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git/compat/winansi.c
Karsten Blees 51822653f5 Win32: reliably detect console pipe handles
As of "Win32: Thread-safe windows console output", child processes may
print to the console even if stdout has been redirected to a file. E.g.:

 git config tar.cat.command "cat"
 git archive -o test.cat HEAD

Detecting whether stdout / stderr point to our console pipe is currently
based on the assumption that OS HANDLE values are never reused. This is
apparently not true if stdout / stderr is replaced via dup2() (as in
builtin/archive.c:17).

Instead of comparing handle values, check if the file descriptor isatty()
backed by a pipe OS handle. This is only possible by swapping the handles
in MSVCRT's internal data structures, as we do in winansi_init().

Reported-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-16 10:56:19 -07:00

579 lines
14 KiB
C

/*
* Copyright 2008 Peter Harris <git@peter.is-a-geek.org>
*/
#undef NOGDI
#include "../git-compat-util.h"
#include <wingdi.h>
#include <winreg.h>
/*
ANSI codes used by git: m, K
This file is git-specific. Therefore, this file does not attempt
to implement any codes that are not used by git.
*/
static HANDLE console;
static WORD plain_attr;
static WORD attr;
static int negative;
static int non_ascii_used = 0;
static HANDLE hthread, hread, hwrite;
static HANDLE hconsole1, hconsole2;
#ifdef __MINGW32__
typedef struct _CONSOLE_FONT_INFOEX {
ULONG cbSize;
DWORD nFont;
COORD dwFontSize;
UINT FontFamily;
UINT FontWeight;
WCHAR FaceName[LF_FACESIZE];
} CONSOLE_FONT_INFOEX, *PCONSOLE_FONT_INFOEX;
#endif
typedef BOOL (WINAPI *PGETCURRENTCONSOLEFONTEX)(HANDLE, BOOL,
PCONSOLE_FONT_INFOEX);
static void warn_if_raster_font(void)
{
DWORD fontFamily = 0;
PGETCURRENTCONSOLEFONTEX pGetCurrentConsoleFontEx;
/* don't bother if output was ascii only */
if (!non_ascii_used)
return;
/* GetCurrentConsoleFontEx is available since Vista */
pGetCurrentConsoleFontEx = (PGETCURRENTCONSOLEFONTEX) GetProcAddress(
GetModuleHandle("kernel32.dll"),
"GetCurrentConsoleFontEx");
if (pGetCurrentConsoleFontEx) {
CONSOLE_FONT_INFOEX cfi;
cfi.cbSize = sizeof(cfi);
if (pGetCurrentConsoleFontEx(console, 0, &cfi))
fontFamily = cfi.FontFamily;
} else {
/* pre-Vista: check default console font in registry */
HKEY hkey;
if (ERROR_SUCCESS == RegOpenKeyExA(HKEY_CURRENT_USER, "Console",
0, KEY_READ, &hkey)) {
DWORD size = sizeof(fontFamily);
RegQueryValueExA(hkey, "FontFamily", NULL, NULL,
(LPVOID) &fontFamily, &size);
RegCloseKey(hkey);
}
}
if (!(fontFamily & TMPF_TRUETYPE)) {
const wchar_t *msg = L"\nWarning: Your console font probably "
L"doesn\'t support Unicode. If you experience strange "
L"characters in the output, consider switching to a "
L"TrueType font such as Consolas!\n";
DWORD dummy;
WriteConsoleW(console, msg, wcslen(msg), &dummy, NULL);
}
}
static int is_console(int fd)
{
CONSOLE_SCREEN_BUFFER_INFO sbi;
HANDLE hcon;
static int initialized = 0;
/* get OS handle of the file descriptor */
hcon = (HANDLE) _get_osfhandle(fd);
if (hcon == INVALID_HANDLE_VALUE)
return 0;
/* check if its a device (i.e. console, printer, serial port) */
if (GetFileType(hcon) != FILE_TYPE_CHAR)
return 0;
/* check if its a handle to a console output screen buffer */
if (!GetConsoleScreenBufferInfo(hcon, &sbi))
return 0;
/* initialize attributes */
if (!initialized) {
console = hcon;
attr = plain_attr = sbi.wAttributes;
negative = 0;
initialized = 1;
}
return 1;
}
#define BUFFER_SIZE 4096
#define MAX_PARAMS 16
static void write_console(unsigned char *str, size_t len)
{
/* only called from console_thread, so a static buffer will do */
static wchar_t wbuf[2 * BUFFER_SIZE + 1];
DWORD dummy;
/* convert utf-8 to utf-16 */
int wlen = xutftowcsn(wbuf, (char*) str, ARRAY_SIZE(wbuf), len);
/* write directly to console */
WriteConsoleW(console, wbuf, wlen, &dummy, NULL);
/* remember if non-ascii characters are printed */
if (wlen != len)
non_ascii_used = 1;
}
#define FOREGROUND_ALL (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)
#define BACKGROUND_ALL (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE)
static void set_console_attr(void)
{
WORD attributes = attr;
if (negative) {
attributes &= ~FOREGROUND_ALL;
attributes &= ~BACKGROUND_ALL;
/* This could probably use a bitmask
instead of a series of ifs */
if (attr & FOREGROUND_RED)
attributes |= BACKGROUND_RED;
if (attr & FOREGROUND_GREEN)
attributes |= BACKGROUND_GREEN;
if (attr & FOREGROUND_BLUE)
attributes |= BACKGROUND_BLUE;
if (attr & BACKGROUND_RED)
attributes |= FOREGROUND_RED;
if (attr & BACKGROUND_GREEN)
attributes |= FOREGROUND_GREEN;
if (attr & BACKGROUND_BLUE)
attributes |= FOREGROUND_BLUE;
}
SetConsoleTextAttribute(console, attributes);
}
static void erase_in_line(void)
{
CONSOLE_SCREEN_BUFFER_INFO sbi;
DWORD dummy; /* Needed for Windows 7 (or Vista) regression */
if (!console)
return;
GetConsoleScreenBufferInfo(console, &sbi);
FillConsoleOutputCharacterA(console, ' ',
sbi.dwSize.X - sbi.dwCursorPosition.X, sbi.dwCursorPosition,
&dummy);
}
static void set_attr(char func, const int *params, int paramlen)
{
int i;
switch (func) {
case 'm':
for (i = 0; i < paramlen; i++) {
switch (params[i]) {
case 0: /* reset */
attr = plain_attr;
negative = 0;
break;
case 1: /* bold */
attr |= FOREGROUND_INTENSITY;
break;
case 2: /* faint */
case 22: /* normal */
attr &= ~FOREGROUND_INTENSITY;
break;
case 3: /* italic */
/* Unsupported */
break;
case 4: /* underline */
case 21: /* double underline */
/* Wikipedia says this flag does nothing */
/* Furthermore, mingw doesn't define this flag
attr |= COMMON_LVB_UNDERSCORE; */
break;
case 24: /* no underline */
/* attr &= ~COMMON_LVB_UNDERSCORE; */
break;
case 5: /* slow blink */
case 6: /* fast blink */
/* We don't have blink, but we do have
background intensity */
attr |= BACKGROUND_INTENSITY;
break;
case 25: /* no blink */
attr &= ~BACKGROUND_INTENSITY;
break;
case 7: /* negative */
negative = 1;
break;
case 27: /* positive */
negative = 0;
break;
case 8: /* conceal */
case 28: /* reveal */
/* Unsupported */
break;
case 30: /* Black */
attr &= ~FOREGROUND_ALL;
break;
case 31: /* Red */
attr &= ~FOREGROUND_ALL;
attr |= FOREGROUND_RED;
break;
case 32: /* Green */
attr &= ~FOREGROUND_ALL;
attr |= FOREGROUND_GREEN;
break;
case 33: /* Yellow */
attr &= ~FOREGROUND_ALL;
attr |= FOREGROUND_RED | FOREGROUND_GREEN;
break;
case 34: /* Blue */
attr &= ~FOREGROUND_ALL;
attr |= FOREGROUND_BLUE;
break;
case 35: /* Magenta */
attr &= ~FOREGROUND_ALL;
attr |= FOREGROUND_RED | FOREGROUND_BLUE;
break;
case 36: /* Cyan */
attr &= ~FOREGROUND_ALL;
attr |= FOREGROUND_GREEN | FOREGROUND_BLUE;
break;
case 37: /* White */
attr |= FOREGROUND_RED |
FOREGROUND_GREEN |
FOREGROUND_BLUE;
break;
case 38: /* Unknown */
break;
case 39: /* reset */
attr &= ~FOREGROUND_ALL;
attr |= (plain_attr & FOREGROUND_ALL);
break;
case 40: /* Black */
attr &= ~BACKGROUND_ALL;
break;
case 41: /* Red */
attr &= ~BACKGROUND_ALL;
attr |= BACKGROUND_RED;
break;
case 42: /* Green */
attr &= ~BACKGROUND_ALL;
attr |= BACKGROUND_GREEN;
break;
case 43: /* Yellow */
attr &= ~BACKGROUND_ALL;
attr |= BACKGROUND_RED | BACKGROUND_GREEN;
break;
case 44: /* Blue */
attr &= ~BACKGROUND_ALL;
attr |= BACKGROUND_BLUE;
break;
case 45: /* Magenta */
attr &= ~BACKGROUND_ALL;
attr |= BACKGROUND_RED | BACKGROUND_BLUE;
break;
case 46: /* Cyan */
attr &= ~BACKGROUND_ALL;
attr |= BACKGROUND_GREEN | BACKGROUND_BLUE;
break;
case 47: /* White */
attr |= BACKGROUND_RED |
BACKGROUND_GREEN |
BACKGROUND_BLUE;
break;
case 48: /* Unknown */
break;
case 49: /* reset */
attr &= ~BACKGROUND_ALL;
attr |= (plain_attr & BACKGROUND_ALL);
break;
default:
/* Unsupported code */
break;
}
}
set_console_attr();
break;
case 'K':
erase_in_line();
break;
default:
/* Unsupported code */
break;
}
}
enum {
TEXT = 0, ESCAPE = 033, BRACKET = '['
};
static DWORD WINAPI console_thread(LPVOID unused)
{
unsigned char buffer[BUFFER_SIZE];
DWORD bytes;
int start, end = 0, c, parampos = 0, state = TEXT;
int params[MAX_PARAMS];
while (1) {
/* read next chunk of bytes from the pipe */
if (!ReadFile(hread, buffer + end, BUFFER_SIZE - end, &bytes,
NULL)) {
/* exit if pipe has been closed or disconnected */
if (GetLastError() == ERROR_PIPE_NOT_CONNECTED ||
GetLastError() == ERROR_BROKEN_PIPE)
break;
/* ignore other errors */
continue;
}
/* scan the bytes and handle ANSI control codes */
bytes += end;
start = end = 0;
while (end < bytes) {
c = buffer[end++];
switch (state) {
case TEXT:
if (c == ESCAPE) {
/* print text seen so far */
if (end - 1 > start)
write_console(buffer + start,
end - 1 - start);
/* then start parsing escape sequence */
start = end - 1;
memset(params, 0, sizeof(params));
parampos = 0;
state = ESCAPE;
}
break;
case ESCAPE:
/* continue if "\033[", otherwise bail out */
state = (c == BRACKET) ? BRACKET : TEXT;
break;
case BRACKET:
/* parse [0-9;]* into array of parameters */
if (c >= '0' && c <= '9') {
params[parampos] *= 10;
params[parampos] += c - '0';
} else if (c == ';') {
/*
* next parameter, bail out if out of
* bounds
*/
parampos++;
if (parampos >= MAX_PARAMS)
state = TEXT;
} else {
/*
* end of escape sequence, change
* console attributes
*/
set_attr(c, params, parampos + 1);
start = end;
state = TEXT;
}
break;
}
}
/* print remaining text unless parsing an escape sequence */
if (state == TEXT && end > start) {
/* check for incomplete UTF-8 sequences and fix end */
if (buffer[end - 1] >= 0x80) {
if (buffer[end -1] >= 0xc0)
end--;
else if (end - 1 > start &&
buffer[end - 2] >= 0xe0)
end -= 2;
else if (end - 2 > start &&
buffer[end - 3] >= 0xf0)
end -= 3;
}
/* print remaining complete UTF-8 sequences */
if (end > start)
write_console(buffer + start, end - start);
/* move remaining bytes to the front */
if (end < bytes)
memmove(buffer, buffer + end, bytes - end);
end = bytes - end;
} else {
/* all data has been consumed, mark buffer empty */
end = 0;
}
}
/* check if the console font supports unicode */
warn_if_raster_font();
CloseHandle(hread);
return 0;
}
static void winansi_exit(void)
{
/* flush all streams */
_flushall();
/* signal console thread to exit */
FlushFileBuffers(hwrite);
DisconnectNamedPipe(hwrite);
/* wait for console thread to copy remaining data */
WaitForSingleObject(hthread, INFINITE);
/* cleanup handles... */
CloseHandle(hwrite);
CloseHandle(hthread);
}
static void die_lasterr(const char *fmt, ...)
{
va_list params;
va_start(params, fmt);
errno = err_win_to_posix(GetLastError());
die_errno(fmt, params);
va_end(params);
}
static HANDLE duplicate_handle(HANDLE hnd)
{
HANDLE hresult, hproc = GetCurrentProcess();
if (!DuplicateHandle(hproc, hnd, hproc, &hresult, 0, TRUE,
DUPLICATE_SAME_ACCESS))
die_lasterr("DuplicateHandle(%li) failed", (long) hnd);
return hresult;
}
/*
* Make MSVCRT's internal file descriptor control structure accessible
* so that we can tweak OS handles and flags directly (we need MSVCRT
* to treat our pipe handle as if it were a console).
*
* We assume that the ioinfo structure (exposed by MSVCRT.dll via
* __pioinfo) starts with the OS handle and the flags. The exact size
* varies between MSVCRT versions, so we try different sizes until
* toggling the FDEV bit of _pioinfo(1)->osflags is reflected in
* isatty(1).
*/
typedef struct {
HANDLE osfhnd;
char osflags;
} ioinfo;
extern __declspec(dllimport) ioinfo *__pioinfo[];
static size_t sizeof_ioinfo = 0;
#define IOINFO_L2E 5
#define IOINFO_ARRAY_ELTS (1 << IOINFO_L2E)
#define FDEV 0x40
static inline ioinfo* _pioinfo(int fd)
{
return (ioinfo*)((char*)__pioinfo[fd >> IOINFO_L2E] +
(fd & (IOINFO_ARRAY_ELTS - 1)) * sizeof_ioinfo);
}
static int init_sizeof_ioinfo()
{
int istty, wastty;
/* don't init twice */
if (sizeof_ioinfo)
return sizeof_ioinfo >= 256;
sizeof_ioinfo = sizeof(ioinfo);
wastty = isatty(1);
while (sizeof_ioinfo < 256) {
/* toggle FDEV flag, check isatty, then toggle back */
_pioinfo(1)->osflags ^= FDEV;
istty = isatty(1);
_pioinfo(1)->osflags ^= FDEV;
/* return if we found the correct size */
if (istty != wastty)
return 0;
sizeof_ioinfo += sizeof(void*);
}
error("Tweaking file descriptors doesn't work with this MSVCRT.dll");
return 1;
}
static HANDLE swap_osfhnd(int fd, HANDLE new_handle)
{
ioinfo *pioinfo;
HANDLE old_handle;
/* init ioinfo size if we haven't done so */
if (init_sizeof_ioinfo())
return INVALID_HANDLE_VALUE;
/* get ioinfo pointer and change the handles */
pioinfo = _pioinfo(fd);
old_handle = pioinfo->osfhnd;
pioinfo->osfhnd = new_handle;
return old_handle;
}
void winansi_init(void)
{
int con1, con2;
char name[32];
/* check if either stdout or stderr is a console output screen buffer */
con1 = is_console(1);
con2 = is_console(2);
if (!con1 && !con2)
return;
/* create a named pipe to communicate with the console thread */
sprintf(name, "\\\\.\\pipe\\winansi%lu", GetCurrentProcessId());
hwrite = CreateNamedPipe(name, PIPE_ACCESS_OUTBOUND,
PIPE_TYPE_BYTE | PIPE_WAIT, 1, BUFFER_SIZE, 0, 0, NULL);
if (hwrite == INVALID_HANDLE_VALUE)
die_lasterr("CreateNamedPipe failed");
hread = CreateFile(name, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
if (hread == INVALID_HANDLE_VALUE)
die_lasterr("CreateFile for named pipe failed");
/* start console spool thread on the pipe's read end */
hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
if (hthread == INVALID_HANDLE_VALUE)
die_lasterr("CreateThread(console_thread) failed");
/* schedule cleanup routine */
if (atexit(winansi_exit))
die_errno("atexit(winansi_exit) failed");
/* redirect stdout / stderr to the pipe */
if (con1)
hconsole1 = swap_osfhnd(1, duplicate_handle(hwrite));
if (con2)
hconsole2 = swap_osfhnd(2, duplicate_handle(hwrite));
}
/*
* Returns the real console handle if stdout / stderr is a pipe redirecting
* to the console. Allows spawn / exec to pass the console to the next process.
*/
HANDLE winansi_get_osfhandle(int fd)
{
HANDLE hnd = (HANDLE) _get_osfhandle(fd);
if ((fd == 1 || fd == 2) && isatty(fd)
&& GetFileType(hnd) == FILE_TYPE_PIPE)
return (fd == 1) ? hconsole1 : hconsole2;
return hnd;
}