1/* Utility to update paths from internal to external forms.
2 Copyright (C) 1997-2017 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU Library General Public License as published by
8the Free Software Foundation; either version 3 of the License, or (at
9your option) any later version.
10
11GCC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14Library General Public License for more details.
15
16You should have received a copy of the GNU Library General Public
17License along with GCC; see the file COPYING3. If not see
18<http://www.gnu.org/licenses/>. */
19
20/* This file contains routines to update a path, both to canonicalize
21 the directory format and to handle any prefix translation.
22
23 This file must be compiled with -DPREFIX= to specify the "prefix"
24 value used by configure. If a filename does not begin with this
25 prefix, it will not be affected other than by directory canonicalization.
26
27 Each caller of 'update_path' may specify both a filename and
28 a translation prefix and consist of the name of the package that contains
29 the file ("@GCC", "@BINUTIL", "@GNU", etc).
30
31 If the prefix is not specified, the filename will only undergo
32 directory canonicalization.
33
34 If it is specified, the string given by PREFIX will be replaced
35 by the specified prefix (with a '@' in front unless the prefix begins
36 with a '$') and further translation will be done as follows
37 until none of the two conditions below are met:
38
39 1) If the filename begins with '@', the string between the '@' and
40 the end of the name or the first '/' or directory separator will
41 be considered a "key" and looked up as follows:
42
43 -- If this is a Win32 OS, then the Registry will be examined for
44 an entry of "key" in
45
46 HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<KEY>
47
48 if found, that value will be used. <KEY> defaults to GCC version
49 string, but can be overridden at configuration time.
50
51 -- If not found (or not a Win32 OS), the environment variable
52 key_ROOT (the value of "key" concatenated with the constant "_ROOT")
53 is tried. If that fails, then PREFIX (see above) is used.
54
55 2) If the filename begins with a '$', the rest of the string up
56 to the end or the first '/' or directory separator will be used
57 as an environment variable, whose value will be returned.
58
59 Once all this is done, any '/' will be converted to DIR_SEPARATOR,
60 if they are different.
61
62 NOTE: using resolve_keyed_path under Win32 requires linking with
63 advapi32.dll. */
64
65
66#include "config.h"
67#include "system.h"
68#include "coretypes.h"
69#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
70#include <windows.h>
71#endif
72#include "prefix.h"
73#include "common/common-target.h"
74
75static const char *std_prefix = PREFIX;
76
77static const char *get_key_value (char *);
78static char *translate_name (char *);
79static char *save_string (const char *, int);
80static void tr (char *, int, int);
81
82#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
83static char *lookup_key (char *);
84static HKEY reg_key = (HKEY) INVALID_HANDLE_VALUE;
85#endif
86
87/* Given KEY, as above, return its value. */
88
89static const char *
90get_key_value (char *key)
91{
92 const char *prefix = 0;
93 char *temp = 0;
94
95#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
96 prefix = lookup_key (key);
97#endif
98
99 if (prefix == 0)
100 prefix = getenv (temp = concat (key, "_ROOT", NULL));
101
102 if (prefix == 0)
103 prefix = std_prefix;
104
105 free (temp);
106
107 return prefix;
108}
109
110/* Return a copy of a string that has been placed in the heap. */
111
112static char *
113save_string (const char *s, int len)
114{
115 char *result = XNEWVEC (char, len + 1);
116
117 memcpy (result, s, len);
118 result[len] = 0;
119 return result;
120}
121
122#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
123
124#ifndef WIN32_REGISTRY_KEY
125# define WIN32_REGISTRY_KEY BASEVER
126#endif
127
128/* Look up "key" in the registry, as above. */
129
130static char *
131lookup_key (char *key)
132{
133 char *dst;
134 DWORD size;
135 DWORD type;
136 LONG res;
137
138 if (reg_key == (HKEY) INVALID_HANDLE_VALUE)
139 {
140 res = RegOpenKeyExA (HKEY_LOCAL_MACHINE, "SOFTWARE", 0,
141 KEY_READ, &reg_key);
142
143 if (res == ERROR_SUCCESS)
144 res = RegOpenKeyExA (reg_key, "Free Software Foundation", 0,
145 KEY_READ, &reg_key);
146
147 if (res == ERROR_SUCCESS)
148 res = RegOpenKeyExA (reg_key, WIN32_REGISTRY_KEY, 0,
149 KEY_READ, &reg_key);
150
151 if (res != ERROR_SUCCESS)
152 {
153 reg_key = (HKEY) INVALID_HANDLE_VALUE;
154 return 0;
155 }
156 }
157
158 size = 32;
159 dst = XNEWVEC (char, size);
160
161 res = RegQueryValueExA (reg_key, key, 0, &type, (LPBYTE) dst, &size);
162 if (res == ERROR_MORE_DATA && type == REG_SZ)
163 {
164 dst = XRESIZEVEC (char, dst, size);
165 res = RegQueryValueExA (reg_key, key, 0, &type, (LPBYTE) dst, &size);
166 }
167
168 if (type != REG_SZ || res != ERROR_SUCCESS)
169 {
170 free (dst);
171 dst = 0;
172 }
173
174 return dst;
175}
176#endif
177
178/* If NAME, a malloc-ed string, starts with a '@' or '$', apply the
179 translation rules above and return a newly malloc-ed name.
180 Otherwise, return the given name. */
181
182static char *
183translate_name (char *name)
184{
185 char code;
186 char *key, *old_name;
187 const char *prefix;
188 int keylen;
189
190 for (;;)
191 {
192 code = name[0];
193 if (code != '@' && code != '$')
194 break;
195
196 for (keylen = 0;
197 (name[keylen + 1] != 0 && !IS_DIR_SEPARATOR (name[keylen + 1]));
198 keylen++)
199 ;
200
201 key = (char *) alloca (keylen + 1);
202 memcpy (key, &name[1], keylen);
203 key[keylen] = 0;
204
205 if (code == '@')
206 {
207 prefix = get_key_value (key);
208 if (prefix == 0)
209 prefix = std_prefix;
210 }
211 else
212 prefix = getenv (key);
213
214 if (prefix == 0)
215 prefix = PREFIX;
216
217 /* We used to strip trailing DIR_SEPARATORs here, but that can
218 sometimes yield a result with no separator when one was coded
219 and intended by the user, causing two path components to run
220 together. */
221
222 old_name = name;
223 name = concat (prefix, &name[keylen + 1], NULL);
224 free (old_name);
225 }
226
227 return name;
228}
229
230/* In a NUL-terminated STRING, replace character C1 with C2 in-place. */
231static void
232tr (char *string, int c1, int c2)
233{
234 do
235 {
236 if (*string == c1)
237 *string = c2;
238 }
239 while (*string++);
240}
241
242/* Update PATH using KEY if PATH starts with PREFIX as a directory.
243 The returned string is always malloc-ed, and the caller is
244 responsible for freeing it. */
245
246char *
247update_path (const char *path, const char *key)
248{
249 char *result, *p;
250 const int len = strlen (std_prefix);
251
252 if (! filename_ncmp (path, std_prefix, len)
253 && (IS_DIR_SEPARATOR (path[len])
254 || path[len] == '\0')
255 && key != 0)
256 {
257 bool free_key = false;
258
259 if (key[0] != '$')
260 {
261 key = concat ("@", key, NULL);
262 free_key = true;
263 }
264
265 result = concat (key, &path[len], NULL);
266 if (free_key)
267 free (CONST_CAST (char *, key));
268 result = translate_name (result);
269 }
270 else
271 result = xstrdup (path);
272
273 p = result;
274 while (1)
275 {
276 char *src, *dest;
277
278 p = strchr (p, '.');
279 if (p == NULL)
280 break;
281 /* Look for `/../' */
282 if (p[1] == '.'
283 && IS_DIR_SEPARATOR (p[2])
284 && (p != result && IS_DIR_SEPARATOR (p[-1])))
285 {
286 *p = 0;
287 if (!targetm_common.always_strip_dotdot
288 && access (result, X_OK) == 0)
289 {
290 *p = '.';
291 break;
292 }
293 else
294 {
295 /* We can't access the dir, so we won't be able to
296 access dir/.. either. Strip out `dir/../'. If `dir'
297 turns out to be `.', strip one more path component. */
298 dest = p;
299 do
300 {
301 --dest;
302 while (dest != result && IS_DIR_SEPARATOR (*dest))
303 --dest;
304 while (dest != result && !IS_DIR_SEPARATOR (dest[-1]))
305 --dest;
306 }
307 while (dest != result && *dest == '.');
308 /* If we have something like `./..' or `/..', don't
309 strip anything more. */
310 if (*dest == '.' || IS_DIR_SEPARATOR (*dest))
311 {
312 *p = '.';
313 break;
314 }
315 src = p + 3;
316 while (IS_DIR_SEPARATOR (*src))
317 ++src;
318 p = dest;
319 while ((*dest++ = *src++) != 0)
320 ;
321 }
322 }
323 else
324 ++p;
325 }
326
327#ifdef UPDATE_PATH_HOST_CANONICALIZE
328 /* Perform host dependent canonicalization when needed. */
329 UPDATE_PATH_HOST_CANONICALIZE (result);
330#endif
331
332#ifdef DIR_SEPARATOR_2
333 /* Convert DIR_SEPARATOR_2 to DIR_SEPARATOR. */
334 if (DIR_SEPARATOR_2 != DIR_SEPARATOR)
335 tr (result, DIR_SEPARATOR_2, DIR_SEPARATOR);
336#endif
337
338#if defined (DIR_SEPARATOR) && !defined (DIR_SEPARATOR_2)
339 if (DIR_SEPARATOR != '/')
340 tr (result, '/', DIR_SEPARATOR);
341#endif
342
343 return result;
344}
345
346/* Reset the standard prefix. */
347void
348set_std_prefix (const char *prefix, int len)
349{
350 std_prefix = save_string (prefix, len);
351}
352