diff --git a/compat/terminal.c b/compat/terminal.c index 3620184e79..7db330c52d 100644 --- a/compat/terminal.c +++ b/compat/terminal.c @@ -1,4 +1,4 @@ -#include "git-compat-util.h" +#include "cache.h" #include "compat/terminal.h" #include "sigchain.h" #include "strbuf.h" @@ -20,39 +20,171 @@ static void restore_term_on_signal(int sig) #define INPUT_PATH "/dev/tty" #define OUTPUT_PATH "/dev/tty" +static volatile sig_atomic_t term_fd_needs_closing; static int term_fd = -1; static struct termios old_term; +static const char *background_resume_msg; +static const char *restore_error_msg; +static volatile sig_atomic_t ttou_received; + +/* async safe error function for use by signal handlers. */ +static void write_err(const char *msg) +{ + write_in_full(2, "error: ", strlen("error: ")); + write_in_full(2, msg, strlen(msg)); + write_in_full(2, "\n", 1); +} + +static void print_background_resume_msg(int signo) +{ + int saved_errno = errno; + sigset_t mask; + struct sigaction old_sa; + struct sigaction sa = { .sa_handler = SIG_DFL }; + + ttou_received = 1; + write_err(background_resume_msg); + sigaction(signo, &sa, &old_sa); + raise(signo); + sigemptyset(&mask); + sigaddset(&mask, signo); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + /* Stopped here */ + sigprocmask(SIG_BLOCK, &mask, NULL); + sigaction(signo, &old_sa, NULL); + errno = saved_errno; +} + +static void restore_terminal_on_suspend(int signo) +{ + int saved_errno = errno; + int res; + struct termios t; + sigset_t mask; + struct sigaction old_sa; + struct sigaction sa = { .sa_handler = SIG_DFL }; + int can_restore = 1; + + if (tcgetattr(term_fd, &t) < 0) + can_restore = 0; + + if (tcsetattr(term_fd, TCSAFLUSH, &old_term) < 0) + write_err(restore_error_msg); + + sigaction(signo, &sa, &old_sa); + raise(signo); + sigemptyset(&mask); + sigaddset(&mask, signo); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + /* Stopped here */ + sigprocmask(SIG_BLOCK, &mask, NULL); + sigaction(signo, &old_sa, NULL); + if (!can_restore) { + write_err(restore_error_msg); + goto out; + } + /* + * If we resume in the background then we receive SIGTTOU when calling + * tcsetattr() below. Set up a handler to print an error message in that + * case. + */ + sigemptyset(&mask); + sigaddset(&mask, SIGTTOU); + sa.sa_mask = old_sa.sa_mask; + sa.sa_handler = print_background_resume_msg; + sa.sa_flags = SA_RESTART; + sigaction(SIGTTOU, &sa, &old_sa); + again: + ttou_received = 0; + sigprocmask(SIG_UNBLOCK, &mask, NULL); + res = tcsetattr(term_fd, TCSAFLUSH, &t); + sigprocmask(SIG_BLOCK, &mask, NULL); + if (ttou_received) + goto again; + else if (res < 0) + write_err(restore_error_msg); + sigaction(SIGTTOU, &old_sa, NULL); + out: + errno = saved_errno; +} + +static void reset_job_signals(void) +{ + if (restore_error_msg) { + signal(SIGTTIN, SIG_DFL); + signal(SIGTTOU, SIG_DFL); + signal(SIGTSTP, SIG_DFL); + restore_error_msg = NULL; + background_resume_msg = NULL; + } +} + +static void close_term_fd(void) +{ + if (term_fd_needs_closing) + close(term_fd); + term_fd_needs_closing = 0; + term_fd = -1; +} + void restore_term(void) { if (term_fd < 0) return; tcsetattr(term_fd, TCSAFLUSH, &old_term); - close(term_fd); - term_fd = -1; + close_term_fd(); sigchain_pop_common(); + reset_job_signals(); } -int save_term(int full_duplex) +int save_term(enum save_term_flags flags) { + struct sigaction sa; + if (term_fd < 0) - term_fd = open("/dev/tty", O_RDWR); + term_fd = ((flags & SAVE_TERM_STDIN) + ? 0 + : open("/dev/tty", O_RDWR)); if (term_fd < 0) return -1; - if (tcgetattr(term_fd, &old_term) < 0) + term_fd_needs_closing = !(flags & SAVE_TERM_STDIN); + if (tcgetattr(term_fd, &old_term) < 0) { + close_term_fd(); return -1; + } sigchain_push_common(restore_term_on_signal); + /* + * If job control is disabled then the shell will have set the + * disposition of SIGTSTP to SIG_IGN. + */ + sigaction(SIGTSTP, NULL, &sa); + if (sa.sa_handler == SIG_IGN) + return 0; + + /* avoid calling gettext() from signal handler */ + background_resume_msg = _("cannot resume in the background, please use 'fg' to resume"); + restore_error_msg = _("cannot restore terminal settings"); + sa.sa_handler = restore_terminal_on_suspend; + sa.sa_flags = SA_RESTART; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SIGTSTP); + sigaddset(&sa.sa_mask, SIGTTIN); + sigaddset(&sa.sa_mask, SIGTTOU); + sigaction(SIGTSTP, &sa, NULL); + sigaction(SIGTTIN, &sa, NULL); + sigaction(SIGTTOU, &sa, NULL); return 0; } -static int disable_bits(tcflag_t bits) +static int disable_bits(enum save_term_flags flags, tcflag_t bits) { struct termios t; - if (save_term(0) < 0) - goto error; + if (save_term(flags) < 0) + return -1; t = old_term; @@ -65,20 +197,50 @@ static int disable_bits(tcflag_t bits) return 0; sigchain_pop_common(); -error: - close(term_fd); - term_fd = -1; + reset_job_signals(); + close_term_fd(); return -1; } -static int disable_echo(void) +static int disable_echo(enum save_term_flags flags) { - return disable_bits(ECHO); + return disable_bits(flags, ECHO); } -static int enable_non_canonical(void) +static int enable_non_canonical(enum save_term_flags flags) { - return disable_bits(ICANON | ECHO); + return disable_bits(flags, ICANON | ECHO); +} + +/* + * On macos it is not possible to use poll() with a terminal so use select + * instead. + */ +static int getchar_with_timeout(int timeout) +{ + struct timeval tv, *tvp = NULL; + fd_set readfds; + int res; + + again: + if (timeout >= 0) { + tv.tv_sec = timeout / 1000; + tv.tv_usec = (timeout % 1000) * 1000; + tvp = &tv; + } + + FD_ZERO(&readfds); + FD_SET(0, &readfds); + res = select(1, &readfds, NULL, NULL, tvp); + if (!res) + return EOF; + if (res < 0) { + if (errno == EINTR) + goto again; + else + return EOF; + } + return getchar(); } #elif defined(GIT_WINDOWS_NATIVE) @@ -126,7 +288,7 @@ void restore_term(void) hconin = hconout = INVALID_HANDLE_VALUE; } -int save_term(int full_duplex) +int save_term(enum save_term_flags flags) { hconin = CreateFileA("CONIN$", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING, @@ -134,7 +296,7 @@ int save_term(int full_duplex) if (hconin == INVALID_HANDLE_VALUE) return -1; - if (full_duplex) { + if (flags & SAVE_TERM_DUPLEX) { hconout = CreateFileA("CONOUT$", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); @@ -154,7 +316,7 @@ int save_term(int full_duplex) return -1; } -static int disable_bits(DWORD bits) +static int disable_bits(enum save_term_flags flags, DWORD bits) { if (use_stty) { struct child_process cp = CHILD_PROCESS_INIT; @@ -191,7 +353,7 @@ static int disable_bits(DWORD bits) use_stty = 0; } - if (save_term(0) < 0) + if (save_term(flags) < 0) return -1; if (!SetConsoleMode(hconin, cmode_in & ~bits)) { @@ -204,14 +366,15 @@ static int disable_bits(DWORD bits) return 0; } -static int disable_echo(void) +static int disable_echo(enum save_term_flags flags) { - return disable_bits(ENABLE_ECHO_INPUT); + return disable_bits(flags, ENABLE_ECHO_INPUT); } -static int enable_non_canonical(void) +static int enable_non_canonical(enum save_term_flags flags) { - return disable_bits(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT); + return disable_bits(flags, + ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT); } /* @@ -245,6 +408,16 @@ static int mingw_getchar(void) } #define getchar mingw_getchar +static int getchar_with_timeout(int timeout) +{ + struct pollfd pfd = { .fd = 0, .events = POLLIN }; + + if (poll(&pfd, 1, timeout) < 1) + return EOF; + + return getchar(); +} + #endif #ifndef FORCE_TEXT @@ -267,7 +440,7 @@ char *git_terminal_prompt(const char *prompt, int echo) return NULL; } - if (!echo && disable_echo()) { + if (!echo && disable_echo(0)) { fclose(input_fh); fclose(output_fh); return NULL; @@ -361,7 +534,7 @@ int read_key_without_echo(struct strbuf *buf) static int warning_displayed; int ch; - if (warning_displayed || enable_non_canonical() < 0) { + if (warning_displayed || enable_non_canonical(SAVE_TERM_STDIN) < 0) { if (!warning_displayed) { warning("reading single keystrokes not supported on " "this platform; reading line instead"); @@ -395,12 +568,7 @@ int read_key_without_echo(struct strbuf *buf) * half a second when we know that the sequence is complete. */ while (!is_known_escape_sequence(buf->buf)) { - struct pollfd pfd = { .fd = 0, .events = POLLIN }; - - if (poll(&pfd, 1, 500) < 1) - break; - - ch = getchar(); + ch = getchar_with_timeout(500); if (ch == EOF) break; strbuf_addch(buf, ch); @@ -413,10 +581,10 @@ int read_key_without_echo(struct strbuf *buf) #else -int save_term(int full_duplex) +int save_term(enum save_term_flags flags) { - /* full_duplex == 1, but no support available */ - return -full_duplex; + /* no duplex support available */ + return -!!(flags & SAVE_TERM_DUPLEX); } void restore_term(void) diff --git a/compat/terminal.h b/compat/terminal.h index 0fb9fa147c..79ed00cf61 100644 --- a/compat/terminal.h +++ b/compat/terminal.h @@ -1,6 +1,13 @@ #ifndef COMPAT_TERMINAL_H #define COMPAT_TERMINAL_H +enum save_term_flags { + /* Save input and output settings */ + SAVE_TERM_DUPLEX = 1 << 0, + /* Save stdin rather than /dev/tty (fails if stdin is not a terminal) */ + SAVE_TERM_STDIN = 1 << 1, +}; + /* * Save the terminal attributes so they can be restored later by a * call to restore_term(). Note that every successful call to @@ -8,7 +15,7 @@ * attributes have not been changed. Returns 0 on success, -1 on * failure. */ -int save_term(int full_duplex); +int save_term(enum save_term_flags flags); /* Restore the terminal attributes that were saved with save_term() */ void restore_term(void);