Constify unpack_varlen_hex & fix fallout

I ran into non-const unpack_varlen_hex while working on something
else, and decided to just fix it first.  Ends up constifying a good
deal of remote packet parsing.

gdb/ChangeLog:
2017-09-29  Pedro Alves  <palves@redhat.com>

	* common/rsp-low.c (unpack_varlen_hex): Constify.
	* common/rsp-low.h (unpack_varlen_hex): Constify.
	* linux-nat.c (linux_child_static_tracepoint_markers_by_strid):
	Constify.
	* remote.c (remote_set_permissions, read_ptid)
	(remote_current_thread, remote_get_threads_with_qthreadinfo)
	(remote_static_tracepoint_marker_at)
	(remote_static_tracepoint_markers_by_strid)
	(stop_reply_extract_thread, remote_parse_stop_reply): Constify.
	* tracepoint.c (parse_trace_status, parse_tracepoint_status)
	(parse_tracepoint_definition, parse_tsv_definition)
	(parse_static_tracepoint_marker_definition): Constify.
	* tracepoint.h (parse_static_tracepoint_marker_definition)
	(parse_trace_status, parse_tracepoint_status)
	(parse_tracepoint_definition, parse_tsv_definition): Constify.

gdb/gdbserver/ChangeLog:
2017-09-29  Pedro Alves  <palves@redhat.com>

	* ax.c (gdb_parse_agent_expr): Constify.
	* ax.h (gdb_parse_agent_expr): Constify.
	* mem-break.c (add_breakpoint_condition, add_breakpoint_commands):
	Constify.
	* mem-break.h (add_breakpoint_condition, add_breakpoint_commands): Constify.
	* remote-utils.c (hex_or_minus_one, read_ptid): Constify.
	* remote-utils.h (read_ptid): Constify.
	* server.c (handle_qxfer_exec_file, handle_query, handle_v_cont)
	(process_point_options, process_serial_event): Constify.
	* tracepoint.c (add_tracepoint_action, cmd_qtdp, cmd_qtdpsrc)
	(cmd_qtdv, cmd_qtenable_disable, cmd_qtro, cmd_qtframe, cmd_qtp)
	(cmd_qtbuffer): Constify.

1 files changed, 12 insertions, 10 deletions

diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index 30e3a3a..b6e7fe5 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -3405,9 +3405,9 @@ merge_uploaded_trace_state_variables (struct uploaded_tsv **uploaded_tsvs)
    the remote protocol and the trace file reader.  */
 
 void
-parse_trace_status (char *line, struct trace_status *ts)
+parse_trace_status (const char *line, struct trace_status *ts)
 {
-  char *p = line, *p1, *p2, *p3, *p_temp;
+  const char *p = line, *p1, *p2, *p3, *p_temp;
   int end;
   ULONGEST val;
 
@@ -3565,7 +3565,7 @@ Status line: '%s'\n"), p, line);
 }
 
 void
-parse_tracepoint_status (char *p, struct breakpoint *bp,
+parse_tracepoint_status (const char *p, struct breakpoint *bp,
 			 struct uploaded_tp *utp)
 {
   ULONGEST uval;
@@ -3588,14 +3588,15 @@ parse_tracepoint_status (char *p, struct breakpoint *bp,
    an "uploaded tracepoint".  */
 
 void
-parse_tracepoint_definition (char *line, struct uploaded_tp **utpp)
+parse_tracepoint_definition (const char *line, struct uploaded_tp **utpp)
 {
-  char *p;
+  const char *p;
   char piece;
   ULONGEST num, addr, step, pass, orig_size, xlen, start;
   int enabled, end;
   enum bptype type;
-  char *cond, *srctype, *buf;
+  const char *srctype;
+  char *cond, *buf;
   struct uploaded_tp *utp = NULL;
 
   p = line;
@@ -3703,9 +3704,10 @@ parse_tracepoint_definition (char *line, struct uploaded_tp **utpp)
    uploaded object.  */
 
 void
-parse_tsv_definition (char *line, struct uploaded_tsv **utsvp)
+parse_tsv_definition (const char *line, struct uploaded_tsv **utsvp)
 {
-  char *p, *buf;
+  const char *p;
+  char *buf;
   ULONGEST num, initval, builtin;
   int end;
   struct uploaded_tsv *utsv = NULL;
@@ -3749,10 +3751,10 @@ free_current_marker (void *arg)
    the parsed marker definition.  */
 
 void
-parse_static_tracepoint_marker_definition (char *line, char **pp,
+parse_static_tracepoint_marker_definition (const char *line, const char **pp,
 					   struct static_tracepoint_marker *marker)
 {
-  char *p, *endp;
+  const char *p, *endp;
   ULONGEST addr;
   int end;