/*

  $Id$

  Copyright 1989-2016 MINES ParisTech

  This file is part of PIPS.

  PIPS 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 3 of the License, or
  any later version.

  PIPS is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.

  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with PIPS.  If not, see <http://www.gnu.org/licenses/>.

*/
#ifdef HAVE_CONFIG_H
    #include "pips_config.h"
#endif
/* Deals with constant expressions and constant entities
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <math.h>

#include "linear.h"
#include "genC.h"
#include "misc.h"

#include "ri-util.h"

#include "pips-libs.h"

int DefaultLengthOfBasic(tag t)
{
	int e=-1;

	switch (t) {
	    case is_basic_overloaded:
		e = 0;
		break;
	    case is_basic_int:
		e = DEFAULT_INTEGER_TYPE_SIZE;
		break;
	    case is_basic_float:
		e = DEFAULT_REAL_TYPE_SIZE;
		break;
	    case is_basic_logical:
		e = DEFAULT_LOGICAL_TYPE_SIZE;
		break;
	    case is_basic_complex:
		e = DEFAULT_COMPLEX_TYPE_SIZE;
		break;
	    case is_basic_string:
		e = DEFAULT_CHARACTER_TYPE_SIZE;
		break;
	    default:
		pips_internal_error("case default");
		break;
	}

	return(e);
}


/* BEGIN_EOLE */ /* - please do not remove this line */
/* Lines between BEGIN_EOLE and END_EOLE tags are automatically included
   in the EOLE project (JZ - 11/98) */

#define INTEGER_CONSTANT_NAME_CHARS \
	"0123456789"

bool integer_constant_name_p(string name)
{
    return strlen(name)==strspn(name, INTEGER_CONSTANT_NAME_CHARS);
}

_int TK_CHARCON_to__int(const char* name)
{
  _int r;

  /* Should be able to decode any C character constant... */
  if(strlen(name)==3 && name[0]=='\'' && name[2]=='\'')
    r=name[1];
  else if(strlen(name)==4 && name[0]=='\'' && name[1]=='\\' && name[3]=='\'')
    switch(name[2]) {
    case '\t' :
      r = 9; // not sure
      break;
    case '\n' :
      r = 10;
      break;
    case '\r' :
      r = 13;
      break;
    default:
      r=name[2];
    }
  else if(strlen(name)==6 && name[0]=='\'' && name[1]=='\\' && name[5]=='\'') {
    /* octal constant */
    string error_string = string_undefined;
    errno = 0;
    r = strtol(&name[2], &error_string, 8);
    if(errno!=0) {
      pips_user_warning("character constant %s not recognized\n",name);
      pips_internal_error("Illegal octal constant");
    }
  }
  else { // Unrecognized format
    pips_user_warning("character constant %s not recognized\n",name);
    // pips_internal_error("not implemented yet");
    r=0;//just temporary
  }

  return r;
}

/* This function creates a constant. a constant is represented in our
   internal representation by a function. Its name is the name of the
   constant, its type is a functional that gives the type of the constant,
   its storage is rom.

   Its initial value is the value of the constant. In case of integer
   constant, the actual value is stored (as an integer) in constant_int.
   values of other constants have to be computed with the name, if
   necessary.

   name is the name of the constant 12, 123E10, '3I12', 015 (C octal
   constant), 0x1ae; (C hexadecimal), 890L (C long constant) ...
   Initial and final quotes are included in the names of string
   constants.

   basic is the basic type of the constant: int, float, ...

   Character constants are typed as int.
*/

entity make_C_or_Fortran_constant_entity(
  const char* name,
  tag bt,
  size_t size,
  bool is_fortran,
  bool (*error_manager)(const char *, const char *))
{
  entity e;

  e = FindOrCreateEntity(TOP_LEVEL_MODULE_NAME, name);

  if (entity_type(e) == type_undefined) {
    functional fe = functional_undefined;
    constant ce = constant_undefined;
    basic be = basic_undefined;

    if (bt == is_basic_string) {
      /* Drop the two quotes, but add space for '\0' in C */
      be = make_basic(bt, (make_value(is_value_constant,
				      (make_constant(is_constant_int,
						     (void*) (strlen(name)-2+1-is_fortran))))));
    }
    else {
      be = make_basic(bt, (void*) size);
    }

    fe = make_functional(NIL, MakeTypeVariable(be, NIL));

    if (bt == is_basic_int && (size==4 || size==8)) { // int constant
      //string unsigned int suffix = "uU";
      //string long int suffix = "lL";
      bool usuffix = (strchr(name, 'U') != NULL) || (strchr(name, 'u') != NULL);
      bool lsuffix = (strchr(name, 'L') != NULL) || (strchr(name, 'l') != NULL);
      int basis = is_fortran? 10 : 0;
      char * error_string = string_undefined;
      long long int l = 0;
      int error_number = 0;
      //int (* conversion)(string, string *, int);

      //pips_debug(8, "unsigned int suffix = %s, strspn = %d\n",
      //	 unsignedintsuffix, usuffix);

      /* See all hexadecimal constant as unsigned on 64 bits, elses
	 0xffffffff generates an overflow, not a -1 (see C-syntax/constants03.c */
      if(strstr(name,"0x")==name) {
        usuffix = true;
        lsuffix = true;
      }
      /*
      if(usuffix)
	if(lsuffix)
	  conversion = (int (*)(string, string *, int)) strtoull;
	else
	  conversion = (int (*)(string, string *, int)) strtoul;
      else
	if(lsuffix)
	  conversion = (int (*)(string, string *, int)) strtoll;
	else
	  conversion = (int (*)(string, string *, int)) strtol;
      */

      errno = 0;
      if(usuffix)
        if(lsuffix)
          l = strtoull(name, &error_string, basis);
        else
          l = strtoul(name, &error_string, basis);
      else
        if(lsuffix)
          l = strtoll(name, &error_string, basis);
        else
          l = strtol(name, &error_string, basis);
      error_number = errno;
      /* %ld, long; %zd, size_t; %td, ptrdiff_t */
      pips_debug(8, "value = %lld, errno=%d\n", l, error_number);
      errno = 0;

      /* Since the value is stored in a NewGen int that has the size of a
	 pointer, verify is is OK to store it. In should not assume
	 this... */
      if(size==4) { // 32 bit target machine
	// Well, no problem...
     }
      else if(size==8) {
	pips_assert("pointers have the right size", sizeof(void *)==8);
      }
      else
	pips_internal_error("Unexpected number of bytes for an integer variable");

      pips_assert("Integer constants are internally stored on 4 or 8 bytes",
		  size==4 || size==8);
      /* Check conversion errors and make the constant */
      if(error_number==EINVAL) {
        pips_user_warning("Integer constant '%s' cannot be converted in %d bytes (%s)\n",
                          name, size, error_string);
	(*error_manager)(__FUNCTION__,
			 "Integer constant conversion error.\n");
      }
      else if(error_number==ERANGE) {
        pips_user_warning("Overflow, Integer constant '%s' cannot be stored in %d bytes\n",
                          name, size);
	(*error_manager)(__FUNCTION__,
                      "Integer constant too large for internal representation.\n");
      }
      else if(error_number!=0 && (l == LONG_MAX || l == LONG_MIN)) {
	pips_internal_error("Conversion error for integer constant string");
      }
      else if(*error_string!='\0' && strspn(error_string, "LlUu")!=strlen(error_string)) {
	pips_internal_error("Illegal characters found in integer constant string");
      }
      else if(name==error_string) {
	pips_internal_error("No digit found in integer constant string.\n");
      }

      /* SG :this ensure everything is ok on 32 bits */
      if(l != (long long int)(intptr_t)l)
      {
      	pips_user_warning("some data lost in conversion, %lli is not representatble in pips \n",l);
        l = ~(intptr_t)0;
      }
      ce = make_constant_int( (intptr_t)l); 
    }
    else if(bt == is_basic_int && size==1) {
      // Character constant
      _int i = TK_CHARCON_to__int(name);
      // fprintf(stderr,"make integer constant:name=%s\n",name);
      ce = make_constant(is_constant_int, (void*) i);
    }
    else {
      ce = make_constant(is_constant_call, e);
    }

    entity_type(e) = make_type(is_type_functional, fe);
    entity_storage(e) = make_storage_rom();
    entity_initial(e) = make_value(is_value_constant, ce);
  }
  return(e);
}

static bool constant_error(const char * f, const char *m)
{
  pips_internal_error("%s in function %s\n.", m, f);
  return true; // Never reached
}

/* For historical reason, call the Fortran version.
 *
 * It is used in bootstrap, instrumentation, ri-util/constant.c,
 * semantics and task_parallelization.
 *
 * It is assumed that no errors can be detected, or it would be a PIPS
 * internal error.
 */
entity make_constant_entity(string name,
			    tag bt,
			    size_t size)
{
  return make_C_or_Fortran_constant_entity(name, bt, size, true, NULL);
}

/* END_EOLE */


/* Make a Fortran constant
 *
 * Apparently partly extended fo C...
 */
entity SafeMakeConstant(string name, tag bt, bool (*error_manager)(const char*, const char *))
{
    entity e;
    size_t len = strlen(name);
    size_t type_length;
    /* SG : I like accurate knowledge of constant suffix to fill all
       cases accurately, there is still work to do there */
    switch(bt) {
        case is_basic_float:
            switch(name[len-1]) {
                case 'f':
                    type_length = DefaultLengthOfBasic(bt);break;
                case 'F':
                default:
		  // SG I am sure the default is double for C, I don't know for Fortran
                    type_length = (c_module_p(get_current_module_entity()) ?
                        2 :
                        1
                        ) *DefaultLengthOfBasic(bt);break;
            } break;
        default:
            type_length = DefaultLengthOfBasic(bt);
    }

    //e = make_constant_entity(name, bt, type_length);
    e = make_C_or_Fortran_constant_entity(name, bt, type_length, true, error_manager);

    /* The LengthOfBasic should be updated for type "string" */

    return e;
}

/* Make a Fortran constant
 *
 * Apparently partly extended fo C...
 */
entity MakeConstant(string name, tag bt)
{
  return SafeMakeConstant(name, bt, constant_error);
}

bool constant_string_entity_p(entity e)
{
  const char * eun = entity_user_name(e);
  bool first_quote = eun[0]=='"';
  bool last_quote = eun[strlen(eun)-1] == '"';
  return first_quote && last_quote;
}

/* make a complex constant from two calls to real or integer constants
 *
 * Problem: does not work if either of the components is negative because
 * negative constants are stored as expressions. For instance, (0, -1) is
 * not a complex constant for PIPS but an expression:
 * cmplx(0,unary_minus(1)).
 *
 * Note: I might have changed that to store DATA statements... (FI)
 */
entity MakeComplexConstant(expression r, expression i)
{
    entity re = call_function(syntax_call(expression_syntax(r)));
    entity ie = call_function(syntax_call(expression_syntax(i)));
    entity e;
    char * name;
    asprintf(&name,"(%s,%s)", entity_local_name(re),  entity_local_name(ie));
    type rt = entity_type(re);
    type it = entity_type(ie);
    type ert = functional_result(type_functional(rt));
    type eit = functional_result(type_functional(it));
    basic rb = variable_basic(type_variable(ert));
    basic ib = variable_basic(type_variable(eit));
    int rsize = basic_type_size(rb);
    int isize = basic_type_size(ib);
    int size = rsize>isize? rsize: isize;

    e = make_constant_entity(name, is_basic_complex, size);
    /* name has to be allocated by strdup because of nested calls to
       concatenate */
    free(name);
    return e;
}

expression MakeComplexConstantExpression(expression r,
					 expression i)
{
    expression cce = expression_undefined;

    if(signed_constant_expression_p(r) && signed_constant_expression_p(i)) {
	basic rb = basic_of_expression(r);
	basic ib = basic_of_expression(i);
	int rsize = basic_type_size(rb);
	int isize = basic_type_size(ib);
	int size = rsize>isize? rsize: isize;

	cce = MakeBinaryCall(local_name_to_top_level_entity
			     (size==4? IMPLIED_COMPLEX_NAME: IMPLIED_DCOMPLEX_NAME), r, i);
    }

    return cce;
}

bool complex_constant_expression_p(expression cce)
{
  bool is_complex_constant_p = false;
  if(expression_call_p(cce)) {
    entity f = call_function(syntax_call(expression_syntax(cce)));
    const char* fn = entity_local_name(f);

    is_complex_constant_p = (strcmp(fn, IMPLIED_COMPLEX_NAME)==0
			     || strcmp(fn, IMPLIED_DCOMPLEX_NAME)==0);
  }

  return is_complex_constant_p;
}

entity float_to_entity(float c)
{
    string num;
    // FI: non-significant zeroes are printed in num...
    asprintf(&num, "%f", c);
    // FI: the period may be skipped when the value is integer and
    //then, for some unknown reason, semantics interprets this as an
    //integer value, maybe because of constant = ... + float:int +...
    //asprintf(&num, "%g", c);

    // Remove trailing zeroes.
    string tz = num+strlen(num)-1;
    while(*tz=='0') {
      *tz = '\000';
      tz--;
    }

    entity e = MakeConstant(num,is_basic_float);

    free(num);
    return e;
}

entity int_to_entity(_int c)
{
    pips_assert("no negative integer entity in pips",c>=0);
    string num;
    asprintf(&num, "%d", (int) c);
    entity e = MakeConstant(num,is_basic_int);
    free(num);
    return e;
}

bool logical_constant_p(entity ent)
{
  bool yes_p = false;
  type t = entity_type(ent);

  if( type_functional_p(t))
    if(value_constant_p(entity_initial(ent))) {
      if(constant_logical_p(value_constant(entity_initial(ent))))
	yes_p = true;
      else if(constant_call_p(value_constant(entity_initial(ent)))) {
	/* In the initial internal representation, only integer
	   constants were distinguished */
	functional f = type_functional(t);
	type rt = functional_result(f); // ultimate type should not be
					// useful for constants
					// generated by a parser
	yes_p = logical_type_p(rt);
      }
    }

  return yes_p;
}

/* ent can be either a numerical or a symbolic float constant */
bool float_constant_p(entity ent)
{
  bool yes_p = false;
  type t = entity_type(ent);

  if( type_functional_p(t))
    if(value_constant_p(entity_initial(ent))) {
      if(constant_float_p(value_constant(entity_initial(ent))))
	yes_p = true;
      else if(constant_call_p(value_constant(entity_initial(ent)))) {
	/* In the initial internal representation, only integer
	   constants were distinguished */
	functional f = type_functional(t);
	type rt = functional_result(f); // ultimate type should not be
					// useful for constants
					// generated by a parser
	yes_p = float_type_p(rt);
      }
    }

  return yes_p;
}

/* Returns the double value associated to a PIPS constant
 *
 * A simpler function alreay exists... and is better for litteral constants...
 */
/*
double float_constant_to_double(entity e)
{
  pips_assert("e is a floating point constant", float_constant_p(e));
  value ev = entity_initial(e);
  constant c = value_constant(ev);
  double d = 0.;

  if(constant_float_p(c))
    d = constant_float(c);
  else if(constant_litteral_p(c)) {
    string s = entity_user_name(e);
    sscanf(s, "%f", &d);
  }
  else if(constant_call_p(c)) {
    pips_internal_error("Not implemented yet\n");
  }
  else
    pips_internal_error("Inconsistency in floating point constant "%s"\n",
			entity_user_name(e));
}
*/

/* BEGIN_EOLE */ /* - please do not remove this line */
/* Lines between BEGIN_EOLE and END_EOLE tags are automatically included
   in the EOLE project (JZ - 11/98) */

/* (*int_p) gets integer constant if any */
bool integer_constant_p(entity ent, int *int_p)
{
    if( type_tag(entity_type(ent))==is_type_functional
       && value_tag(entity_initial(ent))==is_value_constant
       && constant_tag(value_constant(entity_initial(ent)))==is_constant_int ) {
	*int_p = constant_int(value_constant(entity_initial(ent)));
	return(true);
    }
    else
	return(false);
}


/* (*int_p) gets integer constant if any */
bool integer_symbolic_constant_p(entity ent, int *int_p)
{
    if( type_tag(entity_type(ent))==is_type_functional
       && value_tag(entity_initial(ent))==is_value_symbolic
       && constant_tag(symbolic_constant(value_symbolic(entity_initial(ent))))==is_constant_int ) {
	*int_p = constant_int(symbolic_constant(value_symbolic(entity_initial(ent))));
	return(true);
    }
    else
	return(false);
}

/* END_EOLE */

/* this function creates an character constant and then a call to that
constant. */

expression MakeCharacterConstantExpression(string s)
{
    return(MakeNullaryCall(MakeConstant(s, is_basic_string)));
}

/* this function creates a value for a symbolic constant. the expression
e *must* be evaluable. Well, it does not seem necessary any more... */

value MakeValueSymbolic(expression e)
{
  symbolic s;
  value v;

  if (value_unknown_p(v = EvalExpression(e))) {
    /* pips_internal_error("value of parameter must be constant"); */
    free_value(v);
    s = make_symbolic(e, make_constant_unknown());
    /* s = make_symbolic(e, make_constant(is_constant_unknown, UU)); */
  }
  else {
    pips_assert("v is a constant value", value_constant_p(v));

    s = make_symbolic(e, value_constant(v));

    value_constant(v) = constant_undefined;
    free_value(v);
  }

  return make_value(is_value_symbolic, s);
}

bool signed_constant_expression_p(expression e)
{
    syntax es = expression_syntax(e);
    bool ok = true;

    if(syntax_call_p(es)) {
	entity ce = call_function(syntax_call(es));

	if(!entity_constant_p(ce)) {
	    list args = call_arguments(syntax_call(es));

	    if(ce==CreateIntrinsic(UNARY_MINUS_OPERATOR_NAME)) {
		syntax arg = expression_syntax(EXPRESSION(CAR(args)));
		if( syntax_call_p(arg)) {
		    entity mce = call_function(syntax_call(arg));
		    ok = entity_constant_p(mce);
		}
		else {
		    ok = false;
		}
	    }
	    else {
		ok = false;
	    }
	}
    }
    return ok;
}

basic constant_basic(entity c)
{
  basic b = variable_basic(type_variable(functional_result(type_functional(entity_type(c)))));
  return b;
}

double float_constant_to_double(entity c)
{
  double d = 0.0;
  int i = 0;

  pips_assert("entity is constant", entity_constant_p(c));
  pips_assert("constant is float", basic_float_p(constant_basic(c)));

  i = sscanf(module_local_name(c), "%lf", &d);
  if(i!=1)
    i = sscanf(module_local_name(c), "%le", &d);
  if(i!=1)
    i = sscanf(module_local_name(c), "%lg", &d);
  if(i!=1)
    pips_internal_error("No adequate format for float constant");

  return d;
}

/* BEGIN_EOLE */ /* - please do not remove this line */
/* Lines between BEGIN_EOLE and END_EOLE tags are automatically included
   in the EOLE project (JZ - 11/98) */


/* whether the given function is a constant expression, whatever the type.
 * FI -> JZ: unsigned numerical constant expression?
 */
bool expression_is_constant_p(expression e)
{
    syntax s = expression_syntax(e);

    return syntax_call_p(s) ?
	entity_constant_p(call_function(syntax_call(s))) : false ;

}
/* END_EOLE */