[Python-checkins] CVS: python/dist/src/Python dynload_next.c,2.10,2.11

Jack Jansen jackjansen@users.sourceforge.net
Fri, 01 Feb 2002 08:01:07 -0800


Update of /cvsroot/python/python/dist/src/Python
In directory usw-pr-cvs1:/tmp/cvs-serv399

Modified Files:
	dynload_next.c 
Log Message:
A new dynload_next, which actually only works on OSX but isn't renamed yet.

By default every module is imported in its own namespace, but this can
be changed by defining USE_DYLD_GLOBAL_NAMESPACE. In a future version this
define will be replaced by a runtime setting, but that needs a bit more
thought.

This code is largely based on code and feedback from Steven Majewski,
Marcel Prastawa, Manoj Plakal and other on pythonmac-sig.


Index: dynload_next.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/dynload_next.c,v
retrieving revision 2.10
retrieving revision 2.11
diff -C2 -d -r2.10 -r2.11
*** dynload_next.c	2001/12/06 22:58:56	2.10
--- dynload_next.c	2002/02/01 16:01:05	2.11
***************
*** 1,36 ****
  
! /* 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},
--- 1,12 ----
  
! /* Support for dynamic loading of extension modules on Mac OS X
! ** All references to "NeXT" are for historical reasons.
! */
  
  #include "Python.h"
  #include "importdl.h"
  
  #include <mach-o/dyld.h>
  
  const struct filedescr _PyImport_DynLoadFiletab[] = {
  	{".so", "rb", C_EXTENSION},
***************
*** 39,44 ****
  };
  
  dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
! 				    const char *pathname, FILE *fp)
  {
  	dl_funcptr p = NULL;
--- 15,37 ----
  };
  
+ /*
+ ** Python modules are Mach-O MH_BUNDLE files. The best way to load these
+ ** is each in a private namespace, so you can load, say, a module bar and a
+ ** module foo.bar. If we load everything in the global namespace the two
+ ** initbar() symbols will conflict.
+ ** However, it seems some extension packages depend upon being able to access
+ ** each others' global symbols. There seems to be no way to eat our cake and
+ ** have it, so the USE_DYLD_GLOBAL_NAMESPACE define determines which behaviour
+ ** you get.
+ */
+ 
+ #ifdef USE_DYLD_GLOBAL_NAMESPACE
+ #define LINKOPTIONS NSLINKMODULE_OPTION_BINDNOW|NSLINKMODULE_OPTION_RETURN_ON_ERROR
+ #else
+ #define LINKOPTIONS NSLINKMODULE_OPTION_BINDNOW| \
+ 	NSLINKMODULE_OPTION_RETURN_ON_ERROR|NSLINKMODULE_OPTION_PRIVATE
+ #endif
  dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
! 					const char *pathname, FILE *fp)
  {
  	dl_funcptr p = NULL;
***************
*** 47,118 ****
  	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;
--- 40,43 ----
***************
*** 121,125 ****
--- 46,52 ----
  		NSSymbol theSym;
  		const char *errString;
+ 		char errBuf[512];
  	
+ #ifdef USE_DYLD_GLOBAL_NAMESPACE
  		if (NSIsSymbolNameDefined(funcname)) {
  			theSym = NSLookupAndBindSymbol(funcname);
***************
*** 127,156 ****
  			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) {
--- 54,90 ----
  			return p;
  		}
+ #endif
  		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, LINKOPTIONS);
! 			if (newModule == NULL) {
! 				int errNo;
! 				char *fileName, *moreErrorStr;
! 				NSLinkEditErrors c;
! 				NSLinkEditError( &c, &errNo, &fileName, &moreErrorStr );
! 				PyOS_snprintf(errBuf, 512, "Failure linking new module: %s: %s", 
! 						fileName, moreErrorStr);
! 				errString = errBuf;
! 			}
  		}
  		if (errString != NULL) {
***************
*** 158,173 ****
  			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;
--- 92,117 ----
  			return NULL;
  		}
+ #ifdef USE_DYLD_GLOBAL_NAMESPACE
  		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);
+ #else
+ 		theSym = NSLookupSymbolInModule(newModule, funcname);
+ 		if ( theSym == NULL ) {
+ 			NSUnLinkModule(newModule, FALSE);
+ 			PyErr_Format(PyExc_ImportError,
+ 					 "Loaded module does not contain symbol %.200s",
+ 					 funcname);
+ 			return NULL;
+ 		}
+ #endif
  		p = (dl_funcptr)NSAddressOfSymbol(theSym);
! 	}
  
  	return p;