recursive.c   [plain text]

/*
 * compiler/core/recursive.c - finds and marks the recursive types in a module.
 *
 * ALSO:
 * prints msgs for infinitely recursive types (ie recursive component
 * is not OPTIONAL, nor a CHOICE elmt, nor a SET OF nor a SEQ OF elmt.
 * (OPTIONALs can be left out, CHOICE elements have alternatives (hopefully),
 * and SET OF and SEQUENCE OF values can have zero elements)
 *
 * prints msg for recursive types that hold no real information
 *     Foo ::= SET OF Foo (sets of sets of .... of empty sets)
 *
 * finds bogus recursive types (hold no info) (same as above)
 *  A ::= B
 *  B ::= C
 *  D ::= A
 *
 * MS 92
 *
 * Copyright (C) 1991, 1992 Michael Sample
 *            and the University of British Columbia
 *
 * This program 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.
 *
 * $Header: /cvs/Darwin/src/live/Security/SecuritySNACCRuntime/compiler/core/recursive.c,v 1.1 2001/06/20 21:27:58 dmitch Exp $
 * $Log: recursive.c,v $
 * Revision 1.1  2001/06/20 21:27:58  dmitch
 * Adding missing snacc compiler files.
 *
 * Revision 1.1.1.1  1999/03/16 18:06:52  aram
 * Originals from SMIME Free Library.
 *
 * Revision 1.3  1995/07/25 19:41:43  rj
 * changed `_' to `-' in file names.
 *
 * Revision 1.2  1994/09/01  00:43:10  rj
 * snacc_config.h removed; recursive.h includet.
 *
 * Revision 1.1  1994/08/28  09:49:35  rj
 * first check-in. for a list of changes to the snacc-1.1 distribution please refer to the ChangeLog.
 *
 */

#include <stdio.h>

#include "asn-incl.h"
#include "asn1module.h"
#include "recursive.h"
#include "snacc-util.h"

void MkRecTypeDef PROTO ((Module *m, TypeDef *td));

void MkRecType  PROTO ((Module *m, TypeDef *td,Type *t, int optional, int empty));


void
MarkRecursiveTypes PARAMS ((m),
    Module *m)
{
    TypeDef *td;

    /* first set all typedef as un-visited */
    FOR_EACH_LIST_ELMT (td, m->typeDefs)
    {
        td->visited = FALSE;
        td->tmpRefCount = 0;
    }

    FOR_EACH_LIST_ELMT (td, m->typeDefs)
    {
        MkRecTypeDef (m, td);
    }
}  /* MarkRecursiveTypes */



void
MkRecTypeDef PARAMS ((m, td),
    Module *m _AND_
    TypeDef *td)
{
    MkRecType (m, td, td->type, 0, 1);
}  /* MkRecTypeDef */



/*
 * cruise through aggregate types and type refs looking for
 * a type ref to the original type def, td.  If is a ref to
 * the td, then mark the td as recusive.
 *
 * the optional flag is set if the current type branch is
 * optional via an OPTIONAL SET/SEQ elmt, CHOICE elmt, SET OF elmt
 * or SEQ OF elmt.
 *
 * the empty flag is initially TRUE and remains true until a
 * non-type reference type is encountered
 */
void
MkRecType  PARAMS ((m, td, t, optional, empty),
    Module *m _AND_
    TypeDef *td _AND_
    Type *t _AND_
    int optional _AND_
    int empty)
{
    int newOptional;
    NamedType *e;

    switch (t->basicType->choiceId)
    {
        case BASICTYPE_CHOICE:
            if (AsnListCount (t->basicType->a.choice) > 1)
            {
                empty = 0;
                optional = 1;
            }
            FOR_EACH_LIST_ELMT (e, t->basicType->a.choice)
            {
                MkRecType (m, td, e->type, optional, empty);
            }
            break;

        case BASICTYPE_SET:
        case BASICTYPE_SEQUENCE:
            empty = 0;

            FOR_EACH_LIST_ELMT (e, t->basicType->a.set)
            {
                newOptional = optional || (e->type->optional) ||
                              (e->type->defaultVal != NULL);
                MkRecType (m, td, e->type, newOptional, empty);
            }
            break;

        case BASICTYPE_SETOF:
        case BASICTYPE_SEQUENCEOF:
            empty = 0;  /* since an empty set is actual data */
            optional = 1; /* since SET OF and SEQ OF's can be empty */
            MkRecType (m, td, t->basicType->a.setOf, optional, empty);
            break;

        case BASICTYPE_LOCALTYPEREF:
        case BASICTYPE_IMPORTTYPEREF:

            /*
             * check if ref to original type def & mark recursive if so.
             */
/*            if ((strcmp (t->basicType->a.localTypeRef->typeName, td->definedName) == 0) && (t->basicType->a.localTypeRef->module == m))
 easier to just check ptrs!
*/
            if (t->basicType->a.localTypeRef->link == td)
            {
                td->recursive = 1;
                if (empty)
                {
                    PrintErrLoc (m->asn1SrcFileName, td->type->lineNo);
                    fprintf (stderr,"WARNING: Type \"%s\" appears to be infinitely recursive and can hold no values! (circular type references)\n", td->definedName);
                }
                else if (!optional)
                {
                    PrintErrLoc (m->asn1SrcFileName, t->lineNo);
                    fprintf (stderr,"WARNING: Type \"%s\" appears to be infinitely recursive! (infinitely sized values)\n", td->definedName);
                }
            }

            /*
             * else follow this type reference if we aren't in it already
             * (ie another recursive type in td)
             */
            else if (t->basicType->a.localTypeRef->link->tmpRefCount == 0)
            {
                /*
                 * mark this typedef as 'entered' to
                 * detect when looping in a recusive type that is contained
                 * in the original td (use tmpRefCount)
                 */
                 t->basicType->a.localTypeRef->link->tmpRefCount = 1;

                 newOptional = optional || (t->optional) || (t->defaultVal != NULL);
                 MkRecType (m, td, t->basicType->a.localTypeRef->link->type, newOptional, empty);

                /*
                 * un-mark this type since finished with it
                 * for recursive ref's to td
                 */
                 t->basicType->a.localTypeRef->link->tmpRefCount = 0;
            }
            break;

        /*
         * default: other types are not aggregate and
         * do not make recursive refs - they can be ignored
         */
    }
} /* MkRecType */