On Tue, Dec 8, 2009 at 6:28 PM, Ben Finney <ben+python@benfinney.id.au> wrote:
Eric Smith <eric@trueblade.com> writes:
Ben Finney wrote:
I suggest:
* A new attribute ‘sys.import_orphaned_bytecode’. If set ‘True’, the interpreter follows the current behaviour. If ‘False’, any bytecode file satisfies an import only if it has a corresponding source file (where “corresponding” means “this source file would, if compiled, result in a bytecode file replacing this one”).
I agree with this in principle
Thanks.
but I don't see how you're going to implement it. In order to actually check this condition, aren't you going to have to compile the source code anyway? If so, just skip the bytecode file. Although I guess you could store a hash of the source in the compiled file, or other similar optimizations.
You seem to be seeing something I was careful not to write. The check is:
this source file would, if compiled, result in a bytecode file replacing this one
Nowhere there is there anything about the resulting bytecode files being equivalent. I'm limiting the check only to whether the resulting bytecode file would *replace* the existing bytecode file.
This doesn't require knowing anything at all about the contents of the current bytecode file; indeed, my intention was to phrase it so that it's checked before bothering to open the existing bytecode file.
Is there a better term for this? I'm not well-versed enough in the Python import internals to know.
If there was a corresponding source file, it would have been found first -- and the bytecode file would be used *if* it matches the source file (by comparing a timestamp in the bytecode file's header to the actual mtime of the source file). So I'm not sure what there is to do apart from *not* using "lone" bytecode files. (The latter was actually added as a feature at some point so I betcha it's easy to make it conditional on a flag.) -- --Guido van Rossum (python.org/~guido)