btrace: maintenance commands

Add maintenance commands that help debugging the btrace record target.
The following new commands are added:

maint info btrace
  Print information about branch tracing internals.

maint btrace packet-history
  Print the raw branch tracing data.

maint btrace clear-packet-history
  Discard the stored raw branch tracing data.

maint btrace clear
  Discard all branch tracing data.  It will be fetched and processed
  anew by the next "record" command.

maint set|show btrace pt skip-pad
  Set and show whether PAD packets are skipped when computing the
  packet history.

gdb/
	* btrace.c: Include gdbcmd.h, cli/cli-utils.h, and ctype.h.
	(maint_btrace_cmdlist, maint_btrace_set_cmdlist)
	(maint_btrace_show_cmdlist, maint_btrace_pt_set_cmdlist)
	(maint_btrace_pt_show_cmdlist, maint_btrace_pt_skip_pad)
	(btrace_maint_clear): New.
	(btrace_fetch, btrace_clear): Call btrace_maint_clear.
	(pt_print_packet, btrace_maint_decode_pt)
	(btrace_maint_update_pt_packets, btrace_maint_update_packets)
	(btrace_maint_print_packets, get_uint, get_context_size, no_chunk)
	(maint_btrace_packet_history_cmd)
	(maint_btrace_clear_packet_history_cmd, maint_btrace_clear_cmd)
	(maint_btrace_cmd, maint_btrace_set_cmd, maint_btrace_show_cmd)
	(maint_btrace_pt_set_cmd, maint_btrace_pt_show_cmd)
	(maint_info_btrace_cmd, _initialize_btrace): New.
	* btrace.h (btrace_pt_packet, btrace_pt_packet_s)
	(btrace_maint_packet_history, btrace_maint_info): New.
	(btrace_thread_info) <maint>: New.
	* NEWS: Announce it.

doc/
	* gdb.texinfo (Maintenance Commands): Document "maint btrace"
	commands.

1 files changed, 63 insertions, 0 deletions

diff --git a/gdb/btrace.h b/gdb/btrace.h
index 0845b78d0c4..93c84ffa0fb 100644
--- a/gdb/btrace.h
+++ b/gdb/btrace.h
@@ -233,6 +233,66 @@ enum btrace_thread_flag
   BTHR_MOVE = (BTHR_STEP | BTHR_RSTEP | BTHR_CONT | BTHR_RCONT)
 };
 
+#if defined (HAVE_LIBIPT)
+/* A packet.  */
+struct btrace_pt_packet
+{
+  /* The offset in the trace stream.  */
+  uint64_t offset;
+
+  /* The decode error code.  */
+  enum pt_error_code errcode;
+
+  /* The decoded packet.  Only valid if ERRCODE == pte_ok.  */
+  struct pt_packet packet;
+};
+
+/* Define functions operating on a vector of packets.  */
+typedef struct btrace_pt_packet btrace_pt_packet_s;
+DEF_VEC_O (btrace_pt_packet_s);
+#endif /* defined (HAVE_LIBIPT)  */
+
+/* Branch trace iteration state for "maintenance btrace packet-history".  */
+struct btrace_maint_packet_history
+{
+  /* The branch trace packet range from BEGIN (inclusive) to
+     END (exclusive) that has been covered last time.  */
+  unsigned int begin;
+  unsigned int end;
+};
+
+/* Branch trace maintenance information per thread.
+
+   This information is used by "maintenance btrace" commands.  */
+struct btrace_maint_info
+{
+  /* Most information is format-specific.
+     The format can be found in the BTRACE.DATA.FORMAT field of each thread.  */
+  union
+  {
+    /* BTRACE.DATA.FORMAT == BTRACE_FORMAT_BTS  */
+    struct
+    {
+      /* The packet history iterator.
+	 We are iterating over BTRACE.DATA.FORMAT.VARIANT.BTS.BLOCKS.  */
+      struct btrace_maint_packet_history packet_history;
+    } bts;
+
+#if defined (HAVE_LIBIPT)
+    /* BTRACE.DATA.FORMAT == BTRACE_FORMAT_PT  */
+    struct
+    {
+      /* A vector of decoded packets.  */
+      VEC (btrace_pt_packet_s) *packets;
+
+      /* The packet history iterator.
+	 We are iterating over the above PACKETS vector.  */
+      struct btrace_maint_packet_history packet_history;
+    } pt;
+#endif /* defined (HAVE_LIBIPT)  */
+  } variant;
+};
+
 /* Branch trace information per thread.
 
    This represents the branch trace configuration as well as the entry point
@@ -284,6 +344,9 @@ struct btrace_thread_info
 
   /* Why the thread stopped, if we need to track it.  */
   enum target_stop_reason stop_reason;
+
+  /* Maintenance information.  */
+  struct btrace_maint_info maint;
 };
 
 /* Enable branch tracing for a thread.  */