X-Git-Url: https://git.hcoop.net/hcoop/domtool2.git/blobdiff_plain/1a4e5a6c9a8fbbdc980cf0661c444ddc2910544a..411a85f26421358c20b11839310cce6caff8cf77:/src/tycheck.sml diff --git a/src/tycheck.sml b/src/tycheck.sml index 5ce94c8..007a0fe 100644 --- a/src/tycheck.sml +++ b/src/tycheck.sml @@ -14,26 +14,19 @@ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. -*) + *) (* Domtool configuration language type checking *) structure Tycheck :> TYCHECK = struct -open Ast Print +open Ast Print Env -structure SS = StringSet structure SM = StringMap -type env = SS.set * typ SM.map -val empty : env = (SS.add (SS.singleton "int", "string"), - SM.empty) - -fun lookupType (ts, _) name = SS.member (ts, name) -fun lookupVal (_, vs) name = SM.find (vs, name) - -fun bindType (ts, vs) name = (SS.add (ts, name), vs) -fun bindVal (ts, vs) (name, t) = (ts, SM.insert (vs, name, t)) +val externFlag = ref false +fun allowExterns () = externFlag := true +fun disallowExterns () = externFlag := false local val unifCount = ref 0 @@ -123,9 +116,6 @@ datatype type_error = | UnboundVariable of string | WrongPred of string * pred * pred -fun preface (s, d) = printd (PD.hovBox (PD.PPS.Rel 0, - [PD.string s, PD.space 1, d])) - fun describe_unification_error t ue = case ue of UnifyPred (p1, p2) => @@ -184,6 +174,8 @@ fun predImplies (p1All as (p1, _), p2All as (p2, _)) = | (_, CPrefix p2) => predImplies (p1All, p2) | (CNot p1, CNot p2) => predImplies (p2, p1) + | (CRoot, CNot (CConst _, _)) => true + | (CConst s1, CNot (CConst s2, _)) => s1 <> s2 | _ => false @@ -292,6 +284,40 @@ fun whnorm (tAll as (t, loc)) = TUnif (_, ref (SOME tAll)) => whnorm tAll | _ => tAll +fun baseCondition t = + case whnorm t of + (TBase name, _) => typeRule name + | (TList t, _) => + (case baseCondition t of + NONE => NONE + | SOME f => SOME (fn (EList ls, _) => List.all f ls + | _ => false)) + | _ => NONE + +fun hasTyp (e, t1, t2) = + if (case baseCondition t2 of + NONE => false + | SOME rule => rule e) then + () + else + subTyp (t1, t2) + +fun checkPred G (p, loc) = + let + val err = ErrorMsg.error (SOME loc) + in + case p of + CRoot => () + | CConst s => + if lookupContext G s then + () + else + err ("Unbound context " ^ s) + | CPrefix p => checkPred G p + | CNot p => checkPred G p + | CAnd (p1, p2) => (checkPred G p1; checkPred G p2) + end + fun checkTyp G (tAll as (t, loc)) = let val err = ErrorMsg.error (SOME loc) @@ -305,13 +331,32 @@ fun checkTyp G (tAll as (t, loc)) = (TError, loc)) | TList t => (TList (checkTyp G t), loc) | TArrow (d, r) => (TArrow (checkTyp G d, checkTyp G r), loc) - | TAction (p, d, r) => (TAction (p, SM.map (checkTyp G) d, - SM.map (checkTyp G) r), loc) - | TNested (p, t) => (TNested (p, checkTyp G t), loc) + | TAction (p, d, r) => (checkPred G p; + (TAction (p, SM.map (checkTyp G) d, + SM.map (checkTyp G) r), loc)) + | TNested (p, t) => (checkPred G p; + (TNested (p, checkTyp G t), loc)) | TError => raise Fail "TError in parser-generated type" | TUnif _ => raise Fail "TUnif in parser-generated type" end +fun envVarSetFrom v (e, _) = + case e of + ESet (v', e) => + if v = v' then + SOME e + else + NONE + | EGet (_, _, e) => envVarSetFrom v e + | ESeq es => foldr (fn (e, found) => + case found of + SOME _ => found + | NONE => envVarSetFrom v e) + NONE es + | ELocal (_, e) => envVarSetFrom v e + + | _ => NONE + fun checkExp G (eAll as (e, loc)) = let val dte = describe_type_error loc @@ -327,7 +372,7 @@ fun checkExp G (eAll as (e, loc)) = let val t' = checkExp G e' in - (subTyp (t', t); + (hasTyp (eAll, t', t); if isError t' then (TList (TError, loc), loc) else @@ -349,7 +394,7 @@ fun checkExp G (eAll as (e, loc)) = NONE => (newUnif (), loc) | SOME t => checkTyp G t - val G' = bindVal G (x, t) + val G' = bindVal G (x, t, NONE) val t' = checkExp G' e in (TArrow (t, t'), loc) @@ -367,8 +412,8 @@ fun checkExp G (eAll as (e, loc)) = val tf = checkExp G func val ta = checkExp G arg in - (subTyp (tf, (TArrow (dom, ran), loc)); - subTyp (ta, dom) + (hasTyp (func, tf, (TArrow (dom, ran), loc)); + hasTyp (arg, ta, dom) handle Unify ue => dte (WrongType ("Function argument", arg, @@ -385,6 +430,23 @@ fun checkExp G (eAll as (e, loc)) = (TError, loc)) end + | EALam (x, p, e) => + let + val p' = checkPred G p + + val G' = bindVal G (x, (TAction (p, SM.empty, SM.empty), loc), NONE) + val t' = whnorm (checkExp G' e) + in + case t' of + (TAction _, _) => (TNested (p, t'), loc) + | _ => (dte (WrongForm ("Body of nested configuration 'fn'", + "action", + e, + t', + NONE)); + (TError, loc)) + end + | ESet (evar, e) => let val t = checkExp G e @@ -397,7 +459,7 @@ fun checkExp G (eAll as (e, loc)) = | EGet (x, evar, rest) => let val xt = (newUnif (), loc) - val G' = bindVal G (x, xt) + val G' = bindVal G (x, xt, NONE) val rt = whnorm (checkExp G' rest) in @@ -445,21 +507,25 @@ fun checkExp G (eAll as (e, loc)) = (case SM.find (d', name) of NONE => SM.insert (d', name, t) | SOME t' => - (subTyp (t, t') + ((case envVarSetFrom name e1 of + NONE => subTyp (t, t') + | SOME e => hasTyp (e, t, t')) handle Unify ue => dte (WrongType ("Shared environment variable", (EVar name, loc), - t, t', + t, SOME ue)); d')) | SOME t' => - (subTyp (t, t') + ((case envVarSetFrom name e1 of + NONE => subTyp (t, t') + | SOME e => hasTyp (e, t, t')) handle Unify ue => dte (WrongType ("Shared environment variable", (EVar name, loc), - t, t', + t, SOME ue)); d')) d1 d2 @@ -503,21 +569,25 @@ fun checkExp G (eAll as (e, loc)) = (case SM.find (d', name) of NONE => SM.insert (d', name, t) | SOME t' => - (subTyp (t, t') + ((case envVarSetFrom name e1 of + NONE => subTyp (t', t) + | SOME e => hasTyp (e, t', t)) handle Unify ue => dte (WrongType ("Shared environment variable", (EVar name, loc), - t, t', + t, SOME ue)); d')) | SOME t' => - (subTyp (t, t') + ((case envVarSetFrom name e1 of + NONE => subTyp (t', t) + | SOME e => hasTyp (e, t', t)) handle Unify ue => dte (WrongType ("Shared environment variable", (EVar name, loc), - t, t', + t, SOME ue)); d')) d1 d2 @@ -637,10 +707,40 @@ fun checkUnit G (eAll as (_, loc)) = fun checkDecl G (d, _, loc) = case d of - DExternType name => bindType G name - | DExternVal (name, t) => bindVal G (name, checkTyp G t) + DExternType name => + if !externFlag then + bindType G name + else + (ErrorMsg.error (SOME loc) "'extern type' not allowed in untrusted code"; + G) + | DExternVal (name, t) => + if !externFlag then + bindVal G (name, checkTyp G t, NONE) + else + (ErrorMsg.error (SOME loc) "'extern val' not allowed in untrusted code"; + G) + | DVal (name, to, e) => + let + val to = + case to of + NONE => (newUnif (), loc) + | SOME to => checkTyp G to + + val t = checkExp G e + in + hasTyp (e, t, to) + handle Unify ue => + describe_type_error loc + (WrongType ("Bound value", + e, + t, + to, + SOME ue)); + bindVal G (name, to, SOME e) + end + | DContext name => bindContext G name -fun checkFile G tInit (ds, eo) = +fun checkFile G tInit (_, ds, eo) = let val G' = foldl (fn (d, G) => checkDecl G d) G ds in @@ -650,7 +750,7 @@ fun checkFile G tInit (ds, eo) = let val t = checkExp G' e in - subTyp (t, tInit) + hasTyp (e, t, tInit) handle Unify ue => (ErrorMsg.error (SOME loc) "Bad type for final expression of source file."; preface ("Actual:", p_typ t);