diff options
| -rw-r--r-- | gdb/ChangeLog | 10 | ||||
| -rw-r--r-- | gdb/NEWS | 8 | ||||
| -rw-r--r-- | gdb/windows-nat.c | 403 |
3 files changed, 388 insertions, 33 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 3376b1b..b59a749 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2016-10-29 Eli Zaretskii <eliz@gnu.org> + + * NEWS: Mention support for redirection on MS-Windows. + + * windows-nat.c (redir_open, redir_set_redirection) + (redirect_inferior_handles) [!__CYGWIN__]: New functions. + (windows_create_inferior) [!__CYGWIN__]: Use + 'redirect_inferior_handles' to redirect standard handles of the + debuggee if the command line requests that. + 2016-10-28 Pedro Alves <palves@redhat.com> * Makefile.in (CXX_DIALECT): Get from configure. @@ -9,6 +9,14 @@ compiler. The --disable-build-with-cxx configure option has been removed. +* Native debugging on MS-Windows supports command-line redirection + + Command-line arguments used for starting programs on MS-Windows can + now include redirection symbols supported by native Windows shells, + such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such + as "run", "start", and "set args", as well as the corresponding MI + features. + * Support for thread names on MS-Windows. GDB now catches and handles the special exception that programs diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c index c6a809b..4b8adac 100644 --- a/gdb/windows-nat.c +++ b/gdb/windows-nat.c @@ -2116,6 +2116,301 @@ clear_win32_environment (char **env) } #endif +#ifndef __CYGWIN__ + +/* Redirection of inferior I/O streams for native MS-Windows programs. + Unlike on Unix, where this is handled by invoking the inferior via + the shell, on MS-Windows we need to emulate the cmd.exe shell. + + The official documentation of the cmd.exe redirection features is here: + + http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/redirection.mspx + + (That page talks about Windows XP, but there's no newer + documentation, so we assume later versions of cmd.exe didn't change + anything.) + + Caveat: the documentation on that page seems to include a few lies. + For example, it describes strange constructs 1<&2 and 2<&1, which + seem to work only when 1>&2 resp. 2>&1 would make sense, and so I + think the cmd.exe parser of the redirection symbols simply doesn't + care about the < vs > distinction in these cases. Therefore, the + supported features are explicitly documented below. + + The emulation below aims at supporting all the valid use cases + supported by cmd.exe, which include: + + < FILE redirect standard input from FILE + 0< FILE redirect standard input from FILE + <&N redirect standard input from file descriptor N + 0<&N redirect standard input from file descriptor N + > FILE redirect standard output to FILE + >> FILE append standard output to FILE + 1>> FILE append standard output to FILE + >&N redirect standard output to file descriptor N + 1>&N redirect standard output to file descriptor N + >>&N append standard output to file descriptor N + 1>>&N append standard output to file descriptor N + 2> FILE redirect standard error to FILE + 2>> FILE append standard error to FILE + 2>&N redirect standard error to file descriptor N + 2>>&N append standard error to file descriptor N + + Note that using N > 2 in the above construct is supported, but + requires that the corresponding file descriptor be open by some + means elsewhere or outside GDB. Also note that using ">&0" or + "<&2" will generally fail, because the file descriptor redirected + from is normally open in an incompatible mode (e.g., FD 0 is open + for reading only). IOW, use of such tricks is not recommended; + you are on your own. + + We do NOT support redirection of file descriptors above 2, as in + "3>SOME-FILE", because MinGW compiled programs don't (supporting + that needs special handling in the startup code that MinGW + doesn't have). Pipes are also not supported. + + As for invalid use cases, where the redirection contains some + error, the emulation below will detect that and produce some + error and/or failure. But the behavior in those cases is not + bug-for-bug compatible with what cmd.exe does in those cases. + That's because what cmd.exe does then is not well defined, and + seems to be a side effect of the cmd.exe parsing of the command + line more than anything else. For example, try redirecting to an + invalid file name, as in "> foo:bar". + + There are also minor syntactic deviations from what cmd.exe does + in some corner cases. For example, it doesn't support the likes + of "> &foo" to mean redirect to file named literally "&foo"; we + do support that here, because that, too, sounds like some issue + with the cmd.exe parser. Another nicety is that we support + redirection targets that use file names with forward slashes, + something cmd.exe doesn't -- this comes in handy since GDB + file-name completion can be used when typing the command line for + the inferior. */ + +/* Support routines for redirecting standard handles of the inferior. */ + +/* Parse a single redirection spec, open/duplicate the specified + file/fd, and assign the appropriate value to one of the 3 standard + file descriptors. */ +static int +redir_open (const char *redir_string, int *inp, int *out, int *err) +{ + int *fd, ref_fd = -2; + int mode; + const char *fname = redir_string + 1; + int rc = *redir_string; + + switch (rc) + { + case '0': + fname++; + /* FALLTHROUGH */ + case '<': + fd = inp; + mode = O_RDONLY; + break; + case '1': case '2': + fname++; + /* FALLTHROUGH */ + case '>': + fd = (rc == '2') ? err : out; + mode = O_WRONLY | O_CREAT; + if (*fname == '>') + { + fname++; + mode |= O_APPEND; + } + else + mode |= O_TRUNC; + break; + default: + return -1; + } + + if (*fname == '&' && '0' <= fname[1] && fname[1] <= '9') + { + /* A reference to a file descriptor. */ + char *fdtail; + ref_fd = (int) strtol (fname + 1, &fdtail, 10); + if (fdtail > fname + 1 && *fdtail == '\0') + { + /* Don't allow redirection when open modes are incompatible. */ + if ((ref_fd == 0 && (fd == out || fd == err)) + || ((ref_fd == 1 || ref_fd == 2) && fd == inp)) + { + errno = EPERM; + return -1; + } + if (ref_fd == 0) + ref_fd = *inp; + else if (ref_fd == 1) + ref_fd = *out; + else if (ref_fd == 2) + ref_fd = *err; + } + else + { + errno = EBADF; + return -1; + } + } + else + fname++; /* skip the separator space */ + /* If the descriptor is already open, close it. This allows + multiple specs of redirections for the same stream, which is + somewhat nonsensical, but still valid and supported by cmd.exe. + (But cmd.exe only opens a single file in this case, the one + specified by the last redirection spec on the command line.) */ + if (*fd >= 0) + _close (*fd); + if (ref_fd == -2) + { + *fd = _open (fname, mode, _S_IREAD | _S_IWRITE); + if (*fd < 0) + return -1; + } + else if (ref_fd == -1) + *fd = -1; /* reset to default destination */ + else + { + *fd = _dup (ref_fd); + if (*fd < 0) + return -1; + } + /* _open just sets a flag for O_APPEND, which won't be passed to the + inferior, so we need to actually move the file pointer. */ + if ((mode & O_APPEND) != 0) + _lseek (*fd, 0L, SEEK_END); + return 0; +} + +/* Canonicalize a single redirection spec and set up the corresponding + file descriptor as specified. */ +static int +redir_set_redirection (const char *s, int *inp, int *out, int *err) +{ + char buf[__PMAX + 2 + 5]; /* extra space for quotes & redirection string */ + char *d = buf; + const char *start = s; + int quote = 0; + + *d++ = *s++; /* copy the 1st character, < or > or a digit */ + if ((*start == '>' || *start == '1' || *start == '2') + && *s == '>') + { + *d++ = *s++; + if (*s == '>' && *start != '>') + *d++ = *s++; + } + else if (*start == '0' && *s == '<') + *d++ = *s++; + /* cmd.exe recognizes "&N" only immediately after the redirection symbol. */ + if (*s != '&') + { + while (isspace (*s)) /* skip whitespace before file name */ + s++; + *d++ = ' '; /* separate file name with a single space */ + } + + /* Copy the file name. */ + while (*s) + { + /* Remove quoting characters from the file name in buf[]. */ + if (*s == '"') /* could support '..' quoting here */ + { + if (!quote) + quote = *s++; + else if (*s == quote) + { + quote = 0; + s++; + } + else + *d++ = *s++; + } + else if (*s == '\\') + { + if (s[1] == '"') /* could support '..' here */ + s++; + *d++ = *s++; + } + else if (isspace (*s) && !quote) + break; + else + *d++ = *s++; + if (d - buf >= sizeof (buf) - 1) + { + errno = ENAMETOOLONG; + return 0; + } + } + *d = '\0'; + + /* Windows doesn't allow redirection characters in file names, so we + can bail out early if they use them, or if there's no target file + name after the redirection symbol. */ + if (d[-1] == '>' || d[-1] == '<') + { + errno = ENOENT; + return 0; + } + if (redir_open (buf, inp, out, err) == 0) + return s - start; + return 0; +} + +/* Parse the command line for redirection specs and prepare the file + descriptors for the 3 standard streams accordingly. */ +static bool +redirect_inferior_handles (const char *cmd_orig, char *cmd, + int *inp, int *out, int *err) +{ + const char *s = cmd_orig; + char *d = cmd; + int quote = 0; + bool retval = false; + + while (isspace (*s)) + *d++ = *s++; + + while (*s) + { + if (*s == '"') /* could also support '..' quoting here */ + { + if (!quote) + quote = *s; + else if (*s == quote) + quote = 0; + } + else if (*s == '\\') + { + if (s[1] == '"') /* escaped quote char */ + s++; + } + else if (!quote) + { + /* Process a single redirection candidate. */ + if (*s == '<' || *s == '>' + || ((*s == '1' || *s == '2') && s[1] == '>') + || (*s == '0' && s[1] == '<')) + { + int skip = redir_set_redirection (s, inp, out, err); + + if (skip <= 0) + return false; + retval = true; + s += skip; + } + } + if (*s) + *d++ = *s++; + } + *d = '\0'; + return retval; +} +#endif /* !__CYGWIN__ */ + /* Start an inferior windows child process and sets inferior_ptid to its pid. EXEC_FILE is the file to run. ALLARGS is a string containing the arguments to the program. @@ -2138,20 +2433,25 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, size_t len; int tty; int ostdin, ostdout, ostderr; -#else +#else /* !__CYGWIN__ */ char real_path[__PMAX]; char shell[__PMAX]; /* Path to shell */ char *toexec; - char *args; - size_t args_len; - HANDLE tty; + char *args, *allargs_copy; + size_t args_len, allargs_len; + int fd_inp = -1, fd_out = -1, fd_err = -1; + HANDLE tty = INVALID_HANDLE_VALUE; + HANDLE inf_stdin = INVALID_HANDLE_VALUE; + HANDLE inf_stdout = INVALID_HANDLE_VALUE; + HANDLE inf_stderr = INVALID_HANDLE_VALUE; + bool redirected = false; char *w32env; char *temp; size_t envlen; int i; size_t envsize; char **env; -#endif +#endif /* !__CYGWIN__ */ PROCESS_INFORMATION pi; BOOL ret; DWORD flags = 0; @@ -2183,7 +2483,7 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, error (_("Error starting executable: %d"), errno); cygallargs = (wchar_t *) alloca (len * sizeof (wchar_t)); mbstowcs (cygallargs, allargs, len); -#else +#else /* !__USEWIDE */ cygallargs = allargs; #endif } @@ -2199,12 +2499,12 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, + mbstowcs (NULL, allargs, 0) + 2; cygallargs = (wchar_t *) alloca (len * sizeof (wchar_t)); swprintf (cygallargs, len, L" -c 'exec %s %s'", exec_file, allargs); -#else +#else /* !__USEWIDE */ len = (sizeof (" -c 'exec '") + strlen (exec_file) + strlen (allargs) + 2); cygallargs = (char *) alloca (len); xsnprintf (cygallargs, len, " -c 'exec %s %s'", exec_file, allargs); -#endif +#endif /* __USEWIDE */ toexec = shell; flags |= DEBUG_PROCESS; } @@ -2215,12 +2515,12 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, wcscpy (args, toexec); wcscat (args, L" "); wcscat (args, cygallargs); -#else +#else /* !__USEWIDE */ args = (cygwin_buf_t *) alloca (strlen (toexec) + strlen (cygallargs) + 2); strcpy (args, toexec); strcat (args, " "); strcat (args, cygallargs); -#endif +#endif /* !__USEWIDE */ #ifdef CW_CVT_ENV_TO_WINENV /* First try to create a direct Win32 copy of the POSIX environment. */ @@ -2229,7 +2529,7 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, flags |= CREATE_UNICODE_ENVIRONMENT; else /* If that fails, fall back to old method tweaking GDB's environment. */ -#endif +#endif /* CW_CVT_ENV_TO_WINENV */ { /* Reset all Win32 environment variables to avoid leftover on next run. */ clear_win32_environment (environ); @@ -2294,21 +2594,26 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, close (ostdout); close (ostderr); } -#else - toexec = exec_file; - /* Build the command line, a space-separated list of tokens where - the first token is the name of the module to be executed. - To avoid ambiguities introduced by spaces in the module name, - we quote it. */ - args_len = strlen (toexec) + 2 /* quotes */ + strlen (allargs) + 2; - args = (char *) alloca (args_len); - xsnprintf (args, args_len, "\"%s\" %s", toexec, allargs); - - flags |= DEBUG_ONLY_THIS_PROCESS; - - if (!inferior_io_terminal) - tty = INVALID_HANDLE_VALUE; - else +#else /* !__CYGWIN__ */ + allargs_len = strlen (allargs); + allargs_copy = strcpy ((char *) alloca (allargs_len + 1), allargs); + if (strpbrk (allargs_copy, "<>") != NULL) + { + int e = errno; + errno = 0; + redirected = + redirect_inferior_handles (allargs, allargs_copy, + &fd_inp, &fd_out, &fd_err); + if (errno) + warning (_("Error in redirection: %s."), strerror (errno)); + else + errno = e; + allargs_len = strlen (allargs_copy); + } + /* If not all the standard streams are redirected by the command + line, use inferior_io_terminal for those which aren't. */ + if (inferior_io_terminal + && !(fd_inp >= 0 && fd_out >= 0 && fd_err >= 0)) { SECURITY_ATTRIBUTES sa; sa.nLength = sizeof(sa); @@ -2319,15 +2624,41 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, if (tty == INVALID_HANDLE_VALUE) warning (_("Warning: Failed to open TTY %s, error %#x."), inferior_io_terminal, (unsigned) GetLastError ()); + } + if (redirected || tty != INVALID_HANDLE_VALUE) + { + if (fd_inp >= 0) + si.hStdInput = (HANDLE) _get_osfhandle (fd_inp); + else if (tty != INVALID_HANDLE_VALUE) + si.hStdInput = tty; else - { - si.hStdInput = tty; - si.hStdOutput = tty; - si.hStdError = tty; - si.dwFlags |= STARTF_USESTDHANDLES; - } + si.hStdInput = GetStdHandle (STD_INPUT_HANDLE); + if (fd_out >= 0) + si.hStdOutput = (HANDLE) _get_osfhandle (fd_out); + else if (tty != INVALID_HANDLE_VALUE) + si.hStdOutput = tty; + else + si.hStdOutput = GetStdHandle (STD_OUTPUT_HANDLE); + if (fd_err >= 0) + si.hStdError = (HANDLE) _get_osfhandle (fd_err); + else if (tty != INVALID_HANDLE_VALUE) + si.hStdError = tty; + else + si.hStdError = GetStdHandle (STD_ERROR_HANDLE); + si.dwFlags |= STARTF_USESTDHANDLES; } + toexec = exec_file; + /* Build the command line, a space-separated list of tokens where + the first token is the name of the module to be executed. + To avoid ambiguities introduced by spaces in the module name, + we quote it. */ + args_len = strlen (toexec) + 2 /* quotes */ + allargs_len + 2; + args = (char *) alloca (args_len); + xsnprintf (args, args_len, "\"%s\" %s", toexec, allargs_copy); + + flags |= DEBUG_ONLY_THIS_PROCESS; + /* CreateProcess takes the environment list as a null terminated set of strings (i.e. two nulls terminate the list). */ @@ -2366,7 +2697,13 @@ windows_create_inferior (struct target_ops *ops, char *exec_file, &pi); if (tty != INVALID_HANDLE_VALUE) CloseHandle (tty); -#endif + if (fd_inp >= 0) + _close (fd_inp); + if (fd_out >= 0) + _close (fd_out); + if (fd_err >= 0) + _close (fd_err); +#endif /* !__CYGWIN__ */ if (!ret) error (_("Error creating process %s, (error %u)."), |