Improvements around C++ code generation (#1396)

* * Remove UniformState and UniformEntryPointParams types
* Put all output C++ source in an anonymous namespace
* If SLANG_PRELUDE_NAMESPACE is set, make what it defines available in generated file.

* Fix signature issue in performance-profile.slang

* Context -> KernelContext to avoid ambiguity.

* Fix issues around dynamic dispatch and anonymous namespace.

* Fix typo.

2 files changed, 33 insertions, 14 deletions

diff --git a/source/slang/slang-emit-cpp.cpp b/source/slang/slang-emit-cpp.cpp
index c31ef3bc7..53a110632 100644
--- a/source/slang/slang-emit-cpp.cpp
+++ b/source/slang/slang-emit-cpp.cpp
@@ -1612,7 +1612,7 @@ void CPPSourceEmitter::_emitWitnessTableDefinitions()
                     m_writer->emit(",\n");
                 else
                     isFirstEntry = false;
-                m_writer->emit("&Context::");
+                m_writer->emit("&KernelContext::");
                 m_writer->emit(getName(funcVal));
             }
             else
@@ -1660,7 +1660,7 @@ void CPPSourceEmitter::_maybeEmitWitnessTableTypeDefinition(
             else
                 isFirstEntry = false;
             emitType(funcVal->getResultType());
-            m_writer->emit(" (Context::*");
+            m_writer->emit(" (KernelContext::*");
             m_writer->emit(getName(entry->requirementKey.get()));
             m_writer->emit(")");
             m_writer->emit("(");
@@ -2134,6 +2134,20 @@ void CPPSourceEmitter::emitPreprocessorDirectivesImpl()
 
     writer->emit("\n");
 
+    
+    if (m_target == CodeGenTarget::CPPSource)
+    {
+        // Put all into an anonymous namespace
+        // This includes any generated types, and generated intrinsics
+
+        m_writer->emit("namespace { // anonymous \n\n");
+        m_writer->emit("#ifdef SLANG_PRELUDE_NAMESPACE\n");
+        m_writer->emit("using namespace SLANG_PRELUDE_NAMESPACE;\n");
+        m_writer->emit("#endif\n\n");
+
+        m_writer->emit("struct KernelContext;\n\n");
+    }
+
     if (m_target == CodeGenTarget::CSource)
     {
         // For C output we need to emit type definitions.
@@ -2169,7 +2183,6 @@ void CPPSourceEmitter::emitPreprocessorDirectivesImpl()
         {
             _maybeEmitSpecializedOperationDefinition(intrinsic);
         }
-        
     }
 }
 
@@ -2293,14 +2306,14 @@ void CPPSourceEmitter::_emitEntryPointDefinitionStart(IRFunc* func, IRGlobalPara
 
     m_writer->emit("(");
     m_writer->emit(varyingTypeName);
-    m_writer->emit("* varyingInput, UniformEntryPointParams* params, UniformState* uniformState)");
+    m_writer->emit("* varyingInput, void* params, void* uniformState)");
     emitSemantics(func);
     m_writer->emit("\n{\n");
 
     m_writer->indent();
     // Initialize when constructing so that globals are zeroed
-    m_writer->emit("Context context = {};\n");
-    m_writer->emit("context.uniformState = uniformState;\n");
+    m_writer->emit("KernelContext context = {};\n");
+    m_writer->emit("context.uniformState = (UniformState*)uniformState;\n");
     
     if (entryPointGlobalParams)
     {
@@ -2590,11 +2603,11 @@ void CPPSourceEmitter::emitModuleImpl(IRModule* module)
 
     List<EmitAction> actions;
     computeEmitActions(module, actions);
-
+    
     _emitForwardDeclarations(actions);
 
     IRGlobalParam* entryPointGlobalParams = nullptr;
-
+    
     // Output the global parameters in a 'UniformState' structure
     {
         m_writer->emit("struct UniformState\n{\n");
@@ -2605,15 +2618,14 @@ void CPPSourceEmitter::emitModuleImpl(IRModule* module)
         m_writer->dedent();
         m_writer->emit("\n};\n\n");
     }
-
+    
     // Output the 'Context' which will be used for execution
     {
-        m_writer->emit("struct Context\n{\n");
+        m_writer->emit("struct KernelContext\n{\n");
         m_writer->indent();
 
         m_writer->emit("UniformState* uniformState;\n");
 
-        
         m_writer->emit("uint3 dispatchThreadID;\n");
 
         //if (m_semanticUsedFlags & SemanticUsedFlag::GroupID)
@@ -2659,12 +2671,19 @@ void CPPSourceEmitter::emitModuleImpl(IRModule* module)
         }
 
         m_writer->dedent();
-        m_writer->emit("};\n\n");
+        m_writer->emit("};\n\n");   
     }
 
     // Emit all witness table definitions.
     _emitWitnessTableDefinitions();
 
+    if (m_target == CodeGenTarget::CPPSource)
+    {
+        // Need to close the anonymous namespace when outputting for C++
+
+        m_writer->emit("} // anonymous\n\n");
+    }
+
      // Finally we need to output dll entry points
 
     for (auto action : actions)
diff --git a/source/slang/slang-emit-cuda.cpp b/source/slang/slang-emit-cuda.cpp
index 25b06027d..06bbbea96 100644
--- a/source/slang/slang-emit-cuda.cpp
+++ b/source/slang/slang-emit-cuda.cpp
@@ -866,10 +866,10 @@ void CUDASourceEmitter::emitModuleImpl(IRModule* module)
                     //
                     // At the binary level, our generated CUDA compute kernels will take
                     // two pointer parameters: the first points to the per-entry-point
-                    // `uniform` parameter data, and the second poinst to the global-scope
+                    // `uniform` parameter data, and the second points to the global-scope
                     // parameter data (if any).
                     //
-                    m_writer->emit("(UniformEntryPointParams* entryPointShaderParameters, UniformState* uniformState)");
+                    m_writer->emit("(void* entryPointShaderParameters, void* uniformState)");
                 }
                 else
                 {