1

/*

     2

 * (c) 2003 Mario de Sousa

     3

 *

     4

 * Offered to the public under the terms of the GNU General Public License

     5

 * as published by the Free Software Foundation; either version 2 of the

     6

 * License, or (at your option) any later version.

     7

 *

     8

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

     9

 * WITHOUT ANY WARRANTY; without even the implied warranty of

    10

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

    11

 * Public License for more details.

    12

 *

    13

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

    14

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

    15

 */

    16

    17

/*

    18

 * An IEC 61131-3 IL and ST compiler.

    19

 *

    20

 * Based on the

    21

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

    22

 *

    23

 */

    24

    25

/*

    26

 ****************************************************************

    27

 ****************************************************************

    28

 ****************************************************************

    29

 *********                                              *********

    30

 *********                                              *********

    31

 *********   O V E R A L L    A R C H I T E C T U R E   *********

    32

 *********                                              *********

    33

 *********                                              *********

    34

 ****************************************************************

    35

 ****************************************************************

    36

 ****************************************************************

    37

    38

 The compiler works in 4(+1) stages:

    39

 Stage 1   - Lexical analyser      - implemented with flex (iec.flex)

    40

 Stage 2   - Syntax parser         - implemented with bison (iec.y)

    41

 Stage 3   - Semantics analyser    - not yet implemented

    42

 Stage 4   - Code generator        - implemented in C++

    43

 Stage 4+1 - Binary code generator - gcc, javac, etc...

    44

    45

    46

 Data structures passed between stages, in global variables:

    47

 1->2   : tokens (int), and token values (char *)

    48

 2->1   : symbol tables (defined in symtable.hh)

    49

 2->3   : abstract syntax tree (tree of C++ classes, in absyntax.hh file)

    50

 3->4   : Same as 2->3

    51

 4->4+1 : file with program in c, java, etc...

    52

    53

    54

 The compiler works in several passes:

    55

 Pass 1: executes stages 1 and 2 simultaneously

    56

 Pass 2: executes stage 3

    57

 Pass 3: executes stage 4

    58

 Pass 4: executes stage 4+1

    59

*/

    60

    61

    62

    63

//#include <stdio.h>   // printf()

    64

    65

#include <stdlib.h>  // EXIT_FAILURE

    66

#include "absyntax/absyntax.hh"  // symbol_c type

    67

    68

    69

    70

    71

/* A macro for printing out internal parser errors... */

    72

#include <iostream> // required for std::cerr

    73

#define ERROR error_exit(__FILE__,__LINE__)

    74

void error_exit(const char *file_name, int line_no) {

    75

  std::cerr << "\nInternal program error in file " << file_name

    76

            << " at line " << line_no << "\n\n\n";

    77

  exit(EXIT_FAILURE);

    78

}

    79

    80

    81

    82

/* forward declarations... */

    83

int stage1_2(const char *filename, const char *includedir, symbol_c **tree_root);

    84

//int stage3(symbol_c *tree_root);

    85

int stage4(symbol_c *tree_root);

    86

    87

    88

static void printusage(const char *cmd) {

    89

  printf("%s [<input_file>] [-I <include_directory>]\n", cmd);

    90

}

    91

    92

    93

    94

int main(int argc, char **argv) {

    95

  symbol_c *tree_root;

    96

  char * includedir = NULL;

    97

    98

  if (argc == 4) {

    99

    if (strcmp(argv[2], "-I") != 0) {

   100

      printusage(argv[0]);

   101

      return EXIT_FAILURE;

   102

    }

   103

    includedir = argv[3];

   104

    argc = 2;

   105

  }

   106

   107

  if (argc != 2) {

   108

    printusage(argv[0]);

   109

    return EXIT_FAILURE;

   110

  }

   111

   112

  /* 1st Pass */

   113

  if (stage1_2(argv[1], includedir, &tree_root) < 0)

   114

    return EXIT_FAILURE;

   115

   116

  /* 2nd Pass */

   117

  /* not yet implemented... */

   118

  /*

   119

  if (stage3(tree_root) < 0)

   120

    return EXIT_FAILURE;

   121

  */

   122

   123

  /* 3rd Pass */

   124

  if (stage4(tree_root) < 0)

   125

    return EXIT_FAILURE;

   126

   127

  /* 4th Pass */

   128

  /* Currently implemented in the Makefile! */

   129

   130

  return 0;

   131

}

   132

   133