4.3BSD - /usr/src/ucb/window/parser1.c

   1: #ifndef lint
   2: static char sccsid[] = "@(#)parser1.c	3.18 4/24/85";
   3: #endif
   4: 
   5: /*
   6:  * Copyright (c) 1983 Regents of the University of California,
   7:  * All rights reserved.  Redistribution permitted subject to
   8:  * the terms of the Berkeley Software License Agreement.
   9:  */
  10: 
  11: #include "parser.h"
  12: 
  13: p_start()
  14: {
  15:     char flag = 1;
  16: 
  17:     (void) s_gettok();
  18:     for (;;) {
  19:         p_statementlist(flag);
  20:         if (token == T_EOF || p_abort())
  21:             break;
  22:         flag = 0;
  23:         p_synerror();
  24:         while (token != T_EOL && token != T_EOF) {
  25:             if (token == T_STR)
  26:                 str_free(token_str);
  27:             (void) s_gettok();
  28:         }
  29:         if (token == T_EOL)
  30:             (void) s_gettok();
  31:         p_clearerr();
  32:     }
  33: }
  34: 
  35: p_statementlist(flag)
  36: char flag;
  37: {
  38:     for (; p_statement(flag) >= 0; p_clearerr())
  39:         ;
  40: }
  41: 
  42: p_statement(flag)
  43: char flag;
  44: {
  45:     switch (token) {
  46:     case T_EOL:
  47:         (void) s_gettok();
  48:         return 0;
  49:     case T_IF:
  50:         return p_if(flag);
  51:     default:
  52:         return p_expression(flag);
  53:     }
  54: }
  55: 
  56: p_if(flag)
  57: char flag;
  58: {
  59:     struct value t;
  60:     char true = 0;
  61: 
  62: top:
  63:     (void) s_gettok();
  64: 
  65:     if (p_expr(&t, flag) < 0) {
  66:         p_synerror();
  67:         return -1;
  68:     }
  69:     switch (t.v_type) {
  70:     case V_NUM:
  71:         true = !true && t.v_num != 0;
  72:         break;
  73:     case V_STR:
  74:         p_error("if: Numeric value required.");
  75:         str_free(t.v_str);
  76:     case V_ERR:
  77:         flag = 0;
  78:         break;
  79:     }
  80: 
  81:     if (token != T_THEN) {
  82:         p_synerror();
  83:         return -1;
  84:     }
  85: 
  86:     (void) s_gettok();
  87:     p_statementlist(flag && true);
  88:     if (p_erred())
  89:         return -1;
  90: 
  91:     if (token == T_ELSIF)
  92:         goto top;
  93: 
  94:     if (token == T_ELSE) {
  95:         (void) s_gettok();
  96:         p_statementlist(flag && !true);
  97:         if (p_erred())
  98:             return -1;
  99:     }
 100: 
 101:     if (token == T_ENDIF) {
 102:         (void) s_gettok();
 103:         return 0;
 104:     }
 105: 
 106:     p_synerror();
 107:     return -1;
 108: }
 109: 
 110: p_expression(flag)
 111: char flag;
 112: {
 113:     struct value t;
 114:     char *cmd;
 115:     int p_function(), p_assign();
 116: 
 117:     switch (token) {
 118:     case T_NUM:
 119:         t.v_type = V_NUM;
 120:         t.v_num = token_num;
 121:         (void) s_gettok();
 122:         break;
 123:     case T_STR:
 124:         t.v_type = V_STR;
 125:         t.v_str = token_str;
 126:         (void) s_gettok();
 127:         break;
 128:     default:
 129:         if (p_expr(&t, flag) < 0)
 130:             return -1;
 131:         if (token == T_EOF) {
 132:             val_free(t);
 133:             return 0;
 134:         }
 135:     }
 136:     if (token != T_ASSIGN && p_convstr(&t) < 0)
 137:         return -1;
 138:     cmd = t.v_type == V_STR ? t.v_str : 0;
 139:     if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) {
 140:         if (cmd)
 141:             str_free(cmd);
 142:         return -1;
 143:     }
 144:     if (cmd)
 145:         str_free(cmd);
 146:     val_free(t);
 147:     if (token == T_EOL)
 148:         (void) s_gettok();
 149:     else if (token != T_EOF) {
 150:         p_synerror();
 151:         return -1;
 152:     }
 153:     return 0;
 154: }
 155: 
 156: p_convstr(v)
 157: register struct value *v;
 158: {
 159:     if (v->v_type != V_NUM)
 160:         return 0;
 161:     if ((v->v_str = str_itoa(v->v_num)) == 0) {
 162:         p_memerror();
 163:         v->v_type = V_ERR;
 164:         return -1;
 165:     }
 166:     v->v_type = V_STR;
 167:     return 0;
 168: }
 169: 
 170: p_synerror()
 171: {
 172:     if (!cx.x_synerred) {
 173:         cx.x_synerred = cx.x_erred = 1;
 174:         error("Syntax error.");
 175:     }
 176: }
 177: 
 178: /*VARARGS1*/
 179: p_error(msg, a, b, c)
 180: char *msg;
 181: {
 182:     if (!cx.x_erred) {
 183:         cx.x_erred = 1;
 184:         error(msg, a, b, c);
 185:     }
 186: }
 187: 
 188: p_memerror()
 189: {
 190:     cx.x_erred = cx.x_abort = 1;
 191:     error("Out of memory.");
 192: }

Defined functions

Defined variables