parser: makefile ... (und rest von paulchen ss08 kopiert)

[uebersetzerbau-ss10.git] / parser / parser.y

diff --git a/parser/parser.y b/parser/parser.y
new file mode 100644 (file)
index 0000000..1789efe
--- /dev/null
+++ b/parser/parser.y
@@ -0,0 +1,110 @@
+%{
+       #include <stdio.h>
+       #include <stdlib.h>
+%}
+
+%start         Program
+%token         FUNC END STRUCT VAR IF THEN ELSE WHILE DO RETURN OR NOT
+%token         ID NUM ASSIGN GREATER
+
+%%
+
+Program:         Funcdef ';' Program
+               | Structdef ';' Program
+               |
+               ;
+ 
+Funcdef:         FUNC ID '(' Pars ')' Stats END
+               | FUNC ID '(' ')' Stats END
+               ;  
+ 
+Structdef:       STRUCT Ids END
+               ;  
+
+Ids:             ID Ids
+               | 
+               ;
+
+Pars:            Pars ',' ID
+               | ID
+               ; 
+ 
+Stats:           Stat ';' Stats  
+               |
+               ;  
+ 
+Stat:            VAR ID ASSIGN Expr
+               | Lexpr ASSIGN Expr
+               | IF Bool THEN Stats END
+               | IF Bool THEN Stats ELSE Stats END
+               | WHILE Bool DO Stats END
+               | Call
+               | RETURN Expr
+               ;
+ 
+Lexpr:           ID
+               | Field
+               ;
+ 
+Expr:            '-' Term
+               | Term
+               | Term Plusterm
+               | Term Malterm
+               ;
+
+Plusterm:        '+' Term Plusterm
+               | '+' Term
+               ;
+
+Malterm:         '*' Term Malterm
+                       | '*' Term
+               ;
+ 
+Term:            '(' Expr ')'
+               | ID
+               | NUM
+               | Call
+               | Field
+               ;
+
+Bool:            Bterm
+               | Bterm Orterm
+               | NOT Bterm
+               ;
+
+Orterm:                  OR Bterm Orterm
+               | OR Bterm
+               ;
+
+Bterm:           Term GREATER Term
+               | Term '=' Term
+               | '(' Bool ')'
+               ;
+
+Field:           Term '.' ID
+               ;
+
+Call:            ID '(' Exprs ')'
+               | ID '(' ')'
+               ;
+
+Exprs:           Expr
+               | Exprs ',' Expr
+               ;
+
+%%
+
+extern int yylex();
+extern int yylineno;
+
+int yyerror(char *error_text) {
+       fprintf(stderr,"Line %i: %s\n",yylineno, error_text);
+       exit(2);
+}
+
+int main(int argc, char **argv) {
+/*     yydebug=1; */
+       yyparse();
+       return 0;
+}
+