tinyc2.y

TINYCの構文解析拡張版

%{
#include <stdio.h>
%}
%union {char s[17]; int n;}
%token <s> NAME NUMBER
%token <n> IF WHILE DO '?'
%type <n> if0
%token GOTO ELSE INT IN OUT HALT
%right '?' ':'
%left OR
%left AND
%left '|'
%left '^'
%left '&'
%left EQ NE
%left GE LE '<' '>'
%left SHL SHR
%left '+' '-'
%left '*'
%right '!' '~' NEG
%%
statements : statement | statements statement
;
statement : label | intdef | goto | if | while | do | halt | out | assign 
;
label : NAME ':' {printf("%s:\n",$1);}
;
intdef: INT intlist ';'
;
intlist: integer
    | intlist ',' integer
;
integer: NAME {printf("%s: 0\n",$1);}
     | NAME '=' NUMBER {printf("%s: %s\n",$1,$3);}
     | NAME '=' '-' NUMBER {printf("%s: -%s\n",$1,$4);}
;
goto: GOTO NAME ';'  {printf("\tJMP %s\n",$2);}
;
if: if0 {printf("_%03dF:\n",$1);}
  | if0 {printf("\tJMP _%03dT\n_%03dF:\n",$1,$1);} ELSE '{' statements '}' {printf("_%03dT:\n",$1);}
;
if0: IF '(' expr ')' {printf("\tJZ _%03dF\n",$1);} '{' statements '}' {$$=$1;}
;
while: WHILE {printf("_%03dT:\n",$1);} '(' expr ')' {printf("\tJZ _%03dF\n",$1);} '{' statements '}' {printf("\tJMP _%03dT\n_%03dF:\n",$1,$1);}
;
do: DO {printf("_%03dT:\n",$1);} '{' statements '}' WHILE '(' expr ')' ';' {printf("\tJNZ _%03dT\n",$1);}
;
assign: NAME '=' expr ';' {printf("\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} '+' '=' expr ';' {printf("\tADD\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} '-' '=' expr ';' {printf("\tSUB\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} '*' '=' expr ';' {printf("\tMUL\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} SHL '=' expr ';' {printf("\tSHL\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} SHR '=' expr ';' {printf("\tSHR\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} '&' '=' expr ';' {printf("\tBAND\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} '|' '=' expr ';' {printf("\tBOR\n\tPOP %s\n",$1);}
      | NAME {printf("\tPUSH %s\n",$1);} '^' '=' expr ';' {printf("\tBXOR\n\tPOP %s\n",$1);}
;
halt : HALT ';' {printf("\tHALT\n");}
;
out: OUT '(' expr ')' ';' {printf("\tOUT\n");}
;
expr:  NAME {printf("\tPUSH %s\n",$1);}
     | NUMBER {printf("\tPUSHI %s\n",$1);}
     | IN {printf("\tIN\n");}
     | '!' expr {printf("\tNOT\n");}
     | '~' expr {printf("\tBNOT\n");}
     | '-' expr %prec NEG {printf("\tNEG\n");}
     | expr '+' expr {printf("\tADD\n");}
     | expr '-' expr {printf("\tSUB\n");}
     | expr '*' expr {printf("\tMUL\n");}
     | expr AND expr {printf("\tAND\n");}
     | expr OR expr {printf("\tOR\n");}
     | expr '&' expr {printf("\tBAND\n");}
     | expr '|' expr {printf("\tBOR\n");}
     | expr '^' expr {printf("\tBXOR\n");}
     | expr SHL expr {printf("\tSHL\n");}
     | expr SHR expr {printf("\tSHR\n");}
     | expr EQ expr {printf("\tEQ\n");}
     | expr NE expr {printf("\tNE\n");}
     | expr GE expr {printf("\tGE\n");}
     | expr LE expr {printf("\tLE\n");}
     | expr '<' expr {printf("\tLT\n");}
     | expr '>' expr {printf("\tGT\n");}
     | '(' expr ')'
     | expr '?' {printf("\tJZ _%03dF\n",$2);} expr {printf("\tJMP _%03dT\n_%03dF:\n",$2,$2);} ':' expr {printf("_%03dT:\n",$2);}
;

%%
int yyerror(char *s){ printf("%s\n",s); }
int main(){ yyparse(); }