/*

* Copyright 2014 Google Inc. All rights reserved.

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

// independent from idl_parser, since this code is not needed for most clients

#include "flatbuffers/flatbuffers.h"

#include "flatbuffers/idl.h"

#include "flatbuffers/util.h"

#include "flatbuffers/code_generators.h"

namespace flatbuffers {

// Pedantic warning free version of toupper().

inline char ToUpper(char c) {

return static_cast<char>(::toupper(c));

}

static std::string GeneratedFileName(const std::string &path,

const std::string &file_name) {

return path + file_name + "_generated.h";

}

namespace cpp {

class CppGenerator : public BaseGenerator {

public:

CppGenerator(const Parser &parser, const std::string &path,

const std::string &file_name)

: BaseGenerator(parser, path, file_name, "", "::"),

cur_name_space_(nullptr) {}

std::string GenIncludeGuard() const {

// Generate include guard.

std::string guard = file_name_;

// Remove any non-alpha-numeric characters that may appear in a filename.

struct IsAlnum {

bool operator()(char c) { return !isalnum(c); }

};

guard.erase(std::remove_if(guard.begin(), guard.end(), IsAlnum()),

guard.end());

guard = "FLATBUFFERS_GENERATED_" + guard;

guard += "_";

// For further uniqueness, also add the namespace.

auto name_space = parser_.namespaces_.back();

for (auto it = name_space->components.begin();

it != name_space->components.end(); ++it) {

guard += *it + "_";

}

guard += "H_";

std::transform(guard.begin(), guard.end(), guard.begin(), ToUpper);

return guard;

}

void GenIncludeDependencies() {

int num_includes = 0;

for (auto it = parser_.native_included_files_.begin();

it != parser_.native_included_files_.end(); ++it) {

code_ += "#include \"" + *it + "\"";

num_includes++;

}

for (auto it = parser_.included_files_.begin();

it != parser_.included_files_.end(); ++it) {

if (it->second.empty())

continue;

auto noext = flatbuffers::StripExtension(it->second);

auto basename = flatbuffers::StripPath(noext);

code_ += "#include \"" + parser_.opts.include_prefix +

(parser_.opts.keep_include_path ? noext : basename) +

"_generated.h\"";

num_includes++;

}

if (num_includes) code_ += "";

}

// Iterate through all definitions we haven't generate code for (enums,

// structs, and tables) and output them to a single file.

bool generate() {

code_.Clear();

code_ += "// " + std::string(FlatBuffersGeneratedWarning()) + "\n\n";

const auto include_guard = GenIncludeGuard();

code_ += "#ifndef " + include_guard;

code_ += "#define " + include_guard;

code_ += "";

code_ += "#include \"flatbuffers/flatbuffers.h\"";

if (parser_.uses_flexbuffers_) {

code_ += "#include \"flatbuffers/flexbuffers.h\"";

}

code_ += "";

if (parser_.opts.include_dependence_headers) {

GenIncludeDependencies();

}

assert(!cur_name_space_);

// Generate forward declarations for all structs/tables, since they may

// have circular references.

for (auto it = parser_.structs_.vec.begin();

it != parser_.structs_.vec.end(); ++it) {

const auto &struct_def = **it;

if (!struct_def.generated) {

SetNameSpace(struct_def.defined_namespace);

code_ += "struct " + struct_def.name + ";";

if (parser_.opts.generate_object_based_api && !struct_def.fixed) {

code_ += "struct " + NativeName(struct_def.name, &struct_def) + ";";

}

code_ += "";

}

}

// Generate code for all the enum declarations.

for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();

++it) {

const auto &enum_def = **it;

if (!enum_def.generated) {

SetNameSpace(enum_def.defined_namespace);

GenEnum(enum_def);

}

}

// Generate code for all structs, then all tables.

for (auto it = parser_.structs_.vec.begin();

it != parser_.structs_.vec.end(); ++it) {

const auto &struct_def = **it;

if (struct_def.fixed && !struct_def.generated) {

SetNameSpace(struct_def.defined_namespace);

GenStruct(struct_def);

}

}

for (auto it = parser_.structs_.vec.begin();

it != parser_.structs_.vec.end(); ++it) {

const auto &struct_def = **it;

if (!struct_def.fixed && !struct_def.generated) {

SetNameSpace(struct_def.defined_namespace);

GenTable(struct_def);

}

}

for (auto it = parser_.structs_.vec.begin();

it != parser_.structs_.vec.end(); ++it) {

const auto &struct_def = **it;

if (!struct_def.fixed && !struct_def.generated) {

SetNameSpace(struct_def.defined_namespace);

GenTablePost(struct_def);

}

}

// Generate code for union verifiers.

for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();

++it) {

const auto &enum_def = **it;

if (enum_def.is_union && !enum_def.generated) {

SetNameSpace(enum_def.defined_namespace);

GenUnionPost(enum_def);

}

}

// Generate convenient global helper functions:

if (parser_.root_struct_def_) {

auto &struct_def = *parser_.root_struct_def_;

SetNameSpace(struct_def.defined_namespace);

const auto &name = struct_def.name;

const auto qualified_name =

parser_.namespaces_.back()->GetFullyQualifiedName(name);

const auto cpp_name = TranslateNameSpace(qualified_name);

code_.SetValue("STRUCT_NAME", name);

code_.SetValue("CPP_NAME", cpp_name);

// The root datatype accessor:

code_ += "inline \\";

code_ += "const {{CPP_NAME}} *Get{{STRUCT_NAME}}(const void *buf) {";

code_ += " return flatbuffers::GetRoot<{{CPP_NAME}}>(buf);";

code_ += "}";

code_ += "";

if (parser_.opts.mutable_buffer) {

code_ += "inline \\";

code_ += "{{STRUCT_NAME}} *GetMutable{{STRUCT_NAME}}(void *buf) {";

code_ += " return flatbuffers::GetMutableRoot<{{STRUCT_NAME}}>(buf);";

code_ += "}";

code_ += "";

}

if (parser_.file_identifier_.length()) {

// Return the identifier

code_ += "inline const char *{{STRUCT_NAME}}Identifier() {";

code_ += " return \"" + parser_.file_identifier_ + "\";";

code_ += "}";

code_ += "";

// Check if a buffer has the identifier.

code_ += "inline \\";

code_ += "bool {{STRUCT_NAME}}BufferHasIdentifier(const void *buf) {";

code_ += " return flatbuffers::BufferHasIdentifier(";

code_ += " buf, {{STRUCT_NAME}}Identifier());";

code_ += "}";

code_ += "";

}

// The root verifier.

if (parser_.file_identifier_.length()) {

code_.SetValue("ID", name + "Identifier()");

} else {

code_.SetValue("ID", "nullptr");

}

code_ += "inline bool Verify{{STRUCT_NAME}}Buffer(";

code_ += " flatbuffers::Verifier &verifier) {";

code_ += " return verifier.VerifyBuffer<{{CPP_NAME}}>({{ID}});";

code_ += "}";

code_ += "";

if (parser_.file_extension_.length()) {

// Return the extension

code_ += "inline const char *{{STRUCT_NAME}}Extension() {";

code_ += " return \"" + parser_.file_extension_ + "\";";

code_ += "}";

code_ += "";

}

// Finish a buffer with a given root object:

code_ += "inline void Finish{{STRUCT_NAME}}Buffer(";

code_ += " flatbuffers::FlatBufferBuilder &fbb,";

code_ += " flatbuffers::Offset<{{CPP_NAME}}> root) {";

if (parser_.file_identifier_.length())

code_ += " fbb.Finish(root, {{STRUCT_NAME}}Identifier());";

else

code_ += " fbb.Finish(root);";

code_ += "}";

code_ += "";

if (parser_.opts.generate_object_based_api) {

// A convenient root unpack function.

auto native_name =

NativeName(WrapInNameSpace(struct_def), &struct_def);

code_.SetValue("UNPACK_RETURN",

GenTypeNativePtr(native_name, nullptr, false));

code_.SetValue("UNPACK_TYPE",

GenTypeNativePtr(native_name, nullptr, true));

code_ += "inline {{UNPACK_RETURN}} UnPack{{STRUCT_NAME}}(";

code_ += " const void *buf,";

code_ += " const flatbuffers::resolver_function_t *res = nullptr) {";

code_ += " return {{UNPACK_TYPE}}\\";

code_ += "(Get{{STRUCT_NAME}}(buf)->UnPack(res));";

code_ += "}";

code_ += "";

}

}

if (cur_name_space_) SetNameSpace(nullptr);

// Close the include guard.

code_ += "#endif // " + include_guard;

const auto file_path = GeneratedFileName(path_, file_name_);

const auto final_code = code_.ToString();

return SaveFile(file_path.c_str(), final_code, false);

}

private:

CodeWriter code_;

// This tracks the current namespace so we can insert namespace declarations.

const Namespace *cur_name_space_;

const Namespace *CurrentNameSpace() const { return cur_name_space_; }

// Translates a qualified name in flatbuffer text format to the same name in

// the equivalent C++ namespace.

static std::string TranslateNameSpace(const std::string &qualified_name) {

std::string cpp_qualified_name = qualified_name;

size_t start_pos = 0;

while ((start_pos = cpp_qualified_name.find(".", start_pos)) !=

std::string::npos) {

cpp_qualified_name.replace(start_pos, 1, "::");

}

return cpp_qualified_name;

}

void GenComment(const std::vector<std::string> &dc, const char *prefix = "") {

std::string text;

::flatbuffers::GenComment(dc, &text, nullptr, prefix);

code_ += text + "\\";

}

// Return a C++ type from the table in idl.h

std::string GenTypeBasic(const Type &type, bool user_facing_type) const {

static const char *ctypename[] = {

#define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \

#CTYPE,

FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)

#undef FLATBUFFERS_TD

};

if (user_facing_type) {

if (type.enum_def) return WrapInNameSpace(*type.enum_def);

if (type.base_type == BASE_TYPE_BOOL) return "bool";

}

return ctypename[type.base_type];

}

// Return a C++ pointer type, specialized to the actual struct/table types,

// and vector element types.

std::string GenTypePointer(const Type &type) const {

switch (type.base_type) {

case BASE_TYPE_STRING: {

return "flatbuffers::String";

}

case BASE_TYPE_VECTOR: {

const auto type_name = GenTypeWire(type.VectorType(), "", false);

return "flatbuffers::Vector<" + type_name + ">";

}

case BASE_TYPE_STRUCT: {

return WrapInNameSpace(*type.struct_def);

}

case BASE_TYPE_UNION:

// fall through

default: {

return "void";

}

}

}

// Return a C++ type for any type (scalar/pointer) specifically for

// building a flatbuffer.

std::string GenTypeWire(const Type &type, const char *postfix,

bool user_facing_type) const {

if (IsScalar(type.base_type)) {

return GenTypeBasic(type, user_facing_type) + postfix;

} else if (IsStruct(type)) {

return "const " + GenTypePointer(type) + " *";

} else {

return "flatbuffers::Offset<" + GenTypePointer(type) + ">" + postfix;

}

}

// Return a C++ type for any type (scalar/pointer) that reflects its

// serialized size.

std::string GenTypeSize(const Type &type) const {

if (IsScalar(type.base_type)) {

return GenTypeBasic(type, false);

} else if (IsStruct(type)) {

return GenTypePointer(type);

} else {

return "flatbuffers::uoffset_t";

}

}

// TODO(wvo): make this configurable.

static std::string NativeName(const std::string &name, const StructDef *sd) {

return sd && !sd->fixed ? name + "T" : name;

}

const std::string &PtrType(const FieldDef *field) {

auto attr = field ? field->attributes.Lookup("cpp_ptr_type") : nullptr;

return attr ? attr->constant : parser_.opts.cpp_object_api_pointer_type;

}

const std::string NativeString(const FieldDef *field) {

auto attr = field ? field->attributes.Lookup("cpp_str_type") : nullptr;

auto &ret = attr ? attr->constant : parser_.opts.cpp_object_api_string_type;

if (ret.empty()) {

return "std::string";

}

return ret;

}

std::string GenTypeNativePtr(const std::string &type, const FieldDef *field,

bool is_constructor) {

auto &ptr_type = PtrType(field);

if (ptr_type != "naked") {

return ptr_type + "<" + type + ">";

} else if (is_constructor) {

return "";

} else {

return type + " *";

}

}

std::string GenPtrGet(const FieldDef &field) {

auto &ptr_type = PtrType(&field);

return ptr_type == "naked" ? "" : ".get()";

}

std::string GenTypeNative(const Type &type, bool invector,

const FieldDef &field) {

switch (type.base_type) {

case BASE_TYPE_STRING: {

return NativeString(&field);

}

case BASE_TYPE_VECTOR: {

const auto type_name = GenTypeNative(type.VectorType(), true, field);

return "std::vector<" + type_name + ">";

}

case BASE_TYPE_STRUCT: {

auto type_name = WrapInNameSpace(*type.struct_def);

if (IsStruct(type)) {

auto native_type = type.struct_def->attributes.Lookup("native_type");

if (native_type) {

type_name = native_type->constant;

}

if (invector || field.native_inline) {

return type_name;

} else {

return GenTypeNativePtr(type_name, &field, false);

}

} else {

return GenTypeNativePtr(NativeName(type_name, type.struct_def),

&field, false);

}

}

case BASE_TYPE_UNION: {

return type.enum_def->name + "Union";

}

default: {

return GenTypeBasic(type, true);

}

}

}

// Return a C++ type for any type (scalar/pointer) specifically for

// using a flatbuffer.

std::string GenTypeGet(const Type &type, const char *afterbasic,

const char *beforeptr, const char *afterptr,

bool user_facing_type) {

if (IsScalar(type.base_type)) {

return GenTypeBasic(type, user_facing_type) + afterbasic;

} else {

return beforeptr + GenTypePointer(type) + afterptr;

}

}

std::string GenEnumDecl(const EnumDef &enum_def) const {

const IDLOptions &opts = parser_.opts;

return (opts.scoped_enums ? "enum class " : "enum ") + enum_def.name;

}

std::string GenEnumValDecl(const EnumDef &enum_def,

const std::string &enum_val) const {

const IDLOptions &opts = parser_.opts;

return opts.prefixed_enums ? enum_def.name + "_" + enum_val : enum_val;

}

std::string GetEnumValUse(const EnumDef &enum_def,

const EnumVal &enum_val) const {

const IDLOptions &opts = parser_.opts;

if (opts.scoped_enums) {

return enum_def.name + "::" + enum_val.name;

} else if (opts.prefixed_enums) {

return enum_def.name + "_" + enum_val.name;

} else {

return enum_val.name;

}

}

std::string StripUnionType(const std::string &name) {

return name.substr(0, name.size() - strlen(UnionTypeFieldSuffix()));

}

std::string GetUnionElement(const EnumVal &ev, bool wrap, bool actual_type,

bool native_type = false) {

if (ev.union_type.base_type == BASE_TYPE_STRUCT) {

auto name = actual_type ? ev.union_type.struct_def->name : ev.name;

return wrap

? WrapInNameSpace(ev.union_type.struct_def->defined_namespace, name)

: name;

} else if (ev.union_type.base_type == BASE_TYPE_STRING) {

return actual_type

? (native_type ? "std::string" : "flatbuffers::String")

: ev.name;

} else {

assert(false);

return ev.name;

}

}

static std::string UnionVerifySignature(const EnumDef &enum_def) {

return "bool Verify" + enum_def.name +

"(flatbuffers::Verifier &verifier, const void *obj, " +

enum_def.name + " type)";

}

static std::string UnionVectorVerifySignature(const EnumDef &enum_def) {

return "bool Verify" + enum_def.name + "Vector" +

"(flatbuffers::Verifier &verifier, " +

"const flatbuffers::Vector<flatbuffers::Offset<void>> *values, " +

"const flatbuffers::Vector<uint8_t> *types)";

}

static std::string UnionUnPackSignature(const EnumDef &enum_def,

bool inclass) {

return (inclass ? "static " : "") +

std::string("void *") +

(inclass ? "" : enum_def.name + "Union::") +

"UnPack(const void *obj, " + enum_def.name +

" type, const flatbuffers::resolver_function_t *resolver)";

}

static std::string UnionPackSignature(const EnumDef &enum_def, bool inclass) {

return "flatbuffers::Offset<void> " +

(inclass ? "" : enum_def.name + "Union::") +

"Pack(flatbuffers::FlatBufferBuilder &_fbb, " +

"const flatbuffers::rehasher_function_t *_rehasher" +

(inclass ? " = nullptr" : "") + ") const";

}

static std::string TableCreateSignature(const StructDef &struct_def,

bool predecl) {

return "flatbuffers::Offset<" + struct_def.name + "> Create" +

struct_def.name +

"(flatbuffers::FlatBufferBuilder &_fbb, const " +

NativeName(struct_def.name, &struct_def) +

" *_o, const flatbuffers::rehasher_function_t *_rehasher" +

(predecl ? " = nullptr" : "") + ")";

}

static std::string TablePackSignature(const StructDef &struct_def,

bool inclass) {

return std::string(inclass ? "static " : "") +

"flatbuffers::Offset<" + struct_def.name + "> " +

(inclass ? "" : struct_def.name + "::") +

"Pack(flatbuffers::FlatBufferBuilder &_fbb, " +

"const " + NativeName(struct_def.name, &struct_def) + "* _o, " +

"const flatbuffers::rehasher_function_t *_rehasher" +

(inclass ? " = nullptr" : "") + ")";

}

static std::string TableUnPackSignature(const StructDef &struct_def,

bool inclass) {

return NativeName(struct_def.name, &struct_def) + " *" +

(inclass ? "" : struct_def.name + "::") +

"UnPack(const flatbuffers::resolver_function_t *_resolver" +

(inclass ? " = nullptr" : "") + ") const";

}

static std::string TableUnPackToSignature(const StructDef &struct_def,

bool inclass) {

return "void " + (inclass ? "" : struct_def.name + "::") +

"UnPackTo(" + NativeName(struct_def.name, &struct_def) + " *" +

"_o, const flatbuffers::resolver_function_t *_resolver" +

(inclass ? " = nullptr" : "") + ") const";

}

// Generate an enum declaration,

// an enum string lookup table,

// and an enum array of values

void GenEnum(const EnumDef &enum_def) {

code_.SetValue("ENUM_NAME", enum_def.name);

code_.SetValue("BASE_TYPE", GenTypeBasic(enum_def.underlying_type, false));

code_.SetValue("SEP", "");

GenComment(enum_def.doc_comment);

code_ += GenEnumDecl(enum_def) + "\\";

if (parser_.opts.scoped_enums)

code_ += " : {{BASE_TYPE}}\\";

code_ += " {";

int64_t anyv = 0;

const EnumVal *minv = nullptr, *maxv = nullptr;

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

GenComment(ev.doc_comment, " ");

code_.SetValue("KEY", GenEnumValDecl(enum_def, ev.name));

code_.SetValue("VALUE", NumToString(ev.value));

code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";

code_.SetValue("SEP", ",\n");

minv = !minv || minv->value > ev.value ? &ev : minv;

maxv = !maxv || maxv->value < ev.value ? &ev : maxv;

anyv |= ev.value;

}

if (parser_.opts.scoped_enums || parser_.opts.prefixed_enums) {

assert(minv && maxv);

code_.SetValue("SEP", ",\n");

if (enum_def.attributes.Lookup("bit_flags")) {

code_.SetValue("KEY", GenEnumValDecl(enum_def, "NONE"));

code_.SetValue("VALUE", "0");

code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";

code_.SetValue("KEY", GenEnumValDecl(enum_def, "ANY"));

code_.SetValue("VALUE", NumToString(anyv));

code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";

} else { // MIN & MAX are useless for bit_flags

code_.SetValue("KEY",GenEnumValDecl(enum_def, "MIN"));

code_.SetValue("VALUE", GenEnumValDecl(enum_def, minv->name));

code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";

code_.SetValue("KEY",GenEnumValDecl(enum_def, "MAX"));

code_.SetValue("VALUE", GenEnumValDecl(enum_def, maxv->name));

code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";

}

}

code_ += "";

code_ += "};";

if (parser_.opts.scoped_enums && enum_def.attributes.Lookup("bit_flags")) {

code_ += "DEFINE_BITMASK_OPERATORS({{ENUM_NAME}}, {{BASE_TYPE}})";

}

code_ += "";

// Generate an array of all enumeration values

auto num_fields = NumToString(enum_def.vals.vec.size());

code_ += "inline {{ENUM_NAME}} (&EnumValues{{ENUM_NAME}}())[" + num_fields + "] {";

code_ += " static {{ENUM_NAME}} values[] = {";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

auto value = GetEnumValUse(enum_def, ev);

auto suffix = *it != enum_def.vals.vec.back() ? "," : "";

code_ += " " + value + suffix;

}

code_ += " };";

code_ += " return values;";

code_ += "}";

code_ += "";

// Generate a generate string table for enum values.

// Problem is, if values are very sparse that could generate really big

// tables. Ideally in that case we generate a map lookup instead, but for

// the moment we simply don't output a table at all.

auto range =

enum_def.vals.vec.back()->value - enum_def.vals.vec.front()->value + 1;

// Average distance between values above which we consider a table

// "too sparse". Change at will.

static const int kMaxSparseness = 5;

if (range / static_cast<int64_t>(enum_def.vals.vec.size()) <

kMaxSparseness) {

code_ += "inline const char **EnumNames{{ENUM_NAME}}() {";

code_ += " static const char *names[] = {";

auto val = enum_def.vals.vec.front()->value;

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

while (val++ != ev.value) {

code_ += " \"\",";

}

code_ += " \"" + ev.name + "\",";

}

code_ += " nullptr";

code_ += " };";

code_ += " return names;";

code_ += "}";

code_ += "";

code_ += "inline const char *EnumName{{ENUM_NAME}}({{ENUM_NAME}} e) {";

code_ += " const size_t index = static_cast<int>(e)\\";

if (enum_def.vals.vec.front()->value) {

auto vals = GetEnumValUse(enum_def, *enum_def.vals.vec.front());

code_ += " - static_cast<int>(" + vals + ")\\";

}

code_ += ";";

code_ += " return EnumNames{{ENUM_NAME}}()[index];";

code_ += "}";

code_ += "";

}

// Generate type traits for unions to map from a type to union enum value.

if (enum_def.is_union && !enum_def.uses_type_aliases) {

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

if (it == enum_def.vals.vec.begin()) {

code_ += "template<typename T> struct {{ENUM_NAME}}Traits {";

}

else {

auto name = GetUnionElement(ev, true, true);

code_ += "template<> struct {{ENUM_NAME}}Traits<" + name + "> {";

}

auto value = GetEnumValUse(enum_def, ev);

code_ += " static const {{ENUM_NAME}} enum_value = " + value + ";";

code_ += "};";

code_ += "";

}

}

if (parser_.opts.generate_object_based_api && enum_def.is_union) {

// Generate a union type

code_.SetValue("NAME", enum_def.name);

code_.SetValue("NONE",

GetEnumValUse(enum_def, *enum_def.vals.Lookup("NONE")));

code_ += "struct {{NAME}}Union {";

code_ += " {{NAME}} type;";

code_ += " void *value;";

code_ += "";

code_ += " {{NAME}}Union() : type({{NONE}}), value(nullptr) {}";

code_ += " {{NAME}}Union({{NAME}}Union&& u) FLATBUFFERS_NOEXCEPT :";

code_ += " type({{NONE}}), value(nullptr)";

code_ += " { std::swap(type, u.type); std::swap(value, u.value); }";

code_ += " {{NAME}}Union(const {{NAME}}Union &) FLATBUFFERS_NOEXCEPT;";

code_ += " {{NAME}}Union &operator=(const {{NAME}}Union &u) FLATBUFFERS_NOEXCEPT";

code_ += " { {{NAME}}Union t(u); std::swap(type, t.type); std::swap(value, t.value); return *this; }";

code_ += " {{NAME}}Union &operator=({{NAME}}Union &&u) FLATBUFFERS_NOEXCEPT";

code_ += " { std::swap(type, u.type); std::swap(value, u.value); return *this; }";

code_ += " ~{{NAME}}Union() { Reset(); }";

code_ += "";

code_ += " void Reset();";

code_ += "";

if (!enum_def.uses_type_aliases) {

code_ += " template <typename T>";

code_ += " void Set(T&& val) {";

code_ += " Reset();";

code_ += " type = {{NAME}}Traits<typename T::TableType>::enum_value;";

code_ += " if (type != {{NONE}}) {";

code_ += " value = new T(std::forward<T>(val));";

code_ += " }";

code_ += " }";

code_ += "";

}

code_ += " " + UnionUnPackSignature(enum_def, true) + ";";

code_ += " " + UnionPackSignature(enum_def, true) + ";";

code_ += "";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

if (!ev.value) {

continue;

}

const auto native_type =

NativeName(GetUnionElement(ev, true, true, true),

ev.union_type.struct_def);

code_.SetValue("NATIVE_TYPE", native_type);

code_.SetValue("NATIVE_NAME", ev.name);

code_.SetValue("NATIVE_ID", GetEnumValUse(enum_def, ev));

code_ += " {{NATIVE_TYPE}} *As{{NATIVE_NAME}}() {";

code_ += " return type == {{NATIVE_ID}} ?";

code_ += " reinterpret_cast<{{NATIVE_TYPE}} *>(value) : nullptr;";

code_ += " }";

}

code_ += "};";

code_ += "";

}

if (enum_def.is_union) {

code_ += UnionVerifySignature(enum_def) + ";";

code_ += UnionVectorVerifySignature(enum_def) + ";";

code_ += "";

}

}

void GenUnionPost(const EnumDef &enum_def) {

// Generate a verifier function for this union that can be called by the

// table verifier functions. It uses a switch case to select a specific

// verifier function to call, this should be safe even if the union type

// has been corrupted, since the verifiers will simply fail when called

// on the wrong type.

code_.SetValue("ENUM_NAME", enum_def.name);

code_ += "inline " + UnionVerifySignature(enum_def) + " {";

code_ += " switch (type) {";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));

if (ev.value) {

code_.SetValue("TYPE", GetUnionElement(ev, true, true));

code_ += " case {{LABEL}}: {";

auto getptr =

" auto ptr = reinterpret_cast<const {{TYPE}} *>(obj);";

if (ev.union_type.base_type == BASE_TYPE_STRUCT) {

if (ev.union_type.struct_def->fixed) {

code_ += " return true;";

} else {

code_ += getptr;

code_ += " return verifier.VerifyTable(ptr);";

}

} else if (ev.union_type.base_type == BASE_TYPE_STRING) {

code_ += getptr;

code_ += " return verifier.Verify(ptr);";

} else {

assert(false);

}

code_ += " }";

} else {

code_ += " case {{LABEL}}: {";

code_ += " return true;"; // "NONE" enum value.

code_ += " }";

}

}

code_ += " default: return false;";

code_ += " }";

code_ += "}";

code_ += "";

code_ += "inline " + UnionVectorVerifySignature(enum_def) + " {";

code_ += " if (values->size() != types->size()) return false;";

code_ += " for (flatbuffers::uoffset_t i = 0; i < values->size(); ++i) {";

code_ += " if (!Verify" + enum_def.name + "(";

code_ += " verifier, values->Get(i), types->GetEnum<" + enum_def.name + ">(i))) {";

code_ += " return false;";

code_ += " }";

code_ += " }";

code_ += " return true;";

code_ += "}";

code_ += "";

if (parser_.opts.generate_object_based_api) {

// Generate union Unpack() and Pack() functions.

code_ += "inline " + UnionUnPackSignature(enum_def, false) + " {";

code_ += " switch (type) {";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

if (!ev.value) {

continue;

}

code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));

code_.SetValue("TYPE", GetUnionElement(ev, true, true));

code_ += " case {{LABEL}}: {";

code_ += " auto ptr = reinterpret_cast<const {{TYPE}} *>(obj);";

if (ev.union_type.base_type == BASE_TYPE_STRUCT) {

if (ev.union_type.struct_def->fixed) {

code_ += " return new " +

WrapInNameSpace(*ev.union_type.struct_def) + "(*ptr);";

} else {

code_ += " return ptr->UnPack(resolver);";

}

} else if (ev.union_type.base_type == BASE_TYPE_STRING) {

code_ += " return new std::string(ptr->c_str(), ptr->size());";

} else {

assert(false);

}

code_ += " }";

}

code_ += " default: return nullptr;";

code_ += " }";

code_ += "}";

code_ += "";

code_ += "inline " + UnionPackSignature(enum_def, false) + " {";

code_ += " switch (type) {";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

auto &ev = **it;

if (!ev.value) {

continue;

}

code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));

code_.SetValue("TYPE", NativeName(GetUnionElement(ev, true, true, true),

ev.union_type.struct_def));

code_.SetValue("NAME", GetUnionElement(ev, false, true));

code_ += " case {{LABEL}}: {";

code_ += " auto ptr = reinterpret_cast<const {{TYPE}} *>(value);";

if (ev.union_type.base_type == BASE_TYPE_STRUCT) {

if (ev.union_type.struct_def->fixed) {

code_ += " return _fbb.CreateStruct(*ptr).Union();";

} else {

code_ +=

" return Create{{NAME}}(_fbb, ptr, _rehasher).Union();";

}

} else if (ev.union_type.base_type == BASE_TYPE_STRING) {

code_ += " return _fbb.CreateString(*ptr).Union();";

} else {

assert(false);

}

code_ += " }";

}

code_ += " default: return 0;";

code_ += " }";

code_ += "}";

code_ += "";

// Union copy constructor

code_ += "inline {{ENUM_NAME}}Union::{{ENUM_NAME}}Union(const "

"{{ENUM_NAME}}Union &u) FLATBUFFERS_NOEXCEPT : type(u.type), "

"value(nullptr) {";

code_ += " switch (type) {";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

if (!ev.value) {

continue;

}

code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));

code_.SetValue("TYPE", NativeName(GetUnionElement(ev, true, true, true),

ev.union_type.struct_def));

code_ += " case {{LABEL}}: {";

bool copyable = true;

if (ev.union_type.base_type == BASE_TYPE_STRUCT) {

// Don't generate code to copy if table is not copyable.

// TODO(wvo): make tables copyable instead.

for (auto fit = ev.union_type.struct_def->fields.vec.begin();

fit != ev.union_type.struct_def->fields.vec.end(); ++fit) {

const auto &field = **fit;

if (!field.deprecated && field.value.type.struct_def) {

copyable = false;

break;

}

}

}

if (copyable) {

code_ += " value = new {{TYPE}}(*reinterpret_cast<{{TYPE}} *>"

"(u.value));";

} else {

code_ += " assert(false); // {{TYPE}} not copyable.";

}

code_ += " break;";

code_ += " }";

}

code_ += " default:";

code_ += " break;";

code_ += " }";

code_ += "}";

code_ += "";

// Union Reset() function.

code_.SetValue("NONE",

GetEnumValUse(enum_def, *enum_def.vals.Lookup("NONE")));

code_ += "inline void {{ENUM_NAME}}Union::Reset() {";

code_ += " switch (type) {";

for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();

++it) {

const auto &ev = **it;

if (!ev.value) {

continue;

}

code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));

code_.SetValue("TYPE", NativeName(GetUnionElement(ev, true, true, true),

ev.union_type.struct_def));

code_ += " case {{LABEL}}: {";

code_ += " auto ptr = reinterpret_cast<{{TYPE}} *>(value);";

code_ += " delete ptr;";

code_ += " break;";

code_ += " }";

}

code_ += " default: break;";

code_ += " }";

code_ += " value = nullptr;";

code_ += " type = {{NONE}};";

code_ += "}";

code_ += "";

}

}

// Generates a value with optionally a cast applied if the field has a

// different underlying type from its interface type (currently only the

// case for enums. "from" specify the direction, true meaning from the

// underlying type to the interface type.

std::string GenUnderlyingCast(const FieldDef &field, bool from,

const std::string &val) {

if (from && field.value.type.base_type == BASE_TYPE_BOOL) {

return val + " != 0";

} else if ((field.value.type.enum_def &&

IsScalar(field.value.type.base_type)) ||

field.value.type.base_type == BASE_TYPE_BOOL) {

return "static_cast<" + GenTypeBasic(field.value.type, from) + ">(" +

val + ")";

} else {

return val;

}

}

std::string GenFieldOffsetName(const FieldDef &field) {

std::string uname = field.name;

std::transform(uname.begin(), uname.end(), uname.begin(), ToUpper);

return "VT_" + uname;

}

void GenFullyQualifiedNameGetter(const std::string &name) {

if (!parser_.opts.generate_name_strings) {

return;

}

auto fullname = parser_.namespaces_.back()->GetFullyQualifiedName(name);

code_.SetValue("NAME", fullname);

code_.SetValue("CONSTEXPR", "FLATBUFFERS_CONSTEXPR");

code_ += " static {{CONSTEXPR}} const char *GetFullyQualifiedName() {";