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.

1 files changed, 10 insertions, 0 deletions

diff --git a/gdb/serial.h b/gdb/serial.h
index 1f0accd4a7c..49ad4d11ad0 100644
--- a/gdb/serial.h
+++ b/gdb/serial.h
@@ -191,6 +191,11 @@ extern int serial_debug_p (struct serial *scb);
 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