Files
heimdal/lib/asn1/symbol.h
Nicolas Williams 83d4c6ddb5 asn1: Circular types and Topo. sort declarations
Many external ASN.1 modules that we have imported over time define types
like this:

  Foo ::= SEQUENCE { bar Bar }
  Bar ::= SEQUENCE { aMember INTEGER }

and before this change one had to re-order the definitions so that the
one for `Bar` came first.  No more.

We can now have out of order definitions in ASN.1 modules and the
compiler will topologically sort output C type declarations so that one
no longer has to manually sort types in ASN.1 modules when importing
them.

Besides that, it is now possible to create circular data types using
OPTIONAL since we generate such fields as pointers (which can then be
pointers to incomplete struct declarations):

  Circular ::= SEQUENCE {
          name UTF8String,
          next Circular OPTIONAL
  }

Circular types aren't necessarily useful, but they have been used in the
past.  E.g., the rpc.mountd protocol uses a circular type as a linked
list -- it should just have used an array, of course, as that's
semantically equivalent but more space efficient in its encoding, but
the point is that such types exist out there.
2021-01-13 20:17:58 -06:00

183 lines
4.1 KiB
C

/*
* Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* $Id$ */
#ifndef _SYMBOL_H
#define _SYMBOL_H
#include <heimqueue.h>
enum typetype {
TBitString,
TBoolean,
TChoice,
TEnumerated,
TGeneralString,
TTeletexString,
TGeneralizedTime,
TIA5String,
TInteger,
TNull,
TOID,
TOctetString,
TPrintableString,
TSequence,
TSequenceOf,
TSet,
TSetOf,
TTag,
TType,
TUTCTime,
TUTF8String,
TBMPString,
TUniversalString,
TVisibleString
};
typedef enum typetype Typetype;
struct type;
struct value {
enum { booleanvalue,
nullvalue,
integervalue,
stringvalue,
objectidentifiervalue
} type;
union {
int booleanvalue;
int64_t integervalue;
char *stringvalue;
struct objid *objectidentifiervalue;
} u;
};
struct member {
char *name;
char *gen_name;
char *label;
int val;
int optional;
int ellipsis;
struct type *type;
HEIM_TAILQ_ENTRY(member) members;
struct value *defval;
};
typedef struct member Member;
HEIM_TAILQ_HEAD(memhead, member);
struct symbol;
struct tagtype {
int tagclass;
int tagvalue;
enum { TE_IMPLICIT, TE_EXPLICIT } tagenv;
};
struct range {
/*
* We can't represent unsigned 64-bit ranges because max might be
* negative...
*/
int64_t min;
int64_t max;
};
enum ctype { CT_CONTENTS, CT_USER } ;
struct constraint_spec;
struct type {
Typetype type;
struct memhead *members;
struct symbol *symbol;
struct type *subtype;
struct tagtype tag;
struct range *range;
struct constraint_spec *constraint;
unsigned long id;
};
typedef struct type Type;
struct constraint_spec {
enum ctype ctype;
union {
struct {
Type *type;
struct value *encoding;
} content;
} u;
};
struct objid {
const char *label;
int value;
struct objid *next;
};
struct symbol {
char *name;
char *gen_name;
enum { SUndefined, SValue, Stype } stype;
struct value *value;
Type *type;
HEIM_TAILQ_ENTRY(symbol) symlist;
unsigned int emitted_declaration:1;
unsigned int emitted_definition:1;
};
typedef struct symbol Symbol;
//HEIM_TAILQ_HEAD(symhead, symbol);
struct symhead {
struct symbol *tqh_first;
struct symbol **tqh_last;
};
extern struct symhead symbols;
void initsym (void);
Symbol *addsym (char *);
Symbol *getsym(char *name);
void output_name (char *);
int checkundefined(void);
void generate_types(void);
void emitted_declaration(const Symbol *);
void emitted_definition(const Symbol *);
#endif