Esempio n. 1
0
// Generate an accessor struct, builder structs & function for a table.
static void GenTable(const Parser &parser, StructDef &struct_def,
                     const GeneratorOptions &opts, std::string *code_ptr) {
  if (struct_def.generated) return;
  std::string &code = *code_ptr;

  // Generate an accessor struct, with methods of the form:
  // type name() const { return GetField<type>(offset, defaultval); }
  GenComment(struct_def.doc_comment, code_ptr);
  code += "struct " + struct_def.name;
  code += " FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table";
  code += " {\n";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {  // Deprecated fields won't be accessible.
      GenComment(field.doc_comment, code_ptr, "  ");
      code += "  " + GenTypeGet(parser, field.value.type, " ", "const ", " *",
                                true);
      code += field.name + "() const { return ";
      // Call a different accessor for pointers, that indirects.
      std::string call = IsScalar(field.value.type.base_type)
        ? "GetField<"
        : (IsStruct(field.value.type) ? "GetStruct<" : "GetPointer<");
      call += GenTypeGet(parser, field.value.type, "", "const ", " *", false);
      call += ">(" + NumToString(field.value.offset);
      // Default value as second arg for non-pointer types.
      if (IsScalar(field.value.type.base_type))
        call += ", " + field.value.constant;
      call += ")";
      code += GenUnderlyingCast(parser, field, true, call);
      code += "; }\n";
      auto nested = field.attributes.Lookup("nested_flatbuffer");
      if (nested) {
        auto nested_root = parser.structs_.Lookup(nested->constant);
        assert(nested_root);  // Guaranteed to exist by parser.
        code += "  const " + nested_root->name + " *" + field.name;
        code += "_nested_root() const { return flatbuffers::GetRoot<";
        code += nested_root->name + ">(" + field.name + "()->Data()); }\n";
      }
      // Generate a comparison function for this field if it is a key.
      if (field.key) {
        code += "  bool KeyCompareLessThan(const " + struct_def.name;
        code += " *o) const { return ";
        if (field.value.type.base_type == BASE_TYPE_STRING) code += "*";
        code += field.name + "() < ";
        if (field.value.type.base_type == BASE_TYPE_STRING) code += "*";
        code += "o->" + field.name + "(); }\n";
        code += "  int KeyCompareWithValue(";
        if (field.value.type.base_type == BASE_TYPE_STRING) {
          code += "const char *val) const { return strcmp(" + field.name;
          code += "()->c_str(), val); }\n";
        } else {
          code += GenTypeBasic(parser, field.value.type, false);
          code += " val) const { return " + field.name + "() < val ? -1 : ";
          code += field.name + "() > val; }\n";
        }
      }
    }
  }
  // Generate a verifier function that can check a buffer from an untrusted
  // source will never cause reads outside the buffer.
  code += "  bool Verify(flatbuffers::Verifier &verifier) const {\n";
  code += "    return VerifyTableStart(verifier)";
  std::string prefix = " &&\n           ";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {
      code += prefix + "VerifyField";
      if (field.required) code += "Required";
      code += "<" + GenTypeSize(parser, field.value.type);
      code += ">(verifier, " + NumToString(field.value.offset);
      code += " /* " + field.name + " */)";
      switch (field.value.type.base_type) {
        case BASE_TYPE_UNION:
          code += prefix + "Verify" + field.value.type.enum_def->name;
          code += "(verifier, " + field.name + "(), " + field.name + "_type())";
          break;
        case BASE_TYPE_STRUCT:
          if (!field.value.type.struct_def->fixed) {
            code += prefix + "verifier.VerifyTable(" + field.name;
            code += "())";
          }
          break;
        case BASE_TYPE_STRING:
          code += prefix + "verifier.Verify(" + field.name + "())";
          break;
        case BASE_TYPE_VECTOR:
          code += prefix + "verifier.Verify(" + field.name + "())";
          switch (field.value.type.element) {
            case BASE_TYPE_STRING: {
              code += prefix + "verifier.VerifyVectorOfStrings(" + field.name;
              code += "())";
              break;
            }
            case BASE_TYPE_STRUCT: {
              if (!field.value.type.struct_def->fixed) {
                code += prefix + "verifier.VerifyVectorOfTables(" + field.name;
                code += "())";
              }
              break;
            }
            default:
              break;
          }
          break;
        default:
          break;
      }
    }
  }
  code += prefix + "verifier.EndTable()";
  code += ";\n  }\n";
  code += "};\n\n";

  // Generate a builder struct, with methods of the form:
  // void add_name(type name) { fbb_.AddElement<type>(offset, name, default); }
  code += "struct " + struct_def.name;
  code += "Builder {\n  flatbuffers::FlatBufferBuilder &fbb_;\n";
  code += "  flatbuffers::uoffset_t start_;\n";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {
      code += "  void add_" + field.name + "(";
      code += GenTypeWire(parser, field.value.type, " ", true) + field.name;
      code += ") { fbb_.Add";
      if (IsScalar(field.value.type.base_type)) {
        code += "Element<" + GenTypeWire(parser, field.value.type, "", false);
        code += ">";
      } else if (IsStruct(field.value.type)) {
        code += "Struct";
      } else {
        code += "Offset";
      }
      code += "(" + NumToString(field.value.offset) + ", ";
      code += GenUnderlyingCast(parser, field, false, field.name);
      if (IsScalar(field.value.type.base_type))
        code += ", " + field.value.constant;
      code += "); }\n";
    }
  }
  code += "  " + struct_def.name;
  code += "Builder(flatbuffers::FlatBufferBuilder &_fbb) : fbb_(_fbb) ";
  code += "{ start_ = fbb_.StartTable(); }\n";
  code += "  " + struct_def.name + "Builder &operator=(const ";
  code += struct_def.name + "Builder &);\n";
  code += "  flatbuffers::Offset<" + struct_def.name;
  code += "> Finish() {\n    auto o = flatbuffers::Offset<" + struct_def.name;
  code += ">(fbb_.EndTable(start_, ";
  code += NumToString(struct_def.fields.vec.size()) + "));\n";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated && field.required) {
      code += "    fbb_.Required(o, " + NumToString(field.value.offset);
      code += ");  // " + field.name + "\n";
    }
  }
  code += "    return o;\n  }\n};\n\n";

  // Generate a convenient CreateX function that uses the above builder
  // to create a table in one go.
  code += "inline flatbuffers::Offset<" + struct_def.name + "> Create";
  code += struct_def.name;
  code += "(flatbuffers::FlatBufferBuilder &_fbb";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {
      code += ",\n   " + GenTypeWire(parser, field.value.type, " ", true);
      code += field.name + " = ";
      if (field.value.type.enum_def && IsScalar(field.value.type.base_type)) {
        auto ev = field.value.type.enum_def->ReverseLookup(
           static_cast<int>(StringToInt(field.value.constant.c_str())), false);
        if (ev) {
          code += WrapInNameSpace(parser,
                                  field.value.type.enum_def->defined_namespace,
                                  GenEnumVal(*field.value.type.enum_def, *ev,
                                             opts));
        } else {
          code += GenUnderlyingCast(parser, field, true, field.value.constant);
        }
      } else {
        code += field.value.constant;
      }
    }
  }
  code += ") {\n  " + struct_def.name + "Builder builder_(_fbb);\n";
  for (size_t size = struct_def.sortbysize ? sizeof(largest_scalar_t) : 1;
       size;
       size /= 2) {
    for (auto it = struct_def.fields.vec.rbegin();
         it != struct_def.fields.vec.rend();
         ++it) {
      auto &field = **it;
      if (!field.deprecated &&
          (!struct_def.sortbysize ||
           size == SizeOf(field.value.type.base_type))) {
        code += "  builder_.add_" + field.name + "(" + field.name + ");\n";
      }
    }
  }
  code += "  return builder_.Finish();\n}\n\n";
}
Esempio n. 2
0
// Generate an accessor struct, builder structs & function for a table.
static void GenTable(StructDef &struct_def, std::string *code_ptr) {
  if (struct_def.generated) return;
  std::string &code = *code_ptr;

  // Generate an accessor struct, with methods of the form:
  // type name() const { return GetField<type>(offset, defaultval); }
  GenComment(struct_def.doc_comment, code_ptr);
  code += "struct " + struct_def.name + " : private flatbuffers::Table";
  code += " {\n";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {  // Deprecated fields won't be accessible.
      GenComment(field.doc_comment, code_ptr, "  ");
      code += "  " + GenTypeGet(field.value.type, " ", "const ", " *");
      code += field.name + "() const { return ";
      // Call a different accessor for pointers, that indirects.
      code += IsScalar(field.value.type.base_type)
        ? "GetField<"
        : (IsStruct(field.value.type) ? "GetStruct<" : "GetPointer<");
      code += GenTypeGet(field.value.type, "", "const ", " *") + ">(";
      code += NumToString(field.value.offset);
      // Default value as second arg for non-pointer types.
      if (IsScalar(field.value.type.base_type))
        code += ", " + field.value.constant;
      code += "); }\n";
    }
  }
  // Generate a verifier function that can check a buffer from an untrusted
  // source will never cause reads outside the buffer.
  code += "  bool Verify(const flatbuffers::Verifier &verifier) const {\n";
  code += "    return VerifyTable(verifier)";
  std::string prefix = " &&\n           ";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {
      code += prefix + "VerifyField<" + GenTypeSize(field.value.type);
      code += ">(verifier, " + NumToString(field.value.offset);
      code += " /* " + field.name + " */)";
      switch (field.value.type.base_type) {
        case BASE_TYPE_UNION:
          code += prefix + "Verify" + field.value.type.enum_def->name;
          code += "(verifier, " + field.name + "(), " + field.name + "_type())";
          break;
        case BASE_TYPE_STRUCT:
          if (!field.value.type.struct_def->fixed) {
            code += prefix + "verifier.VerifyTable(" + field.name;
            code += "())";
          }
          break;
        case BASE_TYPE_STRING:
          code += prefix + "verifier.Verify(" + field.name + "())";
          break;
        case BASE_TYPE_VECTOR:
          code += prefix + "verifier.Verify(" + field.name + "())";
          switch (field.value.type.element) {
            case BASE_TYPE_STRING: {
              code += prefix + "verifier.VerifyVectorOfStrings(" + field.name;
              code += "())";
              break;
            }
            case BASE_TYPE_STRUCT: {
              if (!field.value.type.struct_def->fixed) {
                code += prefix + "verifier.VerifyVectorOfTables(" + field.name;
                code += "())";
              }
              break;
            }
            default:
              break;
          }
          break;
        default:
          break;
      }
    }
  }
  code += ";\n  }\n";
  code += "};\n\n";

  // Generate a builder struct, with methods of the form:
  // void add_name(type name) { fbb_.AddElement<type>(offset, name, default); }
  code += "struct " + struct_def.name;
  code += "Builder {\n  flatbuffers::FlatBufferBuilder &fbb_;\n";
  code += "  flatbuffers::uoffset_t start_;\n";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {
      code += "  void add_" + field.name + "(";
      code += GenTypeWire(field.value.type, " ") + field.name + ") { fbb_.Add";
      if (IsScalar(field.value.type.base_type))
        code += "Element<" + GenTypeWire(field.value.type, "") + ">";
      else if (IsStruct(field.value.type))
        code += "Struct";
      else
        code += "Offset";
      code += "(" + NumToString(field.value.offset) + ", " + field.name;
      if (IsScalar(field.value.type.base_type))
        code += ", " + field.value.constant;
      code += "); }\n";
    }
  }
  code += "  " + struct_def.name;
  code += "Builder(flatbuffers::FlatBufferBuilder &_fbb) : fbb_(_fbb) ";
  code += "{ start_ = fbb_.StartTable(); }\n";
  code += "  " + struct_def.name + "Builder &operator=(const ";
  code += struct_def.name + "Builder &);\n";
  code += "  flatbuffers::Offset<" + struct_def.name;
  code += "> Finish() { return flatbuffers::Offset<" + struct_def.name;
  code += ">(fbb_.EndTable(start_, ";
  code += NumToString(struct_def.fields.vec.size()) + ")); }\n};\n\n";

  // Generate a convenient CreateX function that uses the above builder
  // to create a table in one go.
  code += "inline flatbuffers::Offset<" + struct_def.name + "> Create";
  code += struct_def.name;
  code += "(flatbuffers::FlatBufferBuilder &_fbb";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (!field.deprecated) {
      code += ", " + GenTypeWire(field.value.type, " ") + field.name;
    }
  }
  code += ") {\n  " + struct_def.name + "Builder builder_(_fbb);\n";
  for (size_t size = struct_def.sortbysize ? sizeof(largest_scalar_t) : 1;
       size;
       size /= 2) {
    for (auto it = struct_def.fields.vec.rbegin();
         it != struct_def.fields.vec.rend();
         ++it) {
      auto &field = **it;
      if (!field.deprecated &&
          (!struct_def.sortbysize ||
           size == SizeOf(field.value.type.base_type))) {
        code += "  builder_.add_" + field.name + "(" + field.name + ");\n";
      }
    }
  }
  code += "  return builder_.Finish();\n}\n\n";
}