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/*-----------------------------------------------------------------------
File : cte_typecheck.c
Author: Simon Cruanes, Petar Vucmirovic, Stephan Schulz
Contents
Type checking and inference for Simple types
Copyright 2011-2020 by the author.
This code is released under the GNU General Public Licence.
See the file COPYING in the main CLIB directory for details.
Run "eprover -h" for contact information.
Created: Mon Jul 8 17:15:05 CEST 2013
-----------------------------------------------------------------------*/
#include "cte_typecheck.h"
#include "cte_termfunc.h"
#include <cte_typebanks.h>
/*---------------------------------------------------------------------*/
/* Global Variables */
/*---------------------------------------------------------------------*/
extern bool app_encode;
/*---------------------------------------------------------------------*/
/* Forward Declarations */
/*---------------------------------------------------------------------*/
/*---------------------------------------------------------------------*/
/* Internal Functions */
/*---------------------------------------------------------------------*/
/*-----------------------------------------------------------------------
//
// Function: term_determine_type()
//
// Given number of arguments and type, return the type of the term
// resulting from consuming the number of arguments. Returned type is
// shared.
//
// Global Variables: -
//
// Side Effects : -
//
/----------------------------------------------------------------------*/
Type_p term_determine_type(Term_p term, Type_p type, TypeBank_p bank)
{
int term_arity = ARG_NUM(term);
if(type->arity-1 == term_arity)
{
return type->args[term_arity];
}
else if(type->arity-1 < term_arity)
{
return NULL;
}
else
{
int start = term_arity;
Type_p* args = TypeArgArrayAlloc(type->arity - start);
for(int i=0; i<type->arity-start; i++)
{
args[i] = type->args[i+start];
}
return TypeBankInsertTypeShared(bank,
AllocArrowType(type->arity - start, args));
}
}
/*-----------------------------------------------------------------------
//
// Function: infer_return_sort
//
// infer the return sort of the given function symbol, given the signature.
//
// Global Variables: -
//
// Side Effects : -
//
/----------------------------------------------------------------------*/
Type_p infer_return_sort(Sig_p sig, FunCode f_code)
{
Type_p res;
if(SigQueryProp(sig, f_code, FPIsInteger) &&
(sig->distinct_props & FPIsInteger))
{
res = sig->type_bank->integer_type;
}
else if(SigQueryProp(sig, f_code, FPIsRational) &&
(sig->distinct_props & FPIsRational))
{
res = sig->type_bank->rational_type;
}
else if(SigQueryProp(sig, f_code, FPIsFloat) &&
(sig->distinct_props & FPIsFloat))
{
res = sig->type_bank->real_type;
}
else
{
res = SigDefaultSort(sig);
}
return res;
}
/*---------------------------------------------------------------------*/
/* Exported Functions */
/*---------------------------------------------------------------------*/
/*-----------------------------------------------------------------------
//
// Function: TypeCheckConsistent
// recursively checks that the subterms of this term have a sort
// that is consistent with the given signature.
//
//
// Global Variables: -
//
// Side Effects : -
//
/----------------------------------------------------------------------*/
bool TypeCheckConsistent(Sig_p sig, Term_p term)
{
bool res = true;
Type_p type;
PStack_p stack = PStackAlloc();
PStackPushP(stack, term);
while (!PStackEmpty(stack))
{
term = PStackPopP(stack);
if (!TermIsVar(term))
{
/* check: same arity, same return sort, sort of arguments (pairwise)*/
if(!SigIsPolymorphic(sig, term->f_code))
{
type = SigGetType(sig, term->f_code);
assert(type);
if(TypeIsArrow(type))
{
if((term->arity != type->arity-1)
|| term->type != type->args[type->arity-1])
{
res = false;
break;
}
}
else
{
if(term->arity != 0 || term->type != type)
{
// other kind of type constructor
res = false;
break;
}
}
/* Check subterms recursively */
for(int i=0; i < type->arity; i++)
{
PStackPushP(stack, term->args[i]);
if(term->args[i]->type != type->args[i])
{
res = false;
break;
}
}
}
}
}
PStackFree(stack);
return res;
}
/*-----------------------------------------------------------------------
//
// Function: TypeInferSort()
//
// Infer the sort of this term. It can either use the type of the
// function symbol, if already known, or guess a type and add it
// to the signature otherwise. By default terms are supposed not to
// be atoms, unless the parser decides that they must be boolean.
//
// Global Variables: -
//
// Side Effects : Modifies term and signature. May exit on type error.
//
/----------------------------------------------------------------------*/
#define TI_ERROR(msg) do{ \
if(in) \
{\
AktTokenError(in, msg, false);\
}\
else\
{\
Error(msg, SYNTAX_ERROR);\
}}while(false)
void TypeInferSort(Sig_p sig, Term_p term, Scanner_p in)
{
Type_p type = NULL;
Type_p sort, *args;
int i;
if(TermIsVar(term))
{
if(!term->type)
{
term->type = SigDefaultSort(sig);
}
}
else
{
if(TermIsPhonyApp(term))
{
type = term->args[0]->type;
}
else if(TermIsLambda(term))
{
// types have to be inferred only during parsing
assert(term->f_code == SIG_NAMED_LAMBDA_CODE);
assert(term->arity == 2);
// type of lambda is 'type of variable' -> 'type of body'
term->type =
TypeBankInsertTypeShared(sig->type_bank,
ArrowTypeFlattened(&(term->args[0]->type), 1,
term->args[1]->type));
}
else if(term->f_code == sig->eqn_code || term->f_code == sig->neqn_code)
{
if(term->arity == 0)
{
AktTokenError(in, "Equality must have at least one argument",
SYNTAX_ERROR);
}
Type_p arg_type = term->args[0]->type;
Type_p eq_type_args[3] = {arg_type, arg_type, sig->type_bank->bool_type};
type = TypeBankInsertTypeShared(sig->type_bank,
AllocArrowTypeCopyArgs(3, eq_type_args));
}
else if(term->f_code == sig->qex_code || term->f_code == sig->qall_code)
{
if(term->arity == 0)
{
AktTokenError(in, "Equality must have at least one argument",
SYNTAX_ERROR);
}
assert(TermIsVar(term->args[0]));
Type_p arg_type = term->args[0]->type;
Type_p quant_type_args[3] = {arg_type, sig->type_bank->bool_type, sig->type_bank->bool_type};
type = TypeBankInsertTypeShared(sig->type_bank,
AllocArrowTypeCopyArgs(3, quant_type_args));
}
else
{
type = SigGetType(sig, term->f_code);
}
/* Use type */
if(type)
{
if(TypeIsArrow(type))
{
if(problemType == PROBLEM_FO && !app_encode
&& term->arity != type->arity-1)
{
fprintf(stderr, "Arity mismatch for ");
TermPrint(stderr, term, sig, DEREF_NEVER);
fprintf(stderr, " and type ");
TypePrintTSTP(stderr, sig->type_bank, type);
fprintf(stderr, "\n");
TI_ERROR("Type error");
}
if(!TermIsPhonyApp(term))
{
for(i=0; SigIsFixedType(sig, term->f_code) && i < term->arity; i++)
{
if(term->args[i]->type != type->args[i])
{
fprintf(stderr, "# Type mismatch in argument #%d of ", i+1);
TermPrint(stderr, term, sig, DEREF_NEVER);
fprintf(stderr, ": expected ");
TypePrintTSTP(stderr, sig->type_bank, type->args[i]);
fprintf(stderr, " but got ");
TypePrintTSTP(stderr, sig->type_bank, term->args[i]->type);
fprintf(stderr, "\n");
TI_ERROR("Type error");
}
}
}
else
{
// probably can be unified with harder to understand code!
for(i=1; i < term->arity; i++)
{
assert(term->arity-1 < type->arity);
if(term->args[i]->type != type->args[i-1])
{
fprintf(stderr, "# Type mismatch in argument #%d of ", i+1);
TermPrint(stderr, term, sig, DEREF_NEVER);
fprintf(stderr, ": expected ");
TypePrintTSTP(stderr, sig->type_bank, type->args[i-1]);
fprintf(stderr, " but got ");
TypePrintTSTP(stderr, sig->type_bank, term->args[i]->type);
fprintf(stderr, "\n");
TI_ERROR("Type error");
}
}
}
term->type = term_determine_type(term, type, sig->type_bank);
if(term->type==NULL)
{
fprintf(stderr, "# too many arguments supplied for %s\n",
SigFindName(sig, term->f_code));
assert(false);
in?AktTokenError(in, "Type error", false):Error("Type error", SYNTAX_ERROR);
}
}
else
{
if(term->arity != 0)
{
fprintf(stderr, "# Type mismatch for ");
TermPrint(stderr, term, sig, DEREF_NEVER);
fprintf(stderr, " and type ");
TypePrintTSTP(stderr, sig->type_bank, type);
fprintf(stderr, "\n");
assert(false);
TI_ERROR("Type error");
}
else
{
term->type = type;
}
}
}
else if(!TermIsLambda(term))
{
/* Infer type */
sort = infer_return_sort(sig, term->f_code);
args = term->arity ? TypeArgArrayAlloc(term->arity+1) : NULL;
for(i=0; i < term->arity; i++)
{
args[i] = term->args[i]->type;
}
if(term->arity)
{
args[term->arity] = sort;
}
type = term->arity ?
TypeBankInsertTypeShared(sig->type_bank,
AllocArrowType(term->arity+1, args))
: sort;
/* Declare the inferred type */
SigDeclareType(sig, term->f_code, type);
term->type = sort;
}
}
}
/*-----------------------------------------------------------------------
//
// Function: TypeDeclareIsPredicate()
//
// declare that the term has a role of predicate (occurs as a boolean atom)
//
// Global Variables: -
//
// Side Effects : Modifies sig, modifies term's sort
//
/----------------------------------------------------------------------*/
void TypeDeclareIsPredicate(Sig_p sig, Term_p term)
{
assert(!TermIsVar(term));
SigDeclareIsPredicate(sig, term->f_code);
term->type = sig->type_bank->bool_type;
}
/*-----------------------------------------------------------------------
//
// Function: TypeDeclareIsNotPredicate()
//
// Declare that this term is not a boolean atom, because it ocurs in
// an equation or is a subterm of another term.
//
// Global Variables: -
//
// Side Effects : Modifies signature, update term's sort
//
/----------------------------------------------------------------------*/
void TypeDeclareIsNotPredicate(Sig_p sig, Term_p term, Scanner_p in)
{
if(!TermIsVar(term))
{
TypeInferSort(sig, term, in);
SigDeclareIsFunction(sig, term->f_code);
}
}
/*---------------------------------------------------------------------*/
/* End of File */
/*---------------------------------------------------------------------*/
|
