[Linux-kernel-mentees] [PATCH v5 1/3] parsing_c: Align C AST and Cocci AST for pointer
Jaskaran Singh
jaskaransingh7654321 at gmail.com
Tue Feb 11 14:01:35 UTC 2020
For a pointer, the C parser constructed an AST dissimilar from that
of the Cocci AST. This caused failures in matching with certain
pointer types. For example, for the following case:
char *1 const *2 id;
The C AST constructed would be:
const Pointer1 -> Pointer2 -> char
The Cocci AST constructed would be:
Pointer2 -> const Pointer1 -> char
Change the pointer rule in the C parser so that an AST similar to the
Cocci AST is constructed.
Make necessary changes in the C pretty printer so that the pointer type
is printed correctly.
Signed-off-by: Jaskaran Singh <jaskaransingh7654321 at gmail.com>
---
parsing_c/parser_c.mly | 4 ++--
parsing_c/pretty_print_c.ml | 15 ++++++++++-----
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/parsing_c/parser_c.mly b/parsing_c/parser_c.mly
index 8d7b761e..4c74f15a 100644
--- a/parsing_c/parser_c.mly
+++ b/parsing_c/parser_c.mly
@@ -1333,14 +1333,14 @@ pointer:
| tmul { (Ast_c.noattr,fun x -> mk_ty (Pointer x) [$1]) }
| tmul pointer
{ let (attr,ptr) = $2 in
- (attr,fun x -> mk_ty (Pointer (ptr x)) [$1]) }
+ (attr,fun x -> ptr (mk_ty (Pointer x) [$1])) }
| tmul type_qualif_list
{ let (attr,tq) = $2 in
(attr,fun x -> (tq.qualifD, mk_tybis (Pointer x) [$1]))}
| tmul type_qualif_list pointer
{ let (attr1,tq) = $2 in
let (attr2,ptr) = $3 in
- (attr1 at attr2,fun x -> (tq.qualifD, mk_tybis (Pointer (ptr x)) [$1])) }
+ (attr1 at attr2,fun x -> ptr (tq.qualifD, mk_tybis (Pointer x) [$1])) }
tmul:
TMul { $1 }
diff --git a/parsing_c/pretty_print_c.ml b/parsing_c/pretty_print_c.ml
index a2e35588..f4821d5c 100644
--- a/parsing_c/pretty_print_c.ml
+++ b/parsing_c/pretty_print_c.ml
@@ -804,11 +804,14 @@ and pp_string_format (e,ii) =
(FunctionType (return=void, params=int i) *)
(*WRONG I THINK, use left & right function *)
(* bug: pp_type_with_ident_rest None t; print_ident ident *)
+ pp_type_left t;
pr_elem i;
- iiqu +> List.iter pr_elem; (* le const est forcement apres le '*' *)
+ iiqu +>
+ List.iter (* le const est forcement apres le '*' *)
+ (function x -> pr_space(); pr_elem x);
if iiqu <> [] || get_comments_after i <> []
then pr_space();
- pp_type_with_ident_rest ident t attrs Ast_c.noattr;
+ print_ident ident
(* ugly special case ... todo? maybe sufficient in practice *)
| (ParenType ttop, [i1;i2]) ->
@@ -885,11 +888,13 @@ and pp_string_format (e,ii) =
match ty, iity with
(NoType,_) -> failwith "pp_type_left: unexpected NoType"
| (Pointer t, [i]) ->
+ pp_type_left t;
pr_elem i;
- iiqu +> List.iter pr_elem; (* le const est forcement apres le '*' *)
+ iiqu +>
+ List.iter (* le const est forcement apres le '*' *)
+ (function x -> pr_space(); pr_elem x);
if iiqu <> [] || get_comments_after i <> []
- then pr_space();
- pp_type_left t
+ then pr_space()
| (Array (eopt, t), [i1;i2]) -> pp_type_left t
| (FunctionType (returnt, paramst), [i1;i2]) -> pp_type_left returnt
--
2.21.1
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