From a64877f04508b1b458e91445862deb6e05a45ae6 Mon Sep 17 00:00:00 2001
From: Kazashi Yoshioka <vnapdv@noreply.localhost>
Date: Tue, 28 Mar 2023 10:45:44 +0200
Subject: [PATCH] Vulkan: Added prerequisite checks for using
 VK_Layer_Validation

This PR adds pre-checks when enabling validation layers.

For validation layers to work some platforms require that
the Vulkan SDK is installed. Validation layers are activated
when running blender with `--debug-gpu`.

Sometimes we expect users to run with `--debug-gpu` for
narrowing down an issue and we cannot expect them to have
the Vulkan SDK installed.

This patch will check if the `VK_LAYER_PATH` is available
and that the configuration file of the validation layer is
present. If this isn't the case we don't activate the
requested validation layer.

Pull Request: https://projects.blender.org/blender/blender/pulls/105922
---
 intern/ghost/intern/GHOST_ContextVK.cpp | 56 +++++++++++++++++++++----
 1 file changed, 48 insertions(+), 8 deletions(-)

diff --git a/intern/ghost/intern/GHOST_ContextVK.cpp b/intern/ghost/intern/GHOST_ContextVK.cpp
index 5ac0e4727e8..b6d64b157eb 100644
--- a/intern/ghost/intern/GHOST_ContextVK.cpp
+++ b/intern/ghost/intern/GHOST_ContextVK.cpp
@@ -23,6 +23,9 @@
 #include <cstdio>
 #include <cstring>
 #include <iostream>
+#include <sstream>
+
+#include <sys/stat.h>
 
 /* Set to 0 to allow devices that do not have the required features.
  * This allows development on OSX until we really needs these features. */
@@ -80,6 +83,21 @@ static const char *vulkan_error_as_string(VkResult result)
   }
 }
 
+enum class VkLayer : uint8_t { KHRONOS_validation };
+
+static bool vklayer_config_exist(const char *vk_extension_config)
+{
+  const char *ev_val = getenv("VK_LAYER_PATH");
+  if (ev_val == nullptr) {
+    return false;
+  }
+  std::stringstream filename;
+  filename << ev_val;
+  filename << "/" << vk_extension_config;
+  struct stat buffer;
+  return (stat(filename.str().c_str(), &buffer) == 0);
+}
+
 #define __STR(A) "" #A
 #define VK_CHECK(__expression) \
   do { \
@@ -401,16 +419,38 @@ static bool checkLayerSupport(vector<VkLayerProperties> &layers_available, const
 
 static void enableLayer(vector<VkLayerProperties> &layers_available,
                         vector<const char *> &layers_enabled,
-                        const char *layer_name,
-                        const bool debug)
+                        const VkLayer layer,
+                        const bool display_warning)
 {
-  if (checkLayerSupport(layers_available, layer_name)) {
-    layers_enabled.push_back(layer_name);
+#define PUSH_VKLAYER(name, name2) \
+  if (vklayer_config_exist("VkLayer_" #name ".json") && \
+      checkLayerSupport(layers_available, "VK_LAYER_" #name2)) { \
+    layers_enabled.push_back("VK_LAYER_" #name2); \
+    enabled = true; \
+  } \
+  else { \
+    warnings << "VK_LAYER_" #name2; \
   }
-  else if (debug) {
-    fprintf(
-        stderr, "Warning: Layer requested, but not supported by the platform. [%s]\n", layer_name);
+
+  bool enabled = false;
+  std::stringstream warnings;
+
+  switch (layer) {
+    case VkLayer::KHRONOS_validation:
+      PUSH_VKLAYER(khronos_validation, KHRONOS_validation);
+  };
+
+  if (enabled) {
+    return;
   }
+
+  if (display_warning) {
+    fprintf(stderr,
+            "Warning: Layer requested, but not supported by the platform. [%s] \n",
+            warnings.str().c_str());
+  }
+
+#undef PUSH_VKLAYER
 }
 
 static bool device_extensions_support(VkPhysicalDevice device, vector<const char *> required_exts)
@@ -864,7 +904,7 @@ GHOST_TSuccess GHOST_ContextVK::initializeDrawingContext()
 
   vector<const char *> layers_enabled;
   if (m_debug) {
-    enableLayer(layers_available, layers_enabled, "VK_LAYER_KHRONOS_validation", m_debug);
+    enableLayer(layers_available, layers_enabled, VkLayer::KHRONOS_validation, m_debug);
   }
 
   vector<const char *> extensions_device;