1 /* Utility functions for finding files relative to GCC binaries.
2    Copyright (C) 1992-2020 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 #include "config.h"
21 #include "system.h"
22 #include "filenames.h"
23 #include "file-find.h"
24 
25 static bool debug = false;
26 
27 void
find_file_set_debug(bool debug_state)28 find_file_set_debug (bool debug_state)
29 {
30   debug = debug_state;
31 }
32 
33 char *
find_a_file(struct path_prefix * pprefix,const char * name,int mode)34 find_a_file (struct path_prefix *pprefix, const char *name, int mode)
35 {
36   char *temp;
37   struct prefix_list *pl;
38   int len = pprefix->max_len + strlen (name) + 1;
39 
40   if (debug)
41     fprintf (stderr, "Looking for '%s'\n", name);
42 
43 #ifdef HOST_EXECUTABLE_SUFFIX
44   len += strlen (HOST_EXECUTABLE_SUFFIX);
45 #endif
46 
47   temp = XNEWVEC (char, len);
48 
49   /* Determine the filename to execute (special case for absolute paths).  */
50 
51   if (IS_ABSOLUTE_PATH (name))
52     {
53       if (access (name, mode) == 0)
54 	{
55 	  strcpy (temp, name);
56 
57 	  if (debug)
58 	    fprintf (stderr, "  - found: absolute path\n");
59 
60 	  return temp;
61 	}
62 
63 #ifdef HOST_EXECUTABLE_SUFFIX
64 	/* Some systems have a suffix for executable files.
65 	   So try appending that.  */
66       strcpy (temp, name);
67 	strcat (temp, HOST_EXECUTABLE_SUFFIX);
68 
69 	if (access (temp, mode) == 0)
70 	  return temp;
71 #endif
72 
73       if (debug)
74 	fprintf (stderr, "  - failed to locate using absolute path\n");
75     }
76   else
77     for (pl = pprefix->plist; pl; pl = pl->next)
78       {
79 	struct stat st;
80 
81 	strcpy (temp, pl->prefix);
82 	strcat (temp, name);
83 
84 	if (stat (temp, &st) >= 0
85 	    && ! S_ISDIR (st.st_mode)
86 	    && access (temp, mode) == 0)
87 	  return temp;
88 
89 #ifdef HOST_EXECUTABLE_SUFFIX
90 	/* Some systems have a suffix for executable files.
91 	   So try appending that.  */
92 	strcat (temp, HOST_EXECUTABLE_SUFFIX);
93 
94 	if (stat (temp, &st) >= 0
95 	    && ! S_ISDIR (st.st_mode)
96 	    && access (temp, mode) == 0)
97 	  return temp;
98 #endif
99       }
100 
101   if (debug && pprefix->plist == NULL)
102     fprintf (stderr, "  - failed: no entries in prefix list\n");
103 
104   free (temp);
105   return 0;
106 }
107 
108 /* Add an entry for PREFIX to prefix list PREFIX.
109    Add at beginning if FIRST is true.  */
110 
111 void
do_add_prefix(struct path_prefix * pprefix,const char * prefix,bool first)112 do_add_prefix (struct path_prefix *pprefix, const char *prefix, bool first)
113 {
114   struct prefix_list *pl, **prev;
115   int len;
116 
117   if (pprefix->plist && !first)
118     {
119       for (pl = pprefix->plist; pl->next; pl = pl->next)
120 	;
121       prev = &pl->next;
122     }
123   else
124     prev = &pprefix->plist;
125 
126   /* Keep track of the longest prefix.  */
127 
128   len = strlen (prefix);
129   if (len > pprefix->max_len)
130     pprefix->max_len = len;
131 
132   pl = XNEW (struct prefix_list);
133   pl->prefix = xstrdup (prefix);
134 
135   if (*prev)
136     pl->next = *prev;
137   else
138     pl->next = (struct prefix_list *) 0;
139   *prev = pl;
140 }
141 
142 /* Add an entry for PREFIX at the end of prefix list PREFIX.  */
143 
144 void
add_prefix(struct path_prefix * pprefix,const char * prefix)145 add_prefix (struct path_prefix *pprefix, const char *prefix)
146 {
147   do_add_prefix (pprefix, prefix, false);
148 }
149 
150 /* Add an entry for PREFIX at the begin of prefix list PREFIX.  */
151 
152 void
add_prefix_begin(struct path_prefix * pprefix,const char * prefix)153 add_prefix_begin (struct path_prefix *pprefix, const char *prefix)
154 {
155   do_add_prefix (pprefix, prefix, true);
156 }
157 
158 /* Take the value of the environment variable ENV, break it into a path, and
159    add of the entries to PPREFIX.  */
160 
161 void
prefix_from_env(const char * env,struct path_prefix * pprefix)162 prefix_from_env (const char *env, struct path_prefix *pprefix)
163 {
164   const char *p;
165   p = getenv (env);
166 
167   if (p)
168     prefix_from_string (p, pprefix);
169 }
170 
171 void
prefix_from_string(const char * p,struct path_prefix * pprefix)172 prefix_from_string (const char *p, struct path_prefix *pprefix)
173 {
174   const char *startp, *endp;
175   char *nstore = XNEWVEC (char, strlen (p) + 3);
176 
177   if (debug)
178     fprintf (stderr, "Convert string '%s' into prefixes, separator = '%c'\n", p, PATH_SEPARATOR);
179 
180   startp = endp = p;
181   while (1)
182     {
183       if (*endp == PATH_SEPARATOR || *endp == 0)
184 	{
185 	  strncpy (nstore, startp, endp-startp);
186 	  if (endp == startp)
187 	    {
188 	      strcpy (nstore, "./");
189 	    }
190 	  else if (! IS_DIR_SEPARATOR (endp[-1]))
191 	    {
192 	      nstore[endp-startp] = DIR_SEPARATOR;
193 	      nstore[endp-startp+1] = 0;
194 	    }
195 	  else
196 	    nstore[endp-startp] = 0;
197 
198 	  if (debug)
199 	    fprintf (stderr, "  - add prefix: %s\n", nstore);
200 
201 	  add_prefix (pprefix, nstore);
202 	  if (*endp == 0)
203 	    break;
204 	  endp = startp = endp + 1;
205 	}
206       else
207 	endp++;
208     }
209   free (nstore);
210 }
211