cosmopolitan/third_party/python/Python/dynload_shlib.c
Justine Tunney d26d7ae0e4 Perform build and magnum tuning
Building o//third_party/python now takes 5 seconds on my PC

This change works towards modifying Python to use runtime dispatching
when appropriate. For example, when loading the magnums in the socket
module, it's a good idea to check if the magnum is zero, because that
means the local system platform doesn't support it.
2021-08-10 10:26:13 -07:00

111 lines
3.1 KiB
C

#include "libc/runtime/dlfcn.h"
#include "third_party/python/Include/Python.h"
#include "third_party/python/Python/importdl.h"
/* clang-format off */
#if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
#define LEAD_UNDERSCORE "_"
#else
#define LEAD_UNDERSCORE ""
#endif
/* The .so extension module ABI tag, supplied by the Makefile via
Makefile.pre.in and configure. This is used to discriminate between
incompatible .so files so that extensions for different Python builds can
live in the same directory. E.g. foomodule.cpython-32.so
*/
const char *_PyImport_DynLoadFiletab[] = {
#ifdef __CYGWIN__
".dll",
#else /* !__CYGWIN__ */
"." SOABI ".so",
".abi" PYTHON_ABI_STRING ".so",
".so",
#endif /* __CYGWIN__ */
NULL,
};
static struct {
dev_t dev;
ino_t ino;
void *handle;
} handles[128];
static int nhandles = 0;
dl_funcptr
_PyImport_FindSharedFuncptr(const char *prefix,
const char *shortname,
const char *pathname, FILE *fp)
{
dl_funcptr p;
void *handle;
char funcname[258];
char pathbuf[260];
int dlopenflags=0;
if (strchr(pathname, '/') == NULL) {
/* Prefix bare filename with "./" */
PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
pathname = pathbuf;
}
PyOS_snprintf(funcname, sizeof(funcname),
LEAD_UNDERSCORE "%.20s_%.200s", prefix, shortname);
if (fp != NULL) {
int i;
struct _Py_stat_struct status;
if (_Py_fstat(fileno(fp), &status) == -1)
return NULL;
for (i = 0; i < nhandles; i++) {
if (status.st_dev == handles[i].dev &&
status.st_ino == handles[i].ino) {
p = (dl_funcptr) dlsym(handles[i].handle,
funcname);
return p;
}
}
if (nhandles < 128) {
handles[nhandles].dev = status.st_dev;
handles[nhandles].ino = status.st_ino;
}
}
dlopenflags = PyThreadState_GET()->interp->dlopenflags;
handle = dlopen(pathname, dlopenflags);
if (handle == NULL) {
PyObject *mod_name;
PyObject *path;
PyObject *error_ob;
const char *error = dlerror();
if (error == NULL)
error = "unknown dlopen() error";
error_ob = PyUnicode_FromString(error);
if (error_ob == NULL)
return NULL;
mod_name = PyUnicode_FromString(shortname);
if (mod_name == NULL) {
Py_DECREF(error_ob);
return NULL;
}
path = PyUnicode_FromString(pathname);
if (path == NULL) {
Py_DECREF(error_ob);
Py_DECREF(mod_name);
return NULL;
}
PyErr_SetImportError(error_ob, mod_name, path);
Py_DECREF(error_ob);
Py_DECREF(mod_name);
Py_DECREF(path);
return NULL;
}
if (fp != NULL && nhandles < 128)
handles[nhandles++].handle = handle;
p = (dl_funcptr) dlsym(handle, funcname);
return p;
}