cpython/Python/dynload_next.c

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/* Support for dynamic loading of extension modules */
#include "Python.h"
#include "importdl.h"
#ifdef WITH_DYLD
#define USE_DYLD
#include <mach-o/dyld.h>
#else /* WITH_DYLD */
#define USE_RLD
/* Define this to 1 if you want be able to load ObjC modules as well:
it switches between two different way of loading modules on the NeXT,
one that directly interfaces with the dynamic loader (rld_load(), which
does not correctly load ObjC object files), and another that uses the
ObjC runtime (objc_loadModules()) to do the job.
You'll have to add ``-ObjC'' to the compiler flags if you set this to 1.
*/
#define HANDLE_OBJC_MODULES 1
#if HANDLE_OBJC_MODULES
#include <objc/Object.h>
#include <objc/objc-load.h>
#endif
#include <mach-o/rld.h>
#endif /* WITH_DYLD */
const struct filedescr _PyImport_DynLoadFiletab[] = {
{".so", "rb", C_EXTENSION},
{"module.so", "rb", C_EXTENSION},
{0, 0}
};
dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
const char *pathname, FILE *fp)
{
dl_funcptr p = NULL;
char funcname[258];
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PyOS_snprintf(funcname, sizeof(funcname), "_init%.200s", shortname);
#ifdef USE_RLD
{
NXStream *errorStream;
struct mach_header *new_header;
const char *filenames[2];
long ret;
unsigned long ptr;
errorStream = NXOpenMemory(NULL, 0, NX_WRITEONLY);
filenames[0] = pathname;
filenames[1] = NULL;
#if HANDLE_OBJC_MODULES
/* The following very bogus line of code ensures that
objc_msgSend, etc are linked into the binary. Without
it, dynamic loading of a module that includes objective-c
method calls will fail with "undefined symbol _objc_msgSend()".
This remains true even in the presence of the -ObjC flag
to the compiler
*/
[Object name];
/* objc_loadModules() dynamically loads the object files
indicated by the paths in filenames. If there are any
errors generated during loading -- typically due to the
inability to find particular symbols -- an error message
will be written to errorStream.
It returns 0 if the module is successfully loaded, 1
otherwise.
*/
ret = !objc_loadModules(filenames, errorStream,
NULL, &new_header, NULL);
#else /* !HANDLE_OBJC_MODULES */
ret = rld_load(errorStream, &new_header,
filenames, NULL);
#endif /* HANDLE_OBJC_MODULES */
/* extract the error messages for the exception */
if(!ret) {
char *streamBuf;
int len, maxLen;
NXPutc(errorStream, (char)0);
NXGetMemoryBuffer(errorStream,
&streamBuf, &len, &maxLen);
PyErr_SetString(PyExc_ImportError, streamBuf);
}
if(ret && rld_lookup(errorStream, funcname, &ptr))
p = (dl_funcptr) ptr;
NXCloseMemory(errorStream, NX_FREEBUFFER);
if(!ret)
return NULL;
}
#endif /* USE_RLD */
#ifdef USE_DYLD
/* This is also NeXT-specific. However, frameworks (the new style
of shared library) and rld() can't be used in the same program;
instead, you have to use dyld, which is mostly unimplemented. */
{
NSObjectFileImageReturnCode rc;
NSObjectFileImage image;
NSModule newModule;
NSSymbol theSym;
const char *errString;
if (NSIsSymbolNameDefined(funcname)) {
theSym = NSLookupAndBindSymbol(funcname);
p = (dl_funcptr)NSAddressOfSymbol(theSym);
return p;
}
rc = NSCreateObjectFileImageFromFile(pathname, &image);
switch(rc) {
default:
case NSObjectFileImageFailure:
case NSObjectFileImageFormat:
/* for these a message is printed on stderr by dyld */
errString = "Can't create object file image";
break;
case NSObjectFileImageSuccess:
errString = NULL;
break;
case NSObjectFileImageInappropriateFile:
errString = "Inappropriate file type for dynamic loading";
break;
case NSObjectFileImageArch:
errString = "Wrong CPU type in object file";
break;
case NSObjectFileImageAccess:
errString = "Can't read object file (no access)";
break;
}
if (errString == NULL) {
newModule = NSLinkModule(image, pathname,
NSLINKMODULE_OPTION_BINDNOW|NSLINKMODULE_OPTION_RETURN_ON_ERROR);
if (!newModule)
errString = "Failure linking new module";
}
if (errString != NULL) {
PyErr_SetString(PyExc_ImportError, errString);
return NULL;
}
if (!NSIsSymbolNameDefined(funcname)) {
/* UnlinkModule() isn't implemented in current versions, but calling it does no harm */
NSUnLinkModule(newModule, FALSE);
PyErr_Format(PyExc_ImportError,
"Loaded module does not contain symbol %.200s",
funcname);
return NULL;
}
theSym = NSLookupAndBindSymbol(funcname);
p = (dl_funcptr)NSAddressOfSymbol(theSym);
}
#endif /* USE_DYLD */
return p;
}