string operators, +, <<, >>

[unix-history] / usr / src / usr.bin / window / parser1.c

#ifndef lint
static  char *sccsid = "@(#)parser1.c   3.12 84/04/05";
#endif

#include "parser.h"

p_start()
{
       char flag = 1;

       (void) s_gettok();
       for (;;) {
               p_statementlist(flag);
               if (token == T_EOF || p_abort())
                       break;
               flag = 0;
               p_synerror();
               while (token != T_EOL && token != T_EOF) {
                       if (token == T_STR)
                               str_free(token_str);
                       (void) s_gettok();
               }
               if (token == T_EOL)
                       (void) s_gettok();
               p_clearerr();
       }
}

p_statementlist(flag)
char flag;
{
       for (; p_statement(flag) >= 0; p_clearerr())
               ;
}

p_statement(flag)
char flag;
{
#ifdef DEBUG
       error("statement: %d.", flag);
#endif
       switch (token) {
       case T_EOL:
#ifdef DEBUG
               error("statement: EOL.", flag);
#endif
               (void) s_gettok();
               return 0;
       case T_IF:
#ifdef DEBUG
               error("statement: IF.", flag);
#endif
               return p_if(flag);
       default:
#ifdef DEBUG
               error("statement: command.", flag);
#endif
               return p_command(flag);
       }
}

p_if(flag)
char flag;
{
       struct value t;
       char true = 0;

top:
       (void) s_gettok();

       if (p_expr(&t, flag) < 0) {
               p_synerror();
               return -1;
       }
       switch (t.v_type) {
       case V_NUM:
               true = !true && t.v_num != 0;
               break;
       case V_STR:
               p_error("Numeric value required for if.");
               str_free(t.v_str);
       case V_ERR:
               flag = 0;
               break;
       }

       if (token != T_THEN) {
               p_synerror();
               return -1;
       }

       (void) s_gettok();
       p_statementlist(flag && true);
       if (p_erred())
               return -1;

       if (token == T_ELSIF)
               goto top;

       if (token == T_ELSE) {
               (void) s_gettok();
               p_statementlist(flag && !true);
               if (p_erred())
                       return -1;
       }

       if (token == T_ENDIF) {
               (void) s_gettok();
               return 0;
       }

       p_synerror();
       return -1;
}

p_command(flag)
char flag;
{
       struct value t;
       char *cmd;

#ifdef DEBUG
       error("command: %d.", flag);
#endif
       switch (token) {
       case T_MOD:
               t.v_type = V_STR;
               t.v_str = str_cpy("%");
               (void) s_gettok();
               break;
       case T_NUM:
               t.v_type = V_NUM;
               t.v_num = token_num;
               (void) s_gettok();
               break;
       case T_STR:
               t.v_type = V_STR;
               t.v_str = token_str;
               (void) s_gettok();
               break;
       default:
               if (p_expr(&t, flag) < 0)
                       return -1;
               if (token == T_EOF) {
#ifdef DEBUG
                       error("command: expression.");
#endif
                       val_free(t);
                       return 0;
               }
       }
       switch (t.v_type) {
       case V_ERR:
               cmd = 0;
               break;
       case V_STR:
               cmd = t.v_str;
               break;
       case V_NUM:
               if ((cmd = str_itoa(t.v_num)) == 0) {
                       p_memerror();
                       return -1;
               }
       }
       if (token == T_ASSIGN) {
#ifdef DEBUG
               error("command: assignment %s.", cmd == 0 ? "ERR" : cmd);
#endif
               if (p_assign(cmd, &t, flag) < 0) {
                       str_free(cmd);
                       return -1;
               }
       } else {
#ifdef DEBUG
               error("command: function %s.", cmd == 0 ? "ERR" : cmd);
#endif
               if (p_function(cmd, &t, flag) < 0) {
                       str_free(cmd);
                       return -1;
               }
       }
       str_free(cmd);
       val_free(t);
       if (token == T_EOL)
               (void) s_gettok();
       else if (token != T_EOF) {
               p_synerror();
               return -1;
       }
       return 0;
}

p_convstr(v)
register struct value *v;
{
       if (v->v_type != V_NUM)
               return 0;
       if ((v->v_str = str_itoa(v->v_num)) == 0) {
               p_memerror();
               v->v_type = V_ERR;
               return -1;
       }
       v->v_type = V_STR;
       return 0;
}

p_synerror()
{
       if (!cx.x_synerred) {
               cx.x_synerred = cx.x_erred = 1;
               error("Syntax error.");
       }
}

/*VARARGS1*/
p_error(msg, a, b, c)
char *msg;
{
       if (!cx.x_erred) {
               cx.x_erred = 1;
               error(msg, a, b, c);
       }
}

p_memerror()
{
       cx.x_erred = cx.x_abort = 1;
       error("Out of memory.");
}