1 /*
2 * This wrapper program executes a python executable hidden inside an
3 * application bundle inside the Python framework. This is needed to run
4 * GUI code: some GUI API's don't work unless the program is inside an
5 * application bundle.
6 *
7 * This program uses posix_spawn rather than plain execv because we need
8 * slightly more control over how the "real" interpreter is executed.
9 *
10 * On OSX 10.4 (and earlier) this falls back to using exec because the
11 * posix_spawnv functions aren't available there.
12 */
13 #pragma weak_import posix_spawnattr_init
14 #pragma weak_import posix_spawnattr_setbinpref_np
15 #pragma weak_import posix_spawnattr_setflags
16 #pragma weak_import posix_spawn
17
18 #include <Python.h>
19 #include <unistd.h>
20 #ifdef HAVE_SPAWN_H
21 #include <spawn.h>
22 #endif
23 #include <stdio.h>
24 #include <string.h>
25 #include <errno.h>
26 #include <err.h>
27 #include <dlfcn.h>
28 #include <stdlib.h>
29
30
31 extern char** environ;
32
33 /*
34 * Locate the python framework by looking for the
35 * library that contains Py_Initialize.
36 *
37 * In a regular framework the structure is:
38 *
39 * Python.framework/Versions/2.7
40 * /Python
41 * /Resources/Python.app/Contents/MacOS/Python
42 *
43 * In a virtualenv style structure the expected
44 * structure is:
45 *
46 * ROOT
47 * /bin/pythonw
48 * /.Python <- the dylib
49 * /.Resources/Python.app/Contents/MacOS/Python
50 *
51 * NOTE: virtualenv's are not an officially supported
52 * feature, support for that structure is provided as
53 * a convenience.
54 */
get_python_path(void)55 static char* get_python_path(void)
56 {
57 size_t len;
58 Dl_info info;
59 char* end;
60 char* g_path;
61
62 if (dladdr(Py_Initialize, &info) == 0) {
63 return NULL;
64 }
65
66 len = strlen(info.dli_fname);
67
68 g_path = malloc(len+60);
69 if (g_path == NULL) {
70 return NULL;
71 }
72
73 strcpy(g_path, info.dli_fname);
74 end = g_path + len - 1;
75 while (end != g_path && *end != '/') {
76 end --;
77 }
78 end++;
79 if (*end == '.') {
80 end++;
81 }
82 strcpy(end, "Resources/Python.app/Contents/MacOS/" PYTHONFRAMEWORK);
83
84 return g_path;
85 }
86
87 #ifdef HAVE_SPAWN_H
88 static void
setup_spawnattr(posix_spawnattr_t * spawnattr)89 setup_spawnattr(posix_spawnattr_t* spawnattr)
90 {
91 size_t ocount;
92 size_t count;
93 cpu_type_t cpu_types[1];
94 short flags = 0;
95 #ifdef __LP64__
96 int ch;
97 #endif
98
99 if ((errno = posix_spawnattr_init(spawnattr)) != 0) {
100 err(2, "posix_spawnattr_int");
101 /* NOTREACHTED */
102 }
103
104 count = 1;
105
106 /* Run the real python executable using the same architecture as this
107 * executable, this allows users to control the architecture using
108 * "arch -ppc python"
109 */
110
111 #if defined(__ppc64__)
112 cpu_types[0] = CPU_TYPE_POWERPC64;
113
114 #elif defined(__x86_64__)
115 cpu_types[0] = CPU_TYPE_X86_64;
116
117 #elif defined(__ppc__)
118 cpu_types[0] = CPU_TYPE_POWERPC;
119 #elif defined(__i386__)
120 cpu_types[0] = CPU_TYPE_X86;
121 #else
122 # error "Unknown CPU"
123 #endif
124
125 if (posix_spawnattr_setbinpref_np(spawnattr, count,
126 cpu_types, &ocount) == -1) {
127 err(1, "posix_spawnattr_setbinpref");
128 /* NOTREACHTED */
129 }
130 if (count != ocount) {
131 fprintf(stderr, "posix_spawnattr_setbinpref failed to copy\n");
132 exit(1);
133 /* NOTREACHTED */
134 }
135
136
137 /*
138 * Set flag that causes posix_spawn to behave like execv
139 */
140 flags |= POSIX_SPAWN_SETEXEC;
141 if ((errno = posix_spawnattr_setflags(spawnattr, flags)) != 0) {
142 err(1, "posix_spawnattr_setflags");
143 /* NOTREACHTED */
144 }
145 }
146 #endif
147
148 int
main(int argc,char ** argv)149 main(int argc, char **argv) {
150 char* exec_path = get_python_path();
151
152 /*
153 * Let argv[0] refer to the new interpreter. This is needed to
154 * get the effect we want on OSX 10.5 or earlier. That is, without
155 * changing argv[0] the real interpreter won't have access to
156 * the Window Server.
157 */
158 argv[0] = exec_path;
159
160 #ifdef HAVE_SPAWN_H
161
162 /* We're weak-linking to posix-spawnv to ensure that
163 * an executable build on 10.5 can work on 10.4.
164 */
165 if (posix_spawn != NULL) {
166 posix_spawnattr_t spawnattr = NULL;
167
168
169 setup_spawnattr(&spawnattr);
170 posix_spawn(NULL, exec_path, NULL,
171 &spawnattr, argv, environ);
172 err(1, "posix_spawn: %s", exec_path);
173 }
174 #endif
175 execve(exec_path, argv, environ);
176 err(1, "execve: %s", argv[0]);
177 /* NOTREACHED */
178 }
179