/*

* 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"

namespace flatbuffers {

namespace js {

static void GenNamespaces(const Parser &parser, std::string *code_ptr,

std::string *exports_ptr) {

std::set<std::string> namespaces;

for (auto it = parser.namespaces_.begin();

it != parser.namespaces_.end(); ++it) {

std::string namespace_so_far;

// Gather all parent namespaces for this namespace

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

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

if (!namespace_so_far.empty()) {

namespace_so_far += '.';

}

namespace_so_far += *component;

namespaces.insert(namespace_so_far);

}

}

// Make sure parent namespaces come before child namespaces

std::vector<std::string> sorted_namespaces(

namespaces.begin(), namespaces.end());

std::sort(sorted_namespaces.begin(), sorted_namespaces.end());

// Emit namespaces in a form that Closure Compiler can optimize

std::string &code = *code_ptr;

std::string &exports = *exports_ptr;

for (auto it = sorted_namespaces.begin();

it != sorted_namespaces.end(); it++) {

code += "/**\n * @const\n*/\n";

if (it->find('.') == std::string::npos) {

code += "var ";

exports += "this." + *it + " = " + *it + ";\n";

}

code += *it + " = " + *it + " || {};\n\n";

}

}

// Ensure that a type is prefixed with its namespace whenever it is used

// outside of its namespace.

static std::string WrapInNameSpace(const Namespace *ns,

const std::string &name) {

std::string qualified_name;

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

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

qualified_name += *it + ".";

}

return qualified_name + name;

}

static std::string WrapInNameSpace(const Definition &def) {

return WrapInNameSpace(def.defined_namespace, def.name);

}

// Generate a documentation comment, if available.

static void GenDocComment(const std::vector<std::string> &dc,

std::string *code_ptr,

const std::string &extra_lines,

const char *indent = nullptr) {

if (dc.empty() && extra_lines.empty()) {

// Don't output empty comment blocks with 0 lines of comment content.

return;

}

std::string &code = *code_ptr;

if (indent) code += indent;

code += "/**\n";

for (auto it = dc.begin(); it != dc.end(); ++it) {

if (indent) code += indent;

code += " *" + *it + "\n";

}

if (!extra_lines.empty()) {

if (!dc.empty()) {

if (indent) code += indent;

code += " *\n";

}

if (indent) code += indent;

std::string::size_type start = 0;

for (;;) {

auto end = extra_lines.find('\n', start);

if (end != std::string::npos) {

code += " * " + extra_lines.substr(start, end - start) + "\n";

start = end + 1;

} else {

code += " * " + extra_lines.substr(start) + "\n";

break;

}

}

}

if (indent) code += indent;

code += " */\n";

}

static void GenDocComment(std::string *code_ptr,

const std::string &extra_lines) {

GenDocComment(std::vector<std::string>(), code_ptr, extra_lines);

}

// Generate an enum declaration and an enum string lookup table.

static void GenEnum(EnumDef &enum_def, std::string *code_ptr,

std::string *exports_ptr) {

if (enum_def.generated) return;

std::string &code = *code_ptr;

std::string &exports = *exports_ptr;

GenDocComment(enum_def.doc_comment, code_ptr, "@enum");

if (enum_def.defined_namespace->components.empty()) {

code += "var ";

exports += "this." + enum_def.name + " = " + enum_def.name + ";\n";

}

code += WrapInNameSpace(enum_def) + " = {\n";

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

it != enum_def.vals.vec.end(); ++it) {

auto &ev = **it;

if (!ev.doc_comment.empty()) {

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

code += '\n';

}

GenDocComment(ev.doc_comment, code_ptr, "", " ");

}

code += " " + ev.name + ": " + NumToString(ev.value);

code += (it + 1) != enum_def.vals.vec.end() ? ",\n" : "\n";

}

code += "};\n\n";

}

static std::string GenType(const Type &type) {

switch (type.base_type) {

case BASE_TYPE_BOOL:

case BASE_TYPE_CHAR: return "Int8";

case BASE_TYPE_UTYPE:

case BASE_TYPE_UCHAR: return "Uint8";

case BASE_TYPE_SHORT: return "Int16";

case BASE_TYPE_USHORT: return "Uint16";

case BASE_TYPE_INT: return "Int32";

case BASE_TYPE_UINT: return "Uint32";

case BASE_TYPE_LONG: return "Int64";

case BASE_TYPE_ULONG: return "Uint64";

case BASE_TYPE_FLOAT: return "Float32";

case BASE_TYPE_DOUBLE: return "Float64";

case BASE_TYPE_STRING: return "String";

case BASE_TYPE_VECTOR: return GenType(type.VectorType());

case BASE_TYPE_STRUCT: return type.struct_def->name;

default: return "Table";

}

}

static std::string GenGetter(const Type &type, const std::string &arguments) {

switch (type.base_type) {

case BASE_TYPE_STRING: return "this.bb.__string" + arguments;

case BASE_TYPE_STRUCT: return "this.bb.__struct" + arguments;

case BASE_TYPE_UNION: return "this.bb.__union" + arguments;

case BASE_TYPE_VECTOR: return GenGetter(type.VectorType(), arguments);

default: {

auto getter = "this.bb.read" + MakeCamel(GenType(type)) + arguments;

if (type.base_type == BASE_TYPE_BOOL) {

getter = "!!" + getter;

}

if (type.enum_def) {

getter = "/** @type {" + WrapInNameSpace(*type.enum_def) + "} */ (" +

getter + ")";

}

return getter;

}

}

}

static std::string GenDefaultValue(const Value &value) {

if (value.type.enum_def) {

if (auto val = value.type.enum_def->ReverseLookup(

atoi(value.constant.c_str()), false)) {

return WrapInNameSpace(*value.type.enum_def) + "." + val->name;

}

}

switch (value.type.base_type) {

case BASE_TYPE_BOOL:

return value.constant == "0" ? "false" : "true";

case BASE_TYPE_STRING:

return "null";

case BASE_TYPE_LONG:

case BASE_TYPE_ULONG:

if (value.constant != "0") {

int64_t constant = StringToInt(value.constant.c_str());

return "new flatbuffers.Long(" + NumToString((int32_t)constant) +

", " + NumToString((int32_t)(constant >> 32)) + ")";

}

return "flatbuffers.Long.ZERO";

default:

return value.constant;

}

}

static std::string GenTypeName(const Type &type, bool input) {

if (!input) {

if (type.base_type == BASE_TYPE_STRING) {

return "string|Uint8Array";

}

if (type.base_type == BASE_TYPE_STRUCT) {

return WrapInNameSpace(*type.struct_def);

}

}

switch (type.base_type) {

case BASE_TYPE_BOOL: return "boolean";

case BASE_TYPE_LONG:

case BASE_TYPE_ULONG: return "flatbuffers.Long";

default:

if (IsScalar(type.base_type)) {

if (type.enum_def) {

return WrapInNameSpace(*type.enum_def);

}

return "number";

}

return "flatbuffers.Offset";

}

}

// Returns the method name for use with add/put calls.

static std::string GenWriteMethod(const Type &type) {

// Forward to signed versions since unsigned versions don't exist

switch (type.base_type) {

case BASE_TYPE_UTYPE:

case BASE_TYPE_UCHAR: return GenWriteMethod(Type(BASE_TYPE_CHAR));

case BASE_TYPE_USHORT: return GenWriteMethod(Type(BASE_TYPE_SHORT));

case BASE_TYPE_UINT: return GenWriteMethod(Type(BASE_TYPE_INT));

case BASE_TYPE_ULONG: return GenWriteMethod(Type(BASE_TYPE_LONG));

default: break;

}

return IsScalar(type.base_type)

? MakeCamel(GenType(type))

: (IsStruct(type) ? "Struct" : "Offset");

}

template <typename T>

static std::string MaybeAdd(T value) {

return value != 0 ? " + " + NumToString(value) : "";

}

template <typename T>

static std::string MaybeScale(T value) {

return value != 1 ? " * " + NumToString(value) : "";

}

static void GenStructArgs(const StructDef &struct_def,

std::string *annotations,

std::string *arguments,

const std::string &nameprefix) {

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(*field.value.type.struct_def, annotations, arguments,

nameprefix + field.name + "_");

} else {

*annotations += "@param {" + GenTypeName(field.value.type, true);

*annotations += "} " + nameprefix + field.name + "\n";

*arguments += ", " + nameprefix + field.name;

}

}

}

static void GenStructBody(const StructDef &struct_def,

std::string *body,

const std::string &nameprefix) {

*body += " builder.prep(";

*body += NumToString(struct_def.minalign) + ", ";

*body += 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) {

*body += " builder.pad(" + NumToString(field.padding) + ");\n";

}

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.

GenStructBody(*field.value.type.struct_def, body,

nameprefix + field.name + "_");

} else {

*body += " builder.write" + GenWriteMethod(field.value.type) + "(";

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

*body += "+";

}

*body += nameprefix + field.name + ");\n";

}

}

}

// Generate an accessor struct with constructor for a flatbuffers struct.

static void GenStruct(const Parser &parser, StructDef &struct_def,

std::string *code_ptr, std::string *exports_ptr) {

if (struct_def.generated) return;

std::string &code = *code_ptr;

std::string &exports = *exports_ptr;

// Emit constructor

bool isStatement = struct_def.defined_namespace->components.empty();

std::string object_name = WrapInNameSpace(struct_def);

GenDocComment(struct_def.doc_comment, code_ptr, "@constructor");

if (isStatement) {

exports += "this." + struct_def.name + " = " + struct_def.name + ";\n";

code += "function " + object_name;

} else {

code += object_name + " = function";

}

code += "() {\n";

code += " /**\n";

code += " * @type {flatbuffers.ByteBuffer}\n";

code += " */\n";

code += " this.bb = null;\n";

code += "\n";

code += " /**\n";

code += " * @type {number}\n";

code += " */\n";

code += " this.bb_pos = 0;\n";

code += isStatement ? "}\n\n" : "};\n\n";

// Generate the __init method that sets the field in a pre-existing

// accessor object. This is to allow object reuse.

code += "/**\n";

code += " * @param {number} i\n";

code += " * @param {flatbuffers.ByteBuffer} bb\n";

code += " * @returns {" + object_name + "}\n";

code += " */\n";

code += object_name + ".prototype.__init = function(i, bb) {\n";

code += " this.bb_pos = i;\n";

code += " this.bb = bb;\n";

code += " return this;\n";

code += "};\n\n";

// Generate a special accessor for the table that when used as the root of a

// FlatBuffer

if (!struct_def.fixed) {

GenDocComment(code_ptr,

"@param {flatbuffers.ByteBuffer} bb\n"

"@param {" + object_name + "=} obj\n"

"@returns {" + object_name + "}");

code += object_name + ".getRootAs" + struct_def.name;

code += " = function(bb, obj) {\n";

code += " return (obj || new " + object_name;

code += ").__init(bb.readInt32(bb.position()) + bb.position(), bb);\n";

code += "};\n\n";

// Generate the identifier check method

if (parser.root_struct_def_ == &struct_def &&

!parser.file_identifier_.empty()) {

GenDocComment(code_ptr,

"@param {flatbuffers.ByteBuffer} bb\n"

"@returns {boolean}");

code += object_name + ".bufferHasIdentifier = function(bb) {\n";

code += " return bb.__has_identifier('" + parser.file_identifier_;

code += "');\n};\n\n";

}

}

// Emit field accessors

for (auto it = struct_def.fields.vec.begin();

it != struct_def.fields.vec.end(); ++it) {

auto &field = **it;

if (field.deprecated) continue;

auto offset_prefix = " var offset = this.bb.__offset(this.bb_pos, " +

NumToString(field.value.offset) + ");\n return offset ? ";

// Emit a scalar field

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

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

GenDocComment(field.doc_comment, code_ptr,

std::string(field.value.type.base_type == BASE_TYPE_STRING ?

"@param {flatbuffers.Encoding=} optionalEncoding\n" : "") +

"@returns {" + GenTypeName(field.value.type, false) + "}");

code += object_name + ".prototype." + MakeCamel(field.name, false);

code += " = function(";

if (field.value.type.base_type == BASE_TYPE_STRING) {

code += "optionalEncoding";

}

code += ") {\n";

if (struct_def.fixed) {

code += " return " + GenGetter(field.value.type, "(this.bb_pos" +

MaybeAdd(field.value.offset) + ")") + ";\n";

} else {

std::string index = "this.bb_pos + offset";

if (field.value.type.base_type == BASE_TYPE_STRING) {

index += ", optionalEncoding";

}

code += offset_prefix + GenGetter(field.value.type,

"(" + index + ")") + " : " + GenDefaultValue(field.value);

code += ";\n";

}

}

// Emit an object field

else {

switch (field.value.type.base_type) {

case BASE_TYPE_STRUCT: {

auto type = WrapInNameSpace(*field.value.type.struct_def);

GenDocComment(field.doc_comment, code_ptr,

"@param {" + type + "=} obj\n@returns {" + type + "}");

code += object_name + ".prototype." + MakeCamel(field.name, false);

code += " = function(obj) {\n";

if (struct_def.fixed) {

code += " return (obj || new " + type;

code += ").__init(this.bb_pos";

code += MaybeAdd(field.value.offset) + ", this.bb);\n";

} else {

code += offset_prefix + "(obj || new " + type + ").__init(";

code += field.value.type.struct_def->fixed

? "this.bb_pos + offset"

: "this.bb.__indirect(this.bb_pos + offset)";

code += ", this.bb) : null;\n";

}

break;

}

case BASE_TYPE_VECTOR: {

auto vectortype = field.value.type.VectorType();

auto vectortypename = GenTypeName(vectortype, false);

auto inline_size = InlineSize(vectortype);

auto index = "this.bb.__vector(this.bb_pos + offset) + index" +

MaybeScale(inline_size);

std::string args = "@param {number} index\n";

if (vectortype.base_type == BASE_TYPE_STRUCT) {

args += "@param {" + vectortypename + "=} obj\n";

} else if (vectortype.base_type == BASE_TYPE_STRING) {

args += "@param {flatbuffers.Encoding=} optionalEncoding\n";

}

GenDocComment(field.doc_comment, code_ptr, args +

"@returns {" + vectortypename + "}");

code += object_name + ".prototype." + MakeCamel(field.name, false);

code += " = function(index";

if (vectortype.base_type == BASE_TYPE_STRUCT) {

code += ", obj";

} else if (vectortype.base_type == BASE_TYPE_STRING) {

code += ", optionalEncoding";

}

code += ") {\n";

if (vectortype.base_type == BASE_TYPE_STRUCT) {

code += offset_prefix + "(obj || new " + vectortypename;

code += ").__init(";

code += vectortype.struct_def->fixed

? index

: "this.bb.__indirect(" + index + ")";

code += ", this.bb)";

} else {

if (vectortype.base_type == BASE_TYPE_STRING) {

index += ", optionalEncoding";

}

code += offset_prefix + GenGetter(vectortype, "(" + index + ")");

}

code += " : ";

if (field.value.type.element == BASE_TYPE_BOOL) {

code += "false";

} else if (field.value.type.element == BASE_TYPE_LONG ||

field.value.type.element == BASE_TYPE_ULONG) {

code += "flatbuffers.Long.ZERO";

} else if (IsScalar(field.value.type.element)) {

code += "0";

} else {

code += "null";

}

code += ";\n";

break;

}

case BASE_TYPE_UNION:

GenDocComment(field.doc_comment, code_ptr,

"@param {flatbuffers.Table} obj\n"

"@returns {?flatbuffers.Table}");

code += object_name + ".prototype." + MakeCamel(field.name, false);

code += " = function(obj) {\n";

code += offset_prefix + GenGetter(field.value.type,

"(obj, this.bb_pos + offset)") + " : null;\n";

break;

default:

assert(0);

}

}

code += "};\n\n";

// Emit a length helper

if (field.value.type.base_type == BASE_TYPE_VECTOR) {

GenDocComment(code_ptr, "@returns {number}");

code += object_name + ".prototype." + MakeCamel(field.name, false);

code += "Length = function() {\n" + offset_prefix;

code += "this.bb.__vector_len(this.bb_pos + offset) : 0;\n};\n\n";

}

}

// Emit a factory constructor

if (struct_def.fixed) {

std::string annotations = "@param {flatbuffers.Builder} builder\n";

std::string arguments;

GenStructArgs(struct_def, &annotations, &arguments, "");

GenDocComment(code_ptr, annotations +

"@returns {flatbuffers.Offset}");

code += object_name + ".create" + struct_def.name + " = function(builder";

code += arguments + ") {\n";

GenStructBody(struct_def, &code, "");

code += " return builder.offset();\n};\n\n";

} else {

// Generate a method to start building a new object

GenDocComment(code_ptr,

"@param {flatbuffers.Builder} builder");

code += object_name + ".start" + struct_def.name;

code += " = function(builder) {\n";

code += " builder.startObject(" + NumToString(

struct_def.fields.vec.size()) + ");\n";

code += "};\n\n";

// Generate a set of static methods that allow table construction

for (auto it = struct_def.fields.vec.begin();

it != struct_def.fields.vec.end(); ++it) {

auto &field = **it;

if (field.deprecated) continue;

auto argname = MakeCamel(field.name, false);

if (!IsScalar(field.value.type.base_type)) {

argname += "Offset";

}

// Generate the field insertion method

GenDocComment(code_ptr,

"@param {flatbuffers.Builder} builder\n"

"@param {" + GenTypeName(field.value.type, true) + "} " +

argname);

code += object_name + ".add" + MakeCamel(field.name);

code += " = function(builder, " + argname + ") {\n";

code += " builder.addField" + GenWriteMethod(field.value.type) + "(";

code += NumToString(it - struct_def.fields.vec.begin()) + ", ";

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

code += "+";

}

code += argname + ", ";

if (!IsScalar(field.value.type.base_type)) {

code += "0";

} else {

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

code += "+";

}

code += GenDefaultValue(field.value);

}

code += ");\n};\n\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);

// Generate a method to create a vector from a JavaScript array

if (!IsStruct(vector_type)) {

GenDocComment(code_ptr,

"@param {flatbuffers.Builder} builder\n"

"@param {Array.<" + GenTypeName(vector_type, true) +

">} data\n"

"@returns {flatbuffers.Offset}");

code += object_name + ".create" + MakeCamel(field.name);

code += "Vector = function(builder, data) {\n";

code += " builder.startVector(" + NumToString(elem_size);

code += ", data.length, " + NumToString(alignment) + ");\n";

code += " for (var i = data.length - 1; i >= 0; i--) {\n";

code += " builder.add" + GenWriteMethod(vector_type) + "(";

if (vector_type.base_type == BASE_TYPE_BOOL) {

code += "+";

}

code += "data[i]);\n";

code += " }\n";

code += " return builder.endVector();\n";

code += "};\n\n";

}

// Generate a method to start a vector, data to be added manually after

GenDocComment(code_ptr,

"@param {flatbuffers.Builder} builder\n"

"@param {number} numElems");

code += object_name + ".start" + MakeCamel(field.name);

code += "Vector = function(builder, numElems) {\n";

code += " builder.startVector(" + NumToString(elem_size);

code += ", numElems, " + NumToString(alignment) + ");\n";

code += "};\n\n";

}

}

// Generate a method to stop building a new object

GenDocComment(code_ptr,

"@param {flatbuffers.Builder} builder\n"

"@returns {flatbuffers.Offset}");

code += object_name + ".end" + struct_def.name;

code += " = function(builder) {\n";

code += " var offset = builder.endObject();\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.requiredField(offset, ";

code += NumToString(field.value.offset);

code += "); // " + field.name + "\n";

}

}

code += " return offset;\n";

code += "};\n\n";

// Generate the method to complete buffer construction

if (parser.root_struct_def_ == &struct_def) {

GenDocComment(code_ptr,

"@param {flatbuffers.Builder} builder\n"

"@param {flatbuffers.Offset} offset");

code += object_name + ".finish" + struct_def.name + "Buffer";

code += " = function(builder, offset) {\n";

code += " builder.finish(offset";

if (!parser.file_identifier_.empty()) {

code += ", '" + parser.file_identifier_ + "'";

}

code += ");\n";

code += "};\n\n";

}

}

}

} // namespace js

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

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

std::string GenerateJS(const Parser &parser) {

using namespace js;

// Generate code for all the enum declarations.

std::string enum_code, exports_code;

for (auto it = parser.enums_.vec.begin();

it != parser.enums_.vec.end(); ++it) {

GenEnum(**it, &enum_code, &exports_code);

}

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

std::string decl_code;

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

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

GenStruct(parser, **it, &decl_code, &exports_code);

}

// Only output file-level code if there were any declarations.

if (enum_code.length() || decl_code.length()) {

std::string code;

code = "// automatically generated by the FlatBuffers compiler,"

" do not modify\n\n";

// Generate code for all the namespace declarations.

GenNamespaces(parser, &code, &exports_code);

// Output the main declaration code from above.

code += enum_code;

code += decl_code;

if (!exports_code.empty() && !parser.opts.skip_js_exports) {

code += "// Exports for Node.js and RequireJS\n";

code += exports_code;

}

return code;

}

return std::string();

}

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

const std::string &file_name) {

return path + file_name + "_generated.js";

}

bool GenerateJS(const Parser &parser,

const std::string &path,

const std::string &file_name) {

auto code = GenerateJS(parser);

return !code.length() ||

SaveFile(GeneratedFileName(path, file_name).c_str(), code, false);

}

std::string JSMakeRule(const Parser &parser,

const std::string &path,

const std::string &file_name) {

std::string filebase = flatbuffers::StripPath(

flatbuffers::StripExtension(file_name));

std::string make_rule = GeneratedFileName(path, filebase) + ": ";

auto included_files = parser.GetIncludedFilesRecursive(file_name);

for (auto it = included_files.begin();

it != included_files.end(); ++it) {

make_rule += " " + *it;

}

return make_rule;

}

} // namespace flatbuffers