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Re: "target remote | " stderr
- From: Vladimir Prus <ghost at cs dot msu dot su>
- To: gdb-patches at sources dot redhat dot com
- Date: Sun, 11 Feb 2007 19:55:03 +0300
- Subject: Re: "target remote | " stderr
- References: <200701261653.53834.vladimir@codesourcery.com> <20070126140028.GA29456@nevyn.them.org> <epq9dd$k4s$1@sea.gmane.org> <20070131144101.GA23780@nevyn.them.org>
Daniel Jacobowitz wrote:
> On Wed, Jan 31, 2007 at 05:34:21PM +0300, Vladimir Prus wrote:
>> Implementing for MinGW required modifying libiberty so that
>> it can catch stderr to a pipe. Here's a patch for gdb that
>> relies on the libiberty patch. Does this sound OK
>> provided libiberty patch is approved?
>
> Do we automatically get a non-blocking pipe on mingw, or do we have to
> set it ourselves?
We have to set it ourself, unfortunately. I had one test case working
fine, but got gdb hanging on some other.
The attached patch works around the blocking issues, and more extensively
tested. OK?
- Volodya
Pass stderr of program run with "target remote |"
via gdb_stderr.
* serial.c (serial_open): Set error_fd to -1.
* serial.h (struct serial): New field error_fd.
* ser-pipe.c (pipe_open): Create another pair
of sockets. Pass stderr to gdb.
* ser-mingw.c (pipe_windows_open): Pass
PEX_STDERR_TO_PIPE to pex_run. Initialize
sd->error_fd.
* ser-base.c (generic_readchar): Check if there's
anything in stderr channel and route that to gdb_stderr.
--- gdb/serial.c (/mirrors/gdb_mainline) (revision 3417)
+++ gdb/serial.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3417)
@@ -211,6 +211,7 @@ serial_open (const char *name)
scb->bufcnt = 0;
scb->bufp = scb->buf;
+ scb->error_fd = -1;
if (scb->ops->open (scb, open_name))
{
--- gdb/serial.h (/mirrors/gdb_mainline) (revision 3417)
+++ gdb/serial.h (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3417)
@@ -191,6 +191,12 @@ extern int serial_debug_p (struct serial
struct serial
{
int fd; /* File descriptor */
+ int error_fd; /* File descriptor for a separate
+ error stream that should be
+ immediately forwarded to gdb_stderr.
+ This may be -1.
+ If != -1, this descriptor should
+ be non-blocking. */
struct serial_ops *ops; /* Function vector */
void *state; /* Local context info for open FD */
serial_ttystate ttystate; /* Not used (yet) */
--- gdb/ser-pipe.c (/mirrors/gdb_mainline) (revision 3417)
+++ gdb/ser-pipe.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3417)
@@ -62,9 +62,12 @@ pipe_open (struct serial *scb, const cha
* published in UNIX Review, Vol. 6, No. 8.
*/
int pdes[2];
+ int err_pdes[2];
int pid;
if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
return -1;
+ if (socketpair (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0)
+ return -1;
/* Create the child process to run the command in. Note that the
apparent call to vfork() below *might* actually be a call to
@@ -77,9 +80,18 @@ pipe_open (struct serial *scb, const cha
{
close (pdes[0]);
close (pdes[1]);
+ close (err_pdes[0]);
+ close (err_pdes[1]);
return -1;
}
+ if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1)
+ {
+ close (err_pdes[0]);
+ close (err_pdes[1]);
+ err_pdes[0] = err_pdes[1] = -1;
+ }
+
/* Child. */
if (pid == 0)
{
@@ -91,6 +103,13 @@ pipe_open (struct serial *scb, const cha
close (pdes[1]);
}
dup2 (STDOUT_FILENO, STDIN_FILENO);
+
+ if (err_pdes[0] != -1)
+ {
+ close (err_pdes[0]);
+ dup2 (err_pdes[1], STDERR_FILENO);
+ close (err_pdes[1]);
+ }
#if 0
/* close any stray FD's - FIXME - how? */
/* POSIX.2 B.3.2.2 "popen() shall ensure that any streams
@@ -109,6 +128,7 @@ pipe_open (struct serial *scb, const cha
state = XMALLOC (struct pipe_state);
state->pid = pid;
scb->fd = pdes[0];
+ scb->error_fd = err_pdes[0];
scb->state = state;
/* If we don't do this, GDB simply exits when the remote side dies. */
--- gdb/ser-base.c (/mirrors/gdb_mainline) (revision 3417)
+++ gdb/ser-base.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3417)
@@ -314,6 +314,7 @@ generic_readchar (struct serial *scb, in
int (do_readchar) (struct serial *scb, int timeout))
{
int ch;
+
if (scb->bufcnt > 0)
{
ch = *scb->bufp;
@@ -343,6 +344,51 @@ generic_readchar (struct serial *scb, in
}
}
}
+ /* Read any error output we might have. */
+ if (scb->error_fd != -1)
+ {
+ ssize_t s;
+ char buf[81];
+
+ for (;;)
+ {
+ char *current;
+ char *newline;
+
+#ifdef _WIN32
+ /* On windows, it's not easy to make a pipe non-blocking,
+ if at all possible. Therefore, first find out
+ how many bytes are in the pipes and read only the available
+ number of bytes so that to avoid blocking. */
+ HANDLE h = (HANDLE) _get_osfhandle (scb->error_fd);
+ DWORD numBytes;
+ BOOL r = PeekNamedPipe (h, NULL, 0, NULL, &numBytes, NULL);
+ if (r == FALSE || numBytes == 0)
+ break;
+ s = read (scb->error_fd, &buf, numBytes > 80 ? 80 : numBytes);
+#else
+ s = read (scb->error_fd, &buf, 80);
+#endif
+ if (s == -1)
+ break;
+
+ /* In theory, embedded newlines are not a problem.
+ But for MI, we want each output line to have just
+ one newline for legibility. So output things
+ in newline chunks. */
+ buf[s] = '\0';
+ current = buf;
+ while ((newline = strstr (current, "\n")) != NULL)
+ {
+ *newline = '\0';
+ fputs_unfiltered (current, gdb_stderr);
+ fputs_unfiltered ("\n", gdb_stderr);
+ current = newline + 1;
+ }
+ fputs_unfiltered (current, gdb_stderr);
+ }
+ }
+
reschedule (scb);
return ch;
}
--- gdb/ser-mingw.c (/mirrors/gdb_mainline) (revision 3417)
+++ gdb/ser-mingw.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3417)
@@ -697,6 +697,7 @@ static int
pipe_windows_open (struct serial *scb, const char *name)
{
struct pipe_state *ps;
+ FILE *pex_stderr;
char **argv = buildargv (name);
struct cleanup *back_to = make_cleanup_freeargv (argv);
@@ -717,7 +718,8 @@ pipe_windows_open (struct serial *scb, c
{
int err;
const char *err_msg
- = pex_run (ps->pex, PEX_SEARCH | PEX_BINARY_INPUT | PEX_BINARY_OUTPUT,
+ = pex_run (ps->pex, PEX_SEARCH | PEX_BINARY_INPUT | PEX_BINARY_OUTPUT
+ | PEX_STDERR_TO_PIPE,
argv[0], argv, NULL, NULL,
&err);
@@ -739,8 +741,13 @@ pipe_windows_open (struct serial *scb, c
ps->output = pex_read_output (ps->pex, 1);
if (! ps->output)
goto fail;
-
scb->fd = fileno (ps->output);
+
+ pex_stderr = pex_read_err (ps->pex, 1);
+ if (! pex_stderr)
+ goto fail;
+ scb->error_fd = fileno (pex_stderr);
+
scb->state = (void *) ps;
discard_cleanups (back_to);
Property changes on:
___________________________________________________________________
Name: csl:base
+/all/mirrors/gdb_mainline
Name: svk:merge
+e7755896-6108-0410-9592-8049d3e74e28:/mirrors/gdb/trunk:162899