genksyms: fix syntax error for attribute after 'union'

A longstanding issue with genksyms is that it has hidden syntax errors.

When a syntax error occurs, yyerror() is called. However,
error_with_pos() is a no-op unless the -w option is provided.

You can observe syntax errors by manually passing the -w option.

For example, with CONFIG_MODVERSIONS=y on v6.13-rc1:

    $ make -s KCFLAGS=-D__GENKSYMS__ fs/lockd/svc.i
    $ cat fs/lockd/svc.i | scripts/genksyms/genksyms -w
        [ snip ]
    ./include/net/addrconf.h:35: syntax error

The syntax error occurs in the following code in include/net/addrconf.h:

    union __packed {
            [ snip ]
    };

The issue arises from __packed, which is defined as
__attribute__((__packed__)), immediately after the 'union' keyword.

This commit allows the 'union' keyword to be followed by attributes.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>

diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y
index 33639232a709ed2e4634a089e4685ab2c34e263b..a2cd035a78c95542b7d6b4825b2e90b4d1bc97a4 100644 (file)
--- a/scripts/genksyms/parse.y
+++ b/scripts/genksyms/parse.y
@@ -236,16 +236,16 @@ type_specifier:
           so that it is easier to expand the definition fully later.  */
        | STRUCT_KEYW attribute_opt IDENT
                { remove_node($1); (*$3)->tag = SYM_STRUCT; $$ = $3; }
-       | UNION_KEYW IDENT
-               { remove_node($1); (*$2)->tag = SYM_UNION; $$ = $2; }
+       | UNION_KEYW attribute_opt IDENT
+               { remove_node($1); (*$3)->tag = SYM_UNION; $$ = $3; }
        | ENUM_KEYW IDENT
                { remove_node($1); (*$2)->tag = SYM_ENUM; $$ = $2; }
 
        /* Full definitions of an s/u/e.  Record it.  */
        | STRUCT_KEYW attribute_opt IDENT class_body
                { record_compound($1, $3, $4, SYM_STRUCT); $$ = $4; }
-       | UNION_KEYW IDENT class_body
-               { record_compound($1, $2, $3, SYM_UNION); $$ = $3; }
+       | UNION_KEYW attribute_opt IDENT class_body
+               { record_compound($1, $3, $4, SYM_UNION); $$ = $4; }
        | ENUM_KEYW IDENT enum_body
                { record_compound($1, $2, $3, SYM_ENUM); $$ = $3; }
        /*
@@ -255,7 +255,7 @@ type_specifier:
                { add_symbol(NULL, SYM_ENUM, NULL, 0); $$ = $2; }
        /* Anonymous s/u definitions.  Nothing needs doing.  */
        | STRUCT_KEYW attribute_opt class_body          { $$ = $3; }
-       | UNION_KEYW class_body                         { $$ = $2; }
+       | UNION_KEYW attribute_opt class_body           { $$ = $3; }
        ;
 
 simple_type_specifier: