8 #include <model-assert.h>
12 #include "stacktrace.h"
15 #define MAX_TRACE_LEN 100
18 int fd_user_out; /**< @brief File descriptor from which to read user program output */
20 #define CONFIG_STACKTRACE
21 /** Print a backtrace of the current program state. */
22 void print_trace(void)
24 #ifdef CONFIG_STACKTRACE
25 print_stacktrace(stdout);
27 void *array[MAX_TRACE_LEN];
31 size = backtrace(array, MAX_TRACE_LEN);
32 strings = backtrace_symbols(array, size);
34 model_print("\nDumping stack trace (%d frames):\n", size);
36 for (i = 0; i < size; i++)
37 model_print("\t%s\n", strings[i]);
40 #endif /* CONFIG_STACKTRACE */
43 void model_print_summary(void)
45 model->print_summary();
48 void assert_hook(void)
50 model_print("Add breakpoint to line %u in file %s.\n",__LINE__,__FILE__);
53 void model_assert(bool expr, const char *file, int line)
57 sprintf(msg, "Program has hit assertion in file %s at line %d\n",
59 model->assert_user_bug(msg);
64 * @brief Setup output redirecting
66 * Redirects user program's stdout to a pipe so that we can dump it
67 * selectively, when displaying bugs, etc.
68 * Also connects a special file 'model_out' directly to stdout, for printing
71 * The model-checker can selectively choose to print/hide the user program
73 * @see clear_program_output
74 * @see print_program_output
76 * Note that the user program's pipe has limited memory, so if a program will
77 * output much data, we will need to buffer it in user-space during execution.
78 * This also means that if ModelChecker decides not to print an execution, it
79 * should promptly clear the pipe.
81 * This function should only be called once.
83 void redirect_output()
87 /* Save stdout for later use */
88 fd = dup(fileno(stdout));
89 model_out = fdopen(fd, "w");
91 /* Redirect program output to a pipe */
93 if (pipe(pipefd) < 0) {
97 fd = dup2(pipefd[1], fileno(stdout)); // STDOUT_FILENO
100 /* Save the "read" side of the pipe for use later */
101 fcntl(pipefd[0], F_SETFL, O_NONBLOCK);
102 fd_user_out = pipefd[0];
106 * @brief Wrapper for reading data to buffer
108 * Besides a simple read, this handles the subtleties of EOF and nonblocking
109 * input (if fd is O_NONBLOCK).
111 * @param fd The file descriptor to read.
112 * @param buf Buffer to read to.
113 * @param maxlen Maximum data to read to buffer
114 * @return The length of data read. If zero, then we hit EOF or ran out of data
117 static ssize_t read_to_buf(int fd, char *buf, size_t maxlen)
119 ssize_t ret = read(fd, buf, maxlen);
121 if (errno == EAGAIN || errno == EWOULDBLOCK) {
131 /** @brief Dump any pending program output without printing */
132 void clear_program_output()
136 while (read_to_buf(fd_user_out, buf, sizeof(buf)));
139 /** @brief Print out any pending program output */
140 void print_program_output()
144 /* Gather all program output */
147 /* Read program output pipe and write to (real) stdout */
150 ret = read_to_buf(fd_user_out, buf, sizeof(buf));
154 int res = fwrite(buf, 1, ret, model_out);
156 errno = ferror(model_out);