Stop lvalue check from segfaulting when coming across buggy IL code (IL operator with no operand!)
/*
* 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)
*
*/
/*
* Separation of type specification and default value constructs
* (for e.g. simple_spec_init_c), into a type specificiation part,
* and a default value part.
*/
#include "../absyntax/absyntax.hh"
#include "../absyntax/visitor.hh"
class spec_init_sperator_c: public null_visitor_c {
private:
/* this is a singleton class... */
static spec_init_sperator_c *class_instance;
static spec_init_sperator_c *get_class_instance(void);
private:
typedef enum {search_spec, search_init} search_what_t;
static search_what_t search_what;
public:
/* the only two public functions... */
static symbol_c *get_spec(symbol_c *spec_init);
static symbol_c *get_init(symbol_c *spec_init);
private:
/*******************************************/
/* B 1.1 - Letters, digits and identifiers */
/*******************************************/
// SYM_TOKEN(identifier_c)
void *visit(identifier_c *symbol);
/********************************/
/* B 1.3.3 - Derived data types */
/********************************/
/* simple_specification ASSIGN constant */
void *visit(simple_spec_init_c *symbol);
/* subrange_specification ASSIGN signed_integer */
void *visit(subrange_spec_init_c *symbol);
/* integer_type_name '(' subrange')' */
void *visit(subrange_specification_c *symbol);
/* array_specification [ASSIGN array_initialization} */
/* array_initialization may be NULL ! */
void *visit(array_spec_init_c *symbol);
/* enumerated_specification ASSIGN enumerated_value */
void *visit(enumerated_spec_init_c *symbol);
/* structure_type_name ASSIGN structure_initialization */
/* structure_initialization may be NULL ! */
//SYM_REF2(initialized_structure_c, structure_type_name, structure_initialization)
void *visit(initialized_structure_c *symbol);
/* function_block_type_name ASSIGN structure_initialization */
/* structure_initialization -> may be NULL ! */
//SYM_REF2(fb_spec_init_c, function_block_type_name, structure_initialization)
void *visit(fb_spec_init_c *symbol);
/******************************************/
/* B 1.4.3 - Declaration & Initialisation */
/******************************************/
/* STRING '[' integer ']'
* STRING ASSIGN single_byte_character_string
* STRING '[' integer ']' ASSIGN single_byte_character_string
*/
void *visit(single_byte_string_spec_c *symbol);
/* WSTRING '[' integer ']'
* WSTRING ASSIGN double_byte_character_string
* WSTRING '[' integer ']' ASSIGN double_byte_character_string
*/
void *visit(double_byte_string_spec_c *symbol);
}; /* class spec_init_sperator_c */