[cocci] Converting compound statement after if to single statement with SmPL?

[cocci] Converting compound statement after if to single statement with SmPL?

[Markus Elfring]

Hello,

I would like to share further test results for two simple source code transformations
which could be expressed by the means of the semantic patch language
also together with the software combination “Coccinelle 1.1.1-00739-g68c580f1”.

Source file example:
int my_test(void)
{
 int rc;
// placeholder 1
 rc = my_work(my_input);
 if (rc) {
    last_action(my_data);
    return rc;
 }
// placeholder 2
 return 0;
}


SmPL script variant 1:
@adjustment1@
@@
 if (...)
-{
-   last_action(my_data);
-   return rc;
-}
+   goto do_last_action;


Markus_Elfring@Sonne:…/Projekte/Coccinelle/Probe> spatch test_last_action_with_return_in_compound_statement.c convert_compound_statement_after_if_to_single_statement1.cocci
…
@@ -3,10 +3,7 @@ int my_test(void)
  int rc;
 // placeholder 1
  rc = my_work(my_input);
- if (rc) {
-    last_action(my_data);
-    return rc;
- }
+ if (rc) goto do_last_action;
 // placeholder 2
  return 0;
 }



SmPL script variant 2:
@adjustment2@
@@
 if (...)
-{
-   last_action(my_data);
-   return rc;
-}
+
+   goto do_last_action;


Markus_Elfring@Sonne:…/Projekte/Coccinelle/Probe> spatch test_last_action_with_return_in_compound_statement.c convert_compound_statement_after_if_to_single_statement2.cocci
…
@@ -3,10 +3,9 @@ int my_test(void)
  int rc;
 // placeholder 1
  rc = my_work(my_input);
- if (rc) {
-    last_action(my_data);
-    return rc;
- }
+ if (rc)
+
+    goto do_last_action;
 // placeholder 2
  return 0;
 }



Will such diff outputs support any development considerations for tweaks
of code pretty-printing?

Regards,
Markus