/* Python interpreter top-level routines, including init/exit */

#include "Python.h"

#include "Python-ast.h"
#undef Yield /* undefine macro conflicting with winbase.h */
#include "grammar.h"
#include "node.h"
#include "token.h"
#include "parsetok.h"
#include "errcode.h"
#include "code.h"
#include "symtable.h"
#include "ast.h"
#include "marshal.h"
#include "osdefs.h"
#include <locale.h>

#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif

#ifdef MS_WINDOWS
#include "malloc.h" /* for alloca */
#endif

#ifdef HAVE_LANGINFO_H
#include <langinfo.h>
#endif

#ifdef MS_WINDOWS
#undef BYTE
#include "windows.h"
#endif

_Py_IDENTIFIER(builtins);
_Py_IDENTIFIER(excepthook);
_Py_IDENTIFIER(flush);
_Py_IDENTIFIER(last_traceback);
_Py_IDENTIFIER(last_type);
_Py_IDENTIFIER(last_value);
_Py_IDENTIFIER(ps1);
_Py_IDENTIFIER(ps2);
_Py_IDENTIFIER(stdin);
_Py_IDENTIFIER(stdout);
_Py_IDENTIFIER(stderr);
_Py_static_string(PyId_string, "<string>");

#ifdef __cplusplus
extern "C" {
#endif

extern grammar _PyParser_Grammar; /* From graminit.c */

/* Forward */
static void flush_io(void);
static PyObject *run_mod(mod_ty, PyObject *, PyObject *, PyObject *,
 PyCompilerFlags *, PyArena *);
static PyObject *run_pyc_file(FILE *, const char *, PyObject *, PyObject *,
 PyCompilerFlags *);
static void err_input(perrdetail *);
static void err_free(perrdetail *);

/* Parse input from a file and execute it */

int
PyRun_AnyFileExFlags(FILE *fp, const char *filename, int closeit,
 PyCompilerFlags *flags)
{
 if (filename == NULL)
 filename = "???";
 if (Py_FdIsInteractive(fp, filename)) {
 int err = PyRun_InteractiveLoopFlags(fp, filename, flags);
 if (closeit)
 fclose(fp);
 return err;
 }
 else
 return PyRun_SimpleFileExFlags(fp, filename, closeit, flags);
}

int
PyRun_InteractiveLoopFlags(FILE *fp, const char *filename_str, PyCompilerFlags *flags)
{
 PyObject *filename, *v;
 int ret, err;
 PyCompilerFlags local_flags;

 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL) {
 PyErr_Print();
 return -1;
 }

 if (flags == NULL) {
 flags = &local_flags;
 local_flags.cf_flags = 0;
 }
 v = _PySys_GetObjectId(&PyId_ps1);
 if (v == NULL) {
 _PySys_SetObjectId(&PyId_ps1, v = PyUnicode_FromString(">>> "));
 Py_XDECREF(v);
 }
 v = _PySys_GetObjectId(&PyId_ps2);
 if (v == NULL) {
 _PySys_SetObjectId(&PyId_ps2, v = PyUnicode_FromString("... "));
 Py_XDECREF(v);
 }
 err = -1;
 for (;;) {
 ret = PyRun_InteractiveOneObject(fp, filename, flags);
 _PY_DEBUG_PRINT_TOTAL_REFS();
 if (ret == E_EOF) {
 err = 0;
 break;
 }
 /*
 if (ret == E_NOMEM)
 break;
 */
 }
 Py_DECREF(filename);
 return err;
}

/* compute parser flags based on compiler flags */
static int PARSER_FLAGS(PyCompilerFlags *flags)
{
 int parser_flags = 0;
 if (!flags)
 return 0;
 if (flags->cf_flags & PyCF_DONT_IMPLY_DEDENT)
 parser_flags |= PyPARSE_DONT_IMPLY_DEDENT;
 if (flags->cf_flags & PyCF_IGNORE_COOKIE)
 parser_flags |= PyPARSE_IGNORE_COOKIE;
 if (flags->cf_flags & CO_FUTURE_BARRY_AS_BDFL)
 parser_flags |= PyPARSE_BARRY_AS_BDFL;
 return parser_flags;
}

#if 0
/* Keep an example of flags with future keyword support. */
#define PARSER_FLAGS(flags) \
 ((flags) ? ((((flags)->cf_flags & PyCF_DONT_IMPLY_DEDENT) ? \
 PyPARSE_DONT_IMPLY_DEDENT : 0) \
 | ((flags)->cf_flags & CO_FUTURE_WITH_STATEMENT ? \
 PyPARSE_WITH_IS_KEYWORD : 0)) : 0)
#endif

int
PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
{
 PyObject *m, *d, *v, *w, *oenc = NULL, *mod_name;
 mod_ty mod;
 PyArena *arena;
 char *ps1 = "", *ps2 = "", *enc = NULL;
 int errcode = 0;
 _Py_IDENTIFIER(encoding);
 _Py_IDENTIFIER(__main__);

 mod_name = _PyUnicode_FromId(&PyId___main__); /* borrowed */
 if (mod_name == NULL) {
 PyErr_Print();
 return -1;
 }

 if (fp == stdin) {
 /* Fetch encoding from sys.stdin if possible. */
 v = _PySys_GetObjectId(&PyId_stdin);
 if (v && v != Py_None) {
 oenc = _PyObject_GetAttrId(v, &PyId_encoding);
 if (oenc)
 enc = PyUnicode_AsUTF8(oenc);
 if (!enc)
 PyErr_Clear();
 }
 }
 v = _PySys_GetObjectId(&PyId_ps1);
 if (v != NULL) {
 v = PyObject_Str(v);
 if (v == NULL)
 PyErr_Clear();
 else if (PyUnicode_Check(v)) {
 ps1 = PyUnicode_AsUTF8(v);
 if (ps1 == NULL) {
 PyErr_Clear();
 ps1 = "";
 }
 }
 }
 w = _PySys_GetObjectId(&PyId_ps2);
 if (w != NULL) {
 w = PyObject_Str(w);
 if (w == NULL)
 PyErr_Clear();
 else if (PyUnicode_Check(w)) {
 ps2 = PyUnicode_AsUTF8(w);
 if (ps2 == NULL) {
 PyErr_Clear();
 ps2 = "";
 }
 }
 }
 arena = PyArena_New();
 if (arena == NULL) {
 Py_XDECREF(v);
 Py_XDECREF(w);
 Py_XDECREF(oenc);
 return -1;
 }
 mod = PyParser_ASTFromFileObject(fp, filename, enc,
 Py_single_input, ps1, ps2,
 flags, &errcode, arena);
 Py_XDECREF(v);
 Py_XDECREF(w);
 Py_XDECREF(oenc);
 if (mod == NULL) {
 PyArena_Free(arena);
 if (errcode == E_EOF) {
 PyErr_Clear();
 return E_EOF;
 }
 PyErr_Print();
 return -1;
 }
 m = PyImport_AddModuleObject(mod_name);
 if (m == NULL) {
 PyArena_Free(arena);
 return -1;
 }
 d = PyModule_GetDict(m);
 v = run_mod(mod, filename, d, d, flags, arena);
 PyArena_Free(arena);
 if (v == NULL) {
 PyErr_Print();
 flush_io();
 return -1;
 }
 Py_DECREF(v);
 flush_io();
 return 0;
}

int
PyRun_InteractiveOneFlags(FILE *fp, const char *filename_str, PyCompilerFlags *flags)
{
 PyObject *filename;
 int res;

 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL) {
 PyErr_Print();
 return -1;
 }
 res = PyRun_InteractiveOneObject(fp, filename, flags);
 Py_DECREF(filename);
 return res;
}


/* Check whether a file maybe a pyc file: Look at the extension,
 the file type, and, if we may close it, at the first few bytes. */

static int
maybe_pyc_file(FILE *fp, const char* filename, const char* ext, int closeit)
{
 if (strcmp(ext, ".pyc") == 0)
 return 1;

 /* Only look into the file if we are allowed to close it, since
 it then should also be seekable. */
 if (closeit) {
 /* Read only two bytes of the magic. If the file was opened in
 text mode, the bytes 3 and 4 of the magic (\r\n) might not
 be read as they are on disk. */
 unsigned int halfmagic = PyImport_GetMagicNumber() & 0xFFFF;
 unsigned char buf[2];
 /* Mess: In case of -x, the stream is NOT at its start now,
 and ungetc() was used to push back the first newline,
 which makes the current stream position formally undefined,
 and a x-platform nightmare.
 Unfortunately, we have no direct way to know whether -x
 was specified. So we use a terrible hack: if the current
 stream position is not 0, we assume -x was specified, and
 give up. Bug 132850 on SourceForge spells out the
 hopelessness of trying anything else (fseek and ftell
 don't work predictably x-platform for text-mode files).
 */
 int ispyc = 0;
 if (ftell(fp) == 0) {
 if (fread(buf, 1, 2, fp) == 2 &&
 ((unsigned int)buf[1]<<8 | buf[0]) == halfmagic)
 ispyc = 1;
 rewind(fp);
 }
 return ispyc;
 }
 return 0;
}

static int
set_main_loader(PyObject *d, const char *filename, const char *loader_name)
{
 PyInterpreterState *interp;
 PyThreadState *tstate;
 PyObject *filename_obj, *bootstrap, *loader_type = NULL, *loader;
 int result = 0;

 filename_obj = PyUnicode_DecodeFSDefault(filename);
 if (filename_obj == NULL)
 return -1;
 /* Get current thread state and interpreter pointer */
 tstate = PyThreadState_GET();
 interp = tstate->interp;
 bootstrap = PyObject_GetAttrString(interp->importlib,
 "_bootstrap_external");
 if (bootstrap != NULL) {
 loader_type = PyObject_GetAttrString(bootstrap, loader_name);
 Py_DECREF(bootstrap);
 }
 if (loader_type == NULL) {
 Py_DECREF(filename_obj);
 return -1;
 }
 loader = PyObject_CallFunction(loader_type, "sN", "__main__", filename_obj);
 Py_DECREF(loader_type);
 if (loader == NULL) {
 return -1;
 }
 if (PyDict_SetItemString(d, "__loader__", loader) < 0) {
 result = -1;
 }
 Py_DECREF(loader);
 return result;
}

int
PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit,
 PyCompilerFlags *flags)
{
 PyObject *m, *d, *v;
 const char *ext;
 int set_file_name = 0, ret = -1;
 size_t len;

 m = PyImport_AddModule("__main__");
 if (m == NULL)
 return -1;
 Py_INCREF(m);
 d = PyModule_GetDict(m);
 if (PyDict_GetItemString(d, "__file__") == NULL) {
 PyObject *f;
 f = PyUnicode_DecodeFSDefault(filename);
 if (f == NULL)
 goto done;
 if (PyDict_SetItemString(d, "__file__", f) < 0) {
 Py_DECREF(f);
 goto done;
 }
 if (PyDict_SetItemString(d, "__cached__", Py_None) < 0) {
 Py_DECREF(f);
 goto done;
 }
 set_file_name = 1;
 Py_DECREF(f);
 }
 len = strlen(filename);
 ext = filename + len - (len > 4 ? 4 : 0);
 if (maybe_pyc_file(fp, filename, ext, closeit)) {
 FILE *pyc_fp;
 /* Try to run a pyc file. First, re-open in binary */
 if (closeit)
 fclose(fp);
 if ((pyc_fp = _Py_fopen(filename, "rb")) == NULL) {
 fprintf(stderr, "python: Can't reopen .pyc file\n");
 goto done;
 }

 if (set_main_loader(d, filename, "SourcelessFileLoader") < 0) {
 fprintf(stderr, "python: failed to set __main__.__loader__\n");
 ret = -1;
 fclose(pyc_fp);
 goto done;
 }
 v = run_pyc_file(pyc_fp, filename, d, d, flags);
 fclose(pyc_fp);
 } else {
 /* When running from stdin, leave __main__.__loader__ alone */
 if (strcmp(filename, "<stdin>") != 0 &&
 set_main_loader(d, filename, "SourceFileLoader") < 0) {
 fprintf(stderr, "python: failed to set __main__.__loader__\n");
 ret = -1;
 goto done;
 }
 v = PyRun_FileExFlags(fp, filename, Py_file_input, d, d,
 closeit, flags);
 }
 flush_io();
 if (v == NULL) {
 PyErr_Print();
 goto done;
 }
 Py_DECREF(v);
 ret = 0;
 done:
 if (set_file_name && PyDict_DelItemString(d, "__file__"))
 PyErr_Clear();
 Py_DECREF(m);
 return ret;
}

int
PyRun_SimpleStringFlags(const char *command, PyCompilerFlags *flags)
{
 PyObject *m, *d, *v;
 m = PyImport_AddModule("__main__");
 if (m == NULL)
 return -1;
 d = PyModule_GetDict(m);
 v = PyRun_StringFlags(command, Py_file_input, d, d, flags);
 if (v == NULL) {
 PyErr_Print();
 return -1;
 }
 Py_DECREF(v);
 return 0;
}

static int
parse_syntax_error(PyObject *err, PyObject **message, PyObject **filename,
 int *lineno, int *offset, PyObject **text)
{
 int hold;
 PyObject *v;
 _Py_IDENTIFIER(msg);
 _Py_IDENTIFIER(filename);
 _Py_IDENTIFIER(lineno);
 _Py_IDENTIFIER(offset);
 _Py_IDENTIFIER(text);

 *message = NULL;
 *filename = NULL;

 /* new style errors. `err' is an instance */
 *message = _PyObject_GetAttrId(err, &PyId_msg);
 if (!*message)
 goto finally;

 v = _PyObject_GetAttrId(err, &PyId_filename);
 if (!v)
 goto finally;
 if (v == Py_None) {
 Py_DECREF(v);
 *filename = _PyUnicode_FromId(&PyId_string);
 if (*filename == NULL)
 goto finally;
 Py_INCREF(*filename);
 }
 else {
 *filename = v;
 }

 v = _PyObject_GetAttrId(err, &PyId_lineno);
 if (!v)
 goto finally;
 hold = _PyLong_AsInt(v);
 Py_DECREF(v);
 if (hold < 0 && PyErr_Occurred())
 goto finally;
 *lineno = hold;

 v = _PyObject_GetAttrId(err, &PyId_offset);
 if (!v)
 goto finally;
 if (v == Py_None) {
 *offset = -1;
 Py_DECREF(v);
 } else {
 hold = _PyLong_AsInt(v);
 Py_DECREF(v);
 if (hold < 0 && PyErr_Occurred())
 goto finally;
 *offset = hold;
 }

 v = _PyObject_GetAttrId(err, &PyId_text);
 if (!v)
 goto finally;
 if (v == Py_None) {
 Py_DECREF(v);
 *text = NULL;
 }
 else {
 *text = v;
 }
 return 1;

finally:
 Py_XDECREF(*message);
 Py_XDECREF(*filename);
 return 0;
}

void
PyErr_Print(void)
{
 PyErr_PrintEx(1);
}

static void
print_error_text(PyObject *f, int offset, PyObject *text_obj)
{
 char *text;
 char *nl;

 text = PyUnicode_AsUTF8(text_obj);
 if (text == NULL)
 return;

 if (offset >= 0) {
 if (offset > 0 && (size_t)offset == strlen(text) && text[offset - 1] == '\n')
 offset--;
 for (;;) {
 nl = strchr(text, '\n');
 if (nl == NULL || nl-text >= offset)
 break;
 offset -= (int)(nl+1-text);
 text = nl+1;
 }
 while (*text == ' ' || *text == '\t' || *text == '\f') {
 text++;
 offset--;
 }
 }
 PyFile_WriteString(" ", f);
 PyFile_WriteString(text, f);
 if (*text == '0円' || text[strlen(text)-1] != '\n')
 PyFile_WriteString("\n", f);
 if (offset == -1)
 return;
 PyFile_WriteString(" ", f);
 while (--offset > 0)
 PyFile_WriteString(" ", f);
 PyFile_WriteString("^\n", f);
}

static void
handle_system_exit(void)
{
 PyObject *exception, *value, *tb;
 int exitcode = 0;

 if (Py_InspectFlag)
 /* Don't exit if -i flag was given. This flag is set to 0
 * when entering interactive mode for inspecting. */
 return;

 PyErr_Fetch(&exception, &value, &tb);
 fflush(stdout);
 if (value == NULL || value == Py_None)
 goto done;
 if (PyExceptionInstance_Check(value)) {
 /* The error code should be in the `code' attribute. */
 _Py_IDENTIFIER(code);
 PyObject *code = _PyObject_GetAttrId(value, &PyId_code);
 if (code) {
 Py_DECREF(value);
 value = code;
 if (value == Py_None)
 goto done;
 }
 /* If we failed to dig out the 'code' attribute,
 just let the else clause below print the error. */
 }
 if (PyLong_Check(value))
 exitcode = (int)PyLong_AsLong(value);
 else {
 PyObject *sys_stderr = _PySys_GetObjectId(&PyId_stderr);
 /* We clear the exception here to avoid triggering the assertion
 * in PyObject_Str that ensures it won't silently lose exception
 * details.
 */
 PyErr_Clear();
 if (sys_stderr != NULL && sys_stderr != Py_None) {
 PyFile_WriteObject(value, sys_stderr, Py_PRINT_RAW);
 } else {
 PyObject_Print(value, stderr, Py_PRINT_RAW);
 fflush(stderr);
 }
 PySys_WriteStderr("\n");
 exitcode = 1;
 }
 done:
 /* Restore and clear the exception info, in order to properly decref
 * the exception, value, and traceback. If we just exit instead,
 * these leak, which confuses PYTHONDUMPREFS output, and may prevent
 * some finalizers from running.
 */
 PyErr_Restore(exception, value, tb);
 PyErr_Clear();
 Py_Exit(exitcode);
 /* NOTREACHED */
}

void
PyErr_PrintEx(int set_sys_last_vars)
{
 PyObject *exception, *v, *tb, *hook;

 if (PyErr_ExceptionMatches(PyExc_SystemExit)) {
 handle_system_exit();
 }
 PyErr_Fetch(&exception, &v, &tb);
 if (exception == NULL)
 return;
 PyErr_NormalizeException(&exception, &v, &tb);
 if (tb == NULL) {
 tb = Py_None;
 Py_INCREF(tb);
 }
 PyException_SetTraceback(v, tb);
 if (exception == NULL)
 return;
 /* Now we know v != NULL too */
 if (set_sys_last_vars) {
 _PySys_SetObjectId(&PyId_last_type, exception);
 _PySys_SetObjectId(&PyId_last_value, v);
 _PySys_SetObjectId(&PyId_last_traceback, tb);
 }
 hook = _PySys_GetObjectId(&PyId_excepthook);
 if (hook) {
 PyObject* stack[3];
 PyObject *result;

 stack[0] = exception;
 stack[1] = v;
 stack[2] = tb;
 result = _PyObject_FastCall(hook, stack, 3);
 if (result == NULL) {
 PyObject *exception2, *v2, *tb2;
 if (PyErr_ExceptionMatches(PyExc_SystemExit)) {
 handle_system_exit();
 }
 PyErr_Fetch(&exception2, &v2, &tb2);
 PyErr_NormalizeException(&exception2, &v2, &tb2);
 /* It should not be possible for exception2 or v2
 to be NULL. However PyErr_Display() can't
 tolerate NULLs, so just be safe. */
 if (exception2 == NULL) {
 exception2 = Py_None;
 Py_INCREF(exception2);
 }
 if (v2 == NULL) {
 v2 = Py_None;
 Py_INCREF(v2);
 }
 fflush(stdout);
 PySys_WriteStderr("Error in sys.excepthook:\n");
 PyErr_Display(exception2, v2, tb2);
 PySys_WriteStderr("\nOriginal exception was:\n");
 PyErr_Display(exception, v, tb);
 Py_DECREF(exception2);
 Py_DECREF(v2);
 Py_XDECREF(tb2);
 }
 Py_XDECREF(result);
 } else {
 PySys_WriteStderr("sys.excepthook is missing\n");
 PyErr_Display(exception, v, tb);
 }
 Py_XDECREF(exception);
 Py_XDECREF(v);
 Py_XDECREF(tb);
}

static void
print_exception(PyObject *f, PyObject *value)
{
 int err = 0;
 PyObject *type, *tb;
 _Py_IDENTIFIER(print_file_and_line);

 if (!PyExceptionInstance_Check(value)) {
 err = PyFile_WriteString("TypeError: print_exception(): Exception expected for value, ", f);
 err += PyFile_WriteString(Py_TYPE(value)->tp_name, f);
 err += PyFile_WriteString(" found\n", f);
 if (err)
 PyErr_Clear();
 return;
 }

 Py_INCREF(value);
 fflush(stdout);
 type = (PyObject *) Py_TYPE(value);
 tb = PyException_GetTraceback(value);
 if (tb && tb != Py_None)
 err = PyTraceBack_Print(tb, f);
 if (err == 0 &&
 _PyObject_HasAttrId(value, &PyId_print_file_and_line))
 {
 PyObject *message, *filename, *text;
 int lineno, offset;
 if (!parse_syntax_error(value, &message, &filename,
 &lineno, &offset, &text))
 PyErr_Clear();
 else {
 PyObject *line;

 Py_DECREF(value);
 value = message;

 line = PyUnicode_FromFormat(" File \"%U\", line %d\n",
 filename, lineno);
 Py_DECREF(filename);
 if (line != NULL) {
 PyFile_WriteObject(line, f, Py_PRINT_RAW);
 Py_DECREF(line);
 }

 if (text != NULL) {
 print_error_text(f, offset, text);
 Py_DECREF(text);
 }

 /* Can't be bothered to check all those
 PyFile_WriteString() calls */
 if (PyErr_Occurred())
 err = -1;
 }
 }
 if (err) {
 /* Don't do anything else */
 }
 else {
 PyObject* moduleName;
 char* className;
 _Py_IDENTIFIER(__module__);
 assert(PyExceptionClass_Check(type));
 className = PyExceptionClass_Name(type);
 if (className != NULL) {
 char *dot = strrchr(className, '.');
 if (dot != NULL)
 className = dot+1;
 }

 moduleName = _PyObject_GetAttrId(type, &PyId___module__);
 if (moduleName == NULL || !PyUnicode_Check(moduleName))
 {
 Py_XDECREF(moduleName);
 err = PyFile_WriteString("<unknown>", f);
 }
 else {
 if (!_PyUnicode_EqualToASCIIId(moduleName, &PyId_builtins))
 {
 err = PyFile_WriteObject(moduleName, f, Py_PRINT_RAW);
 err += PyFile_WriteString(".", f);
 }
 Py_DECREF(moduleName);
 }
 if (err == 0) {
 if (className == NULL)
 err = PyFile_WriteString("<unknown>", f);
 else
 err = PyFile_WriteString(className, f);
 }
 }
 if (err == 0 && (value != Py_None)) {
 PyObject *s = PyObject_Str(value);
 /* only print colon if the str() of the
 object is not the empty string
 */
 if (s == NULL) {
 PyErr_Clear();
 err = -1;
 PyFile_WriteString(": <exception str() failed>", f);
 }
 else if (!PyUnicode_Check(s) ||
 PyUnicode_GetLength(s) != 0)
 err = PyFile_WriteString(": ", f);
 if (err == 0)
 err = PyFile_WriteObject(s, f, Py_PRINT_RAW);
 Py_XDECREF(s);
 }
 /* try to write a newline in any case */
 if (err < 0) {
 PyErr_Clear();
 }
 err += PyFile_WriteString("\n", f);
 Py_XDECREF(tb);
 Py_DECREF(value);
 /* If an error happened here, don't show it.
 XXX This is wrong, but too many callers rely on this behavior. */
 if (err != 0)
 PyErr_Clear();
}

static const char cause_message[] =
 "\nThe above exception was the direct cause "
 "of the following exception:\n\n";

static const char context_message[] =
 "\nDuring handling of the above exception, "
 "another exception occurred:\n\n";

static void
print_exception_recursive(PyObject *f, PyObject *value, PyObject *seen)
{
 int err = 0, res;
 PyObject *cause, *context;

 if (seen != NULL) {
 /* Exception chaining */
 if (PySet_Add(seen, value) == -1)
 PyErr_Clear();
 else if (PyExceptionInstance_Check(value)) {
 cause = PyException_GetCause(value);
 context = PyException_GetContext(value);
 if (cause) {
 res = PySet_Contains(seen, cause);
 if (res == -1)
 PyErr_Clear();
 if (res == 0) {
 print_exception_recursive(
 f, cause, seen);
 err |= PyFile_WriteString(
 cause_message, f);
 }
 }
 else if (context &&
 !((PyBaseExceptionObject *)value)->suppress_context) {
 res = PySet_Contains(seen, context);
 if (res == -1)
 PyErr_Clear();
 if (res == 0) {
 print_exception_recursive(
 f, context, seen);
 err |= PyFile_WriteString(
 context_message, f);
 }
 }
 Py_XDECREF(context);
 Py_XDECREF(cause);
 }
 }
 print_exception(f, value);
 if (err != 0)
 PyErr_Clear();
}

void
PyErr_Display(PyObject *exception, PyObject *value, PyObject *tb)
{
 PyObject *seen;
 PyObject *f = _PySys_GetObjectId(&PyId_stderr);
 if (PyExceptionInstance_Check(value)
 && tb != NULL && PyTraceBack_Check(tb)) {
 /* Put the traceback on the exception, otherwise it won't get
 displayed. See issue #18776. */
 PyObject *cur_tb = PyException_GetTraceback(value);
 if (cur_tb == NULL)
 PyException_SetTraceback(value, tb);
 else
 Py_DECREF(cur_tb);
 }
 if (f == Py_None) {
 /* pass */
 }
 else if (f == NULL) {
 _PyObject_Dump(value);
 fprintf(stderr, "lost sys.stderr\n");
 }
 else {
 /* We choose to ignore seen being possibly NULL, and report
 at least the main exception (it could be a MemoryError).
 */
 seen = PySet_New(NULL);
 if (seen == NULL)
 PyErr_Clear();
 print_exception_recursive(f, value, seen);
 Py_XDECREF(seen);
 }
}

PyObject *
PyRun_StringFlags(const char *str, int start, PyObject *globals,
 PyObject *locals, PyCompilerFlags *flags)
{
 PyObject *ret = NULL;
 mod_ty mod;
 PyArena *arena;
 PyObject *filename;

 filename = _PyUnicode_FromId(&PyId_string); /* borrowed */
 if (filename == NULL)
 return NULL;

 arena = PyArena_New();
 if (arena == NULL)
 return NULL;

 mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
 if (mod != NULL)
 ret = run_mod(mod, filename, globals, locals, flags, arena);
 PyArena_Free(arena);
 return ret;
}

PyObject *
PyRun_FileExFlags(FILE *fp, const char *filename_str, int start, PyObject *globals,
 PyObject *locals, int closeit, PyCompilerFlags *flags)
{
 PyObject *ret = NULL;
 mod_ty mod;
 PyArena *arena = NULL;
 PyObject *filename;

 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL)
 goto exit;

 arena = PyArena_New();
 if (arena == NULL)
 goto exit;

 mod = PyParser_ASTFromFileObject(fp, filename, NULL, start, 0, 0,
 flags, NULL, arena);
 if (closeit)
 fclose(fp);
 if (mod == NULL) {
 goto exit;
 }
 ret = run_mod(mod, filename, globals, locals, flags, arena);

exit:
 Py_XDECREF(filename);
 if (arena != NULL)
 PyArena_Free(arena);
 return ret;
}

static void
flush_io(void)
{
 PyObject *f, *r;
 PyObject *type, *value, *traceback;

 /* Save the current exception */
 PyErr_Fetch(&type, &value, &traceback);

 f = _PySys_GetObjectId(&PyId_stderr);
 if (f != NULL) {
 r = _PyObject_CallMethodId(f, &PyId_flush, NULL);
 if (r)
 Py_DECREF(r);
 else
 PyErr_Clear();
 }
 f = _PySys_GetObjectId(&PyId_stdout);
 if (f != NULL) {
 r = _PyObject_CallMethodId(f, &PyId_flush, NULL);
 if (r)
 Py_DECREF(r);
 else
 PyErr_Clear();
 }

 PyErr_Restore(type, value, traceback);
}

static PyObject *
run_mod(mod_ty mod, PyObject *filename, PyObject *globals, PyObject *locals,
 PyCompilerFlags *flags, PyArena *arena)
{
 PyCodeObject *co;
 PyObject *v;
 co = PyAST_CompileObject(mod, filename, flags, -1, arena);
 if (co == NULL)
 return NULL;
 v = PyEval_EvalCode((PyObject*)co, globals, locals);
 Py_DECREF(co);
 return v;
}

static PyObject *
run_pyc_file(FILE *fp, const char *filename, PyObject *globals,
 PyObject *locals, PyCompilerFlags *flags)
{
 PyCodeObject *co;
 PyObject *v;
 long magic;
 long PyImport_GetMagicNumber(void);

 magic = PyMarshal_ReadLongFromFile(fp);
 if (magic != PyImport_GetMagicNumber()) {
 if (!PyErr_Occurred())
 PyErr_SetString(PyExc_RuntimeError,
 "Bad magic number in .pyc file");
 return NULL;
 }
 /* Skip mtime and size */
 (void) PyMarshal_ReadLongFromFile(fp);
 (void) PyMarshal_ReadLongFromFile(fp);
 if (PyErr_Occurred())
 return NULL;

 v = PyMarshal_ReadLastObjectFromFile(fp);
 if (v == NULL || !PyCode_Check(v)) {
 Py_XDECREF(v);
 PyErr_SetString(PyExc_RuntimeError,
 "Bad code object in .pyc file");
 return NULL;
 }
 co = (PyCodeObject *)v;
 v = PyEval_EvalCode((PyObject*)co, globals, locals);
 if (v && flags)
 flags->cf_flags |= (co->co_flags & PyCF_MASK);
 Py_DECREF(co);
 return v;
}

PyObject *
Py_CompileStringObject(const char *str, PyObject *filename, int start,
 PyCompilerFlags *flags, int optimize)
{
 PyCodeObject *co;
 mod_ty mod;
 PyArena *arena = PyArena_New();
 if (arena == NULL)
 return NULL;

 mod = PyParser_ASTFromStringObject(str, filename, start, flags, arena);
 if (mod == NULL) {
 PyArena_Free(arena);
 return NULL;
 }
 if (flags && (flags->cf_flags & PyCF_ONLY_AST)) {
 PyObject *result = PyAST_mod2obj(mod);
 PyArena_Free(arena);
 return result;
 }
 co = PyAST_CompileObject(mod, filename, flags, optimize, arena);
 PyArena_Free(arena);
 return (PyObject *)co;
}

PyObject *
Py_CompileStringExFlags(const char *str, const char *filename_str, int start,
 PyCompilerFlags *flags, int optimize)
{
 PyObject *filename, *co;
 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL)
 return NULL;
 co = Py_CompileStringObject(str, filename, start, flags, optimize);
 Py_DECREF(filename);
 return co;
}

/* For use in Py_LIMITED_API */
#undef Py_CompileString
PyObject *
PyCompileString(const char *str, const char *filename, int start)
{
 return Py_CompileStringFlags(str, filename, start, NULL);
}

struct symtable *
Py_SymtableStringObject(const char *str, PyObject *filename, int start)
{
 struct symtable *st;
 mod_ty mod;
 PyCompilerFlags flags;
 PyArena *arena;

 arena = PyArena_New();
 if (arena == NULL)
 return NULL;

 flags.cf_flags = 0;
 mod = PyParser_ASTFromStringObject(str, filename, start, &flags, arena);
 if (mod == NULL) {
 PyArena_Free(arena);
 return NULL;
 }
 st = PySymtable_BuildObject(mod, filename, 0);
 PyArena_Free(arena);
 return st;
}

struct symtable *
Py_SymtableString(const char *str, const char *filename_str, int start)
{
 PyObject *filename;
 struct symtable *st;

 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL)
 return NULL;
 st = Py_SymtableStringObject(str, filename, start);
 Py_DECREF(filename);
 return st;
}

/* Preferred access to parser is through AST. */
mod_ty
PyParser_ASTFromStringObject(const char *s, PyObject *filename, int start,
 PyCompilerFlags *flags, PyArena *arena)
{
 mod_ty mod;
 PyCompilerFlags localflags;
 perrdetail err;
 int iflags = PARSER_FLAGS(flags);

 node *n = PyParser_ParseStringObject(s, filename,
 &_PyParser_Grammar, start, &err,
 &iflags);
 if (flags == NULL) {
 localflags.cf_flags = 0;
 flags = &localflags;
 }
 if (n) {
 flags->cf_flags |= iflags & PyCF_MASK;
 mod = PyAST_FromNodeObject(n, flags, filename, arena);
 PyNode_Free(n);
 }
 else {
 err_input(&err);
 mod = NULL;
 }
 err_free(&err);
 return mod;
}

mod_ty
PyParser_ASTFromString(const char *s, const char *filename_str, int start,
 PyCompilerFlags *flags, PyArena *arena)
{
 PyObject *filename;
 mod_ty mod;
 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL)
 return NULL;
 mod = PyParser_ASTFromStringObject(s, filename, start, flags, arena);
 Py_DECREF(filename);
 return mod;
}

mod_ty
PyParser_ASTFromFileObject(FILE *fp, PyObject *filename, const char* enc,
 int start, const char *ps1,
 const char *ps2, PyCompilerFlags *flags, int *errcode,
 PyArena *arena)
{
 mod_ty mod;
 PyCompilerFlags localflags;
 perrdetail err;
 int iflags = PARSER_FLAGS(flags);

 node *n = PyParser_ParseFileObject(fp, filename, enc,
 &_PyParser_Grammar,
 start, ps1, ps2, &err, &iflags);
 if (flags == NULL) {
 localflags.cf_flags = 0;
 flags = &localflags;
 }
 if (n) {
 flags->cf_flags |= iflags & PyCF_MASK;
 mod = PyAST_FromNodeObject(n, flags, filename, arena);
 PyNode_Free(n);
 }
 else {
 err_input(&err);
 if (errcode)
 *errcode = err.error;
 mod = NULL;
 }
 err_free(&err);
 return mod;
}

mod_ty
PyParser_ASTFromFile(FILE *fp, const char *filename_str, const char* enc,
 int start, const char *ps1,
 const char *ps2, PyCompilerFlags *flags, int *errcode,
 PyArena *arena)
{
 mod_ty mod;
 PyObject *filename;
 filename = PyUnicode_DecodeFSDefault(filename_str);
 if (filename == NULL)
 return NULL;
 mod = PyParser_ASTFromFileObject(fp, filename, enc, start, ps1, ps2,
 flags, errcode, arena);
 Py_DECREF(filename);
 return mod;
}

/* Simplified interface to parsefile -- return node or set exception */

node *
PyParser_SimpleParseFileFlags(FILE *fp, const char *filename, int start, int flags)
{
 perrdetail err;
 node *n = PyParser_ParseFileFlags(fp, filename, NULL,
 &_PyParser_Grammar,
 start, NULL, NULL, &err, flags);
 if (n == NULL)
 err_input(&err);
 err_free(&err);

 return n;
}

/* Simplified interface to parsestring -- return node or set exception */

node *
PyParser_SimpleParseStringFlags(const char *str, int start, int flags)
{
 perrdetail err;
 node *n = PyParser_ParseStringFlags(str, &_PyParser_Grammar,
 start, &err, flags);
 if (n == NULL)
 err_input(&err);
 err_free(&err);
 return n;
}

node *
PyParser_SimpleParseStringFlagsFilename(const char *str, const char *filename,
 int start, int flags)
{
 perrdetail err;
 node *n = PyParser_ParseStringFlagsFilename(str, filename,
 &_PyParser_Grammar, start, &err, flags);
 if (n == NULL)
 err_input(&err);
 err_free(&err);
 return n;
}

node *
PyParser_SimpleParseStringFilename(const char *str, const char *filename, int start)
{
 return PyParser_SimpleParseStringFlagsFilename(str, filename, start, 0);
}

/* May want to move a more generalized form of this to parsetok.c or
 even parser modules. */

void
PyParser_ClearError(perrdetail *err)
{
 err_free(err);
}

void
PyParser_SetError(perrdetail *err)
{
 err_input(err);
}

static void
err_free(perrdetail *err)
{
 Py_CLEAR(err->filename);
}

/* Set the error appropriate to the given input error code (see errcode.h) */

static void
err_input(perrdetail *err)
{
 PyObject *v, *w, *errtype, *errtext;
 PyObject *msg_obj = NULL;
 char *msg = NULL;
 int offset = err->offset;

 errtype = PyExc_SyntaxError;
 switch (err->error) {
 case E_ERROR:
 return;
 case E_SYNTAX:
 errtype = PyExc_IndentationError;
 if (err->expected == INDENT)
 msg = "expected an indented block";
 else if (err->token == INDENT)
 msg = "unexpected indent";
 else if (err->token == DEDENT)
 msg = "unexpected unindent";
 else {
 errtype = PyExc_SyntaxError;
 msg = "invalid syntax";
 }
 break;
 case E_TOKEN:
 msg = "invalid token";
 break;
 case E_EOFS:
 msg = "EOF while scanning triple-quoted string literal";
 break;
 case E_EOLS:
 msg = "EOL while scanning string literal";
 break;
 case E_INTR:
 if (!PyErr_Occurred())
 PyErr_SetNone(PyExc_KeyboardInterrupt);
 goto cleanup;
 case E_NOMEM:
 PyErr_NoMemory();
 goto cleanup;
 case E_EOF:
 msg = "unexpected EOF while parsing";
 break;
 case E_TABSPACE:
 errtype = PyExc_TabError;
 msg = "inconsistent use of tabs and spaces in indentation";
 break;
 case E_OVERFLOW:
 msg = "expression too long";
 break;
 case E_DEDENT:
 errtype = PyExc_IndentationError;
 msg = "unindent does not match any outer indentation level";
 break;
 case E_TOODEEP:
 errtype = PyExc_IndentationError;
 msg = "too many levels of indentation";
 break;
 case E_DECODE: {
 PyObject *type, *value, *tb;
 PyErr_Fetch(&type, &value, &tb);
 msg = "unknown decode error";
 if (value != NULL)
 msg_obj = PyObject_Str(value);
 Py_XDECREF(type);
 Py_XDECREF(value);
 Py_XDECREF(tb);
 break;
 }
 case E_LINECONT:
 msg = "unexpected character after line continuation character";
 break;

 case E_IDENTIFIER:
 msg = "invalid character in identifier";
 break;
 case E_BADSINGLE:
 msg = "multiple statements found while compiling a single statement";
 break;
 default:
 fprintf(stderr, "error=%d\n", err->error);
 msg = "unknown parsing error";
 break;
 }
 /* err->text may not be UTF-8 in case of decoding errors.
 Explicitly convert to an object. */
 if (!err->text) {
 errtext = Py_None;
 Py_INCREF(Py_None);
 } else {
 errtext = PyUnicode_DecodeUTF8(err->text, err->offset,
 "replace");
 if (errtext != NULL) {
 Py_ssize_t len = strlen(err->text);
 offset = (int)PyUnicode_GET_LENGTH(errtext);
 if (len != err->offset) {
 Py_DECREF(errtext);
 errtext = PyUnicode_DecodeUTF8(err->text, len,
 "replace");
 }
 }
 }
 v = Py_BuildValue("(OiiN)", err->filename,
 err->lineno, offset, errtext);
 if (v != NULL) {
 if (msg_obj)
 w = Py_BuildValue("(OO)", msg_obj, v);
 else
 w = Py_BuildValue("(sO)", msg, v);
 } else
 w = NULL;
 Py_XDECREF(v);
 PyErr_SetObject(errtype, w);
 Py_XDECREF(w);
cleanup:
 Py_XDECREF(msg_obj);
 if (err->text != NULL) {
 PyObject_FREE(err->text);
 err->text = NULL;
 }
}


#if defined(USE_STACKCHECK)
#if defined(WIN32) && defined(_MSC_VER)

/* Stack checking for Microsoft C */

#include <malloc.h>
#include <excpt.h>

/*
 * Return non-zero when we run out of memory on the stack; zero otherwise.
 */
int
PyOS_CheckStack(void)
{
 __try {
 /* alloca throws a stack overflow exception if there's
 not enough space left on the stack */
 alloca(PYOS_STACK_MARGIN * sizeof(void*));
 return 0;
 } __except (GetExceptionCode() == STATUS_STACK_OVERFLOW ?
 EXCEPTION_EXECUTE_HANDLER :
 EXCEPTION_CONTINUE_SEARCH) {
 int errcode = _resetstkoflw();
 if (errcode == 0)
 {
 Py_FatalError("Could not reset the stack!");
 }
 }
 return 1;
}

#endif /* WIN32 && _MSC_VER */

/* Alternate implementations can be added here... */

#endif /* USE_STACKCHECK */

/* Deprecated C API functions still provided for binary compatibility */

#undef PyParser_SimpleParseFile
PyAPI_FUNC(node *)
PyParser_SimpleParseFile(FILE *fp, const char *filename, int start)
{
 return PyParser_SimpleParseFileFlags(fp, filename, start, 0);
}

#undef PyParser_SimpleParseString
PyAPI_FUNC(node *)
PyParser_SimpleParseString(const char *str, int start)
{
 return PyParser_SimpleParseStringFlags(str, start, 0);
}

#undef PyRun_AnyFile
PyAPI_FUNC(int)
PyRun_AnyFile(FILE *fp, const char *name)
{
 return PyRun_AnyFileExFlags(fp, name, 0, NULL);
}

#undef PyRun_AnyFileEx
PyAPI_FUNC(int)
PyRun_AnyFileEx(FILE *fp, const char *name, int closeit)
{
 return PyRun_AnyFileExFlags(fp, name, closeit, NULL);
}

#undef PyRun_AnyFileFlags
PyAPI_FUNC(int)
PyRun_AnyFileFlags(FILE *fp, const char *name, PyCompilerFlags *flags)
{
 return PyRun_AnyFileExFlags(fp, name, 0, flags);
}

#undef PyRun_File
PyAPI_FUNC(PyObject *)
PyRun_File(FILE *fp, const char *p, int s, PyObject *g, PyObject *l)
{
 return PyRun_FileExFlags(fp, p, s, g, l, 0, NULL);
}

#undef PyRun_FileEx
PyAPI_FUNC(PyObject *)
PyRun_FileEx(FILE *fp, const char *p, int s, PyObject *g, PyObject *l, int c)
{
 return PyRun_FileExFlags(fp, p, s, g, l, c, NULL);
}

#undef PyRun_FileFlags
PyAPI_FUNC(PyObject *)
PyRun_FileFlags(FILE *fp, const char *p, int s, PyObject *g, PyObject *l,
 PyCompilerFlags *flags)
{
 return PyRun_FileExFlags(fp, p, s, g, l, 0, flags);
}

#undef PyRun_SimpleFile
PyAPI_FUNC(int)
PyRun_SimpleFile(FILE *f, const char *p)
{
 return PyRun_SimpleFileExFlags(f, p, 0, NULL);
}

#undef PyRun_SimpleFileEx
PyAPI_FUNC(int)
PyRun_SimpleFileEx(FILE *f, const char *p, int c)
{
 return PyRun_SimpleFileExFlags(f, p, c, NULL);
}


#undef PyRun_String
PyAPI_FUNC(PyObject *)
PyRun_String(const char *str, int s, PyObject *g, PyObject *l)
{
 return PyRun_StringFlags(str, s, g, l, NULL);
}

#undef PyRun_SimpleString
PyAPI_FUNC(int)
PyRun_SimpleString(const char *s)
{
 return PyRun_SimpleStringFlags(s, NULL);
}

#undef Py_CompileString
PyAPI_FUNC(PyObject *)
Py_CompileString(const char *str, const char *p, int s)
{
 return Py_CompileStringExFlags(str, p, s, NULL, -1);
}

#undef Py_CompileStringFlags
PyAPI_FUNC(PyObject *)
Py_CompileStringFlags(const char *str, const char *p, int s,
 PyCompilerFlags *flags)
{
 return Py_CompileStringExFlags(str, p, s, flags, -1);
}

#undef PyRun_InteractiveOne
PyAPI_FUNC(int)
PyRun_InteractiveOne(FILE *f, const char *p)
{
 return PyRun_InteractiveOneFlags(f, p, NULL);
}

#undef PyRun_InteractiveLoop
PyAPI_FUNC(int)
PyRun_InteractiveLoop(FILE *f, const char *p)
{
 return PyRun_InteractiveLoopFlags(f, p, NULL);
}

#ifdef __cplusplus
}
#endif