Don't process unused bindings when debugging vulkan shaders

* These will not be in the reflection data, so we can't try to process them and
  fill out their variables as there won't be anything to map to.
* Signature elements which are 'unused' by not being referenced but are present
  in a pre-1.4 SPIR-V module will be considered used still.

renderdoc/driver/shaders/spirv/spirv_debug_setup.cpp

@@ -1076,6 +1076,9 @@ ShaderDebugTrace *Debugger::BeginDebug(DebugAPIWrapper *api, const ShaderStage s
     else if(v.storage == StorageClass::Uniform || v.storage == StorageClass::StorageBuffer ||
             v.storage == StorageClass::PushConstant)
     {
+      if(!patchData.usedIds.contains(v.id))
+        continue;
+
       ShaderVariable var;
       var.name = GetRawName(v.id);
 
@@ -1261,6 +1264,9 @@ ShaderDebugTrace *Debugger::BeginDebug(DebugAPIWrapper *api, const ShaderStage s
     }
     else if(v.storage == StorageClass::UniformConstant)
     {
+      if(!patchData.usedIds.contains(v.id))
+        continue;
+
       // only images/samplers are allowed to be in UniformConstant
       ShaderVariable var;
       var.rows = 1;

renderdoc/driver/shaders/spirv/spirv_reflect.cpp

@@ -1146,6 +1146,15 @@ void Reflector::MakeReflection(const GraphicsAPI sourceAPI, const ShaderStage st
     usedIds.clear();
     usedIds.insert(entry->usedIds.begin(), entry->usedIds.end());
   }
+  else
+  {
+    // before that, still consider all entry interface used just not exclusively
+    usedIds.insert(entry->usedIds.begin(), entry->usedIds.end());
+  }
+
+  patchData.usedIds.reserve(usedIds.size());
+  for(Id id : usedIds)
+    patchData.usedIds.push_back(id);
 
   // arrays of elements, which can be appended to in any order and then sorted
   rdcarray<SigParameter> inputs;

renderdoc/driver/shaders/spirv/spirv_reflect.h

@@ -68,6 +68,9 @@ struct SPIRVPatchData
   rdcarray<rdcspv::Id> rwInterface;
   rdcarray<rdcspv::Id> samplerInterface;
 
+  // set of used IDs
+  rdcarray<rdcspv::Id> usedIds;
+
   // the spec IDs in order - these are the order of constants encountered while parsing, and are
   // used for byte offsets into the resulting data blob (each constant takes 64-bits).
   // The shader constants reported already have the write offset, but this allows looking up the