%{ #include #include #include #include "symtable.h" %} %start Input %token STRUCT END METHOD VAR IF THEN ELSE WHILE DO RETURN NOT OR THIS IDENT NUM ASSIGN @macro xxputsin(xx,) @i xx = @Statement.sin@; @end @macro statinout() @i @Statement.sout@ = @Statement.sin@; /* das *> xxputsin(@Statement.sout@,) * geht nicht, weil verschachtelte macros deaktiviert sind */ @end @autoinh s @attributes { char *name; } IDENT @attributes { struct symbol *f; } FeldID Parms Structdef Program @attributes { struct symbol *s; } Methoddef Statseq Lexpr Expr Minusterm Multerm Orterm Term Exprs Feld @attributes { struct symbol *sin; struct symbol *sout; } Statement @traversal @postorder c %% Input: Program @{ @i @Program.f@ = tab_new(); @} ; Program: Methoddef ';' Program @{ @i @Methoddef.s@ = @Program.0.f@; @i @Program.1.f@ = @Program.0.f@; @} | Structdef ';' Program @{ @i @Program.1.f@ = tab_merge(@Program.0.f@, @Structdef.f@, 1); @} | ; Methoddef: METHOD IDENT '(' Parms ')' Statseq END @{ @i @Statseq.s@ = tab_merge(@Methoddef.s@, @Parms.f@, 0); @} ; Structdef: STRUCT FeldID END @{ @i @Structdef.f@ = @FeldID.f@; @} ; Parms: /* lokale Vars werden in Statement in die tabelle eingefuegt */ IDENT Parms @{ @i @Parms.0.f@ = tab_add_symbol(@Parms.1.f@, @IDENT.name@, S_VAR, 1); @} | @{ @i @Parms.f@ = tab_new(); @} ; FeldID: IDENT FeldID @{ @i @FeldID.0.f@ = tab_add_symbol(@FeldID.1.f@, @IDENT.name@, S_FIELD, 1); @} | @{ @i @FeldID.f@ = tab_new(); @} ; Statseq: Statement ';' Statseq @{ @i @Statement.sin@ = @Statseq.0.s@; @i @Statseq.1.s@ = @Statement.sout@; @} | ; Statement: Lexpr ASSIGN Expr @{ statinout() xxputsin(@Lexpr.s@,) xxputsin(@Expr.s@,) @} | VAR IDENT ASSIGN Expr @{ /* tab_clone ist hier noetig, vgl. folgendes statement * > var x := x - 1; */ @i @Statement.sout@ = tab_add_symbol(tab_clone(@Statement.sin@), @IDENT.name@, S_VAR, 1); xxputsin(@Expr.s@,) @} | Expr @{ statinout() xxputsin(@Expr.s@,) @} | IF Expr THEN Statseq END @{ statinout() xxputsin(@Expr.s@,) xxputsin(@Statseq.s@,) @} | IF Expr THEN Statseq ELSE Statseq END @{ statinout() xxputsin(@Expr.s@,) xxputsin(@Statseq.0.s@,) xxputsin(@Statseq.1.s@,) @} | WHILE Expr DO Statseq END @{ statinout() xxputsin(@Expr.s@,) xxputsin(@Statseq.s@,) @} | RETURN Expr @{ statinout() xxputsin(@Expr.s@,) @} ; Lexpr: IDENT @{ @c check(@Lexpr.s@, @IDENT.name@, S_VAR); @} | Feld ; Feld: Term '.' IDENT @{ @c check(@Feld.s@, @IDENT.name@, S_FIELD); @} ; Expr: Term | NOT Term | Term Minusterm | Term Multerm | Term Orterm | Term '<' Term | Term '=' Term ; Minusterm: '-' Term Minusterm | '-' Term ; Multerm: '*' Term Multerm | '*' Term ; Orterm: OR Term Orterm | OR Term ; Term: '(' Expr ')' | NUM | '-' NUM | THIS | IDENT @{ @c check(@Term.s@, @IDENT.name@, S_VAR); @} | Feld | IDENT '(' Exprs ')' | Term '.' IDENT '(' Exprs ')' ; Exprs: Expr ',' Exprs | Expr | ; %% extern int yylex(); extern int yylineno; int yyerror(char *error_text) { fprintf(stderr,"Zeile %i: %s\n", yylineno, error_text); exit(2); } int main(int argc, char **argv) { #if 0 yydebug=1; #endif yyparse(); return 0; }