Merge GDB 7.5.1

gdb/gnulib/import/localcharset.c

+/* Determine a canonical name for the current locale's character encoding.
+
+   Copyright (C) 2000-2006, 2008-2012 Free Software Foundation, Inc.
+
+   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, or (at your option)
+   any later version.
+
+   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 along
+   with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "localcharset.h"
+
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#if defined __APPLE__ && defined __MACH__ && HAVE_LANGINFO_CODESET
+# define DARWIN7 /* Darwin 7 or newer, i.e. Mac OS X 10.3 or newer */
+#endif
+
+#if defined _WIN32 || defined __WIN32__
+# define WINDOWS_NATIVE
+#endif
+
+#if defined __EMX__
+/* Assume EMX program runs on OS/2, even if compiled under DOS.  */
+# ifndef OS2
+#  define OS2
+# endif
+#endif
+
+#if !defined WINDOWS_NATIVE
+# include <unistd.h>
+# if HAVE_LANGINFO_CODESET
+#  include <langinfo.h>
+# else
+#  if 0 /* see comment below */
+#   include <locale.h>
+#  endif
+# endif
+# ifdef __CYGWIN__
+#  define WIN32_LEAN_AND_MEAN
+#  include <windows.h>
+# endif
+#elif defined WINDOWS_NATIVE
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+#if defined OS2
+# define INCL_DOS
+# include <os2.h>
+#endif
+
+#if ENABLE_RELOCATABLE
+# include "relocatable.h"
+#else
+# define relocate(pathname) (pathname)
+#endif
+
+/* Get LIBDIR.  */
+#ifndef LIBDIR
+# include "configmake.h"
+#endif
+
+/* Define O_NOFOLLOW to 0 on platforms where it does not exist.  */
+#ifndef O_NOFOLLOW
+# define O_NOFOLLOW 0
+#endif
+
+#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
+  /* Native Windows, Cygwin, OS/2, DOS */
+# define ISSLASH(C) ((C) == '/' || (C) == '\\')
+#endif
+
+#ifndef DIRECTORY_SEPARATOR
+# define DIRECTORY_SEPARATOR '/'
+#endif
+
+#ifndef ISSLASH
+# define ISSLASH(C) ((C) == DIRECTORY_SEPARATOR)
+#endif
+
+#if HAVE_DECL_GETC_UNLOCKED
+# undef getc
+# define getc getc_unlocked
+#endif
+
+/* The following static variable is declared 'volatile' to avoid a
+   possible multithread problem in the function get_charset_aliases. If we
+   are running in a threaded environment, and if two threads initialize
+   'charset_aliases' simultaneously, both will produce the same value,
+   and everything will be ok if the two assignments to 'charset_aliases'
+   are atomic. But I don't know what will happen if the two assignments mix.  */
+#if __STDC__ != 1
+# define volatile /* empty */
+#endif
+/* Pointer to the contents of the charset.alias file, if it has already been
+   read, else NULL.  Its format is:
+   ALIAS_1 '\0' CANONICAL_1 '\0' ... ALIAS_n '\0' CANONICAL_n '\0' '\0'  */
+static const char * volatile charset_aliases;
+
+/* Return a pointer to the contents of the charset.alias file.  */
+static const char *
+get_charset_aliases (void)
+{
+  const char *cp;
+
+  cp = charset_aliases;
+  if (cp == NULL)
+    {
+#if !(defined DARWIN7 || defined VMS || defined WINDOWS_NATIVE || defined __CYGWIN__)
+      const char *dir;
+      const char *base = "charset.alias";
+      char *file_name;
+
+      /* Make it possible to override the charset.alias location.  This is
+         necessary for running the testsuite before "make install".  */
+      dir = getenv ("CHARSETALIASDIR");
+      if (dir == NULL || dir[0] == '\0')
+        dir = relocate (LIBDIR);
+
+      /* Concatenate dir and base into freshly allocated file_name.  */
+      {
+        size_t dir_len = strlen (dir);
+        size_t base_len = strlen (base);
+        int add_slash = (dir_len > 0 && !ISSLASH (dir[dir_len - 1]));
+        file_name = (char *) malloc (dir_len + add_slash + base_len + 1);
+        if (file_name != NULL)
+          {
+            memcpy (file_name, dir, dir_len);
+            if (add_slash)
+              file_name[dir_len] = DIRECTORY_SEPARATOR;
+            memcpy (file_name + dir_len + add_slash, base, base_len + 1);
+          }
+      }
+
+      if (file_name == NULL)
+        /* Out of memory.  Treat the file as empty.  */
+        cp = "";
+      else
+        {
+          int fd;
+
+          /* Open the file.  Reject symbolic links on platforms that support
+             O_NOFOLLOW.  This is a security feature.  Without it, an attacker
+             could retrieve parts of the contents (namely, the tail of the
+             first line that starts with "* ") of an arbitrary file by placing
+             a symbolic link to that file under the name "charset.alias" in
+             some writable directory and defining the environment variable
+             CHARSETALIASDIR to point to that directory.  */
+          fd = open (file_name,
+                     O_RDONLY | (HAVE_WORKING_O_NOFOLLOW ? O_NOFOLLOW : 0));
+          if (fd < 0)
+            /* File not found.  Treat it as empty.  */
+            cp = "";
+          else
+            {
+              FILE *fp;
+
+              fp = fdopen (fd, "r");
+              if (fp == NULL)
+                {
+                  /* Out of memory.  Treat the file as empty.  */
+                  close (fd);
+                  cp = "";
+                }
+              else
+                {
+                  /* Parse the file's contents.  */
+                  char *res_ptr = NULL;
+                  size_t res_size = 0;
+
+                  for (;;)
+                    {
+                      int c;
+                      char buf1[50+1];
+                      char buf2[50+1];
+                      size_t l1, l2;
+                      char *old_res_ptr;
+
+                      c = getc (fp);
+                      if (c == EOF)
+                        break;
+                      if (c == '\n' || c == ' ' || c == '\t')
+                        continue;
+                      if (c == '#')
+                        {
+                          /* Skip comment, to end of line.  */
+                          do
+                            c = getc (fp);
+                          while (!(c == EOF || c == '\n'));
+                          if (c == EOF)
+                            break;
+                          continue;
+                        }
+                      ungetc (c, fp);
+                      if (fscanf (fp, "%50s %50s", buf1, buf2) < 2)
+                        break;
+                      l1 = strlen (buf1);
+                      l2 = strlen (buf2);
+                      old_res_ptr = res_ptr;
+                      if (res_size == 0)
+                        {
+                          res_size = l1 + 1 + l2 + 1;
+                          res_ptr = (char *) malloc (res_size + 1);
+                        }
+                      else
+                        {
+                          res_size += l1 + 1 + l2 + 1;
+                          res_ptr = (char *) realloc (res_ptr, res_size + 1);
+                        }
+                      if (res_ptr == NULL)
+                        {
+                          /* Out of memory. */
+                          res_size = 0;
+                          free (old_res_ptr);
+                          break;
+                        }
+                      strcpy (res_ptr + res_size - (l2 + 1) - (l1 + 1), buf1);
+                      strcpy (res_ptr + res_size - (l2 + 1), buf2);
+                    }
+                  fclose (fp);
+                  if (res_size == 0)
+                    cp = "";
+                  else
+                    {
+                      *(res_ptr + res_size) = '\0';
+                      cp = res_ptr;
+                    }
+                }
+            }
+
+          free (file_name);
+        }
+
+#else
+
+# if defined DARWIN7
+      /* To avoid the trouble of installing a file that is shared by many
+         GNU packages -- many packaging systems have problems with this --,
+         simply inline the aliases here.  */
+      cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
+           "ISO8859-2" "\0" "ISO-8859-2" "\0"
+           "ISO8859-4" "\0" "ISO-8859-4" "\0"
+           "ISO8859-5" "\0" "ISO-8859-5" "\0"
+           "ISO8859-7" "\0" "ISO-8859-7" "\0"
+           "ISO8859-9" "\0" "ISO-8859-9" "\0"
+           "ISO8859-13" "\0" "ISO-8859-13" "\0"
+           "ISO8859-15" "\0" "ISO-8859-15" "\0"
+           "KOI8-R" "\0" "KOI8-R" "\0"
+           "KOI8-U" "\0" "KOI8-U" "\0"
+           "CP866" "\0" "CP866" "\0"
+           "CP949" "\0" "CP949" "\0"
+           "CP1131" "\0" "CP1131" "\0"
+           "CP1251" "\0" "CP1251" "\0"
+           "eucCN" "\0" "GB2312" "\0"
+           "GB2312" "\0" "GB2312" "\0"
+           "eucJP" "\0" "EUC-JP" "\0"
+           "eucKR" "\0" "EUC-KR" "\0"
+           "Big5" "\0" "BIG5" "\0"
+           "Big5HKSCS" "\0" "BIG5-HKSCS" "\0"
+           "GBK" "\0" "GBK" "\0"
+           "GB18030" "\0" "GB18030" "\0"
+           "SJIS" "\0" "SHIFT_JIS" "\0"
+           "ARMSCII-8" "\0" "ARMSCII-8" "\0"
+           "PT154" "\0" "PT154" "\0"
+         /*"ISCII-DEV" "\0" "?" "\0"*/
+           "*" "\0" "UTF-8" "\0";
+# endif
+
+# if defined VMS
+      /* To avoid the troubles of an extra file charset.alias_vms in the
+         sources of many GNU packages, simply inline the aliases here.  */
+      /* The list of encodings is taken from the OpenVMS 7.3-1 documentation
+         "Compaq C Run-Time Library Reference Manual for OpenVMS systems"
+         section 10.7 "Handling Different Character Sets".  */
+      cp = "ISO8859-1" "\0" "ISO-8859-1" "\0"
+           "ISO8859-2" "\0" "ISO-8859-2" "\0"
+           "ISO8859-5" "\0" "ISO-8859-5" "\0"
+           "ISO8859-7" "\0" "ISO-8859-7" "\0"
+           "ISO8859-8" "\0" "ISO-8859-8" "\0"
+           "ISO8859-9" "\0" "ISO-8859-9" "\0"
+           /* Japanese */
+           "eucJP" "\0" "EUC-JP" "\0"
+           "SJIS" "\0" "SHIFT_JIS" "\0"
+           "DECKANJI" "\0" "DEC-KANJI" "\0"
+           "SDECKANJI" "\0" "EUC-JP" "\0"
+           /* Chinese */
+           "eucTW" "\0" "EUC-TW" "\0"
+           "DECHANYU" "\0" "DEC-HANYU" "\0"
+           "DECHANZI" "\0" "GB2312" "\0"
+           /* Korean */
+           "DECKOREAN" "\0" "EUC-KR" "\0";
+# endif
+
+# if defined WINDOWS_NATIVE || defined __CYGWIN__
+      /* To avoid the troubles of installing a separate file in the same
+         directory as the DLL and of retrieving the DLL's directory at
+         runtime, simply inline the aliases here.  */
+
+      cp = "CP936" "\0" "GBK" "\0"
+           "CP1361" "\0" "JOHAB" "\0"
+           "CP20127" "\0" "ASCII" "\0"
+           "CP20866" "\0" "KOI8-R" "\0"
+           "CP20936" "\0" "GB2312" "\0"
+           "CP21866" "\0" "KOI8-RU" "\0"
+           "CP28591" "\0" "ISO-8859-1" "\0"
+           "CP28592" "\0" "ISO-8859-2" "\0"
+           "CP28593" "\0" "ISO-8859-3" "\0"
+           "CP28594" "\0" "ISO-8859-4" "\0"
+           "CP28595" "\0" "ISO-8859-5" "\0"
+           "CP28596" "\0" "ISO-8859-6" "\0"
+           "CP28597" "\0" "ISO-8859-7" "\0"
+           "CP28598" "\0" "ISO-8859-8" "\0"
+           "CP28599" "\0" "ISO-8859-9" "\0"
+           "CP28605" "\0" "ISO-8859-15" "\0"
+           "CP38598" "\0" "ISO-8859-8" "\0"
+           "CP51932" "\0" "EUC-JP" "\0"
+           "CP51936" "\0" "GB2312" "\0"
+           "CP51949" "\0" "EUC-KR" "\0"
+           "CP51950" "\0" "EUC-TW" "\0"
+           "CP54936" "\0" "GB18030" "\0"
+           "CP65001" "\0" "UTF-8" "\0";
+# endif
+#endif
+
+      charset_aliases = cp;
+    }
+
+  return cp;
+}
+
+/* Determine the current locale's character encoding, and canonicalize it
+   into one of the canonical names listed in config.charset.
+   The result must not be freed; it is statically allocated.
+   If the canonical name cannot be determined, the result is a non-canonical
+   name.  */
+
+#ifdef STATIC
+STATIC
+#endif
+const char *
+locale_charset (void)
+{
+  const char *codeset;
+  const char *aliases;
+
+#if !(defined WINDOWS_NATIVE || defined OS2)
+
+# if HAVE_LANGINFO_CODESET
+
+  /* Most systems support nl_langinfo (CODESET) nowadays.  */
+  codeset = nl_langinfo (CODESET);
+
+#  ifdef __CYGWIN__
+  /* Cygwin < 1.7 does not have locales.  nl_langinfo (CODESET) always
+     returns "US-ASCII".  Return the suffix of the locale name from the
+     environment variables (if present) or the codepage as a number.  */
+  if (codeset != NULL && strcmp (codeset, "US-ASCII") == 0)
+    {
+      const char *locale;
+      static char buf[2 + 10 + 1];
+
+      locale = getenv ("LC_ALL");
+      if (locale == NULL || locale[0] == '\0')
+        {
+          locale = getenv ("LC_CTYPE");
+          if (locale == NULL || locale[0] == '\0')
+            locale = getenv ("LANG");
+        }
+      if (locale != NULL && locale[0] != '\0')
+        {
+          /* If the locale name contains an encoding after the dot, return
+             it.  */
+          const char *dot = strchr (locale, '.');
+
+          if (dot != NULL)
+            {
+              const char *modifier;
+
+              dot++;
+              /* Look for the possible @... trailer and remove it, if any.  */
+              modifier = strchr (dot, '@');
+              if (modifier == NULL)
+                return dot;
+              if (modifier - dot < sizeof (buf))
+                {
+                  memcpy (buf, dot, modifier - dot);
+                  buf [modifier - dot] = '\0';
+                  return buf;
+                }
+            }
+        }
+
+      /* The Windows API has a function returning the locale's codepage as a
+         number: GetACP().  This encoding is used by Cygwin, unless the user
+         has set the environment variable CYGWIN=codepage:oem (which very few
+         people do).
+         Output directed to console windows needs to be converted (to
+         GetOEMCP() if the console is using a raster font, or to
+         GetConsoleOutputCP() if it is using a TrueType font).  Cygwin does
+         this conversion transparently (see winsup/cygwin/fhandler_console.cc),
+         converting to GetConsoleOutputCP().  This leads to correct results,
+         except when SetConsoleOutputCP has been called and a raster font is
+         in use.  */
+      sprintf (buf, "CP%u", GetACP ());
+      codeset = buf;
+    }
+#  endif
+
+# else
+
+  /* On old systems which lack it, use setlocale or getenv.  */
+  const char *locale = NULL;
+
+  /* But most old systems don't have a complete set of locales.  Some
+     (like SunOS 4 or DJGPP) have only the C locale.  Therefore we don't
+     use setlocale here; it would return "C" when it doesn't support the
+     locale name the user has set.  */
+#  if 0
+  locale = setlocale (LC_CTYPE, NULL);
+#  endif
+  if (locale == NULL || locale[0] == '\0')
+    {
+      locale = getenv ("LC_ALL");
+      if (locale == NULL || locale[0] == '\0')
+        {
+          locale = getenv ("LC_CTYPE");
+          if (locale == NULL || locale[0] == '\0')
+            locale = getenv ("LANG");
+        }
+    }
+
+  /* On some old systems, one used to set locale = "iso8859_1". On others,
+     you set it to "language_COUNTRY.charset". In any case, we resolve it
+     through the charset.alias file.  */
+  codeset = locale;
+
+# endif
+
+#elif defined WINDOWS_NATIVE
+
+  static char buf[2 + 10 + 1];
+
+  /* The Windows API has a function returning the locale's codepage as a
+     number: GetACP().
+     When the output goes to a console window, it needs to be provided in
+     GetOEMCP() encoding if the console is using a raster font, or in
+     GetConsoleOutputCP() encoding if it is using a TrueType font.
+     But in GUI programs and for output sent to files and pipes, GetACP()
+     encoding is the best bet.  */
+  sprintf (buf, "CP%u", GetACP ());
+  codeset = buf;
+
+#elif defined OS2
+
+  const char *locale;
+  static char buf[2 + 10 + 1];
+  ULONG cp[3];
+  ULONG cplen;
+
+  /* Allow user to override the codeset, as set in the operating system,
+     with standard language environment variables.  */
+  locale = getenv ("LC_ALL");
+  if (locale == NULL || locale[0] == '\0')
+    {
+      locale = getenv ("LC_CTYPE");
+      if (locale == NULL || locale[0] == '\0')
+        locale = getenv ("LANG");
+    }
+  if (locale != NULL && locale[0] != '\0')
+    {
+      /* If the locale name contains an encoding after the dot, return it.  */
+      const char *dot = strchr (locale, '.');
+
+      if (dot != NULL)
+        {
+          const char *modifier;
+
+          dot++;
+          /* Look for the possible @... trailer and remove it, if any.  */
+          modifier = strchr (dot, '@');
+          if (modifier == NULL)
+            return dot;
+          if (modifier - dot < sizeof (buf))
+            {
+              memcpy (buf, dot, modifier - dot);
+              buf [modifier - dot] = '\0';
+              return buf;
+            }
+        }
+
+      /* Resolve through the charset.alias file.  */
+      codeset = locale;
+    }
+  else
+    {
+      /* OS/2 has a function returning the locale's codepage as a number.  */
+      if (DosQueryCp (sizeof (cp), cp, &cplen))
+        codeset = "";
+      else
+        {
+          sprintf (buf, "CP%u", cp[0]);
+          codeset = buf;
+        }
+    }
+
+#endif
+
+  if (codeset == NULL)
+    /* The canonical name cannot be determined.  */
+    codeset = "";
+
+  /* Resolve alias. */
+  for (aliases = get_charset_aliases ();
+       *aliases != '\0';
+       aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1)
+    if (strcmp (codeset, aliases) == 0
+        || (aliases[0] == '*' && aliases[1] == '\0'))
+      {
+        codeset = aliases + strlen (aliases) + 1;
+        break;
+      }
+
+  /* Don't return an empty string.  GNU libc and GNU libiconv interpret
+     the empty string as denoting "the locale's character encoding",
+     thus GNU libiconv would call this function a second time.  */
+  if (codeset[0] == '\0')
+    codeset = "ASCII";
+
+  return codeset;
+}