1 /*
2 * Copyright 2008 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 // A calculator example used to demonstrate the cmockery testing library.
18
19 #include <assert.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23
24 // If this is being built for a unit test.
25 #if UNIT_TESTING
26
27 /* Redirect printf to a function in the test application so it's possible to
28 * test the standard output. */
29 #ifdef printf
30 #undef printf
31 #endif // printf
32 #define printf example_test_printf
33
34 extern void print_message(const char *format, ...);
35
36 /* Redirect fprintf to a function in the test application so it's possible to
37 * test error messages. */
38 #ifdef fprintf
39 #undef fprintf
40 #endif // fprintf
41 #define fprintf example_test_fprintf
42
43 extern int example_test_fprintf(FILE * const file, const char *format, ...);
44
45 // Redirect assert to mock_assert() so assertions can be caught by cmockery.
46 #ifdef assert
47 #undef assert
48 #endif // assert
49 #define assert(expression) \
50 mock_assert((int)(expression), #expression, __FILE__, __LINE__)
51 void mock_assert(const int result, const char* expression, const char *file,
52 const int line);
53
54 /* Redirect calloc and free to test_calloc() and test_free() so cmockery can
55 * check for memory leaks. */
56 #ifdef calloc
57 #undef calloc
58 #endif // calloc
59 #define calloc(num, size) _test_calloc(num, size, __FILE__, __LINE__)
60 #ifdef free
61 #undef free
62 #endif // free
63 #define free(ptr) _test_free(ptr, __FILE__, __LINE__)
64 void* _test_calloc(const size_t number_of_elements, const size_t size,
65 const char* file, const int line);
66 void _test_free(void* const ptr, const char* file, const int line);
67
68 /* main is defined in the unit test so redefine name of the the main function
69 * here. */
70 #define main example_main
71
72 /* All functions in this object need to be exposed to the test application,
73 * so redefine static to nothing. */
74 #define static
75
76 #endif // UNIT_TESTING
77
78
79 // A binary arithmetic integer operation (add, subtract etc.)
80 typedef int (*BinaryOperator)(int a, int b);
81
82 // Structure which maps operator strings to functions.
83 typedef struct OperatorFunction {
84 const char* operator;
85 BinaryOperator function;
86 } OperatorFunction;
87
88
89 static int add(int a, int b);
90 static int subtract(int a, int b);
91 static int multiply(int a, int b);
92 static int divide(int a, int b);
93
94 // Associate operator strings to functions.
95 static OperatorFunction operator_function_map[] = {
96 {"+", add},
97 {"-", subtract},
98 {"*", multiply},
99 {"/", divide},
100 };
101
add(int a,int b)102 static int add(int a, int b) {
103 return a + b;
104 }
105
subtract(int a,int b)106 static int subtract(int a, int b) {
107 return a - b;
108 }
109
multiply(int a,int b)110 static int multiply(int a, int b) {
111 return a * b;
112 }
113
divide(int a,int b)114 static int divide(int a, int b) {
115 assert(b); // Check for divde by zero.
116 return a / b;
117 }
118
119 /* Searches the specified array of operator_functions for the function
120 * associated with the specified operator_string. This function returns the
121 * function associated with operator_string if successful, NULL otherwise.
122 */
find_operator_function_by_string(const size_t number_of_operator_functions,const OperatorFunction * const operator_functions,const char * const operator_string)123 static BinaryOperator find_operator_function_by_string(
124 const size_t number_of_operator_functions,
125 const OperatorFunction * const operator_functions,
126 const char* const operator_string) {
127 size_t i;
128 assert(!number_of_operator_functions || operator_functions);
129 assert(operator_string);
130
131 for (i = 0; i < number_of_operator_functions; i++) {
132 const OperatorFunction *const operator_function =
133 &operator_functions[i];
134 if (strcmp(operator_function->operator, operator_string) == 0) {
135 return operator_function->function;
136 }
137 }
138 return NULL;
139 }
140
141 /* Perform a series of binary arithmetic integer operations with no operator
142 * precedence.
143 *
144 * The input expression is specified by arguments which is an array of
145 * containing number_of_arguments strings. Operators invoked by the expression
146 * are specified by the array operator_functions containing
147 * number_of_operator_functions, OperatorFunction structures. The value of
148 * each binary operation is stored in a pointer returned to intermediate_values
149 * which is allocated by malloc().
150 *
151 * If successful, this function returns the integer result of the operations.
152 * If an error occurs while performing the operation error_occurred is set to
153 * 1, the operation is aborted and 0 is returned.
154 */
perform_operation(int number_of_arguments,char * arguments[],const size_t number_of_operator_functions,const OperatorFunction * const operator_functions,int * const number_of_intermediate_values,int ** const intermediate_values,int * const error_occurred)155 static int perform_operation(
156 int number_of_arguments, char *arguments[],
157 const size_t number_of_operator_functions,
158 const OperatorFunction * const operator_functions,
159 int * const number_of_intermediate_values,
160 int ** const intermediate_values, int * const error_occurred) {
161 char *end_of_integer;
162 int value;
163 unsigned int i;
164 assert(!number_of_arguments || arguments);
165 assert(!number_of_operator_functions || operator_functions);
166 assert(error_occurred);
167 assert(number_of_intermediate_values);
168 assert(intermediate_values);
169
170 *error_occurred = 0;
171 *number_of_intermediate_values = 0;
172 *intermediate_values = NULL;
173 if (!number_of_arguments)
174 return 0;
175
176 // Parse the first value.
177 value = (int)strtol(arguments[0], &end_of_integer, 10);
178 if (end_of_integer == arguments[0]) {
179 // If an error occurred while parsing the integer.
180 fprintf(stderr, "Unable to parse integer from argument %s\n",
181 arguments[0]);
182 *error_occurred = 1;
183 return 0;
184 }
185
186 // Allocate an array for the output values.
187 *intermediate_values = calloc(((number_of_arguments - 1) / 2),
188 sizeof(**intermediate_values));
189
190 i = 1;
191 while (i < number_of_arguments) {
192 int other_value;
193 const char* const operator_string = arguments[i];
194 const BinaryOperator function = find_operator_function_by_string(
195 number_of_operator_functions, operator_functions, operator_string);
196 int * const intermediate_value =
197 &((*intermediate_values)[*number_of_intermediate_values]);
198 (*number_of_intermediate_values) ++;
199
200 if (!function) {
201 fprintf(stderr, "Unknown operator %s, argument %d\n",
202 operator_string, i);
203 *error_occurred = 1;
204 break;
205 }
206 i ++;
207
208 if (i == number_of_arguments) {
209 fprintf(stderr, "Binary operator %s missing argument\n",
210 operator_string);
211 *error_occurred = 1;
212 break;
213 }
214
215 other_value = (int)strtol(arguments[i], &end_of_integer, 10);
216 if (end_of_integer == arguments[i]) {
217 // If an error occurred while parsing the integer.
218 fprintf(stderr, "Unable to parse integer %s of argument %d\n",
219 arguments[i], i);
220 *error_occurred = 1;
221 break;
222 }
223 i ++;
224
225 // Perform the operation and store the intermediate value.
226 *intermediate_value = function(value, other_value);
227 value = *intermediate_value;
228 }
229 if (*error_occurred) {
230 free(*intermediate_values);
231 *intermediate_values = NULL;
232 *number_of_intermediate_values = 0;
233 return 0;
234 }
235 return value;
236 }
237
main(int argc,char * argv[])238 int main(int argc, char *argv[]) {
239 int return_value;
240 int number_of_intermediate_values;
241 int *intermediate_values;
242 // Peform the operation.
243 const int result = perform_operation(
244 argc - 1, &argv[1],
245 sizeof(operator_function_map) / sizeof(operator_function_map[0]),
246 operator_function_map, &number_of_intermediate_values,
247 &intermediate_values, &return_value);
248
249 // If no errors occurred display the result.
250 if (!return_value && argc > 1) {
251 unsigned int i;
252 unsigned int intermediate_value_index = 0;
253 printf("%s\n", argv[1]);
254 for (i = 2; i < argc; i += 2) {
255 assert(intermediate_value_index < number_of_intermediate_values);
256 printf(" %s %s = %d\n", argv[i], argv[i + 1],
257 intermediate_values[intermediate_value_index++]);
258 }
259 printf("= %d\n", result);
260 }
261 if (intermediate_values) {
262 free(intermediate_values);
263 }
264
265 return return_value;
266 }
267