src/gen_cxx.ml

   1 (* C++ code generation *)
   2
   3 open ExtLib
   4 open Prelude
   5 open Printf
   6
   7 open Stmt
   8 open Gen
   9 open Sql
  10
  11 module Values = struct
  12
  13 let names = List.map fst
  14 let join = String.concat ", "
  15 let inline = join $ names
  16 let to_string = join $ (List.map (fun (n,t) -> t ^ " " ^ n))
  17
  18 end
  19
  20 let rec freshname name scope =
  21   match List.find_all ((=) name) scope with
  22   | [] -> name
  23   | _ -> freshname (name ^ "_") scope
  24
  25 let quote = String.replace_chars (function '\n' -> "\\n\\\n" | '\r' -> "" | '"' -> "\\\"" | c -> String.make 1 c)
  26 let quote s = "\"" ^ quote s ^ "\""
  27
  28 let quote_comment_inline = String.replace_chars (function '\n' -> "\n// " | c -> String.make 1 c)
  29 let comment () fmt = Printf.kprintf (indent_endline $ quote_comment_inline $ (^) "// ") fmt
  30 let empty_line () = print_newline ()
  31 let open_curly () = output "{"; inc_indent ()
  32 let close_curly fmt = dec_indent (); indent "}"; print fmt
  33 let start_struct name =
  34    output "struct %s" name;
  35    open_curly ()
  36 let end_struct name =
  37    close_curly "; // struct %s" name;
  38    empty_line ()
  39 let out_public () = dec_indent(); output "public:"; inc_indent()
  40 let out_private () = dec_indent(); output "private:"; inc_indent()
  41
  42 module L = struct
  43   let as_api_type = Type.to_string
  44   let as_lang_type t = "typename Traits::" ^ (as_api_type t)
  45 end
  46
  47 module T = Translate(L)
  48
  49 open L
  50 open T
  51
  52 let column_action action attr index =
  53   let typ = as_api_type attr.RA.domain in
  54   let name = name_of attr index in
  55   output "Traits::%s_column_%s(row, %u, %s);" action typ index name
  56
  57 let func head name args ?tail k =
  58   let tail = match tail with
  59   | Some s -> " " ^ s
  60   | None -> ""
  61   in
  62   let head = match head with "" -> "" | s -> s ^ " " in
  63   output "%s%s(%s)%s" head name (Values.to_string args) tail;
  64   open_curly ();
  65   k ();
  66   close_curly ""
  67
  68 let set_param arg index param =
  69   let (id,_) = param in
  70   output "Traits::set_param(%s, %s, %u);"
  71 (*     (param_type_to_string t) *)
  72     arg
  73     (param_name_to_string id index)
  74     index
  75
  76 let output_value_defs vals =
  77   vals |> List.iter (fun (name,t) -> output "%s %s;" t name)
  78
  79 let output_schema_binder _ schema =
  80   out_private ();
  81   let name = "output" in
  82   output "template <class T>";
  83   start_struct name;
  84
  85   let vals = schema_to_values schema in
  86   output_value_defs vals;
  87   empty_line ();
  88
  89   output "enum { count = %u };" (List.length schema);
  90   empty_line ();
  91
  92   let mthd action active =
  93     func "void" action
  94       (["row","typename Traits::row"] @ (if active then ["result","T"] else []))
  95       (fun () ->
  96         List.iteri (fun index attr -> column_action action attr index) schema;
  97         if active then output "result(%s);" (Values.inline vals)
  98       )
  99   in
 100
 101   mthd "get" true;
 102   mthd "bind" false;
 103
 104   end_struct name;
 105   name
 106
 107 let output_schema_binder index schema =
 108   match schema with
 109   | [] -> None
 110   | _ -> Some (output_schema_binder index schema)
 111
 112 let make_const_values = List.map (fun (name,t) -> name, sprintf "%s const&" t)
 113
 114 (*
 115 let output_schema_data index schema =
 116   out_public ();
 117   let name = "data" in
 118   start_struct name;
 119   schema |> schema_to_values |> output_value_defs;
 120   end_struct name
 121 *)
 122
 123 let value_inits vals =
 124   match vals with
 125   | [] -> ""
 126   | _ -> sprintf ": %s" (String.concat "," (List.map (fun (name,_) -> sprintf "%s(%s)" name name) vals))
 127
 128 let struct_params name values k =
 129   start_struct name;
 130   output_value_defs values;
 131   empty_line ();
 132   k ();
 133   end_struct name
 134
 135 let struct_ctor name values k =
 136   struct_params name values (fun () ->
 137     func "" name values ~tail:(value_inits values) identity;
 138     empty_line ();
 139     k ())
 140
 141 let output_params_binder _ params =
 142   out_private ();
 143   let name = "params" in
 144   let values = params_to_values params in
 145   struct_ctor name (make_const_values values) (fun () ->
 146     comment () "binding slots in a query (one param may be bound several times)";
 147     output "enum { count = %u };" (List.length params);
 148     empty_line ();
 149     let arg = freshname "target" (name :: Values.names values) in
 150     output "template <class T>";
 151     func "void" "set_params" [arg,"T&"] (fun () -> List.iteri (set_param arg) params);
 152     empty_line ()
 153   );
 154   name
 155
 156 let output_params_binder index params =
 157   match params with
 158   | [] -> "typename Traits::no_params"
 159   | _ -> output_params_binder index params
 160
 161 type t = unit
 162
 163 let start () = ()
 164
 165 let make_stmt index stmt =
 166    let name = choose_name stmt.props stmt.kind index in
 167    let sql = quote (get_sql stmt) in
 168    struct_params name ["stmt","typename Traits::statement"] (fun () ->
 169     func "" name ["db","typename Traits::connection"] ~tail:(sprintf ": stmt(db,SQLGG_STR(%s))" sql) identity;
 170    let schema_binder_name = output_schema_binder index stmt.schema in
 171    let params_binder_name = output_params_binder index stmt.params in
 172 (*    if (Option.is_some schema_binder_name) then output_schema_data index stmt.schema; *)
 173    out_public ();
 174    if (Option.is_some schema_binder_name) then output "template<class T>";
 175    let values = params_to_values stmt.params in
 176    let result = match schema_binder_name with None -> [] | Some _ -> ["result","T"] in
 177    let all_params = (make_const_values values) @ result in
 178    let inline_params = Values.inline (make_const_values values) in
 179    func "bool" "operator()" all_params (fun () ->
 180     begin match schema_binder_name with
 181     | None -> output "return stmt.execute(%s(%s));" params_binder_name inline_params
 182     | Some schema_name -> output "return stmt.select(result,%s<T>(),%s(%s));"
 183           schema_name params_binder_name inline_params
 184     end);
 185    );
 186    name
 187
 188 let make_all name names =
 189   List.iter (fun name -> output "%s %s;" name name) names;
 190   empty_line ();
 191   let tail = match names with
 192   | [] -> ""
 193   | _ -> ": " ^ (String.concat ", " (List.map (fun name -> sprintf "%s(db)" name) names))
 194   in
 195   func "" name ["db","typename Traits::connection"] ~tail identity
 196
 197 let generate () name stmts =
 198   output "#pragma once";
 199   empty_line ();
 200   output "template <class Traits>";
 201   start_struct name;
 202   let stmts = List.of_enum stmts in
 203   let names = List.mapi make_stmt stmts in
 204   make_all name names;
 205   end_struct name
 206