| 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 | * %sccs.include.redist.c% |
| 9 | */ |
| 10 | |
| 11 | #ifndef lint |
| 12 | static char sccsid[] = "@(#)parser3.c 3.9 (Berkeley) %G%"; |
| 13 | #endif /* not lint */ |
| 14 | |
| 15 | #include "parser.h" |
| 16 | |
| 17 | /* |
| 18 | * = |
| 19 | * ? : |
| 20 | * || |
| 21 | * && |
| 22 | * | |
| 23 | * ^ |
| 24 | * & |
| 25 | * == != |
| 26 | * <= >= |
| 27 | * << >> |
| 28 | * + - |
| 29 | * * / % |
| 30 | * unary - + ~ ! |
| 31 | */ |
| 32 | p_expr(v, flag) |
| 33 | register struct value *v; |
| 34 | char flag; |
| 35 | { |
| 36 | struct value t; |
| 37 | int ret; |
| 38 | |
| 39 | if (p_expr0(&t, flag) < 0) |
| 40 | return -1; |
| 41 | |
| 42 | if (token != T_ASSIGN) { |
| 43 | *v = t; |
| 44 | return 0; |
| 45 | } |
| 46 | switch (t.v_type) { |
| 47 | case V_NUM: |
| 48 | p_error("%d: Not a variable.", t.v_num); |
| 49 | case V_ERR: |
| 50 | t.v_str = 0; |
| 51 | break; |
| 52 | } |
| 53 | ret = p_assign(t.v_str, v, flag); |
| 54 | if (t.v_str != 0) |
| 55 | str_free(t.v_str); |
| 56 | return ret; |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * ? : |
| 61 | */ |
| 62 | p_expr0(v, flag) |
| 63 | register struct value *v; |
| 64 | char flag; |
| 65 | { |
| 66 | struct value t; |
| 67 | char true; |
| 68 | |
| 69 | if (p_expr1(v, flag) < 0) |
| 70 | return -1; |
| 71 | if (token != T_QUEST) |
| 72 | return 0; |
| 73 | switch (v->v_type) { |
| 74 | case V_NUM: |
| 75 | true = v->v_num != 0; |
| 76 | break; |
| 77 | case V_STR: |
| 78 | p_error("?: Numeric left operand required."); |
| 79 | str_free(v->v_str); |
| 80 | v->v_type = V_ERR; |
| 81 | case V_ERR: |
| 82 | flag = 0; |
| 83 | break; |
| 84 | } |
| 85 | (void) s_gettok(); |
| 86 | v->v_type = V_ERR; |
| 87 | if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0) |
| 88 | return -1; |
| 89 | if (token != T_COLON) { |
| 90 | val_free(*v); |
| 91 | p_synerror(); |
| 92 | return -1; |
| 93 | } |
| 94 | (void) s_gettok(); |
| 95 | return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0); |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * || |
| 100 | */ |
| 101 | p_expr1(v, flag) |
| 102 | register struct value *v; |
| 103 | char flag; |
| 104 | { |
| 105 | char true = 0; |
| 106 | |
| 107 | if (p_expr2(v, flag) < 0) |
| 108 | return -1; |
| 109 | if (token != T_OROR) |
| 110 | return 0; |
| 111 | for (;;) { |
| 112 | switch (v->v_type) { |
| 113 | case V_NUM: |
| 114 | v->v_num = true = true || v->v_num != 0; |
| 115 | break; |
| 116 | case V_STR: |
| 117 | p_error("||: Numeric operands required."); |
| 118 | str_free(v->v_str); |
| 119 | v->v_type = V_ERR; |
| 120 | case V_ERR: |
| 121 | flag = 0; |
| 122 | break; |
| 123 | } |
| 124 | if (token != T_OROR) |
| 125 | return 0; |
| 126 | (void) s_gettok(); |
| 127 | if (p_expr2(v, flag && !true) < 0) |
| 128 | return -1; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | /* |
| 133 | * && |
| 134 | */ |
| 135 | p_expr2(v, flag) |
| 136 | register struct value *v; |
| 137 | char flag; |
| 138 | { |
| 139 | char true = 1; |
| 140 | |
| 141 | if (p_expr3_10(3, v, flag) < 0) |
| 142 | return -1; |
| 143 | if (token != T_ANDAND) |
| 144 | return 0; |
| 145 | for (;;) { |
| 146 | switch (v->v_type) { |
| 147 | case V_NUM: |
| 148 | v->v_num = true = true && v->v_num != 0; |
| 149 | break; |
| 150 | case V_STR: |
| 151 | p_error("&&: Numeric operands required."); |
| 152 | str_free(v->v_str); |
| 153 | v->v_type = V_ERR; |
| 154 | case V_ERR: |
| 155 | flag = 0; |
| 156 | break; |
| 157 | } |
| 158 | if (token != T_ANDAND) |
| 159 | return 0; |
| 160 | (void) s_gettok(); |
| 161 | if (p_expr3_10(3, v, flag && true) < 0) |
| 162 | return -1; |
| 163 | } |
| 164 | /*NOTREACHED*/ |
| 165 | } |