I believe the missing action here is a bug. For rules with no explicit action, the following default is used: { $$ = $1; } However, in this case, $1 is the value of attribute_opt itself. As a result, the value of attribute_opt is always NULL. The following test code demonstrates inconsistent behavior. int x __attribute__((__aligned__(4))); int y __attribute__((__aligned__(4))) = 0; The attribute is recorded only when followed by an initializer. This commit adds the correct action to propagate the value of the ATTRIBUTE_PHRASE token. With this change, the attribute in the example above is consistently recorded for both 'x' and 'y'. [Before] $ cat <<EOF | scripts/genksyms/genksyms -d int x __attribute__((__aligned__(4))); int y __attribute__((__aligned__(4))) = 0; EOF Defn for type0 x == <int x > Defn for type0 y == <int y __attribute__ ( ( __aligned__ ( 4 ) ) ) > Hash table occupancy 2/4096 = 0.000488281 [After] $ cat <<EOF | scripts/genksyms/genksyms -d int x __attribute__((__aligned__(4))); int y __attribute__((__aligned__(4))) = 0; EOF Defn for type0 x == <int x __attribute__ ( ( __aligned__ ( 4 ) ) ) > Defn for type0 y == <int y __attribute__ ( ( __aligned__ ( 4 ) ) ) > Hash table occupancy 2/4096 = 0.000488281 Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- scripts/genksyms/parse.y | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y index 33a6aab53b69..e3c160046143 100644 --- a/scripts/genksyms/parse.y +++ b/scripts/genksyms/parse.y @@ -480,7 +480,7 @@ member_bitfield_declarator: attribute_opt: /* empty */ { $$ = NULL; } - | attribute_opt ATTRIBUTE_PHRASE + | attribute_opt ATTRIBUTE_PHRASE { $$ = $2; } ; enum_body: -- 2.43.0