Revert "[frontend][clang][RFC] fix translation of enum constant"

Reviewed By: ezgicicek

Differential Revision: D21662044

fbshipit-source-id: ecaf0c36a

infer/src/clang/cTrans.ml

@@ -867,47 +867,47 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
     decl_ref_trans ~context:DeclRefExpr trans_state stmt_info decl_ref
 
 
-  and enum_constant_trans trans_state decl_ref =
+  (** evaluates an enum constant *)
-    let typ =
+  and enum_const_eval context enum_constant_pointer prev_enum_constant_opt zero =
-      let {CContext.tenv} = trans_state.context in
+    match CAst_utils.get_decl enum_constant_pointer with
-      let _, _, qual_type = CAst_utils.get_info_from_decl_ref decl_ref in
-      CType_decl.qual_type_to_sil_type tenv qual_type
-    in
-    let zero () = mk_trans_result (Exp.Const (Const.Cint IntLit.zero), typ) empty_control in
-    (* translate enum declaration statements *)
-    let rec trans_enum_decl ~prev_decl_pointer_opt decl_pointer =
-      match CAst_utils.get_decl decl_pointer with
     | Some (Clang_ast_t.EnumConstantDecl (_, _, _, enum_constant_decl_info)) -> (
       match enum_constant_decl_info.Clang_ast_t.ecdi_init_expr with
       | Some stmt ->
-            instruction trans_state stmt
+          expression_trans context stmt
       | None -> (
-          match prev_decl_pointer_opt with
+        match prev_enum_constant_opt with
-          | Some prev_decl_pointer ->
+        | Some prev_constant_pointer ->
-              let ({return= exp, typ} as trans_result) = trans_with_cache prev_decl_pointer in
+            let previous_exp = get_enum_constant_expr context prev_constant_pointer in
-              {trans_result with return= (CArithmetic_trans.sil_const_plus_one exp, typ)}
+            CArithmetic_trans.sil_const_plus_one previous_exp
         | None ->
-              zero () ) )
+            zero ) )
     | _ ->
-          zero ()
+        zero
-    (* try looking up from cache before calling [trans_enum_decl] *)
+
-    and trans_with_cache decl_pointer =
+
+  (** get the sil value of the enum constant from the map or by evaluating it *)
+  and get_enum_constant_expr context enum_constant_pointer =
+    let zero = Exp.Const (Const.Cint IntLit.zero) in
     try
-        let prev_decl_pointer_opt, cached_exp = CAst_utils.get_enum_constant_exp_exn decl_pointer in
+      let prev_enum_constant_opt, sil_exp_opt =
-        match cached_exp with
+        CAst_utils.get_enum_constant_exp_exn enum_constant_pointer
+      in
+      match sil_exp_opt with
       | Some exp ->
-            mk_trans_result (exp, typ) empty_control
+          exp
       | None ->
-            let trans_result = trans_enum_decl ~prev_decl_pointer_opt decl_pointer in
+          let exp = enum_const_eval context enum_constant_pointer prev_enum_constant_opt zero in
-            ( match fst trans_result.return with
+          CAst_utils.update_enum_map_exn enum_constant_pointer exp ;
-            | Exp.Const _ as exp ->
+          exp
-                CAst_utils.update_enum_map_exn decl_pointer exp
+    with Not_found_s _ | Caml.Not_found -> zero
-            | _ ->
+
-                () ) ;
+
-            trans_result
+  and enum_constant_trans trans_state decl_ref =
-      with Not_found_s _ | Caml.Not_found -> zero ()
+    let context = trans_state.context in
-    in
+    let _, _, qual_type = CAst_utils.get_info_from_decl_ref decl_ref in
-    trans_with_cache decl_ref.Clang_ast_t.dr_decl_pointer
+    let typ = CType_decl.qual_type_to_sil_type context.CContext.tenv qual_type in
+    let const_exp = get_enum_constant_expr context decl_ref.Clang_ast_t.dr_decl_pointer in
+    mk_trans_result (const_exp, typ) empty_control
 
 
   and arraySubscriptExpr_trans trans_state expr_info stmt_list =
@@ -3898,6 +3898,12 @@ module CTrans_funct (F : CModule_type.CFrontend) : CModule_type.CTranslation = s
     exec_trans_instrs trans_state stmt_trans_fun
 
 
+  and expression_trans context stmt =
+    let trans_state = CTrans_utils.default_trans_state context in
+    let res_trans_stmt = instruction trans_state stmt in
+    fst res_trans_stmt.return
+
+
   let instructions_trans context body extra_instrs exit_node ~is_destructor_wrapper =
     let default_trans_state = CTrans_utils.default_trans_state context in
     let trans_state = {default_trans_state with succ_nodes= [exit_node]} in

infer/tests/codetoanalyze/c/bufferoverrun/global.c

@@ -22,7 +22,7 @@ void compare_global_const_enum_Bad() {
     arr[10] = 1;
 }
 
-void compare_global_const_enum_Good() {
+void compare_global_const_enum_Good_FP() {
   char arr[10];
   if (global_const > 10)
     arr[10] = 1;

infer/tests/codetoanalyze/c/bufferoverrun/issues.exp

@@ -127,9 +127,8 @@ codetoanalyze/c/bufferoverrun/get_field.c, call_get_v2_Bad, 8, BUFFER_OVERRUN_L5
 codetoanalyze/c/bufferoverrun/get_field.c, call_get_v2_Good_FP, 8, BUFFER_OVERRUN_L5, no_bucket, ERROR, [<Offset trace>,Call,Assignment,<Length trace>,Array declaration,Array access: Offset: [-oo, +oo] Size: 10]
 codetoanalyze/c/bufferoverrun/get_field.c, call_get_v_Bad, 8, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Offset trace>,Assignment,Call,Parameter `l->next->prev->v`,Assignment,<Length trace>,Array declaration,Array access: Offset: 10 Size: 10]
 codetoanalyze/c/bufferoverrun/get_field.c, make_many_locations, 1, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, [Here]
-codetoanalyze/c/bufferoverrun/global.c, compare_global_const_enum_Bad, 2, CONDITION_ALWAYS_TRUE, no_bucket, WARNING, [Here]
 codetoanalyze/c/bufferoverrun/global.c, compare_global_const_enum_Bad, 3, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 10 Size: 10]
-codetoanalyze/c/bufferoverrun/global.c, compare_global_const_enum_Good, 2, CONDITION_ALWAYS_FALSE, no_bucket, WARNING, [Here]
+codetoanalyze/c/bufferoverrun/global.c, compare_global_const_enum_Good_FP, 3, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 10 Size: 10]
 codetoanalyze/c/bufferoverrun/global.c, compare_global_variable_bad, 3, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Length trace>,Array declaration,Array access: Offset: 10 Size: 10]
 codetoanalyze/c/bufferoverrun/global.c, copyfilter_Good_FP, 3, INTEGER_OVERFLOW_L5, no_bucket, ERROR, [<LHS trace>,Assignment,Binary operation: ([0, +oo] + 1):signed32]
 codetoanalyze/c/bufferoverrun/global.c, use_global_const_ten_Bad, 2, BUFFER_OVERRUN_L1, no_bucket, ERROR, [<Offset trace>,Assignment,<Length trace>,Array declaration,Array access: Offset: 10 Size: 5]