute_output_file_names (void)
+{
+  compute_file_name_parts ();

 
 

-     If --yacc is used, do as if the input file was `y.y'.  */
-  {
-    const char *name_base = yacc_flag ? "y.y" : infile;
+  /* If not yet done. */
+  if (!src_extension)
+    src_extension = xstrdup (".c");
+  if (!header_extension)
+    header_extension = xstrdup (".h");

 
 

-    /* BASE_LENGTH gets length of BASE_NAME, sans ".y" suffix if any.  */
+  parser_file_name =
+    (spec_outfile
+     ? xstrdup (spec_outfile)
+     : concat2 (all_but_ext, src_extension));

 
 

-    base_length = strlen (name_base);
+  if (defines_flag)
+    {
+      if (! spec_defines_file)
+       spec_defines_file = concat2 (all_but_ext, header_extension);
+    }

 
 

-    ext_index = get_extension_index (name_base);
-    /* If the initial segment of extension contains a 'y' or a 'Y', I assume
-       that it is a yacc or bison grammar file.  */
-    if (ext_index)
-      ext_index = (strspn (name_base + ext_index + 1, "yY")) ? ext_index : 0;
-    if (ext_index)
-      {
-       base_length -= strlen (name_base + ext_index);
-       compute_exts_from_gf (name_base + ext_index);
-      }
+  if (graph_flag)
+    {
+      if (! spec_graph_file)
+       spec_graph_file = concat2 (all_but_tab_ext, ".dot");
+      output_file_name_check (&spec_graph_file);
+    }

 
 

-    short_base_length = base_length;
-    short_base_name = strndup (name_base, short_base_length);
+  if (xml_flag)
+    {
+      if (! spec_xml_file)
+       spec_xml_file = concat2 (all_but_tab_ext, ".xml");
+      output_file_name_check (&spec_xml_file);
+    }

 
 

-    base_name = XMALLOC (char,
-                        strlen (short_base_name) + strlen (EXT_TAB) + 1);
-    stpcpy (stpcpy (base_name, short_base_name), EXT_TAB);
+  if (report_flag)
+    {
+      if (!spec_verbose_file)
+        spec_verbose_file = concat2 (all_but_tab_ext, OUTPUT_EXT);
+      output_file_name_check (&spec_verbose_file);
+    }

 
 

-    return;
-  }
+  free (all_but_tab_ext);
+  free (src_extension);
+  free (header_extension);

 }
 
 }
 

-/*-------------------------------------------------------.
-| Close the open files, compute the output files names.  |
-`-------------------------------------------------------*/
-

 void
 void

-compute_output_file_names (void)
+output_file_name_check (char **file_name)

 {
 {

-  compute_base_names ();
-
-  parser_file_name =
-    spec_outfile ? spec_outfile : stringappend (base_name, src_extension);
-
-  /* If not yet done. */
-  if (!src_extension)
-    src_extension = ".c";
-  if (!header_extension)
-    header_extension = ".h";
-
-  /* It the defines filename if not given, we create it.  */
-  if (!spec_defines_file)
-    spec_defines_file = stringappend (base_name, header_extension);
-
-  /* It the graph filename if not given, we create it.  */
-  if (!spec_graph_file)
-    spec_graph_file = stringappend (short_base_name, ".vcg");
-
-  spec_verbose_file = stringappend (short_base_name, EXT_OUTPUT);
+  bool conflict = false;
+  if (0 == strcmp (*file_name, grammar_file))
+    {
+      complain (_("refusing to overwrite the input file %s"),
+                quote (*file_name));
+      conflict = true;
+    }
+  else
+    {
+      int i;
+      for (i = 0; i < file_names_count; i++)
+        if (0 == strcmp (file_names[i], *file_name))
+          {
+            warn (_("conflicting outputs to file %s"),
+                  quote (*file_name));
+            conflict = true;
+          }
+    }
+  if (conflict)
+    {
+      free (*file_name);
+      *file_name = strdup ("/dev/null");
+    }
+  else
+    {
+      file_names = xnrealloc (file_names, ++file_names_count,
+                              sizeof *file_names);
+      file_names[file_names_count-1] = xstrdup (*file_name);
+    }
+}

 
 

-  attrsfile = stringappend (short_base_name, EXT_STYPE_H);
-#ifndef MSDOS
-  attrsfile = stringappend (attrsfile, header_extension);
-#endif /* MSDOS */
+void
+output_file_names_free (void)
+{
+  free (all_but_ext);
+  free (spec_verbose_file);
+  free (spec_graph_file);
+  free (spec_xml_file);
+  free (spec_defines_file);
+  free (parser_file_name);
+  free (dir_prefix);
+  {
+    int i;
+    for (i = 0; i < file_names_count; i++)
+      free (file_names[i]);
+  }
+  free (file_names);

 }
 }