vulkan: Add support for non-fatal missing functions in vulkan loader

When a function is added by a later revision of an extension, and the
loader expects to deal with drivers written against revisions before and
after that point, we need to not fail hard on missing that function.

Change-Id: Iac6383f6a424afe6e7f83acc86b674669a118c51
Test: Run Vulkan-LoaderAndValidationLayers Cube demo
diff --git a/vulkan/libvulkan/driver_gen.cpp b/vulkan/libvulkan/driver_gen.cpp
index a98a091..9c58c56 100644
--- a/vulkan/libvulkan/driver_gen.cpp
+++ b/vulkan/libvulkan/driver_gen.cpp
@@ -308,20 +308,20 @@
 
 #define UNLIKELY(expr) __builtin_expect((expr), 0)
 
-#define INIT_PROC(obj, proc)                                           \
+#define INIT_PROC(required, obj, proc)                                 \
     do {                                                               \
         data.driver.proc =                                             \
             reinterpret_cast<PFN_vk##proc>(get_proc(obj, "vk" #proc)); \
-        if (UNLIKELY(!data.driver.proc)) {                             \
+        if (UNLIKELY(required && !data.driver.proc)) {                 \
             ALOGE("missing " #obj " proc: vk" #proc);                  \
             success = false;                                           \
         }                                                              \
     } while (0)
 
-#define INIT_PROC_EXT(ext, obj, proc)  \
-    do {                               \
-        if (extensions[ProcHook::ext]) \
-            INIT_PROC(obj, proc);      \
+#define INIT_PROC_EXT(ext, required, obj, proc) \
+    do {                                        \
+        if (extensions[ProcHook::ext])          \
+            INIT_PROC(required, obj, proc);     \
     } while (0)
 
 bool InitDriverTable(VkInstance instance,
@@ -331,14 +331,14 @@
     bool success = true;
 
     // clang-format off
-    INIT_PROC(instance, DestroyInstance);
-    INIT_PROC(instance, EnumeratePhysicalDevices);
-    INIT_PROC(instance, GetInstanceProcAddr);
-    INIT_PROC(instance, CreateDevice);
-    INIT_PROC(instance, EnumerateDeviceExtensionProperties);
-    INIT_PROC_EXT(EXT_debug_report, instance, CreateDebugReportCallbackEXT);
-    INIT_PROC_EXT(EXT_debug_report, instance, DestroyDebugReportCallbackEXT);
-    INIT_PROC_EXT(EXT_debug_report, instance, DebugReportMessageEXT);
+    INIT_PROC(true, instance, DestroyInstance);
+    INIT_PROC(true, instance, EnumeratePhysicalDevices);
+    INIT_PROC(true, instance, GetInstanceProcAddr);
+    INIT_PROC(true, instance, CreateDevice);
+    INIT_PROC(true, instance, EnumerateDeviceExtensionProperties);
+    INIT_PROC_EXT(EXT_debug_report, true, instance, CreateDebugReportCallbackEXT);
+    INIT_PROC_EXT(EXT_debug_report, true, instance, DestroyDebugReportCallbackEXT);
+    INIT_PROC_EXT(EXT_debug_report, true, instance, DebugReportMessageEXT);
     // clang-format on
 
     return success;
@@ -351,16 +351,16 @@
     bool success = true;
 
     // clang-format off
-    INIT_PROC(dev, GetDeviceProcAddr);
-    INIT_PROC(dev, DestroyDevice);
-    INIT_PROC(dev, GetDeviceQueue);
-    INIT_PROC(dev, CreateImage);
-    INIT_PROC(dev, DestroyImage);
-    INIT_PROC(dev, AllocateCommandBuffers);
-    INIT_PROC_EXT(ANDROID_native_buffer, dev, GetSwapchainGrallocUsageANDROID);
-    INIT_PROC_EXT(ANDROID_native_buffer, dev, GetSwapchainGrallocUsage2ANDROID);
-    INIT_PROC_EXT(ANDROID_native_buffer, dev, AcquireImageANDROID);
-    INIT_PROC_EXT(ANDROID_native_buffer, dev, QueueSignalReleaseImageANDROID);
+    INIT_PROC(true, dev, GetDeviceProcAddr);
+    INIT_PROC(true, dev, DestroyDevice);
+    INIT_PROC(true, dev, GetDeviceQueue);
+    INIT_PROC(true, dev, CreateImage);
+    INIT_PROC(true, dev, DestroyImage);
+    INIT_PROC(true, dev, AllocateCommandBuffers);
+    INIT_PROC_EXT(ANDROID_native_buffer, true, dev, GetSwapchainGrallocUsageANDROID);
+    INIT_PROC_EXT(ANDROID_native_buffer, false, dev, GetSwapchainGrallocUsage2ANDROID);
+    INIT_PROC_EXT(ANDROID_native_buffer, true, dev, AcquireImageANDROID);
+    INIT_PROC_EXT(ANDROID_native_buffer, true, dev, QueueSignalReleaseImageANDROID);
     // clang-format on
 
     return success;