[Qemu-devel] [RFC PATCH v2 01/17] fuzz: Move initialization from main to qemu_init

["Oleinik, Alexander" <alxndr@bu.edu>]

Using this, we avoid needing a special case to break out of main(),
early, when initializing the fuzzer, as we can just call qemu_init.
There is still a #define around main(), since it otherwise conflicts
with the libfuzzer main().

Signed-off-by: Alexander Oleinik <alxndr@bu.edu>
---
 include/sysemu/sysemu.h |  5 +++++
 vl.c                    | 25 +++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 984c439ac9..a63d5ccce3 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -184,6 +184,8 @@ QemuOpts *qemu_get_machine_opts(void);
 
 bool defaults_enabled(void);
 
+int qemu_init(int argc, char **argv, char **envp);
+
 extern QemuOptsList qemu_legacy_drive_opts;
 extern QemuOptsList qemu_common_drive_opts;
 extern QemuOptsList qemu_drive_opts;
@@ -197,4 +199,7 @@ extern QemuOptsList qemu_global_opts;
 extern QemuOptsList qemu_mon_opts;
 extern QemuOptsList qemu_semihosting_config_opts;
 
+#ifdef CONFIG_FUZZ
+int real_main(int argc, char **argv, char **envp);
+#endif
 #endif
diff --git a/vl.c b/vl.c
index 130a389712..914bb9b2de 100644
--- a/vl.c
+++ b/vl.c
@@ -130,6 +130,10 @@ int main(int argc, char **argv)
 #include "sysemu/iothread.h"
 #include "qemu/guest-random.h"
 
+#ifdef CONFIG_FUZZ
+#include "tests/libqtest.h"
+#endif
+
 #define MAX_VIRTIO_CONSOLES 1
 
 static const char *data_dir[16];
@@ -2854,7 +2858,7 @@ static void user_register_global_props(void)
                       global_init_func, NULL, NULL);
 }
 
-int main(int argc, char **argv, char **envp)
+int qemu_init(int argc, char **argv, char **envp)
 {
     int i;
     int snapshot, linux_boot;
@@ -4453,7 +4457,7 @@ int main(int argc, char **argv, char **envp)
     if (vmstate_dump_file) {
         /* dump and exit */
         dump_vmstate_json_to_file(vmstate_dump_file);
-        return 0;
+        exit(0);
     }
 
     if (incoming) {
@@ -4470,6 +4474,23 @@ int main(int argc, char **argv, char **envp)
     accel_setup_post(current_machine);
     os_setup_post();
 
+    return 0;
+}
+#ifdef CONFIG_FUZZ
+/*
+ * Without this, the compiler complains about all of the unused
+ * cleanup and shutdown() functions
+ */
+int real_main(int argc, char **argv, char **envp)
+#else
+int main(int argc, char **argv, char **envp)
+#endif
+{
+    int ret = qemu_init(argc, argv, envp);
+    if (ret != 0) {
+        return ret;
+    }
+
     main_loop();
 
     gdbserver_cleanup();
-- 
2.20.1