tools lib traceevent: Support function __get_dynamic_array_len

Support helper function __get_dynamic_array_len() in libtraceevent, this
function is used accompany with __print_array() or __print_hex(), but
currently it is not an available function in the function list of
process_function().

The total allocated length of the dynamic array is embedded in the top
half of __data_loc_##item field. This patch adds new arg type
PRINT_DYNAMIC_ARRAY_LEN to return the length to eval_num_arg(),

Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1440822125-52691-32-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 4d88593..1244797 100644 (file)
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -848,6 +848,7 @@ static void free_arg(struct print_arg *arg)
                free(arg->bitmask.bitmask);
                break;
        case PRINT_DYNAMIC_ARRAY:
+       case PRINT_DYNAMIC_ARRAY_LEN:
                free(arg->dynarray.index);
                break;
        case PRINT_OP:
@@ -2729,6 +2730,42 @@ process_dynamic_array(struct event_format *event, struct print_arg *arg, char **
 }
 
 static enum event_type
+process_dynamic_array_len(struct event_format *event, struct print_arg *arg,
+                         char **tok)
+{
+       struct format_field *field;
+       enum event_type type;
+       char *token;
+
+       if (read_expect_type(EVENT_ITEM, &token) < 0)
+               goto out_free;
+
+       arg->type = PRINT_DYNAMIC_ARRAY_LEN;
+
+       /* Find the field */
+       field = pevent_find_field(event, token);
+       if (!field)
+               goto out_free;
+
+       arg->dynarray.field = field;
+       arg->dynarray.index = 0;
+
+       if (read_expected(EVENT_DELIM, ")") < 0)
+               goto out_err;
+
+       type = read_token(&token);
+       *tok = token;
+
+       return type;
+
+ out_free:
+       free_token(token);
+ out_err:
+       *tok = NULL;
+       return EVENT_ERROR;
+}
+
+static enum event_type
 process_paren(struct event_format *event, struct print_arg *arg, char **tok)
 {
        struct print_arg *item_arg;
@@ -2975,6 +3012,10 @@ process_function(struct event_format *event, struct print_arg *arg,
                free_token(token);
                return process_dynamic_array(event, arg, tok);
        }
+       if (strcmp(token, "__get_dynamic_array_len") == 0) {
+               free_token(token);
+               return process_dynamic_array_len(event, arg, tok);
+       }
 
        func = find_func_handler(event->pevent, token);
        if (func) {
@@ -3655,14 +3696,25 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg
                        goto out_warning_op;
                }
                break;
+       case PRINT_DYNAMIC_ARRAY_LEN:
+               offset = pevent_read_number(pevent,
+                                           data + arg->dynarray.field->offset,
+                                           arg->dynarray.field->size);
+               /*
+                * The total allocated length of the dynamic array is
+                * stored in the top half of the field, and the offset
+                * is in the bottom half of the 32 bit field.
+                */
+               val = (unsigned long long)(offset >> 16);
+               break;
        case PRINT_DYNAMIC_ARRAY:
                /* Without [], we pass the address to the dynamic data */
                offset = pevent_read_number(pevent,
                                            data + arg->dynarray.field->offset,
                                            arg->dynarray.field->size);
                /*
-                * The actual length of the dynamic array is stored
-                * in the top half of the field, and the offset
+                * The total allocated length of the dynamic array is
+                * stored in the top half of the field, and the offset
                 * is in the bottom half of the 32 bit field.
                 */
                offset &= 0xffff;

diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 204befb..6fc83c7 100644 (file)
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -294,6 +294,7 @@ enum print_arg_type {
        PRINT_OP,
        PRINT_FUNC,
        PRINT_BITMASK,
+       PRINT_DYNAMIC_ARRAY_LEN,
 };
 
 struct print_arg {

diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 1bd593b..544509c 100644 (file)
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -221,6 +221,7 @@ static void define_event_symbols(struct event_format *event,
                break;
        case PRINT_BSTRING:
        case PRINT_DYNAMIC_ARRAY:
+       case PRINT_DYNAMIC_ARRAY_LEN:
        case PRINT_STRING:
        case PRINT_BITMASK:
                break;

diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index ace2484..aa9e125 100644 (file)
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -251,6 +251,7 @@ static void define_event_symbols(struct event_format *event,
                /* gcc warns for these? */
        case PRINT_BSTRING:
        case PRINT_DYNAMIC_ARRAY:
+       case PRINT_DYNAMIC_ARRAY_LEN:
        case PRINT_FUNC:
        case PRINT_BITMASK:
                /* we should warn... */