1 /* Implementation of file prefix remapping support (-f*-prefix-map options).
2 Copyright (C) 2017-2020 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 3, or (at your option) any
7 later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; see the file COPYING3. If not see
16 <http://www.gnu.org/licenses/>. */
17
18 #include "config.h"
19 #include "system.h"
20 #include "coretypes.h"
21 #include "diagnostic.h"
22 #include "file-prefix-map.h"
23
24 /* Structure recording the mapping from source file and directory names at
25 compile time to those to be embedded in the compilation result (debug
26 information, the __FILE__ macro expansion, etc). */
27 struct file_prefix_map
28 {
29 const char *old_prefix;
30 const char *new_prefix;
31 size_t old_len;
32 size_t new_len;
33 struct file_prefix_map *next;
34 };
35
36 /* Record a file prefix mapping in the specified map. ARG is the argument to
37 -f*-prefix-map and must be of the form OLD=NEW. OPT is the option name
38 for diagnostics. */
39 static void
add_prefix_map(file_prefix_map * & maps,const char * arg,const char * opt)40 add_prefix_map (file_prefix_map *&maps, const char *arg, const char *opt)
41 {
42 file_prefix_map *map;
43 const char *p, *old;
44 size_t oldlen;
45
46 /* Note: looking for the last '='. The thinking is we can control the paths
47 inside our projects but not where the users build them. */
48 p = strrchr (arg, '=');
49 if (!p)
50 {
51 error ("invalid argument %qs to %qs", arg, opt);
52 return;
53 }
54 if (*arg == '$')
55 {
56 char *env = xstrndup (arg + 1, p - (arg + 1));
57 old = getenv(env);
58 if (!old)
59 {
60 warning (0, "environment variable %qs not set in argument to "
61 "%s", env, opt);
62 free(env);
63 return;
64 }
65 oldlen = strlen(old);
66 free(env);
67 }
68 else
69 {
70 old = xstrndup (arg, p - arg);
71 oldlen = p - arg;
72 }
73 map = XNEW (file_prefix_map);
74 map->old_prefix = old;
75 map->old_len = oldlen;
76 p++;
77 map->new_prefix = xstrdup (p);
78 map->new_len = strlen (p);
79 map->next = maps;
80 maps = map;
81 }
82
83 /* Perform user-specified mapping of filename prefixes. Return the
84 GC-allocated new name corresponding to FILENAME or FILENAME if no
85 remapping was performed. */
86
87 static const char *
remap_filename(file_prefix_map * maps,const char * filename)88 remap_filename (file_prefix_map *maps, const char *filename)
89 {
90 file_prefix_map *map;
91 char *s;
92 const char *name;
93 size_t name_len;
94
95 for (map = maps; map; map = map->next)
96 if (filename_ncmp (filename, map->old_prefix, map->old_len) == 0)
97 break;
98 if (!map)
99 return filename;
100 name = filename + map->old_len;
101 name_len = strlen (name) + 1;
102
103 s = (char *) ggc_alloc_atomic (name_len + map->new_len);
104 memcpy (s, map->new_prefix, map->new_len);
105 memcpy (s + map->new_len, name, name_len);
106 return s;
107 }
108
109 /* NOTE: if adding another -f*-prefix-map option then don't forget to
110 ignore it in DW_AT_producer (dwarf2out.c). */
111
112 /* Linked lists of file_prefix_map structures. */
113 static file_prefix_map *macro_prefix_maps; /* -fmacro-prefix-map */
114 static file_prefix_map *debug_prefix_maps; /* -fdebug-prefix-map */
115
116 /* Record a file prefix mapping for -fmacro-prefix-map. */
117 void
add_macro_prefix_map(const char * arg)118 add_macro_prefix_map (const char *arg)
119 {
120 add_prefix_map (macro_prefix_maps, arg, "-fmacro-prefix-map");
121 }
122
123 /* Record a file prefix mapping for -fdebug-prefix-map. */
124 void
add_debug_prefix_map(const char * arg)125 add_debug_prefix_map (const char *arg)
126 {
127 add_prefix_map (debug_prefix_maps, arg, "-fdebug-prefix-map");
128 }
129
130 /* Record a file prefix mapping for all -f*-prefix-map. */
131 void
add_file_prefix_map(const char * arg)132 add_file_prefix_map (const char *arg)
133 {
134 add_prefix_map (macro_prefix_maps, arg, "-ffile-prefix-map");
135 add_prefix_map (debug_prefix_maps, arg, "-ffile-prefix-map");
136 }
137
138 /* Remap using -fmacro-prefix-map. Return the GC-allocated new name
139 corresponding to FILENAME or FILENAME if no remapping was performed. */
140 const char *
remap_macro_filename(const char * filename)141 remap_macro_filename (const char *filename)
142 {
143 return remap_filename (macro_prefix_maps, filename);
144 }
145
146 /* Original GCC version disabled. The NetBSD version handles regex */
147 #if 0
148 /* Remap using -fdebug-prefix-map. Return the GC-allocated new name
149 corresponding to FILENAME or FILENAME if no remapping was performed. */
150 const char *
151 remap_debug_filename (const char *filename)
152 {
153 return remap_filename (debug_prefix_maps, filename);
154 }
155 #endif
156
157 /*****
158 ***** The following code is a NetBSD extension that allows regex and
159 ***** \[0-9] substitutition arguments.
160 *****/
161
162 /* Perform user-specified mapping of debug filename prefixes. Return
163 the new name corresponding to FILENAME. */
164
165 static const char *
remap_debug_prefix_filename(const char * filename)166 remap_debug_prefix_filename (const char *filename)
167 {
168 file_prefix_map *map;
169 char *s;
170 const char *name;
171 size_t name_len;
172
173 for (map = debug_prefix_maps; map; map = map->next)
174 if (filename_ncmp (filename, map->old_prefix, map->old_len) == 0)
175 break;
176 if (!map)
177 return filename;
178 name = filename + map->old_len;
179 name_len = strlen (name) + 1;
180 s = (char *) alloca (name_len + map->new_len);
181 memcpy (s, map->new_prefix, map->new_len);
182 memcpy (s + map->new_len, name, name_len);
183 return ggc_strdup (s);
184 }
185
186 #include <regex.h>
187
188 typedef struct debug_regex_map
189 {
190 regex_t re;
191 const char *sub;
192 struct debug_regex_map *next;
193 } debug_regex_map;
194
195 /* Linked list of such structures. */
196 debug_regex_map *debug_regex_maps;
197
198
199 /* Record a debug file regex mapping. ARG is the argument to
200 -fdebug-regex-map and must be of the form OLD=NEW. */
201
202 void
add_debug_regex_map(const char * arg)203 add_debug_regex_map (const char *arg)
204 {
205 debug_regex_map *map;
206 const char *p;
207 char *old;
208 char buf[1024];
209 regex_t re;
210 int e;
211
212 p = strchr (arg, '=');
213 if (!p)
214 {
215 error ("invalid argument %qs to -fdebug-regex-map", arg);
216 return;
217 }
218
219 old = xstrndup (arg, p - arg);
220 if ((e = regcomp(&re, old, REG_EXTENDED)) != 0)
221 {
222 regerror(e, &re, buf, sizeof(buf));
223 warning (0, "regular expression compilation for %qs in argument to "
224 "-fdebug-regex-map failed: %qs", old, buf);
225 free(old);
226 return;
227 }
228 free(old);
229
230 map = XNEW (debug_regex_map);
231 map->re = re;
232 p++;
233 map->sub = xstrdup (p);
234 map->next = debug_regex_maps;
235 debug_regex_maps = map;
236 }
237
238 extern "C" ssize_t regasub(char **, const char *,
239 const regmatch_t *rm, const char *);
240
241 /* Perform user-specified mapping of debug filename regular expressions. Return
242 the new name corresponding to FILENAME. */
243
244 static const char *
remap_debug_regex_filename(const char * filename)245 remap_debug_regex_filename (const char *filename)
246 {
247 debug_regex_map *map;
248 char *s;
249 regmatch_t rm[10];
250
251 for (map = debug_regex_maps; map; map = map->next)
252 if (regexec (&map->re, filename, 10, rm, 0) == 0
253 && regasub (&s, map->sub, rm, filename) >= 0)
254 {
255 const char *name = ggc_strdup(s);
256 free(s);
257 return name;
258 }
259 return filename;
260 }
261
262 const char *
remap_debug_filename(const char * filename)263 remap_debug_filename (const char *filename)
264 {
265 return remap_debug_regex_filename (remap_debug_prefix_filename (filename));
266 }
267