Treat entry point variables consistently with other functions

renderdoc/driver/shaders/spirv/spirv_debug.cpp

@@ -474,6 +474,15 @@ void ThreadState::SkipIgnoredInstructions()
   }
 }
 
+void ThreadState::EnterEntryPoint(ShaderDebugState *state)
+{
+  m_State = state;
+
+  EnterFunction({});
+
+  m_State = NULL;
+}
+
 void ThreadState::StepNext(ShaderDebugState *state, const rdcarray<ThreadState> &workgroup)
 {
   m_State = state;

renderdoc/driver/shaders/spirv/spirv_debug.h

@@ -176,7 +176,7 @@ struct ThreadState
   ThreadState(uint32_t workgroupIdx, Debugger &debug, const GlobalState &globalState);
   ~ThreadState();
 
-  void EnterFunction(const rdcarray<Id> &arguments);
+  void EnterEntryPoint(ShaderDebugState *state);
   void StepNext(ShaderDebugState *state, const rdcarray<ThreadState> &workgroup);
 
   enum DerivDir
@@ -238,6 +238,7 @@ struct ThreadState
   void WritePointerValue(Id pointer, const ShaderVariable &val);
 
 private:
+  void EnterFunction(const rdcarray<Id> &arguments);
   void SetDst(Id id, const ShaderVariable &val);
   void ProcessScopeChange(const rdcarray<Id> &oldLive, const rdcarray<Id> &newLive);
   void JumpToLabel(Id target);

renderdoc/driver/shaders/spirv/spirv_debug_setup.cpp

@@ -1020,24 +1020,31 @@ rdcarray<ShaderDebugState> Debugger::ContinueDebug()
   // initialise the first ShaderDebugState if we haven't stepped yet
   if(steps == 0)
   {
-    // we should be sitting at the entry point function prologue, step forward into the first block
-    // and past any function-local variable declarations
-    for(ThreadState &thread : workgroup)
-      thread.EnterFunction({});
-
     ShaderDebugState initial;
 
-    initial.nextInstruction = active.nextInstruction;
+    // we should be sitting at the entry point function prologue, step forward into the first block
+    // and past any function-local variable declarations
+    for(size_t lane = 0; lane < workgroup.size(); lane++)
+    {
+      ThreadState &thread = workgroup[lane];
 
-    for(const Id &v : active.live)
+      if(lane == activeLaneIndex)
+      {
+        thread.EnterEntryPoint(&initial);
+        thread.FillCallstack(initial);
+        initial.nextInstruction = thread.nextInstruction;
+        initial.sourceVars = thread.sourceVars;
+      }
+      else
+      {
+        thread.EnterEntryPoint(NULL);
+      }
+    }
+
+    // globals won't be filled out by entering the entry point, ensure their change is registered.
+    for(const Id &v : liveGlobals)
       initial.changes.push_back({ShaderVariable(), GetPointerValue(active.ids[v])});
 
-    initial.sourceVars = active.sourceVars;
-
-    initial.stepIndex = steps;
-
-    active.FillCallstack(initial);
-
     ret.push_back(initial);
 
     steps++;