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1.1 root 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: }
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