adamc@134: (* Copyright (c) 2008, Adam Chlipala
adamc@134:  * All rights reserved.
adamc@134:  *
adamc@134:  * Redistribution and use in source and binary forms, with or without
adamc@134:  * modification, are permitted provided that the following conditions are met:
adamc@134:  *
adamc@134:  * - Redistributions of source code must retain the above copyright notice,
adamc@134:  *   this list of conditions and the following disclaimer.
adamc@134:  * - Redistributions in binary form must reproduce the above copyright notice,
adamc@134:  *   this list of conditions and the following disclaimer in the documentation
adamc@134:  *   and/or other materials provided with the distribution.
adamc@134:  * - The names of contributors may not be used to endorse or promote products
adamc@134:  *   derived from this software without specific prior written permission.
adamc@134:  *
adamc@134:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
adamc@134:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
adamc@134:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
adamc@134:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
adamc@134:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
adamc@134:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
adamc@134:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
adamc@134:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
adamc@134:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
adamc@134:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
adamc@134:  * POSSIBILITY OF SUCH DAMAGE.
adamc@134:  *)
adamc@134: 
adamc@134: (* Remove unused definitions from a file *)
adamc@134: 
adamc@134: structure MonoShake :> MONO_SHAKE = struct
adamc@134: 
adamc@134: open Mono
adamc@134: 
adamc@134: structure U = MonoUtil
adamc@134: 
adamc@134: structure IS = IntBinarySet
adamc@134: structure IM = IntBinaryMap
adamc@134: 
adamc@134: type free = {
adamc@134:      con : IS.set,
adamc@134:      exp : IS.set
adamc@134: }
adamc@134: 
adamc@134: fun shake file =
adamc@134:     let
adamc@134:         val page_es = List.foldl
adamc@144:                           (fn ((DExport (_, _, n, _), _), page_es) => n :: page_es
adamc@134:                             | (_, page_es) => page_es) [] file
adamc@134: 
adamc@178:         val (cdef, edef) = foldl (fn ((DDatatype (_, n, xncs), _), (cdef, edef)) =>
adamc@178:                                      (IM.insert (cdef, n, xncs), edef)
adamc@178:                                    | ((DVal (_, n, t, e, _), _), (cdef, edef)) =>
adamc@178:                                      (cdef, IM.insert (edef, n, (t, e)))
adamc@134:                                    | ((DValRec vis, _), (cdef, edef)) =>
adamc@134:                                      (cdef, foldl (fn ((_, n, t, e, _), edef) => IM.insert (edef, n, (t, e))) edef vis)
adamc@271:                                    | ((DExport _, _), acc) => acc
adamc@273:                                    | ((DTable _, _), acc) => acc
adamc@338:                                    | ((DSequence _, _), acc) => acc
adamc@271:                                    | ((DDatabase _, _), acc) => acc)
adamc@134:                                  (IM.empty, IM.empty) file
adamc@134: 
adamc@164:         fun typ (c, s) =
adamc@164:             case c of
adamc@196:                 TDatatype (n, _) =>
adamc@164:                 if IS.member (#con s, n) then
adamc@164:                     s
adamc@164:                 else
adamc@178:                     let
adamc@178:                         val s' = {exp = #exp s,
adamc@178:                                   con = IS.add (#con s, n)}
adamc@178:                     in
adamc@178:                         case IM.find (cdef, n) of
adamc@178:                             NONE => s'
adamc@178:                           | SOME xncs => foldl (fn ((_, _, to), s) =>
adamc@178:                                                    case to of
adamc@178:                                                        NONE => s
adamc@178:                                                      | SOME t => shakeTyp s t)
adamc@178:                                          s' xncs
adamc@178:                     end
adamc@164:               | _ => s
adamc@134: 
adamc@178:         and shakeTyp s = U.Typ.fold typ s
adamc@178: 
adamc@134:         fun exp (e, s) =
adamc@134:             case e of
adamc@134:                 ENamed n =>
adamc@134:                 if IS.member (#exp s, n) then
adamc@134:                     s
adamc@134:                 else
adamc@134:                     let
adamc@134:                         val s' = {exp = IS.add (#exp s, n),
adamc@134:                                   con = #con s}
adamc@134:                     in
adamc@134:                         case IM.find (edef, n) of
adamc@134:                             NONE => s'
adamc@134:                           | SOME (t, e) => shakeExp s' e
adamc@134:                     end
adamc@134:               | _ => s
adamc@134: 
adamc@134:         and shakeExp s = U.Exp.fold {typ = typ, exp = exp} s
adamc@134: 
adamc@134:         val s = {con = IS.empty, exp = IS.addList (IS.empty, page_es)}
adamc@134: 
adamc@134:         val s = foldl (fn (n, s) =>
adamc@134:                           case IM.find (edef, n) of
adamc@134:                               NONE => raise Fail "Shake: Couldn't find 'val'"
adamc@134:                             | SOME (t, e) => shakeExp s e) s page_es
adamc@134:     in
adamc@164:         List.filter (fn (DDatatype (_, n, _), _) => IS.member (#con s, n)
adamc@164:                       | (DVal (_, n, _, _, _), _) => IS.member (#exp s, n)
adamc@134:                       | (DValRec vis, _) => List.exists (fn (_, n, _, _, _) => IS.member (#exp s, n)) vis
adamc@271:                       | (DExport _, _) => true
adamc@273:                       | (DTable _, _) => true
adamc@338:                       | (DSequence _, _) => true
adamc@271:                       | (DDatabase _, _) => true) file
adamc@134:     end
adamc@134: 
adamc@134: end