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, 42 insertions, 0 deletions

diff --git a/gdb/ser-base.c b/gdb/ser-base.c
index a051157b316..fe5a83394db 100644
--- a/gdb/ser-base.c
+++ b/gdb/ser-base.c
@@ -343,6 +343,48 @@ generic_readchar (struct serial *scb, int timeout,
 	    }
 	}
     }
+  /* 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;
 }