Re: "target remote | " stderr -- try2

Vladimir Prus
2007-04-06T06:07:51Z

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Daniel Jacobowitz wrote:

> On Sun, Mar 25, 2007 at 04:35:13PM +0300, Vladimir Prus wrote:
>>
>> This is a revision of my earlier patch to make
>> stderr output from program run with
>>
>> target remote | some_program
>>
>> to be routed through gdb_stderr, so that MI
>> frontend sees that output.
>>
>> The original patch is at:
>>
>> http://thread.gmane.org/gmane.comp.gdb.patches/32540
>>
>> and this version differs by not having any #ifdef WIN32 inside
>> ser-base.c, but instead using new method in 'struct serial_ops',
>> that is initialized in ser-mingw.c.
>>
>> OK?
>
> This version is OK. Thanks!

Doh! It turns out I've attached a patch that won't even compile.
Although the difference to the real patch is trivial, for avoidance
of doubt I attach the "right" patch and the delta to the previous
one. Is this version OK?

Sorry,
Volodya

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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.
(struct serial_opts): New field avail.
* 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.
(pipe_avail): New.
(_initialize_ser_windows): Hook pipe_avail.
* ser-base.c (generic_readchar): Check if there's
anything in stderr channel and route that to gdb_stderr.

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--- gdb/ser-base.c (revision 3592)
+++ gdb/ser-base.c (local)
@@ -361,6 +361,9 @@ generic_readchar (struct serial *scb, in
if (num_bytes != -1)
to_read = (num_bytes < to_read) ? num_bytes : to_read;

+ if (to_read == 0)
+ break;
+
s = read (scb->error_fd, &buf, to_read);
if (s == -1)
break;
--- gdb/ser-mingw.c (revision 3592)
+++ gdb/ser-mingw.c (local)
@@ -875,7 +875,7 @@ pipe_done_wait_handle (struct serial *sc
static int
pipe_avail (struct serial *scb, int fd)
{
- HANDLE h = (HANDLE) _get_osfhandle (scb->error_fd);
+ HANDLE h = (HANDLE) _get_osfhandle (fd);
DWORD numBytes;
BOOL r = PeekNamedPipe (h, NULL, 0, NULL, &numBytes, NULL);
if (r == FALSE)
--- gdb/serial.h (revision 3592)
+++ gdb/serial.h (local)
@@ -255,7 +255,7 @@ struct serial_ops
without blocking. Return value of -1 means that the
the read will not block even if less that requested bytes
are available. */
- int (*avail)(struct serial *scb);
+ int (*avail)(struct serial *scb, int fd);

#ifdef USE_WIN32API
/* Return a handle to wait on, indicating available data from SCB

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--- gdb/serial.c (/mirrors/gdb_mainline) (revision 3593)
+++ gdb/serial.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3593)
@@ -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 3593)
+++ gdb/serial.h (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3593)
@@ -191,6 +191,11 @@ extern int serial_debug_p (struct serial
struct serial
{
int fd; /* File descriptor */
+ /* 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 or
+ ops->avail should be non-NULL. */
+ int error_fd;
struct serial_ops *ops; /* Function vector */
void *state; /* Local context info for open FD */
serial_ttystate ttystate; /* Not used (yet) */
@@ -246,6 +251,11 @@ struct serial_ops
/* Perform a low-level write operation, writing (at most) COUNT
bytes from BUF. */
int (*write_prim)(struct serial *scb, const void *buf, size_t count);
+ /* Return that number of bytes that can be read from FD
+ without blocking. Return value of -1 means that the
+ the read will not block even if less that requested bytes
+ are available. */
+ int (*avail)(struct serial *scb, int fd);

#ifdef USE_WIN32API
/* Return a handle to wait on, indicating available data from SCB
--- gdb/ser-pipe.c (/mirrors/gdb_mainline) (revision 3593)
+++ gdb/ser-pipe.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3593)
@@ -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 3593)
+++ gdb/ser-base.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3593)
@@ -343,6 +343,48 @@ 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;
+ int to_read = 80;
+
+ int num_bytes = -1;
+ if (scb->ops->avail)
+ num_bytes = (scb->ops->avail)(scb, scb->error_fd);
+ if (num_bytes != -1)
+ to_read = (num_bytes < to_read) ? num_bytes : to_read;
+
+ if (to_read == 0)
+ break;
+
+ s = read (scb->error_fd, &buf, to_read);
+ 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 3593)
+++ gdb/ser-mingw.c (/patches/gdb/remote_stderr_try2/gdb_mainline) (revision 3593)
@@ -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);
@@ -865,6 +872,17 @@ pipe_done_wait_handle (struct serial *sc
WaitForSingleObject (ps->wait.have_stopped, INFINITE);
}

+static int
+pipe_avail (struct serial *scb, int fd)
+{
+ HANDLE h = (HANDLE) _get_osfhandle (fd);
+ DWORD numBytes;
+ BOOL r = PeekNamedPipe (h, NULL, 0, NULL, &numBytes, NULL);
+ if (r == FALSE)
+ numBytes = 0;
+ return numBytes;
+}
+
struct net_windows_state
{
HANDLE read_event;
@@ -1164,6 +1182,7 @@ _initialize_ser_windows (void)
ops->write_prim = pipe_windows_write;
ops->wait_handle = pipe_wait_handle;
ops->done_wait_handle = pipe_done_wait_handle;
+ ops->avail = pipe_avail;

serial_add_interface (ops);

Property changes on:
___________________________________________________________________
Name: csl:base
+/all/mirrors/gdb_mainline
Name: svk:merge
+e7755896-6108-0410-9592-8049d3e74e28:/mirrors/gdb/trunk:166548