Issue 5216 - [emscripten] Use a more reliable way of retrieving mangled function name

compiled/bindings/generator.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 121 matching lines @@
           signature += 'd';
           break;
         default:
           throw std::runtime_error("Unexpected function argument type");
       }
       args.push_back(type);
     }
 
     int nameLength = GetFunctionName(nullptr, function, signature.c_str());
     name.resize(nameLength);
     GetFunctionName(name.data(), function, signature.c_str());

[sergei, 2017/05/08 09:16:29]

if std::string::data() returns only a const pointer then one may use `&name[0]`.

[Wladimir Palant, 2017/05/08 10:17:18]

Oh, so the C++ standard in its most recent iteration finally managed to define a
non-const std::string::data() and the data buffer can now be modified in a
non-hacky way? Progress is nice, done :)

   }
 
   bool FunctionInfo::empty() const
   {
-    return name.size() == 0;
+    return name.empty();
   }
 
   ClassInfo* find_class(TYPEID classID)
   {
     for (auto& classInfo : classes)
       if (classInfo.id == classID)
         return &classInfo;
     return nullptr;
   }
 
@@ skipping 107 matching lines @@
 
   std::string generateCall(const FunctionInfo& call,
       std::vector<std::string>& params)
   {
     if (call.returnType == TypeCategory::DEPENDENT_STRING ||
         call.returnType == TypeCategory::OWNED_STRING)
     {
       params.insert(params.begin(), "string");
     }
 
-    std::string call_str(call.name.data());
+    std::string call_str(call.name);
     call_str += "(";
     for (int i = 0; i < params.size(); i++)
     {
       if (i > 0)
         call_str += ", ";
       call_str += params[i];
     }
     call_str += ")";
 
     switch (call.returnType)
@@ skipping 23 matching lines @@
         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 " + std::string(call.name.data()) + " returns pointer to unknown class");
+          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 " + std::string(call.name.data()));
+        throw std::runtime_error("Unexpected return type for " + call.name);
     }
   }
 
   std::string wrapCall(const FunctionInfo& call, bool isFunction)
   {
     bool hasStringArgs = false;
     std::vector<std::string> params;
     std::string prefix;
 
     if (isFunction)
@@ skipping 155 matching lines @@
 
 void printBindings()
 {
   bindings_internal::printHelpers();
 
   for (const auto& item : classes)
     bindings_internal::printClass(item);
   for (const auto& item : namespaces)
     bindings_internal::printNamespace(item);
 }