Added some comments. Fixed some accesses to potential NULL pointers.
/*
* (c) 2003 Mario de Sousa
*
* Offered to the public 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.
*
* This program 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.
*
* This code is made available on the understanding that it will not be
* used in safety-critical situations without a full and competent review.
*/
/*
* An IEC 61131-3 IL and ST compiler.
*
* Based on the
* FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
*
*/
/*
* Code to be included into the code generated by the 4th stage.
*
* This is part of the 4th stage that generates
* a c++ source program equivalent to the IL and ST
* code.
*/
#ifndef __PLCIEC_H
#define __PLCIEC_H
//#include <stdio.h>
#include "plc.h"
#include <math.h>
#include <time.h>
/* function that generates an IEC runtime error */
void IEC_error(void) {
/* TODO... */
fprintf(stderr, "IEC 61131-3 runtime error.\n");
exit(1);
}
typedef bool BOOL;
#define TRUE true
#define FALSE false
typedef i8 SINT;
typedef i16 INT;
typedef i32 DINT;
typedef i64 LINT;
typedef u8 USINT;
typedef u16 UINT;
typedef u32 UDINT;
typedef u64 ULINT;
typedef u8 BYTE;
typedef u16 WORD;
typedef u32 DWORD;
typedef u64 LWORD;
typedef f32 REAL;
typedef f64 LREAL;
/*********************************************/
/* TIME AND DATE data trypes */
/*********************************************/
/* NOTE: All the time and date data types use a struct timespec
* internally to store the time and date. This is so as to ease all the
* operations (add, subtract, multiply and division) the standard defines
* on these same data types.
* However, in order to ease the implementation of the comparison operators
* (==, =>, <=, <, >, <>), the two elements in the timespec structure
* must be handled in such a way as to guarantee the following:
* - The stored time is always the result of the operation tv_sec + tv_nsec*1e-9
* - tv_sec and tv_nsec will always have the same sign
* (i.e. either both positive or both negative)
* - tv_nsec always holds a value in the range ]-1, +1[ seconds.
* (note that -1 and +1 are excluded form the range)
*/
/* NOTE: According to the C++ standard, the result of the % and / operations is implementation dependent
* when the at least one of the operands is negative! However, whatever the result of the operations, we are
* guaranteed that (a/b)*b + (a%b) is always equal to a.
* This means that, even knowing that both tv_sec and tv_sec always have the same sign (we make it so this is true),
* we must still re-normailze the result for both the addition and subtraction operations!
*/
static inline void __normalizesign_timespec (struct timespec *ts) {
if ((ts->tv_sec > 0) && (ts->tv_nsec < 0)) {
ts->tv_sec--;
ts->tv_nsec += 1000000000;
}
if ((ts->tv_sec < 0) && (ts->tv_nsec > 0)) {
ts->tv_sec++;
ts->tv_nsec -= 1000000000;
}
}
static inline struct timespec __add_timespec (const struct timespec &t1, const struct timespec &t2) {
/* NOTE the following sum works correctly because a long can hold a litle more than 2 seconds expressed in nano seconds! */
long nsec;
nsec = t1.tv_nsec + t2.tv_nsec;
struct timespec ts;
ts.tv_sec = t1.tv_sec + t2.tv_sec + (nsec / 1000000000);
ts.tv_nsec = nsec % 1000000000;
__normalizesign_timespec(&ts);
return ts;
}
static inline struct timespec __sub_timespec (const struct timespec &t1, const struct timespec &t2) {
/* NOTE the following subtraction works correctly because a long can hold a litle more than 2 seconds expressed in nano seconds! */
long nsec = t1.tv_nsec - t2.tv_nsec;
struct timespec ts;
ts.tv_sec = t1.tv_sec - t2.tv_sec + nsec / 1000000000;
ts.tv_nsec = nsec % 1000000000;
__normalizesign_timespec(&ts);
return ts;
}
static inline struct timespec __mul_timespec (const struct timespec &t1, const long double value) {
#if 0
/* A simple implementation that risks reducing the precision of the TIME value */
long double sec_d1 = t1.tv_nsec / (long double)1e9 * value;
long double sec_d2 = t1.tv_sec * value;
long int sec = (long int)truncl(sec_d1 + sec_d2);
struct timespec ts;
ts.tv_sec = sec;
ts.tv_nsec = (long int)((sec_d1 + sec_d2 - sec)*1e9);
return ts;
#else
/* A more robust implementation that reduces the loss of precision of the TIME value */
/* NOTE: The following assumes that the value stored in tv_nsec is never larger than 1 sec
* and is also based on the fact that tv_nsec can safely store slighlty more thanb 2 sec.
*/
long double sec_d1 = t1.tv_nsec / (long double)1e9 * value;
long double sec_d2 = t1.tv_sec * value;
long int sec1 = (long int)sec_d1;
long int sec2 = (long int)sec_d2;
struct timespec ts;
ts.tv_sec = sec1 + sec2;
ts.tv_nsec = (long int)(((sec_d1 - sec1) + (sec_d2 - sec2))*1e9);
/* re-normalize the value of tv_nsec */
/* i.e. guarantee that it falls in the range ]-1, +1[ seconds. */
if (ts.tv_nsec >= 1000000000) {ts.tv_nsec -= 1000000000; ts.tv_sec += 1;}
if (ts.tv_nsec <= -1000000000) {ts.tv_nsec += 1000000000; ts.tv_sec -= 1;}
/* We don't need to re-normalize the sign, since we are guaranteed that tv_sec and tv_nsec
* will still both have the same sign after being multiplied by the same value.
*/
return ts;
#endif
}
/* Helper Macro for the comparison operators... */
#define __compare_timespec(CMP, t1, t2) ((t1.tv_sec == t2.tv_sec)? t1.tv_nsec CMP t2.tv_nsec : t1.tv_sec CMP t2.tv_sec)
/* Some necessary forward declarations... */
class TIME;
class TOD;
class DT;
class DATE;
typedef struct timespec __timebase_t;
class TIME{
private:
/* private variable that contains the value of time. */
/* NOTE: The stored value is _always_ (time.tv_sec + time.tv_nsec),
no matter whether tv_sec is positive or negative, or tv_nsec is positive or negative.
*/
__timebase_t time;
public:
/* conversion to __timebase_t */
operator __timebase_t(void) {return time;}
/* constructors... */
TIME (void) {time.tv_sec = 0; time.tv_nsec = 0;}
TIME (__timebase_t time) {this->time = time;}
TIME (const TIME &time) {this->time = time.time;} /* copy constructor */
TIME(int sign, double mseconds, double seconds=0, double minutes=0, double hours=0, double days=0) {
/* sign is 1 for positive values, -1 for negative time... */
long double total_sec = ((days*24 + hours)*60 + minutes)*60 + seconds + mseconds/1e3;
if (sign >= 0) sign = 1; else sign = -1;
time.tv_sec = sign * (long int)total_sec;
time.tv_nsec = sign * (long int)((total_sec - time.tv_sec)*1e9);
}
/* used in plciec.cc to set the value of the __CURRENT_TIME variable without having to call a
* TIME((__timebase_t time) constructor followed by the copy constructor.
*/
void operator= (__timebase_t time) {this->time = time;}
/* Arithmetic operators (section 2.5.1.5.6. of version 2 of the IEC 61131-3 standard) */
TIME operator+ (const TIME &time) {return TIME(__add_timespec(this->time, time.time));}
TIME operator- (const TIME &time) {return TIME(__sub_timespec(this->time, time.time));}
friend TOD operator+ (const TIME &time, const TOD &tod);
friend TOD operator+ (const TOD &tod, const TIME &time);
friend TOD operator- (const TOD &tod, const TIME &time);
friend DT operator+ (const TIME &time, const DT &dt);
friend DT operator+ (const DT &dt, const TIME &time);
friend DT operator- (const DT &dt, const TIME &time);
friend TIME operator* (const TIME &time, const long double value);
friend TIME operator* (const long double value, const TIME &time);
friend TIME operator/ (const TIME &time, const long double value);
/* Comparison operators (section 2.5.1.5.4. of version 2 of the IEC 61131-3 standard) */
BOOL operator> (const TIME &time) {return __compare_timespec(>, this->time, time.time);}
BOOL operator>= (const TIME &time) {return __compare_timespec(>=, this->time, time.time);}
BOOL operator< (const TIME &time) {return __compare_timespec(<, this->time, time.time);}
BOOL operator<= (const TIME &time) {return __compare_timespec(<=, this->time, time.time);}
BOOL operator== (const TIME &time) {return __compare_timespec(==, this->time, time.time);}
BOOL operator!= (const TIME &time) {return !__compare_timespec(==, this->time, time.time);}
};
/* Time of Day */
class TOD {
private:
__timebase_t time;
public:
/* conversion to __timebase_t */
operator __timebase_t(void) {return time;}
/* constructors... */
TOD (void) {time.tv_sec = 0; time.tv_nsec = 0;}
TOD (__timebase_t time) {this->time = time;}
TOD (const TOD &tod) {this->time = tod.time;} /* copy constructor */
TOD (double seconds, double minutes=0, double hours=0) {
long double total_sec = (hours*60 + minutes)*60 + seconds;
time.tv_sec = (long int)total_sec;
time.tv_nsec = (long int)((total_sec - time.tv_sec)*1e9);
}
/* Arithmetic operators (section 2.5.1.5.6. of version 2 of the IEC 61131-3 standard) */
TIME operator- (const TOD &tod) {return TIME(__sub_timespec(this->time, tod.time));}
friend TOD operator+ (const TIME &time, const TOD &tod);
friend TOD operator+ (const TOD &tod, const TIME &time);
friend TOD operator- (const TOD &tod, const TIME &time);
/* The following operation is not in the standard,
* but will ease the implementation of the default function CONCAT_DATE_TOD
*/
friend DT operator+ (const DATE &date, const TOD &tod);
friend DT operator+ (const TOD &tod, const DATE &date);
/* Comparison operators (section 2.5.1.5.4. of version 2 of the IEC 61131-3 standard) */
BOOL operator> (const TOD &tod) {return __compare_timespec(>, this->time, tod.time);}
BOOL operator>= (const TOD &tod) {return __compare_timespec(>=, this->time, tod.time);}
BOOL operator< (const TOD &tod) {return __compare_timespec(<, this->time, tod.time);}
BOOL operator<= (const TOD &tod) {return __compare_timespec(<=, this->time, tod.time);}
BOOL operator== (const TOD &tod) {return __compare_timespec(==, this->time, tod.time);}
BOOL operator!= (const TOD &tod) {return !__compare_timespec(==, this->time, tod.time);}
};
//typedef DATE;
class DATE {
private:
__timebase_t time;
public:
/* conversion to __timebase_t */
operator __timebase_t(void) {return time;}
/* constructors... */
DATE (void) {time.tv_sec = 0; time.tv_nsec = 0;}
DATE (__timebase_t time) {this->time = time;}
DATE (const DATE &date) {this->time = date.time;} /* copy constructor */
DATE (int day, int month, int year) {
struct tm broken_down_time;
broken_down_time.tm_sec = 0;
broken_down_time.tm_min = 0;
broken_down_time.tm_hour = 0;
broken_down_time.tm_mday = day; /* day of month, from 1 to 31 */
broken_down_time.tm_mon = month - 1; /* month since January, in the range 0 to 11 */
broken_down_time.tm_year = year - 1900; /* number of years since 1900 */
time_t epoch_seconds = mktime(&broken_down_time); /* determine number of seconds since the epoch, i.e. Jan 1st 1970 */
if ((time_t)(-1) == epoch_seconds)
IEC_error();
time.tv_sec = epoch_seconds;
time.tv_nsec = 0;
}
/* Arithmetic operators (section 2.5.1.5.6. of version 2 of the IEC 61131-3 standard) */
TIME operator- (const DATE &date) {return TIME(__sub_timespec(this->time, date.time));}
/* The following operation is not in the standard,
* but will ease the implementation of the default function CONCAT_DATE_TOD
*/
friend DT operator+ (const DATE &date, const TOD &tod);
friend DT operator+ (const TOD &tod, const DATE &date);
/* Comparison operators (section 2.5.1.5.4. of version 2 of the IEC 61131-3 standard) */
BOOL operator> (const DATE &date) {return __compare_timespec(>, this->time, date.time);}
BOOL operator>= (const DATE &date) {return __compare_timespec(>=, this->time, date.time);}
BOOL operator< (const DATE &date) {return __compare_timespec(<, this->time, date.time);}
BOOL operator<= (const DATE &date) {return __compare_timespec(<=, this->time, date.time);}
BOOL operator== (const DATE &date) {return __compare_timespec(==, this->time, date.time);}
BOOL operator!= (const DATE &date) {return !__compare_timespec(==, this->time, date.time);}
};
class DT {
private:
__timebase_t time;
public:
/* conversion to __timebase_t */
operator __timebase_t(void) {return time;}
/* constructors... */
DT (void) {time.tv_sec = 0; time.tv_nsec = 0;}
DT (__timebase_t time) {this->time = time;}
DT (const DT &dt) {this->time = dt.time;} /* copy constructor */
DT (double seconds, double minutes, double hours, int day, int month, int year) {
long double total_sec = (hours*60 + minutes)*60 + seconds;
time.tv_sec = (long int)total_sec;
time.tv_nsec = (long int)((total_sec - time.tv_sec)*1e9);
struct tm broken_down_time;
broken_down_time.tm_sec = 0;
broken_down_time.tm_min = 0;
broken_down_time.tm_hour = 0;
broken_down_time.tm_mday = day; /* day of month, from 1 to 31 */
broken_down_time.tm_mon = month - 1; /* month since January, in the range 0 to 11 */
broken_down_time.tm_year = year - 1900; /* number of years since 1900 */
time_t epoch_seconds = mktime(&broken_down_time); /* determine number of seconds since the epoch, i.e. Jan 1st 1970 */
if ((time_t)(-1) == epoch_seconds)
IEC_error();
time.tv_sec += epoch_seconds;
if (time.tv_sec < epoch_seconds)
/* since the TOD is always positive, if the above happens then we had an overflow */
IEC_error();
}
/* Helpers to conversion operators (section 2.5.1.5.6. of version 2 of the IEC 61131-3 standard) */
DATE __to_DATE(void) {
#if 0
/* slow version */
struct tm broken_down_time;
time_t seconds = time.tv_sec;
if (NULL == gmtime_r(seconds, &broken_down_time)) /* get the UTC (GMT) broken down time */
IEC_error();
return DATE(broken_down_time.tm_mday, broken_down_time.tm_mon, broken_down_time.tm_year);
#else
/* Faster version, based on the fact that the date will always be a multiple of 60*60*24 seconds,
* and that the value of tv_nsec falls in the range ]-1, +1[
*/
/* The above is true since the Unix function mktime() seems to ignore all leap seconds! */
struct timespec date_time = {time.tv_sec - (time.tv_sec % (24*60*60)), 0};
return DATE(date_time);
#endif
}
TOD __to_TOD(void) {
#if 0
/* slow version */
struct tm broken_down_time;
time_t seconds = time.tv_sec;
if (NULL == gmtime_r(seconds, &broken_down_time)) /* get the UTC (GMT) broken down time */
IEC_error();
return TOD(broken_down_time.tm_sec, broken_down_time.tm_min, broken_down_time.tm_hour);
#else
/* Faster version, based on the fact that the date will always be a multiple of 60*60*24 seconds
* and that the value of tv_nsec falls in the range ]-1, +1[
*/
/* The above is true since the Unix function mktime() seems to ignore all leap seconds! */
struct timespec time_time = {time.tv_sec % (24*60*60), time.tv_nsec};
return TOD(time_time);
#endif
}
/* Arithmetic operators (section 2.5.1.5.6. of version 2 of the IEC 61131-3 standard) */
TIME operator- (const DT &dt) {return TIME(__sub_timespec(this->time, dt.time));}
friend DT operator+ (const TIME &time, const DT &dt);
friend DT operator+ (const DT &dt, const TIME &time);
friend DT operator- (const DT &dt, const TIME &time);
/* Comparison operators (section 2.5.1.5.4. of version 2 of the IEC 61131-3 standard) */
BOOL operator> (const DT &dt) {return __compare_timespec(>, this->time, dt.time);}
BOOL operator>= (const DT &dt) {return __compare_timespec(>=, this->time, dt.time);}
BOOL operator< (const DT &dt) {return __compare_timespec(<, this->time, dt.time);}
BOOL operator<= (const DT &dt) {return __compare_timespec(<=, this->time, dt.time);}
BOOL operator== (const DT &dt) {return __compare_timespec(==, this->time, dt.time);}
BOOL operator!= (const DT &dt) {return !__compare_timespec(==, this->time, dt.time);}
};
/* The operations on time and data types... */
TOD operator+ (const TIME &time, const TOD &tod) {return TOD(__add_timespec(tod.time, time.time));};
TOD operator+ (const TOD &tod, const TIME &time) {return TOD(__add_timespec(tod.time, time.time));};
TOD operator- (const TOD &tod, const TIME &time) {return TOD(__sub_timespec(tod.time, time.time));};
DT operator+ (const TIME &time, const DT &dt) {return DT(__add_timespec(dt.time, time.time));};
DT operator+ (const DT &dt, const TIME &time) {return DT(__add_timespec(dt.time, time.time));};
DT operator- (const DT &dt, const TIME &time) {return DT(__sub_timespec(dt.time, time.time));};
TIME operator* (const TIME &time, const long double value) {return TIME(__mul_timespec(time.time, value));}
TIME operator* (const long double value, const TIME &time) {return TIME(__mul_timespec(time.time, value));}
TIME operator/ (const TIME &time, const long double value) {return TIME(__mul_timespec(time.time, 1.0/value));}
/* The following operation is not in the standard,
* but will ease the implementation of the default function CONCAT_DATE_TOD
*/
DT operator+ (const DATE &date, const TOD &tod) {return DT(__add_timespec(date.time, tod.time));};
DT operator+ (const TOD &tod, const DATE &date) {return DT(__add_timespec(date.time, tod.time));};
/* global variable that will be used to implement the timers TON, TOFF and TP */
extern TIME __CURRENT_TIME;
//typedef STRING;
//typedef WSTRING;
typedef union __IL_DEFVAR_T {
BOOL BOOLvar;
SINT SINTvar;
INT INTvar;
DINT DINTvar;
LINT LINTvar;
USINT USINTvar;
UINT UINTvar;
UDINT UDINTvar;
ULINT ULINTvar;
BYTE BYTEvar;
WORD WORDvar;
DWORD DWORDvar;
LWORD LWORDvar;
REAL REALvar;
LREAL LREALvar;
/* NOTE: since the TIME, DATE, ... classes all have constructors,
* C++ does not allow them to be used as members of a union.
* The workaround is to use a base data type (in this case __timebase_t) that
* contains all the internal data these classes require, and then add an operator
* member function to each class that allows it to be converted to that same base data type,
* acompanied by a constructor using that data type.
*/
/*
TIME TIMEvar;
TOD TODvar;
DT DTvar;
DATE DATEvar;
*/
__timebase_t TIMEvar;
__timebase_t TODvar;
__timebase_t DTvar;
__timebase_t DATEvar;
} __IL_DEFVAR_T;
/*TODO TODO TODO TODO TODO TODO TODO TODO TODO
* How do we add support for the possibility of storing
* data values of derived data types into the default register,
* to be later used for calling functions, stroing in another
* variable, etc...?
*
* For example:
* TYPE
* point_t : STRUCT
* x : INT;
* y : INT;
* END_STRUCT;
* END_TYPE
*
* VAR p1, p2, p3 : point_t;
*
* LD p1
* ST p2
*
*
* We could do it with a pointer to void, that would contain not
* the value itself, but rather the address in which the value
* is currently stored.
* For example, we could add a
* void *generic_ptr
* to this union, and then have the above LD and ST instructions
* converted to:
* __IL_DEFVAR.generic_ptr = (void *)(&p1);
* p2 = *((point_t *)__IL_DEFVAR.generic_ptr);
*
* Unfortunately the above will only work as long as the p1 variable
* does not get a chance to change its value before the default register
* gets loaded with something esle (and therefore the value is no
* longer needed).
* Additionally, a scenario where the value of p1 may change before the
* default register gets a new value is if p1 is used in a function block
* call for an output parameter!
* For example:
*
* LD p1
* CAL funcblock(
* param1 => p1
* )
* ST p2
*
* In the above scenario, p1 gets a new value when the function block
* funcblock is called. When we get to copy the default register to
* p2, we will no longer be copying the value that got stored in the default
* register when we did 'LD p1', but rather the value returned by the
* function block call!!!
*
* How the do we implement this???
* We will probably need to declare a default variable of the correct data
* type whenever we get these values stored to the default register.
* For example
* LD p1
* ST p2
*
* would be converted to:
* union {
* point_tvar point_t;
* } __IL_DEFVAR_special ;
*
* __IL_DEFVAR_special.point_tvar = p1;
* p2 = __IL_DEFVAR_special.point_tvar;
*
* The above requires that we iterate through the whole Instruction list
* before we start the conversion, in order to first determine if we need
* to declare that new variable for the default register.
*
* Since we have to do this, it would probaly be a better idea to simply
* do away with the __IL_DEFVAR_T data type we declare here, and
* declare the __IL_DEFVAR at the begining of each IL code segment
* with all the data types that get used in that segment!
*/
/* Names start with double underscore so as not to clash with
* names in ST or IL source code! Names including a double underscore are
* ilegal under IL and ST!
*/
/* This is an abstract base class, that cannot be instantiated... */
template<typename value_type> class __ext_ref_c {
public:
virtual void operator= (value_type value) = 0;
virtual operator value_type(void) = 0;
};
/* Names start with double underscore so as not to clash with
* names in ST or IL source code! Names including a double underscore are
* ilegal under IL and ST!
*/
template<typename value_type> class __ext_element_c
: public __ext_ref_c<value_type> {
//{
private:
value_type value;
public:
virtual void operator= (value_type value) {
this->value = value;
}
virtual operator value_type(void) {
return value;
}
__ext_element_c(void) {}
__ext_element_c(value_type value) {
this->value = value;
}
};
/* Names start with double underscore so as not to clash with
* names in ST or IL source code! Names including a double underscore are
* ilegal under IL and ST!
*/
template<typename value_type, int size = 8 * sizeof(value_type) /* in bits */> class __plc_pt_c
: public __ext_ref_c<value_type> {
private:
plc_pt_t plc_pt;
bool valid_plc_pt;
private:
void init_name(const char *pt_name) {
/* assume error! */
valid_plc_pt = false;
plc_pt = plc_pt_by_name(pt_name);
if (plc_pt.valid == 0) {
plc_pt = plc_pt_null();
return;
}
/* We can't have this check here, otherwise the boolean variables won't work correctly,
* since MatPLC uses 1 bit for boolean variables, whereas g++ uses 8 bits.
*/
/*
if (plc_pt_len(plc_pt) != size) {
plc_pt = plc_pt_null();
return;
}
*/
valid_plc_pt = true;
}
public:
virtual void operator= (value_type value) {
plc_set(plc_pt, *((u32 *)&value));
}
virtual operator value_type(void) {
u32 tmp_val = plc_get(plc_pt);
return *((value_type *)&tmp_val);
}
__plc_pt_c(const char *pt_name) {
init_name(pt_name);
}
__plc_pt_c(const char *pt_name, value_type init_value) {
init_name(pt_name);
*this = init_value;
}
bool valid(void) {return valid_plc_pt;}
};
#define DEFAULT_MODULE_NAME "iec"
#endif /* __PLCIEC_H */