su4sml/src/codegen/gcg_core.sml

136 lines
5.4 KiB
Standard ML

(*****************************************************************************
* su4sml GCG - Generic Code Generator
*
* gcg_core.sml - implements functor GCG_Core
* transcribes a su4sml model according to a template tree
* into code specific to a target language cartridge C
* Copyright (C) 2005 Raphael Eidenbenz <eraphael@student.ethz.ch>
*
* This file is part of su4sml-gcg.
*
* su4sml is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* su4sml is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
******************************************************************************)
(** A Code generator *)
signature GCG =
sig
val writeLine : string -> unit
val generate : Rep.Model -> string -> unit
end
(** builds a code generator from a cartridge chain. *)
functor GCG_Core (C: CARTRIDGE): GCG =
struct
open library
val curFile = ref ""
val out = ref TextIO.stdOut
fun closeFile () = if (!curFile = "")
then ()
else (TextIO.closeOut (!out);
info ("closing "^(!curFile));
curFile := "")
fun openFile file = (closeFile ();
info ("opening "^file^"...");
Gcg_Helper.assureDir file;
out := (TextIO.openOut file);
curFile := file
)
fun openFileIfNotExists file = (closeFile ();
(if ((OS.FileSys.fileSize file) > 0)
then openFile "/dev/null"
else openFile file
) handle SysErr => ( openFile file ))
fun initOut () = (out := TextIO.stdOut;
curFile := "")
fun writeLine s = TextIO.output (!out,s)
fun eval s = (info "<eval>"; CompilerExt.eval true s)
(** applies f to every other element in l starting with the second
*)
fun map2EveryOther f [] = []
| map2EveryOther f [a] = [a]
| map2EveryOther f (a::b::z) = a::(f b)::(map2EveryOther f z)
fun substituteVars e s =
let val tkl = Gcg_Helper.joinEscapeSplitted "$" (Gcg_Helper.fieldSplit #"$" s)
in
String.concat (map2EveryOther (C.lookup e) tkl)
handle ex => (error_msg ("in GCG_Core.substituteVars: \
\variable lookup failure in string \""^s^"\".");
s)
end
(** traverses a templateParseTree and executes the given instructions *)
fun write env (Tpl_Parser.RootNode(l)) = List.app (write env) l
| write env (Tpl_Parser.OpenFileLeaf(file)) = openFile (substituteVars env file)
| write env (Tpl_Parser.OpenFileIfNotExistsLeaf(file)) =
openFileIfNotExists (substituteVars env file)
| write env (Tpl_Parser.EvalLeaf(l)) =
let fun collectEval [] = ""
| collectEval ((Tpl_Parser.TextLeaf(expr))::t) = expr^"\n"^(collectEval t)
| collectEval _ =
error "in GCG_Core.write: No TextLeaf in EvalLeaf"
in
eval (substituteVars env (collectEval l))
end
| write env (Tpl_Parser.TextLeaf(s)) = writeLine (substituteVars env s)
| write env (Tpl_Parser.IfNode(cond,l)) =
let fun writeThen _ [] = ()
| writeThen _ [Tpl_Parser.ElseNode(_)] = ()
| writeThen e (h::t) = (write e h ;writeThen e t)
in
(if (C.test env cond)
then writeThen env l
else case (List.last l) of nd as (Tpl_Parser.ElseNode(_)) => write env nd
| _ => ())
handle ex => () (* ignore failed/unknown predicates *)
end
| write env (Tpl_Parser.ElseNode(l)) = List.app (write env) l
| write env (Tpl_Parser.ForEachNode(listType,children))=
let val list_of_environments = C.foreach listType env
fun write_children e = List.app (fn tree => write e tree) children
in
List.app (fn e => write_children e) list_of_environments
handle ex => (error_msg ("in GCG_Core.write: error in foreach node "^listType^
": "^General.exnMessage ex);
())
end
(** generate code according to the given template file for the given model *)
fun generate model template
= let val env = C.initEnv model
val tree = Tpl_Parser.parse template
in
(initOut();
(*printTTree tree;*)
write env tree;
closeFile () )
handle ex => (closeFile(); raise ex)
end
end