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(*
* Copyright (c) 2015 - present Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*)
open! Utils
open LAst
exception ImproperTypeError of string
exception MalformedMetadata of string
exception Unimplemented of string
let source_only_location source_file : Location.t =
let open Location in { line = -1; col = -1; file = source_file; nLOC = !Config.nLOC }
let ident_of_variable (var : LAst.variable) : Ident.t = (* TODO: use unique stamps *)
Ident.create_normal (Ident.string_to_name (LAst.string_of_variable var)) 0
let trans_variable (var : LAst.variable) : Exp.t = Exp.Var (ident_of_variable var)
let trans_constant : LAst.constant -> Exp.t = function
| Cint i -> Exp.Const (Const.Cint (IntLit.of_int i))
| Cnull -> Exp.null
let trans_operand : LAst.operand -> Exp.t = function
| Var var -> trans_variable var
| Const const -> trans_constant const
let rec trans_typ : LAst.typ -> Typ.t = function
| Tint _i -> Typ.Tint Typ.IInt (* TODO: check what size int is needed here *)
| Tfloat -> Typ.Tfloat Typ.FFloat
| Tptr tp -> Typ.Tptr (trans_typ tp, Typ.Pk_pointer)
| Tvector (i, tp)
| Tarray (i, tp) -> Typ.Tarray (trans_typ tp, Some (IntLit.of_int i))
| Tfunc _ -> Typ.Tfun false
| Tlabel -> raise (ImproperTypeError "Tried to generate Sil type from LLVM label type.")
| Tmetadata -> raise (ImproperTypeError "Tried to generate Sil type from LLVM metadata type.")
let location_of_annotation_option source_file (metadata : LAst.metadata_map)
: LAst.annotation option -> Location.t = function
| None -> source_only_location source_file (* no source line/column numbers *)
| Some (Annotation i) ->
begin match MetadataMap.find i metadata with
| Components (TypOperand (_, Const (Cint line_num)) :: _) ->
let open Location in
{ line = line_num; col = -1; file = source_file; nLOC = !Config.nLOC }
| Location loc ->
let open Location in
{ line = loc.line; col = loc.col; file = source_file; nLOC = !Config.nLOC }
| _ -> raise (MalformedMetadata ("Instruction annotation refers to metadata node " ^
"without line number as first component."))
end
let procname_of_function_variable (func_var : LAst.variable) : Procname.t =
Procname.from_string_c_fun (LAst.string_of_variable func_var)
(* Generate list of SIL instructions and list of local variables *)
let rec trans_annotated_instructions
source_file
(cfg : Cfg.cfg) (procdesc : Cfg.Procdesc.t) (metadata : LAst.metadata_map)
: LAst.annotated_instruction list -> Sil.instr list * (Mangled.t * Typ.t) list = function
| [] -> ([], [])
| (instr, anno) :: t ->
let (sil_instrs, locals) = trans_annotated_instructions source_file cfg procdesc metadata t in
let location = location_of_annotation_option source_file metadata anno in
begin match instr with
| Ret None -> (sil_instrs, locals)
| Ret (Some (tp, exp)) ->
let procname = Cfg.Procdesc.get_proc_name procdesc in
let ret_var = Pvar.get_ret_pvar procname in
let new_sil_instr =
Sil.Store (Exp.Lvar ret_var, trans_typ tp, trans_operand exp, location) in
(new_sil_instr :: sil_instrs, locals)
| Load (var, tp, ptr) ->
let new_sil_instr =
Sil.Load (ident_of_variable var, trans_variable ptr, trans_typ tp, location) in
(new_sil_instr :: sil_instrs, locals)
| Store (op, tp, var) ->
let new_sil_instr =
Sil.Store (trans_variable var, trans_typ tp, trans_operand op, location) in
(new_sil_instr :: sil_instrs, locals)
| Alloc (var, tp, _num_elems) ->
(* num_elems currently ignored *)
begin match var with
| Global (Name var_name) | Local (Name var_name) ->
let new_local = (Mangled.from_string var_name, trans_typ (Tptr tp)) in
(sil_instrs, new_local :: locals)
| _ ->
raise
(ImproperTypeError
"Not expecting alloca instruction to a numbered variable.")
end
| Call (ret_var, func_var, typed_args) ->
let new_sil_instr = Sil.Call (
(* TODO: translate type of ret_var *)
Some (ident_of_variable ret_var, Tvoid),
Exp.Const (Const.Cfun (procname_of_function_variable func_var)),
IList.map (fun (tp, arg) -> (trans_operand arg, trans_typ tp)) typed_args,
location, CallFlags.default) in
(new_sil_instr :: sil_instrs, locals)
| _ -> raise (Unimplemented "Need to translate instruction to SIL.")
end
let callees_of_function_def : LAst.function_def -> Procname.t list = function
FunctionDef (_, _, _, annotated_instrs) ->
let callee_of_instruction : LAst.instruction -> Procname.t option = begin function
| Call (_, func_var, _) -> Some (procname_of_function_variable func_var)
| _ -> None
end in
IList.flatten_options (
IList.map
(fun annotated_instr -> callee_of_instruction (fst annotated_instr))
annotated_instrs)
(* Update CFG and call graph with new function definition *)
let trans_function_def source_file (cfg : Cfg.cfg) (cg: Cg.t) (metadata : LAst.metadata_map)
(func_def : LAst.function_def) : unit =
(* each procedure has different scope: start names from id 0 *)
Ident.NameGenerator.reset ();
match func_def with
FunctionDef (func_name, ret_tp_opt, params, annotated_instrs) ->
let proc_name = procname_of_function_variable func_name in
let ret_type =
match ret_tp_opt with
| None -> Typ.Tvoid
| Some ret_tp -> trans_typ ret_tp in
let (proc_attrs : ProcAttributes.t) =
{ (ProcAttributes.default proc_name Config.Clang) with
ProcAttributes.formals =
IList.map (fun (tp, name) -> (Mangled.from_string name, trans_typ tp)) params;
is_defined = true; (* is defined and not just declared *)
loc = source_only_location source_file;
locals = []; (* TODO *)
ret_type;
} in
let procdesc = Cfg.Procdesc.create cfg proc_attrs in
let start_kind = Cfg.Node.Start_node procdesc in
let start_node =
Cfg.Node.create cfg (source_only_location source_file) start_kind [] procdesc in
let exit_kind = Cfg.Node.Exit_node procdesc in
let exit_node =
Cfg.Node.create cfg (source_only_location source_file) exit_kind [] procdesc in
let node_of_sil_instr cfg procdesc sil_instr =
Cfg.Node.create cfg (Sil.instr_get_loc sil_instr) (Cfg.Node.Stmt_node "method_body")
[sil_instr] procdesc in
let rec link_nodes (start_node : Cfg.Node.t) : Cfg.Node.t list -> unit = function
(* link all nodes in a chain for now *)
| [] ->
Cfg.Node.set_succs_exn cfg start_node [exit_node] [exit_node]
| nd :: nds ->
Cfg.Node.set_succs_exn cfg start_node [nd] [exit_node]; link_nodes nd nds in
let (sil_instrs, locals) =
trans_annotated_instructions source_file cfg procdesc metadata annotated_instrs in
let nodes = IList.map (node_of_sil_instr cfg procdesc) sil_instrs in
Cfg.Procdesc.set_start_node procdesc start_node;
Cfg.Procdesc.set_exit_node procdesc exit_node;
link_nodes start_node nodes;
Cfg.Node.add_locals_ret_declaration start_node locals;
Cg.add_defined_node cg proc_name;
IList.iter (Cg.add_edge cg proc_name) (callees_of_function_def func_def)
let trans_program source_file : LAst.program -> Cfg.cfg * Cg.t * Tenv.t = function
Program (func_defs, metadata) ->
let cfg = Cfg.Node.create_cfg () in
let cg = Cg.create (Some source_file) in
let tenv = Tenv.create () in
IList.iter (trans_function_def source_file cfg cg metadata) func_defs;
(cfg, cg, tenv)