make: switch the PYTHON default to `py.exe -3` on Windows
Python3 _is_ named `python.exe` on Windows, but that isn't necessarily on PATH
when installing from python.org. I do happen to have a python.exe on PATH in
`$LOCALAPPDATA/Microsoft/WindowsApps`, but it appears to be 0 bytes (likely
because of permission issues), and doesn't run:
$ python -V
- Cannot open
Pulkit hit the same error as I did though, so it isn't just my system:
$ make -C . local
make: Entering directory `/home/Dell/repos/hg-committed`
python setup.py \
build_py -c -d . \
build_ext -i \
build_hgexe -i \
build_mo
- Cannot openmake: *** [local] Error 1
The `py.exe` dispatcher lives in the Windows directory (so it is on PATH), looks
up the python.org installation, and invokes that interpreter directly. I get a
warning with py39, but if it's our issue, it was an existing one:
$ make -C .. local
make: Entering directory `/c/Users/Matt/hg'
py -3 setup.py \
build_py -c -d . \
build_ext -i \
build_hgexe -i \
build_mo
C:\Users\Matt\AppData\Local\Programs\Python\Python39\lib\site-packages\setuptools\distutils_patch.py:25:
UserWarning: Distutils was imported before Setuptools. This usage is discouraged and may
exhibit undesirable behaviors or errors. Please use Setuptools' objects directly or at least
import Setuptools first.
warnings.warn(
The end result is a py3 based hg.exe that annoyingly won't run because it can't
find python39.dll. It will run tests (the ones without the `python3` shbang
line anyway), because the test runner adjusts PATH to include the python running
it.
Differential Revision: https://phab.mercurial-scm.org/D9361
#include "pyutil.h"
#include <iostream>
#include <string>
namespace contrib
{
#if PY_MAJOR_VERSION >= 3
#define HG_FUZZER_PY3 1
PyMODINIT_FUNC PyInit_parsers(void);
#else
PyMODINIT_FUNC initparsers(void);
#endif
static char cpypath[8192] = "\0";
static PyObject *mainmod;
static PyObject *globals;
void initpy(const char *cselfpath)
{
#ifdef HG_FUZZER_PY3
const std::string subdir = "/sanpy/lib/python3.8";
#else
const std::string subdir = "/sanpy/lib/python2.7";
#endif
/* HACK ALERT: we need a full Python installation built without
pymalloc and with ASAN, so we dump one in
$OUT/sanpy/lib/python2.7. This helps us wire that up. */
std::string selfpath(cselfpath);
std::string pypath;
auto pos = selfpath.rfind("/");
if (pos == std::string::npos) {
char wd[8192];
if (!getcwd(wd, 8192)) {
std::cerr << "Failed to call getcwd: errno " << errno
<< std::endl;
exit(1);
}
pypath = std::string(wd) + subdir;
} else {
pypath = selfpath.substr(0, pos) + subdir;
}
strncpy(cpypath, pypath.c_str(), pypath.size());
setenv("PYTHONPATH", cpypath, 1);
setenv("PYTHONNOUSERSITE", "1", 1);
/* prevent Python from looking up users in the fuzz environment */
setenv("PYTHONUSERBASE", cpypath, 1);
#ifdef HG_FUZZER_PY3
std::wstring wcpypath(pypath.begin(), pypath.end());
Py_SetPythonHome(wcpypath.c_str());
#else
Py_SetPythonHome(cpypath);
#endif
Py_InitializeEx(0);
mainmod = PyImport_AddModule("__main__");
globals = PyModule_GetDict(mainmod);
#ifdef HG_FUZZER_PY3
PyObject *mod = PyInit_parsers();
#else
initparsers();
PyObject *mod = PyImport_ImportModule("parsers");
#endif
PyDict_SetItemString(globals, "parsers", mod);
}
PyObject *pyglobals()
{
return globals;
}
} // namespace contrib