wayland-egl: Add wl_egl_window ABI checker

Add a small ABI checker for wl_egl_window so that we can check for
backwards incompatible changes at 'make check' time.

Signed-off-by: Miguel A. Vico <[email protected]>
Reviewed-by: James Jones <[email protected]>
Acked-by: Daniel Stone <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>

2 files changed, 180 insertions, 1 deletions

diff --git a/src/egl/wayland/wayland-egl/Makefile.am b/src/egl/wayland/wayland-egl/Makefile.am
index 8c45e8e26d7..846fa6247b2 100644
--- a/src/egl/wayland/wayland-egl/Makefile.am
+++ b/src/egl/wayland/wayland-egl/Makefile.am
@@ -14,7 +14,11 @@ libwayland_egl_la_LDFLAGS = \
 	$(GC_SECTIONS) \
 	$(LD_NO_UNDEFINED)
 
-TESTS = wayland-egl-symbols-check
+TESTS = wayland-egl-symbols-check \
+        wayland-egl-abi-check
+
 EXTRA_DIST = wayland-egl-symbols-check
 
+check_PROGRAMS = wayland-egl-abi-check
+
 include $(top_srcdir)/install-lib-links.mk
diff --git a/src/egl/wayland/wayland-egl/wayland-egl-abi-check.c b/src/egl/wayland/wayland-egl/wayland-egl-abi-check.c
new file mode 100644
index 00000000000..9701ea14531
--- /dev/null
+++ b/src/egl/wayland/wayland-egl/wayland-egl-abi-check.c
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stddef.h> // offsetof
+#include <stdio.h>  // printf
+
+#include "wayland-egl-priv.h" // Current struct wl_egl_window implementation
+
+/*
+ * Following are previous implementations of wl_egl_window.
+ *
+ * DO NOT EVER CHANGE!
+ */
+
+/* From: 214fc6e850 - Benjamin Franzke : egl: Implement libwayland-egl */
+struct wl_egl_window_v0 {
+    struct wl_surface *surface;
+
+    int width;
+    int height;
+    int dx;
+    int dy;
+
+    int attached_width;
+    int attached_height;
+};
+
+/* From: ca3ed3e024 - Ander Conselvan de Oliveira : egl/wayland: Don't invalidate drawable on swap buffers */
+struct wl_egl_window_v1 {
+    struct wl_surface *surface;
+
+    int width;
+    int height;
+    int dx;
+    int dy;
+
+    int attached_width;
+    int attached_height;
+
+    void *private;
+    void (*resize_callback)(struct wl_egl_window *, void *);
+};
+
+/* From: 690ead4a13 - Stencel, Joanna : egl/wayland-egl: Fix for segfault in dri2_wl_destroy_surface. */
+struct wl_egl_window_v2 {
+    struct wl_surface *surface;
+
+    int width;
+    int height;
+    int dx;
+    int dy;
+
+    int attached_width;
+    int attached_height;
+
+    void *private;
+    void (*resize_callback)(struct wl_egl_window *, void *);
+    void (*destroy_window_callback)(void *);
+};
+
+
+/* This program checks we keep a backwards-compatible struct wl_egl_window
+ * definition whenever it is modified in wayland-egl-priv.h.
+ *
+ * The previous definition should be added above as a new struct
+ * wl_egl_window_vN, and the appropriate checks should be added below
+ */
+
+#define MEMBER_SIZE(type, member) sizeof(((type *)0)->member)
+
+#define CHECK_MEMBERS(a_ver, b_ver, a_member, b_member)                             \
+    do {                                                                            \
+        if (offsetof(struct wl_egl_window ## a_ver, a_member) !=                    \
+            offsetof(struct wl_egl_window ## b_ver, b_member)) {                    \
+            printf("Backards incompatible change detected!\n   "                    \
+                   "offsetof(struct wl_egl_window" #a_ver "::" #a_member ") != "    \
+                   "offsetof(struct wl_egl_window" #b_ver "::" #b_member ")\n");    \
+            return 1;                                                               \
+        }                                                                           \
+                                                                                    \
+        if (MEMBER_SIZE(struct wl_egl_window ## a_ver, a_member) !=                 \
+            MEMBER_SIZE(struct wl_egl_window ## b_ver, b_member)) {                 \
+            printf("Backards incompatible change detected!\n   "                    \
+                   "MEMBER_SIZE(struct wl_egl_window" #a_ver "::" #a_member ") != " \
+                   "MEMBER_SIZE(struct wl_egl_window" #b_ver "::" #b_member ")\n"); \
+            return 1;                                                               \
+        }                                                                           \
+    } while (0)
+
+#define CHECK_MEMBER(a_ver, b_ver, member) CHECK_MEMBERS(a_ver, b_ver, member, member)
+#define CHECK_MEMBER_CURRENT(a_ver, member) CHECK_MEMBER(a_ver,, member)
+
+#define CHECK_SIZE(a_ver, b_ver)                                                    \
+    do {                                                                            \
+        if (sizeof(struct wl_egl_window ## a_ver) >                                 \
+            sizeof(struct wl_egl_window ## b_ver)) {                                \
+            printf("Backards incompatible change detected!\n   "                    \
+                   "sizeof(struct wl_egl_window" #a_ver ") > "                      \
+                   "sizeof(struct wl_egl_window" #b_ver ")\n");                     \
+            return 1;                                                               \
+        }                                                                           \
+    } while (0)
+
+#define CHECK_SIZE_CURRENT(a_ver)                                                   \
+    do {                                                                            \
+        if (sizeof(struct wl_egl_window ## a_ver) !=                                \
+            sizeof(struct wl_egl_window)) {                                         \
+            printf("Backards incompatible change detected!\n   "                    \
+                   "sizeof(struct wl_egl_window" #a_ver ") != "                     \
+                   "sizeof(struct wl_egl_window)\n");                               \
+            return 1;                                                               \
+        }                                                                           \
+    } while (0)
+
+int main(int argc, char **argv)
+{
+    /* Check wl_egl_window_v1 ABI against wl_egl_window_v0 */
+    CHECK_MEMBER(_v0, _v1, surface);
+    CHECK_MEMBER(_v0, _v1, width);
+    CHECK_MEMBER(_v0, _v1, height);
+    CHECK_MEMBER(_v0, _v1, dx);
+    CHECK_MEMBER(_v0, _v1, dy);
+    CHECK_MEMBER(_v0, _v1, attached_width);
+    CHECK_MEMBER(_v0, _v1, attached_height);
+
+    CHECK_SIZE(_v0, _v1);
+
+    /* Check wl_egl_window_v2 ABI against wl_egl_window_v1 */
+    CHECK_MEMBER(_v1, _v2, surface);
+    CHECK_MEMBER(_v1, _v2, width);
+    CHECK_MEMBER(_v1, _v2, height);
+    CHECK_MEMBER(_v1, _v2, dx);
+    CHECK_MEMBER(_v1, _v2, dy);
+    CHECK_MEMBER(_v1, _v2, attached_width);
+    CHECK_MEMBER(_v1, _v2, attached_height);
+    CHECK_MEMBER(_v1, _v2, private);
+    CHECK_MEMBER(_v1, _v2, resize_callback);
+
+    CHECK_SIZE(_v1, _v2);
+
+    /* Check current wl_egl_window ABI against wl_egl_window_v2 */
+    CHECK_MEMBER_CURRENT(_v2, surface);
+    CHECK_MEMBER_CURRENT(_v2, width);
+    CHECK_MEMBER_CURRENT(_v2, height);
+    CHECK_MEMBER_CURRENT(_v2, dx);
+    CHECK_MEMBER_CURRENT(_v2, dy);
+    CHECK_MEMBER_CURRENT(_v2, attached_width);
+    CHECK_MEMBER_CURRENT(_v2, attached_height);
+    CHECK_MEMBER_CURRENT(_v2, private);
+    CHECK_MEMBER_CURRENT(_v2, resize_callback);
+    CHECK_MEMBER_CURRENT(_v2, destroy_window_callback);
+
+    CHECK_SIZE_CURRENT(_v2);
+
+    return 0;
+}