Critical Mass Modula-3: m3tk/src/sem/M3CSundries.m3

m3tk/src/sem/M3CSundries.m3

MODULE M3CSundries;

************************************************************************* Copyright (C) Olivetti 1989 All Rights reserved Use and copy of this software and preparation of derivative works based upon this software are permitted to any person, provided this same copyright notice and the following Olivetti warranty disclaimer are included in any copy of the software or any modification thereof or derivative work therefrom made by any person. This software is made available AS IS and Olivetti disclaims all warranties with respect to this software, whether expressed or implied under any law, including all implied warranties of merchantibility and fitness for any purpose. In no event shall Olivetti be liable for any damages whatsoever resulting from loss of use, data or profits or otherwise arising out of or in connection with the use or performance of this software. *************************************************************************

IMPORT Text;

IMPORT AST, M3AST_AS;

IMPORT M3AST_AS_F, M3AST_SM_F;

IMPORT ASTWalk;

IMPORT M3Error, M3CDuplicate, M3CNameClash;

PROCEDURE Call(call: M3AST_AS.Call; isStatement: BOOLEAN) RAISES {}=
  VAR
    noResult: BOOLEAN;
  BEGIN
    TYPECASE call.as_callexp.sm_exp_type_spec OF
    | NULL =>
    | M3AST_AS.Procedure_type(procType) =>
        noResult := procType.as_result_type = NIL;
        IF noResult # isStatement THEN
          VAR
            e: Text.T;
          BEGIN
            IF isStatement THEN
              e := "call of function procedure cannot be used as a statement";
            ELSE
              e := "call of proper procedure cannot be used in an expression";
            END; (* if *)
            M3Error.Report(call, e);
          END;
        END; (* if *)
    ELSE
    END; (* typecase *)
  END Call;

PROCEDURE Procedure(p: M3AST_AS.Proc_decl; isModule: BOOLEAN) RAISES {}=
  VAR
    hasBody := p.as_body # NIL;
  BEGIN
    IF hasBody # isModule THEN
      VAR
        e: Text.T;
      BEGIN
        IF hasBody THEN
          e := "procedure in interface cannot have body";
        ELSE
          e := "procedure in module must have body";
        END; (* if *)
        M3Error.Report(p, e);
      END;
    END; (* if *)
  END Procedure;

REVEAL
  Handle = BRANDED OBJECT
    inModule, isProperCall: BOOLEAN;
    loopCount, procNesting: INTEGER := 0;
  END;

PROCEDURE Check(h: Handle; any: AST.NODE; v: ASTWalk.VisitMode) RAISES {}=
  BEGIN
    IF v = ASTWalk.VisitMode.Entry THEN
      TYPECASE any OF
      | M3AST_AS.Loop_st, M3AST_AS.While_st,
        M3AST_AS.For_st, M3AST_AS.Repeat_st =>
          INC(h.loopCount);
      | M3AST_AS.Call_st =>
          h.isProperCall := TRUE;
      | M3AST_AS.Call(call) =>
          Call(call, h.isProperCall);
          h.isProperCall := FALSE;
      | M3AST_AS.Proc_decl(proc_decl) =>
          INC(h.procNesting);
          Procedure(proc_decl, h.inModule);
      | M3AST_AS.Exit_st =>
          IF h.loopCount = 0 THEN
            M3Error.Report(any, "EXIT must be inside loop");
          END;
      | M3AST_AS.Case_st(case_st) =>
          M3CDuplicate.CaseLabels(case_st);
      | M3AST_AS.Try_except(try_except) =>
          M3CDuplicate.HandlerExceptions(try_except);
      | M3AST_AS.Enumeration_type(enumeration_type)=>
          M3CNameClash.Enumeration(enumeration_type);
      | M3AST_AS.Record_type(record_type) =>
          M3CNameClash.Record(record_type);
      | M3AST_AS.Object_type(object_type) =>
          M3CNameClash.Object(object_type);
      | M3AST_AS.Procedure_type(procedure_type) =>
          M3CNameClash.Procedure(procedure_type);
      | M3AST_AS.Exc_decl_s =>
          IF h.procNesting # 0 THEN
            M3Error.Report(any,
                "exception must be declared at top level");
          END;
      | M3AST_AS.Concrete_reveal, M3AST_AS.Subtype_reveal =>
          IF h.procNesting # 0 THEN
            M3Error.Report(any,
                "type can only be revealed at top level");
          END;
      ELSE
        (* nothing *)
      END; (* if *)
    ELSE
      TYPECASE any OF
      | M3AST_AS.Loop_st, M3AST_AS.While_st,
        M3AST_AS.For_st, M3AST_AS.Repeat_st =>
          DEC(h.loopCount);
      | M3AST_AS.Proc_decl =>
          DEC(h.procNesting);
      ELSE
        (* nothing *)
      END; (* case *)
    END; (* case *)
  END Check;

PROCEDURE NewHandle(
    inModule, isProperCall, inLoop, inProc: BOOLEAN)
    : Handle
    RAISES {}=
  VAR
    new := NEW(Handle, inModule := inModule, isProperCall := isProperCall);
  BEGIN
    IF inLoop THEN INC(new.loopCount) END;
    IF inProc THEN INC(new.procNesting) END;
    RETURN new;
  END NewHandle;

BEGIN
END M3CSundries.