1

/*

     2

 *  matiec - a compiler for the programming languages defined in IEC 61131-3

     3

 *

     4

 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

     6

 *

     7

 *  This program is free software: you can redistribute it and/or modify

     8

 *  it under the terms of the GNU General Public License as published by

     9

 *  the Free Software Foundation, either version 3 of the License, or

    10

 *  (at your option) any later version.

    11

 *

    12

 *  This program is distributed in the hope that it will be useful,

    13

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

    14

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    15

 *  GNU General Public License for more details.

    16

 *

    17

 *  You should have received a copy of the GNU General Public License

    18

 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

    19

 *

    20

 *

    21

 * This code is made available on the understanding that it will not be

    22

 * used in safety-critical situations without a full and competent review.

    23

 */

    24

    25

/*

    26

 * An IEC 61131-3 compiler.

    27

 *

    28

 * Based on the

    29

 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

    30

 *

    31

 */

    32

    33

    34

/*

    35

 * Function parameter iterator.

    36

 * Iterate through the in/out parameters of a function declaration.

    37

 * Function blocks are also suported.

    38

 *

    39

 * This is part of the 4th stage that generates

    40

 * a c++ source program equivalent to the IL and ST

    41

 * code.

    42

 */

    43

    44

/* Given a function_declaration_c, iterate through each

    45

 * function in/out/inout parameter, returning the name

    46

 * of each parameter...function_param_iterator_c

    47

 */

    48

    49

    50

#include "../absyntax/visitor.hh"

    51

    52

    53

class function_param_iterator_c : public null_visitor_c {

    54

  public:

    55

    /* A type to specify the type of parameter.

    56

     * VAR_INPUT => direction_in

    57

     * VAR_OUTPUT => direction_out

    58

     * VAR_IN_OUT => direction_inout

    59

     * VAR_EXTERNAL => direction_extref

    60

     *

    61

     * Note that VAR_EXTERNAL declares variables that are in reality references

    62

     * to global variables. This is used only inside programs!

    63

     * These references to external variables must be correctly initialised to refer

    64

     * to the correct global variable. Note that the user may define which variable is to be

    65

     * referenced in a CONFIGURATION, and that different instantiations of a program

    66

     * may have the same external variable reference diffenrent global variables!

    67

     * The references must therefore be correctly initialised when the program instance

    68

     * is created. This may be done by the PROGRAM class constructor since the ST and IL

    69

     * languages do not allow the VAR_EXTERNAL reference to change at runtime

    70

     * for a specific instance.

    71

     *

    72

     * We therefore need to call a PROGRAM class constructor with the variables

    73

     * that should be refernced by the VAR_EXTERNAL variables. The direction_extref will

    74

     * be used to identify these parameters!

    75

     */

    76

    typedef enum {direction_in, direction_out, direction_inout, direction_extref} param_direction_t ;

    77

    78

    79

  private:

    80

    /* a pointer to the function_block_declaration_c

    81

    * or function_declaration_c currently being analysed.

    82

    */

    83

    symbol_c *f_decl;

    84

    int next_param, param_count;

    85

    /* used when called to search() for a parameter by name */

    86

    identifier_c *search_param_name;

    87

    /* used when called to iterate() for a parameter */

    88

    identifier_c *current_param_name;

    89

    symbol_c *current_param_type;

    90

    symbol_c *current_param_default_value;

    91

    param_direction_t current_param_direction;

    92

    bool en_eno_param_implicit;

    93

    /* Which operation of the class was called...

    94

     * Search a parameter, or iterate to the next parameter.

    95

     */

    96

    typedef enum {iterate_op, search_op} operation_t;

    97

    operation_t current_operation;

    98

    99

  private:

   100

    void* handle_param_list(list_c *list);

   101

    void* handle_single_param(symbol_c *var_name);

   102

   103

    void* iterate_list(list_c *list);

   104

   105

  public:

   106

    /* start off at the first parameter once again... */

   107

    void reset(void);

   108

   109

    /* initialise the iterator object.

   110

     * We must be given a reference to one of the following

   111

     *     - function_declaration_c

   112

     *     - function_block_declaration_c

   113

     *     - program_declaration_c

   114

     * that will be analysed...

   115

     */

   116

    function_param_iterator_c(symbol_c *pou_decl);

   117

   118

    /* Skip to the next parameter. After object creation,

   119

     * the object references on parameter _before_ the first, so

   120

     * this function must be called once to get the object to

   121

     * reference the first parameter...

   122

     *

   123

     * Returns the parameter's name!

   124

     */

   125

    identifier_c *next(void);

   126

   127

    /* Search for the parameter named <param_name>...  */

   128

    /* The seach() function does not in any way affect the internal state related 

   129

     * to the iterate() function.

   130

     * It will, however, affect the internal state necessary to correctly

   131

     * return the param_type() and default_value() of the found parameter.

   132

     */

   133

    identifier_c *search(symbol_c *param_name);

   134

   135

    /* Returns the currently referenced parameter's default value,

   136

     * or NULL if none is specified in the function declrataion itself.

   137

     */

   138

    symbol_c *default_value(void);

   139

   140

    /* Returns the currently referenced parameter's type name. */

   141

    symbol_c *param_type(void);

   142

   143

    /* Returns if currently referenced parameter is an implicit defined EN/ENO parameter. */

   144

    bool is_en_eno_param_implicit(void);

   145

   146

    /* Returns the currently referenced parameter's data passing direction.

   147

     * i.e. VAR_INPUT, VAR_OUTPUT or VAR_INOUT

   148

     */

   149

    param_direction_t param_direction(void);

   150

   151

    private:

   152

    void *visit(implicit_definition_c *symbol);

   153

    /******************************************/

   154

    /* B 1.4.3 - Declaration & Initialisation */

   155

    /******************************************/

   156

    void *visit(input_declarations_c *symbol);

   157

   158

    void *visit(input_declaration_list_c *symbol);

   159

   160

    void *visit(edge_declaration_c *symbol);

   161

    void *visit(en_param_declaration_c *symbol);

   162

    /* var1_list ':' array_spec_init */

   163

    //SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)

   164

    void *visit(array_var_init_decl_c *symbol);

   165

   166

    /*  var1_list ':' initialized_structure */

   167

    //SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)

   168

    void *visit(structured_var_init_decl_c *symbol);

   169

   170

#if 0

   171

/* name_list ':' function_block_type_name ASSIGN structure_initialization */

   172

/* structure_initialization -> may be NULL ! */

   173

SYM_REF4(fb_name_decl_c, fb_name_list, function_block_type_name, structure_initialization, unused)

   174

   175

/* name_list ',' fb_name */

   176

SYM_LIST(fb_name_list_c)

   177

#endif

   178

   179

    void *visit(output_declarations_c *symbol);

   180

    void *visit(eno_param_declaration_c *symbol);

   181

    void *visit(input_output_declarations_c *symbol);

   182

    void *visit(var_declaration_list_c *symbol);

   183

   184

   185

    /*  var1_list ':' array_specification */

   186

    //SYM_REF2(array_var_declaration_c, var1_list, array_specification)

   187

    void *visit(array_var_declaration_c *symbol);

   188

   189

    /*  var1_list ':' structure_type_name */

   190

    //SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name)

   191

    void *visit(structured_var_declaration_c *symbol);

   192

   193

    /* VAR [CONSTANT] var_init_decl_list END_VAR */

   194

    void *visit(var_declarations_c *symbol);

   195

   196

#if 0

   197

/*  VAR RETAIN var_init_decl_list END_VAR */

   198

SYM_REF2(retentive_var_declarations_c, var_init_decl_list, unused)

   199

   200

/*  VAR [CONSTANT|RETAIN|NON_RETAIN] located_var_decl_list END_VAR */

   201

/* option -> may be NULL ! */

   202

SYM_REF2(located_var_declarations_c, option, located_var_decl_list)

   203

   204

/* helper symbol for located_var_declarations */

   205

/* located_var_decl_list located_var_decl ';' */

   206

SYM_LIST(located_var_decl_list_c)

   207

   208

/*  [variable_name] location ':' located_var_spec_init */

   209

/* variable_name -> may be NULL ! */

   210

SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

   211

#endif

   212

   213

    /*| VAR_EXTERNAL [CONSTANT] external_declaration_list END_VAR */

   214

    /* option -> may be NULL ! */

   215

    // SYM_REF2(external_var_declarations_c, option, external_declaration_list)

   216

    void *visit(external_var_declarations_c *symbol);

   217

   218

    /* helper symbol for external_var_declarations */

   219

    /*| external_declaration_list external_declaration';' */

   220

    // SYM_LIST(external_declaration_list_c)

   221

    void *visit(external_declaration_list_c *symbol);

   222

   223

    /*  global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */

   224

    //SYM_REF2(external_declaration_c, global_var_name, specification)

   225

    void *visit(external_declaration_c *symbol);

   226

   227

   228

#if 0

   229

/*| VAR_GLOBAL [CONSTANT|RETAIN] global_var_decl_list END_VAR */

   230

/* option -> may be NULL ! */

   231

SYM_REF2(global_var_declarations_c, option, global_var_decl_list)

   232

   233

/* helper symbol for global_var_declarations */

   234

/*| global_var_decl_list global_var_decl ';' */

   235

SYM_LIST(global_var_decl_list_c)

   236

   237

/*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

   238

/* type_specification ->may be NULL ! */

   239

SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

   240

   241

/*| global_var_name location */

   242

SYM_REF2(global_var_spec_c, global_var_name, location)

   243

   244

/*  AT direct_variable */

   245

SYM_REF2(location_c, direct_variable, unused)

   246

   247

/*| global_var_list ',' global_var_name */

   248

SYM_LIST(global_var_list_c)

   249

   250

/*  var1_list ':' single_byte_string_spec */

   251

SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec)

   252

   253

/*  STRING ['[' integer ']'] [ASSIGN single_byte_character_string] */

   254

/* integer ->may be NULL ! */

   255

/* single_byte_character_string ->may be NULL ! */

   256

SYM_REF2(single_byte_string_spec_c, integer, single_byte_character_string)

   257

   258

/*  var1_list ':' double_byte_string_spec */

   259

SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec)

   260

   261

/*  WSTRING ['[' integer ']'] [ASSIGN double_byte_character_string] */

   262

/* integer ->may be NULL ! */

   263

/* double_byte_character_string ->may be NULL ! */

   264

SYM_REF2(double_byte_string_spec_c, integer, double_byte_character_string)

   265

   266

/*| VAR [RETAIN|NON_RETAIN] incompl_located_var_decl_list END_VAR */

   267

/* option ->may be NULL ! */

   268

SYM_REF2(incompl_located_var_declarations_c, option, incompl_located_var_decl_list)

   269

   270

/* helper symbol for incompl_located_var_declarations */

   271

/*| incompl_located_var_decl_list incompl_located_var_decl ';' */

   272

SYM_LIST(incompl_located_var_decl_list_c)

   273

   274

/*  variable_name incompl_location ':' var_spec */

   275

SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused)

   276

   277

/*  AT incompl_location_token */

   278

SYM_TOKEN(incompl_location_c)

   279

#endif

   280

   281

   282

    void *visit(var1_init_decl_c *symbol);

   283

    void *visit(var1_list_c *symbol);

   284

    void *visit(var_init_decl_list_c *symbol);

   285

   286

   287

    /***********************/

   288

    /* B 1.5.1 - Functions */

   289

    /***********************/

   290

    void *visit(function_declaration_c *symbol);

   291

    /* intermediate helper symbol for function_declaration */

   292

    void *visit(var_declarations_list_c *symbol);

   293

    void *visit(function_var_decls_c *symbol);

   294

   295

   296

    /*****************************/

   297

    /* B 1.5.2 - Function Blocks */

   298

    /*****************************/

   299

    /*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

   300

    void *visit(function_block_declaration_c *symbol);

   301

   302

    /* intermediate helper symbol for function_declaration */

   303

    /*  { io_var_declarations | other_var_declarations }   */

   304

    /*

   305

     * NOTE: we re-use the var_declarations_list_c

   306

     */

   307

   308

    /*  VAR_TEMP temp_var_decl_list END_VAR */

   309

    void *visit(temp_var_decls_c *symbol);

   310

    void *visit(temp_var_decls_list_c *symbol);

   311

   312

    /*  VAR NON_RETAIN var_init_decl_list END_VAR */

   313

    void *visit(non_retentive_var_decls_c *symbol);

   314

   315

   316

    /**********************/

   317

    /* B 1.5.3 - Programs */

   318

    /**********************/

   319

    /*  PROGRAM program_type_name program_var_declarations_list function_block_body END_PROGRAM */

   320

    // SYM_REF4(program_declaration_c, program_type_name, var_declarations, function_block_body, unused)

   321

    void *visit(program_declaration_c *symbol);

   322

   323

    /* intermediate helper symbol for program_declaration_c */

   324

    /*  { io_var_declarations | other_var_declarations }   */

   325

    /*

   326

     * NOTE: we re-use the var_declarations_list_c

   327

     */

   328

   329

}; // function_param_iterator_c

   330

   331

   332

   333

   334

   335

   336