/* Python interpreter main program */

#include "Python.h"

#include "pycore_initconfig.h"

#include "pycore_pylifecycle.h"

#include "pycore_pymem.h"

#include "pycore_pystate.h"

#ifdef __FreeBSD__

# include <fenv.h> /* fedisableexcept() */

#endif

/* Includes for exit_sigint() */

#include <stdio.h> /* perror() */

#ifdef HAVE_SIGNAL_H

# include <signal.h> /* SIGINT */

#endif

#if defined(HAVE_GETPID) && defined(HAVE_UNISTD_H)

# include <unistd.h> /* getpid() */

#endif

#ifdef MS_WINDOWS

# include <windows.h> /* STATUS_CONTROL_C_EXIT */

#endif

/* End of includes for exit_sigint() */

#define COPYRIGHT \

"Type \"help\", \"copyright\", \"credits\" or \"license\" " \

"for more information."

#ifdef __cplusplus

extern "C" {

#endif

/* --- pymain_init() ---------------------------------------------- */

static PyStatus

pymain_init(const _PyArgv *args)

{

PyStatus status;

status = _PyRuntime_Initialize();

if (_PyStatus_EXCEPTION(status)) {

return status;

}

/* 754 requires that FP exceptions run in "no stop" mode by default,

* and until C vendors implement C99's ways to control FP exceptions,

* Python requires non-stop mode. Alas, some platforms enable FP

* exceptions by default. Here we disable them.

*/

#ifdef __FreeBSD__

fedisableexcept(FE_OVERFLOW);

#endif

PyPreConfig preconfig;

PyPreConfig_InitPythonConfig(&preconfig);

status = _Py_PreInitializeFromPyArgv(&preconfig, args);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

PyConfig config;

status = PyConfig_InitPythonConfig(&config);

if (_PyStatus_EXCEPTION(status)) {

goto done;

}

/* pass NULL as the config: config is read from command line arguments,

environment variables, configuration files */

if (args->use_bytes_argv) {

status = PyConfig_SetBytesArgv(&config, args->argc, args->bytes_argv);

}

else {

status = PyConfig_SetArgv(&config, args->argc, args->wchar_argv);

}

if (_PyStatus_EXCEPTION(status)) {

goto done;

}

status = Py_InitializeFromConfig(&config);

if (_PyStatus_EXCEPTION(status)) {

goto done;

}

status = _PyStatus_OK();

done:

PyConfig_Clear(&config);

return status;

}

/* --- pymain_run_python() ---------------------------------------- */

/* Non-zero if filename, command (-c) or module (-m) is set

on the command line */

static inline int config_run_code(const PyConfig *config)

{

return (config->run_command != NULL

|| config->run_filename != NULL

|| config->run_module != NULL);

}

/* Return non-zero is stdin is a TTY or if -i command line option is used */

static int

stdin_is_interactive(const PyConfig *config)

{

return (isatty(fileno(stdin)) || config->interactive);

}

/* Display the current Python exception and return an exitcode */

static int

pymain_err_print(int *exitcode_p)

{

int exitcode;

if (_Py_HandleSystemExit(&exitcode)) {

*exitcode_p = exitcode;

return 1;

}

PyErr_Print();

return 0;

}

static int

pymain_exit_err_print(void)

{

int exitcode = 1;

pymain_err_print(&exitcode);

return exitcode;

}

/* Write an exitcode into *exitcode and return 1 if we have to exit Python.

Return 0 otherwise. */

static int

pymain_get_importer(const wchar_t *filename, PyObject **importer_p, int *exitcode)

{

PyObject *sys_path0 = NULL, *importer;

sys_path0 = PyUnicode_FromWideChar(filename, wcslen(filename));

if (sys_path0 == NULL) {

goto error;

}

importer = PyImport_GetImporter(sys_path0);

if (importer == NULL) {

goto error;

}

if (importer == Py_None) {

Py_DECREF(sys_path0);

Py_DECREF(importer);

return 0;

}

Py_DECREF(importer);

*importer_p = sys_path0;

return 0;

error:

Py_XDECREF(sys_path0);

PySys_WriteStderr("Failed checking if argv[0] is an import path entry\n");

return pymain_err_print(exitcode);

}

static int

pymain_sys_path_add_path0(PyInterpreterState *interp, PyObject *path0)

{

_Py_IDENTIFIER(path);

PyObject *sys_path;

PyObject *sysdict = interp->sysdict;

if (sysdict != NULL) {

sys_path = _PyDict_GetItemIdWithError(sysdict, &PyId_path);

if (sys_path == NULL && PyErr_Occurred()) {

return -1;

}

}

else {

sys_path = NULL;

}

if (sys_path == NULL) {

PyErr_SetString(PyExc_RuntimeError, "unable to get sys.path");

return -1;

}

if (PyList_Insert(sys_path, 0, path0)) {

return -1;

}

return 0;

}

static void

pymain_header(const PyConfig *config)

{

if (config->quiet) {

return;

}

if (!config->verbose && (config_run_code(config) || !stdin_is_interactive(config))) {

return;

}

fprintf(stderr, "Python %s on %s\n", Py_GetVersion(), Py_GetPlatform());

if (config->site_import) {

fprintf(stderr, "%s\n", COPYRIGHT);

}

}

static void

pymain_import_readline(const PyConfig *config)

{

if (config->isolated) {

return;

}

if (!config->inspect && config_run_code(config)) {

return;

}

if (!isatty(fileno(stdin))) {

return;

}

PyObject *mod = PyImport_ImportModule("readline");

if (mod == NULL) {

PyErr_Clear();

}

else {

Py_DECREF(mod);

}

}

static int

pymain_run_command(wchar_t *command, PyCompilerFlags *cf)

{

PyObject *unicode, *bytes;

int ret;

unicode = PyUnicode_FromWideChar(command, -1);

if (unicode == NULL) {

goto error;

}

if (PySys_Audit("cpython.run_command", "O", unicode) < 0) {

return pymain_exit_err_print();

}

bytes = PyUnicode_AsUTF8String(unicode);

Py_DECREF(unicode);

if (bytes == NULL) {

goto error;

}

ret = PyRun_SimpleStringFlags(PyBytes_AsString(bytes), cf);

Py_DECREF(bytes);

return (ret != 0);

error:

PySys_WriteStderr("Unable to decode the command from the command line:\n");

return pymain_exit_err_print();

}

static int

pymain_run_module(const wchar_t *modname, int set_argv0)

{

PyObject *module, *runpy, *runmodule, *runargs, *result;

if (PySys_Audit("cpython.run_module", "u", modname) < 0) {

return pymain_exit_err_print();

}

runpy = PyImport_ImportModule("runpy");

if (runpy == NULL) {

fprintf(stderr, "Could not import runpy module\n");

return pymain_exit_err_print();

}

runmodule = PyObject_GetAttrString(runpy, "_run_module_as_main");

if (runmodule == NULL) {

fprintf(stderr, "Could not access runpy._run_module_as_main\n");

Py_DECREF(runpy);

return pymain_exit_err_print();

}

module = PyUnicode_FromWideChar(modname, wcslen(modname));

if (module == NULL) {

fprintf(stderr, "Could not convert module name to unicode\n");

Py_DECREF(runpy);

Py_DECREF(runmodule);

return pymain_exit_err_print();

}

runargs = Py_BuildValue("(Oi)", module, set_argv0);

if (runargs == NULL) {

fprintf(stderr,

"Could not create arguments for runpy._run_module_as_main\n");

Py_DECREF(runpy);

Py_DECREF(runmodule);

Py_DECREF(module);

return pymain_exit_err_print();

}

result = PyObject_Call(runmodule, runargs, NULL);

Py_DECREF(runpy);

Py_DECREF(runmodule);

Py_DECREF(module);

Py_DECREF(runargs);

if (result == NULL) {

return pymain_exit_err_print();

}

Py_DECREF(result);

return 0;

}

static int

pymain_run_file(PyConfig *config, PyCompilerFlags *cf)

{

const wchar_t *filename = config->run_filename;

if (PySys_Audit("cpython.run_file", "u", filename) < 0) {

return pymain_exit_err_print();

}

FILE *fp = _Py_wfopen(filename, L"rb");

if (fp == NULL) {

char *cfilename_buffer;

const char *cfilename;

int err = errno;

cfilename_buffer = _Py_EncodeLocaleRaw(filename, NULL);

if (cfilename_buffer != NULL)

cfilename = cfilename_buffer;

else

cfilename = "<unprintable file name>";

fprintf(stderr, "%ls: can't open file '%s': [Errno %d] %s\n",

config->program_name, cfilename, err, strerror(err));

PyMem_RawFree(cfilename_buffer);

return 2;

}

if (config->skip_source_first_line) {

int ch;

/* Push back first newline so line numbers remain the same */

while ((ch = getc(fp)) != EOF) {

if (ch == '\n') {

(void)ungetc(ch, fp);

break;

}

}

}

struct _Py_stat_struct sb;

if (_Py_fstat_noraise(fileno(fp), &sb) == 0 && S_ISDIR(sb.st_mode)) {

fprintf(stderr,

"%ls: '%ls' is a directory, cannot continue\n",

config->program_name, filename);

fclose(fp);

return 1;

}

/* call pending calls like signal handlers (SIGINT) */

if (Py_MakePendingCalls() == -1) {

fclose(fp);

return pymain_exit_err_print();

}

PyObject *unicode, *bytes = NULL;

const char *filename_str;

unicode = PyUnicode_FromWideChar(filename, wcslen(filename));

if (unicode != NULL) {

bytes = PyUnicode_EncodeFSDefault(unicode);

Py_DECREF(unicode);

}

if (bytes != NULL) {

filename_str = PyBytes_AsString(bytes);

}

else {

PyErr_Clear();

filename_str = "<filename encoding error>";

}

/* PyRun_AnyFileExFlags(closeit=1) calls fclose(fp) before running code */

int run = PyRun_AnyFileExFlags(fp, filename_str, 1, cf);

Py_XDECREF(bytes);

return (run != 0);

}

static int

pymain_run_startup(PyConfig *config, PyCompilerFlags *cf, int *exitcode)

{

const char *startup = _Py_GetEnv(config->use_environment, "PYTHONSTARTUP");

if (startup == NULL) {

return 0;

}

if (PySys_Audit("cpython.run_startup", "s", startup) < 0) {

return pymain_err_print(exitcode);

}

FILE *fp = _Py_fopen(startup, "r");

if (fp == NULL) {

int save_errno = errno;

PySys_WriteStderr("Could not open PYTHONSTARTUP\n");

errno = save_errno;

PyErr_SetFromErrnoWithFilename(PyExc_OSError, startup);

return pymain_err_print(exitcode);

}

(void) PyRun_SimpleFileExFlags(fp, startup, 0, cf);

PyErr_Clear();

fclose(fp);

return 0;

}

/* Write an exitcode into *exitcode and return 1 if we have to exit Python.

Return 0 otherwise. */

static int

pymain_run_interactive_hook(int *exitcode)

{

PyObject *sys, *hook, *result;

sys = PyImport_ImportModule("sys");

if (sys == NULL) {

goto error;

}

hook = PyObject_GetAttrString(sys, "__interactivehook__");

Py_DECREF(sys);

if (hook == NULL) {

PyErr_Clear();

return 0;

}

if (PySys_Audit("cpython.run_interactivehook", "O", hook) < 0) {

goto error;

}

result = _PyObject_CallNoArg(hook);

Py_DECREF(hook);

if (result == NULL) {

goto error;

}

Py_DECREF(result);

return 0;

error:

PySys_WriteStderr("Failed calling sys.__interactivehook__\n");

return pymain_err_print(exitcode);

}

static int

pymain_run_stdin(PyConfig *config, PyCompilerFlags *cf)

{

if (stdin_is_interactive(config)) {

config->inspect = 0;

Py_InspectFlag = 0; /* do exit on SystemExit */

int exitcode;

if (pymain_run_startup(config, cf, &exitcode)) {

return exitcode;

}

if (pymain_run_interactive_hook(&exitcode)) {

return exitcode;

}

}

/* call pending calls like signal handlers (SIGINT) */

if (Py_MakePendingCalls() == -1) {

return pymain_exit_err_print();

}

if (PySys_Audit("cpython.run_stdin", NULL) < 0) {

return pymain_exit_err_print();

}

int run = PyRun_AnyFileExFlags(stdin, "<stdin>", 0, cf);

return (run != 0);

}

static void

pymain_repl(PyConfig *config, PyCompilerFlags *cf, int *exitcode)

{

/* Check this environment variable at the end, to give programs the

opportunity to set it from Python. */

if (!config->inspect && _Py_GetEnv(config->use_environment, "PYTHONINSPECT")) {

config->inspect = 1;

Py_InspectFlag = 1;

}

if (!(config->inspect && stdin_is_interactive(config) && config_run_code(config))) {

return;

}

config->inspect = 0;

Py_InspectFlag = 0;

if (pymain_run_interactive_hook(exitcode)) {

return;

}

int res = PyRun_AnyFileFlags(stdin, "<stdin>", cf);

*exitcode = (res != 0);

}

static void

pymain_run_python(int *exitcode)

{

PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();

/* pymain_run_stdin() modify the config */

PyConfig *config = &interp->config;

PyObject *main_importer_path = NULL;

if (config->run_filename != NULL) {

/* If filename is a package (ex: directory or ZIP file) which contains

__main__.py, main_importer_path is set to filename and will be

prepended to sys.path.

Otherwise, main_importer_path is left unchanged. */

if (pymain_get_importer(config->run_filename, &main_importer_path,

exitcode)) {

return;

}

}

if (main_importer_path != NULL) {

if (pymain_sys_path_add_path0(interp, main_importer_path) < 0) {

goto error;

}

}

else if (!config->isolated) {

PyObject *path0 = NULL;

int res = _PyPathConfig_ComputeSysPath0(&config->argv, &path0);

if (res < 0) {

goto error;

}

if (res > 0) {

if (pymain_sys_path_add_path0(interp, path0) < 0) {

Py_DECREF(path0);

goto error;

}

Py_DECREF(path0);

}

}

PyCompilerFlags cf = _PyCompilerFlags_INIT;

pymain_header(config);

pymain_import_readline(config);

if (config->run_command) {

*exitcode = pymain_run_command(config->run_command, &cf);

}

else if (config->run_module) {

*exitcode = pymain_run_module(config->run_module, 1);

}

else if (main_importer_path != NULL) {

*exitcode = pymain_run_module(L"__main__", 0);

}

else if (config->run_filename != NULL) {

*exitcode = pymain_run_file(config, &cf);

}

else {

*exitcode = pymain_run_stdin(config, &cf);

}

pymain_repl(config, &cf, exitcode);

goto done;

error:

*exitcode = pymain_exit_err_print();

done:

Py_XDECREF(main_importer_path);

}

/* --- pymain_main() ---------------------------------------------- */

static void

pymain_free(void)

{

_PyImport_Fini2();

/* Free global variables which cannot be freed in Py_Finalize():

configuration options set before Py_Initialize() which should

remain valid after Py_Finalize(), since

Py_Initialize()-Py_Finalize() can be called multiple times. */

_PyPathConfig_ClearGlobal();

_Py_ClearStandardStreamEncoding();

_Py_ClearArgcArgv();

_PyRuntime_Finalize();

}

static int

exit_sigint(void)

{

/* bpo-1054041: We need to exit via the

* SIG_DFL handler for SIGINT if KeyboardInterrupt went unhandled.

* If we don't, a calling process such as a shell may not know

* about the user's ^C. https://www.cons.org/cracauer/sigint.html */

#if defined(HAVE_GETPID) && !defined(MS_WINDOWS)

if (PyOS_setsig(SIGINT, SIG_DFL) == SIG_ERR) {

perror("signal"); /* Impossible in normal environments. */

} else {

kill(getpid(), SIGINT);

}

/* If setting SIG_DFL failed, or kill failed to terminate us,

* there isn't much else we can do aside from an error code. */

#endif /* HAVE_GETPID && !MS_WINDOWS */

#ifdef MS_WINDOWS

/* cmd.exe detects this, prints ^C, and offers to terminate. */

/* https://msdn.microsoft.com/en-us/library/cc704588.aspx */

return STATUS_CONTROL_C_EXIT;

#else

return SIGINT + 128;

#endif /* !MS_WINDOWS */

}

static void _Py_NO_RETURN

pymain_exit_error(PyStatus status)

{

if (_PyStatus_IS_EXIT(status)) {

/* If it's an error rather than a regular exit, leave Python runtime

alive: Py_ExitStatusException() uses the current exception and use

sys.stdout in this case. */

pymain_free();

}

Py_ExitStatusException(status);

}

int

Py_RunMain(void)

{

int exitcode = 0;

pymain_run_python(&exitcode);

if (Py_FinalizeEx() < 0) {

/* Value unlikely to be confused with a non-error exit status or

other special meaning */

exitcode = 120;

}

pymain_free();

if (_Py_UnhandledKeyboardInterrupt) {

exitcode = exit_sigint();

}

return exitcode;

}

static int

pymain_main(_PyArgv *args)

{

PyStatus status = pymain_init(args);

if (_PyStatus_IS_EXIT(status)) {

pymain_free();

return status.exitcode;

}

if (_PyStatus_EXCEPTION(status)) {

pymain_exit_error(status);

}

return Py_RunMain();

}

int

Py_Main(int argc, wchar_t **argv)

{

_PyArgv args = {

.argc = argc,

.use_bytes_argv = 0,

.bytes_argv = NULL,

.wchar_argv = argv};

return pymain_main(&args);

}

int

Py_BytesMain(int argc, char **argv)

{

_PyArgv args = {

.argc = argc,

.use_bytes_argv = 1,

.bytes_argv = argv,

.wchar_argv = NULL};

return pymain_main(&args);

}

#ifdef __cplusplus

}

#endif