diff options
| author | Masahiro Yamada <masahiroy@kernel.org> | 2025-01-14 00:00:45 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2025-01-18 09:11:46 +0900 |
| commit | c2f1846ba87ead7ac544be624c13249d6b90eca0 (patch) | |
| tree | c36134b82b39c5312101a7cf665aaa4f6088e4e5 /scripts | |
| parent | a95298656c434357b38bec242412c65dcf6114d1 (diff) | |
genksyms: restrict direct-abstract-declarator to take one parameter-type-list
While there is no more grammatical ambiguity in genksyms, the parser
logic is still inaccurate.
For example, genksyms accepts the following invalid C code:
void my_func(int ()(int));
This should result in a syntax error because () cannot be reduced to
<direct-abstract-declarator>.
( <abstract-declarator> ) can be reduced, but <abstract-declarator>
must not be empty in the following grammar from K&R [1]:
<direct-abstract-declarator> ::= ( <abstract-declarator> )
| {<direct-abstract-declarator>}? [ {<constant-expression>}? ]
| {<direct-abstract-declarator>}? ( {<parameter-type-list>}? )
Furthermore, genksyms accepts the following weird code:
void my_func(int (*callback)(int)(int)(int));
The parser allows <direct-abstract-declarator> to recursively absorb
multiple ( {<parameter-type-list>}? ), but this behavior is incorrect.
In the example above, (*callback) should be followed by at most one
(int).
[1]: https://cs.wmich.edu/~gupta/teaching/cs4850/sumII06/The%20syntax%20of%20C%20in%20Backus-Naur%20form.htm
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nicolas Schier <n.schier@avm.de>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/genksyms/parse.y | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/scripts/genksyms/parse.y b/scripts/genksyms/parse.y index fafce939c32f..03cdd8d53c13 100644 --- a/scripts/genksyms/parse.y +++ b/scripts/genksyms/parse.y @@ -381,20 +381,24 @@ abstract_declarator: ; direct_abstract_declarator: + direct_abstract_declarator1 + | direct_abstract_declarator1 open_paren parameter_declaration_clause ')' + { $$ = $4; } + | open_paren parameter_declaration_clause ')' + { $$ = $3; } + ; + +direct_abstract_declarator1: IDENT { /* For version 2 checksums, we don't want to remember private parameter names. */ remove_node($1); $$ = $1; } - | direct_abstract_declarator open_paren parameter_declaration_clause ')' - { $$ = $4; } - | direct_abstract_declarator open_paren error ')' + | direct_abstract_declarator1 open_paren error ')' { $$ = $4; } - | direct_abstract_declarator BRACKET_PHRASE + | direct_abstract_declarator1 BRACKET_PHRASE { $$ = $2; } - | open_paren parameter_declaration_clause ')' - { $$ = $3; } | open_paren abstract_declarator ')' { $$ = $3; } | open_paren error ')' |