Add support for non-standard VOID datatype. May ony be used to define functions returning VOID.
/*
* matiec - a compiler for the programming languages defined in IEC 61131-3
*
* Copyright (C) 2003-2011 Mario de Sousa (msousa@fe.up.pt)
* Copyright (C) 2007-2011 Laurent Bessard and Edouard Tisserant
*
* 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 3 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* 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 compiler.
*
* Based on the
* FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
*
*/
/*
* Determine the default initial value of a type declaration.
*
* This is part of the 4th stage that generates
* a c++ source program equivalent to the IL and ST
* code.
*/
/* Given a type definition declration, determine its default
* initial value. Note that types based on other types
* may have to iterate through each type it is based on
* to determine the initial value.
* E.g.
* TYPE
* A_t : INT := 10;
* B_t : A_t := 20;
* C_t : B_t;
* D_t : C_t := 40;
* END_TYPE
* Where the default initial value for C_t is 20!
*/
/* NOTE: The main program only needs one instance of
* this class of object. This class
* is therefore a singleton.
*/
#include "absyntax_utils.hh"
//#define DEBUG
#ifdef DEBUG
#define TRACE(classname) printf("\n____%s____\n",classname);
#else
#define TRACE(classname)
#endif
type_initial_value_c *type_initial_value_c::instance(void) {
if (_instance != NULL)
return _instance;
_instance = new type_initial_value_c;
null_literal = new ref_value_null_literal_c();
real_0 = new real_c("0");
integer_0 = new integer_c("0");
integer_1 = new integer_c("1");
bool_0 = new boolean_literal_c(new bool_type_name_c(),new boolean_false_c());
/* FIXME: Our current implementation only allows dates from 1970 onwards,
* but the standard defines the date 0001-01-01 as the default value
* for the DATE data type. Untill we fix our implementation, we use 1970-01-01
* as our default value!!
*/
//date_literal_0 = new date_literal_c(integer_1, integer_1, integer_1);
date_literal_0 = new date_literal_c(new integer_c("1970"), integer_1, integer_1);
daytime_literal_0 = new daytime_c(integer_0, integer_0, real_0);
time_0 = new duration_c (new time_type_name_c(), NULL, new interval_c(NULL, NULL, NULL, integer_0, NULL)); // T#0s
date_0 = new date_c (new date_type_name_c(), date_literal_0); // D#0001-01-01
tod_0 = new time_of_day_c (new tod_type_name_c(), daytime_literal_0); // TOD#00:00:00
dt_0 = new date_and_time_c(new dt_type_name_c(), date_literal_0, daytime_literal_0); // DT#0001-01-01-00:00:00
string_0 = new single_byte_character_string_c("''");
wstring_0 = new double_byte_character_string_c("\"\"");
return _instance;
}
type_initial_value_c::type_initial_value_c(void) {}
symbol_c *type_initial_value_c::get(symbol_c *type) {
TRACE("type_initial_value_c::get(): called ");
return (symbol_c *)type->accept(*type_initial_value_c::instance());
}
void *type_initial_value_c::handle_type_spec(symbol_c *base_type_name, symbol_c *type_spec_init) {
if (type_spec_init != NULL)
return type_spec_init;
/* no initial value specified, so we return the initial value of the type this type is based on... */
return base_type_name->accept(*this);
}
void *type_initial_value_c::handle_type_name(symbol_c *type_name) {
/* look up the type declaration... */
type_symtable_t::iterator iter = type_symtable.find(type_name);
/* Type declaration not found!! */
/* NOTE: Variables declared out of function block 'data types',for eg: VAR timer: TON; END_VAR
* do not have a default value, so (TON) will never be found in the type symbol table. This means
* we cannot simply consider this an error and abort, but must rather return a NULL.
*/
if (iter == type_symtable.end()) return NULL;
return iter->second->accept(*this); // iter->second is the type_decl
}
/* visitor for identifier_c should no longer be necessary. All references to derived datatypes are now stored in then */
/* AST using either poutype_identifier_c or derived_datatype_identifier_c. In principe, the following should not be necesasry */
void *type_initial_value_c::visit( identifier_c *symbol) {return handle_type_name(symbol);} /* should never occur */
void *type_initial_value_c::visit( poutype_identifier_c *symbol) {return handle_type_name(symbol);} /* in practice it might never get called, as FB, Functions and Programs do not have initial value */
void *type_initial_value_c::visit(derived_datatype_identifier_c *symbol) {return handle_type_name(symbol);}
/***********************************/
/* B 1.3.1 - Elementary Data Types */
/***********************************/
void *type_initial_value_c::visit(time_type_name_c *symbol) {return (void *)time_0;}
void *type_initial_value_c::visit(bool_type_name_c *symbol) {return (void *)bool_0;}
void *type_initial_value_c::visit(sint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(int_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(dint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(lint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(usint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(uint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(udint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(ulint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(real_type_name_c *symbol) {return (void *)real_0;}
void *type_initial_value_c::visit(lreal_type_name_c *symbol) {return (void *)real_0;}
void *type_initial_value_c::visit(date_type_name_c *symbol) {return (void *)date_0;}
void *type_initial_value_c::visit(tod_type_name_c *symbol) {return (void *)tod_0;}
void *type_initial_value_c::visit(dt_type_name_c *symbol) {return (void *)dt_0;}
void *type_initial_value_c::visit(byte_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(word_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(dword_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(lword_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(string_type_name_c *symbol) {return (void *)string_0;}
void *type_initial_value_c::visit(wstring_type_name_c *symbol) {return (void *)wstring_0;}
void *type_initial_value_c::visit(safetime_type_name_c *symbol) {return (void *)time_0;}
void *type_initial_value_c::visit(safebool_type_name_c *symbol) {return (void *)bool_0;}
void *type_initial_value_c::visit(safesint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safeint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safedint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safelint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safeusint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safeuint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safeudint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safeulint_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safereal_type_name_c *symbol) {return (void *)real_0;}
void *type_initial_value_c::visit(safelreal_type_name_c *symbol) {return (void *)real_0;}
void *type_initial_value_c::visit(safedate_type_name_c *symbol) {return (void *)date_0;}
void *type_initial_value_c::visit(safetod_type_name_c *symbol) {return (void *)tod_0;}
void *type_initial_value_c::visit(safedt_type_name_c *symbol) {return (void *)dt_0;}
void *type_initial_value_c::visit(safebyte_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safeword_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safedword_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safelword_type_name_c *symbol) {return (void *)integer_0;}
void *type_initial_value_c::visit(safestring_type_name_c *symbol) {return (void *)string_0;}
void *type_initial_value_c::visit(safewstring_type_name_c *symbol) {return (void *)wstring_0;}
/********************************/
/* B 1.3.3 - Derived data types */
/********************************/
/* simple_type_name ':' simple_spec_init */
void *type_initial_value_c::visit(simple_type_declaration_c *symbol) {
return symbol->simple_spec_init->accept(*this);
}
/* simple_specification ASSIGN constant */
void *type_initial_value_c::visit(simple_spec_init_c *symbol) {
return handle_type_spec(symbol->simple_specification, symbol->constant);
}
/* subrange_type_name ':' subrange_spec_init */
void *type_initial_value_c::visit(subrange_type_declaration_c *symbol) {
return symbol->subrange_spec_init->accept(*this);
}
/* subrange_specification ASSIGN signed_integer */
void *type_initial_value_c::visit(subrange_spec_init_c *symbol) {
return handle_type_spec(symbol->subrange_specification, symbol->signed_integer);
}
/* integer_type_name '(' subrange')' */
void *type_initial_value_c::visit(subrange_specification_c *symbol) {
/* if no initial value explicitly given, then use the lowest value of the subrange */
if (symbol->subrange != NULL)
return symbol->subrange->accept(*this);
else
return symbol->integer_type_name->accept(*this);
}
/* signed_integer DOTDOT signed_integer */
void *type_initial_value_c::visit(subrange_c *symbol) {return symbol->lower_limit;}
/* enumerated_type_name ':' enumerated_spec_init */
void *type_initial_value_c::visit(enumerated_type_declaration_c *symbol) {
return symbol->enumerated_spec_init->accept(*this);
}
/* enumerated_specification ASSIGN enumerated_value */
void *type_initial_value_c::visit(enumerated_spec_init_c *symbol) {
return handle_type_spec(symbol->enumerated_specification, symbol->enumerated_value);
}
/* helper symbol for enumerated_specification->enumerated_spec_init */
/* enumerated_value_list ',' enumerated_value */
void *type_initial_value_c::visit(enumerated_value_list_c *symbol) {
/* stage1_2 never creates an enumerated_value_list_c with no entries. If this occurs, then something must have changed! */
if (symbol->n <= 0) ERROR;
/* if no initial value explicitly given, then use the lowest value of the subrange */
return (void *)symbol->elements[0];
}
/* enumerated_type_name '#' identifier */
// SYM_REF2(enumerated_value_c, type, value)
void *type_initial_value_c::visit(enumerated_value_c *symbol) {ERROR; return NULL;}
/* identifier ':' array_spec_init */
void *type_initial_value_c::visit(array_type_declaration_c *symbol) {
return symbol->array_spec_init->accept(*this);
}
/* array_specification [ASSIGN array_initialization} */
/* array_initialization may be NULL ! */
void *type_initial_value_c::visit(array_spec_init_c *symbol) {
return handle_type_spec(symbol->array_specification, symbol->array_initialization);
}
/* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */
void *type_initial_value_c::visit(array_specification_c *symbol) {
//symbol_c *init_value = (symbol_c *)symbol->non_generic_type_name->accept(*this);
/* Now build a array_initial_elements_list_c list, and populate it
* with 1 element of the array_initial_elements_c class
*/
/* The array_initial_elements_c will contain a reference to the init_value,
* and another constant representing the number of elements in the array.
* In essence, we are building the equivilant of the following ST/IL code:
* New_array_t : ARRAY [1..30, 51..60] of INT := [40(XXX)];
* from the user given code
* New_array_t : ARRAY [1..30, 51..60] of INT;
* and replacing XXX with the default initial value of INT.
*/
/* now we need to determine the number of elements in the array... */
/* Easier said than done, as the array may have a list of subranges, as in the
* example given above!!
*/
/* TODO !!!!!*/
/* For now, just assume an array with 1 element.
* I (Mario) want to finish off this part of the code before getting boged down
* in something else...
*/
// NOTE: We are leaking memory, as the integer will never get free'd!!
//integer_c *integer = new integer_c("1");
// NOTE: We are leaking memory, as the array_initial_elements will never get free'd!!
//array_initial_elements_c *array_initial_elements = new array_initial_elements_c(integer, init_value);
// NOTE: We are leaking memory, as the array_initial_elements_list will never get free'd!!
array_initial_elements_list_c *array_initial_elements_list = new array_initial_elements_list_c();
//array_initial_elements_list->add_element(array_initial_elements);
return array_initial_elements_list;
}
/* helper symbol for array_specification */
/* array_subrange_list ',' subrange */
void *type_initial_value_c::visit(array_subrange_list_c *symbol) {ERROR; return NULL;}
/* array_initialization: '[' array_initial_elements_list ']' */
/* helper symbol for array_initialization */
/* array_initial_elements_list ',' array_initial_elements */
void *type_initial_value_c::visit(array_initial_elements_list_c *symbol) {ERROR; return NULL;}
/* integer '(' [array_initial_element] ')' */
/* array_initial_element may be NULL ! */
void *type_initial_value_c::visit(array_initial_elements_c *symbol) {ERROR; return NULL;}
/* TODO: from this point forward... */
/* structure_type_name ':' structure_specification */
void *type_initial_value_c::visit(structure_type_declaration_c *symbol) {return NULL;}
/* structure_type_name ASSIGN structure_initialization */
/* structure_initialization may be NULL ! */
void *type_initial_value_c::visit(initialized_structure_c *symbol) {
return handle_type_spec(symbol->structure_type_name, symbol->structure_initialization);
}
/* helper symbol for structure_declaration */
/* structure_declaration: STRUCT structure_element_declaration_list END_STRUCT */
/* structure_element_declaration_list structure_element_declaration ';' */
void *type_initial_value_c::visit(structure_element_declaration_list_c *symbol) {
structure_element_initialization_list_c *structure_element_initialization_list = new structure_element_initialization_list_c();
return structure_element_initialization_list;
}
/* structure_element_name ':' *_spec_init */
void *type_initial_value_c::visit(structure_element_declaration_c *symbol) {return NULL;}
/* helper symbol for structure_initialization */
/* structure_initialization: '(' structure_element_initialization_list ')' */
/* structure_element_initialization_list ',' structure_element_initialization */
void *type_initial_value_c::visit(structure_element_initialization_list_c *symbol) {return NULL;}
/* structure_element_name ASSIGN value */
void *type_initial_value_c::visit(structure_element_initialization_c *symbol) {return NULL;}
/* string_type_name ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init */
/*
* NOTE:
* (Summary: Contrary to what is expected, the
* string_type_declaration_c is not used to store
* simple string type declarations that do not include
* size limits.
* For e.g.:
* str1_type: STRING := "hello!"
* will be stored in a simple_type_declaration_c
* instead of a string_type_declaration_c.
* The following:
* str2_type: STRING [64] := "hello!"
* will be stored in a sring_type_declaration_c
*
* Read on for why this is done...
* End Summary)
*
* According to the spec, the valid construct
* TYPE new_str_type : STRING := "hello!"; END_TYPE
* has two possible routes to type_declaration...
*
* Route 1:
* type_declaration: single_element_type_declaration
* single_element_type_declaration: simple_type_declaration
* simple_type_declaration: identifier ':' simple_spec_init
* simple_spec_init: simple_specification ASSIGN constant
* (shift: identifier <- 'new_str_type')
* simple_specification: elementary_type_name
* elementary_type_name: STRING
* (shift: elementary_type_name <- STRING)
* (reduce: simple_specification <- elementary_type_name)
* (shift: constant <- "hello!")
* (reduce: simple_spec_init: simple_specification ASSIGN constant)
* (reduce: ...)
*
*
* Route 2:
* type_declaration: string_type_declaration
* string_type_declaration: identifier ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init
* (shift: identifier <- 'new_str_type')
* elementary_string_type_name: STRING
* (shift: elementary_string_type_name <- STRING)
* (shift: string_type_declaration_size <- empty )
* string_type_declaration_init: ASSIGN character_string
* (shift: character_string <- "hello!")
* (reduce: string_type_declaration_init <- ASSIGN character_string)
* (reduce: string_type_declaration <- identifier ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init )
* (reduce: type_declaration <- string_type_declaration)
*
*
* At first glance it seems that removing route 1 would make
* the most sense. Unfortunately the construct 'simple_spec_init'
* shows up multiple times in other rules, so changing this construct
* would also mean changing all the rules in which it appears.
* I (Mario) therefore chose to remove route 2 instead. This means
* that the above declaration gets stored in a
* simple_type_declaration_c, and not in a string_type_declaration_c
* as would be expected!
*/
/* string_type_name ':' elementary_string_type_name string_type_declaration_size string_type_declaration_init */
// SYM_REF4(string_type_declaration_c, string_type_name,
// elementary_string_type_name,
// string_type_declaration_size,
// string_type_declaration_init) /* may be == NULL! */
void *type_initial_value_c::visit(string_type_declaration_c *symbol) {
return handle_type_spec(symbol->elementary_string_type_name, symbol->string_type_declaration_init);
}
/* REF_TO (non_generic_type_name | function_block_type_name) */
void *type_initial_value_c::visit(ref_spec_c *symbol) {
return null_literal;
}
/* ref_spec [ ASSIGN ref_initialization ]; */
/* NOTE: ref_initialization may be NULL!! */
void *type_initial_value_c::visit(ref_spec_init_c *symbol) {
return handle_type_spec(symbol->ref_spec, symbol->ref_initialization);
}
/* identifier ':' ref_spec_init */
void *type_initial_value_c::visit(ref_type_decl_c *symbol) {
return symbol->ref_spec_init->accept(*this);
}
type_initial_value_c *type_initial_value_c::_instance = NULL;
ref_value_null_literal_c *type_initial_value_c::null_literal = NULL;
real_c *type_initial_value_c::real_0 = NULL;
integer_c *type_initial_value_c::integer_0 = NULL;
integer_c *type_initial_value_c::integer_1 = NULL;
boolean_literal_c *type_initial_value_c::bool_0 = NULL;
date_literal_c *type_initial_value_c::date_literal_0 = NULL;
daytime_c *type_initial_value_c::daytime_literal_0 = NULL;
duration_c *type_initial_value_c::time_0 = NULL;
date_c *type_initial_value_c::date_0 = NULL;
time_of_day_c *type_initial_value_c::tod_0 = NULL;
date_and_time_c *type_initial_value_c::dt_0 = NULL;
single_byte_character_string_c *type_initial_value_c::string_0 = NULL;
double_byte_character_string_c *type_initial_value_c::wstring_0 = NULL;