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fuchsia / third_party / flatbuffers / d6f06c33f7492ae1803824abea5f3bb3b0ad9d72 / . / src / idl_gen_cpp.cpp
blob: dadd474ab413d33321ca390b5844437cce8a2a83 [file] [log] [blame]
/*
* 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 <string>
#include <unordered_set>
#include "flatbuffers/base.h"
#include "flatbuffers/code_generators.h"
#include "flatbuffers/flatbuffers.h"
#include "flatbuffers/flatc.h"
#include "flatbuffers/idl.h"
#include "flatbuffers/util.h"
#ifndef FLATBUFFERS_CPP_OBJECT_UNPACKTO
#define FLATBUFFERS_CPP_OBJECT_UNPACKTO 0
#endif
namespace flatbuffers {
// Make numerical literal with type-suffix.
// This function is only needed for C++! Other languages do not need it.
static inline std::string NumToStringCpp(std::string val, BaseType type) {
// Avoid issues with -2147483648, -9223372036854775808.
switch (type) {
case BASE_TYPE_INT:
return (val != "-2147483648") ? val : ("(-2147483647 - 1)");
case BASE_TYPE_ULONG: return (val == "0") ? val : (val + "ULL");
case BASE_TYPE_LONG:
if (val == "-9223372036854775808")
return "(-9223372036854775807LL - 1LL)";
else
return (val == "0") ? val : (val + "LL");
default: return val;
}
}
static std::string GenIncludeGuard(const std::string &file_name,
const Namespace &name_space,
const std::string &postfix = "") {
// 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) const { return !is_alnum(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.
for (auto it = name_space.components.begin();
it != name_space.components.end(); ++it) {
guard += *it + "_";
}
// Anything extra to add to the guard?
if (!postfix.empty()) { guard += postfix + "_"; }
guard += "H_";
std::transform(guard.begin(), guard.end(), guard.begin(), CharToUpper);
return guard;
}
namespace cpp {
enum CppStandard { CPP_STD_X0 = 0, CPP_STD_11, CPP_STD_17 };
// Define a style of 'struct' constructor if it has 'Array' fields.
enum GenArrayArgMode {
kArrayArgModeNone, // don't generate initialization args
kArrayArgModeSpanStatic, // generate flatbuffers::span<T,N>
};
// Extension of IDLOptions for cpp-generator.
struct IDLOptionsCpp : public IDLOptions {
// All fields start with 'g_' prefix to distinguish from the base IDLOptions.
CppStandard g_cpp_std; // Base version of C++ standard.
bool g_only_fixed_enums; // Generate underlaying type for all enums.
IDLOptionsCpp(const IDLOptions &opts)
: IDLOptions(opts), g_cpp_std(CPP_STD_11), g_only_fixed_enums(true) {}
};
class CppGenerator : public BaseGenerator {
public:
CppGenerator(const Parser &parser, const std::string &path,
const std::string &file_name, IDLOptionsCpp opts)
: BaseGenerator(parser, path, file_name, "", "::", "h"),
cur_name_space_(nullptr),
opts_(opts),
float_const_gen_("std::numeric_limits<double>::",
"std::numeric_limits<float>::", "quiet_NaN()",
"infinity()") {
static const char *const keywords[] = {
"alignas",
"alignof",
"and",
"and_eq",
"asm",
"atomic_cancel",
"atomic_commit",
"atomic_noexcept",
"auto",
"bitand",
"bitor",
"bool",
"break",
"case",
"catch",
"char",
"char16_t",
"char32_t",
"class",
"compl",
"concept",
"const",
"constexpr",
"const_cast",
"continue",
"co_await",
"co_return",
"co_yield",
"decltype",
"default",
"delete",
"do",
"double",
"dynamic_cast",
"else",
"enum",
"explicit",
"export",
"extern",
"false",
"float",
"for",
"friend",
"goto",
"if",
"import",
"inline",
"int",
"long",
"module",
"mutable",
"namespace",
"new",
"noexcept",
"not",
"not_eq",
"nullptr",
"operator",
"or",
"or_eq",
"private",
"protected",
"public",
"register",
"reinterpret_cast",
"requires",
"return",
"short",
"signed",
"sizeof",
"static",
"static_assert",
"static_cast",
"struct",
"switch",
"synchronized",
"template",
"this",
"thread_local",
"throw",
"true",
"try",
"typedef",
"typeid",
"typename",
"union",
"unsigned",
"using",
"virtual",
"void",
"volatile",
"wchar_t",
"while",
"xor",
"xor_eq",
nullptr,
};
for (auto kw = keywords; *kw; kw++) keywords_.insert(*kw);
}
// Adds code to check that the included flatbuffers.h is of the same version
// as the generated code. This check currently looks for exact version match,
// as we would guarantee that they are compatible, but in theory a newer
// version of flatbuffers.h should work with a old code gen if we do proper
// backwards support.
void GenFlatbuffersVersionCheck() {
code_ +=
"// Ensure the included flatbuffers.h is the same version as when this "
"file was";
code_ += "// generated, otherwise it may not be compatible.";
code_ += "static_assert(FLATBUFFERS_VERSION_MAJOR == " +
std::to_string(FLATBUFFERS_VERSION_MAJOR) + " &&";
code_ += " FLATBUFFERS_VERSION_MINOR == " +
std::to_string(FLATBUFFERS_VERSION_MINOR) + " &&";
code_ += " FLATBUFFERS_VERSION_REVISION == " +
std::to_string(FLATBUFFERS_VERSION_REVISION) + ",";
code_ += " \"Non-compatible flatbuffers version included\");";
}
void GenIncludeDependencies() {
if (opts_.generate_object_based_api) {
for (auto it = parser_.native_included_files_.begin();
it != parser_.native_included_files_.end(); ++it) {
code_ += "#include \"" + *it + "\"";
}
}
// Get the directly included file of the file being parsed.
std::vector<std::string> included_files(parser_.GetIncludedFiles());
// We are safe to sort them alphabetically, since there shouldn't be any
// interdependence between them.
std::stable_sort(included_files.begin(), included_files.end());
// The absolute path of the file being parsed.
const std::string parsed_path =
flatbuffers::StripFileName(AbsolutePath(parser_.file_being_parsed_));
for (const std::string &included_file : included_files) {
// The base name of the file, without path or extensions.
std::string basename =
flatbuffers::StripPath(flatbuffers::StripExtension(included_file));
// If we are keeping the prefix
if (opts_.keep_prefix) {
// The absolute path of the included file.
const std::string included_path =
flatbuffers::StripFileName(AbsolutePath(included_file));
// The relative path of the parsed file to the included file.
const std::string relative_path =
RelativeToRootPath(parsed_path, included_path).substr(2);
// Only consider cases where the included path is a subdirectory of the
// parsed path.
if (strncmp("..", relative_path.c_str(), 2) != 0) {
basename = relative_path + kPathSeparator + basename;
}
}
code_ += "#include \"" +
GeneratedFileName(opts_.include_prefix, basename, opts_) + "\"";
}
if (!parser_.native_included_files_.empty() || !included_files.empty()) {
code_ += "";
}
}
void GenExtraIncludes() {
for (std::size_t i = 0; i < opts_.cpp_includes.size(); ++i) {
code_ += "#include \"" + opts_.cpp_includes[i] + "\"";
}
if (!opts_.cpp_includes.empty()) { code_ += ""; }
}
std::string EscapeKeyword(const std::string &name) const {
return keywords_.find(name) == keywords_.end() ? name : name + "_";
}
std::string Name(const FieldDef &field) const {
// the union type field suffix is immutable.
static size_t union_suffix_len = strlen(UnionTypeFieldSuffix());
const bool is_union_type = field.value.type.base_type == BASE_TYPE_UTYPE;
// early return if no case transformation required
if (opts_.cpp_object_api_field_case_style ==
IDLOptions::CaseStyle_Unchanged)
return EscapeKeyword(field.name);
std::string name = field.name;
// do not change the case style of the union type field suffix
if (is_union_type) {
FLATBUFFERS_ASSERT(name.length() > union_suffix_len);
name.erase(name.length() - union_suffix_len, union_suffix_len);
}
if (opts_.cpp_object_api_field_case_style == IDLOptions::CaseStyle_Upper)
name = ConvertCase(name, Case::kUpperCamel);
else if (opts_.cpp_object_api_field_case_style ==
IDLOptions::CaseStyle_Lower)
name = ConvertCase(name, Case::kLowerCamel);
// restore the union field type suffix
if (is_union_type) name.append(UnionTypeFieldSuffix(), union_suffix_len);
return EscapeKeyword(name);
}
std::string Name(const Definition &def) const {
return EscapeKeyword(def.name);
}
std::string Name(const EnumVal &ev) const { return EscapeKeyword(ev.name); }
bool generate_bfbs_embed() {
code_.Clear();
code_ += "// " + std::string(FlatBuffersGeneratedWarning()) + "\n\n";
// If we don't have a root struct definition,
if (!parser_.root_struct_def_) {
// put a comment in the output why there is no code generated.
code_ += "// Binary schema not generated, no root struct found";
} else {
auto &struct_def = *parser_.root_struct_def_;
const auto include_guard =
GenIncludeGuard(file_name_, *struct_def.defined_namespace, "bfbs");
code_ += "#ifndef " + include_guard;
code_ += "#define " + include_guard;
code_ += "";
if (parser_.opts.gen_nullable) {
code_ += "#pragma clang system_header\n\n";
}
code_ += "#include \"flatbuffers/flatbuffers.h\"";
code_ += "";
GenFlatbuffersVersionCheck();
code_ += "";
SetNameSpace(struct_def.defined_namespace);
auto name = Name(struct_def);
code_.SetValue("STRUCT_NAME", name);
// Create code to return the binary schema data.
auto binary_schema_hex_text =
BufferToHexText(parser_.builder_.GetBufferPointer(),
parser_.builder_.GetSize(), 105, " ", "");
code_ += "struct {{STRUCT_NAME}}BinarySchema {";
code_ += " static const uint8_t *data() {";
code_ += " // Buffer containing the binary schema.";
code_ += " static const uint8_t bfbsData[" +
NumToString(parser_.builder_.GetSize()) + "] = {";
code_ += binary_schema_hex_text;
code_ += " };";
code_ += " return bfbsData;";
code_ += " }";
code_ += " static size_t size() {";
code_ += " return " + NumToString(parser_.builder_.GetSize()) + ";";
code_ += " }";
code_ += " const uint8_t *begin() {";
code_ += " return data();";
code_ += " }";
code_ += " const uint8_t *end() {";
code_ += " return data() + size();";
code_ += " }";
code_ += "};";
code_ += "";
if (cur_name_space_) SetNameSpace(nullptr);
// Close the include guard.
code_ += "#endif // " + include_guard;
}
// We are just adding "_bfbs" to the generated filename.
const auto file_path =
GeneratedFileName(path_, file_name_ + "_bfbs", opts_);
const auto final_code = code_.ToString();
return SaveFile(file_path.c_str(), final_code, false);
}
// 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(file_name_, *parser_.current_namespace_);
code_ += "#ifndef " + include_guard;
code_ += "#define " + include_guard;
code_ += "";
if (opts_.gen_nullable) { code_ += "#pragma clang system_header\n\n"; }
code_ += "#include \"flatbuffers/flatbuffers.h\"";
if (parser_.uses_flexbuffers_) {
code_ += "#include \"flatbuffers/flexbuffers.h\"";
code_ += "#include \"flatbuffers/flex_flat_util.h\"";
}
code_ += "";
GenFlatbuffersVersionCheck();
code_ += "";
if (opts_.include_dependence_headers) { GenIncludeDependencies(); }
GenExtraIncludes();
FLATBUFFERS_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 " + Name(struct_def) + ";";
if (!struct_def.fixed) {
code_ += "struct " + Name(struct_def) + "Builder;";
}
if (opts_.generate_object_based_api) {
auto nativeName = NativeName(Name(struct_def), &struct_def, opts_);
if (!struct_def.fixed) { code_ += "struct " + nativeName + ";"; }
}
code_ += "";
}
}
// Generate forward declarations for all equal operators
if (opts_.generate_object_based_api && opts_.gen_compare) {
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);
auto nativeName = NativeName(Name(struct_def), &struct_def, opts_);
code_ += "bool operator==(const " + nativeName + " &lhs, const " +
nativeName + " &rhs);";
code_ += "bool operator!=(const " + nativeName + " &lhs, const " +
nativeName + " &rhs);";
}
}
code_ += "";
}
// Generate preablmle code for mini reflection.
if (opts_.mini_reflect != IDLOptions::kNone) {
// To break cyclic dependencies, first pre-declare all tables/structs.
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);
GenMiniReflectPre(&struct_def);
}
}
}
// 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 code for mini reflection.
if (opts_.mini_reflect != IDLOptions::kNone) {
// Then the unions/enums that may refer to them.
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);
GenMiniReflect(nullptr, &enum_def);
}
}
// Then the full tables/structs.
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);
GenMiniReflect(&struct_def, nullptr);
}
}
}
// Generate convenient global helper functions:
if (parser_.root_struct_def_) {
auto &struct_def = *parser_.root_struct_def_;
SetNameSpace(struct_def.defined_namespace);
auto name = Name(struct_def);
auto qualified_name = cur_name_space_->GetFullyQualifiedName(name);
auto cpp_name = TranslateNameSpace(qualified_name);
code_.SetValue("STRUCT_NAME", name);
code_.SetValue("CPP_NAME", cpp_name);
code_.SetValue("NULLABLE_EXT", NullableExtension());
// The root datatype accessor:
code_ += "inline \\";
code_ +=
"const {{CPP_NAME}} *{{NULLABLE_EXT}}Get{{STRUCT_NAME}}(const void "
"*buf) {";
code_ += " return flatbuffers::GetRoot<{{CPP_NAME}}>(buf);";
code_ += "}";
code_ += "";
code_ += "inline \\";
code_ +=
"const {{CPP_NAME}} "
"*{{NULLABLE_EXT}}GetSizePrefixed{{STRUCT_NAME}}(const void "
"*buf) {";
code_ += " return flatbuffers::GetSizePrefixedRoot<{{CPP_NAME}}>(buf);";
code_ += "}";
code_ += "";
if (opts_.mutable_buffer) {
code_ += "inline \\";
code_ += "{{STRUCT_NAME}} *GetMutable{{STRUCT_NAME}}(void *buf) {";
code_ += " return flatbuffers::GetMutableRoot<{{STRUCT_NAME}}>(buf);";
code_ += "}";
code_ += "";
code_ += "inline \\";
code_ +=
"{{CPP_NAME}} "
"*{{NULLABLE_EXT}}GetMutableSizePrefixed{{STRUCT_NAME}}(void "
"*buf) {";
code_ +=
" return "
"flatbuffers::GetMutableSizePrefixedRoot<{{CPP_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_ += "";
// Check if a size-prefixed buffer has the identifier.
code_ += "inline \\";
code_ +=
"bool SizePrefixed{{STRUCT_NAME}}BufferHasIdentifier(const void "
"*buf) {";
code_ += " return flatbuffers::BufferHasIdentifier(";
code_ += " buf, {{STRUCT_NAME}}Identifier(), true);";
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_ += "";
code_ += "inline bool VerifySizePrefixed{{STRUCT_NAME}}Buffer(";
code_ += " flatbuffers::Verifier &verifier) {";
code_ +=
" return verifier.VerifySizePrefixedBuffer<{{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_ += "";
code_ += "inline void FinishSizePrefixed{{STRUCT_NAME}}Buffer(";
code_ += " flatbuffers::FlatBufferBuilder &fbb,";
code_ += " flatbuffers::Offset<{{CPP_NAME}}> root) {";
if (parser_.file_identifier_.length())
code_ += " fbb.FinishSizePrefixed(root, {{STRUCT_NAME}}Identifier());";
else
code_ += " fbb.FinishSizePrefixed(root);";
code_ += "}";
code_ += "";
if (opts_.generate_object_based_api) {
// A convenient root unpack function.
auto native_name = WrapNativeNameInNameSpace(struct_def, opts_);
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_ += "";
code_ += "inline {{UNPACK_RETURN}} UnPackSizePrefixed{{STRUCT_NAME}}(";
code_ += " const void *buf,";
code_ += " const flatbuffers::resolver_function_t *res = nullptr) {";
code_ += " return {{UNPACK_TYPE}}\\";
code_ += "(GetSizePrefixed{{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_, opts_);
const auto final_code = code_.ToString();
// Save the file and optionally generate the binary schema code.
return SaveFile(file_path.c_str(), final_code, false) &&
(!parser_.opts.binary_schema_gen_embed || generate_bfbs_embed());
}
private:
CodeWriter code_;
std::unordered_set<std::string> keywords_;
// This tracks the current namespace so we can insert namespace declarations.
const Namespace *cur_name_space_;
const IDLOptionsCpp opts_;
const TypedFloatConstantGenerator float_const_gen_;
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;
}
bool TypeHasKey(const Type &type) {
if (type.base_type != BASE_TYPE_STRUCT) { return false; }
for (auto it = type.struct_def->fields.vec.begin();
it != type.struct_def->fields.vec.end(); ++it) {
const auto &field = **it;
if (field.key) { return true; }
}
return false;
}
bool VectorElementUserFacing(const Type &type) const {
return (opts_.scoped_enums && IsEnum(type)) ||
(opts_.g_cpp_std >= cpp::CPP_STD_17 && opts_.g_only_fixed_enums &&
IsEnum(type));
}
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 {
// clang-format off
static const char *const ctypename[] = {
#define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, ...) \
#CTYPE,
FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
#undef FLATBUFFERS_TD
};
// clang-format on
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(), "", VectorElementUserFacing(type.VectorType()));
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";
}
}
std::string NullableExtension() {
return opts_.gen_nullable ? " _Nullable " : "";
}
static std::string NativeName(const std::string &name, const StructDef *sd,
const IDLOptions &opts) {
return sd && !sd->fixed ? opts.object_prefix + name + opts.object_suffix
: name;
}
std::string WrapNativeNameInNameSpace(const StructDef &struct_def,
const IDLOptions &opts) {
return WrapInNameSpace(struct_def.defined_namespace,
NativeName(Name(struct_def), &struct_def, opts));
}
const std::string &PtrType(const FieldDef *field) {
auto attr = field ? field->attributes.Lookup("cpp_ptr_type") : nullptr;
return attr ? attr->constant : 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 : opts_.cpp_object_api_string_type;
if (ret.empty()) { return "std::string"; }
return ret;
}
bool FlexibleStringConstructor(const FieldDef *field) {
auto attr = field
? (field->attributes.Lookup("cpp_str_flex_ctor") != nullptr)
: false;
auto ret = attr ? attr : opts_.cpp_object_api_string_flexible_constructor;
return ret && NativeString(field) !=
"std::string"; // Only for custom string types.
}
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 != "default_ptr_type"
? ptr_type
: opts_.cpp_object_api_pointer_type) +
"<" + type + ">";
} else if (is_constructor) {
return "";
} else {
return type + " *";
}
}
std::string GenPtrGet(const FieldDef &field) {
auto cpp_ptr_type_get = field.attributes.Lookup("cpp_ptr_type_get");
if (cpp_ptr_type_get) return cpp_ptr_type_get->constant;
auto &ptr_type = PtrType(&field);
return ptr_type == "naked" ? "" : ".get()";
}
std::string GenOptionalNull() { return "flatbuffers::nullopt"; }
std::string GenOptionalDecl(const Type &type) {
return "flatbuffers::Optional<" + GenTypeBasic(type, true) + ">";
}
std::string GenTypeNative(const Type &type, bool invector,
const FieldDef &field, bool forcopy = false) {
switch (type.base_type) {
case BASE_TYPE_STRING: {
return NativeString(&field);
}
case BASE_TYPE_VECTOR: {
const auto type_name = GenTypeNative(type.VectorType(), true, field);
if (type.struct_def &&
type.struct_def->attributes.Lookup("native_custom_alloc")) {
auto native_custom_alloc =
type.struct_def->attributes.Lookup("native_custom_alloc");
return "std::vector<" + type_name + "," +
native_custom_alloc->constant + "<" + type_name + ">>";
} else
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 || forcopy) {
return type_name;
} else {
return GenTypeNativePtr(type_name, &field, false);
}
} else {
const auto nn = WrapNativeNameInNameSpace(*type.struct_def, opts_);
return forcopy ? nn : GenTypeNativePtr(nn, &field, false);
}
}
case BASE_TYPE_UNION: {
auto type_name = WrapInNameSpace(*type.enum_def);
return type_name + "Union";
}
default: {
return field.IsScalarOptional() ? GenOptionalDecl(type)
: 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 if (IsArray(type)) {
auto element_type = type.VectorType();
// Check if enum arrays are used in C++ without specifying --scoped-enums
if (IsEnum(element_type) && !opts_.g_only_fixed_enums) {
LogCompilerError(
"--scoped-enums must be enabled to use enum arrays in C++");
FLATBUFFERS_ASSERT(true);
}
return beforeptr +
(IsScalar(element_type.base_type)
? GenTypeBasic(element_type, user_facing_type)
: GenTypePointer(element_type)) +
afterptr;
} else {
return beforeptr + GenTypePointer(type) + afterptr;
}
}
std::string GenTypeSpan(const Type &type, bool immutable, size_t extent) {
// Generate "flatbuffers::span<const U, extent>".
FLATBUFFERS_ASSERT(IsSeries(type) && "unexpected type");
auto element_type = type.VectorType();
std::string text = "flatbuffers::span<";
text += immutable ? "const " : "";
if (IsScalar(element_type.base_type)) {
text += GenTypeBasic(element_type, IsEnum(element_type));
} else {
switch (element_type.base_type) {
case BASE_TYPE_STRING: {
text += "char";
break;
}
case BASE_TYPE_STRUCT: {
FLATBUFFERS_ASSERT(type.struct_def);
text += WrapInNameSpace(*type.struct_def);
break;
}
default:
FLATBUFFERS_ASSERT(false && "unexpected element's type");
break;
}
}
if (extent != flatbuffers::dynamic_extent) {
text += ", ";
text += NumToString(extent);
}
text += "> ";
return text;
}
std::string GenEnumValDecl(const EnumDef &enum_def,
const std::string &enum_val) const {
return opts_.prefixed_enums ? Name(enum_def) + "_" + enum_val : enum_val;
}
std::string GetEnumValUse(const EnumDef &enum_def,
const EnumVal &enum_val) const {
if (opts_.scoped_enums) {
return Name(enum_def) + "::" + Name(enum_val);
} else if (opts_.prefixed_enums) {
return Name(enum_def) + "_" + Name(enum_val);
} else {
return Name(enum_val);
}
}
std::string StripUnionType(const std::string &name) {
return name.substr(0, name.size() - strlen(UnionTypeFieldSuffix()));
}
std::string GetUnionElement(const EnumVal &ev, bool native_type,
const IDLOptions &opts) {
if (ev.union_type.base_type == BASE_TYPE_STRUCT) {
auto name = ev.union_type.struct_def->name;
if (native_type) {
name = NativeName(name, ev.union_type.struct_def, opts);
}
return WrapInNameSpace(ev.union_type.struct_def->defined_namespace, name);
} else if (IsString(ev.union_type)) {
return native_type ? "std::string" : "flatbuffers::String";
} else {
FLATBUFFERS_ASSERT(false);
return Name(ev);
}
}
std::string UnionVerifySignature(const EnumDef &enum_def) {
return "bool Verify" + Name(enum_def) +
"(flatbuffers::Verifier &verifier, const void *obj, " +
Name(enum_def) + " type)";
}
std::string UnionVectorVerifySignature(const EnumDef &enum_def) {
auto name = Name(enum_def);
auto type = opts_.scoped_enums ? name : "uint8_t";
return "bool Verify" + name + "Vector" +
"(flatbuffers::Verifier &verifier, " +
"const flatbuffers::Vector<flatbuffers::Offset<void>> *values, " +
"const flatbuffers::Vector<" + type + "> *types)";
}
std::string UnionUnPackSignature(const EnumDef &enum_def, bool inclass) {
return (inclass ? "static " : "") + std::string("void *") +
(inclass ? "" : Name(enum_def) + "Union::") +
"UnPack(const void *obj, " + Name(enum_def) +
" type, const flatbuffers::resolver_function_t *resolver)";
}
std::string UnionPackSignature(const EnumDef &enum_def, bool inclass) {
return "flatbuffers::Offset<void> " +
(inclass ? "" : Name(enum_def) + "Union::") +
"Pack(flatbuffers::FlatBufferBuilder &_fbb, " +
"const flatbuffers::rehasher_function_t *_rehasher" +
(inclass ? " = nullptr" : "") + ") const";
}
std::string TableCreateSignature(const StructDef &struct_def, bool predecl,
const IDLOptions &opts) {
return "flatbuffers::Offset<" + Name(struct_def) + "> Create" +
Name(struct_def) + "(flatbuffers::FlatBufferBuilder &_fbb, const " +
NativeName(Name(struct_def), &struct_def, opts) +
" *_o, const flatbuffers::rehasher_function_t *_rehasher" +
(predecl ? " = nullptr" : "") + ")";
}
std::string TablePackSignature(const StructDef &struct_def, bool inclass,
const IDLOptions &opts) {
return std::string(inclass ? "static " : "") + "flatbuffers::Offset<" +
Name(struct_def) + "> " + (inclass ? "" : Name(struct_def) + "::") +
"Pack(flatbuffers::FlatBufferBuilder &_fbb, " + "const " +
NativeName(Name(struct_def), &struct_def, opts) + "* _o, " +
"const flatbuffers::rehasher_function_t *_rehasher" +
(inclass ? " = nullptr" : "") + ")";
}
std::string TableUnPackSignature(const StructDef &struct_def, bool inclass,
const IDLOptions &opts) {
return NativeName(Name(struct_def), &struct_def, opts) + " *" +
(inclass ? "" : Name(struct_def) + "::") +
"UnPack(const flatbuffers::resolver_function_t *_resolver" +
(inclass ? " = nullptr" : "") + ") const";
}
std::string TableUnPackToSignature(const StructDef &struct_def, bool inclass,
const IDLOptions &opts) {
return "void " + (inclass ? "" : Name(struct_def) + "::") + "UnPackTo(" +
NativeName(Name(struct_def), &struct_def, opts) + " *" +
"_o, const flatbuffers::resolver_function_t *_resolver" +
(inclass ? " = nullptr" : "") + ") const";
}
void GenMiniReflectPre(const StructDef *struct_def) {
code_.SetValue("NAME", struct_def->name);
code_ += "inline const flatbuffers::TypeTable *{{NAME}}TypeTable();";
code_ += "";
}
void GenMiniReflect(const StructDef *struct_def, const EnumDef *enum_def) {
code_.SetValue("NAME", struct_def ? struct_def->name : enum_def->name);
code_.SetValue("SEQ_TYPE",
struct_def ? (struct_def->fixed ? "ST_STRUCT" : "ST_TABLE")
: (enum_def->is_union ? "ST_UNION" : "ST_ENUM"));
auto num_fields =
struct_def ? struct_def->fields.vec.size() : enum_def->size();
code_.SetValue("NUM_FIELDS", NumToString(num_fields));
std::vector<std::string> names;
std::vector<Type> types;
if (struct_def) {
for (auto it = struct_def->fields.vec.begin();
it != struct_def->fields.vec.end(); ++it) {
const auto &field = **it;
names.push_back(Name(field));
types.push_back(field.value.type);
}
} else {
for (auto it = enum_def->Vals().begin(); it != enum_def->Vals().end();
++it) {
const auto &ev = **it;
names.push_back(Name(ev));
types.push_back(enum_def->is_union ? ev.union_type
: Type(enum_def->underlying_type));
}
}
std::string ts;
std::vector<std::string> type_refs;
std::vector<uint16_t> array_sizes;
for (auto it = types.begin(); it != types.end(); ++it) {
auto &type = *it;
if (!ts.empty()) ts += ",\n ";
auto is_vector = IsVector(type);
auto is_array = IsArray(type);
auto bt = is_vector || is_array ? type.element : type.base_type;
auto et = IsScalar(bt) || bt == BASE_TYPE_STRING
? bt - BASE_TYPE_UTYPE + ET_UTYPE
: ET_SEQUENCE;
int ref_idx = -1;
std::string ref_name = type.struct_def ? WrapInNameSpace(*type.struct_def)
: type.enum_def ? WrapInNameSpace(*type.enum_def)
: "";
if (!ref_name.empty()) {
auto rit = type_refs.begin();
for (; rit != type_refs.end(); ++rit) {
if (*rit == ref_name) {
ref_idx = static_cast<int>(rit - type_refs.begin());
break;
}
}
if (rit == type_refs.end()) {
ref_idx = static_cast<int>(type_refs.size());
type_refs.push_back(ref_name);
}
}
if (is_array) { array_sizes.push_back(type.fixed_length); }
ts += "{ flatbuffers::" + std::string(ElementaryTypeNames()[et]) + ", " +
NumToString(is_vector || is_array) + ", " + NumToString(ref_idx) +
" }";
}
std::string rs;
for (auto it = type_refs.begin(); it != type_refs.end(); ++it) {
if (!rs.empty()) rs += ",\n ";
rs += *it + "TypeTable";
}
std::string as;
for (auto it = array_sizes.begin(); it != array_sizes.end(); ++it) {
as += NumToString(*it);
as += ", ";
}
std::string ns;
for (auto it = names.begin(); it != names.end(); ++it) {
if (!ns.empty()) ns += ",\n ";
ns += "\"" + *it + "\"";
}
std::string vs;
const auto consecutive_enum_from_zero =
enum_def && enum_def->MinValue()->IsZero() &&
((enum_def->size() - 1) == enum_def->Distance());
if (enum_def && !consecutive_enum_from_zero) {
for (auto it = enum_def->Vals().begin(); it != enum_def->Vals().end();
++it) {
const auto &ev = **it;
if (!vs.empty()) vs += ", ";
vs += NumToStringCpp(enum_def->ToString(ev),
enum_def->underlying_type.base_type);
}
} else if (struct_def && struct_def->fixed) {
for (auto it = struct_def->fields.vec.begin();
it != struct_def->fields.vec.end(); ++it) {
const auto &field = **it;
vs += NumToString(field.value.offset);
vs += ", ";
}
vs += NumToString(struct_def->bytesize);
}
code_.SetValue("TYPES", ts);
code_.SetValue("REFS", rs);
code_.SetValue("ARRAYSIZES", as);
code_.SetValue("NAMES", ns);
code_.SetValue("VALUES", vs);
code_ += "inline const flatbuffers::TypeTable *{{NAME}}TypeTable() {";
if (num_fields) {
code_ += " static const flatbuffers::TypeCode type_codes[] = {";
code_ += " {{TYPES}}";
code_ += " };";
}
if (!type_refs.empty()) {
code_ += " static const flatbuffers::TypeFunction type_refs[] = {";
code_ += " {{REFS}}";
code_ += " };";
}
if (!as.empty()) {
code_ += " static const int16_t array_sizes[] = { {{ARRAYSIZES}} };";
}
if (!vs.empty()) {
// Problem with uint64_t values greater than 9223372036854775807ULL.
code_ += " static const int64_t values[] = { {{VALUES}} };";
}
auto has_names =
num_fields && opts_.mini_reflect == IDLOptions::kTypesAndNames;
if (has_names) {
code_ += " static const char * const names[] = {";
code_ += " {{NAMES}}";
code_ += " };";
}
code_ += " static const flatbuffers::TypeTable tt = {";
code_ += std::string(" flatbuffers::{{SEQ_TYPE}}, {{NUM_FIELDS}}, ") +
(num_fields ? "type_codes, " : "nullptr, ") +
(!type_refs.empty() ? "type_refs, " : "nullptr, ") +
(!as.empty() ? "array_sizes, " : "nullptr, ") +
(!vs.empty() ? "values, " : "nullptr, ") +
(has_names ? "names" : "nullptr");
code_ += " };";
code_ += " return &tt;";
code_ += "}";
code_ += "";
}
// 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", Name(enum_def));
code_.SetValue("BASE_TYPE", GenTypeBasic(enum_def.underlying_type, false));
GenComment(enum_def.doc_comment);
code_ +=
(opts_.scoped_enums ? "enum class " : "enum ") + Name(enum_def) + "\\";
if (opts_.g_only_fixed_enums) { code_ += " : {{BASE_TYPE}}\\"; }
code_ += " {";
code_.SetValue("SEP", ",");
auto add_sep = false;
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
const auto &ev = **it;
if (add_sep) code_ += "{{SEP}}";
GenComment(ev.doc_comment, " ");
code_.SetValue("KEY", GenEnumValDecl(enum_def, Name(ev)));
code_.SetValue("VALUE",
NumToStringCpp(enum_def.ToString(ev),
enum_def.underlying_type.base_type));
code_ += " {{KEY}} = {{VALUE}}\\";
add_sep = true;
}
const EnumVal *minv = enum_def.MinValue();
const EnumVal *maxv = enum_def.MaxValue();
if (opts_.scoped_enums || opts_.prefixed_enums) {
FLATBUFFERS_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",
NumToStringCpp(enum_def.AllFlags(),
enum_def.underlying_type.base_type));
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, Name(*minv)));
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
code_.SetValue("KEY", GenEnumValDecl(enum_def, "MAX"));
code_.SetValue("VALUE", GenEnumValDecl(enum_def, Name(*maxv)));
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
}
}
code_ += "";
code_ += "};";
if (opts_.scoped_enums && enum_def.attributes.Lookup("bit_flags")) {
code_ +=
"FLATBUFFERS_DEFINE_BITMASK_OPERATORS({{ENUM_NAME}}, {{BASE_TYPE}})";
}
code_ += "";
// Generate an array of all enumeration values
auto num_fields = NumToString(enum_def.size());
code_ += "inline const {{ENUM_NAME}} (&EnumValues{{ENUM_NAME}}())[" +
num_fields + "] {";
code_ += " static const {{ENUM_NAME}} values[] = {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
const auto &ev = **it;
auto value = GetEnumValUse(enum_def, ev);
auto suffix = *it != enum_def.Vals().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.Distance();
// Average distance between values above which we consider a table
// "too sparse". Change at will.
static const uint64_t kMaxSparseness = 5;
if (range / static_cast<uint64_t>(enum_def.size()) < kMaxSparseness) {
code_ += "inline const char * const *EnumNames{{ENUM_NAME}}() {";
code_ += " static const char * const names[" +
NumToString(range + 1 + 1) + "] = {";
auto val = enum_def.Vals().front();
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
auto ev = *it;
for (auto k = enum_def.Distance(val, ev); k > 1; --k) {
code_ += " \"\",";
}
val = ev;
code_ += " \"" + Name(*ev) + "\",";
}
code_ += " nullptr";
code_ += " };";
code_ += " return names;";
code_ += "}";
code_ += "";
code_ += "inline const char *EnumName{{ENUM_NAME}}({{ENUM_NAME}} e) {";
code_ += " if (flatbuffers::IsOutRange(e, " +
GetEnumValUse(enum_def, *enum_def.MinValue()) + ", " +
GetEnumValUse(enum_def, *enum_def.MaxValue()) +
")) return \"\";";
code_ += " const size_t index = static_cast<size_t>(e)\\";
if (enum_def.MinValue()->IsNonZero()) {
auto vals = GetEnumValUse(enum_def, *enum_def.MinValue());
code_ += " - static_cast<size_t>(" + vals + ")\\";
}
code_ += ";";
code_ += " return EnumNames{{ENUM_NAME}}()[index];";
code_ += "}";
code_ += "";
} else {
code_ += "inline const char *EnumName{{ENUM_NAME}}({{ENUM_NAME}} e) {";
code_ += " switch (e) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
code_ += " case " + GetEnumValUse(enum_def, ev) + ": return \"" +
Name(ev) + "\";";
}
code_ += " default: return \"\";";
code_ += " }";
code_ += "}";
code_ += "";
}
// Generate type traits for unions to map from a type to union enum value.
if (enum_def.is_union && !enum_def.uses_multiple_type_instances) {
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
if (it == enum_def.Vals().begin()) {
code_ += "template<typename T> struct {{ENUM_NAME}}Traits {";
} else {
auto name = GetUnionElement(ev, false, opts_);
code_ += "template<> struct {{ENUM_NAME}}Traits<" + name + "> {";
}
auto value = GetEnumValUse(enum_def, ev);
code_ += " static const {{ENUM_NAME}} enum_value = " + value + ";";
code_ += "};";
code_ += "";
}
}
if (opts_.generate_object_based_api && enum_def.is_union) {
// Generate a union type and a trait type for it.
code_.SetValue("NAME", Name(enum_def));
FLATBUFFERS_ASSERT(enum_def.Lookup("NONE"));
code_.SetValue("NONE", GetEnumValUse(enum_def, *enum_def.Lookup("NONE")));
if (!enum_def.uses_multiple_type_instances) {
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
if (it == enum_def.Vals().begin()) {
code_ += "template<typename T> struct {{NAME}}UnionTraits {";
} else {
auto name = GetUnionElement(ev, true, opts_);
code_ += "template<> struct {{NAME}}UnionTraits<" + name + "> {";
}
auto value = GetEnumValUse(enum_def, ev);
code_ += " static const {{ENUM_NAME}} enum_value = " + value + ";";
code_ += "};";
code_ += "";
}
}
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 &);";
code_ += " {{NAME}}Union &operator=(const {{NAME}}Union &u)";
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_multiple_type_instances) {
code_ += " template <typename T>";
code_ += " void Set(T&& val) {";
code_ += " typedef typename std::remove_reference<T>::type RT;";
code_ += " Reset();";
code_ += " type = {{NAME}}UnionTraits<RT>::enum_value;";
code_ += " if (type != {{NONE}}) {";
code_ += " value = new RT(std::forward<T>(val));";
code_ += " }";
code_ += " }";
code_ += "";
}
code_ += " " + UnionUnPackSignature(enum_def, true) + ";";
code_ += " " + UnionPackSignature(enum_def, true) + ";";
code_ += "";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
if (ev.IsZero()) { continue; }
const auto native_type = GetUnionElement(ev, true, opts_);
code_.SetValue("NATIVE_TYPE", native_type);
code_.SetValue("NATIVE_NAME", Name(ev));
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_ += " const {{NATIVE_TYPE}} *As{{NATIVE_NAME}}() const {";
code_ += " return type == {{NATIVE_ID}} ?";
code_ +=
" reinterpret_cast<const {{NATIVE_TYPE}} *>(value) : nullptr;";
code_ += " }";
}
code_ += "};";
code_ += "";
if (opts_.gen_compare) {
code_ += "";
code_ +=
"inline bool operator==(const {{NAME}}Union &lhs, const "
"{{NAME}}Union &rhs) {";
code_ += " if (lhs.type != rhs.type) return false;";
code_ += " switch (lhs.type) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
code_.SetValue("NATIVE_ID", GetEnumValUse(enum_def, ev));
if (ev.IsNonZero()) {
const auto native_type = GetUnionElement(ev, true, opts_);
code_.SetValue("NATIVE_TYPE", native_type);
code_ += " case {{NATIVE_ID}}: {";
code_ +=
" return *(reinterpret_cast<const {{NATIVE_TYPE}} "
"*>(lhs.value)) ==";
code_ +=
" *(reinterpret_cast<const {{NATIVE_TYPE}} "
"*>(rhs.value));";
code_ += " }";
} else {
code_ += " case {{NATIVE_ID}}: {";
code_ += " return true;"; // "NONE" enum value.
code_ += " }";
}
}
code_ += " default: {";
code_ += " return false;";
code_ += " }";
code_ += " }";
code_ += "}";
code_ += "";
code_ +=
"inline bool operator!=(const {{NAME}}Union &lhs, const "
"{{NAME}}Union &rhs) {";
code_ += " return !(lhs == rhs);";
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", Name(enum_def));
code_ += "inline " + UnionVerifySignature(enum_def) + " {";
code_ += " switch (type) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
const auto &ev = **it;
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
if (ev.IsNonZero()) {
code_.SetValue("TYPE", GetUnionElement(ev, false, opts_));
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_.SetValue("ALIGN",
NumToString(ev.union_type.struct_def->minalign));
code_ +=
" return verifier.VerifyField<{{TYPE}}>("
"static_cast<const uint8_t *>(obj), 0, {{ALIGN}});";
} else {
code_ += getptr;
code_ += " return verifier.VerifyTable(ptr);";
}
} else if (IsString(ev.union_type)) {
code_ += getptr;
code_ += " return verifier.VerifyString(ptr);";
} else {
FLATBUFFERS_ASSERT(false);
}
code_ += " }";
} else {
code_ += " case {{LABEL}}: {";
code_ += " return true;"; // "NONE" enum value.
code_ += " }";
}
}
code_ += " default: return true;"; // unknown values are OK.
code_ += " }";
code_ += "}";
code_ += "";
code_ += "inline " + UnionVectorVerifySignature(enum_def) + " {";
code_ += " if (!values || !types) return !values && !types;";
code_ += " if (values->size() != types->size()) return false;";
code_ += " for (flatbuffers::uoffset_t i = 0; i < values->size(); ++i) {";
code_ += " if (!Verify" + Name(enum_def) + "(";
code_ += " verifier, values->Get(i), types->GetEnum<" +
Name(enum_def) + ">(i))) {";
code_ += " return false;";
code_ += " }";
code_ += " }";
code_ += " return true;";
code_ += "}";
code_ += "";
if (opts_.generate_object_based_api) {
// Generate union Unpack() and Pack() functions.
code_ += "inline " + UnionUnPackSignature(enum_def, false) + " {";
code_ += " (void)resolver;";
code_ += " switch (type) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
if (ev.IsZero()) { continue; }
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", GetUnionElement(ev, false, opts_));
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 (IsString(ev.union_type)) {
code_ += " return new std::string(ptr->c_str(), ptr->size());";
} else {
FLATBUFFERS_ASSERT(false);
}
code_ += " }";
}
code_ += " default: return nullptr;";
code_ += " }";
code_ += "}";
code_ += "";
code_ += "inline " + UnionPackSignature(enum_def, false) + " {";
code_ += " (void)_rehasher;";
code_ += " switch (type) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
auto &ev = **it;
if (ev.IsZero()) { continue; }
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", GetUnionElement(ev, true, opts_));
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_.SetValue("NAME", ev.union_type.struct_def->name);
code_ +=
" return Create{{NAME}}(_fbb, ptr, _rehasher).Union();";
}
} else if (IsString(ev.union_type)) {
code_ += " return _fbb.CreateString(*ptr).Union();";
} else {
FLATBUFFERS_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) : type(u.type), value(nullptr) {";
code_ += " switch (type) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
if (ev.IsZero()) { continue; }
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", GetUnionElement(ev, true, opts_));
code_ += " case {{LABEL}}: {";
bool copyable = true;
if (opts_.g_cpp_std < cpp::CPP_STD_11 &&
ev.union_type.base_type == BASE_TYPE_STRUCT &&
!ev.union_type.struct_def->fixed) {
// 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 &&
!field.native_inline) {
copyable = false;
break;
}
}
}
if (copyable) {
code_ +=
" value = new {{TYPE}}(*reinterpret_cast<{{TYPE}} *>"
"(u.value));";
} else {
code_ +=
" FLATBUFFERS_ASSERT(false); // {{TYPE}} not copyable.";
}
code_ += " break;";
code_ += " }";
}
code_ += " default:";
code_ += " break;";
code_ += " }";
code_ += "}";
code_ += "";
// Union Reset() function.
FLATBUFFERS_ASSERT(enum_def.Lookup("NONE"));
code_.SetValue("NONE", GetEnumValUse(enum_def, *enum_def.Lookup("NONE")));
code_ += "inline void {{ENUM_NAME}}Union::Reset() {";
code_ += " switch (type) {";
for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
++it) {
const auto &ev = **it;
if (ev.IsZero()) { continue; }
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", GetUnionElement(ev, true, opts_));
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 = Name(field);
std::transform(uname.begin(), uname.end(), uname.begin(), CharToUpper);
return "VT_" + uname;
}
void GenFullyQualifiedNameGetter(const StructDef &struct_def,
const std::string &name) {
if (!opts_.generate_name_strings) { return; }
auto fullname = struct_def.defined_namespace->GetFullyQualifiedName(name);
code_.SetValue("NAME", fullname);
code_.SetValue("CONSTEXPR", "FLATBUFFERS_CONSTEXPR_CPP11");
code_ += " static {{CONSTEXPR}} const char *GetFullyQualifiedName() {";
code_ += " return \"{{NAME}}\";";
code_ += " }";
}
std::string GenDefaultConstant(const FieldDef &field) {
if (IsFloat(field.value.type.base_type))
return float_const_gen_.GenFloatConstant(field);
else
return NumToStringCpp(field.value.constant, field.value.type.base_type);
}
std::string GetDefaultScalarValue(const FieldDef &field, bool is_ctor) {
const auto &type = field.value.type;
if (field.IsScalarOptional()) {
return GenOptionalNull();
} else if (type.enum_def && IsScalar(type.base_type)) {
auto ev = type.enum_def->FindByValue(field.value.constant);
if (ev) {
return WrapInNameSpace(type.enum_def->defined_namespace,
GetEnumValUse(*type.enum_def, *ev));
} else {
return GenUnderlyingCast(
field, true, NumToStringCpp(field.value.constant, type.base_type));
}
} else if (type.base_type == BASE_TYPE_BOOL) {
return field.value.constant == "0" ? "false" : "true";
} else if (field.attributes.Lookup("cpp_type")) {
if (is_ctor) {
if (PtrType(&field) == "naked") {
return "nullptr";
} else {
return "";
}
} else {
return "0";
}
} else if (IsStruct(type) && (field.value.constant == "0")) {
return "nullptr";
} else {
return GenDefaultConstant(field);
}
}
void GenParam(const FieldDef &field, bool direct, const char *prefix) {
code_.SetValue("PRE", prefix);
code_.SetValue("PARAM_NAME", Name(field));
if (direct && IsString(field.value.type)) {
code_.SetValue("PARAM_TYPE", "const char *");
code_.SetValue("PARAM_VALUE", "nullptr");
} else if (direct && IsVector(field.value.type)) {
const auto vtype = field.value.type.VectorType();
std::string type;
if (IsStruct(vtype)) {
type = WrapInNameSpace(*vtype.struct_def);
} else {
type = GenTypeWire(vtype, "", VectorElementUserFacing(vtype));
}
if (TypeHasKey(vtype)) {
code_.SetValue("PARAM_TYPE", "std::vector<" + type + "> *");
} else {
code_.SetValue("PARAM_TYPE", "const std::vector<" + type + "> *");
}
code_.SetValue("PARAM_VALUE", "nullptr");
} else {
const auto &type = field.value.type;
code_.SetValue("PARAM_VALUE", GetDefaultScalarValue(field, false));
if (field.IsScalarOptional())
code_.SetValue("PARAM_TYPE", GenOptionalDecl(type) + " ");
else
code_.SetValue("PARAM_TYPE", GenTypeWire(type, " ", true));
}
code_ += "{{PRE}}{{PARAM_TYPE}}{{PARAM_NAME}} = {{PARAM_VALUE}}\\";
}
// Generate a member, including a default value for scalars and raw pointers.
void GenMember(const FieldDef &field) {
if (!field.deprecated && // Deprecated fields won't be accessible.
field.value.type.base_type != BASE_TYPE_UTYPE &&
(field.value.type.base_type != BASE_TYPE_VECTOR ||
field.value.type.element != BASE_TYPE_UTYPE)) {
auto type = GenTypeNative(field.value.type, false, field);
auto cpp_type = field.attributes.Lookup("cpp_type");
auto full_type =
(cpp_type
? (IsVector(field.value.type)
? "std::vector<" +
GenTypeNativePtr(cpp_type->constant, &field,
false) +
"> "
: GenTypeNativePtr(cpp_type->constant, &field, false))
: type + " ");
// Generate default member initializers for >= C++11.
std::string field_di = "";
if (opts_.g_cpp_std >= cpp::CPP_STD_11) {
field_di = "{}";
auto native_default = field.attributes.Lookup("native_default");
// Scalar types get parsed defaults, raw pointers get nullptrs.
if (IsScalar(field.value.type.base_type)) {
field_di =
" = " + (native_default ? std::string(native_default->constant)
: GetDefaultScalarValue(field, true));
} else if (field.value.type.base_type == BASE_TYPE_STRUCT) {
if (IsStruct(field.value.type) && native_default) {
field_di = " = " + native_default->constant;
}
}
}
code_.SetValue("FIELD_TYPE", full_type);
code_.SetValue("FIELD_NAME", Name(field));
code_.SetValue("FIELD_DI", field_di);
code_ += " {{FIELD_TYPE}}{{FIELD_NAME}}{{FIELD_DI}};";
}
}
// Returns true if `struct_def` needs a copy constructor and assignment
// operator because it has one or more table members, struct members with a
// custom cpp_type and non-naked pointer type, or vector members of those.
bool NeedsCopyCtorAssignOp(const StructDef &struct_def) {
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto &type = field.value.type;
if (field.deprecated) continue;
if (type.base_type == BASE_TYPE_STRUCT) {
const auto cpp_type = field.attributes.Lookup("cpp_type");
const auto cpp_ptr_type = field.attributes.Lookup("cpp_ptr_type");
const bool is_ptr = !(IsStruct(type) && field.native_inline) ||
(cpp_type && cpp_ptr_type->constant != "naked");
if (is_ptr) { return true; }
} else if (IsVector(type)) {
const auto vec_type = type.VectorType();
if (vec_type.base_type == BASE_TYPE_UTYPE) continue;
const auto cpp_type = field.attributes.Lookup("cpp_type");
const auto cpp_ptr_type = field.attributes.Lookup("cpp_ptr_type");
const bool is_ptr =
(vec_type.base_type == BASE_TYPE_STRUCT && !IsStruct(vec_type)) ||
(cpp_type && cpp_ptr_type->constant != "naked");
if (is_ptr) { return true; }
}
}
return false;
}
// Generate the default constructor for this struct. Properly initialize all
// scalar members with default values.
void GenDefaultConstructor(const StructDef &struct_def) {
code_.SetValue("NATIVE_NAME",
NativeName(Name(struct_def), &struct_def, opts_));
// In >= C++11, default member initializers are generated. To allow for
// aggregate initialization, do not emit a default constructor at all, with
// the exception of types that need a copy/move ctors and assignment
// operators.
if (opts_.g_cpp_std >= cpp::CPP_STD_11) {
if (NeedsCopyCtorAssignOp(struct_def)) {
code_ += " {{NATIVE_NAME}}() = default;";
}
return;
}
std::string initializer_list;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (!field.deprecated && // Deprecated fields won't be accessible.
field.value.type.base_type != BASE_TYPE_UTYPE) {
auto cpp_type = field.attributes.Lookup("cpp_type");
auto native_default = field.attributes.Lookup("native_default");
// Scalar types get parsed defaults, raw pointers get nullptrs.
if (IsScalar(field.value.type.base_type)) {
if (!initializer_list.empty()) { initializer_list += ",\n "; }
initializer_list += Name(field);
initializer_list +=
"(" +
(native_default ? std::string(native_default->constant)
: GetDefaultScalarValue(field, true)) +
")";
} else if (field.value.type.base_type == BASE_TYPE_STRUCT) {
if (IsStruct(field.value.type)) {
if (native_default) {
if (!initializer_list.empty()) {
initializer_list += ",\n ";
}
initializer_list +=
Name(field) + "(" + native_default->constant + ")";
}
}
} else if (cpp_type && field.value.type.base_type != BASE_TYPE_VECTOR) {
if (!initializer_list.empty()) { initializer_list += ",\n "; }
initializer_list += Name(field) + "(0)";
}
}
}
if (!initializer_list.empty()) {
initializer_list = "\n : " + initializer_list;
}
code_.SetValue("INIT_LIST", initializer_list);
code_ += " {{NATIVE_NAME}}(){{INIT_LIST}} {";
code_ += " }";
}
// Generate the >= C++11 copy/move constructor and assignment operator
// declarations if required. Tables that are default-copyable do not get
// user-provided copy/move constructors and assignment operators so they
// remain aggregates.
void GenCopyMoveCtorAndAssigOpDecls(const StructDef &struct_def) {
if (opts_.g_cpp_std < cpp::CPP_STD_11) return;
if (!NeedsCopyCtorAssignOp(struct_def)) return;
code_.SetValue("NATIVE_NAME",
NativeName(Name(struct_def), &struct_def, opts_));
code_ += " {{NATIVE_NAME}}(const {{NATIVE_NAME}} &o);";
code_ +=
" {{NATIVE_NAME}}({{NATIVE_NAME}}&&) FLATBUFFERS_NOEXCEPT = "
"default;";
code_ +=
" {{NATIVE_NAME}} &operator=({{NATIVE_NAME}} o) FLATBUFFERS_NOEXCEPT;";
}
// Generate the >= C++11 copy constructor and assignment operator definitions.
void GenCopyCtorAssignOpDefs(const StructDef &struct_def) {
if (opts_.g_cpp_std < cpp::CPP_STD_11) return;
if (!NeedsCopyCtorAssignOp(struct_def)) return;
std::string initializer_list;
std::string vector_copies;
std::string swaps;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto &type = field.value.type;
if (field.deprecated || type.base_type == BASE_TYPE_UTYPE) continue;
if (type.base_type == BASE_TYPE_STRUCT) {
if (!initializer_list.empty()) { initializer_list += ",\n "; }
const auto cpp_type = field.attributes.Lookup("cpp_type");
const auto cpp_ptr_type = field.attributes.Lookup("cpp_ptr_type");
auto type_name = (cpp_type) ? cpp_type->constant
: GenTypeNative(type, /*invector*/ false,
field, /*forcopy*/ true);
const bool is_ptr = !(IsStruct(type) && field.native_inline) ||
(cpp_type && cpp_ptr_type->constant != "naked");
CodeWriter cw;
cw.SetValue("FIELD", Name(field));
cw.SetValue("TYPE", type_name);
if (is_ptr) {
cw +=
"{{FIELD}}((o.{{FIELD}}) ? new {{TYPE}}(*o.{{FIELD}}) : "
"nullptr)\\";
initializer_list += cw.ToString();
} else {
cw += "{{FIELD}}(o.{{FIELD}})\\";
initializer_list += cw.ToString();
}
} else if (IsVector(type)) {
const auto vec_type = type.VectorType();
if (vec_type.base_type == BASE_TYPE_UTYPE) continue;
const auto cpp_type = field.attributes.Lookup("cpp_type");
const auto cpp_ptr_type = field.attributes.Lookup("cpp_ptr_type");
const auto type_name = (cpp_type)
? cpp_type->constant
: GenTypeNative(vec_type, /*invector*/ true,
field, /*forcopy*/ true);
const bool is_ptr =
(vec_type.base_type == BASE_TYPE_STRUCT && !IsStruct(vec_type)) ||
(cpp_type && cpp_ptr_type->constant != "naked");
CodeWriter cw(" ");
cw.SetValue("FIELD", Name(field));
cw.SetValue("TYPE", type_name);
if (is_ptr) {
// Use emplace_back to construct the potentially-smart pointer element
// from a raw pointer to a new-allocated copy.
cw.IncrementIdentLevel();
cw += "{{FIELD}}.reserve(o.{{FIELD}}.size());";
cw +=
"for (const auto &{{FIELD}}_ : o.{{FIELD}}) { "
"{{FIELD}}.emplace_back(({{FIELD}}_) ? new {{TYPE}}(*{{FIELD}}_) "
": nullptr); }";
vector_copies += cw.ToString();
} else {
// For non-pointer elements, use std::vector's copy constructor in the
// initializer list. This will yield better performance than an insert
// range loop for trivially-copyable element types.
if (!initializer_list.empty()) { initializer_list += ",\n "; }
cw += "{{FIELD}}(o.{{FIELD}})\\";
initializer_list += cw.ToString();
}
} else {
if (!initializer_list.empty()) { initializer_list += ",\n "; }
CodeWriter cw;
cw.SetValue("FIELD", Name(field));
cw += "{{FIELD}}(o.{{FIELD}})\\";
initializer_list += cw.ToString();
}
{
if (!swaps.empty()) { swaps += "\n "; }
CodeWriter cw;
cw.SetValue("FIELD", Name(field));
cw += "std::swap({{FIELD}}, o.{{FIELD}});\\";
swaps += cw.ToString();
}
}
if (!initializer_list.empty()) {
initializer_list = "\n : " + initializer_list;
}
if (!swaps.empty()) { swaps = " " + swaps; }
code_.SetValue("NATIVE_NAME",
NativeName(Name(struct_def), &struct_def, opts_));
code_.SetValue("INIT_LIST", initializer_list);
code_.SetValue("VEC_COPY", vector_copies);
code_.SetValue("SWAPS", swaps);
code_ +=
"inline {{NATIVE_NAME}}::{{NATIVE_NAME}}(const {{NATIVE_NAME}} &o)"
"{{INIT_LIST}} {";
code_ += "{{VEC_COPY}}}\n";
code_ +=
"inline {{NATIVE_NAME}} &{{NATIVE_NAME}}::operator="
"({{NATIVE_NAME}} o) FLATBUFFERS_NOEXCEPT {";
code_ += "{{SWAPS}}";
code_ += " return *this;\n}\n";
}
void GenCompareOperator(const StructDef &struct_def,
std::string accessSuffix = "") {
std::string compare_op;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto accessor = Name(field) + accessSuffix;
const auto lhs_accessor = "lhs." + accessor;
const auto rhs_accessor = "rhs." + accessor;
if (!field.deprecated && // Deprecated fields won't be accessible.
field.value.type.base_type != BASE_TYPE_UTYPE &&
(field.value.type.base_type != BASE_TYPE_VECTOR ||
field.value.type.element != BASE_TYPE_UTYPE)) {
if (!compare_op.empty()) { compare_op += " &&\n "; }
if (struct_def.fixed || field.native_inline ||
field.value.type.base_type != BASE_TYPE_STRUCT) {
// If the field is a vector of tables, the table need to be compared
// by value, instead of by the default unique_ptr == operator which
// compares by address.
if (field.value.type.base_type == BASE_TYPE_VECTOR &&
field.value.type.element == BASE_TYPE_STRUCT &&
!field.value.type.struct_def->fixed) {
const auto type =
GenTypeNative(field.value.type.VectorType(), true, field);
const auto equal_length =
lhs_accessor + ".size() == " + rhs_accessor + ".size()";
const auto elements_equal =
"std::equal(" + lhs_accessor + ".cbegin(), " + lhs_accessor +
".cend(), " + rhs_accessor + ".cbegin(), [](" + type +
" const &a, " + type +
" const &b) { return (a == b) || (a && b && *a == *b); })";
compare_op += "(" + equal_length + " && " + elements_equal + ")";
} else {
compare_op += "(" + lhs_accessor + " == " + rhs_accessor + ")";
}
} else {
// Deep compare of std::unique_ptr. Null is not equal to empty.
std::string both_null =
"(" + lhs_accessor + " == " + rhs_accessor + ")";
std::string not_null_and_equal = "(lhs." + accessor + " && rhs." +
accessor + " && *lhs." + accessor +
" == *rhs." + accessor + ")";
compare_op += "(" + both_null + " || " + not_null_and_equal + ")";
}
}
}
std::string cmp_lhs;
std::string cmp_rhs;
if (compare_op.empty()) {
cmp_lhs = "";
cmp_rhs = "";
compare_op = " return true;";
} else {
cmp_lhs = "lhs";
cmp_rhs = "rhs";
compare_op = " return\n " + compare_op + ";";
}
code_.SetValue("CMP_OP", compare_op);
code_.SetValue("CMP_LHS", cmp_lhs);
code_.SetValue("CMP_RHS", cmp_rhs);
code_ += "";
code_ +=
"inline bool operator==(const {{NATIVE_NAME}} &{{CMP_LHS}}, const "
"{{NATIVE_NAME}} &{{CMP_RHS}}) {";
code_ += "{{CMP_OP}}";
code_ += "}";
code_ += "";
code_ +=
"inline bool operator!=(const {{NATIVE_NAME}} &lhs, const "
"{{NATIVE_NAME}} &rhs) {";
code_ += " return !(lhs == rhs);";
code_ += "}";
code_ += "";
}
void GenOperatorNewDelete(const StructDef &struct_def) {
if (auto native_custom_alloc =
struct_def.attributes.Lookup("native_custom_alloc")) {
code_ += " inline void *operator new (std::size_t count) {";
code_ += " return " + native_custom_alloc->constant +
"<{{NATIVE_NAME}}>().allocate(count / sizeof({{NATIVE_NAME}}));";
code_ += " }";
code_ += " inline void operator delete (void *ptr) {";
code_ += " return " + native_custom_alloc->constant +
"<{{NATIVE_NAME}}>().deallocate(static_cast<{{NATIVE_NAME}}*>("
"ptr),1);";
code_ += " }";
}
}
void GenNativeTable(const StructDef &struct_def) {
const auto native_name = NativeName(Name(struct_def), &struct_def, opts_);
code_.SetValue("STRUCT_NAME", Name(struct_def));
code_.SetValue("NATIVE_NAME", native_name);
// Generate a C++ object that can hold an unpacked version of this table.
code_ += "struct {{NATIVE_NAME}} : public flatbuffers::NativeTable {";
code_ += " typedef {{STRUCT_NAME}} TableType;";
GenFullyQualifiedNameGetter(struct_def, native_name);
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
GenMember(**it);
}
GenOperatorNewDelete(struct_def);
GenDefaultConstructor(struct_def);
GenCopyMoveCtorAndAssigOpDecls(struct_def);
code_ += "};";
code_ += "";
}
void GenNativeTablePost(const StructDef &struct_def) {
if (opts_.gen_compare) {
const auto native_name = NativeName(Name(struct_def), &struct_def, opts_);
code_.SetValue("STRUCT_NAME", Name(struct_def));
code_.SetValue("NATIVE_NAME", native_name);
GenCompareOperator(struct_def);
code_ += "";
}
}
// Generate the code to call the appropriate Verify function(s) for a field.
void GenVerifyCall(const FieldDef &field, const char *prefix) {
code_.SetValue("PRE", prefix);
code_.SetValue("NAME", Name(field));
code_.SetValue("REQUIRED", field.IsRequired() ? "Required" : "");
code_.SetValue("SIZE", GenTypeSize(field.value.type));
code_.SetValue("OFFSET", GenFieldOffsetName(field));
if (IsScalar(field.value.type.base_type) || IsStruct(field.value.type)) {
code_.SetValue("ALIGN", NumToString(InlineAlignment(field.value.type)));
code_ +=
"{{PRE}}VerifyField{{REQUIRED}}<{{SIZE}}>(verifier, "
"{{OFFSET}}, {{ALIGN}})\\";
} else {
code_ += "{{PRE}}VerifyOffset{{REQUIRED}}(verifier, {{OFFSET}})\\";
}
switch (field.value.type.base_type) {
case BASE_TYPE_UNION: {
code_.SetValue("ENUM_NAME", field.value.type.enum_def->name);
code_.SetValue("SUFFIX", UnionTypeFieldSuffix());
code_ +=
"{{PRE}}Verify{{ENUM_NAME}}(verifier, {{NAME}}(), "
"{{NAME}}{{SUFFIX}}())\\";
break;
}
case BASE_TYPE_STRUCT: {
if (!field.value.type.struct_def->fixed) {
code_ += "{{PRE}}verifier.VerifyTable({{NAME}}())\\";
}
break;
}
case BASE_TYPE_STRING: {
code_ += "{{PRE}}verifier.VerifyString({{NAME}}())\\";
break;
}
case BASE_TYPE_VECTOR: {
code_ += "{{PRE}}verifier.VerifyVector({{NAME}}())\\";
switch (field.value.type.element) {
case BASE_TYPE_STRING: {
code_ += "{{PRE}}verifier.VerifyVectorOfStrings({{NAME}}())\\";
break;
}
case BASE_TYPE_STRUCT: {
if (!field.value.type.struct_def->fixed) {
code_ += "{{PRE}}verifier.VerifyVectorOfTables({{NAME}}())\\";
}
break;
}
case BASE_TYPE_UNION: {
code_.SetValue("ENUM_NAME", field.value.type.enum_def->name);
code_ +=
"{{PRE}}Verify{{ENUM_NAME}}Vector(verifier, {{NAME}}(), "
"{{NAME}}_type())\\";
break;
}
default: break;
}
auto nfn = GetNestedFlatBufferName(field);
if (!nfn.empty()) {
code_.SetValue("CPP_NAME", nfn);
// FIXME: file_identifier.
code_ +=
"{{PRE}}verifier.VerifyNestedFlatBuffer<{{CPP_NAME}}>"
"({{NAME}}(), nullptr)\\";
} else if (field.flexbuffer) {
code_ +=
"{{PRE}}flexbuffers::VerifyNestedFlexBuffer"
"({{NAME}}(), verifier)\\";
}
break;
}
default: {
break;
}
}
}
// Generate CompareWithValue method for a key field.
void GenKeyFieldMethods(const FieldDef &field) {
FLATBUFFERS_ASSERT(field.key);
const bool is_string = (IsString(field.value.type));
code_ += " bool KeyCompareLessThan(const {{STRUCT_NAME}} *o) const {";
if (is_string) {
// use operator< of flatbuffers::String
code_ += " return *{{FIELD_NAME}}() < *o->{{FIELD_NAME}}();";
} else {
code_ += " return {{FIELD_NAME}}() < o->{{FIELD_NAME}}();";
}
code_ += " }";
if (is_string) {
code_ += " int KeyCompareWithValue(const char *_{{FIELD_NAME}}) const {";
code_ += " return strcmp({{FIELD_NAME}}()->c_str(), _{{FIELD_NAME}});";
code_ += " }";
} else {
FLATBUFFERS_ASSERT(IsScalar(field.value.type.base_type));
auto type = GenTypeBasic(field.value.type, false);
if (opts_.scoped_enums && field.value.type.enum_def &&
IsScalar(field.value.type.base_type)) {
type = GenTypeGet(field.value.type, " ", "const ", " *", true);
}
// Returns {field<val: -1, field==val: 0, field>val: +1}.
code_.SetValue("KEY_TYPE", type);
code_ +=
" int KeyCompareWithValue({{KEY_TYPE}} _{{FIELD_NAME}}) const {";
code_ +=
" return static_cast<int>({{FIELD_NAME}}() > _{{FIELD_NAME}}) - "
"static_cast<int>({{FIELD_NAME}}() < _{{FIELD_NAME}});";
code_ += " }";
}
}
void GenTableUnionAsGetters(const FieldDef &field) {
const auto &type = field.value.type;
auto u = type.enum_def;
if (!type.enum_def->uses_multiple_type_instances)
code_ +=
" template<typename T> "
"const T *{{NULLABLE_EXT}}{{FIELD_NAME}}_as() const;";
for (auto u_it = u->Vals().begin(); u_it != u->Vals().end(); ++u_it) {
auto &ev = **u_it;
if (ev.union_type.base_type == BASE_TYPE_NONE) { continue; }
auto full_struct_name = GetUnionElement(ev, false, opts_);
// @TODO: Mby make this decisions more universal? How?
code_.SetValue("U_GET_TYPE",
EscapeKeyword(Name(field) + UnionTypeFieldSuffix()));
code_.SetValue("U_ELEMENT_TYPE", WrapInNameSpace(u->defined_namespace,
GetEnumValUse(*u, ev)));
code_.SetValue("U_FIELD_TYPE", "const " + full_struct_name + " *");
code_.SetValue("U_FIELD_NAME", Name(field) + "_as_" + Name(ev));
code_.SetValue("U_NULLABLE", NullableExtension());
// `const Type *union_name_asType() const` accessor.
code_ += " {{U_FIELD_TYPE}}{{U_NULLABLE}}{{U_FIELD_NAME}}() const {";
code_ +=
" return {{U_GET_TYPE}}() == {{U_ELEMENT_TYPE}} ? "
"static_cast<{{U_FIELD_TYPE}}>({{FIELD_NAME}}()) "
": nullptr;";
code_ += " }";
}
}
void GenTableFieldGetter(const FieldDef &field) {
const auto &type = field.value.type;
const auto offset_str = GenFieldOffsetName(field);
GenComment(field.doc_comment, " ");
// Call a different accessor for pointers, that indirects.
if (false == field.IsScalarOptional()) {
const bool is_scalar = IsScalar(type.base_type);
std::string accessor;
if (is_scalar)
accessor = "GetField<";
else if (IsStruct(type))
accessor = "GetStruct<";
else
accessor = "GetPointer<";
auto offset_type = GenTypeGet(type, "", "const ", " *", false);
auto call = accessor + offset_type + ">(" + offset_str;
// Default value as second arg for non-pointer types.
if (is_scalar) { call += ", " + GenDefaultConstant(field); }
call += ")";
std::string afterptr = " *" + NullableExtension();
code_.SetValue("FIELD_TYPE",
GenTypeGet(type, " ", "const ", afterptr.c_str(), true));
code_.SetValue("FIELD_VALUE", GenUnderlyingCast(field, true, call));
code_.SetValue("NULLABLE_EXT", NullableExtension());
code_ += " {{FIELD_TYPE}}{{FIELD_NAME}}() const {";
code_ += " return {{FIELD_VALUE}};";
code_ += " }";
} else {
auto wire_type = GenTypeBasic(type, false);
auto face_type = GenTypeBasic(type, true);
auto opt_value = "GetOptional<" + wire_type + ", " + face_type + ">(" +
offset_str + ")";
code_.SetValue("FIELD_TYPE", GenOptionalDecl(type));
code_ += " {{FIELD_TYPE}} {{FIELD_NAME}}() const {";
code_ += " return " + opt_value + ";";
code_ += " }";
}
if (type.base_type == BASE_TYPE_UNION) { GenTableUnionAsGetters(field); }
}
void GenTableFieldType(const FieldDef &field) {
const auto &type = field.value.type;
const auto offset_str = GenFieldOffsetName(field);
if (!field.IsScalarOptional()) {
std::string afterptr = " *" + NullableExtension();
code_.SetValue("FIELD_TYPE",
GenTypeGet(type, "", "const ", afterptr.c_str(), true));
code_ += " {{FIELD_TYPE}}\\";
} else {
code_.SetValue("FIELD_TYPE", GenOptionalDecl(type));
code_ += " {{FIELD_TYPE}}\\";
}
}
void GenStructFieldType(const FieldDef &field) {
const auto is_array = IsArray(field.value.type);
std::string field_type =
GenTypeGet(field.value.type, "", is_array ? "" : "const ",
is_array ? "" : " &", true);
code_.SetValue("FIELD_TYPE", field_type);
code_ += " {{FIELD_TYPE}}\\";
}
void GenFieldTypeHelper(const StructDef &struct_def) {
if (struct_def.fields.vec.empty()) { return; }
code_ += " template<size_t Index>";
code_ += " using FieldType = \\";
code_ += "decltype(std::declval<type>().get_field<Index>());";
}
void GenIndexBasedFieldGetter(const StructDef &struct_def) {
if (struct_def.fields.vec.empty()) { return; }
code_ += " template<size_t Index>";
code_ += " auto get_field() const {";
size_t index = 0;
bool need_else = false;
// Generate one index-based getter for each field.
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) {
// Deprecated fields won't be accessible.
continue;
}
code_.SetValue("FIELD_NAME", Name(field));
code_.SetValue("FIELD_INDEX",
std::to_string(static_cast<long long>(index++)));
if (need_else) {
code_ += " else \\";
} else {
code_ += " \\";
}
need_else = true;
code_ += "if constexpr (Index == {{FIELD_INDEX}}) \\";
code_ += "return {{FIELD_NAME}}();";
}
code_ += " else static_assert(Index != Index, \"Invalid Field Index\");";
code_ += " }";
}
// Sample for Vec3:
//
// static constexpr std::array<const char *, 3> field_names = {
// "x",
// "y",
// "z"
// };
//
void GenFieldNames(const StructDef &struct_def) {
code_ += " static constexpr std::array<\\";
code_ += "const char *, fields_number> field_names = {\\";
if (struct_def.fields.vec.empty()) {
code_ += "};";
return;
}
code_ += "";
// Generate the field_names elements.
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) {
// Deprecated fields won't be accessible.
continue;
}
code_.SetValue("FIELD_NAME", Name(field));
code_ += " \"{{FIELD_NAME}}\"\\";
if (it + 1 != struct_def.fields.vec.end()) { code_ += ","; }
}
code_ += "\n };";
}
void GenFieldsNumber(const StructDef &struct_def) {
const auto non_deprecated_field_count = std::count_if(
struct_def.fields.vec.begin(), struct_def.fields.vec.end(),
[](const FieldDef *field) { return !field->deprecated; });
code_.SetValue(
"FIELD_COUNT",
std::to_string(static_cast<long long>(non_deprecated_field_count)));
code_ += " static constexpr size_t fields_number = {{FIELD_COUNT}};";
}
void GenTraitsStruct(const StructDef &struct_def) {
code_.SetValue(
"FULLY_QUALIFIED_NAME",
struct_def.defined_namespace->GetFullyQualifiedName(Name(struct_def)));
code_ += "struct {{STRUCT_NAME}}::Traits {";
code_ += " using type = {{STRUCT_NAME}};";
if (!struct_def.fixed) {
// We have a table and not a struct.
code_ += " static auto constexpr Create = Create{{STRUCT_NAME}};";
}
if (opts_.cpp_static_reflection) {
code_ += " static constexpr auto name = \"{{STRUCT_NAME}}\";";
code_ +=
" static constexpr auto fully_qualified_name = "
"\"{{FULLY_QUALIFIED_NAME}}\";";
GenFieldsNumber(struct_def);
GenFieldNames(struct_def);
GenFieldTypeHelper(struct_def);
}
code_ += "};";
code_ += "";
}
void GenTableFieldSetter(const FieldDef &field) {
const auto &type = field.value.type;
const bool is_scalar = IsScalar(type.base_type);
if (is_scalar && IsUnion(type))
return; // changing of a union's type is forbidden
auto offset_str = GenFieldOffsetName(field);
if (is_scalar) {
const auto wire_type = GenTypeWire(type, "", false);
code_.SetValue("SET_FN", "SetField<" + wire_type + ">");
code_.SetValue("OFFSET_NAME", offset_str);
code_.SetValue("FIELD_TYPE", GenTypeBasic(type, true));
code_.SetValue("FIELD_VALUE",
GenUnderlyingCast(field, false, "_" + Name(field)));
code_ += " bool mutate_{{FIELD_NAME}}({{FIELD_TYPE}} _{{FIELD_NAME}}\\";
if (false == field.IsScalarOptional()) {
code_.SetValue("DEFAULT_VALUE", GenDefaultConstant(field));
code_.SetValue(
"INTERFACE_DEFAULT_VALUE",
GenUnderlyingCast(field, true, GenDefaultConstant(field)));
// GenUnderlyingCast for a bool field generates 0 != 0
// So the type has to be checked and the appropriate default chosen
if (IsBool(field.value.type.base_type)) {
code_ += " = {{DEFAULT_VALUE}}) {";
} else {
code_ += " = {{INTERFACE_DEFAULT_VALUE}}) {";
}
code_ +=
" return {{SET_FN}}({{OFFSET_NAME}}, {{FIELD_VALUE}}, "
"{{DEFAULT_VALUE}});";
} else {
code_ += ") {";
code_ += " return {{SET_FN}}({{OFFSET_NAME}}, {{FIELD_VALUE}});";
}
code_ += " }";
} else {
auto postptr = " *" + NullableExtension();
auto wire_type = GenTypeGet(type, " ", "", postptr.c_str(), true);
std::string accessor = IsStruct(type) ? "GetStruct<" : "GetPointer<";
auto underlying = accessor + wire_type + ">(" + offset_str + ")";
code_.SetValue("FIELD_TYPE", wire_type);
code_.SetValue("FIELD_VALUE", GenUnderlyingCast(field, true, underlying));
code_ += " {{FIELD_TYPE}}mutable_{{FIELD_NAME}}() {";
code_ += " return {{FIELD_VALUE}};";
code_ += " }";
}
}
std::string GetNestedFlatBufferName(const FieldDef &field) {
auto nested = field.attributes.Lookup("nested_flatbuffer");
if (!nested) return "";
std::string qualified_name = nested->constant;
auto nested_root = parser_.LookupStruct(nested->constant);
if (nested_root == nullptr) {
qualified_name =
parser_.current_namespace_->GetFullyQualifiedName(nested->constant);
nested_root = parser_.LookupStruct(qualified_name);
}
FLATBUFFERS_ASSERT(nested_root); // Guaranteed to exist by parser.
(void)nested_root;
return TranslateNameSpace(qualified_name);
}
// Generate an accessor struct, builder structs & function for a table.
void GenTable(const StructDef &struct_def) {
if (opts_.generate_object_based_api) { GenNativeTable(struct_def); }
// Generate an accessor struct, with methods of the form:
// type name() const { return GetField<type>(offset, defaultval); }
GenComment(struct_def.doc_comment);
code_.SetValue("STRUCT_NAME", Name(struct_def));
code_ +=
"struct {{STRUCT_NAME}} FLATBUFFERS_FINAL_CLASS"
" : private flatbuffers::Table {";
if (opts_.generate_object_based_api) {
code_ += " typedef {{NATIVE_NAME}} NativeTableType;";
}
code_ += " typedef {{STRUCT_NAME}}Builder Builder;";
if (opts_.g_cpp_std >= cpp::CPP_STD_17) { code_ += " struct Traits;"; }
if (opts_.mini_reflect != IDLOptions::kNone) {
code_ +=
" static const flatbuffers::TypeTable *MiniReflectTypeTable() {";
code_ += " return {{STRUCT_NAME}}TypeTable();";
code_ += " }";
}
GenFullyQualifiedNameGetter(struct_def, Name(struct_def));
// Generate field id constants.
if (struct_def.fields.vec.size() > 0) {
// We need to add a trailing comma to all elements except the last one as
// older versions of gcc complain about this.
code_.SetValue("SEP", "");
code_ +=
" enum FlatBuffersVTableOffset FLATBUFFERS_VTABLE_UNDERLYING_TYPE {";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) {
// Deprecated fields won't be accessible.
continue;
}
code_.SetValue("OFFSET_NAME", GenFieldOffsetName(field));
code_.SetValue("OFFSET_VALUE", NumToString(field.value.offset));
code_ += "{{SEP}} {{OFFSET_NAME}} = {{OFFSET_VALUE}}\\";
code_.SetValue("SEP", ",\n");
}
code_ += "";
code_ += " };";
}
// Generate the accessors.
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) {
// Deprecated fields won't be accessible.
continue;
}
code_.SetValue("FIELD_NAME", Name(field));
GenTableFieldGetter(field);
if (opts_.mutable_buffer) { GenTableFieldSetter(field); }
auto nfn = GetNestedFlatBufferName(field);
if (!nfn.empty()) {
code_.SetValue("CPP_NAME", nfn);
code_ += " const {{CPP_NAME}} *{{FIELD_NAME}}_nested_root() const {";
code_ +=
" return "
"flatbuffers::GetRoot<{{CPP_NAME}}>({{FIELD_NAME}}()->Data());";
code_ += " }";
}
if (field.flexbuffer) {
code_ +=
" flexbuffers::Reference {{FIELD_NAME}}_flexbuffer_root()"
" const {";
// Both Data() and size() are const-methods, therefore call order
// doesn't matter.
code_ +=
" return flexbuffers::GetRoot({{FIELD_NAME}}()->Data(), "
"{{FIELD_NAME}}()->size());";
code_ += " }";
}
// Generate a comparison function for this field if it is a key.
if (field.key) { GenKeyFieldMethods(field); }
}
if (opts_.cpp_static_reflection) { GenIndexBasedFieldGetter(struct_def); }
// 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 {";
code_ += " return VerifyTableStart(verifier)\\";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) { continue; }
GenVerifyCall(field, " &&\n ");
}
code_ += " &&\n verifier.EndTable();";
code_ += " }";
if (opts_.generate_object_based_api) {
// Generate the UnPack() pre declaration.
code_ += " " + TableUnPackSignature(struct_def, true, opts_) + ";";
code_ += " " + TableUnPackToSignature(struct_def, true, opts_) + ";";
code_ += " " + TablePackSignature(struct_def, true, opts_) + ";";
}
code_ += "};"; // End of table.
code_ += "";
// Explicit specializations for union accessors
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated || field.value.type.base_type != BASE_TYPE_UNION) {
continue;
}
auto u = field.value.type.enum_def;
if (u->uses_multiple_type_instances) continue;
code_.SetValue("FIELD_NAME", Name(field));
for (auto u_it = u->Vals().begin(); u_it != u->Vals().end(); ++u_it) {
auto &ev = **u_it;
if (ev.union_type.base_type == BASE_TYPE_NONE) { continue; }
auto full_struct_name = GetUnionElement(ev, false, opts_);
code_.SetValue(
"U_ELEMENT_TYPE",
WrapInNameSpace(u->defined_namespace, GetEnumValUse(*u, ev)));
code_.SetValue("U_FIELD_TYPE", "const " + full_struct_name + " *");
code_.SetValue("U_ELEMENT_NAME", full_struct_name);
code_.SetValue("U_FIELD_NAME", Name(field) + "_as_" + Name(ev));
// `template<> const T *union_name_as<T>() const` accessor.
code_ +=
"template<> "
"inline {{U_FIELD_TYPE}}{{STRUCT_NAME}}::{{FIELD_NAME}}_as"
"<{{U_ELEMENT_NAME}}>() const {";
code_ += " return {{U_FIELD_NAME}}();";
code_ += "}";
code_ += "";
}
}
GenBuilders(struct_def);
if (opts_.generate_object_based_api) {
// Generate a pre-declaration for a CreateX method that works with an
// unpacked C++ object.
code_ += TableCreateSignature(struct_def, true, opts_) + ";";
code_ += "";
}
}
// Generate code to force vector alignment. Return empty string for vector
// that doesn't need alignment code.
std::string GenVectorForceAlign(const FieldDef &field,
const std::string &field_size) {
FLATBUFFERS_ASSERT(IsVector(field.value.type));
// Get the value of the force_align attribute.
const auto *force_align = field.attributes.Lookup("force_align");
const int align = force_align ? atoi(force_align->constant.c_str()) : 1;
// Generate code to do force_align for the vector.
if (align > 1) {
const auto vtype = field.value.type.VectorType();
const auto type = IsStruct(vtype) ? WrapInNameSpace(*vtype.struct_def)
: GenTypeWire(vtype, "", false);
return "_fbb.ForceVectorAlignment(" + field_size + ", sizeof(" + type +
"), " + std::to_string(static_cast<long long>(align)) + ");";
}
return "";
}
void GenBuilders(const StructDef &struct_def) {
code_.SetValue("STRUCT_NAME", Name(struct_def));
// Generate a builder struct:
code_ += "struct {{STRUCT_NAME}}Builder {";
code_ += " typedef {{STRUCT_NAME}} Table;";
code_ += " flatbuffers::FlatBufferBuilder &fbb_;";
code_ += " flatbuffers::uoffset_t start_;";
bool has_string_or_vector_fields = false;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) continue;
const bool is_scalar = IsScalar(field.value.type.base_type);
const bool is_default_scalar = is_scalar && !field.IsScalarOptional();
const bool is_string = IsString(field.value.type);
const bool is_vector = IsVector(field.value.type);
if (is_string || is_vector) { has_string_or_vector_fields = true; }
std::string offset = GenFieldOffsetName(field);
std::string name = GenUnderlyingCast(field, false, Name(field));
std::string value = is_default_scalar ? GenDefaultConstant(field) : "";
// Generate accessor functions of the form:
// void add_name(type name) {
// fbb_.AddElement<type>(offset, name, default);
// }
code_.SetValue("FIELD_NAME", Name(field));
code_.SetValue("FIELD_TYPE", GenTypeWire(field.value.type, " ", true));
code_.SetValue("ADD_OFFSET", Name(struct_def) + "::" + offset);
code_.SetValue("ADD_NAME", name);
code_.SetValue("ADD_VALUE", value);
if (is_scalar) {
const auto type = GenTypeWire(field.value.type, "", false);
code_.SetValue("ADD_FN", "AddElement<" + type + ">");
} else if (IsStruct(field.value.type)) {
code_.SetValue("ADD_FN", "AddStruct");
} else {
code_.SetValue("ADD_FN", "AddOffset");
}
code_ += " void add_{{FIELD_NAME}}({{FIELD_TYPE}}{{FIELD_NAME}}) {";
code_ += " fbb_.{{ADD_FN}}(\\";
if (is_default_scalar) {
code_ += "{{ADD_OFFSET}}, {{ADD_NAME}}, {{ADD_VALUE}});";
} else {
code_ += "{{ADD_OFFSET}}, {{ADD_NAME}});";
}
code_ += " }";
}
// Builder constructor
code_ +=
" explicit {{STRUCT_NAME}}Builder(flatbuffers::FlatBufferBuilder "
"&_fbb)";
code_ += " : fbb_(_fbb) {";
code_ += " start_ = fbb_.StartTable();";
code_ += " }";
// Finish() function.
code_ += " flatbuffers::Offset<{{STRUCT_NAME}}> Finish() {";
code_ += " const auto end = fbb_.EndTable(start_);";
code_ += " auto o = flatbuffers::Offset<{{STRUCT_NAME}}>(end);";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (!field.deprecated && field.IsRequired()) {
code_.SetValue("FIELD_NAME", Name(field));
code_.SetValue("OFFSET_NAME", GenFieldOffsetName(field));
code_ += " fbb_.Required(o, {{STRUCT_NAME}}::{{OFFSET_NAME}});";
}
}
code_ += " return o;";
code_ += " }";
code_ += "};";
code_ += "";
// Generate a convenient CreateX function that uses the above builder
// to create a table in one go.
code_ +=
"inline flatbuffers::Offset<{{STRUCT_NAME}}> "
"Create{{STRUCT_NAME}}(";
code_ += " flatbuffers::FlatBufferBuilder &_fbb\\";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (!field.deprecated) { GenParam(field, false, ",\n "); }
}
code_ += ") {";
code_ += " {{STRUCT_NAME}}Builder builder_(_fbb);";
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) {
const auto &field = **it;
if (!field.deprecated && (!struct_def.sortbysize ||
size == SizeOf(field.value.type.base_type))) {
code_.SetValue("FIELD_NAME", Name(field));
if (field.IsScalarOptional()) {
code_ +=
" if({{FIELD_NAME}}) { "
"builder_.add_{{FIELD_NAME}}(*{{FIELD_NAME}}); }";
} else {
code_ += " builder_.add_{{FIELD_NAME}}({{FIELD_NAME}});";
}
}
}
}
code_ += " return builder_.Finish();";
code_ += "}";
code_ += "";
// Definition for type traits for this table type. This allows querying var-
// ious compile-time traits of the table.
if (opts_.g_cpp_std >= cpp::CPP_STD_17) { GenTraitsStruct(struct_def); }
// Generate a CreateXDirect function with vector types as parameters
if (opts_.cpp_direct_copy && has_string_or_vector_fields) {
code_ +=
"inline flatbuffers::Offset<{{STRUCT_NAME}}> "
"Create{{STRUCT_NAME}}Direct(";
code_ += " flatbuffers::FlatBufferBuilder &_fbb\\";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (!field.deprecated) { GenParam(field, true, ",\n "); }
}
// Need to call "Create" with the struct namespace.
const auto qualified_create_name =
struct_def.defined_namespace->GetFullyQualifiedName("Create");
code_.SetValue("CREATE_NAME", TranslateNameSpace(qualified_create_name));
code_ += ") {";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (!field.deprecated) {
code_.SetValue("FIELD_NAME", Name(field));
if (IsString(field.value.type)) {
if (!field.shared) {
code_.SetValue("CREATE_STRING", "CreateString");
} else {
code_.SetValue("CREATE_STRING", "CreateSharedString");
}
code_ +=
" auto {{FIELD_NAME}}__ = {{FIELD_NAME}} ? "
"_fbb.{{CREATE_STRING}}({{FIELD_NAME}}) : 0;";
} else if (IsVector(field.value.type)) {
const std::string force_align_code =
GenVectorForceAlign(field, Name(field) + "->size()");
if (!force_align_code.empty()) {
code_ += " if ({{FIELD_NAME}}) { " + force_align_code + " }";
}
code_ += " auto {{FIELD_NAME}}__ = {{FIELD_NAME}} ? \\";
const auto vtype = field.value.type.VectorType();
const auto has_key = TypeHasKey(vtype);
if (IsStruct(vtype)) {
const auto type = WrapInNameSpace(*vtype.struct_def);
code_ += (has_key ? "_fbb.CreateVectorOfSortedStructs<"
: "_fbb.CreateVectorOfStructs<") +
type + ">\\";
} else if (has_key) {
const auto type = WrapInNameSpace(*vtype.struct_def);
code_ += "_fbb.CreateVectorOfSortedTables<" + type + ">\\";
} else {
const auto type =
GenTypeWire(vtype, "", VectorElementUserFacing(vtype));
code_ += "_fbb.CreateVector<" + type + ">\\";
}
code_ +=
has_key ? "({{FIELD_NAME}}) : 0;" : "(*{{FIELD_NAME}}) : 0;";
}
}
}
code_ += " return {{CREATE_NAME}}{{STRUCT_NAME}}(";
code_ += " _fbb\\";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (!field.deprecated) {
code_.SetValue("FIELD_NAME", Name(field));
code_ += ",\n {{FIELD_NAME}}\\";
if (IsString(field.value.type) || IsVector(field.value.type)) {
code_ += "__\\";
}
}
}
code_ += ");";
code_ += "}";
code_ += "";
}
}
std::string GenUnionUnpackVal(const FieldDef &afield,
const char *vec_elem_access,
const char *vec_type_access) {
auto type_name = WrapInNameSpace(*afield.value.type.enum_def);
return type_name + "Union::UnPack(" + "_e" + vec_elem_access + ", " +
EscapeKeyword(afield.name + UnionTypeFieldSuffix()) + "()" +
vec_type_access + ", _resolver)";
}
std::string GenUnpackVal(const Type &type, const std::string &val,
bool invector, const FieldDef &afield) {
switch (type.base_type) {
case BASE_TYPE_STRING: {
if (FlexibleStringConstructor(&afield)) {
return NativeString(&afield) + "(" + val + "->c_str(), " + val +
"->size())";
} else {
return val + "->str()";
}
}
case BASE_TYPE_STRUCT: {
if (IsStruct(type)) {
const auto &struct_attrs = type.struct_def->attributes;
const auto native_type = struct_attrs.Lookup("native_type");
if (native_type) {
std::string unpack_call = "flatbuffers::UnPack";
const auto pack_name = struct_attrs.Lookup("native_type_pack_name");
if (pack_name) { unpack_call += pack_name->constant; }
unpack_call += "(*" + val + ")";
return unpack_call;
} else if (invector || afield.native_inline) {
return "*" + val;
} else {
const auto name = WrapInNameSpace(*type.struct_def);
const auto ptype = GenTypeNativePtr(name, &afield, true);
return ptype + "(new " + name + "(*" + val + "))";
}
} else {
const auto ptype = GenTypeNativePtr(
WrapNativeNameInNameSpace(*type.struct_def, opts_), &afield,
true);
return ptype + "(" + val + "->UnPack(_resolver))";
}
}
case BASE_TYPE_UNION: {
return GenUnionUnpackVal(
afield, invector ? "->Get(_i)" : "",
invector ? ("->GetEnum<" + type.enum_def->name + ">(_i)").c_str()
: "");
}
default: {
return val;
break;
}
}
}
std::string GenUnpackFieldStatement(const FieldDef &field,
const FieldDef *union_field) {
std::string code;
switch (field.value.type.base_type) {
case BASE_TYPE_VECTOR: {
auto name = Name(field);
if (field.value.type.element == BASE_TYPE_UTYPE) {
name = StripUnionType(Name(field));
}
code += "{ _o->" + name + ".resize(_e->size()); ";
if (!field.value.type.enum_def && !IsBool(field.value.type.element) &&
IsOneByte(field.value.type.element)) {
// For vectors of bytes, std::copy is used to improve performance.
// This doesn't work for:
// - enum types because they have to be explicitly static_cast.
// - vectors of bool, since they are a template specialization.
// - multiple-byte types due to endianness.
code +=
"std::copy(_e->begin(), _e->end(), _o->" + name + ".begin()); }";
} else {
std::string indexing;
if (field.value.type.enum_def) {
indexing += "static_cast<" +
WrapInNameSpace(*field.value.type.enum_def) + ">(";
}
indexing += "_e->Get(_i)";
if (field.value.type.enum_def) { indexing += ")"; }
if (field.value.type.element == BASE_TYPE_BOOL) {
indexing += " != 0";
}
// Generate code that pushes data from _e to _o in the form:
// for (uoffset_t i = 0; i < _e->size(); ++i) {
// _o->field.push_back(_e->Get(_i));
// }
auto access =
field.value.type.element == BASE_TYPE_UTYPE
? ".type"
: (field.value.type.element == BASE_TYPE_UNION ? ".value"
: "");
code += "for (flatbuffers::uoffset_t _i = 0;";
code += " _i < _e->size(); _i++) { ";
auto cpp_type = field.attributes.Lookup("cpp_type");
if (cpp_type) {
// Generate code that resolves the cpp pointer type, of the form:
// if (resolver)
// (*resolver)(&_o->field, (hash_value_t)(_e));
// else
// _o->field = nullptr;
code += "//vector resolver, " + PtrType(&field) + "\n";
code += "if (_resolver) ";
code += "(*_resolver)";
code += "(reinterpret_cast<void **>(&_o->" + name + "[_i]" +
access + "), ";
code +=
"static_cast<flatbuffers::hash_value_t>(" + indexing + "));";
if (PtrType(&field) == "naked") {
code += " else ";
code += "_o->" + name + "[_i]" + access + " = nullptr";
} else {
// code += " else ";
// code += "_o->" + name + "[_i]" + access + " = " +
// GenTypeNativePtr(cpp_type->constant, &field, true) + "();";
code += "/* else do nothing */";
}
} else {
// clang-format off
#if FLATBUFFERS_CPP_OBJECT_UNPACKTO
const bool is_pointer =
field.value.type.VectorType().base_type == BASE_TYPE_STRUCT &&
!IsStruct(field.value.type.VectorType());
if (is_pointer) {
code += "if(_o->" + name + "[_i]" + ") { ";
code += indexing + "->UnPackTo(_o->" + name +
"[_i].get(), _resolver);";
code += " } else { ";
}
#endif
code += "_o->" + name + "[_i]" + access + " = ";
code += GenUnpackVal(field.value.type.VectorType(), indexing, true,
field);
#if FLATBUFFERS_CPP_OBJECT_UNPACKTO
if (is_pointer) { code += "; }"; }
#endif
// clang-format on
}
code += "; } }";
}
break;
}
case BASE_TYPE_UTYPE: {
FLATBUFFERS_ASSERT(union_field->value.type.base_type ==
BASE_TYPE_UNION);
// Generate code that sets the union type, of the form:
// _o->field.type = _e;
code += "_o->" + union_field->name + ".type = _e;";
break;
}
case BASE_TYPE_UNION: {
// Generate code that sets the union value, of the form:
// _o->field.value = Union::Unpack(_e, field_type(), resolver);
code += "_o->" + Name(field) + ".value = ";
code += GenUnionUnpackVal(field, "", "");
code += ";";
break;
}
default: {
auto cpp_type = field.attributes.Lookup("cpp_type");
if (cpp_type) {
// Generate code that resolves the cpp pointer type, of the form:
// if (resolver)
// (*resolver)(&_o->field, (hash_value_t)(_e));
// else
// _o->field = nullptr;
code += "//scalar resolver, " + PtrType(&field) + " \n";
code += "if (_resolver) ";
code += "(*_resolver)";
code += "(reinterpret_cast<void **>(&_o->" + Name(field) + "), ";
code += "static_cast<flatbuffers::hash_value_t>(_e));";
if (PtrType(&field) == "naked") {
code += " else ";
code += "_o->" + Name(field) + " = nullptr;";
} else {
// code += " else ";
// code += "_o->" + Name(field) + " = " +
// GenTypeNativePtr(cpp_type->constant, &field, true) + "();";
code += "/* else do nothing */;";
}
} else {
// Generate code for assigning the value, of the form:
// _o->field = value;
// clang-format off
#if FLATBUFFERS_CPP_OBJECT_UNPACKTO
const bool is_pointer =
field.value.type.base_type == BASE_TYPE_STRUCT &&
!IsStruct(field.value.type);
if (is_pointer) {
code += "{ if(_o->" + Name(field) + ") { ";
code += "_e->UnPackTo(_o->" + Name(field) + ".get(), _resolver);";
code += " } else { ";
}
#endif
code += "_o->" + Name(field) + " = ";
code += GenUnpackVal(field.value.type, "_e", false, field) + ";";
#if FLATBUFFERS_CPP_OBJECT_UNPACKTO
if (is_pointer) { code += " } }"; }
#endif
// clang-format on
}
break;
}
}
return code;
}
std::string GenCreateParam(const FieldDef &field) {
std::string value = "_o->";
if (field.value.type.base_type == BASE_TYPE_UTYPE) {
value += StripUnionType(Name(field));
value += ".type";
} else {
value += Name(field);
}
if (field.value.type.base_type != BASE_TYPE_VECTOR &&
field.attributes.Lookup("cpp_type")) {
auto type = GenTypeBasic(field.value.type, false);
value =
"_rehasher ? "
"static_cast<" +
type + ">((*_rehasher)(" + value + GenPtrGet(field) + ")) : 0";
}
std::string code;
switch (field.value.type.base_type) {
// String fields are of the form:
// _fbb.CreateString(_o->field)
// or
// _fbb.CreateSharedString(_o->field)
case BASE_TYPE_STRING: {
if (!field.shared) {
code += "_fbb.CreateString(";
} else {
code += "_fbb.CreateSharedString(";
}
code += value;
code.push_back(')');
// For optional fields, check to see if there actually is any data
// in _o->field before attempting to access it. If there isn't,
// depending on set_empty_strings_to_null either set it to 0 or an empty
// string.
if (!field.IsRequired()) {
auto empty_value = opts_.set_empty_strings_to_null
? "0"
: "_fbb.CreateSharedString(\"\")";
code = value + ".empty() ? " + empty_value + " : " + code;
}
break;
}
// Vector fields come in several flavours, of the forms:
// _fbb.CreateVector(_o->field);
// _fbb.CreateVector((const utype*)_o->field.data(),
// _o->field.size()); _fbb.CreateVectorOfStrings(_o->field)
// _fbb.CreateVectorOfStructs(_o->field)
// _fbb.CreateVector<Offset<T>>(_o->field.size() [&](size_t i) {
// return CreateT(_fbb, _o->Get(i), rehasher);
// });
case BASE_TYPE_VECTOR: {
auto vector_type = field.value.type.VectorType();
switch (vector_type.base_type) {
case BASE_TYPE_STRING: {
if (NativeString(&field) == "std::string") {
code += "_fbb.CreateVectorOfStrings(" + value + ")";
} else {
// Use by-function serialization to emulate
// CreateVectorOfStrings(); this works also with non-std strings.
code +=
"_fbb.CreateVector<flatbuffers::Offset<flatbuffers::String>>"
" ";
code += "(" + value + ".size(), ";
code += "[](size_t i, _VectorArgs *__va) { ";
code +=
"return __va->__fbb->CreateString(__va->_" + value + "[i]);";
code += " }, &_va )";
}
break;
}
case BASE_TYPE_STRUCT: {
if (IsStruct(vector_type)) {
const auto &struct_attrs =
field.value.type.struct_def->attributes;
const auto native_type = struct_attrs.Lookup("native_type");
if (native_type) {
code += "_fbb.CreateVectorOfNativeStructs<";
code += WrapInNameSpace(*vector_type.struct_def) + ", " +
native_type->constant + ">";
code += "(" + value;
const auto pack_name =
struct_attrs.Lookup("native_type_pack_name");
if (pack_name) {
code += ", flatbuffers::Pack" + pack_name->constant;
}
code += ")";
} else {
code += "_fbb.CreateVectorOfStructs";
code += "(" + value + ")";
}
} else {
code += "_fbb.CreateVector<flatbuffers::Offset<";
code += WrapInNameSpace(*vector_type.struct_def) + ">> ";
code += "(" + value + ".size(), ";
code += "[](size_t i, _VectorArgs *__va) { ";
code += "return Create" + vector_type.struct_def->name;
code += "(*__va->__fbb, __va->_" + value + "[i]" +
GenPtrGet(field) + ", ";
code += "__va->__rehasher); }, &_va )";
}
break;
}
case BASE_TYPE_BOOL: {
code += "_fbb.CreateVector(" + value + ")";
break;
}
case BASE_TYPE_UNION: {
code +=
"_fbb.CreateVector<flatbuffers::"
"Offset<void>>(" +
value +
".size(), [](size_t i, _VectorArgs *__va) { "
"return __va->_" +
value + "[i].Pack(*__va->__fbb, __va->__rehasher); }, &_va)";
break;
}
case BASE_TYPE_UTYPE: {
value = StripUnionType(value);
auto type = opts_.scoped_enums ? Name(*field.value.type.enum_def)
: "uint8_t";
auto enum_value = "__va->_" + value + "[i].type";
if (!opts_.scoped_enums)
enum_value = "static_cast<uint8_t>(" + enum_value + ")";
code += "_fbb.CreateVector<" + type + ">(" + value +
".size(), [](size_t i, _VectorArgs *__va) { return " +
enum_value + "; }, &_va)";
break;
}
default: {
if (field.value.type.enum_def &&
!VectorElementUserFacing(vector_type)) {
// For enumerations, we need to get access to the array data for
// the underlying storage type (eg. uint8_t).
const auto basetype = GenTypeBasic(
field.value.type.enum_def->underlying_type, false);
code += "_fbb.CreateVectorScalarCast<" + basetype +
">(flatbuffers::data(" + value + "), " + value +
".size())";
} else if (field.attributes.Lookup("cpp_type")) {
auto type = GenTypeBasic(vector_type, false);
code += "_fbb.CreateVector<" + type + ">(" + value + ".size(), ";
code += "[](size_t i, _VectorArgs *__va) { ";
code += "return __va->__rehasher ? ";
code += "static_cast<" + type + ">((*__va->__rehasher)";
code += "(__va->_" + value + "[i]" + GenPtrGet(field) + ")) : 0";
code += "; }, &_va )";
} else {
code += "_fbb.CreateVector(" + value + ")";
}
break;
}
}
// If set_empty_vectors_to_null option is enabled, for optional fields,
// check to see if there actually is any data in _o->field before
// attempting to access it.
if (field.attributes.Lookup("nested_flatbuffer") ||
(opts_.set_empty_vectors_to_null && !field.IsRequired())) {
code = value + ".size() ? " + code + " : 0";
}
break;
}
case BASE_TYPE_UNION: {
// _o->field.Pack(_fbb);
code += value + ".Pack(_fbb)";
break;
}
case BASE_TYPE_STRUCT: {
if (IsStruct(field.value.type)) {
const auto &struct_attribs = field.value.type.struct_def->attributes;
const auto native_type = struct_attribs.Lookup("native_type");
if (native_type) {
code += "flatbuffers::Pack";
const auto pack_name =
struct_attribs.Lookup("native_type_pack_name");
if (pack_name) { code += pack_name->constant; }
code += "(" + value + ")";
} else if (field.native_inline) {
code += "&" + value;
} else {
code += value + " ? " + value + GenPtrGet(field) + " : nullptr";
}
} else {
// _o->field ? CreateT(_fbb, _o->field.get(), _rehasher);
const auto type = field.value.type.struct_def->name;
code += value + " ? Create" + type;
code += "(_fbb, " + value + GenPtrGet(field) + ", _rehasher)";
code += " : 0";
}
break;
}
default: {
code += value;
break;
}
}
return code;
}
// Generate code for tables that needs to come after the regular definition.
void GenTablePost(const StructDef &struct_def) {
if (opts_.generate_object_based_api) { GenNativeTablePost(struct_def); }
code_.SetValue("STRUCT_NAME", Name(struct_def));
code_.SetValue("NATIVE_NAME",
NativeName(Name(struct_def), &struct_def, opts_));
if (opts_.generate_object_based_api) {
// Generate the >= C++11 copy ctor and assignment operator definitions.
GenCopyCtorAssignOpDefs(struct_def);
// Generate the X::UnPack() method.
code_ +=
"inline " + TableUnPackSignature(struct_def, false, opts_) + " {";
if (opts_.g_cpp_std == cpp::CPP_STD_X0) {
auto native_name = WrapNativeNameInNameSpace(struct_def, parser_.opts);
code_.SetValue("POINTER_TYPE",
GenTypeNativePtr(native_name, nullptr, false));
code_ +=
" {{POINTER_TYPE}} _o = {{POINTER_TYPE}}(new {{NATIVE_NAME}}());";
} else if (opts_.g_cpp_std == cpp::CPP_STD_11) {
code_ +=
" auto _o = std::unique_ptr<{{NATIVE_NAME}}>(new "
"{{NATIVE_NAME}}());";
} else {
code_ += " auto _o = std::make_unique<{{NATIVE_NAME}}>();";
}
code_ += " UnPackTo(_o.get(), _resolver);";
code_ += " return _o.release();";
code_ += "}";
code_ += "";
code_ +=
"inline " + TableUnPackToSignature(struct_def, false, opts_) + " {";
code_ += " (void)_o;";
code_ += " (void)_resolver;";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.deprecated) { continue; }
// Assign a value from |this| to |_o|. Values from |this| are stored
// in a variable |_e| by calling this->field_type(). The value is then
// assigned to |_o| using the GenUnpackFieldStatement.
const bool is_union = field.value.type.base_type == BASE_TYPE_UTYPE;
const auto statement =
GenUnpackFieldStatement(field, is_union ? *(it + 1) : nullptr);
code_.SetValue("FIELD_NAME", Name(field));
auto prefix = " { auto _e = {{FIELD_NAME}}(); ";
auto check = IsScalar(field.value.type.base_type) ? "" : "if (_e) ";
auto postfix = " }";
code_ += std::string(prefix) + check + statement + postfix;
}
code_ += "}";
code_ += "";
// Generate the X::Pack member function that simply calls the global
// CreateX function.
code_ += "inline " + TablePackSignature(struct_def, false, opts_) + " {";
code_ += " return Create{{STRUCT_NAME}}(_fbb, _o, _rehasher);";
code_ += "}";
code_ += "";
// Generate a CreateX method that works with an unpacked C++ object.
code_ +=
"inline " + TableCreateSignature(struct_def, false, opts_) + " {";
code_ += " (void)_rehasher;";
code_ += " (void)_o;";
code_ +=
" struct _VectorArgs "
"{ flatbuffers::FlatBufferBuilder *__fbb; "
"const " +
NativeName(Name(struct_def), &struct_def, opts_) +
"* __o; "
"const flatbuffers::rehasher_function_t *__rehasher; } _va = { "
"&_fbb, _o, _rehasher}; (void)_va;";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
auto &field = **it;
if (field.deprecated) { continue; }
if (IsVector(field.value.type)) {
const std::string force_align_code =
GenVectorForceAlign(field, "_o->" + Name(field) + ".size()");
if (!force_align_code.empty()) { code_ += " " + force_align_code; }
}
code_ += " auto _" + Name(field) + " = " + GenCreateParam(field) + ";";
}
// Need to call "Create" with the struct namespace.
const auto qualified_create_name =
struct_def.defined_namespace->GetFullyQualifiedName("Create");
code_.SetValue("CREATE_NAME", TranslateNameSpace(qualified_create_name));
code_ += " return {{CREATE_NAME}}{{STRUCT_NAME}}(";
code_ += " _fbb\\";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
auto &field = **it;
if (field.deprecated) { continue; }
bool pass_by_address = false;
if (field.value.type.base_type == BASE_TYPE_STRUCT) {
if (IsStruct(field.value.type)) {
auto native_type =
field.value.type.struct_def->attributes.Lookup("native_type");
if (native_type) { pass_by_address = true; }
}
}
// Call the CreateX function using values from |_o|.
if (pass_by_address) {
code_ += ",\n &_" + Name(field) + "\\";
} else {
code_ += ",\n _" + Name(field) + "\\";
}
}
code_ += ");";
code_ += "}";
code_ += "";
}
}
static void GenPadding(
const FieldDef &field, std::string *code_ptr, int *id,
const std::function<void(int bits, std::string *code_ptr, int *id)> &f) {
if (field.padding) {
for (int i = 0; i < 4; i++) {
if (static_cast<int>(field.padding) & (1 << i)) {
f((1 << i) * 8, code_ptr, id);
}
}
FLATBUFFERS_ASSERT(!(field.padding & ~0xF));
}
}
static void PaddingDefinition(int bits, std::string *code_ptr, int *id) {
*code_ptr += " int" + NumToString(bits) + "_t padding" +
NumToString((*id)++) + "__;";
}
static void PaddingInitializer(int bits, std::string *code_ptr, int *id) {
(void)bits;
if (!code_ptr->empty()) *code_ptr += ",\n ";
*code_ptr += "padding" + NumToString((*id)++) + "__(0)";
}
static void PaddingNoop(int bits, std::string *code_ptr, int *id) {
(void)bits;
if (!code_ptr->empty()) *code_ptr += '\n';
*code_ptr += " (void)padding" + NumToString((*id)++) + "__;";
}
void GenStructDefaultConstructor(const StructDef &struct_def) {
std::string init_list;
std::string body;
bool first_in_init_list = true;
int padding_initializer_id = 0;
int padding_body_id = 0;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto field = *it;
const auto field_name = Name(*field) + "_";
if (first_in_init_list) {
first_in_init_list = false;
} else {
init_list += ",";
init_list += "\n ";
}
init_list += field_name;
if (IsStruct(field->value.type) || IsArray(field->value.type)) {
// this is either default initialization of struct
// or
// implicit initialization of array
// for each object in array it:
// * sets it as zeros for POD types (integral, floating point, etc)
// * calls default constructor for classes/structs
init_list += "()";
} else {
init_list += "(0)";
}
if (field->padding) {
GenPadding(*field, &init_list, &padding_initializer_id,
PaddingInitializer);
GenPadding(*field, &body, &padding_body_id, PaddingNoop);
}
}
if (init_list.empty()) {
code_ += " {{STRUCT_NAME}}()";
code_ += " {}";
} else {
code_.SetValue("INIT_LIST", init_list);
code_ += " {{STRUCT_NAME}}()";
code_ += " : {{INIT_LIST}} {";
if (!body.empty()) { code_ += body; }
code_ += " }";
}
}
void GenStructConstructor(const StructDef &struct_def,
GenArrayArgMode array_mode) {
std::string arg_list;
std::string init_list;
int padding_id = 0;
auto first = struct_def.fields.vec.begin();
// skip arrays if generate ctor without array assignment
const auto init_arrays = (array_mode != kArrayArgModeNone);
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto &type = field.value.type;
const auto is_array = IsArray(type);
const auto arg_name = "_" + Name(field);
if (!is_array || init_arrays) {
if (it != first && !arg_list.empty()) { arg_list += ", "; }
arg_list += !is_array ? GenTypeGet(type, " ", "const ", " &", true)
: GenTypeSpan(type, true, type.fixed_length);
arg_list += arg_name;
}
// skip an array with initialization from span
if (false == (is_array && init_arrays)) {
if (it != first && !init_list.empty()) { init_list += ",\n "; }
init_list += Name(field) + "_";
if (IsScalar(type.base_type)) {
auto scalar_type = GenUnderlyingCast(field, false, arg_name);
init_list += "(flatbuffers::EndianScalar(" + scalar_type + "))";
} else {
FLATBUFFERS_ASSERT((is_array && !init_arrays) || IsStruct(type));
if (!is_array)
init_list += "(" + arg_name + ")";
else
init_list += "()";
}
}
if (field.padding)
GenPadding(field, &init_list, &padding_id, PaddingInitializer);
}
if (!arg_list.empty()) {
code_.SetValue("ARG_LIST", arg_list);
code_.SetValue("INIT_LIST", init_list);
if (!init_list.empty()) {
code_ += " {{STRUCT_NAME}}({{ARG_LIST}})";
code_ += " : {{INIT_LIST}} {";
} else {
code_ += " {{STRUCT_NAME}}({{ARG_LIST}}) {";
}
padding_id = 0;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto &type = field.value.type;
if (IsArray(type) && init_arrays) {
const auto &element_type = type.VectorType();
const auto is_enum = IsEnum(element_type);
FLATBUFFERS_ASSERT(
(IsScalar(element_type.base_type) || IsStruct(element_type)) &&
"invalid declaration");
const auto face_type = GenTypeGet(type, " ", "", "", is_enum);
std::string get_array =
is_enum ? "CastToArrayOfEnum<" + face_type + ">" : "CastToArray";
const auto field_name = Name(field) + "_";
const auto arg_name = "_" + Name(field);
code_ += " flatbuffers::" + get_array + "(" + field_name +
").CopyFromSpan(" + arg_name + ");";
}
if (field.padding) {
std::string padding;
GenPadding(field, &padding, &padding_id, PaddingNoop);
code_ += padding;
}
}
code_ += " }";
}
}
void GenArrayAccessor(const Type &type, bool mutable_accessor) {
FLATBUFFERS_ASSERT(IsArray(type));
const auto is_enum = IsEnum(type.VectorType());
// The Array<bool,N> is a tricky case, like std::vector<bool>.
// It requires a specialization of Array class.
// Generate Array<uint8_t> for Array<bool>.
const auto face_type = GenTypeGet(type, " ", "", "", is_enum);
std::string ret_type = "flatbuffers::Array<" + face_type + ", " +
NumToString(type.fixed_length) + ">";
if (mutable_accessor)
code_ += " " + ret_type + " *mutable_{{FIELD_NAME}}() {";
else
code_ += " const " + ret_type + " *{{FIELD_NAME}}() const {";
std::string get_array =
is_enum ? "CastToArrayOfEnum<" + face_type + ">" : "CastToArray";
code_ += " return &flatbuffers::" + get_array + "({{FIELD_VALUE}});";
code_ += " }";
}
// Generate an accessor struct with constructor for a flatbuffers struct.
void GenStruct(const StructDef &struct_def) {
// Generate an accessor struct, with private variables of the form:
// type name_;
// Generates manual padding and alignment.
// Variables are private because they contain little endian data on all
// platforms.
GenComment(struct_def.doc_comment);
code_.SetValue("ALIGN", NumToString(struct_def.minalign));
code_.SetValue("STRUCT_NAME", Name(struct_def));
code_ +=
"FLATBUFFERS_MANUALLY_ALIGNED_STRUCT({{ALIGN}}) "
"{{STRUCT_NAME}} FLATBUFFERS_FINAL_CLASS {";
code_ += " private:";
int padding_id = 0;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto &field_type = field.value.type;
code_.SetValue("FIELD_TYPE", GenTypeGet(field_type, " ", "", " ", false));
code_.SetValue("FIELD_NAME", Name(field));
code_.SetValue("ARRAY",
IsArray(field_type)
? "[" + NumToString(field_type.fixed_length) + "]"
: "");
code_ += (" {{FIELD_TYPE}}{{FIELD_NAME}}_{{ARRAY}};");
if (field.padding) {
std::string padding;
GenPadding(field, &padding, &padding_id, PaddingDefinition);
code_ += padding;
}
}
// Generate GetFullyQualifiedName
code_ += "";
code_ += " public:";
if (opts_.g_cpp_std >= cpp::CPP_STD_17) { code_ += " struct Traits;"; }
// Make TypeTable accessible via the generated struct.
if (opts_.mini_reflect != IDLOptions::kNone) {
code_ +=
" static const flatbuffers::TypeTable *MiniReflectTypeTable() {";
code_ += " return {{STRUCT_NAME}}TypeTable();";
code_ += " }";
}
GenFullyQualifiedNameGetter(struct_def, Name(struct_def));
// Generate a default constructor.
GenStructDefaultConstructor(struct_def);
// Generate a constructor that takes all fields as arguments,
// excluding arrays.
GenStructConstructor(struct_def, kArrayArgModeNone);
auto arrays_num = std::count_if(struct_def.fields.vec.begin(),
struct_def.fields.vec.end(),
[](const flatbuffers::FieldDef *fd) {
return IsArray(fd->value.type);
});
if (arrays_num > 0) {
GenStructConstructor(struct_def, kArrayArgModeSpanStatic);
}
// Generate accessor methods of the form:
// type name() const { return flatbuffers::EndianScalar(name_); }
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
const auto &type = field.value.type;
const auto is_scalar = IsScalar(type.base_type);
const auto is_array = IsArray(type);
const auto field_type = GenTypeGet(type, " ", is_array ? "" : "const ",
is_array ? "" : " &", true);
auto member = Name(field) + "_";
auto value =
is_scalar ? "flatbuffers::EndianScalar(" + member + ")" : member;
code_.SetValue("FIELD_NAME", Name(field));
code_.SetValue("FIELD_TYPE", field_type);
code_.SetValue("FIELD_VALUE", GenUnderlyingCast(field, true, value));
GenComment(field.doc_comment, " ");
// Generate a const accessor function.
if (is_array) {
GenArrayAccessor(type, false);
} else {
code_ += " {{FIELD_TYPE}}{{FIELD_NAME}}() const {";
code_ += " return {{FIELD_VALUE}};";
code_ += " }";
}
// Generate a mutable accessor function.
if (opts_.mutable_buffer) {
auto mut_field_type =
GenTypeGet(type, " ", "", is_array ? "" : " &", true);
code_.SetValue("FIELD_TYPE", mut_field_type);
if (is_scalar) {
code_.SetValue("ARG", GenTypeBasic(type, true));
code_.SetValue("FIELD_VALUE",
GenUnderlyingCast(field, false, "_" + Name(field)));
code_ += " void mutate_{{FIELD_NAME}}({{ARG}} _{{FIELD_NAME}}) {";
code_ +=
" flatbuffers::WriteScalar(&{{FIELD_NAME}}_, "
"{{FIELD_VALUE}});";
code_ += " }";
} else if (is_array) {
GenArrayAccessor(type, true);
} else {
code_ += " {{FIELD_TYPE}}mutable_{{FIELD_NAME}}() {";
code_ += " return {{FIELD_VALUE}};";
code_ += " }";
}
}
// Generate a comparison function for this field if it is a key.
if (field.key) { GenKeyFieldMethods(field); }
}
code_.SetValue("NATIVE_NAME", Name(struct_def));
GenOperatorNewDelete(struct_def);
if (opts_.cpp_static_reflection) { GenIndexBasedFieldGetter(struct_def); }
code_ += "};";
code_.SetValue("STRUCT_BYTE_SIZE", NumToString(struct_def.bytesize));
code_ += "FLATBUFFERS_STRUCT_END({{STRUCT_NAME}}, {{STRUCT_BYTE_SIZE}});";
if (opts_.gen_compare) GenCompareOperator(struct_def, "()");
code_ += "";
// Definition for type traits for this table type. This allows querying var-
// ious compile-time traits of the table.
if (opts_.g_cpp_std >= cpp::CPP_STD_17) { GenTraitsStruct(struct_def); }
}
// Set up the correct namespace. Only open a namespace if the existing one is
// different (closing/opening only what is necessary).
//
// The file must start and end with an empty (or null) namespace so that
// namespaces are properly opened and closed.
void SetNameSpace(const Namespace *ns) {
if (cur_name_space_ == ns) { return; }
// Compute the size of the longest common namespace prefix.
// If cur_name_space is A::B::C::D and ns is A::B::E::F::G,
// the common prefix is A::B:: and we have old_size = 4, new_size = 5
// and common_prefix_size = 2
size_t old_size = cur_name_space_ ? cur_name_space_->components.size() : 0;
size_t new_size = ns ? ns->components.size() : 0;
size_t common_prefix_size = 0;
while (common_prefix_size < old_size && common_prefix_size < new_size &&
ns->components[common_prefix_size] ==
cur_name_space_->components[common_prefix_size]) {
common_prefix_size++;
}
// Close cur_name_space in reverse order to reach the common prefix.
// In the previous example, D then C are closed.
for (size_t j = old_size; j > common_prefix_size; --j) {
code_ += "} // namespace " + cur_name_space_->components[j - 1];
}
if (old_size != common_prefix_size) { code_ += ""; }
// open namespace parts to reach the ns namespace
// in the previous example, E, then F, then G are opened
for (auto j = common_prefix_size; j != new_size; ++j) {
code_ += "namespace " + ns->components[j] + " {";
}
if (new_size != common_prefix_size) { code_ += ""; }
cur_name_space_ = ns;
}
};
} // namespace cpp
bool GenerateCPP(const Parser &parser, const std::string &path,
const std::string &file_name) {
cpp::IDLOptionsCpp opts(parser.opts);
// The '--cpp_std' argument could be extended (like ASAN):
// Example: "flatc --cpp_std c++17:option1:option2".
auto cpp_std = !opts.cpp_std.empty() ? opts.cpp_std : "C++11";
std::transform(cpp_std.begin(), cpp_std.end(), cpp_std.begin(), CharToUpper);
if (cpp_std == "C++0X") {
opts.g_cpp_std = cpp::CPP_STD_X0;
opts.g_only_fixed_enums = false;
} else if (cpp_std == "C++11") {
// Use the standard C++11 code generator.
opts.g_cpp_std = cpp::CPP_STD_11;
opts.g_only_fixed_enums = true;
} else if (cpp_std == "C++17") {
opts.g_cpp_std = cpp::CPP_STD_17;
// With c++17 generate strong enums only.
opts.scoped_enums = true;
// By default, prefixed_enums==true, reset it.
opts.prefixed_enums = false;
} else {
LogCompilerError("Unknown value of the '--cpp-std' switch: " +
opts.cpp_std);
return false;
}
// The opts.scoped_enums has priority.
opts.g_only_fixed_enums |= opts.scoped_enums;
if (opts.cpp_static_reflection && opts.g_cpp_std < cpp::CPP_STD_17) {
LogCompilerError(
"--cpp-static-reflection requires using --cpp-std at \"C++17\" or "
"higher.");
return false;
}
cpp::CppGenerator generator(parser, path, file_name, opts);
return generator.generate();
}
std::string CPPMakeRule(const Parser &parser, const std::string &path,
const std::string &file_name) {
const auto filebase =
flatbuffers::StripPath(flatbuffers::StripExtension(file_name));
cpp::CppGenerator geneartor(parser, path, file_name, parser.opts);
const auto included_files = parser.GetIncludedFilesRecursive(file_name);
std::string make_rule =
geneartor.GeneratedFileName(path, filebase, parser.opts) + ": ";
for (auto it = included_files.begin(); it != included_files.end(); ++it) {
make_rule += " " + *it;
}
return make_rule;
}
} // namespace flatbuffers