gdbserver: btrace enums

Fixes:

 ../../../src/gdb/gdbserver/linux-low.c: In function ‘int linux_low_read_btrace(btrace_target_info*, buffer*, int)’:
 ../../../src/gdb/gdbserver/linux-low.c:6827:48: error: invalid conversion from ‘int’ to ‘btrace_read_type’ [-fpermissive]
    err = linux_read_btrace (&btrace, tinfo, type);
						 ^
 In file included from ../../../src/gdb/gdbserver/linux-low.c:98:0:
 ../../../src/gdb/gdbserver/../nat/linux-btrace.h:116:26: error:   initializing argument 3 of ‘btrace_error linux_read_btrace(btrace_data*, btrace_target_info*, btrace_read_type)’ [-fpermissive]
  extern enum btrace_error linux_read_btrace (struct btrace_data *btrace,
			   ^

The cyclic dependency the comment talks about is no longer relevant:
  https://sourceware.org/ml/gdb-patches/2015-10/msg00643.html

gdb/gdbserver/ChangeLog:
2015-10-29  Pedro Alves  <palves@redhat.com>

	* linux-low.c (linux_low_read_btrace): Change type of 'type'
	parameter.
	* server.c (handle_qxfer_btrace): Change type of 'type'
	local.
	* target.h (struct target_ops) <read_btrace>: Change type of
	'type' parameter.  Update comment.

4 files changed, 24 insertions, 5 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 0dfecf1..9b8a7d7 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -16,6 +16,24 @@
 	* linux-x86-low.c (x86_regsets): Likewise.
 	* linux-xtensa-low.c (xtensa_regsets): Likewise.
 
+2015-10-29  Pedro Alves  <palves@redhat.com>
+
+	* linux-low.h (NULL_REGSET): Define.
+	* linux-aarch64-low.c (aarch64_regsets): Use NULL_REGSET.
+	* linux-arm-low.c (arm_regsets): Likewise.
+	* linux-crisv32-low.c (cris_regsets): Likewise.
+	* linux-m68k-low.c (m68k_regsets): Likewise.
+	* linux-mips-low.c (mips_regsets): Likewise.
+	* linux-nios2-low.c (nios2_regsets): Likewise.
+	* linux-ppc-low.c (ppc_regsets): Likewise.
+	* linux-s390-low.c (s390_regsets): Likewise.
+	* linux-sh-low.c (sh_regsets): Likewise.
+	* linux-sparc-low.c (sparc_regsets): Likewise.
+	* linux-tic6x-low.c (tic6x_regsets): Likewise.
+	* linux-tile-low.c (tile_regsets): Likewise.
+	* linux-x86-low.c (x86_regsets): Likewise.
+	* linux-xtensa-low.c (xtensa_regsets): Likewise.
+
 2015-10-26  Doug Evans  <dje@google.com>
 
 	* linux-low.c (__SIGRTMIN): Move to nat/linux-nat.h.
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index e778c4c..41ab510 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -6815,7 +6815,7 @@ linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data,
 
 static int
 linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer,
-		       int type)
+		       enum btrace_read_type type)
 {
   struct btrace_data btrace;
   struct btrace_block *block;
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index ad6626e..024399d 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -1608,7 +1608,8 @@ handle_qxfer_btrace (const char *annex,
 {
   static struct buffer cache;
   struct thread_info *thread;
-  int type, result;
+  enum btrace_read_type type;
+  int result;
 
   if (the_target->read_btrace == NULL || writebuf != NULL)
     return -2;
diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h
index a14c6ff..769c876 100644
--- a/gdb/gdbserver/target.h
+++ b/gdb/gdbserver/target.h
@@ -399,11 +399,11 @@ struct target_ops
      Returns zero on success, non-zero otherwise.  */
   int (*disable_btrace) (struct btrace_target_info *tinfo);
 
-  /* Read branch trace data into buffer.  We use an int to specify the type
-     to break a cyclic dependency.
+  /* Read branch trace data into buffer.
      Return 0 on success; print an error message into BUFFER and return -1,
      otherwise.  */
-  int (*read_btrace) (struct btrace_target_info *, struct buffer *, int type);
+  int (*read_btrace) (struct btrace_target_info *, struct buffer *,
+		      enum btrace_read_type type);
 
   /* Read the branch trace configuration into BUFFER.
      Return 0 on success; print an error message into BUFFER and return -1