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b470a02c SC |
1 | %{ |
2 | ||
3 | /* | |
4 | * (C) Copyright 2014, Stephen M. Cameron. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | * | |
19 | */ | |
20 | ||
21 | #include <stdio.h> | |
22 | #include <string.h> | |
ae46966a | 23 | #include <math.h> |
b470a02c SC |
24 | struct parser_value_type { |
25 | double dval; | |
26 | long long ival; | |
27 | int has_dval; | |
28 | int has_error; | |
29 | }; | |
30 | ||
31 | typedef union valtype { | |
32 | struct parser_value_type v; | |
33 | } PARSER_VALUE_TYPE; | |
34 | ||
35 | #define YYSTYPE PARSER_VALUE_TYPE | |
36 | ||
37 | int yyerror(__attribute__((unused)) long long *result, | |
38 | __attribute__((unused)) double *dresult, | |
39 | __attribute__((unused)) int *has_error, | |
40 | __attribute__((unused)) int *bye, const char *msg); | |
41 | ||
42 | extern int yylex(void); | |
43 | extern void yyrestart(FILE *file); | |
44 | ||
45 | %} | |
46 | ||
47 | %union valtype { | |
48 | struct parser_value_type { | |
49 | double dval; | |
50 | long long ival; | |
51 | int has_dval; | |
52 | int has_error; | |
53 | } v; | |
54 | }; | |
55 | ||
56 | %token <v> NUMBER | |
57 | %token <v> BYE | |
18722a18 | 58 | %token <v> SUFFIX |
b470a02c SC |
59 | %left '-' '+' |
60 | %left '*' '/' | |
ae46966a | 61 | %right '^' |
b470a02c SC |
62 | %nonassoc UMINUS |
63 | %parse-param { long long *result } | |
64 | %parse-param { double *dresult } | |
65 | %parse-param { int *has_error } | |
66 | %parse-param { int *bye } | |
67 | ||
68 | %type <v> expression | |
69 | %% | |
70 | ||
71 | top_level: expression { | |
72 | *result = $1.ival; | |
73 | *dresult = $1.dval; | |
74 | *has_error = $1.has_error; | |
75 | } | |
76 | | expression error { | |
77 | *result = $1.ival; | |
78 | *dresult = $1.dval; | |
79 | *has_error = 1; | |
80 | } | |
81 | expression: expression '+' expression { | |
82 | if (!$1.has_dval && !$3.has_dval) | |
83 | $$.ival = $1.ival + $3.ival; | |
84 | else | |
85 | $$.ival = (long long) ($1.dval + $3.dval); | |
86 | $$.dval = $1.dval + $3.dval; | |
87 | $$.has_error = $1.has_error || $3.has_error; | |
88 | } | |
89 | | expression '-' expression { | |
90 | if (!$1.has_dval && !$3.has_dval) | |
91 | $$.ival = $1.ival - $3.ival; | |
92 | else | |
93 | $$.ival = (long long) ($1.dval - $3.dval); | |
94 | $$.dval = $1.dval - $3.dval; | |
95 | $$.has_error = $1.has_error || $3.has_error; | |
96 | } | |
97 | | expression '*' expression { | |
98 | if (!$1.has_dval && !$3.has_dval) | |
99 | $$.ival = $1.ival * $3.ival; | |
100 | else | |
101 | $$.ival = (long long) ($1.dval * $3.dval); | |
102 | $$.dval = $1.dval * $3.dval; | |
103 | $$.has_error = $1.has_error || $3.has_error; | |
104 | } | |
105 | | expression '/' expression { | |
106 | if ($3.ival == 0) | |
107 | yyerror(0, 0, 0, 0, "divide by zero"); | |
108 | else | |
109 | $$.ival = $1.ival / $3.ival; | |
110 | if ($3.dval < 1e-20 && $3.dval > -1e-20) | |
111 | yyerror(0, 0, 0, 0, "divide by zero"); | |
112 | else | |
113 | $$.dval = $1.dval / $3.dval; | |
114 | if ($3.has_dval || $1.has_dval) | |
115 | $$.ival = (long long) $$.dval; | |
116 | $$.has_error = $1.has_error || $3.has_error; | |
117 | } | |
118 | | '-' expression %prec UMINUS { | |
119 | $$.ival = -$2.ival; | |
120 | $$.dval = -$2.dval; | |
121 | $$.has_error = $2.has_error; | |
122 | } | |
123 | | '(' expression ')' { $$ = $2; } | |
18722a18 SC |
124 | | expression SUFFIX { |
125 | if (!$1.has_dval && !$2.has_dval) | |
126 | $$.ival = $1.ival * $2.ival; | |
127 | else | |
128 | $$.ival = (long long) $1.dval * $2.dval; | |
129 | if ($1.has_dval || $2.has_dval) | |
130 | $$.dval = $1.dval * $2.dval; | |
131 | else | |
132 | $$.dval = $1.ival * $2.ival; | |
133 | $$.has_error = $1.has_error || $2.has_error; | |
134 | } | |
ae46966a SC |
135 | | expression '^' expression { |
136 | $$.has_error = $1.has_error || $3.has_error; | |
137 | if (!$1.has_dval && !$3.has_dval) { | |
138 | int i; | |
139 | ||
140 | if ($3.ival == 0) { | |
141 | $$.ival = 1; | |
142 | } else if ($3.ival > 0) { | |
143 | long long tmp = $1.ival; | |
144 | $$.ival = 1.0; | |
145 | for (i = 0; i < $3.ival; i++) | |
146 | $$.ival *= tmp; | |
147 | } else { | |
148 | /* integers, 2^-3, ok, we now have doubles */ | |
149 | double tmp; | |
150 | if ($1.ival == 0 && $3.ival == 0) { | |
151 | tmp = 1.0; | |
152 | $$.has_error = 1; | |
153 | } else { | |
154 | tmp = pow((double) $1.ival, | |
155 | (double) $3.ival); | |
156 | } | |
157 | $$.ival = (long long) tmp; | |
158 | } | |
159 | $$.dval = pow($1.dval, $3.dval); | |
160 | } else { | |
161 | $$.dval = pow($1.dval, $3.dval); | |
162 | $$.ival = (long long) $$.dval; | |
163 | } | |
164 | } | |
b470a02c SC |
165 | | NUMBER { $$ = $1; } |
166 | | BYE { $$ = $1; *bye = 1; }; | |
167 | %% | |
168 | #include <stdio.h> | |
169 | ||
170 | /* Urgh. yacc and lex are kind of horrible. This is not thread safe, obviously. */ | |
171 | static int lexer_read_offset = 0; | |
172 | static char lexer_input_buffer[1000]; | |
173 | ||
174 | int lexer_input(char* buffer, int *bytes_read, int bytes_requested) | |
175 | { | |
176 | int bytes_left = strlen(lexer_input_buffer) - lexer_read_offset; | |
177 | ||
178 | if (bytes_requested > bytes_left ) | |
179 | bytes_requested = bytes_left; | |
180 | memcpy(buffer, &lexer_input_buffer[lexer_read_offset], bytes_requested); | |
181 | *bytes_read = bytes_requested; | |
182 | lexer_read_offset += bytes_requested; | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static void setup_to_parse_string(const char *string) | |
187 | { | |
188 | unsigned int len; | |
189 | ||
190 | len = strlen(string); | |
191 | if (len > sizeof(lexer_input_buffer) - 3) | |
192 | len = sizeof(lexer_input_buffer) - 3; | |
193 | ||
194 | strncpy(lexer_input_buffer, string, len); | |
195 | lexer_input_buffer[len] = '\0'; | |
196 | lexer_input_buffer[len + 1] = '\0'; /* lex/yacc want string double null terminated! */ | |
197 | lexer_read_offset = 0; | |
198 | } | |
199 | ||
200 | int evaluate_arithmetic_expression(const char *buffer, long long *ival, double *dval) | |
201 | { | |
202 | int rc, bye = 0, has_error = 0; | |
203 | ||
204 | setup_to_parse_string(buffer); | |
205 | rc = yyparse(ival, dval, &has_error, &bye); | |
206 | yyrestart(NULL); | |
207 | if (rc || bye || has_error) { | |
208 | *ival = 0; | |
209 | *dval = 0; | |
210 | has_error = 1; | |
211 | } | |
212 | return has_error; | |
213 | } | |
214 | ||
215 | int yyerror(__attribute__((unused)) long long *result, | |
216 | __attribute__((unused)) double *dresult, | |
217 | __attribute__((unused)) int *has_error, | |
218 | __attribute__((unused)) int *bye, const char *msg) | |
219 | { | |
220 | fprintf(stderr, "%s\n", msg); | |
221 | return 0; | |
222 | } | |
223 |