gcc/prefix.c

   1 /* Utility to update paths from internal to external forms.
   2    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU Library General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or (at
  10 your option) any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* This file contains routines to update a path, both to canonicalize
  23    the directory format and to handle any prefix translation.
  24
  25    This file must be compiled with -DPREFIX= to specify the "prefix"
  26    value used by configure.  If a filename does not begin with this
  27    prefix, it will not be affected other than by directory canonicalization.
  28
  29    Each caller of 'update_path' may specify both a filename and
  30    a translation prefix and consist of the name of the package that contains
  31    the file ("@GCC", "@BINUTIL", "@GNU", etc).
  32
  33    If the prefix is not specified, the filename will only undergo
  34    directory canonicalization.
  35
  36    If it is specified, the string given by PREFIX will be replaced
  37    by the specified prefix (with a '@' in front unless the prefix begins
  38    with a '$') and further translation will be done as follows
  39    until none of the two conditions below are met:
  40
  41    1) If the filename begins with '@', the string between the '@' and
  42    the end of the name or the first '/' or directory separator will
  43    be considered a "key" and looked up as follows:
  44
  45    -- If this is a Win32 OS, then the Registry will be examined for
  46       an entry of "key" in
  47
  48       HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<KEY>
  49
  50       if found, that value will be used. <KEY> defaults to GCC version
  51       string, but can be overridden at configuration time.
  52
  53    -- If not found (or not a Win32 OS), the environment variable
  54       key_ROOT (the value of "key" concatenated with the constant "_ROOT")
  55       is tried.  If that fails, then PREFIX (see above) is used.
  56
  57    2) If the filename begins with a '$', the rest of the string up
  58    to the end or the first '/' or directory separator will be used
  59    as an environment variable, whose value will be returned.
  60
  61    Once all this is done, any '/' will be converted to DIR_SEPARATOR,
  62    if they are different.
  63
  64    NOTE:  using resolve_keyed_path under Win32 requires linking with
  65    advapi32.dll.  */
  66
  67
  68 #include "config.h"
  69 #include "system.h"
  70 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
  71 #include <windows.h>
  72 #endif
  73 #include "prefix.h"
  74
  75 static const char *std_prefix = PREFIX;
  76
  77 static const char *get_key_value        PARAMS ((char *));
  78 static char *translate_name             PARAMS ((char *));
  79 static char *save_string                PARAMS ((const char *, int));
  80 static void tr                          PARAMS ((char *, int, int));
  81
  82 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
  83 static char *lookup_key         PARAMS ((char *));
  84 static HKEY reg_key = (HKEY) INVALID_HANDLE_VALUE;
  85 #endif
  86
  87 /* Given KEY, as above, return its value.  */
  88
  89 static const char *
  90 get_key_value (key)
  91      char *key;
  92 {
  93   const char *prefix = 0;
  94   char *temp = 0;
  95
  96 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
  97   prefix = lookup_key (key);
  98 #endif
  99
 100   if (prefix == 0)
 101     prefix = getenv (temp = concat (key, "_ROOT", NULL));
 102
 103   if (prefix == 0)
 104     prefix = std_prefix;
 105
 106   if (temp)
 107     free (temp);
 108
 109   return prefix;
 110 }
 111
 112 /* Return a copy of a string that has been placed in the heap.  */
 113
 114 static char *
 115 save_string (s, len)
 116   const char *s;
 117   int len;
 118 {
 119   char *result = xmalloc (len + 1);
 120
 121   memcpy (result, s, len);
 122   result[len] = 0;
 123   return result;
 124 }
 125
 126 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
 127
 128 /* Look up "key" in the registry, as above.  */
 129
 130 static char *
 131 lookup_key (key)
 132      char *key;
 133 {
 134   char *dst;
 135   DWORD size;
 136   DWORD type;
 137   LONG res;
 138
 139   if (reg_key == (HKEY) INVALID_HANDLE_VALUE)
 140     {
 141       res = RegOpenKeyExA (HKEY_LOCAL_MACHINE, "SOFTWARE", 0,
 142                            KEY_READ, &reg_key);
 143
 144       if (res == ERROR_SUCCESS)
 145         res = RegOpenKeyExA (reg_key, "Free Software Foundation", 0,
 146                              KEY_READ, &reg_key);
 147
 148       if (res == ERROR_SUCCESS)
 149         res = RegOpenKeyExA (reg_key, WIN32_REGISTRY_KEY, 0,
 150                              KEY_READ, &reg_key);
 151
 152       if (res != ERROR_SUCCESS)
 153         {
 154           reg_key = (HKEY) INVALID_HANDLE_VALUE;
 155           return 0;
 156         }
 157     }
 158
 159   size = 32;
 160   dst = (char *) xmalloc (size);
 161
 162   res = RegQueryValueExA (reg_key, key, 0, &type, dst, &size);
 163   if (res == ERROR_MORE_DATA && type == REG_SZ)
 164     {
 165       dst = (char *) xrealloc (dst, size);
 166       res = RegQueryValueExA (reg_key, key, 0, &type, dst, &size);
 167     }
 168
 169   if (type != REG_SZ || res != ERROR_SUCCESS)
 170     {
 171       free (dst);
 172       dst = 0;
 173     }
 174
 175   return dst;
 176 }
 177 #endif
 178
 179 /* If NAME, a malloc-ed string, starts with a '@' or '$', apply the
 180    translation rules above and return a newly malloc-ed name.
 181    Otherwise, return the given name.  */
 182
 183 static char *
 184 translate_name (name)
 185      char *name;
 186 {
 187   char code;
 188   char *key, *old_name;
 189   const char *prefix;
 190   int keylen;
 191
 192   for (;;)
 193     {
 194       code = name[0];
 195       if (code != '@' && code != '$')
 196         break;
 197
 198       for (keylen = 0;
 199            (name[keylen + 1] != 0 && !IS_DIR_SEPARATOR (name[keylen + 1]));
 200            keylen++)
 201         ;
 202
 203       key = (char *) alloca (keylen + 1);
 204       strncpy (key, &name[1], keylen);
 205       key[keylen] = 0;
 206
 207       if (code == '@')
 208         {
 209           prefix = get_key_value (key);
 210           if (prefix == 0)
 211             prefix = std_prefix;
 212         }
 213       else
 214         prefix = getenv (key);
 215
 216       if (prefix == 0)
 217         prefix = PREFIX;
 218
 219       /* We used to strip trailing DIR_SEPARATORs here, but that can
 220          sometimes yield a result with no separator when one was coded
 221          and intended by the user, causing two path components to run
 222          together.  */
 223
 224       old_name = name;
 225       name = concat (prefix, &name[keylen + 1], NULL);
 226       free (old_name);
 227     }
 228
 229   return name;
 230 }
 231
 232 /* In a NUL-terminated STRING, replace character C1 with C2 in-place.  */
 233 static void
 234 tr (string, c1, c2)
 235      char *string;
 236      int c1, c2;
 237 {
 238   do
 239     {
 240       if (*string == c1)
 241         *string = c2;
 242     }
 243   while (*string++);
 244 }
 245
 246 /* Update PATH using KEY if PATH starts with PREFIX.  The returned
 247    string is always malloc-ed, and the caller is responsible for
 248    freeing it.  */
 249
 250 char *
 251 update_path (path, key)
 252   const char *path;
 253   const char *key;
 254 {
 255   char *result, *p;
 256
 257   if (! strncmp (path, std_prefix, strlen (std_prefix)) && key != 0)
 258     {
 259       bool free_key = false;
 260
 261       if (key[0] != '$')
 262         {
 263           key = concat ("@", key, NULL);
 264           free_key = true;
 265         }
 266
 267       result = concat (key, &path[strlen (std_prefix)], NULL);
 268       if (free_key)
 269         free ((char *) key);
 270       result = translate_name (result);
 271     }
 272   else
 273     result = xstrdup (path);
 274
 275 #ifndef ALWAYS_STRIP_DOTDOT
 276 #define ALWAYS_STRIP_DOTDOT 0
 277 #endif
 278
 279   p = result;
 280   while (1)
 281     {
 282       char *src, *dest;
 283
 284       p = strchr (p, '.');
 285       if (p == NULL)
 286         break;
 287       /* Get rid of a leading `./' and replace `/./' with `/', when
 288          such components are followed with another `.'.  */
 289       if (IS_DIR_SEPARATOR (p[1])
 290           && (p == result || IS_DIR_SEPARATOR (p[-1])))
 291         {
 292           src = p + 2;
 293           /* Be careful about .//foo  */
 294           while (IS_DIR_SEPARATOR (*src))
 295             ++src;
 296           if (*src == '.')
 297             {
 298               dest = p;
 299               while ((*dest++ = *src++) != 0)
 300                 ;
 301             }
 302           else
 303             ++p;
 304         }
 305       /* Look for `/../'  */
 306       else if (p[1] == '.'
 307                && IS_DIR_SEPARATOR (p[2])
 308                && (p != result && IS_DIR_SEPARATOR (p[-1])))
 309         {
 310           *p = 0;
 311           if (!ALWAYS_STRIP_DOTDOT && access (result, X_OK) == 0)
 312             {
 313               *p = '.';
 314               p += 3;
 315             }
 316           else
 317             {
 318               /* We can't access the dir, so we won't be able to
 319                  access dir/.. either.  Strip out dir/..  We know dir
 320                  isn't `.' because we've rid ourselves of `.' path
 321                  components above.  */
 322               dest = p - 1;
 323               while (dest != result && IS_DIR_SEPARATOR (*dest))
 324                 --dest;
 325               while (dest != result && !IS_DIR_SEPARATOR (dest[-1]))
 326                 --dest;
 327               /* Don't strip leading `/'.  */
 328               while (IS_DIR_SEPARATOR (*dest))
 329                 ++dest;
 330               src = p + 3;
 331               while (IS_DIR_SEPARATOR (*src))
 332                 ++src;
 333               p = dest;
 334               while ((*dest++ = *src++) != 0)
 335                 ;
 336             }
 337         }
 338       else
 339         ++p;
 340     }
 341
 342 #ifdef UPDATE_PATH_HOST_CANONICALIZE
 343   /* Perform host dependent canonicalization when needed.  */
 344   UPDATE_PATH_HOST_CANONICALIZE (result);
 345 #endif
 346
 347 #ifdef DIR_SEPARATOR_2
 348   /* Convert DIR_SEPARATOR_2 to DIR_SEPARATOR.  */
 349   if (DIR_SEPARATOR_2 != DIR_SEPARATOR)
 350     tr (result, DIR_SEPARATOR_2, DIR_SEPARATOR);
 351 #endif
 352
 353 #if defined (DIR_SEPARATOR) && !defined (DIR_SEPARATOR_2)
 354   if (DIR_SEPARATOR != '/')
 355     tr (result, '/', DIR_SEPARATOR);
 356 #endif
 357
 358   return result;
 359 }
 360
 361 /* Reset the standard prefix */
 362 void
 363 set_std_prefix (prefix, len)
 364   const char *prefix;
 365   int len;
 366 {
 367   std_prefix = save_string (prefix, len);
 368 }