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flatbuffers-bigfoot/src/idl_gen_general.cpp

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/*
* 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 <algorithm>
namespace flatbuffers {
// Convert an underscore_based_indentifier in to camelCase.
// Also uppercases the first character if first is true.
std::string MakeCamel(const std::string &in, bool first) {
std::string s;
for (size_t i = 0; i < in.length(); i++) {
if (!i && first)
s += static_cast<char>(toupper(in[0]));
else if (in[i] == '_' && i + 1 < in.length())
s += static_cast<char>(toupper(in[++i]));
else
s += in[i];
}
return s;
}
struct CommentConfig {
const char *first_line;
const char *content_line_prefix;
const char *last_line;
};
// Generate a documentation comment, if available.
void GenComment(const std::vector<std::string> &dc, std::string *code_ptr,
const CommentConfig *config, const char *prefix) {
if (dc.begin() == dc.end()) {
// Don't output empty comment blocks with 0 lines of comment content.
return;
}
std::string &code = *code_ptr;
if (config != nullptr && config->first_line != nullptr) {
code += std::string(prefix) + std::string(config->first_line) + "\n";
}
std::string line_prefix = std::string(prefix) +
((config != nullptr && config->content_line_prefix != nullptr) ?
config->content_line_prefix : "///");
for (auto it = dc.begin();
it != dc.end();
++it) {
code += line_prefix + *it + "\n";
}
if (config != nullptr && config->last_line != nullptr) {
code += std::string(prefix) + std::string(config->last_line) + "\n";
}
}
// These arrays need to correspond to the IDLOptions::k enum.
struct LanguageParameters {
IDLOptions::Language language;
// Whether function names in the language typically start with uppercase.
bool first_camel_upper;
const char *file_extension;
const char *string_type;
const char *bool_type;
const char *open_curly;
const char *const_decl;
const char *unsubclassable_decl;
const char *enum_decl;
const char *enum_separator;
const char *getter_prefix;
const char *getter_suffix;
const char *inheritance_marker;
const char *namespace_ident;
const char *namespace_begin;
const char *namespace_end;
const char *set_bb_byteorder;
const char *get_bb_position;
const char *get_fbb_offset;
const char *includes;
CommentConfig comment_config;
};
LanguageParameters language_parameters[] = {
{
IDLOptions::kJava,
false,
".java",
"String",
"boolean ",
" {\n",
" final ",
"final ",
"final class ",
";\n",
"()",
"",
" extends ",
"package ",
";",
"",
"_bb.order(ByteOrder.LITTLE_ENDIAN); ",
"position()",
"offset()",
"import java.nio.*;\nimport java.lang.*;\nimport java.util.*;\n"
"import com.google.flatbuffers.*;\n\n@SuppressWarnings(\"unused\")\n",
{
"/**",
" *",
" */",
},
},
{
IDLOptions::kCSharp,
true,
".cs",
"string",
"bool ",
"\n{\n",
" readonly ",
"sealed ",
"enum ",
",\n",
" { get",
"} ",
" : ",
"namespace ",
"\n{",
"\n}\n",
"",
"Position",
"Offset",
"using System;\nusing FlatBuffers;\n\n",
{
nullptr,
"///",
nullptr,
},
},
// TODO: add Go support to the general generator.
// WARNING: this is currently only used for generating make rules for Go.
{
IDLOptions::kGo,
true,
".go",
"string",
"bool ",
"\n{\n",
"const ",
" ",
"class ",
";\n",
"()",
"",
"",
"package ",
"",
"",
"",
"position()",
"offset()",
"import (\n\tflatbuffers \"github.com/google/flatbuffers/go\"\n)",
{
nullptr,
"///",
nullptr,
},
}
};
static_assert(sizeof(language_parameters) / sizeof(LanguageParameters) ==
IDLOptions::kMAX,
"Please add extra elements to the arrays above.");
static std::string FunctionStart(const LanguageParameters &lang, char upper) {
return std::string() +
(lang.language == IDLOptions::kJava
? static_cast<char>(tolower(upper))
: upper);
}
static bool IsEnum(const Type& type) {
return type.enum_def != nullptr && IsInteger(type.base_type);
}
// Ensure that a type is prefixed with its namespace whenever it is used
// outside of its namespace.
static std::string WrapInNameSpace(const Parser &parser, const Namespace *ns,
const std::string &name) {
if (parser.namespaces_.back() != ns) {
std::string qualified_name;
for (auto it = ns->components.begin();
it != ns->components.end(); ++it) {
qualified_name += *it + ".";
}
return qualified_name + name;
} else {
return name;
}
}
static std::string WrapInNameSpace(const Parser &parser,
const Definition &def) {
return WrapInNameSpace(parser, def.defined_namespace, def.name);
}
static std::string GenTypeBasic(const LanguageParameters &lang, const Parser &parser,
const Type &type,
bool enableLangOverrides) {
static const char *gtypename[] = {
#define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \
#JTYPE, #NTYPE, #GTYPE,
FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
#undef FLATBUFFERS_TD
};
if (enableLangOverrides) {
if (lang.language == IDLOptions::kCSharp) {
if (IsEnum(type)) return WrapInNameSpace(parser, *type.enum_def);
if (type.base_type == BASE_TYPE_STRUCT) {
return "Offset<" + WrapInNameSpace(parser, *type.struct_def) + ">";
}
}
}
return gtypename[type.base_type * IDLOptions::kMAX + lang.language];
}
static std::string GenTypeBasic(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
return GenTypeBasic(lang, parser, type, true);
}
static std::string GenTypeGet(const LanguageParameters &lang, const Parser &parser,
const Type &type);
static std::string GenTypePointer(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
switch (type.base_type) {
case BASE_TYPE_STRING:
return lang.string_type;
case BASE_TYPE_VECTOR:
return GenTypeGet(lang, parser, type.VectorType());
case BASE_TYPE_STRUCT:
return WrapInNameSpace(parser, *type.struct_def);
case BASE_TYPE_UNION:
// Unions in C# use a generic Table-derived type for better type safety
if (lang.language == IDLOptions::kCSharp) return "TTable";
// fall through
default:
return "Table";
}
}
static std::string GenTypeGet(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
return IsScalar(type.base_type)
? GenTypeBasic(lang, parser, type)
: GenTypePointer(lang, parser, type);
}
// Find the destination type the user wants to receive the value in (e.g.
// one size higher signed types for unsigned serialized values in Java).
static Type DestinationType(const LanguageParameters &lang, const Parser &parser, const Type &type,
bool vectorelem) {
if (lang.language != IDLOptions::kJava) return type;
switch (type.base_type) {
// We use int for both uchar/ushort, since that generally means less casting
// than using short for uchar.
case BASE_TYPE_UCHAR: return Type(BASE_TYPE_INT);
case BASE_TYPE_USHORT: return Type(BASE_TYPE_INT);
case BASE_TYPE_UINT: return Type(BASE_TYPE_LONG);
case BASE_TYPE_VECTOR:
if (vectorelem)
return DestinationType(lang, parser, type.VectorType(), vectorelem);
// else fall thru:
default: return type;
}
}
static std::string GenOffsetType(const LanguageParameters &lang, const Parser &parser,
const StructDef &struct_def) {
if(lang.language == IDLOptions::kCSharp) {
return "Offset<" + WrapInNameSpace(parser, struct_def) + ">";
} else {
return "int";
}
}
static std::string GenOffsetConstruct(const LanguageParameters &lang, const Parser &parser,
const StructDef &struct_def,
const std::string &variable_name)
{
if(lang.language == IDLOptions::kCSharp) {
return "new Offset<" + WrapInNameSpace(parser, struct_def) + ">(" + variable_name + ")";
}
return variable_name;
}
static std::string GenVectorOffsetType(const LanguageParameters &lang) {
if(lang.language == IDLOptions::kCSharp) {
return "VectorOffset";
} else {
return "int";
}
}
// Generate destination type name
static std::string GenTypeNameDest(const LanguageParameters &lang, const Parser &parser, const Type &type)
{
return GenTypeGet(lang, parser, DestinationType(lang, parser, type, true));
}
// Mask to turn serialized value into destination type value.
static std::string DestinationMask(const LanguageParameters &lang,
const Type &type, bool vectorelem) {
if (lang.language != IDLOptions::kJava) return "";
switch (type.base_type) {
case BASE_TYPE_UCHAR: return " & 0xFF";
case BASE_TYPE_USHORT: return " & 0xFFFF";
case BASE_TYPE_UINT: return " & 0xFFFFFFFFL";
case BASE_TYPE_VECTOR:
if (vectorelem)
return DestinationMask(lang, type.VectorType(), vectorelem);
// else fall thru:
default: return "";
}
}
// Casts necessary to correctly read serialized data
static std::string DestinationCast(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
if (type.base_type == BASE_TYPE_VECTOR) {
return DestinationCast(lang, parser, type.VectorType());
} else {
switch (lang.language) {
case IDLOptions::kJava:
// Cast necessary to correctly read serialized unsigned values.
if (type.base_type == BASE_TYPE_UINT) return "(long)";
break;
case IDLOptions::kCSharp:
// Cast from raw integral types to enum.
if (IsEnum(type)) return "(" + WrapInNameSpace(parser, *type.enum_def) + ")";
break;
default:
break;
}
}
return "";
}
// Cast statements for mutator method parameters.
// In Java, parameters representing unsigned numbers need to be cast down to their respective type.
// For example, a long holding an unsigned int value would be cast down to int before being put onto the buffer.
// In C#, one cast directly cast an Enum to its underlying type, which is essential before putting it onto the buffer.
static std::string SourceCast(const LanguageParameters &lang, const Parser &parser,
const Type &type,
bool castFromDest) {
if (type.base_type == BASE_TYPE_VECTOR) {
return SourceCast(lang, parser, type.VectorType(), castFromDest);
} else {
switch (lang.language) {
case IDLOptions::kJava:
if (castFromDest) {
if (type.base_type == BASE_TYPE_UINT) return "(int)";
else if (type.base_type == BASE_TYPE_USHORT) return "(short)";
else if (type.base_type == BASE_TYPE_UCHAR) return "(byte)";
}
break;
case IDLOptions::kCSharp:
if (IsEnum(type)) return "(" + GenTypeBasic(lang, parser, type, false) + ")";
break;
default:
break;
}
}
return "";
}
static std::string SourceCast(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
return SourceCast(lang, parser, type, true);
}
static std::string SourceCastBasic(const LanguageParameters &lang, const Parser &parser,
const Type &type,
bool castFromDest) {
return IsScalar(type.base_type) ? SourceCast(lang, parser, type, castFromDest) : "";
}
static std::string SourceCastBasic(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
return SourceCastBasic(lang, parser, type, true);
}
static std::string GenEnumDefaultValue(const Parser &parser, const Value &value) {
auto enum_def = value.type.enum_def;
auto vec = enum_def->vals.vec;
auto default_value = StringToInt(value.constant.c_str());
auto result = value.constant;
for (auto it = vec.begin(); it != vec.end(); ++it) {
auto enum_val = **it;
if (enum_val.value == default_value) {
result = WrapInNameSpace(parser, *enum_def) + "." + enum_val.name;
break;
}
}
return result;
}
static std::string GenDefaultValue(const LanguageParameters &lang, const Parser &parser,
const Value &value, bool enableLangOverrides) {
if (enableLangOverrides) {
// handles both enum case and vector of enum case
if (lang.language == IDLOptions::kCSharp &&
value.type.enum_def != nullptr &&
value.type.base_type != BASE_TYPE_UNION) {
return GenEnumDefaultValue(parser, value);
}
}
return value.type.base_type == BASE_TYPE_BOOL
? (value.constant == "0" ? "false" : "true")
: value.constant;
}
static std::string GenDefaultValue(const LanguageParameters &lang, const Parser &parser,
const Value &value) {
return GenDefaultValue(lang, parser, value, true);
}
static std::string GenDefaultValueBasic(const LanguageParameters &lang, const Parser &parser,
const Value &value, bool enableLangOverrides) {
if (!IsScalar(value.type.base_type)) {
if (enableLangOverrides) {
if (lang.language == IDLOptions::kCSharp) {
switch (value.type.base_type) {
case BASE_TYPE_STRING:
return "default(StringOffset)";
case BASE_TYPE_STRUCT:
return "default(Offset<" + WrapInNameSpace(parser, *value.type.struct_def) + ">)";
case BASE_TYPE_VECTOR:
return "default(VectorOffset)";
default:
break;
}
}
}
return "0";
}
return GenDefaultValue(lang, parser, value, enableLangOverrides);
}
static std::string GenDefaultValueBasic(const LanguageParameters &lang, const Parser &parser,
const Value &value) {
return GenDefaultValueBasic(lang, parser, value, true);
}
static void GenEnum(const LanguageParameters &lang, const Parser &parser, EnumDef &enum_def,
std::string *code_ptr) {
std::string &code = *code_ptr;
if (enum_def.generated) return;
// Generate enum definitions of the form:
// public static (final) int name = value;
// In Java, we use ints rather than the Enum feature, because we want them
// to map directly to how they're used in C/C++ and file formats.
// That, and Java Enums are expensive, and not universally liked.
GenComment(enum_def.doc_comment, code_ptr, &lang.comment_config);
code += std::string("public ") + lang.enum_decl + enum_def.name;
if (lang.language == IDLOptions::kCSharp) {
code += lang.inheritance_marker + GenTypeBasic(lang, parser, enum_def.underlying_type, false);
}
code += lang.open_curly;
if (lang.language == IDLOptions::kJava) {
code += " private " + enum_def.name + "() { }\n";
}
for (auto it = enum_def.vals.vec.begin();
it != enum_def.vals.vec.end();
++it) {
auto &ev = **it;
GenComment(ev.doc_comment, code_ptr, &lang.comment_config, " ");
if (lang.language != IDLOptions::kCSharp) {
code += " public static";
code += lang.const_decl;
code += GenTypeBasic(lang, parser, enum_def.underlying_type, false);
}
code += " " + ev.name + " = ";
code += NumToString(ev.value);
code += lang.enum_separator;
}
// Generate a generate string table for enum values.
// We do not do that for C# where this functionality is native.
if (lang.language != IDLOptions::kCSharp) {
// 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 += "\n private static";
code += lang.const_decl;
code += lang.string_type;
code += "[] names = { ";
auto val = enum_def.vals.vec.front()->value;
for (auto it = enum_def.vals.vec.begin();
it != enum_def.vals.vec.end();
++it) {
while (val++ != (*it)->value) code += "\"\", ";
code += "\"" + (*it)->name + "\", ";
}
code += "};\n\n";
code += " public static ";
code += lang.string_type;
code += " " + MakeCamel("name", lang.first_camel_upper);
code += "(int e) { return names[e";
if (enum_def.vals.vec.front()->value)
code += " - " + enum_def.vals.vec.front()->name;
code += "]; }\n";
}
}
// Close the class
code += "};\n\n";
}
// Returns the function name that is able to read a value of the given type.
static std::string GenGetter(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
switch (type.base_type) {
case BASE_TYPE_STRING: return "__string";
case BASE_TYPE_STRUCT: return "__struct";
case BASE_TYPE_UNION: return "__union";
case BASE_TYPE_VECTOR: return GenGetter(lang, parser, type.VectorType());
default: {
std::string getter = "bb." + FunctionStart(lang, 'G') + "et";
if (type.base_type == BASE_TYPE_BOOL) {
getter = "0!=" + getter;
} else if (GenTypeBasic(lang, parser, type, false) != "byte") {
getter += MakeCamel(GenTypeBasic(lang, parser, type, false));
}
return getter;
}
}
}
// Direct mutation is only allowed for scalar fields.
// Hence a setter method will only be generated for such fields.
static std::string GenSetter(const LanguageParameters &lang, const Parser &parser,
const Type &type) {
if (IsScalar(type.base_type)) {
std::string setter = "bb." + FunctionStart(lang, 'P') + "ut";
if (GenTypeBasic(lang, parser, type, false) != "byte" &&
type.base_type != BASE_TYPE_BOOL) {
setter += MakeCamel(GenTypeBasic(lang, parser, type, false));
}
return setter;
} else {
return "";
}
}
// Returns the method name for use with add/put calls.
static std::string GenMethod(const LanguageParameters &lang, const Parser &parser, const Type &type) {
return IsScalar(type.base_type)
? MakeCamel(GenTypeBasic(lang, parser, type, false))
: (IsStruct(type) ? "Struct" : "Offset");
}
// Recursively generate arguments for a constructor, to deal with nested
// structs.
static void GenStructArgs(const LanguageParameters &lang, const Parser &parser,
const StructDef &struct_def,
std::string *code_ptr, const char *nameprefix) {
std::string &code = *code_ptr;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end();
++it) {
auto &field = **it;
if (IsStruct(field.value.type)) {
// Generate arguments for a struct inside a struct. To ensure names
// don't clash, and to make it obvious these arguments are constructing
// a nested struct, prefix the name with the field name.
GenStructArgs(lang, parser, *field.value.type.struct_def, code_ptr,
(nameprefix + (field.name + "_")).c_str());
} else {
code += ", ";
code += GenTypeBasic(lang, parser, DestinationType(lang, parser, field.value.type, false));
code += " ";
code += nameprefix;
code += MakeCamel(field.name, lang.first_camel_upper);
}
}
}
// Recusively generate struct construction statements of the form:
// builder.putType(name);
// and insert manual padding.
static void GenStructBody(const LanguageParameters &lang, const Parser &parser,
const StructDef &struct_def,
std::string *code_ptr, const char *nameprefix) {
std::string &code = *code_ptr;
code += " builder." + FunctionStart(lang, 'P') + "rep(";
code += NumToString(struct_def.minalign) + ", ";
code += NumToString(struct_def.bytesize) + ");\n";
for (auto it = struct_def.fields.vec.rbegin();
it != struct_def.fields.vec.rend(); ++it) {
auto &field = **it;
if (field.padding) {
code += " builder." + FunctionStart(lang, 'P') + "ad(";
code += NumToString(field.padding) + ");\n";
}
if (IsStruct(field.value.type)) {
GenStructBody(lang, parser, *field.value.type.struct_def, code_ptr,
(nameprefix + (field.name + "_")).c_str());
} else {
code += " builder." + FunctionStart(lang, 'P') + "ut";
code += GenMethod(lang, parser, field.value.type) + "(";
code += SourceCast(lang, parser, field.value.type);
auto argname = nameprefix + MakeCamel(field.name, lang.first_camel_upper);
code += argname;
code += ");\n";
}
}
}
static void GenStruct(const LanguageParameters &lang, const Parser &parser,
StructDef &struct_def, std::string *code_ptr) {
if (struct_def.generated) return;
std::string &code = *code_ptr;
// Generate a struct accessor class, with methods of the form:
// public type name() { return bb.getType(i + offset); }
// or for tables of the form:
// public type name() {
// int o = __offset(offset); return o != 0 ? bb.getType(o + i) : default;
// }
GenComment(struct_def.doc_comment, code_ptr, &lang.comment_config);
code += "public ";
if (lang.language == IDLOptions::kCSharp &&
struct_def.attributes.Lookup("csharp_partial")) {
// generate a partial class for this C# struct/table
code += "partial ";
}
else {
code += lang.unsubclassable_decl;
}
code += "class " + struct_def.name + lang.inheritance_marker;
code += struct_def.fixed ? "Struct" : "Table";
code += " {\n";
if (!struct_def.fixed) {
// Generate a special accessor for the table that when used as the root
// of a FlatBuffer
std::string method_name = FunctionStart(lang, 'G') + "etRootAs" + struct_def.name;
std::string method_signature = " public static " + struct_def.name + " " + method_name;
// create convenience method that doesn't require an existing object
code += method_signature + "(ByteBuffer _bb) ";
code += "{ return " + method_name + "(_bb, new " + struct_def.name+ "()); }\n";
// create method that allows object reuse
code += method_signature + "(ByteBuffer _bb, " + struct_def.name + " obj) { ";
code += lang.set_bb_byteorder;
code += "return (obj.__init(_bb." + FunctionStart(lang, 'G');
code += "etInt(_bb.";
code += lang.get_bb_position;
code += ") + _bb.";
code += lang.get_bb_position;
code += ", _bb)); }\n";
if (parser.root_struct_def_ == &struct_def) {
if (parser.file_identifier_.length()) {
// Check if a buffer has the identifier.
code += " public static ";
code += lang.bool_type + struct_def.name;
code += "BufferHasIdentifier(ByteBuffer _bb) { return ";
code += "__has_identifier(_bb, \"" + parser.file_identifier_;
code += "\"); }\n";
}
}
}
// Generate the __init method that sets the field in a pre-existing
// accessor object. This is to allow object reuse.
code += " public " + struct_def.name;
code += " __init(int _i, ByteBuffer _bb) ";
code += "{ bb_pos = _i; bb = _bb; return this; }\n\n";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end();
++it) {
auto &field = **it;
if (field.deprecated) continue;
GenComment(field.doc_comment, code_ptr, &lang.comment_config, " ");
std::string type_name = GenTypeGet(lang, parser, field.value.type);
std::string type_name_dest = GenTypeNameDest(lang, parser, field.value.type);
std::string dest_mask = DestinationMask(lang, field.value.type, true);
std::string dest_cast = DestinationCast(lang, parser, field.value.type);
std::string src_cast = SourceCast(lang, parser, field.value.type);
std::string method_start = " public " + type_name_dest + " " +
MakeCamel(field.name, lang.first_camel_upper);
// Most field accessors need to retrieve and test the field offset first,
// this is the prefix code for that:
auto offset_prefix = " { int o = __offset(" +
NumToString(field.value.offset) +
"); return o != 0 ? ";
// Generate the accessors that don't do object reuse.
if (field.value.type.base_type == BASE_TYPE_STRUCT) {
// Calls the accessor that takes an accessor object with a new object.
if (lang.language == IDLOptions::kCSharp) {
code += method_start + " { get { return Get";
code += MakeCamel(field.name, lang.first_camel_upper);
code += "(new ";
code += type_name + "()); } }\n";
method_start = " public " + type_name_dest + " Get" + MakeCamel(field.name, lang.first_camel_upper);
}
else {
code += method_start + "() { return ";
code += MakeCamel(field.name, lang.first_camel_upper);
code += "(new ";
code += type_name + "()); }\n";
}
} else if (field.value.type.base_type == BASE_TYPE_VECTOR &&
field.value.type.element == BASE_TYPE_STRUCT) {
// Accessors for vectors of structs also take accessor objects, this
// generates a variant without that argument.
if (lang.language == IDLOptions::kCSharp) {
method_start = " public " + type_name_dest + " Get" + MakeCamel(field.name, lang.first_camel_upper);
code += method_start + "(int j) { return Get";
} else {
code += method_start + "(int j) { return ";
}
code += MakeCamel(field.name, lang.first_camel_upper);
code += "(new ";
code += type_name + "(), j); }\n";
} else if (field.value.type.base_type == BASE_TYPE_VECTOR) {
if (lang.language == IDLOptions::kCSharp) {
method_start = " public " + type_name_dest + " Get" + MakeCamel(field.name, lang.first_camel_upper);
}
} else if (field.value.type.base_type == BASE_TYPE_UNION) {
if (lang.language == IDLOptions::kCSharp) {
// union types in C# use generic Table-derived type for better type safety
method_start = " public " + type_name_dest + " Get" + MakeCamel(field.name, lang.first_camel_upper) + "<TTable>";
offset_prefix = " where TTable : Table" + offset_prefix;
type_name = type_name_dest;
}
}
std::string getter = dest_cast + GenGetter(lang, parser, field.value.type);
code += method_start;
std::string default_cast = "";
// only create default casts for c# scalars or vectors of scalars
if (lang.language == IDLOptions::kCSharp &&
(IsScalar(field.value.type.base_type) ||
(field.value.type.base_type == BASE_TYPE_VECTOR && IsScalar(field.value.type.element)))) {
// For scalars, default value will be returned by GetDefaultValue(). If the scalar is an enum, GetDefaultValue()
// returns an actual c# enum that doesn't need to be casted. However, default values for enum elements of
// vectors are integer literals ("0") and are still casted for clarity.
if (field.value.type.enum_def == nullptr || field.value.type.base_type == BASE_TYPE_VECTOR) {
default_cast = "(" + type_name_dest + ")";
}
}
std::string member_suffix = "";
if (IsScalar(field.value.type.base_type)) {
code += lang.getter_prefix;
member_suffix = lang.getter_suffix;
if (struct_def.fixed) {
code += " { return " + getter;
code += "(bb_pos + " + NumToString(field.value.offset) + ")";
code += dest_mask;
} else {
code += offset_prefix + getter;
code += "(o + bb_pos)" + dest_mask + " : " + default_cast;
code += GenDefaultValue(lang, parser, field.value);
}
} else {
switch (field.value.type.base_type) {
case BASE_TYPE_STRUCT:
code += "(" + type_name + " obj";
if (struct_def.fixed) {
code += ") { return obj.__init(bb_pos + ";
code += NumToString(field.value.offset) + ", bb)";
} else {
code += ")";
code += offset_prefix;
code += "obj.__init(";
code += field.value.type.struct_def->fixed
? "o + bb_pos"
: "__indirect(o + bb_pos)";
code += ", bb) : null";
}
break;
case BASE_TYPE_STRING:
code += lang.getter_prefix;
member_suffix = lang.getter_suffix;
code += offset_prefix + getter + "(o + bb_pos) : null";
break;
case BASE_TYPE_VECTOR: {
auto vectortype = field.value.type.VectorType();
code += "(";
if (vectortype.base_type == BASE_TYPE_STRUCT) {
code += type_name + " obj, ";
getter = "obj.__init";
}
code += "int j)" + offset_prefix + getter +"(";
auto index = "__vector(o) + j * " +
NumToString(InlineSize(vectortype));
if (vectortype.base_type == BASE_TYPE_STRUCT) {
code += vectortype.struct_def->fixed
? index
: "__indirect(" + index + ")";
code += ", bb";
} else {
code += index;
}
code += ")" + dest_mask + " : ";
code += field.value.type.element == BASE_TYPE_BOOL ? "false" :
(IsScalar(field.value.type.element) ? default_cast + "0" : "null");
break;
}
case BASE_TYPE_UNION:
code += "(" + type_name + " obj)" + offset_prefix + getter;
code += "(obj, o) : null";
break;
default:
assert(0);
}
}
code += "; ";
code += member_suffix;
code += "}\n";
if (field.value.type.base_type == BASE_TYPE_VECTOR) {
code += " public int " + MakeCamel(field.name, lang.first_camel_upper);
code += "Length";
code += lang.getter_prefix;
code += offset_prefix;
code += "__vector_len(o) : 0; ";
code += lang.getter_suffix;
code += "}\n";
}
// Generate a ByteBuffer accessor for strings & vectors of scalars.
if ((field.value.type.base_type == BASE_TYPE_VECTOR &&
IsScalar(field.value.type.VectorType().base_type)) ||
field.value.type.base_type == BASE_TYPE_STRING) {
switch (lang.language) {
case IDLOptions::kJava:
code += " public ByteBuffer ";
code += MakeCamel(field.name, lang.first_camel_upper);
code += "AsByteBuffer() { return __vector_as_bytebuffer(";
code += NumToString(field.value.offset) + ", ";
code += NumToString(field.value.type.base_type == BASE_TYPE_STRING ? 1 :
InlineSize(field.value.type.VectorType()));
code += "); }\n";
break;
case IDLOptions::kCSharp:
code += " public ArraySegment<byte>? Get";
code += MakeCamel(field.name, lang.first_camel_upper);
code += "Bytes() { return __vector_as_arraysegment(";
code += NumToString(field.value.offset);
code += "); }\n";
break;
default:
break;
}
}
// generate object accessors if is nested_flatbuffer
auto nested = field.attributes.Lookup("nested_flatbuffer");
if (nested) {
auto nested_qualified_name =
parser.namespaces_.back()->GetFullyQualifiedName(nested->constant);
auto nested_type = parser.structs_.Lookup(nested_qualified_name);
auto nested_type_name = WrapInNameSpace(parser, *nested_type);
auto nestedMethodName = MakeCamel(field.name, lang.first_camel_upper)
+ "As" + nested_type_name;
auto getNestedMethodName = nestedMethodName;
if (lang.language == IDLOptions::kCSharp) {
getNestedMethodName = "Get" + nestedMethodName;
}
code += " public " + nested_type_name + " ";
code += nestedMethodName + "() { return ";
code += getNestedMethodName + "(new " + nested_type_name + "()); }\n";
code += " public " + nested_type_name + " " + getNestedMethodName;
code += "(" + nested_type_name + " obj) { ";
code += "int o = __offset(" + NumToString(field.value.offset) +"); ";
code += "return o != 0 ? obj.__init(__indirect(__vector(o)), bb) : null; }\n";
}
// generate mutators for scalar fields or vectors of scalars
if (parser.opts.mutable_buffer) {
auto underlying_type = field.value.type.base_type == BASE_TYPE_VECTOR
? field.value.type.VectorType()
: field.value.type;
// boolean parameters have to be explicitly converted to byte representation
auto setter_parameter = underlying_type.base_type == BASE_TYPE_BOOL ? "(byte)(" + field.name + " ? 1 : 0)" : field.name;
auto mutator_prefix = MakeCamel("mutate", lang.first_camel_upper);
//a vector mutator also needs the index of the vector element it should mutate
auto mutator_params = (field.value.type.base_type == BASE_TYPE_VECTOR ? "(int j, " : "(") +
GenTypeNameDest(lang, parser, underlying_type) + " " +
field.name + ") { ";
auto setter_index = field.value.type.base_type == BASE_TYPE_VECTOR
? "__vector(o) + j * " + NumToString(InlineSize(underlying_type))
: (struct_def.fixed ? "bb_pos + " + NumToString(field.value.offset) : "o + bb_pos");
if (IsScalar(field.value.type.base_type) ||
(field.value.type.base_type == BASE_TYPE_VECTOR &&
IsScalar(field.value.type.VectorType().base_type))) {
code += " public ";
code += struct_def.fixed ? "void " : lang.bool_type;
code += mutator_prefix + MakeCamel(field.name, true);
code += mutator_params;
if (struct_def.fixed) {
code += GenSetter(lang, parser, underlying_type) + "(" + setter_index + ", ";
code += src_cast + setter_parameter + "); }\n";
} else {
code += "int o = __offset(" + NumToString(field.value.offset) + ");";
code += " if (o != 0) { " + GenSetter(lang, parser, underlying_type);
code += "(" + setter_index + ", " + src_cast + setter_parameter + "); return true; } else { return false; } }\n";
}
}
}
}
code += "\n";
if (struct_def.fixed) {
// create a struct constructor function
code += " public static " + GenOffsetType(lang, parser, struct_def) + " ";
code += FunctionStart(lang, 'C') + "reate";
code += struct_def.name + "(FlatBufferBuilder builder";
GenStructArgs(lang, parser, struct_def, code_ptr, "");
code += ") {\n";
GenStructBody(lang, parser, struct_def, code_ptr, "");
code += " return ";
code += GenOffsetConstruct(lang, parser, struct_def, "builder." + std::string(lang.get_fbb_offset));
code += ";\n }\n";
} else {
// Generate a method that creates a table in one go. This is only possible
// when the table has no struct fields, since those have to be created
// inline, and there's no way to do so in Java.
bool has_no_struct_fields = true;
int num_fields = 0;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
auto &field = **it;
if (field.deprecated) continue;
if (IsStruct(field.value.type)) {
has_no_struct_fields = false;
} else {
num_fields++;
}
}
if (has_no_struct_fields && num_fields) {
// Generate a table constructor of the form:
// public static int createName(FlatBufferBuilder builder, args...)
code += " public static " + GenOffsetType(lang, parser, struct_def) + " ";
code += FunctionStart(lang, 'C') + "reate" + struct_def.name;
code += "(FlatBufferBuilder builder";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
auto &field = **it;
if (field.deprecated) continue;
code += ",\n ";
code += GenTypeBasic(lang, parser, DestinationType(lang, parser, field.value.type, false));
code += " ";
code += field.name;
if (!IsScalar(field.value.type.base_type)) code += "Offset";
// Java doesn't have defaults, which means this method must always
// supply all arguments, and thus won't compile when fields are added.
if (lang.language != IDLOptions::kJava) {
code += " = ";
code += GenDefaultValueBasic(lang, parser, field.value);
}
}
code += ") {\n builder.";
code += FunctionStart(lang, 'S') + "tartObject(";
code += NumToString(struct_def.fields.vec.size()) + ");\n";
for (size_t size = struct_def.sortbysize ? sizeof(largest_scalar_t) : 1;
size;
size /= 2) {
for (auto it = struct_def.fields.vec.rbegin();
it != struct_def.fields.vec.rend(); ++it) {
auto &field = **it;
if (!field.deprecated &&
(!struct_def.sortbysize ||
size == SizeOf(field.value.type.base_type))) {
code += " " + struct_def.name + ".";
code += FunctionStart(lang, 'A') + "dd";
code += MakeCamel(field.name) + "(builder, " + field.name;
if (!IsScalar(field.value.type.base_type)) code += "Offset";
code += ");\n";
}
}
}
code += " return " + struct_def.name + ".";
code += FunctionStart(lang, 'E') + "nd" + struct_def.name;
code += "(builder);\n }\n\n";
}
// Generate a set of static methods that allow table construction,
// of the form:
// public static void addName(FlatBufferBuilder builder, short name)
// { builder.addShort(id, name, default); }
// Unlike the Create function, these always work.
code += " public static void " + FunctionStart(lang, 'S') + "tart";
code += struct_def.name;
code += "(FlatBufferBuilder builder) { builder.";
code += FunctionStart(lang, 'S') + "tartObject(";
code += NumToString(struct_def.fields.vec.size()) + "); }\n";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end(); ++it) {
auto &field = **it;
if (field.deprecated) continue;
code += " public static void " + FunctionStart(lang, 'A') + "dd";
code += MakeCamel(field.name);
code += "(FlatBufferBuilder builder, ";
code += GenTypeBasic(lang, parser, DestinationType(lang, parser, field.value.type, false));
auto argname = MakeCamel(field.name, false);
if (!IsScalar(field.value.type.base_type)) argname += "Offset";
code += " " + argname + ") { builder." + FunctionStart(lang, 'A') + "dd";
code += GenMethod(lang, parser, field.value.type) + "(";
code += NumToString(it - struct_def.fields.vec.begin()) + ", ";
code += SourceCastBasic(lang, parser, field.value.type);
code += argname;
if(!IsScalar(field.value.type.base_type) && field.value.type.base_type != BASE_TYPE_UNION && lang.language == IDLOptions::kCSharp) {
code += ".Value";
}
code += ", " + GenDefaultValue(lang, parser, field.value, false);
code += "); }\n";
if (field.value.type.base_type == BASE_TYPE_VECTOR) {
auto vector_type = field.value.type.VectorType();
auto alignment = InlineAlignment(vector_type);
auto elem_size = InlineSize(vector_type);
if (!IsStruct(vector_type)) {
// Generate a method to create a vector from a Java array.
code += " public static " + GenVectorOffsetType(lang) + " " + FunctionStart(lang, 'C') + "reate";
code += MakeCamel(field.name);
code += "Vector(FlatBufferBuilder builder, ";
code += GenTypeBasic(lang, parser, vector_type) + "[] data) ";
code += "{ builder." + FunctionStart(lang, 'S') + "tartVector(";
code += NumToString(elem_size);
code += ", data." + FunctionStart(lang, 'L') + "ength, ";
code += NumToString(alignment);
code += "); for (int i = data.";
code += FunctionStart(lang, 'L') + "ength - 1; i >= 0; i--) builder.";
code += FunctionStart(lang, 'A') + "dd";
code += GenMethod(lang, parser, vector_type);
code += "(";
code += SourceCastBasic(lang, parser, vector_type, false);
code += "data[i]";
if (lang.language == IDLOptions::kCSharp &&
(vector_type.base_type == BASE_TYPE_STRUCT || vector_type.base_type == BASE_TYPE_STRING))
code += ".Value";
code += "); return ";
code += "builder." + FunctionStart(lang, 'E') + "ndVector(); }\n";
}
// Generate a method to start a vector, data to be added manually after.
code += " public static void " + FunctionStart(lang, 'S') + "tart";
code += MakeCamel(field.name);
code += "Vector(FlatBufferBuilder builder, int numElems) ";
code += "{ builder." + FunctionStart(lang, 'S') + "tartVector(";
code += NumToString(elem_size);
code += ", numElems, " + NumToString(alignment);
code += "); }\n";
}
}
code += " public static " + GenOffsetType(lang, parser, struct_def) + " ";
code += FunctionStart(lang, 'E') + "nd" + struct_def.name;
code += "(FlatBufferBuilder builder) {\n int o = builder.";
code += FunctionStart(lang, 'E') + "ndObject();\n";
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end();
++it) {
auto &field = **it;
if (!field.deprecated && field.required) {
code += " builder." + FunctionStart(lang, 'R') + "equired(o, ";
code += NumToString(field.value.offset);
code += "); // " + field.name + "\n";
}
}
code += " return " + GenOffsetConstruct(lang, parser, struct_def, "o") + ";\n }\n";
if (parser.root_struct_def_ == &struct_def) {
code += " public static void ";
code += FunctionStart(lang, 'F') + "inish" + struct_def.name;
code += "Buffer(FlatBufferBuilder builder, " + GenOffsetType(lang, parser, struct_def) + " offset) {";
code += " builder." + FunctionStart(lang, 'F') + "inish(offset";
if (lang.language == IDLOptions::kCSharp) {
code += ".Value";
}
if (parser.file_identifier_.length())
code += ", \"" + parser.file_identifier_ + "\"";
code += "); }\n";
}
}
code += "};\n\n";
}
// Save out the generated code for a single class while adding
// declaration boilerplate.
static bool SaveClass(const LanguageParameters &lang, const Parser &parser,
const std::string &defname, const std::string &classcode,
const std::string &path, bool needs_includes, bool onefile) {
if (!classcode.length()) return true;
std::string namespace_general;
std::string namespace_dir = path; // Either empty or ends in separator.
auto &namespaces = parser.namespaces_.back()->components;
for (auto it = namespaces.begin(); it != namespaces.end(); ++it) {
if (namespace_general.length()) {
namespace_general += ".";
}
namespace_general += *it;
if (!onefile) {
namespace_dir += *it + kPathSeparator;
}
}
EnsureDirExists(namespace_dir);
std::string code = "// automatically generated, do not modify\n\n";
if (!namespace_general.empty()) {
code += lang.namespace_ident + namespace_general + lang.namespace_begin;
code += "\n\n";
}
if (needs_includes) code += lang.includes;
code += classcode;
if (!namespace_general.empty()) code += lang.namespace_end;
auto filename = namespace_dir + defname + lang.file_extension;
return SaveFile(filename.c_str(), code, false);
}
bool GenerateGeneral(const Parser &parser,
const std::string &path,
const std::string & file_name) {
assert(parser.opts.lang <= IDLOptions::kMAX);
auto lang = language_parameters[parser.opts.lang];
std::string one_file_code;
for (auto it = parser.enums_.vec.begin();
it != parser.enums_.vec.end(); ++it) {
std::string enumcode;
GenEnum(lang, parser, **it, &enumcode);
if (parser.opts.one_file) {
one_file_code += enumcode;
}
else {
if (!SaveClass(lang, parser, (**it).name, enumcode, path, false, false))
return false;
}
}
for (auto it = parser.structs_.vec.begin();
it != parser.structs_.vec.end(); ++it) {
std::string declcode;
GenStruct(lang, parser, **it, &declcode);
if (parser.opts.one_file) {
one_file_code += declcode;
}
else {
if (!SaveClass(lang, parser, (**it).name, declcode, path, true, false))
return false;
}
}
if (parser.opts.one_file) {
return SaveClass(lang, parser, file_name, one_file_code,path, true, true);
}
return true;
}
static std::string ClassFileName(const LanguageParameters &lang,
const Parser &parser, const Definition &def,
const std::string &path) {
std::string namespace_general;
std::string namespace_dir = path;
auto &namespaces = parser.namespaces_.back()->components;
for (auto it = namespaces.begin(); it != namespaces.end(); ++it) {
if (namespace_general.length()) {
namespace_general += ".";
namespace_dir += kPathSeparator;
}
namespace_general += *it;
namespace_dir += *it;
}
return namespace_dir + kPathSeparator + def.name + lang.file_extension;
}
std::string GeneralMakeRule(const Parser &parser,
const std::string &path,
const std::string &file_name) {
assert(parser.opts.lang <= IDLOptions::kMAX);
auto lang = language_parameters[parser.opts.lang];
std::string make_rule;
for (auto it = parser.enums_.vec.begin();
it != parser.enums_.vec.end(); ++it) {
if (make_rule != "")
make_rule += " ";
make_rule += ClassFileName(lang, parser, **it, path);
}
for (auto it = parser.structs_.vec.begin();
it != parser.structs_.vec.end(); ++it) {
if (make_rule != "")
make_rule += " ";
make_rule += ClassFileName(lang, parser, **it, path);
}
make_rule += ": ";
auto included_files = parser.GetIncludedFilesRecursive(file_name);
for (auto it = included_files.begin();
it != included_files.end(); ++it) {
make_rule += " " + *it;
}
return make_rule;
}
std::string BinaryFileName(const Parser &parser,
const std::string &path,
const std::string &file_name) {
auto ext = parser.file_extension_.length() ? parser.file_extension_ : "bin";
return path + file_name + "." + ext;
}
bool GenerateBinary(const Parser &parser,
const std::string &path,
const std::string &file_name) {
return !parser.builder_.GetSize() ||
flatbuffers::SaveFile(
BinaryFileName(parser, path, file_name).c_str(),
reinterpret_cast<char *>(parser.builder_.GetBufferPointer()),
parser.builder_.GetSize(),
true);
}
std::string BinaryMakeRule(const Parser &parser,
const std::string &path,
const std::string &file_name) {
if (!parser.builder_.GetSize()) return "";
std::string filebase = flatbuffers::StripPath(
flatbuffers::StripExtension(file_name));
std::string make_rule = BinaryFileName(parser, path, filebase) + ": " +
file_name;
auto included_files = parser.GetIncludedFilesRecursive(
parser.root_struct_def_->file);
for (auto it = included_files.begin();
it != included_files.end(); ++it) {
make_rule += " " + *it;
}
return make_rule;
}
} // namespace flatbuffers
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