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fuchsia / third_party / flatbuffers / 34aea4361f829d3e4f1e4d50324e155ad4adec67 / . / src / idl_gen_cpp.cpp
blob: 623ada2f199f20125a297cc0fa9f5111a6475f1d [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 "flatbuffers/flatbuffers.h"
#include "flatbuffers/idl.h"
#include "flatbuffers/util.h"
#include "flatbuffers/code_generators.h"
namespace flatbuffers {
// Pedantic warning free version of toupper().
inline char ToUpper(char c) {
return static_cast<char>(::toupper(c));
}
static std::string GeneratedFileName(const std::string &path,
const std::string &file_name) {
return path + file_name + "_generated.h";
}
namespace cpp {
class CppGenerator : public BaseGenerator {
public:
CppGenerator(const Parser &parser, const std::string &path,
const std::string &file_name)
: BaseGenerator(parser, path, file_name, "", "::"),
cur_name_space_(nullptr) {
const char *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);
}
std::string GenIncludeGuard() const {
// Generate include guard.
std::string guard = file_name_;
// Remove any non-alpha-numeric characters that may appear in a filename.
struct IsAlnum {
bool operator()(char c) { return !isalnum(c); }
};
guard.erase(std::remove_if(guard.begin(), guard.end(), IsAlnum()),
guard.end());
guard = "FLATBUFFERS_GENERATED_" + guard;
guard += "_";
// For further uniqueness, also add the namespace.
auto name_space = parser_.current_namespace_;
for (auto it = name_space->components.begin();
it != name_space->components.end(); ++it) {
guard += *it + "_";
}
guard += "H_";
std::transform(guard.begin(), guard.end(), guard.begin(), ToUpper);
return guard;
}
void GenIncludeDependencies() {
int num_includes = 0;
for (auto it = parser_.native_included_files_.begin();
it != parser_.native_included_files_.end(); ++it) {
code_ += "#include \"" + *it + "\"";
num_includes++;
}
for (auto it = parser_.included_files_.begin();
it != parser_.included_files_.end(); ++it) {
if (it->second.empty())
continue;
auto noext = flatbuffers::StripExtension(it->second);
auto basename = flatbuffers::StripPath(noext);
code_ += "#include \"" + parser_.opts.include_prefix +
(parser_.opts.keep_include_path ? noext : basename) +
"_generated.h\"";
num_includes++;
}
if (num_includes) code_ += "";
}
std::string EscapeKeyword(const std::string &name) const {
return keywords_.find(name) == keywords_.end() ? name : name + "_";
}
std::string Name(const Definition &def) const {
return EscapeKeyword(def.name);
}
std::string Name(const EnumVal &ev) const {
return EscapeKeyword(ev.name);
}
// Iterate through all definitions we haven't generate code for (enums,
// structs, and tables) and output them to a single file.
bool generate() {
code_.Clear();
code_ += "// " + std::string(FlatBuffersGeneratedWarning()) + "\n\n";
const auto include_guard = GenIncludeGuard();
code_ += "#ifndef " + include_guard;
code_ += "#define " + include_guard;
code_ += "";
if (parser_.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_ += "";
if (parser_.opts.include_dependence_headers) {
GenIncludeDependencies();
}
assert(!cur_name_space_);
// Generate forward declarations for all structs/tables, since they may
// have circular references.
for (auto it = parser_.structs_.vec.begin();
it != parser_.structs_.vec.end(); ++it) {
const auto &struct_def = **it;
if (!struct_def.generated) {
SetNameSpace(struct_def.defined_namespace);
code_ += "struct " + Name(struct_def) + ";";
if (parser_.opts.generate_object_based_api && !struct_def.fixed) {
code_ += "struct " +
NativeName(Name(struct_def), &struct_def, parser_.opts) +
";";
}
code_ += "";
}
}
// Generate code for all the enum declarations.
for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();
++it) {
const auto &enum_def = **it;
if (!enum_def.generated) {
SetNameSpace(enum_def.defined_namespace);
GenEnum(enum_def);
}
}
// Generate code for all structs, then all tables.
for (auto it = parser_.structs_.vec.begin();
it != parser_.structs_.vec.end(); ++it) {
const auto &struct_def = **it;
if (struct_def.fixed && !struct_def.generated) {
SetNameSpace(struct_def.defined_namespace);
GenStruct(struct_def);
}
}
for (auto it = parser_.structs_.vec.begin();
it != parser_.structs_.vec.end(); ++it) {
const auto &struct_def = **it;
if (!struct_def.fixed && !struct_def.generated) {
SetNameSpace(struct_def.defined_namespace);
GenTable(struct_def);
}
}
for (auto it = parser_.structs_.vec.begin();
it != parser_.structs_.vec.end(); ++it) {
const auto &struct_def = **it;
if (!struct_def.fixed && !struct_def.generated) {
SetNameSpace(struct_def.defined_namespace);
GenTablePost(struct_def);
}
}
// Generate code for union verifiers.
for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();
++it) {
const auto &enum_def = **it;
if (enum_def.is_union && !enum_def.generated) {
SetNameSpace(enum_def.defined_namespace);
GenUnionPost(enum_def);
}
}
// Generate code for mini reflection.
if (parser_.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);
}
}
// 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_ += "";
if (parser_.opts.mutable_buffer) {
code_ += "inline \\";
code_ += "{{STRUCT_NAME}} *GetMutable{{STRUCT_NAME}}(void *buf) {";
code_ += " return flatbuffers::GetMutableRoot<{{STRUCT_NAME}}>(buf);";
code_ += "}";
code_ += "";
}
if (parser_.file_identifier_.length()) {
// Return the identifier
code_ += "inline const char *{{STRUCT_NAME}}Identifier() {";
code_ += " return \"" + parser_.file_identifier_ + "\";";
code_ += "}";
code_ += "";
// Check if a buffer has the identifier.
code_ += "inline \\";
code_ += "bool {{STRUCT_NAME}}BufferHasIdentifier(const void *buf) {";
code_ += " return flatbuffers::BufferHasIdentifier(";
code_ += " buf, {{STRUCT_NAME}}Identifier());";
code_ += "}";
code_ += "";
}
// The root verifier.
if (parser_.file_identifier_.length()) {
code_.SetValue("ID", name + "Identifier()");
} else {
code_.SetValue("ID", "nullptr");
}
code_ += "inline bool Verify{{STRUCT_NAME}}Buffer(";
code_ += " flatbuffers::Verifier &verifier) {";
code_ += " return verifier.VerifyBuffer<{{CPP_NAME}}>({{ID}});";
code_ += "}";
code_ += "";
if (parser_.file_extension_.length()) {
// Return the extension
code_ += "inline const char *{{STRUCT_NAME}}Extension() {";
code_ += " return \"" + parser_.file_extension_ + "\";";
code_ += "}";
code_ += "";
}
// Finish a buffer with a given root object:
code_ += "inline void Finish{{STRUCT_NAME}}Buffer(";
code_ += " flatbuffers::FlatBufferBuilder &fbb,";
code_ += " flatbuffers::Offset<{{CPP_NAME}}> root) {";
if (parser_.file_identifier_.length())
code_ += " fbb.Finish(root, {{STRUCT_NAME}}Identifier());";
else
code_ += " fbb.Finish(root);";
code_ += "}";
code_ += "";
if (parser_.opts.generate_object_based_api) {
// A convenient root unpack function.
auto native_name =
NativeName(WrapInNameSpace(struct_def), &struct_def, parser_.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_ += "";
}
}
if (cur_name_space_) SetNameSpace(nullptr);
// Close the include guard.
code_ += "#endif // " + include_guard;
const auto file_path = GeneratedFileName(path_, file_name_);
const auto final_code = code_.ToString();
return SaveFile(file_path.c_str(), final_code, false);
}
private:
CodeWriter code_;
std::set<std::string> keywords_;
// This tracks the current namespace so we can insert namespace declarations.
const Namespace *cur_name_space_;
const Namespace *CurrentNameSpace() const { return cur_name_space_; }
// Translates a qualified name in flatbuffer text format to the same name in
// the equivalent C++ namespace.
static std::string TranslateNameSpace(const std::string &qualified_name) {
std::string cpp_qualified_name = qualified_name;
size_t start_pos = 0;
while ((start_pos = cpp_qualified_name.find(".", start_pos)) !=
std::string::npos) {
cpp_qualified_name.replace(start_pos, 1, "::");
}
return cpp_qualified_name;
}
void GenComment(const std::vector<std::string> &dc, const char *prefix = "") {
std::string text;
::flatbuffers::GenComment(dc, &text, nullptr, prefix);
code_ += text + "\\";
}
// Return a C++ type from the table in idl.h
std::string GenTypeBasic(const Type &type, bool user_facing_type) const {
static const char *ctypename[] = {
#define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \
#CTYPE,
FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
#undef FLATBUFFERS_TD
};
if (user_facing_type) {
if (type.enum_def) return WrapInNameSpace(*type.enum_def);
if (type.base_type == BASE_TYPE_BOOL) return "bool";
}
return ctypename[type.base_type];
}
// Return a C++ pointer type, specialized to the actual struct/table types,
// and vector element types.
std::string GenTypePointer(const Type &type) const {
switch (type.base_type) {
case BASE_TYPE_STRING: {
return "flatbuffers::String";
}
case BASE_TYPE_VECTOR: {
const auto type_name = GenTypeWire(type.VectorType(), "", false);
return "flatbuffers::Vector<" + type_name + ">";
}
case BASE_TYPE_STRUCT: {
return WrapInNameSpace(*type.struct_def);
}
case BASE_TYPE_UNION:
// fall through
default: {
return "void";
}
}
}
// Return a C++ type for any type (scalar/pointer) specifically for
// building a flatbuffer.
std::string GenTypeWire(const Type &type, const char *postfix,
bool user_facing_type) const {
if (IsScalar(type.base_type)) {
return GenTypeBasic(type, user_facing_type) + postfix;
} else if (IsStruct(type)) {
return "const " + GenTypePointer(type) + " *";
} else {
return "flatbuffers::Offset<" + GenTypePointer(type) + ">" + postfix;
}
}
// Return a C++ type for any type (scalar/pointer) that reflects its
// serialized size.
std::string GenTypeSize(const Type &type) const {
if (IsScalar(type.base_type)) {
return GenTypeBasic(type, false);
} else if (IsStruct(type)) {
return GenTypePointer(type);
} else {
return "flatbuffers::uoffset_t";
}
}
std::string NullableExtension() {
return parser_.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;
}
const std::string &PtrType(const FieldDef *field) {
auto attr = field ? field->attributes.Lookup("cpp_ptr_type") : nullptr;
return attr ? attr->constant : parser_.opts.cpp_object_api_pointer_type;
}
const std::string NativeString(const FieldDef *field) {
auto attr = field ? field->attributes.Lookup("cpp_str_type") : nullptr;
auto &ret = attr ? attr->constant : parser_.opts.cpp_object_api_string_type;
if (ret.empty()) {
return "std::string";
}
return ret;
}
std::string GenTypeNativePtr(const std::string &type, const FieldDef *field,
bool is_constructor) {
auto &ptr_type = PtrType(field);
if (ptr_type != "naked") {
return ptr_type + "<" + type + ">";
} else if (is_constructor) {
return "";
} else {
return type + " *";
}
}
std::string GenPtrGet(const FieldDef &field) {
auto &ptr_type = PtrType(&field);
return ptr_type == "naked" ? "" : ".get()";
}
std::string GenTypeNative(const Type &type, bool invector,
const FieldDef &field) {
switch (type.base_type) {
case BASE_TYPE_STRING: {
return NativeString(&field);
}
case BASE_TYPE_VECTOR: {
const auto type_name = GenTypeNative(type.VectorType(), true, field);
return "std::vector<" + type_name + ">";
}
case BASE_TYPE_STRUCT: {
auto type_name = WrapInNameSpace(*type.struct_def);
if (IsStruct(type)) {
auto native_type = type.struct_def->attributes.Lookup("native_type");
if (native_type) {
type_name = native_type->constant;
}
if (invector || field.native_inline) {
return type_name;
} else {
return GenTypeNativePtr(type_name, &field, false);
}
} else {
return GenTypeNativePtr(NativeName(type_name, type.struct_def, parser_.opts),
&field, false);
}
}
case BASE_TYPE_UNION: {
return type.enum_def->name + "Union";
}
default: {
return GenTypeBasic(type, true);
}
}
}
// Return a C++ type for any type (scalar/pointer) specifically for
// using a flatbuffer.
std::string GenTypeGet(const Type &type, const char *afterbasic,
const char *beforeptr, const char *afterptr,
bool user_facing_type) {
if (IsScalar(type.base_type)) {
return GenTypeBasic(type, user_facing_type) + afterbasic;
} else {
return beforeptr + GenTypePointer(type) + afterptr;
}
}
std::string GenEnumDecl(const EnumDef &enum_def) const {
const IDLOptions &opts = parser_.opts;
return (opts.scoped_enums ? "enum class " : "enum ") + Name(enum_def);
}
std::string GenEnumValDecl(const EnumDef &enum_def,
const std::string &enum_val) const {
const IDLOptions &opts = parser_.opts;
return opts.prefixed_enums ? Name(enum_def) + "_" + enum_val : enum_val;
}
std::string GetEnumValUse(const EnumDef &enum_def,
const EnumVal &enum_val) const {
const IDLOptions &opts = parser_.opts;
if (opts.scoped_enums) {
return 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 wrap, bool actual_type,
bool native_type = false) {
if (ev.union_type.base_type == BASE_TYPE_STRUCT) {
auto name = actual_type ? ev.union_type.struct_def->name : Name(ev);
return wrap
? WrapInNameSpace(ev.union_type.struct_def->defined_namespace, name)
: name;
} else if (ev.union_type.base_type == BASE_TYPE_STRING) {
return actual_type
? (native_type ? "std::string" : "flatbuffers::String")
: Name(ev);
} else {
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) {
return "bool Verify" + Name(enum_def) + "Vector" +
"(flatbuffers::Verifier &verifier, " +
"const flatbuffers::Vector<flatbuffers::Offset<void>> *values, " +
"const flatbuffers::Vector<uint8_t> *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 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->vals.vec.size();
code_.SetValue("NUM_FIELDS", NumToString(num_fields));
std::vector<std::string> names;
std::vector<Type> types;
bool consecutive_enum_from_zero = true;
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.vec.begin(); it != enum_def->vals.vec.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));
if (static_cast<int64_t>(it - enum_def->vals.vec.begin()) != ev.value) {
consecutive_enum_from_zero = false;
}
}
}
std::string ts;
std::vector<std::string> type_refs;
for (auto it = types.begin(); it != types.end(); ++it) {
auto &type = *it;
if (!ts.empty()) ts += ",\n ";
auto is_vector = type.base_type == BASE_TYPE_VECTOR;
auto bt = is_vector ? 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);
}
}
ts += "{ flatbuffers::" + std::string(ElementaryTypeNames()[et]) + ", " +
NumToString(is_vector) + ", " + 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 ns;
for (auto it = names.begin(); it != names.end(); ++it) {
if (!ns.empty()) ns += ",\n ";
ns += "\"" + *it + "\"";
}
std::string vs;
if (enum_def && !consecutive_enum_from_zero) {
for (auto it = enum_def->vals.vec.begin(); it != enum_def->vals.vec.end();
++it) {
const auto &ev = **it;
if (!vs.empty()) vs += ", ";
vs += NumToString(ev.value);
}
} 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("NAMES", ns);
code_.SetValue("VALUES", vs);
code_ += "inline flatbuffers::TypeTable *{{NAME}}TypeTable() {";
if (num_fields) {
code_ += " static flatbuffers::TypeCode type_codes[] = {";
code_ += " {{TYPES}}";
code_ += " };";
}
if (!type_refs.empty()) {
code_ += " static flatbuffers::TypeFunction type_refs[] = {";
code_ += " {{REFS}}";
code_ += " };";
}
if (!vs.empty()) {
code_ += " static const int32_t values[] = { {{VALUES}} };";
}
auto has_names = num_fields &&
parser_.opts.mini_reflect == IDLOptions::kTypesAndNames;
if (has_names) {
code_ += " static const char *names[] = {";
code_ += " {{NAMES}}";
code_ += " };";
}
code_ += " static flatbuffers::TypeTable tt = {";
code_ += std::string(" flatbuffers::{{SEQ_TYPE}}, {{NUM_FIELDS}}, ") +
(num_fields ? "type_codes, " : "nullptr, ") +
(!type_refs.empty() ? "type_refs, ": "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));
code_.SetValue("SEP", "");
GenComment(enum_def.doc_comment);
code_ += GenEnumDecl(enum_def) + "\\";
if (parser_.opts.scoped_enums)
code_ += " : {{BASE_TYPE}}\\";
code_ += " {";
int64_t anyv = 0;
const EnumVal *minv = nullptr, *maxv = nullptr;
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
GenComment(ev.doc_comment, " ");
code_.SetValue("KEY", GenEnumValDecl(enum_def, Name(ev)));
code_.SetValue("VALUE", NumToString(ev.value));
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
code_.SetValue("SEP", ",\n");
minv = !minv || minv->value > ev.value ? &ev : minv;
maxv = !maxv || maxv->value < ev.value ? &ev : maxv;
anyv |= ev.value;
}
if (parser_.opts.scoped_enums || parser_.opts.prefixed_enums) {
assert(minv && maxv);
code_.SetValue("SEP", ",\n");
if (enum_def.attributes.Lookup("bit_flags")) {
code_.SetValue("KEY", GenEnumValDecl(enum_def, "NONE"));
code_.SetValue("VALUE", "0");
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
code_.SetValue("KEY", GenEnumValDecl(enum_def, "ANY"));
code_.SetValue("VALUE", NumToString(anyv));
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
} else { // MIN & MAX are useless for bit_flags
code_.SetValue("KEY",GenEnumValDecl(enum_def, "MIN"));
code_.SetValue("VALUE", GenEnumValDecl(enum_def, minv->name));
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
code_.SetValue("KEY",GenEnumValDecl(enum_def, "MAX"));
code_.SetValue("VALUE", GenEnumValDecl(enum_def, maxv->name));
code_ += "{{SEP}} {{KEY}} = {{VALUE}}\\";
}
}
code_ += "";
code_ += "};";
if (parser_.opts.scoped_enums && enum_def.attributes.Lookup("bit_flags")) {
code_ += "DEFINE_BITMASK_OPERATORS({{ENUM_NAME}}, {{BASE_TYPE}})";
}
code_ += "";
// Generate an array of all enumeration values
auto num_fields = NumToString(enum_def.vals.vec.size());
code_ += "inline {{ENUM_NAME}} (&EnumValues{{ENUM_NAME}}())[" + num_fields + "] {";
code_ += " static {{ENUM_NAME}} values[] = {";
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
auto value = GetEnumValUse(enum_def, ev);
auto suffix = *it != enum_def.vals.vec.back() ? "," : "";
code_ += " " + value + suffix;
}
code_ += " };";
code_ += " return values;";
code_ += "}";
code_ += "";
// Generate a generate string table for enum values.
// Problem is, if values are very sparse that could generate really big
// tables. Ideally in that case we generate a map lookup instead, but for
// the moment we simply don't output a table at all.
auto range =
enum_def.vals.vec.back()->value - enum_def.vals.vec.front()->value + 1;
// Average distance between values above which we consider a table
// "too sparse". Change at will.
static const int kMaxSparseness = 5;
if (range / static_cast<int64_t>(enum_def.vals.vec.size()) <
kMaxSparseness) {
code_ += "inline const char **EnumNames{{ENUM_NAME}}() {";
code_ += " static const char *names[] = {";
auto val = enum_def.vals.vec.front()->value;
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
while (val++ != ev.value) {
code_ += " \"\",";
}
code_ += " \"" + Name(ev) + "\",";
}
code_ += " nullptr";
code_ += " };";
code_ += " return names;";
code_ += "}";
code_ += "";
code_ += "inline const char *EnumName{{ENUM_NAME}}({{ENUM_NAME}} e) {";
code_ += " const size_t index = static_cast<int>(e)\\";
if (enum_def.vals.vec.front()->value) {
auto vals = GetEnumValUse(enum_def, *enum_def.vals.vec.front());
code_ += " - static_cast<int>(" + vals + ")\\";
}
code_ += ";";
code_ += " return EnumNames{{ENUM_NAME}}()[index];";
code_ += "}";
code_ += "";
}
// Generate type traits for unions to map from a type to union enum value.
if (enum_def.is_union && !enum_def.uses_type_aliases) {
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
if (it == enum_def.vals.vec.begin()) {
code_ += "template<typename T> struct {{ENUM_NAME}}Traits {";
}
else {
auto name = GetUnionElement(ev, true, true);
code_ += "template<> struct {{ENUM_NAME}}Traits<" + name + "> {";
}
auto value = GetEnumValUse(enum_def, ev);
code_ += " static const {{ENUM_NAME}} enum_value = " + value + ";";
code_ += "};";
code_ += "";
}
}
if (parser_.opts.generate_object_based_api && enum_def.is_union) {
// Generate a union type
code_.SetValue("NAME", Name(enum_def));
code_.SetValue("NONE",
GetEnumValUse(enum_def, *enum_def.vals.Lookup("NONE")));
code_ += "struct {{NAME}}Union {";
code_ += " {{NAME}} type;";
code_ += " void *value;";
code_ += "";
code_ += " {{NAME}}Union() : type({{NONE}}), value(nullptr) {}";
code_ += " {{NAME}}Union({{NAME}}Union&& u) FLATBUFFERS_NOEXCEPT :";
code_ += " type({{NONE}}), value(nullptr)";
code_ += " { std::swap(type, u.type); std::swap(value, u.value); }";
code_ += " {{NAME}}Union(const {{NAME}}Union &) FLATBUFFERS_NOEXCEPT;";
code_ += " {{NAME}}Union &operator=(const {{NAME}}Union &u) FLATBUFFERS_NOEXCEPT";
code_ += " { {{NAME}}Union t(u); std::swap(type, t.type); std::swap(value, t.value); return *this; }";
code_ += " {{NAME}}Union &operator=({{NAME}}Union &&u) FLATBUFFERS_NOEXCEPT";
code_ += " { std::swap(type, u.type); std::swap(value, u.value); return *this; }";
code_ += " ~{{NAME}}Union() { Reset(); }";
code_ += "";
code_ += " void Reset();";
code_ += "";
if (!enum_def.uses_type_aliases) {
code_ += "#ifndef FLATBUFFERS_CPP98_STL";
code_ += " template <typename T>";
code_ += " void Set(T&& val) {";
code_ += " Reset();";
code_ += " type = {{NAME}}Traits<typename T::TableType>::enum_value;";
code_ += " if (type != {{NONE}}) {";
code_ += " value = new T(std::forward<T>(val));";
code_ += " }";
code_ += " }";
code_ += "#endif // FLATBUFFERS_CPP98_STL";
code_ += "";
}
code_ += " " + UnionUnPackSignature(enum_def, true) + ";";
code_ += " " + UnionPackSignature(enum_def, true) + ";";
code_ += "";
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
if (!ev.value) {
continue;
}
const auto native_type =
NativeName(GetUnionElement(ev, true, true, true),
ev.union_type.struct_def, parser_.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 (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.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
if (ev.value) {
code_.SetValue("TYPE", GetUnionElement(ev, true, true));
code_ += " case {{LABEL}}: {";
auto getptr =
" auto ptr = reinterpret_cast<const {{TYPE}} *>(obj);";
if (ev.union_type.base_type == BASE_TYPE_STRUCT) {
if (ev.union_type.struct_def->fixed) {
code_ += " return true;";
} else {
code_ += getptr;
code_ += " return verifier.VerifyTable(ptr);";
}
} else if (ev.union_type.base_type == BASE_TYPE_STRING) {
code_ += getptr;
code_ += " return verifier.Verify(ptr);";
} else {
assert(false);
}
code_ += " }";
} else {
code_ += " case {{LABEL}}: {";
code_ += " return true;"; // "NONE" enum value.
code_ += " }";
}
}
code_ += " default: return false;";
code_ += " }";
code_ += "}";
code_ += "";
code_ += "inline " + UnionVectorVerifySignature(enum_def) + " {";
code_ += " if (values->size() != types->size()) return false;";
code_ += " for (flatbuffers::uoffset_t i = 0; i < values->size(); ++i) {";
code_ += " if (!Verify" + 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 (parser_.opts.generate_object_based_api) {
// Generate union Unpack() and Pack() functions.
code_ += "inline " + UnionUnPackSignature(enum_def, false) + " {";
code_ += " switch (type) {";
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
if (!ev.value) {
continue;
}
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", GetUnionElement(ev, true, true));
code_ += " case {{LABEL}}: {";
code_ += " auto ptr = reinterpret_cast<const {{TYPE}} *>(obj);";
if (ev.union_type.base_type == BASE_TYPE_STRUCT) {
if (ev.union_type.struct_def->fixed) {
code_ += " return new " +
WrapInNameSpace(*ev.union_type.struct_def) + "(*ptr);";
} else {
code_ += " return ptr->UnPack(resolver);";
}
} else if (ev.union_type.base_type == BASE_TYPE_STRING) {
code_ += " return new std::string(ptr->c_str(), ptr->size());";
} else {
assert(false);
}
code_ += " }";
}
code_ += " default: return nullptr;";
code_ += " }";
code_ += "}";
code_ += "";
code_ += "inline " + UnionPackSignature(enum_def, false) + " {";
code_ += " switch (type) {";
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
auto &ev = **it;
if (!ev.value) {
continue;
}
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", NativeName(GetUnionElement(ev, true, true, true),
ev.union_type.struct_def, parser_.opts));
code_.SetValue("NAME", GetUnionElement(ev, false, true));
code_ += " case {{LABEL}}: {";
code_ += " auto ptr = reinterpret_cast<const {{TYPE}} *>(value);";
if (ev.union_type.base_type == BASE_TYPE_STRUCT) {
if (ev.union_type.struct_def->fixed) {
code_ += " return _fbb.CreateStruct(*ptr).Union();";
} else {
code_ +=
" return Create{{NAME}}(_fbb, ptr, _rehasher).Union();";
}
} else if (ev.union_type.base_type == BASE_TYPE_STRING) {
code_ += " return _fbb.CreateString(*ptr).Union();";
} else {
assert(false);
}
code_ += " }";
}
code_ += " default: return 0;";
code_ += " }";
code_ += "}";
code_ += "";
// Union copy constructor
code_ += "inline {{ENUM_NAME}}Union::{{ENUM_NAME}}Union(const "
"{{ENUM_NAME}}Union &u) FLATBUFFERS_NOEXCEPT : type(u.type), "
"value(nullptr) {";
code_ += " switch (type) {";
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
if (!ev.value) {
continue;
}
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", NativeName(GetUnionElement(ev, true, true, true),
ev.union_type.struct_def, parser_.opts));
code_ += " case {{LABEL}}: {";
bool copyable = true;
if (ev.union_type.base_type == BASE_TYPE_STRUCT) {
// Don't generate code to copy if table is not copyable.
// TODO(wvo): make tables copyable instead.
for (auto fit = ev.union_type.struct_def->fields.vec.begin();
fit != ev.union_type.struct_def->fields.vec.end(); ++fit) {
const auto &field = **fit;
if (!field.deprecated && field.value.type.struct_def) {
copyable = false;
break;
}
}
}
if (copyable) {
code_ += " value = new {{TYPE}}(*reinterpret_cast<{{TYPE}} *>"
"(u.value));";
} else {
code_ += " assert(false); // {{TYPE}} not copyable.";
}
code_ += " break;";
code_ += " }";
}
code_ += " default:";
code_ += " break;";
code_ += " }";
code_ += "}";
code_ += "";
// Union Reset() function.
code_.SetValue("NONE",
GetEnumValUse(enum_def, *enum_def.vals.Lookup("NONE")));
code_ += "inline void {{ENUM_NAME}}Union::Reset() {";
code_ += " switch (type) {";
for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
++it) {
const auto &ev = **it;
if (!ev.value) {
continue;
}
code_.SetValue("LABEL", GetEnumValUse(enum_def, ev));
code_.SetValue("TYPE", NativeName(GetUnionElement(ev, true, true, true),
ev.union_type.struct_def, parser_.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(), ToUpper);
return "VT_" + uname;
}
void GenFullyQualifiedNameGetter(const StructDef &struct_def,
const std::string &name) {
if (!parser_.opts.generate_name_strings) {
return;
}
auto fullname = struct_def.defined_namespace->GetFullyQualifiedName(name);
code_.SetValue("NAME", fullname);
code_.SetValue("CONSTEXPR", "FLATBUFFERS_CONSTEXPR");
code_ += " static {{CONSTEXPR}} const char *GetFullyQualifiedName() {";
code_ += " return \"{{NAME}}\";";
code_ += " }";
}
std::string GenDefaultConstant(const FieldDef &field) {
return field.value.type.base_type == BASE_TYPE_FLOAT
? field.value.constant + "f"
: field.value.constant;
}
std::string GetDefaultScalarValue(const FieldDef &field) {
if (field.value.type.enum_def && IsScalar(field.value.type.base_type)) {
auto ev = field.value.type.enum_def->ReverseLookup(
static_cast<int>(StringToInt(field.value.constant.c_str())), false);
if (ev) {
return WrapInNameSpace(
field.value.type.enum_def->defined_namespace,
GetEnumValUse(*field.value.type.enum_def, *ev));
} else {
return GenUnderlyingCast(field, true, field.value.constant);
}
} else if (field.value.type.base_type == BASE_TYPE_BOOL) {
return field.value.constant == "0" ? "false" : "true";
} 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 && field.value.type.base_type == BASE_TYPE_STRING) {
code_.SetValue("PARAM_TYPE", "const char *");
code_.SetValue("PARAM_VALUE", "nullptr");
} else if (direct && field.value.type.base_type == BASE_TYPE_VECTOR) {
auto type = GenTypeWire(field.value.type.VectorType(), "", false);
code_.SetValue("PARAM_TYPE", "const std::vector<" + type + "> *");
code_.SetValue("PARAM_VALUE", "nullptr");
} else {
code_.SetValue("PARAM_TYPE", GenTypeWire(field.value.type, " ", true));
code_.SetValue("PARAM_VALUE", GetDefaultScalarValue(field));
}
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 ? cpp_type->constant + " *" : type + " ");
code_.SetValue("FIELD_TYPE", full_type);
code_.SetValue("FIELD_NAME", Name(field));
code_ += " {{FIELD_TYPE}}{{FIELD_NAME}};";
}
}
// Generate the default constructor for this struct. Properly initialize all
// scalar members with default values.
void GenDefaultConstructor(const StructDef& struct_def) {
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");
// 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 += "(" + GetDefaultScalarValue(field) + ")";
} else if (field.value.type.base_type == BASE_TYPE_STRUCT) {
if (IsStruct(field.value.type)) {
auto native_default = field.attributes.Lookup("native_default");
if (native_default) {
if (!initializer_list.empty()) {
initializer_list += ",\n ";
}
initializer_list +=
Name(field) + "(" + native_default->constant + ")";
}
}
} else if (cpp_type) {
if (!initializer_list.empty()) {
initializer_list += ",\n ";
}
initializer_list += Name(field) + "(0)";
}
}
}
if (!initializer_list.empty()) {
initializer_list = "\n : " + initializer_list;
}
code_.SetValue("NATIVE_NAME", NativeName(Name(struct_def), &struct_def, parser_.opts));
code_.SetValue("INIT_LIST", initializer_list);
code_ += " {{NATIVE_NAME}}(){{INIT_LIST}} {";
code_ += " }";
}
void GenNativeTable(const StructDef &struct_def) {
const auto native_name = NativeName(Name(struct_def), &struct_def, parser_.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);
}
GenDefaultConstructor(struct_def);
code_ += "};";
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.required ? "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_ +=
"{{PRE}}VerifyField{{REQUIRED}}<{{SIZE}}>(verifier, {{OFFSET}})\\";
} 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.Verify({{NAME}}())\\";
break;
}
case BASE_TYPE_VECTOR: {
code_ += "{{PRE}}verifier.Verify({{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;
}
break;
}
default: {
break;
}
}
}
// Generate an accessor struct, builder structs & function for a table.
void GenTable(const StructDef &struct_def) {
if (parser_.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 (parser_.opts.generate_object_based_api) {
code_ += " typedef {{NATIVE_NAME}} NativeTableType;";
}
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 {";
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;
}
const bool is_struct = IsStruct(field.value.type);
const bool is_scalar = IsScalar(field.value.type.base_type);
code_.SetValue("FIELD_NAME", Name(field));
// Call a different accessor for pointers, that indirects.
std::string accessor = "";
if (is_scalar) {
accessor = "GetField<";
} else if (is_struct) {
accessor = "GetStruct<";
} else {
accessor = "GetPointer<";
}
auto offset_str = GenFieldOffsetName(field);
auto offset_type =
GenTypeGet(field.value.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();
GenComment(field.doc_comment, " ");
code_.SetValue("FIELD_TYPE",
GenTypeGet(field.value.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_ += " }";
if (field.value.type.base_type == BASE_TYPE_UNION) {
auto u = field.value.type.enum_def;
code_ += " template<typename T> "
"const T *{{NULLABLE_EXT}}{{FIELD_NAME}}_as() const;";
for (auto u_it = u->vals.vec.begin();
u_it != u->vals.vec.end(); ++u_it) {
auto &ev = **u_it;
if (ev.union_type.base_type == BASE_TYPE_NONE) {
continue;
}
auto full_struct_name = GetUnionElement(ev, true, true);
// @TODO: Mby make this decisions more universal? How?
code_.SetValue("U_GET_TYPE", 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_ += " }";
}
}
if (parser_.opts.mutable_buffer) {
if (is_scalar) {
const auto type = GenTypeWire(field.value.type, "", false);
code_.SetValue("SET_FN", "SetField<" + type + ">");
code_.SetValue("OFFSET_NAME", offset_str);
code_.SetValue("FIELD_TYPE", GenTypeBasic(field.value.type, true));
code_.SetValue("FIELD_VALUE",
GenUnderlyingCast(field, false, "_" + Name(field)));
code_.SetValue("DEFAULT_VALUE", GenDefaultConstant(field));
code_ += " bool mutate_{{FIELD_NAME}}({{FIELD_TYPE}} "
"_{{FIELD_NAME}}) {";
code_ += " return {{SET_FN}}({{OFFSET_NAME}}, {{FIELD_VALUE}}, {{DEFAULT_VALUE}});";
code_ += " }";
} else {
auto postptr = " *" + NullableExtension();
auto type = GenTypeGet(field.value.type, " ", "", postptr.c_str(), true);
auto underlying = accessor + type + ">(" + offset_str + ")";
code_.SetValue("FIELD_TYPE", type);
code_.SetValue("FIELD_VALUE",
GenUnderlyingCast(field, true, underlying));
code_ += " {{FIELD_TYPE}}mutable_{{FIELD_NAME}}() {";
code_ += " return {{FIELD_VALUE}};";
code_ += " }";
}
}
auto nested = field.attributes.Lookup("nested_flatbuffer");
if (nested) {
std::string qualified_name =
parser_.current_namespace_->GetFullyQualifiedName(
nested->constant);
auto nested_root = parser_.LookupStruct(qualified_name);
assert(nested_root); // Guaranteed to exist by parser.
(void)nested_root;
code_.SetValue("CPP_NAME", TranslateNameSpace(qualified_name));
code_ += " const {{CPP_NAME}} *{{FIELD_NAME}}_nested_root() const {";
code_ += " auto data = {{FIELD_NAME}}()->Data();";
code_ += " return flatbuffers::GetRoot<{{CPP_NAME}}>(data);";
code_ += " }";
}
if (field.flexbuffer) {
code_ += " flexbuffers::Reference {{FIELD_NAME}}_flexbuffer_root()"
" const {";
code_ += " auto v = {{FIELD_NAME}}();";
code_ += " return flexbuffers::GetRoot(v->Data(), v->size());";
code_ += " }";
}
// Generate a comparison function for this field if it is a key.
if (field.key) {
const bool is_string = (field.value.type.base_type == BASE_TYPE_STRING);
code_ += " bool KeyCompareLessThan(const {{STRUCT_NAME}} *o) const {";
if (is_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 *val) const {";
code_ += " return strcmp({{FIELD_NAME}}()->c_str(), val);";
code_ += " }";
} else {
auto type = GenTypeBasic(field.value.type, false);
if (parser_.opts.scoped_enums && field.value.type.enum_def &&
IsScalar(field.value.type.base_type)) {
type = GenTypeGet(field.value.type, " ", "const ", " *", true);
}
code_.SetValue("KEY_TYPE", type);
code_ += " int KeyCompareWithValue({{KEY_TYPE}} val) const {";
code_ += " const auto key = {{FIELD_NAME}}();";
code_ += " if (key < val) {";
code_ += " return -1;";
code_ += " } else if (key > val) {";
code_ += " return 1;";
code_ += " } else {";
code_ += " return 0;";
code_ += " }";
code_ += " }";
}
}
}
// 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 (parser_.opts.generate_object_based_api) {
// Generate the UnPack() pre declaration.
code_ += " " + TableUnPackSignature(struct_def, true, parser_.opts) + ";";
code_ += " " + TableUnPackToSignature(struct_def, true, parser_.opts) + ";";
code_ += " " + TablePackSignature(struct_def, true, parser_.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_type_aliases) continue;
code_.SetValue("FIELD_NAME", Name(field));
for (auto u_it = u->vals.vec.begin();
u_it != u->vals.vec.end(); ++u_it) {
auto &ev = **u_it;
if (ev.union_type.base_type == BASE_TYPE_NONE) {
continue;
}
auto full_struct_name = GetUnionElement(ev, true, true);
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 (parser_.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, parser_.opts) + ";";
code_ += "";
}
}
void GenBuilders(const StructDef &struct_def) {
code_.SetValue("STRUCT_NAME", Name(struct_def));
// Generate a builder struct:
code_ += "struct {{STRUCT_NAME}}Builder {";
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) {
const bool is_scalar = IsScalar(field.value.type.base_type);
const bool is_string = field.value.type.base_type == BASE_TYPE_STRING;
const bool is_vector = field.value.type.base_type == BASE_TYPE_VECTOR;
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_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_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_ += " }";
// Assignment operator;
code_ += " {{STRUCT_NAME}}Builder &operator="
"(const {{STRUCT_NAME}}Builder &);";
// 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.required) {
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));
code_ += " builder_.add_{{FIELD_NAME}}({{FIELD_NAME}});";
}
}
}
code_ += " return builder_.Finish();";
code_ += "}";
code_ += "";
// Generate a CreateXDirect function with vector types as parameters
if (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_ += ") {";
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));
if (field.value.type.base_type == BASE_TYPE_STRING) {
code_ += ",\n {{FIELD_NAME}} ? "
"_fbb.CreateString({{FIELD_NAME}}) : 0\\";
} else if (field.value.type.base_type == BASE_TYPE_VECTOR) {
auto type = GenTypeWire(field.value.type.VectorType(), "", false);
code_ += ",\n {{FIELD_NAME}} ? "
"_fbb.CreateVector<" + type + ">(*{{FIELD_NAME}}) : 0\\";
} else {
code_ += ",\n {{FIELD_NAME}}\\";
}
}
}
code_ += ");";
code_ += "}";
code_ += "";
}
}
std::string GenUnionUnpackVal(const FieldDef &afield,
const char *vec_elem_access,
const char *vec_type_access) {
return afield.value.type.enum_def->name + "Union::UnPack(" + "_e" +
vec_elem_access + ", " + Name(afield) + 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: {
return val + "->str()";
}
case BASE_TYPE_STRUCT: {
const auto name = WrapInNameSpace(*type.struct_def);
if (IsStruct(type)) {
auto native_type = type.struct_def->attributes.Lookup("native_type");
if (native_type) {
return "flatbuffers::UnPack(*" + val + ")";
} else if (invector || afield.native_inline) {
return "*" + val;
} else {
const auto ptype = GenTypeNativePtr(name, &afield, true);
return ptype + "(new " + name + "(*" + val + "))";
}
} else {
const auto ptype = GenTypeNativePtr(NativeName(name, type.struct_def, parser_.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: {
std::string indexing;
if (field.value.type.enum_def) {
indexing += "(" + field.value.type.enum_def->name + ")";
}
indexing += "_e->Get(_i)";
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 name = Name(field);
if (field.value.type.element == BASE_TYPE_UTYPE) {
name = StripUnionType(Name(field));
}
auto access = field.value.type.element == BASE_TYPE_UTYPE
? ".type"
: (field.value.type.element == BASE_TYPE_UNION
? ".value"
: "");
code += "{ _o->" + name + ".resize(_e->size()); ";
code += "for (flatbuffers::uoffset_t _i = 0;";
code += " _i < _e->size(); _i++) { ";
code += "_o->" + name + "[_i]" + access + " = ";
code += GenUnpackVal(field.value.type.VectorType(),
indexing, true, field);
code += "; } }";
break;
}
case BASE_TYPE_UTYPE: {
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 += "if (_resolver) ";
code += "(*_resolver)";
code += "(reinterpret_cast<void **>(&_o->" + Name(field) + "), ";
code += "static_cast<flatbuffers::hash_value_t>(_e));";
code += " else ";
code += "_o->" + Name(field) + " = nullptr;";
} else {
// Generate code for assigning the value, of the form:
// _o->field = value;
code += "_o->" + Name(field) + " = ";
code += GenUnpackVal(field.value.type, "_e", false, field) + ";";
}
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.attributes.Lookup("cpp_type")) {
auto type = GenTypeBasic(field.value.type, false);
value = "_rehasher ? "
"static_cast<" + type + ">((*_rehasher)(" + value + ")) : 0";
}
std::string code;
switch (field.value.type.base_type) {
// String fields are of the form:
// _fbb.CreateString(_o->field)
case BASE_TYPE_STRING: {
code += "_fbb.CreateString(" + value + ")";
// For optional fields, check to see if there actually is any data
// in _o->field before attempting to access it.
if (!field.required) {
code = value + ".empty() ? 0 : " + 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: {
code += "_fbb.CreateVectorOfStrings(" + value + ")";
break;
}
case BASE_TYPE_STRUCT: {
if (IsStruct(vector_type)) {
auto native_type =
field.value.type.struct_def->attributes.Lookup("native_type");
if (native_type) {
code += "_fbb.CreateVectorOfNativeStructs<";
code += WrapInNameSpace(*vector_type.struct_def) + ">";
} 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);
code += "_fbb.CreateVector<uint8_t>(" + value +
".size(), [](size_t i, _VectorArgs *__va) { "
"return static_cast<uint8_t>(__va->_" + value +
"[i].type); }, &_va)";
break;
}
default: {
if (field.value.type.enum_def) {
// 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.CreateVector((const " + basetype + "*)" + value +
".data(), " + value + ".size())";
} else {
code += "_fbb.CreateVector(" + value + ")";
}
break;
}
}
// For optional fields, check to see if there actually is any data
// in _o->field before attempting to access it.
if (!field.required) {
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)) {
auto native_type =
field.value.type.struct_def->attributes.Lookup("native_type");
if (native_type) {
code += "flatbuffers::Pack(" + value + ")";
} else if (field.native_inline) {
code += "&" + value;
} else {
code += value + " ? " + value + GenPtrGet(field) + " : 0";
}
} 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) {
code_.SetValue("STRUCT_NAME", Name(struct_def));
code_.SetValue("NATIVE_NAME", NativeName(Name(struct_def), &struct_def, parser_.opts));
if (parser_.opts.generate_object_based_api) {
// Generate the X::UnPack() method.
code_ += "inline " + TableUnPackSignature(struct_def, false, parser_.opts) + " {";
code_ += " auto _o = new {{NATIVE_NAME}}();";
code_ += " UnPackTo(_o, _resolver);";
code_ += " return _o;";
code_ += "}";
code_ += "";
code_ += "inline " + TableUnPackToSignature(struct_def, false, parser_.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, parser_.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, parser_.opts) + " {";
code_ += " (void)_rehasher;";
code_ += " (void)_o;";
code_ +=
" struct _VectorArgs "
"{ flatbuffers::FlatBufferBuilder *__fbb; "
"const " +
NativeName(Name(struct_def), &struct_def, parser_.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;
}
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);
}
}
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;
*code_ptr += ",\n padding" + NumToString((*id)++) + "__(0)";
}
static void PaddingNoop(int bits, std::string *code_ptr, int *id) {
(void)bits;
*code_ptr += " (void)padding" + NumToString((*id)++) + "__;";
}
// 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_ += "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;
code_.SetValue("FIELD_TYPE",
GenTypeGet(field.value.type, " ", "", " ", false));
code_.SetValue("FIELD_NAME", Name(field));
code_ += " {{FIELD_TYPE}}{{FIELD_NAME}}_;";
if (field.padding) {
std::string padding;
GenPadding(field, &padding, &padding_id, PaddingDefinition);
code_ += padding;
}
}
// Generate GetFullyQualifiedName
code_ += "";
code_ += " public:";
GenFullyQualifiedNameGetter(struct_def, Name(struct_def));
// Generate a default constructor.
code_ += " {{STRUCT_NAME}}() {";
code_ += " memset(this, 0, sizeof({{STRUCT_NAME}}));";
code_ += " }";
// Generate a constructor that takes all fields as arguments.
std::string arg_list;
std::string init_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 member_name = Name(field) + "_";
const auto arg_name = "_" + Name(field);
const auto arg_type =
GenTypeGet(field.value.type, " ", "const ", " &", true);
if (it != struct_def.fields.vec.begin()) {
arg_list += ", ";
init_list += ",\n ";
}
arg_list += arg_type;
arg_list += arg_name;
init_list += member_name;
if (IsScalar(field.value.type.base_type)) {
auto type = GenUnderlyingCast(field, false, arg_name);
init_list += "(flatbuffers::EndianScalar(" + type + "))";
} else {
init_list += "(" + arg_name + ")";
}
if (field.padding) {
GenPadding(field, &init_list, &padding_id, PaddingInitializer);
}
}
code_.SetValue("ARG_LIST", arg_list);
code_.SetValue("INIT_LIST", init_list);
code_ += " {{STRUCT_NAME}}({{ARG_LIST}})";
code_ += " : {{INIT_LIST}} {";
padding_id = 0;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
const auto &field = **it;
if (field.padding) {
std::string padding;
GenPadding(field, &padding, &padding_id, PaddingNoop);
code_ += padding;
}
}
code_ += " }";
// 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;
auto field_type = GenTypeGet(field.value.type, " ", "const ", " &", true);
auto is_scalar = IsScalar(field.value.type.base_type);
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, " ");
code_ += " {{FIELD_TYPE}}{{FIELD_NAME}}() const {";
code_ += " return {{FIELD_VALUE}};";
code_ += " }";
if (parser_.opts.mutable_buffer) {
auto mut_field_type = GenTypeGet(field.value.type, " ", "", " &", true);
code_.SetValue("FIELD_TYPE", mut_field_type);
if (is_scalar) {
code_.SetValue("ARG", GenTypeBasic(field.value.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 {
code_ += " {{FIELD_TYPE}}mutable_{{FIELD_NAME}}() {";
code_ += " return {{FIELD_NAME}}_;";
code_ += " }";
}
}
// Generate a comparison function for this field if it is a key.
if (field.key) {
code_ += " bool KeyCompareLessThan(const {{STRUCT_NAME}} *o) const {";
code_ += " return {{FIELD_NAME}}() < o->{{FIELD_NAME}}();";
code_ += " }";
auto type = GenTypeBasic(field.value.type, false);
if (parser_.opts.scoped_enums && field.value.type.enum_def &&
IsScalar(field.value.type.base_type)) {
type = GenTypeGet(field.value.type, " ", "const ", " *", true);
}
code_.SetValue("KEY_TYPE", type);
code_ += " int KeyCompareWithValue({{KEY_TYPE}} val) const {";
code_ += " const auto key = {{FIELD_NAME}}();";
code_ += " return static_cast<int>(key > val) - static_cast<int>(key < val);";
code_ += " }";
}
}
code_ += "};";
code_.SetValue("STRUCT_BYTE_SIZE", NumToString(struct_def.bytesize));
code_ += "STRUCT_END({{STRUCT_NAME}}, {{STRUCT_BYTE_SIZE}});";
code_ += "";
}
// 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::CppGenerator generator(parser, path, file_name);
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));
const auto included_files = parser.GetIncludedFilesRecursive(file_name);
std::string make_rule = GeneratedFileName(path, filebase) + ": ";
for (auto it = included_files.begin(); it != included_files.end(); ++it) {
make_rule += " " + *it;
}
return make_rule;
}
} // namespace flatbuffers