[PATCH 19/21] tests/qtest: add API to declare an expected crash signal

["Daniel P. Berrangé" <berrange@redhat.com>]

Most qtests are validating positive behaviour, but some might
wish to validate that QEMU crashes. Add an API for libqtest
that allows declaring an expected crash signal.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 tests/qtest/libqtest.c | 36 +++++++++++++++++++++++++++---------
 tests/qtest/libqtest.h | 11 +++++++++++
 2 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
index 05d88476154..e65451171e4 100644
--- a/tests/qtest/libqtest.c
+++ b/tests/qtest/libqtest.c
@@ -86,6 +86,9 @@ struct QTestState
     DWORD exit_code;
 #endif
     int expected_status;
+#ifndef _WIN32
+    int expected_signal;
+#endif
     bool big_endian;
     bool irq_level[MAX_IRQ];
     GString *rx;
@@ -185,6 +188,13 @@ void qtest_set_expected_status(QTestState *s, int status)
     s->expected_status = status;
 }
 
+#ifndef _WIN32
+void qtest_set_expected_signal(QTestState *s, int signal)
+{
+    s->expected_signal = signal;
+}
+#endif
+
 static void qtest_check_status(QTestState *s)
 {
     assert(s->qemu_pid == -1);
@@ -195,20 +205,28 @@ static void qtest_check_status(QTestState *s)
      */
 #ifndef _WIN32
     int wstatus = s->wstatus;
-    if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != s->expected_status) {
-        fprintf(stderr, "%s:%d: kill_qemu() tried to terminate QEMU "
-                "process but encountered exit status %d (expected %d)\n",
-                __FILE__, __LINE__, WEXITSTATUS(wstatus), s->expected_status);
-        abort();
+    if (WIFEXITED(wstatus)) {
+        if (s->expected_signal) {
+            fprintf(stderr, "%s:%d: encountered exit status %d but expected signal %d\n",
+                    __FILE__, __LINE__, WEXITSTATUS(wstatus), s->expected_signal);
+            abort();
+        } else if (WEXITSTATUS(wstatus) != s->expected_status) {
+            fprintf(stderr, "%s:%d: kill_qemu() tried to terminate QEMU "
+                    "process but encountered exit status %d (expected %d)\n",
+                    __FILE__, __LINE__, WEXITSTATUS(wstatus), s->expected_status);
+            abort();
+        }
     } else if (WIFSIGNALED(wstatus)) {
         int sig = WTERMSIG(wstatus);
         const char *signame = strsignal(sig) ?: "unknown ???";
         const char *dump = WCOREDUMP(wstatus) ? " (core dumped)" : "";
 
-        fprintf(stderr, "%s:%d: kill_qemu() detected QEMU death "
-                "from signal %d (%s)%s\n",
-                __FILE__, __LINE__, sig, signame, dump);
-        abort();
+        if (sig != s->expected_signal) {
+            fprintf(stderr, "%s:%d: kill_qemu() detected QEMU death "
+                    "from signal %d (%s)%s\n",
+                    __FILE__, __LINE__, sig, signame, dump);
+            abort();
+        }
     }
 #else
     if (s->exit_code != s->expected_status) {
diff --git a/tests/qtest/libqtest.h b/tests/qtest/libqtest.h
index 20982d3fe8d..ddcf075e33a 100644
--- a/tests/qtest/libqtest.h
+++ b/tests/qtest/libqtest.h
@@ -1155,6 +1155,17 @@ bool qtest_probe_child(QTestState *s);
  */
 void qtest_set_expected_status(QTestState *s, int status);
 
+#ifndef _WIN32
+/**
+ * qtest_set_expected_signal:
+ * @s: QTestState instance to operate on.
+ * @signal: an expected crash signal.
+ *
+ * Set expected crash signal of the child.
+ */
+void qtest_set_expected_signal(QTestState *s, int signal);
+#endif
+
 QTestState *qtest_inproc_init(QTestState **s, bool log, const char* arch,
                     void (*send)(void*, const char*));
 
-- 
2.56.0