From 253d5414daafe5350ac7ccb7d9d156fc02314f58 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Sun, 3 Mar 2019 22:12:46 +1100
Subject: [PATCH] spec: avoid infinite InstanceProcAddr cycles

---
 load/vtable.cpp |  6 ------
 tools/hello.cpp |  9 ++++++++-
 tools/spec.py   | 35 ++++++++++++++++++++++++-----------
 traits.cpp      |  6 ++++++
 4 files changed, 38 insertions(+), 18 deletions(-)

diff --git a/load/vtable.cpp b/load/vtable.cpp
index 745448a..8d92d42 100644
--- a/load/vtable.cpp
+++ b/load/vtable.cpp
@@ -1,7 +1 @@
 #include <cruft/vk/load/vtable.hpp>
-
-using cruft::vk::load::instance_table;
-
-
-///////////////////////////////////////////////////////////////////////////////
-cruft::vk::load::vendor_table const *cruft::vk::load::v_table = nullptr;
diff --git a/tools/hello.cpp b/tools/hello.cpp
index 0681d33..944d5a4 100644
--- a/tools/hello.cpp
+++ b/tools/hello.cpp
@@ -314,7 +314,7 @@ main (void)
     //-------------------------------------------------------------------------
     cruft::vk::instance instance (
         cruft::make_view (layers),
-        cruft::make_view (extensions.data (), extensions.data () + extensions.size ())
+        cruft::make_view (extensions.data (), extensions.size ())
     );
 
     load_traits (instance);
@@ -332,6 +332,13 @@ main (void)
         ;
 
     debug_info.pfnCallback = vk_debug_callback;
+    if (0) {
+        VkDebugReportCallbackEXT obj;
+        auto res = vkCreateDebugReportCallbackEXT (instance.native (), &debug_info, nullptr, &obj);
+        if (res != VK_SUCCESS)
+            panic ("deport report callback");
+    }
+
     auto debug_callback = cruft::vk::make_owned<cruft::vk::debug_report> (
         instance, &debug_info, nullptr
     );
diff --git a/tools/spec.py b/tools/spec.py
index 8a347d3..afbfc0f 100644
--- a/tools/spec.py
+++ b/tools/spec.py
@@ -851,6 +851,8 @@ def write_dispatch(dst: TextIO, q: List[Type], reg: Registry):
     #include <cruft/vk/load/dispatch.hpp>
 
     #include <cruft/util/debug.hpp>
+    
+    #include <cstring>
 
     #pragma GCC diagnostic ignored "-Wunused-parameter"
 
@@ -881,15 +883,10 @@ def write_dispatch(dst: TextIO, q: List[Type], reg: Registry):
         """,
 
         'vkGetInstanceProcAddr': """
-            if (instance == VK_NULL_HANDLE) {
-                return (PFN_vkVoidFunction)cruft::vk::load::v_table->vk_icdGetInstanceProcAddr (instance, pName);
-            }
-        
-            auto const entry = reinterpret_cast<indirect<VkInstance,cruft::vk::load::instance_table> const*> (instance);
-
-            return (entry->table.vkGetInstanceProcAddr)(
-                entry->handle, pName
-            );
+            #define ATTEMPT(NAME) if (!strcmp (#NAME, pName)) return reinterpret_cast<PFN_vkVoidFunction> (&NAME);
+            MAP_INSTANCE_COMMANDS(ATTEMPT)
+            #undef ATTEMPT
+            return nullptr;
         """,
 
         'vkCreateDevice': """
@@ -924,7 +921,7 @@ def write_dispatch(dst: TextIO, q: List[Type], reg: Registry):
                 auto wrapped = std::make_unique<indirect<VkPhysicalDevice,cruft::vk::load::instance_table>> ();
                 wrapped->handle = res[i];
                 
-                #define GET(NAME) wrapped->table.NAME = wrapped->table.NAME ?: reinterpret_cast<decltype(&NAME)> (vkGetInstanceProcAddr (instance, #NAME));
+                #define GET(NAME) wrapped->table.NAME = wrapped->table.NAME ?: reinterpret_cast<decltype(&NAME)> (entry->table.vkGetInstanceProcAddr (instance, #NAME));
                 MAP_INSTANCE_COMMANDS(GET)
                 #undef GET
                 
@@ -957,13 +954,29 @@ def write_dispatch(dst: TextIO, q: List[Type], reg: Registry):
             is_creating = False
 
         if obj.is_instance(reg) and obj.params[0].type not in ['VkInstance', 'VkPhysicalDevice']:
-            forwarding = f"return ::cruft::vk::load::i_table->{obj.name} ({', '.join (i.name for i in obj.params)});"
+            forwarding = f"""
+            if (::cruft::vk::load::i_table->{obj.name})
+                return ::cruft::vk::load::i_table->{obj.name} ({', '.join (i.name for i in obj.params)});
+            else {{
+                auto ptr= cruft::vk::load::v_table->vk_icdGetInstanceProcAddr (nullptr, "{obj.name}");
+                return ((decltype({obj.name})*) (ptr)) ({', '.join (i.name for i in obj.params)});
+            }}
+            """
         else:
             forwarding = f"""
+                if constexpr (std::is_same_v<{obj.params[0].type}, VkInstance> ||
+                              std::is_same_v<{obj.params[0].type}, VkPhysicalDevice>) {{
+                    if ({obj.params[0].name} == VK_NULL_HANDLE) {{
+                        auto ptr= cruft::vk::load::v_table->vk_icdGetInstanceProcAddr (nullptr, "{obj.name}");
+                        return ((decltype({obj.name})*) (ptr)) ({', '.join (i.name for i in obj.params)});
+                    }}
+                }}
+
                 auto const entry = reinterpret_cast<
                     indirect<{obj.params[0].type},cruft::vk::load::{table}_table> const*
                 > ({obj.params[0].name});
 
+                std::clog << "{obj.name}\\n";
                 return (entry->table.{obj.name})(
                     {", ".join(['entry->handle'] + [p.name for p in obj.params[1:]])}
                 );
diff --git a/traits.cpp b/traits.cpp
index dbaa80f..e901c40 100644
--- a/traits.cpp
+++ b/traits.cpp
@@ -13,17 +13,20 @@
 
 
 ///////////////////////////////////////////////////////////////////////////////
+#if 0
 #define INSTANTIATE(KLASS, NAME, FUNC) \
 decltype(FUNC)* cruft::vk::life_traits<KLASS>::NAME = nullptr
 
 INSTANTIATE(VkDebugReportCallbackEXT, create,  vkCreateDebugReportCallbackEXT);
 INSTANTIATE(VkDebugReportCallbackEXT, destroy, vkDestroyDebugReportCallbackEXT);
+#endif
 
 
 ///////////////////////////////////////////////////////////////////////////////
 void
 cruft::vk::load_traits (instance &i)
 {
+#if 0
     #define LOAD(KLASS,NAME,FUNC) \
     try { \
         cruft::vk::life_traits<KLASS>::NAME = i.proc<decltype(&FUNC)> (#FUNC); \
@@ -32,4 +35,7 @@ cruft::vk::load_traits (instance &i)
 
     LOAD(VkDebugReportCallbackEXT, create,  vkCreateDebugReportCallbackEXT);
     LOAD(VkDebugReportCallbackEXT, destroy, vkDestroyDebugReportCallbackEXT);
+#else
+    (void)i;
+#endif
 }