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1 | (* |
2 | * Copyright 2005-2009, Ecole des Mines de Nantes, University of Copenhagen | |
3 | * Yoann Padioleau, Julia Lawall, Rene Rydhof Hansen, Henrik Stuart, Gilles Muller | |
4 | * This file is part of Coccinelle. | |
5 | * | |
6 | * Coccinelle is free software: you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation, according to version 2 of the License. | |
9 | * | |
10 | * Coccinelle is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with Coccinelle. If not, see <http://www.gnu.org/licenses/>. | |
17 | * | |
18 | * The authors reserve the right to distribute this or future versions of | |
19 | * Coccinelle under other licenses. | |
20 | *) | |
21 | ||
22 | ||
23 | module T = Type_cocci | |
24 | module Ast = Ast_cocci | |
25 | module Ast0 = Ast0_cocci | |
26 | module V0 = Visitor_ast0 | |
27 | ||
28 | (* Type inference: | |
29 | Just propagates information based on declarations. Could try to infer | |
30 | more precise information about expression metavariables, but not sure it is | |
31 | worth it. The most obvious goal is to distinguish between test expressions | |
32 | that have pointer, integer, and boolean type when matching isomorphisms, | |
33 | but perhaps other needs will become apparent. *) | |
34 | ||
35 | (* "functions" that return a boolean value *) | |
36 | let bool_functions = ["likely";"unlikely"] | |
37 | ||
38 | let err wrapped ty s = | |
39 | T.typeC ty; Format.print_newline(); | |
40 | failwith (Printf.sprintf "line %d: %s" (Ast0.get_line wrapped) s) | |
41 | ||
42 | type id = Id of string | Meta of (string * string) | |
43 | ||
44 | let int_type = T.BaseType(T.IntType) | |
45 | let bool_type = T.BaseType(T.BoolType) | |
46 | let char_type = T.BaseType(T.CharType) | |
47 | let float_type = T.BaseType(T.FloatType) | |
48 | ||
49 | let rec lub_type t1 t2 = | |
50 | match (t1,t2) with | |
51 | (None,None) -> None | |
52 | | (None,Some t) -> t2 | |
53 | | (Some t,None) -> t1 | |
54 | | (Some t1,Some t2) -> | |
55 | let rec loop = function | |
56 | (T.Unknown,t2) -> t2 | |
57 | | (t1,T.Unknown) -> t1 | |
58 | | (T.ConstVol(cv1,ty1),T.ConstVol(cv2,ty2)) when cv1 = cv2 -> | |
59 | T.ConstVol(cv1,loop(ty1,ty2)) | |
60 | ||
61 | (* pad: in pointer arithmetic, as in ptr+1, the lub must be ptr *) | |
62 | | (T.Pointer(ty1),T.Pointer(ty2)) -> | |
63 | T.Pointer(loop(ty1,ty2)) | |
64 | | (ty1,T.Pointer(ty2)) -> T.Pointer(ty2) | |
65 | | (T.Pointer(ty1),ty2) -> T.Pointer(ty1) | |
66 | ||
67 | | (T.Array(ty1),T.Array(ty2)) -> T.Array(loop(ty1,ty2)) | |
68 | | (T.TypeName(s1),t2) -> t2 | |
69 | | (t1,T.TypeName(s1)) -> t1 | |
70 | | (t1,_) -> t1 in (* arbitrarily pick the first, assume type correct *) | |
71 | Some (loop (t1,t2)) | |
72 | ||
73 | let lub_envs envs = | |
74 | List.fold_left | |
75 | (function acc -> | |
76 | function env -> | |
77 | List.fold_left | |
78 | (function acc -> | |
79 | function (var,ty) -> | |
80 | let (relevant,irrelevant) = | |
81 | List.partition (function (x,_) -> x = var) acc in | |
82 | match relevant with | |
83 | [] -> (var,ty)::acc | |
84 | | [(x,ty1)] -> | |
85 | (match lub_type (Some ty) (Some ty1) with | |
86 | Some new_ty -> (var,new_ty)::irrelevant | |
87 | | None -> irrelevant) | |
88 | | _ -> failwith "bad type environment") | |
89 | acc env) | |
90 | [] envs | |
91 | ||
92 | let rec propagate_types env = | |
93 | let option_default = None in | |
94 | let bind x y = option_default in (* no generic way of combining types *) | |
95 | ||
96 | let mcode x = option_default in | |
97 | ||
98 | let ident r k i = | |
99 | match Ast0.unwrap i with | |
100 | Ast0.Id(id) -> | |
101 | (try Some(List.assoc (Id(Ast0.unwrap_mcode id)) env) | |
102 | with Not_found -> None) | |
103 | | Ast0.MetaId(id,_,_) -> | |
104 | (try Some(List.assoc (Meta(Ast0.unwrap_mcode id)) env) | |
105 | with Not_found -> None) | |
106 | | _ -> k i in | |
107 | ||
108 | let strip_cv = function | |
109 | Some (T.ConstVol(_,t)) -> Some t | |
110 | | t -> t in | |
111 | ||
112 | (* types that might be integer types. should char be allowed? *) | |
113 | let rec is_int_type = function | |
114 | T.BaseType(T.IntType) | |
115 | | T.BaseType(T.LongType) | |
116 | | T.BaseType(T.ShortType) | |
117 | | T.MetaType(_,_,_) | |
118 | | T.TypeName _ | |
119 | | T.SignedT(_,None) -> true | |
120 | | T.SignedT(_,Some ty) -> is_int_type ty | |
121 | | _ -> false in | |
122 | ||
123 | let expression r k e = | |
124 | let res = k e in | |
125 | let ty = | |
126 | match Ast0.unwrap e with | |
127 | (* pad: the type of id is set in the ident visitor *) | |
128 | Ast0.Ident(id) -> Ast0.set_type e res; res | |
129 | | Ast0.Constant(const) -> | |
130 | (match Ast0.unwrap_mcode const with | |
131 | Ast.String(_) -> Some (T.Pointer(char_type)) | |
132 | | Ast.Char(_) -> Some (char_type) | |
133 | | Ast.Int(_) -> Some (int_type) | |
134 | | Ast.Float(_) -> Some (float_type)) | |
135 | (* pad: note that in C can do either ptr(...) or ( *ptr)(...) | |
136 | * so I am not sure this code is enough. | |
137 | *) | |
138 | | Ast0.FunCall(fn,lp,args,rp) -> | |
139 | (match Ast0.get_type fn with | |
140 | Some (T.FunctionPointer(ty)) -> Some ty | |
141 | | _ -> | |
142 | (match Ast0.unwrap fn with | |
143 | Ast0.Ident(id) -> | |
144 | (match Ast0.unwrap id with | |
145 | Ast0.Id(id) -> | |
146 | if List.mem (Ast0.unwrap_mcode id) bool_functions | |
147 | then Some(bool_type) | |
148 | else None | |
149 | | _ -> None) | |
150 | | _ -> None)) | |
151 | | Ast0.Assignment(exp1,op,exp2,_) -> | |
152 | let ty = lub_type (Ast0.get_type exp1) (Ast0.get_type exp2) in | |
153 | Ast0.set_type exp1 ty; Ast0.set_type exp2 ty; ty | |
154 | | Ast0.CondExpr(exp1,why,Some exp2,colon,exp3) -> | |
155 | let ty = lub_type (Ast0.get_type exp2) (Ast0.get_type exp3) in | |
156 | Ast0.set_type exp2 ty; Ast0.set_type exp3 ty; ty | |
157 | | Ast0.CondExpr(exp1,why,None,colon,exp3) -> Ast0.get_type exp3 | |
158 | | Ast0.Postfix(exp,op) | Ast0.Infix(exp,op) -> (* op is dec or inc *) | |
159 | Ast0.get_type exp | |
160 | | Ast0.Unary(exp,op) -> | |
161 | (match Ast0.unwrap_mcode op with | |
162 | Ast.GetRef -> | |
163 | (match Ast0.get_type exp with | |
164 | None -> Some (T.Pointer(T.Unknown)) | |
165 | | Some t -> Some (T.Pointer(t))) | |
166 | | Ast.DeRef -> | |
167 | (match Ast0.get_type exp with | |
168 | Some (T.Pointer(t)) -> Some t | |
169 | | _ -> None) | |
170 | | Ast.UnPlus -> Ast0.get_type exp | |
171 | | Ast.UnMinus -> Ast0.get_type exp | |
172 | | Ast.Tilde -> Ast0.get_type exp | |
173 | | Ast.Not -> Some(bool_type)) | |
174 | | Ast0.Nested(exp1,op,exp2) -> failwith "nested in type inf not possible" | |
175 | | Ast0.Binary(exp1,op,exp2) -> | |
176 | let ty1 = Ast0.get_type exp1 in | |
177 | let ty2 = Ast0.get_type exp2 in | |
178 | let same_type = function | |
179 | (None,None) -> Some (int_type) | |
180 | ||
181 | (* pad: pointer arithmetic handling as in ptr+1 *) | |
182 | | (Some (T.Pointer ty1),Some ty2) when is_int_type ty2 -> | |
183 | Some (T.Pointer ty1) | |
184 | | (Some ty1,Some (T.Pointer ty2)) when is_int_type ty1 -> | |
185 | Some (T.Pointer ty2) | |
186 | ||
187 | | (t1,t2) -> | |
188 | let ty = lub_type t1 t2 in | |
189 | Ast0.set_type exp1 ty; Ast0.set_type exp2 ty; ty in | |
190 | (match Ast0.unwrap_mcode op with | |
191 | Ast.Arith(op) -> same_type (ty1, ty2) | |
192 | | Ast.Logical(op) -> | |
193 | let ty = lub_type ty1 ty2 in | |
194 | Ast0.set_type exp1 ty; Ast0.set_type exp2 ty; | |
195 | Some(bool_type)) | |
196 | | Ast0.Paren(lp,exp,rp) -> Ast0.get_type exp | |
197 | | Ast0.ArrayAccess(exp1,lb,exp2,rb) -> | |
198 | (match strip_cv (Ast0.get_type exp2) with | |
199 | None -> Ast0.set_type exp2 (Some(int_type)) | |
200 | | Some(ty) when is_int_type ty -> () | |
201 | | Some ty -> err exp2 ty "bad type for an array index"); | |
202 | (match strip_cv (Ast0.get_type exp1) with | |
203 | None -> None | |
204 | | Some (T.Array(ty)) -> Some ty | |
205 | | Some (T.Pointer(ty)) -> Some ty | |
206 | | Some (T.MetaType(_,_,_)) -> None | |
207 | | Some x -> err exp1 x "ill-typed array reference") | |
208 | (* pad: should handle structure one day and look 'field' in environment *) | |
209 | | Ast0.RecordAccess(exp,pt,field) -> | |
210 | (match strip_cv (Ast0.get_type exp) with | |
211 | None -> None | |
212 | | Some (T.StructUnionName(_,_,_)) -> None | |
213 | | Some (T.TypeName(_)) -> None | |
214 | | Some (T.MetaType(_,_,_)) -> None | |
215 | | Some x -> err exp x "non-structure type in field ref") | |
216 | | Ast0.RecordPtAccess(exp,ar,field) -> | |
217 | (match strip_cv (Ast0.get_type exp) with | |
218 | None -> None | |
219 | | Some (T.Pointer(t)) -> | |
220 | (match strip_cv (Some t) with | |
221 | | Some (T.Unknown) -> None | |
222 | | Some (T.MetaType(_,_,_)) -> None | |
223 | | Some (T.TypeName(_)) -> None | |
224 | | Some (T.StructUnionName(_,_,_)) -> None | |
225 | | Some x -> | |
226 | err exp (T.Pointer(t)) | |
227 | "non-structure pointer type in field ref" | |
228 | | _ -> failwith "not possible") | |
229 | | Some (T.MetaType(_,_,_)) -> None | |
230 | | Some (T.TypeName(_)) -> None | |
231 | | Some x -> err exp x "non-structure pointer type in field ref") | |
232 | | Ast0.Cast(lp,ty,rp,exp) -> Some(Ast0.ast0_type_to_type ty) | |
233 | | Ast0.SizeOfExpr(szf,exp) -> Some(int_type) | |
234 | | Ast0.SizeOfType(szf,lp,ty,rp) -> Some(int_type) | |
235 | | Ast0.TypeExp(ty) -> None | |
236 | | Ast0.MetaErr(name,_,_) -> None | |
237 | | Ast0.MetaExpr(name,_,Some [ty],_,_) -> Some ty | |
238 | | Ast0.MetaExpr(name,_,ty,_,_) -> None | |
239 | | Ast0.MetaExprList(name,_,_) -> None | |
240 | | Ast0.EComma(cm) -> None | |
241 | | Ast0.DisjExpr(_,exp_list,_,_) -> | |
242 | let types = List.map Ast0.get_type exp_list in | |
243 | let combined = List.fold_left lub_type None types in | |
244 | (match combined with | |
245 | None -> None | |
246 | | Some t -> | |
247 | List.iter (function e -> Ast0.set_type e (Some t)) exp_list; | |
248 | Some t) | |
249 | | Ast0.NestExpr(starter,expr_dots,ender,None,multi) -> | |
250 | let _ = r.V0.combiner_expression_dots expr_dots in None | |
251 | | Ast0.NestExpr(starter,expr_dots,ender,Some e,multi) -> | |
252 | let _ = r.V0.combiner_expression_dots expr_dots in | |
253 | let _ = r.V0.combiner_expression e in None | |
254 | | Ast0.Edots(_,None) | Ast0.Ecircles(_,None) | Ast0.Estars(_,None) -> | |
255 | None | |
256 | | Ast0.Edots(_,Some e) | Ast0.Ecircles(_,Some e) | |
257 | | Ast0.Estars(_,Some e) -> | |
258 | let _ = r.V0.combiner_expression e in None | |
259 | | Ast0.OptExp(exp) -> Ast0.get_type exp | |
260 | | Ast0.UniqueExp(exp) -> Ast0.get_type exp in | |
261 | Ast0.set_type e ty; | |
262 | ty in | |
263 | ||
264 | let donothing r k e = k e in | |
265 | ||
266 | let rec strip id = | |
267 | match Ast0.unwrap id with | |
268 | Ast0.Id(name) -> Id(Ast0.unwrap_mcode name) | |
269 | | Ast0.MetaId(name,_,_) -> Meta(Ast0.unwrap_mcode name) | |
270 | | Ast0.MetaFunc(name,_,_) -> Meta(Ast0.unwrap_mcode name) | |
271 | | Ast0.MetaLocalFunc(name,_,_) -> Meta(Ast0.unwrap_mcode name) | |
272 | | Ast0.OptIdent(id) -> strip id | |
273 | | Ast0.UniqueIdent(id) -> strip id in | |
274 | ||
275 | let process_whencode notfn allfn exp = function | |
276 | Ast0.WhenNot(x) -> let _ = notfn x in () | |
277 | | Ast0.WhenAlways(x) -> let _ = allfn x in () | |
278 | | Ast0.WhenModifier(_) -> () | |
279 | | Ast0.WhenNotTrue(x) -> let _ = exp x in () | |
280 | | Ast0.WhenNotFalse(x) -> let _ = exp x in () in | |
281 | ||
282 | (* assume that all of the declarations are at the beginning of a statement | |
283 | list, which is required by C, but not actually required by the cocci | |
284 | parser *) | |
285 | let rec process_statement_list r acc = function | |
286 | [] -> acc | |
287 | | (s::ss) -> | |
288 | (match Ast0.unwrap s with | |
289 | Ast0.Decl(_,decl) -> | |
290 | let rec process_decl decl = | |
291 | match Ast0.unwrap decl with | |
292 | Ast0.Init(_,ty,id,_,exp,_) -> | |
293 | let _ = | |
294 | (propagate_types acc).V0.combiner_initialiser exp in | |
295 | [(strip id,Ast0.ast0_type_to_type ty)] | |
296 | | Ast0.UnInit(_,ty,id,_) -> | |
297 | [(strip id,Ast0.ast0_type_to_type ty)] | |
298 | | Ast0.MacroDecl(_,_,_,_,_) -> [] | |
299 | | Ast0.TyDecl(ty,_) -> [] | |
300 | (* pad: should handle typedef one day and add a binding *) | |
301 | | Ast0.Typedef(_,_,_,_) -> [] | |
302 | | Ast0.DisjDecl(_,disjs,_,_) -> | |
303 | List.concat(List.map process_decl disjs) | |
304 | | Ast0.Ddots(_,_) -> [] (* not in a statement list anyway *) | |
305 | | Ast0.OptDecl(decl) -> process_decl decl | |
306 | | Ast0.UniqueDecl(decl) -> process_decl decl in | |
307 | let new_acc = (process_decl decl)@acc in | |
308 | process_statement_list r new_acc ss | |
309 | | Ast0.Dots(_,wc) -> | |
310 | (* why is this case here? why is there none for nests? *) | |
311 | List.iter | |
312 | (process_whencode r.V0.combiner_statement_dots | |
313 | r.V0.combiner_statement r.V0.combiner_expression) | |
314 | wc; | |
315 | process_statement_list r acc ss | |
316 | | Ast0.Disj(_,statement_dots_list,_,_) -> | |
317 | let new_acc = | |
318 | lub_envs | |
319 | (List.map | |
320 | (function x -> process_statement_list r acc (Ast0.undots x)) | |
321 | statement_dots_list) in | |
322 | process_statement_list r new_acc ss | |
323 | | _ -> | |
324 | let _ = (propagate_types acc).V0.combiner_statement s in | |
325 | process_statement_list r acc ss) in | |
326 | ||
327 | let statement_dots r k d = | |
328 | match Ast0.unwrap d with | |
329 | Ast0.DOTS(l) | Ast0.CIRCLES(l) | Ast0.STARS(l) -> | |
330 | let _ = process_statement_list r env l in option_default in | |
331 | let statement r k s = | |
332 | match Ast0.unwrap s with | |
333 | Ast0.FunDecl(_,fninfo,name,lp,params,rp,lbrace,body,rbrace) -> | |
334 | let rec get_binding p = | |
335 | match Ast0.unwrap p with | |
336 | Ast0.Param(ty,Some id) -> | |
337 | [(strip id,Ast0.ast0_type_to_type ty)] | |
338 | | Ast0.OptParam(param) -> get_binding param | |
339 | | _ -> [] in | |
340 | let fenv = List.concat (List.map get_binding (Ast0.undots params)) in | |
341 | (propagate_types (fenv@env)).V0.combiner_statement_dots body | |
342 | | Ast0.IfThen(_,_,exp,_,_,_) | Ast0.IfThenElse(_,_,exp,_,_,_,_,_) | |
343 | | Ast0.While(_,_,exp,_,_,_) | Ast0.Do(_,_,_,_,exp,_,_) | |
344 | | Ast0.For(_,_,_,_,Some exp,_,_,_,_,_) | Ast0.Switch(_,_,exp,_,_,_,_) -> | |
345 | let _ = k s in | |
346 | let rec process_test exp = | |
347 | match (Ast0.unwrap exp,Ast0.get_type exp) with | |
348 | (Ast0.Edots(_,_),_) -> None | |
349 | | (Ast0.NestExpr(_,_,_,_,_),_) -> None | |
350 | | (Ast0.MetaExpr(_,_,_,_,_),_) -> | |
351 | (* if a type is known, it is specified in the decl *) | |
352 | None | |
353 | | (Ast0.Paren(lp,exp,rp),None) -> process_test exp | |
354 | | (_,None) -> Some (int_type) | |
355 | | _ -> None in | |
356 | let new_expty = process_test exp in | |
357 | (match new_expty with | |
358 | None -> () (* leave things as they are *) | |
359 | | Some ty -> Ast0.set_type exp new_expty); | |
360 | None | |
361 | | _ -> k s | |
362 | ||
363 | and case_line r k c = | |
364 | match Ast0.unwrap c with | |
365 | Ast0.Default(def,colon,code) -> let _ = k c in None | |
366 | | Ast0.Case(case,exp,colon,code) -> | |
367 | let _ = k c in | |
368 | (match Ast0.get_type exp with | |
369 | None -> Ast0.set_type exp (Some (int_type)) | |
370 | | _ -> ()); | |
371 | None | |
372 | | Ast0.OptCase(case) -> k c in | |
373 | ||
374 | V0.combiner bind option_default | |
375 | mcode mcode mcode mcode mcode mcode mcode mcode mcode mcode mcode mcode | |
376 | donothing donothing donothing statement_dots donothing donothing | |
377 | ident expression donothing donothing donothing donothing statement | |
378 | case_line donothing | |
379 | ||
380 | let type_infer code = | |
381 | let prop = propagate_types [(Id("NULL"),T.Pointer(T.Unknown))] in | |
382 | let fn = prop.V0.combiner_top_level in | |
383 | let _ = List.map fn code in | |
384 | () |