Add wasm binding to get reflection json. (shader-slang#5536)

Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

Author: csyonghe

.gitignore

@@ -93,3 +93,4 @@ vkd3d-proton.cache.write
 *~
 .*.swp
 .*.swo
+/generators

include/slang.h

@@ -3322,6 +3322,11 @@ struct ShaderReflection
         return (VariableLayoutReflection*)spReflection_getGlobalParamsVarLayout(
             (SlangReflection*)this);
     }
+
+    SlangResult toJson(ISlangBlob** outBlob)
+    {
+        return spReflection_ToJson((SlangReflection*)this, nullptr, outBlob);
+    }
 };
 
 

source/slang-wasm/slang-wasm-bindings.cpp

@@ -54,6 +54,7 @@ EMSCRIPTEN_BINDINGS(slang)
         .function("getBindingIndex", &slang::wgsl::VariableLayoutReflection::getBindingIndex);
 
     class_<slang::wgsl::ProgramLayout>("ProgramLayout")
+        .function("toJsonObject", &slang::wgsl::ProgramLayout::toJsonObject)
         .function("getParameterCount", &slang::wgsl::ProgramLayout::getParameterCount)
         .function(
             "getParameterByIndex",

source/slang-wasm/slang-wasm.cpp

@@ -415,6 +415,19 @@ unsigned int ProgramLayout::getParameterCount()
     return interface()->getParameterCount();
 }
 
+emscripten::val ProgramLayout::toJsonObject()
+{
+    Slang::ComPtr<ISlangBlob> blob;
+    if (SLANG_FAILED(interface()->toJson(blob.writeRef())))
+        return {};
+    auto jsonString = std::string(
+        (char*)blob->getBufferPointer(),
+        (char*)blob->getBufferPointer() + blob->getBufferSize());
+    emscripten::val parsedObject =
+        emscripten::val::global("JSON").call<emscripten::val>("parse", jsonString);
+    return parsedObject;
+}
+
 VariableLayoutReflection* ProgramLayout::getParameterByIndex(unsigned int index)
 {
     return (slang::wgsl::VariableLayoutReflection*)(interface()->getParameterByIndex(index));

source/slang-wasm/slang-wasm.h

@@ -82,6 +82,8 @@ class ProgramLayout
     slang::wgsl::TypeLayoutReflection* getGlobalParamsTypeLayout();
 
     slang::ProgramLayout* interface() const { return (slang::ProgramLayout*)this; }
+
+    emscripten::val toJsonObject();
 };
 
 class Session;

source/slang/slang-reflection-json.cpp

@@ -1071,7 +1071,7 @@ static void emitReflectionEntryPointJSON(
     }
 
     // If code generation has been performed, print out the parameter usage by this entry point.
-    if ((request->getCompileFlags() & SLANG_COMPILE_FLAG_NO_CODEGEN) == 0)
+    if (request && (request->getCompileFlags() & SLANG_COMPILE_FLAG_NO_CODEGEN) == 0)
     {
         writer << ",\n\"bindings\": [\n";
         writer.indent();