cpython/Python/dynload_shlib.c
Eric Snow b2fc549278
gh-101758: Clean Up Uses of Import State (gh-101919)
This change is almost entirely moving code around and hiding import state behind internal API.  We introduce no changes to behavior, nor to non-internal API.  (Since there was already going to be a lot of churn, I took this as an opportunity to re-organize import.c into topically-grouped sections of code.)  The motivation is to simplify a number of upcoming changes.

Specific changes:

* move existing import-related code to import.c, wherever possible
* add internal API for interacting with import state (both global and per-interpreter)
* use only API outside of import.c (to limit churn there when changing the location, etc.)
* consolidate the import-related state of PyInterpreterState into a single struct field (this changes layout slightly)
* add macros for import state in import.c (to simplify changing the location)
* group code in import.c into sections
*remove _PyState_AddModule()

https://github.com/python/cpython/issues/101758
2023-02-15 15:32:31 -07:00

112 lines
2.9 KiB
C

/* Support for dynamic loading of extension modules */
#include "Python.h"
#include "pycore_interp.h" // _PyInterpreterState.dlopenflags
#include "pycore_pystate.h" // _PyInterpreterState_GET()
#include "importdl.h"
#include <sys/types.h>
#include <sys/stat.h>
#if defined(__NetBSD__)
#include <sys/param.h>
#if (NetBSD < 199712)
#include <nlist.h>
#include <link.h>
#define dlerror() "error in dynamic linking"
#endif
#endif /* NetBSD */
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
#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",
#ifdef ALT_SOABI
"." ALT_SOABI ".so",
#endif
".abi" PYTHON_ABI_STRING ".so",
".so",
#endif /* __CYGWIN__ */
NULL,
};
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) {
struct _Py_stat_struct status;
if (_Py_fstat(fileno(fp), &status) == -1)
return NULL;
}
dlopenflags = _PyImport_GetDLOpenFlags(_PyInterpreterState_GET());
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_DecodeLocale(error, "surrogateescape");
if (error_ob == NULL)
return NULL;
mod_name = PyUnicode_FromString(shortname);
if (mod_name == NULL) {
Py_DECREF(error_ob);
return NULL;
}
path = PyUnicode_DecodeFSDefault(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;
}
p = (dl_funcptr) dlsym(handle, funcname);
return p;
}