From 6db395dc74f329e04dbe539495c1c34a9d2fdb89 Mon Sep 17 00:00:00 2001
From: Frediano Ziglio <fziglio@redhat.com>
Date: Wed, 22 May 2019 13:42:21 +0100
Subject: [PATCH] Make sure empty structure are ABI compatible

Empty structure are not really portable however adding
an zero size array seems to be the way to have a zero
size structure portably.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
---
 server/red-worker.h | 10 ++++++++++
 server/stat.h       |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/server/red-worker.h b/server/red-worker.h
index 525359d1..7d3c8e05 100644
--- a/server/red-worker.h
+++ b/server/red-worker.h
@@ -133,6 +133,7 @@ typedef struct RedWorkerMessageDelMemslot {
 } RedWorkerMessageDelMemslot;
 
 typedef struct RedWorkerMessageDestroySurfaces {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageDestroySurfaces;
 
 typedef struct RedWorkerMessageDestroySurfacesAsync {
@@ -161,18 +162,23 @@ typedef struct RedWorkerMessageCreatePrimarySurface {
 } RedWorkerMessageCreatePrimarySurface;
 
 typedef struct RedWorkerMessageResetImageCache {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageResetImageCache;
 
 typedef struct RedWorkerMessageResetCursor {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageResetCursor;
 
 typedef struct RedWorkerMessageWakeup {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageWakeup;
 
 typedef struct RedWorkerMessageOom {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageOom;
 
 typedef struct RedWorkerMessageStart {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageStart;
 
 typedef struct RedWorkerMessageFlushSurfacesAsync {
@@ -180,6 +186,7 @@ typedef struct RedWorkerMessageFlushSurfacesAsync {
 } RedWorkerMessageFlushSurfacesAsync;
 
 typedef struct RedWorkerMessageStop {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageStop;
 
 /* this command is sync, so it's ok to pass a pointer */
@@ -224,12 +231,15 @@ typedef struct RedWorkerMessageMonitorsConfigAsync {
 } RedWorkerMessageMonitorsConfigAsync;
 
 typedef struct RedWorkerMessageDriverUnload {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageDriverUnload;
 
 typedef struct RedWorkerMessageGlScanout {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageGlScanout;
 
 typedef struct RedWorkerMessageClose {
+    uint8_t dummy_empty_field[0]; // C/C++ compatibility
 } RedWorkerMessageClose;
 
 typedef struct RedWorkerMessageGlDraw {
diff --git a/server/stat.h b/server/stat.h
index 26b31460..477c1a4d 100644
--- a/server/stat.h
+++ b/server/stat.h
@@ -30,12 +30,14 @@ typedef struct {
 #ifdef RED_STATISTICS
     uint64_t *counter;
 #endif
+    uint8_t dummy_empty_field[0]; /* C/C++ compatibility */
 } RedStatCounter;
 
 typedef struct {
 #ifdef RED_STATISTICS
     uint32_t ref;
 #endif
+    uint8_t dummy_empty_field[0]; /* C/C++ compatibility */
 } RedStatNode;
 
 #ifdef RED_STATISTICS
@@ -95,6 +97,7 @@ typedef struct {
 #if defined(RED_WORKER_STAT) || defined(COMPRESS_STAT)
     stat_time_t time;
 #endif
+    uint8_t dummy_empty_field[0]; /* C/C++ compatibility */
 } stat_start_time_t;
 
 #if defined(RED_WORKER_STAT) || defined(COMPRESS_STAT)
@@ -117,6 +120,7 @@ typedef struct {
     uint64_t comp_size;
 #endif
 #endif
+    uint8_t dummy_empty_field[0]; /* C/C++ compatibility */
 } stat_info_t;
 
 static inline void stat_start_time_init(G_GNUC_UNUSED stat_start_time_t *tm,