[PATCH bpf-next v2] tools: bpftool: fix variable shadowing in emit_obj_refs_json()

[PATCH bpf-next v2] tools: bpftool: fix variable shadowing in emit_obj_refs_json()

[Quentin Monnet]

Building bpftool yields the following complaint:

    pids.c: In function 'emit_obj_refs_json':
    pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow]
      175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
          |                                                                 ~~~~~~~~~~~~~~~^~~~~~~~
    In file included from pids.c:11:
    main.h:141:23: note: shadowed declaration is here
      141 | extern json_writer_t *json_wtr;
          |                       ^~~~~~~~

Let's rename the variable.

v2:
- Rename the variable instead of calling the global json_wtr directly.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
---
v1 was "tools: bpftool: do not pass json_wtr to emit_obj_refs_json()"
---
 tools/bpf/bpftool/pids.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c
index 3474a91743ff..2709be4de2b1 100644
--- a/tools/bpf/bpftool/pids.c
+++ b/tools/bpf/bpftool/pids.c
@@ -172,7 +172,8 @@ void delete_obj_refs_table(struct obj_refs_table *table)
 	}
 }
 
-void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
+void emit_obj_refs_json(struct obj_refs_table *table, __u32 id,
+			json_writer_t *json_writer)
 {
 	struct obj_refs *refs;
 	struct obj_ref *ref;
@@ -187,16 +188,16 @@ void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *j
 		if (refs->ref_cnt == 0)
 			break;
 
-		jsonw_name(json_wtr, "pids");
-		jsonw_start_array(json_wtr);
+		jsonw_name(json_writer, "pids");
+		jsonw_start_array(json_writer);
 		for (i = 0; i < refs->ref_cnt; i++) {
 			ref = &refs->refs[i];
-			jsonw_start_object(json_wtr);
-			jsonw_int_field(json_wtr, "pid", ref->pid);
-			jsonw_string_field(json_wtr, "comm", ref->comm);
-			jsonw_end_object(json_wtr);
+			jsonw_start_object(json_writer);
+			jsonw_int_field(json_writer, "pid", ref->pid);
+			jsonw_string_field(json_writer, "comm", ref->comm);
+			jsonw_end_object(json_writer);
 		}
-		jsonw_end_array(json_wtr);
+		jsonw_end_array(json_writer);
 		break;
 	}
 }
-- 
2.20.1

Re: [PATCH bpf-next v2] tools: bpftool: fix variable shadowing in emit_obj_refs_json()

[Andrii Nakryiko]

On Tue, Jun 23, 2020 at 2:39 PM Quentin Monnet <quentin@isovalent.com> wrote:
>
> Building bpftool yields the following complaint:
>
>     pids.c: In function 'emit_obj_refs_json':
>     pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow]
>       175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
>           |                                                                 ~~~~~~~~~~~~~~~^~~~~~~~
>     In file included from pids.c:11:
>     main.h:141:23: note: shadowed declaration is here
>       141 | extern json_writer_t *json_wtr;
>           |                       ^~~~~~~~
>
> Let's rename the variable.
>
> v2:
> - Rename the variable instead of calling the global json_wtr directly.
>
> Signed-off-by: Quentin Monnet <quentin@isovalent.com>
> ---

Thanks.

Acked-by: Andrii Nakryiko <andriin@fb.com>

[...]

Re: [PATCH bpf-next v2] tools: bpftool: fix variable shadowing in emit_obj_refs_json()

[Daniel Borkmann]

On 6/23/20 11:36 PM, Quentin Monnet wrote:
> Building bpftool yields the following complaint:
> 
>      pids.c: In function 'emit_obj_refs_json':
>      pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow]
>        175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
>            |                                                                 ~~~~~~~~~~~~~~~^~~~~~~~
>      In file included from pids.c:11:
>      main.h:141:23: note: shadowed declaration is here
>        141 | extern json_writer_t *json_wtr;
>            |                       ^~~~~~~~
> 
> Let's rename the variable.
> 
> v2:
> - Rename the variable instead of calling the global json_wtr directly.
> 
> Signed-off-by: Quentin Monnet <quentin@isovalent.com>

Applied, thanks!