cosmopolitan/third_party/python/Parser/myreadline.c
Justine Tunney 9b29358511 Make whitespace changes
Status lines for Emacs and Vim have been added to Python sources so
they'll be easier to edit using Python's preferred coding style.

Some DNS helper functions have been broken up into multiple files. It's
nice to have one function per file whenever possible, since that way we
don't need -ffunction-sections.  Another reason it's good to have small
source files, is because the build will be enforcing resource limits on
compilation and testing soon.
2021-08-13 03:20:45 -07:00

408 lines
12 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=4 sts=4 sw=4 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Python 3 │
│ https://docs.python.org/3/license.html │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/errno.h"
#include "libc/limits.h"
#include "libc/stdio/stdio.h"
#include "third_party/python/Include/ceval.h"
#include "third_party/python/Include/intrcheck.h"
#include "third_party/python/Include/pyerrors.h"
#include "third_party/python/Include/pymem.h"
#include "third_party/python/Include/pystate.h"
/* clang-format off */
/* Readline interface for tokenizer.c and [raw_]input() in bltinmodule.c.
By default, or when stdin is not a tty device, we have a super
simple my_readline function using fgets.
Optionally, we can use the GNU readline library.
my_readline() has a different return value from GNU readline():
- NULL if an interrupt occurred or if an error occurred
- a malloc'ed empty string if EOF was read
- a malloc'ed string ending in \n normally
*/
PyThreadState* _PyOS_ReadlineTState;
#ifdef WITH_THREAD
#include "third_party/python/Include/pythread.h"
static PyThread_type_lock _PyOS_ReadlineLock = NULL;
#endif
int (*PyOS_InputHook)(void) = NULL;
/* This function restarts a fgets() after an EINTR error occurred
except if PyOS_InterruptOccurred() returns true. */
static int
my_fgets(char *buf, int len, FILE *fp)
{
#ifdef MS_WINDOWS
HANDLE hInterruptEvent;
#endif
char *p;
int err;
while (1) {
if (PyOS_InputHook != NULL)
(void)(PyOS_InputHook)();
errno = 0;
clearerr(fp);
p = fgets(buf, len, fp);
if (p != NULL)
return 0; /* No error */
err = errno;
#ifdef MS_WINDOWS
/* Ctrl-C anywhere on the line or Ctrl-Z if the only character
on a line will set ERROR_OPERATION_ABORTED. Under normal
circumstances Ctrl-C will also have caused the SIGINT handler
to fire which will have set the event object returned by
_PyOS_SigintEvent. This signal fires in another thread and
is not guaranteed to have occurred before this point in the
code.
Therefore: check whether the event is set with a small timeout.
If it is, assume this is a Ctrl-C and reset the event. If it
isn't set assume that this is a Ctrl-Z on its own and drop
through to check for EOF.
*/
if (GetLastError()==ERROR_OPERATION_ABORTED) {
hInterruptEvent = _PyOS_SigintEvent();
switch (WaitForSingleObjectEx(hInterruptEvent, 10, FALSE)) {
case WAIT_OBJECT_0:
ResetEvent(hInterruptEvent);
return 1; /* Interrupt */
case WAIT_FAILED:
return -2; /* Error */
}
}
#endif /* MS_WINDOWS */
if (feof(fp)) {
clearerr(fp);
return -1; /* EOF */
}
#ifdef EINTR
if (err == EINTR) {
int s;
#ifdef WITH_THREAD
PyEval_RestoreThread(_PyOS_ReadlineTState);
#endif
s = PyErr_CheckSignals();
#ifdef WITH_THREAD
PyEval_SaveThread();
#endif
if (s < 0)
return 1;
/* try again */
continue;
}
#endif
if (PyOS_InterruptOccurred()) {
return 1; /* Interrupt */
}
return -2; /* Error */
}
/* NOTREACHED */
}
#ifdef MS_WINDOWS
/* Readline implementation using ReadConsoleW */
extern char _get_console_type(HANDLE handle);
char *
_PyOS_WindowsConsoleReadline(HANDLE hStdIn)
{
static wchar_t wbuf_local[1024 * 16];
const DWORD chunk_size = 1024;
DWORD n_read, total_read, wbuflen, u8len;
wchar_t *wbuf;
char *buf = NULL;
int err = 0;
n_read = (DWORD)-1;
total_read = 0;
wbuf = wbuf_local;
wbuflen = sizeof(wbuf_local) / sizeof(wbuf_local[0]) - 1;
while (1) {
if (PyOS_InputHook != NULL) {
(void)(PyOS_InputHook)();
}
if (!ReadConsoleW(hStdIn, &wbuf[total_read], wbuflen - total_read, &n_read, NULL)) {
err = GetLastError();
goto exit;
}
if (n_read == (DWORD)-1 && (err = GetLastError()) == ERROR_OPERATION_ABORTED) {
break;
}
if (n_read == 0) {
int s;
err = GetLastError();
if (err != ERROR_OPERATION_ABORTED)
goto exit;
err = 0;
HANDLE hInterruptEvent = _PyOS_SigintEvent();
if (WaitForSingleObjectEx(hInterruptEvent, 100, FALSE)
== WAIT_OBJECT_0) {
ResetEvent(hInterruptEvent);
#ifdef WITH_THREAD
PyEval_RestoreThread(_PyOS_ReadlineTState);
#endif
s = PyErr_CheckSignals();
#ifdef WITH_THREAD
PyEval_SaveThread();
#endif
if (s < 0)
goto exit;
}
break;
}
total_read += n_read;
if (total_read == 0 || wbuf[total_read - 1] == L'\n') {
break;
}
wbuflen += chunk_size;
if (wbuf == wbuf_local) {
wbuf[total_read] = '\0';
wbuf = (wchar_t*)PyMem_RawMalloc(wbuflen * sizeof(wchar_t));
if (wbuf)
wcscpy_s(wbuf, wbuflen, wbuf_local);
else {
PyErr_NoMemory();
goto exit;
}
}
else {
wchar_t *tmp = PyMem_RawRealloc(wbuf, wbuflen * sizeof(wchar_t));
if (tmp == NULL) {
PyErr_NoMemory();
goto exit;
}
wbuf = tmp;
}
}
if (wbuf[0] == '\x1a') {
buf = PyMem_RawMalloc(1);
if (buf)
buf[0] = '\0';
else {
PyErr_NoMemory();
}
goto exit;
}
u8len = WideCharToMultiByte(CP_UTF8, 0, wbuf, total_read, NULL, 0, NULL, NULL);
buf = PyMem_RawMalloc(u8len + 1);
if (buf == NULL) {
PyErr_NoMemory();
goto exit;
}
u8len = WideCharToMultiByte(CP_UTF8, 0, wbuf, total_read, buf, u8len, NULL, NULL);
buf[u8len] = '\0';
exit:
if (wbuf != wbuf_local)
PyMem_RawFree(wbuf);
if (err) {
#ifdef WITH_THREAD
PyEval_RestoreThread(_PyOS_ReadlineTState);
#endif
PyErr_SetFromWindowsErr(err);
#ifdef WITH_THREAD
PyEval_SaveThread();
#endif
}
return buf;
}
#endif
/* Readline implementation using fgets() */
char *
PyOS_StdioReadline(FILE *sys_stdin, FILE *sys_stdout, const char *prompt)
{
size_t n;
char *p, *pr;
#ifdef MS_WINDOWS
if (!Py_LegacyWindowsStdioFlag && sys_stdin == stdin) {
HANDLE hStdIn, hStdErr;
_Py_BEGIN_SUPPRESS_IPH
hStdIn = (HANDLE)_get_osfhandle(fileno(sys_stdin));
hStdErr = (HANDLE)_get_osfhandle(fileno(stderr));
_Py_END_SUPPRESS_IPH
if (_get_console_type(hStdIn) == 'r') {
fflush(sys_stdout);
if (prompt) {
if (_get_console_type(hStdErr) == 'w') {
wchar_t *wbuf;
int wlen;
wlen = MultiByteToWideChar(CP_UTF8, 0, prompt, -1,
NULL, 0);
if (wlen) {
wbuf = PyMem_RawMalloc(wlen * sizeof(wchar_t));
if (wbuf == NULL) {
PyErr_NoMemory();
return NULL;
}
wlen = MultiByteToWideChar(CP_UTF8, 0, prompt, -1,
wbuf, wlen);
if (wlen) {
DWORD n;
fflush(stderr);
/* wlen includes null terminator, so subtract 1 */
WriteConsoleW(hStdErr, wbuf, wlen - 1, &n, NULL);
}
PyMem_RawFree(wbuf);
}
} else {
fprintf(stderr, "%s", prompt);
fflush(stderr);
}
}
clearerr(sys_stdin);
return _PyOS_WindowsConsoleReadline(hStdIn);
}
}
#endif
n = 100;
p = (char *)PyMem_RawMalloc(n);
if (p == NULL) {
PyErr_NoMemory();
return NULL;
}
fflush(sys_stdout);
if (prompt)
fprintf(stderr, "%s", prompt);
fflush(stderr);
switch (my_fgets(p, (int)n, sys_stdin)) {
case 0: /* Normal case */
break;
case 1: /* Interrupt */
PyMem_RawFree(p);
return NULL;
case -1: /* EOF */
case -2: /* Error */
default: /* Shouldn't happen */
*p = '\0';
break;
}
n = strlen(p);
while (n > 0 && p[n-1] != '\n') {
size_t incr = n+2;
if (incr > INT_MAX) {
PyMem_RawFree(p);
PyErr_SetString(PyExc_OverflowError, "input line too long");
return NULL;
}
pr = (char *)PyMem_RawRealloc(p, n + incr);
if (pr == NULL) {
PyMem_RawFree(p);
PyErr_NoMemory();
return NULL;
}
p = pr;
if (my_fgets(p+n, (int)incr, sys_stdin) != 0)
break;
n += strlen(p+n);
}
pr = (char *)PyMem_RawRealloc(p, n+1);
if (pr == NULL) {
PyMem_RawFree(p);
PyErr_NoMemory();
return NULL;
}
return pr;
}
/* By initializing this function pointer, systems embedding Python can
override the readline function.
Note: Python expects in return a buffer allocated with PyMem_Malloc. */
char *(*PyOS_ReadlineFunctionPointer)(FILE *, FILE *, const char *);
/* Interface used by tokenizer.c and bltinmodule.c */
char *
PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, const char *prompt)
{
char *rv, *res;
size_t len;
if (_PyOS_ReadlineTState == PyThreadState_GET()) {
PyErr_SetString(PyExc_RuntimeError,
"can't re-enter readline");
return NULL;
}
if (PyOS_ReadlineFunctionPointer == NULL) {
PyOS_ReadlineFunctionPointer = PyOS_StdioReadline;
}
#ifdef WITH_THREAD
if (_PyOS_ReadlineLock == NULL) {
_PyOS_ReadlineLock = PyThread_allocate_lock();
if (_PyOS_ReadlineLock == NULL) {
PyErr_SetString(PyExc_MemoryError, "can't allocate lock");
return NULL;
}
}
#endif
_PyOS_ReadlineTState = PyThreadState_GET();
Py_BEGIN_ALLOW_THREADS
#ifdef WITH_THREAD
PyThread_acquire_lock(_PyOS_ReadlineLock, 1);
#endif
/* This is needed to handle the unlikely case that the
* interpreter is in interactive mode *and* stdin/out are not
* a tty. This can happen, for example if python is run like
* this: python -i < test1.py
*/
if (!isatty (fileno (sys_stdin)) || !isatty (fileno (sys_stdout)))
rv = PyOS_StdioReadline (sys_stdin, sys_stdout, prompt);
else
rv = (*PyOS_ReadlineFunctionPointer)(sys_stdin, sys_stdout,
prompt);
Py_END_ALLOW_THREADS
#ifdef WITH_THREAD
PyThread_release_lock(_PyOS_ReadlineLock);
#endif
_PyOS_ReadlineTState = NULL;
if (rv == NULL)
return NULL;
len = strlen(rv) + 1;
res = PyMem_Malloc(len);
if (res != NULL) {
memcpy(res, rv, len);
}
else {
PyErr_NoMemory();
}
PyMem_RawFree(rv);
return res;
}