xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/prefix.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Utility to update paths from internal to external forms.
2    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3    2007  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 3 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 COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 /* This file contains routines to update a path, both to canonicalize
22    the directory format and to handle any prefix translation.
23 
24    This file must be compiled with -DPREFIX= to specify the "prefix"
25    value used by configure.  If a filename does not begin with this
26    prefix, it will not be affected other than by directory canonicalization.
27 
28    Each caller of 'update_path' may specify both a filename and
29    a translation prefix and consist of the name of the package that contains
30    the file ("@GCC", "@BINUTIL", "@GNU", etc).
31 
32    If the prefix is not specified, the filename will only undergo
33    directory canonicalization.
34 
35    If it is specified, the string given by PREFIX will be replaced
36    by the specified prefix (with a '@' in front unless the prefix begins
37    with a '$') and further translation will be done as follows
38    until none of the two conditions below are met:
39 
40    1) If the filename begins with '@', the string between the '@' and
41    the end of the name or the first '/' or directory separator will
42    be considered a "key" and looked up as follows:
43 
44    -- If this is a Win32 OS, then the Registry will be examined for
45       an entry of "key" in
46 
47       HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<KEY>
48 
49       if found, that value will be used. <KEY> defaults to GCC version
50       string, but can be overridden at configuration time.
51 
52    -- If not found (or not a Win32 OS), the environment variable
53       key_ROOT (the value of "key" concatenated with the constant "_ROOT")
54       is tried.  If that fails, then PREFIX (see above) is used.
55 
56    2) If the filename begins with a '$', the rest of the string up
57    to the end or the first '/' or directory separator will be used
58    as an environment variable, whose value will be returned.
59 
60    Once all this is done, any '/' will be converted to DIR_SEPARATOR,
61    if they are different.
62 
63    NOTE:  using resolve_keyed_path under Win32 requires linking with
64    advapi32.dll.  */
65 
66 
67 #include "config.h"
68 #include "system.h"
69 #include "coretypes.h"
70 #include "tm.h"
71 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
72 #include <windows.h>
73 #endif
74 #include "prefix.h"
75 
76 static const char *std_prefix = PREFIX;
77 
78 static const char *get_key_value (char *);
79 static char *translate_name (char *);
80 static char *save_string (const char *, int);
81 static void tr (char *, int, int);
82 
83 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
84 static char *lookup_key (char *);
85 static HKEY reg_key = (HKEY) INVALID_HANDLE_VALUE;
86 #endif
87 
88 /* Given KEY, as above, return its value.  */
89 
90 static const char *
91 get_key_value (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 (const char *s, int len)
116 {
117   char *result = XNEWVEC (char, len + 1);
118 
119   memcpy (result, s, len);
120   result[len] = 0;
121   return result;
122 }
123 
124 #if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
125 
126 #ifndef WIN32_REGISTRY_KEY
127 # define WIN32_REGISTRY_KEY BASEVER
128 #endif
129 
130 /* Look up "key" in the registry, as above.  */
131 
132 static char *
133 lookup_key (char *key)
134 {
135   char *dst;
136   DWORD size;
137   DWORD type;
138   LONG res;
139 
140   if (reg_key == (HKEY) INVALID_HANDLE_VALUE)
141     {
142       res = RegOpenKeyExA (HKEY_LOCAL_MACHINE, "SOFTWARE", 0,
143 			   KEY_READ, &reg_key);
144 
145       if (res == ERROR_SUCCESS)
146 	res = RegOpenKeyExA (reg_key, "Free Software Foundation", 0,
147 			     KEY_READ, &reg_key);
148 
149       if (res == ERROR_SUCCESS)
150 	res = RegOpenKeyExA (reg_key, WIN32_REGISTRY_KEY, 0,
151 			     KEY_READ, &reg_key);
152 
153       if (res != ERROR_SUCCESS)
154 	{
155 	  reg_key = (HKEY) INVALID_HANDLE_VALUE;
156 	  return 0;
157 	}
158     }
159 
160   size = 32;
161   dst = xmalloc (size);
162 
163   res = RegQueryValueExA (reg_key, key, 0, &type, (LPBYTE) dst, &size);
164   if (res == ERROR_MORE_DATA && type == REG_SZ)
165     {
166       dst = xrealloc (dst, size);
167       res = RegQueryValueExA (reg_key, key, 0, &type, (LPBYTE) dst, &size);
168     }
169 
170   if (type != REG_SZ || res != ERROR_SUCCESS)
171     {
172       free (dst);
173       dst = 0;
174     }
175 
176   return dst;
177 }
178 #endif
179 
180 /* If NAME, a malloc-ed string, starts with a '@' or '$', apply the
181    translation rules above and return a newly malloc-ed name.
182    Otherwise, return the given name.  */
183 
184 static char *
185 translate_name (char *name)
186 {
187   char code;
188   char *key, *old_name;
189   const char *prefix;
190   int keylen;
191 
192   for (;;)
193     {
194       code = name[0];
195       if (code != '@' && code != '$')
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 (char *string, int c1, int c2)
235 {
236   do
237     {
238       if (*string == c1)
239 	*string = c2;
240     }
241   while (*string++);
242 }
243 
244 /* Update PATH using KEY if PATH starts with PREFIX as a directory.
245    The returned string is always malloc-ed, and the caller is
246    responsible for freeing it.  */
247 
248 char *
249 update_path (const char *path, const char *key)
250 {
251   char *result, *p;
252   const int len = strlen (std_prefix);
253 
254   if (! strncmp (path, std_prefix, len)
255       && (IS_DIR_SEPARATOR(path[len])
256           || path[len] == '\0')
257       && 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[len], NULL);
268       if (free_key)
269 	free (CONST_CAST (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       /* Look for `/../'  */
288       if (p[1] == '.'
289 	  && IS_DIR_SEPARATOR (p[2])
290 	  && (p != result && IS_DIR_SEPARATOR (p[-1])))
291 	{
292 	  *p = 0;
293 	  if (!ALWAYS_STRIP_DOTDOT && access (result, X_OK) == 0)
294 	    {
295 	      *p = '.';
296 	      break;
297 	    }
298 	  else
299 	    {
300 	      /* We can't access the dir, so we won't be able to
301 		 access dir/.. either.  Strip out `dir/../'.  If `dir'
302 		 turns out to be `.', strip one more path component.  */
303 	      dest = p;
304 	      do
305 		{
306 		  --dest;
307 		  while (dest != result && IS_DIR_SEPARATOR (*dest))
308 		    --dest;
309 		  while (dest != result && !IS_DIR_SEPARATOR (dest[-1]))
310 		    --dest;
311 		}
312 	      while (dest != result && *dest == '.');
313 	      /* If we have something like `./..' or `/..', don't
314 		 strip anything more.  */
315 	      if (*dest == '.' || IS_DIR_SEPARATOR (*dest))
316 		{
317 		  *p = '.';
318 		  break;
319 		}
320 	      src = p + 3;
321 	      while (IS_DIR_SEPARATOR (*src))
322 		++src;
323 	      p = dest;
324 	      while ((*dest++ = *src++) != 0)
325 		;
326 	    }
327 	}
328       else
329 	++p;
330     }
331 
332 #ifdef UPDATE_PATH_HOST_CANONICALIZE
333   /* Perform host dependent canonicalization when needed.  */
334   UPDATE_PATH_HOST_CANONICALIZE (result);
335 #endif
336 
337 #ifdef DIR_SEPARATOR_2
338   /* Convert DIR_SEPARATOR_2 to DIR_SEPARATOR.  */
339   if (DIR_SEPARATOR_2 != DIR_SEPARATOR)
340     tr (result, DIR_SEPARATOR_2, DIR_SEPARATOR);
341 #endif
342 
343 #if defined (DIR_SEPARATOR) && !defined (DIR_SEPARATOR_2)
344   if (DIR_SEPARATOR != '/')
345     tr (result, '/', DIR_SEPARATOR);
346 #endif
347 
348   return result;
349 }
350 
351 /* Reset the standard prefix.  */
352 void
353 set_std_prefix (const char *prefix, int len)
354 {
355   std_prefix = save_string (prefix, len);
356 }
357