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1.1 root 1: /*
2: * Copyright (c) 1983 Regents of the University of California.
3: * All rights reserved.
4: *
5: * This code is derived from software contributed to Berkeley by
6: * Edward Wang at The University of California, Berkeley.
7: *
8: * Redistribution and use in source and binary forms are permitted provided
9: * that: (1) source distributions retain this entire copyright notice and
10: * comment, and (2) distributions including binaries display the following
11: * acknowledgement: ``This product includes software developed by the
12: * University of California, Berkeley and its contributors'' in the
13: * documentation or other materials provided with the distribution and in
14: * all advertising materials mentioning features or use of this software.
15: * Neither the name of the University nor the names of its contributors may
16: * be used to endorse or promote products derived from this software without
17: * specific prior written permission.
18: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
19: * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
20: * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21: */
22:
23: #ifndef lint
24: static char sccsid[] = "@(#)parser3.c 3.9 (Berkeley) 6/6/90";
25: #endif /* not lint */
26:
27: #include "parser.h"
28:
29: /*
30: * =
31: * ? :
32: * ||
33: * &&
34: * |
35: * ^
36: * &
37: * == !=
38: * <= >=
39: * << >>
40: * + -
41: * * / %
42: * unary - + ~ !
43: */
44: p_expr(v, flag)
45: register struct value *v;
46: char flag;
47: {
48: struct value t;
49: int ret;
50:
51: if (p_expr0(&t, flag) < 0)
52: return -1;
53:
54: if (token != T_ASSIGN) {
55: *v = t;
56: return 0;
57: }
58: switch (t.v_type) {
59: case V_NUM:
60: p_error("%d: Not a variable.", t.v_num);
61: case V_ERR:
62: t.v_str = 0;
63: break;
64: }
65: ret = p_assign(t.v_str, v, flag);
66: if (t.v_str != 0)
67: str_free(t.v_str);
68: return ret;
69: }
70:
71: /*
72: * ? :
73: */
74: p_expr0(v, flag)
75: register struct value *v;
76: char flag;
77: {
78: struct value t;
79: char true;
80:
81: if (p_expr1(v, flag) < 0)
82: return -1;
83: if (token != T_QUEST)
84: return 0;
85: switch (v->v_type) {
86: case V_NUM:
87: true = v->v_num != 0;
88: break;
89: case V_STR:
90: p_error("?: Numeric left operand required.");
91: str_free(v->v_str);
92: v->v_type = V_ERR;
93: case V_ERR:
94: flag = 0;
95: break;
96: }
97: (void) s_gettok();
98: v->v_type = V_ERR;
99: if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0)
100: return -1;
101: if (token != T_COLON) {
102: val_free(*v);
103: p_synerror();
104: return -1;
105: }
106: (void) s_gettok();
107: return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0);
108: }
109:
110: /*
111: * ||
112: */
113: p_expr1(v, flag)
114: register struct value *v;
115: char flag;
116: {
117: char true = 0;
118:
119: if (p_expr2(v, flag) < 0)
120: return -1;
121: if (token != T_OROR)
122: return 0;
123: for (;;) {
124: switch (v->v_type) {
125: case V_NUM:
126: v->v_num = true = true || v->v_num != 0;
127: break;
128: case V_STR:
129: p_error("||: Numeric operands required.");
130: str_free(v->v_str);
131: v->v_type = V_ERR;
132: case V_ERR:
133: flag = 0;
134: break;
135: }
136: if (token != T_OROR)
137: return 0;
138: (void) s_gettok();
139: if (p_expr2(v, flag && !true) < 0)
140: return -1;
141: }
142: }
143:
144: /*
145: * &&
146: */
147: p_expr2(v, flag)
148: register struct value *v;
149: char flag;
150: {
151: char true = 1;
152:
153: if (p_expr3_10(3, v, flag) < 0)
154: return -1;
155: if (token != T_ANDAND)
156: return 0;
157: for (;;) {
158: switch (v->v_type) {
159: case V_NUM:
160: v->v_num = true = true && v->v_num != 0;
161: break;
162: case V_STR:
163: p_error("&&: Numeric operands required.");
164: str_free(v->v_str);
165: v->v_type = V_ERR;
166: case V_ERR:
167: flag = 0;
168: break;
169: }
170: if (token != T_ANDAND)
171: return 0;
172: (void) s_gettok();
173: if (p_expr3_10(3, v, flag && true) < 0)
174: return -1;
175: }
176: /*NOTREACHED*/
177: }
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