Merge GDB 7.5.1

gdb/gdbserver/hostio.c

Index: gdb/gdbserver/hostio.c
diff --git a/gdb/gdbserver/hostio.c b/gdb/gdbserver/hostio.c
index b1508ec3babb41bc00954722efb7629790d36ac1..72e334c414ce19ec5f042dda95575090d469c971 100644
--- a/gdb/gdbserver/hostio.c
+++ b/gdb/gdbserver/hostio.c
@@ -328,10 +328,15 @@ handle_pread (char *own_buf, int *new_packet_len)
 #ifdef HAVE_PREAD
   ret = pread (fd, data, len, offset);
 #else
-  ret = lseek (fd, offset, SEEK_SET);
-  if (ret != -1)
-    ret = read (fd, data, len);
+  ret = -1;
 #endif
+  /* If we have no pread or it failed for this file, use lseek/read.  */
+  if (ret == -1)
+    {
+      ret = lseek (fd, offset, SEEK_SET);
+      if (ret != -1)
+	ret = read (fd, data, len);
+    }
 
   if (ret == -1)
     {
@@ -376,10 +381,15 @@ handle_pwrite (char *own_buf, int packet_len)
 #ifdef HAVE_PWRITE
   ret = pwrite (fd, data, len, offset);
 #else
-  ret = lseek (fd, offset, SEEK_SET);
-  if (ret != -1)
-    ret = write (fd, data, len);
+  ret = -1;
 #endif
+  /* If we have no pwrite or it failed for this file, use lseek/write.  */
+  if (ret == -1)
+    {
+      ret = lseek (fd, offset, SEEK_SET);
+      if (ret != -1)
+	ret = write (fd, data, len);
+    }
 
   if (ret == -1)
     {
@@ -456,6 +466,41 @@ handle_unlink (char *own_buf)
   hostio_reply (own_buf, ret);
 }
 
+static void
+handle_readlink (char *own_buf, int *new_packet_len)
+{
+#if defined (HAVE_READLINK)
+  char filename[PATH_MAX], linkname[PATH_MAX];
+  char *p;
+  int ret, bytes_sent;
+
+  p = own_buf + strlen ("vFile:readlink:");
+
+  if (require_filename (&p, filename)
+      || require_end (p))
+    {
+      hostio_packet_error (own_buf);
+      return;
+    }
+
+  ret = readlink (filename, linkname, sizeof linkname);
+  if (ret == -1)
+    {
+      hostio_error (own_buf);
+      return;
+    }
+
+  bytes_sent = hostio_reply_with_data (own_buf, linkname, ret, new_packet_len);
+
+  /* If the response does not fit into a single packet, do not attempt
+     to return a partial response, but simply fail.  */
+  if (bytes_sent < ret)
+    sprintf (own_buf, "F-1,%x", FILEIO_ENAMETOOLONG);
+#else /* ! HAVE_READLINK */
+    sprintf (own_buf, "F-1,%x", FILEIO_ENOSYS);
+#endif
+}
+
 /* Handle all the 'F' file transfer packets.  */
 
 int
@@ -471,6 +516,8 @@ handle_vFile (char *own_buf, int packet_len, int *new_packet_len)
     handle_close (own_buf);
   else if (strncmp (own_buf, "vFile:unlink:", 13) == 0)
     handle_unlink (own_buf);
+  else if (strncmp (own_buf, "vFile:readlink:", 15) == 0)
+    handle_readlink (own_buf, new_packet_len);
   else
     return 0;