From: Steven Rostedt <rostedt@goodmis.org>

When printing a dynamic array in a trace event, the method is rather ugly.
It has the format of:

  __print_array(__get_dynamic_array(array),
            __get_dynmaic_array_len(array) / el_size, el_size)

Since dynamic arrays are known to the tracing infrastructure, create a
helper macro that does the above for you.

  __print_dynamic_array(array, el_size)

Which would expand to the same output.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
---
Changes in v5:
Patch introduced in the series.

Changes in v6:
No changes other than rebasing on top of tip/master.
---
 include/trace/stages/stage3_trace_output.h | 8 ++++++++
 include/trace/stages/stage7_class_define.h | 1 +
 samples/trace_events/trace-events-sample.h | 7 ++++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/trace/stages/stage3_trace_output.h b/include/trace/stages/stage3_trace_output.h
index c1fb1355d309..8e3215093e1f 100644
--- a/include/trace/stages/stage3_trace_output.h
+++ b/include/trace/stages/stage3_trace_output.h
@@ -119,6 +119,14 @@
 		trace_print_array_seq(p, array, count, el_size);	\
 	})
 
+#undef __print_dynamic_array
+#define __print_dynamic_array(array, el_size)				\
+	({								\
+		__print_array(__get_dynamic_array(array),		\
+			      __get_dynamic_array_len(array) / el_size,	\
+			      el_size);					\
+	})
+
 #undef __print_hex_dump
 #define __print_hex_dump(prefix_str, prefix_type,			\
 			 rowsize, groupsize, buf, len, ascii)		\
diff --git a/include/trace/stages/stage7_class_define.h b/include/trace/stages/stage7_class_define.h
index bcb960d16fc0..fcd564a590f4 100644
--- a/include/trace/stages/stage7_class_define.h
+++ b/include/trace/stages/stage7_class_define.h
@@ -22,6 +22,7 @@
 #undef __get_rel_cpumask
 #undef __get_rel_sockaddr
 #undef __print_array
+#undef __print_dynamic_array
 #undef __print_hex_dump
 #undef __get_buf
 
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 55f9a3da92d5..999f78d380ae 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -319,7 +319,7 @@ TRACE_EVENT(foo_bar,
 		__assign_cpumask(cpum, cpumask_bits(mask));
 	),
 
-	TP_printk("foo %s %d %s %s %s %s %s (%s) (%s) %s", __entry->foo, __entry->bar,
+	TP_printk("foo %s %d %s %s %s %s %s %s (%s) (%s) %s", __entry->foo, __entry->bar,
 
 /*
  * Notice here the use of some helper functions. This includes:
@@ -363,6 +363,11 @@ TRACE_EVENT(foo_bar,
 		  __print_array(__get_dynamic_array(list),
 				__get_dynamic_array_len(list) / sizeof(int),
 				sizeof(int)),
+
+/*     A shortcut is to use __print_dynamic_array for dynamic arrays */
+
+		  __print_dynamic_array(list, sizeof(int)),
+
 		  __get_str(str), __get_str(lstr),
 		  __get_bitmask(cpus), __get_cpumask(cpum),
 		  __get_str(vstr))
-- 
2.43.0

> From: Avadhut Naik <avadhut.naik@amd.com>
> [...]
> diff --git a/include/trace/stages/stage3_trace_output.h
> b/include/trace/stages/stage3_trace_output.h
> index c1fb1355d309..8e3215093e1f 100644
> --- a/include/trace/stages/stage3_trace_output.h
> +++ b/include/trace/stages/stage3_trace_output.h
> @@ -119,6 +119,14 @@
>  		trace_print_array_seq(p, array, count, el_size);	\
>  	})
> 
> +#undef __print_dynamic_array
> +#define __print_dynamic_array(array, el_size)				\
> +	({								\
> +		__print_array(__get_dynamic_array(array),		\
> +			      __get_dynamic_array_len(array) / el_size,	\
> +			      el_size);					\
> +	})
> +

When running the check below: 

    ${LINUX}/scripts/checkpatch.pl --strict  <this patch> 

it complains:

    CHECK: Macro argument 'el_size' may be better as '(el_size)' to avoid precedence issues
    #36: FILE: include/trace/stages/stage3_trace_output.h:123:
    +#define __print_dynamic_array(array, el_size)                          \
    +       ({                                                              \
    +               __print_array(__get_dynamic_array(array),               \
    +                             __get_dynamic_array_len(array) / el_size, \
    +                             el_size);                                 \
    +       })

-Qiuxu
> [...]

On Thu, 17 Oct 2024 06:58:30 +0000
"Zhuo, Qiuxu" <qiuxu.zhuo@intel.com> wrote:

> When running the check below: 
> 
>     ${LINUX}/scripts/checkpatch.pl --strict  <this patch> 
> 
> it complains:
> 
>     CHECK: Macro argument 'el_size' may be better as '(el_size)' to avoid precedence issues
>     #36: FILE: include/trace/stages/stage3_trace_output.h:123:
>     +#define __print_dynamic_array(array, el_size)                          \
>     +       ({                                                              \
>     +               __print_array(__get_dynamic_array(array),               \
>     +                             __get_dynamic_array_len(array) / el_size, \
>     +                             el_size);                                 \
>     +       })

For once I actually agree with checkpatch in an include/trace file.

I can send another version for you.

-- Steve

> From: Steven Rostedt <rostedt@goodmis.org>
> [...]
> For once I actually agree with checkpatch in an include/trace file.
> 
> I can send another version for you.
> 

Thanks, Steven. 
This way, Avadhut can include it in his next version.

-Qiuxu