Noissue - [emscripten] Replace sprintf() usage by safe alternatives

compiled/bindings.ipp

 /*
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #pragma once
 
 #include <cstddef>
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
 #include <exception>
-#include <functional>
 #include <map>
 #include <string>
 #include <type_traits>
 #include <utility>
 #include <vector>
 
 #include <emscripten.h>
 
 #include "String.h"
 #include "intrusive_ptr.h"
 
 namespace bindings_internal
 {
   typedef void* TYPEID;
 
   enum class TypeCategory
   {
     UNKNOWN,
     VOID,
     INT,
-    FLOAT,
     DEPENDENT_STRING,
     OWNED_STRING,
     STRING_REF,
     CLASS_PTR
   };
 
   template<typename T>
   struct TypeInfo
   {
     /*
@@ skipping 11 matching lines @@
     }
 
     constexpr operator TypeCategory() const
     {
       if (std::is_void<T>())
         return TypeCategory::VOID;
 
       if (std::is_integral<T>() || std::is_enum<T>())
         return TypeCategory::INT;
 
-      if (std::is_floating_point<T>())
-        return TypeCategory::FLOAT;
-
       if (std::is_same<DependentString, T>() || std::is_same<const DependentString, T>())
         return TypeCategory::DEPENDENT_STRING;
 
       if (std::is_same<OwnedString, T>() || std::is_same<const OwnedString, T>())
         return TypeCategory::OWNED_STRING;
 
       if (std::is_same<String&, T>() || std::is_same<const String&, T>() ||
         std::is_same<DependentString&, T>())
       {
         return TypeCategory::STRING_REF;
@@ skipping 39 matching lines @@
           instance_function(instance_function)
     {
       name[0] = '\0';
 
       // The function parameter is a pointer to the function pointer.
       // Emscripten's "function pointers" are actually integers indicating the
       // position in the call table. 0 represents nullptr.
       if (!*reinterpret_cast<int*>(function))
         return;
 
-      char signature[256];
-      int pos = 0;
+      for (const auto& item : argTypes)
+      {
+        if (item != TypeCategory::INT && item != TypeCategory::STRING_REF &&
+            item != TypeCategory::CLASS_PTR)
+        {
+          throw std::runtime_error("Unexpected function argument type");
+        }
+        args.push_back(item);
+      }
+
+      if (returnType != TypeCategory::VOID && returnType != TypeCategory::INT &&
+          returnType != TypeCategory::DEPENDENT_STRING &&
+          returnType != TypeCategory::OWNED_STRING &&
+          returnType != TypeCategory::STRING_REF &&
+          returnType != TypeCategory::CLASS_PTR)
+      {
+        throw std::runtime_error("Unexpected function return type");
+      }
+
+      effectiveArgs = args.size();
+      effectiveReturnType = returnType;
+      if (instance_function)
+        effectiveArgs++;
+
       if (returnType == TypeCategory::DEPENDENT_STRING ||
           returnType == TypeCategory::OWNED_STRING)
       {
-        // Objects aren't really returned but passed as parameter. Note that
-        // this pointer might come before it but we don't care because both
-        // are integers (pointers) as far as Emscripten is concerned.
-        signature[pos++] = 'v';
-        signature[pos++] = 'i';
-      }
-      else if (returnType == TypeCategory::VOID)
-        signature[pos++] = 'v';
-      else if (returnType == TypeCategory::FLOAT)
-        signature[pos++] = 'd';
-      else if (returnType == TypeCategory::INT ||
-          returnType == TypeCategory::STRING_REF ||
-          returnType == TypeCategory::CLASS_PTR)
-      {
-        signature[pos++] = 'i';
-      }
-      else
-        throw std::runtime_error("Unexpected function return type");
-
-      if (instance_function)
-      {
-        // this pointer is an implicit parameter
-        signature[pos++] = 'i';
-      }
-
-      for (const auto& item : argTypes)
-      {
-        if (item == TypeCategory::INT || item == TypeCategory::STRING_REF ||
-            item == TypeCategory::CLASS_PTR)
-        {
-          signature[pos++] = 'i';
-        }
-        else if (item == TypeCategory::FLOAT)
-          signature[pos++] = 'd';
-        else
-          throw std::runtime_error("Unexpected function argument type");
-        args.push_back(item);
-      }
-
-      signature[pos] = 0;
-
-      get_function_name(function, signature);
+        effectiveArgs++;
+        effectiveReturnType = TypeCategory::VOID;
+      }
+
+      get_function_name(function, effectiveArgs,
+          effectiveReturnType == TypeCategory::VOID);
     }
 
     template<typename ReturnType, typename... Args>
     FunctionInfo(ReturnType (*function)(Args...))
         : FunctionInfo(TypeInfo<ReturnType>(),
           TypeInfo<ReturnType>().pointer_type(), { TypeInfo<Args>()... }, false,
           &function)
     {
     }
 
@@ skipping 11 matching lines @@
           TypeInfo<ReturnType>().pointer_type(), { TypeInfo<Args>()... }, true,
           &function)
     {
     }
 
     bool empty() const
     {
       return name[0] == '\0';
     }
 
-    void get_function_name(void* ptr, char* signature)
+    void get_function_name(void* ptr, int numArgs, bool voidResult)
     {
       // This is a hack, C++ won't let us get the mangled function name.
       // JavaScript is more dynamic so we pass the pointer to our function
       // there. With that and the function signature we can call the function -
       // with a full stack so that we will cause it to abort. Sometimes the
       // function we are calling will also be missing from the build. The result
       // is the same: abort() is called which in turn calls stackTrace(). By
       // replacing stackTrace() we get access to the call stack and search it
       // for the name of our function.
 
       EM_ASM_ARGS({
-        var signature = AsciiToString($2);
+        var signature = $3 ? "v" : "i";
         var args = [];
-        for (var i = 1; i < signature.length; i++)
+        for (var i = 0; i < $2; i++)
+        {
+          signature += "i";
           args.push(0);
+        }
 
         var oldPrint = Module.print;
         var oldPrintErr = Module.printErr;
         var oldStackTrace = stackTrace;
         var sp = Runtime.stackSave();
         Module.print = function(){};
         Module.printErr = function(){};
         stackTrace = function()
         {
           var stack = [];
@@ skipping 24 matching lines @@
         {
           Module.stringToAscii(e, $0);
         }
         finally
         {
           Runtime.stackRestore(sp);
           Module.print = oldPrint;
           Module.printErr = oldPrintErr;
           stackTrace = oldStackTrace;
         }
-      }, name, ptr, signature);
+      }, name, ptr, numArgs, voidResult);
     }
   };
 
   class NoBaseClass
   {
   };
 
   struct PropertyInfo
   {
     std::string name;
@@ skipping 13 matching lines @@
     size_t offset;
     std::vector<std::pair<int, std::string>> mapping;
   };
 
   struct ClassInfo
   {
     ClassInfo* baseClass;
     std::string name;
     std::vector<PropertyInfo> properties;
     std::vector<MethodInfo> methods;
+    std::vector<FunctionInfo> initializers;
     DifferentiatorInfo subclass_differentiator;
     ptrdiff_t ref_counted_offset;
   };
 
-  typedef std::function<void()>  CustomGenerator;
-
   std::map<TYPEID, ClassInfo> classes;
-  std::vector<CustomGenerator> customGenerators;
 
   void register_class(const char* name, TYPEID classID, TYPEID baseClassID,
                       ptrdiff_t ref_counted_offset)
   {
     auto it = classes.find(classID);
     if (it != classes.end())
       throw std::runtime_error(std::string("Duplicate definition for class ") + name);
 
     ClassInfo* baseClass = nullptr;
     if (baseClassID != TypeInfo<NoBaseClass>())
@@ skipping 34 matching lines @@
     auto it = classes.find(classID);
     if (it == classes.end())
       throw std::runtime_error(std::string("Method defined on unknown class: ") + name);
 
     MethodInfo methodInfo;
     methodInfo.name = name;
     methodInfo.call = call;
     it->second.methods.push_back(methodInfo);
   }
 
+  void register_initializer(TYPEID classID, const FunctionInfo& call)
+  {
+    auto it = classes.find(classID);
+    if (it == classes.end())
+      throw std::runtime_error("Initializer defined on unknown class");
+
+    it->second.initializers.push_back(call);
+  }
+
   void register_differentiator(TYPEID classID, size_t offset,
       std::vector<std::pair<int, std::string>>& mapping)
   {
     auto it = classes.find(classID);
     if (it == classes.end())
       throw std::runtime_error("Subclass differentiator defined on unknown class");
 
     if (it->second.subclass_differentiator.offset != SIZE_MAX)
       throw std::runtime_error("More than one subclass differentiator defined for class " + it->second.name);
 
@@ skipping 17 matching lines @@
     for (int i = 0; i < params.size(); i++)
     {
       if (i > 0)
         call_str += ", ";
       call_str += params[i];
     }
     call_str += ")";
 
     if (call.returnType == TypeCategory::VOID)
       return "  " + call_str + ";\n";
-    else if (call.returnType == TypeCategory::INT ||
-          call.returnType == TypeCategory::FLOAT)
-    {
+    else if (call.returnType == TypeCategory::INT)
       return "  var result = " + call_str + ";\n";
-    }
     else if (call.returnType == TypeCategory::DEPENDENT_STRING ||
         call.returnType == TypeCategory::OWNED_STRING)
     {
       std::string result;
       result += "  var string = createString();\n";
       result += "  " + call_str + ";\n";
       result += "  var result = readString(string);\n";
       if (call.returnType == TypeCategory::OWNED_STRING)
         result += "  Module._DestroyString(string);\n";
       return result;
     }
     else if (call.returnType == TypeCategory::STRING_REF)
     {
       return "  var result = readString(" + call_str + ");\n";
     }
     else if (call.returnType == TypeCategory::CLASS_PTR)
     {
       std::string result;
       result += "  var result = " + call_str + ";\n";
       result += "  if (result)\n";
       result += "  {\n";
 
       auto it = classes.find(call.pointerType);
       if (it == classes.end())
         throw std::runtime_error("Function " + std::string(call.name) + " returns pointer to unknown class");
 
       const ClassInfo& cls = it->second;
       auto offset = cls.subclass_differentiator.offset;
       if (offset == SIZE_MAX)
-        result += "    result = exports." + cls.name + "(result);\n";
+        result += "    result = " + cls.name + "(result);\n";
       else
-        result += "    result = exports." + cls.name + ".fromPointer(result);\n";
+      {
+        result += "    var type = HEAP32[result + " + std::to_string(offset)+ " >> 2];\n";
+        result += "    if (type in " + cls.name + "_mapping)\n";
+        result += "      result = new (exports[" + cls.name + "_mapping[type]])(result);\n";
+        result += "    else\n";
+        result += "      throw new Error('Unexpected " + cls.name + " type: ' + type);\n";
+      }
 
       result += "  }\n";
-      result += "  else\n";
-      result += "    result = null;\n";
       return result;
     }
     else
       throw std::runtime_error("Unexpected return type for " + std::string(call.name));
   }
 
   const std::string wrapCall(const FunctionInfo& call)
   {
     bool hasStringArgs = false;
     std::vector<std::string> params;
     std::string prefix = "function(";
     for (int i = 0; i < call.args.size(); i++)
     {
       std::string argName("arg" + std::to_string(i));
       if (i > 0)
         prefix += ", ";
       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");
       else
         params.push_back(argName);
     }
     prefix += ")\n{\n";
 
     std::string suffix = "}";
     if (call.returnType != TypeCategory::VOID)
       suffix = "  return result;\n" + suffix;
 
     if (call.returnType == TypeCategory::DEPENDENT_STRING ||
@@ skipping 67 matching lines @@
         {
           Module._ReleaseRef(this._pointer + ref_counted_offset);
         };
         return result;
       }
     )");
   }
 
   void printClass(const ClassInfo& cls)
   {
-    printf("exports.%s = createClass(%s, %i);\n", cls.name.c_str(),
-        (cls.baseClass ? ("exports." + cls.baseClass->name).c_str() : "null"),
-        cls.ref_counted_offset);
-
     DifferentiatorInfo differentiator = cls.subclass_differentiator;
     if (differentiator.offset != SIZE_MAX)
     {
       printf("var %s_mapping = \n", cls.name.c_str());
       puts("{");
       for (const auto& item : differentiator.mapping)
         printf("  %i: '%s',\n", item.first, item.second.c_str());
       puts("};");
-
-      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 (exports[%s_mapping[type]])(ptr);\n", cls.name.c_str());
-      printf("  throw new Error('Unexpected %s type: ' + type);\n", cls.name.c_str());
-      puts("};");
-    }
-    else
-    {
-      printf("exports.%s.fromPointer = function(ptr)\n", cls.name.c_str());
-      puts("{");
-      printf("  return new exports.%s(ptr);\n", cls.name.c_str());
-      puts("};");
-    }
+    }
+
+    printf("exports.%s = createClass(%s, %i);\n", cls.name.c_str(),
+        (cls.baseClass ? ("exports." + cls.baseClass->name).c_str() : "null"),
+        cls.ref_counted_offset);
 
     for (const auto& item : cls.properties)
     {
       printf("Object.defineProperty(exports.%s.prototype, '%s', {%s});\n",
           cls.name.c_str(), item.name.c_str(),
           generatePropertyDescriptor(item).c_str());
     }
 
     for (const auto& item : cls.methods)
     {
       std::string obj("exports." + cls.name);
       if (item.call.instance_function)
         obj += ".prototype";
       printf("%s.%s = %s;\n", obj.c_str(), item.name.c_str(),
           wrapCall(item.call).c_str());
     }
+
+    for (const auto& item : cls.initializers)
+      printf("%s()\n", item.name);
   }
 
   void printBindings()
   {
     printHelpers();
 
     for (const auto& item : classes)
       printClass(item.second);
-
-    for (const auto& item : customGenerators)
-      item();
   }
 }
 
 #if defined(PRINT_BINDINGS)
   // Bindings generation step: collect bindings information and print
   // corresponding JS code.
   #define EMSCRIPTEN_BINDINGS \
-      void InitializeBindings();\
-      int main()\
-      {\
-        try\
-        {\
-          InitializeBindings();\
-          bindings_internal::printBindings();\
-        }\
-        catch (const std::exception& e)\
-        {\
-          EM_ASM_ARGS(\
-            console.error("Error occurred generating JavaScript bindings: " +\
-                Module.AsciiToString($0)), e.what()\
-          );\
-          abort();\
-        }\
-        return 0;\
-      }\
-      void InitializeBindings()
+      struct BindingsInitializer {\
+          BindingsInitializer();\
+          BindingsInitializer(bool dummy)\
+          {\
+            try\
+            {\
+              BindingsInitializer();\
+              bindings_internal::printBindings();\
+            }\
+            catch (const std::exception& e)\
+            {\
+              EM_ASM_ARGS(\
+                console.error("Error occurred generating JavaScript bindings: " +\
+                    Module.AsciiToString($0)), e.what()\
+              );\
+              abort();\
+            }\
+          }\
+      } BindingsInitializer_instance(true);\
+      BindingsInitializer::BindingsInitializer()
 #else
   // Actual compilation step: ignore bindings information but define some
   // exported helper functions necessary for the bindings.
   #define EMSCRIPTEN_BINDINGS \
       extern "C"\
       {\
         void EMSCRIPTEN_KEEPALIVE InitString(DependentString* str,\
             String::value_type* data, String::size_type len)\
         {\
           /* String is already allocated on stack, we merely need to call*/\
@@ skipping 80 matching lines @@
   }
 
   template<typename ReturnType, typename... Args>
   const class_& class_function(const char* name, ReturnType (*method)(Args...)) const
   {
     bindings_internal::register_method(
         bindings_internal::TypeInfo<ClassType>(), name, method);
     return *this;
   }
 
+  const class_& class_initializer(void (*function)()) const
+  {
+    bindings_internal::register_initializer(
+        bindings_internal::TypeInfo<ClassType>(), function);
+    return *this;
+  }
+
   template<typename ReturnType,
       typename std::enable_if<std::is_convertible<ReturnType, int32_t>::value>::type* = nullptr>
   const class_& subclass_differentiator(ReturnType ClassType::* member,
       std::initializer_list<std::pair<ReturnType, const char*>> list) const
   {
     ClassType* instance = nullptr;
     size_t offset = (char*)&(instance->*member) - (char*)instance;
 
     std::vector<std::pair<int, std::string>> mapping;
     for (const auto& item : list)
       mapping.emplace_back(item.first, item.second);
 
     bindings_internal::register_differentiator(
         bindings_internal::TypeInfo<ClassType>(), offset, mapping);
     return *this;
   }
 };
-
-void custom_generator(bindings_internal::CustomGenerator generator)
-{
-  bindings_internal::customGenerators.push_back(generator);
-}