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