ag: parser.y und scanner.lex von parser/

diff --git a/ag/parser.y b/ag/parser.y
index 994b76cb521b5b4b1167a40ec3599d8c08dd16d8..181bc5a0a9ffb6fb38474568b055587075fa3ade 100644 (file)
--- a/ag/parser.y
+++ b/ag/parser.y
@@ -1,201 +1,114 @@
 %{
        #include <stdio.h>
        #include <stdlib.h>
-       #include <string.h>
-       #include "symtable.h"
 %}
 
-%start         Input
-%token         FUNC END STRUCT VAR IF THEN ELSE WHILE DO RETURN OR NOT
-%token         ID NUM ASSIGN GREATER
-
-@autoinh symbols
-
-@attributes    { char *name; } ID
-@attributes    { struct symbol *fields; struct symbol *symbols; } Program
-@attributes    { struct symbol *fields; } Ids Structdef
-@attributes    { struct symbol *pars; } Pars
-@attributes    { struct symbol *symbols; } Funcdef Stats Bool Expr Call Lexpr Field Term Plusterm Malterm Bterm Orterm Exprs
-@attributes    { struct symbol *in_symbols; struct symbol *out_symbols; } Stat
-
-@traversal @postorder c
+%start Program
+%token STRUCT END METHOD VAR IF THEN ELSE WHILE DO RETURN NOT OR THIS
+%token IDENT NUM
 
 %%
 
-Input:           Program
-               @{ @i @Program.symbols@ = @Program.fields@; @}
-
-               ;
-
-Program:         Funcdef ';' Program
-               @{
-                  @i @Program.0.fields@ = @Program.1.fields@;
-               @}
-
-               | Structdef ';' Program
-               @{
-                  @i @Program.0.fields@ = tab_merge(@Structdef.fields@, @Program.1.fields@, 1);
-               @}
-
-               |
-               @{ @i @Program.fields@ = new_tab(); @}
-
-               ;
- 
-Funcdef:         FUNC ID '(' Pars ')' Stats END
-                       @{ @i @Stats.symbols@ = tab_merge(@Funcdef.symbols@, @Pars.pars@, 0); @}
-
-               ;  
- 
-Structdef:       STRUCT Ids END
-               @{ @i @Structdef.fields@ = @Ids.fields@; @}
-
-               ;  
-
-Ids:             ID Ids
-               @{ @i @Ids.0.fields@ = tab_add_symbol(@Ids.1.fields@, @ID.name@, S_FIELD, 1); @}
-
-               |
-               @{ @i @Ids.fields@ = new_tab(); @}
-
-               ;
-
-Pars:            Pars ',' ID
-               @{ @i @Pars.0.pars@ = tab_add_symbol(@Pars.1.pars@, @ID.name@, S_VAR, 0); @}
-
-               | ID
-               @{ @i @Pars.pars@ = tab_add_symbol(new_tab(), @ID.name@, S_VAR, 0); @}
-
-               |
-               @{ @i @Pars.pars@ = new_tab(); @}
-
-               ; 
- 
-Stats:           Stat ';' Stats
-               @{
-                  @i @Stat.in_symbols@ = @Stats.0.symbols@;
-                  @i @Stats.1.symbols@ = @Stat.out_symbols@;
-               @}
-
-               |
-               ;  
- 
-Stat:            VAR ID ASSIGN Expr
-               @{
-                  @i @Stat.out_symbols@ = tab_add_symbol(clone_tab(@Stat.in_symbols@), @ID.name@, S_VAR, 0);
-                  @i @Expr.symbols@ = @Stat.in_symbols@;
-               @}
-
-               | Lexpr ASSIGN Expr
-               @{
-                  @i @Stat.out_symbols@ = @Stat.in_symbols@;
-                  @i @Lexpr.symbols@ = @Stat.in_symbols@;
-                  @i @Expr.symbols@ = @Stat.in_symbols@;
-               @}
-
-               | IF Bool THEN Stats END
-               @{
-                  @i @Bool.symbols@ = @Stat.in_symbols@;
-                  @i @Stats.symbols@ = @Stat.in_symbols@;
-                  @i @Stat.out_symbols@ = @Stat.in_symbols@;
-               @}
-
-               | IF Bool THEN Stats ELSE Stats END
-               @{
-                  @i @Bool.symbols@ = @Stat.in_symbols@;
-                  @i @Stats.0.symbols@ = @Stat.in_symbols@;
-                  @i @Stats.1.symbols@ = @Stat.in_symbols@;
-                  @i @Stat.out_symbols@ = @Stat.in_symbols@;
-               @}
-
-               | WHILE Bool DO Stats END
-               @{
-                  @i @Bool.symbols@ = @Stat.in_symbols@;
-                  @i @Stats.symbols@ = @Stat.in_symbols@;
-                  @i @Stat.out_symbols@ = @Stat.in_symbols@;
-               @}
-
-               | Call
-               @{
-                  @i @Call.symbols@ = @Stat.in_symbols@;
-                  @i @Stat.out_symbols@ = @Stat.in_symbols@;
-               @}
-
-               | RETURN Expr
-               @{
-                  @i @Expr.symbols@ = @Stat.in_symbols@;
-                  @i @Stat.out_symbols@ = @Stat.in_symbols@;
-               @}
-
-               ;
- 
-Lexpr:           ID
-               @{ @c check_variable(@Lexpr.symbols@, @ID.name@); @}
-
-               | Field
-               ;
- 
-Expr:            '-' Term
-               | Term
-               | Term Plusterm
-               | Term Malterm
-               ;
-
-Plusterm:        '+' Term Plusterm
-               | '+' Term
-               ;
-
-Malterm:         '*' Term Malterm
-                       | '*' Term
-               ;
- 
-Term:            '(' Expr ')'
-               | ID
-               @{ @c check_variable(@Term.symbols@, @ID.name@); @}
-
-               | 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
-               @{ @c check_field(@Field.symbols@, @ID.name@); @}
-
-               ;
-
-Call:            ID '(' Exprs ')'
-               | ID '(' ')'
-               ;
-
-Exprs:           Expr
-               | Exprs ',' Expr
-               ;
+Program:
+         Methoddef ';' Program
+       | Structdef ';' Program
+       |
+       ;
+
+Structdef:
+         STRUCT Idents END
+       ;
+
+Methoddef:
+         METHOD IDENT '(' Idents ')' Statseq END
+       ;
+
+Idents:
+         IDENT Idents
+       |
+       ;
+
+Statseq:
+         Statement ';' Statseq
+       |
+       ;
+
+Statement:
+         Lexpr ':=' Expr
+       | VAR IDENT ':=' Expr
+       | Expr
+       | IF Expr THEN Statseq END
+       | IF Expr THEN Statseq ELSE Statseq END
+       | WHILE Expr DO Statseq END
+       | RETURN Expr
+       ;
+
+Lexpr:
+         IDENT
+       | Term '.' IDENT
+       ;
+
+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
+       | Term '.' IDENT
+       | IDENT '(' Exprs ')'
+       | Term '.' IDENT '(' Exprs ')'
+       ;
+
+/* beachte dass hier auch "nichts" vorkommen kann
+ * sonst waer ein aufruf der art 'f()' nicht
+ * moeglich (leere parameterliste) */
+Exprs:
+       | Expr
+       | Exprs ',' Expr
+       ;
 
 %%
 
 extern int yylex();
 extern int yylineno;
 
-int yyerror(char *error_text) {
-       fprintf(stderr,"Line %i: %s\n",yylineno, error_text);
+int yyerror(char *error_text)
+{
+       fprintf(stderr,"Line %i: %s\n", yylineno, error_text);
        exit(2);
 }
 
-int main(int argc, char **argv) {
+int main(int argc, char **argv)
+{
+       #if 0
+       yydebug=1;
+       #endif
        yyparse();
        return 0;
 }

diff --git a/ag/scanner.lex b/ag/scanner.lex
index f66b947cab8cd0b06705cc5dfc4d5752953732d7..049cdd2c1e54245ce7aad3a3f12b63dd65da5130 100644 (file)
--- a/ag/scanner.lex
+++ b/ag/scanner.lex
@@ -3,65 +3,57 @@
        #include <string.h>
        #include "parser.h"
 
-KEYWORD                func|end|struct|var|if|then|else|while|do|return|or|not
-IDENTIFIER     [[:alpha:]_][[:alnum:]_]*
-NUMBER_HEX     [0-9][0-9A-Fa-f]*H
-NUMBER_DEC     [0-9]+
-WHITESPACE     [\t\n\r ]
-COMMENT_START  \(\*
-COMMENT_END    \*\)
+KEYWORD struct|end|method|var|if|then|else|while|do|return|not|or|this
+SPECIAL_CHAR \;|\(|\)|\:=|\.|\-|\*|\<|\=|\,
+IDENTIFIER [a-zA-Z_][0-9a-zA-Z_]*
+NUMBER_HEX 0x[0-9A-Fa-f]+
+NUMBER_DEC [0-9]+
+WHITESPACE [\t\n\r ]
+COMMENT_START \/\*
+COMMENT_END    \*\/
 
 %x COMMENT
 %option yylineno
 %%
 
+{COMMENT_START} BEGIN(COMMENT);
 
-{COMMENT_START}                        BEGIN(COMMENT);
+<COMMENT>{COMMENT_END} BEGIN(INITIAL);
 
-<COMMENT>{COMMENT_END}         BEGIN(INITIAL);
+<COMMENT><<EOF>> {
+       fprintf(stderr, "Kommentar nicht geschlossen\n");
+       exit(1);
+}
 
-<COMMENT>{COMMENT_START}       fprintf(stderr, "Possibly nested comment on line %i\n", yylineno);
+<COMMENT>(.|\n) /* alles im kommentar wird ignoriert */
 
-<COMMENT><<EOF>>               { fprintf(stderr, "Unterminated comment.\n"); exit(1); }
+struct return(STRUCT);
+end return(END);
+method return(METHOD);
+var return(VAR);
+if return(IF);
+then return(THEN);
+else return(ELSE);
+while return(WHILE);
+do return(DO);
+return return(RETURN);
+not return(NOT);
+or return(OR);
+this return(THIS);
 
-<COMMENT>{WHITESPACE}          /* ignore */
+{IDENTIFIER} return(IDENT);
 
-<COMMENT>.                     /* ignore everything inside comment */
+{NUMBER_DEC} return(NUM);
+{NUMBER_HEX} return(NUM);
 
-func                           return(FUNC);
-end                            return(END);
-struct                         return(STRUCT);
-var                            return(VAR);
-if                             return(IF);
-then                           return(THEN);
-else                           return(ELSE);
-while                          return(WHILE);
-do                             return(DO);
-return                         return(RETURN);
-or                             return(OR);
-not                            return(NOT);
+{SPECIAL_CHAR} return(*yytext);
 
-{IDENTIFIER}                   return(ID); @{ @ID.name@=strdup(yytext); @}
+{WHITESPACE} /* ignore */
 
-{NUMBER_DEC}                   return(NUM);
-{NUMBER_HEX}                   return(NUM);
-                               
-\:=                            return(ASSIGN);
->=                             return(GREATER);
-\;                             return(';');
-\.                             return('.');
-\(                             return('(');
-\)                             return(')');
-\,                             return(',');
-\-                             return('-');
-\+                             return('+');
-\*                             return('*');
-=                              return('=');
-
-{WHITESPACE}                   /* ignore */
-
-.                              { fprintf(stderr, "Lexical error on line %i\n", yylineno); exit(1); }
+. {
+               fprintf(stderr, "Lexical error on line %i\n", yylineno);
+               exit(1);
+}
 
 %%
 
-