[Qemu-devel] [PATCH 4/9] runstate_set(): Check for valid transitions

[Luiz Capitulino <lcapitulino@redhat.com>]

This commit could have been folded with the previous one, however
doing it separately will allow for easy bisect and revert if needed.

Checking and testing all valid transitions wasn't trivial, chances
are this will need broader testing to become more stable.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 vl.c |  149 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 148 insertions(+), 1 deletions(-)

diff --git a/vl.c b/vl.c
index 9926d2a..fe3628a 100644
--- a/vl.c
+++ b/vl.c
@@ -332,9 +332,156 @@ bool runstate_check(RunState state)
     return current_run_state == state;
 }
 
+/* This function will abort() on invalid state transitions */
 void runstate_set(RunState new_state)
 {
-    assert(new_state < RSTATE_MAX);
+    switch (current_run_state) {
+    case RSTATE_NO_STATE:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+        case RSTATE_IN_MIGRATE:
+        case RSTATE_PRE_LAUNCH:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_DEBUG:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_IN_MIGRATE:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+        case RSTATE_PRE_LAUNCH:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_PANICKED:
+        switch (new_state) {
+        case RSTATE_PAUSED:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_IO_ERROR:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_PAUSED:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_POST_MIGRATE:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_PRE_LAUNCH:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+        case RSTATE_POST_MIGRATE:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_PRE_MIGRATE:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+        case RSTATE_POST_MIGRATE:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_RESTORE:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_RUNNING:
+        switch (new_state) {
+        case RSTATE_DEBUG:
+        case RSTATE_PANICKED:
+        case RSTATE_IO_ERROR:
+        case RSTATE_PAUSED:
+        case RSTATE_PRE_MIGRATE:
+        case RSTATE_RESTORE:
+        case RSTATE_SAVEVM:
+        case RSTATE_SHUTDOWN:
+        case RSTATE_WATCHDOG:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_SAVEVM:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_SHUTDOWN:
+        switch (new_state) {
+        case RSTATE_PAUSED:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    case RSTATE_WATCHDOG:
+        switch (new_state) {
+        case RSTATE_RUNNING:
+            goto transition_ok;
+        default:
+            /* invalid transition */
+            abort();
+        }
+        abort();
+    default:
+        fprintf(stderr, "current run state is invalid: %s\n",
+                runstate_as_string());
+        abort();
+    }
+
+transition_ok:
     current_run_state = new_state;
 }
 
-- 
1.7.7.rc0.72.g4b5ea