1/* Implementation of file prefix remapping support (-f*-prefix-map options).
2 Copyright (C) 2017-2023 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). */
27struct 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 bool canonicalize;
34 struct file_prefix_map *next;
35};
36
37/* Record a file prefix mapping in the specified map. ARG is the argument to
38 -f*-prefix-map and must be of the form OLD=NEW. OPT is the option name
39 for diagnostics. */
40static void
41add_prefix_map (file_prefix_map *&maps, const char *arg, const char *opt)
42{
43 file_prefix_map *map;
44 const char *p;
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 (s: arg, c: '=');
49 if (!p)
50 {
51 error ("invalid argument %qs to %qs", arg, opt);
52 return;
53 }
54 map = XNEW (file_prefix_map);
55 map->canonicalize = flag_canon_prefix_map;
56 map->old_prefix = xstrndup (arg, p - arg);
57 map->old_len = p - arg;
58 if (map->canonicalize)
59 {
60 char *realname = lrealpath (map->old_prefix);
61 free (ptr: const_cast <char *> (map->old_prefix));
62 map->old_prefix = realname;
63 map->old_len = strlen (s: realname);
64 }
65 p++;
66 map->new_prefix = xstrdup (p);
67 map->new_len = strlen (s: p);
68 map->next = maps;
69 maps = map;
70}
71
72/* Perform user-specified mapping of filename prefixes. Return the
73 GC-allocated new name corresponding to FILENAME or FILENAME if no
74 remapping was performed. */
75
76static const char *
77remap_filename (file_prefix_map *maps, const char *filename)
78{
79 file_prefix_map *map;
80 char *s;
81 const char *name;
82 const char *realname = NULL;
83 size_t name_len;
84
85 if (!filename)
86 return filename;
87
88 for (map = maps; map; map = map->next)
89 if (map->canonicalize)
90 {
91 if (realname == NULL)
92 {
93 if (lbasename (filename) == filename)
94 realname = filename;
95 else
96 realname = lrealpath (filename);
97 }
98 if (filename_ncmp (s1: realname, s2: map->old_prefix, n: map->old_len) == 0)
99 break;
100 }
101 else if (filename_ncmp (s1: filename, s2: map->old_prefix, n: map->old_len) == 0)
102 break;
103 if (!map)
104 {
105 if (realname != filename)
106 free (ptr: const_cast <char *> (realname));
107 return filename;
108 }
109 if (map->canonicalize)
110 name = realname + map->old_len;
111 else
112 name = filename + map->old_len;
113 name_len = strlen (s: name) + 1;
114
115 s = (char *) ggc_alloc_atomic (s: name_len + map->new_len);
116 memcpy (dest: s, src: map->new_prefix, n: map->new_len);
117 memcpy (dest: s + map->new_len, src: name, n: name_len);
118 if (realname != filename)
119 free (ptr: const_cast <char *> (realname));
120 return s;
121}
122
123/* NOTE: if adding another -f*-prefix-map option then don't forget to
124 ignore it in DW_AT_producer (gen_command_line_string in opts.cc). */
125
126/* Linked lists of file_prefix_map structures. */
127static file_prefix_map *macro_prefix_maps; /* -fmacro-prefix-map */
128static file_prefix_map *debug_prefix_maps; /* -fdebug-prefix-map */
129static file_prefix_map *profile_prefix_maps; /* -fprofile-prefix-map */
130
131/* Record a file prefix mapping for -fmacro-prefix-map. */
132void
133add_macro_prefix_map (const char *arg)
134{
135 add_prefix_map (maps&: macro_prefix_maps, arg, opt: "-fmacro-prefix-map");
136}
137
138/* Record a file prefix mapping for -fdebug-prefix-map. */
139void
140add_debug_prefix_map (const char *arg)
141{
142 add_prefix_map (maps&: debug_prefix_maps, arg, opt: "-fdebug-prefix-map");
143}
144
145/* Record a file prefix mapping for all -f*-prefix-map. */
146void
147add_file_prefix_map (const char *arg)
148{
149 add_prefix_map (maps&: macro_prefix_maps, arg, opt: "-ffile-prefix-map");
150 add_prefix_map (maps&: debug_prefix_maps, arg, opt: "-ffile-prefix-map");
151 add_prefix_map (maps&: profile_prefix_maps, arg, opt: "-ffile-prefix-map");
152}
153
154/* Record a file prefix mapping for -fprofile-prefix-map. */
155void
156add_profile_prefix_map (const char *arg)
157{
158 add_prefix_map (maps&: profile_prefix_maps, arg, opt: "-fprofile-prefix-map");
159}
160
161/* Remap using -fmacro-prefix-map. Return the GC-allocated new name
162 corresponding to FILENAME or FILENAME if no remapping was performed. */
163const char *
164remap_macro_filename (const char *filename)
165{
166 return remap_filename (maps: macro_prefix_maps, filename);
167}
168
169/* Remap using -fdebug-prefix-map. Return the GC-allocated new name
170 corresponding to FILENAME or FILENAME if no remapping was performed. */
171const char *
172remap_debug_filename (const char *filename)
173{
174 return remap_filename (maps: debug_prefix_maps, filename);
175}
176
177/* Remap using -fprofile-prefix-map. Return the GC-allocated new name
178 corresponding to FILENAME or FILENAME if no remapping was performed. */
179const char *
180remap_profile_filename (const char *filename)
181{
182 return remap_filename (maps: profile_prefix_maps, filename);
183}
184

source code of gcc/file-prefix-map.cc