/* Top level execution of Python code (including in __main__) */

/* To help control the interfaces between the startup, execution and

* shutdown code, the phases are split across separate modules (bootstrap,

* pythonrun, shutdown)

*/

/* TODO: Cull includes following phase split */

#include <stdbool.h>

#include "Python.h"

#include "pycore_ast.h" // PyAST_mod2obj()

#include "pycore_ceval.h" // _Py_EnterRecursiveCall()

#include "pycore_compile.h" // _PyAST_Compile()

#include "pycore_interp.h" // PyInterpreterState.importlib

#include "pycore_object.h" // _PyDebug_PrintTotalRefs()

#include "pycore_parser.h" // _PyParser_ASTFromString()

#include "pycore_pyerrors.h" // _PyErr_GetRaisedException()

#include "pycore_pylifecycle.h" // _Py_FdIsInteractive()

#include "pycore_pystate.h" // _PyInterpreterState_GET()

#include "pycore_pythonrun.h" // export _PyRun_InteractiveLoopObject()

#include "pycore_sysmodule.h" // _PySys_Audit()

#include "pycore_traceback.h" // _PyTraceBack_Print()

#include "errcode.h" // E_EOF

#include "marshal.h" // PyMarshal_ReadLongFromFile()

#ifdef MS_WINDOWS

# include "malloc.h" // alloca()

#endif

#ifdef MS_WINDOWS

# undef BYTE

# include "windows.h"

#endif

/* Forward */

static void flush_io(void);

static PyObject *run_mod(mod_ty, PyObject *, PyObject *, PyObject *,

PyCompilerFlags *, PyArena *, PyObject*, int);

static PyObject *run_pyc_file(FILE *, PyObject *, PyObject *,

PyCompilerFlags *);

static int PyRun_InteractiveOneObjectEx(FILE *, PyObject *, PyCompilerFlags *);

static PyObject* pyrun_file(FILE *fp, PyObject *filename, int start,

PyObject *globals, PyObject *locals, int closeit,

PyCompilerFlags *flags);

static PyObject *

_PyRun_StringFlagsWithName(const char *str, PyObject* name, int start,

PyObject *globals, PyObject *locals, PyCompilerFlags *flags,

int generate_new_source);

int

_PyRun_AnyFileObject(FILE *fp, PyObject *filename, int closeit,

PyCompilerFlags *flags)

{

int decref_filename = 0;

if (filename == NULL) {

filename = PyUnicode_FromString("???");

if (filename == NULL) {

PyErr_Print();

return -1;

}

decref_filename = 1;

}

int res;

if (_Py_FdIsInteractive(fp, filename)) {

res = _PyRun_InteractiveLoopObject(fp, filename, flags);

if (closeit) {

fclose(fp);

}

}

else {

res = _PyRun_SimpleFileObject(fp, filename, closeit, flags);

}

if (decref_filename) {

Py_DECREF(filename);

}

return res;

}

int

PyRun_AnyFileExFlags(FILE *fp, const char *filename, int closeit,

PyCompilerFlags *flags)

{

PyObject *filename_obj = NULL;

if (filename != NULL) {

filename_obj = PyUnicode_DecodeFSDefault(filename);

if (filename_obj == NULL) {

PyErr_Print();

return -1;

}

}

int res = _PyRun_AnyFileObject(fp, filename_obj, closeit, flags);

Py_XDECREF(filename_obj);

return res;

}

int

_PyRun_InteractiveLoopObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)

{

PyCompilerFlags local_flags = _PyCompilerFlags_INIT;

if (flags == NULL) {

flags = &local_flags;

}

PyThreadState *tstate = _PyThreadState_GET();

PyObject *v = _PySys_GetAttr(tstate, &_Py_ID(ps1));

if (v == NULL) {

_PySys_SetAttr(&_Py_ID(ps1), v = PyUnicode_FromString(">>> "));

Py_XDECREF(v);

}

v = _PySys_GetAttr(tstate, &_Py_ID(ps2));

if (v == NULL) {

_PySys_SetAttr(&_Py_ID(ps2), v = PyUnicode_FromString("... "));

Py_XDECREF(v);

}

#ifdef Py_REF_DEBUG

int show_ref_count = _Py_GetConfig()->show_ref_count;

#endif

int err = 0;

int ret;

int nomem_count = 0;

do {

ret = PyRun_InteractiveOneObjectEx(fp, filename, flags);

if (ret == -1 && PyErr_Occurred()) {

/* Prevent an endless loop after multiple consecutive MemoryErrors

* while still allowing an interactive command to fail with a

* MemoryError. */

if (PyErr_ExceptionMatches(PyExc_MemoryError)) {

if (++nomem_count > 16) {

PyErr_Clear();

err = -1;

break;

}

} else {

nomem_count = 0;

}

PyErr_Print();

flush_io();

} else {

nomem_count = 0;

}

#ifdef Py_REF_DEBUG

if (show_ref_count) {

_PyDebug_PrintTotalRefs();

}

#endif

} while (ret != E_EOF);

return err;

}

int

PyRun_InteractiveLoopFlags(FILE *fp, const char *filename, PyCompilerFlags *flags)

{

PyObject *filename_obj = PyUnicode_DecodeFSDefault(filename);

if (filename_obj == NULL) {

PyErr_Print();

return -1;

}

int err = _PyRun_InteractiveLoopObject(fp, filename_obj, flags);

Py_DECREF(filename_obj);

return err;

}

// Call _PyParser_ASTFromFile() with sys.stdin.encoding, sys.ps1 and sys.ps2

static int

pyrun_one_parse_ast(FILE *fp, PyObject *filename,

PyCompilerFlags *flags, PyArena *arena,

mod_ty *pmod, PyObject** interactive_src)

{

PyThreadState *tstate = _PyThreadState_GET();

// Get sys.stdin.encoding (as UTF-8)

PyObject *attr; // borrowed ref

PyObject *encoding_obj = NULL;

const char *encoding = NULL;

if (fp == stdin) {

attr = _PySys_GetAttr(tstate, &_Py_ID(stdin));

if (attr && attr != Py_None) {

encoding_obj = PyObject_GetAttr(attr, &_Py_ID(encoding));

if (encoding_obj) {

encoding = PyUnicode_AsUTF8(encoding_obj);

if (!encoding) {

PyErr_Clear();

}

}

}

}

// Get sys.ps1 (as UTF-8)

attr = _PySys_GetAttr(tstate, &_Py_ID(ps1));

PyObject *ps1_obj = NULL;

const char *ps1 = "";

if (attr != NULL) {

ps1_obj = PyObject_Str(attr);

if (ps1_obj == NULL) {

PyErr_Clear();

}

else if (PyUnicode_Check(ps1_obj)) {

ps1 = PyUnicode_AsUTF8(ps1_obj);

if (ps1 == NULL) {

PyErr_Clear();

ps1 = "";

}

}

}

// Get sys.ps2 (as UTF-8)

attr = _PySys_GetAttr(tstate, &_Py_ID(ps2));

PyObject *ps2_obj = NULL;

const char *ps2 = "";

if (attr != NULL) {

ps2_obj = PyObject_Str(attr);

if (ps2_obj == NULL) {

PyErr_Clear();

}

else if (PyUnicode_Check(ps2_obj)) {

ps2 = PyUnicode_AsUTF8(ps2_obj);

if (ps2 == NULL) {

PyErr_Clear();

ps2 = "";

}

}

}

int errcode = 0;

*pmod = _PyParser_InteractiveASTFromFile(fp, filename, encoding,

Py_single_input, ps1, ps2,

flags, &errcode, interactive_src, arena);

Py_XDECREF(ps1_obj);

Py_XDECREF(ps2_obj);

Py_XDECREF(encoding_obj);

if (*pmod == NULL) {

if (errcode == E_EOF) {

PyErr_Clear();

return E_EOF;

}

return -1;

}

return 0;

}

/* A PyRun_InteractiveOneObject() auxiliary function that does not print the

* error on failure. */

static int

PyRun_InteractiveOneObjectEx(FILE *fp, PyObject *filename,

PyCompilerFlags *flags)

{

PyArena *arena = _PyArena_New();

if (arena == NULL) {

return -1;

}

mod_ty mod;

PyObject *interactive_src;

int parse_res = pyrun_one_parse_ast(fp, filename, flags, arena, &mod, &interactive_src);

if (parse_res != 0) {

_PyArena_Free(arena);

return parse_res;

}

PyObject *main_module = PyImport_AddModuleRef("__main__");

if (main_module == NULL) {

_PyArena_Free(arena);

return -1;

}

PyObject *main_dict = PyModule_GetDict(main_module); // borrowed ref

PyObject *res = run_mod(mod, filename, main_dict, main_dict, flags, arena, interactive_src, 1);

_PyArena_Free(arena);

Py_DECREF(main_module);

if (res == NULL) {

return -1;

}

Py_DECREF(res);

flush_io();

return 0;

}

int

PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)

{

int res;

res = PyRun_InteractiveOneObjectEx(fp, filename, flags);

if (res == -1) {

PyErr_Print();

flush_io();

}

return res;

}

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, PyObject *filename, int closeit)

{

PyObject *ext = PyUnicode_FromString(".pyc");

if (ext == NULL) {

return -1;

}

Py_ssize_t endswith = PyUnicode_Tailmatch(filename, ext, 0, PY_SSIZE_T_MAX, +1);

Py_DECREF(ext);

if (endswith) {

return 1;

}

/* Only look into the file if we are allowed to close it, since

it then should also be seekable. */

if (!closeit) {

return 0;

}

/* 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;

}

static int

set_main_loader(PyObject *d, PyObject *filename, const char *loader_name)

{

PyInterpreterState *interp = _PyInterpreterState_GET();

PyObject *loader_type = _PyImport_GetImportlibExternalLoader(interp,

loader_name);

if (loader_type == NULL) {

return -1;

}

PyObject *loader = PyObject_CallFunction(loader_type,

"sO", "__main__", filename);

Py_DECREF(loader_type);

if (loader == NULL) {

return -1;

}

if (PyDict_SetItemString(d, "__loader__", loader) < 0) {

Py_DECREF(loader);

return -1;

}

Py_DECREF(loader);

return 0;

}

int

_PyRun_SimpleFileObject(FILE *fp, PyObject *filename, int closeit,

PyCompilerFlags *flags)

{

int ret = -1;

PyObject *main_module = PyImport_AddModuleRef("__main__");

if (main_module == NULL)

return -1;

PyObject *dict = PyModule_GetDict(main_module); // borrowed ref

int set_file_name = 0;

int has_file = PyDict_ContainsString(dict, "__file__");

if (has_file < 0) {

goto done;

}

if (!has_file) {

if (PyDict_SetItemString(dict, "__file__", filename) < 0) {

goto done;

}

if (PyDict_SetItemString(dict, "__cached__", Py_None) < 0) {

goto done;

}

set_file_name = 1;

}

int pyc = maybe_pyc_file(fp, filename, closeit);

if (pyc < 0) {

goto done;

}

PyObject *v;

if (pyc) {

FILE *pyc_fp;

/* Try to run a pyc file. First, re-open in binary */

if (closeit) {

fclose(fp);

}

pyc_fp = _Py_fopen_obj(filename, "rb");

if (pyc_fp == NULL) {

fprintf(stderr, "python: Can't reopen .pyc file\n");

goto done;

}

if (set_main_loader(dict, 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, dict, dict, flags);

} else {

/* When running from stdin, leave __main__.__loader__ alone */

if ((!PyUnicode_Check(filename) || !PyUnicode_EqualToUTF8(filename, "<stdin>")) &&

set_main_loader(dict, filename, "SourceFileLoader") < 0) {

fprintf(stderr, "python: failed to set __main__.__loader__\n");

ret = -1;

goto done;

}

v = pyrun_file(fp, filename, Py_file_input, dict, dict,

closeit, flags);

}

flush_io();

if (v == NULL) {

Py_CLEAR(main_module);

PyErr_Print();

goto done;

}

Py_DECREF(v);

ret = 0;

done:

if (set_file_name) {

if (PyDict_PopString(dict, "__file__", NULL) < 0) {

PyErr_Print();

}

if (PyDict_PopString(dict, "__cached__", NULL) < 0) {

PyErr_Print();

}

}

Py_XDECREF(main_module);

return ret;

}

int

PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit,

PyCompilerFlags *flags)

{

PyObject *filename_obj = PyUnicode_DecodeFSDefault(filename);

if (filename_obj == NULL) {

return -1;

}

int res = _PyRun_SimpleFileObject(fp, filename_obj, closeit, flags);

Py_DECREF(filename_obj);

return res;

}

int

_PyRun_SimpleStringFlagsWithName(const char *command, const char* name, PyCompilerFlags *flags) {

PyObject *main_module = PyImport_AddModuleRef("__main__");

if (main_module == NULL) {

return -1;

}

PyObject *dict = PyModule_GetDict(main_module); // borrowed ref

PyObject *res = NULL;

if (name == NULL) {

res = PyRun_StringFlags(command, Py_file_input, dict, dict, flags);

} else {

PyObject* the_name = PyUnicode_FromString(name);

if (!the_name) {

PyErr_Print();

return -1;

}

res = _PyRun_StringFlagsWithName(command, the_name, Py_file_input, dict, dict, flags, 0);

Py_DECREF(the_name);

}

Py_DECREF(main_module);

if (res == NULL) {

PyErr_Print();

return -1;

}

Py_DECREF(res);

return 0;

}

int

PyRun_SimpleStringFlags(const char *command, PyCompilerFlags *flags)

{

return _PyRun_SimpleStringFlagsWithName(command, NULL, flags);

}

int

_Py_HandleSystemExit(int *exitcode_p)

{

int inspect = _Py_GetConfig()->inspect;

if (inspect) {

/* Don't exit if -i flag was given. This flag is set to 0

* when entering interactive mode for inspecting. */

return 0;

}

if (!PyErr_ExceptionMatches(PyExc_SystemExit)) {

return 0;

}

fflush(stdout);

int exitcode = 0;

PyObject *exc = PyErr_GetRaisedException();

if (exc == NULL) {

goto done;

}

assert(PyExceptionInstance_Check(exc));

/* The error code should be in the `code' attribute. */

PyObject *code = PyObject_GetAttr(exc, &_Py_ID(code));

if (code) {

Py_SETREF(exc, code);

if (exc == 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(exc)) {

exitcode = (int)PyLong_AsLong(exc);

}

else {

PyThreadState *tstate = _PyThreadState_GET();

PyObject *sys_stderr = _PySys_GetAttr(tstate, &_Py_ID(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(exc, sys_stderr, Py_PRINT_RAW);

} else {

PyObject_Print(exc, stderr, Py_PRINT_RAW);

fflush(stderr);

}

PySys_WriteStderr("\n");

exitcode = 1;

}

done:

Py_CLEAR(exc);

*exitcode_p = exitcode;

return 1;

}

static void

handle_system_exit(void)

{

int exitcode;

if (_Py_HandleSystemExit(&exitcode)) {

Py_Exit(exitcode);

}

}

static void

_PyErr_PrintEx(PyThreadState *tstate, int set_sys_last_vars)

{

PyObject *typ = NULL, *tb = NULL;

handle_system_exit();

PyObject *exc = _PyErr_GetRaisedException(tstate);

if (exc == NULL) {

goto done;

}

assert(PyExceptionInstance_Check(exc));

typ = Py_NewRef(Py_TYPE(exc));

tb = PyException_GetTraceback(exc);

if (tb == NULL) {

tb = Py_NewRef(Py_None);

}

if (set_sys_last_vars) {

if (_PySys_SetAttr(&_Py_ID(last_exc), exc) < 0) {

_PyErr_Clear(tstate);

}

/* Legacy version: */

if (_PySys_SetAttr(&_Py_ID(last_type), typ) < 0) {

_PyErr_Clear(tstate);

}

if (_PySys_SetAttr(&_Py_ID(last_value), exc) < 0) {

_PyErr_Clear(tstate);

}

if (_PySys_SetAttr(&_Py_ID(last_traceback), tb) < 0) {

_PyErr_Clear(tstate);

}

}

PyObject *hook = _PySys_GetAttr(tstate, &_Py_ID(excepthook));

if (_PySys_Audit(tstate, "sys.excepthook", "OOOO", hook ? hook : Py_None,

typ, exc, tb) < 0) {

if (PyErr_ExceptionMatches(PyExc_RuntimeError)) {

PyErr_Clear();

goto done;

}

PyErr_FormatUnraisable("Exception ignored in audit hook");

}

if (hook) {

PyObject* args[3] = {typ, exc, tb};

PyObject *result = PyObject_Vectorcall(hook, args, 3, NULL);

if (result == NULL) {

handle_system_exit();

PyObject *exc2 = _PyErr_GetRaisedException(tstate);

assert(exc2 && PyExceptionInstance_Check(exc2));

fflush(stdout);

PySys_WriteStderr("Error in sys.excepthook:\n");

PyErr_DisplayException(exc2);

PySys_WriteStderr("\nOriginal exception was:\n");

PyErr_DisplayException(exc);

Py_DECREF(exc2);

}

else {

Py_DECREF(result);

}

}

else {

PySys_WriteStderr("sys.excepthook is missing\n");

PyErr_DisplayException(exc);

}

done:

Py_XDECREF(typ);

Py_XDECREF(exc);

Py_XDECREF(tb);

}

void

_PyErr_Print(PyThreadState *tstate)

{

_PyErr_PrintEx(tstate, 1);

}

void

PyErr_PrintEx(int set_sys_last_vars)

{

PyThreadState *tstate = _PyThreadState_GET();

_PyErr_PrintEx(tstate, set_sys_last_vars);

}

void

PyErr_Print(void)

{

PyErr_PrintEx(1);

}

struct exception_print_context

{

PyObject *file;

PyObject *seen; // Prevent cycles in recursion

};

static int

print_exception_invalid_type(struct exception_print_context *ctx,

PyObject *value)

{

PyObject *f = ctx->file;

const char *const msg = "TypeError: print_exception(): Exception expected "

"for value, ";

if (PyFile_WriteString(msg, f) < 0) {

return -1;

}

if (PyFile_WriteString(Py_TYPE(value)->tp_name, f) < 0) {

return -1;

}

if (PyFile_WriteString(" found\n", f) < 0) {

return -1;

}

return 0;

}

static int

print_exception_traceback(struct exception_print_context *ctx, PyObject *value)

{

PyObject *f = ctx->file;

int err = 0;

PyObject *tb = PyException_GetTraceback(value);

if (tb && tb != Py_None) {

const char *header = EXCEPTION_TB_HEADER;

err = _PyTraceBack_Print(tb, header, f);

}

Py_XDECREF(tb);

return err;

}

static int

print_exception_file_and_line(struct exception_print_context *ctx,

PyObject **value_p)

{

PyObject *f = ctx->file;

PyObject *tmp;

int res = PyObject_GetOptionalAttr(*value_p, &_Py_ID(print_file_and_line), &tmp);

if (res <= 0) {

if (res < 0) {

PyErr_Clear();

}

return 0;

}

Py_DECREF(tmp);

PyObject *filename = NULL;

Py_ssize_t lineno = 0;

PyObject* v = PyObject_GetAttr(*value_p, &_Py_ID(filename));

if (!v) {

return -1;

}

if (v == Py_None) {

Py_DECREF(v);

_Py_DECLARE_STR(anon_string, "<string>");

filename = Py_NewRef(&_Py_STR(anon_string));

}

else {

filename = v;

}

PyObject *line = PyUnicode_FromFormat(" File \"%S\", line %zd\n",

filename, lineno);

Py_DECREF(filename);

if (line == NULL) {

goto error;

}

if (PyFile_WriteObject(line, f, Py_PRINT_RAW) < 0) {

goto error;

}

Py_CLEAR(line);

assert(!PyErr_Occurred());

return 0;

error:

Py_XDECREF(line);

return -1;

}

/* Prints the message line: module.qualname[: str(exc)] */

static int

print_exception_message(struct exception_print_context *ctx, PyObject *type,

PyObject *value)

{

PyObject *f = ctx->file;

if (PyErr_GivenExceptionMatches(value, PyExc_MemoryError)) {

// The Python APIs in this function require allocating memory

// for various objects. If we're out of memory, we can't do that,

return -1;

}

assert(PyExceptionClass_Check(type));

PyObject *modulename = PyObject_GetAttr(type, &_Py_ID(__module__));

if (modulename == NULL || !PyUnicode_Check(modulename)) {

Py_XDECREF(modulename);

PyErr_Clear();

if (PyFile_WriteString("<unknown>.", f) < 0) {

return -1;

}

}

else {

if (!_PyUnicode_Equal(modulename, &_Py_ID(builtins)) &&

!_PyUnicode_Equal(modulename, &_Py_ID(__main__)))

{

int res = PyFile_WriteObject(modulename, f, Py_PRINT_RAW);

Py_DECREF(modulename);

if (res < 0) {

return -1;

}

if (PyFile_WriteString(".", f) < 0) {

return -1;

}

}

else {

Py_DECREF(modulename);

}

}

PyObject *qualname = PyType_GetQualName((PyTypeObject *)type);

if (qualname == NULL || !PyUnicode_Check(qualname)) {

Py_XDECREF(qualname);

PyErr_Clear();

if (PyFile_WriteString("<unknown>", f) < 0) {

return -1;

}

}

else {

int res = PyFile_WriteObject(qualname, f, Py_PRINT_RAW);

Py_DECREF(qualname);

if (res < 0) {

return -1;

}

}

if (Py_IsNone(value)) {

return 0;

}

PyObject *s = PyObject_Str(value);

if (s == NULL) {

PyErr_Clear();

if (PyFile_WriteString(": <exception str() failed>", f) < 0) {

return -1;

}

}

else {

/* only print colon if the str() of the

object is not the empty string

*/

if (!PyUnicode_Check(s) || PyUnicode_GetLength(s) != 0) {

if (PyFile_WriteString(": ", f) < 0) {

Py_DECREF(s);

return -1;

}

}

int res = PyFile_WriteObject(s, f, Py_PRINT_RAW);

Py_DECREF(s);

if (res < 0) {

return -1;

}

}

return 0;

}

static int

print_exception(struct exception_print_context *ctx, PyObject *value)

{

PyObject *f = ctx->file;

if (!PyExceptionInstance_Check(value)) {

return print_exception_invalid_type(ctx, value);

}

Py_INCREF(value);

fflush(stdout);

if (print_exception_traceback(ctx, value) < 0) {

goto error;

}

/* grab the type and notes now because value can change below */

PyObject *type = (PyObject *) Py_TYPE(value);

if (print_exception_file_and_line(ctx, &value) < 0) {

goto error;

}

if (print_exception_message(ctx, type, value) < 0) {

goto error;

}

if (PyFile_WriteString("\n", f) < 0) {

goto error;

}

Py_DECREF(value);

assert(!PyErr_Occurred());

return 0;

error:

Py_DECREF(value);

return -1;

}

static const char cause_message[] =

"The above exception was the direct cause "

"of the following exception:\n";

static const char context_message[] =

"During handling of the above exception, "

"another exception occurred:\n";

static int

print_exception_recursive(struct exception_print_context*, PyObject*);

static int

print_chained(struct exception_print_context* ctx, PyObject *value,

const char * message, const char *tag)

{

PyObject *f = ctx->file;

if (_Py_EnterRecursiveCall(" in print_chained")) {

return -1;

}

int res = print_exception_recursive(ctx, value);

_Py_LeaveRecursiveCall();

if (res < 0) {

return -1;

}

if (PyFile_WriteString("\n", f) < 0) {

return -1;

}

if (PyFile_WriteString(message, f) < 0) {

return -1;

}

if (PyFile_WriteString("\n", f) < 0) {

return -1;

}

return 0;

}

/* Return true if value is in seen or there was a lookup error.

* Return false if lookup succeeded and the item was not found.

* We suppress errors because this makes us err on the side of

* under-printing which is better than over-printing irregular

* exceptions (e.g., unhashable ones).

*/

static bool

print_exception_seen_lookup(struct exception_print_context *ctx,

PyObject *value)

{

PyObject *check_id = PyLong_FromVoidPtr(value);

if (check_id == NULL) {

PyErr_Clear();

return true;

}

int in_seen = PySet_Contains(ctx->seen, check_id);

Py_DECREF(check_id);

if (in_seen == -1) {

PyErr_Clear();

return true;

}

if (in_seen == 1) {

/* value is in seen */

return true;

}

return false;

}

static int

print_exception_cause_and_context(struct exception_print_context *ctx,

PyObject *value)

{

PyObject *value_id = PyLong_FromVoidPtr(value);

if (value_id == NULL || PySet_Add(ctx->seen, value_id) == -1) {

PyErr_Clear();

Py_XDECREF(value_id);

return 0;

}

Py_DECREF(value_id);

if (!PyExceptionInstance_Check(value)) {

return 0;

}

PyObject *cause = PyException_GetCause(value);

if (cause) {

int err = 0;

if (!print_exception_seen_lookup(ctx, cause)) {

err = print_chained(ctx, cause, cause_message, "cause");