parser.y

   1 %{
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include "parser.h"
   5 #include "base.h"
   6 #include "ast.h"
   7 #include "symbol_table.h"
   8
   9 /*extern char *yytext;*/
  10 extern FILE *yyin;
  11
  12 static void yyerror (/*YYLTYPE *locp, */const char *msg);
  13 /*int yylex (YYSTYPE *yylval_param, YYLTYPE *yylloc_param);*/
  14
  15 %}
  16
  17 %defines
  18 %locations
  19 %pure-parser
  20 %error-verbose
  21 /*%parse-param {ValaParser *parser}
  22 %lex-param {ValaParser *parser}*/
  23
  24 %union {
  25     char* lexeme;
  26     int integer;
  27     int boolean;
  28 }
  29
  30 %token T_INTEGER
  31 %token T_BOOLEAN
  32
  33 %token T_VAR
  34 %token T_BEGIN
  35 %token T_END
  36 %token T_PROCEDURE
  37 %token T_FUNCTION
  38
  39 %token T_PRINT_INT
  40 %token T_PRINT_BOOL
  41 %token T_PRINT_LINE
  42
  43 %token T_ASSIGNMENT
  44
  45 %token T_ADD
  46 %token T_SUB
  47 %token T_DIV
  48 %token T_MULT
  49
  50 %token T_MAJOR
  51 %token T_MINOR
  52 %token T_EQUAL
  53 %token T_NOTEQUAL
  54 %token T_MAJOREQUAL
  55 %token T_MINOREQUAL
  56
  57 %token T_LPAR
  58 %token T_RPAR
  59 %token T_SEMICOLON
  60 %token T_COLON
  61 %token T_COMMA
  62 %token T_DOT
  63
  64 %token <lexeme> IDENTIFIER
  65 %token <integer> NUMBER
  66 %token <boolean> BOOLEAN
  67
  68 /*%type <symbol> program
  69 %type <symbol> var_decl_list
  70 %type <symbol> var_decl
  71 %type <symbol> var_type
  72 %type <symbol> proc_func_list
  73 %type <symbol> proc_func_decl
  74 %type <symbol> proc_func_body
  75 %type <symbol> proc_decl
  76 %type <symbol> func_decl
  77 %type <symbol> param_list
  78 %type <symbol> single_param
  79 %type <symbol> multi_param
  80 %type <symbol> code_block
  81 %type <symbol> statements
  82 %type <symbol> statement*/
  83
  84 %type <lexeme> assignment
  85 %type <integer> numeric_expression
  86 %type <boolean> relational_expression
  87 %type <integer> number_literal
  88
  89 /*%type <symbol> print_statement
  90 %type <symbol> print_integer
  91 %type <symbol> print_boolean
  92 %type <symbol> print_line*/
  93
  94 %start program
  95
  96 %%
  97 program:
  98     var_decl_list proc_func_list code_block T_DOT { printf("program\n"); }
  99     ;
 100
 101 var_decl_list:
 102     var_decl_list var_decl { printf("\n"); }
 103     | /* empty */
 104     ;
 105
 106 var_decl:
 107     T_VAR IDENTIFIER T_COLON var_type T_SEMICOLON
 108     { printf("var_decl\n") }
 109     ;
 110
 111 var_type:
 112     T_INTEGER
 113     { printf("var_type\n") }
 114     | T_BOOLEAN
 115     { printf("var_type\n") }
 116     ;
 117
 118 proc_func_list:
 119     /* empty */
 120     { printf("proc_func_list\n") }
 121     | proc_func_list proc_decl
 122     { printf("proc_func_list\n") }
 123     | proc_func_list func_decl
 124     { printf("proc_func_list\n") }
 125     ;
 126
 127 proc_func_decl:
 128     IDENTIFIER T_LPAR param_list T_RPAR
 129     { printf("proc_func_decl\n") }
 130     ;
 131
 132 proc_func_body:
 133     var_decl_list code_block T_SEMICOLON
 134     { printf("proc_func_body\n") }
 135     ;
 136
 137 proc_decl:
 138     T_PROCEDURE proc_func_decl T_SEMICOLON proc_func_body
 139     { printf("proc_decl\n") }
 140     ;
 141
 142 func_decl:
 143     T_FUNCTION proc_func_decl T_COLON var_type T_SEMICOLON proc_func_body
 144     { printf("func_decl\n") }
 145     ;
 146
 147 param_list:
 148     /* empty */
 149     { printf("param_list\n") }
 150     | single_param multi_param
 151     { printf("param_list\n") }
 152     ;
 153
 154 single_param:
 155     IDENTIFIER T_COLON var_type
 156     { printf("single_param\n") }
 157     ;
 158
 159 multi_param:
 160     /* empty */
 161     { printf("multi_param\n") }
 162     | T_COMMA single_param multi_param
 163     { printf("multi_param\n") }
 164     ;
 165
 166 code_block:
 167     T_BEGIN statements T_END
 168     { printf("code_block\n") }
 169     ;
 170
 171 statements:
 172     /* empty */
 173     | statements statement T_SEMICOLON
 174     ;
 175
 176 statement:
 177     assignment
 178     | print_statement
 179     ;
 180
 181 assignment:
 182     IDENTIFIER T_ASSIGNMENT expression
 183     | IDENTIFIER T_ASSIGNMENT NUMBER { $$ = $1; }
 184     ;
 185
 186 expression:
 187     numeric_expression
 188     | relational_expression
 189     ;
 190
 191 numeric_expression:
 192     numeric_expression T_ADD numeric_expression { $$ = $1 + $3; }
 193     | numeric_expression T_SUB numeric_expression { $$ = $1 - $3; }
 194     | number_literal { $$ = $1; }
 195     ;
 196
 197 number_literal:
 198     NUMBER { $$ = $1; }
 199     ;
 200
 201 relational_expression:
 202     numeric_expression relational_operator numeric_expression
 203     ;
 204
 205 relational_operator:
 206     T_MINOR
 207     | T_MINOREQUAL
 208     | T_MAJOR
 209     | T_MAJOREQUAL
 210     | T_EQUAL
 211     | T_NOTEQUAL
 212     ;
 213
 214 print_statement:
 215     print_integer
 216     | print_boolean
 217     | print_line
 218     ;
 219
 220 print_integer:
 221     T_PRINT_INT T_LPAR NUMBER T_RPAR { printf ("%d", $3); }
 222
 223 print_boolean:
 224     T_PRINT_BOOL T_LPAR BOOLEAN T_RPAR { printf ("%s", ($3 == 0 ? "False" : "True")); }
 225
 226 print_line:
 227     T_PRINT_LINE T_LPAR T_RPAR { printf ("\n"); }
 228 %%
 229
 230 static void
 231 yyerror (/*YYLTYPE *locp,*/ const char *msg)
 232 {
 233     fprintf(stderr,"error: %s\n", msg);
 234 }
 235
 236 int
 237 main(int argc, char **argv)
 238 {
 239     if (argc > 1)
 240         yyin = fopen(argv[1], "r");
 241     else
 242         yyin = stdin;
 243
 244     /*yylloc.first_line = yylloc.last_line = 1;
 245     yylloc.first_column = yylloc.last_column = 0;*/
 246
 247     return yyparse();
 248 }
 249