cosmopolitan/third_party/python/Lib/launchpy.py

import sys
from importlib import _bootstrap_external

def run_module_as_main(mod_name):
    path = "/zip/.python/%s.pyc" % (mod_name.replace(".", "/"))
    loader = _bootstrap_external.SourcelessFileLoader(mod_name, path)
    code = loader.get_code(mod_name)
    globs = sys.modules["__main__"].__dict__
    globs["__name__"] = "__main__"
    globs["__file__"] = path[:-1]
    globs["__package__"] = None
    globs["__loader__"] = loader
    globs["__spec__"] = None
    exec(code, globs)
    return globs
Decentralize Python native module linkage We can now link even smaller Python binaries. For example, the hello.com program in the Python build directory is a compiled linked executable of hello.py which just prints hello world. Using decentralized sections, we can make that binary 1.9mb in size (noting that python.com is 6.3 megs!) This works for nontrivial programs too. For example, say we want an APE binary that's equivalent to python.com -m http.server. Our makefile now builds such a binary using the new launcher and it's only 3.2mb in size since Python sources get turned into ELF objects, which tell our linker that we need things like native hashing algorithm code. 2021-09-07 18:40:11 +00:00			`import sys`
			`from importlib import _bootstrap_external`

			`def run_module_as_main(mod_name):`
			`path = "/zip/.python/%s.pyc" % (mod_name.replace(".", "/"))`
			`loader = _bootstrap_external.SourcelessFileLoader(mod_name, path)`
			`code = loader.get_code(mod_name)`
			`globs = sys.modules["__main__"].__dict__`
			`globs["__name__"] = "__main__"`
Begin incorporating Python unit tests into build We now build a separate APE binary for each test so they can run in parallel. We've got 148 tests running fast and stable so far. 2021-09-13 04:04:44 +00:00			`globs["__file__"] = path[:-1]`
Decentralize Python native module linkage We can now link even smaller Python binaries. For example, the hello.com program in the Python build directory is a compiled linked executable of hello.py which just prints hello world. Using decentralized sections, we can make that binary 1.9mb in size (noting that python.com is 6.3 megs!) This works for nontrivial programs too. For example, say we want an APE binary that's equivalent to python.com -m http.server. Our makefile now builds such a binary using the new launcher and it's only 3.2mb in size since Python sources get turned into ELF objects, which tell our linker that we need things like native hashing algorithm code. 2021-09-07 18:40:11 +00:00			`globs["__package__"] = None`
			`globs["__loader__"] = loader`
			`globs["__spec__"] = None`
			`exec(code, globs)`
			`return globs`