Issue 5137 - [emscripten] Added basic filter storage implementation

compiled/bindings/generator.cpp

Index: compiled/bindings/generator.cpp
===================================================================
--- a/compiled/bindings/generator.cpp
+++ b/compiled/bindings/generator.cpp
@@ -123,30 +123,32 @@ namespace bindings_internal
   {
     for (auto& classInfo : classes)
       if (classInfo.id == classID)
         return &classInfo;
     return nullptr;
   }
 
   void register_class(const char* name, TYPEID classID, TYPEID baseClassID,
-                      ptrdiff_t ref_counted_offset)
+                      ptrdiff_t ref_counted_offset,
+                      const FunctionInfo& instanceGetter)
   {
     if (find_class(classID))
       throw std::runtime_error(std::string("Duplicate definition for class ") + name);
 
     if (baseClassID != TypeInfo<NoBaseClass>() && !find_class(baseClassID))
       throw std::runtime_error(std::string("Unknown base class defined for class ") + name);
 
     ClassInfo classInfo;
     classInfo.id = classID;
     classInfo.baseClass = baseClassID;
     classInfo.name = name;
     classInfo.subclass_differentiator.offset = SIZE_MAX;
     classInfo.ref_counted_offset = ref_counted_offset;
+    classInfo.instanceGetter = instanceGetter;
     classes.push_back(classInfo);
   }
 
   void register_property(TYPEID classID, const char* name,
       const FunctionInfo& getter, const FunctionInfo& setter,
       const char* jsValue)
   {
     ClassInfo* classInfo = find_class(classID);
@@ -240,39 +242,38 @@ namespace bindings_internal
       }
       case TypeCategory::STRING_REF:
         return "  var result = readString(" + call_str + ");\n";
       case TypeCategory::CLASS_PTR:
       {
         std::string result;
         result += "  var result = " + call_str + ";\n";
         result += "  if (result)\n";
-        result += "  {\n";
 
         const ClassInfo* cls = find_class(call.pointerType);
         if (!cls)
           throw std::runtime_error("Function " + call.name + " returns pointer to unknown class");
 
         auto offset = cls->subclass_differentiator.offset;
         if (offset == SIZE_MAX)
           result += "    result = exports." + cls->name + "(result);\n";
         else
           result += "    result = exports." + cls->name + ".fromPointer(result);\n";
 
-        result += "  }\n";
         result += "  else\n";
         result += "    result = null;\n";
         return result;
       }
       default:
         throw std::runtime_error("Unexpected return type for " + call.name);
     }
   }
 
-  std::string wrapCall(const FunctionInfo& call, bool isFunction)
+  std::string wrapCall(const FunctionInfo& call, bool isFunction,
+      const FunctionInfo& instanceGetter)
   {
     bool hasStringArgs = false;
     std::vector<std::string> params;
     std::string prefix;
 
     if (isFunction)
       prefix += "function";
     prefix += "(";
@@ -284,17 +285,17 @@ namespace bindings_internal
       prefix += argName;
 
       if (call.args[i] == TypeCategory::STRING_REF)
       {
         hasStringArgs = true;
         params.push_back(std::string("createString(") + argName + ")");
       }
       else if (call.args[i] == TypeCategory::CLASS_PTR)
-        params.push_back(argName + "._pointer");
+        params.push_back(argName + " ? " + argName + "._pointer : 0");
       else if (call.args[i] == TypeCategory::INT64)
       {
         // 64-bit integers are passed as two integer parameters
         params.push_back(argName + " >>> 0");
         params.push_back(argName + " / 0x100000000 >>> 0");
       }
       else
         params.push_back(argName);
@@ -308,17 +309,22 @@ namespace bindings_internal
     if (call.returnType == TypeCategory::DEPENDENT_STRING ||
         call.returnType == TypeCategory::OWNED_STRING || hasStringArgs)
     {
       prefix += "  var sp = Runtime.stackSave();\n";
       suffix = "  Runtime.stackRestore(sp);\n" + suffix;
     }
 
     if (call.instance_function)
-      params.insert(params.begin(), "this._pointer");
+    {
+      if (instanceGetter.empty())
+        params.insert(params.begin(), "this._pointer");
+      else
+        params.insert(params.begin(), instanceGetter.name + "()");
+    }
 
     return prefix + generateCall(call, params) + suffix;
   }
 
   void printHelpers()
   {
     printf("var sizeofString = %i;\n", sizeof(String));
 
@@ -375,50 +381,61 @@ namespace bindings_internal
         return result;
       }
     )");
   }
 
   void printClass(const ClassInfo& cls)
   {
     // Begin class definition
-
-    ClassInfo* baseClass = find_class(cls.baseClass);
-    printf("exports.%s = createClass(%s, %i, {\n", cls.name.c_str(),
-        (baseClass ? ("exports." + baseClass->name).c_str() : "null"),
-        cls.ref_counted_offset);
+    bool singleton = !cls.instanceGetter.empty();
+    if (singleton)
+      printf("exports.%s = {\n", cls.name.c_str());
+    else
+    {
+      ClassInfo* baseClass = find_class(cls.baseClass);
+      printf("exports.%s = createClass(%s, %i, {\n", cls.name.c_str(),
+          (baseClass ? ("exports." + baseClass->name).c_str() : "null"),
+          cls.ref_counted_offset);
+    }
 
     // Print prototype members
-
     for (const auto& property : cls.properties)
     {
       if (property.jsValue.empty())
       {
         printf("get %s%s,\n", property.name.c_str(),
-               wrapCall(property.getter, false).c_str());
+               wrapCall(property.getter, false, cls.instanceGetter).c_str());
         if (!property.setter.empty())
         {
           printf("set %s%s,\n", property.name.c_str(),
-                 wrapCall(property.setter, false).c_str());
+                 wrapCall(property.setter, false, cls.instanceGetter).c_str());
         }
       }
       else
         printf("%s: %s,\n", property.name.c_str(), property.jsValue.c_str());
     }
 
     for (const auto& method : cls.methods)
+    {
       if (method.call.instance_function)
-        printf("%s: %s,\n", method.name.c_str(), wrapCall(method.call).c_str());
+      {
+        printf("%s: %s,\n",
+            method.name.c_str(),
+            wrapCall(method.call, true, cls.instanceGetter).c_str());
+      }
+    }
 
     // End class definition
-
-    printf("});\n");
+    if (singleton)
+      printf("};\n");
+    else
+      printf("});\n");
 
     // Print static members
-
     DifferentiatorInfo differentiator = cls.subclass_differentiator;
     if (differentiator.offset != SIZE_MAX)
     {
       printf("exports.%s.fromPointer = function(ptr)\n", cls.name.c_str());
       puts("{");
       printf("  var type = HEAP32[ptr + %i >> 2];\n", differentiator.offset);
       printf("  if (type in %s_mapping)\n", cls.name.c_str());
       printf("    return new %s_mapping[type](ptr);\n", cls.name.c_str());