A patch for t/cli.c which adds a signal handler for dumping code coverage data

cli.patch

diff --git a/t/cli.c b/t/cli.c
index 8d9b68b..99cc4ab 100644
--- a/t/cli.c
+++ b/t/cli.c
@@ -19,6 +19,11 @@
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  * IN THE SOFTWARE.
  */
+
+/*
+ * This is a modified version of t/cli.c
+ */
+
 #ifndef _XOPEN_SOURCE
 #define _XOPEN_SOURCE 700 /* required for glibc to use getaddrinfo, etc. */
 #endif
@@ -29,6 +34,7 @@
 #include <fcntl.h>
 #include <getopt.h>
 #include <inttypes.h>
+#include <signal.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/select.h>
@@ -45,6 +51,17 @@
 #include "picotls/openssl.h"
 #include "util.h"
 
+// forward declaration of __gcov_flush()
+void __gcov_flush();
+
+// signal handler definition which flushes coverage data
+void signal_handler(int signum)
+{
+    fprintf(stderr, "received signal %d, dump code coverage data\n", signum);
+    __gcov_flush();
+    exit(1);
+}
+
 static void shift_buffer(ptls_buffer_t *buf, size_t delta)
 {
     if (delta != 0) {
@@ -318,6 +335,13 @@ int main(int argc, char **argv)
     struct sockaddr_storage sa;
     socklen_t salen;
     int family = 0;
+    int signum;
+
+    printf("set a signal handler\n");
+    if (signal(SIGINT, signal_handler) == SIG_ERR) {
+        fprintf(stderr, "couldn't set a handler for signal: %d\n", signum);
+        exit(1);
+    }
 
     while ((ch = getopt(argc, argv, "46aC:c:i:k:nes:Sl:vh")) != -1) {
         switch (ch) {