#include <execinfo.h>
#include <stdio.h>
#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <model-assert.h>
#include "common.h"
#include "model.h"
+#include "stacktrace.h"
+#include "output.h"
#define MAX_TRACE_LEN 100
+/** @brief Model-checker output file descriptor; default to stdout until redirected */
+int model_out = STDOUT_FILENO;
+
+#define CONFIG_STACKTRACE
/** Print a backtrace of the current program state. */
void print_trace(void)
{
+#ifdef CONFIG_STACKTRACE
+ FILE *file = fdopen(model_out, "w");
+ print_stacktrace(file);
+ fclose(file);
+#else
void *array[MAX_TRACE_LEN];
char **strings;
int size, i;
size = backtrace(array, MAX_TRACE_LEN);
strings = backtrace_symbols(array, size);
- printf("\nDumping stack trace (%d frames):\n", size);
+ model_print("\nDumping stack trace (%d frames):\n", size);
for (i = 0; i < size; i++)
- printf("\t%s\n", strings[i]);
+ model_print("\t%s\n", strings[i]);
free(strings);
+#endif /* CONFIG_STACKTRACE */
+}
+
+void assert_hook(void)
+{
+ model_print("Add breakpoint to line %u in file %s.\n", __LINE__, __FILE__);
+}
+
+void model_assert(bool expr, const char *file, int line)
+{
+ if (!expr) {
+ char msg[100];
+ sprintf(msg, "Program has hit assertion in file %s at line %d\n",
+ file, line);
+ model->assert_user_bug(msg);
+ }
}
-void model_print_summary(void)
+#ifndef CONFIG_DEBUG
+
+static int fd_user_out; /**< @brief File descriptor from which to read user program output */
+
+/**
+ * @brief Setup output redirecting
+ *
+ * Redirects user program's stdout to a pipe so that we can dump it
+ * selectively, when displaying bugs, etc.
+ * Also connects a file descriptor 'model_out' directly to stdout, for printing
+ * data when needed.
+ *
+ * The model-checker can selectively choose to print/hide the user program
+ * output.
+ * @see clear_program_output
+ * @see print_program_output
+ *
+ * Note that the user program's pipe has limited memory, so if a program will
+ * output much data, we will need to buffer it in user-space during execution.
+ * This also means that if ModelChecker decides not to print an execution, it
+ * should promptly clear the pipe.
+ *
+ * This function should only be called once.
+ */
+void redirect_output()
{
- model->print_summary();
+ /* Save stdout for later use */
+ model_out = dup(STDOUT_FILENO);
+ if (model_out < 0) {
+ perror("dup");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Redirect program output to a pipe */
+ int pipefd[2];
+ if (pipe(pipefd) < 0) {
+ perror("pipe");
+ exit(EXIT_FAILURE);
+ }
+ if (dup2(pipefd[1], STDOUT_FILENO) < 0) {
+ perror("dup2");
+ exit(EXIT_FAILURE);
+ }
+ close(pipefd[1]);
+
+ /* Save the "read" side of the pipe for use later */
+ if (fcntl(pipefd[0], F_SETFL, O_NONBLOCK) < 0) {
+ perror("fcntl");
+ exit(EXIT_FAILURE);
+ }
+ fd_user_out = pipefd[0];
+}
+
+/**
+ * @brief Wrapper for reading data to buffer
+ *
+ * Besides a simple read, this handles the subtleties of EOF and nonblocking
+ * input (if fd is O_NONBLOCK).
+ *
+ * @param fd The file descriptor to read.
+ * @param buf Buffer to read to.
+ * @param maxlen Maximum data to read to buffer
+ * @return The length of data read. If zero, then we hit EOF or ran out of data
+ * (non-blocking)
+ */
+static ssize_t read_to_buf(int fd, char *buf, size_t maxlen)
+{
+ ssize_t ret = read(fd, buf, maxlen);
+ if (ret < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ return 0;
+ } else {
+ perror("read");
+ exit(EXIT_FAILURE);
+ }
+ }
+ return ret;
+}
+
+/** @brief Dump any pending program output without printing */
+void clear_program_output()
+{
+ fflush(stdout);
+ char buf[200];
+ while (read_to_buf(fd_user_out, buf, sizeof(buf)));
+}
+
+/** @brief Print out any pending program output */
+void print_program_output()
+{
+ char buf[200];
+
+ /* Gather all program output */
+ fflush(stdout);
+
+ /* Read program output pipe and write to (real) stdout */
+ ssize_t ret;
+ while (1) {
+ ret = read_to_buf(fd_user_out, buf, sizeof(buf));
+ if (!ret)
+ break;
+ while (ret > 0) {
+ ssize_t res = write(model_out, buf, ret);
+ if (res < 0) {
+ perror("write");
+ exit(EXIT_FAILURE);
+ }
+ ret -= res;
+ }
+ }
}
+#endif /* ! CONFIG_DEBUG */
projects / model-checker.git / blobdiff