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git/compat/mingw.c
Johannes Sixt 7e5d776854 Windows: Implement a custom spawnve().
The problem with Windows's own implementation is that it tries to be
clever when a console program is invoked from a GUI application: In this
case it sometimes automatically allocates a new console window. As a
consequence, the IO channels of the spawned program are directed to the
console, but the invoking application listens on channels that are now
directed to nowhere.

In this implementation we use the lowlevel facilities of CreateProcess(),
which offers a flag to tell the system not to open a console. As a side
effect, only stdin, stdout, and stderr channels will be accessible from
C programs that are spawned. Other channels (file handles, pipe handles,
etc.) are still inherited by the spawned program, but it doesn't get
enough information to access them.

Johannes Schindelin integrated path quoting and unified the various
*execv* and *spawnv* helpers. Eric Raible suggested to also quote '{'.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-26 08:45:10 +02:00

827 lines
18 KiB
C

#include "../git-compat-util.h"
#include "../strbuf.h"
unsigned int _CRT_fmode = _O_BINARY;
#undef open
int mingw_open (const char *filename, int oflags, ...)
{
va_list args;
unsigned mode;
va_start(args, oflags);
mode = va_arg(args, int);
va_end(args);
if (!strcmp(filename, "/dev/null"))
filename = "nul";
int fd = open(filename, oflags, mode);
if (fd < 0 && (oflags & O_CREAT) && errno == EACCES) {
DWORD attrs = GetFileAttributes(filename);
if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
errno = EISDIR;
}
return fd;
}
unsigned int sleep (unsigned int seconds)
{
Sleep(seconds*1000);
return 0;
}
int mkstemp(char *template)
{
char *filename = mktemp(template);
if (filename == NULL)
return -1;
return open(filename, O_RDWR | O_CREAT, 0600);
}
int gettimeofday(struct timeval *tv, void *tz)
{
SYSTEMTIME st;
struct tm tm;
GetSystemTime(&st);
tm.tm_year = st.wYear-1900;
tm.tm_mon = st.wMonth-1;
tm.tm_mday = st.wDay;
tm.tm_hour = st.wHour;
tm.tm_min = st.wMinute;
tm.tm_sec = st.wSecond;
tv->tv_sec = tm_to_time_t(&tm);
if (tv->tv_sec < 0)
return -1;
tv->tv_usec = st.wMilliseconds*1000;
return 0;
}
int pipe(int filedes[2])
{
int fd;
HANDLE h[2], parent;
if (_pipe(filedes, 8192, 0) < 0)
return -1;
parent = GetCurrentProcess();
if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[0]),
parent, &h[0], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
close(filedes[0]);
close(filedes[1]);
return -1;
}
if (!DuplicateHandle (parent, (HANDLE)_get_osfhandle(filedes[1]),
parent, &h[1], 0, FALSE, DUPLICATE_SAME_ACCESS)) {
close(filedes[0]);
close(filedes[1]);
CloseHandle(h[0]);
return -1;
}
fd = _open_osfhandle((int)h[0], O_NOINHERIT);
if (fd < 0) {
close(filedes[0]);
close(filedes[1]);
CloseHandle(h[0]);
CloseHandle(h[1]);
return -1;
}
close(filedes[0]);
filedes[0] = fd;
fd = _open_osfhandle((int)h[1], O_NOINHERIT);
if (fd < 0) {
close(filedes[0]);
close(filedes[1]);
CloseHandle(h[1]);
return -1;
}
close(filedes[1]);
filedes[1] = fd;
return 0;
}
int poll(struct pollfd *ufds, unsigned int nfds, int timeout)
{
int i, pending;
if (timeout != -1)
return errno = EINVAL, error("poll timeout not supported");
/* When there is only one fd to wait for, then we pretend that
* input is available and let the actual wait happen when the
* caller invokes read().
*/
if (nfds == 1) {
if (!(ufds[0].events & POLLIN))
return errno = EINVAL, error("POLLIN not set");
ufds[0].revents = POLLIN;
return 0;
}
repeat:
pending = 0;
for (i = 0; i < nfds; i++) {
DWORD avail = 0;
HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd);
if (h == INVALID_HANDLE_VALUE)
return -1; /* errno was set */
if (!(ufds[i].events & POLLIN))
return errno = EINVAL, error("POLLIN not set");
/* this emulation works only for pipes */
if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) {
int err = GetLastError();
if (err == ERROR_BROKEN_PIPE) {
ufds[i].revents = POLLHUP;
pending++;
} else {
errno = EINVAL;
return error("PeekNamedPipe failed,"
" GetLastError: %u", err);
}
} else if (avail) {
ufds[i].revents = POLLIN;
pending++;
} else
ufds[i].revents = 0;
}
if (!pending) {
/* The only times that we spin here is when the process
* that is connected through the pipes is waiting for
* its own input data to become available. But since
* the process (pack-objects) is itself CPU intensive,
* it will happily pick up the time slice that we are
* relinguishing here.
*/
Sleep(0);
goto repeat;
}
return 0;
}
struct tm *gmtime_r(const time_t *timep, struct tm *result)
{
/* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
memcpy(result, gmtime(timep), sizeof(struct tm));
return result;
}
struct tm *localtime_r(const time_t *timep, struct tm *result)
{
/* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
memcpy(result, localtime(timep), sizeof(struct tm));
return result;
}
#undef getcwd
char *mingw_getcwd(char *pointer, int len)
{
int i;
char *ret = getcwd(pointer, len);
if (!ret)
return ret;
for (i = 0; pointer[i]; i++)
if (pointer[i] == '\\')
pointer[i] = '/';
return ret;
}
/*
* See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
* (Parsing C++ Command-Line Arguments)
*/
static const char *quote_arg(const char *arg)
{
/* count chars to quote */
int len = 0, n = 0;
int force_quotes = 0;
char *q, *d;
const char *p = arg;
if (!*p) force_quotes = 1;
while (*p) {
if (isspace(*p) || *p == '*' || *p == '?' || *p == '{')
force_quotes = 1;
else if (*p == '"')
n++;
else if (*p == '\\') {
int count = 0;
while (*p == '\\') {
count++;
p++;
len++;
}
if (*p == '"')
n += count*2 + 1;
continue;
}
len++;
p++;
}
if (!force_quotes && n == 0)
return arg;
/* insert \ where necessary */
d = q = xmalloc(len+n+3);
*d++ = '"';
while (*arg) {
if (*arg == '"')
*d++ = '\\';
else if (*arg == '\\') {
int count = 0;
while (*arg == '\\') {
count++;
*d++ = *arg++;
}
if (*arg == '"') {
while (count-- > 0)
*d++ = '\\';
*d++ = '\\';
}
}
*d++ = *arg++;
}
*d++ = '"';
*d++ = 0;
return q;
}
static const char *parse_interpreter(const char *cmd)
{
static char buf[100];
char *p, *opt;
int n, fd;
/* don't even try a .exe */
n = strlen(cmd);
if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
return NULL;
fd = open(cmd, O_RDONLY);
if (fd < 0)
return NULL;
n = read(fd, buf, sizeof(buf)-1);
close(fd);
if (n < 4) /* at least '#!/x' and not error */
return NULL;
if (buf[0] != '#' || buf[1] != '!')
return NULL;
buf[n] = '\0';
p = strchr(buf, '\n');
if (!p)
return NULL;
*p = '\0';
if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
return NULL;
/* strip options */
if ((opt = strchr(p+1, ' ')))
*opt = '\0';
return p+1;
}
/*
* Splits the PATH into parts.
*/
static char **get_path_split(void)
{
char *p, **path, *envpath = getenv("PATH");
int i, n = 0;
if (!envpath || !*envpath)
return NULL;
envpath = xstrdup(envpath);
p = envpath;
while (p) {
char *dir = p;
p = strchr(p, ';');
if (p) *p++ = '\0';
if (*dir) { /* not earlier, catches series of ; */
++n;
}
}
if (!n)
return NULL;
path = xmalloc((n+1)*sizeof(char*));
p = envpath;
i = 0;
do {
if (*p)
path[i++] = xstrdup(p);
p = p+strlen(p)+1;
} while (i < n);
path[i] = NULL;
free(envpath);
return path;
}
static void free_path_split(char **path)
{
if (!path)
return;
char **p = path;
while (*p)
free(*p++);
free(path);
}
/*
* exe_only means that we only want to detect .exe files, but not scripts
* (which do not have an extension)
*/
static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
{
char path[MAX_PATH];
snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
if (!isexe && access(path, F_OK) == 0)
return xstrdup(path);
path[strlen(path)-4] = '\0';
if ((!exe_only || isexe) && access(path, F_OK) == 0)
return xstrdup(path);
return NULL;
}
/*
* Determines the absolute path of cmd using the the split path in path.
* If cmd contains a slash or backslash, no lookup is performed.
*/
static char *path_lookup(const char *cmd, char **path, int exe_only)
{
char *prog = NULL;
int len = strlen(cmd);
int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
if (strchr(cmd, '/') || strchr(cmd, '\\'))
prog = xstrdup(cmd);
while (!prog && *path)
prog = lookup_prog(*path++, cmd, isexe, exe_only);
return prog;
}
static int env_compare(const void *a, const void *b)
{
char *const *ea = a;
char *const *eb = b;
return strcasecmp(*ea, *eb);
}
static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
int prepend_cmd)
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
struct strbuf envblk, args;
unsigned flags;
BOOL ret;
/* Determine whether or not we are associated to a console */
HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL, NULL);
if (cons == INVALID_HANDLE_VALUE) {
/* There is no console associated with this process.
* Since the child is a console process, Windows
* would normally create a console window. But
* since we'll be redirecting std streams, we do
* not need the console.
*/
flags = CREATE_NO_WINDOW;
} else {
/* There is already a console. If we specified
* CREATE_NO_WINDOW here, too, Windows would
* disassociate the child from the console.
* Go figure!
*/
flags = 0;
CloseHandle(cons);
}
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
si.dwFlags = STARTF_USESTDHANDLES;
si.hStdInput = (HANDLE) _get_osfhandle(0);
si.hStdOutput = (HANDLE) _get_osfhandle(1);
si.hStdError = (HANDLE) _get_osfhandle(2);
/* concatenate argv, quoting args as we go */
strbuf_init(&args, 0);
if (prepend_cmd) {
char *quoted = (char *)quote_arg(cmd);
strbuf_addstr(&args, quoted);
if (quoted != cmd)
free(quoted);
}
for (; *argv; argv++) {
char *quoted = (char *)quote_arg(*argv);
if (*args.buf)
strbuf_addch(&args, ' ');
strbuf_addstr(&args, quoted);
if (quoted != *argv)
free(quoted);
}
if (env) {
int count = 0;
char **e, **sorted_env;
for (e = env; *e; e++)
count++;
/* environment must be sorted */
sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
strbuf_init(&envblk, 0);
for (e = sorted_env; *e; e++) {
strbuf_addstr(&envblk, *e);
strbuf_addch(&envblk, '\0');
}
free(sorted_env);
}
memset(&pi, 0, sizeof(pi));
ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
env ? envblk.buf : NULL, NULL, &si, &pi);
if (env)
strbuf_release(&envblk);
strbuf_release(&args);
if (!ret) {
errno = ENOENT;
return -1;
}
CloseHandle(pi.hThread);
return (pid_t)pi.hProcess;
}
pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env)
{
pid_t pid;
char **path = get_path_split();
char *prog = path_lookup(cmd, path, 0);
if (!prog) {
errno = ENOENT;
pid = -1;
}
else {
const char *interpr = parse_interpreter(prog);
if (interpr) {
const char *argv0 = argv[0];
char *iprog = path_lookup(interpr, path, 1);
argv[0] = prog;
if (!iprog) {
errno = ENOENT;
pid = -1;
}
else {
pid = mingw_spawnve(iprog, argv, env, 1);
free(iprog);
}
argv[0] = argv0;
}
else
pid = mingw_spawnve(prog, argv, env, 0);
free(prog);
}
free_path_split(path);
return pid;
}
static int try_shell_exec(const char *cmd, char *const *argv, char **env)
{
const char *interpr = parse_interpreter(cmd);
char **path;
char *prog;
int pid = 0;
if (!interpr)
return 0;
path = get_path_split();
prog = path_lookup(interpr, path, 1);
if (prog) {
int argc = 0;
const char **argv2;
while (argv[argc]) argc++;
argv2 = xmalloc(sizeof(*argv) * (argc+1));
argv2[0] = (char *)cmd; /* full path to the script file */
memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
pid = mingw_spawnve(prog, argv2, env, 1);
if (pid >= 0) {
int status;
if (waitpid(pid, &status, 0) < 0)
status = 255;
exit(status);
}
pid = 1; /* indicate that we tried but failed */
free(prog);
free(argv2);
}
free_path_split(path);
return pid;
}
static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
{
/* check if git_command is a shell script */
if (!try_shell_exec(cmd, argv, (char **)env)) {
int pid, status;
pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
if (pid < 0)
return;
if (waitpid(pid, &status, 0) < 0)
status = 255;
exit(status);
}
}
void mingw_execvp(const char *cmd, char *const *argv)
{
char **path = get_path_split();
char *prog = path_lookup(cmd, path, 0);
if (prog) {
mingw_execve(prog, argv, environ);
free(prog);
} else
errno = ENOENT;
free_path_split(path);
}
char **copy_environ()
{
char **env;
int i = 0;
while (environ[i])
i++;
env = xmalloc((i+1)*sizeof(*env));
for (i = 0; environ[i]; i++)
env[i] = xstrdup(environ[i]);
env[i] = NULL;
return env;
}
void free_environ(char **env)
{
int i;
for (i = 0; env[i]; i++)
free(env[i]);
free(env);
}
static int lookup_env(char **env, const char *name, size_t nmln)
{
int i;
for (i = 0; env[i]; i++) {
if (0 == strncmp(env[i], name, nmln)
&& '=' == env[i][nmln])
/* matches */
return i;
}
return -1;
}
/*
* If name contains '=', then sets the variable, otherwise it unsets it
*/
char **env_setenv(char **env, const char *name)
{
char *eq = strchrnul(name, '=');
int i = lookup_env(env, name, eq-name);
if (i < 0) {
if (*eq) {
for (i = 0; env[i]; i++)
;
env = xrealloc(env, (i+2)*sizeof(*env));
env[i] = xstrdup(name);
env[i+1] = NULL;
}
}
else {
free(env[i]);
if (*eq)
env[i] = xstrdup(name);
else
for (; env[i]; i++)
env[i] = env[i+1];
}
return env;
}
/* this is the first function to call into WS_32; initialize it */
#undef gethostbyname
struct hostent *mingw_gethostbyname(const char *host)
{
WSADATA wsa;
if (WSAStartup(MAKEWORD(2,2), &wsa))
die("unable to initialize winsock subsystem, error %d",
WSAGetLastError());
atexit((void(*)(void)) WSACleanup);
return gethostbyname(host);
}
int mingw_socket(int domain, int type, int protocol)
{
int sockfd;
SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
if (s == INVALID_SOCKET) {
/*
* WSAGetLastError() values are regular BSD error codes
* biased by WSABASEERR.
* However, strerror() does not know about networking
* specific errors, which are values beginning at 38 or so.
* Therefore, we choose to leave the biased error code
* in errno so that _if_ someone looks up the code somewhere,
* then it is at least the number that are usually listed.
*/
errno = WSAGetLastError();
return -1;
}
/* convert into a file descriptor */
if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
closesocket(s);
return error("unable to make a socket file descriptor: %s",
strerror(errno));
}
return sockfd;
}
#undef connect
int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
{
SOCKET s = (SOCKET)_get_osfhandle(sockfd);
return connect(s, sa, sz);
}
#undef rename
int mingw_rename(const char *pold, const char *pnew)
{
/*
* Try native rename() first to get errno right.
* It is based on MoveFile(), which cannot overwrite existing files.
*/
if (!rename(pold, pnew))
return 0;
if (errno != EEXIST)
return -1;
if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
return 0;
/* TODO: translate more errors */
if (GetLastError() == ERROR_ACCESS_DENIED) {
DWORD attrs = GetFileAttributes(pnew);
if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY)) {
errno = EISDIR;
return -1;
}
}
errno = EACCES;
return -1;
}
struct passwd *getpwuid(int uid)
{
static char user_name[100];
static struct passwd p;
DWORD len = sizeof(user_name);
if (!GetUserName(user_name, &len))
return NULL;
p.pw_name = user_name;
p.pw_gecos = "unknown";
p.pw_dir = NULL;
return &p;
}
static HANDLE timer_event;
static HANDLE timer_thread;
static int timer_interval;
static int one_shot;
static sig_handler_t timer_fn = SIG_DFL;
/* The timer works like this:
* The thread, ticktack(), is a trivial routine that most of the time
* only waits to receive the signal to terminate. The main thread tells
* the thread to terminate by setting the timer_event to the signalled
* state.
* But ticktack() interrupts the wait state after the timer's interval
* length to call the signal handler.
*/
static __stdcall unsigned ticktack(void *dummy)
{
while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
if (timer_fn == SIG_DFL)
die("Alarm");
if (timer_fn != SIG_IGN)
timer_fn(SIGALRM);
if (one_shot)
break;
}
return 0;
}
static int start_timer_thread(void)
{
timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
if (timer_event) {
timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
if (!timer_thread )
return errno = ENOMEM,
error("cannot start timer thread");
} else
return errno = ENOMEM,
error("cannot allocate resources for timer");
return 0;
}
static void stop_timer_thread(void)
{
if (timer_event)
SetEvent(timer_event); /* tell thread to terminate */
if (timer_thread) {
int rc = WaitForSingleObject(timer_thread, 1000);
if (rc == WAIT_TIMEOUT)
error("timer thread did not terminate timely");
else if (rc != WAIT_OBJECT_0)
error("waiting for timer thread failed: %lu",
GetLastError());
CloseHandle(timer_thread);
}
if (timer_event)
CloseHandle(timer_event);
timer_event = NULL;
timer_thread = NULL;
}
static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
{
return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
}
int setitimer(int type, struct itimerval *in, struct itimerval *out)
{
static const struct timeval zero;
static int atexit_done;
if (out != NULL)
return errno = EINVAL,
error("setitimer param 3 != NULL not implemented");
if (!is_timeval_eq(&in->it_interval, &zero) &&
!is_timeval_eq(&in->it_interval, &in->it_value))
return errno = EINVAL,
error("setitimer: it_interval must be zero or eq it_value");
if (timer_thread)
stop_timer_thread();
if (is_timeval_eq(&in->it_value, &zero) &&
is_timeval_eq(&in->it_interval, &zero))
return 0;
timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
one_shot = is_timeval_eq(&in->it_interval, &zero);
if (!atexit_done) {
atexit(stop_timer_thread);
atexit_done = 1;
}
return start_timer_thread();
}
int sigaction(int sig, struct sigaction *in, struct sigaction *out)
{
if (sig != SIGALRM)
return errno = EINVAL,
error("sigaction only implemented for SIGALRM");
if (out != NULL)
return errno = EINVAL,
error("sigaction: param 3 != NULL not implemented");
timer_fn = in->sa_handler;
return 0;
}
#undef signal
sig_handler_t mingw_signal(int sig, sig_handler_t handler)
{
if (sig != SIGALRM)
return signal(sig, handler);
sig_handler_t old = timer_fn;
timer_fn = handler;
return old;
}