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/*

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

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 *

     4

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

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 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

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 *

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

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

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

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 *  (at your option) any later version.

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 *

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

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

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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

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

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 *

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 *

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

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

    23

 */

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#include <string.h>

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/*  This file cotains two main classes:

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 *   - generate_c_base_c

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 *   - generate_c_base_and_typeid_c

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 * 

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 *  generate_c_base_c

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 *  -----------------

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 *   This class generates C code for all literals and varables. In short, all the basic stuff

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 *   that will probably be needed in all other code generating classes.

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 *   It does not however handle derived datatypes.

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 *

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 * generate_c_base_and_typeid_c

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 * ----------------------------

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 *   This is similar to the generate_c_base_c (from which it inherits), but it also handles

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 *   all the derived datatypes. Note that it does not generate C code for the declaration of

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 *   those datatypes (that is what generate_c_typedecl_c is for), but rather it merely

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 *   generates the name/id of a derived datatype.

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 *   Note too that not all derived datatypes in the IEC 61131-3 have a name (for example, 

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 *   VAR a: ARRAY [3..5] of INT END_VAR), in which case an alias for this datatype should 

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 *   have been previously generated by either generate_c_typedecl_c or generate_implicit_typedecl_c.

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 */ 

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typedef struct

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{

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  symbol_c *param_name;

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  symbol_c *param_value;

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  symbol_c *param_type;

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  function_param_iterator_c::param_direction_t param_direction;

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} FUNCTION_PARAM;

    61

    62

#define DECLARE_PARAM_LIST()\

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  std::list<FUNCTION_PARAM*> param_list;\

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  std::list<FUNCTION_PARAM*>::iterator pt;\

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  FUNCTION_PARAM *param;

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#define ADD_PARAM_LIST(name, value, type, direction)\

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  param = new FUNCTION_PARAM;\

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  param->param_name = name;\

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  param->param_value = value;\

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  param->param_type = type;\

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  param->param_direction = direction;\

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  param_list.push_back(param);

    74

    75

#define PARAM_LIST_ITERATOR() for(pt = param_list.begin(); pt != param_list.end(); pt++)

    76

    77

#define PARAM_NAME (*pt)->param_name

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#define PARAM_VALUE (*pt)->param_value

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#define PARAM_TYPE (*pt)->param_type

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#define PARAM_DIRECTION (*pt)->param_direction

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    82

#define CLEAR_PARAM_LIST()\

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  PARAM_LIST_ITERATOR()\

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    delete *pt;\

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  param_list.clear();

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    87

    88

/*  generate_c_base_c

    89

 *  -----------------

    90

 *   This class generates C code for all literals and varables. In short, all the basic stuff

    91

 *   that will probably be needed in all other code generating classes.

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 *   It does not however handle derived datatypes.

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 */

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class generate_c_base_c: public iterator_visitor_c {

    95

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  protected:

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    stage4out_c &s4o;

    98

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  private:

   100

    /* Unlike programs that are mapped onto C++ classes, Function Blocks are mapped onto a data structure type

   101

     * and a separate function containing the code. This function is passed a pointer to an instance of the data

   102

     * structure. This means that the code inside the functions must insert a pointer to the data structure whenever

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     * it wishes to access a Function Block variable.

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     * The variable_prefix_ variable will contain the correct string which needs to be prefixed to all variable accesses.

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     * This string is set with the set_variable_prefix() member function.

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     */

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    const char *variable_prefix_;

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   109

  public:

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    generate_c_base_c(stage4out_c *s4o_ptr): s4o(*s4o_ptr) {

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      variable_prefix_ = NULL;

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    }

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    ~generate_c_base_c(void) {}

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    void set_variable_prefix(const char *variable_prefix) {variable_prefix_ = variable_prefix;}

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    const char *get_variable_prefix(void) {return variable_prefix_;}

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    bool is_variable_prefix_null(void) {return variable_prefix_ == NULL;}

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    void print_variable_prefix(void) {

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      if (variable_prefix_ != NULL)

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        s4o.print(variable_prefix_);

   121

    }

   122

   123

    void print_line_directive(symbol_c *symbol) {

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      if (!generate_line_directives__) return; /* global variable generate_line_directives__ is defined in generate_c.cc */

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      s4o.print("#line ");

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      s4o.print(symbol->first_line);

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      s4o.print(" \"");

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      s4o.print(symbol->first_file);

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      s4o.print("\"\n");    

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    }

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   132

    void *print_token(token_c *token, int offset = 0) {

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      return s4o.printupper((token->value)+offset);

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    }

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    void *print_literal(symbol_c *type, symbol_c *value) {

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      s4o.print("__");

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      type->accept(*this);

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      s4o.print("_LITERAL(");

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      value->accept(*this);

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      s4o.print(")");

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      return NULL;

   143

    }

   144

   145

    void *print_striped_token(token_c *token, int offset = 0) {

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      std::string str = "";

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      bool leading_zero = true;

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      for (unsigned int i = offset; i < strlen(token->value); i++) {

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        if (leading_zero

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            && (   token->value[i] != '0'

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                || i == strlen(token->value) - 1

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                || token->value[i + 1] == '.'

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                )

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            )

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          leading_zero = false;

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            if (!leading_zero && token->value[i] != '_')

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          str += token->value[i];

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      }

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      return s4o.printupper(str);

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    }

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   162

    void *print_striped_binary_token(token_c *token, unsigned int offset = 0) {

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      /* convert the binary value to hexadecimal format... */

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      unsigned char value, bit_mult;

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      unsigned int i;

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      int total_bits;

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      char str[2] = {'A', '\0'};  /* since the s4o object is not prepared to print out one character at a time... */

   168

   169

      s4o.print("0x");

   170

   171

      total_bits = 0;

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      for (i = offset; i < strlen(token->value); i++)

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        if (token->value[i] != '_')

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          total_bits++;

   175

   176

      value = 0;

   177

      bit_mult = (unsigned char)1 << (((total_bits+3)%4)+1);

   178

      for (i = offset; i < strlen(token->value); i++) {

   179

        if (token->value[i] != '_') {

   180

          bit_mult /= 2;

   181

          value += bit_mult * ((token->value[i] == '0')? 0:1);

   182

          if (bit_mult == 1) {

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            str[0] = (value <= 9)? (char)'0' + value : (char)'A' + value - 10;

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            s4o.print(str);

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            bit_mult = 0x10;

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            value = 0;

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          }

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        }

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      }

   190

   191

      return NULL;

   192

    }

   193

   194

    void *print_list(list_c *list,

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                     std::string pre_elem_str = "",

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                     std::string inter_elem_str = "",

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                     std::string post_elem_str = "",

   198

                     visitor_c *visitor = NULL) {

   199

      if (visitor == NULL) visitor = this;

   200

   201

      if (list->n > 0) {

   202

//std::cout << "generate_c_base_c::print_list(n = " << list->n << ")   000\n";

   203

        s4o.print(pre_elem_str);

   204

        list->get_element(0)->accept(*visitor);

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      }

   206

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      for(int i = 1; i < list->n; i++) {

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//std::cout << "generate_c_base_c::print_list   " << i << "\n";

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        s4o.print(inter_elem_str);

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        list->get_element(i)->accept(*visitor);

   211

      }

   212

   213

      if (list->n > 0)

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        s4o.print(post_elem_str);

   215

   216

      return NULL;

   217

    }

   218

   219

   220

    void *print_binary_expression(symbol_c *l_exp,

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                                  symbol_c *r_exp,

   222

                                  const char *operation) {

   223

      s4o.print("(");

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      l_exp->accept(*this);

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      s4o.print(operation);

   226

      r_exp->accept(*this);

   227

      s4o.print(")");

   228

      return NULL;

   229

    }

   230

   231

    void *print_unary_expression(symbol_c *exp,

   232

                                 const char *operation) {

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      s4o.print(operation);

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      s4o.print("(");

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      exp->accept(*this);

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      s4o.print(")");

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      return NULL;

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    }

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    void *print_binary_function(const char *function,

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          symbol_c *l_exp,

   242

          symbol_c *r_exp) {

   243

      s4o.print(function);

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      s4o.print("(");

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      l_exp->accept(*this);

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      s4o.print(", ");

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      r_exp->accept(*this);

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      s4o.print(")");

   249

      return NULL;

   250

    }

   251

   252

    /* Call a standard library function that does a comparison (GT, NE, EQ, LT, ...)

   253

     * NOTE: Typically, the function will have the following parameters: 

   254

     *         1st parameter: EN  (enable)

   255

     *         2nd parameter: ENO (enable output)

   256

     *         3rd parameter: number of operands we will be passing (required because we are calling an extensible standard function!)

   257

     *         4th parameter: the left  hand side of the comparison expression (in out case, the IL implicit variable)

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     *         4th parameter: the right hand side of the comparison expression (in out case, current operand)

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     *       

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     *         The 1st and 2nd parameter may not be present, only issue them if NE and ENO are being generated!

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     *         The 3rd parameter must not be generated when the 'NE' function is called (it is not an extensible function!)

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     * 

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     *  NOTE: To implement this correctly, this function should really instantiate a 

   264

     *   function_invocation_c and have the generate_c visitor generate the code automatically for this

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     *   function invocation. However, the code for function invocations is currently duplicated 

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     *   for IL and ST. Until this code is not re-formulated into a single piece of general code, for now

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     *   we generate the function call directly here in print_compare_function()

   268

     */ 

   269

    void *print_compare_function(const char *function,

   270

          symbol_c *compare_type,

   271

          symbol_c *l_exp,

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          symbol_c *r_exp) {

   273

      // Print out the name of the function we will call.

   274

      // It will be something like LE_TIME, LE_DATE, GT_DATE, ...

   275

      //    (in other words, we are calling an overloaded function!)

   276

      s4o.print(function); // the GT, LE, ... part

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      s4o.print("_");  // the '_' part...

   278

      compare_type->accept(*this); // the TIME, DATE, ... part.

   279

      s4o.print("(");  // start of parameters to function call...

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      // Determine whether this function has the EN parameter

   281

      //    (we just check the base LE, GT, .. function, as it should have

   282

      //     the same parameters as the overloaded function!)

   283

      function_symtable_t::iterator lower = function_symtable.lower_bound(function);

   284

      if (lower == function_symtable.end()) ERROR;  // We want to call a function that does not exist!!?? Hmm...

   285

      search_var_instance_decl_c search_var(function_symtable.get_value(lower));

   286

      identifier_c  en_var("EN");

   287

      identifier_c eno_var("ENO");

   288

      if (search_var.get_vartype(& en_var) == search_var_instance_decl_c::input_vt)

   289

        s4o.print("__BOOL_LITERAL(TRUE), "); // function has EN parameter, pass TRUE

   290

      if (search_var.get_vartype(&eno_var) == search_var_instance_decl_c::output_vt)

   291

        s4o.print("NULL, "); // function has ENO parameter, pass NULL

   292

      if (strcmp(function, "NE") != 0) // All comparison library functions are extensible, except for 'NE'!!

   293

        s4o.print("2, "); // function is extensible, so must first pass the number of parameters that follow

   294

      l_exp->accept(*this);

   295

      s4o.print(", ");

   296

      r_exp->accept(*this);

   297

      s4o.print(")");

   298

      return NULL;

   299

    }

   300

   301

    void *print_check_function(symbol_c *type,

   302

          symbol_c *value,

   303

          symbol_c *fb_name = NULL,

   304

          bool temp = false) {

   305

      if (!get_datatype_info_c::is_type_valid(type)) ERROR;

   306

      bool is_subrange = get_datatype_info_c::is_subrange(type);

   307

      if (is_subrange) {

   308

        s4o.print("__CHECK_");

   309

        type->accept(*this);

   310

        s4o.print("(");

   311

      }

   312

      if (fb_name != NULL) {

   313

        s4o.print(GET_VAR);

   314

        s4o.print("(");

   315

        print_variable_prefix();

   316

        fb_name->accept(*this);

   317

        s4o.print(".");

   318

        value->accept(*this);

   319

        s4o.print(")");

   320

      }

   321

      else {

   322

        if (temp)

   323

        s4o.print(TEMP_VAR);

   324

        value->accept(*this);

   325

      }

   326

      if (is_subrange)

   327

        s4o.print(")");

   328

      return NULL;

   329

    }

   330

   331

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

   332

/* 2.1.6 - Pragmas  */

   333

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

   334

    void *visit(enable_code_generation_pragma_c * symbol)   {s4o.enable_output();  return NULL;}

   335

    void *visit(disable_code_generation_pragma_c * symbol)  {s4o.disable_output(); return NULL;} 

   336

   337

    /* Do not use print_token() as it will change everything into uppercase */

   338

    void *visit(pragma_c *symbol) {

   339

        s4o.print("#define GetFbVar(var,...) __GET_VAR(data__->var,__VA_ARGS__)\n");

   340

        s4o.print(s4o.indent_spaces);

   341

        s4o.print("#define SetFbVar(var,val,...) __SET_VAR(data__->,var,__VA_ARGS__,val)\n");

   342

        s4o.print(symbol->value);

   343

        s4o.print("\n");

   344

        s4o.print(s4o.indent_spaces);

   345

        s4o.print("#undef GetFbVar\n");

   346

        s4o.print(s4o.indent_spaces);

   347

        s4o.print("#undef SetFbVar\n");

   348

        return NULL;

   349

    }

   350

   351

   352

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

   353

/* B 0 - Programming Model */

   354

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

   355

  /* leave for derived classes... */

   356

   357

   358

   359

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

   360

/* B.1 - Common elements */

   361

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

   362

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

   363

/* B 1.1 - Letters, digits and identifiers */

   364

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

   365

    void *visit(                 identifier_c *symbol) {return print_token(symbol);}

   366

    void *visit(         poutype_identifier_c *symbol) {return print_token(symbol);}

   367

    /* If you need the derived_datatype_identifier_c visitor, then you should probably be 

   368

     * inheriting from generate_c_base_and_typeid_c and not generate_c_base_c !!

   369

     */

   370

    void *visit(derived_datatype_identifier_c *symbol) {ERROR; return NULL;}

   371

   372

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

   373

/* B 1.2 - Constants */

   374

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

   375

  /* originally empty... */

   376

   377

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

   378

/* B 1.2.XX - Reference Literals */

   379

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

   380

/* defined in IEC 61131-3 v3 - Basically the 'NULL' keyword! */

   381

    void *visit(ref_value_null_literal_c *symbol) {s4o.print("NULL"); return NULL;}

   382

   383

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

   384

/* B 1.2.1 - Numeric Literals */

   385

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

   386

    void *visit(real_c *symbol) {return print_striped_token(symbol);}

   387

    void *visit(integer_c *symbol) {return print_striped_token(symbol);}

   388

    void *visit(binary_integer_c *symbol) {return print_striped_binary_token(symbol, 2);}

   389

    void *visit(octal_integer_c *symbol) {s4o.print("0"); return print_striped_token(symbol, 2);}

   390

    void *visit(hex_integer_c *symbol) {s4o.print("0x"); return print_striped_token(symbol, 3);}

   391

   392

    void *visit(neg_real_c *symbol) {

   393

      s4o.print("-");

   394

      symbol->exp->accept(*this);

   395

      return NULL;

   396

    }

   397

   398

    void *visit(neg_integer_c *symbol) {

   399

      s4o.print("-");

   400

      symbol->exp->accept(*this);

   401

      return NULL;

   402

    }

   403

   404

    void *visit(integer_literal_c *symbol) {return print_literal(symbol->type, symbol->value);}

   405

    void *visit(real_literal_c *symbol) {return print_literal(symbol->type, symbol->value);}

   406

    void *visit(bit_string_literal_c *symbol) {return print_literal(symbol->type, symbol->value);}

   407

    void *visit(boolean_literal_c *symbol) {

   408

      if (NULL != symbol->type)

   409

        return print_literal(symbol->type, symbol->value);

   410

      else {

   411

        bool_type_name_c bool_type;

   412

        return print_literal(&bool_type, symbol->value);

   413

      }

   414

    }

   415

   416

    /* helper class for boolean_literal_c */

   417

    void *visit(boolean_true_c *symbol) {s4o.print("TRUE"); return NULL;}

   418

    void *visit(boolean_false_c *symbol) {s4o.print("FALSE"); return NULL;}

   419

   420

    void *visit(neg_expression_c *symbol) {

   421

      s4o.print("-");

   422

      symbol->exp->accept(*this);

   423

      return NULL;

   424

    }

   425

   426

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

   427

/* B.1.2.2   Character Strings */

   428

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

   429

    void *visit(double_byte_character_string_c *symbol) {

   430

      // TO DO ...

   431

      ERROR;

   432

      return print_token(symbol);

   433

    }

   434

   435

    void *visit(single_byte_character_string_c *symbol) {

   436

      std::string str = "";

   437

      unsigned int count = 0; 

   438

      str += '"';

   439

      /* we ignore the first and last bytes, they will be the character ' */

   440

      for (unsigned int i = 1; i < strlen(symbol->value) - 1; i++) {

   441

        char c = symbol->value[i];

   442

        if ((c == '\\') || (c == '"'))

   443

          {str += '\\'; str += c; count ++; continue;}

   444

        if (c != '$')

   445

          {str += c; count++; continue;}

   446

        /* this should be safe, since the code has passed the syntax parser!! */

   447

        c = symbol->value[++i];

   448

        switch (c) {

   449

          case '$':

   450

          case '\'':

   451

            {str += c; count++; continue;}

   452

          case 'L':

   453

          case 'l':

   454

            {str += "\x0A"; /* LF */; count++; continue;}

   455

          case 'N':

   456

          case 'n':

   457

            {str += "\\x0A"; /* NL */; count++; continue;}

   458

          case 'P':

   459

          case 'p':

   460

            {str += "\\f"; /* FF */; count++; continue;}

   461

          case 'R':

   462

          case 'r':

   463

            {str += "\\r"; /* CR */; count++; continue;}

   464

          case 'T':

   465

          case 't':

   466

            {str += "\\t"; /* tab */; count++; continue;}

   467

          default: {

   468

            if (isxdigit(c)) {

   469

              /* this should be safe, since the code has passed the syntax parser!! */

   470

              char c2 = symbol->value[++i];

   471

              if (isxdigit(c2)) {

   472

                str += '\\'; str += 'x'; str += c; str += c2;

   473

                count++; continue;

   474

              }

   475

            }

   476

          }

   477

          /* otherwise we have an invalid string!! */

   478

          /* This should not have got through the syntax parser! */

   479

          ERROR;

   480

        } /* switch() */

   481

      } /* for() */

   482

   483

      str += '"';

   484

      s4o.print("__STRING_LITERAL(");

   485

      s4o.print(count); 

   486

      s4o.print(",");

   487

      s4o.print(str);

   488

      s4o.print(")");

   489

      return NULL;

   490

    }

   491

   492

   493

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

   494

/* B 1.2.3 - Time Literals */

   495

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

   496

   497

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

   498

/* B 1.2.3.1 - Duration */

   499

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

   500

/* The following output is actually the parameters to the constructor of the TIME class! */

   501

   502

/* SYM_REF0(neg_time_c) */

   503

void *visit(neg_time_c *symbol) {s4o.print("-1"); /* negative time value */; return NULL;}

   504

   505

   506

/* SYM_REF2(duration_c, neg, interval) */