blob: 9dfb77f6ff41c3f5e711c385fa24d44a0784213a [file] [log] [blame]
/*
* This wrapper program executes a python executable hidden inside an
* application bundle inside the Python framework. This is needed to run
* GUI code: some GUI API's don't work unless the program is inside an
* application bundle.
*
* This program uses posix_spawn rather than plain execv because we need
* slightly more control over how the "real" interpreter is executed.
*
* On OSX 10.4 (and earlier) this falls back to using exec because the
* posix_spawnv functions aren't available there.
*/
#pragma weak_import posix_spawnattr_init
#pragma weak_import posix_spawnattr_setbinpref_np
#pragma weak_import posix_spawnattr_setflags
#pragma weak_import posix_spawn
#include <Python.h>
#include <unistd.h>
#ifdef HAVE_SPAWN_H
#include <spawn.h>
#endif
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <err.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <mach-o/dyld.h>
extern char** environ;
/*
* Locate the python framework by looking for the
* library that contains Py_Initialize.
*
* In a regular framework the structure is:
*
* Python.framework/Versions/2.7
* /Python
* /Resources/Python.app/Contents/MacOS/Python
*
* In a virtualenv style structure the expected
* structure is:
*
* ROOT
* /bin/pythonw
* /.Python <- the dylib
* /.Resources/Python.app/Contents/MacOS/Python
*
* NOTE: virtualenv's are not an officially supported
* feature, support for that structure is provided as
* a convenience.
*/
static char* get_python_path(void)
{
size_t len;
Dl_info info;
char* end;
char* g_path;
if (dladdr(Py_Initialize, &info) == 0) {
return NULL;
}
len = strlen(info.dli_fname);
g_path = malloc(len+60);
if (g_path == NULL) {
return NULL;
}
strcpy(g_path, info.dli_fname);
end = g_path + len - 1;
while (end != g_path && *end != '/') {
end --;
}
end++;
if (*end == '.') {
end++;
}
strcpy(end, "Resources/Python.app/Contents/MacOS/" PYTHONFRAMEWORK);
return g_path;
}
#ifdef HAVE_SPAWN_H
static void
setup_spawnattr(posix_spawnattr_t* spawnattr)
{
size_t ocount;
size_t count;
cpu_type_t cpu_types[1];
short flags = 0;
if ((errno = posix_spawnattr_init(spawnattr)) != 0) {
err(2, "posix_spawnattr_int");
/* NOTREACHTED */
}
count = 1;
/* Run the real python executable using the same architecture as this
* executable, this allows users to control the architecture using
* "arch -ppc python"
*/
#if defined(__ppc64__)
cpu_types[0] = CPU_TYPE_POWERPC64;
#elif defined(__x86_64__)
cpu_types[0] = CPU_TYPE_X86_64;
#elif defined(__ppc__)
cpu_types[0] = CPU_TYPE_POWERPC;
#elif defined(__i386__)
cpu_types[0] = CPU_TYPE_X86;
#elif defined(__arm64__)
cpu_types[0] = CPU_TYPE_ARM64;
#else
# error "Unknown CPU"
#endif
if (posix_spawnattr_setbinpref_np(spawnattr, count,
cpu_types, &ocount) == -1) {
err(1, "posix_spawnattr_setbinpref");
/* NOTREACHTED */
}
if (count != ocount) {
fprintf(stderr, "posix_spawnattr_setbinpref failed to copy\n");
exit(1);
/* NOTREACHTED */
}
/*
* Set flag that causes posix_spawn to behave like execv
*/
flags |= POSIX_SPAWN_SETEXEC;
if ((errno = posix_spawnattr_setflags(spawnattr, flags)) != 0) {
err(1, "posix_spawnattr_setflags");
/* NOTREACHTED */
}
}
#endif
int
main(int argc, char **argv) {
char* exec_path = get_python_path();
static char path[PATH_MAX * 2];
static char real_path[PATH_MAX * 2];
int status;
uint32_t size = PATH_MAX * 2;
/* Set the original executable path in the environment. */
status = _NSGetExecutablePath(path, &size);
if (status == 0) {
/*
* Note: don't call 'realpath', that will
* erase symlink information, and that
* breaks "pyvenv --symlink"
*
* It is nice to have the directory name
* as a cleaned up absolute path though,
* therefore call realpath on dirname(path)
*/
char* slash = strrchr(path, '/');
if (slash) {
char replaced;
replaced = slash[1];
slash[1] = 0;
if (realpath(path, real_path) == NULL) {
err(1, "realpath: %s", path);
}
slash[1] = replaced;
if (strlcat(real_path, slash, sizeof(real_path)) > sizeof(real_path)) {
errno = EINVAL;
err(1, "realpath: %s", path);
}
} else {
if (realpath(".", real_path) == NULL) {
err(1, "realpath: %s", path);
}
if (strlcat(real_path, "/", sizeof(real_path)) > sizeof(real_path)) {
errno = EINVAL;
err(1, "realpath: %s", path);
}
if (strlcat(real_path, path, sizeof(real_path)) > sizeof(real_path)) {
errno = EINVAL;
err(1, "realpath: %s", path);
}
}
/*
* The environment variable is used to pass the value of real_path
* to the actual python interpreter, and is read by code in
* Python/coreconfig.c.
*
* This way the real interpreter knows how the user invoked the
* interpreter and can behave as if this launcher is the real
* interpreter (looking for pyvenv configuration, ...)
*/
setenv("__PYVENV_LAUNCHER__", real_path, 1);
}
/*
* Let argv[0] refer to the new interpreter. This is needed to
* get the effect we want on OSX 10.5 or earlier. That is, without
* changing argv[0] the real interpreter won't have access to
* the Window Server.
*/
argv[0] = exec_path;
#ifdef HAVE_SPAWN_H
/* We're weak-linking to posix-spawnv to ensure that
* an executable build on 10.5 can work on 10.4.
*/
if (&posix_spawn != NULL) {
posix_spawnattr_t spawnattr = NULL;
setup_spawnattr(&spawnattr);
posix_spawn(NULL, exec_path, NULL,
&spawnattr, argv, environ);
err(1, "posix_spawn: %s", exec_path);
}
#endif
execve(exec_path, argv, environ);
err(1, "execve: %s", argv[0]);
/* NOTREACHED */
}